JP2012175007A - Reflection film composition for light emitting element, the light emitting element, and manufacturing method of the light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting element which prevents the deterioration of a reflection film due to heat and environment, simplifies the manufacturing processes, and drastically improves the running cost by improving a thin film formation method of the reflection film reflecting light emitted from the light emitting element and having a role of an electrode, and to provide a manufacturing method of the light emitting element.SOLUTION: A light emitting element 1 includes: a light emitting layer 30, a translucent substrate 20, and a reflection film 10 reflecting light emitted from the light emitting layer in this order, and the reflection film 10 includes metal nanoparticles. Preferably, in the light emitting element 1, the reflection film 10 includes a reinforcement film including a binder.

Description

  The present invention relates to a composition for a reflective film for a light-emitting element, a light-emitting element produced from the composition for a reflective film for a light-emitting element, and a method for producing the light-emitting element. More specifically, a light-emitting element including a light-emitting layer, a light-transmitting substrate, a reflective film that reflects light emitted from the light-emitting layer, and a reflective film that efficiently reflects light emitted from the light-emitting layer in this order, and manufacture thereof Regarding the method.

  In recent years, light-emitting elements, especially LED light sources, have been used in various fields with increasing brightness. In particular, since a white LED light source can be realized, it is used for applications such as lighting fixtures and backlights of liquid crystal displays.

  In order to further increase the luminance and the like of the LED light source, it has been studied to efficiently use the light emitted from the LED element. The substrate, the LED element mounted on the support substrate, and a sealing agent containing a fluorescent agent There is disclosed an LED light source including an Ag plating electrode film that reflects light emitted from an LED element between a substrate and the LED element, and having a titanium thin film on the Ag plating electrode film (Patent Document 1).

  In this LED light source, by providing a reflective film layer between the substrate and the LED element, the light from the light emitter is efficiently reflected to increase the light emission intensity. Here, the Ag thin film and the titanium thin film are formed by a plating method or a vacuum film forming method.

  In general, the plating method is expected to generate complicated processes and waste liquid, and the vacuum film forming method requires a large cost because it maintains and operates a large vacuum film forming apparatus. Since the LED light source is subject to thermal degradation and light degradation only with an Ag plating electrode film, a titanium thin film is required, and a combination of a plating method and a vacuum film forming method is required.

  The present invention is directed to a light emitting element including a light emitting layer, a translucent substrate, and a reflective film that reflects light emitted from the light emitting layer in this order, and the reflective film is disposed between the light emitting layer and the translucent substrate. Although it does not exist, thermal degradation and light degradation occur only with the Ag plating electrode film, so that it is necessary to use a plating method and a vacuum film formation method in combination.

JP 2009-231568 A

  This invention makes it a subject to solve the said subject. The present invention improves the thin film formation method of the reflective film that reflects the light emitted from the light emitting element and plays the role of an electrode, thereby suppressing the deterioration of the reflective film due to heat and the environment and simplifying the manufacturing process. It is another object of the present invention to provide a light-emitting element capable of significantly improving running cost and a method for manufacturing the same.

The present invention relates to a composition for a reflective film for a light-emitting element, a composition for a reinforcing film for a light-emitting element, and a light-emitting element that have solved the above problems with the following configuration.
(1) A composition for a reflective film for a light-emitting device comprising a light-emitting layer, a translucent substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order, wherein the reflective film composition is a metal nanoparticle The composition for reflective films for light emitting elements characterized by including.
(2) The composition for a reflective film for a light emitting device according to (1), further comprising an additive.
(3) A composition for a reinforcing film for a light-emitting device comprising a light-emitting layer, a translucent substrate, a reflective film that reflects light emitted from the light-emitting layer, and a reinforcing film in this order, the reinforcing film composition The composition for reinforcement films for light emitting elements containing a binder.
(4) A light-emitting element comprising a light-emitting layer, a light-transmitting substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order, wherein the reflective film includes metal nanoparticles. Light emitting element.
(5) The light emitting device according to (4), wherein the reflective film further contains an additive.
(6) A light emitting device comprising a light emitting layer, a translucent substrate, a reflective film reflecting light emitted from the light emitting layer, and a reinforcing film in this order, wherein the reinforcing film contains a binder (4) Or the light emitting element of (5) description.
(7) The light emitting device according to any one of (4) to (6), wherein the reflective film and / or the reinforcing film is produced by a wet coating method.
(8) The light emitting element according to any one of (4) to (7), wherein the reflective film has a thickness of 0.05 to 1.0 μm.

Moreover, this invention relates to the manufacturing method of the following light emitting elements.
(9) A reflective film composition containing metal nanoparticles and an additive is applied on a translucent substrate by a wet coating method, and then a reflective film is formed by baking or curing. A method for manufacturing a light-emitting element, comprising forming a light-emitting layer on an opposite surface of a reflective film.
(10) After forming the reflective film, before forming the light emitting layer, the composition for reinforcing film containing a binder is further applied on the reflective film by a wet coating method, and then baked or cured for reinforcement. The method for producing a light-emitting device according to (9), wherein a film is formed.

  According to the present invention (1), even with a high-power light-emitting device, the heat resistance and corrosion resistance can be increased by the metal nanoparticles, and the deterioration of the reflective film due to heat and environment generated from the light-emitting layer is suppressed. It is possible to provide a light emitting element having a long lifetime. This reflective film can be used for various light sources, and is particularly suitable for LED light sources. Moreover, since this reflective film can be produced by a wet coating method, the production process can be simplified and produced at low cost. Moreover, according to this invention (2), the light emitting element with higher heat resistance and corrosion resistance can be provided.

  According to this invention (3), the adhesiveness of a translucent board | substrate and a light emitting layer becomes high, and the reliability of a light emitting element can be improved.

  The light emitting device of the present invention (4) has high heat resistance and corrosion resistance, suppresses deterioration of the reflective film due to heat and environment generated from the light emitting layer, and has a long life.

  According to the present invention (9), a light emitting device having high heat resistance and corrosion resistance can be obtained simply and at low cost.

It is sectional drawing which shows an example of the light emitting element of this invention. It is sectional drawing which shows a preferable example of the light emitting element of this invention.

  Hereinafter, the present invention will be specifically described based on embodiments. Unless otherwise indicated, “%” means “% by mass” unless otherwise specified.

[Reflective film composition for light-emitting elements]
A composition for a reflective film for a light-emitting element according to the present invention (hereinafter referred to as a composition for a reflective film) is a light emission comprising a light-emitting layer, a translucent substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order. A composition for a reflective film for an element, wherein the reflective film composition contains metal nanoparticles.

  The metal nanoparticles impart reflectivity of light emitted from the light emitting layer to the composition for a reflective film after baking or curing, that is, the reflective film. As the metal nanoparticles, one or two or more mixed compositions or alloy compositions selected from the group consisting of silver, gold, platinum, palladium, ruthenium, nickel, copper, tin, indium, zinc, iron, chromium and manganese Silver and gold are preferable from the viewpoints of reflectivity and conductivity. The average particle diameter of the metal nanoparticles is preferably 10 to 50 nm. Here, an average particle diameter is measured using the BET method by the specific surface measurement by QUANTACHROME AUTOSORB-1. The shape of the metal nanoparticles is preferably spherical or plate-like from the viewpoints of dispersibility and reflectivity.

