JP6127791B2 - Resin composition for light scattering layer, light scattering layer, and organic electroluminescence device - Google Patents

Description

The present invention relates to a resin composition for a light scattering layer used to increase the light emission efficiency of an organic electroluminescence (hereinafter also referred to as EL) device, a light scattering layer formed from the resin composition for a light scattering layer, and the The present invention relates to an organic EL device having a light scattering layer.

An organic EL element is a self-luminous element utilizing the principle that a fluorescent substance or the like emits light by recombination energy between holes injected from an anode and electrons injected from a cathode when an electric field is applied. In recent years, organic EL elements have been actively researched and developed in applications such as lighting devices and display devices.
In this specification, the “organic EL device” refers to all devices using organic EL elements such as an organic EL lighting device and an organic EL display device.

  For example, the organic EL display device has advantages in terms of visibility and viewing angle as compared with conventional CRTs and LCDs, and has excellent features such as weight reduction, thinning, and flexibility. However, in general, the refractive index of the organic layer including the light emitting layer is 1.6 to 2.1, which is higher than that of air. Therefore, total reflection or interference easily occurs at the interface of the emitted light, the light extraction efficiency is less than 20%, and most of the light is lost.

The basic structure of the organic EL device is a structure in which a translucent electrode, at least one organic layer including a light emitting layer, and a back electrode are sequentially stacked on a translucent substrate.
In an active matrix organic EL device, for example, a TFT substrate in which a plurality of pixel electrodes forming the back electrode and TFTs (thin film transistors) as switching elements are formed in a matrix is stacked on the organic layer. .

  Light emitted from the organic layer is reflected directly or by a back electrode formed of aluminum or the like, and is emitted from the translucent substrate. At that time, it is preferable that the generated light is efficiently extracted to the translucent substrate side. However, depending on the angle of incidence on the interface between adjacent layers having different refractive indexes, the light undergoes total reflection, and becomes guided light that is totally reflected in the surface direction inside the device, and is absorbed and attenuated inside to be extracted outside. I can't. The ratio of the guided light is determined by the relative refractive index of the adjacent layer. In the case of a general organic EL device, the relationship of the refractive index n is, for example, air (n = 1.0) / translucent substrate (n = 1.5) / translucent electrode (n = 2.0) / Organic layer (n = 1.7) / back electrode. In this case, the ratio of light that is not emitted to the atmosphere (air) but is guided inside the device is about 81%, and only about 19% of the total light emission amount can be effectively used.

  Providing a light scattering layer has been proposed as a method for improving the light extraction efficiency (see, for example, Patent Documents 1 to 3). In Patent Document 1, a light-transmitting layer having a refractive index equal to or higher than that of the light-emitting layer is provided on the light extraction surface side of the light-transmitting electrode, and adjacent to the light extraction surface side of the light-transmitting layer or An EL element in which a light scattering layer is substantially formed inside a light-transmitting layer is described. In Patent Documents 2 and 3, many proposals have been made regarding characteristics such as the characteristics of the light scattering particles of the light scattering layer, the difference in refractive index between the light scattering particles and the binder material, and the refractive index of the binder material. .

JP 2004-296429 A JP 2005-190931 A JP 2009-110930 A JP-A-11-329742 JP 2007-109575 A

The organic EL device includes a light emitting layer that emits white light, a light emitting layer that emits a specific color light such as blue, and three primary colors depending on the use of the lighting device or the display device. The thing using the multiple types of light emitting layer which light-emits different color light etc. are used. However, since the improvement rate of light extraction by the light scattering layer generally depends on the wavelength, the methods described in Patent Documents 1 to 3 have a problem that the color tone changes when used in a wide wavelength region.

In particular, in a color display device using an organic EL element, a light scattering layer or the like is provided in order to enhance viewing angle characteristics and color purity (for example, Patent Document 4). The problem of collapse. Patent Document 5 discloses a method of adjusting the extraction efficiency by changing the thickness of the light scattering layer for each color of the EL element, but this method is not practical because it requires complicated steps.

  The present invention is used as a light scattering layer installed between a translucent electrode and a translucent substrate in order to improve the light extraction efficiency of an organic EL device, and the wavelength dependency of the light extraction efficiency improvement rate is small and wide. It aims at providing the resin composition for light-scattering layers which can be used in a wavelength range, the light-scattering layer formed using this, and the organic EL apparatus which comprises this light-scattering layer.

The inventors of the present invention have reached the present invention as a result of intensive studies to solve the above-mentioned problems.
The resin composition for a light scattering layer of the present invention is
A resin composition for a light scattering layer used for forming a light scattering layer of an organic electroluminescence (EL) device,
It consists of a binder material containing at least one resin (A) and light scattering particles (B),
The light scattering particles (B) contain fluorine, the average particle diameter in the resin composition for light scattering layers is 200 nm or more and 600 nm or less, and the particle diameter is 600 nm or more with respect to the total amount of the light scattering particles (B). The content of the particles is 20% by volume or less,
The resin composition for a light scattering layer, wherein a difference in refractive index between the binder material and the light scattering particles (B) is 0.1 or more.

In the resin composition for a light scattering layer of the present invention, the binder material preferably has a refractive index of 1.65 or more.

In the light scattering layer resin composition of the present invention, the binder material preferably further contains metal oxide fine particles (C) having an average primary particle diameter of 100 nm or less.

The metal oxide fine particles (C) preferably include at least one metal oxide particle selected from the group consisting of ZrO ₂ and TiO ₂ .

