JP2012038660A - Water-capturing agent and organic electronic device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-capturing agent which, in an organic EL element of a solid-state airtight encapsulated structure, can secure fluidity at filling without affecting an organic layer and also can prevent physical breakdown of the organic layer.SOLUTION: A water-capturing agent fills an airtight container which is made airtight with an insulative element substrate and an encapsulation substrate in such a way as to include on the insulative element substrate a laminate comprised of organic layers on the element substrate which are held in place between a pair of electrodes. The water-capturing agent contains as a drying ingredient an organic metal compound with an organic solvent added, which is represented by the chemical formula shown below, and is obtained by solvent-substituting the organic solvent by a viscous substitution material having compatibility with the drying ingredient.

Description

  The present invention relates to a water catching agent that captures moisture of an electronic component enclosed in an airtight container over a long period of time, and particularly has an effect on an organic layer when filled in an organic EL element having a solid adhesion sealing structure. In particular, the present invention relates to a water-capturing agent that can secure fluidity at the time of filling and prevent physical destruction to an organic layer, and an organic electronic device using the same.

  In recent years, research on various organic electronic devices such as organic EL (Electroluminescence) elements, organic light emitting devices such as organic EL displays and organic EL lighting, and organic semiconductors and organic solar cells has been actively conducted. Expansion to basic elements and applications is expected.

  The organic EL element has a structure in which an organic layer, which is a thin film containing a fluorescent organic compound, is sandwiched between an anode and a cathode forming a pair of electrodes, and holes and electrons are injected into the thin film. In this self-luminous element, excitons (excitons) are generated by recombination, and light emission (fluorescence / phosphorescence) is generated when the excitons are deactivated.

  By the way, the biggest problem of the organic EL element is improvement of durability, and among them, generation of a non-light emitting portion called a dark spot and prevention of its growth are the biggest problems. When the diameter of the dark spot grows to several tens of μm, a non-light emitting portion can be visually confirmed. It is known that the main causes of dark spots are the influence of moisture and oxygen, and particularly, the influence of moisture is extremely large even in a very small amount.

  Therefore, a method for preventing moisture from entering the organic EL element has been considered, and it can be said that a “hollow sealing structure” disclosed in Patent Document 1 below is a typical typical sealing structure. This hollow sealing structure is a method of suppressing the intrusion amount of moisture and oxygen by sealing an organic EL element in an inert gas atmosphere dried.

As shown in FIG. 5, in the hollow sealing structure of the organic EL element 31, an anode 35 made of an ITO film is formed on an element substrate 32 having insulating properties and translucency. An organic layer 34 made of a thin film of an organic compound material is laminated on the upper surface of the anode 35 by, for example, a PVD method such as molecular beam vapor deposition or resistance heating, and copper phthalocyanine (as a hole injection layer 34a) is formed on the anode 35. CuPc), Bis [N- (1-naphthyl) -N-pheny] benzidine (α-NPD) as a hole transport layer 34b on the upper surface of the hole injection layer 34a, and a light emitting layer / electron on the upper surface of the hole injection layer 34b. It has a three-layer structure of tris (8-quinolinolato) aluminum (Alq ₃ ) as the transport layer 34c. A light emitting portion is formed by a laminate having a laminated structure of the anode 35, the organic layer 34, and a cathode 36 described later. The cathode 36 is formed as a metal thin film on the top surface of the light emitting layer / electron transport layer 34c in the organic layer 34, and a part of the cathode is drawn to the end of the element substrate 32 and connected to a drive circuit (not shown). . Further, a dry film 37 is provided as a drying means on the sealing substrate 33 inside the container kept airtight by the element substrate 32, the sealing substrate 33, and the adhesive 38.

  However, since the performance of the sealing seal is not sufficient in the hollow sealing structure, a counterbore process is required to create a space for installing a drying means such as an inorganic drying sheet for chemically or physically adsorbing moisture therein, resulting in a low manufacturing cost. There was a problem of being bulky. Moreover, since there is nothing in contact with the upper surface of the cathode and heat can be dissipated only by radiation and convection in the panel, for example, the organic EL for illumination cannot sufficiently exhaust heat. Further, in a panel having a size larger than a certain size, there is a possibility that bending occurs when the center portion is pressed down, resulting in physical destruction due to contact with the element.

  Therefore, as disclosed in Patent Document 1 below, “solid adhesion sealing, which has excellent heat dissipation and panel strength and slows the infiltration rate of moisture and oxygen by sealing the organic layer in a resin or glass film. "Structure" has been proposed.