  The composition for a reflective film preferably contains an additive from the viewpoints of adhesion and reflectivity of the reflective film. As an additive, it is more preferable from a viewpoint of reflectivity and adhesiveness to contain at least one selected from the group consisting of organic polymers, metal oxides, metal hydroxides, organometallic compounds, and silicone oils.

  The organic polymer used as the additive is preferably at least one selected from the group consisting of polyvinylpyrrolidone, polyvinylpyrrolidone copolymer, and water-soluble cellulose from the viewpoint of reflectivity. Examples of the polyvinylpyrrolidone copolymer include a PVP-methacrylate copolymer, a PVP-styrene copolymer, and a PVP-vinyl acetate copolymer. Examples of the water-soluble cellulose include cellulose ethers such as hydroxypropyl methylcellulose, methylcellulose, and hydroxyethylmethylcellulose.

  The metal oxide used as an additive is at least selected from the group consisting of aluminum, silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, tin, indium, and antimony An oxide or composite oxide containing one kind is preferable. Specific examples of the composite oxide include ITO, ATO, IZO, AZO and the like described above.

  The metal hydroxide used as an additive is selected from the group consisting of aluminum, silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, tin, indium, and antimony. A hydroxide containing at least one kind is preferred.

  As an organic metal compound used as an additive, a metal soap containing at least one selected from the group consisting of silicon, titanium, zirconium, chromium, manganese, iron, cobalt, nickel, silver, copper, zinc, molybdenum, and tin Metal complexes, metal alkoxides or hydrolysates of metal alkoxides are preferred. Examples of the metal soap include chromium acetate, manganese formate, iron citrate, cobalt formate, nickel acetate, silver citrate, copper acetate, copper citrate, tin acetate, zinc acetate, zinc oxalate, and molybdenum acetate. Examples of the metal complex include an acetylacetone zinc complex, an acetylacetone chromium complex, and an acetylacetone nickel complex. Examples of the metal alkoxide include titanium isopropoxide, methyl silicate, isoanatopropyltrimethoxysilane, aminopropyltrimethoxysilane and the like.

  As the silicone oil used as an additive, both straight silicone oil and modified silicone oil can be used. Modified silicone oils are those in which organic groups are introduced into part of the side chain of polysiloxane (side chain type), those in which organic groups are introduced into both ends of polysiloxane (both ends type), and both ends of polysiloxane One having an organic group introduced into one of them (one-end type), and one having a side chain of polysiloxane and an organic group introduced into both ends (both side-end type) can be used. . The modified silicone oil includes a reactive silicone oil and a non-reactive silicone oil. Both types can be used as the additive of the present invention. Reactive silicone oil means amino modification, epoxy modification, carboxy modification, carbinol modification, mercapto modification, and heterogeneous functional group modification (epoxy group, amino group, polyether group). Indicates polyether modification, methylstyryl group modification, alkyl modification, higher fatty acid ester modification, fluorine modification, and hydrophilic special modification.

  Moreover, it is preferable that the composition for reflective films contains a dispersion medium from a viewpoint of coating property. The dispersion medium is a solvent compatible with 1% by mass or more, preferably 2% by mass or more of water and 2% by mass or more, preferably 3% by mass or more of water with respect to 100% by mass of all the dispersion media, for example, It is preferable to contain alcohols. For example, when the dispersion medium is composed of only water and alcohols, it contains 98% by mass of alcohol when it contains 2% by mass of water, and 98% by mass of water when it contains 2% by mass of alcohol. Furthermore, the dispersion medium, that is, the protective molecule chemically modified on the surface of the metal nanoparticles contains one or both of a hydroxyl group (—OH) and a carbonyl group (—C═O). The water content is preferably in the range of 1% by mass or more with respect to 100% by mass of all the dispersion media. This is because when the water content is less than 2% by mass, it becomes difficult to sinter the film obtained by applying the composition for a reflective film by a wet coating method at a low temperature. Furthermore, it is because the reflectance of the reflective film after baking will fall. In addition, when a hydroxyl group (—OH) is contained in a protective agent that chemically modifies metal nanoparticles such as silver nanoparticles, it is excellent in dispersion stability of the composition for a reflective film and effective for low-temperature sintering of a coating film. There is an effect. In addition, when a carbonyl group (—C═O) is contained in a protective agent that chemically modifies metal nanoparticles such as silver nanoparticles, it is excellent in dispersion stability of the reflective film composition as described above, There is also an effective action for low-temperature sintering. As the solvent compatible with water used for the dispersion medium, alcohols are preferable. Among these, as the alcohols, it is more preferable to use one or more selected from the group consisting of methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, isobornyl hexanol and erythritol. .

  The metal nanoparticles are preferably 75 parts by mass or more with respect to 100 parts by mass of the composition for a reflective film excluding the dispersion medium, and more preferably 80 parts by mass or more from the viewpoint of reflectivity. Moreover, it is preferable from a viewpoint of the adhesiveness of a reflecting film as it is 95 mass parts or less, and it is more preferable in it being 80 mass parts or more. In addition, when providing electroconductivity to a reflecting film, it is preferable in it being 75 mass parts or more with respect to 100 mass parts of reflecting films, and it is more preferable in it being 80 mass parts or more.

  The dispersion medium is preferably 50 to 99 parts by mass with respect to 100 parts by mass of the reflective film composition from the viewpoint of coatability.

  Moreover, it is preferable that the composition for reflective films adds a low resistance agent and a water-soluble cellulose derivative according to the component to be used. As the low resistance agent, one or more selected from the group consisting of mineral salts and organic acid salts of cobalt, iron, indium, nickel, lead, tin, titanium and zinc are more preferable. For example, a mixture of nickel acetate and ferric chloride, zinc naphthenate, a mixture of tin octylate and antimony chloride, a mixture of indium nitrate and lead acetate, a mixture of titanium acetyl acetate and cobalt octylate and the like can be mentioned. The low resistance agent is preferably 0.2 to 15 parts by mass with respect to 100 parts by mass of the composition for a reflective film. The water-soluble cellulose derivative is a non-ionizing surfactant, and has an extremely high ability to disperse metal nanoparticles even when added in a small amount compared to other surfactants, and is formed by the addition of a water-soluble cellulose derivative. The reflectivity of the reflective film is also improved. Examples of the water-soluble cellulose derivative include hydroxypropyl cellulose and hydroxypropyl methylcellulose. The water-soluble cellulose derivative is preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the reflective film composition.

  The composition for a reflective film is blended with an antioxidant, a leveling agent, a thixotropic agent, a filler, a stress relaxation agent, other additives, etc., as necessary, as long as the object of the present invention is not impaired. be able to.

[Composition for reinforcing membrane]
A composition for a reinforcing film for a light emitting element (hereinafter referred to as a composition for a reinforcing film) includes a light emitting layer, a translucent substrate, a reflective film that reflects light emitted from the light emitting layer, and a reinforcing film in this order. A composition for reinforcing film for light emitting device, wherein the composition for reinforcing film contains a binder. The composition for reinforcing film can form a reinforcing film, and when there is a hole in the reflecting film, it penetrates into the reflecting film, and the hole in the reflecting film and / or the reflecting film and the enhanced reflection transparent film The binder can be contained in the interface between the reflective film itself and the strength of the reflective film itself and the adhesion strength between the reflective film and the enhanced reflective transparent film.