In the resin composition for a light scattering layer of the present invention, the coefficient of variation of the light scattering particles (B) is preferably 30% or less.

  In the resin composition for a light scattering layer of the present invention, the resin (A) preferably has a double bond equivalent of 400 g / mol to 1600 g / mol.

In the resin composition for a light scattering layer of the present invention, the resin (A) preferably contains a cyclic skeleton in the main chain and / or side chain.

In the resin composition for a light scattering layer of the present invention, the resin (A) preferably contains an alkali-soluble group.

  In the light scattering layer resin composition of the present invention, it is preferable that the binder material further contains an ethylenically unsaturated monomer (D) having a double bond equivalent of 80 g / mol or more and 140 g / mol or less.

In the light scattering layer resin composition of the present invention, the binder material preferably further contains a silane compound (E) represented by the following general formula (1) having a urethane skeleton or an amide skeleton.

[In General Formula (1), R ¹ is an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a carbon number. An aralkyl group having 7 to 30 carbon atoms or an alkaryl group having 7 to 30 carbon atoms is represented.
X represents an alkylene group having 1 to 20 carbon atoms, an arylene group having 1 to 20 carbon atoms, or an alkyleneoxy group having 1 to 20 carbon atoms.
R ² _, R ³ and R ⁴ are each independently an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Represents an aralkyl group having 7 to 30 carbon atoms, an alkaryl group having 7 to 30 carbon atoms, a siloxane group having a substituent, a halogen atom, a hydroxy group, or a hydrogen atom. ]

The silane compound (E) has a mass average molecular weight (Mw) of 200 or more and 5000 or less, and a content in the total solid content of 100% by mass of the resin composition for a light scattering layer is 3% by mass or more and 50% by mass or less. Preferably there is.

In the resin composition for a light scattering layer of the present invention, the binder material preferably further contains an oxime ester photopolymerization initiator (F).

  The light scattering layer of the present invention is formed using the above-described resin composition for a light scattering layer of the present invention.

An organic electroluminescence (EL) device according to the present invention includes a light-transmitting layer according to the present invention, a light-transmitting first electrode, and at least one organic layer including a light-emitting layer on a light-transmitting substrate. The second electrode having light reflectivity is sequentially laminated.
The organic EL device of the present invention can be applied to a lighting device or a display device.

According to the present invention, in order to improve the light extraction efficiency of the organic EL device, it is used as a light scattering layer installed between the translucent electrode and the translucent substrate, and the wavelength dependence of the light extraction efficiency improvement rate is small. A resin composition for a light scattering layer that can be used in a wide wavelength region, a light scattering layer formed using the resin composition, and an organic EL device including the light scattering layer can be provided.

Schematic cross section of bottom emission EL element Schematic cross section of thin film printing device

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. Not specific to the content.

The resin composition for a light scattering layer of the present invention is
A resin composition for a light scattering layer used for forming a light scattering layer of an organic EL device,
It consists of a binder material containing at least one resin (A) and light scattering particles (B),
The light-scattering particles (B) contain fluorine, particles having an average particle diameter of 200 nm to 600 nm in the resin composition for light scattering layer, and a particle diameter of 600 nm or more with respect to the total amount of the light scattering particles (B). Content of 20% by volume or less,
A resin composition for a light scattering layer, wherein the difference in refractive index between the binder material and the light scattering particles (B) is 0.1 or more.

<Light scattering particles (B)>
First, the light scattering particles (B) will be described.
The light scattering particle (B) is not particularly limited as long as it has an effect of scattering and extracting light guided by total reflection in the organic EL device, and contains fluorine. Alternatively, inorganic particles may be used.
As the organic particles, fluorine group-containing polymethyl methacrylate beads, fluorine group-containing acrylic-styrene copolymer beads, fluorine group-containing polycarbonate beads, polyvinyl fluoride beads, and the like are used. As the inorganic particles, magnesium fluoride, lithium fluoride, calcium fluoride or the like is used. These may be used alone or in combination of two or more.
Preferred are trifluoroethyl methacrylate copolymer beads that have good dispersibility in the binder and can have a large refractive index difference from the binder material. The higher the fluorine content in the trifluoroethyl methacrylate copolymer, the lower the refractive index. Preferably, the content of trifluoroethyl methacrylate is 50% in 100% by weight of the monomer constituting the copolymer. % By weight to 100% by weight, more preferably 60% by weight to 100% by weight.

In the light scattering layer resin composition of the present invention, the light scattering particles (B) have an average particle diameter in the resin composition for light scattering layers of 200 nm to 600 nm and are based on the total amount of the light scattering particles (B). The content of particles having a particle diameter of 600 nm or more is 20% by volume or less.

If the average particle diameter of the light-scattering particles (B) is less than 200 nm, a sufficient scattering effect does not appear, and the refractive index of the binder material is affected. On the other hand, if it is larger than 600 nm, even if the scattering intensity (haze value) is high, the scattering angle becomes narrow, so that effective scattering for total reflection cannot be obtained, the extraction efficiency decreases, and the light extraction efficiency changes with wavelength. In some cases, it becomes large and the color tone tends to change, which is not preferable. More preferably, it is 250 nm-500 nm.

If the content of particles having a particle diameter of 600 nm or more with respect to the total amount of the light scattering particles (B) is more than 20% by volume, the change in the light extraction efficiency depending on the wavelength increases and the color tone tends to change, which may not be preferable. In addition, since the surface roughness of the light scattering layer is increased, unevenness in the film thickness or protrusions of the translucent electrode may occur, resulting in uneven brightness and a reduction in lifetime. The content of particles of 600 nm or more is more preferably 15% by volume or less.