As shown in FIG. 6, the organic EL element 41 having a solid adhesion sealing structure has an anode 45 made of an ITO film formed on an element substrate 42 having insulation and translucency. An organic layer 44 made of a thin film of an organic compound material is laminated on the upper surface of the anode 45 by, for example, a PVD method such as a molecular beam evaporation method or a resistance heating method, and copper phthalocyanine (as a hole injection layer 44a) is formed on the anode 45. CuPc), Bis [N- (1-naphthyl) -N-pheny] benzidine (α-NPD) as a hole transport layer 44b on the upper surface of the hole injection layer 44a, and a light emitting layer 44c on the upper surface of the hole injection layer 44b. Of tris (8-quinolinolato) aluminum (Alq ₃ ) and lithium fluoride (LiF) as an electron injection layer 44d on the upper surface of the light emitting layer 44c. The cathode 46 is formed as a metal thin film on the upper surface of the light emitting layer 44 d in the organic layer 44, and a passivation film 48 such as SiN, SiON, or SiO ₂ is formed by physical vapor deposition as a protective film that protects against moisture through the buffer layer 47. A film is being formed. The element substrate 42, the sealing substrate 43, and the adhesive 49 constitute an airtight container.

JP 2002-33187 A

  However, in a top emission type solid sealing structure in which EL light generated in the organic EL element is extracted from the sealing substrate side to the outside, the protective substrate on the light extraction side does not have translucency. Since it is difficult to place the desiccant freely, and there is a possibility that the sealing performance cannot be sufficiently secured without placing the desiccant, it is necessary to form a film to protect the organic layer with a passivation film with many steps. ing. Therefore, there is a problem that the manufacturing cost and the manufacturing time increase due to an increase in the number of steps for forming the protective film.

  In addition, it is conceivable to suppress the generation of dark spots by sealing the organic EL element on the substrate with a sealing substrate and filling it with a water capturing agent that is a drying means. An organic solvent for adjusting viscosity is added to the water-transmitting agent having translucency, and there is a problem that the organic layer is affected by contact with the organic layer at the time of filling. For this reason, the organic solvent is volatilized by performing a drying step after filling the water catching agent, but the water catching agent dried by this drying step is hardened due to the volatilization of the organic solvent, making internal filling difficult and cured. There is a possibility that the organic layer may be physically destroyed by contact with the water capturing agent.

  Furthermore, this type of water catching agent may cause cracks when moisture in the element is adsorbed, and the extracted light will be diffusely reflected and the transmittance will be reduced, so it is particularly applicable to top emission type structures. I couldn't.

  Therefore, the present invention has been made in view of the above problems, and has no effect on the organic layer when filled into an organic EL element having a solid adhesive sealing structure, and ensures fluidity at the time of filling to ensure the organic layer. It is an object of the present invention to provide a water-capturing agent that can prevent physical destruction of water and an organic electronic device using the same.

In order to achieve the above object, the water capturing agent according to claim 1 includes the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. A water-absorbing agent filled in an airtight container hermetically sealed with
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 1) to which an organic solvent is added as a dry component, and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. .

（式中、Ｒは炭素数１個以上のアルキル基，アリール基，アルコキシ基，シクロアルキル基，複素環基, アシル基を含む有機基を示し、Ｍは３価の金属原子を示し、ｎは重合度を示す１以上の整数である。なお、Ｒはそれぞれ同じ有機基でも異なる有機基でも良い。）

(In the formula, R represents an organic group containing an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, or an acyl group, M represents a trivalent metal atom, and n represents (It is an integer greater than or equal to 1 indicating the degree of polymerization. R may be the same or different organic groups.)

The water-absorbing agent according to claim 2 is an airtight container hermetically sealed between the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. A water catching agent filled inside,
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 2) to which an organic solvent is added as a dry component and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. .

（式中、Ｒ₁ 〜Ｒ₃ 、Ｒ₅ は炭素数1 個以上のアルキル基，アリール基，アルコキシ基，シクロアルキル基，複素環基, アシル基を含む有機基を示し、Ｍは３価の金属原子を示す。なお、Ｒ₁ 〜Ｒ₃ 、Ｒ₅ はそれぞれ同じ有機基でも異なる有機基でも良い。）

(Wherein R _{1 to} R ₃ and R ₅ represent an organic group including an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, and an acyl group, and M represents a trivalent group. Represents a metal atom, wherein R _{1 to} R ₃ and R ₅ may be the same or different organic groups.

The water-absorbing agent according to claim 3 is an airtight container hermetically sealed between the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. A water catching agent filled inside,
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 3) to which an organic solvent is added as a dry component, and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. .

（式中、Ｒ₁ 、Ｒ₃ 、Ｒ₄ は炭素数1 個以上のアルキル基，アリール基，アルコキシ基，シクロアルキル基，複素環基, アシル基を含む有機基を示し、Ｍは４価の金属原子を示す。）

(Wherein R ₁ , R ₃ , and R ₄ represent an organic group including an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, and an acyl group, and M represents a tetravalent group. Indicates a metal atom.)

  The water catching agent according to claim 4 is the water catching agent according to any one of claims 1 to 3, wherein the viscous displacement material has an average molecular weight in the range of 300 to 3700 and a content concentration of 5 to 75%. It is a long-chain hydrocarbon polymer capable of obtaining a viscosity of 600 Pa · S or less when heated to 60 ° C. in the range.