  The binder is either an organic or inorganic base material of a polymer type binder or an inorganic base material of a non-polymer type binder that is cured by being irradiated with ultraviolet light, heated, or heated after being irradiated with ultraviolet light. It is preferable to include one or both. The organic base material of the polymer binder may include one or more selected from the group consisting of acrylic, epoxy, urethane, acrylic urethane, epoxy acrylic, cellulose, and siloxane polymers. preferable.

  As the acrylic binder, an acrylic polymer obtained by adding a photopolymerization initiator to an acrylic monomer, irradiating the mixture with ultraviolet rays (UV), and performing photopolymerization is used. As acrylic monomers, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, neopentylglycol diacrylate, tetramethylolmethane tetraacrylate, ditrimethylolpropane tetraacrylate, 1,9-nonanediol diacrylate, tripropylene Examples thereof include one or two or more single monomers or mixed monomers selected from the group consisting of glycol diacrylate, ethoxylated isocyanuric acid triacrylate, and tetramethylolmethane tetraacrylate. A solvent such as MIBK (methyl isobutyl ketone), PGME (1-methoxy-2-propanol), PGMEA (propylene glycol monomethyl ether acetate) is preferably added to these monomers. However, if it is a general organic solvent capable of dissolving the above monomers, ethanol, methanol, benzene, toluene, xylene, NMP (N-methylpyrrolidone), acrylonitrile, acetonitrile, THF (tetrahydrofuran), ethyl acetate, MEK (methyl ethyl ketone), butyl Carbitol, butyl carbitol acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, IPA (isopropyl alcohol), acetone, DMF (dimethylformamide), DMSO (dimethyl sulfoxide), piperidine, phenol and the like can be used. Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-hydroxy-1- [4- [4- ( 2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl] -2-methyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl- 1-propan-1-one and the like can be mentioned. The acrylic monomer can be used after being diluted with the above-mentioned arbitrary solvent, adjusted to a viscosity that is easy to apply. 0.1-30 mass parts of photoinitiators are added with respect to 100 mass parts of acrylic monomers. This is because when the addition amount of the photopolymerization initiator is less than 0.1 parts by mass with respect to 100% by mass of the acrylic monomer, curing is insufficient, and when it exceeds 30 parts by mass, the cured film (reinforcing film) is discolored. This is because stress remains and causes poor adhesion. Thus, a solvent and a photoinitiator are added to an acrylic monomer and stirred, and the resulting mixed liquid is used as the base liquid of the reinforcing film composition. In addition, you may heat to about 40 degreeC, when a solvent and a photoinitiator are added to an acryl-type monomer, and the liquid mixture obtained by stirring does not become uniform.

  As an epoxy binder, an epoxy polymer obtained by adding a solvent to an epoxy resin and stirring, adding a thermosetting agent to this mixed liquid, and heating the mixed liquid obtained by stirring is used. It is done. Examples of the epoxy resin include biphenyl type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and naphthalene type epoxy resin. Examples of the solvent include BCA (butyl carbitol acetate), ECA (ethyl carbitol acetate), BC (butyl carbitol) and the like. However, if it is a general organic solvent that can dissolve the epoxy resin, ethanol, methanol, benzene, toluene, xylene, PGME (1-methoxy-2-propanol), PGMEA (propylene glycol monomethyl ether acetate), NMP (N- Methylpyrrolidone), MIBK (methyl isobutyl ketone), acrylonitrile, acetonitrile, THF (tetrahydrofuran), ethyl acetate, MEK (methyl ethyl ketone), butyl carbitol, butyl carbitol acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate , IPA (isopropyl alcohol), acetone, DMF (dimethylformamide), DMSO (dimethyl sulfoxide), piperidine, The Nord and the like can be used. Furthermore, as the thermosetting agent, 2-ethyl-4-methylimidazole, boron fluoride / monoethanolamine, DICY (dicyandiamide), diethylaminopropylamine, isophoronediamine, diaminodiphenylmethane, piperidine, 2,4,6-tris- (Dimethylaminomethyl) phenol, 2-methylimidazole, hexahydrophthalic anhydride, 7,11-octadecandiene-1,18-dicarbohydrazide and the like. The epoxy resin can be used after being diluted with the above-mentioned arbitrary solvent, adjusted to a viscosity that is easy to apply. 0.5-20 mass parts of thermosetting agents are added with respect to 100 mass parts of epoxy resins. This is because when the addition amount of the thermosetting agent is less than 0.5 parts by mass with respect to 100 parts by mass of the epoxy resin, curing is insufficient, and when it exceeds 20 parts by mass, a large internal stress is applied to the cured product (reinforcing film). This is because it occurs and causes poor adhesion. Thus, a solvent and a thermosetting agent are added to an epoxy resin, and the mixed liquid obtained by stirring is used as the base liquid of the reinforcing film composition. In addition, you may heat to about 40 degreeC, when the liquid mixture obtained by adding a solvent to an epoxy resin and stirring does not become uniform.

  The cellulose binder is obtained by adding a solvent to the cellulose polymer and stirring, adding gelatin to the mixed solution, and heating the mixed solution obtained by stirring. Examples of the cellulose polymer include water-soluble cellulose derivatives such as hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, and hydroxyethylmethylcellulose. Examples of the solvent include IPA (isopropyl alcohol), ethanol, methanol, PGME (propylene glycol monomethyl ether), PGMEA (propylene glycol monomethyl ether acetate), MIBK (methyl isobutyl ketone), acetone and the like. The cellulosic polymer can be used after being diluted with the above-mentioned arbitrary solvent to adjust the viscosity to be easily applied. The gelatin is added in an amount of 0.1 to 20 parts by mass with respect to 100 parts by mass of the cellulose polymer. This is because if the amount of gelatin added is less than 0.1 parts by mass or more than 20 parts by mass with respect to 100 parts by mass of the cellulosic polymer, viscosity suitable for coating cannot be obtained. In this way, a mixed liquid obtained by adding a solvent and gelatin to a cellulose resin and stirring the mixture is used as a base liquid of the reinforcing membrane composition. In addition, a solvent and gelatin are added to a cellulose-type polymer, and it heats at about 30 degreeC and stirs, and a liquid mixture becomes uniform.

