KR102554163B1 - Ink composition containing light emitting particles, light conversion layer and light emitting device - Google Patents

Abstract

An object of the present invention is to provide an ink composition containing light emitting particles capable of forming a cured product having excellent storage stability and excellent heat stability, a light conversion layer using the ink composition, and a light emitting element. The ink composition containing luminescent particles of the present invention contains nanoparticles containing luminescent nanocrystals, a photopolymerizable compound, a photopolymerization initiator, and an antioxidant, and contains two or more acylphosphine oxide-based compounds as the photopolymerization initiator, As said antioxidant, it is characterized by containing at least one compound selected from the group consisting of a compound having a hydroxyphenyl group and a compound having a phosphorous acid ester structure.

Description

Ink composition containing light emitting particles, light conversion layer and light emitting device

The present invention relates to an ink composition containing light emitting particles, a light conversion layer, and a light emitting device.

Conventionally, a color filter pixel portion in a display such as a liquid crystal display device uses a curable resist material containing, for example, red organic pigment particles or green organic pigment particles, an alkali-soluble resin and/or an acrylic monomer, and It has been manufactured by a lithography method.

In recent years, there has been a strong demand for low power consumption of displays, and instead of the red organic pigment particles or green organic pigment particles, for example, quantum dots, quantum rods, and other inorganic phosphor particles, etc. luminescent nanoparticles are used to provide red light or green light. A color filter pixel unit that extracts is being actively researched.

[0005] However, the manufacturing method of the color filter by the photolithography method has a drawback in that resist materials other than the pixel portion including relatively expensive semiconductor nanocrystals are wasted due to the characteristics of the manufacturing method. Under such circumstances, in order to eliminate the waste of the resist material as described above, the formation of the pixel portion of the photo-conversion substrate by the inkjet method has begun to be examined (Patent Document 1).

Nanoparticles containing semiconductor nanocrystals are characterized in that they emit fluorescence or phosphorescence and have a narrow half-width of the emission wavelength. As the semiconductor nanocrystal, CdSe was initially used, but in order to avoid its harmfulness, recently InP or one having a perovskite structure has been used. As a semiconductor nanocrystal of a perovskite structure, for example, a compound represented by CsPbX ₃ (X is a halogen element and represents Cl, Br or I) is known.

Among them, semiconductor nanocrystals having a perovskite structure have an advantage of excellent productivity because the emission wavelength can be controlled by adjusting the type of halogen element and its abundance. And, for example, a composition containing a light emitting crystal having a perovskite type structure and a solid polymer derived from an acrylate polymer and a light emitting component are disclosed (Patent Document 2). Further, a film (light conversion layer) obtained by curing a composition containing fluorescent particles containing a perovskite compound, a photopolymerizable compound, a photopolymerization initiator, and an antioxidant is disclosed (Patent Document 3).

However, in the composition disclosed in Patent Literature 3, since the content of the photopolymerization initiator in the composition is small, curing of the obtained light conversion layer becomes insufficient in practice. Therefore, when the photo-conversion layer is heated, the luminescent crystals included in the photo-conversion layer and having the perovskite structure are deteriorated by thermal oxidation, and there is a problem that the decrease in luminescence intensity cannot be suppressed. On the other hand, when the content of the photopolymerization initiator is increased in order to obtain a sufficiently cured light conversion layer, the viscosity of the ink of the composition increases or precipitation due to the photopolymerization initiator occurs, resulting in a decrease in storage stability of the ink. there is

International Publication No. 2008/001693 International Publication No. 2018/028870 Japanese Patent Laid-Open No. 2020-70374

An object of the present invention is to provide an ink composition containing light emitting particles capable of forming a cured product having excellent storage stability and excellent heat stability, a light conversion layer using the ink composition, and a light emitting element.

In order to solve the above problems, the present invention focuses on a nanoparticle-containing ink composition containing a photopolymerizable compound, a photopolymerization initiator, and an antioxidant, and as a result of repeated intensive studies, two or more specific compounds are used as photopolymerization initiators. , while having excellent storage stability, an ink composition using an antioxidant containing a specific compound was found to be capable of forming a photocured product having excellent thermal stability, and the present invention was completed.

That is, the present invention contains nanoparticles made of metal halide and containing semiconductor nanocrystals having luminescence, a photopolymerizable compound, a photopolymerization initiator, and an antioxidant, and as the photopolymerization initiator, an acylphosphine oxide-based compound and at least one compound selected from the group consisting of a compound having a hydroxyphenyl group and a compound having a phosphorous acid ester structure as the antioxidant. .

In addition, the present invention provides a light conversion layer made of a cured product of a nanoparticle-containing ink composition containing semiconductor nanocrystals, and a light emitting device using the light conversion layer.

According to the present invention, it is possible to provide an ink composition containing nanoparticles containing semiconductor nanocrystals capable of forming a cured product having excellent storage stability and excellent thermal stability, a light conversion layer using the ink composition, and a light emitting device. there is.

1 is a cross-sectional view showing one embodiment of a method for producing nanoparticles containing semiconductor nanocrystals according to the present invention.
2 is a cross-sectional view showing another configuration example of nanoparticles containing semiconductor nanocrystals according to the present invention. (a) shows hollow particle-enclosed light-emitting particles, and (b) shows polymer-coated light-emitting particles.
3 is a cross-sectional view showing another embodiment of nanoparticles containing semiconductor nanocrystals according to the present invention. (a) shows silica-coated light-emitting particles, and (b) shows polymer-coated light-emitting particles.
4 is a cross-sectional view showing an embodiment of a light emitting device according to the present invention.
5 is a schematic diagram showing the configuration of an active matrix circuit.
Fig. 6 is a schematic diagram showing the configuration of an active matrix circuit.

Hereinafter, an ink composition containing nanoparticles containing semiconductor nanocrystals, a manufacturing method thereof, and a light emitting element of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. 1 is a cross-sectional view showing one embodiment of a method for producing nanoparticles containing semiconductor nanocrystals of the present invention. A production example in the case of using hollow silica particles as hollow particles is shown. In Fig. 1, description of the pores 912b is omitted in the hollow particles 912 after the application of the nanocrystal raw material at the lower end. 2 and 3 are cross-sectional views showing other structural examples of nanoparticles.

1. Ink composition containing nanoparticles containing semiconductor nanocrystals

The nanoparticle-containing ink composition containing semiconductor nanocrystals of the embodiment of the present invention contains a photopolymerizable compound, at least two or more photopolymerization initiators, and at least one or more antioxidants. As will be described later, the ink composition containing nanoparticles containing semiconductor nanocrystals of one embodiment can be suitably used for forming a light conversion layer of a light emitting display device using organic EL by an inkjet method. The ink composition does not unnecessarily consume materials such as nanoparticles and photopolymerizable compounds containing semiconductor nanocrystals having a relatively high luminescent property, and can produce a pixel portion (photoconversion layer) only by using the required amount in a necessary location. It is preferable to prepare and use suitably so that it may be suitable for an inkjet method rather than a photolithography method from the point which can be formed.

By containing two or more types of photopolymerization initiators, the ink composition can achieve sufficient curing with a small addition amount of the photopolymerization initiator, that is, the addition amount of the photopolymerization initiator can be reduced compared to the case where one type of photopolymerization initiator is used. Therefore, in the ink composition, since the solubility of the photopolymerization initiator in the photopolymerizable compound can be ensured, an increase in ink viscosity can be suppressed and precipitation caused by the photopolymerization initiator can be suppressed. Therefore, the ink composition can obtain excellent storage stability. Further, in general, the reaction of the photopolymerization compound proceeds by the catalytic action of the photopolymerization initiator during storage, and the ink viscosity may increase. On the other hand, since the ink composition of this invention contains a specific antioxidant, the rise of ink viscosity can be further suppressed. In addition, since the ink composition can form a sufficiently cured light conversion layer with at least the amount of the photopolymerization initiator added, when the light conversion layer is heated, the nanoparticles containing the luminescent nanocrystals are degraded by thermal oxidation. can be suppressed to prevent a decrease in light emission intensity. Moreover, since the said ink composition contains the antioxidant mentioned above, the said thermal oxidation can be suppressed more reliably. Therefore, the light conversion layer obtained by the ink composition can obtain excellent external quantum efficiency, in other words, excellent thermal stability.

Hereinafter, an inkjet ink composition for forming a color filter pixel portion constituting a light conversion layer will be taken as an example, and an ink composition containing nanoparticles containing semiconductor nanocrystals and components thereof will be described. Examples of constituent components include nanoparticles containing semiconductor nanocrystals, photopolymerizable compounds, photopolymerization initiators and antioxidants, as well as ligands, light diffusing particles, and polymer dispersants.

1-1. Nanoparticles including semiconductor nanocrystals

The nanoparticles containing semiconductor nanocrystals in the present invention, for example, absorb light of a predetermined wavelength, thereby emitting light (fluorescence or phosphorescence) of a different wavelength from the absorbed wavelength. Represents nanoparticles containing nanocrystals. That is, the luminescent property is preferably a property of emitting light by excitation of electrons, and more preferably a property of emitting light by excitation of electrons by excitation light. The luminescent nanocrystals may be red luminescent nanocrystals that emit light (red light) having a peak emission wavelength in the range of 605 to 665 nm, and emit light (green light) having a peak emission wavelength in the range of 500 to 560 nm. It may be a luminescent nanocrystal, or may be a blue luminescent nanocrystal particle that emits light (blue light) having an emission peak wavelength in the range of 420 to 480 nm.

The luminescent semiconductor nanocrystal may be a luminescent nanocrystal particle (luminescent semiconductor nanocrystal) containing a semiconductor material. Examples of semiconductor nanocrystals having luminescent properties include quantum dots and quantum rods. Among these, quantum dots are preferable from the viewpoint of being easy to control the emission spectrum, securing reliability, reducing production cost, and improving mass productivity. Further, the luminescent nanocrystal is preferably a quantum dot made of a metal halide from the viewpoint of obtaining a luminescence peak having a narrower half-width. In this embodiment, nanoparticles made of quantum dots made of metal halide will be described below, but the present invention is not limited to this, and is applicable to nanoparticles made of semiconductor nanocrystals having various luminescent properties.

1-1-1. Luminescent Particles Encapsulating Hollow Particles

The nanoparticles containing semiconductor nanocrystals in the present invention are the light emitting particles 91 shown in FIG. ), and a semiconductor nanocrystal 911 accommodated in the hollow portion 912a, made of metal halide, and having luminescence (hereinafter, simply referred to as “nanocrystal 911” in some cases). Hereinafter, it may also be referred to as "the hollow particle-encapsulated light-emitting particle 91"). Such light-emitting particles 91 can be obtained by, for example, depositing nanocrystals 911 in hollow portions 912a of hollow particles 912 . Since the nanocrystals 911 of the light emitting particles 91 are protected by the hollow particles 912, excellent stability against heat or oxygen can be obtained, and as a result, excellent light emitting characteristics can be obtained.

The luminescent particles 91 are more preferably luminescent particles 90 having a polymer layer 92 made of a hydrophobic polymer on their surface (hereinafter sometimes referred to as "polymer-coated luminescent particles"). Since the polymer-coated light-emitting particles 90 are provided with the polymer layer 92, their stability against heat and oxygen can be further improved, and excellent particle dispersibility can be obtained. characteristics can be obtained.

<Nano Crystal (911)>

The nanocrystals 911 are nano-sized crystals (nanocrystal particles) that are made of metal halide and emit fluorescence or phosphorescence by absorbing excitation light. The nanocrystal 911 is a crystal having a maximum particle size of 100 nm or less as measured by, for example, a transmission electron microscope or a scanning electron microscope. The nanocrystal 911 may emit fluorescence or phosphorescence by being excited by, for example, light energy or electrical energy of a predetermined wavelength.

The nanocrystal 911 made of metal halide is a compound represented by the general formula: A _a M _b X _c .

In formula, A is at least 1 sort(s) of an organic cation and a metal cation. Examples of organic cations include ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, and protonated thiourea. Examples of metal cations include Cs, Rb, K, Na, Li, etc. cations of

M is at least one metal cation. As the metal cation, a metal cation selected from group 1, group 2, group 3, group 4, group 5, group 6, group 7, group 8, group 9, group 10, group 11, group 13, group 14 and group 15 can be heard More preferably, Ag, Au, Bi, Ca, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ge, Hf, In, Ir, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os , Pb, Pd, Pt, Re, Rh, Ru, Sb, Sc, Sm, Sn, Sr, Ta, Te, Ti, V, W, Zn, and Zr cations.

X is at least one kind of anion. As anion, a chloride ion, a bromide ion, an iodide ion, a cyanide ion, etc. are mentioned.

a is 1 to 7, b is 1 to 4, and c is 3 to 16.

The emission wavelength (emission color) of these nanocrystals 911 can be controlled by adjusting the size of the particles and the type and proportion of anions constituting the X site.

The compound represented by the general formula _{A a} M _m X _x is, specifically, AMX, A ₄ MX, AMX ₂ , AMX ₃ , A ₂ MX 3 , AM _{2 X 3} , A ₂ MX ₄ , A ₂ MX ₅ , A ₃ MX ₅ , A ₃ M ₂ X ₅ , A ₃ MX ₆ , A ₄ MX ₆ , AM ₂ X ₆ , A ₂ MX ₆ , A ₄ M ₂ X ₆ , A ₃ MX ₈ , A ₃ M ₂ X ₉ , A ₃ M ₃ X ₉ , A ₂ M ₂ X ₁₀ , A ₇ M ₃ X ₁₆ compounds are preferred.

In formula, A is at least 1 sort(s) of an organic cation and a metal cation. Examples of organic cations include ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, and protonated thiourea. Examples of metal cations include Cs, Rb, K, Na, Li, etc. cations of

In formula, M is at least 1 sort(s) of metal cation. Specifically, one type of metal cation (M ¹ ), two types of metal cations (M ¹ _α M ² _β ), three types of metal cations (M ¹ _α M ² _β M ³ _γ ), and four types of metal cations (M ¹ _α M ² _β M ³ _γ M ⁴ _δ ) and the like. However, α, β, γ, and δ represent real numbers of 0 to 1, respectively, and represent α+β+γ+δ = 1. As the metal cation, a metal cation selected from group 1, group 2, group 3, group 4, group 5, group 6, group 7, group 8, group 9, group 10, group 11, group 13, group 14 and group 15 can be heard More preferably, Ag, Au, Bi, Ca, Ce, Co, Cr, Cu, Eu, Fe, Ga, Ge, Hf, In, Ir, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os , Pb, Pd, Pt, Re, Rh, Ru, Sb, Sc, Sm, Sn, Sr, Ta, Te, Ti, V, W, Zn, and Zr cations.

In formula, X is an anion containing at least 1 type of halogen. Specifically, one type of halogen anion (X ¹ ), two types of halogen anion (X ¹ _α X ² _β ), and the like are exemplified. Examples of the anion include chloride ion, bromide ion, iodide ion, cyanide ion and the like, and at least one kind of halide ion is included.

The metal halide compound represented by the general formula A _a M _m X _x may be one in which metal ions such as Bi, Mn, Ca, Eu, Sb, Yb are added (doped) in order to improve the light emission characteristics. do.

Among the compounds composed of metal halides represented by the general formula A _a M _m X _x , the compound having a perovskite-type crystal structure adjusts its particle size, the type and abundance of metal cations constituting the M site, Moreover, since the emission wavelength (emission color) can be controlled by adjusting the type and abundance of anions constituting the X site, it is particularly preferable for use as semiconductor nanocrystals. Specifically, compounds represented by AMX ₃ , A ₃ MX ₅ , A ₃ MX ₆ , A ₄ MX ₆ , and A ₂ MX ₆ are preferable. A, M and X in the formula are as described above. As described above, the compound having a perovskite crystal structure may be one to which metal ions such as Bi, Mn, Ca, Eu, Sb, and Yb are added (doped).

Among the compounds exhibiting a perovskite-type crystal structure, A is Cs, Rb, K, Na, Li, and M is one metal cation (M ¹ ) or two metals in order to exhibit better light emission characteristics. It is a cation (M ¹ _α M ² _β ), and X is preferably a chloride ion, bromide ion, or iodide ion. However, α and β represent real numbers of 0 to 1, respectively, and represent α+β=1. Specifically, M is preferably selected from Ag, Au, Bi, Cu, Eu, Fe, Ge, K, In, Na, Mn, Pb, Pd, Sb, Si, Sn, Yb, Zn, and Zr. .

As a specific composition of the nanocrystal 911 made of metal halide and having a perovskite-type crystal structure, nanocrystals using Pb as M such as CsPbBr ₃ , CH ₃ NH ₃ PbBr ₃ , CHN ₂ H ₄ PbBr ₃ ( 911) is preferred because of its excellent light intensity and excellent quantum efficiency. In addition, CsSnBr ₃ , CsSnCl ₃ , CsSnBr _1.5 Cl _1.5 , Cs ₃ Sb ₂ Br ₉ , (CH ₃ NH ₃ ) ₃ Bi ₂ Br ₉ , (C ₄ H ₉ NH ₃ ) ₂ AgBiBr ₆ , other than Pb as M The nanocrystal 911 using metal cations is preferable because of its low toxicity and low environmental impact.

As the nanocrystal 911, a red luminescent crystal emitting light (red light) having an emission peak in a wavelength range of 605 to 665 nm, and a green luminescent crystal emitting light (green light) having an emission peak in a wavelength range of 500 to 560 nm. , and blue light-emitting crystals that emit light (blue light) having an emission peak in the wavelength range of 420 to 480 nm can be selected and used. Further, in one embodiment, a plurality of these nanocrystals may be used in combination.

In addition, the wavelength of the emission peak of the nanocrystal 911 can be confirmed in a fluorescence spectrum or phosphorescence spectrum measured using, for example, an absolute PL quantum yield measuring device.

The red light emitting nanocrystal 911 is 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 655 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, 635 nm or less Hereinafter, those having an emission peak in a wavelength range of 632 nm or less or 630 nm or less are preferable, and those having an emission peak in a wavelength range of 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more are preferred. desirable.

These upper limit values and lower limit values can be arbitrarily combined. In addition, even in the same description below, the upper limit value and the lower limit value described individually can be combined arbitrarily.

The green light-emitting nanocrystal 911 emits light in a wavelength range of 560 nm or less, 557 nm or less, 555 nm or less, 550 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 540 nm or less, 537 nm or less, 535 nm or less, 532 nm or less, or 530 nm or less. It is preferable to have a peak, and it is preferable to have an emission peak in a wavelength range of 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.

The blue light-emitting nanocrystal 911 emits light in a wavelength range of 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 465 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less, 452 nm or less, or 450 nm or less. It is preferable to have a peak, and it is preferable to have an emission peak in a wavelength range of 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.

The shape of the nanocrystal 911 is not particularly limited, and may be an arbitrary geometric shape or an arbitrary irregular shape. Examples of the shape of the nanocrystal 911 include a rectangular parallelepiped shape, a cubic shape, a sphere shape, a regular tetrahedron shape, an ellipsoid shape, a pyramidal shape, a disk shape, a branch shape, a net shape, and a rod shape. Further, as the shape of the nanocrystal 911, a rectangular parallelepiped shape, a cubic shape, or a spherical shape is preferable.

The average particle diameter (volume average diameter) of the nanocrystals 911 is preferably 40 nm or less, more preferably 30 nm or less, still more preferably 20 nm or less. In addition, the average particle diameter of the nanocrystals 911 is preferably 1 nm or more, more preferably 1.5 nm or more, and even more preferably 2 nm or more. The nanocrystal 911 having such an average particle diameter is preferable in that it easily emits light of a desired wavelength. In addition, the average particle diameter of the nanocrystal 911 is obtained by measuring with a transmission electron microscope or a scanning electron microscope and calculating the volume average diameter.

<Hollow Particles (912)>

The hollow particle 912 may have a hollow part 912a, which is a space capable of accommodating the nanocrystal 911 therein, and a pore 912b communicating with the hollow part 912a, and the overall shape is a rectangular parallelepiped. shape, cubic shape, spherical shape (approximately true sphere shape), elongated sphere shape (elliptical sphere shape), honeycomb shape (a shape in which cylinders with a hexagonal cross section and open ends are lined up without gaps), etc. available. The rectangular parallelepiped, cubic, substantially spherical, and elliptical spherical hollow particles are particles having a balloon structure or a hollow structure. Hollow particles having a balloon structure or a hollow structure are more preferable because stability against heat or oxygen can be obtained more reliably by covering the nanocrystal 911 accommodated in the hollow portion 912a over the entirety. Further, in the obtained luminescent nanoparticles 90, since the hollow particles 912 are interposed between the polymer layer 92 described later, the stability of the nanocrystals 911 against oxygen gas and moisture is also improved.

One nanocrystal 911 may be accommodated in the hollow part 912a, or a plurality of nanocrystals 911 may be accommodated. In addition, the whole hollow part 912a may be occupied by one or a plurality of nanocrystals 911, or only a part thereof may be occupied.

As the hollow particles, any material may be used as long as the nanocrystal 911 can be protected. From the viewpoint of ease of synthesis, transmittance, cost, etc., the hollow particles are preferably hollow inorganic nanoparticles such as hollow silica particles, hollow alumina particles, hollow titanium oxide particles, or hollow polymer particles such as hollow polystyrene particles and hollow PMMA particles. , more preferably hollow silica particles or hollow alumina particles. From the viewpoint of easy particle surface treatment, hollow silica particles are more preferred.

The average outer diameter of the hollow particles 912 is not particularly limited, but is preferably 5 to 300 nm, more preferably 6 to 100 nm, still more preferably 8 to 50 nm, and particularly preferably 10 to 25 nm. With the hollow particles 912 having such a size, stability of the nanocrystal 911 against oxygen, moisture, and heat can be sufficiently increased.

The average inner diameter of the hollow particles 912, that is, the diameter of the hollow part 912a is not particularly limited, but is preferably 1 to 250 nm, more preferably 2 to 100 nm, and even more preferably 3 to 50 nm , 5 to 15 nm is particularly preferred. If the average inner diameter of the hollow particles 912 is excessively small, there is a concern that the nanocrystal 911 may not precipitate in the hollow part 912a, and if the average inner diameter of the hollow particle 912 is excessively large, the nanocrystal 911 in the hollow part 91a ) may be excessively aggregated and the luminous efficiency may decrease. If the hollow particle 912 has an average inner diameter within the above range, the nanocrystal 911 can be precipitated while suppressing aggregation.

The size of the pores 912b is not particularly limited, but is preferably 0.5 to 10 nm, and more preferably 1 to 5 nm. In this case, the solution containing the raw material compound of the nanocrystal 911 can be smoothly and reliably permeated into the hollow portion 912a.

As shown in FIG. 1 , for example, the hollow silica particles as an example of the hollow particles 912 include (a) an aliphatic polyamine chain (x1) having a primary amino group and/or a secondary amino group and a hydrophobic organic segment (x2) ) with an aqueous medium to form an aggregate (XA) composed of a core containing a hydrophobic organic segment (x2) as a main component and a shell layer containing an aliphatic polyamine chain (x1) as a main component; (b) a silica raw material (Y) is added to an aqueous medium containing the aggregate (XA), and a sol-gel reaction of the silica raw material (Y) is performed using the aggregate (XA) as a template (template) to obtain silica It can be produced by a step of precipitating to obtain core-shell type silica nanoparticles (YA), and (c) a step of removing copolymer (X) from core-shell type silica nanoparticles (YA).

As an aliphatic polyamine chain (x1), a polyethyleneimine chain, a polyallylamine chain, etc. are mentioned, for example. Since core-shell type silica nanoparticles (YA), which are precursors of the hollow silica nanoparticles 912, can be efficiently produced, a polyethyleneimine chain is more preferable. The molecular weight of the aliphatic polyamine chain (x1) is preferably in the range of 5 to 10,000, and more preferably in the range of 10 to 8,000 for the number of repeating units in order to achieve a balance with the molecular weight of the hydrophobic organic segment (x2). desirable.

The molecular structure of the aliphatic polyamine chain (x1) is not particularly limited either, and examples thereof include linear, branched, dendrimer, star, and comb shapes. A branched polyethyleneimine chain is preferable because it can efficiently form an aggregate used as a template for silica precipitation, and from the viewpoints of manufacturing cost and the like.

Examples of the hydrophobic organic segment (x2) include a segment derived from an alkyl compound and a segment derived from a hydrophobic polymer such as polyacrylate, polystyrene, and polyurethane.

In the case of an alkyl compound, it is preferable that it is a compound which has an alkylene chain of 5 or more carbon atoms, and it is more preferable that it is a compound which has an alkylene chain of 10 or more carbon atoms. The chain length of the hydrophobic organic segment (x2) is not particularly limited as long as it can stabilize the association (XA) to a nano size, but the number of repeating units is preferably in the range of 5 to 10,000, and is in the range of 5 to 1,000. is more preferable.

The hydrophobic organic segment (x2) may be bonded to the terminal of the aliphatic polyamine chain (x1) by coupling, or may be bonded to the end of the aliphatic polyamine chain (x1) by grafting. Only one hydrophobic organic segment (x2) may be bonded to one aliphatic polyamine chain (x1), or a plurality of hydrophobic organic segments (x2) may be bonded.

The ratio of the aliphatic polyamine chain (x1) and the hydrophobic organic segment (x2) contained in the copolymer (X) is not particularly limited as long as a stable association (XA) can be formed in an aqueous medium. Specifically, the proportion of the aliphatic polyamine chain (x1) is preferably in the range of 10 to 90% by mass, more preferably in the range of 30 to 70% by mass, and even more preferably in the range of 40 to 60% by mass. .

In step (a), by dissolving the copolymer (X) in an aqueous medium, the association body (XA) having a core-shell structure can be formed by self-organization. The core of this association (XA) has a hydrophobic organic segment (x2) as its main component, and the shell layer has an aliphatic polyamine chain (x1) as its main component. It is thought to form an association (XA). As an aqueous medium, water, the mixed solution of water and a water-soluble solvent, etc. are mentioned, for example. When using a mixed solution, the amount of water contained in the mixed solution is preferably 0.5/9.5 to 3/7, and more preferably 0.1/9.9 to 5/5 water/water-soluble solvent in terms of volume ratio. From the viewpoints of productivity, environment, cost and the like, it is preferable to use water alone or a mixed solution of water and alcohol.

The amount of copolymer (X) contained in the aqueous medium is preferably 0.05 to 15% by mass, more preferably 0.1 to 10% by mass, still more preferably 0.2 to 5% by mass. When forming the association (XA) by self-organization of the copolymer (X) in an aqueous medium, an organic crosslinkable compound having two or more functional groups may be used to crosslink the aliphatic polyamine chain (x1) in the shell layer. . Examples of such an organic crosslinkable compound include aldehyde-containing compounds, epoxy-containing compounds, unsaturated double bond-containing compounds, and carboxylic acid group-containing compounds.

Next, a sol-gel reaction of the silica raw material (Y) is performed in the presence of water, using the aggregate (XA) as a template. Examples of the silica raw material (Y) include water glass, tetraalkoxysilanes, and oligomers such as tetraalkoxysilane. As tetraalkoxysilanes, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetra-t-butoxysilane etc. are mentioned, for example. As oligomers, tetramethoxysilane tetramer, tetramethoxysilane heptomer, tetraethoxysilane pentamer, tetraethoxysilane 10mer, etc. are mentioned, for example.

The sol-gel reaction does not occur in the continuous phase of the solvent and proceeds selectively only in the association (XA) phase. Therefore, the reaction conditions can be arbitrarily set within the range in which the aggregate (XA) is not disintegrated. In the sol-gel reaction, the ratio of the aggregate (XA) and the silica raw material (Y) can be set appropriately.

The temperature of the sol-gel reaction is not particularly limited, and is preferably in the range of 0 to 90°C, more preferably in the range of 10 to 40°C, and still more preferably in the range of 15 to 30°C. In this case, core-shell type silica nanoparticles (YA) can be efficiently obtained.

In the case of the silica raw material (Y) having high reaction activity, the time of the sol-gel reaction is preferably in the range of 1 minute to 24 hours, and more preferably in the range of 30 minutes to 5 hours. Further, in the case of the silica raw material (Y) having low reaction activity, the sol-gel reaction time is preferably 5 hours or more, and more preferably one week.

By step (b), it is possible to obtain core-shell type silica nanoparticles (YA) having a uniform particle size without aggregation. The particle size distribution of the obtained core-shell silica nanoparticles (YA) varies depending on the production conditions and the target particle size, but is ±15% or less, preferably ±10% of the target particle size (average particle size). It can be set below.

The core-shell silica nanoparticles (YA) have a shell layer composed of a core containing a hydrophobic organic segment (x2) as a main component, a composite containing an aliphatic polyamine chain (x1) and silica as a main component. Here, the main component means that the intentional third component is not included. The shell layer in the core-shell silica nanoparticles (YA) is an organic-inorganic composite formed by complexing an aliphatic polyamine chain (x1) with a matrix formed of silica.

The particle size of the core-shell silica nanoparticles (YA) is preferably 5 to 300 nm, more preferably 6 to 100 nm, still more preferably 8 to 50 nm, and particularly preferably 10 to 25 nm. This particle size can be adjusted by the type, composition and molecular weight of the copolymer (X), the type of the silica raw material (Y), the sol-gel reaction conditions, and the like. In addition, since the core-shell silica nanoparticles (YA) are formed by self-organization of molecules, they exhibit very excellent monodispersity and can have a particle size distribution width of ±15% or less with respect to the average particle size.

The shape of the core-shell silica nanoparticles (YA) can be spherical or elongated spherical with an aspect ratio of 2 or more. In addition, core-shell type silica nanoparticles (YA) having a plurality of cores in one particle can also be produced. The shape and structure of these particles can be adjusted by changing the composition of the copolymer (X), the type of the silica raw material (Y), and the sol-gel reaction conditions.

The amount of silica contained in the core-shell type silica nanoparticles (YA) is preferably in the range of 30 to 95% by mass, and more preferably in the range of 60 to 90% by mass. The amount of silica can be adjusted by changing the amount of the aliphatic polyamine chain (x1) contained in the copolymer (X), the amount of the aggregate (XA), the type and amount of the silica raw material (Y), the sol-gel reaction time and temperature, and the like. can

Next, in step (c), the target hollow silica nanoparticles 912 can be obtained by removing the copolymer (X) from the core-shell silica nanoparticles (YA).

Examples of the method for removing the copolymer (X) include firing treatment and treatment by solvent washing, but a firing treatment method in a firing furnace is preferable from the viewpoint of the removal rate of the copolymer (X). Examples of the firing treatment include high-temperature firing in the presence of air or oxygen and high-temperature firing in the presence of an inert gas (eg, nitrogen or helium), but high-temperature firing in air is preferable. The firing temperature is preferably 300°C or higher, and more preferably in the range of 300 to 1000°C.

In the above manner, the hollow silica particles 912 are produced. In addition, a commercial item can also be used for the hollow silica particle 912. As such a commercial item, "SiliNax SP-PN(b)" by Nittetsu Mining Co., Ltd., etc. are mentioned, for example. Hollow alumina particles, hollow titanium oxide particles, or hollow polymer particles can also be produced by the same method.

<Method for producing hollow particle-encapsulating light-emitting particles 91>

In the present invention, the hollow particles obtained in this way are impregnated with a solution (Z) containing a raw material compound for semiconductor nanocrystals ((d) in FIG. 1) and dried, thereby forming the hollow portion 912a of the hollow particles Inside, perovskite-type semiconductor nanocrystals having luminescent properties precipitate ((d) in Fig. 1), and luminescent particles (luminescent particles containing hollow particles) 91 are obtained.

Further, the obtained light-emitting particles 91 can be added to a photopolymerizable compound described later, specifically, for example, isobornyl methacrylate, to form a dispersion containing the light-emitting particles 91.

As the solution (Z) containing the raw material compound for semiconductor nanocrystals, a solution having a solid content concentration of 0.5 to 20% by mass is preferable from the viewpoint of impregnation into the hollow particles 912 . The organic solvent may be a good solvent for the nanocrystal 911, but in particular, dimethylsulfoxide, N,N-dimethylformamide, N-methylformamide, ethanol, methanol, 2-propanol, γ-butyrolactone , ethyl acetate, water, and mixed solvents thereof are preferred from the point of compatibility.

Moreover, as a method of preparing a solution, it is preferable to mix a raw material compound and an organic solvent in a reaction vessel under an inert gas atmosphere such as argon. The temperature conditions at this time are preferably from room temperature to 350°C, and the stirring time during mixing is preferably from 1 minute to 10 hours.

