JP2001164245A - Color conversion film and organic electroluminescence device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel rhodamine-based compound which is a fluorescent dye capable of converting blue light into red light with high conversion efficiency by combining a light emitting source such as an organic EL device and another fluorescent dye, Provided are a color conversion film which is excellent in UV properties and heat resistance and has high conversion efficiency, and an organic EL element capable of emitting red light with high efficiency. SOLUTION: A dye comprising a novel rhodamine compound having at least one cycloalkylalkane group as a steric hindrance group, a color conversion film comprising a resin in which a rhodamine dye is dispersed, and at least one organic compound layer comprising An organic EL device containing a rhodamine dye.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel rhodamine-based compound which is a fluorescent dye, a color conversion film, and an organic electroluminescence device (hereinafter, electroluminescence is abbreviated as "EL"). For more information,
A novel rhodamine-based compound, a color conversion film that is a fluorescent dye that can convert blue light to red light with high conversion efficiency when used in combination with a light emitting source such as an organic EL element and used in combination with a green or orange fluorescent dye And an organic EL device capable of emitting red light with high efficiency.

[0002]

2. Description of the Related Art An organic EL device is a completely solid-state device, has excellent visibility, can be reduced in weight and thickness, and can be driven at a low voltage of several volts. Therefore, research is currently being actively conducted. The biggest problem when using an organic EL element as a display is the development of a method for full-color display. In order to realize this full-color display, light emission of three primary colors of blue, green, and red must be finely arranged in a two-dimensional direction. Currently, the following methods have been proposed. Three-color array method Color filter method Color conversion film method

The above-mentioned method is a method of forming one color pixel by three pixels using light emission sources of three primary colors.
Since organic EL elements are difficult to perform wet patterning,
There is a disadvantage that it is difficult to produce a high-definition display. The above method uses a white light source and performs color conversion with a color filter to obtain three primary colors.
This method is easy to pattern, but has the disadvantage that the luminance of each color obtained is significantly lower than the luminance of the white light source. The above method is similar to the above method, but is characterized in that blue light is used as a light source. In this method, green and red light is emitted by the fluorescence of the dye excited by the blue light, which is the light source. Therefore, there is an advantage that loss of luminance is smaller than that of the color filter method. Under such circumstances, the present inventors have been studying full-color organic EL devices by the color conversion film method, but the conversion efficiency from blue to red is low and can be sufficiently satisfied. It was not something. On the other hand, it is actually difficult for an organic EL element to emit red light with high efficiency. Therefore, it has been desired to develop an organic EL element capable of emitting red light with high efficiency.

[0004]

Under such circumstances, the present invention can convert blue light, green light and orange light into red light with high conversion efficiency by combining with a light emitting source such as an organic EL element. An object of the present invention is to provide a novel rhodamine compound which is a fluorescent dye, a color conversion film having excellent UV resistance and heat resistance, high conversion efficiency, and an organic EL device capable of emitting red light with high efficiency. .

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, rhodamine-based dyes having a specific sterically hindered group have suppressed the association of the dye and have a concentration quenching. The color conversion film made of a resin in which such a rhodamine-based dye is dispersed can convert orange light to red light with high conversion efficiency, and at least one layer of the organic compound layer, It has been found that an organic EL device containing a rhodamine dye can emit red light with high efficiency. The present invention has been completed based on such findings. To convert blue light into red light, a dye such as a fluorescent dye that converts blue light into green light (for example, coumarin 6) and a fluorescent dye that converts green light into orange light (for example, rhodamine 6G) It is desirable to use a color conversion film in which a rhodamine-based compound that converts orange light into red light is dispersed in a resin. That is,
The present invention provides a color conversion film comprising a resin in which a rhodamine-based dye having at least one cycloalkylalkyl group as a steric hindrance group is dispersed, an organic EL device using the same, and at least a cycloalkylalkyl group useful as a fluorescent dye. Another object of the present invention is to provide a novel rhodamine-based compound. The cycloalkylalkane group is preferably a group in which a cycloalkyl group having 3 to 12 ring carbon atoms and an alkyl group having 1 to 18 carbon atoms are bonded. It is preferable that the resin is at least one selected from a urea resin, a benzoguanamine resin and a melamine resin. The resin may contain at least one selected from urea resin, benzoguanamine resin and melamine resin in the photoresist resin. The color conversion film in combination with the other colors, when combined with a light emitting source, allows the light of the light emitting source to be emitted from a short wavelength of 450 to 600 nm to 5 nm.
It is good for wavelength conversion to a long wavelength of 00 to 650 nm. In such a conversion film of a rhodamine-based dye alone, the wavelength of 500-600 nm light of the light emission source can be converted to a long wavelength of 550-650 nm. It is preferable that the light emitting source is an organic electroluminescence element. The organic EL device is an organic EL device including a pair of electrodes and an organic compound layer having at least an organic light emitting layer sandwiched between the electrodes.
In the L element, at least one of the organic compound layers preferably contains the rhodamine-based dye of the present invention.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The rhodamine dye used in the color conversion film and the organic EL device of the present invention needs to have at least one cycloalkylalkane group as a steric hindrance group. The rhodamine-based dye having such a sterically hindered group effectively suppresses the association of the dye and consequently suppresses the concentration quenching of the dye. Therefore, when used in a color conversion film or an organic EL device, the present invention provides Aim is achieved.
Among the rhodamine-based dyes having at least one cycloalkyl group, those represented by the general formula (I)

[0007]

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Compounds represented by the following formulas can be preferably mentioned. In the general formula (I), R ^{1 to} R ⁴ are each independently at least one unsubstituted or substituted cycloalkylalkane group having 4 to 20 carbon atoms, the remainder being a hydrogen atom, 1 to 1 carbon atoms. 32 cycloalkyl groups or unsubstituted or substituted nuclear carbon atoms having 6 to 24 carbon atoms
Is an aryl group. Here, examples of the cycloalkylalkane group having 4 to 20 carbon atoms include a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a cyclooctylmethyl group, a 2-cyclopentylethyl group, a 2-cyclohexylethyl group, and a 2-cyclohexylethyl group. Cyclooctylethyl group, 3-cyclobutylpropyl group, 3-cyclopentylpropyl group, 3-cyclohexylpropyl group,
3-cyclooctylpropyl group, 4-cyclooctylbutyl group, 6-cyclohexylhexyl group, 2- (4-methylcyclohexyl) ethyl group, 3- (4-methylcyclohexyl) propyl group, 3,5-dimethylcyclohexylmethyl group And the like. The substituents that may be introduced into the cycloalkylalkane group will be described later. The alkyl group having 1 to 32 carbon atoms may be linear or branched, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Groups, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, behenyl and the like. Examples of the aryl group having 6 to 24 carbon atoms include a phenyl group, a biphenyl group, a naphthyl group,
Anthranyl group, terphenyl group, pyrenyl group and the like can be mentioned. The substituents that may be introduced into the aryl group will be described later. R ⁵ is a hydrogen atom, an alkyl group having 1 to 32 carbon atoms, an unsubstituted or substituted cycloalkyl group having 3 to 12 ring carbon atoms, an unsubstituted or substituted aryl group having 6 to 24 nuclear carbon atoms. Group or aralkyl group. Here, the alkyl group having 1 to 32 carbon atoms, the cycloalkyl group having 3 to 12 ring carbon atoms, and the aryl group having 6 to 24 core carbon atoms are as described above. Examples of the aralkyl group having 6 to 24 carbon atoms include a benzyl group, a phenethyl group, a phenylpropyl group,
Examples include a naphthylmethyl group and a phenylbenzyl group.