  A urethane binder using a thermosetting urethane resin is prepared as follows. First, an excess amount of polyisocyanate compound typified by tolylene diisocyanate (TDI), diphenylmethane isocyanate (MDI) or the like is reacted with a polyol component typified by a polyhydric alcohol compound such as trimethylolpropane or neopentyl glycol. A terminally active isocyanate group-containing urethane prepolymer is obtained. Next, the terminal active isocyanate group-containing urethane prepolymer is added to a phenolic system represented by methylphenol, a lactam system represented by β-butyrolactam, or an oxime system represented by methylethylketone oxime. The blocking agent is reacted. As the solvent, ketones, alkylbenzenes, cellosolves, esters, alcohols and the like are used. Specific examples of ketones include acetone and methyl ethyl ketone, and specific examples of alkylbenzenes include benzene and toluene. Specific examples of cellosolves include methyl cellosolve and butyl cellosolve. Specific examples of esters include butyl cellosolve acetate and butyl acetate. Specific examples of alcohols include isopropyl alcohol and butyl alcohol. Etc. On the other hand, polyamine is used as the thermosetting agent (reactant). Specific examples of polyamines include N-octyl-N-aminopropyl-N′-aminopropylpropylenediamine, N-lauryl-N-aminopropyl-N′-aminopropylpropylenediamine, N-myristyl-N-aminopropyl- Examples thereof include N′-aminopropylpropylenediamine, N-octyl-N-aminopropyl-N ′, N′-di (aminopropyl) propylenediamine, and the like. The terminal active isocyanate group-containing urethane prepolymer obtained by reacting the polyol component with an isocyanate compound was blocked with a blocking agent to produce a blocked polyisocyanate. The equivalent ratio of the amino group of the polyamine to the isocyanate group of the block polyisocyanate is preferably about 1 (in the range of 0.7 to 1.1). This is because when the equivalent ratio of the amino group of the polyamine to the isocyanate group of the block polyisocyanate is less than 0.7 or exceeds 1.1, either the block polyisocyanate or the polyamine increases, and the reaction is insufficient. This is because the curing is insufficient. The urethane polymer can be used after being diluted with the above-mentioned arbitrary solvent, adjusted to a viscosity that is easy to apply.

  As the acrylic urethane binder, purple light UV-3310B or purple light UV-6100B (manufactured by Nippon Gosei Co., Ltd.), EBECRYL4820 or EBECRYL284 (manufactured by Daicel-Cytec), which contains a urethane acrylate oligomer and is cured by irradiation with ultraviolet rays (UV). ), U-4HA or UA-32P (manufactured by Shin-Nakamura Chemical Co., Ltd.). Then, if necessary, a photopolymerization initiator (for example, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, etc.) used in an acrylate system is added. Thus, curability can be improved. As the solvent, ketones, alkylbenzenes, cellosolves, esters, alcohols and the like are used. Specific examples of ketones include acetone and methyl ethyl ketone, and specific examples of alkylbenzenes include benzene and toluene. Specific examples of cellosolves include methyl cellosolve and butyl cellosolve. Specific examples of esters include butyl cellosolve acetate and butyl acetate. Specific examples of alcohols include isopropyl alcohol and butyl alcohol. Can be mentioned. A photoinitiator is added in the range of 0.1-30 mass parts with respect to 100 mass parts of acryl urethane type polymers as needed. This is because curing is insufficient when the addition amount of the photopolymerization initiator is less than 0.1 parts by mass, and when the amount exceeds 30 parts by mass, the internal stress of the back electrode reinforcing film increases, resulting in poor adhesion. . The acrylic urethane monomer can be used after being diluted with the above-mentioned arbitrary solvent to adjust the viscosity to be easily applied.

  An epoxy acrylic polymer is used as the epoxy acrylic binder. Examples of the epoxy acrylic polymer include bisphenol A type epoxy acrylate (for example, NK Oligo EA-1020 manufactured by Shin-Nakamura Chemical Co., Ltd.) and 1,6-hexanediol diglycidyl ether diacrylate (for example, manufactured by Shin-Nakamura Chemical Co., Ltd.). NK oligo EA-5521) and the like. Further, Neopole 8318, Neopole 8355, etc., manufactured by Nippon Iupika may be used. As the solvent, ketones, alkylbenzenes, cellosolves, esters, alcohols and the like are used. Specific examples of ketones include acetone and methyl ethyl ketone, and specific examples of alkylbenzenes include benzene and toluene. Specific examples of cellosolves include methyl cellosolve and butyl cellosolve. Specific examples of the esters include butyl cellosolve acetate and butyl acetate. Specific examples of alcohols include isopropyl alcohol and butyl alcohol. A thermosetting agent or a photopolymerization initiator is added to the epoxy acrylic polymer as necessary. Then, heat curing or UV curing is performed with a thermosetting agent or a photopolymerization initiator, or heat curing is performed after UV curing. In addition, the epoxy acrylic polymer can be used after being diluted with the above-mentioned arbitrary solvent, adjusted to a viscosity that allows easy coating.

  A siloxane polymer is used as the siloxane binder. Examples of the siloxane polymer include polydimethylsiloxane, polymethylhydrogensiloxane, and polymethylphenylsiloxane. As the siloxane polymer shown here, both straight silicone oil and modified silicone oil can be used. Modified silicone oils include those in which organic groups are introduced into part of the side chain of polysiloxane (side chain type), those in which organic groups are introduced at both ends of polysiloxane (both end type), and polysiloxane. Using an organic group introduced at one of the ends (one-end type), a part of the polysiloxane side chain and an organic group introduced at both ends (both side-chain type) it can. Modified silicone oil includes reactive silicone oil and non-reactive silicone oil, both of which can be used. Reactive silicone oil means amino modification, epoxy modification, carboxy modification, carbinol modification, mercapto modification, or heterogeneous functional group modification (epoxy group, amino group, polyether group). Indicates polyether modification, methylstyryl group modification, alkyl modification, higher fatty acid ester modification, fluorine modification, or hydrophilic special modification. As the solvent, ketones, alkylbenzenes, cellosolves, esters, alcohols and the like are used. Specific examples of ketones include acetone and methyl ethyl ketone. Specific examples of alkylbenzenes include benzene and toluene. Specific examples of cellosolves include methyl cellosolve and butyl cellosolve. Specific examples of the esters include butyl cellosolve acetate and butyl acetate. Specific examples of alcohols include isopropyl alcohol and butyl alcohol. It is possible to add a thermosetting agent or photopolymerization initiator to the siloxane-based polymer as necessary, but if the film is cured without adding a thermosetting agent, no thermosetting agent is required. It is. The siloxane-based polymer can be used after being diluted with the above-mentioned arbitrary solvent, adjusted to a viscosity that is easy to apply.

  The inorganic base material of the polymer binder preferably contains one or more selected from the group consisting of metal soaps, metal complexes, metal alkoxides, and hydrolysates of metal alkoxides. The inorganic base material of these polymer type polymer binders is changed from an organic base material to an inorganic base material by heating. That is, a film having the properties of an inorganic base material can be formed by firing. The metal contained in the metal soap, metal complex, metal alkoxide or metal alkoxide hydrolyzate is preferably one or more selected from the group consisting of aluminum, silicon, titanium, zirconium and tin. . Examples of the metal soap include chromium acetate, manganese formate, iron citrate, cobalt formate, nickel acetate, silver citrate, copper acetate, copper citrate, tin acetate, zinc acetate, zinc oxalate, and molybdenum acetate. Examples of the metal complex include an acetylacetone zinc complex, an acetylacetone chromium complex, and an acetylacetone nickel complex. Examples of the metal alkoxide include titanium isopropoxide, methyl silicate, isoanatopropyltrimethoxysilane, and aminopropyltriethoxysilane.