As for the raw material compound for semiconductor nanocrystals, for example, when preparing a lead cesium tribromide solution, it is preferable to mix cesium bromide and lead (II) bromide with the organic solvent. At this time, it is preferable to adjust the respective addition amounts so that the cesium bromide is 0.5 to 200 parts by mass and the lead (II) bromide is 0.5 to 200 parts by mass with respect to 1000 parts by mass of the good solvent.

Next, the hollow portion 912a of the hollow silica particle 912 is impregnated with the lead cesium tribromide solution by adding the hollow silica particle 912 to the reaction vessel at room temperature. After that, by filtering the solution in the reaction solution, the excess lead cesium tribromide solution is removed and the solid is recovered. And the obtained solid material is dried under reduced pressure at -50-200 degreeC. As a result of the above, the light-emitting particles 91 in which the perovskite type semiconductor nanocrystals 911 are deposited in the hollow portions 912a of the hollow silica particles 912 can be obtained.

<Modified example of hollow particle-encapsulating light-emitting particle 91>

Further, as shown in FIG. 2(a) , the hollow particle-encapsulating light-emitting particle 91 is located between the wall surface of the hollow part 912a of the hollow particle 92 and the semiconductor nanocrystal 911, and is a semiconductor nanocrystal. It is preferable to provide an intermediate layer 913 composed of a ligand coordinated on the surface of the crystal 911. The luminescent particles 91 shown in Fig. 2(a) have oleic acid, oleylamine, etc. The intermediate layer 913 is formed by coordinating . In addition, in FIG. 2 (a), in the hollow particle 912, description of the pore 912b is abbreviate|omitted. In the light emitting particle 91 including the intermediate layer 913 , stability of the nanocrystal 911 against oxygen, moisture, heat, and the like can be further enhanced by the intermediate layer 913 .

For light-emitting particles 91 having an intermediate layer 913 composed of ligands, a ligand is added to a solution containing a raw material compound for nanocrystals 911, and hollow silica particles 912 are impregnated with this solution and dried. can be obtained by doing

The ligand is preferably a compound having an associative group that binds to cations included in the nanocrystal 911 . Examples of the bondable group include at least one of a carboxyl group, a carboxylic acid anhydride group, an amino group, an ammonium group, a mercapto group, a phosphine group, a phosphine oxide group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfonic acid group, and a boronic acid group. It is preferable, and it is more preferable that it is at least 1 sort(s) of a carboxyl group and an amino group. Examples of such a ligand include compounds containing a carboxyl group or an amino group, and either one of these ligands may be used alone or two or more types may be used in combination.

As a carboxyl group-containing compound, a C1-C30 linear or branched aliphatic carboxylic acid is mentioned, for example. Specific examples of such carboxyl group-containing compounds include arachidonic acid, crotonic acid, trans-2-decenoic acid, erucic acid, 3-decenoic acid, cis-4,7,10,13,16,19-docosa Hexaenoic acid, 4-decenoic acid, all cis-5,8,11,14,17-eicosapentaenoic acid, all cis-8,11,14-eicosatrienoic acid, cis-9-hexadecenoic acid , trans-3-hexenoic acid, trans-2-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 2-hexadecenoic acid, linolenic acid, linoleic acid, γ-linolenic acid, 3-nonenoic acid, 2-nonenoic acid, trans -2-octenoic acid, petroselic acid, elaidic acid, oleic acid, 3-octenoic acid, trans-2-pentenoic acid, trans-3-pentenoic acid, ricinolic acid, sorbic acid, 2-tridecenoic acid, cis-15 -Tetrachosenoic acid, 10-undecenoic acid, 2-undecenoic acid, acetic acid, butyric acid, behenic acid, cerotic acid, decanoic acid, arachidic acid, heneicosanoic acid, heptadecanoic acid, heptanoic acid, hexanoic acid, heptacosanoic acid, Lauric acid, myristic acid, melissic acid, octacosanoic acid, nonadecanoic acid, nonacosanoic acid, n-octanoic acid, palmitic acid, pentadecanoic acid, propionic acid, pentacosanoic acid, nonanoic acid, stearic acid, ligno Seric acid, trichosanoic acid, tridecanoic acid, undecanoic acid, valeric acid, etc. are mentioned.

Examples of the amino group-containing compound include linear or branched aliphatic amines having 1 to 30 carbon atoms. Specific examples of such an amino group-containing compound include 1-aminoheptadecane, 1-aminononadecane, heptadecan-9-amine, stearylamine, oleylamine, and 2-n-octyl-1-dodecylamine. , allylamine, amylamine, 2-ethoxyethylamine, 3-ethoxypropylamine, isobutylamine, isoamylamine, 3-methoxypropylamine, 2-methoxyethylamine, 2-methylbutylamine, neo Pentylamine, propylamine, methylamine, ethylamine, butylamine, hexylamine, heptylamine, n-octylamine, 1-aminodecane, nonylamine, 1-aminoundecane, dodecylamine, 1-aminopentadecane, 1-aminotridecane, hexadecylamine, tetradecylamine, etc. are mentioned.

Further, when the light-emitting particles 91 are produced, a ligand having a reactive group (for example, 3-aminopropyltrimethoxysilane) may be added to a solution containing a raw material compound for the nanocrystals 911 . In this case, as shown in FIG. 2, the ligand is located between the hollow particle 912 and the nanocrystal 911 and is coordinated on the surface of the nanocrystal 911, and the ligand molecules form a siloxane bond. It is also possible to set it as the mother particle 91 which has the intermediate|middle layer 913 which exists. According to this configuration, the nanocrystals 911 can be firmly fixed by the hollow particles 912 through the intermediate layer 913 .

The ligand having a reactive group is preferably a compound having a reactive group that forms a siloxane bond by containing Si and a bonding group that binds to a cation contained in the nanocrystal 911 . In addition, the reactive group can also react with the hollow particles 912 .

Examples of the bondable group include a carboxyl group, a carboxylic acid anhydride group, an amino group, an ammonium group, a mercapto group, a phosphine group, a phosphine oxide group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfonic acid group, and a boronic acid group. . Especially, as a bondable group, it is preferable that it is at least 1 sort(s) of a carboxyl group and an amino group. These bondable groups have higher affinity (reactivity) to cations contained in the nanocrystal 911 than reactive groups. For this reason, the ligand is coordinated with the bonding group toward the nanocrystal 911 side, and the intermediate layer 913 can be formed more easily and reliably.

On the other hand, as the reactive group, a hydrolyzable silyl group such as a silanol group and an alkoxysilyl group having 1 to 6 carbon atoms is preferable since a siloxane bond is easily formed.

As such a ligand, a carboxyl group or an amino group-containing silicon compound, etc. are mentioned, and these 1 type can be used individually, or 2 or more types can be used together.

Specific examples of the carboxyl group-containing silicon compound include trimethoxysilylpropyl acid, triethoxysilylpropyl acid, N-[3-(trimethoxysilyl)propyl]-N'-carboxymethylethylenediamine, N- [3-(trimethoxysilyl)propyl] phthalamide, N-[3-(trimethoxysilyl)propyl]ethylenediamine-N,N',N'-triacetic acid, etc. are mentioned.

On the other hand, specific examples of the amino group-containing silicon compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethylethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldipropoxysilane, N-(2-aminoethyl)-3-aminopropyl Methyldiisopropoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl )-3-aminopropyltripropoxysilane, N-(2-aminoethyl)-3-aminopropyltriisopropoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N -(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyl Silanetriol, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N,N-bis[3-(tri) Methoxysilyl) propyl] ethylenediamine, (aminoethylaminoethyl) phenyltrimethoxysilane, (aminoethylaminoethyl) phenyltriethoxysilane, (aminoethylaminoethyl) phenyltripropoxysilane, (aminoethylaminoethyl ) Phenyltriisopropoxysilane, (aminoethylaminomethyl)phenyltrimethoxysilane, (aminoethylaminomethyl)phenyltriethoxysilane, (aminoethylaminomethyl)phenyltripropoxysilane, (aminoethylaminomethyl) Phenyltriisopropoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropylmethyldimethoxysilane, N -β-(N-vinylbenzylaminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane, N-β-(N-di(vinylbenzyl)aminoethyl)-γ- Aminopropyltrimethoxysilane, N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane, methylbenzylaminoethylaminopropyltri Methoxysilane, dimethylbenzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-(N- Phenyl)aminopropyltrimethoxysilane, N,N-bis[3-(trimethoxysilyl)propyl]ethylenediamine, (aminoethylaminoethyl)phenethyltrimethoxysilane, (aminoethylaminoethyl)phenethyltriethoxy Silane, (aminoethylaminoethyl)phenethyltripropoxysilane, (aminoethylaminoethyl)phenethyltriisopropoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)phenethyltrie Toxysilane, (aminoethylaminomethyl)phenethyltripropoxysilane, (aminoethylaminomethyl)phenethyltriisopropoxysilane, N-[2-[3-(trimethoxysilyl)propylamino]ethyl]ethylene Diamine, N-[2-[3-(triethoxysilyl)propylamino]ethyl]ethylenediamine, N-[2-[3-(tripropoxysilyl)propylamino]ethyl]ethylenediamine, N-[2 -[3-(triisopropoxysilyl)propylamino]ethyl]ethylenediamine etc. are mentioned.

Further, as shown in (b) of FIG. 2 , the light-emitting particles 90 provided with a polymer layer 92 made of a hydrophobic polymer on the surface of the hollow particle-encapsulated light-emitting particles 91 (hereinafter referred to as “polymer-coated light-emitting particles 90)” in some cases.) is more preferable. Since the polymer-coated light-emitting particles 90 are provided with the polymer layer 92, their stability against heat and oxygen can be further improved, and excellent particle dispersibility can be obtained. characteristics can be obtained.

1-1-2. Silica-coated luminescent particles

Fig. 3(a) and Fig. 3(b) show other forms of nanoparticles containing semiconductor nanocrystals in the present invention. The luminescent particles 91 shown in Fig. 3(a) include a semiconductor nanocrystal made of a metal halide and having luminescence (hereinafter sometimes simply referred to as "nanocrystal 911"), and this nanocrystal. It is composed of ligands coordinated on the surface of the crystal 911, and also has a surface layer 914 in which molecules that are silane compounds among the ligands form siloxane bonds (hereinafter referred to as “silica-coated light-emitting particles 91”). There are also). The light-emitting particles 91 mix, for example, a precursor of the nanocrystal 911, a ligand such as oleic acid or oleylamine, and a ligand having a site capable of binding to siloxane, thereby precipitating the nanocrystal 911 and at the same time It can be obtained by coordinating the ligand to the surface of the nanocrystal 911 and then generating a siloxane bond. In the luminescent particles 91, since the nanocrystals 911 are protected by the silica surface layer 914, excellent stability to heat or oxygen can be obtained, and as a result, excellent luminescent properties can be obtained.

Further, as shown in (b) of FIG. 3, as shown in the silica-coated light-emitting particles 91, the silica-coated light-emitting particles 91 are provided with a polymer layer 92 made of a hydrophobic polymer on the surface of the light-emitting particles ( 90) (hereinafter sometimes referred to as “polymer-coated luminescent particles 90”) is more preferable. Since the polymer-coated light-emitting particles 90 are provided with the polymer layer 92, their stability against heat and oxygen can be further improved, and excellent particle dispersibility can be obtained. characteristics can be obtained.

The silica-coated light-emitting particles 91 shown in Fig. 3(a) are composed of the nanocrystal 911 having luminescence and a ligand coordinated on the surface of the nanocrystal 911, and a silane compound among the ligands. It has a surface layer 914 in which phosphorus molecules form siloxane bonds. Therefore, since the nanocrystals 911 of the silica-coated light-emitting particles 91 are protected by the surface layer 914, excellent light-emitting characteristics can be maintained.

The silica-coated light-emitting particles 91 are a solution containing a raw material compound for semiconductor nanocrystals, a solution containing an aliphatic carboxylic acid, and an aliphatic amine containing a compound containing Si and having a reactive group capable of forming a siloxane bond. by mixing to precipitate perovskite-type semiconductor nanocrystals having luminescence, coordinating the compound to the surface of the semiconductor nanocrystal, and then condensing the reactive groups in the coordinated compound, thereby forming the semiconductor nanocrystal. It can be manufactured by a method of obtaining the particles 91 having a surface layer having the above siloxane bond formed on the surface of the crystal.

This silica-coated luminescent particle 91 can be used as a luminescent particle by itself.

<Surface layer 914>

The surface layer 914 is composed of a ligand containing a compound capable of coordinating to the surface of the nanocrystal 911 and allowing molecules to form siloxane bonds.

Such a ligand is a compound having a binding group that binds to a cation included in the nanocrystal 911, and includes a compound containing Si and having a reactive group forming a siloxane bond. Examples of the bonding group include at least one of a carboxyl group, a carboxylic acid anhydride group, an amino group, an ammonium group, a mercapto group, a phosphine group, a phosphine oxide group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfonic acid group, and a boronic acid group. It is preferable, and it is more preferable that it is at least 1 sort(s) of a carboxyl group and an amino group. Examples of such a ligand include compounds containing a carboxyl group or an amino group, and either one of these ligands may be used alone or two or more types may be used in combination.

As a carboxyl group-containing compound, a C1-C30 linear or branched aliphatic carboxylic acid is mentioned, for example. Specific examples of such carboxyl group-containing compounds include arachidonic acid, crotonic acid, trans-2-decenoic acid, erucic acid, 3-decenoic acid, cis-4,7,10,13,16,19-docosa Hexaenoic acid, 4-decenoic acid, all cis-5,8,11,14,17-eicosapentaenoic acid, all cis-8,11,14-eicosatrienoic acid, cis-9-hexadecenoic acid , trans-3-hexenoic acid, trans-2-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 2-hexadecenoic acid, linolenic acid, linoleic acid, γ-linolenic acid, 3-nonenoic acid, 2-nonenoic acid, trans -2-octenoic acid, petroselic acid, elaidic acid, oleic acid, 3-octenoic acid, trans-2-pentenoic acid, trans-3-pentenoic acid, ricinolic acid, sorbic acid, 2-tridecenoic acid, cis-15 -Tetrachosenoic acid, 10-undecenoic acid, 2-undecenoic acid, acetic acid, butyric acid, behenic acid, cerotic acid, decanoic acid, arachidic acid, heneicosanoic acid, heptadecanoic acid, heptanoic acid, hexanoic acid, heptacosanoic acid, Lauric acid, myristic acid, melissic acid, octacosanoic acid, nonadecanoic acid, nonacosanoic acid, n-octanoic acid, palmitic acid, pentadecanoic acid, propionic acid, pentacosanoic acid, nonanoic acid, stearic acid, ligno Seric acid, trichosanoic acid, tridecanoic acid, undecanoic acid, valeric acid, etc. are mentioned.

Examples of the amino group-containing compound include linear or branched aliphatic amines having 1 to 30 carbon atoms. Specific examples of such an amino group-containing compound include 1-aminoheptadecane, 1-aminononadecane, heptadecan-9-amine, stearylamine, oleylamine, and 2-n-octyl-1-dodecylamine. , allylamine, amylamine, 2-ethoxyethylamine, 3-ethoxypropylamine, isobutylamine, isoamylamine, 3-methoxypropylamine, 2-methoxyethylamine, 2-methylbutylamine, neo Pentylamine, propylamine, methylamine, ethylamine, butylamine, hexylamine, heptylamine, n-octylamine, 1-aminodecane, nonylamine, 1-aminoundecane, dodecylamine, 1-aminopentadecane, 1-aminotridecane, hexadecylamine, tetradecylamine, etc. are mentioned.

In addition, the compound containing Si and having a reactive group forming a siloxane bond preferably has a bonding group that binds to a cation contained in the nanocrystal 911 .

As the reactive group, a hydrolyzable silyl group such as a silanol group and an alkoxysilyl group having 1 to 6 carbon atoms is preferable since a siloxane bond is easily formed.

Examples of the bondable group include a carboxyl group, an amino group, an ammonium group, a mercapto group, a phosphine group, a phosphine oxide group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group, a sulfonic acid group, and a boronic acid group. Especially, as a bondable group, it is preferable that it is at least 1 sort(s) of a carboxyl group, a mercapto group, and an amino group. These bondable groups have higher affinity for cations contained in the nanocrystal 911 than the above-mentioned reactive groups. For this reason, the ligand is coordinated with the bonding group toward the nanocrystal 911 side, and the surface layer 914 can be formed more easily and reliably.

As the compound containing Si and having a reactive group forming a siloxane bond, one or more types of silicon compounds containing a bondable group may be contained, or two or more types may be used in combination.

Preferably, any one of a carboxyl group-containing silicon compound, an amino group-containing silicon compound, and a mercapto group-containing silicon compound may be contained, or two or more kinds may be used in combination.

Specific examples of the carboxyl group-containing silicon compound include 3-(trimethoxysilyl)propionic acid, 3-(triethoxysilyl)propionic acid, 2-carboxyethylphenylbis(2-methoxyethoxy)silane, N- [3-(trimethoxysilyl)propyl]-N'-carboxymethylethylenediamine, N-[3-(trimethoxysilyl)propyl]phthalamide, N-[3-(trimethoxysilyl)propyl]ethylene Diamine-N,N',N'-triacetic acid, etc. are mentioned.

On the other hand, specific examples of the amino group-containing silicon compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldipropoxysilane, N-(2-aminoethyl)-3-aminopropyl Methyldiisopropoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl )-3-aminopropyltripropoxysilane, N-(2-aminoethyl)-3-aminopropyltriisopropoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N -(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyl Silanetriol, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N,N-bis[3-(tri) Methoxysilyl) propyl] ethylenediamine, (aminoethylaminoethyl) phenyltrimethoxysilane, (aminoethylaminoethyl) phenyltriethoxysilane, (aminoethylaminoethyl) phenyltripropoxysilane, (aminoethylaminoethyl ) Phenyltriisopropoxysilane, (aminoethylaminomethyl)phenyltrimethoxysilane, (aminoethylaminomethyl)phenyltriethoxysilane, (aminoethylaminomethyl)phenyltripropoxysilane, (aminoethylaminomethyl) Phenyltriisopropoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropylmethyldimethoxysilane, N -β-(N-vinylbenzylaminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane, N-β-(N-di(vinylbenzyl)aminoethyl)-γ- Aminopropyltrimethoxysilane, N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane, methylbenzylaminoethylaminopropyltri Methoxysilane, dimethylbenzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-(N- Phenyl)aminopropyltrimethoxysilane, N,N-bis[3-(trimethoxysilyl)propyl]ethylenediamine, (aminoethylaminoethyl)phenethyltrimethoxysilane, (aminoethylaminoethyl)phenethyltriethoxy Silane, (aminoethylaminoethyl)phenethyltripropoxysilane, (aminoethylaminoethyl)phenethyltriisopropoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)phenethyltrie Toxysilane, (aminoethylaminomethyl)phenethyltripropoxysilane, (aminoethylaminomethyl)phenethyltriisopropoxysilane, N-[2-[3-(trimethoxysilyl)propylamino]ethyl]ethylene Diamine, N-[2-[3-(triethoxysilyl)propylamino]ethyl]ethylenediamine, N-[2-[3-(tripropoxysilyl)propylamino]ethyl]ethylenediamine, N-[2 -[3-(triisopropoxysilyl)propylamino]ethyl]ethylenediamine etc. are mentioned.

Specific examples of the mercapto group-containing silicon compound include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyl. Diethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 2-mercaptoethylmethyldimethoxysilane, 2-mercaptoethylmethyldiethoxysilane, 3-[ethoxybis (3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silyl]-1-propanethiol etc. are mentioned.

Silica-coated light emitting particles 91 shown in FIG. 3(a) have oleic acid, oleylamine, and 3-aminopropyltrimethoxysilane as ligands on the surface of nanocrystals 911 containing Pb cations as M sites. and further reacting with 3-aminopropyltrimethoxysilane to form the surface layer 914.

The thickness of the surface layer 914 is preferably 0.5 to 50 nm, and more preferably 1.0 to 30 nm. If the light emitting particle 91 has the surface layer 914 having such a thickness, the stability of the nanocrystal 911 against heat can be sufficiently increased.

In addition, the thickness of the surface layer 914 can be changed by adjusting the number of atoms (chain length) of the linkage structure connecting the bonding group and the reactive group of the ligand.

<Method of producing silica-coated luminescent particles 91>

Such silica-coated light-emitting particles 91 contain a solution containing the raw material compound of the nanocrystal 911, a compound having a bonding group that binds to a cation contained in the nanocrystal 911, and Si to bond to a siloxane. After mixing a solution containing a compound having a reactive group capable of forming, by condensing the reactive group in the compound having a reactive group capable of forming a siloxane bond by containing Si coordinated to the surface of the precipitated nanocrystal 911. , can be easily fabricated. At this time, there is a method of manufacturing by heating and a method of manufacturing without heating.

First, a method for producing silica-coated light-emitting particles 91 by heating will be described. Solutions containing two kinds of raw material compounds for synthesizing semiconductor nanocrystals by reaction are prepared respectively. At this time, a compound having an associative group binding to cations included in the nanocrystal 911 is added to one of the two solutions, and a compound having a reactive group capable of forming a siloxane bond containing Si is added to the other solution. put Then, these are mixed under an inert gas atmosphere and reacted under temperature conditions of 140 to 260°C. Subsequently, a method of precipitating nanocrystals by cooling to -20 to 30°C and stirring is exemplified. The precipitated nanocrystal becomes one in which a surface layer 914 having a siloxane bond is formed on the surface of the nanocrystal 911, and the nanocrystal can be obtained by a standard method such as centrifugation.

Specifically, for example, a solution containing cesium carbonate, oleic acid, and an organic solvent is prepared. As the organic solvent, 1-octadecene, dioctyl ether, diphenyl ether and the like can be used. At this time, it is preferable to adjust the respective addition amounts so that cesium carbonate is 0.2 to 2 g and oleic acid is 0.1 to 10 mL with respect to 40 mL of the organic solvent. After drying the obtained solution under reduced pressure at 90 to 150°C for 10 to 180 minutes, the cesium-oleic acid solution is obtained by heating at 100 to 200°C under an inert gas atmosphere such as argon or nitrogen.

On the other hand, a solution containing lead (II) bromide and the same organic solvent as described above is prepared. At this time, 20 to 100 mg of lead (II) bromide is added to 5 mL of organic solvent. After drying the obtained solution under reduced pressure at 90 to 150°C for 10 to 180 minutes, 0.1 to 2 mL of 3-aminopropyltriethoxysilane is added under an inert gas atmosphere such as argon or nitrogen.

Then, the solution containing lead (II) bromide and 3-aminopropyltriethoxysilane is heated to 140 to 260° C., and the above-described cesium-oleic acid solution is added, followed by heating and stirring for 1 to 10 seconds to react. , The obtained reaction solution is cooled in an ice bath. At this time, it is preferable to add 0.1 to 1 mL of a cesium-oleic acid solution to 5 mL of a solution containing lead (II) bromide and 3-aminopropyltriethoxysilane. While stirring at -20 to 30°C, the nanocrystals 911 are precipitated, and 3-aminopropyltriethoxysilane and oleic acid are coordinated on the surface of the nanocrystals 911.

Then, after stirring the obtained reaction solution under air at room temperature (10 to 30°C, humidity 5 to 60%) for 5 to 300 minutes, a suspension is obtained by adding 0.1 to 50 mL of ethanol. The alkoxysilyl group of 3-aminopropyltriethoxysilane is condensed under air and stirring at room temperature to form a surface layer 914 having siloxane bonds on the surface of the nanocrystal 911 .

A solid substance is recovered by centrifuging the resulting suspension, and the solid substance is added to hexane to obtain silica-coated light-emitting particles (91) having a surface layer (914) having siloxane bonds on the surface of nanocrystals (911) made of lead cesium tribromide A dispersion of luminescent particles in which is dispersed in toluene can be obtained.

In addition, by adding the recovered solid material to isobornyl methacrylate, which is a photopolymerizable compound described later, silica having a surface layer 914 having siloxane bonds on the surface of nanocrystals 911 made of lead methylammonium tribromide crystals A dispersion of light-emitting particles in which the coated light-emitting particles 91 are dispersed in isobornyl methacrylate can be obtained.

Next, a method for producing the silica-coated light-emitting particles 91 without heating will be described. A solution containing a raw material compound for semiconductor nanocrystals and a compound having an associative group binding to cations included in the nanocrystal 911 (a compound having a reactive group capable of forming a siloxane bond by containing Si is not included) , A method in which nanocrystals are precipitated by dropping and mixing a compound containing Si and having a reactive group capable of forming a siloxane bond dissolved in an organic solvent that is a poor solvent for nanocrystals under air. The amount of organic solvent used is preferably 10 to 1000 times the mass of semiconductor nanocrystals. In addition, the precipitated nanocrystal becomes one in which a surface layer 914 having siloxane bonds is formed on the surface of the nanocrystal 911, and the nanocrystal can be obtained by a conventional method such as centrifugation.

Specifically, as a solution containing a raw material compound for semiconductor nanocrystals, for example, a solution containing lead (II) bromide, cesium bromide, oleic acid, oleylamine, and an organic solvent is prepared. The organic solvent may be a good solvent for nanocrystals, but is preferably dimethyl sulfoxide, N,N-dimethylformamide, N-methylformamide, or a mixed solvent thereof from the viewpoint of compatibility. At this time, it is preferable to adjust the respective addition amounts so that lead (II) bromide is 10 to 50 mg, cesium bromide is 5 to 25 mg, oleic acid is 0.2 to 2 mL, and oleylamine is 0.05 to 0.5 ml with respect to 10 mL of the organic solvent. do.

On the other hand, as a solution containing a compound containing Si and having a reactive group capable of forming a siloxane bond, and an organic solvent that is a poor solvent for the nanocrystal, for example, 3-aminopropyltriethoxysilane and a poor solvent are prepared do. As a poor solvent, isopropyl alcohol, toluene, hexane, etc. can be used. At this time, it is preferable to adjust each addition amount so that 3-aminopropyltriethoxysilane is 0.01 to 0.5 mL with respect to 5 mL of the poor solvent.

Then, 0.1 to 1 mL of the solution containing the above-described lead (II) bromide, cesium bromide, oleic acid, and oleylamine was mixed with 5 mL of the above-described solution containing 3-aminopropyltriethoxysilane and a poor solvent under atmospheric conditions. , After adding at 0 to 30 ° C., stirred for 5 to 180 seconds in an instant in the atmosphere, the solid is recovered by centrifugation. When the mixture is added to a poor solvent, nanocrystals 911 precipitate, and 3-aminopropyltriethoxysilane, oleic acid, and oleylamine are coordinated on the surface of nanocrystals 911. Then, during stirring in the air, the alkoxysilyl groups of 3-aminopropyltriethoxysilane condense to form a surface layer 914 having siloxane bonds on the surface of the nanocrystals 911 .

By adding this recovered solid material to toluene, silica-coated light-emitting particles 91 having a surface layer 914 having siloxane bonds on the surface of nanocrystals 911 made of lead cesium tribromide crystals are dispersed in toluene, dispersion can be obtained.

Further, by adding the recovered solid matter to isobornyl methacrylate, which is a photopolymerizable compound described later, nanocrystals 911 made of lead cesium tribromide crystals are coated with silica having a surface layer 914 having siloxane bonds on the surface. A dispersion of light-emitting particles in which the light-emitting particles 91 are dispersed in isobornyl methacrylate can also be obtained.

1-1-3. Titanium-coated luminescent particles

As another form of nanoparticles containing semiconductor nanocrystals in the present invention, the semiconductor nanocrystals may be coated with titanium oxide. In the case of coating with titanium oxide, it can be obtained by adding an appropriate amount of titanium alkoxide to a solution in which semiconductor nanocrystals are dispersed in a hydrophobic solvent under an inert atmosphere that does not contain water and oxygen, followed by stirring. By coating the surface of the semiconductor nanocrystal with titanium oxide, surface defects of the crystal can be compensated for, and it becomes possible to suppress a decrease in light emission characteristics. As titanium oxide, it is, for example, a hydrolysis product of titanium alkoxide, and (RO) ₃ -Ti-O- (R each independently represents an alkyl group having 1 to 8 carbon atoms that may be linear or branched. .) can be used.

Such titanium-coated luminescent particles can be formed by the following method.

First, nanocrystals are dispersed in a hydrophobic organic solvent. The hydrophobic organic solvent is not particularly limited, but toluene, chloroform, hexane, and cyclohexane are preferable, and toluene and cyclohexane are more preferable. These hydrophobic organic solvents may be used alone or in combination of two or more. Next, by adding titanium alkoxide to the nanocrystal dispersion solution and stirring it, the nanocrystal surface is coordinated and reacted, so that the crystal surface can be coated.

When tetravalent titanium alkoxide is used as the titanium alkoxide, one alkoxy group in the titanium alkoxide is partially hydrolyzed by water slightly contained in the solvent to generate (RO) ₃ -Ti-O-. . As the titanium alkoxide, a compound represented by general formula Ti(OR) ₄ is preferable. In the above formula, R each independently represents a methyl group, an ethyl group, an isopropyl group, or a 2-ethylhexyl group.

As such a titanium alkoxide, specifically, titanium isopropoxide, titanium methoxide, tetraethyl orthotitanate, titanium-2-ethylhexyl oxide, titanium-diisopropoxide-bis (acetylacetonate) etc. can be mentioned. These titanium alkoxides may be used alone or in combination of two or more, but when two or more titanium alkoxides are used, the amount and timing of addition are controlled by paying attention to the reaction rate of each, so that the nanocrystal surface is Covering is preferred.

Alternatively, after forming a surface layer on the surface of the nanocrystal, the surface layer may be further coated with a layer containing a polymer of Compound C having a hydrolysable silyl group.

In addition, after forming a surface layer on the surface of the nanocrystal, a polymer B having a first structural unit having a basic group and a second structural unit having no basic group and having a solvent affinity and a polymer of compound C having a hydrolyzable silyl group are prepared. You may coat|cover the surface layer with the layer containing.

The polymer B is an amphiphilic compound, and is a polymer having a first structural unit having a basic group and a solvent-philic second structural unit having excellent affinity for a dispersion medium and having no basic group. The dispersion medium referred to herein is a dispersion medium in a dispersion containing silica-coated luminescent particles, and may be a resin such as an organic solvent or a photopolymerizable compound.

The polymer B has a first structural unit having a basic group represented by the following formula (D) 1) and a solventphilic second structural unit represented by the following formula (D) 2) more preferable

(In the formula, R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ^B1 represents a monovalent group having basicity, and R ^B2 represents a monovalent group having an organic group having excellent affinity for a dispersion medium. represents a flag,

R ^B1 is a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, an imino group, a pyridyl group, a pyrimidine group, a piperazinyl group, a piperidyl group, an imidazolyl group, a pyrrolidinyl group, represents a basic group containing a dazolidinyl group;

X ¹ and X ² each independently represent -COO-, -OCO-, an alkyl chain having 1 to 8 carbon atoms, or a single bond;

R ^B2 is a linear or branched alkyl group having 2 to 15 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms which may have a substituent, a polyalkylene oxide group having 10 to 50 carbon atoms whose terminal is a hydroxyl group or an alkoxy group, and a substituent Indicates an aromatic group that may be present.)

In the polymer B, structural units represented by the silicon-containing compound (D) 1) and the silicon-containing compound (D) 2) may be used alone or in combination of two or more. Further, the polymer B has, as a first polymer block, a first structural unit represented by a silicon-containing compound (D) 1) and a second structural unit represented by a silicon-containing compound (D) 2) as a second polymer block. It is more preferable that it is a block copolymer which has as a polymer block.

The content of the first structural unit in the polymer B is preferably, for example, 5 mol% or more, 7 mol% or more, or 10 mol% or more based on all the structural units constituting the polymer B, and 50 It is preferable that it is mol% or less, 30 mol% or less, or 20 mol% or less.

The content of the second structural unit in the polymer B is, for example, 70 mol% or more, 75 mol% or more, or 80 mol% or more based on the total structural units constituting the polymer B. It is preferable that it is mol% or less, 93 mol% or less, or 90 mol% or less.

Polymer B may contain other structural units in addition to the first structural unit and the second structural unit. In that case, the total content of the first structural unit and the second structural unit in the polymer B is, for example, 70 mol% or more, 80 mol% or more, based on all the structural units constituting the polymer B. Or it is preferable that it is 90 mol% or more.