  An organic electronic device according to a fifth aspect is characterized in that the water capturing agent according to any one of the first to fourth aspects is filled in the container as water capturing means in an airtight container.

  According to the water-absorbing agent of the present invention, a novel water-absorbing agent can be provided in which the organic layer is not attacked by the filled water-retaining agent when used in an organic electronic device having a solid adhesion sealing structure. . In addition, since the viscous replacement material has an appropriate viscosity, it can be easily filled in the hermetic container, and can exhibit the effect of absorbing physical impact and preventing physical destruction of the organic layer. Furthermore, since it does not cause cracking or the like during water catching and does not become opaque, it can also be used in a top emission type structure that extracts light from the side opposite to the element substrate.

It is sectional drawing which shows the structure of the organic EL element of the solid contact | adherence sealing structure concerning this invention. It is a graph which shows the characteristic of the temperature and viscosity in the water catching agent which concerns on this invention. (A)-(d) It is sectional drawing which shows the manufacturing process of the organic EL element of the solid adhesion sealing structure which concerns on this invention. It is a graph which shows the light emission area ratio in the elapsed time of the organic EL element using the water catching agent which concerns on this invention. It is sectional drawing of the organic EL element of the conventional hollow sealing structure. It is sectional drawing of the organic EL element of the conventional solid contact | adherence sealing structure.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and all other forms, examples, operation techniques, etc. that can be implemented by those skilled in the art based on this form are included in the scope of the present invention. .

  The water-absorbing agent of the present invention is a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate such as an organic EL element, an organic EL display, an organic EL illumination, an organic semiconductor, an organic solar cell, etc. It is used in various organic electronic devices having a solid close-sealing structure in which a body is hermetically sealed between an element substrate and a sealing substrate, and adsorbs moisture to suppress the generation of dark spots in the organic layer. In the following description, an example in which the water catching agent of this example is used for an organic EL element will be described.

  As shown in FIG. 1, the organic EL element 1 having a solid close-sealing structure is based on an element substrate 2 made of a rectangular glass substrate having insulating properties and translucency. In FIG. 1, an anode 5 made of an ITO film is formed on a device substrate 2 as a conductive material having transparency. The ITO film is formed on the element substrate 2 by a PVD (Physical Vapor Deposition) method such as a vacuum deposition method or a sputtering method. Thereafter, the anode 5 is formed by patterning into a predetermined pattern shape by etching by means of a photoresist method. A part of the anode 5 as an electrode is drawn to the end of the element substrate 2 and connected to a drive circuit (not shown).

On the upper surface of the anode 5, for example, an organic layer 4 made of a thin film of an organic compound material is laminated by a PVD method such as a vacuum evaporation method or a resistance heating method. The organic layer 4 in the example of FIG. 1 has copper phthalocyanine (CuPc) as the hole injection layer 4a formed on the anode 5 with a film thickness of several tens of nm and a film thickness of several tens of nm on the upper surface of the hole injection layer 4a. Bis [N- (1-naphthyl) -N-pheny] benzidine (α-NPD) as the formed hole transport layer 4b and light emission formed with a film thickness of several tens of nm on the upper surface of the hole transport layer 4b It has a four-layer structure of tris (8-quinolinolato) aluminum (Alq ₃ ) as the layer 4c and lithium fluoride (LiF) as the electron transport layer 4d formed to a thickness of several nm on the upper surface of the light emitting layer 4c. . And the light emission part is formed with the laminated body which consists of a laminated structure with the anode 5, the organic layer 4, and the cathode 6 mentioned later.

  As shown in FIG. 1, the cathode 6 has a metal thin film formed on the upper surface of the organic layer 4 (electron transport layer 4d). As a material for the metal thin film, for example, a metal material having a small work function such as Al, Li, Mg, or In or an alloy having a small work function such as Al—Li or Mg—Ag is used. The cathode 6 is formed with a film thickness of, for example, several tens nm to several hundreds nm (preferably 50 nm to 200 nm). A part of the cathode 6 is drawn to the end of the element substrate 2 and connected to a drive circuit (not shown).

  On the outer periphery of the element substrate 2, a rectangular sealing substrate 3 as a sealing member is sealed with, for example, an ultraviolet curable resin in a dry atmosphere with an inert gas (for example, dry nitrogen) or dry air from which moisture is removed as much as possible. It is fixed by the agent 8. Thereby, the anode 5, the organic layer 4, and the cathode 6 are protected.

  Further, an organic metal compound mixed with an organic metal compound is added to an organic metal compound that functions as a dry component shown in Chemical Formula 1 as a drying means inside a container that is kept airtight by the element substrate 2, the sealing substrate 3, and the sealing sealant 8. The water-absorbing agent 7 obtained by adding a solvent and a viscous displacement material for solvent substitution is filled.