On the other hand, the inorganic base material of the non-polymer type binder includes a SiO ₂ binder. This SiO ₂ binder is produced as in the following example. First, HCl is dissolved in pure water while stirring to prepare an aqueous HCL solution. Next, tetraethoxysilane and ethyl alcohol are mixed, and the aqueous HCl solution is added to the mixture, followed by heating to react. Thus, SiO ₂ binding agent is produced. The non-polymer binder is one or more selected from the group consisting of metal soap, metal complex, metal alkoxide, hydrolyzate of metal alkoxide, halosilanes, 2-alkoxyethanol, β-diketone and alkyl acetate. It is preferable to contain. The hydrolyzate of the metal alkoxide includes sol-gel. The metal contained in the metal soap, metal complex, metal alkoxide or metal alkoxide hydrolyzate is preferably one or more selected from the group consisting of aluminum, silicon, titanium, zirconium and tin. . Examples of metal soaps include chromium acetate, manganese formate, iron citrate, cobalt formate, nickel acetate, silver citrate, copper acetate, copper citrate, tin acetate, zinc acetate, zinc oxalate, and molybdenum acetate. Examples of the complex include an acetylacetone zinc complex, an acetylacetone chromium complex, and an acetylacetone nickel complex. Examples of the metal alkoxide include titanium isopropoxide, methyl silicate, isoanatopropyltrimethoxysilane, and aminopropyltriethoxysilane. Examples of halosilanes include chlorosilane, bromosilane, and fluorosilane. Examples of 2-alkoxyethanol include 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and the like. Examples of β-diketone include 2,4-pentanedione and 1,3-diphenyl-1,3-propanedione. Examples of the alkyl acetate include ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate.

  Moreover, the composition for reinforcement films may contain 1 type, or 2 or more types chosen from the group which consists of a silane coupling agent, an aluminum coupling agent, and a titanium coupling agent. When the reinforcing film composition contains a silane coupling agent, an aluminum coupling agent, or the like, the adhesion of the reinforcing film to the reflective film can be further improved. For this reason, after forming a large number of light-emitting layers on a single light-transmitting substrate, when using a step of dividing the light-transmitting substrate from the reflective film side by dicing and dividing the light-emitting elements into each light-emitting element, It can suppress that a reinforcement film | membrane peels from a reflecting film.

Further, the reinforcing membrane composition can include one or more metal oxide fine particles or flat particles selected from the group consisting of colloidal silica, fumed silica particles, silica particles, mica particles, and smectite particles. . Colloidal silica is a colloid of SiO ₂ or its hydrate, and has an average particle diameter of 1 to 100 nm, preferably 5 to 50 nm, and does not have a certain structure. The fumed silica particles are produced by vaporizing silicon chloride and being oxidized in a gas phase in a high-temperature flame, and have an average particle size of 1 to 50 nm, preferably 5 to 30 nm. The silica particles are particles having an average particle diameter of 1 to 100 nm, preferably 5 to 50 nm. The mica particles are particles produced by a synthesis method and having an average particle diameter of 10 to 50000 nm, preferably flat particles having an average diameter of 1 to 20 μm and an average thickness of 10 to 100 nm. Smectite particles are a kind of ion-exchangeable layered silicate compounds that have a crystal structure in which surfaces formed by ionic bonds and the like are stacked in parallel with each other with a weak binding force, and particles having an average particle diameter of 10 to 100,000 nm, preferably Are flat particles having an average diameter of 1 to 20 μm and an average thickness of 10 to 100 nm. When the composition for reinforcing membrane contains colloidal silica, fumed silica particles, etc., the hardness of the reinforcing membrane can be further increased. For this reason, after forming the separation groove by dicing, even if the burrs and debris remaining in the separation groove are removed with an air knife or the like, the reinforcement film has good wear resistance and impact resistance. The edge part in a groove | channel is not chipped. 0.1-30 mass parts is preferable with respect to 100 mass parts of compositions for reinforcement films, and, as for these addition amounts, 0.2-20 mass parts is more preferable. If the amount is less than 0.1 parts by mass, it is difficult to obtain the effect. On the other hand, if the amount exceeds 30 parts by mass, the adhesion tends to decrease. In the present invention, the average particle diameter of each particle and each fine particle is measured as follows. A 50% average particle diameter (D ₅₀ ) measured with a laser diffraction / scattering particle size distribution measuring apparatus (Horiba, Ltd., model number: LA-950) and calculated using the particle diameter standard as the number. The number-based average particle diameter measured by the laser diffraction / scattering particle size distribution measuring device is an arbitrary 50 in an image observed with a scanning electron microscope (manufactured by Hitachi High-Technologies, model numbers: S-4300SE and S-900). The average particle diameter when the particle diameter of each particle is actually measured is substantially the same. Further, the average diameter and average thickness of the above-mentioned flat particles and the average diameter and average thickness of each flat fine particle described later are also measured in the same manner as described above.

  The reason why the average particle size of colloidal silica is limited to the range of 1 to 100 nm is that colloidal is unstable and easily aggregated if it is less than 1 nm, and if it exceeds 100 nm, the particle size is large and does not become a dispersion. In addition, the size of fumed silica particles, silica particles, mica particles, and smectite particles is limited to the above range because it is an available particle size or larger than the thickness of the lower layer film (reflection film). This is because the size range is not allowed.

  Furthermore, the composition for reinforcing film is one or more metals selected from the group consisting of gold, platinum, palladium, ruthenium, nickel, copper, tin, indium, zinc, iron, chromium, manganese and aluminum, or Fine particles or flat fine particles containing these metal oxides can be included. The average particle diameter of these fine particles is set in the range of 1 to 50000 nm, preferably 100 to 5000 nm. The average diameter of the flat fine particles is preferably 1 to 50000 nm, and the average thickness of the flat fine particles is preferably 100 to 20000 nm. When the reinforcing film composition contains fine particles such as gold and platinum or flat fine particles, the reinforcing film can be further flexible. For this reason, even if stress occurs in the reinforcing film during dicing, the stress can be relaxed by the ductility and malleability of the reinforcing film. Here, the size of the metal fine particles is limited to the above range because the size of the obtained fine particles is limited. The size of the metal flat fine particles is limited to the above range. This is because the size range does not exceed the above. 0.1-30 mass parts is preferable and, as for the addition amount of these microparticles | fine-particles or flat microparticles | fine-particles, 0.2-20 mass parts is more preferable. This is because if the amount is less than 0.1 parts by mass, it is difficult to obtain the effect, while if the amount exceeds 30 parts by mass, the adhesiveness tends to decrease. The content of the metal or metal oxide in the fine particles or flat fine particles is set to 70% by mass or more, preferably in the range of 80 to 100% by mass. This is because if it is less than 70% by mass, the workability of the reinforcing film is lowered.

  The reinforcing membrane composition may further contain an antioxidant, a leveling agent, a thixotropic agent, a stress relaxation agent, other additives, etc., as necessary, as long as the object of the present invention is not impaired. it can.

[Light emitting element]
The light-emitting element of the present invention is a light-emitting element including a light-emitting layer, a light-transmitting substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order, and the reflective film includes metal nanoparticles. Features.

  FIG. 1 shows a cross-sectional view of an example of a light-emitting element. The light emitting element 1 includes a reflective film 10, a translucent substrate 20, and a light emitting layer 30 in this order. In general, the reflective film 10 is bonded to the support substrate 60 with an adhesive layer 50, and a desired wiring is formed on the light emitting layer 30, followed by sealing with a sealing material 40.