The silane compound C has a hydrolyzable silyl group, and when the silyl group condenses to form a siloxane bond, a layer containing a polymer of the silane compound C is formed on the surface of the surface layer 914, and the semiconductor nanocrystal is formed. Light-emitting particles having a surface layer containing Si on the surface of the nanoparticles are formed.

It is preferable that the said silane compound C is a compound represented by the following formula (C1), for example.

In the formula, R ^C1 and R ^C2 each independently represent an alkyl group, R ^C3 and R ^C4 each independently represent a hydrogen atom or an alkyl group, n represents 0 or 1, and m represents an integer of 1 or greater. It is preferable that m is an integer of 10 or less.

The compound represented by formula (C1) is specifically, for example, tetrabutoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, Methyltriethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane, vinyltriethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltriethoxysilane, n-hexyl Trimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-dodecyl Triethoxysilane, n-hexadecyltrimethoxysilane, n-hexadecyltriethoxysilane, n-octadecyltrimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane, tri of methoxy(pentafluorophenyl)silane, trimethoxy(11-pentafluorophenoxyundecyl)silane, trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, tetramethoxysilane Partially hydrolyzed oligomer (product name: methylsilicate 51, methylsilicate 53A (above, manufactured by Colcoat Co., Ltd.)), partially hydrolyzed oligomer of tetraethoxysilane (product name: ethylsilicate 40, ethylsilicate 48 (above, manufactured by Colcoat Co., Ltd.)) ), a partially hydrolyzed oligomer of a mixture of tetramethoxysilane and tetraethoxysilane (product name: EMS-485 (manufactured by Colcoat Co., Ltd.)), and the like.

As the silane compound C, in addition to the compound represented by the formula (C1) described above, it is also possible to use together a compound represented by the following formula (C2) and a compound represented by (C3), for example.

In the formula, R ^C21 , R ^C22 , and R ^C31 each independently represent an alkyl group, and R ^C23 , R ^C24 , R ^C32 , R ^C33 , and R ^C34 each independently represent a hydrogen atom or an alkyl group which may have a substituent; A phenyl group or a cyclohexyl group is shown, the carbon atom in the alkyl group may be substituted with an oxygen atom or a nitrogen atom, and m2 represents an integer of 1 or more and 10 or less.

Specific examples of the compound represented by the formula (C2) and the compound represented by the formula (C3) include dimethyldiethoxysilane, diphenyldimethoxysilane, methylethyldimethoxysilane, and trimethylmethoxysilane. can The compound represented by formula (C1) can be used individually by 1 type, or can also be used in combination of 2 or more type. The compound represented by formula (C2) and the compound represented by (C3) can be used singly or in combination of two or more kinds with the compound represented by general formula (C1).

1-1-4. polymer-coated luminescent particles

The polymer-coated light-emitting particles 90 shown in FIGS. 1, 2(b) and 3(b) are the hollow particle-encapsulated light-emitting particles 91 or the silica-coated light-emitting particles 91 obtained in the above steps. Particles (hereinafter, these luminescent particles 91 may be referred to as "mother particles 91"), and the surface of the mother particles 91 is coated with a hydrophobic polymer to form a polymer layer 92. can be obtained by doing Since the polymer-coated light-emitting particles 90 are provided with the hydrophobic polymer layer 92, the light-emitting particles 90 can be given high stability to oxygen and moisture, and furthermore, the dispersion stability of the light-emitting particles 90 can improve

<Method of producing polymer-coated luminescent particles>

Such a polymer layer 92 can be formed by the following method I, method II, or the like.

Method I: The surface of the base particle 91 is coated with the hydrophobic polymer by adding and mixing the base particle 91 to a varnish containing the hydrophobic polymer.

Method II: A polymerizable unsaturated monomer soluble in a non-aqueous solvent and insoluble or sparingly soluble after polymerization is supported on the surface of the parent particle 91 together with a polymer containing a polymerizable unsaturated group soluble in a non-aqueous solvent, and then It can be formed by a method of polymerizing a polymer and the polymerizable unsaturated monomer.

In addition, the hydrophobic polymer in method I includes the polymer obtained by polymerizing the polymer in method II and a polymerizable unsaturated monomer.

Especially, it is preferable to form the polymer layer 92 by method II. According to Method II, the polymer layer 92 having a uniform thickness and excellent adhesion to the base particles 91 can be formed.

Hereinafter, the above-described method II for forming the polymer layer will be described in detail.

[Non-aqueous solvent]

The non-aqueous solvent is preferably an organic solvent capable of dissolving the hydrophobic polymer, and more preferably a non-aqueous solvent capable of uniformly dispersing the luminescent particles 91 . By using such a non-aqueous solvent, it is possible to coat the polymer layer 92 by adsorbing the hydrophobic polymer to the light emitting particles 91 very simply. Also, preferably, the non-aqueous solvent is a low dielectric constant solvent. By using a low dielectric constant solvent, the hydrophobic polymer is strongly adsorbed to the surface of the light emitting particles 91 and the polymer layer can be coated simply by mixing the hydrophobic polymer and the light emitting particles 91 in the non-aqueous solvent.

The polymer layer 92 thus obtained is difficult to remove from the light-emitting particles 91 even when the light-emitting particles 90 are washed with a solvent, as will be described later. In addition, the dielectric constant of the non-aqueous solvent is so preferable that it is low. Specifically, the dielectric constant of the non-aqueous solvent is preferably 10 or less, more preferably 6 or less, and particularly preferably 5 or less. As a preferable non-aqueous solvent, it is preferable that it is an organic solvent containing at least one selected from the group which consists of an aliphatic hydrocarbon-type solvent, an alicyclic hydrocarbon-type solvent, and an aromatic hydrocarbon-type solvent.

Examples of the aliphatic hydrocarbon-based solvent include n-hexane, n-heptane, n-octane, isohexane, and the like, and examples of the alicyclic hydrocarbon-based solvent include cyclopentane, cyclohexane, and ethylcyclohexane. These etc. are mentioned, As an aromatic hydrocarbon type solvent, toluene, xylene, etc. are mentioned.

Further, a mixed solvent in which another organic solvent is mixed with at least one selected from the group consisting of aliphatic hydrocarbon-based solvents, alicyclic hydrocarbon-based solvents, and aromatic hydrocarbon-based solvents as a non-aqueous solvent within a range that does not impair the effects of the present invention. You can also use Examples of such other organic solvents include ester solvents such as methyl acetate, ethyl acetate, n-butyl acetate, and amyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and cyclohexanone; and alcohol solvents such as methanol, ethanol, n-propanol, i-propanol, and n-butanol.

When used as a mixed solvent, the amount of at least one of the group consisting of aliphatic hydrocarbon-based solvents, alicyclic hydrocarbon-based solvents and aromatic hydrocarbon-based solvents is preferably 50% by mass or more, more preferably 60% by mass or more. do.

[Polymer Containing Polymerizable Unsaturated Group Soluble in Non-Aqueous Solvents]

The polymer containing a polymerizable unsaturated group soluble in a non-aqueous solvent used in this step (hereinafter also referred to as “polymer (P)”) includes an alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms (A1) , (meth)acrylate (A2) having a polymerizable functional group at the terminal, a fluorine-containing compound having a polymerizable unsaturated group, a silicon-containing compound (D), C), or a polymerizable silicon-containing compound (D) having a polymerizable unsaturated group, as a monomer component A polymer in which a polymerizable unsaturated group is introduced into the copolymer, or an alkyl (meth)acrylate (A1) having an alkyl group having 4 or more carbon atoms, (meth)acrylate (A2) having a polymerizable functional group at the terminal, macromonomers composed of monomers having a polymerizable unsaturated group mainly composed of fluorine compounds (D) and C), or copolymers of monomers having a polymerizable unsaturated group containing silicon compounds (D) as a main component; .

Examples of the alkyl (meth)acrylate (A1) include n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Late, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate , isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

Moreover, as (meth)acrylate (A2) which has a polymerizable functional group at the terminal, it is dimethylamino (meth)acrylate, diethylamino (meth)acrylate, for example; and diester compounds of unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid with monohydric alcohols. Here, in this specification, "(meth)acrylate" means both methacrylate and acrylate. The same applies to the expression "(meth)acryloyl".

Moreover, as a fluorine-containing compound and silicon-containing compound (D)) which has a polymerizable unsaturated group, the compound represented by the following general formula silicon-containing compound (D) 1) is mentioned, for example.

In Formula (B1), R ⁴ is a hydrogen atom, a fluorine atom, a methyl group, a cyano group, a phenyl group, a benzyl group, or -C _n H _2n -Rf ^a (provided that n is an integer of 1 to 8, and Rf ^a is It is any one group of formulas (Rf-1) to (Rf-7) described later.).

Moreover, in the said general formula (B1), L is any one group represented by the following formula (L-1) - (L-10).

In the formulas (L-1), (L-3), (L-5), (L-6) and (L-7), n is an integer of 1 to 8. In the formulas (L-8), (L-9) and (L-10), m is an integer of 1 to 8, and n is an integer of 0 to 8. Rf ^b in the formulas (L-6) and (L-7) is any one of the following formulas (Rf-1) to (Rf-7).

Moreover, in the said general formula (B1), Rf is the group of any one of the following formulas (Rf-1) - (Rf-7).

In the formulas (Rf-1) to (Rf-4), n is an integer of 4 to 6. In the formula (Rf-5), m is an integer of 1 to 5, n is an integer of 0 to 4, and the sum of m and n is 4 to 5. In the formula (Rf-6), m is an integer of 0 to 4, n is an integer of 1 to 4, p is an integer of 0 to 4, and the sum of m, n and p is 4 to 5.

Moreover, as a preferable specific example of the compound represented by the said general formula (B1), the methacrylate represented by the following formula (B1-1) - (B1-7), the following (B1-8) - (B1-15) The acrylate etc. shown are mentioned. In addition, these compounds may be used individually by 1 type, and may use 2 or more types together.

Examples of the fluorine-containing compound (C) having a polymerizable unsaturated group include a poly(perfluoroalkylene ether) chain and a compound having a polymerizable unsaturated group at both ends thereof.

The poly(perfluoroalkylene ether) chain preferably has a structure in which divalent fluorocarbon groups having 1 to 3 carbon atoms and oxygen atoms are alternately connected.

Such a poly(perfluoroalkylene ether) chain may include only one type of divalent fluorocarbon group having 1 to 3 carbon atoms or may include multiple types. As a specific poly(perfluoroalkylene ether), the structure represented by the following general formula (C1) is mentioned.

In the general formula (C1), X represents the following formulas (C1-1) to (C1-5). A plurality of X's may be the same or different. In the case of containing different X (when a plurality of types of repeating units X-O are included), a plurality of identical repeating units X-O may exist in a random shape or block shape. Moreover, n is the number of repeating units, and is an integer greater than or equal to 1.

Among them, the poly(perfluoroalkylene ether) chain has a good balance between the number of fluorine atoms and the number of oxygen atoms, so that the polymer (P) easily adheres to the surface of the mother particle 91. A structure in which perfluoromethylene represented by (C1-1) and perfluoroethylene represented by the formula (C1-2) coexist is preferable.

In this case, the abundance ratio of perfluoromethylene represented by the formula (C1-1) and perfluoroethylene represented by the formula (C1-2) is the molar ratio [perfluoromethylene (C1-1) /perfluoroethylene (C1-2)], preferably 1/10 to 10/1, more preferably 2/8 to 8/2, still more preferably 3/7 to 7/3 .

Moreover, it is preferable that it is 3-100, and, as for n in the said General formula (C1), it is more preferable that it is 6-70. Moreover, it is preferable that it is 18-200 in total, and, as for the number of fluorine atoms contained in a poly(perfluoroalkylene ether) chain, it is more preferable that it is 25-150. In the poly(perfluoroalkylene ether) chain having such a structure, the balance between the number of fluorine atoms and the number of oxygen atoms is further improved.

As a raw material compound which has a poly(perfluoroalkylene ether) chain before introduce|transducing polymerizable unsaturated groups at both terminals, the following formula (C2-1) - (C2-6) is mentioned, for example. In addition, "-PFPE-" in the following formulas (C2-1) to (C2-6) is a poly(perfluoroalkylene ether) chain.

Examples of the polymerizable unsaturated groups introduced at both ends of the poly(perfluoroalkylene ether) chain include structures represented by the following formulas (U-1) to (U-5).

Among them, the acryloyloxy group represented by the formula U-1 or the formula U- The methacryloyloxy group represented by 2 is preferable.

Specific examples of the fluorine-containing compound (C) include compounds represented by the following formulas (C-1) to (C-13). In addition, "-PFPE-" in the following formulas (C-1) to (C-13) is a poly(perfluoroalkylene ether) chain.

Among them, as the fluorine-containing compound (C), the compounds represented by the formulas (C-1), (C-2), (C-5) or (C-6) can be used because industrial production is easy. Preferably, since the polymer (P) that easily sticks to the surface of the parent particle 91 can be synthesized, acryl is attached to both ends of the poly(perfluoroalkylene ether) chain represented by the formula (C-1). A compound having a diary group or a compound having methacryloyl groups at both ends of the poly(perfluoroalkylene ether) chain represented by the formula (C-2) is more preferable.

Moreover, as a silicon-containing compound (D) which has a polymerizable unsaturated group, the compound represented by the following general formula (D1) is mentioned, for example.

In the general formula (D1), P is a polymerizable functional group, X ^a is SiR ¹¹ R ²² , Rd is a hydrogen atom, a fluorine atom, a methyl group, an acryloyl group or a methacryloyl group (provided that R ¹¹ and R ²² are A methyl group, or a Si(CH ₃ ) group, an amino group, or a glycidyl group, m is an integer of 0 to 100, and n is an integer of 0 to 4).

Specific examples of the silicon-containing compound (D) include compounds represented by the following formulas (D-1) to (D-13).

In addition, an alkyl (meth)acrylate (A1) usable as a monomer having a polymerizable unsaturated group, a (meth)acrylate compound (A2) having a polymerizable functional group at the terminal, a fluorine-containing compound (B, C), and a silicon-containing compound Examples of compounds other than (D) include aromatic vinyl compounds such as styrene, α-methylstyrene, p-t-butylstyrene, and vinyltoluene; and (meth)acrylate-based compounds such as benzyl (meth)acrylate, dibromopropyl (meth)acrylate, and tribromophenyl (meth)acrylate.

These compounds are random copolymers of alkyl (meth)acrylate (A1), (meth)acrylate having a polymerizable functional group at the terminal (A2), fluorine-containing compound (B, C) or silicon-containing compound (D). It is preferable to use as In this way, the solubility of the obtained polymer (P) in a non-aqueous solvent can be sufficiently increased.

The compound usable as a monomer having the polymerizable unsaturated group may be used alone or in combination of two or more. Among them, alkyl (meth) acrylates having a linear or branched alkyl group having 4 to 12 carbon atoms, such as n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl methacrylate; It is preferred to use (A1).

A copolymer of a monomer having a polymerizable unsaturated group is obtained by polymerizing a monomer having a polymerizable unsaturated group by a conventional method.

Further, polymer (P) is obtained by introducing a polymerizable unsaturated group into such a copolymer.

As a method for introducing a polymerizable unsaturated group, the following methods III to VI are exemplified.

In Method III, a carboxylic acid group-containing polymerizable monomer such as acrylic acid or methacrylic acid or an amino group-containing polymerizable monomer such as dimethylaminoethyl methacrylate or dimethylaminopropyl acrylamide is blended and copolymerized as a copolymerization component in advance to form a carboxylic acid group or an amino group. After obtaining a copolymer having , a monomer having a glycidyl group such as glycidyl methacrylate and a polymerizable unsaturated group is reacted with the carboxylic acid group or amino group.

In Method IV, a hydroxyl group-containing monomer such as 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate is blended in advance as a copolymerization component and copolymerized to obtain a copolymer having a hydroxyl group, and then isocyanate ethyl methacrylate is added to the hydroxyl group. It is a method of reacting a monomer having an isocyanate group such as acrylate and a polymerizable unsaturated group.

Method V introduces a carboxyl group to the terminal of the copolymer using thioglycolic acid as a chain transfer agent during polymerization, and reacts the carboxyl group with a monomer having a glycidyl group such as glycidyl methacrylate and a polymerizable unsaturated group. way.

Method VI introduces a carboxyl group into the copolymer using a carboxyl group-containing azo initiator such as azobiscyanopentanoic acid as a polymerization initiator, and the carboxyl group has a glycidyl group such as glycidyl methacrylate and a polymerizable unsaturated group. A method for reacting monomers.

Among them, Method III is preferred because it is the most convenient.

[Polymerizable Unsaturated Monomer Soluble in Non-Aqueous Solvents and Insoluble or Slightly Soluble After Polymerization]

As the polymerizable unsaturated monomer (hereinafter also referred to as “monomer (M)”) that is soluble in the above-mentioned non-aqueous solvent and becomes insoluble or sparingly soluble after polymerization, for example, a vinyl-based monomer having no reactive polar group (functional group) amide bond-containing vinyl monomers, (meth)acryloyloxyalkyl phosphates, (meth)acryloyloxyalkyl phosphites, phosphorus atom-containing vinyl monomers, hydroxyl group-containing polymerizable unsaturated monomers, Alkylaminoalkyl (meth)acrylates, epoxy group-containing polymerizable unsaturated monomers, isocyanate group-containing α,β-ethylenically unsaturated monomers, alkoxysilyl group-containing polymerizable unsaturated monomers, carboxyl group-containing α,β-ethylenically unsaturated monomers Monomers etc. are mentioned.

Specific examples of vinyl monomers having no reactive polar group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and i-propyl (meth)acrylate. and olefins such as (meth)acrylates, (meth)acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride.

Specific examples of the amide bond-containing vinyl monomers include (meth)acrylamide, dimethyl (meth)acrylamide, N-t-butyl (meth)acrylamide, N-octyl (meth)acrylamide, and diacetone acrylamide. , dimethylaminopropyl acrylamide, and alkoxylated N-methylolized (meth)acrylamides.

As a specific example of (meth)acryloyloxyalkyl phosphates, dialkyl [(meth)acryloyloxyalkyl] phosphates, (meth)acryloyloxyalkyl acid phosphates, etc. are mentioned, for example.

Specific examples of (meth)acryloyloxyalkyl phosphites include dialkyl[(meth)acryloyloxyalkyl] phosphites, (meth)acryloyloxyalkyl acid phosphites, and the like. can

Specific examples of the phosphorus atom-containing vinyl monomers include, for example, alkylene oxide adducts of the above-mentioned (meth)acryloyloxyalkyl acid phosphates or (meth)acryloyloxyalkyl acid phosphites, glycidyl Ester compounds of epoxy group-containing vinyl monomers such as (meth)acrylate and methylglycidyl (meth)acrylate with phosphoric acid, phosphorous acid, or acid esters thereof, 3-chloro-2-acid phosphoxypropyl (meth) Acrylates etc. are mentioned.

Specific examples of the hydroxyl group-containing polymerizable unsaturated monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, di-2- Hydroxyalkyl esters of polymerizable unsaturated carboxylic acids such as hydroxyethyl fumarate, mono-2-hydroxyethyl monobutyl fumarate, polypropylene glycol mono(meth)acrylate, and polyethylene glycol mono(meth)acrylate, or these and ε-caprolactone; polymerizable unsaturated carboxylic acids such as unsaturated mono- or dicarboxylic acids such as (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid, and monoesters of dicarboxylic acids and monohydric alcohols; Hydroxyalkyl esters of the above polymerizable unsaturated carboxylic acids and anhydrides of polycarboxylic acids (maleic acid, succinic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, benzene tricarboxylic acid, benzene tetracarboxylic acid, "hymic acid", tetrachlorophthalic acid, Monoglycidyl esters of monovalent carboxylic acids (eg, coconut oil fatty acid glycidyl ester, octylic acid glycidyl ester, etc.), butyl glycidyl ether, ethylene oxide , adducts of monoepoxy compounds such as propylene oxide, or adducts of these and ε-caprolactone; Hydroxy vinyl ether etc. are mentioned.

As a specific example of dialkylaminoalkyl (meth)acrylates, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc. are mentioned, for example.

Specific examples of the epoxy group-containing polymerizable unsaturated monomers include, for example, polymerizable unsaturated carboxylic acids, equimolar adducts of a hydroxyl group-containing vinyl monomer and an anhydride of the polycarboxylic acid (mono-2-(meth)acryloyloxymonoethylphthalate, etc. ) Epoxy group-containing polymerizable compounds obtained by addition reaction of various polyepoxy compounds having at least two epoxy groups in an equimolar ratio to various unsaturated carboxylic acids, such as glycidyl (meth)acrylate, (β-methyl) glycol Cydyl (meth)acrylate, (meth)allyl glycidyl ether, etc. are mentioned.

Specific examples of the isocyanate group-containing α,β-ethylenically unsaturated monomers include isocyanates such as equimolar adducts of 2-hydroxyethyl (meth)acrylate and hexamethylene diisocyanate, and isocyanate ethyl (meth)acrylate. group and a monomer having a vinyl group; and the like.

Specific examples of the alkoxysilyl group-containing polymerizable unsaturated monomers include silicone monomers such as vinylethoxysilane, α-methacryloxypropyltrimethoxysilane, and trimethylsiloxyethyl (meth)acrylate. can

Specific examples of the α,β-ethylenically unsaturated monomers containing a carboxyl group include, for example, unsaturated mono- or dicarboxylic acids such as (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid; α,β-ethylenically unsaturated carboxylic acids such as monoesters of polyhydric alcohols; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl ( meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl-mono α,β-unsaturated carboxylic acid hydroalkyl esters such as butyl fumarate and polyethylene glycol mono(meth)acrylate, maleic acid, succinic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, benzene tricarboxylic acid, benzene tetracarboxylic acid, adducts of anhydrides of polycarboxylic acids such as "hymic acid", tetrachlorophthalic acid, and dodecinylsuccinic acid.

Especially, as a monomer (M), it is preferable that it is an alkyl (meth)acrylate which has a C3 or less alkyl group like methyl (meth)acrylate and ethyl (meth)acrylate.

When polymerizing the polymer (P) and the monomer (M), it is preferable to copolymerize a polymerizable unsaturated monomer having at least one of a functional group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group, a hydroxyl group, and a dimethylamino group. As a result, the interaction with the siloxane bond of the polymer (polymer layer 92) to be formed is increased, so that adhesion to the surface of the light-emitting particles 91 can be improved.

In the case of a polymer having a tertiary amino group such as a dimethylamino group as a monomer, since the tertiary amino group that does not contribute to reactions such as coordination bonds is oxidized, formaldehyde, a harmful substance, is generated due to this amino group when exposed to high temperatures. Here, oxidation of the amino group in the polymer forming the polymer layer covering the light-emitting particles 90 can be suppressed by coexisting phosphite as the antioxidant B. In addition, deterioration of light-emitting particles due to formaldehyde can be suppressed because formaldehyde generated from an amino group in the polymer and phosphorous acid ester react irreversibly.

Further, in order to prevent or suppress elution of the hydrophobic polymer from the obtained light-emitting particles 90, the hydrophobic polymer (polymer (P)) is preferably crosslinked.

As a polyfunctional polymerizable unsaturated monomer usable as a crosslinking component, for example, divinylbenzene, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, Polyethylene glycoldi(meth)acrylate, 1,3-butanedioldi(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, neopentylglycoldi Methacrylate, trimethylolpropane triethoxytri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaeryth Litol hexa(meth)acrylate, allyl methacrylate, etc. are mentioned.

Moreover, in the range where the hydrophobic polymer obtained does not dissolve in a non-aqueous solvent, you may copolymerize other polymerizable unsaturated monomers. Examples of other polymerizable unsaturated monomers include the alkyl (meth)acrylates (A), fluorine-containing compounds (B, C), and compounds exemplified as polymerizable unsaturated monomers for polymers (P) that can be used other than these. can be heard

The polymer layer 92 made of a hydrophobic polymer is formed by polymerizing the monomer (M) in the presence of the luminescent particles 91, a non-aqueous solvent, and the polymer (P).

The luminescent particles 91 and the polymer P are preferably mixed before polymerization. For mixing, a homogenizer, a disper, a bead mill, a paint shaker, a kneader, a roll mill, a ball mill, an attritor, a sand mill or the like can be used, for example.

In the present invention, the shape of the luminescent particles 91 to be used is not particularly limited, and may be slurry, wet cake, powder or the like.

After mixing the light-emitting particles 91 and the polymer (P), the monomer (M) and a polymerization initiator described later are further mixed to perform polymerization, thereby forming a polymer layer composed of a polymer of the polymer (P) and the monomer (M). (92) is formed. In this way, the luminescent particles 90 are obtained.

At this time, the number average molecular weight of the polymer (P) is preferably 1,000 to 500,000, more preferably 2,000 to 200,000, still more preferably 3,000 to 100,000. By using the polymer (P) having a molecular weight within such a range, the polymer layer 92 can be satisfactorily coated on the surfaces of the light emitting particles 91 .

In addition, since the amount of polymer (P) used is appropriately set according to the purpose, it is not particularly limited, but is usually preferably 0.5 to 50 parts by mass, and 1 to 40 parts by mass with respect to 100 parts by mass of the luminescent particles 91. It is more preferable, and it is still more preferable that it is 2-35 mass parts.

In addition, since the amount of the monomer (M) is appropriately set according to the purpose, it is not particularly limited, but is usually preferably 0.5 to 40 parts by mass, and 1 to 35 parts by mass relative to 100 parts by mass of the luminescent particles 91. It is more preferable, and it is more preferable that it is 2-30 mass parts.

The amount of the hydrophobic polymer finally covering the surface of the light-emitting particles 91 is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass, and 3 to 40 parts by mass, based on 100 parts by mass of the light-emitting particles 91. It is more preferable that it is a mass part.

In this case, the amount of the monomer (M) is usually preferably 10 to 100 parts by mass, more preferably 30 to 90 parts by mass, still more preferably 50 to 80 parts by mass, relative to 100 parts by mass of the polymer (P). .

The thickness of the polymer layer 92 is preferably 0.5 to 100 nm, more preferably 0.7 to 50 nm, and still more preferably 1 to 30 nm. When the thickness of the polymer layer 92 is less than 0.5 nm, dispersion stability is often not obtained. When the thickness of the polymer layer 92 exceeds 100 nm, it is often difficult to contain the luminescent particles 91 at a high concentration. By covering the light-emitting particles 91 with the polymer layer 92 having such a thickness, the stability of the light-emitting particles 90 against oxygen and moisture can be further improved.

Polymerization of the monomer (M) in the presence of the luminescent particles 91, the non-aqueous solvent and the polymer (P) can be carried out by a known polymerization method, but is preferably carried out in the presence of a polymerization initiator.

Examples of these polymerization initiators include dimethyl-2,2-azobis(2-methylpropionate), azobisisobutyronitrile (AIBN), and 2,2-azobis(2,4-dimethylvalero). nitrile), 2,2-azobis (2-methylbutyronitrile), benzoyl peroxide, t-butylperbenzoate, t-butyl-2-ethylhexanoate, t-butylhydroperoxide, di-t -Butyl peroxide, cumene hydroperoxide, etc. are mentioned. These polymerization initiators may be used individually by 1 type, and may use 2 or more types together.

The polymerization initiator, which is sparingly soluble in non-aqueous solvents, is preferably added to the liquid mixture containing the luminescent particles 91 and the polymer (P) in a dissolved state in the monomer (M).

Alternatively, the monomer (M) or the monomer (M) in which the polymerization initiator is dissolved may be added dropwise to the mixed solution having reached the polymerization temperature for polymerization. It is preferable because it is stable.

The polymerization temperature is preferably in the range of 60 to 130°C, and more preferably in the range of 70 to 100°C. When the polymerization of the monomer (M) is carried out at such a polymerization temperature, shape change (eg, deterioration, crystal growth, etc.) of the nanocrystal 911 can be suitably prevented.

After the polymerization of the monomer M, the polymer not adsorbed on the surface of the light-emitting particle 91 is removed, thereby forming the light-emitting particle (polymer-coated light-emitting particle) 90 on which the polymer layer 92 is formed on the surface of the light-emitting particle 91. get Centrifugal sedimentation and ultrafiltration are examples of methods for removing the polymer that has not been adsorbed. In the centrifugal sedimentation, a dispersion containing the polymer-coated light-emitting particles 90 and the polymer that has not been adsorbed is rotated at high speed to cause the polymer-coated light-emitting particles 90 in the dispersion to settle, thereby separating the polymer that has not been adsorbed. In ultrafiltration, a dispersion containing the polymer-coated light-emitting particles 90 and the polymer that was not adsorbed is diluted with an appropriate solvent, and the diluted solution is passed through a filtration membrane having an appropriate pore size, and the polymer-coated light-emitting particles that are not adsorbed and the polymer-coated light-emitting particles ( 90) is separated.

In the above manner, polymer-coated light-emitting particles 90 are obtained. The polymer-coated light-emitting particles 90 may be stored in a dispersed state (i.e., as a dispersion liquid) in a dispersion medium, resin, or polymeric compound, or may be stored as a powder (polymer of the polymer-coated light-emitting particles 90) after removing the dispersion medium. do.

When the ink composition containing luminescent particles contains the polymer-coated luminescent particles 90, the content of the polymer-coated luminescent particles 90 is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, , It is more preferable that it is 1-10 mass %. Similarly, when the ink composition containing luminescent particles includes the nanocrystals 911 not covered by the polymer layer 92, the luminescent particles 91 encapsulating hollow particles, and the luminescent particles 91 coated with silica, the luminescent particles ( The content of 91) is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and still more preferably 1 to 10% by mass. By setting the content of the polymer-coated luminescent particles 90 (or the luminescent particles 91) in the ink composition containing luminescent particles within the above range, when the ink composition containing luminescent particles is ejected by the inkjet printing method, the ejection stability can be improved. can be further improved. In addition, it is difficult for the light emitting particles 90 (or the light emitting particles 91) to aggregate, so that the external quantum efficiency of the resulting light emitting layer (light conversion layer) can be increased.

The ink composition may contain at least two of red light-emitting particles, green light-emitting particles and blue light-emitting particles as light-emitting particles 90 (or light-emitting particles 91) containing light-emitting nanocrystals, but preferably these are contains only one of the particles. When the ink composition contains red luminescent particles, the content of green luminescent particles and the content of blue luminescent particles are preferably 5% by mass or less, more preferably 0% by mass, based on the total mass of the luminescent particles. am. When the ink composition contains green luminescent particles, the content of red luminescent particles and the content of blue luminescent particles are preferably 5% by mass or less, more preferably 0% by mass, based on the total mass of the luminescent particles. am.

1-2. photopolymerizable compound

The photopolymerizable compound contained in the ink composition containing nanoparticles containing luminescent nanocrystals of the present invention is a compound that polymerizes by irradiation with light (active energy rays), which functions as a binder in a cured product, and is a photopolymerizable monomer or Oligomers may also be used. These are basically used together with a photoinitiator.

As the photopolymerizable compound, a radically polymerizable compound, a cationically polymerizable compound, an anionic polymerizable compound, or the like can be used, but it is preferable to use a radically polymerizable compound from the viewpoint of fast curing property.

A radically polymerizable compound is, for example, a compound having an ethylenically unsaturated group. In this specification, an ethylenically unsaturated group means a group having an ethylenically unsaturated bond (polymerizable carbon-carbon double bond). The number of ethylenically unsaturated bonds (for example, the number of ethylenically unsaturated groups) in the compound having an ethylenically unsaturated group is 1 to 4, for example.

As a compound which has an ethylenically unsaturated group, the compound which has an ethylenically unsaturated group, such as a vinyl group, a vinylene group, a vinylidene group, and a (meth)acryloyl group, is mentioned, for example. From the viewpoint of further improving the external quantum efficiency, compounds having a (meth)acryloyl group are preferred, monofunctional or polyfunctional (meth)acrylates are more preferred, and monofunctional or bifunctional (meth)acrylates are preferred. Acrylates are more preferred. In addition, in this specification, a "(meth)acryloyl group" means an "acryloyl group" and the "methacryloyl group" corresponding to it. The same applies to the expression "(meth)acrylate". In addition, monofunctional (meth)acrylate means (meth)acrylate having one (meth)acryloyl group, and polyfunctional (meth)acrylate means two (meth)acryloyl groups. It means (meth)acrylate having above.

Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, and 2- Ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (metha)acrylate ) Acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, nonylphenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, Dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl Oxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, benzyl (meth)acryl Late, phenylbenzyl (meth)acrylate, mono(2-acryloyloxyethyl) succinate, N-[2-(acryloyloxy)ethyl]phthalimide, N-[2-(acryloyloxy) ) Ethyl] tetrahydrophthalimide, trimethylolpropane formal acrylate, etc. are mentioned.

Polyfunctional (meth)acrylates are bifunctional (meth)acrylates, trifunctional (meth)acrylates, tetrafunctional (meth)acrylates, pentafunctional (meth)acrylates, hexafunctional (meth)acrylates, and the like. . For example, di(meth)acrylate in which two hydroxyl groups of a diol compound are substituted by (meth)acryloyloxy groups, and two or three hydroxyl groups of a triol compound are substituted by (meth)acryloyloxy groups. Di or tri(meth)acrylates may be used.

Specific examples of the bifunctional (meth)acrylate include 1,3-butylene glycol di(meth)acrylate, 1,4-butanedioldi(meth)acrylate, and 1,5-pentanedioldi(meth)acrylate. )Acrylate, 3-methyl-1,5-pentanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, neopentylglycoldi(meth)acrylate, 1,8-octanediol Di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalic acid ester diacrylate , di(meth)acrylate in which two hydroxyl groups of tris(2-hydroxyethyl)isocyanurate are substituted by (meth)acryloyloxy groups, 4 moles or more of ethylene oxide or propylene per mole of neopentyl glycol Di(meth)acrylate in which two hydroxyl groups of a diol obtained by adding an oxide are substituted by (meth)acryloyloxy groups, 2 of a diol obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A Di(meth)acrylate in which two hydroxyl groups are substituted by (meth)acryloyloxy groups, and two hydroxyl groups of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane are (meth) Di(meth)acrylate substituted by acryloyloxy groups, two hydroxyl groups of diol obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A are substituted by (meth)acryloyloxy groups Di(meth)acrylate etc. are mentioned.

Specific examples of the trifunctional (meth)acrylate include trimethylolpropane tri(meth)acrylate, glycerin triacrylate, pentaerythritol tri(meth)acrylate, and 3 moles or more to 1 mole of trimethylolpropane. and tri(meth)acrylates in which three hydroxyl groups of a triol obtained by adding ethylene oxide or propylene oxide are substituted with (meth)acryloyloxy groups.

As a specific example of tetrafunctional (meth)acrylate, pentaerythritol tetra (meth)acrylate, ditrimethylol-propane tetra (meth)acrylate, etc. are mentioned, for example.

As a specific example of a pentafunctional (meth)acrylate, dipentaerythritol penta (meth)acrylate etc. are mentioned, for example.

As a specific example of 6 functional (meth)acrylate, dipentaerythritol hexa(meth)acrylate etc. are mentioned, for example.

The poly(meth)acrylate may be a poly(meth)acrylate in which a plurality of hydroxyl groups of dipentaerythritol, such as dipentaerythritol hexa(meth)acrylate, are substituted by (meth)acryloyloxy groups.

The (meth)acrylate compound may be an ethylene oxide-modified phosphoric acid (meth)acrylate or an ethylene oxide-modified alkyl phosphoric acid (meth)acrylate having a phosphoric acid group.

In the ink composition of the present invention, when the curable component is composed of only a photopolymerizable compound or a photopolymerizable compound as a main component, as the photopolymerizable compound, a bifunctional or higher photopolymerizable compound having two or more polymerizable functional groups in one molecule is essential It is more preferable to use it as a component in view of further enhancing the durability (strength, heat resistance, etc.) of the cured product.

Monofunctional from the viewpoint of excellent viscosity stability when preparing the ink composition, better discharge stability, and the viewpoint of suppressing the decrease in smoothness of the coating film due to curing shrinkage during production of the luminescent particle coating film. It is preferable to use a combination of (meth)acrylate and polyfunctional (meth)acrylate.

The molecular weight of the photopolymerizable compound is, for example, 50 or more, and may be 100 or more or 150 or more. The molecular weight of the photopolymerizable compound is, for example, 500 or less, and may be 400 or less or 300 or less. From the viewpoint of easy compatibility between the viscosity as an inkjet ink and the volatility of the ink after ejection, it is preferably 50 to 500, more preferably 100 to 400.

From the viewpoint of reducing the stickiness (tack) of the surface of the cured product of the ink composition, it is preferable to use a radically polymerizable compound having a cyclic structure as the photopolymerizable compound. The cyclic structure may be an aromatic ring structure or a non-aromatic ring structure. The number of cyclic structures (total number of aromatic rings and non-aromatic rings) is 1 or 2 or more, but is preferably 3 or less. The number of carbon atoms constituting the cyclic structure is, for example, 4 or more, preferably 5 or more or 6 or more. The number of carbon atoms is, for example, 20 or less, and preferably 18 or less.

It is preferable that an aromatic ring structure is a structure which has a C6-C18 aromatic ring. As a C6-C18 aromatic ring, a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, etc. are mentioned. The aromatic ring structure may be a structure having an aromatic heterocycle. As an aromatic heterocycle, a furan ring, a pyrrole ring, a pyran ring, a pyridine ring etc. are mentioned, for example. The number of aromatic rings may be 1 or 2 or more, but is preferably 3 or less. The organic group may have a structure in which two or more aromatic rings are bonded through a single bond (for example, a biphenyl structure).

It is preferable that a non-aromatic ring structure is a structure which has a C5-C20 alicyclic ring, for example. Examples of the alicyclic ring having 5 to 20 carbon atoms include a cycloalkane ring such as a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring, a cycloalkene ring such as a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, and a cyclooctene ring; A dioxane ring etc. are mentioned. The alicyclic ring may be a condensed ring such as a bicycloundecane ring, a decahydronaphthalene ring, a norbornene ring, a norbornadiene ring, and an isobornyl ring. The non-aromatic ring structure may be a structure having a non-aromatic heterocycle. As a non-aromatic heterocycle, a tetrahydrofuran ring, a pyrrolidine ring, a tetrahydropyran ring, a pyridine ring etc. are mentioned, for example.

The radically polymerizable compound having a cyclic structure is preferably a monofunctional or polyfunctional (meth)acrylate having a cyclic structure, more preferably a monofunctional (meth)acrylate having a cyclic structure. Specifically, phenoxyethyl (meth)acrylate, phenoxybenzyl (meth)acrylate, biphenyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclo Pentenyloxyethyl (meth)acrylate, trimethylolpropane formal acrylate and the like are preferably used.

The content of the radically polymerizable compound having a cyclic structure is in the ink composition from the viewpoint of easily suppressing the stickiness (tack) of the surface of the ink composition, easy to obtain an appropriate viscosity as an inkjet ink, and easy to obtain excellent ejection properties. Based on the total mass of the photopolymerizable compound in, it is preferably 3 to 85% by mass, more preferably 5 to 65% by mass, more preferably 10 to 45% by mass, and more preferably 15 to 35% by mass is particularly preferred.

From the viewpoint of easily obtaining excellent ejection properties, it is preferable to use a radically polymerizable compound having a linear structure with 3 or more carbon atoms as the ink composition, and more preferably a radically polymerizable compound with a linear structure with 4 or more carbon atoms is used. . The straight-chain structure refers to a hydrocarbon chain having 3 or more carbon atoms. In the radically polymerizable compound having a linear structure, a hydrogen atom directly connected to a carbon atom constituting the linear structure may be substituted with a methyl group or an ethyl group, but the number of substitutions is preferably 3 or less. The radically polymerizable compound having a linear structure having 4 or more carbon atoms is preferably a structure in which atoms other than hydrogen atoms are connected without branching, and even if it has heteroatoms such as oxygen atoms in addition to carbon atoms and hydrogen atoms, do. That is, the linear structure is not limited to a structure in which three or more carbon atoms are continuous in a straight chain, and a structure in which three or more carbon atoms are connected in a straight chain through a hetero atom such as an oxygen atom may be used. The linear structure may have an unsaturated bond, but preferably consists of only a saturated bond. The number of carbon atoms constituting the linear structure is preferably 5 or more, more preferably 6 or more, still more preferably 7 or more. The number of carbon atoms constituting the linear structure is preferably 25 or less, more preferably 20 or less, still more preferably 15 or less. In addition, a radically polymerizable compound having a linear structure in which the total number of carbon atoms is 3 or more (the number does not include carbon atoms in methyl groups or ethyl groups in which hydrogen atoms directly connected to carbon atoms forming the linear structure are substituted), from the viewpoint of ejection properties , it is preferable not to have a cyclic structure.

It is preferable that a linear structure is a structure which has a C4 or more linear alkyl group, for example. Examples of the straight-chain alkyl group having 4 or more carbon atoms include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, and the like. there is. As a radically polymerizable compound having such a structure, an alkyl (meth)acrylate obtained by directly bonding the straight-chain alkyl group to a (meth)acryloyloxy group is preferably used.

It is preferable that a linear structure is a structure which has a C4 or more linear alkylene group, for example. Examples of the straight-chain alkylene group having 4 or more carbon atoms include a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, A pentadecylene group etc. are mentioned. As the radically polymerizable compound having such a structure, an alkylene glycol di(meth)acrylate obtained by bonding two (meth)acryloyloxy groups to the straight-chain alkylene group is preferably used.

The linear structure is preferably a structure in which a linear alkyl group and one or more linear alkylene groups are bonded via an oxygen atom (a structure having an alkyl (poly)oxyalkylene group), for example. The number of straight-chain alkylene groups is 2 or more and preferably 6 or less. When the number of straight-chain alkylene groups is two or more, the two or more alkylene groups may be the same or different. The number of carbon atoms in the straight-chain alkyl group and the straight-chain alkylene group may be 1 or more, and may be 2 or more or 3 or more, but is preferably 4 or less. As a straight-chain alkyl group, a methyl group, an ethyl group, and a propyl group other than the above-mentioned straight-chain alkyl group of 4 or more carbon atoms are mentioned. As a straight-chain alkylene group, a methylene group, an ethylene group, and a propylene group other than the above-mentioned straight-chain alkylene group having 4 or more carbon atoms are mentioned. As the radically polymerizable compound having such a structure, an alkyl (poly) oxyalkylene (meth) acrylate formed by directly bonding the above-mentioned alkyl (poly) oxyalkylene group to a (meth) acryloyloxy group is preferably used.

The content of the radically polymerizable compound having a linear structure having 3 or more carbon atoms makes it easy to obtain an appropriate viscosity as an inkjet ink and easily obtains excellent ejection properties, the viewpoint of excellent curability of the ink composition, and the stickiness of the surface of the ink composition ( From the viewpoint of easily suppressing tack), based on the total mass of the photopolymerizable compound in the ink composition, it is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and 20 to 70% by mass % is particularly preferred.

As the photopolymerizable compound, it is preferable to use two or more types of radically polymerizable compounds from the viewpoint of excellent surface uniformity of the pixel portion. It is more preferable to use in combination with a radically polymerizable compound having. In order to improve the external quantum efficiency, when the amount of nanoparticles containing luminescent nanocrystals is increased, the uniformity of the surface of the pixel portion may decrease. Even in this case, according to the combination of the photopolymerizable compound, There is a tendency for a pixel portion with excellent surface uniformity to be obtained.

When the radical polymerizable compound having a cyclic structure described above and the radical polymerizable compound having a linear structure having 3 or more carbon atoms are used in combination, the number of carbon atoms is 3 relative to the content M _C of the radical polymerizable compound having a cyclic structure. The mass ratio (M _L /M _C ) of the content M _L of the radically polymerizable compound having the above linear structure is preferably 0.05 to 5, and more preferably 0.1 to 3.5 from the viewpoint of excellent surface uniformity of the pixel portion. And, it is particularly preferably 0.1 to 2.

It is preferable that the photopolymerizable compound is alkali insoluble from the viewpoint of obtaining a highly reliable picture element (cured product of the ink composition) easily. In the present specification, the photopolymerizable compound is alkali insoluble means that the amount of dissolution of the photopolymerizable compound at 25 ° C. in 1% by mass of potassium hydroxide aqueous solution is 30% by mass or less based on the total mass of the photopolymerizable compound. it means. The dissolution amount of the photopolymerizable compound is preferably 10% by mass or less, and more preferably 3% by mass or less.

The content of the photopolymerizable compound contained in the ink composition is determined from the viewpoint of obtaining an appropriate viscosity as an inkjet ink, the viewpoint of improving the curability of the ink composition, and the solvent resistance and abrasion resistance of the pixel portion (cured product of the ink composition). From the viewpoint of improvement and obtaining more excellent optical properties (e.g., external quantum efficiency), it is preferably 70 to 95% by mass, and preferably 75 to 93% by mass, based on the total mass of the ink composition. It is more preferable, and it is still more preferable that it is 80-90 mass %.

1-3. photopolymerization initiator

The photopolymerization initiator used in the ink composition of the present invention contains two or more types of acylphosphine oxide-based compounds. This makes it possible to lower the viscosity of the ink because of its excellent solubility in polymerizable compounds, and also prevents precipitation of the photopolymerization initiator due to storage. In addition, it is possible to form a coating film having excellent internal curing properties and a small initial degree of coloring of the cured film. In particular, the ink composition of the present invention is an ultraviolet light emitting diode (UV-LED) having a narrow spectrum output of ±15 nanometers centered on a specific wavelength, such as 365 nanometers, 385 nanometers, 395 nanometers or 405 nanometers. ) is suitable for

In particular, as the photopolymerization initiator, it is preferable to use together at least one type of monoacylphosphine oxide type compound and at least one type of bisacylphosphine oxide type compound. By using these together, it becomes possible to reliably achieve both reduction in ink viscosity and suppression of precipitation of the photopolymerization initiator.

Examples of the monoacylphosphine oxide compound include, but are not particularly limited to, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethoxyphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, 2 , 4,6-triethyl benzoyl diphenyl phosphine oxide and 2,4,6- triphenyl benzoyl diphenyl phosphine oxide are mentioned. Among these, it is preferable that it is 2,4,6- trimethylbenzoyl diphenyl phosphine oxide.

As a commercial item of a monoacylphosphine oxide type compound, for example, Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), Omnirad TPO-L (ethoxyphenyl (2,4,6- trimethylbenzoyl) phosphine oxide) (above, manufactured by IGM Resins B.V.).

Examples of the bisacylphosphine oxide-based compound include, but are not particularly limited to, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4, 4-trimethylpentylphosphine oxide is mentioned. Among these, it is preferable that it is bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

As a commercial item of a bisacylphosphine oxide type compound, Omnirad 819 (bis (2,4,6- trimethylbenzoyl) phenylphosphine oxide) (made by IGM Resins B.V.) is mentioned, for example.

The content of the photopolymerization initiator is from the viewpoint of solubility in the photopolymerizable compound, the curability of the ink composition, and the stability over time of the pixel portion (cured product of the ink composition) (maintenance stability of external quantum efficiency), With respect to 100 mass% of the photopolymerizable compound, it is preferably 1 to 15 mass%, more preferably 2 to 12 mass%, still more preferably 3 to 9 mass%, and particularly preferably 3 to 7 mass%. do.

From the viewpoint of the curability of the ink composition, the content of the acylphosphine oxide-based compound in the photopolymerization initiator is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, and 70 to 100% by mass. is particularly preferred.

In addition, the content ratio of the bisacylphosphine oxide-based compound to the monoacylphosphine oxide-based compound (mass% of the bisacylphosphine oxide-based compound / mass% of the monoacylphosphine oxide-based compound) is the molar extinction coefficient 0.1-6.0 are preferable, 0.2-5.0 are more preferable, and 0.5-4.0 are especially preferable from a large viewpoint and a solubility viewpoint with respect to a photopolymerizable compound.

Moreover, the ink composition of this invention may further contain other photoinitiators other than an acylphosphine oxide type compound. Examples of other photopolymerization initiators include alkylphenone-based photopolymerization initiators, titanocene-based alkylphenone-based photopolymerization initiators, oxime ester-based photopolymerization initiators, and oxyphenylacetic acid ester-based photopolymerization initiators. The content of the photopolymerization initiator other than the acylphosphine oxide compound is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, and 0 to 20% by mass based on 100% by mass of the photopolymerization initiator. It is more preferable, and it is especially preferable that it is 0-10 mass %.

1-4. antioxidant

The ink composition of the present invention contains at least one compound selected from the group consisting of a compound having a hydroxyphenyl group and a compound having a phosphorous acid ester structure as an antioxidant. By containing the antioxidant, the ink composition of the present invention can suppress the storage stability of the ink composition and the decrease in the external quantum efficiency of the coating film due to heat.

As the antioxidant, it is preferable to use together a first antioxidant A containing at least one compound having a hydroxyphenyl group and a second antioxidant B containing at least one compound having a phosphorous acid ester structure. By using these together, a higher antioxidant effect can be obtained.

1-4-1. Primary antioxidant A

Said 1st antioxidant A contains 1 or more types of compounds which have a hydroxyphenyl group. This compound captures the highly active peroxy radical in the early stages of the oxidation reaction and gives a metastable hydroperoxide.

Specifically, as the first antioxidant A containing the compound having a hydroxyphenyl group, for example, IRGANOX 1010 (product name, manufactured by BASF Japan Co., Ltd.), ADEKA STAB AO-60 (product name, manufactured by ADEKA Co., Ltd.), "Tetrakis[methylene-3(3'5'-di-t-butyl-4') commercially available as SUMILIZER BP-101 (product name, manufactured by Sumitomo Chemical Co., Ltd.), Tominox TT (product name, manufactured by Yoshitomi Pharmaceutical Co., Ltd.), etc. -Hydroxyphenyl)propionate] methane” (melting point 110-130°C, molecular weight 1178), “2,2’-thiodiethylbis[3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate]" (melting point 63°C, molecular weight 643), IRGANOX 1076 (product name, manufactured by BASF Japan), Adekastab AO-50 (product name) "n-octadecyl-3 (3',5'- Di-t-butyl-4'-hydroxyphenyl)propionate" (melting point 50 to 55°C, molecular weight 531), "N,N'-Hexa commercially available as IRGANOX 1098 (product name, manufactured by BASF Japan Co., Ltd.), etc. Methylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide]” (melting point 156-161°C, molecular weight 637), marketed as IRGANOX 1135 (product name, manufactured by BASF Japan Co., Ltd.), etc. "Isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate" (melting point 63-78°C, molecular weight 643), IRGANOX 1330 (product name, manufactured by BASF Japan Co., Ltd.) "2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene" commercially available as ADEKA STAB AO-330 (product name, manufactured by ADEKA Co., Ltd.) ( "2,4-bis[(dodecylthio)methyl]-6-methylphenol" (melting point 27-29) commercially available as IRGANOX 1726 (product name, manufactured by BASF Japan Co., Ltd.), etc. °C, molecular weight 537), "calcium bis[3,5-di(tert-butyl)-4-hydroxybenzyl(ethoxy)phosphinate] commercially available as IRGANOX 1425 WL (product name, manufactured by BASF Japan Co., Ltd.), etc. "2,4-bis(octylthiomethyl)-6-methylphenol" (melting point of about 14°C, molecular weight 425), "bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionic acid] [ethylenebis(oxyethylene)] commercially available as IRGANOX 245 (product name, manufactured by BASF Japan Co., Ltd.), etc. (melting point 76-79°C, molecular weight 587), "1,6-hexanediolbis[3-(3,5-di-tert-butyl-4) commercially available as IRGANOX 259 (product name, manufactured by BASF Japan Co., Ltd.) -Hydroxyphenyl)propionate] (melting point 104-108°C, molecular weight 639), IRGANOX 3114 (product name, manufactured by BASF Japan Co., Ltd.), Adecastab AO-20 (product name, manufactured by ADEKA Co., Ltd.), which are commercially available. "4-di-t-butyl-4-hydroxybenzyl) isocyanate" (melting point: 218 to 223°C, molecular weight: 784), IRGANOX 565 (product name, manufactured by BASF Japan Corporation), etc. [[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-2,6-di-tert-butylphenol” (melting point 91-96°C, molecular weight 589), "Diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate" (melting point: 116 to 121°C, molecular weight: 356), commercially available as IRGAMOD 295 (product name, manufactured by BASF Japan Co., Ltd.), SUMILIZER GA- "3,9-bis[2-[3-(3-tert-butyl-4-hydride) commercially available as 80 (product name, manufactured by Sumitomo Chemical Co., Ltd.), ADEKA STAB AO-80 (product name, manufactured by ADEKA Corporation), Roxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane” (melting point 110-120°C, molecular weight 741), SUMILIZER GS ( "Acrylic acid 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl" marketed as a product name, manufactured by Sumitomo Chemical Co., Ltd.), etc. (melting point 127°C, molecular weight 549), Adekastab AO-30 (product name, manufactured by ADEKA Co., Ltd.), etc. "1,1,3-tris(2-methyl-4-hydroxy-5-tert-butyl phenyl) butane” (melting point 183 to 185° C., molecular weight 545), “4,4’-butylidenebis(3-methyl-6- tert-butyl)phenol" (melting point 210-214°C, molecular weight 383), "2,2'-methylenebis(6-tert-butyl-p) commercially available as SUMILIZER MDP-S (product name, manufactured by Sumitomo Chemical Co., Ltd.), etc. -cresol)" (melting point 118-128°C, molecular weight 341), "4,4'-thiobis(6-tert-butyl-m-cresol) commercially available as SUMILIZER WX-R (product name, manufactured by Sumitomo Chemical Co., Ltd.), etc. )" (melting point 160-165 ° C., molecular weight 359), ANTAGE BHT (product name, manufactured by Kawaguchi Chemical Industry Co., Ltd.), "butyl hydroxytoluene" (melting point 70 ° C. , molecular weight 220), "2,5-di-tert-amylhydroquinone" (melting point 179-180 ° C, molecular weight 250), ANTAGE DBH (product name, "2,5-di-tert-butylhydroquinone" (melting point: 213 to 214°C, molecular weight: 222), ANGATE W-300 (product name: manufactured by Kawaguchi Chemical Industry Co., Ltd.), etc. Commercially available as "4,4'-butylidenebis(6-tert-butyl-m-cresol)" (melting point: 209°C, molecular weight: 383), ANTAGE W-400 (product name, manufactured by Kawaguchi Chemical Industry Co., Ltd.), etc. "2,2'-methylenebis(6-tert-butyl-p-cresol)" (melting point 118-128, molecular weight 341), ANTAGE W-500 (product name, manufactured by Kawaguchi Chemical Industry Co., Ltd.), etc. "2,2'-methylenebis(6-tert-butyl-4-ethylphenol)" (melting point 123, molecular weight 369), etc. are mentioned.

In addition, the first antioxidant A has a molecular weight of 500 or more and 1500 or less, and a softening point and a melting point of 70°C or more, from the viewpoint of being able to suppress the decrease in external quantum efficiency due to heat of the storage stability of the ink composition and the cured coating film. It is more preferable that it is 250 degreeC or less.

In addition, the first antioxidant A is a compound having a hydroxyphenyl group in the following general formula (I) from the viewpoint of being able to more suppress the decrease in the external quantum efficiency due to the storage stability of the ink composition and the heat of the cured coating film It is more preferable that it is a compound shown.

In the above general formula (I), M ¹ is a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a 2,4,8,10-tetraoxaspiro[5,5]undecane group, or carbon. represents an atom or a hydrocarbon group having 1 to 20 carbon atoms, and one or two or more -CH ₂ - in the hydrocarbon group are -O-, -CO-, -COO-, or -OCO within a range where oxygen atoms are not directly adjacent to each other. -, -NH- may be substituted, and any hydrogen atom in the hydrocarbon group may be substituted by a phenyl group having a substituent, and X ¹ is an alkylene group having 1 to 15 carbon atoms, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, Represents -C≡C-, a single bond, a 1,4-phenylene group or a trans-1,4-cyclohexylene group, which may be the same as or different from each other, and one or two or more -CH ₂ of the above alkylene groups. - may be substituted with -O-, -CO-, -COO-, or -OCO- within the range where the oxygen atom is not directly adjacent, and the 1,4-phenylene group is a hydrocarbon having any hydrogen atom having 1 to 6 carbon atoms. may be substituted with a group, R ¹¹ and R ¹² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and k represents an integer of 2 to 6.

As a compound represented by the said formula (I), the following formula (I-1) - (I-6) etc. are mentioned.

Specific examples of the first antioxidant A containing the compound represented by the general formula (I) include, for example, IRGANOX 1010, IRGANOX 1098, IRGANOX 245, IRGANOX 259 (above, manufactured by BASF Japan Co., Ltd.), Adecastab AO -30, Adeka Stab AO-60, Adeka Stab AO-80 (above, manufactured by ADEKA Co., Ltd.), Sumilizer BP-101, Sumilizer GA-80 (manufactured by Sumitomo Chemical Co., Ltd.), KEMINOX101 (manufactured by Chemipro Kasei Co., Ltd.) etc. can be mentioned.

The content of the first antioxidant A in the ink composition is preferably 0.05 to 3.0% by mass, more preferably 0.1 to 2.0% by mass, and still more preferably 0.1 to 1.0% by mass with respect to 100% by mass of the ink composition. desirable. At a content lower than this range, since the antioxidant effect is lowered, the effect of suppressing an increase in ink viscosity and preventing a decrease in external quantum efficiency due to heat of the coating film cannot be expected, and at a content higher than this range, the antioxidant acts as a plasticizer, It is undesirable because it hinders curing of the ink composition.

1-4-2. Secondary Antioxidant B

The second antioxidant B contains at least one compound having a phosphorous acid ester structure. The second antioxidant B decomposes the hydroperoxide produced by the first antioxidant A to give a stable alcohol compound.

Specifically, as the antioxidant B containing the compound having the phosphite structure, for example, Adekastab 1178 (product name, manufactured by ADEKA Co., Ltd.), JP-351 (product name, manufactured by Johoku Chemical Industry Co., Ltd.), etc. Commercially available "tris(4-nonylphenyl) phosphite" (melting point 6°C, molecular weight 689), Adekastab 2112 (product name, manufactured by ADEKA Co., Ltd.), IRGAFOS168 (product name, manufactured by BASF Japan Co., Ltd.), JP-650 (product name, "Tris(2,4-di-tert-butylphenyl" (melting point: 183°C, molecular weight: 647), ADEKA STAB HP-10 (product name, manufactured by ADEKA Co., Ltd.), etc. "2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1,3, 2] Dioxaphosphosine” (melting point 148° C., molecular weight 583), “3 ,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane” (softening point: 52°C, molecular weight: 733), Adekastab PEP-24 (Product name, manufactured by ADEKA Co., Ltd.) "3,9-bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro commercially available as [5.5] Undecane” (melting point 165°C, molecular weight 604), “3,9-bis(2,6-di-tert-butyl- 4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane" (melting point: 237°C, molecular weight: 633), Adecastab TPP (product name, manufactured by ADEKA Co., Ltd.) ), "Triphenylphosphite" (melting point 25 ° C., molecular weight 310) commercially available as JP-360 (product name, manufactured by Johoku Chemical Industries, Ltd.), JP-351 (product name, manufactured by Johoku Chemical Industries, Ltd.), etc. Commercially available "trisnonylphenyl phosphite" (melting point 20 ° C or less, molecular weight 689), JP-3CP "tricresyl phosphite" (melting point 20 ° C or less, molecular weight 352), JP-302 (product name, Johoku Chemical "Triethyl phosphite" (melting point -122 ° C, molecular weight 166), commercially available as JP-308E (product name, manufactured by Johoku Chemical Industry Co., Ltd.), etc. "Phosphite" (melting point 20 ° C. or less, molecular weight 419), JP-310 (product name, manufactured by Johoku Chemical Industry Co., Ltd.), "tridecyl phosphite" (product name, commercially available as ADEKA Co., Ltd.), etc. "Trilauryl phosphite" (melting point 20 ° C or less, molecular weight 589), JP-333 (product name, "Tris (tridecyl) phosphite" (melting point 20 ° C. or less, molecular weight 629), which is marketed as Johoku Chemical Industry Co., Ltd.), JP-318-O (product name, Johoku Chemical Industry Co., Ltd.), etc. “Trioleylphosphite” (melting point 20° C. or lower, molecular weight 833), JPM-308 (product name, manufactured by Johoku Chemical Industry Co., Ltd.), and “Di "Diphenyl monodecyl phosphite" (melting point 18 ℃, molecular weight 375), "diphenyl mono (tridecyl) phosphite" (melting point 20 ° C. or less, molecular weight 416) commercially available as JPM-313 (product name, manufactured by Johoku Chemical Industry Co., Ltd.), JA-805 (product name "Tetra-C12-15-alkyl (propane-2,2-diylbis(4,1-phenylene) ) "bis(phosphite)" (melting point 20 ° C. or less, molecular weight 1112), "bis (decyl) pentaerythritol diphosphite" (melting point 20 ° C. Hereinafter, molecular weight 508), "tristearyl phosphite" (melting point 45-52 ° C, molecular weight 839), HOSTANOX P-EPQ (product name, Clariant "Tetrakis(2,4-di-tert-butylphenyl)-1,1-biphenyl-4,4'-diylbisphosphonate" (melting point: 85 to 100°C, molecular weight: 1035 ), "tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylene diphosphonate" commercially available as GSY-P100 (product name, manufactured by Sakai Chemical Industry Co., Ltd.), etc. (melting point of 235 to 240°C, molecular weight of 1092), and the like.

As the antioxidant B, the molecular weight is 500 or more and 1500 or less, and the softening point and melting point are 70 ° C. It is more preferable that it is a compound.

In addition, the antioxidant B is a phosphorous acid ester represented by the following general formula (II) or general formula (III) from the viewpoint of suppressing the storage stability of the ink composition and the decrease in external quantum efficiency due to heat of the cured coating film. It is more preferable that it is a compound with a structure.

(In general formula (II), R ²⁰ to R ²⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and one methyl group in the alkyl group may be substituted with an aryl group .)

(In Formula (III), R ³⁰ to R ³⁷ each independently represent a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms, and R ^3a and R ^3b each independently represent a hydrogen atom , represents a straight-chain or branched alkyl group having 1 to 6 carbon atoms, or R ^3a and R ^3b may form one ring structure, and Z ³¹ is a straight-chain alkyl group having 1 to 10 carbon atoms, or represents an aryl group, and any hydrogen atom in the aryl group may be substituted with a straight-chain or branched alkyl group having 1 to 6 carbon atoms.)

As a compound represented by the said formula (II), the following formula (II-1) - following formula (II-3) etc. are mentioned.

Specific examples of the antioxidant B containing the compound represented by the general formula (II) include, for example, Adekastab PEP-24, Adekastab PEP-36, and Adekastab PEP-45 (above, manufactured by ADEKA Corporation). ) and the like.

Examples of the compound represented by the formula (III) include formula (III-1) and formula (III-2).

As a specific example of antioxidant B containing the compound represented by the said general formula (III), Adekastab 2112, Adekastab HP-10 (above, made by ADEKA Corporation), etc. are mentioned, for example.

The content of the antioxidant B in the ink composition is preferably 0.01 to 3.0% by mass, more preferably 0.05 to 2.0% by mass, and even more preferably 0.1 to 1.0% by mass with respect to 100% by mass of the ink composition. do. At a content lower than this range, since the antioxidant effect is lowered, the effect of suppressing an increase in ink viscosity and preventing a decrease in external quantum efficiency due to heat of the coating film cannot be expected, and at a content higher than this range, the antioxidant acts as a plasticizer, It is undesirable because it hinders curing of the ink composition.

The total content of the first antioxidant A and the second antioxidant B in the present invention is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and 0.1 to 3% by mass relative to the total amount of the ink composition. ~ 2% by mass is particularly preferred. If it is within the above range, it can be dissolved satisfactorily in the ink composition, the precipitation of unnecessary components is small, and it is difficult to affect the luminescent properties (external quantum efficiency) of the obtained coating film.

The mass ratio (A/B) of the first antioxidant A and the second antioxidant B in the present invention is preferably 0.05 to 5.0, more preferably 0.1 to 4.0, still more preferably 0.15 to 3.0. And, it is particularly preferably 0.2 to 2.0. When it is within the above range, the heat resistance of the coating film is high, and it is more difficult to affect the light emission characteristics (external quantum efficiency) of the coating film.

1-5. light diffusing particles

The ink composition of the present invention preferably contains light-diffusing particles. The light-diffusing particles are, for example, optically inactive inorganic fine particles. The light-diffusing particles can scatter the light from the light source unit irradiated to the light emitting layer (light conversion layer).

