JP2012190647A - Organic electroluminescent light source device, multilayer film, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL light source device which has high light extraction efficiency and is capable of suppressing a reduction in the light extraction efficiency over time.SOLUTION: An organic electroluminescent light source device 100 comprises a first transparent electrode layer 121, a light-emitting layer 122, a second transparent electrode layer 123, an adhesive layer 130, and a reflective layer 143 in this order from the light exit surface side. The reflective layer 143 has an uneven surface 143U on the adhesive layer side of the reflective layer 143. The adhesive layer 130 contains an acrylic polymer containing a hydroxyl group, and inorganic particulates.

Description

  The present invention relates to an organic electroluminescence light source device, a multilayer film for producing the organic electroluminescence light source device, and methods for producing them.

  2. Description of the Related Art Conventionally, in an organic electroluminescence light source device (hereinafter, appropriately referred to as “organic EL light source device”), which is a light source device provided with an organic electroluminescence element (hereinafter, appropriately referred to as “organic EL element”), the light emitting surface thereof has been conventionally used. Attempts have been made to improve the light extraction efficiency by providing a reflective layer with irregularities on the opposite side (see Patent Document 1). In addition, in order to further improve the light extraction efficiency, studies have been made to define the refractive index of the layer between the organic EL element and the reflective layer (see Patent Document 2).

Japanese Patent No. 4506904 JP 2010-73667 A

However, in the conventional technique, the light extraction efficiency of the organic EL light source device tends to decrease with time. Therefore, an organic EL light source device that has high light extraction efficiency and can suppress a decrease in the light extraction efficiency over time has been desired.
The present invention was devised in view of the above problems, and has an organic light source device that has high light extraction efficiency and can suppress a decrease in light extraction efficiency over time, and a compound for manufacturing the organic EL light source device. An object of the present invention is to provide a layer film and a production method thereof.

As a result of intensive studies to solve the above-described problems, the present inventor provided an uneven surface on the adhesive layer side of the reflective layer in the organic EL light source device having the organic EL element, the adhesive layer, and the reflective layer in this order, and It has been found that by including an acrylic polymer containing hydroxyl groups and inorganic fine particles in the adhesive layer, the light extraction efficiency can be improved and the light extraction efficiency can be maintained high for a long period of time. I let you.
That is, the gist of the present invention is the following [1] to [8].

[1] An organic electroluminescence light source device having a first transparent electrode layer, a light emitting layer, a second transparent electrode layer, an adhesive layer, and a reflective layer in this order from the light exit surface side,
The reflective layer has an uneven surface on the adhesive layer side of the reflective layer,
The said adhesion layer is an organic electroluminescent light source device containing the acrylic polymer and inorganic fine particle containing a hydroxyl group.
[2] The organic electroluminescence light source device according to [1], wherein the adhesive layer has an acrylic acid content of 3% by weight or less based on the acrylic polymer.
[3] The organic electroluminescence light source device according to [1] or [2], wherein the adhesive layer has a refractive index of 1.65 or more.
[4] The organic electroluminescence light source device according to any one of [1] to [3], wherein the reflective layer includes at least one of silver and aluminum.
[5] The organic electroluminescence light source device according to any one of [1] to [4], wherein the uneven surface has an average inclination angle of 17 ° to 45 °.
[6] A multilayer film for producing the organic electroluminescence light source device according to any one of [1] to [5],
The multilayer film which has the said reflection layer, the said adhesion layer, and the separator film which can be peeled from the said adhesion layer in this order.
[7] A method for producing an organic electroluminescence light source device according to any one of [1] to [5],
[6] Peel off the separator film from the multilayer film according to [6],
The manufacturing method of an organic electroluminescent light source device including bonding the said adhesion layer and the organic electroluminescent element which has a said 1st transparent electrode layer, the said light emitting layer, and a said 2nd transparent electrode layer in this order.
[8] A method for producing a multilayer film according to [6],
Forming the adhesive layer on the surface of the separator film;
The manufacturing method of a multilayer film including bonding the said adhesion layer and the said reflection layer together.

The organic electroluminescence optical device of the present invention has a high light extraction efficiency and can suppress a decrease in the light extraction efficiency over time.
According to the multilayer film of the present invention, it is possible to produce an organic electroluminescence optical device that has a high light extraction efficiency and can suppress a decrease in the light extraction efficiency over time.
According to the method for manufacturing an organic electroluminescence optical device of the present invention, it is possible to manufacture an organic electroluminescence optical device that has high light extraction efficiency and can suppress a decrease in the light extraction efficiency over time.
According to the method for producing a multilayer film of the present invention, it is possible to produce a multilayer film used for the production of an organic electroluminescence optical device having high light extraction efficiency and capable of suppressing a decrease in light extraction efficiency over time.

FIG. 1 is a cross-sectional view schematically showing a layer configuration of the organic EL light source device according to the first embodiment of the present invention. FIG. 2 is a perspective view schematically showing a part of the reflecting member of the organic EL light source device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a cross section of the reflecting member shown in FIG. 2 cut along a plane passing through the line 2A. FIG. 4 is a diagram for explaining a method for producing the organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a reflecting member. FIG. 5 is a diagram for explaining a method for producing the organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a reflecting member. FIG. 6 is a diagram for explaining a method for producing the organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a reflecting member. FIG. 7 is a diagram for explaining a method for producing the organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a reflecting member. FIG. 8 is a diagram for explaining a method for producing the organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a multilayer film for producing the organic EL light source device. . FIG. 9 is a diagram for explaining a method for producing an organic EL light source device according to the first embodiment of the present invention, and schematically showing a method for producing a multilayer film for producing an organic EL light source device. . FIG. 10 is a diagram illustrating a method for manufacturing the organic EL light source device according to the first embodiment of the present invention. FIG. 11 is a cross-sectional view schematically showing the layer structure of the organic EL light source device according to the second embodiment of the present invention. FIG. 12 is a cross-sectional view schematically showing the layer structure of the organic EL light source device according to the third embodiment of the present invention. FIG. 13 is a perspective view schematically showing a part of the reflecting member of the organic EL light source device according to the fourth embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and the gist of the present invention and its equivalent scope are described below. You may implement arbitrarily changing in the range which does not deviate. In the following description, the substrate includes not only a rigid member but also a flexible member such as a resin film.

[1. First embodiment]
FIG. 1 is a cross-sectional view schematically showing a layer configuration of the organic EL light source device according to the first embodiment of the present invention. In the present specification, unless otherwise specified, the organic EL light source device will be described in a state where the light emitting layer of the organic EL light source device is level and the light emitting surface of the device is placed upward. Therefore, unless otherwise specified, in the following description, the “horizontal plane” is a plane parallel to the main surface of the light emitting layer, the upper side of the light source device is the light emitting surface side, and the lower side is the opposite side of the light emitting surface. In addition, the main surface of the light emitting layer is usually parallel to the light emitting surface of the organic EL light source device. Furthermore, in the present specification, the fact that each component is “parallel” or “vertical” may include an error within a range that does not impair the effects of the present invention, for example, ± 5 from a parallel or vertical angle. An error of ° may be included.

  As shown in FIG. 1, the organic EL light source device 100 includes an organic EL element 110, an adhesive layer 130, and a reflective member 140 adhered to the lower side of the organic EL element 110 through the adhesive layer 130. . The organic EL element 110 includes a sealing substrate 111, a light emitting element 120 provided below the sealing substrate 111, and a substrate 112 provided below the light emitting element 120. The light emitting element 120 includes a first transparent electrode layer 121, a light emitting layer 122, and a second transparent electrode layer 123 in order from the top.