  FIG. 2 is a cross-sectional view illustrating a preferable example of a light-emitting element. When the light-emitting element 1 includes the reinforcing film 12, the reflective film 11, the substrate 21, and the light-emitting layer 31, the reinforcing film 12 can increase the heat resistance and corrosion resistance of the reflective film 11, and the translucent substrate. And the reflective film 11 can be made highly adhesive, and peeling of the reflective film 11 from the substrate 21 in the dicing process can be suppressed. The reinforcing film 12 can be manufactured by a wet coating method if it contains a binder, but it is more preferable, but the heat resistance and corrosion resistance of the reflective film 10 can be improved even if manufactured by a vacuum film forming method or the like. It is.

<Reflective film>
The reflective film reflects the light of the light emitting layer that has passed through the substrate. The reflective film preferably contains metal nanoparticles and further contains an additive. The metal nanoparticles and additives are as described above.

  The content of the additive is preferably 0.1 to 25 parts by mass and more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the transparent conductive film. If it is 0.1 parts by mass or more, the adhesive strength with the transparent conductive film is good, and if it is 25 parts by mass or less, film unevenness at the time of film formation hardly occurs.

  The thickness of the reflective film is preferably 0.05 to 1.0 μm and more preferably 0.1 to 0.5 μm from the viewpoint of reflectivity and conductivity.

When the pores present on the surface of the reflective film on the side of the translucent substrate have an average diameter of 100 nm or less, an average depth of 100 nm or less, and a number density of 30 / μm ² , a wavelength range of 380 to 780 nm Can achieve a high diffuse reflectance of 80% or more of the theoretical reflectance. In general, the reflection spectrum shows items having high reflectance on the long wavelength side and low on the short wavelength side. If the average diameter of the pores exceeds 100 nm, the inflection point at which the reflectance starts to decrease shifts to a longer wavelength side and a good reflectance cannot be obtained. Therefore, the average diameter is preferably 100 nm or less. In addition, when the average pore depth exceeds 100 nm, the gradient (inclination) of the reflection spectrum increases, and good reflectance cannot be obtained. Therefore, the average pore depth is preferably 100 nm or less. If the number density of the pores exceeds 30 / μm ² , the reflectance on the long wavelength side is lowered and a good reflectance cannot be obtained. Therefore, the number density of the pores is preferably 30 / μm ² or less.

《Reinforcing membrane》
The reinforcing film increases the heat resistance and corrosion resistance of the reflective film, and suppresses peeling of the reflective film when dicing is used in the manufacturing process of the light emitting element. The reinforcing film includes a binder, and the binder is as described above.

  The thickness of the reinforcing film is preferably 0.01 to 0.5 μm and more preferably 0.01 to 0.2 μm from the viewpoints of heat resistance and corrosion resistance.

[Method for Manufacturing Light-Emitting Element]
The method for producing a light-emitting element of the present invention is a method for forming a reflective film by applying a composition for a reflective film containing metal nanoparticles and an additive on a light-transmitting substrate by a wet coating method, followed by baking or curing. The light-emitting layer is formed on the opposite surface of the light-transmitting substrate to the reflective film.

  First, a reflective film composition containing metal nanoparticles, preferably containing an additive, is applied on a light-transmitting substrate by a wet coating method. The application here is performed so that the thickness after firing is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.5 μm. Subsequently, the coating film is dried at a temperature of 120 to 350 ° C., preferably 150 to 250 ° C., for 5 to 60 minutes, preferably 15 to 40 minutes. In this way, a reflective film is formed.

  The translucent substrate is not particularly limited as long as the light emitting layer can be formed, but a sapphire substrate is preferable from the viewpoint of translucency and heat dissipation.

  A composition for a reflective film is prepared by mixing desired components with a paint shaker, a ball mill, a sand mill, a centrimill, a three-roll mill, etc., and dispersing a translucent binder, and optionally transparent conductive particles, in a conventional manner. can do. Of course, it can also be produced by a normal stirring operation. In addition, after mixing the component except a metal nanoparticle, it is preferable from a viewpoint that it is easy to obtain the composition for homogeneous reflective films when it mixes with the dispersion medium containing the metal nanoparticle separately disperse | distributed previously.

  The wet coating method is preferably a spray coating method, a dispenser coating method, a spin coating method, a knife coating method, a slit coating method, an inkjet coating method, a screen printing method, an offset printing method, or a die coating method. However, the present invention is not limited to this, and any method can be used.

  The spray coating method is a method in which the composition for a reflective film is made into a mist with compressed air and applied to a light-transmitting substrate, or the dispersion itself is pressurized to form a mist and applied to the light-transmitting substrate. The method is, for example, a method in which a composition for a reflective film is placed in a syringe, and a dispersion is discharged from a fine nozzle at the tip of the syringe by pushing a piston of the syringe and applied to a light-transmitting substrate. The spin coating method is a method in which a reflective film composition is dropped onto a rotating translucent substrate, and the dropped reflective film composition is spread on the periphery of the translucent substrate by its centrifugal force. In the coating method, a translucent substrate having a predetermined gap from the tip of the knife is provided so as to be movable in the horizontal direction, and the composition for the reflective film is supplied onto the translucent substrate upstream of the knife. In this method, the optical substrate is moved horizontally toward the downstream side. The slit coating method is a method in which the reflective film composition is allowed to flow out of a narrow slit and applied onto a light-transmitting substrate. The inkjet coating method is performed by filling the ink cartridge of a commercially available inkjet printer with the reflective film composition. In this method, ink jet printing is performed on a translucent substrate. The screen printing method is a method of using a ridge as a pattern indicating material and transferring the composition for a reflective film to a translucent substrate through a plate image formed thereon. In the offset printing method, the composition for the reflective film attached to the plate is not directly attached to the translucent substrate, but is transferred from the plate to the rubber sheet once, and then transferred again from the rubber sheet to the translucent substrate. This is a printing method utilizing the water repellency of the composition. The die coating method is a method in which the composition for a reflective film supplied into a die is distributed by a manifold and extruded onto a thin film from a slit, and the surface of a traveling translucent substrate is applied. The die coating method includes a slot coat method, a slide coat method, and a curtain coat method.

  Finally, the translucent substrate having a reflective coating is preferably 5 to 60 at a temperature of 130 to 250 ° C., more preferably 180 to 220 ° C. in the air or an inert gas atmosphere such as nitrogen or argon. It is fired by holding for 15 minutes, preferably 15 to 40 minutes. When the binder reacts by hydrolysis or the like, it can be cured at a lower temperature.

  The reason why the baking temperature of the translucent substrate having the coating film is in the range of 130 to 250 ° C. is that when the temperature is less than 130 ° C., the reflective film has a problem of insufficient curing. On the other hand, if it exceeds 250 ° C., the production merit of the low temperature process cannot be utilized, that is, the manufacturing cost increases and the productivity decreases. In addition, the light emitting layer is relatively weak against heat, and the light emission efficiency is lowered by the baking process.

  The reason why the baking time of the translucent substrate having the coating film is in the range of 5 to 60 minutes is that when the baking time is less than the lower limit value, there is a problem that binder baking is not sufficient in the reflective film. If the firing time exceeds the upper limit, the manufacturing cost will increase more than necessary, resulting in a decrease in productivity, and a problem that the light emission efficiency of the light emitting layer will decrease.