The same substituent R ⁶ as R ⁵ may be introduced into the benzene ring to which —COOR ⁵ is bonded. The substituent and the substituent that may be introduced into the cycloalkylalkane group, the aryl group, and the aralkyl group are not particularly limited.
2 alkyl groups or alkoxy groups, cycloalkyl groups or cycloalkoxy groups having 3 to 12 ring carbon atoms, 6 carbon atoms
To 24 aryl groups or aryloxy groups, hydroxyl groups, amino groups, alkylamino groups, halogen groups (F,
Cl, Br, I), a nitro group, a cyano group, an alkylamide group, an arylamide group, a carboxyl group, an arylester group, an alkylester group, and a sulfone group. R ^{7 to} R ¹² are each independently a hydrogen atom or an alkyl group having 1 to 16 carbon atoms. A ⁻ represents a counter ion, for example, a halogen ion, a boron-containing complex ion, a metal complex ion, a peroxide ion and the like. Examples ^{F -, Cl -, Br -} , I
_{^{-, BF 4 -, BPh 4}} -, B (Ph-Cl) 4 -, B
(Ph-F) ₄ ⁻ , ZnCl ₄ ²⁻ , ClO ₄ ⁻ , IO ₄
^-

[0010]

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And the like. Ph represents a phenyl group. As another example having at least one cycloalkyl group, a compound represented by the general formula (II):

[0012]

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Compounds represented by the following formula (1) are preferred. In the general formula (II), R ^{1 to} R ^{4 and} R ⁶
To R ¹² are the same as those in the general formula (I). A ^- is the same as in the above general formula (I). Substituents which may be introduced into the cycloalkylalkane group, the aryl group and the aralkyl group are the same as those in the general formula (I). A novel rhodamine compound useful as the fluorescent dye of the present invention has the general formula (III)

[0014]

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## EQU1 ## In this general formula (III),
R ^{1 ′ to} R ^{4 ′} are each independently at least one unsubstituted or substituted cyclohexylmethyl group or a cyclohexylpropyl group, and the remainder is an alkyl group having 1 to 18 carbon atoms, or at least one is unsubstituted or A cyclohexylmethyl group or a cyclohexylpropyl group having a substituent. R ^{5 ′} is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, and A ⁻ is the same as in the above general formula (I). The substituents that may be introduced into the cycloalkylalkane group are the same as those in the general formula (I). Examples of the substituent which may be introduced into the cyclohexylmethyl group and the cyclohexylpropyl group include an alkyl group having 1 to 18 carbon atoms. Further, as another example of a novel rhodamine compound useful as the fluorescent dye of the present invention, a compound represented by the general formula (IV):

[0016]

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## EQU1 ## In this general formula (IV), R
^{1 ′} , R ^{2 ′} , R ^{3 ′} and R ^{4 ′} are the same as in the general formula (III), and A ⁻ is the same as in the general formula (I). The substituents that may be introduced into the cycloalkylalkane group, cyclohexylmethyl group and cyclohexylpropyl group are the same as those in the general formula (I). The rhodamine dye used in the present invention is characterized by having at least one cycloalkylalkane group as a steric hindrance group. It is generally known that when a dye is dispersed at a high concentration in a solution or a resin, an aggregate is formed between the dye molecules and the fluorescence is significantly reduced. This phenomenon is called concentration quenching. The present invention suppresses the above-mentioned undesirable phenomenon due to steric hindrance by introducing a cycloalkyl alkane group into a rhodamine dye molecule. Specific examples of the rhodamine dyes represented by the general formulas (I) to (IV) are shown below. In addition, Me:
Methyl group, Et: ethyl group, t-Bu: tert-butyl group, Ph: phenyl group.

[0018]

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[0019]

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[0020]

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[0021]

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The color conversion film of the present invention is composed of a resin in which the above-mentioned rhodamine dye according to the present invention, for example, a compound represented by any one of formulas (I) to (IV) is dispersed. Other dyes may be used in combination and dispersed. Examples of the dye other than the rhodamine dye according to the present invention include a coumarin dye, a perylene dye, a phthalocyanine dye, a stilbene dye, a cyanine dye, a polyphenylene dye, and other rhodamine dyes.
The total content of the dye in the resin is not particularly limited, but it is preferable that the dye be contained in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of the resin. The resin in which these dyes are dispersed is transparent (light transmittance in the visible light region is 50% or more).
A resin having a small coefficient of thermal expansion is preferable, and a photosensitive resin to which a photolithography method can be applied is preferable in order to pattern the color conversion film and dispose the color conversion film two-dimensionally. As a material that satisfies such conditions, for example, a photocurable resist material having a reactive vinyl group such as an acrylic acid type, a methacrylic acid type, a polyvinyl cinnamate type, and a ring rubber type may be used. When a printing method is used, a printing ink (medium) using a transparent resin is selected. For example, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic resin, oligomer or polymer of polyamide resin, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, Transparent resins such as hydroxyethyl cellulose and carboxymethyl cellulose can be used. Other examples include aromatic sulfonamide resins, urea resins, benzoguanamine resins, viridyl vinyl resins, and the like.

Among these resins, a urea resin, a benzoguanamine resin and a melamine resin are preferred from the viewpoint of coloring. In addition, the said resin may be used independently and may be used in combination of 2 or more type. The color conversion film of the present invention is formed by dispersing the above-described dye in a resin and forming the same on a light-transmitting substrate, but the film forming method is not particularly limited. Specifically, a casting method, a spin coating method, a coating method, a vapor deposition method, an electrolytic method, a printing method and the like can be mentioned, but a spin coating method is generally preferred. The film thickness of the color conversion film formed by the above method needs to be appropriately selected from the film thickness required to convert incident light into a desired wavelength, but is preferably in the range of 1 to 100 μm. More preferably, it is selected in the range of 1 to 20 μm.

The light-transmitting substrate used for forming the color conversion film of the present invention may be a smooth substrate having a light transmittance of 50% or more in a visible light region of 400 to 700 nm of 50% or more. preferable. Specific examples include a glass substrate and a polymer plate. Glass plates include soda-lime glass, barium / strontium-containing glass, lead glass,
Examples include aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic resin, polyethylene terephthalate, polyether sulfide, and polysulfone.