  The reflective member 140 includes a reflective substrate 141, a concavo-convex structure layer 142 provided on the top surface of the reflective substrate 141 and having a concavo-convex structure, and a reflective layer 143 provided on the top surface of the concavo-convex structure layer 142. The reflective layer 143 is adhered to the lower side of the substrate 112 via the adhesive layer 130. Therefore, the organic EL light source device 100 according to this embodiment includes the sealing substrate 111, the first transparent electrode layer 121, the light emitting layer 122, the second transparent electrode layer 123, the substrate 112, and the adhesive layer 130 in this order from the light exit surface side. , The reflective layer 143, the concavo-convex structure layer 142, and the reflective substrate 141 are provided in this order.

(1-1. Substrate and sealing substrate)
The sealing substrate 111 and the substrate 112 seal the light emitting element 120. Thereby, when the organic EL light source device 100 is used, it is possible to prevent the light emitting element 120 from being deteriorated due to contact with oxygen, moisture, or the like of the outside air.

  As the sealing substrate 111 and the substrate 112, a transparent material is used. Here, the term “transparent” means that it has a light transmittance suitable for use as an optical member. In the present embodiment, when the transparent member usually has a total light transmittance of 80% or more, it is handled as transparent. Specific examples include substrates that can be normally used as substrates for organic EL light-emitting elements, such as glass substrates, quartz glass substrates, and plastic substrates. The material constituting the sealing substrate 111 may be the same as or different from the material constituting the substrate 112. Both the thickness of the sealing substrate 111 and the substrate 112 may be set to 0.01 mm to 5 mm, for example.

(1-2. Light Emitting Element)
The light emitting element 120 includes a first transparent electrode layer 121, a light emitting layer 122, and a second transparent electrode layer 123 in this order, and power supplied from the first transparent electrode layer 121 and the second transparent electrode layer 123. As a result, the light emitting layer 122 emits light.

  The first transparent electrode layer 121 and the second transparent electrode layer 123 are positioned closer to the light exit surface 111U than the light emitting layer 122 and closer to the reflective layer 143, respectively, and either one functions as an anode. The other functions as a cathode. The material which comprises these is not specifically limited, You may select suitably the known material used as a transparent electrode of an organic electroluminescent light emitting element. Further, between the first transparent electrode layer 121 and the second transparent electrode layer 123, in addition to the light emitting layer 122, for example, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a gas barrier layer, etc. Another layer (not shown) may be further included.

Examples of the material of the first transparent electrode layer 121 and the second transparent electrode layer 123 include a metal thin film, ITO (indium tin oxide), IZO (indium zinc oxide), and SnO ₂ . In addition, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

  Specific examples of the layer configuration of the light emitting element 120 include, for example, an anode / hole transport layer / light emitting layer / cathode configuration, an anode / hole transport layer / light emitting layer / electron injection layer / cathode configuration, and an anode / hole. Structure of injection layer / light emitting layer / cathode, anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode structure, anode / hole transport layer / light emitting layer / electron injection layer / Equipotential surface formation layer / hole transport layer / light emitting layer / electron injection layer / cathode structure, anode / hole transport layer / light emitting layer / electron injection layer / charge generation layer / hole transport layer / light emitting layer / electron An injection layer / cathode configuration and the like can be mentioned.

  The light emitting element 120 includes a light emitting layer 122 between an anode and a cathode. At this time, the light-emitting layer 122 may be a single-layer structure including only one layer, or may be a multilayer structure including two or more layers. Further, as the light-emitting layer 122, a stacked body of a plurality of layers having different emission colors or a mixed layer in which a different dye is doped in a certain dye layer may be used.

The material of each layer is not particularly limited, and the type of material may be one type or two or more types. Examples of the material included in the light emitting layer 122 include polyparaphenylene vinylene-based, polyfluorene-based, and polyvinylcarbazole-based materials. Examples of materials contained in the hole injection layer and the hole transport layer include phthalocyanine-based, arylamine-based, and polythiophene-based materials. Examples of materials contained in the electron injection layer and the electron transport layer include aluminum complexes and lithium fluoride. Examples of the equipotential surface forming layer or the charge generation layer include transparent electrodes such as ITO, IZO, and SnO _2, and metal thin films such as Ag and Al.

  For example, the first transparent electrode layer 121, the light emitting layer 122, the second transparent electrode layer 123, and other optional layers constituting the light emitting element 120 are sequentially stacked on the surface of the sealing substrate 111 or the substrate 112. Can be provided. The thickness of each of these layers may be, for example, 10 nm to 1000 nm.

(1-3. Adhesive layer)
The adhesive layer 130 is a layer formed of an adhesive material. Here, the material having adhesiveness is a material exhibiting adhesiveness at the use temperature, and for example, an adhesive having a shear storage elastic modulus at 23 ° C. of less than 1 MPa can be used. The reflective member 140 can be fixed to the organic EL element 110 by the adhesive layer 130 adhering the reflective layer 143 and the layer (the substrate 112 in this embodiment) in contact with the adhesive layer 130 on the upper side. The adhesive layer 130 is a flexible layer. When the adhesive layer 130 is pressed against the uneven surface 143U of the reflective layer 143, the adhesive layer 130 enters the recess 144 (see FIG. 2) of the uneven surface 143U, The entire surface of the concavo-convex surface 143U can be in close contact.

  The adhesion layer 130 includes an acrylic polymer containing a hydroxyl group (that is, an —OH group). When the acrylic polymer contains a hydroxyl group, the adhesion of the adhesive layer 130 to an inorganic material such as metal, glass, metal compound (ITO, etc.) is increased, and the adhesive layer 130 is hardly peeled off from the organic EL element 110 and the reflecting member 140. be able to. Further, the high adhesion of the pressure-sensitive adhesive layer 130 is unlikely to decrease over time. For this reason, the temporal degradation of the light extraction efficiency due to the peeling of the adhesive layer 130 can be suppressed. The reason why the adhesion can be improved by the hydroxyl group is not necessarily clear, but it is assumed that the high adhesion as described above can be realized by bonding the hydroxyl group to the polar group existing on the surface of the inorganic material. .

  Further, unlike a carboxyl group (—COOH group) or the like, a hydroxyl group hardly corrodes a metal. For this reason, even when the reflective layer 143 that is in close contact with the adhesive layer 130 is formed of metal, the reflectance of the reflective layer 143 is hardly reduced due to corrosion. Therefore, the light extraction efficiency due to the decrease in the reflectance of the reflective layer 143 is reduced. A decrease with time can be suppressed.

  Moreover, a molecule | numerator can be bridge | crosslinked because an acrylic polymer contains a hydroxyl group. By crosslinking, the cohesive strength of the pressure-sensitive adhesive is increased, and heat resistance and moisture resistance are improved.

  Furthermore, when the acrylic polymer contains a hydroxyl group, the dispersibility of the inorganic fine particles contained in the adhesive layer 130 can be improved. For this reason, inorganic fine particles can be prevented from aggregating into a lump, and the refractive index of the adhesive layer 130 can be adjusted stably by the inorganic fine particles.

  An acrylic polymer means a polymer of acrylic acid or an acrylic acid derivative. Moreover, an acrylic polymer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. In this embodiment, since the acrylic polymer contains a hydroxyl group, the acrylic polymer according to this embodiment is usually a polymer obtained by polymerizing an acrylic monomer containing a hydroxyl group. Therefore, the acrylic polymer according to the present embodiment usually includes a repeating unit derived from an acrylic monomer containing a hydroxyl group.