In the present specification, the “average particle diameter” and “particle diameter” of the light scattering particles (B) are different from the average primary particle diameter described later, and light scattering taking into consideration the particle diameter of secondary particles due to aggregation. It is the dispersed particle size in the layer composition. These can be obtained by actual measurement with an optical microscope or by a dynamic light scattering method. Here, the reason for distinguishing from the average primary particle diameter is that the scattering state of the light scattering particles (B) in the composition for the light scattering layer is used even when the scattering particles having the same average primary particle diameter are used. This is because the average particle size and the particle size distribution may differ.
“Average particle size” is the value of the dispersed particle size in 50% by volume of the measurement sample, and the content of particles having a particle size of 600 nm or more is the volume% of the particle size of 600 nm or more in the dispersed particle size of the measurement sample. It is. These can be measured by “Nanotrack UPA” manufactured by Nikkiso Co., Ltd. in the dynamic light scattering method.

The particle size distribution of the light scattering particles (B) preferably has a variation coefficient of 30% or less. The “variation coefficient” is expressed as a percentage of a value obtained by dividing the standard deviation of the particle diameter by the average particle diameter, and is an index of the degree of variation with respect to the average particle diameter.
If the coefficient of variation is greater than 30%, the change in the light extraction efficiency with the wavelength increases and the color tone tends to change, which may not be preferable. More preferably, the coefficient of variation is 20% or less.

As the light scattering particles (B), it is preferable to use a dispersion liquid previously dispersed in a solvent.
As the dispersion method, a method using a dispersing agent in accordance with the surface state of the light scattering particles (B) and using a disperser is preferable.
Dispersers include paint conditioner (manufactured by Red Devil), ball mill, sand mill (such as “Dyno mill” manufactured by Shinmaru Enterprises), attritor, pearl mill (such as “DCP mill” manufactured by Eirich), coball mill, homomixer, Homogenizers (such as “Clairemix” manufactured by M Technique Co., Ltd.), wet jet mills (“Genus PY” manufactured by Genus, “Nanomizer” manufactured by Nanomizer), microbead mills (“Super Apeck Mill” manufactured by Kotobuki Industries Co., Ltd.) And “Ultra Apeck Mill”).
When media are used in the disperser, glass beads, zirconia beads, alumina beads, magnetic beads, polystyrene beads, and the like are preferably used.
Regarding dispersion, two or more types of dispersers or two or more types of media having different sizes may be used and may be implemented step by step.

  In the case of inorganic particles, the average particle size and particle size distribution of the light-scattering particles (B) are adjusted to a suitable range by appropriately adjusting the dispersion conditions such as a disperser, a dispersion medium, a dispersion time, and a dispersant. Is possible. In the case of organic particles, it can be adjusted by the synthesis conditions such as the polymerization temperature and the polymerization composition, or the dispersion conditions such as the disperser, dispersion medium, dispersion time, and dispersant.

  1-20 mass% is preferable in the resin composition for light scattering layers, and, as for the usage-amount of a light-scattering particle (B), 1-10 mass% is more preferable. If it is less than 1% by mass, a sufficient scattering effect may not appear, and if it exceeds 20% by mass, the particles tend to aggregate and the surface roughness of the light scattering layer may increase.

<Refractive index difference>
In the resin composition for a light scattering layer of the present invention, the refractive index difference between the binder material containing at least one resin (A) and the light scattering particles (B) is 0.1 or more.
Here, the binder material containing at least one kind of resin (A) is a portion excluding the light scattering particles (B) in the resin composition for a light scattering layer. For example, the resin composition for a light scattering layer has a component (A): component (B): component (C): component (E): component (F) = 35: 10: 40: 10: 5 (mass ratio). In the case of a mixture composition, the binder material is a mixed composition of component (A): component (C): component (E): component (F) = 35: 40: 10: 5 (mass ratio). When the refractive index difference is 0.1 or more, the light guided by total reflection in the EL element is scattered at the interface between the binder material and the light scattering particles (B), and the light extraction efficiency is improved. As the refractive index difference increases, the light extraction efficiency improves.

  Since the refractive index of the translucent substrate is about 1.5 and the refractive index of the translucent electrode is about 1.8 to 2.0, the refractive index of the binder material is 1.5 to 2.0. It is desirable to be. It is particularly desirable that the refractive index is 1.65 or more in that the refractive index with the translucent electrode is close and more light can be introduced and the wavelength dependence of the light extraction efficiency is small.

The refractive index of the binder material is determined by the composition ratio of each component used. The metal oxide particles (C) that can be optionally added, which will be described later, function as a refractive index adjusting agent for the binder material. The refractive index of the light scattering particles (B) is usually 1.5 to 1.8 in the case of organic particles, and is usually 1.3 to 2.5 in the case of inorganic particles. Therefore, the refractive index difference can be made 0.1 or more by appropriately selecting the binder material and the light scattering particles (B).
When the light scattering particles (B) contain fluorine, the refractive index tends to be lower, so that a resin composition for a light scattering layer having a larger refractive index difference from the binder material can be designed.