The color conversion film of the present invention is preferably used for wavelength conversion of light from the light emitting source by being combined with a light emitting source, and the light source is not particularly limited. Diode), cold-cathode tube,
Examples thereof include an inorganic EL element, a fluorescent lamp, an incandescent lamp, and sunlight, and among these, an organic EL element is preferable. That is, it is advantageous to use the color conversion film of the present invention when a display using an organic EL element is made full-color.
When the color of the light emitting source is wavelength-converted by the color conversion film of the present invention, a color filter may be additionally provided depending on a desired wavelength to adjust the color purity. Such color filters include, for example, perylene pigments, lake pigments,
Azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone pigments, indophenol pigments, Examples of the pigment include a single pigment such as a cyanine pigment and a dioxazine pigment, and a pigment only composed of a mixture of at least two or more pigments, or a solid pigment in which the pigment is dissolved or dispersed in a binder resin. The configuration using the color conversion film of the present invention includes the following examples. (1) Light source / color conversion film (2) Light source / light transmission substrate / color conversion film (3) Light source / color conversion film / light transmission substrate (4) Light source / light transmission substrate / color conversion film / light transmission (5) Light source / color conversion film / color filter (6) Light source / light-transmitting substrate / color conversion film / color filter (7) Light source / color conversion film / light-transmitting substrate / color filter (8) light source / Transparent substrate / color conversion film / transparent substrate / color filter (9) Light source / transparent substrate / color conversion film / color filter / transparent substrate (10) Light source / color conversion film / color filter / transparent Optical substrate

In the case of manufacturing the above-described structure, the respective components may be sequentially laminated or bonded. Also,
In the case of manufacturing, there is no particular limitation on the order, and in the above configuration, the order may be left to right or right to left. Next, the organic EL device of the present invention will be described. The organic EL device of the present invention is a device in which the above-mentioned rhodamine dye according to the present invention is contained in at least one layer of an organic compound layer having at least an organic light emitting layer sandwiched between a pair of electrodes. Organic EL containing the dye
When the device is manufactured, there is no particular limitation on the configuration, material, and the like, and the device may be manufactured in accordance with the configuration, material, and the like when an organic EL device is manufactured.

The constitution of the organic EL device of the present invention includes, for example, anode / light-emitting layer / cathode anode / hole injection layer / light-emitting layer / cathode anode / light-emitting layer / electron injection layer / cathode anode / hole injection layer / light emission Layer / electron injection layer / cathode anode / organic semiconductor layer / light emitting layer / cathode anode / organic semiconductor layer / electron barrier layer / light emitting layer / cathode anode / organic semiconductor layer / light emitting layer / adhesion improving layer / cathode anode / hole injection Layer / hole transport layer / light-emitting layer / electron injection layer / cathode, etc. Among them, a normal structure is preferably used. Rhodamine dyes according to the present invention,
It is necessary that at least one of the organic compound layers in these structures be contained. The content is 0.0 based on the total amount of organic compounds in the layer containing the rhodamine dye.
1 to 50 mol% is preferable, and 0.01 to 10 mol% is particularly preferable.

Translucent substrate: The organic EL device of the present invention is manufactured on a translucent substrate. This translucent substrate is made of the organic E
It is preferable that the substrate which supports the L element has a transmittance of light of at least 50% in a visible light region of 400 to 700 mm and a smooth surface. Specific examples include a glass plate and a polymer plate. As the glass plate, in particular, soda-lime glass, glass containing barium and strontium,
Lead glass, aluminosilicate glass, borosilicate glass,
Barium borosilicate glass, quartz and the like can be mentioned. Examples of the polymer plate include polycarbonate, acrylic resin, polyethylene terephthalate, polyether sulfide, and polysulfone.

Anode: As the anode, a metal, an alloy, an electrically conductive compound, or a mixture thereof having a large work function (4 eV or more) is preferably used as an electrode material. Specific examples of such an electrode material include metals such as Au, CuI, ITO (indium tin oxide), S
Conductive materials such as nO ₂ and ZnO can be used. And
The anode can be manufactured by forming a thin film from these electrode substances by a method such as an evaporation method or a sputtering method. When the light emission of the light emitting layer is extracted from the anode formed in this way, the transmittance of the anode with respect to the light emission is set to 10%.
%. Similarly, the sheet resistance of the anode is preferably several hundred Ω / □ or less. In order to ensure the above-mentioned performance, the thickness of the anode is selected in the range of usually 10 nm to 1 μm, preferably 10 to 200 nm, although it depends on the material of the anode.

Light emitting layer: The light emitting layer of the organic EL device has the following functions. That is, an injection function; a function of injecting holes from an anode or a hole injection layer when an electric field is applied, and of injecting electrons from a cathode or an electron injection layer. Transport function; injected charges (electrons and holes) The function of moving an electron by the force of an electric field Emitting function; It provides a field for recombination of electrons and holes, and has a function of connecting it to light emission. However, there may be a difference between the ease of injecting holes and the ease of injecting electrons, and the transportability represented by the mobility of holes and electrons may be large or small. It is preferable to transfer charges. Next, the light emitting material of the light emitting layer of the organic EL element is mainly an organic compound, and a compound to be used is selected according to a desired color tone. From this viewpoint, the relationship between the color tone and the compound is specifically classified as follows.
First, when obtaining violet light emission from the ultraviolet region, a compound represented by the following general formula may be mentioned.

[0031]

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In this general formula, X represents the following groups.

[0033]

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Here, m is an integer of 2 to 5. Also Y
Represents a phenyl group or a naphthyl group. The groups represented by X and Y, ie, phenylene, phenyl, and naphthyl are alkyl, alkoxy, hydroxyl, sulfonyl, carbonyl, amino, dimethylamino, diphenylamino groups having 1 to 4 carbon atoms. May be substituted singly or plurally. Further, they may combine with each other to form a saturated 5-membered ring or 6-membered ring. Further, a phenyl group, a phenylene group, or a naphthyl group bonded at the para position is preferable for forming a smooth vapor-deposited film because it has good binding to a light-transmitting substrate. Specifically, they are the following compounds. In particular, p-quarter phenyl derivatives and p-quink phenyl derivatives are preferred.

[0035]

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Next, in order to obtain blue to green light emission, for example, benzothiazole-based, benzimidazole-based, benzoxazole-based fluorescent whitening agents, metal-chelated oxinoid compounds, and styrylbenzene-based compounds can be mentioned. . Specific examples of the compound name include those disclosed in JP-A-59-194393. In addition, other useful compounds are described in Chemistry of Synthetic Soy, 1971,62.
Listed on pages 8-637 and 640. Examples of the chelated oxinoid compounds include, for example,
The one disclosed in JP-A-3-295695 can be used. Typical examples thereof include 8-hydroxyquinoline-based metal complexes such as tris (8-quinolinol) aluminum (hereinafter abbreviated as Alq) and dilithium epinetridione. Examples of the styrylbenzene compound include, for example, European Patent No. 0319.
881 and EP 0 375 582 can be used.