Examples of the material constituting the light-diffusing particles include simple metals such as tungsten, zirconium, titanium, platinum, bismuth, rhodium, palladium, silver, tin, platinum, and gold; Silica, barium sulfate, barium carbonate, calcium carbonate, talc, titanium oxide, clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, alumina white, titanium oxide, magnesium oxide, barium oxide, aluminum oxide, bismuth oxide, zirconium oxide, metal oxides such as zinc oxide; metal carbonates such as magnesium carbonate, barium carbonate, bismuth carbonate, and calcium carbonate; metal hydroxides such as aluminum hydroxide; complex oxides such as barium zirconate, calcium zirconate, calcium titanate, barium titanate, and strontium titanate; and metal salts such as bismuth nitrate.

Among them, at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and silica is used as the material constituting the light-diffusing particles, from the viewpoint of a more excellent effect of reducing light leakage. It is preferably contained, more preferably at least one selected from the group consisting of titanium oxide, barium sulfate and calcium carbonate, and particularly preferably titanium oxide.

When using titanium oxide, it is preferable that it is surface-treated titanium oxide from a dispersible viewpoint. Although there are well-known methods for treating the surface of titanium oxide, it is more preferable that the surface treatment is performed including at least alumina.

Titanium oxide subjected to surface treatment with alumina refers to a treatment in which at least alumina is deposited on the surface of titanium oxide particles, and silica or the like can be used in addition to alumina. Moreover, those hydrates are also contained in alumina or silica.

In this way, by subjecting the titanium oxide particles to a surface treatment containing alumina, the surfaces of the titanium oxide particles are uniformly surface coated, and when titanium oxide particles surface-treated with at least alumina are used, the dispersibility of the titanium oxide particles is good. It happens.

Further, when the treatment with silica and the treatment with alumina are applied to the titanium oxide particles, the treatment with alumina and silica may be performed simultaneously, in particular, the alumina treatment may be performed first, followed by the silica treatment. In addition, when processing alumina and silica respectively, it is preferable that the processing amount of alumina and silica has more silica than alumina.

Surface treatment of the titanium oxide with a metal oxide such as alumina or silica can be performed by a wet method. For example, titanium oxide particles subjected to surface treatment of alumina or silica can be produced as follows.

Titanium oxide particles (number average primary particle diameter: 200 to 400 nm) are dispersed in water at a concentration of 50 to 350 g/L to form an aqueous slurry, to which a water-soluble silicate or a water-soluble aluminum compound is added. Thereafter, alkali or acid is added to neutralize, and silica or alumina is deposited on the surface of the titanium oxide particles. Subsequently, filtration, washing, and drying are performed to obtain the target surface-treated titanium oxide. When sodium silicate is used as the water-soluble silicate, it can be neutralized with an acid such as sulfuric acid, nitric acid, or hydrochloric acid. On the other hand, when aluminum sulfate is used as the water-soluble aluminum compound, it can be neutralized with an alkali such as sodium hydroxide or potassium hydroxide.

In the present invention, it is preferable to use a polymeric dispersing agent as the dispersing agent for the light-diffusing particles, and it is more preferable to use a polymeric dispersing agent having an amine value. For example, Disparon DA-325 (amine value: 14mgKOH/g), Disparon DA-234 (amine value: 20mgKOH/g), DA-703-50 (amine value: 40mgKOH/g) (above, Kusumoto Chemical Co., Ltd.) Co., Ltd.), Ajisper PB821 (amine value: 10 mgKOH/g), Ajisper PB822 (amine value: 17 mgKOH/g), Ajisper PB824 (amine value: 17 mgKOH/g), Ajisper PB881 (amine value: 17 mgKOH/g) (above, manufactured by Ajinomoto Fine Techno Co., Ltd.), Efka PU4046 (amine value: 19 mgKOH/g), Efka PX4300 (amine value: 56 mgKOH/g), Efka PX4320 (amine value: 28 mgKOH/g), Efka PX4330 (amine value: 28 mgKOH/g), Efka PX4350 ( Amine value: 12mgKOH/g), Efka PX4700 (amine value: 60mgKOH/g), Efka PX4701 (amine value: 40mgKOH/g), Efka4731 (amine value: 25mgKOH/g), Efka-4732 (amine value: 25mgKOH/g), Efka4751 (amine value: 25mgKOH/g) : 12mgKOH/g), Dispex Ultra FA4420 (amine value: 35mgKOH/g), Dispex Ultra FA4425 (amine value: 35mgKOH/g) (above, manufactured by BASF Japan Co., Ltd.), DISPERBYK-162, DISPERBYK-163, DISPERBYK-164, DISPERBYK- 180, DISPERBYK-109, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2050, DISPERBYK-2150 (manufactured by Big Chemie Japan Co., Ltd.), Solspers 24000GR, Solspers 32000, Solspers 26000, Solspers 13240, Solspers 13940, Solsperse 33500, Solsperse 38500, Solsperse 71000 (Nippon Lubrizol Co., Ltd.), etc. are mentioned.

As the shape of the light-diffusing particles, those having various shapes such as a spherical shape, a filament shape, and an irregular shape can be used. However, as the light-diffusing particles, the uniformity, fluidity, and light diffusion of the ink composition containing luminescent particles can be further improved by using particles having little directionality (for example, spherical, tetrahedral, etc.) as the particle shape. preferred in this respect.

The average particle diameter (volume average diameter) of the light-diffusing particles in the ink composition containing luminescent particles is preferably 0.05 μm or more, 0.2 μm or more, or 0.3 μm or more from the viewpoint of a more excellent effect of reducing leakage light. The average particle diameter (volume average diameter) of the light-diffusing particles in the ink composition containing luminescent particles is preferably 1.0 µm or less, 0.6 µm or less, or 0.4 µm or less from the viewpoint of excellent storage stability and ejection stability of the ink. The average particle diameter (volume average diameter) of the light-diffusing particles in the ink composition containing luminescent particles is 0.05 to 1.0 μm, 0.05 to 0.6 μm, 0.05 to 0.4 μm, 0.2 to 1.0 μm, 0.2 to 0.6 μm, 0.2 to 0.4 μm, It is preferably 0.3 to 1.0 μm, 0.3 to 0.6 μm, or 0.3 to 0.4 μm. From the standpoint of obtaining such an average particle diameter (volume average diameter) easily, the average particle diameter (volume average diameter) of the light-diffusing particles to be used is preferably 50 nm or more and 1000 nm or less. The average particle diameter (volume average diameter) of the light-diffusing particles in the ink composition containing luminescent particles is obtained by measuring with a dynamic light-diffusion nanotrack particle size distribution analyzer and calculating the volume average diameter. The average particle diameter (volume average diameter) of the light-diffusing particles to be used is obtained by measuring the particle diameter of each particle with, for example, a transmission electron microscope or a scanning electron microscope and calculating the volume average diameter.

In order to disperse and prepare the light diffusing particles in the above particle size range, for example, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, A paint shaker or the like can be used.

The content of the light-diffusing particles is 0.1% by mass or more, 1% by mass or more, 5% by mass or more, and 7% by mass based on the mass of the non-volatile matter of the ink composition containing luminescent particles, from the viewpoint of a better effect of reducing leakage light. Above, it is preferable that it is 10 mass % or more and 12 mass % or more. The content of the light-diffusing particles is 60% by mass or less, 50% by mass or less, and 40% by mass, based on the mass of the non-volatile matter of the ink composition containing luminescent particles, from the viewpoint of better reducing light leakage and excellent ejection stability. % or less, 30 mass% or less, 25 mass% or less, 20 mass% or less, and preferably 15 mass% or less. In this embodiment, since the ink composition containing luminescent particles contains a polymer dispersant, the light-diffusion particles can be well dispersed even when the content of the light-diffusion particles is within the above range.

The mass ratio of the content of the light-diffusing particles to the content of the light-diffusing particles 90 (light-diffusing particles/nanoparticles containing light-emitting nanocrystals) is 0.1 or more, 0.2 or more, or 0.5 or more from the viewpoint of a more excellent effect of reducing leakage light. it is desirable The mass ratio (light-diffusing particles/nanoparticles containing luminescent nanocrystals) is preferably 5.0 or less, 2.0 or less, or 1.5 or less from the viewpoint of a more excellent light leakage reduction effect and excellent continuous ejection property during inkjet printing. In addition, it is considered that the leakage light reduction by the light-diffusing particles is based on the following mechanism. That is, in the case where the light-diffusing particles are not present, it is considered that there is little chance that the backlight light is absorbed by the light-emitting particles 90 because it only passes almost straight through the inside of the pixel portion. On the other hand, if the light-diffusing particles are present in the same pixel portion as the light-emitting particles 90, backlight light is scattered in all directions within the pixel portion, and the light-emitting particles 90 can receive light, so the same backlight is used. Even if there is, it is considered that the amount of light absorption in the pixel portion increases. As a result, it is considered that it has become possible to prevent leakage light with such a mechanism.

1-6. polymeric dispersant

The ink composition of the present invention may contain a polymer dispersant, or may contain it simultaneously with light-diffusing particles. The polymeric dispersing agent may be a polymeric dispersing agent having a functional group having affinity for nanoparticles and light-diffusing particles containing luminescent nanocrystals, and has a function of dispersing nanoparticles and light-diffusing particles containing luminescent nanocrystals. Moreover, it is more preferable that it is a polymeric dispersing agent having a functional group having affinity for light-diffusion particles, and it is more preferable to have a function of dispersing light-diffusion particles. The polymeric dispersing agent also contributes to the dispersion stability of the luminescent particles.

The polymer dispersant may use either a polymer of a single monomer (homopolymer) or a copolymer of multiple types of monomers (copolymer). Moreover, any of a random copolymer, a block copolymer, or a graft copolymer may be sufficient as a polymer dispersing agent. Further, when the polymer dispersing agent is a graft copolymer, either a comb-shaped graft copolymer or a star-shaped graft copolymer may be used. As the polymer dispersant, for example, polyamines such as acrylic resins, polyester resins, polyurethane resins, polyamide resins, polyethers, phenolic resins, silicone resins, polyurea resins, amino resins, polyethyleneimine and polyallylamine, epoxies A resin, a polyimide, etc. are mentioned.

As the polymeric dispersant, a block copolymer is particularly preferred. As an effect of applying a block copolymer to the polymer dispersant, the block copolymer is composed of a hydrophilic region and a pigment adsorption region, so that high dispersibility can be obtained, and superior dispersibility than random copolymers or crossover copolymers. You can get it.

Specifically, in a random copolymer or the like, the monomers constituting the copolymer are more likely to be stably disposed in the copolymer sterically or electrically during formation of the polymer. Monomer Since the part (molecule) in which the monomer is stably arranged is sterically or electrically stable, it often becomes an obstacle when adsorbing to the surface of the pigment. In contrast, in a block copolymer type polymer dispersant in which the molecular arrangement is controlled, a portion that hinders the adsorption of the dispersant to the pigment can be disposed away from the adsorbing portion of the pigment and the dispersant. That is, by arranging a portion suitable for adsorption of the pigment and the dispersant and arranging a portion suitable for adsorption in a portion requiring solvent affinity, in particular, inkjet ink of a system containing a pigment having a small crystal size can be obtained. In dispersion, it is estimated that good dispersibility can be realized by the molecular arrangement constituted by this block copolymer.

As the polymer dispersant according to the present invention, there is no limitation as long as it has the above characteristics, and a block copolymer synthesized using a known ethylenically unsaturated monomer can be applied. As the ethylenically unsaturated monomer, for example, the following can hear

styrene and styrene derivatives such as α-methylstyrene or vinyltoluene; vinyl esters of carboxylic acids such as vinyl acetate and vinyl propionate; vinyl halide; ethylenically unsaturated monocarboxylic and dicarboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, maleic acid or fumaric acid, and alkanols of the aforementioned dicarboxylic acids, preferably having from 1 to 4 carbon atoms; monoalkyl esters of, and derivatives of the above monoalkyl esters, and N-substituted derivatives thereof, aryl esters, and derivatives thereof; amides of unsaturated carboxylic acids, such as acrylamide, methacrylamide, N-methylolacrylamide or methacrylamide, N-alkylacrylamide; ethylenic monomers containing sulfonic acid groups and ammonium or alkali metal salts thereof, such as vinylsulfonic acid, vinylbenzenesulfonic acid, α-acrylamidemethylpropanesulfonic acid, 2-sulfoethylene methacrylate; amides of vinylamine, such as vinylformamide, vinylacetamide; unsaturated ethylenic monomers containing secondary, tertiary or quaternary amino groups or nitrogen-containing heterocyclic groups, such as vinylpyridine, vinylimidazole, aminoalkyl(meth)acrylates, aminoalkyl(meth)acrylamides , dimethylaminoethyl acrylic acid or methacrylic acid, di-t-butylaminoethyl acrylic acid or methacrylic acid, or dimethylaminomethylacrylamide or methacrylamide; zwitterionic monomers such as sulfopropyl(dimethyl)aminopropylacrylate; dienes such as butadiene, isoprene, chloroprene; (meth)acrylic acid ester; vinyl nitriles; vinylphosphonic acid and derivatives thereof.

Using such an ethylenically unsaturated monomer, a block copolymer can be synthesized according to a known method, for example, a synthesis method such as Japanese Patent Laid-Open No. 2005-60669 or Japanese Unexamined Patent Publication No. 2007-314617. can

Among them, it is preferable to use a (meth)acrylic block copolymer, for example, Japanese Unexamined Patent Publication No. 60-89452, Japanese Unexamined Patent Publication No. 9-62002, P. Lutz, P. Massonetal, Polym. Bull. 12, 79 (1984), B. C. Anderson, G. D. Andrews et al, Macromolecules, 14, 1601 (1981), K. Hatada, K. Ute, et al, Polym. J. 17, 977 (1985), K. Hatada, K. Ute, et al., Polym. J. 18, 1037(1986), Koichi Ute, Koichi Hatada, Polymer Processing, 36, 366(1987), Toshinobu Higashimura, Mitsuo Sawamoto, Journal of Polymers, 46, 189(1989), M. Kuroki, T Aida, J. Am. Chem. Sic, 109, 4737 (1987), Takuzo Aida, Shohei Inoue, Organic Synthetic Chemistry, 43, 300 (1985), D. Y. Sogoh, W. R. Hertleretal, Macromolecules, 20, 1473 (1987), K. Matyaszewski et al, Chem. Rev. 2001, 101, 2921-2990, etc., and can be synthesized by referring to known methods.

The polymeric dispersant used in the present invention has an alkaline polar group, and examples of the alkaline functional group include primary, secondary, and tertiary amino groups, ammonium groups, imino groups, and pyridine, pyrimidine, pyrazine, imidazole, and triazole. A nitrogen heterocyclic group etc. are mentioned. The amine value of the polymer dispersant is preferably 6 to 90 mgKOH/g, more preferably 7 to 70 mgKOH/g, and even more preferably 8 to 50 mgKOH/g. When the amine value of the polymer dispersant is less than 6 mgKOH/g, the adsorption of the polymer dispersant to the light diffusing particles is low, and when the amine value is greater than 90 mgKOH/g, the polarity increases, easily causing aggregation and deterioration of storage stability, and under the influence thereof The dispersibility of the luminescent particles also deteriorates.

The amine value of the polymer dispersing agent can be measured as follows. Prepare a sample solution by dissolving 1 mL of polymer dispersant xg and bromophenol blue TS in 50 mL of a mixed solution of toluene and ethanol mixed at a volume ratio of 1:1, and titrate with 0.5 mol/L hydrochloric acid until the sample solution turns green. , and the amine titer can be calculated by the following formula.

Amin value = y/x × 28.05

In the formula, y represents the titration amount (mL) of 0.5 mol/L hydrochloric acid required for titration, and x represents the mass (g) of the polymer dispersant.

The polymer dispersant according to the present invention, in addition to the characteristics of the above amine value, is a nitrogen-containing aromatic heterocycle or a salt thereof, or an aromatic amine (eg, aniline, anisidine, p-toluidine, α-naphthylamine, m-phenyl It is more preferable that it is a block copolymer which has landiamine, 1, 8-diaminonaphthalene, benzylamine, N-methylaniline, N-methylbenzylamine, etc.) as a part of structure. In the case where there is a site having an aromatic group in a part of the structure of the block copolymer, in addition to the acid-base interaction, the steric hindrance effect due to the bulky structure is easily obtained, and it is presumed that the dispersibility is improved. Examples of the nitrogen-containing aromatic heterocycle include 5-membered aromatic heterocycles such as pyrrole, imidazole, pyrazole, oxazole, isoxazole, thiazole, and isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, 6-membered aromatic heterocycles such as triazine, polycyclic aromatics such as quinoline, isoquinoline, quinazoline, phthalazine, pteridine, benzodiazepine, indole, benzimidazole, purine, acridine, phenoxazine, and phenothiazine Heterocycle or its salt (for example, inorganic salt, organic salt, etc.) etc. are mentioned, Each may have a substituent.

As the polymer dispersant having an alkaline functional group of a tertiary amino group or a nitrogen-containing heterocyclic ring, specifically, for example, "DISPERBYK-164" (amine value: 18 mgKOH/g), "DISPERBYK-167" (amine value: 13 mgKOH/g), “DISPERBYK-2164” (amine value: 23 mgKOH/g), “BYK-LP N6919” (amine value: 120 mgKOH/g), “BYK-LP N21116” (amine value: 29 mgKOH/g) (above, manufactured by Big Chemie Japan Co., Ltd.) , "Solsperse 20000" (amine value: 32 mgKOH/g) (manufactured by Lubrizol, Japan), "Efka PX4320" (amine value: 28 mgKOH/g), "Dispex Ultra PX4585" (amine value: 20 mgKOH/g), "Efka PX4701 ( Amine value: 40 mgKOH/g)” (manufactured by BASF Japan Co., Ltd.) and the like.

In addition to the basic functional group, the said polymeric dispersing agent may have another functional group. Examples of other functional groups include at least one functional group selected from the group consisting of acidic functional groups and nonionic functional groups. These functional groups preferably have affinity for light diffusing particles. The acidic functional group has a dissociable proton, and may be neutralized with a base such as an amine or hydroxide ion.

As the acidic functional group, a carboxyl group (-COOH), a sulfo group (-SO3H), a sulfate group (-OSO3H), a phosphonic acid group (-PO(OH)3), a phosphoric acid group (-OPO(OH)3), a phosphinic acid group (- PO(OH)-) and mercapto group (-SH).

Examples of the nonionic functional group include a hydroxyl group, an ether group, a thioether group, a sulfinyl group (-SO-), a sulfonyl group (-SO2-), a carbonyl group, a formyl group, an ester group, a carbonate ester group, an amide group, and a carbamoyl group. , ureido group, thioamide group, thioureido group, sulfamoyl group, cyano group, alkenyl group, alkynyl group, phosphine oxide group, and phosphine sulfide group.

In addition to a basic functional group, the polymeric dispersing agent which has an acidic functional group has an acid value in addition to an amine value. The acid value of the polymer dispersant having an acidic functional group is preferably 0 to 50 mgKOH/g, more preferably 0 to 40 mgKOH/g, still more preferably 0 to 30 mgKOH/g, and 0 to 20 mgKOH/g or less. When the acid value is 50 mgKOH/g or less, the storage stability of the picture element portion (cured product of the ink composition) is less likely to decrease.

The acid value of the polymer dispersing agent can be measured as follows. A sample solution was prepared by dissolving 1 mL of polymer dispersant pg and phenolphthalein TS in 50 mL of a mixed solution of toluene and ethanol mixed at a volume ratio of 1: 1, and preparing a 0.1 mol/L ethanolic potassium hydroxide solution (7.0 g of potassium hydroxide in 5.0 mL of distilled water). dissolved in and adjusted to 1000 mL by adding 95 vol% ethanol), titration is performed until the sample solution shows a pink color, and the acid value can be calculated by the following formula.

Acid value = q × r × 5.611/p

In the formula, q represents the titration (mL) of 0.1 mol/L ethanol potassium hydroxide solution required for titration, r represents the titer of 0.1 mol/L ethanol potassium hydroxide solution required for titration, and p is the mass of the polymer dispersant (g) is shown.

Examples of the polymer dispersant having an amine value and an acid value include "DISPERBYK-142" (amine value: 43 mgKOH/g, acid value: 46 mgKOH/g) and "DISPERBYK-145" (amine value: 71 mgKOH/g, acid value: 76 mgKOH/g). , "DISPERBYK-2001" (amine value: 29mgKOH/g, acid value: 19mgKOH/g), "DISPERBYK-2025" (amine value: 37mgKOH/g, acid value: 38mgKOH/g), "DISPERBYK-9076" (amine value: 44mgKOH/g) , Acid value: 38 mgKOH/g) (above, manufactured by Big Chemie Japan Co., Ltd.), “Solsperse 24000GR” (amine value: 42 mgKOH/g, acid value: 25 mgKOH/g), “Solsperse 32000” (amine value: 31 mgKOH/g, acid value : 15mgKOH/g), “Solsperse 33000” (amine value: 43mgKOH/g, acid value: 26mgKOH/g), “Solsperse 34750”, “Solsperse 35100” (amine value: 14mgKOH/g, acid value: 6mgKOH/g), “Solsperse 35200” (amine value: 14mgKOH/g, acid value: 6mgKOH/g), “Solsperse 37500” (amine value: 11mgKOH/g, acid value: 5mgKOH/g), “Solsperse 39000” (amine value: 29mgKOH/g, Acid value: 16 mgKOH/g), (manufactured by Lubrizol, Japan), "Ajisper PB821" (amine value: 10 mgKOH/g, acid value: 17 mgKOH/g), "Ajisper PB822" (amine value: 17 mgKOH/g, acid value: 14 mgKOH/g) g), "Ajisper PB824" (amine value: 17 mgKOH/g, acid value: 21 mgKOH/g), "Ajisper PB881" (amine value: 17 mgKOH/g, acid value: 17 mgKOH/g) (above, manufactured by Ajinomoto Fine Techno Co., Ltd.), etc. can be heard

The polymer dispersing agent according to the present invention is preferably an acrylic block copolymer having a partial structure represented by the following general formulas (a) to (c).

(In general formula (b), R ^b1 represents a hydrogen atom or a methyl group, and R ^b2 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.)

(In formula (c), R ^c1 represents a hydrogen atom or a methyl group, R ^c2 represents an alkylene group having 2 to 3 carbon atoms, m represents an integer of 5 to 15, and R ^c3 represents an alkyl group having 1 to 25 carbon atoms. , A phenyl group or a phenyl group substituted with an alkyl group having 1 to 18 carbon atoms.)

As the monomeric monomer providing the structural unit represented by the general formula (a), specifically, 2-vinylpyridine or pyridium ion, 4-vinylpyridine or pyridium ion is preferable, and 2-vinylpyridine, 4- Vinylpyridine is more preferred.

In the general formula (b), R ^b1 is preferably an alkyl group of 2 to 8 carbon atoms, more preferably an alkyl group of 4 to 8 carbon atoms, and still more preferably an n-butyl group.

In the general formula (c), m is preferably an integer of 7 to 12, and R ^c3 is preferably an alkyl group having 1 to 4 carbon atoms.

Since the polymeric dispersing agent containing the structural units (a) to (c) has a high adsorbability of pyridine contained in the constituent monomers of the dispersing agent to the light-diffusing particles, the surface of the light-diffusing particle is covered with the dispersing agent during dispersion. and the light-diffusing particles can be dispersed in the ink composition by electrostatic repulsion and/or steric repulsion of the dispersants. The polymer dispersant is preferably bound to the surface of the light-diffusing particles and adsorbed to the light-diffusing particles, but may be bound to the surface of the light-diffusing particles and adsorbed to the light-emitting particles, or may be free in the ink composition.

Further, in the polymer dispersing agent containing the structural units (a) to (c), the structural unit (c) of the block copolymer has excellent affinity to the photopolymerizable compound, and the structural unit (a) of the copolymer and (c), the excellent dispersibility of the light-diffusing particles and the affinity of the photopolymerizable compound are made compatible.

The copolymer having the monomer units represented by the structural units (a) to (c) is not particularly limited, but can be suitably synthesized by living radical polymerization using a nitroxide initiator (NMP initiator).

In the case of a copolymer having monomer units represented by structural units (a), (b), and (c) in the polymer dispersant, the content of the monomer units in the polymer dispersant is the total monomer units constituting the polymer dispersant. When the total of is 100 mol%, it is preferable that it is 5-50 mol%, and, as for the structural unit (a), it is more preferable that it is 10-30 mol%. Within this range, the storage stability of the ink and the dispersibility of the light-diffusing particles are more excellent.

Moreover, in the said polymeric dispersing agent, it is preferable that the molar ratio of content of the monomer unit represented by formula (b) and content of the monomer unit represented by formula (c) is 1:2-2:1, and it is 1: It is more preferable that it is 1.5-1.5:1.

The weight average molecular weight (Mw) of the polymer dispersant is from the viewpoint of being able to disperse the light-diffusing particles well, further improving the effect of reducing leakage light, and improving the luminous properties of the ink composition, and also the viscosity of the inkjet ink. It is preferably 10,000 to 70,000, more preferably 12,000 to 30,000, still more preferably 13,000 to 25,000, and particularly preferably 15,000 to 20,000 from the viewpoint of making the viscosity suitable for ejection and stable ejection. In addition, in this specification, a weight average molecular weight is a weight average molecular weight in terms of polystyrene measured by GPC (Gel Permeation Chromatography).

The content of the polymeric dispersant in the ink composition is 0.5 to 50% by mass based on 100% by mass of the light-diffusion particles, from the viewpoint of the dispersibility of the light-diffusion particles and the wet heat stability of the pixel portion (dispersion liquid or cured product of the ink composition). It is preferable that it is, it is more preferable that it is 2-30 mass %, and it is still more preferable that it is 5-10 mass %.

Specifically, as a polymer dispersant having a partial structure represented by the general formulas (a) to (c), for example, "Efka PX4320" (amine value: 28 mgKOH / g), "Dispex Ultra PX4585" (amine value: 20 mgKOH /g), "Efka PX4701" (amine value: 40 mgKOH/g) (manufactured by BASF Japan Co., Ltd.), and the like.

1-7. other ingredients

The ink composition may further contain components other than the components described above within a range that does not impair the effects of the present invention.

1-7-1. sensitizer

As the sensitizer, photopolymerizable compounds and amines that do not cause an addition reaction can be used. Examples of the sensitizer include trimethylamine, methyl dimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine, 4,4'-bis (diethylamino) benzophenone etc. are mentioned.

1-7-2. solvent

The ink composition may further contain, for example, a solvent. Examples of the solvent include cyclohexane, hexane, heptane, chloroform, toluene, octane, chlorobenzene, tetralin, diphenyl ether, propylene glycol monomethyl ether acetate, butyl carbitol acetate, or mixtures thereof. there is. It is preferable that the boiling point of a solvent is 180 degreeC or more from a viewpoint of continuous ejection stability of inkjet ink. In addition, since it is necessary to remove the solvent from the ink composition before curing the ink composition at the time of forming the pixel portion, it is preferable that the boiling point of the solvent is 300°C or less from the viewpoint of easy removal of the solvent. However, since the photopolymerizable compound also functions as a dispersion medium in the ink composition of the present embodiment, it is possible to disperse the light-diffusing particles and the light-emitting particles without a solvent. In this case, there is an advantage that the process of removing the solvent by drying becomes unnecessary when forming the pixel portion. When the ink composition contains a solvent, the content of the solvent is preferably 0 to 5% by mass or less based on the total mass (including the solvent) of the ink composition.

1-7-3. Surfactants

The surfactant is not particularly limited, but is preferably a compound capable of reducing film thickness unevenness in the case of forming a thin film containing the luminescent particles 91 and 90 with ink ejection properties.

Examples of such surfactants include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and the like. Nonionic surfactants such as polyoxyethylene/polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and silicone-based or fluorine-based surfactants are included.

As a specific example of a silicone type surfactant, "KF-351A", "KF-352A", "KF-642", "X-22-4272" (above, manufactured by Shin-Etsu Chemical Industry Co., Ltd.), "BYK -300”, “BYK-302”, “BYK-306”, “BYK-307”, “BYK-310”, “BYK-313” “BYK-315N”, “BYK-320”, “BYK-322” , "BYK-323", "BYK-325", "BYK-330", "BYK-331", "BYK-333", "BYK-342", "BYK-345", "BYK-347", " BYK-348", "BYK-349", "BYK-370", "BYK-377", "BYK-UV3500", "BYK-UV3510", "BYK-UV3530", "BYK-UV3570", "BYK- "Silclean3700", "BYK-Silclean3720" (above, manufactured by Big Chemie Japan Co., Ltd.), "TEGO Rad2100", "TEGO Rad2011", "TEGO Rad2200N", "TEGO Rad2250", "TEGO Rad2300", "TEGO Rad2500", " TEGO Rad2600”, “TEGO Rad2650”, “TEGO Rad2700”, “TEGO Flow425”, “TEGO Glide410”, “TEGO Glide432”, “TEGO Glide440”, “TEGO Glide450”, “TEGO GlideZG400”, “TEGO Twin4000”, “ TEGO Twin4100”, “TEGO Twin4200” (above, manufactured by Evonik Industries, Ltd.), “DOWSIL L-7001”, “DOWSIL L-7002”, “DOWSIL 57ADDTIVE”, “DOWSIL L-7064”, “DOWSIL FZ- 2110”, “FZ-2105”, “DOWSIL 67ADDTIVE”, (above, manufactured by Dow-Toray Co., Ltd.), “Polyflo KL-400HF”, “Polyflo KL-401”, “Polyflo KL-402”, “Polyflo KL-402” Flo KL-403", "Poly Flo KL-404" (above, manufactured by Kyoeisha Chemical Co., Ltd.), etc. are mentioned.

Specific examples of the fluorine-based surfactant include "Megapack F-114", "Megapack F-251", "Megapack F-281", "Megapack F-410", and "Megapack F-430". ”, “Megapack F-444”, “Megapack F-472SF”, “Megapack F-477”, “Megapack F-510”, “Megapack F-511”, “Megapack F-552”, “Megapack F-553”, “Megapack F-554”, “Megapack F-555”, “Megapack F-556”, “Megapack F-557”, “Megapack F-558”, “Megapack F-558” "Megapack F-559", "Megapack F-560", "Megapack F-561", "Megapack F-562", "Megapack F-563", "Megapack F-565", "Megapack F -567”, “Megapack F-568”, “Megapack F-569”, “Megapack F-570”, “Megapack F-571”, “Megapack R-40”, “Megapack R-41” ”, “Megapack R-43”, “Megapack R-94”, “Megapack RS-72-K”, “Megapack RS-75”, “Megapack RS-76-E”, “Megapack RS -76-NS”, “Megapack RS-90”, “Megapack EXP.TF-1367”, “Megapack EXP.TF1437”, “Megapack EXP.TF1537”, “Megapack EXP.TF-2066” ( The above, manufactured by DIC Corporation), etc. are mentioned.

As other specific examples of fluorine-based surfactants, for example, "Ptergent 100", "Ptergent 100C", "Ptergent 110", "Ptergent 150", "Ptergent 150CH", "Ptergent 100A-K" , 「Phtergent 300」, 「Ptergent 310」, 「Ptergent 320」, 「Ptergent 400SW」, 「Ptergent 251」, 「Ptergent 215M」, 「Ptergent 212M」, 「Ptergent 215M」, 「 "Ptergent 250", "Ptergent 222F", "Ptergent 212D", "FTX-218", "Ptergent 209F", "Ptergent 245F", "Ptergent 208G", "Ptergent 240G", "Ptergent 240G" 212P", "Ptergent 220P", "Ptergent 228P", "DFX-18", "Ptergent 601AD", "Ptergent 602A", "Ptergent 650A", "Ptergent 750FM", "FTX-730FM" , "Putergent 730FL", "Putergent 710FS", "Putergent 710FM", "Putergent 710FL", "Putergent 750LL", "FTX-730LS", "Putergent 730LM" (above, manufactured by Neos Co., Ltd.) " "FC-4430", "FC-4432" (above, manufactured by 3M Japan Co., Ltd.), "Unydyne NS" (above, manufactured by Daikin Industrial Co., Ltd.), "Suplon S-241", "Suplon S-242", "Suplon S-243", "Suplon S-420", "Suplon S-611", "Suplon S-651", "Suplon S-386" (above, manufactured by AGC Seimi Chemical Co., Ltd.), "Floren AO-82", "Floren AO-98", "Floren AO-108" (above, Kyoeisha Chemical Co., Ltd. make), etc. are mentioned.