Examples of refractive index values are described below.
Examples of the resin (A) include epoxy resin: 1.53 to 1.57 and acrylate resin: 1.49 to 1.59.
Examples of the metal oxide particles (C) include titanium oxide (TiO ₂ ): 2.5, zirconium oxide (ZrO ₂ ): 2.2, zinc oxide (ZnO): 1.9, and tin oxide (SnO ₂ ). : 2.0.
The refractive index of the binder material containing the resin (A) and, if necessary, the metal oxide particles (C) is preferably 1.5 to 2.0.
Examples of the light scattering particles (B) include fluorine group-containing methacrylate copolymer beads: 1.43 to 1.60, fluorine group-containing acrylic-styrene copolymer beads: 1.48 to 1.58, and MgF. ₂ : 1.37. Preferred are trifluoroethyl methacrylate copolymer beads: 1.43 to 1.47, which have good dispersibility in the binder and can have a large refractive index difference from the binder material.
In the present specification, the “refractive index of the binder material” is a value measured by an Abbe refractometer.

<Resin (A)>
The resin (A) is not particularly limited as long as it is light-transmitting with respect to light emitted from the light emitting layer, for example, light in a predetermined wavelength band such as visible light, near infrared light, or near ultraviolet light. A curable resin such as thermoplasticity, thermosetting property, light (electromagnetic wave) curable property by visible light, ultraviolet ray or infrared ray, or electron beam curable property by electron beam irradiation is preferably used. Examples of such resins include polycarbonate (PC), polystyrene (PS), polyether, polyester, polyarylate, polyamide, phenol-formaldehyde resin (phenol resin), polydiethylene glycol bisallyl carbonate, acrylonitrile / styrene copolymer. (AS resin), methyl methacrylate / styrene copolymer (MS resin), poly-4-methylpentene, norbornene polymer, urethane resin, epoxy resin, acrylic resin, and silicone resin. These can be used singly or as a mixture of two or more at any ratio as required.

The resin (A) preferably contains a double bond and / or a crosslinkable group and has a mass average molecular weight (Mw) of 5,000 or more and 20,000 or less.
The organic EL device is generally manufactured by sequentially laminating a translucent electrode, an organic layer including a light emitting layer, and a back electrode on a translucent substrate. At this time, the adhesion between the layers is an important point that affects the performance of the organic EL device. Among these, the adhesion between the substrate and the translucent electrode is particularly important. For example, in the step of forming a translucent electrode, a high temperature treatment for reducing the resistance value of the electrode and an etching treatment for forming an electrode pattern are performed, and before the organic layer is laminated on the formed translucent electrode. In addition, cleaning with a solvent for removing impurities is performed. At this time, if the adhesion between the base material and the translucent electrode is low, the translucent electrode is finely cracked or peeled off. As a result, when the organic EL device is caused to emit light, dark spots, luminance unevenness, or life reduction Will cause.
When the properties of the resin (A) are in the above range, the light-scattering layer composition is cured when a light-transmitting electrode is laminated on the light-scattering layer and necessary treatments such as heating, etching, and solvent cleaning are performed. There is an effect of reducing shrinkage and suppressing fine cracks or peeling occurring in the translucent electrode.

  “Mass average molecular weight (Mw)” in the present specification is a value measured using gel permeation chromatography, and can be measured, for example, by gel permeation chromatography GPC-101 manufactured by Showa Denko K.K.

When the mass average molecular weight (Mw) of the resin (A) is less than 5000, the chemical resistance of the light scattering layer is insufficient, and the light scattering layer or the translucent electrode is peeled off in the solvent washing step before laminating the organic layer. There is a risk. Further, when the mass average molecular weight (Mw) is 20000 or more, the viscosity is high, the light scattering particles (B) or the metal oxide fine particles (C) are aggregated, the surface roughness of the light scattering layer becomes rough, and the light transmission When forming a conductive electrode, it may cause a short circuit or a reduction in life, and may cause fine protrusions.

The 5% thermal decomposition temperature of the resin (A) is preferably 200 ° C. or higher.
The “5% thermal decomposition temperature” in the present specification indicates a temperature when a mass of 5% is reduced by heating, and is a value measured by thermogravimetry. For example, it can be measured with a differential thermothermal gravimetric simultaneous measurement apparatus EXSTER TG / DTA6300 manufactured by Seiko Instruments Inc. When the 5% thermal decomposition temperature of the resin (A) is less than 200 ° C., the heat resistance is low, and it is not possible to sufficiently heat in the lamination step of the translucent electrode, and the resistance value of the electrode may not be lowered.

The resin (A) preferably contains a cyclic skeleton in the main chain or the side chain from the viewpoints of translucency and etchant resistance. The “cyclic skeleton” referred to here is an aliphatic ring, an aromatic ring, and a heterocyclic ring containing an O atom and / or an N atom.
In particular,
Aliphatic rings such as hydrogenated bisphenol A skeleton, cyclohexyl skeleton, norbornene skeleton, and adamantane skeleton;
Aromatic rings such as phenyl, phenylene, indene, bisphenol A skeleton, and fluorene skeleton;
Ester resin having one or more cyclic skeletons selected from heterocycles containing O atoms and / or N atoms such as tetrahydrofuran skeleton, furan skeleton, tetrahydropyran skeleton, pyran skeleton, isocyanurate skeleton, and oxazolidone skeleton , Urethane resin, epoxy resin, and acrylic resin.
Among these, acrylic resins are preferably used from the viewpoints of heat resistance and light resistance.

The amount of the resin (A) used in the resin composition for light scattering layer of the present invention is preferably 5 to 70% by mass and more preferably 10 to 60% by mass in the resin composition for light scattering layer. . When the amount is less than 5% by mass, the amount of ethylenically unsaturated monomer (D), which will be described later, increases in the composition for a light-scattering layer, so that curing shrinkage increases, and fine cracks and peeling occur in the translucent electrode. There is. If it exceeds 70% by mass, sufficient etchant resistance may not be maintained.