Further, a distyrylpyrazine derivative disclosed in JP-A-2-252793 can also be used as a material for the light emitting layer. As other materials, for example, a polyphenyl-based compound disclosed in European Patent No. 0377715 can also be used as a material for the light-emitting layer. Further, in addition to the above-described fluorescent brightener, metal chelated oxinoid compound, styrylbenzene-based compound and the like, for example, 12-phthaloperinone (J. Appl.
hys., Vol. 27, L713 (1988)), 1, 4
-Diphenyl-1,3-butadiene, 1,1,4,4-
Tetraphenyl-1,3-butadiene (Appl.
Phys. Lett., Vol. 56, L799 (1990)
Year)), a naphthalimide derivative (JP-A-2-30588)
No. 6), perylene derivatives (JP-A-2-189890)
), Oxadiazole derivatives (JP-A-2-216)
No. 791, or an oxadiazole derivative disclosed by Hamada et al. At the 38th Lecture Meeting on Applied Physics, an aldazine derivative (JP-A-2-220393), and a pyrazirine derivative (JP-A-2-220394). ), Cyclopentadiene derivatives (JP-A-2-2896)
No. 75), pyrrolopyrrole derivatives (JP-A-2-29)
No.6891), styrylamine derivatives (Appl.
Phys. Lett., Vol. 56, L799 (1990)
Coumarin compounds (JP-A-2-191694), International Patent Publication WO90 / 13148 and Appl.
Phys. Lett., Vol 58, 18, P1982.
(1991) can also be used as a material for the light emitting layer. In the present invention, particularly, as a material for the light emitting layer, an aromatic dimethylidin-based compound (European Patent No. 0388768 or Japanese Unexamined Patent Application Publication No.
It is preferable to use those disclosed in JP-A-231970). As a specific example, 4,4′-bis (2,2-di-
t-butylphenylvinyl) biphenyl, (hereinafter DT)
BPBBi), 4,4'-bis (2,2-diphenylvinyl) biphenyl (hereinafter abbreviated as DPVBi), and the like, and derivatives thereof.

Further, Japanese Patent Application Laid-Open No. Hei 5-258862 discloses
General formula (Rs-Q) described _Two-Al-OL
In the above formula, L is phenyl
A hydrocarbon comprising 6 to 24 carbon atoms comprising
Where OL is a phenolate ligand and Q is a substituted 8-
Represents a quinolinolate ligand, and Rs is an aluminum atom
Has more than two substituted 8-quinolinolato ligands
8-quinolinola chosen to sterically hinder
Represents a ring substituent). Specifically, bis (2-methyl
-8-quinolinolate) (para-phenylphenolate)
G) Aluminum (III) (hereinafter PC-7), screws
(2-Methyl-8-quinolinolate) (1-Naphtholar
G) Aluminum (III) (hereinafter PC-17)
I can do it.

In addition, there is a method of obtaining highly efficient mixed emission of blue and green using doping according to Japanese Patent Application Laid-Open No. 6-9953. In this case, as the host, the above-mentioned luminescent material can be used, and as the dopant, a strong fluorescent dye from blue to green, for example, a coumarin-based fluorescent dye or a fluorescent dye similar to that used as the above-mentioned host can be used. Specifically, as a host, a luminescent material having a distyrylarylene skeleton, particularly preferably DP
As VBi and the dopant, diphenylaminovinylarylene, particularly preferably, for example, N, N-diphenylaminovinylbenzene (DPAVB) can be mentioned. The light-emitting layer that emits white light is not particularly limited, and examples thereof include the following. A white light-emitting element is described as an example of an element using tunnel injection similarly to an element that specifies the energy level of each layer of the organic EL laminated structure and emits light using tunnel injection (European Patent No. 0390551). (Japanese Unexamined Patent Application Publication No. 3-2)
Japanese Patent Application Laid-Open No. 30584/1990 describes a light emitting layer having a two-layer structure.
Japanese Patent Application Laid-Open No. 220390 and Japanese Patent Application Laid-Open No. 216790/1990 The light-emitting layer is divided into a plurality of layers and made of materials having different emission wavelengths (Japanese Patent Application Laid-Open No. 4-51491). Blue light emitter (fluorescence peak 380 to 480 nm) And a green light-emitting material (480-580 nm) laminated thereon and further containing a red phosphor (JP-A-6-207).
No. 170) A structure in which a blue light-emitting layer contains a blue fluorescent dye, a green light-emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (JP-A-7-142169) The above configuration is preferably used. Further, as the red phosphor, it is preferable to use the rhodamine-based dye according to the present invention, but other substances can also be used in combination. Examples of red phosphors other than the rhodamine dye according to the present invention are shown below.

[0040]

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As a method for forming a light emitting layer using the above-mentioned materials, a known method such as a vapor deposition method, a spin coating method, and an LB method can be applied. The light emitting layer is particularly preferably a molecular deposition film. This molecular deposition film is a thin film formed by deposition from a material compound in a gaseous state, or a film formed by solidification from a material compound in a solution state or a liquid phase state. And the thin film (accumulated molecular film) formed by the LB method can be classified according to the difference in the aggregation structure and the higher-order structure and the functional difference caused by the difference. Further, as disclosed in JP-A-57-51781, after a binder such as a resin and a material compound are dissolved in a solvent to form a solution, the solution is formed into a thin film by a spin coating method or the like. Also, a light emitting layer can be formed. The thickness of the light emitting layer formed in this manner is not particularly limited and can be appropriately selected depending on the situation, but is usually preferably in the range of 5 nm to 5 μm. The light-emitting layer may be composed of one or more of the above-mentioned materials, or may be a laminate of light-emitting layers made of a compound different from the light-emitting layer.

Hole injection layer: Next, the hole injection layer is not always necessary for the device of the present invention, but is preferably used for improving the light emitting performance. This hole injection layer is a layer that facilitates and facilitates the injection of holes into the light emitting layer, has a high hole mobility, and a small ionization energy of usually 5.5 eV or less. As such a hole injecting layer, a material that transports holes to the light emitting layer with a lower electric field strength is preferable, and the mobility of holes is, for example, 10 ⁴ to 10
^When an electric field of ⁶ V / cm is applied, at least 10 ⁻⁶ cm ² /
V · sec is preferred. Such a hole injecting material is not particularly limited as long as it has the above-mentioned preferable properties, and a material commonly used as a charge transporting material for holes in a photoconductive material and a positive electrode material of an EL element have been conventionally used. Any one of known materials used for the hole injection layer can be selected and used.