  Examples of acrylic monomers containing hydroxyl groups include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, chloro-2-hydroxypropyl (meth) acrylate, etc. (Meth) acrylates containing the hydroxyl groups of Here, (meth) acrylate means acrylate and methacrylate. Moreover, the acrylic monomer containing a hydroxyl group may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The acrylic polymer according to this embodiment may be a copolymer of an acrylic monomer containing a hydroxyl group and a monomer copolymerizable with the acrylic monomer. Therefore, the acrylic polymer according to the present embodiment may include a repeating unit derived from a monomer copolymerizable with an acrylic monomer containing a hydroxyl group.

  When the example of the monomer copolymerizable with the acrylic monomer containing a hydroxyl group is given, As a monomer which does not contain acidic groups, such as a carboxyl group, (meth) acrylic acid ester, a styrene monomer, a vinyl monomer, etc. are mentioned.

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl. Examples include (meth) acrylate, cyclohexyl (meth) acrylate, diethylene glycol mono (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, acrylamide, and glycidyl (meth) acrylate.

  Examples of the styrenic monomer include styrene; alkyl styrene such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; Halogenated styrene such as chlorostyrene, bromostyrene, dibromostyrene and iodostyrene; nitrostyrene, acetylstyrene and methoxystyrene.

  Examples of vinyl monomers include vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, divinyl benzene, vinyl acetate and acrylonitrile; conjugated diene monomers such as butadiene, isoprene and chloroprene; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride And vinylidene halides such as

  Examples of monomers that contain an acidic group among monomers that can be copolymerized with a hydroxyl group-containing acrylic monomer include (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, and fumaric acid. , Crotonic acid, maleic anhydride, itaconic anhydride, styrene sulfonic acid and the like.

  Here, (meth) acrylic acid means acrylic acid and methacrylic acid. Moreover, the monomer copolymerizable with the acrylic monomer containing a hydroxyl group may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  As the monomer copolymerizable with the above-mentioned acrylic monomer containing a hydroxyl group, it is preferable to use a monomer that does not contain an acidic group. This is because the acidic group may corrode the metal of the reflective layer 143 or prevent the dispersion of inorganic fine particles.

  The acrylic monomer containing a hydroxyl group is usually at least 2.0 parts by weight, preferably 5. 5 parts by weight, based on 100 parts by weight of all monomers (that is, the total of acrylic monomers containing a hydroxyl group and monomers copolymerizable therewith). 0 parts by weight or more, more preferably 7.0 parts by weight or more, usually 50 parts by weight or less, preferably 40 parts by weight or less, more preferably 30 parts by weight or less. This is because a sufficient amount of the acrylic monomer containing a hydroxyl group is secured, and the above-described action of the hydroxyl group is stably exhibited. In general, the amount of the repeating unit derived from the acrylic monomer containing a hydroxyl group when all the repeating units contained in the acrylic polymer are 100 parts by weight is the same as the range of the monomer.

  The weight average molecular weight of the acrylic polymer containing a hydroxyl group is usually 100,000 or more, preferably 300,000 or more, more preferably 500,000 or more, and usually 2 million or less, preferably 1.5 million or less, more preferably 1 million or less. is there. Thereby, it is possible to suitably perform punching, re-peeling, and the like of the film on which the adhesive layer is formed. The weight average molecular weight of the acrylic polymer containing a hydroxyl group can be measured by gel permeation chromatography (GPC).

  The synthesis of the acrylic polymer may be performed by a known polymerization method. For example, an acrylic polymer can be produced by dissolving or dispersing a monomer in an organic solvent and reacting the solution or dispersion in a reactor substituted with an inert gas such as nitrogen gas.

  Moreover, the adhesion layer 130 contains inorganic fine particles. The inorganic fine particles are dispersed in the pressure-sensitive adhesive layer 130 and have an effect of increasing the refractive index of the pressure-sensitive adhesive layer 130. By increasing the refractive index of the adhesive layer 130, the difference in refractive index can be reduced at the interface 112D between the adhesive layer 130 and the layer that contacts the adhesive layer 130 on the upper side (the substrate 112 in this embodiment). It is possible to reduce reflection. By reducing the reflection at the interface 112D of the light generated in the light emitting layer 122, the effect of improving the light extraction efficiency due to the reflection at the reflection layer 143 can be enhanced.

  The specific refractive index range of the adhesive layer 130 is preferably 1.65 or more, more preferably 1.70 or more, particularly preferably 1.75 or more, and preferably 3.0 or less, preferably 2.5 or less. More preferred is 2.2 or less.

  As the inorganic fine particles, for example, fine particles of titanium oxide, zirconium oxide, zinc oxide, tantalum pentoxide, barium titanate, silicon nitride, ITO, IZO and the like can be suitably used. In addition, one kind of inorganic fine particles may be used alone, or two or more kinds may be used in combination at any ratio.

The inorganic fine particles are preferably subjected to a surface treatment in order to improve dispersibility in the adhesive layer 130. As an example of the surface treatment, a treatment for coating the surface of the inorganic fine particles with an appropriate surface treatment agent may be mentioned.
Examples of surface treatment agents include silane coupling agents; metal chelating agents; hydroxyl, phosphate, carboxyl, amino, and alkoxy groups as adsorbing components for inorganic fine particles, polyester, polyether, acrylic, urethane And organic dispersants having a main skeleton of epoxy, silicone and the like; isocyanate compounds having a polymerizable functional group, and the like. Of these, silane coupling agents and isocyanate compounds having a polymerizable functional group are preferred.

  Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n -Octyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropro Lutriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyl Trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, vinyltrimethoxysilane, vinyltriethoxysilane, p- styryl trimethoxysilane, 3-methacryloxypropyl trimethoxy silane, 3-methacryloxypropyl triethoxysilane, 3-acryloxy propyl trimethoxy silane and the like.

Examples of the isocyanate compound having a polymerizable functional group include acryloxymethyl isocyanate, methacryloxymethyl isocyanate, acryloxyethyl isocyanate, methacryloxyethyl isocyanate, acryloxypropyl isocyanate, methacryloxypropyl isocyanate, 1,1-bis (acrylic). Roxymethyl) ethyl isocyanate and the like.
In addition, a surface treating agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The primary particle diameter of the inorganic fine particles is a median diameter, usually 5 nm or more, preferably 10 nm or more, more preferably 15 nm or more, and usually 150 nm or less, preferably 100 nm or less, more preferably 80 nm or less. By setting the primary particle size to be not less than the lower limit of the above range, the dispersion stability of the inorganic fine particles can be improved, and by setting the primary particle size to be not more than the upper limit, the transparency of the pressure-sensitive adhesive layer 130 can be increased. The median diameter as the primary particle diameter of the inorganic fine particles can be measured by a dynamic light scattering method.

  The amount of inorganic fine particles contained in the adhesive layer is usually 50 parts by weight or more, preferably 60 parts by weight or more, more preferably 65 parts by weight or more, and usually 90 parts by weight with respect to 100 parts by weight of the acrylic polymer containing a hydroxyl group. Part or less, preferably 80 parts by weight or less, more preferably 75 parts by weight or less. By setting the amount of the inorganic fine particles to be equal to or higher than the lower limit value of the above range, the refractive index of the pressure-sensitive adhesive layer 130 can be effectively increased.

  The adhesive layer 130 may contain components other than the acrylic polymer containing hydroxyl groups and the inorganic fine particles as long as the effects of the present invention are not significantly impaired. Examples of such a component include an acrylic polymer not containing a hydroxyl group, a crosslinking agent, and an optional additive. However, also about these components, what does not contain an acidic group is preferable. Moreover, these components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Examples of the crosslinking agent include polyisocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, melamine compounds, polyfunctional (meth) acrylates, and the like. Of these, polyisocyanate compounds and polyfunctional (meth) acrylates are more preferable.

  Examples of the polyisocyanate compounds include tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, diphenylmethane diisocyanate double product, reaction product of trimethylolpropane and tolylene diisocyanate, trimethylolpropane and hexaxylene. A reaction product with methylene diisocyanate, polyether polyisocyanate, polyester polyisocyanate and the like can be mentioned.