The addition amount of the surfactant is preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of photopolymerizable compounds contained in the ink composition containing luminescent particles.

1-7-4. chain transfer agent

The chain transfer agent is a component used for the purpose of further improving the adhesion of the ink composition containing luminescent particles to a substrate. As a chain transfer agent, it is aromatic hydrocarbons, for example; halogenated hydrocarbons such as chloroform, carbon tetrachloride, carbon tetrabromide, and bromotrichloromethane; Octyl mercaptan, n-butyl mercaptan, n-pentyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, n-dodecyl mercaptan, t-tetradecyl mercaptan, t-dodecyl mercaptan Mercaptan compounds such as; Hexanedithiol, decanedithiol, 1,4-butanediolbisthiopropionate, 1,4-butanediolbisthioglycolate, ethylene glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropanetrithioglycol Late, trimethylolpropanetrithiopropionate, trimethylolpropanetris(3-mercaptobutyrate), pentaerythritol tetrakithioglycolate, pentaerythritoltetrakithiopropionate, trimercaptopropionic acid tris(2- Hydroxyethyl)isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-triazine, 2-(N,N-dibutylamino)-4,6-di thiol compounds such as mercapto-s-triazine; sulfide compounds such as dimethylxanthogen disulfide, diethylxanthogen disulfide, diisopropylxantogen disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide and tetrabutylthiuram disulfide; N,N-dimethylaniline, N,N-divinylaniline, pentaphenylethane, α-methylstyrene dimer, acrolein, allyl alcohol, terpinolene, α-terpinene, γ-terpinene, dipentene, etc. However, 2,4-diphenyl-4-methyl-1-pentene and thiol compounds are preferred.

As a specific example of a chain transfer agent, the compound represented by the following general formula (9-1) - (9-12) is preferable, for example.

In the formula, R ⁹⁵ represents an alkyl group having 2 to 18 carbon atoms, the alkyl group may be straight-chain or branched-chain, and one or more methylene groups in the alkyl group may be an oxygen atom without direct bonding of an oxygen atom and a sulfur atom to each other. , a sulfur atom, -CO-, -OCO-, -COO- or -CH=CH- may be substituted.

R ⁹⁶ represents an alkylene group having 2 to 18 carbon atoms, and at least one methylene group in the alkylene group is an oxygen atom and a sulfur atom, -CO-, -OCO-, without direct bonding of oxygen atoms and sulfur atoms to each other; -COO- or -CH=CH- may be substituted.

The added amount of the chain transfer agent is preferably 0.1 to 10% by mass, and more preferably 1.0 to 5% by mass, based on the total amount of photopolymerizable compounds contained in the ink composition containing luminescent particles.

1-7-5. light stabilizer

The ink composition of this invention may contain the light stabilizer which has a structure represented by following formula (1). The light stabilizer may be a light stabilizer having one or two or more hindered amino groups. And the ink composition may use only 1 type as a light stabilizer, and may use 2 or more types.

(In Formula (1), R ¹ represents a hydrogen atom or a substituent, and * represents a bond.)

As R ^<1> , a hydrogen atom, an alkyl group, an alkoxy group, etc. are mentioned more specifically, Among these, an alkyl group or an alkoxy group is preferable, and a methyl group is more preferable.

* represents a bond, and may be, for example, a bonding site with a carbon atom, a nitrogen atom, or an oxygen atom.

The light stabilizer may be a compound further having a 1,3,5-triazine ring which may have a substituent. For example, the structure represented by Formula (1) may couple|bond with the 1,3,5-triazine ring directly or through another atom (for example, nitrogen atom).

As the light stabilizer, for example, a liquid at 20°C or a solid at 20°C may be used. However, considering that the cured product of the ink composition may be heated to, for example, about 50°C with light irradiation, the light stabilizer preferably has a higher melting point, and is 70°C or higher, 80°C or higher, or 85°C or higher. desirable. If the light stabilizer has a melting point of 70°C or higher, even when the cured product of the ink composition is heated to a high temperature of about 50°C, the light stabilizer does not liquefy. Occurrence of exudation (bleed phenomenon) can be prevented (bleed resistance). On the other hand, considering the solubility in the ink composition, the light stabilizer preferably has a melting point of 180°C or less.

The molecular weight (or molar mass) or mass average molecular weight of the light stabilizer may be 1000 or more. In this specification, "mass average molecular weight" can employ the value measured using gel permeation chromatography (GPC) using polystyrene as a standard substance. If the molecular weight or mass average molecular weight is within the above range, since the melting point is high, bleed resistance in a high-temperature environment can be obtained reliably, and light resistance becomes more excellent.

The light stabilizer is considered to capture free radicals at the nitrogen atom site in the above general formula (1), and in order to effectively capture free radicals generated in the light conversion layer, the light stabilizer is represented by the general formula (1) in the molecule The greater the functional group equivalent represented by the formula below, which indicates the proportion of the site, the more excellent the light resistance.

Functional group equivalent = molecular weight of light stabilizer / number of sites represented by general formula (1) in light stabilizer

It is preferable that it is 200-400, and, as for functional group equivalent, it is more preferable that it is 250-370 from a viewpoint excellent in free radical trapping property and a solubility viewpoint.

The light stabilizer is preferably a compound represented by the following formulas (1a) to (1e), for example. It is more preferable that the light stabilizer is a compound represented by the following formula (1a) or the following formula (1b) from the viewpoint of further excellent curability and the viewpoint of further superior light resistance under high temperature.

(In Formula (1a), n represents an integer of 1 to 15.)

(In formula (1b), n represents an integer from 1 to 15.)

As a commercially available light stabilizer, for example, TINUVIN NOR371 (melting point: 91 to 104°C, mass average molecular weight: 2800 to 4000, functional group equivalent: 350, manufactured by BASF Japan Co., Ltd.) having a structure represented by the formula (1a) above. , Adekastab LA-63P (melting point: 85 to 105 ° C., molecular weight: about 2000, functional group equivalent: 276, manufactured by BASF Japan Co., Ltd.), having a structure represented by the above formula (1b), represented by the above formula (1c) TINUVIN123 (melting point <20 ° C. (liquid phase), molecular weight: 737, functional group equivalent: 368, manufactured by BASF Japan Co., Ltd.), which has a structure, Adecastab LA-81 (melting point < 20°C (liquid), molecular weight 681, functional group equivalent: 340, manufactured by ADEKA Co., Ltd.), Adecastab LA-52 having the structure represented by the above formula (1e) (melting point > 65°C, molecular weight 847, functional group equivalent: 212, BASF Japan Co., Ltd.) etc. are mentioned.

The light stabilizer is preferably 0.1% by mass to 5.0% by mass, more preferably 0.2% by mass to 3.0% by mass, based on the total mass of the ink composition, from the viewpoint of providing better light resistance at high temperatures. , It is particularly preferable that they are 2.0 mass % - 0.3 mass % or more.

1-8. Viscosity of the ink composition

The viscosity of the ink composition according to the present invention is preferably 2 mPa·s or more, more preferably 5 mPa·s or more, and still more preferably 7 mPa·s or more, from the viewpoint of ejection stability during inkjet printing, for example. The viscosity of the ink composition is preferably 20 mPa·s or less, more preferably 15 mPa·s or less, and still more preferably 12 mPa·s or less. When the viscosity of the ink composition is 2 mPa·s or more, since the meniscus shape of the ink composition at the tip of the ink ejection hole of the ejection head is stable, the ejection control of the ink composition (for example, the ejection amount and ejection timing) control) is easier. On the other hand, when the viscosity is 20 mPa·s or less, the ink composition can be smoothly discharged from the ink discharge hole. The viscosity of the ink composition is preferably 2 to 20 mPa·s, more preferably 5 to 15 mPa·s, and still more preferably 7 to 12 mPa·s. The viscosity of the ink composition is measured by, for example, an E-type viscometer. The viscosity of the ink composition can be adjusted within a desired range by changing the photopolymerizable compound, photopolymerization initiator, and the like, for example.

1-9. Surface tension of ink composition

The surface tension of the ink composition according to the present invention is preferably a surface tension suitable for an inkjet method, specifically, preferably in the range of 20 to 40 mN/m, more preferably 25 to 35 mN/m. By setting the surface tension within the range, the occurrence of flight deflection can be suppressed. In addition, flight bending means that the landing position of the ink composition shifts by 30 µm or more from the target position when the ink composition is ejected from the ink ejection hole. When the surface tension is 40 mN/m or less, since the meniscus shape at the tip of the ink ejection hole is stable, ejection control of the ink composition (for example, control of ejection amount and ejection timing) becomes easy. On the other hand, when the surface tension is 20 mN/m or less, the occurrence of flight deflection can be suppressed. That is, a pixel portion in which filling of the ink composition is insufficient occurs because the pixel portion formation region to be landed is not accurately landed, or the ink composition lands on a pixel portion formation region (or a pixel portion) adjacent to the pixel portion formation region to be landed. Thus, there is no deterioration in color reproducibility. The surface tension of the ink composition can be adjusted to a desired range by, for example, combining the above-mentioned silicone surfactant, fluorine surfactant, and the like.

1-10. Method for preparing ink composition

The ink composition of the present invention, for example, an active energy ray-curable ink composition, can be prepared by blending each of the above components, and can be used as ink for inkjet. A specific method of preparing an ink composition for inkjet is to synthesize the light-emitting particles 90 or 91 in an organic solvent, remove the organic solvent from the precipitate fractionated by centrifugation, and then disperse in a photopolymerizable compound. . Dispersion of the luminescent particles 90 or 91 can be carried out by using a dispersing machine such as a ball mill, sand mill, bead mill, three roll mill, paint conditioner, attritor, dispersion stirrer, or ultrasonic wave, for example. there is. Moreover, it can prepare by adding a photoinitiator and antioxidant to this dispersion liquid, and mixing by stirring. In the case of using light-diffusion particles, a mill base in which the light-diffusion particles and a polymer dispersant are mixed and dispersed in the photopolymerizable compound by a bead mill is separately prepared, and together with the light-emitting particles, a photopolymerizable compound and a photopolymerization initiator It can be prepared by mixing.

Next, the preparation method of the ink composition according to the present invention will be described in detail. The ink composition can be obtained, for example, by mixing the components of the ink composition described above and performing a dispersion treatment. In addition, it can be obtained by individually mixing the constituent components, preparing a dispersion liquid subjected to dispersion treatment as necessary, and mixing each dispersion liquid. Hereinafter, as an example of a method for producing an ink composition, a method for producing an ink composition further containing light-diffusing particles and a polymer dispersant will be described.

In the step of preparing a dispersion of light-diffusion particles, a dispersion of light-diffusion particles can be prepared by mixing the light-diffusion particles, a polymeric dispersant, and a photopolymerizable compound and performing dispersion treatment. The mixing and dispersing treatment can be performed using a dispersing device such as a bead mill, a paint conditioner, or a planetary stirrer. According to the method described above, it is preferable to use a bead mill or a paint conditioner from the viewpoint of improving the dispersibility of the light-diffusion particles and facilitating adjustment of the average particle diameter of the light-diffusion particles to a desired range.

The ink composition preparation method may further include a step of preparing a dispersion of luminescent particles containing luminescent particles and a photopolymerizable compound before the second step. In this case, in the second step, a dispersion of light-diffusing particles, a dispersion of light-emitting particles, a photopolymerization initiator, and an antioxidant are mixed. According to this method, the luminescent particles can be sufficiently dispersed. Therefore, while being able to reduce light leakage in a pixel part, an ink composition excellent in ejection stability can be obtained easily. In the step of preparing the dispersion of light-diffusing particles, mixing and dispersing treatment of the light-emitting particles and the photopolymerizable compound may be performed using the same dispersing device as in the step of preparing the dispersion of light-diffusing particles.

When using the ink composition of this embodiment as an ink composition for an inkjet system, it is preferably applied to a piezojet system inkjet recording apparatus using a mechanical ejection mechanism using a piezoelectric element. In the piezojet method, the ink composition is not instantly exposed to a high temperature during ejection, and the quality of the light-emitting particles is difficult to change, so that a color filter pixel portion (light conversion layer) having desired light-emitting characteristics can be obtained. there is.

As mentioned above, although one embodiment of the ink composition for color filters was described, the ink composition of the above-mentioned embodiment can also be used by a photolithographic method other than the inkjet method. In this case, the ink composition contains an alkali-soluble resin as a binder polymer.

When using the ink composition by photolithography, first, the ink composition is applied onto a substrate, and when the ink composition contains a solvent, the ink composition is further dried to form a coating film. The coating film obtained in this way is soluble in an alkaline developer, and is patterned by being treated with an alkaline developer. At this time, since most of the alkaline developing solution is an aqueous solution from the viewpoint of the ease of wastewater treatment of the developing solution, the coated film of the ink composition is treated with an aqueous solution. On the other hand, in the case of an ink composition using light-emitting particles (e.g., quantum dots), the light-emitting particles are unstable to water, and luminescence (eg, fluorescence) is impaired by moisture. For this reason, in this embodiment, the inkjet method which does not need to process with an alkaline developing solution (aqueous solution) is preferable.

In addition, even when the coating film of the ink composition is not treated with an alkali developer, when the ink composition is alkali-soluble, the coating film of the ink composition easily absorbs moisture in the atmosphere, and as time passes, the luminescent particles (both The luminescence (for example, fluorescence) of dots etc.) is impaired. From this point of view, in the present embodiment, it is preferable that the coating film of the ink composition is alkali insoluble. That is, it is preferable that the ink composition of this embodiment is an ink composition which can form an alkali-insoluble coating film. Such an ink composition can be obtained by using an alkali-insoluble photopolymerizable compound as a photopolymerizable compound. That the coated film of the ink composition is insoluble in alkali means that the amount of dissolution of the coated film of the ink composition at 25° C. in a 1% by mass aqueous solution of potassium hydroxide is 30% by mass or less based on the total mass of the coated film of the ink composition do. The dissolution amount of the coated film of the ink composition is preferably 10% by mass or less, and more preferably 3% by mass or less. In addition, the reason why the ink composition is an ink composition capable of forming an alkali-insoluble coating film is that a coating film having a thickness of 1 μm obtained by applying the ink composition on a substrate and then drying it under conditions of 80° C. for 3 minutes when containing a solvent is described above. It can be confirmed by measuring the amount of dissolution.

2. Example of use of ink composition containing luminescent particles

The above-described ink composition containing luminescent particles can be cured by forming a film on a substrate by various methods such as, for example, an inkjet printer, photolithography, or spin coater, and heating and curing the film. Hereinafter, a case in which a color filter pixel portion of a light emitting device having a blue organic LED backlight is formed from an ink composition containing light emitting particles will be described as an example.

Fig. 3 is a cross-sectional view showing one embodiment of the light emitting element of the present invention, and Figs. 4 and 5 are schematic diagrams each showing the configuration of an active matrix circuit. In addition, in FIG. 3, for convenience, the dimensions of each part and their ratio are exaggerated and shown, and may differ from reality. In addition, the materials, dimensions, etc. shown below are examples, and the present invention is not limited thereto, and can be appropriately changed within a range that does not change the gist thereof. Hereinafter, for convenience of description, the upper side of FIG. 3 is referred to as “upper side” or “upper side”, and the lower side is referred to as “lower side” or “lower side”. In addition, in FIG. 3, description of hatching which shows a cross section is abbreviate|omitted in order to avoid complicating a drawing.

As shown in Fig. 3, the light emitting element 100 includes a lower substrate 1, an EL light source unit 200, a filling layer 10, a protective layer 11, and light emitting particles 90. It has a structure in which a light conversion layer 12 serving as a light emitting layer and an upper substrate 13 are laminated in this order. The light-emitting particles 90 contained in the light conversion layer 12 may be polymer-coated light-emitting particles 90 or may be light-emitting particles 91 not covered with the polymer layer 92 . The EL light source unit 200 includes an anode 2, an EL layer 14 composed of a plurality of layers, a cathode 8, a polarizing plate (not shown), and an encapsulation layer 9 in this order. The EL layer 14 includes a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, and an electron injection layer 7 sequentially stacked from the anode 2 side. ).

The light emitting element 100 absorbs and re-radiates or transmits the light emitted from the EL light source unit 200 (EL layer 14) by the light conversion layer 12, and transmits the light from the upper substrate 13 side to the outside. It is a photoluminescence element taken out with. At this time, the light is converted into light of a predetermined color by the light emitting particles 90 included in the light conversion layer 12 . Hereinafter, each layer is sequentially described.

<Lower Substrate 1 and Upper Substrate 13>

The lower substrate 1 and the upper substrate 13 each have a function of supporting and/or protecting each layer constituting the light emitting element 100 . When the light emitting device 100 is a top emission type, the upper substrate 13 is formed of a transparent substrate. Meanwhile, when the light emitting device 100 is a bottom emission type, the lower substrate 1 is formed of a transparent substrate. Here, the transparent substrate means a substrate capable of transmitting light of a wavelength in the visible light region, and the transparent substrate includes colorless transparency, colored transparency, and translucency.

As the transparent substrate, for example, quartz glass, Pyrex (registered trademark) glass, transparent glass substrates such as synthetic quartz plates, quartz substrates, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES) , a plastic substrate (resin substrate) made of polyimide (PI), polycarbonate (PC), etc., a metal substrate made of iron, stainless steel, aluminum, copper, etc., a silicon substrate, a gallium arsenide substrate, or the like can be used. Among these, it is preferable to use the glass substrate which consists of an alkali-free glass which does not contain an alkali component in glass. Specifically, "7059 Glass", "1737 Glass", "Eagle 200" and "Eagle XG" manufactured by Corning, "AN100" manufactured by Asahi Glass, "OA-10G" and "OA" manufactured by Nippon Denki Glass, Inc. -11” is suitable. These are materials with a small coefficient of thermal expansion and are excellent in dimensional stability and workability in high-temperature heat treatment. In the case of imparting flexibility to the light emitting element 100, each of the lower substrate 1 and the upper substrate 13 includes a plastic substrate (a substrate mainly composed of a polymer material) and a metal substrate having a relatively small thickness. is selected

The thickness of the lower substrate 1 and the upper substrate 13 is not particularly limited, respectively, but is preferably in the range of 100 to 1,000 μm, and more preferably in the range of 300 to 800 μm.

In addition, either one or both of the lower substrate 1 and the upper substrate 13 may be omitted depending on the usage form of the light emitting element 100 .

As shown in FIG. 4 , on the lower substrate 1, a signal line drive circuit C1 and a scan line for controlling the supply of current to the anode 2 constituting the pixel electrode PE represented by R, G, and B are provided. A driving circuit C2, a control circuit C3 for controlling the operation of these circuits, a plurality of signal lines 706 connected to the signal line driving circuit C1, and a plurality of scanning lines connected to the scanning line driving circuit C2 (707) is provided. In the vicinity of the intersection of each signal line 706 and each scan line 707, as shown in Fig. 5, a capacitor 701, a drive transistor 702, and a switching transistor 708 are provided.

The capacitor 701 has one electrode connected to the gate electrode of the drive transistor 702 and the other electrode connected to the source electrode of the drive transistor 702 . The driving transistor 702 has a gate electrode connected to one electrode of the capacitor 701, a source electrode connected to the other electrode of the capacitor 701 and a power supply line 703 supplying drive current, and a drain. An electrode is connected to the anode 4 of the EL light source section 200.

The switching transistor 708 has a gate electrode connected to the scan line 707, a source electrode connected to the signal line 706, and a drain electrode connected to the gate electrode of the driving transistor 702. In this embodiment, the common electrode 705 constitutes the cathode 8 of the EL light source unit 200. In addition, the driving transistor 702 and the switching transistor 708 can be constituted by, for example, a thin film transistor or the like.

The scan line driving circuit C2 supplies or blocks a scan voltage according to a scan signal to the gate electrode of the switching transistor 708 via the scan line 707 to turn the switching transistor 708 on or off. In this way, the scan line driver circuit C2 adjusts the timing at which the signal line driver circuit C1 writes the signal voltage. Meanwhile, the signal line driving circuit C1 supplies or cuts off a signal voltage according to a video signal to the gate electrode of the driving transistor 702 through the signal line 706 and the switching transistor 708, so that the EL light source unit 200 Adjust the amount of signal current supplied.

Therefore, when the scan voltage from the scan line driver circuit C2 is supplied to the gate electrode of the switching transistor 708 and the switching transistor 708 is turned on, the signal voltage from the signal line driver circuit C1 is applied to the gate electrode of the switching transistor 708. supplied to the electrode. At this time, the drain current corresponding to this signal voltage is supplied from the power supply line 703 to the EL light source section 200 as a signal current. As a result, the EL light source unit 200 emits light according to the supplied signal current.

<EL light source unit 200>

[Anode (2)]

The anode 2 has a function of supplying holes from an external power source toward the light emitting layer 5 . The constituent material (anode material) of the anode 2 is not particularly limited, and examples thereof include a metal such as gold (Au), a metal halide such as copper iodide (CuI), indium tin oxide (ITO), and tin oxide ( and metal oxides such as SnO ₂ ) and zinc oxide (ZnO). These may be used individually by 1 type, and may use 2 or more types together.

The thickness of the anode 2 is not particularly limited, but is preferably in the range of 10 to 1,000 nm, and more preferably in the range of 10 to 200 nm.

The anode 2 can be formed by, for example, a dry film forming method such as a vacuum deposition method or a sputtering method. At this time, the anode 2 having a predetermined pattern may be formed by a photolithography method or a method using a mask.

[Cathode (8)]

The cathode 8 has a function of supplying electrons from an external power source toward the light emitting layer 5 . The constituent material (cathode material) of the negative electrode 8 is not particularly limited, and examples thereof include lithium, sodium, magnesium, aluminum, silver, a sodium-potassium alloy, a magnesium/aluminum mixture, a magnesium/silver mixture, and magnesium/indium. mixtures, aluminum/aluminum oxide (Al ₂ O ₃ ) mixtures, rare earth metals, and the like. These may be used individually by 1 type, and may use 2 or more types together.

The thickness of the cathode 8 is not particularly limited, but is preferably in the range of 0.1 to 1,000 nm, and more preferably in the range of 1 to 200 nm.

The cathode 8 can be formed by, for example, a dry film forming method such as a vapor deposition method or a sputtering method.

[Hole Injection Layer (3)]

The hole injection layer 3 has a function of receiving holes supplied from the anode 2 and injecting them into the hole transport layer 4 . In addition, the hole injection layer 3 may be provided as needed, and may be omitted.

The constituent material (hole injection material) of the hole injection layer 3 is not particularly limited, and examples thereof include phthalocyanine compounds such as copper phthalocyanine; triphenylamine derivatives such as 4,4',4''-tris[phenyl(m-tolyl)amino]triphenylamine; such as 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane cyano compounds; metal oxides such as vanadium oxide and molybdenum oxide; amorphous carbon; and polymers such as polyaniline (emeraldine), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT-PSS), and polypyrrole. Among these, the hole injection material is preferably a polymer, and more preferably PEDOT-PSS. In addition, the hole injection materials described above may be used alone or in combination of two or more.

The thickness of the hole injection layer 3 is not particularly limited, but is preferably in the range of 0.1 to 500 mm, more preferably in the range of 1 to 300 nm, and still more preferably in the range of 2 to 200 nm. The hole injection layer 3 may have a single-layer structure or a laminated structure in which two or more layers are stacked.

Such a hole injection layer 4 can be formed by a wet film forming method or a dry film forming method. In the case where the hole injection layer 3 is formed by a wet film forming method, usually, ink containing the hole injection material described above is applied by various coating methods, and the obtained coating film is dried. The coating method is not particularly limited, and examples thereof include inkjet printing (droplet dispensing method), spin coating method, cast method, LB method, relief printing method, gravure printing method, screen printing method, nozzle print printing method, and the like. can be heard On the other hand, in the case of forming the hole injection layer 3 by a dry film forming method, a vacuum deposition method, a sputtering method, or the like can be suitably used.

[Hole Transport Layer (4)]

The hole transport layer 4 has a function of receiving holes from the hole injection layer 3 and transporting them efficiently to the light emitting layer 6 . In addition, the hole transport layer 4 may have a function of preventing electron transport. In addition, the hole transport layer 4 may be provided as needed and may be omitted.

The constituent material (hole transport material) of the hole transport layer 4 is not particularly limited, but is, for example, TPD(N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1' -Biphenyl-4,4' diamine), α-NPD (4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl), m-MTDATA (4,4',4 low molecular weight triphenylamine derivatives such as ''-tris(3-methylphenylphenylamino)triphenylamine); polyvinylcarbazole; Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (poly-TPA), polyfluorene (PF), poly[N,N'-bis(4 -Butylphenyl) -N, N'-bis (phenyl) -benzidine (Poly-TPD), poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4'- conjugated compound polymers such as (N-(sec-butylphenyl)diphenylamine))(TFB) and polyphenylenevinylene (PPV); and copolymers containing these monomer units.

Among these, the hole transport material is preferably a triphenylamine derivative or a polymer compound obtained by polymerizing a triphenylamine derivative introduced with a substituent, and more preferably a polymer compound obtained by polymerizing a triphenylamine derivative introduced with a substituent. do. In addition, the hole transport materials described above may be used alone or in combination of two or more.

The thickness of the hole transport layer 4 is not particularly limited, but is preferably in the range of 1 to 500 nm, more preferably in the range of 5 to 300 nm, and still more preferably in the range of 10 to 200 nm. The hole transport layer 4 may have a single-layer structure or a laminated structure in which two or more layers are laminated.

Such a hole transport layer 4 can be formed by a wet film forming method or a dry film forming method. In the case where the hole transport layer 4 is formed by a wet film forming method, usually ink containing the hole transport material described above is applied by various coating methods, and the obtained coating film is dried. The coating method is not particularly limited, and examples thereof include inkjet printing (droplet dispensing method), spin coating method, cast method, LB method, relief printing method, gravure printing method, screen printing method, nozzle print printing method, and the like. can be heard On the other hand, when the hole transport layer 4 is formed by a dry film forming method, a vacuum deposition method, a sputtering method, or the like can be suitably used.

[Electron Injection Layer 7]

The electron injection layer 7 has a function of receiving electrons supplied from the cathode 8 and injecting them into the electron transport layer 6 . In addition, the electron injection layer 7 may be provided as needed, and may be omitted.

The constituent material (electron injection material) of the electron injection layer 7 is not particularly limited, and examples thereof include alkali metal chalcogenides such as Li ₂ O, LiO, Na ₂ S, Na ₂ Se, and NaO; alkaline earth metal chalcogenides such as CaO, BaO, SrO, BeO, BaS, MgO, CaSe; alkali metal halides such as CsF, LiF, NaF, KF, LiCl, KCl, NaCl; alkali metal salts such as 8-hydroxyquinolinolatolithium (Liq); and alkaline earth metal halides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ , and BeF ₂ . Among these, alkali metal chalcogenides, alkaline earth metal halides, and alkali metal salts are preferable. In addition, the electron injecting materials described above may be used alone or in combination of two or more.

The thickness of the electron injection layer 7 is not particularly limited, but is preferably in the range of 0.1 to 100 nm, more preferably in the range of 0.2 to 50 nm, and still more preferably in the range of 0.5 to 10 nm. The electron injection layer 7 may have a single-layer structure or a laminated structure in which two or more layers are stacked.

Such an electron injection layer 7 can be formed by a wet film forming method or a dry film forming method. In the case where the electron injection layer 7 is formed by a wet film forming method, usually ink containing the electron injection material described above is applied by various coating methods, and the obtained coating film is dried. The coating method is not particularly limited, and examples thereof include inkjet printing (droplet dispensing method), spin coating method, cast method, LB method, relief printing method, gravure printing method, screen printing method, nozzle print printing method, and the like. can be heard On the other hand, in the case of forming the electron injection layer 7 by a dry film forming method, a vacuum deposition method, a sputtering method, or the like may be applied.

[Electron Transport Layer (8)]

The electron transport layer 8 has a function of receiving electrons from the electron injection layer 7 and efficiently transporting them to the light emitting layer 5 . Also, the electron transport layer 8 may have a function of preventing transport of holes. In addition, the electron transport layer 8 may be provided as needed, and may be omitted.

The constituent material (electron transport material) of the electron transport layer 8 is not particularly limited, and examples thereof include tris(8-quinolinato) aluminum (Alq3) and tris(4-methyl-8-quinolinolato). Aluminum (Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium (BeBq2), bis(2-methyl-8-quinolinolato)(p-phenylphenolato)aluminum (BAlq), bis metal complexes having a quinoline skeleton or a benzoquinoline skeleton such as (8-quinolinolato) zinc (Znq); metal complexes having a benzoxazoline skeleton such as bis[2-(2'-hydroxyphenyl)benzoxazolato] zinc (Zn(BOX)2); metal complexes having a benzothiazoline skeleton such as bis[2-(2'-hydroxyphenyl)benzothiazolato] zinc (Zn(BTZ)2); 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 3-(4-biphenylyl)-4-phenyl-5- (4-tert-butylphenyl)-1,2,4-triazole (TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2- tris or diazole derivatives such as yl]benzene (OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]carbazole (CO11); 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazole)(TPBI), 2-[3-(dibenzothiophen-4-yl ) Imidazole derivatives such as phenyl] -1-phenyl-1H-benzoimidazole (mDBTBIm-II); quinoline derivatives; perylene derivatives; pyridine derivatives such as 4,7-diphenyl-1,10-phenanthroline (BPhen); pyrimidine derivatives; triazine derivatives; quinoxaline derivatives; diphenylquinone derivatives; nitro-substituted fluorene derivatives; and metal oxides such as zinc oxide (ZnO) and titanium oxide (TiO ₂ ). Among these, as an electron transport material, it is preferable that they are an imidazole derivative, a pyridine derivative, a pyrimidine derivative, a triazine derivative, and a metal oxide (inorganic oxide). Moreover, the above-mentioned electron transport material may be used individually by 1 type, and may use 2 or more types together.

The thickness of the electron transport layer 7 is not particularly limited, but is preferably in the range of 5 to 500 nm, and more preferably in the range of 5 to 200 nm. The electron transport layer 6 may be a single layer or a laminate of two or more layers.

Such an electron transport layer 7 can be formed by a wet film forming method or a dry film forming method. In the case of forming the electron transport layer 6 by a wet film forming method, usually, ink containing the electron transport material described above is applied by various coating methods, and the obtained coating film is dried. The coating method is not particularly limited, and examples thereof include inkjet printing (droplet dispensing method), spin coating method, cast method, LB method, relief printing method, gravure printing method, screen printing method, nozzle print printing method, and the like. can be heard On the other hand, in the case of forming the electron transport layer 6 by a dry film forming method, a vacuum deposition method, a sputtering method, or the like may be applied.

[Light emitting layer (5)]

The light emitting layer 5 has a function of generating light emission using energy generated by recombination of holes and electrons injected into the light emitting layer 5 . The light emitting layer 5 of this embodiment emits blue light with a wavelength in the range of 400 to 500 nm, more preferably in the range of 420 to 480 nm.

The light-emitting layer 5 preferably contains a light-emitting material (guest material or dopant material) and a host material. In this case, the mass ratio of the host material and the light emitting material is not particularly limited, but is preferably in the range of 10:1 to 300:1. For the light emitting material, a compound capable of converting singlet excitation energy into light or a compound capable of converting triplet excitation energy into light can be used. Further, the luminescent material preferably includes at least one selected from the group consisting of organic low-molecular-weight fluorescent materials, organic high-molecular fluorescent materials, and organic phosphorescent materials.

Examples of the compound capable of converting singlet excitation energy into light include organic low-molecular fluorescent materials and organic high-molecular fluorescent materials that emit fluorescence.

The organic low-molecular-weight fluorescent material has an anthracene structure, a tetracene structure, a chrysene structure, a phenanthrene structure, a pyrene structure, a perylene structure, a stilbene structure, an acridone structure, a coumarin structure, a phenoxazine structure, or a phenothiazine structure. compounds are preferred.