As specific examples, for example, a triazole derivative (see US Pat. No. 3,112,197), an oxadiazole derivative (see US Pat. No. 3,189,447, etc.), an imidazole derivative (Japanese Patent Publication No. Sho 37) -16
No. 096, etc.) and polyarylalkane derivatives (U.S. Pat. Nos. 3,615,402 and 3,82).
Nos. 0,989, 3,542,544, JP-B-45-555, JP-B-51-10983, JP-A-51-93224, and 55-171.
Nos. 05, 56-4148, 55-108
Nos. 667 and 55-15653 and 56-
No. 36656), pyrazoline derivatives and pyrazolone derivatives (U.S. Pat. Nos. 3,180,729 and 4,278,746; JP-A-55-8).
Nos. 8064, 55-88065, 49-
Nos. 105537, 55-51086 and 5
JP-A-6-80051, JP-A-56-88141, JP-A-57-45545, JP-A-54-112637, JP-A-55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404) Specification, JP-B-51-10105, 46-3712
JP-A-47-25336, JP-A-54-53
No. 435, No. 54-110536, No. 54-
No. 119925), arylamine derivatives (U.S. Pat. Nos. 3,567,450 and 3,1).
Nos. 80,703, 3,240,597, 3,658,520 and 4,23
2,103, 4,175,961, 4,012,376, JP-B-49-3
5702, 39-27577 and JP-A-5
JP-A-5-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,11
0,518), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501),
Oxazole derivatives (those disclosed in U.S. Pat. No. 3,257,203), styryl anthracene derivatives (see JP-A-56-46234, etc.), and fluorenone derivatives (see JP-A-54-110837, etc.) ),
Hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143, and JP-A-55-520)
Nos. 63, 55-52064 and 55-46.
760, 55-85495, 57-1
1350, 57-148749, JP-A-2-311591, etc.), stilbene derivatives (JP-A-61-210363, 61-228)
No. 451, No. 61-14642, No. 61-7
Nos. 2255, 62-47646 and 62-
36674, 62-10652, 62
-30255, 60-93455, 6
JP-A-0-94462, JP-A-60-174747,
No. 60-175052), silazane derivatives (U.S. Pat. No. 4,950,950), polysilanes (JP-A-2-204996), and aniline-based copolymers (JP-A-2-282263). Gazette),
Conductive polymer oligomers (especially thiophene oligomers) disclosed in Japanese Patent Application Laid-Open No. 211399 can be used.

As the material for the hole injection layer, those described above can be used.
No. 3,295,965, etc.), aromatic tertiary amine compounds and styrylamine compounds (U.S. Pat. No. 4,127,412, JP-A-53-2703).
No. 3, No. 54-58445, No. 54-149
Nos. 634, 54-64299, 55-7
9450, 55-144250, 56
JP-119132, JP-A-61-295558,
JP-A-61-98353, JP-A-63-295695, etc.), and it is particularly preferable to use an aromatic tertiary amine compound. In addition, for example, 4,4′-bis (N- (1-naphthyl) -N having two condensed aromatic rings described in US Pat. No. 5,061,569 in a molecule.
-Phenylamino) biphenyl (hereinafter abbreviated as NPD) and 4,4 ', 4 "-tris in which three triphenylamine units described in JP-A-4-308688 are connected in a star-burst form. (N- (3-
Methylphenyl) -N-phenylamino) triphenylamine (hereinafter abbreviated as MTDATA) and the like.

Further, in addition to the above-mentioned aromatic dimethylidin compound shown as a material for the light emitting layer, p-type Si, p-type
An inorganic compound such as SiC can also be used as a material for the hole injection layer. The hole injection layer can be formed by thinning the above-mentioned compound by a known method such as a vacuum evaporation method, a spin coating method, a casting method, and an LB method. The thickness of the hole injection layer is not particularly limited, but is usually 5 nm to 5 μm. This hole injection layer is
It may be composed of one or more layers of the above-mentioned materials, or may be a layer obtained by laminating a hole injection layer made of a compound different from the hole injection layer.
The organic semiconductor layer facilitates and facilitates the injection of holes or electrons into the light-emitting layer, and preferably has a conductivity of 10 ⁻¹⁰ S / cm or more. As a material for such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer or an arylamine-containing oligomer disclosed in JP-A-8-193191, or a conductive dendrimer such as an arylamine-containing dendrimer is used. be able to.

Electron injection layer: The electron injection layer is a layer which assists the injection of electrons into the light-emitting layer, has a high electron mobility, and the adhesion improving layer is one of the electron injection layers, particularly the one which adheres to the cathode. Is a layer made of a good material. As a material used for the electron injection layer, a metal complex of 8-hydroxyquinoline or a derivative thereof is preferable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include a metal chelate oxinoid compound containing a chelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline). For example, A described in the section of the luminescent material
lq can be used as the electron injection layer. On the other hand, examples of the oxadiazole derivative include an electron transfer compound represented by the following general formula.

[0047]

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(Wherein Ar ¹ , Ar ² , Ar ³ , Ar ⁵ ,
Ar ⁶ and Ar ⁹ each represent a substituted or unsubstituted aryl group, which may be the same as or different from each other. Ar ⁴ , Ar ⁷ , and Ar ^{8 each} represent a substituted or unsubstituted arylene group, which may be the same or different. Here, the aryl group is a phenyl group, a biphenyl group,
Examples include an anthranyl group, a perylenyl group, and a pyrenyl group. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, an anthranylene group, a perylenylene group, a pyrenylene group, and the like. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a cyano group. This electron transfer compound is preferably a thin film-forming compound. Specific examples of the electron transfer compound include the following.

[0049]

Embedded image

The electron injection layer can be formed by thinning the above-mentioned compound by a known method such as a vacuum evaporation method, a spin coating method, a casting method, and an LB method. The thickness of the electron injection layer is not particularly limited,
Usually, it is 5 nm to 5 μm. The electron injection layer may be composed of one layer or one or more of the above-mentioned materials, or may be an electron injection layer formed of a compound different from the electron injection layer. .

Cathode: The cathode has a small work function (4
eV or less) A metal, an alloy, an electrically conductive compound, and a mixture thereof are used as an electrode material. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium-silver alloy, aluminum / aluminum oxide, aluminum-lithium alloy, indium, and rare earth metals. The cathode can be manufactured by forming a thin film from these electrode materials by a method such as evaporation or sputtering. Here, when light emission from the light emitting layer is taken out from the cathode, the transmittance for the light emission of the cathode is 10%.
%. Further, the sheet resistance as the cathode is preferably several hundred Ω / □ or less, and
It is preferably from 0 nm to 1 μm, more preferably from 50 to 200 nm.