Further, the resin (A) has a double bond and / or a crosslinkable group, thereby improving heat resistance and chemical resistance.
Double bonds include (meth) acrylate groups and unsaturated groups such as maleimide groups. The crosslinkable group preferably has a heat crosslinkable group or an ultraviolet ray or electron beam crosslinkable group. Examples of thermally crosslinkable sites include hydroxyl groups, epoxy groups, oxetanyl groups, acid (carboxyl) groups, and isocyanate groups. Examples of the ultraviolet or electron beam crosslinkable site include an epoxy group and an oxetanyl group. These can be used alone or in combination of two or more.

The resin (A) preferably contains an unsaturated group such as a (meth) acrylate group and a maleimide group, and the double bond equivalent is preferably 400 g / mol or more and 1600 g / mol or less. When the double bond equivalent of the resin (A) is less than 400 g / mol, curing shrinkage of the resin is increased, so that a fine crack or peeling may occur in the translucent electrode. On the other hand, if the double bond equivalent is more than 1600 g / mol, the crosslinking is insufficient, so that the etching resistance may be insufficient, or the light scattering layer or the translucent electrode may be peeled off in the solvent washing step before the organic layer lamination.

There is no restriction | limiting in particular as a method of obtaining polyacrylate suitable as resin (A) in the resin composition for light-scattering layers of this invention.
For example, an unsaturated monomer component containing an ethylenically unsaturated monomer having one or more functional groups selected from a hydroxyl group, an epoxy group, an acid (carboxyl) group, and an isocyanate group is polymerized. And a method in which a functional group in the copolymer is modified with an ethylenically unsaturated monomer having a functional group capable of reacting with the functional group.
The combination of the functional group of the copolymer and the functional group of the ethylenically unsaturated monomer used for modification is not particularly limited. For example, a hydroxyl group and an isocyanate group, a hydroxyl group and an epoxy group, and an epoxy group and an acid (carboxyl) ) Group and the like.

(Ethylenically unsaturated monomer having a hydroxyl group)
Examples of the ethylenically unsaturated monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2- or 3- or 4-hydroxybutyl (meth) acrylate, and glycerol. Examples include (meth) acrylates and hydroxyalkyl (meth) acrylates such as cyclohexanedimethanol mono (meth) acrylate.

(Ethylenically unsaturated monomer having an epoxy group)
Examples of the ethylenically unsaturated monomer having an epoxy group include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, β-propylglycidyl (meth) acrylate, β-methylglycidyl-α-ethyl acrylate, 3-methyl-3,4-epoxybutyl (meth) acrylate, 4-methyl-4,5-epoxypentyl (meth) acrylate, 5-methyl-5,6-epoxyhexyl (meth) acrylate, glycidyl vinyl ether, etc. Can be mentioned. Among these, glycidyl (meth) acrylate is preferable.

(Ethylenically unsaturated monomer having acid (carboxyl) group)
As an ethylenically unsaturated monomer having an acid group, for example,
(Meth) acrylic acid, itaconic acid, crotonic acid, o-, m-, p-vinylbenzoic acid, monocarboxylic acid such as α-position haloalkyl, alkoxyl, halogen, nitro, or cyano substituent of (meth) acrylic acid, etc. An ethylenically unsaturated monomer (unsaturated monobasic acid) having a carboxyl group;
Examples thereof include polybasic acid anhydrides such as tetrahydrophthalic anhydride, phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and maleic anhydride.
Among these, (meth) acrylic acid is particularly preferable.

(Unsaturated monomer having an isocyanate group)
Examples of the ethylenically unsaturated monomer having an isocyanate group include 2- (meth) acryloyloxyethyl isocyanate and 1,1-bis [(meth) acryloyloxy] ethyl isocyanate.

  The other ethylenically unsaturated monomer component constituting the resin (A) is not particularly limited as long as it has an ethylenically unsaturated group, and examples thereof include (meth) acrylic acid esters, N-vinyl. Examples include pyrrolidone, styrenes, acrylamides, other vinyl compounds, and macromonomers.

Among these, as described above, it is preferable to copolymerize an ethylenically unsaturated monomer that introduces a cyclic skeleton into the main chain or side chain of the resin (A).
As an ethylenically unsaturated monomer that introduces a cyclic skeleton into the main chain,
Cyclic dienes such as indene, benzofuran, norbornene, and cyclohexene;
and,
Examples include a monomer that undergoes an intramolecular cyclization reaction during copolymerization with a methacrylic acid ester such as vinylcyclopropane to form a 5- or 6-membered ring in the main chain.
As an ethylenically unsaturated monomer that introduces a cyclic skeleton into the side chain,
Aliphatic ring-containing (meth) acrylates such as isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and 1-adamandane (meth) acrylate;
Aromatic ring-containing (meth) acrylates such as benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, and paracumyl EO modified (meth) acrylate;
Styrene and its derivatives, styrenes such as methylstyrene;
Tetrahydrofurfuryl (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate, (2-ethyl-2-methyl-1,3-dioxolan-4-yl) (meth) acrylate, (2-isobutyl-2- Methyl-1,3-dioxolan-4-yl) (meth) acrylate, (1,4-dioxaspiro [4,5] dec-2-yl) (meth) acrylate, pentamethylpiperidyl (meth) acrylate, and oxazolidone ( Heterocycle-containing (meth) acrylates containing O atoms and / or N atoms such as (meth) acrylates may be mentioned.
These can be used singly or as a mixture of two or more at any ratio as required.