Here, the desiccant and the viscous displacement material added to the water catching agent 7 filled in the organic EL element 1 will be described.
[desiccant]
The desiccant functioning as a drying component in the water catching agent 7 of the present example is as shown in (Chemical Formula 1), where R is an alkyl group having 1 or more carbon atoms, aryl group, alkoxy group, cycloalkyl group, heterocyclic ring. Group, an organic group containing an acyl group, M is a trivalent metal atom, and n is an organometallic compound which is an integer of 1 or more indicating the degree of polymerization.

When the organometallic compound represented by (Chemical Formula 1) is n = 3, R _{1 to} R ₃ are independently an alkyl group, aryl group, or alkoxy group having 1 or more carbon atoms as represented by the following chemical formula (Chemical Formula 4). , A cycloalkyl group, a heterocyclic group, and an organic group containing an acyl group, and M has a cyclic structure showing a trivalent metal atom. Moreover, the reaction formula with water when (Chemical Formula 1) becomes a cyclic structure is shown in the following chemical formula (Chemical Formula 5). As shown in (Chemical Formula 5), the reaction undergoes an addition reaction with water molecules to capture water in the container.

以上から、この有機金属化合物が化学的に水分を除去する機能を有することが推定できる。

From the above, it can be estimated that this organometallic compound has a function of chemically removing moisture.

An example of the substituent is shown below, but is not limited thereto, and each R may be the same or different organic group.
R represents an alkyl group having 1 or more carbon atoms, an alkenyl group, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, or an acyl group. The alkyl group is substituted or unsubstituted, and specific examples include methyl group, ethyl group, propyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group. , Nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl, etc. 8 or more is good. These oligomers and polymers may also be used. The alkenyl group is substituted or unsubstituted, and specific examples include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and the like, and preferably those having 8 or more carbon atoms. These oligomers and polymers may also be used.

  The aryl group is substituted or unsubstituted, and specific examples include phenyl group, tolyl group, 4-cyanophenyl group, biphenyl group, o, m, p-terphenyl group, naphthyl group, anthranyl group, phenanthrenyl group, There are a fluorenyl group, a 9-phenylanthranyl group, a 9,10-diphenylanthranyl group, a pyrenyl group, and the like, preferably those having 8 or more carbon atoms. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted alkoxy group include a methoxy group, an n-butoxy group, a tert-butoxy group, a trichloromethoxy group, and a trifluoromethoxy group, and preferably those having 8 or more carbon atoms. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a norbonane group, an adamantane group, a 4-methylcyclohexyl group, a 4-cyanocyclohexyl group, and preferably those having 8 or more carbon atoms. good. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted heterocyclic group include pyrrole group, pyrroline group, pyrazole group, pyrazoline group, imidazole group, triazole group, pyridine group, pyridazine group, pyrimidine group, pyrazine group, triazine group, indole group, Benzimidazole group, purine group, quinoline group, isoquinoline group, sinoline group, quinoxaline group, benzoquinoline group, fluorenone group, dicyanofluorenone group, carbazole group, oxazole group, oxadiazole group, thiazole group, thiadiazole group, benzoxazole group Benzothiazole group, benzotriazole group, bisbenzoxazole group, bisbenzothiazole group, bisbenzimidazole group and the like. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group Group, malonyl group, succinyl group, glutaryl group, adipoyl group, pimeloyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group, isocrotonoyl group, oleoyl group, elidoyl group, maleoyl group , Fumaroyl group, citraconoyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group , Cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, glycoloyl group, lactoyl group, glyceroyl group, tartronoyl group, maloyl group, tartaloyl group, tropoyl group, benzyloyl group, salicyloyl group, anisoyl group, vanilloyl group, veratroyl group Group, piperoniloyl group, protocatechuyl group, galloyl group, glyoxyloyl group, pyrvoyl group, acetoacetyl group, mesooxalyl group, mesooxalo group, oxalacetyl group, oxalaceto group, levulinoyl group fluorine, chlorine, these acyl groups Bromine, iodine, etc. may be substituted. Preferably, the acyl group has 8 or more carbon atoms. These oligomers and polymers may also be used.

  As an example of an organometallic compound in which R is substituted with the above substituent and the trivalent metal is aluminum, the following chemical formulas (Chemical Formula 6) to (Chemical Formula 13) are raised.

  Furthermore, the present inventors have found that the organometallic compound shown in (Chemical Formula 2) captures water by performing a substitution reaction with water molecules as shown in the following chemical formula (Chemical Formula 14), and is used as a desiccant for organic EL elements. Since it is presumed to have the action and principle of being able to be performed, it was found that the organometallic compound shown in (Chemical Formula 2) is effective as a drying means.

Although an example of a substituent is shown below, it is not restricted to these. R _{1 to} R ₃ and R ₅ each represent an alkyl group having 1 or more carbon atoms, an alkenyl group, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, or an acyl group. The alkyl group is substituted or unsubstituted, and specific examples include methyl group, ethyl group, propyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group. , Nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl and the like. These oligomers and polymers may also be used. The alkenyl group is substituted or unsubstituted, and specific examples include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and the like, and preferably those having 8 or more carbon atoms. These oligomers and polymers may also be used.