  Examples of the polyfunctional (meth) acrylate include compounds having at least two (meth) acryloyl groups. Here, the (meth) acryloyl group means an acryloyl group and a methacryloyl group. Specific examples of the compound having at least two (meth) acryloyl groups include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetraacrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-one hexanediol di (meth) acrylate, 1,12-dodecanediol Di (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, hexane All di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tetramethylol methanetri (meth) acrylate, allyl (meth) Examples include acrylate, vinyl (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate.

  Examples of additives include tackifiers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, silane coupling agents, antistatic agents, and flame retardants. Etc.

In the adhesive layer 130, the content of acrylic acid is preferably 3% by weight or less, more preferably 1.5% or less, and ideally particularly preferably 0% with respect to the acrylic polymer containing a hydroxyl group. When an acrylic polymer containing a hydroxyl group is produced, the product may contain acrylic acid due to, for example, remaining unreacted monomers. When this acrylic acid remains in the adhesive layer 130, the metal contained in the layer in contact with the adhesive layer 130 is corroded by acrylic acid, and the light extraction efficiency of the organic EL light source device 100 decreases with time, or the organic EL light source device 100 There is a possibility that the color of the light extracted from the yellow will become yellowish. For this reason, it is preferable that the content of acrylic acid in the adhesive layer 130 is small as described above. In addition, when the inorganic fine particles are surface-treated with a surface treatment agent, depending on the type of the surface treatment agent, there may be one that reacts with an acidic group to form a gel. There is also an advantage that the dispersibility of the inorganic fine particles can be improved by suppressing.
In order to reduce the content of acrylic acid in this way, for example, a monomer that is a material of an acrylic polymer containing a hydroxyl group may be appropriately selected, or acrylic acid may be extracted and removed after synthesis of the acrylic polymer. .

  The thickness of the pressure-sensitive adhesive layer 130 is preferably 110 or more, more preferably 120 or more, still more preferably 130 or more, preferably 200 or less, when the height of the uneven layer formed on the reflective layer is 100. Preferably it is 190 or less, More preferably, it is 180 or less.

(1-4. Reflective layer)
The reflective layer 143 is a layer that is in direct contact with the adhesive layer 130 without passing through another layer, and has an uneven surface 143U. The uneven surface 143U is a surface on the upper side of the reflective layer 143, and thus is a surface on the adhesive layer side of the reflective layer 143. Therefore, the reflective layer 143 and the adhesive layer 130 are in close contact with each other on the uneven surface 143U.

  In the organic EL light source device 100, part of the light emitted from the light emitting layer 122 may be internally reflected by the light exit surface 111U due to a large incident angle. However, even such light is diffused when reflected by the uneven surface 143U of the reflective layer 143, whereby the incident angle to the light exit surface 111U is reduced and the light exit surface 111U can be transmitted. Thus, by providing the reflective layer 143, the light that can be transmitted through the light exit surface 111U can be increased, so that the light extraction efficiency can be improved.

  For example, as shown in FIG. 1, the reflective layer 143 having the uneven surface 143 </ b> U is provided with an uneven structure layer 142 having an uneven structure on the upper surface of the reflective substrate 141, and is further reflected with a uniform film thickness on the surface of the uneven structure layer 142. By forming the layer 143, a structure can be obtained. In this case, normally, the main surface of the reflective substrate 141 is parallel to the main surface of the light emitting layer 122.

  Examples of the material constituting the reflective substrate 141 include the same materials as those constituting the sealing substrate 111 and the substrate 112. Among these, a resin substrate is preferable because of easy handling. Moreover, when using photocurable resin when forming the uneven | corrugated structure layer 142, it is preferable that the reflective base material 141 is transparent.

  The uneven structure layer 142 is usually formed of a transparent resin. Examples of the transparent resin include a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, and an electron beam curable resin. Among these, a thermoplastic resin is preferable because it can be easily deformed by heat, and an ultraviolet curable resin has high curability and high efficiency, so that the uneven structure layer 142 can be formed efficiently.

  Examples of the thermoplastic resin include polyester-based, polyacrylate-based, and cycloolefin polymer-based resins. Examples of the ultraviolet curable resin include epoxy resins, acrylic resins, urethane resins, ene / thiol resins, and isocyanate resins. These resins are preferably those having a plurality of polymerizable functional groups. In addition, the said resin may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  An example of the material of the reflective layer 143 is metal. By forming the reflective layer 143 from a metal, the reflective layer 143 can play a role of blocking oxygen and moisture in the air from entering the light emitting element 120 in addition to the substrate 112. Among these, as the material for the reflective layer 143, it is preferable to use at least one of aluminum and silver. This is because the reflectance by the reflective layer 143 can be effectively increased. Furthermore, silver is preferable from the viewpoint of suppressing light absorption by the metal and realizing a particularly high reflectance. Moreover, aluminum is preferable from the viewpoint that the barrier property can be easily improved by increasing the thickness of the reflective layer 143 because it is inexpensive.

  At this time, the material of the reflective layer 143 may be used alone or in combination of two or more at any ratio. In addition, the reflective layer 143 may be a single-layer structure including only one layer, or a multilayer structure including two or more layers. For example, the reflective layer 143 may have a multilayer structure in which a silver layer and an aluminum layer are combined, and the silver layer may be exposed on the uneven surface 143U. Thereby, both the high reflectance of silver and the excellent barrier property of aluminum can be utilized. Therefore, both the reflection performance and the sealing performance can be achieved, and the thickness of the reflection layer 143 as a whole can be suppressed.

FIG. 2 is a perspective view schematically showing a part of the reflecting member 140 of the organic EL light source device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a cross section of the reflecting member 140 shown in FIG. 2 cut along a plane passing through the line 2A.
As shown in FIGS. 2 and 3, the uneven surface 143U of the reflective layer 143 has an uneven structure, and thus has inclined surfaces 144A to 144D that are not parallel to the horizontal plane. Light is diffused by reflection at these inclined surfaces 144A to 144D, and the incident angle of the light emitted from the light emitting layer 122 to the light exit surface 111U can be reduced, so that the light extraction efficiency of the organic EL light source device 100 can be improved. It is like that.

  From the viewpoint of further increasing the light extraction efficiency, the average inclination angle of the concavo-convex surface 143U of the reflective layer 143 is preferably 17 ° or more, more preferably 20 ° or more, particularly preferably 25 ° or more, preferably 45 ° or less. More preferably, it is 40 ° or less, particularly preferably 35 ° or less. Here, the average inclination angle is an average value of the angle θ between the uneven surface 143U and the horizontal plane of the organic EL light source device 100.

  In the present embodiment, as shown in FIG. 2, the concavo-convex structure of the concavo-convex surface 143U has a shape in which regular quadrangular pyramid-shaped concavities 144 are provided side by side in two orthogonal directions. Here, for example, assuming that the length L of one side of the bottom surface of the regular quadrangular pyramid of the concave portion 144 is 0.1 mm and the depth (that is, the height of the regular quadrangular pyramid) H of the concave portion 144 is 0.05 mm, the concave portion 144. These four slopes 144A to 144D all form an angle θ of 45 ° with respect to the horizontal plane. Further, in this case, if the pitch P of the recesses 144 is 0.1 mm, the uneven surface 143U has no surface other than the slopes 144A to 144D. In this case, the uneven surface of the reflective layer 143 The average inclination angle of 143U is 45 °.