Example of manufacturing an organic EL device: An anode, a light emitting layer, a hole injection layer and / or an electron injection layer as necessary are formed by the materials and methods exemplified above, and an organic material is formed by forming a cathode. An EL element can be manufactured. In addition, from the cathode to the anode, the organic EL is reversed in the order described above.
An element can also be manufactured. Hereinafter, an example of manufacturing an organic EL element having a structure in which an anode / a hole injection layer / a light emitting layer / an electron injection layer / a cathode is provided in this order on a light-transmitting substrate will be described. First, a thin film made of an anode material is formed to a thickness of 1 μm or less, preferably 1 μm, on a suitable translucent substrate by a method such as evaporation or sputtering.
The anode is formed so as to have a thickness in the range of 0 to 200 nm. Next, a hole injection layer is provided on the anode.
As described above, the hole injection layer can be formed by a vacuum deposition method, a spin coating method, a casting method, an LB method, or the like, but a uniform film is easily obtained and pinholes are not easily generated. From the viewpoint of the above, it is preferable to form by a vacuum evaporation method. When the hole injection layer is formed by a vacuum evaporation method, the deposition conditions vary depending on the compound to be used (the material of the hole injection layer), the crystal structure and the recombination structure of the target hole injection layer, etc. Source temperature 50 to 450 ° C., degree of vacuum 10 ⁻⁷ to 10 ⁻³ torr, deposition rate 0.01 to 50
nm / sec, substrate temperature -50 to 300 ° C, film thickness 5 nm to 5
It is preferable to appropriately select within the range of μm.

Next, the formation of the light emitting layer in which the light emitting layer is provided on the hole injecting layer is also performed by a vacuum evaporation method using a desired organic light emitting material.
It can be formed by thinning the organic light-emitting material by a method such as sputtering, spin coating, or casting, but is formed by a vacuum evaporation method from the viewpoint that a uniform film is easily obtained and pinholes are hardly generated. Is preferred. When the light emitting layer is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used, but can be generally selected from the same condition range as the hole injection layer.

Next, an electron injection layer is provided on the light emitting layer. Like the hole injection layer and the light emitting layer, it is preferable to form the film by a vacuum deposition method from the viewpoint of obtaining a uniform film. The deposition conditions can be selected from the same condition ranges as for the hole injection layer and the light emitting layer. The specific rhodamine-based dye which is a feature of the present invention differs depending on which layer is contained,
When a vacuum evaporation method is used, co-evaporation with another material can be performed. When the spin coating method is used, it can be contained by mixing with another material.
Finally, a cathode is laminated to obtain an organic EL device. The cathode is made of a metal, and an evaporation method or sputtering can be used. However, in order to protect the underlying organic layer from damage such as heat during film formation, a vacuum deposition method is preferable. It is preferable that the organic EL element is manufactured by sequentially laminating under vacuum without contacting with the outside air from the formation of the anode to the formation of the cathode. In addition, organic EL
When a DC voltage is applied to the device, light emission can be observed when a voltage of 5 to 40 V is applied with the anode having a positive polarity and the cathode having a negative polarity. Does not occur at all. Furthermore, when an AC voltage is applied, uniform light emission is observed only when the anode has a positive polarity and the cathode has a negative polarity. The waveform of the applied alternating current may be arbitrary.

[0055]

Next, the present invention will be described in more detail with reference to Synthesis Examples and Examples, but the present invention is not limited to these Examples. Synthesis Example 1 (Synthesis of Rh-101 closed-ring form) 3- [N-cyclohexylmethyl-N-methyl] aminophenol (2 parts by weight), zinc chloride (0.76 parts by weight)
, Phthalic anhydride (0.7 parts by weight) were mixed in this order,
The mixture was stirred at 170 ° C. for 5 hours. After cooling to room temperature, the reaction mixture was dissolved in methanol (70 parts by weight), filtered, and the filtrate was concentrated to obtain a dark red solid. This solid is dissolved in toluene (30
Parts by weight), water (50 parts by weight) and 48% caustic soda (5 parts by weight) and stirred at 80 ° C. for 3 hours. After cooling to room temperature, the toluene layer was concentrated to obtain crude rhodamine. The obtained crude rhodamine was purified by silica gel column chromatography to obtain 1.8 parts by weight (yield: 38%) of pale purple target compound Rh-101. As a result of mass spectrometry, the obtained mass was MS (field desorption mass spectrum) = 551 (m / z) (M ⁺ -99). Table 1 shows the yield and analysis results. FIG. 1 shows the NMR spectrum of Rh-101.

Synthesis Examples 2 to 10 (Rh-102 to Rh-1)
10) In Synthesis Example 1, 3- [N-cyclohexylmethyl-
The target compound was obtained in the same manner except that N-substituted and N-substituted aminophenols shown in Table 1 were used instead of [N-methyl] aminophenol. Table 1 shows the yield and analysis results.

Synthesis Example 11 (Rh-111 carboxylic acid C
Synthesis of 10 ₄ salt) 3- [N-cyclohexylmethyl-N-methyl] aminophenol (2 parts by weight) and phthalic anhydride (1.5 parts by weight) were mixed with zinc chloride (1 part by weight), 160
Stirred at C for 6 hours. After cooling to room temperature, the reaction mixture was dissolved in methanol (85 parts by weight), filtered, and the filtrate was concentrated to obtain a dark red solid. This solid was mixed with toluene (40 parts by weight), water (70 parts by weight), and 48% caustic soda (7 parts by weight) and stirred at 80 ° C. for 2 hours. After cooling to room temperature, the toluene layer was separated and concentrated to obtain crude rhodamine as a dark brown solid. 35 parts by weight of methanol and 7 parts by weight of a 60% aqueous solution of perchloric acid were added to the obtained crude rhodamine, and the mixture was stirred for 12 hours. Concentrate the reaction mixture and add water 150
Parts by weight were added dropwise. The generated precipitate is separated by filtration under reduced pressure,
Drying at 60 ° C. provided the target compound Rh-111, a perchlorate of rhodamine, as a dark red solid (1.75 parts by weight, 61% yield). As a result of mass spectrometry, the obtained mass was MS = 552 (m / z) (M ⁺ -99). Table 2 shows the yield and analysis results. NM of Rh-111
The R spectrum is shown in FIG.

Synthesis Examples 12 to 19 (Rh-112 to Rh-
119) In the same manner as in Synthesis Example 11, except that N-substituted and N-substituted aminophenols shown in Table 2 were used instead of 3- [N-cyclohexylmethyl-N-methyl] aminophenol, the target compound was obtained. I got Table 1 shows the yield and analysis results.

Synthesis Example 20 (Synthesis of Rh-120 carboxylate ClO ₄ salt) 3- [N-cyclohexylmethyl-N-methyl] aminophenol (2 parts by weight) and phthalic anhydride (1.5 parts by weight) Mix with zinc chloride (1 part by weight)
Stirred at C for 6 hours. After cooling to room temperature, the reaction mixture was dissolved in methanol (85 parts by weight), filtered, and the filtrate was concentrated to obtain a dark red solid. This solid was mixed with toluene (40 parts by weight), water (70 parts by weight), and 48% caustic soda (7 parts by weight) and stirred at 80 ° C. for 2 hours. After cooling to room temperature, the toluene layer was separated and concentrated to obtain crude rhodamine as a dark brown solid. The obtained crude rhodamine was dissolved in 1-dodecanol (5.5 parts by weight), and hydrogen chloride gas was passed at 145 ° C for 20 minutes. After stirring for 2 hours, the reaction mixture was cooled, diluted with 150 parts by weight of chloroform, and washed with water. The organic layer was separated and concentrated to dryness to obtain a crude ester. 34 parts by weight of methanol and a 60% aqueous solution of perchloric acid (7 parts by weight) were added to the obtained crude rhodamine ester, and the mixture was stirred for 12 hours. The reaction mixture was concentrated, and 150 parts by weight of water was added dropwise. The resulting precipitate was separated by filtration under reduced pressure, and purified by silica gel column chromatography to obtain the desired compound Rh-120 (1.4 parts by weight, yield: 38%).
As a result of mass spectrometry, the mass obtained was MS = 720 (m / m
z) (M ⁺ -99). Table 2 shows the yield and analysis results.
Shown in FIG. 3 shows the NMR spectrum of Rh-120.