  The aryl group is substituted or unsubstituted, and specific examples include phenyl group, tolyl group, 4-cyanophenyl group, biphenyl group, o, m, p-terphenyl group, naphthyl group, anthranyl group, phenanthrenyl group, Examples include a fluorenyl group, a 9-phenylanthranyl group, a 9,10-diphenylanthranyl group, and a pyrenyl group. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted alkoxy group include a methoxy group, an n-butoxy group, a tert-butoxy group, a trichloromethoxy group, and a trifluoromethoxy group. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a norbonane group, an adamantane group, a 4-methylcyclohexyl group, a 4-cyanocyclohexyl group, and the like. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted heterocyclic group include pyrrole group, pyrroline group, pyrazole group, pyrazoline group, imidazole group, triazole group, pyridine group, pyridazine group, pyrimidine group, pyrazine group, triazine group, indole group, Benzimidazole group, purine group, quinoline group, isoquinoline group, sinoline group, quinoxaline group, benzoquinoline group, fluorenone group, dicyanofluorenone group, carbazole group, oxazole group, oxadiazole group, thiazole group, thiadiazole group, benzoxazole group Benzothiazole group, benzotriazole group, bisbenzoxazole group, bisbenzothiazole group, bisbenzimidazole group and the like. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted acyl group include formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group Group, malonyl group, succinyl group, glutaryl group, adipoyl group, pimeloyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group, isocrotonoyl group, oleoyl group, elidoyl group, maleoyl group , Fumaroyl group, citraconoyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group , Cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, glycoloyl group, lactoyl group, glyceroyl group, tartronoyl group, maloyl group, tartaloyl group, tropoyl group, benzyloyl group, salicyloyl group, anisoyl group, vanilloyl group, veratroyl group Group, piperoniloyl group, protocatechuyl group, galloyl group, glyoxyloyl group, pyrvoyl group, acetoacetyl group, mesooxalyl group, mesooxalo group, oxalacetyl group, oxalaceto group, levulinoyl group fluorine, chlorine, these acyl groups Bromine, iodine, etc. may be substituted. These oligomers and polymers may also be used.

  Examples of organometallic compounds in which R is substituted with the above substituent and the trivalent metal is aluminum include organometallic compounds represented by the following chemical formulas (Chemical Formula 15) to (Chemical Formula 18).

  An example of an organometallic compound in which the trivalent metal is lanthanum is a compound represented by the following chemical formula (Formula 19).

  One example of an organometallic compound in which the trivalent metal is yttrium is a compound represented by the following chemical formula (Formula 20).

  An example of an organometallic compound in which the trivalent metal is gallium is a compound represented by the following chemical formula (Formula 21).

  Furthermore, the inventors of the present application have found that the organometallic compound represented by (Chemical Formula 3) captures water by performing a substitution reaction with water molecules as represented by Chemical Formula (Chemical Formula 14), as in (Chemical Formula 2). Since it is presumed to have the action and principle that it can be used as a desiccant for the device, it was found that the organometallic compound shown in (Chemical Formula 3) is effective as a drying means. Although an example of a substituent is shown below, it is not restricted to these.

R ₁ , R ₃ and R ₄ each represent an alkyl group having 1 or more carbon atoms, an alkenyl group, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group or an acyl group. The alkyl group is substituted or unsubstituted, and specific examples include methyl group, ethyl group, propyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group. , Nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl and the like. These oligomers and polymers may also be used. The alkenyl group is substituted or unsubstituted, and specific examples include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and the like, and preferably those having 8 or more carbon atoms. These oligomers and polymers may also be used.

  The aryl group is substituted or unsubstituted, and specific examples include phenyl group, tolyl group, 4-cyanophenyl group, biphenyl group, o, m, p-terphenyl group, naphthyl group, anthranyl group, phenanthrenyl group, Examples include a fluorenyl group, a 9-phenylanthranyl group, a 9,10-diphenylanthranyl group, and a pyrenyl group. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted alkoxy group include a methoxy group, an n-butoxy group, a tert-butoxy group, a trichloromethoxy group, and a trifluoromethoxy group. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a norbonane group, an adamantane group, a 4-methylcyclohexyl group, a 4-cyanocyclohexyl group, and the like. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted heterocyclic group include pyrrole group, pyrroline group, pyrazole group, pyrazoline group, imidazole group, triazole group, pyridine group, pyridazine group, pyrimidine group, pyrazine group, triazine group, indole group, Benzimidazole group, purine group, quinoline group, isoquinoline group, sinoline group, quinoxaline group, benzoquinoline group, fluorenone group, dicyanofluorenone group, carbazole group, oxazole group, oxadiazole group, thiazole group, thiadiazole group, benzoxazole group Benzothiazole group, benzotriazole group, bisbenzoxazole group, bisbenzothiazole group, bisbenzimidazole group and the like. These oligomers and polymers may also be used.