When the uneven structure of the uneven surface 143U is a more complicated shape such as a polyhedron or a curved surface, the average inclination angle is defined as follows. That is, when the concavo-convex surface 143U is divided into n minute areas sufficiently smaller than the unit of the concavo-convex structure (in this embodiment, the recess 144), and each minute area is denoted by ΔS _i , the aforementioned ΔS _i The angle of inclination with the substrate plane is θ _i , and the average tilt angle is

Stipulated in here

Represents the entire area of the concavo-convex surface 143U of the reflective layer 143.

(1-5. Main advantages)
The organic EL light source device 100 according to the first embodiment of the present invention is configured as described above. Therefore, in use, the light emitting layer 122 is caused to emit light by applying a voltage to the first transparent electrode layer 121 and the second transparent electrode layer 123. A part of the light generated in the light emitting layer 122 is transmitted through the first transparent electrode layer 121 and the sealing substrate 111, and is emitted to the outside of the organic EL light source device 100 through the light emitting surface 111U. The other part of the generated light can take various paths. For example, after passing through the second transparent electrode layer 123, the light passes through the substrate 112 and the adhesive layer 130 and reaches the uneven surface 143 </ b> U of the reflective layer 143. Then, the light is reflected by the concavo-convex surface 143U, follows an upward path, and exits from the light exit surface 111U. Furthermore, in addition to the reflection on the uneven surface 143U of the reflective layer 143, reflection can also occur at the interface between the layers from the sealing substrate 111 to the adhesive layer 130. Of these, the sealing substrate 111 to the adhesive layer 130 are reflected. The light reflected downward at the interface between the respective layers is changed in the traveling direction by the concavo-convex surface 143U of the reflective layer 143 and is emitted to the outside of the organic EL light source device 100. In the organic EL light source device 100, light is diffused when reflected by the concave and convex surface 143U of the reflective layer 143, so that the light extraction efficiency can be increased.

  Further, since the uneven surface 143U of the reflective layer 143 is non-planar, the distance between the light emitting layer 122 and the reflective layer 143 is not constant. For this reason, normally, the interference of the light between each layer from the sealing substrate 111 to the adhesion layer 130 can be suppressed. Therefore, it is possible to suppress the reduction of the light amount due to the interference and increase the light extraction efficiency.

  Moreover, since the adhesive layer 130 contains inorganic fine particles, the refractive index of the adhesive layer 130 is increased. When a material having a close refractive index difference between the adhesive layer 130 and the substrate 112 is used, reflection of light at the interface 112D can be reduced. For this reason, since the amount of light that is reflected by both the light exit surface 111U and the interface 112D and cannot be extracted from the organic EL light source device 100 can be reduced, the effect of improving the light extraction efficiency by reflection at the reflective layer 143 is enhanced. Can do.

  In addition, since the adhesive layer 130 includes an acrylic polymer containing a hydroxyl group, the adhesiveness of the adhesive layer 130 to the substrate 112 and the reflective layer 143 can be improved, and a decrease in light extraction efficiency over time due to peeling of the adhesive layer 130 can be suppressed. .

Furthermore, since an acrylic polymer containing a hydroxyl group is unlikely to cause metal corrosion, a decrease in dispersibility of inorganic fine particles, and generation of a gel, high light extraction efficiency can be maintained over a long period of time.
Here, as a technique for preventing the corrosion of the metal contained in the reflective layer 143, a protective layer may be provided on the uneven surface 143U of the reflective layer 143. However, in that case, the cost increases by the amount of the protective layer. Moreover, since the range of the refractive index of a protective layer is restrict | limited from a viewpoint of making the refractive index difference of the adhesion layer 130 and a protective layer small, the freedom degree of material selection of a protective layer becomes low. On the other hand, the organic EL light source device 100 of the present embodiment is preferable because there is no such problem.

(1-6. Manufacturing method)
The organic EL light source device 100 of the present embodiment includes, for example, a multilayer film 160 (see FIG. 9) having a reflective layer 143, an adhesive layer 130, and a separator film 151 (see FIG. 8) that can be peeled from the adhesive layer 130 in this order. The separator film 151 is peeled from the multilayer film 160, and the exposed adhesive layer 130 and the organic EL element 110 are bonded together.
The multilayer film 160 can be manufactured by a manufacturing method including forming the adhesive layer 130 on the surface of the separator film 151 and bonding the adhesive layer 130 and the reflective layer 143 together.
Hereinafter, these manufacturing methods will be described with reference to the drawings.

FIGS. 4 to 7 are views for explaining a method for producing the organic EL light source device 100 according to the first embodiment of the present invention, and schematically showing a method for producing the reflecting member 140.
As shown in FIG. 4, when manufacturing the reflective member 140, first, a transparent resin is applied to the surface of the reflective substrate 141 to form a transparent resin coating film 145.

  Then, as shown in FIG. 5, the uneven | corrugated structure layer 142 is obtained by pressing the type | mold 146 to the coating film 145, and hardening the coating film 145 in the state. Here, it is assumed that the coating film 145 is cured by irradiating the coating film 145 with light through the reflective substrate 141 as indicated by an arrow A1. The mold 146 has a concavo-convex structure in which the concavo-convex structure of the concavo-convex surface 143U of the reflective layer 143 is inverted. Therefore, the concavo-convex structure similar to the concavo-convex surface 143U of the reflective layer 143 is transferred to the concavo-convex structure layer 142, which is a layer obtained by curing the coating film 145, as shown in FIG.

  Thereafter, the mold 146 is removed from the concavo-convex structure layer 142, and a reflective layer 143 is formed on the surface of the concavo-convex structure layer 142 as shown in FIG. The reflective layer 143 may be formed by evaporating a metal material on the surface of the concavo-convex structure layer 142, for example, as indicated by an arrow A2. The vapor deposition method is preferable in that a uniform layer having a large area can be formed. By forming the reflective layer 143, the reflective member 140 including the reflective substrate 141, the concavo-convex structure layer 142, and the reflective layer 143 in this order is obtained. Since the thickness of the reflective layer 143 is uniform, the shape of the upper surface of the reflective layer 143 is the same as the shape of the surface of the concavo-convex structure layer 142. Therefore, an uneven surface 143U having a desired uneven structure is formed on the upper surface of the reflective layer 143.

FIGS. 8 and 9 are diagrams for explaining a method of manufacturing the organic EL light source device 100 according to the first embodiment of the present invention, and manufacturing a multilayer film 160 for manufacturing the organic EL light source device 100. It is a figure which shows a method typically.
As shown in FIG. 8, when manufacturing the multilayer film 160, the adhesive film 150 provided with the adhesion layer 130 and the separator film 151 which can be peeled from the adhesion layer 130 in this order is prepared. The pressure-sensitive adhesive film 150 is, for example, applied to the surface of the separator film 151 with a liquid composition containing an acrylic polymer or a monomer thereof, inorganic fine particles, an appropriate solvent, and other components used as necessary. It can manufacture by removing a solvent from a coating film by drying, and polymerizing or bridge | crosslinking the component in a coating film as needed, and hardening a coating film.

  The prepared adhesive film 150 is bonded to the reflecting member 140 as shown by an arrow A3 in FIG. The direction of bonding is such that the pressure-sensitive adhesive layer 130 of the pressure-sensitive adhesive film 150 and the reflective layer 143 of the reflective member 140 are bonded together. Thereby, as shown in FIG. 9, the multilayer film 160 provided with the reflective substrate 141, the uneven structure layer 142, the reflective layer 143, the adhesion layer 130, and the separator film 151 in this order is manufactured. Since the multilayer film 160 obtained in this manner includes the reflective layer 143 having the uneven surface 143U having a shape corresponding to the application, the organic EL light source device 100 is specified by specifying not only the layer configuration but also the shape of the uneven surface 143U. It can be specified that the film is for production of

  Then, as shown in FIG. 10, after peeling the separator film 151 from the multilayer film 160, the exposed adhesive layer 130 is bonded to the substrate 112 of the organic EL element 110 as indicated by an arrow A4. An organic EL light source device 100 as shown in FIG. 1 can be manufactured.