Synthesis Examples 21 to 32 (Rh-121 to Rh-
132) The target compound was prepared in the same manner as in Synthesis Example 20 except that N-substituted and N-substituted aminophenols shown in Table 3 were used instead of 3- [N-cyclohexylmethyl-N-methyl] aminophenol. I got Table 2 shows the yield and analysis results.

Synthesis Example 33 (Synthesis of Rh-133 carboxylate Cl salt) In Synthesis Example 10, 1 part by weight of the obtained crude rhodamine was dissolved in 1-dodecanol (5.5 parts by weight), and hydrogen chloride gas was added. It was aerated at 145 ° C. for 20 minutes. After stirring for 2 hours, the reaction mixture was cooled, diluted with 150 parts by weight of chloroform, and washed with water. The organic layer was separated and concentrated to dryness to obtain a crude ester. The obtained crude rhodamine ester was purified by silica gel column chromatography to obtain the desired compound Rh-133 (2.1 parts by weight, yield 42%). As a result of mass spectrometry, the obtained mass was MS = 997 (m / z).
(M ⁺ -99). Table 4 shows the yield and analysis results.

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 4]

Example 1 (Preparation and evaluation of color conversion film) In a sample bottle, 3 mmol of Rh-101 was added as a dye, and benzoguanamine resin (manufactured by Schinloich) 1.0
g, 4.0 g of an acrylic photosensitive resin (V259PA: manufactured by Nippon Steel Chemical Co., Ltd.) and 1 g of propylene glycol-1-monomethyl ether-2-acetate were added, stirred and dissolved. Put a few drops of this solution on a commercial slide glass,
20 at a rotation speed of 700 rpm using a spin coater.
The film was formed by rotating a slide glass (2.5 cm × 5 cm) for seconds. This was dried on a hot plate at 80 ° C. for 15 minutes to produce a color conversion film. The thickness of the produced color conversion film was measured using a surface roughness meter (DEKTAK3030). A few drops of an inert liquid Fluorinert (manufactured by 3M) are applied on the glass substrate of the organic EL device, and a color conversion film is superimposed on the substrate of the organic EL device.
The L element is driven to emit light, and the luminance and chromaticity (CIE chromaticity coordinates) of the light transmitted through the color conversion film are measured with a chromaticity meter (CS10 manufactured by Minolta).
0).

Then, the color conversion efficiency was calculated by the following equation by comparing the measured value of the luminance of the light when the color conversion film was not overlapped with the organic EL element. Color conversion efficiency (%) = (E1 / E0) × 100 (E1 in the expression indicates the luminance (nit) of transmitted light when the color conversion films are superimposed, and E0 does not superimpose the color conversion films. The luminance (nit) of the transmitted light at the time is shown.) As a result,
At the film thickness of 24.1 μm, the luminance after conversion was 21 nit, the conversion efficiency was 52%, and the chromaticity coordinates were (0.659, 0.330). Table 5 shows the results. The light emission luminance and CIE chromaticity coordinates of the orange organic EL element serving as a light source are 40 n.
It, (0.586, 0.405) was used.

Examples 2 to 38 (Production and Evaluation of Color Conversion Film) In Example 1, Rh-10 was used instead of Rh-101.
A color conversion film was prepared in the same manner except that 2-Rh-138 was used, and the luminance and chromaticity of transmitted light of the color conversion film were measured.
The color conversion efficiency was calculated. The fluorescence wavelength and relative peak intensity of the color conversion film were measured using a fluorescence spectrophotometer. Tables 5 and 6 show these results.

Comparative Example 1 (Production and Evaluation of Color Conversion Film) In the same manner as in Example 1, except that Rhodamine Bbase (manufactured by Aldrich: CAS No. 509-34-2) was used instead of Rh-101. A color conversion film was prepared, and the luminance and chromaticity of light transmitted through the color conversion film were measured, and the color conversion efficiency was calculated. Table 6 shows the results. As shown in the table,
When the conversion efficiency is almost the same as in the embodiment, the Y coordinate of the chromaticity is large and the peak intensity of light emission is small.

Comparative Example 2 (Preparation and Evaluation of Color Conversion Film) A color conversion film was prepared in the same manner as in Example 1 except that Rhodamine B (manufactured by BASF: BASONYL RED560) was used instead of Rh-101. Then, the luminance and chromaticity of the light transmitted through the color conversion film were measured, and the color conversion efficiency was calculated. Table 6 shows the results. As shown in the table,
The conversion efficiency is lower and the peak intensity of the fluorescence is lower than in the examples.

[0071]

[Table 5]

[0072]

[Table 6]

As described above, the first to third embodiments according to the present invention are described.
The color conversion film of No. 8 has a significantly higher color conversion efficiency and chromaticity than the conventional color conversion films using Rhodamine B dyes of Comparative Examples 1 and 2 by using a dye having a cyclohexylalkyl substituent. are doing. For this reason, the red conversion efficiency was greatly improved.

Examples 39 to 41 The color conversion films produced in Examples 1, 18, and 30 and Comparative Example 2 were irradiated with UV (1500 mJ / cm ² ) and further heated at 160 ° C. for 2 hours. For these samples, the change in the emission peak intensity was measured using a fluorescence spectrophotometer. Table 7 shows the results.

[Table 7] As shown in the table, the color conversion films of the examples were excellent in UV resistance and heat resistance as compared with the comparative examples.

Example 42 (Production of Organic EL Element) First, a transparent anode of indium tin oxide coated on glass was provided. About 75 indium tin oxide
0 Angstroms thick and the glass is (25 mm
× 75 mm × 1.1 mm). This was put into a vacuum evaporation system (manufactured by Japan Vacuum Engineering Co., Ltd.) and
The pressure was reduced to 0 ^-6 torr. Next, the following MTDATA is
Deposited to a thickness of 00 Å. The deposition rate at this time was 2 Å / sec. Next, the following NP
D was deposited to a thickness of 200 angstroms. The deposition rate at this time was 2 Å / sec. Next, the following Alq and Rh-101 were co-deposited to form 400
A light emitting layer having a thickness of Å was formed. At this time, the deposition rate of Alq was 50 angstroms / second,
The deposition rate of Rh-101 was 1 Å / sec. Further, only Alq was deposited at a deposition rate of 2 Å / sec. Finally, a cathode was formed with a thickness of 2000 Å by co-evaporating magnesium and silver. At this time, the deposition rate of magnesium is 20
Å / sec, and the silver deposition rate was 1 Å / sec. When a voltage of 8 V was applied to the obtained element, a current density was 3.4 mA / cm ² and red light emission with a luminance of 100 nit was obtained. Luminous efficiency is 1.2
Lumen / W.