  The method for forming the light emitting layer on the opposite surface of the light-transmitting substrate to the reflective film is not particularly limited, and known organic vapor phase epitaxy (MOCVD), hydride vapor phase epitaxy (HVPE), molecular beam epitaxy ( MBE) or the like.

  As described above, the manufacturing method of the present invention can eliminate a vacuum process such as a vacuum vapor deposition method and a sputtering method as much as possible by using a wet coating method, so that a reflective film can be manufactured at a lower cost. A light-emitting element with high performance and corrosion resistance can be easily manufactured at low cost. Note that when the light-emitting element is bonded to another member, it is preferable that the reflective film be directly joined with Au—Sn solder, which is high-temperature solder, because the reflective film may be eroded by the Au—Sn solder. Absent.

  In addition, after forming the reflective film, before forming the light emitting layer, the reinforcing film composition containing a binder is further applied on the reflective film by a wet coating method, and then baked or cured to form the reinforcing film. It is preferable because the heat resistance and corrosion resistance of the light-emitting element can be further increased, and further, peeling of the reflective film when dicing is used in the manufacturing process of the light-emitting element can be suppressed.

  The binder of the reinforcing film is as described above, and the manufacturing method of the reinforcing film composition and the wet coating method are the same as those of the reflective film composition. However, in the case of the reinforcing film composition, The thickness is preferably 0.01 to 0.5 μm, more preferably 0.01 to 0.2 μm. In addition, what is necessary is just to select the heating method and ultraviolet irradiation method for hardening suitably according to the kind of binder of the composition for reinforcing films.

  As a method of adding the necessary particles, fine particles, flat fine particles and other additives to the base liquid of the reinforcing membrane composition and dispersing these additives in the base liquid, blade stirring such as disper stirring is used. , Dispersion using a planetary stirrer or a three-roll mill, dispersion using beads including a bead mill or a paint shaker, and the like. Moreover, you may employ | adopt the method of mixing what was previously disperse | distributed by the above methods to the solvent component in a base liquid. Furthermore, when the additive itself is already in a dispersion liquid dispersed in a suitable solvent, a liquid mixing method using an ultrasonic homogenizer or ultrasonic vibration can be used in addition to the above method.

  As described above, by using the wet coating method, a transparent conductive film can be produced at a lower cost, and a light-emitting element having higher heat resistance and corrosion resistance can be produced simply and at low cost.

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.

[Example 1]
First, the composition for reflective films was produced. The production procedure is shown below.

<< Preparation of composition for reflective film >>
Silver nitrate was dissolved in deionized water to prepare an aqueous metal salt solution. In addition, sodium citrate was dissolved in deionized water to prepare a sodium citrate aqueous solution having a concentration of 26% by mass. In this sodium citrate aqueous solution, granular ferrous sulfate is directly added and dissolved in a nitrogen gas stream maintained at 35 ° C., and citrate ions and ferrous ions are contained in a molar ratio of 3: 2. A reducing agent aqueous solution was prepared.

  Next, a magnetic stirrer stirrer is placed in the reducing agent aqueous solution while maintaining the nitrogen gas flow at 35 ° C., and the reducing agent aqueous solution is stirred at a rotating speed of the stirrer: 100 rpm. An aqueous salt solution was added dropwise and mixed. Here, the concentration of each solution is adjusted so that the amount of the metal salt aqueous solution added to the reducing agent aqueous solution is 1/10 or less of the amount of the reducing agent aqueous solution. The reaction temperature was kept at 40 ° C. The mixing ratio of the reducing agent aqueous solution and the metal salt aqueous solution is such that the molar ratio of citrate ions and ferrous ions in the reducing agent aqueous solution to the total valence of metal ions in the metal salt aqueous solution is 3 The moles were doubled. After the addition of the aqueous metal salt solution to the reducing agent aqueous solution is completed, the mixture is further stirred for 15 minutes to generate silver nanoparticles inside the mixture, and the silver nanoparticle dispersion in which the silver nanoparticles are dispersed Got. The pH of the silver nanoparticle dispersion was 5.5, and the stoichiometric amount of silver nanoparticles in the dispersion was 5 g / liter.

  The obtained silver nanoparticle dispersion was allowed to stand at room temperature, so that the silver nanoparticles in the dispersion were allowed to settle, and aggregates of the precipitated silver nanoparticles were separated by decantation. Deionized water was added to the separated silver nanoparticle aggregates to form a dispersion, and after desalting by ultrafiltration, the metal (silver) content was adjusted to 50% by mass by washing with methanol. . Thereafter, using a centrifuge, the centrifugal force of the centrifuge is adjusted to separate relatively large silver particles having a particle size of more than 100 nm, whereby silver nanoparticles having a primary particle size of 10 to 50 nm are separated. Was adjusted to contain 71% in number average. That is, the silver nanoparticle dispersion liquid was obtained by adjusting the ratio of silver nanoparticles in the range of the primary particle diameter of 10 to 50 nm to 71% with respect to 100% of all silver nanoparticles. The obtained silver nanoparticles were chemically modified with a protective agent for sodium citrate.

  Next, 10 parts by mass of the obtained metal nanoparticles were dispersed by adding and mixing in 90 parts by mass of a mixed solution containing water, ethanol and methanol to prepare a reflective film composition. In addition, the metal nanoparticle which comprises the composition for reflective films contains 75 mass% or more metal nanoparticles.

  About the composition for reflective films, the reflective coating film was formed into a glass substrate by spin coating, and it baked at 200 degreeC in nitrogen atmosphere for 20 minutes, and the reflective film of thickness: 200nm was obtained. Here, the film thickness was measured by cross-sectional observation using a scanning electron microscope (SEM, device names: S-4300, SU-8000) manufactured by Hitachi High-Technologies. In other examples and comparative examples, the film thickness was measured in the same manner.

[Example 2]
After producing a silver nanoparticle dispersion liquid in the same manner as in Example 1, the obtained metal nanoparticles were dispersed by adding and mixing 10 parts by mass with 90 parts by mass of a mixed solution containing water, ethanol and methanol. In addition, polyvinylpyrrolidone (PVP, molecular weight: 360,000) and tin acetate were added so as to have a ratio of metal nanoparticles: 96 parts by mass and PVP: 4 parts by mass to prepare a composition for a reflective film. In addition, the metal nanoparticle which comprises the composition for reflective films contains 75 mass% or more metal nanoparticles. Next, a reflective film having a thickness of 100 nm was obtained in the same manner as in Example 1.

Example 3

  After producing a silver nanoparticle dispersion liquid in the same manner as in Example 1, the obtained metal nanoparticles were dispersed by adding and mixing 10 parts by mass with 90 parts by mass of a mixed solution containing water, ethanol and methanol. In addition, zinc acetate was added so as to have a ratio of metal nanoparticles: 95 parts by mass and zinc acetate: 5 parts by mass to prepare a composition for a reflective film. Next, a reflective film having a thickness of 200 nm was obtained in the same manner as in Example 1.

  Next, a composition for reinforcing membrane was prepared. The production procedure is shown below.