  The ratio of the ethylenically unsaturated monomer for introducing the cyclic skeleton into the main chain or the side chain is not particularly limited, but is 5 to 50 mass with respect to 100 mass% of the total monomers constituting the resin (A). % Is preferred. If the amount of the ethylenically unsaturated monomer that introduces a cyclic skeleton into the main chain or side chain is too large, it may be difficult to control the polymerization and it may be difficult to obtain a desired molecular weight. On the other hand, if the amount is too small, the etchant resistance may be insufficient.

Examples of other copolymerizable ethylenically unsaturated monomers other than the ethylenically unsaturated monomer containing a cyclic skeleton in the main chain or side chain include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meta ) Acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate (meta) ) Acrylic esters;
Acrylamides such as (meth) acrylamide, methylol (meth) acrylamide, alkoxymethylol (meth) acrylamide, diacetone (meth) acrylamide;
Vinyl compounds such as (meth) acrylonitrile, ethylene, propylene, butylene, vinyl chloride, and vinyl acetate;
Etc.
These can be used singly or as a mixture of two or more at any ratio as required.

  The 5% thermal decomposition temperature and double bond equivalent of the resin (A) can be controlled by the type and blending of the ethylenically unsaturated monomer used for copolymerization and modification. The mass average molecular weight (Mw) can be controlled by polymerization conditions such as the type and amount of the polymerization initiator.

Resin (A) can impart any physical properties depending on the type and blending of the ethylenically unsaturated monomer used.
For example, when imparting developability to the resin (A), an acid group such as a carboxyl group is introduced in order to express alkali solubility. The method for introducing the acid group is not particularly limited. However, the above-described copolymer containing an ethylenically unsaturated monomer having an acid group is modified so that the acid group remains, or the hydroxyl group described above. And a method of modifying a copolymer containing an ethylenically unsaturated monomer having a polybasic acid anhydride as described above.
When imparting developability, the acid value of the resin (A) is preferably 30 mgKOH / g or more and 200 mgKOH / g or less. If the acid value is less than 30 mg KOH / g, sufficient developability cannot be secured, and if it exceeds 200 mg KOH / g, hydrolysis of the silane compound (E) described later is promoted, and the adhesion of the light scattering layer decreases with time. There is a risk.
The “adhesiveness of the light-scattering layer” (hereinafter sometimes simply referred to as “adhesiveness”) referred to in this specification is the adhesiveness of the light-scattering layer to the translucent substrate and the translucent electrode.

In the synthesis of the resin (A), the ethylenically unsaturated monomer is copolymerized and modified in the presence of a polymerization initiator, under an inert gas stream, generally at 50 to 150 ° C. for 2 to 10 hours. I do. The method for the polymerization reaction is not particularly limited, and various conventionally known polymerization methods can be adopted, but the solution polymerization method is particularly preferable.
The polymerization temperature and the polymerization concentration defined by the following formula vary depending on the types and ratios of the monomer components used and the molecular weight of the target polymer, but preferably the polymerization temperature is 40 to 150 ° C. More preferably, the polymerization temperature is 60 to 130 ° C., and the polymerization concentration is 10 to 40%.
Polymerization concentration (%) = [total mass of monomer component / (total mass of monomer component + solvent mass)] × 100

As the polymerization initiator used for the synthesis of the resin (A), organic peroxides, azo compounds and the like can be used.
Examples of the organic peroxide include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, diisopropyl peroxycarbonate, di-t-butyl peroxide, and t-butyl peroxybenzoate.
Examples of the azo compound include azo compounds such as 2,2′-azobisisobutyronitrile.
The polymerization initiator is preferably used in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the ethylenically unsaturated monomer.

Examples of the solvent used for the synthesis of the resin (A) include water, a water-miscible organic solvent, acetate ester, ketones, xylene, and ethylbenzene.
Examples of the water-miscible organic solvent include alcohol solvents such as ethyl alcohol, isopropyl alcohol, and n-propyl alcohol, and mono- or dialkyl ethers of ethylene glycol or diethylene glycol.
Examples of the acetate ester include ethyl cellosolve acetate and propylene glycol monomethyl ether acetate.
Examples of ketones include cyclohexanone and methyl isobutyl ketone.

<Metal oxide fine particles (C)>
The binder material can contain metal oxide fine particles (C) in addition to the resin (A). Thereby, binder material can be adjusted to arbitrary refractive indexes.
The metal oxide fine particles (C) used in the present invention desirably have a refractive index of 1.8 to 2.8 in the visible light region.
In the present specification, the “refractive index of the metal oxide fine particles (C)” means the bulk refractive index of the material constituting the metal oxide fine particles. The refractive index of the bulk material can be measured using an Abbe refractometer or a V block refractometer.

Specifically, as the metal oxide fine particles (C), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), hafnium oxide (HfO ₂ ), niobium pentoxide (Nb ₂ O) ₅ ), tantalum pentoxide (Ta ₂ O ₅ ), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), indium tin oxide (ITO), and at least selected from the group consisting of zinc oxide (ZnO) A particle composed of one kind of material can be mentioned.

In order to maintain the translucency of the light scattering layer, it is preferable that there is no strong aggregation between the particles. Therefore, the average primary particle diameter of the metal oxide fine particles (C) is preferably 100 nm or less. By defining the average primary particle size to 100 nm or less, a binder material that is transparent in the visible light region can be obtained.
The “average primary particle diameter” in the present specification means an individual particle diameter not taking aggregation into account, and is, for example, 50 actually measured using a transmission electron microscope (TEM) or a scanning electron microscope (SEM). It is the average value of the particle diameter.