MTDATA

Embedded image

NPD

Embedded image

Alq

Embedded image

Comparative Example 4 An organic EL device was manufactured in the same manner as in Example 1, except that Rhodamine Bbase was used instead of Rh-101. When a voltage of 8 V was applied to the obtained element, the current density was 14.5 mA / cm ² and the luminance was 88 nit.
It was red light emission. The luminous efficiency was 0.24 lumen / W.

[0080]

Since the rhodamine compound and the novel rhodamine compound contained in the color conversion film of the present invention have at least one cycloalkylalkane group as a steric hindrance group, the association of the dye is effectively suppressed. And the concentration quenching is suppressed. For this reason, by combining a light emitting source such as an organic EL element and another fluorescent dye, blue light, green light and orange light can be converted into red light with high conversion efficiency. A color conversion film using these rhodamine-based compounds is resistant to U
Excellent in V properties and heat resistance, and high in conversion efficiency. Further, the organic EL device of the present invention in which the above rhodamine-based compound is contained in at least one of the organic compound layers can emit red light with high efficiency.

[Brief description of the drawings]

FIG. 1 shows a compound Rh-10 synthesized in Synthesis Example 1.
FIG. 2 is a diagram showing an NMR spectrum of Sample No. 1.

FIG. 2 shows a compound Rh-1 synthesized in Synthesis Example 11.
It is a figure which shows the NMR spectrum of No. 11.

FIG. 3 shows a compound Rh-1 synthesized in Synthesis Example 20.
It is a figure which shows the NMR spectrum of 20.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshiharu Iinuma 1-1-1, Kamitobakamichocho-cho, Minami-ku, Kyoto-shi, Kyoto (72) Inventor Yoshio Hironaka 1280, Kamiizumi, Kamiizumi, Sodegaura-shi, Chiba 3K007 AB03 AB04 AB14 BB06 CA01 CA02 CA05 CB01 DA00 DB03 EB00 FA01 4C062 HH21 4H056 BA02 BB05 BB14 BC01 BD01 BF27F BF29F FA01 FA05

Claims (11)

[Claims] 1. A color conversion film comprising a resin in which a rhodamine dye having at least one cycloalkylalkane group as a steric hindrance group is dispersed. 2. A rhodamine-based dye having at least one cycloalkylalkane group is represented by the general formula (I): (Wherein, R ^{1 to} R ⁴ each independently represent at least one unsubstituted or substituted cycloalkyl alkane group having 4 to 20 carbon atoms, the remainder being an alkyl group having 1 to 32 carbon atoms, A cycloalkyl group having 3 to 12 carbon atoms or an aryl group having 6 to 24 nuclear carbon atoms, which is unsubstituted or substituted, wherein R ⁵ has a hydrogen atom, an alkyl group having 1 to 32 carbon atoms, and an unsubstituted or substituted group; 3-12 ring carbon atoms
A cycloalkyl group, an unsubstituted or substituted aryl group having 6 to 24 nuclear carbon atoms or an aralkyl group,
The same substituent R ⁶ as R ⁵ may be introduced into the benzene ring to which —COOR ⁵ is bonded, and R ^{7 to} R ¹²
Each independently represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, and A ^- represents a counter ion. The color conversion film according to claim 1, which is a compound represented by the formula: 3. A rhodamine-based dye having at least one cycloalkylalkane group is represented by the general formula (II): (Wherein, R ^{1 to} R ⁴ each independently represent at least one unsubstituted or substituted cycloalkyl alkane group having 4 to 20 carbon atoms, the remainder being an alkyl group having 1 to 32 carbon atoms, A cycloalkyl group of 3 to 12 or an unsubstituted or substituted aryl group having 6 to 24 core carbon atoms, an R ⁶ hydrogen atom, an alkyl group of 1 to 32 carbon atoms, an unsubstituted or substituted ring A cycloalkyl group having 3 to 12 carbon atoms, an unsubstituted or substituted aryl group having 6 to 24 carbon atoms or an aralkyl group, and R ^{7 to} R ¹² each independently represent a hydrogen atom or a carbon atom having 1 carbon atom; It indicates ~ 16 alkyl group, a ^- is a color conversion film according to claim 1, wherein the compound represented by represents a counter ion).. 4. The cycloalkyl alkane group is a group in which a cycloalkyl group having 3 to 12 ring carbon atoms and an alkyl group having 1 to 18 carbon atoms are bonded.
4. The color conversion film according to any one of 3. 5. The color conversion film according to claim 1, wherein the resin is at least one selected from a urea resin, a benzoguanamine resin and a melamine resin. 6. The color conversion according to claim 1, wherein the resin contains at least one selected from urea resin, benzoguanamine resin and melamine resin in the photoresist resin. film. 7. When combined with a light emitting source, light from the light emitting source can be emitted from a short wavelength of 450 to 600 nm to 500 to 6 nm.
The color conversion film according to any one of claims 1 to 6, wherein wavelength conversion is performed to a long wavelength of 50 nm. 8. The color conversion film according to claim 1, wherein the light emitting source is an organic electroluminescence device. 9. An organic electroluminescence device comprising a pair of electrodes and an organic compound layer having at least an organic light emitting layer sandwiched between the pair of electrodes, wherein at least one of the organic compound layers has a structure as defined in claim 1 to 3. An organic electroluminescent device comprising the rhodamine-based dye according to any one of the above. 10. A novel rhodamine compound represented by the following general formula (III). General formula (III) (In the formula, each of R ^{1 ′ to} R ^{4 ′} independently represents a cyclohexylmethyl group or a cyclohexylpropyl group having at least one unsubstituted or substituted group, and the rest having 1 carbon atom.
Or at least one is an unsubstituted or substituted cyclohexylmethyl group or a cyclohexylpropyl group, and R ^{5 ′} is a hydrogen atom,
Indicates to 18 alkyl group, A ^- represents a counter ion. ) 11. A novel rhodamine compound represented by the following general formula (IV): General formula (IV) (In the formula, each of R ^{1 ′ to} R ^{4 ′} independently represents a cyclohexylmethyl group or a cyclohexylpropyl group having at least one unsubstituted or substituted group, and the rest having 1 carbon atom.
To -18 alkyl groups, or at least one of them is an unsubstituted or substituted cyclohexylmethyl group or a cyclohexylpropyl group. )