Specific examples of the organic low-molecular-weight fluorescent material include, for example, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine, 5,6-bis[4'- (10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine, N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N, N'-diphenylstilbene-4,4'-diamine, 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine, 4-(9H- Carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine, N,9-diphenyl-N-[4-(10-phenyl-9-anthryl) Phenyl]-9H-carbazol-3-amine, 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine, 4-[4 -(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine, perylene, 2,5,8,11-tetra (tert- Butyl) perylene, N, N'-diphenyl-N, N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine, N,N' -bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]-pyrene-1,6-diamine, N,N'-bis(diamine) Benzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine, N,N'-bis(dibenzothiophen-2-yl)-N,N'-diphenylpyrene-1 ,6-diamine, N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N'-triphenyl-1,4- phenylenediamine], N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine, N-[4-(9, 10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine, N,N,N',N',N'',N'', N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine, coumarin 30, N-(9,10-diphenyl-2-anthryl )-N,9-diphenyl-9H-carbazol-3-amine, N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenyl Rendiamine, N,N,9-triphenylanthracen-9-amine, Coumarin 6, Coumarin 545T, N,N'-Diphenylquinacridone, Rubrene, 5,12-bis(1,1'-biphenyl) -4-yl)-6,11-diphenyltetracene, 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propane Dinitrile, 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran -4-ylidene} propanedinitrile, N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine, 7,14-diphenyl-N,N,N', N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine, 2-{2-isopropyl-6-[2-(1,1,7, 7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile, 2 -{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine-9- yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile, 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylly Den) Propanedinitrile, 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile, 5,10,15,20-tetraphenylbisbenzo[5,6]indeno[1, 2,3-cd:1',2',3'-lm] perylene; and the like.

Specific examples of organic polymer fluorescent materials include, for example, homopolymers composed of units based on fluorene derivatives, copolymers composed of units based on fluorene derivatives and units based on tetraphenylphenylenediamine derivatives, and terphenyl derivatives. and homopolymers composed of units based on diphenylbenzofluorene derivatives, and the like.

As the compound capable of converting triplet excitation energy into light, an organic phosphorescent material that emits phosphorescence is preferable. Specific examples of the organic phosphorescent material include, for example, iridium, rhodium, platinum, ruthenium, osmium, scandium, yttrium, gadolinium, palladium, silver, gold, a metal containing at least one metal atom selected from the group consisting of aluminum Complexes are exemplified. Among them, as the organic phosphorescent material, a metal complex containing at least one metal atom selected from the group consisting of iridium, rhodium, platinum, ruthenium, osmium, scandium, yttrium, gadolinium, and palladium is preferable, and iridium, rhodium, A metal complex containing at least one metal atom selected from the group consisting of platinum and ruthenium is more preferable, and an iridium complex or a platinum complex is still more preferable.

As the host material, it is preferable to use at least one compound having an energy gap larger than that of the light emitting material. In addition, when the light emitting material is a phosphorescent material, it is preferable to select a compound having a higher triplet excitation energy than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light emitting material as the host material.

As the host material, for example, tris(8-quinolinolato) aluminum (III), tris(4-methyl-8-quinolinolato) aluminum (III), bis(10-hydroxybenzo[h] quinolinato) beryllium(II), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III), bis(8-quinolinolato) zinc(II), bis[ 2-(2-benzoxazolyl)phenolato] zinc(II), bis[2-(2-benzothiazolyl)phenolato] zinc(II), 2-(4-biphenylyl)-5-(4 -tert-butylphenyl)-1,3,4-oxadiazole, 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene, 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole, 2,2',2''-(1,3,5- Benzenetriyl) tris (1-phenyl-1H-benzoimidazole), vasophenanthroline, vasocuproin, 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl )phenyl] -9H-carbazole, 9,10-diphenylanthracene, N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine , 4-(10-phenyl-9-anthryl)triphenylamine, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-car Bazol-3-amine, 6,12-dimethoxy-5,11-diphenylchrysene, 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole, 3,6-di Phenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole, 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole Bazole, 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole, 6-[3-(9,10-diphenyl-2-anthryl) Phenyl]-benzo[b]naphtho[1,2-d]furan, 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene , 9,10-bis (3,5-diphenylphenyl) anthracene, 9,10-di (2-naphthyl) anthracene, 2-tert-butyl-9,10-di (2-naphthyl) anthracene, 9 ,9'-bianthril, 9,9'-(stilbene-3,3'-diyl)diphenanthrene, 9,9'-(stilbene-4,4'-diyl)diphenanthrene, 1,3 ,5-tri(1-pyrenyl)benzene, 5,12-diphenyltetracene, or 5,12-bis(biphenyl-2-yl)tetracene; and the like. These host materials may be used individually by 1 type, and may use 2 or more types together.

The thickness of the light emitting layer 5 is not particularly limited, but is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 50 nm.

Such a light emitting layer 5 can be formed by a wet film forming method or a dry film forming method. In the case where the light emitting layer 5 is formed by a wet film forming method, usually, an ink containing the light emitting material and the host material described above is applied by various coating methods, and the obtained coating film is dried. The coating method is not particularly limited, and examples thereof include inkjet printing (droplet dispensing method), spin coating method, cast method, LB method, relief printing method, gravure printing method, screen printing method, nozzle print printing method, and the like. can be heard On the other hand, in the case of forming the light emitting layer 5 by a dry film forming method, a vacuum deposition method, a sputtering method, or the like may be applied.

Further, the EL light source unit 200 may also have banks (partition walls) partitioning the hole injection layer 3, the hole transport layer 4, and the light emitting layer 5, for example. The height of the banks is not particularly limited, but is preferably in the range of 0.1 to 5 μm, more preferably in the range of 0.2 to 4 μm, still more preferably in the range of 0.2 to 3 μm.

The width of the opening of the bank is preferably in the range of 10 to 200 μm, more preferably in the range of 30 to 200 μm, and still more preferably in the range of 50 to 100 μm. The length of the opening of the bank is preferably in the range of 10 to 400 μm, more preferably in the range of 20 to 200 μm, and still more preferably in the range of 50 to 200 μm. Further, the inclination angle of the bank is preferably in the range of 10 to 100°, more preferably in the range of 10 to 90°, and still more preferably in the range of 10 to 80°.

<Light conversion layer 12>

The light conversion layer 12 converts the light emitted from the EL light source unit 200 and re-emits it, or transmits the light emitted from the EL light source unit 200. As shown in FIG. 3 , the pixel unit 20 includes a first pixel unit 20a that converts light of a wavelength within the above range to emit red light, and a second pixel that converts light of a wavelength within the above range to emit green light. It has a portion 20b and a third pixel portion 20c that transmits light having a wavelength in the above range. A plurality of first pixel portions 20a, second pixel portions 20b, and third pixel portions 20c are arranged in a grid pattern so as to repeat in this order. And, between adjacent pixel units, that is, between the first pixel unit 20a and the second pixel unit 20b, between the second pixel unit 20b and the third pixel unit 20c, and between the third pixel unit 20b and the third pixel unit 20c. Between the portion 20c and the first pixel portion 20a, a light blocking portion 30 for shielding light is provided. In other words, these pixel parts adjacent to each other are spaced apart by the light blocking part 30 . In addition, the first pixel portion 20a and the second pixel portion 20b may contain color materials corresponding to respective colors.

The first pixel portion 20a and the second pixel portion 20b each contain a cured product of the light emitting particle-containing ink composition of the above-described embodiment. The cured product preferably contains light-emitting particles 90 and a curing component as essential, and also includes light-diffusing particles in order to scatter light and reliably take it out to the outside. The curing component is a cured product of a thermosetting resin, for example, a cured product obtained by polymerization of a resin containing an epoxy group. That is, the first pixel portion 20a includes a first curing component 22a, and first light-emitting particles 90a and first light-diffusing particles 21a respectively dispersed in the first curing component 22a. . Similarly, the second pixel portion 20b includes a second curing component 22b, and second light-emitting particles 90b and second light-diffusing particles 21b respectively dispersed in the second curing component 22b. . In the 1st pixel part 20a and the 2nd pixel part 20b, the 1st hardening component 22a and the 2nd hardening component 22b may be the same or different, and the 1st light-diffusion particle 22a and The second light-diffusing particles 22b may be the same or different.

The first light-emitting particles 90a are red light-emitting particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a peak emission wavelength in the range of 605 to 665 nm. That is, the first pixel portion 20a may be referred to as a red pixel portion for converting blue light into red light. Further, the second light-emitting particles 90b are green light-emitting particles that absorb light having a wavelength in the range of 420 to 480 nm and emit light having a peak emission wavelength in the range of 500 to 560 nm. That is, the second pixel portion 20b may be referred to as a green pixel portion for converting blue light into green light.

The content of the luminescent particles 90 in the pixel portions 20a and 20b containing the cured product of the luminescent particle-containing ink composition is, from the standpoint of a more excellent external quantum efficiency improvement effect and excellent luminous intensity obtained, the luminescence Based on the total mass of the cured product of the particle-containing ink composition, it is preferably 0.1% by mass or more. From the same viewpoint, the content of the luminescent particles 90 is preferably 1% by mass or more, 2% by mass or more, 3% by mass or more, or 5% by mass or more based on the total mass of the cured product of the ink composition containing the luminescent particles. . The content of the luminescent particles 90 is preferably 30% by mass or less based on the total mass of the ink composition containing the luminescent particles, from the viewpoint of excellent reliability of the pixel portions 20a and 20b and excellent luminous intensity. am. From the same point of view, the content of the luminescent particles 90 is preferably 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less based on the total mass of the cured product of the ink composition containing luminescent particles. .

The content of the light-diffusing particles 21a, 21b in the pixel portions 20a, 20b containing the cured product of the ink composition containing luminescent particles is, from the viewpoint of a more excellent external quantum efficiency improving effect, the cured product of the ink composition. It is preferably 0.1% by mass or more, 1% by mass or more, 5% by mass or more, 7% by mass or more, 10% by mass or more, and 12% by mass or more based on the total mass. The content of the light-diffusing particles 21a, 21b is 60% by mass based on the total mass of the cured product of the ink composition, from the viewpoint of improving the external quantum efficiency and the reliability of the pixel portion 20. Below, it is preferable that it is 50 mass % or less, 40 mass % or less, 30 mass % or less, 25 mass % or less, 20 mass % or less, and 15 mass % or less.

The third pixel portion 20c has a transmittance of 30% or more to light having a wavelength in the range of 420 to 480 nm. Therefore, the third pixel portion 20c functions as a blue pixel portion when a light source emitting light having a wavelength in the range of 420 to 480 nm is used. The third pixel portion 20c includes, for example, a cured product of a composition containing the thermosetting resin described above. The cured product contains the third cured component (22cc). The third curing component 22c is a cured product of a thermosetting resin, specifically, a cured product obtained by polymerization of a resin containing an epoxy group. That is, the third pixel portion 20c includes the third curing component 22c. When the third pixel portion 20c includes the cured product described above, the composition containing the thermosetting resin has a transmittance of light having a wavelength in the range of 420 to 480 nm of 30% or more, as long as the composition contains the above-described light emission. Among the components contained in the particle-containing ink composition, components other than a thermosetting resin, a curing agent, and a solvent may be further contained. In addition, the transmittance of the third pixel portion 20c can be measured by a microscopy device.

The thickness of the pixel portions (first pixel portion 20a, second pixel portion 20b, and third pixel portion 20c) is not particularly limited, but is preferably, for example, 1 μm or more, 2 μm or more, or 3 μm or more. do. The thickness of the pixel portions (first pixel portion 20a, second pixel portion 20b, and third pixel portion 20c) is preferably 30 μm or less, 25 μm or less, or 20 μm or less, for example.

[Method of Forming Light Conversion Layer 12]

The light conversion layer 12 having the above first to third pixel portions 20a to 20c can be formed by drying, heating, and curing a coating film formed by a wet film forming method. The first pixel portion 20a and the second pixel portion 20b can be formed using the ink composition containing light-emitting particles of the present invention, and the third pixel portion 20c is included in the ink composition containing light-emitting particles. It can be formed using an ink composition that does not contain the light emitting particles 90 . Hereinafter, the method for forming a coating film using the ink composition containing luminescent particles of the present invention will be described in detail, but the same can be carried out in the case of using the ink composition containing luminescent particles of the present invention.

A coating method for obtaining a coating film of the ink composition containing luminescent particles of the present invention is not particularly limited, and examples thereof include inkjet printing method (piezo method or thermal method droplet discharging method), spin coating method, casting method, and LB method. , a relief printing method, a gravure printing method, a screen printing method, a nozzle print printing method, and the like. Here, the nozzle print printing method is a method in which an ink composition containing luminescent particles is applied in a stripe form from a nozzle hole as a liquid column. Among them, as the coating method, an inkjet printing method (particularly, a piezo-type droplet discharging method) is preferable. This makes it possible to reduce the heat load when discharging the ink composition containing the luminescent particles, and to prevent the luminescent particles 90 from deteriorating due to heat.

The conditions of the inkjet printing method are preferably set as follows. The discharge amount of the ink composition containing luminescent particles is not particularly limited, but is preferably 1 to 50 pL/time, more preferably 1 to 30 pL/time, and still more preferably 1 to 20 pL/time.

Moreover, it is preferable that it is the range of 5-50 micrometers, and, as for the opening diameter of a nozzle hole, it is more preferable that it is the range of 10-30 micrometers. Accordingly, it is possible to increase the ejection accuracy of the ink composition containing the luminescent particles while preventing nozzle holes from being clogged.

The temperature at the time of forming the coating film is not particularly limited, but is preferably in the range of 10 to 50°C, more preferably in the range of 15 to 40°C, and still more preferably in the range of 15 to 30°C. By discharging liquid droplets at such a temperature, crystallization of various components included in the ink composition containing light emitting particles can be suppressed.

In addition, the relative humidity at the time of forming the coating film is also not particularly limited, but is preferably in the range of 0.01 ppm to 80%, more preferably in the range of 0.05 ppm to 60%, and in the range of 0.1 ppm to 15% More preferably, it is particularly preferably in the range of 1 ppm to 1%, and most preferably in the range of 5 to 100 ppm. Control of the conditions at the time of forming a coating film as a relative humidity is more than the said lower limit becomes easy. On the other hand, when the relative humidity is equal to or less than the above upper limit value, the amount of moisture adsorbed to the coating film, which may adversely affect the obtained light conversion layer 12, can be reduced.

When the ink composition containing luminescent particles contains an organic solvent, it is preferable to remove the organic solvent from the coating film by drying before curing the coating film. The drying may be performed by leaving it at room temperature (25°C) or by heating, but from the viewpoint of productivity, it is preferable to perform the drying by heating. When drying is performed by heating, the drying temperature is not particularly limited, but is preferably set to a temperature in consideration of the boiling point and vapor pressure of the organic solvent used in the ink composition containing luminescent particles. The drying temperature is preferably 50 to 130°C, more preferably 60 to 120°C, and particularly preferably 70 to 110°C, as a prebaking step for removing the organic solvent in the coating film. If the drying temperature is 50 ° C. or less, the organic solvent may not be removed. On the other hand, if the drying temperature is 130 ° C. or more, the removal of the organic solvent occurs instantaneously and the appearance of the coating film may be remarkably deteriorated. This is not preferable. Moreover, it is preferable to perform drying under reduced pressure, and it is more preferable to perform it under reduced pressure of 0.001-100 Pa. In addition, the drying time is preferably 1 to 30 minutes, more preferably 1 to 15 minutes, and particularly preferably 1 to 10 minutes. By drying the coating film under such drying conditions, the organic solvent is reliably removed from the coating film, and the external quantum efficiency of the obtained light conversion layer 12 can be further improved.

The ink composition containing luminescent particles of the present invention can be cured by irradiation with active energy rays (eg, ultraviolet rays). As the irradiation source (light source), for example, a mercury lamp, a metal halide lamp, a xenon lamp, an LED or the like is used, but from the viewpoint of reducing the heat load on the coating film and reducing power consumption, the LED is preferable.

It is preferable that it is 200 nm or more, and, as for the wavelength of the light to irradiate, it is more preferable that it is 440 nm or less. Moreover, it is preferable that it is 0.2-2 kW/cm ^<2> , and, as for the intensity of light, it is more preferable that it is 0.4-1 kW/cm ^<2> . A light intensity of less than 0.2 kW/cm ² cannot sufficiently cure the coating film, and a light intensity of 2 kW/cm ² or more causes non-uniformity in the curing degree of the surface of the coating film and the inside, and the smoothness of the surface of the coating film is poor, so it is not preferable. not. It is preferable that it is 10 mJ/cm ^<2> or more, and, as for the irradiation amount (exposure amount) of light, it is more preferable that it is 4000 mJ/cm ^{<2> or} less.

Although the curing of the coating film can be performed in air or in an inert gas, it is more preferable to perform curing in an inert gas in order to suppress oxygen inhibition on the surface of the coating film and oxidation of the coating film. As an inert gas, nitrogen, argon, carbon dioxide, etc. are mentioned. By curing the coating film under such conditions, since the coating film can be completely cured, the external quantum efficiency of the obtained light conversion layer 9 can be further improved.

As described above, since the luminescent particle ink composition of the present invention is excellent in heat stability, good light emission can be realized even in the pixel portion 20, which is a molded body after thermal curing. Furthermore, since the luminescent particle composition of the present invention has excellent dispersibility, the luminescent particles 90 have excellent dispersibility, and a flat pixel portion 20 can be obtained.

In addition, the light-emitting particles 90 included in the first pixel portion 20a and the second pixel portion 20b have absorption in the wavelength region of 300 to 500 nm in order to include semiconductor nanocrystals having a perovskite type. big. Therefore, in the first pixel portion 20a and the second pixel portion 20b, the blue light incident on the first pixel portion 20a and the second pixel portion 20b is transmitted toward the upper substrate 13 side. That is, leakage of blue light to the upper substrate 13 can be prevented. Therefore, according to the first pixel portion 20a and the second pixel portion 20b of the present invention, red light and green light having high color purity can be extracted without mixing blue light.

The light blocking unit 30 is a so-called black matrix installed for the purpose of preventing color mixing by separating adjacent pixel units 20 from each other and preventing light leakage from a light source. The material constituting the light-shielding portion 30 is not particularly limited, and a cured product of an ink composition in which light-blocking particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments are contained in a binder polymer in addition to metals such as chromium, etc. is available. Examples of the binder polymer used herein include polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, one or a mixture of two or more resins such as cellulose, photosensitive resin, O/W An emulsion-type ink composition (for example, one obtained by emulsifying reactive silicone) or the like can be used. It is preferable that the thickness of the light-shielding part 30 is 1 micrometer or more and 15 micrometer or less, for example.

The light emitting element 100 can also be configured as a bottom emission type instead of a top emission type. In addition, instead of the EL light source unit 200, other light sources may be used for the light emitting element 100.

In the above, the ink composition containing light-emitting particles of the present invention, its manufacturing method, and the light-emitting element provided with a light conversion layer manufactured using the ink composition have been described, but the present invention is limited to the configuration of the above-described embodiment. it is not going to be For example, the light-emitting particles, the light-emitting particle dispersion, the ink composition containing light-emitting particles, and the light-emitting element of the present invention may each have the same functions as those of the above-described embodiments by adding other arbitrary structures. It may be substituted with an arbitrary structure to exert. In addition, the manufacturing method of the light-emitting particle of the present invention may have other arbitrary steps in the configuration of the above-described embodiment, or may be substituted with an arbitrary step exhibiting the same effect.

[Example]

Hereinafter, the present invention will be described in detail with examples, but the present invention is not limited thereto. In addition, "part" and "%" are based on mass unless there is particular notice.

In the following examples, operations for producing luminescent particles and operations for preparing an ink composition containing luminescent particles were carried out in a glove box filled with nitrogen or in a flask under a nitrogen stream while shutting off the atmosphere. In addition, all the raw materials exemplified below were used after replacing the atmosphere in the container with nitrogen gas introduced into the container. The liquid material was used after replacing dissolved oxygen in the liquid material with nitrogen gas introduced into the container.

In addition, isobornyl acrylate, isobornyl methacrylate, lauryl acrylate, lauryl methacrylate, phenoxyethyl methacrylate, 1,6-hexanediol diacrylate, 1,6-hexane used below Diol dimethacrylate, 2 moles of propoxy-modified neopentyl glycol diacrylate, 3 moles of propoxy-modified glycerin triacrylate, and ditrimethylolpropane tetraacrylate are prepared using molecular sieves (3A or 4A) ), which was dehydrated for more than 48 hours. Titanium oxide was heated at 120° C. for 2 hours under a reduced pressure of 1 mmHg before use and allowed to cool in a nitrogen gas atmosphere.

<Preparation of Light-Emitting Particle Dispersion>

(Preparation of luminescent particle dispersion 1)

As hollow particles, particles of "SiliNax SP-PN(b)" manufactured by Nippon Mining Co., Ltd. were used. These hollow particles are silica particles having a hollow structure with a rectangular parallelepiped as a whole, and have an average outer diameter of 100 nm and an average inner diameter of 80 nm. First, these hollow silica particles were dried under reduced pressure at 150°C for 8 hours. Next, 200.0 parts by mass of the dried hollow silica particles were weighed and taken in a Kiriyama funnel.

Next, 63.9 parts of cesium bromide, 110.1 parts of lead (II) bromide, and 3000 parts of N-methylformamide were supplied to a three-necked flask under an argon atmosphere, followed by stirring at 50°C for 30 minutes to obtain cesium tribromide. got a solution.

Thereafter, dried hollow silica particles were supplied to the three-necked flask, and after impregnating the hollow silica particles with the resultant lead cesium tribromide solution, the excess lead cesium tribromide solution was removed by filtration, and solid matter was recovered. The resulting solid material was dried under reduced pressure at 150°C for 1 hour to obtain luminescent particles X-1 (212.7 parts by mass) in which hollow silica particles contained perovskite nanocrystals made of lead cesium tribromide. The luminescent particle X-1 is a hollow particle-enclosed luminescent particle.

Luminous particle dispersion 1 in which the luminescent particles X-1 are dispersed by dispersing the obtained luminescent particles X-1 in isobornyl methacrylate (light ester IB-X; manufactured by Kyoeisha Chemical Co., Ltd.) so that the solid concentration is 2.5% by mass got

(Preparation of luminescent particle dispersion 2)

190 parts by mass of heptane was supplied to a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube, and the temperature was raised to 85°C. After reaching the same temperature, 66.5 parts by mass of lauryl methacrylate, 3.5 parts by mass of dimethylaminoethyl methacrylate and 0.5 parts by mass of dimethyl-2,2-azobis(2-methylpropionate) were mixed with 20 parts by mass of heptane. The mixture dissolved in was added dropwise over 3.5 hours to the heptane in the four-necked flask, and even after the addition was completed, the reaction was continued by holding at the same temperature for 10 hours. Then, after the temperature of the reaction solution was lowered to 50 ° C., a solution in which 0.01 part by mass of t-butylpyrocatechol was dissolved in 1.0 part by mass of heptane was added, and further 1.0 part by mass of glycidyl methacrylate was added. After that, the temperature was raised to 85°C, and the reaction was continued at the same temperature for 5 hours. In this way, a solution containing the polymer (P) was obtained. Moreover, the quantity of the non-volatile matter (NV) contained in the solution was 25.1 mass %, and the weight average molecular weight (Mw) of the polymer (P) was 10,000.

Next, in a four-necked flask equipped with a thermometer, stirrer, reflux condenser and nitrogen gas inlet tube, 26 parts by mass of heptane, 3 parts by mass of the above-mentioned luminescent particles X-1, and 3.6 parts by mass of the above-mentioned polymer (P) were contained. A solution was supplied. Further, 0.2 parts by mass of ethylene glycol dimethacrylate, 0.4 parts by mass of methyl methacrylate, and 0.12 parts by mass of dimethyl-2,2-azobis(2-methylpropionate) were supplied to the four-necked flask. Then, after stirring the liquid mixture in the said four-necked flask at room temperature for 30 minutes, it heated up at 80 degreeC, and continued reaction at the same temperature for 15 hours. After completion of the reaction, the polymer not adsorbed to the luminescent particle A in the reaction solution is separated by centrifugation, and then the precipitated particles are vacuum-dried at room temperature for 2 hours, so that the surface of the luminescent particle X-1 as the mother particle is a hydrophobic polymer. Polymer-coated light-emitting particles X-2 coated with a polymer layer consisting of were obtained.

When the obtained polymer-coated light-emitting particles X-2 was observed with a transmission electron microscope, a polymer layer having a thickness of about 10 nm was formed on the surface of the light-emitting particles X-2. Then, the obtained polymer-coated light-emitting particles X-2 was dispersed in isobornyl methacrylate so that the solid content concentration was 2.5% by mass, thereby obtaining a light-emitting particle dispersion liquid 2.

(Preparation of luminescent particle dispersion 3)

First, hollow silica particles identical to those used for the luminescent particle dispersion 1 ("SiliNax SP-PN(b)" manufactured by Nittetsu Mining Co., Ltd.) were dried under reduced pressure at 150°C for 8 hours. Then, 200.0 parts by mass of the dried hollow silica particles were weighed out in a Kiriyama funnel.

Next, 63.9 parts of cesium bromide, 110.1 parts of lead (II) bromide, and 3000 parts of N-methylformamide were supplied to a three-necked flask under an argon atmosphere, followed by stirring at 50°C for 30 minutes to obtain cesium tribromide. got a solution.

Next, hollow silica particles were supplied to the three-necked flask, and the obtained lead tribromide solution was impregnated into the hollow silica particles, and then the excess lead cesium tribromide solution was removed by filtration and solid matter was recovered. Thereafter, the obtained solid material was dried under reduced pressure at 120°C for 1 hour to obtain luminescent particles X-3 in which hollow silica particles contained perovskite nanocrystals composed of lead cesium tribromide. The luminescent particles X-3 are hollow particle-enclosed luminescent particles.

A luminescent particle dispersion 3 in which the luminescent particles X-3 were dispersed was obtained by dispersing the obtained luminescent particles X-3 in isobornyl methacrylate so that the solid concentration was 2.5% by mass.

(Preparation of luminescent particle dispersion 4)

First, 15.0 mg of lead(II) bromide, 8.5 mg of cesium bromide, oleic acid and oleylamine were added to a 1 mL N,N-dimethylformamide solution to obtain a solution containing the raw material compound for semiconductor nanocrystals. .

On the other hand, 0.25 mL of 3-aminopropyltriethoxysilane and 5 mL of toluene were mixed to obtain an ethoxysilane-toluene solution. Thereafter, 1 mL of the solution containing the raw material compound for semiconductor nanocrystals described above was added to the 20 mL ethoxysilane-toluene solution described above while stirring at room temperature under air, and further stirred at 1500 rpm for 20 seconds at room temperature did. After that, the solid was collected by centrifugation (12,100 rotations/minute, 5 minutes) to obtain luminescent particles X-4.

The luminescent particles X-4 were perovskite type lead cesium tribromide crystals provided with a surface layer, and the average particle size was 11 nm as observed with a transmission electron microscope. In addition, the surface layer was a layer composed of 3-aminopropyltriethoxysilane and had a thickness of about 1 nm. That is, the luminescent particle X-4 is a particle coated with silica.

Further, the luminescent particle dispersion 4 in which the luminescent particles X-4 were dispersed was obtained by dispersing the luminescent particles X-4 in isobornyl methacrylate so that the solid content concentration was 2.5% by mass.

(Preparation of luminescent particle dispersion 5)

First, except that the luminescent particle X-4 was used instead of the luminescent particle X-1, in the same manner as in the polymer-coated luminescent particle X-2, the luminescent particle X-4 as the mother particle was coated with a polymer layer composed of a hydrophobic polymer. Coated luminescent particles X-5 were obtained. Then, a luminescent particle dispersion 5 was obtained in the same manner as in the luminescent particle dispersion 2, except that polymer-coated luminescent particles X-5 were used instead of the polymer-coated luminescent particles X-2 as the luminescent particles.

(Preparation of luminescent particle dispersion 6)

First, 0.814 parts by mass of cesium carbonate, 40 parts by mass of octadecene, and 2.5 parts by mass of oleic acid were supplied to a four-necked flask equipped with a thermometer, stirrer, septum, and nitrogen gas inlet tube, and uniformly stirred at 150° C. in a nitrogen atmosphere. It was heated and stirred until it became a solution. After dissolving all of them, a cesium oleate solution was obtained by cooling to 100°C.

Next, 0.069 parts by mass of lead (II) bromide and 5 parts by mass of octadecene were supplied to a four-necked flask equipped with a thermometer, stirrer, septum and nitrogen gas inlet tube, and heated at 120 ° C. for 1 hour in a nitrogen atmosphere Stirred. Subsequently, 0.5 parts by mass of oleylamine and 0.5 parts by mass of oleic acid were supplied to the four-necked flask, and heating and stirring were performed under a nitrogen atmosphere at 160°C until a uniform solution was obtained. Further, 0.4 part by weight of a cesium oleate solution was supplied to the four-necked flask, and after stirring at 160°C for 5 seconds, the four-necked flask was ice-cooled. The resulting reaction solution was separated by centrifugation, and the supernatant was removed to obtain 0.45 parts by mass of perovskite lead cesium tribromide crystals coordinated with oleic acid and oleylamine as luminescent particles X-6. Thereafter, a luminescent particle dispersion 6 was obtained by dispersing the obtained luminescent particles X-6 in isobornyl methacrylate so that the solid concentration was 2.5% by mass.

(Preparation of luminescent particle dispersion 7)

As the photopolymerizable compound, instead of isobornyl methacrylate, a solution obtained by mixing isobornyl methacrylate and phenoxyethyl methacrylate at a ratio of 30 parts by mass: 28.5 parts by mass was used in the same manner as in the light-emitting particle dispersion 1. , obtaining luminescent particle dispersion 7.

(Preparation of luminescent particle dispersion 8)

As the photopolymerizable compound, instead of isobornyl methacrylate, a solution obtained by mixing isobornyl methacrylate and phenoxyethyl methacrylate in a ratio of 30 parts by mass: 28.5 parts by mass was used in the same manner as in the light-emitting particle dispersion 4. , to obtain a dispersion of luminescent particles 8.

(Preparation of luminescent particle dispersion 9)

As the photopolymerizable compound, instead of isobornyl methacrylate, a solution obtained by mixing isobornyl methacrylate and lauryl methacrylate at a ratio of 30 parts by mass: 28.5 parts by mass was used in the same manner as in the light-emitting particle dispersion 1, A dispersion of luminescent particles 9 was obtained.

(Preparation of luminescent particle dispersion 10)

As the photopolymerizable compound, a solution obtained by mixing isobornyl methacrylate and lauryl methacrylate at a ratio of 31.5 parts by mass: 19.5 parts by mass was used instead of isobornyl methacrylate, and the concentration of the light-emitting particles X-1 was 2.86. A luminescent particle dispersion 10 was obtained in the same manner as in the luminescent particle dispersion 1, except that the mass% was adjusted.

(Preparation of luminescent particle dispersion 11)

As the photopolymerizable compound, a solution obtained by mixing isobornyl methacrylate and lauryl methacrylate at a ratio of 16 parts by mass: 30 parts by mass was used instead of isobornyl methacrylate, and the concentration of the light-emitting particles X-1 was 3.16. A luminescent particle dispersion 11 was obtained in the same manner as in the luminescent particle dispersion 1, except that the mass% was adjusted.

(Preparation of luminescent particle dispersion 12)

A luminescent particle dispersion 8 was obtained in the same manner as in the luminescent particle dispersion 4, except that phenoxyethyl methacrylate was used as the photopolymerizable compound instead of isobornyl methacrylate.

(Preparation of luminescent particle dispersion 13)

First, 0.12 g of cesium carbonate, 5 mL of 1-octadecene, and 0.5 mL of oleic acid were mixed to obtain a liquid mixture. Next, after drying this liquid mixture under reduced pressure at 120°C for 30 minutes, it was heated at 150°C in an argon atmosphere. In this way, a cesium-oleic acid solution was obtained.

On the other hand, 0.1 g of lead (II) bromide, 7.5 mL of 1-octadecene, and 0.75 mL of oleic acid were mixed to obtain a liquid mixture. Next, after drying this mixed solution under reduced pressure at 90°C for 10 minutes, 0.75 mL of 3-aminopropyltriethoxysilane was added to the mixed solution in an argon atmosphere. After that, it was further dried under reduced pressure for 20 minutes and then heated at 140°C in an argon atmosphere.