As the metal oxide fine particles (C), powder can be used as it is, or a dispersion liquid previously dispersed in a solvent may be used. Among them, it is preferable to use a dispersion liquid in order to maintain a dispersion state with an average particle diameter of 200 nm or less.
The dispersion method is preferably a method using a disperser using a dispersant in accordance with the surface state of the metal oxide fine particles (C), similarly to the light scattering particles (B).

As the metal oxide fine particles (C), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), zinc oxide (ZnO), and tin oxide (SnO ₂ ) are preferable. Titanium oxide (TiO ₂ ) and zirconium oxide (ZrO ₂ ) are particularly preferable from the viewpoints of translucency, dispersibility, weather resistance, light resistance, and the like.

  The binder material containing the resin (A) and the metal oxide fine particles (C) preferably has a light transmittance of 80% or more, more preferably 85% or more in a visible light wavelength region and an optical path length of 1 mm. This light transmittance varies depending on the content of the metal oxide fine particles (C) in the binder material.

  Since the refractive index of the metal oxide fine particles (C) is usually 1.8 to 2.5, the refractive index of the resin (A) is 1.4 by dispersing the metal oxide fine particles (C) in the binder material. Compared with about ~ 1.5, the refractive index of the entire light scattering layer can be improved.

The amount of the metal oxide fine particles (C) used in the resin composition for a light scattering layer of the present invention is preferably 70% by mass or less and more preferably 50% by mass or less in the resin composition for a light scattering layer. preferable. If it exceeds 70% by mass, the particles may aggregate or the amount of the resin (A) decreases, and the coating film may become brittle.

  The binder material can further contain a polyfunctional monomer. By including this, the etchant resistance is excellent. Among these, an ethylenically unsaturated monomer (D) having a double bond equivalent of 80 g / mol or more and 140 g / mol or less is particularly preferable from the viewpoint of maintaining transmittance and balancing the crosslink density and adhesion.

<Ethylenically unsaturated monomer (D)>
Examples of the ethylenically unsaturated monomer (D) having a double bond equivalent of 80 g / mol or more and 140 g / mol or less include 1,6-hexanediol di (meth) acrylate, 1.4-butanediol di ( Tri (meth) acrylates such as (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol triacrylate, and trimethylolpropane tri (meth) acrylate;
Aliphatic polyfunctional (meth) acrylates such as pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, and dipentaerythritol (monohydroxy) pentaacrylate;
Polyfunctional alicyclic (meth) acrylates such as dicyclopentadienyl di (meth) acrylate;
Other examples include polyurethane ether (meth) acrylate, polyester (meth) acrylate, and epoxy (meth) acrylate having a double bond equivalent of 80 g / mol or more and 140 g / mol or less and having two or more functions.
These may be used singly or in combination of two or more at any ratio as necessary.

  It is preferable that the usage-amount of the ethylenically unsaturated monomer (D) used with the resin composition for light scattering layers of this invention is 15-40 mass% or less in the resin composition for light scattering layers. If it is less than 15% by mass, sufficient etchant resistance may not be obtained. If it exceeds 40% by mass, curing shrinkage will increase, fine cracks will occur in the translucent substrate or translucent electrode, or the adhesion between the translucent substrate or translucent electrode and the light scattering layer will decrease. May peel.

<Silane compound (E)>
It is preferable that the binder material further contains a silane compound (E) represented by the following general formula (1) having a urethane skeleton or an amide skeleton.

[In General Formula (1), R ¹ is an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a carbon number. An aralkyl group having 7 to 30 carbon atoms or an alkaryl group having 7 to 30 carbon atoms is represented.
X represents an alkylene group having 1 to 20 carbon atoms, an arylene group having 1 to 20 carbon atoms, or an alkyleneoxy group having 1 to 20 carbon atoms.
R ² _, R ³ and R ⁴ are each independently an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Represents an aralkyl group having 7 to 30 carbon atoms, an alkaryl group having 7 to 30 carbon atoms, a siloxane group having a substituent, a halogen atom, a hydroxy group, or a hydrogen atom. ]

  By including the silane compound (E) represented by the general formula (1), the adhesion between the light transmissive substrate or the light transmissive electrode and the light scattering layer is improved.

Examples of the silane compound (E) represented by the general formula (1) include (3-carbamateethyl) propyltriethoxysilane, (3-carbamateethyl) propyltrimethoxysilane, and (3-carbamateethyl) propyltripropoxysilane. , (3-carbamatepropyl) propyltriethoxysilane, (3-carbamatepropyl) propyltrimethoxysilane, (3-carbamatepropyl) propyltripropoxysilane, (3-carbamatebutyl) propyltriethoxysilane, (3-carbamate (Butyl) propyltrimethoxysilane, (3-carbamatebutyl) propyltripropoxysilane, (3-carbamatebutyl) butyltripropoxysilane, (3-carbamatebutyl) propylmethyldiethoxysilane, ( -Carbamate pentyl) propyl triethoxy silane, (3-carbamate hexyl) propyl triethoxy silane, 3-carbamate octyl) pent tilt riboxy silane, (3-carbamate ethyl) propyl silyl trichloride, (3-carbamate ethyl) propyl trimethyl silane , 3-carbamateethyl) propyldimethylsilane, 3-carbamateethyl) propyltributylsilane, 3-carbamateethyl) ethyl-p-xylenetriethoxysilane, and 3-carbamateethyl) -p-phenylenetriethoxysilane. .
The silane compound (E) represented by the general formula (1) may be added to the light scattering layer composition in the form of a silanol compound that is a hydrolyzate or in the form of a polyorganosiloxane compound that is a condensate. Good.