According to the manufacturing method described here, the organic EL light source device 100 according to the present embodiment can be easily manufactured. In particular, providing the adhesive layer 130 on the reflective layer 143 by bonding the adhesive film 150 and the reflective member 140 is effective in improving the light extraction efficiency of the organic EL light source device 100. Hereinafter, this point will be described.
As a method of forming the adhesive layer 130 on the reflective layer 143, for example, a method of forming the adhesive layer 130 by applying a composition for forming the adhesive layer 130 on the reflective layer 143 and drying it. However, in this method, the liquid composition cannot completely enter the concave portion 144 of the concave and convex surface 143U of the reflective layer 143, and there is a possibility that minute bubbles are generated. Further, in a composition including a solvent, an acid such as acrylic acid and an acidic group such as a carboxyl group included in the composition may easily corrode a metal included in the reflective layer 143. In particular, when the composition is heated or irradiated with ultraviolet rays to cure the composition, the corrosion may be accelerated.
On the other hand, when the adhesive layer 130 is provided on the reflective layer 143 by bonding the adhesive film 150 and the reflective member 140 as in the present embodiment, the adhesive layer 130 is uneven by applying pressure during the bonding. Since it can be easily adhered to the surface 143U, generation of bubbles can be prevented. Moreover, since the adhesive layer 130 after hardening is bonded together, it is also possible to suppress the corrosion of the metal contained in the reflective layer 143. In order to prevent the deterioration of the organic EL element 110, the bonding temperature is preferably 40 ° C. or lower.

  In addition, in the manufacturing method mentioned above, you may perform another process. For example, before the reflecting member 140 and the adhesive film 150 are bonded together, a process of removing dirt on the uneven surface 143U that is the surface of the reflecting layer 143 may be performed. Examples of the treatment in the step of removing dirt include removal with an adhesive roll, plasma treatment, corona treatment, and UV ozone treatment.

[2. Second embodiment]
FIG. 11 is a cross-sectional view schematically showing a layer structure of the organic EL light source device 200 according to the second embodiment of the present invention. As shown in FIG. 11, in the organic EL light source device 200, the organic EL element 210 does not include the sealing substrate 112, and the adhesive layer 130 directly adheres to the second transparent electrode layer 123 without passing through other layers. Except that, it is the same as the first embodiment.

  Also in this organic EL light source device 200, light is diffused when reflected by the concave and convex surface 143U of the reflective layer 143, so that the light extraction efficiency can be increased. Further, since the adhesive layer 130 contains inorganic fine particles, the refractive index of the adhesive layer 130 is increased, and the refractive index difference at the interface 123D between the adhesive layer 130 and the second transparent electrode layer 123 can be reduced. The effect of improving the light extraction efficiency due to the reflection of the light can be enhanced. Furthermore, since the adhesive layer 130 includes an acrylic polymer containing a hydroxyl group, the adhesiveness of the adhesive layer 130 to the second transparent electrode layer 123 and the reflective layer 143 is improved, and the light extraction efficiency due to the peeling of the adhesive layer 130 over time is increased. Reduction can be suppressed. Since the acrylic polymer containing a hydroxyl group hardly causes a decrease in the conductivity of the second transparent electrode layer 123, high luminous efficiency can be obtained over a long period of time. Also, the organic EL light source device 200 of the present embodiment can obtain the same advantages as the organic EL light source device 100 of the first embodiment.

[3. Third Embodiment]
FIG. 12 is a cross-sectional view schematically showing a layer configuration of the organic EL light source device 300 according to the third embodiment of the present invention. As shown in FIG. 12, the organic EL light source device 300 employs a concavo-convex structure having a curved surface as the concavo-convex structure layer 342 of the reflection member 340, and a reflective layer having a uniform film thickness on the surface of the concavo-convex structure layer 342. Except that the uneven surface 343U, which is the upper surface of the reflective layer 343, has a curved surface by providing 343, it is the same as in the first embodiment. Also in the organic EL light source device 300 of the present embodiment, the same advantages as those of the organic EL light source device 100 of the first embodiment can be obtained. Furthermore, since the uneven surface 343U has a curved surface, the reflection direction on the uneven surface 343U is more diffused than when an uneven surface composed only of a flat surface is adopted, and the light extraction efficiency can be further increased. . In general, when the light exit surface 111U is observed, it is possible to prevent an image of an object existing at a position closer to the observer than the light exit surface 111U from being reflected.

[4. Fourth Embodiment]
FIG. 13 is a perspective view schematically showing a part of the reflecting member 440 of the organic EL light source device according to the fourth embodiment of the present invention. As shown in FIG. 13, the reflective member 440 of the organic EL light source device according to the present embodiment employs a concavo-convex structure layer 442 that has a concavo-convex concavo-convex structure arranged in parallel to each other, and this concavo-convex structure layer 442. In the same manner as in the first embodiment, except that the uneven surface 443U, which is the upper surface of the reflective layer 443, is arranged in parallel with each other by providing the reflective layer 443 with a uniform film thickness on the surface of It is. Here, the line shape means a periodic shape in which pillars such as prisms and cylinders are arranged in parallel. In FIG. 13, since the concavo-convex structure has a shape in which triangular prisms are arranged, a cross section of the organic EL light source device according to the present embodiment taken along a plane orthogonal to the direction in which the triangular prisms extend is shown in FIG. It becomes the same as the organic EL light source device 100 shown. In the organic EL light source device of this embodiment, the same advantages as those of the organic EL light source device 100 of the first embodiment can be obtained.

[5. Other variations)
The above-described embodiment may be further modified and implemented.
For example, the uneven surface of the reflective layer may have a shape other than the shape in each of the above embodiments. Specifically, instead of the regular quadrangular pyramid as shown in FIG. 2, the shape of the concave portion is a pyramid other than the regular quadrangular pyramid, a prism, a trapezoidal cross-sectional shape that is a part of a pyramid, a cone, a sphere, or an elliptic rotating body. It may be partly shaped. Further, for example, a convex portion may be provided instead of the concave portion of these shapes, or a combination of the concave portion and the convex portion may be provided. Furthermore, the concave and convex surfaces may have different shapes of concave portions or convex portions, may have different sizes of concave portions or convex portions, and there is an interval between adjacent concave portions or convex portions. It may be. However, it is preferable that the height H of the concave portion or the convex portion of these uneven surfaces is 0.3 μm to 100 μm as the difference between the highest portion and the lower portion. Further, the pitch P of the concave or convex portions is usually 0.1 μm or more, preferably 0.15 μm or more, more preferably 0.2 μm or more, and usually 500 μm or less, preferably 450 μm or less, more preferably 400 μm or less. .

  Further, for example, in the above-described embodiment, the member including the reflective base material, the concavo-convex structure layer, and the reflective layer is shown as the reflective member. It may be configured from the above, and conversely, an arbitrary layer may be further included in addition to these layers.

  Furthermore, for example, another layer may be provided in the organic EL light source device described above. Specific examples thereof include a gas barrier layer that protects the organic EL element from the outside air and moisture, an ultraviolet cut layer that blocks ultraviolet rays, and a diffusion layer that diffuses light. Furthermore, you may provide the arbitrary components which comprise a light source device, such as the sealing member which seals the edge of a light emitting element, and the electricity supply means for supplying with electricity to an electrode layer.