  Specific examples of the substituted or unsubstituted acyl group include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, lauroyl, myristoyl, palmitoyl, stearoyl, oxalyl Group, malonyl group, succinyl group, glutaryl group, adipoyl group, pimeloyl group, suberoyl group, azelaoil group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group, isocrotonoyl group, oleoyl group, elidoyl group, maleoyl group , Fumaroyl group, citraconoyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group, atropoyl group , Cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, glycoloyl group, lactoyl group, glyceroyl group, tartronoyl group, maloyl group, tartaloyl group, tropoyl group, benzyloyl group, salicyloyl group, anisoyl group, vanilloyl group, veratroyl group Group, piperoniloyl group, protocatechuyl group, galloyl group, glyoxyloyl group, pyrvoyl group, acetoacetyl group, mesooxalyl group, mesooxalo group, oxalacetyl group, oxalaceto group, levulinoyl group fluorine, chlorine, these acyl groups Bromine, iodine, etc. may be substituted. These oligomers and polymers may also be used.

  As an example of an organometallic compound in which R is substituted with the above substituent and the tetravalent metal is germanium or silicon, an organometallic compound of (Chemical Formula 22) or (Chemical Formula 23) can be given.

  Furthermore, since the substance represented by (Chemical Formula 1) (Chemical Formula 2) (Chemical Formula 3) is dissolved in an aromatic organic solvent such as toluene or xylene or an aliphatic organic solvent such as n-decane, a general desiccant is used. It is presumed that it has an action and principle that a physical adsorption type desiccant such as zeolite and a chemical adsorption type desiccant such as calcium oxide, strontium oxide and barium oxide can be dispersed and mounted.

[Viscosity replacement material]
The viscous replacement material for solvent replacement with the organic solvent added to the desiccant has compatibility with the desiccant and an appropriate viscosity so that it can be filled easily when filled, and the organic layer 4 when filled into the organic EL element. The following three materials can be arbitrarily selected and used: a long-chain hydrocarbon polymer, silicone oil, and liquefied synthetic rubber. Further, even if it is adopted in a top emission type structure in which light is extracted from the side opposite to the element substrate 2, it has a property that it does not become opaque due to cracks or the like during water capture.

(Long-chain hydrocarbon polymer)
The long-chain hydrocarbon polymer is a long-chain hydrocarbon having an average molecular weight of 300 to 3700 and a viscosity of 600 Pa · S or less when heated to 60 ° C. in a content concentration of 5 to 75%. It is a polymer and has a composition represented by the following chemical formula (Formula 24). The average molecular weight of the organic layer 4 is about 500 to 600, and the organic layer 4 is easily affected near this range. Therefore, the average molecular weight of the long-chain hydrocarbon polymer to be used should be 600 or more. preferable.

  The addition amount of the long-chain hydrocarbon polymer depends on the addition amount of the organic solvent added to the organometallic compound and the filling method of the water catching agent 7 (dispenser method, screen printing method, spray method, hot melt method, etc.). Although the amount added can be adjusted as appropriate, it can be added in a range of approximately 5 to 95 wt%. For example, in the dispenser method, a range of 25 to 75 wt% is preferable. That is, it is preferable that the application work has a viscosity of 600 Pa · S or less. When the average molecular weight of the long-chain hydrocarbon polymer is 1400 or less, the addition amount is preferably 5 to 75 wt%. FIG. 2 is a graph showing the temperature and viscosity characteristics according to the amount of the long-chain hydrocarbon polymer having an average molecular weight of 1400. As shown, the long-chain hydrocarbon polymer having an average molecular weight of 1400 is shown in FIG. It can be seen that when the addition amount is 5 to 75 wt%, a viscosity of 600 Pa · s or less is easily obtained at 60 ° C. In addition, when applying the water catching agent 7 to the sealing substrate 3, in order to increase the flexibility of the water catching agent 7 and make it easy to apply, the application work is performed by applying a temperature (30 to 60 ° C.) higher than normal temperature during the application. It becomes easy to do.

(Silicone oil)
As the silicone oil, a double-terminal carboxy-modified structure in which various organic groups are introduced into a part of a methyl group as shown in the following chemical formula (Chemical Formula 25) or a side chain type carboxy as shown in the following chemical formula (Chemical Formula 26) is used. It has a modified structure.

  In addition, the amount of silicone oil added is determined by the amount of organic solvent added to the organometallic compound or the method of filling the water catching agent 7 (dispenser method, screen printing method, spray method, hot melt method, etc.). For example, in the dispenser method, 10 to 25 wt% is preferable.

(Liquefied synthetic rubber)
The liquefied synthetic rubber is a terminal carboxyl group-containing butadiene rubber having an average molecular weight of 4200, and has a composition represented by the following chemical formula (Chemical Formula 27).

  The amount of liquefied synthetic rubber added is determined by the amount of organic solvent added to the organometallic compound or the filling method of the water catching agent 7 (dispenser method, screen printing method, spray method, hot melt method, etc.). For example, in the dispenser method, 10 to 25 wt% is preferable.