<< Preparation of composition for reinforcing membrane >>
Using neopentyl glycol diacrylate as a raw material monomer, 10 g was dissolved in PGME: 100 cm ³ , 0.5 g of 1-hydroxy-cyclohexyl-phenyl-ketone was added, kept at 50 ° C., and stirred vigorously. Acrylic resin was synthesized by maintaining the time. The acrylic resin was diluted with ethanol so that the solid content concentration became 1% by mass to prepare a reinforcing membrane composition.

  On the reflective film, a composition for reinforcing film was formed with a spin coater. Furthermore, it baked at 150 degreeC for 10 minutes, and obtained the reinforcement film | membrane.

Example 4
After producing a silver nanoparticle dispersion liquid in the same manner as in Example 1, the obtained metal nanoparticles were dispersed by adding and mixing 10 parts by mass with 90 parts by mass of a mixed solution containing water, ethanol and methanol. In addition, copper acetate was added so as to have a ratio of metal nanoparticles: 95 parts by mass and copper acetate: 5 parts by mass to prepare a composition for a reflective film. Next, a reflective film having a thickness of 150 nm was obtained in the same manner as in Example 1.

Next, the SiO ₂ binder used as the reinforcing membrane composition was a 500 cm ³ glass four-necked flask, added with 140 g of tetraethoxysilane and 140 g of ethyl alcohol, and stirred with 1.7 g 60% nitric acid was dissolved in 120 g of pure water and added at once, and then reacted at 50 ° C. for 3 hours.

  A transparent conductive film was formed on the reflective film by spin coating on the reflective film and baked at 160 ° C. for 30 minutes to obtain a transparent conductive film having a thickness of 100 nm.

[Examples 5 to 6, 17]
Examples 5 to 6 and 17 were produced in the same manner as in Example 4 except that the compositions and film thicknesses described in Table 1 were used. Incidentally, the SiO ₂ used in Example 5, were used SiO ₂ binding agent used in Example 4.

[Examples 7 to 16, 18 to 20]
Examples 7 to 16 and 18 to 20 were produced in the same manner as in Example 3 except that the compositions and film thicknesses described in Table 1 were used. Here, neopentyl glycol diacrylate is used for the acrylic type used in the reinforcing agent composition, bisphenol A type epoxy resin is used for the epoxy type, methylcellulose is used for the cellulose type, and diphenylmethane isocyanate and methylphenol are used for the urethane type. did.

Example 21
Example 21 was produced in the same manner as in Example 2 except that the composition and film thickness described in Table 1 were used. Incidentally, the SiO ₂ used in this embodiment, SiO ₂ was used binding agent used in Example 4.

[Comparative Example 1]
A silver thin film with a thickness of 100 nm was formed on a glass substrate by sputtering using a vacuum film formation method.

[Comparative Example 2]
A silver thin film having a thickness of 100 nm was formed on a glass substrate by sputtering, and a titanium thin film having a thickness of 30 nm was further formed by sputtering.

[Measurement of reflectance]
Evaluation of the reflectance of Examples 1-21 and Comparative Examples 1-2 measured the diffuse reflectance of the reflective film in wavelength 450nm by the combination of an ultraviolet visible spectrophotometer and an integrating sphere. Further, the heat treatment test was conducted at 200 ° C. for 1000 hours, and the sulfide test as a corrosion resistance test was conducted at hydrogen sulfide: 10 ppm, temperature: 25 ° C., relative humidity: 75% RH, 504 hours, and the reflectivity after each test was obtained. It was measured. Tables 1 and 2 show these results.

[Adhesion evaluation]
Regarding the adhesion evaluation, in Examples 2 and 5 after the reflectance measurement, the tape was adhered to the film and peeled off by the method according to the tape test (JIS K-5600). The evaluation was based on three levels: excellent, acceptable, and impossible, depending on the degree of peeling or turning up. The case where the film formation does not stick to the tape side and only the adhesive tape is peeled off is excellent, and the case where the peeling of the adhesive tape and the state where the photoelectric conversion layer as the base material is exposed is allowed is mixed. The case where the whole surface of the photoelectric conversion layer surface used as a base material was exposed by peeling was made impossible. Example 2 was acceptable and Example 5 was excellent.

  As is apparent from Table 1, in Examples 1 and 2, the initial reflectance after heat treatment was high, and the reflectance after the sulfidation test was about 30%. On the other hand, Comparative Example 1 produced by the sputtering method had a high initial reflectance, but the deterioration after the heat treatment was large, and the reflectance after the sulfidation test was greatly reduced to 14%. In Examples 3 to 21, the reflectivity after the initial stage, after the heat treatment, and after the sulfidation test is very high, and the heat resistance and the corrosion resistance are very high. It was found that few light emitting elements can be manufactured. On the other hand, Comparative Example 2 produced by the sputtering method had a low reflectance of 65% after the sulfidation test.

  The light-emitting element of the present invention can increase heat resistance and corrosion resistance even if it is a high-power light-emitting element by providing a reflective film containing metal nanoparticles between the light-transmitting substrate and the light-emitting layer. The deterioration of the reflective film due to heat generated from the light emitting layer and the environment can be suppressed. Since this reflective film can be manufactured by a wet coating method, the manufacturing process can be simplified and the cost can be reduced. Further, by providing a transparent conductive film containing a light-transmitting binder between the light emitting layer and the reflective film, the heat resistance and light resistance can be further increased, which is very useful.

DESCRIPTION OF SYMBOLS 1, 2 Light emitting element 10, 11 Reflective film 12 Reinforcing film 20, 21 Translucent substrate 30, 31 Light emitting layer 40, 41 Sealing material 50 Adhesive layer 60 Support substrate

Claims (10)

  A composition for a reflective film for a light-emitting element comprising a light-emitting layer, a light-transmitting substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order, the reflective film composition containing metal nanoparticles A composition for a reflective film for a light-emitting device, characterized by:   Furthermore, the composition for reflective films for light emitting elements of Claim 1 containing an additive.   A composition for a reinforcing film for a light emitting device comprising a light emitting layer, a translucent substrate, a reflective film that reflects light emitted from the light emitting layer, and a reinforcing film in this order, wherein the reinforcing film composition is a binder A composition for a reinforcing film for a light emitting device, comprising:   A light-emitting element comprising a light-emitting layer, a light-transmitting substrate, and a reflective film that reflects light emitted from the light-emitting layer in this order, wherein the reflective film includes metal nanoparticles.   The light emitting device according to claim 4, wherein the reflective film further contains an additive.   The light-emitting element comprising a light-emitting layer, a translucent substrate, a reflective film that reflects light emitted from the light-emitting layer, and a reinforcing film in this order, wherein the reinforcing film contains a binder. Light emitting element.   The light emitting device according to any one of claims 4 to 6, wherein the reflective film and / or the reinforcing film is produced by a wet coating method.   The light emitting element of any one of Claims 4-7 whose thickness of a reflecting film is 0.05-1.0 micrometer.   A reflective film composition containing metal nanoparticles and an additive is applied on a translucent substrate by a wet coating method, and then the reflective film is formed by baking or curing. A method for producing a light-emitting element, comprising forming a light-emitting layer on an opposite surface. After forming the reflective film, before forming the light-emitting layer, further, a reinforcing film composition containing a binder is applied on the reflective film by a wet coating method, and then baked or cured to form the reinforcing film. The manufacturing method of the light emitting element of Claim 9.