[6. (Use)
Although the use of the organic EL light source device of the present invention is not particularly limited, it may be used as a light source for a backlight of a liquid crystal display device, an illumination device, etc., taking advantage of high light extraction efficiency and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples shown below, and may be arbitrarily selected within the scope of the gist of the present invention and its equivalent scope. You may change and implement. In the following description, “parts” and “%” indicating amounts are based on weight unless otherwise specified. In addition, the operations described below were performed under normal temperature and normal pressure conditions unless otherwise specified.

[Production of organic EL element]
A light emitting element including a first transparent electrode layer, an organic light emitting layer, and a second transparent electrode layer was provided on one surface of a 0.7 mm thick high refractive index glass substrate (refractive index 1.8). . A sealant (refractive index 1.53) was applied on one surface of a 0.7 mm thick glass sealing substrate (refractive index 1.51). The surface where the sealing agent of the sealing substrate was applied and the surface on the second transparent electrode layer side of the light emitting element were bonded together. An energization means for the first transparent electrode layer and the second transparent electrode layer was provided in the peripheral part of the light emitting element, and the peripheral part was sealed with a sealant to obtain an organic EL element.

[Manufacture of reflective layer having uneven surface]
Acrylic UV curable resin (“World Rock 5550” manufactured by Kyoritsu Chemical Industry Co., Ltd., refractive index n = 1.53) is applied to one surface of a reflective substrate made of a polyester film (“Lumirror U34” manufactured by Toray Industries, Inc.) Then, a coating film was formed. A metal mold having a predetermined shape was pressed against the coating film, and the coating film was cured by irradiating the coating film with an integrated light amount of 1000 mJ / cm ² through a reflective substrate. Thereby, an uneven structure layer was formed on the surface of the reflective substrate.

  Next, the mold was peeled from the concavo-convex structure layer to obtain a concavo-convex substrate including a reflective substrate and a concavo-convex structure layer. The surface of the concavo-convex structure layer of the obtained concavo-convex substrate has a concavo-convex concavo-convex surface. Met. The angle θ formed by the inclined surface constituting the recess with respect to the surface of the reflective substrate was 30 °. Further, the length L of the bottom of the recess (that is, the bottom of the regular quadrangular pyramid) was 20 μm. Further, the recesses were arranged at a pitch P of 20 μm in two directions orthogonal to each other within the surface of the concavo-convex structure layer. A reflective layer was formed by vacuum-depositing silver with a thickness of 200 nm on the uneven surface of the obtained uneven substrate. Thereby, the reflective member provided with the reflective substrate, the uneven structure layer, and the reflective layer in this order was obtained. In the reflective layer of this reflective member, the surface of the reflective layer was an uneven surface having the same shape as the uneven surface of the uneven substrate.

[Composition of acrylic adhesive coating solution]
[Production of Acrylic Copolymer A]
80.0 parts by weight of n-butyl acrylate, 10.0 parts by weight of cyclohexyl acrylate, 10.0 parts by weight of 2-hydroxyethyl acrylate, and 0.4 parts by weight of 2,2-azoisobutyl nitrile as a polymerization initiator were mixed with ethyl acetate. It melt | dissolved in 100 weight part, and after nitrogen substitution, it superposed | polymerized at 80 degreeC for 8 hours, and obtained the acrylic copolymer A with a weight average molecular weight 900,000.

[Production of Acrylic Copolymer B]
80.0 parts by weight of n-butyl acrylate, 10.0 parts by weight of cyclohexyl acrylate, 10.0 parts by weight of acrylic acid, and 0.4 parts by weight of 2,2-azoisobutyl nitrile as a polymerization initiator were added to 100 parts by weight of ethyl acetate. After being substituted with nitrogen, the mixture was polymerized at 80 ° C. for 8 hours to obtain an acrylic copolymer B having a weight average molecular weight of 900,000.

[Production of Acrylic Copolymer C]
80.0 parts by weight of n-butyl acrylate, 10.0 parts by weight of cyclohexyl acrylate, 7.0 parts by weight of 2-hydroxyethyl acrylate, 3.0 parts by weight of acrylic acid, and 2,2-azoisobutylnitrile which is a polymerization initiator 0.4 part by weight was dissolved in 100 parts by weight of ethyl acetate, purged with nitrogen, and then polymerized at 80 ° C. for 8 hours to obtain an acrylic copolymer C having a weight average molecular weight of 900,000.

[Production of Acrylic Copolymer D]
80.0 parts by weight of n-butyl acrylate, 20.0 parts by weight of cyclohexyl acrylate, and 0.4 parts by weight of 2,2-azoisobutyl nitrile as a polymerization initiator were dissolved in 100 parts by weight of ethyl acetate. Polymerization was carried out at 80 ° C. for 8 hours to obtain an acrylic copolymer D having a weight average molecular weight of 900,000.

[Preparation of formulation liquid A]
ZrO ₂ nanoparticles (“ZR-010-02” manufactured by Solar Co., Ltd., average particle size 33.7 nm, methyl ethyl ketone dispersion) were added to the acrylic copolymer A, and ZrO ₂ was added to 100 parts by weight of the acrylic copolymer. ₂ nanoparticles were added to 70 parts by weight, diluted with ethyl acetate to a solid content concentration of 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Preparation of Formulation B]
To the acrylic copolymer A, TiO ₂ nanoparticles (“NOD-742GTF” manufactured by Nagase ChemteX Corporation, average particle size 48 nm, polyethylene glycol monomethyl ether dispersion) were added to TiO _{2 with} respect to 100 parts by weight of the acrylic copolymer. The nanoparticles were added to 70 parts by weight, diluted with ethyl acetate to a solid content concentration of 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Preparation of Compound C]
Ethyl acetate was added to the acrylic copolymer A, diluted so that the solid content concentration became 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Preparation of Formulation D]
ZrO ₂ nanoparticles (“ZR-010-02” manufactured by Solar Co., Ltd., average particle size 33.7 nm, methyl ethyl ketone dispersion) were added to the acrylic copolymer B, and ZrO ₂ was added to 100 parts by weight of the acrylic copolymer. ₂ nanoparticles were added to 70 parts by weight, diluted with ethyl acetate to a solid content concentration of 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Preparation of Formulation E]
ZrO ₂ nanoparticles (“ZR-010-02” manufactured by Solar Co., Ltd., average particle size 33.7 nm, methyl ethyl ketone dispersion) were added to the acrylic copolymer C, and ZrO ₂ was added to 100 parts by weight of the acrylic copolymer. ₂ nanoparticles were added to 70 parts by weight, diluted with ethyl acetate to a solid content concentration of 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Preparation of Formulation F]
ZrO ₂ nanoparticles (“ZR-010-02” manufactured by Solar Co., Ltd., average particle diameter 33.7 nm, methyl ethyl ketone dispersion) were added to the acrylic copolymer D, and ZrO ₂ was added to 100 parts by weight of the acrylic copolymer. ₂ nanoparticles were added to 70 parts by weight, diluted with ethyl acetate to a solid content concentration of 30 parts by weight, and sufficiently stirred. Hexamethylene diisocyanate was further added to the resulting blend so that hexamethylene diisocyanate was 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and the mixture was sufficiently stirred.

[Manufacture and evaluation of organic EL light source device]
[Example 1]
On the surface of the separator film subjected to the release treatment (“38X” manufactured by Lintec Corporation), the above blended solution A was applied so that the thickness after drying was 40 μm, dried at 80 ° C. for 15 minutes, and an adhesive layer was formed. Formed (adhesive film 1). As a result of analyzing the adhesive layer by gas chromatography mass spectrometry (GC-MS), the acrylic acid content was 0.0%. Moreover, it was 1.65 when the refractive index of the adhesion layer was measured with the spectroscopic ellipsometer.