  Next, the synthesis process of the water capturing agent 7 according to the present invention and the manufacturing process of the organic EL element using the water capturing agent 7 will be specifically described. Note that the following steps do not limit the present invention, and any design changes in light of the gist of the preceding and following descriptions are included in the technical scope of the present invention.

[Example 1]
(Method for synthesizing water catching agent)
Aluminum oxide octylate, which is one of the organometallic compounds represented by (Chemical Formula 5), is mixed with 10 wt% of n-decane having a boiling point of 170 ° C. to prepare a desiccant having an n-decane concentration of 10%.

  Next, 150 g of this desiccant was taken in an eggplant-shaped flask, 15 g of polybutene (HV15 (average molecular weight 630): Shin Nippon Oil Co., Ltd.) was added as a viscous displacement material, and the mixture was heated in a vacuum with an evaporator. As a result, n-decane contained in the desiccant was evaporated to obtain a water catching agent 7 in which the solvent was replaced with polybutene, which is a viscous replacement material.

[Method of manufacturing organic EL element]
First, as shown in FIG. 3A, an anode made of ITO as a transparent conductive material is formed on the element substrate 2 by a sputtering method with a film thickness of 140 nm, and further, a predetermined pattern shape is formed by etching using a photoresist method. Then, the anode 5 is formed. A part of ITO is drawn to the end of the element substrate 2 and connected to a drive circuit (not shown). Next, copper phthalocyanine (CuPc) as a hole injection layer 4a formed with a thickness of 70 nm by a resistance heating method on the upper surface of the anode 5 and a film thickness of 30 nm were formed on the upper surface of the hole injection layer 4a. Bis [N- (1-naphthyl) -N-pheny] benzidine (α-NPD) as the hole transport layer 4b and Tris as the light emitting layer 4c formed with a film thickness of 50 nm on the upper surface of the hole transport layer 4b (8-Quinolinolato) aluminum (Alq ₃ ) was deposited. Next, lithium fluoride (LiF) as an electron transport layer 4d formed to a thickness of 7 nm was formed on the upper surface of the light emitting layer 4c, and Al was physically vapor-deposited as a cathode 6 to a thickness of 150 nm. A part of the cathode 6 is drawn to the end of the element substrate 2 and connected to a drive circuit (not shown).

  In a glove box substituted with nitrogen having a dew point of −76 ° C. or less, as shown in FIG. 3B, the synthesized water catching agent 7 can be filled in a pre-measured container on the sealing substrate 3. Only the volume was applied with a dispenser. Next, a sealing sealant 8 made of an ultraviolet curable resin was applied with a dispenser so as to surround the water catching agent 7 filled on the sealing substrate.

  Then, as shown in FIG. 3C, the element substrate 2 on which the organic layer 4 is laminated and the sealing substrate 3 are bonded together, and then sealed by UV irradiation and heating at 80 ° C., and FIG. As shown, an organic EL element 1 having a solid close-sealing structure in which a water replenisher 7 was filled in an airtight container was obtained.

FIG. 4 is a microscopic observation of the growth of dark spots after 300 hours in a high-temperature and high-humidity standing test in an environment of a temperature of 85 ° C. and a humidity of 85% with respect to the light emitting portion of the organic EL element 1.
As a comparison object, a mixture in which the amount of the organic solvent (petroleum hydrocarbon) was mixed with the aluminum oxide octylate (trade name: HOPE Pharmaceutical Olope AOO) shown in the above (Chemical Formula 5) to be about 52 wt% of the total Uses an organic EL element with a hollow sealing structure that uses a conventional water-trapping agent that is vacuum heated to a viscosity that can be applied with a dispenser of 300 to 500 Pa · s (25 ° C.) to remove 13% by weight of the solvent component. It was.

  As shown in the figure, the lighting state after 300 hours had a light emission area ratio equivalent to that obtained when the conventional water catching agent 7 was dried at 150 ° C. for 10 minutes. In addition, it was the same after 780 hours, and the product performance was sufficiently satisfied. Furthermore, when the conventional water catching agent 7 is mounted on an organic EL element without being subjected to a drying treatment, the organic layer 4 is attacked by evaporation of the organic solvent, and a lot of dark spots (non-light emitting portions) are generated. In the case of the element mounted with the water capturing agent 7, the organic solvent was replaced with a viscous replacement material, so that the organic layer 4 was not attacked and was different from the initial state.

[Example 2]
In Example 2, the modified silicone oil (X-22-3701E: manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a viscous replacement material for the water-absorbing agent 7 used in Example 1. Others are the same as in the first embodiment. Thereafter, the growth of dark spots after 200 hours in a high-temperature and high-humidity standing test in an environment of a temperature of 85 ° C. and a humidity of 85% was observed with a microscope. The comparison object used the organic EL element of the hollow sealing structure using the conventional water catching agent whose solvent component which used aluminum oxide octylate as the organometallic compound similarly to Example 1 is 13 wt%.