Thereafter, 0.75 mL of the cesium-oleic acid solution was added to the mixture containing lead (II) bromide at 150°C, followed by heating and stirring for 5 seconds to react, followed by cooling in an ice bath. 60 mL of methyl acetate was then added. After the obtained suspension was centrifuged (10,000 rpm, 1 minute), a supernatant was removed to obtain a solid substance containing precursor particles. In addition, the nanocrystal constituting the precursor particle was a perovskite-type lead cesium tribromide crystal, and when analyzed by scanning transmission electron microscopy, the average particle diameter was 10 nm. As polymer B, 800 mg of a block copolymer (S2VP, manufactured by PolymerSource.) having a structure represented by the following formula (B3) was added to 80 mL of toluene, and dissolved by heating at 60°C. To the solid containing the precursor particles, 80 mL of toluene in which the block copolymer was dissolved was added, stirred for 15 minutes, centrifuged, and the supernatant was recovered to obtain a toluene dispersion containing the precursor particles and the block copolymer.

To 2 mL of the toluene dispersion, 10 µL of a compound represented by the following formula (C4) (MS-51, manufactured by Colcoat Co., Ltd., the average value of m in the formula (C4) is 4) was added, stirred for 5 minutes, and then , 5 µL of ion-exchanged water was further added, and the mixture was stirred for 2 hours.

The resulting solution was centrifuged at 9,000 rpm for 5 minutes, and 2 mL of the supernatant was recovered to obtain a luminescent particle dispersion T in which luminescent particles were dispersed in toluene. The average particle diameter of the luminescent particles dispersed in the luminescent particle dispersion T was measured using a dynamic light scattering nanotrac particle size distribution analyzer and found to be 109 nm. Elemental distribution of the light-emitting particles was evaluated by energy dispersive X-ray spectroscopy (STEM-EDS) using a scanning transmission electron microscope, and it was confirmed that Si was contained in the surface layer. Moreover, the thickness of the said surface layer was 49 nm.

By removing toluene from the luminescent particle dispersion T, 0.20 parts by mass of silica-coated lead cesium tribromide crystals were obtained as luminescent particles X-7. Thereafter, a luminescent particle dispersion liquid 13 was obtained by dispersing the obtained luminescent particles X-7 in phenoxyethyl acrylate so that the solid concentration was 2.5% by mass.

Table 1 below shows the dispersoids, the presence or absence of an inorganic coating layer, and the presence or absence of a polymer layer in the obtained dispersions of light-emitting particles 1 to 13.

<Preparation of Light Diffusing Particle Dispersion>

(Preparation of light diffusing particle dispersion 1)

In a container filled with nitrogen gas, 10.0 parts by mass of titanium oxide (“CR60-2” manufactured by Ishihara Sangyo Co., Ltd.) and 1.0 parts by mass of a polymer dispersant “Efka PX4701” (amine value: 40.0 mgKOH/g, manufactured by BASF Japan Co., Ltd.) 1.0 parts by mass, 14.0 parts by mass of phenoxyethyl methacrylate (light ester PO; manufactured by Kyoeisha Chemical Co., Ltd.) was mixed. Further, zirconia beads (diameter: 1.25 mm) were added to the obtained formulation, the container was hermetically sealed and shaken for 2 hours using a paint conditioner to disperse the formulation, thereby obtaining a light-diffusing particle dispersion 1. . The average particle diameter of the light-diffusing particles after the dispersion treatment was measured using NANOTRAC WAVE II and found to be 0.245 µm.

(Preparation of light diffusing particle dispersion 2)

As the polymer dispersant, "Ajisper PB821" (amine value: 10 mgKOH/g, acid value: 17 mgKOH/g, manufactured by Ajinomoto Fine Techno Co., Ltd.) was used instead of "Efka PX4701". Particle dispersion 2 was obtained. The average particle diameter of the light-diffusing particles after the dispersion treatment was measured using NANOTRAC WAVE II and found to be 0.315 µm.

(Preparation of light diffusing particle dispersion 3)

Light-diffusion particle dispersion 3 was obtained in the same manner as in light-diffusion particle dispersion 1, except that "DISPERBYK-111" (acid value: 129 mgKOH/g, manufactured by Big Chemie Japan Co., Ltd.) was used instead of "Efka PX4701" as the polymer dispersant. . The average particle diameter of the light-diffusing particles after the dispersion treatment was measured using NANOTRAC WAVE II and found to be 0.550 µm.

(Preparation of light diffusing particle dispersion 4)

In a container filled with nitrogen gas, 10.0 parts by mass of titanium oxide (“CR60-2” manufactured by Ishihara Sangyo Co., Ltd.) and 14.0 parts by mass of phenoxyethyl methacrylate (light ester PO; manufactured by Kyoeisha Chemical Co., Ltd.) were mixed. Further, zirconia beads (diameter: 1.25 mm) were added to the obtained formulation, the container was hermetically sealed and shaken for 2 hours using a paint conditioner to disperse the formulation, thereby obtaining a light-diffusing particle dispersion 4. In addition, the light-diffusing particle dispersion 4 does not contain a polymeric dispersant. The average particle diameter of the light-diffusing particles after the dispersion treatment was measured using NANOTRAC WAVE II and found to be 0.855 μm.

<Preparation of Ink Composition Containing Luminous Particles>

(Preparation of Ink Composition (1) Containing Luminescent Particles)

An ink composition containing luminescent particles of Example 1, comprising 6.0 parts by mass of luminescent particle dispersion 1 (concentration of luminescent particles: 2.5% by mass), 0.75 parts by mass of light-diffusing particle dispersion 1 (content of titanium oxide: 40.0% by mass), and a photopolymerizable compound. As "lauryl methacrylate" (product name: light ester LM, manufactured by Kyoeisha Chemical Co., Ltd.) 0.65 parts by mass and "1,6-hexanediol dimethacrylate" (product name: light ester 1,6-HX, Kyoeisha Chemical Co., Ltd.) 2.0 parts by mass of Eisha Chemical Co., Ltd.) and 0.3 parts by mass of "diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide" (product name: Omnirad TPO-H, manufactured by BASF Japan Co., Ltd.) as a photopolymerization initiator and "phenyl Bis (2,4,6-trimethylbenzoyl) phosphine oxide” (product name: Omnirad 819, manufactured by BASF Japan Co., Ltd.) 0.1 parts by mass, and “pentaerythritol tetrakis [3-(3 ,5-di-tert-butyl-4-hydroxyphenyl)propionate]" (product name: Irganox 1010, manufactured by BASF Japan Co., Ltd.) 0.1 parts by mass, and as the second antioxidant (B), "3,9-bis( 2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane” (product name: Adekastab PEP-36 , manufactured by ADEKA Co., Ltd.) After mixing and uniformly dissolving 0.1 part by mass in a container filled with argon gas, the melt was filtered with a filter having a pore size of 5 μm in a glove box. Furthermore, argon gas was introduced into the container containing the obtained filtrate, and the inside of the container was saturated with argon gas. Subsequently, the pressure was reduced and argon gas was removed to obtain the ink composition (1) containing luminescent particles. The content of luminescent particles is 1.5% by mass, the content of IB-X is 58.5% by mass, the content of LM is 6.5% by mass, the content of PO is 4.2% by mass, and the content of 1,6-HX is 20.0% by mass The content of TPO-H is 3.0% by mass, the content of 819 is 1.0% by mass, the content of Irganox1010 is 1.0% by mass, the content of PEP-36 is 1.0% by mass, and the content of light scattering particles is 3.0% by mass %, and the content of the polymer dispersant was 0.3% by mass. In addition, the said content is a content based on the total mass of an ink composition.

(Preparation of Ink Compositions (2) to (37) and (C1) to (C5) Containing Luminous Particles)

Luminous particle dispersion 1 to 11, light diffusing particle dispersion 1 to 4, photopolymerizable compound D-1 to D-8, photopolymerization initiator E-1 to E-4, first antioxidant (A) A-1 to A-3 and second antioxidants (B) B-1 to B-4 and light stabilizers H-1 to H-4, except that the addition amounts shown in Tables 2 to 6 below were changed, the ink composition containing luminescent particles ( Under the same conditions as the preparation in 1), ink compositions (2) to (37) containing luminescent particles of Examples 2 to 37 and ink compositions (C1) to (C5) containing luminescent particles of Comparative Examples 1 to 5 were obtained.

Further, in Tables 7 and 8 below, the ratio of antioxidant A to antioxidant B used in the ink composition containing luminescent particles (A/B) and the photopolymerizable compound having a cyclic structure in the total amount of the photopolymerizable compound (M) The mass ratio (Mc/M) of the compound _{( Mc} ) and the mass ratio (M _L /M _C ).

(First antioxidant A)

Compound (A-1): "tetrakis[methylene-3(3'5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane" (product name: IRGANOX 1010, melting point 110-130°C) , molecular weight 1178, manufactured by BASF Japan Co., Ltd.)

Compound (A-2): "3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2; 4,8,10-tetraoxaspiro[5.5]undecane” (product name: Adekastab AO-80, melting point 110-120°C, molecular weight 741, manufactured by ADEKA Co., Ltd.)

Compound (A-3): “butyl hydroxytoluene” (product name: ANTAGE BHT, melting point 70° C., molecular weight 220, manufactured by Kawaguchi Chemical Industry Co., Ltd.)

(Second antioxidant B)

Compound (B-1): "3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro [ 5.5] Undecane" (product name: Adekastab PEP-36, melting point 237°C, molecular weight 633, manufactured by ADEKA Co., Ltd.)

Compound (B-2): "tris(2,4-di-tert-butylphenyl) phosphite" (product name: Adekastab 2112, melting point 183°C, molecular weight 647, manufactured by ADEKA Corporation)

Compound (B-3): "2,4,8,10-tetrakis(1,1-dimethylethyl)-6-[(2-ethylhexyl)oxy]-12H-dibenzo[d,g][1 ,3,2]dioxaphosphosine” (product name: Adekastab HP-10, melting point 148°C, molecular weight 583, manufactured by ADEKA Co., Ltd.)

Compound (B-4): “triphenylphosphite” (product name: JP-360, melting point 25° C., molecular weight 310, manufactured by Johoku Chemical Industry Co., Ltd.)

(photopolymerizable compound)

Compound (D-1): "Isobornyl methacrylate" (Product name: Light Ester IB-X, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-2): "Lauryl methacrylate" (Product name: Light Ester L, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-3): "Phenoxyethyl methacrylate" (Product name: Light Ester PO, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-4): “1,6-hexanediol dimethacrylate” (product name: light ester 1,6-HX, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-5): "1,6-hexanedioldiacrylate" (product name: light acrylate 1,6-HX-A, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-6): "Neopentylglycol diacrylate" (product name: Light Acrylate NP-A, manufactured by Kyoeisha Chemical Co., Ltd.)

Compound (D-7): "PO modified glycerin triacrylate" (product name: OTA480, manufactured by Daicel Allnex Co., Ltd.)

Compound (D-8): "Ditrimethylolpropane tetraacrylate" (product name: LUMICURE DTA-400S, manufactured by Toagosei Co., Ltd.)

(photopolymerization initiator)

Compound (E-1): "Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide" (product name: Omnirad TPO-H, monoacylphosphine oxide compound, manufactured by IGM RESINS)

Compound (E-2): “ethyl phenyl (2,4,6-trimethylbenzoyl) phosphinate” (product name: Omnirad TPO-L, monoacylphosphine oxide compound, manufactured by IGM RESINS)

Compound (E-3): "Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide" (product name: Omnirad 819, bisacylphosphine oxide compound, manufactured by IGM RESINS)

Compound (E-4): "2,2-dimethoxy-2-phenylacetophenone" (product name: Omnirad 651, acetophenone compound, manufactured by IGM RESINS)

(light stabilizer)

Compound (H-1): ADEKA STAB LA63P (product name, manufactured by ADEKA Corporation, functional group equivalent: 269)

Compound (H-2): TinuvinNOR371FF (product name, manufactured by BASF Japan Co., Ltd., functional group equivalent: 350)

Compound (H-3): ADEKA STAB LA72 (product name, manufactured by ADEKA Co., Ltd., functional group equivalent: 255)

Compound (H-4): ADEKA STAB LA52 (product name, manufactured by ADEKA Co., Ltd., functional group equivalent: 212)

<Evaluation of Ink Composition Containing Luminous Particles>

(Example 1)

(stability of ink viscosity)

The viscosity stability of the ink composition containing luminescent particles (1) of the present invention was evaluated by the following method. The viscosity of the ink composition immediately after preparation and the viscosity of the ink composition stored in a thermostat at 40°C for one week after preparation were compared to calculate the rate of increase in viscosity. Specifically, when η ₀ was the viscosity of the ink composition immediately after preparation and η ₁ was the viscosity of the ink composition stored in a thermostat at 40°C for 1 week after preparation, it was 0.11%.

Viscosity increase rate (%) = (η ₁ -η ₀ )/η ₀ × 100

(variance stability)

After the ink composition (1) containing luminescent particles of the present invention was left in the atmosphere for 10 days, the presence or absence of a precipitate was visually confirmed on the bottom surface of the container, and no precipitate was formed.

〔Evaluation standard〕

A: No precipitate was formed.

B: A precipitate is formed very little. Shaking dissolves the precipitate.

C: A lot of precipitate is formed. Shaking also leaves a precipitate.

D: A precipitate is formed considerably, and the precipitate and the liquid component are clearly separated. Shaking also leaves a precipitate.

(Examples 2 to 30)

Evaluation of the initial viscosity, viscosity stability and dispersion stability of the ink compositions (2) to (37) containing luminescent particles was performed in the same manner as in Example 1 using the ink compositions (2) to (37) containing luminescent particles of the present invention. did

(Comparative Examples 1 to 6)

Using the comparative luminescent particle-containing ink compositions (C1) to (C6), the initial viscosity, viscosity stability, and dispersion stability of the luminescent particle-containing ink compositions (C1) to (C6) were evaluated in the same manner as in Example 1. .

The results are shown in Table 9 and Table 10.

<Evaluation of light conversion layer>

(Example 31)

The ink composition (1) containing luminescent particles of the present invention was applied onto a glass substrate in air with a spin coater so that the film thickness after drying was 15 µm. The coated film was cured by UV irradiation in a nitrogen atmosphere with a UV irradiation device using a LED lamp with a dominant wavelength of 395 nm to a cumulative light amount of 10 J/cm ² , and then in a glove box with an oxygen concentration of 1 vol% or less at 180 ° C. for 30 minutes. It was heated to form a layer made of a cured product of the ink composition on a glass substrate, and this was referred to as the light conversion layer 1. The surface smoothness and external quantum efficiency retention rate of the light conversion layer were evaluated as follows.

(Coating film curability)

The surface of the obtained light conversion layer 1 was evaluated by the following criteria by palpation using a cotton swab. The surface of the coating film was not damaged and had a slightly tacky feeling, but the level was satisfactory in practical use.

〔Evaluation standard〕

◎: No damage to the surface of the coating film

○: There is no scratch on the surface of the coating film, and there is a slight tackiness, but it is a level that is not problematic in practical use.

△: The surface of the coating film is slightly scratched and has a tacky feel

×: The surface of the coating film is scratched, and a part of the cured film adheres to the cotton swab

(surface smoothness evaluation)

The surface roughness (Sa value; unit μm) of the obtained light conversion layer 1 was measured using VertScan3.0R4300 of Ryoka Systems, and was 0.07 μm.

(Evaluation of external quantum efficiency (EQE))

An integrating sphere was placed above a blue LED (peak emission wavelength: 450 nm) manufactured by CISS Co., Ltd. as a surface emitting light source, and a radiation spectrophotometer manufactured by Otsuka Electric Co., Ltd. (trade name "MCPD-9800") was connected to the integrating sphere. . Next, the evaluation sample 1 described above was inserted between the blue LED and the integrating sphere, the blue LED was turned on, and the observed spectrum and illuminance at each wavelength were measured with a radiation spectrophotometer. From the obtained spectrum and illuminance, the external quantum efficiency (EQE) was determined as follows.

The external quantum efficiency is a value indicating what ratio of light (photons) incident on the light conversion layer is emitted to the observer side as fluorescence. Therefore, when this value is large, it indicates that the light conversion layer has excellent light emitting properties, and is an important evaluation index. The external quantum efficiency (EQE) is calculated by the following formula (1).

EQE[%]=P2/E(Blue)×100... (One)

In the formula, E (Blue) represents the total value of “illuminance × wavelength ÷ hc” in the wavelength range of 380 to 490 nm, and P2 is “illuminance × wavelength ÷ hc” in the wavelength range of 500 to 650 nm. represents the total value of , and these are values corresponding to the number of observed photons. In addition, h represents Planck's constant, and c represents the speed of light.

And, when the EQE measured immediately after producing the light conversion layer 1 was set as the initial external quantum efficiency EQE ₀ and EQE ₀ was measured, it was 32%. Thereafter, the photoconversion layer 1 was stored at 80°C and in the air for 1 week. The external quantum efficiency after storage was set to EQE _h , and the retention rate EQE _HT [%] of the external quantum efficiency of the light conversion layer was calculated by the following formula (2).

EQE _HT [%]=EQE _h /EQE ₀ ×100… (2)

Here, EQE ₀ means that the higher the numerical value, the smaller the deterioration of the semiconductor nanocrystal by ultraviolet rays in the curing process of the coating film, that is, the better the stability against ultraviolet rays. For use as a light conversion layer, EQE ₀ is preferably 20% or more, more preferably 25% or more, and means excellent. In addition, the photo conversion layer preferably has a higher EQE _h in addition to EQE ₀ , and the higher the external quantum efficiency retention rate EQE _HT , the higher the stability of the photo conversion layer including light-emitting particles against oxygen gas and water vapor. means that

(Evaluation of coating light resistance)

The light conversion layer 1 was continuously irradiated with LED light at 50° C. for one week. The external quantum efficiency after irradiation was set to EQE _u , and the retention rate EQE _UV [%] of the external quantum efficiency of the light conversion layer was calculated by the following formula (3).

EQE _UV [%]=EQE _u /EQE ₀ ×100… (3)

The photoconversion layer preferably has a higher EQE _u in addition to EQE ₀ . A light conversion layer means that the light resistance under high temperature is excellent, so that the external quantum efficiency retention rate EQE _UV is high.

(Examples 39 to 74)

Surface roughness Sa (μm), EQE ₀ (%), EQE _HT (% ) and EQE _UV (%) were evaluated.

(Comparative Examples 7 to 12)

Surface roughness Sa (μm), EQE ₀ (%) and EQE _HT (%) of the light conversion layers C1 to C6 using the comparative light-emitting particle-containing ink compositions (C1) to (C6), as in Example 38 and EQE _UV (%) were evaluated.

A result is shown in Table 11 and Table 12.

<Evaluation results of ink composition containing light emitting particles and light conversion layer>

First, the light-emitting particle-containing ink compositions of Examples 1 to 11 and Comparative Examples 1 to 6, and the light conversion layers of Examples 38 to 48 and Comparative Examples 7 to 11 prepared using them are examined. Since the ink composition containing luminescent particles of Comparative Example 1 uses only one photopolymerization initiator and does not contain an antioxidant, the increase in ink viscosity over time is not suppressed, and the EQE in the light conversion layer of Comparative Example 7 is not suppressed. _HT and EQE _UVs are low. In Comparative Examples 2 to 4 and 6, antioxidants are included, but since only one type of photopolymerization initiator is used in a large amount, the ink initial viscosity is high, and the increase in viscosity with time is not suppressed, and Comparative Examples 8 to In the light conversion layers of Nos. 10 and 12, the curability was poor, the coating film surface was rougher, and EQE _HT and EQE _UV were low. Further, the ink composition containing luminescent particles of Comparative Example 5 uses only one photopolymerization initiator and a very small amount of 0.5% by mass, and the ink viscosity is suppressed to a low level. However, when forming the light conversion layer of Comparative Example 11, Sufficient curability was not obtained, and it did not have any performance as a light conversion layer.

In contrast, the ink compositions containing luminescent particles of Examples 1 to 6 contain the first antioxidant and the second antioxidant while reducing the total amount of use by using two types of photopolymerization initiators, so that the ink initial viscosity is It is low, and the thickening over time is suppressed, and the curability, surface roughness, EQE _HT and EQE _UV when the light conversion layers of Examples 38 to 43 are also good. In addition, the luminescent particle-containing ink compositions of Examples 7 to 11 contain less appropriate amounts of the first antioxidant and the second antioxidant while reducing the total usage amount by using two types of photopolymerization initiators, The initial viscosity of the ink is lower, and the thickening over time is suppressed, and the curability, surface roughness, EQE _HT and EQE _UV when the light conversion layers of Examples 44 to 48 are also good. From this, compared with Comparative Examples 1 to 4, the ink compositions containing luminescent particles of Examples 1 to 11 maintain a suitable ink viscosity and dispersion stability for inkjet, and when formed into a coating film, have no problem in curability and smoothness. A light conversion layer can be formed, and it is clear that the coating film is a light conversion layer that secures excellent stability against oxygen, water vapor and heat and has excellent light emitting properties.

Next, the light-emitting particle-containing ink compositions of Examples 1 and 12 to 15 and the photoconversion layers of Examples 38 and 49 to 52 prepared using them are reviewed. The ink compositions of Examples 1 and 12 to 15 use luminescent particles having a silica coating layer on the surface, and the ink compositions of Examples 12 and 15 use luminescent particles further coated with a polymer layer. These ink compositions have excellent stability of ink viscosity and dispersion stability, good curability in the light conversion layer of Examples 49 and 52, small surface roughness, and excellent EQE _HT and EQE _UV . The most excellent properties were obtained when the ink composition of Example 15 contained the luminescent particles used. From this, it is clear that when two types of photopolymerization initiators are used and the first antioxidant and the second antioxidant are contained, using light-emitting particles coated with a silica layer and a polymer layer gives excellent properties. .

Next, the light-emitting particle-containing ink compositions of Examples 7, 17, and 19, and the photoconversion layers of Examples 44, 54, and 56 prepared using them are reviewed. These ink compositions contain polymerizable compounds having different structures, specifically, compounds having a cyclic structure and compounds having a chain structure. The ink compositions of Examples 7 and 17 containing a large amount of the photopolymerizable compound having a cyclic structure are excellent in ink viscosity stability and dispersion stability, and the curability, surface roughness, EQE _HT and EQE _UV is also good. On the other hand, the ink composition of Example 19 is slightly inferior in ink viscosity stability and dispersion stability, and slightly inferior in EQE _HT and EQE _UV in the light conversion layer of Example 56, but it is a level that is not problematic in practical use. Obvious. From these points, it is clear that the ratio of the photopolymerizable compound having a cyclic structure in the photopolymerizable compound in the ink composition containing the luminescent particles is excellent in ink properties and properties in the light conversion layer.

In addition, the light-emitting particle-containing ink compositions of Examples 19 to 25 and the light conversion layers of Examples 56 to 62 produced using them are reviewed. In these ink compositions, although the types of the bifunctional or higher-functional photopolymerizable compound acting as a crosslinking component are different, when the first antioxidant A and the second antioxidant B are contained, the stability of the ink viscosity in either composition. , excellent in dispersion stability, and excellent in curability, surface roughness, EQE _HT and EQE _UV in the light conversion layer, it is clear that the ink composition is satisfactory in practical use.

Next, the light-emitting particle-containing ink compositions of Examples 19, 26 to 28 and Comparative Example 4, and the light conversion layer of Examples 56, 63 to 65 and Comparative Example 10 prepared using them are reviewed. In the ink compositions of Examples 19 and 26 to 28, all of them contain two or more types of acylphosphine oxide compounds, and also contain first antioxidant A and second antioxidant B, and the type of photopolymerization initiator and Although the addition amount is different, in any ink composition, the stability of ink viscosity and dispersion stability are excellent, and the curability, surface roughness and EQE retention rate in the light conversion layers of Examples 56 and 63 to 65 are also excellent, and acylphos Compositions containing only pinoxide-based compounds are particularly preferred. On the other hand, in the ink composition of Comparative Example 4, only one type of photopolymerization initiator of an acylphosphine oxide compound is contained, but a large amount is contained in order to impart a certain degree of curability, and as a result, the first and second antioxidants are Even if it is contained, the ink viscosity and dispersion stability are inferior, and the characteristics in the light conversion layer of Comparative Example 10 are also inferior. From this, it turns out that it is important to ensure solubility in an ink composition by containing two types of photoinitiators.

In addition, the light-emitting particle-containing ink compositions of Examples 19 and 29 to 30 and Comparative Example 6 and the photoconversion layer of Examples 56 and 66 to 67 and Comparative Example 12 prepared using them are reviewed. The ink compositions of Examples 19 and 29 to 30 contained different polymer dispersants, and the ink composition of Comparative Example 6 had only one photopolymerization initiator and did not contain a polymer dispersant. The ink compositions of Examples 19 and 29 to 30 contain polymeric dispersants having different amine values and acid values. From these evaluation results, good dispersion stability of the light-scattering particles and the light-emitting particles is shown in the ink composition containing the polymer dispersant having an amine value. In particular, it can be seen that a polymer dispersant having only an amine value has very excellent dispersion stability. In the ink composition of Example 30, which is slightly inferior in dispersion stability of the ink, the surface roughness of the light conversion layer of Example 67 is slightly inferior. From this, it can be seen that excellent dispersion stability is important as an ink composition in order to obtain a flat light conversion layer. These ink compositions are not at a level that becomes a problem on actual use. On the other hand, the ink composition of Comparative Example 6 containing not only one photopolymerization initiator but also no polymer dispersant had a remarkably high initial ink viscosity, very poor viscosity stability, and poor dispersion stability. Therefore, each characteristic of the light conversion layer of Comparative Example 12 is also very inferior, and it is clear that it cannot withstand practical use.

Next, the light-emitting particle-containing ink compositions of Examples 31 to 37 and the light conversion layers of Examples 68 to 74 prepared using them are examined. The ink composition of Example 31 uses luminescent particles having a silica coating layer on the surface. This ink composition has excellent ink viscosity stability and dispersion stability, good curability in the light conversion layer of Example 68, small surface roughness, and excellent EQE _HT and EQE _UV . In addition, the ink compositions of Examples 32 and 33 use light-emitting particles having a thicker silica layer on the surface, and thus have excellent ink viscosity stability and dispersion stability, and in the light conversion layers of Examples 69 and 70 The curability of is very good, and EQE _HT and EQE _UV are also very good. In addition, the ink compositions of Examples 34 to 37 use a light stabilizer, and are excellent in stability of ink viscosity and dispersion stability, and the curability, EQE _HT and EQE _UV in the light conversion layer of Examples 71 to 74 are excellent. very excellent From this, it is clear that using the luminescent particles covered by the silica layer imparts excellent characteristics.

From the above, it is clear that the light conversion layers of Examples 38 to 74 obtained by the ink compositions containing light emitting particles of Examples 1 to 37 have excellent light emission properties and have smooth surfaces. Therefore, when the color filter pixel portion of the light emitting element is constituted using these light conversion layers, it can be expected that excellent light emitting characteristics can be obtained.

100 light-emitting elements
200 EL light source
1 lower board
2 anode
3 hole injection layer
4 hole transport layer
5 light emitting layer
6 electron transport layer
7 electron injection layer
8 cathode
9 bag layers
10 packed bed
11 protective layer
12 light conversion layer
13 upper board
14 EL layer
20 pixel part
20a first pixel unit
20b second pixel unit
20c third pixel unit
21a first light diffusion particles
21b second light diffusing particles
21c third light-diffusing particles
22a first curing component
22b second curing component
22c third curing component
90a first luminous particles
90b second luminous particles
30 light blocking part
90 Luminescent Particles, Polymer Coated Particles
91 Luminous Particles
911 nanocrystal
912 hollow nanoparticles
912a hollow part
912b handwork
913 Intermediate Layer
914 surface layer
92 polymer layer
701 capacitor
702 drive transistor
705 common electrode
706 signal line
707 scanline
708 switching transistor
C1 signal line driving circuit
C2 scan line driving circuit
C3 control circuit
PE, R, G, B pixel electrodes
X copolymer
XA association
x1 aliphatic polyamine chain
x2 hydrophobic organic segment
YA core-shell silica nanoparticles
A solution containing raw material compounds of Z semiconductor nanocrystals

Claims (17)

Containing nanoparticles made of metal halide and containing semiconductor nanocrystals having luminescent properties, a photopolymerizable compound, a photopolymerization initiator, and an antioxidant;
As the photopolymerization initiator, two or more types of acylphosphine oxide compounds are contained,
An ink composition containing luminescent particles characterized by containing at least one compound selected from the group consisting of a compound having a hydroxyphenyl group and a compound having a phosphorous acid ester structure as the antioxidant. The method of claim 1,
An ink composition containing luminescent particles, characterized in that the content of the photopolymerization initiator is 1 to 15% by mass. According to claim 1 or claim 2,
The antioxidant comprises a first antioxidant A containing at least one compound having a hydroxyphenyl group and a second antioxidant B containing at least one compound having a phosphorous acid ester structure. An ink composition containing luminescent particles. The method of claim 3,
The mass ratio (A/B) of the first antioxidant A to the second antioxidant B is 0.05 to 5.0, the ink composition containing luminescent particles. The method of claim 3,
The compound having a hydroxyphenyl group contained in the first antioxidant A or the compound having a phosphorous acid ester structure contained in the second antioxidant B has a molecular weight of 500 or more and 1500 or less, and a softening point and a melting point of 70 ° C. or more and 250 C or lower, the ink composition containing luminescent particles. The method of claim 3,
An ink composition containing luminescent particles, wherein the first antioxidant A contains one or two or more compounds represented by the general formula (I).

(In formula (I), M ¹ is a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a 2,4,8,10-tetraoxaspiro[5,5]undecane group, or a carbon atom , represents a hydrocarbon group having 1 to 20 carbon atoms, and one or two or more -CH ₂ - in the hydrocarbon group are -O-, -CO-, -COO-, -OCO- in a range where oxygen atoms are not directly adjacent to each other. , -NH- may be substituted, and any hydrogen atom in the hydrocarbon group may be substituted by a phenyl group having a substituent,
X ¹ is an alkylene group having 1 to 15 carbon atoms, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH=CH-COO-, -CH=CH-OCO-, -COO- CH=CH-, -OCO-CH=CH-, -CH=CH-, -C≡C-, a single bond, a 1,4-phenylene group or a trans-1,4-cyclohexylene group, but the same It may or may not be different, and one or two or more -CH ₂ - in the alkylene group may be substituted with -O-, -CO-, -COO-, or -OCO- within a range where oxygen atoms are not directly adjacent to each other. And, in the 1,4-phenylene group, any hydrogen atom may be substituted by a hydrocarbon group having 1 to 6 carbon atoms,
R ¹¹ and R ¹² each independently represent a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms;
k represents an integer from 2 to 6.) The method of claim 3,
The second antioxidant B is of the general formula (II)

(In Formula II, R ²⁰ to R ²⁴ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and one methyl group in the alkyl group may be substituted with an aryl group.)
or the general formula (III)

(In formula (III), R ³⁰ to R ³⁷ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms;
R ^3a and R ^3b each independently represent a hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms, or R ^3a and R ^3b may form one ring structure;
Z ³¹ represents a straight-chain alkyl group or aryl group having 1 to 10 carbon atoms, and any hydrogen atom in the aryl group may be substituted with a straight-chain or branched alkyl group having 1 to 6 carbon atoms.)
An ink composition containing luminescent particles containing one or two or more compounds represented by According to claim 1 or claim 2,
An ink composition containing light-emitting particles, wherein the semiconductor nanocrystal is a compound having a perovskite crystal structure. According to claim 1 or claim 2,
An ink composition containing luminescent particles, wherein the nanoparticles containing semiconductor nanocrystals have an inorganic coating layer made of an inorganic material on the surface of the particles. The method of claim 9,
An ink composition containing luminescent particles characterized by comprising a resin coating layer comprising a resin which coats the surface of the nanoparticles containing the semiconductor nanocrystals having an inorganic coating layer. According to claim 1 or claim 2,
An ink composition containing luminescent particles, wherein the photopolymerizable compound contains at least two monomers selected from the group consisting of monofunctional (meth)acrylate monomers and polyfunctional (meth)acrylate monomers. The method of claim 11,
An ink composition containing light-emitting particles, wherein at least one of the two or more monomers contained in the photopolymerizable compound is a (meth)acrylate monomer having a cyclic structure. According to claim 1 or claim 2,
An ink composition containing light-diffusing particles, further comprising light-diffusing particles. The method of claim 13,
An ink composition containing luminescent particles, further containing a polymeric dispersant. According to claim 1 or claim 2,
An ink composition containing luminescent particles used in an inkjet method. As a light conversion layer having a pixel portion,
The light conversion layer, characterized in that the pixel portion comprises a cured product of the light emitting particle-containing ink composition according to claim 1 or claim 2. A light emitting element comprising the light conversion layer according to claim 16.

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