The multi-layer film 1 was obtained by pressing the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film 1 against the reflective layer of the reflective member and pressurizing and pressing the pressure-sensitive layer to 0.5 MPa.
The separator film of the obtained multilayer film 1 was peeled off and bonded to the highly refractive glass substrate of the organic EL element to produce an organic EL light source device.

A constant current was passed through the obtained organic EL light source device to emit light, and the luminous intensity was measured using a viewing angle characteristic measuring / evaluating apparatus “EZ-contrast” manufactured by ELDIM, and the total amount of light was obtained. This value is taken as 100%.
Thereafter, the organic EL light source device was placed in a high-temperature and high-humidity tank at 65 ° C. and 90% RH for 250 hours, and the wet heat test was performed by measuring the total amount of light by emitting light in the same manner. There was no peeling of the adhesive layer after the wet heat test, and there was no decrease in the total amount of light compared to before the wet heat test.

[Example 2]
A multilayer film 2 was produced in the same manner as in Example 1 except that the blending liquid A was changed to the blending liquid B. The acrylic acid content of the adhesive layer of the multilayer film 2 was 0.0%, and the refractive index of the adhesive layer was 1.77.

  An organic EL light source device was manufactured and evaluated in the same manner as in Example 1 except that the multilayer film 2 was used instead of the multilayer film 1. Compared with Example 1, the total light quantity of the organic EL light source device before the wet heat test was improved by 15%. In addition, there was no peeling of the adhesive layer after the wet heat test, and there was no decrease in the total light quantity compared to before the wet heat test.

Example 3
A multilayer film 3 was produced in the same manner as in Example 1 except that the blending liquid A was changed to the blending liquid E. The acrylic acid content of the adhesive layer of the multilayer film 3 was 1.5%, and the refractive index of the adhesive layer was 1.65.

  An organic EL light source device was manufactured and evaluated in the same manner as in Example 1 except that the multilayer film 3 was used instead of the multilayer film 1. The total amount of light of the organic EL light source device before the wet heat test was the same value as in Example 1. Further, there was no peeling of the adhesive layer after the wet heat test, and the total light quantity was reduced by 5% compared to before the wet heat test.

[Comparative Example 1]
A multilayer film 4 was produced in the same manner as in Example 1 except that the blending liquid A was changed to the blending liquid C. The acrylic acid content of the adhesive layer of the multilayer film 4 was 0.0%, and the refractive index of the adhesive layer was 1.49.

  An organic EL light source device was manufactured and evaluated in the same manner as in Example 1 except that the multilayer film 4 was used instead of the multilayer film 1. The total amount of light of the organic EL light source device before the wet heat test was reduced by 20% compared to Example 1. In addition, there was no peeling of the adhesive layer after the wet heat test, and there was no decrease in the total light quantity compared to before the wet heat test.

[Comparative Example 2]
A multilayer film 5 was produced in the same manner as in Example 1 except that the blending liquid A was changed to the blending liquid D. The acrylic acid content of the adhesive layer of the multilayer film 5 was 4.0%, and the refractive index of the adhesive layer was 1.65.

  An organic EL light source device was manufactured and evaluated in the same manner as in Example 1 except that the multilayer film 5 was used instead of the multilayer film 1. The total amount of light of the organic EL light source device before the wet heat test was the same value as in Example 1. Further, there was no peeling of the adhesive layer after the wet heat test, and the total light quantity was reduced by 40% compared to before the wet heat test.

[Comparative Example 3]
A multilayer film 6 was produced in the same manner as in Example 1 except that the blending liquid A was changed to the blending liquid F. The acrylic acid content of the adhesive layer of the multilayer film 6 was 0.0%, and the refractive index of the adhesive layer was 1.65.

  An organic EL light source device was manufactured and evaluated in the same manner as in Example 1 except that the multilayer film 6 was used instead of the multilayer film 1. The total amount of light of the organic EL light source device before the wet heat test was the same value as in Example 1. Further, after the wet heat test, the pressure-sensitive adhesive layer was largely peeled from the end portion.

[Consideration]
Comparing Examples 1 to 3 with Comparative Example 1, the refractive index of the adhesive layer was improved by the inorganic fine particles, and the refractive index difference between the adhesive layer and the glass substrate was reduced. It can be seen that the reflection at the interface between the two decreases and the extraction efficiency is improved.
Moreover, when Examples 1-3 are compared with Comparative Example 2, it turns out that the fall of the total light quantity after a wet heat test was suppressed because the acrylic polymer contained in an adhesion layer contains a hydroxyl group. Even when used in a harsh environment such as a wet heat test, the decrease in the total light amount can be suppressed, so the decrease in light extraction efficiency over time is suppressed in the samples of Examples 1 to 3, and the high light extraction efficiency over a long period of time. I can expect.
Furthermore, when Examples 1 to 3 are compared with Comparative Example 3, the acrylic polymer containing a hydroxyl group can maintain high adhesion between the adhesive layer and the glass substrate, so the light extraction efficiency due to peeling of the adhesive layer over time. It turns out that a fall can be suppressed.
From the above, according to the present invention, it was confirmed that an organic EL light source device having high light extraction efficiency and capable of suppressing a temporal decrease in the light extraction efficiency can be realized.

DESCRIPTION OF SYMBOLS 100 Organic EL light source device 110 Organic EL element 111 Sealing substrate 111U Light emission surface 112 Substrate 112D Interface between substrate and adhesive layer 120 Light emitting element 121 First transparent electrode layer 122 Light emitting layer 123 Second transparent electrode layer 123D Second Interface between transparent electrode layer and adhesive layer 130 Adhesive layer 140 Reflective member 141 Reflective substrate 142 Concavity and convexity structure layer 143 Reflective layer 143U Concavity and convexity 144 Concavity 144A to 144D Slope 145 Coating film 146 Type 150 Adhesive film 151 Separator film 160 Multi-layer film 200 Organic EL light source device 210 Organic EL element 300 Organic EL light source device 340 Reflective member 342 Uneven structure layer 343 Reflective layer 343U Uneven surface 440 Reflective member 442 Uneven structure layer 443 Reflective layer 443U Uneven surface

Claims (8)

In order from the light-emitting surface side, an organic electroluminescence light source device having a first transparent electrode layer, a light emitting layer, a second transparent electrode layer, an adhesive layer and a reflective layer in this order,
The reflective layer has an uneven surface on the adhesive layer side of the reflective layer,
The said adhesion layer is an organic electroluminescent light source device containing the acrylic polymer and inorganic fine particle containing a hydroxyl group.   The organic electroluminescence light source device according to claim 1, wherein the adhesive layer has an acrylic acid content of 3% by weight or less based on the acrylic polymer.   The organic electroluminescence light source device according to claim 1 or 2, wherein the adhesive layer has a refractive index of 1.65 or more.   The organic electroluminescence light source device according to any one of claims 1 to 3, wherein the reflective layer includes at least one of silver and aluminum.   The organic electroluminescence light source device according to any one of claims 1 to 4, wherein an average inclination angle of the irregular surface is 17 ° to 45 °. It is a multilayer film for manufacture of the organic electroluminescence light source device according to any one of claims 1 to 5,
The multilayer film which has the said reflection layer, the said adhesion layer, and the separator film which can be peeled from the said adhesion layer in this order. It is a manufacturing method of the organic electroluminescence light source device according to any one of claims 1 to 5,
The separator film is peeled off from the multilayer film according to claim 6,
The manufacturing method of an organic electroluminescent light source device including bonding the said adhesion layer and the organic electroluminescent element which has a said 1st transparent electrode layer, the said light emitting layer, and a said 2nd transparent electrode layer in this order. It is a manufacturing method of the multilayer film of Claim 6, Comprising:
Forming the adhesive layer on the surface of the separator film;
The manufacturing method of a multilayer film including bonding the said adhesion layer and the said reflection layer together.

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