  As shown in FIG. 4, the lighting state after the elapse of 300 hours was a light emitting area ratio substantially equal to that obtained when the conventional water catching agent was dried at 150 ° C. for 10 minutes. Moreover, it was the same after 780 hours, and the water-absorbing agent 7 of this example was a result that sufficiently satisfied the product performance. Furthermore, in the case of the element mounted with the water catching agent 7 of this example, the organic solvent was replaced with the viscous replacement material, so that there was no difference from the initial state without the organic layer 4 being attacked.

[Example 3]
In Example 3, the terminal carboxyl group-containing butadiene rubber (HYCAR CTB 2000: manufactured by Ube Industries, Ltd.) was used as a viscous replacement material for the water catching agent 7 used in Example 1. Others are the same as in the first embodiment. Thereafter, the growth of dark spots after 200 hours in a high-temperature and high-humidity standing test in an environment of a temperature of 85 ° C. and a humidity of 85% was observed with a microscope. The comparison object used the organic EL element of the hollow sealing structure using the conventional water catching agent whose solvent component which used aluminum oxide octylate as the organometallic compound similarly to Example 1 is 13 wt%.

  As shown in FIG. 4, the lighting state after the elapse of 300 hours was a light emitting area ratio substantially equal to that obtained when the conventional water catching agent was dried at 150 ° C. for 10 minutes. In addition, even after 780 hours had elapsed, although the light emission area ratio dropped by about 10% compared to the conventional water catching agent, the water catching agent 7 of this example was a result that sufficiently satisfied the product performance. Furthermore, in the case of the element mounted with the water catching agent 7 of this example, the organic solvent was replaced with the viscous replacement material, so that there was no difference from the initial state without the organic layer 4 being attacked.

[Example 4]
In Example 4, the silicone oil 7 (X-22-162C, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the viscous replacement material for the water-capturing agent 7. Others are the same as in the first embodiment. Thereafter, the growth of dark spots after 200 hours in a high-temperature and high-humidity standing test in an environment of a temperature of 85 ° C. and a humidity of 85% was observed with a microscope. The comparison object used the organic EL element of the hollow sealing structure using the conventional water catching agent whose solvent component which used aluminum oxide octylate as the organometallic compound similarly to Example 1 is 13 wt%.

  As shown in FIG. 4, the lighting state after 300 hours had a light emission area ratio substantially equal to that obtained when the conventional water catching agent 7 was dried at 150 ° C. for 10 minutes. In addition, even after 780 hours had elapsed, although the light emission area ratio fell by about 20% compared to the conventional water catching agent 7, the water catching agent 7 of this example was a result that sufficiently satisfied the product performance. Furthermore, in the case of the element mounted with the water catching agent 7 of this example, the organic solvent was replaced with the viscous replacement material, so that there was no difference from the initial state without the organic layer 4 being attacked.

DESCRIPTION OF SYMBOLS 1 ... Organic EL element 2 ... Element substrate 3 ... Sealing substrate 4 ... Organic layer (4a ... Hole injection layer, 4b ... Hole transport layer, 4c ... Light emitting layer, 4d ... Electron transport layer)
5 ... Anode 6 ... Cathode 7 ... Water trapping agent 8 ... Sealing sealant

Claims (5)

A water-absorbing agent filled in an airtight container hermetically sealed with the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. And
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 1) to which an organic solvent is added as a dry component, and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. Water catcher.

(In the formula, R represents an organic group containing an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, or an acyl group, M represents a trivalent metal atom, and n represents (It is an integer greater than or equal to 1 indicating the degree of polymerization. R may be the same or different organic groups.) A water-absorbing agent filled in an airtight container hermetically sealed with the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. And
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 2) to which an organic solvent is added as a dry component and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. Water catcher.

(Wherein R _{1 to} R ₃ and R ₅ represent an organic group including an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, and an acyl group, and M represents a trivalent group. Represents a metal atom, wherein R _{1 to} R ₃ and R ₅ may be the same or different organic groups. A water-absorbing agent filled in an airtight container hermetically sealed with the element substrate and the sealing substrate so as to enclose a laminate in which an organic layer is sandwiched between a pair of electrodes on an insulating element substrate. And
It is obtained by using an organometallic compound represented by the following chemical formula (Chemical Formula 3) to which an organic solvent is added as a dry component, and replacing the organic solvent with a viscous replacement material having compatibility with the dry component. Water catcher.

(Wherein R ₁ , R ₃ , and R ₄ represent an organic group including an alkyl group having 1 or more carbon atoms, an aryl group, an alkoxy group, a cycloalkyl group, a heterocyclic group, and an acyl group, and M represents a tetravalent group. Indicates a metal atom.) The viscous displacement material is a long-chain hydrocarbon polymer having an average molecular weight of 300 to 3700 and a viscosity of 600 Pa · S or less when heated to 60 ° C. in a concentration range of 5 to 75%. The water catching agent according to any one of claims 1 to 3, wherein the water catching agent is provided. An organic electronic device comprising the container filled with the water capturing agent according to claim 1 as water capturing means in an airtight container.

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