  The mass average molecular weight (Mw) of the silane compound (E) used in the present invention is preferably 200 or more and 5000 or less. When the mass average molecular weight (Mw) of the silane compound (E) exceeds 200, sufficient adhesion may not be obtained, and when it is 5000 or more, the etchant resistance deteriorates, which may not be preferable.

  The amount of the silane compound (E) used in the resin composition for a light scattering layer of the present invention is preferably 3% by mass or more and 50% by mass or less in the resin composition for a light scattering layer, and 10 to 40% by mass. % Is more preferable. If it is less than 3% by mass, sufficient adhesion cannot be obtained, and if it exceeds 50% by mass, the transmittance may decrease.

For example, isocyanate group-containing silane compounds such as 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanatopropyltripropoxysilane are used as solvents, resins, and single amounts in the resin composition for light scattering layers. It may become cloudy or gel when it reacts with the body and moisture. In addition, the cured coating film may not exhibit stable adhesion.
On the other hand, since the silane compound (E) represented by the general formula (1) does not have a highly reactive site such as an isocyanate group, it is thermally and chemically stable, and a resin composition for a light scattering layer. Among them, it is excellent in stability over time, and can stably exhibit good adhesion.

<Photopolymerization initiator>
The resin composition for a light scattering layer of the present invention can be thermally polymerized without blending a polymerization initiator. However, when it is desired to cure in a short time with UV light, or when it is desired to form a light scattering layer by a photolithography method as a solvent developing type or alkali developing type photosensitive light scattering layer resin composition, the binder material A photopolymerization initiator can be added to the mixture.

As a photopolymerization initiator,
4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2- Acetophenones such as benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one Photopolymerization initiators;
1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime) and ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole Oxime ester photopolymerization initiators such as -3-yl]-, 1- (o-acetyloxime);
Benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal;
Benzophenone-based photopolymerization initiators such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, and 4-benzoyl-4′-methyldiphenyl sulfide;
Thioxanthone photopolymerization initiators such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone;
2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s -Triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloro) Methyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, and 2,4-trichloromethyl (4'-methoxystyryl) -6 -Triazine photoinitiators such as triazine;
Borate photopolymerization initiator;
Carbazole photopolymerization initiator:
In addition, imidazole photopolymerization initiators and the like are used.
These can be used alone or in admixture of two or more.

  Among them, the oxime ester-based photopolymerization initiator (F) is preferable because it has a high sensitivity, so that the addition amount may be small and the transmittance of the light scattering layer is high. Furthermore, 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime) does not turn yellow during the heating step, and therefore provides a light scattering layer with high transmittance. Is more preferable.

  It is preferable to use a photoinitiator in the quantity of 1-30 mass% in the resin composition for light-scattering layers, and it is more preferable to use it in the quantity of 1-10 mass% from a viewpoint of the transmittance | permeability.

The binder material further includes α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′- as a sensitizer. Diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, diethylthioxanthone, 4,4′-diethylaminobenzophenone, and the like can be included.
The sensitizer can be used in an amount of 0.1 to 150 parts by mass with respect to 100 parts by mass of the photopolymerization initiator.

  Binder materials can be monofunctional monomers, UV absorbers, antioxidants, heat stabilizers, light stabilizers, antistatic agents, surfactants, storage stabilizers, leveling agents, and light stabilizers as needed. An agent and the like can also be included.

<Thermal reactive compound (G)>
The resin composition for a light scattering layer of the present invention can further contain a heat-reactive compound in order to further impart coating film durability. The thermoreactive compound is non-reactive at room temperature, but exhibits a crosslinking reaction, a polymerization reaction, a polycondensation reaction, or a polyaddition reactivity at a temperature of 100 ° C. or higher (preferably 150 ° C. or higher), for example. A compound. Although the molecular weight of a thermoreactive compound is not specifically limited, Preferably it is 50-2000, More preferably, it is 100-1000.

Examples of the thermally reactive compound (G) include melamine compounds, benzoguanamine compounds, carbodiimide compounds, epoxy compounds, oxetane compounds, phenol compounds, benzoxazine compounds, blocked carboxylic acid compounds, blocked isocyanate compounds, acrylate monomers, and One or more compounds selected from the group consisting of silane coupling agents can be used. Particularly preferred is a thermoreactive compound (G) containing at least a melamine compound or a benzoguanamine compound.

  Examples of the melamine compound or benzoguanamine compound include those having an imino group, a methylol group, or an alkoxymethyl group. Among these, a melamine compound or a benzoguanamine compound containing an alkoxyalkyl group is preferable. When the melamine compound or benzoguanamine compound containing an alkoxyalkyl group is used, the storage stability of the resin composition for a light scattering layer of the present invention is remarkably improved.

  Examples of the melamine compound or benzoguanamine compound containing an alkoxyalkyl group include hexamethoxymethylol melamine, hexabutoxymethylol melamine, tetramethoxymethylol benzoguanamine, tetrabutoxymethylol benzoguanamine and the like, but are not necessarily limited thereto. .

  Specific examples of commercially available melamine compounds include the following. However, it is not necessarily limited to these.

  Nikarak MW-30M, MW-30, MW-22, MS-21, MS-11, MW-24X, MS-001, MX-002, MX-730, MX750, MX-708, MX- manufactured by Sanwa Chemical Co., Ltd. 706, MX-042, MX-035, MX-45, MX-500, MX-520, MX-43, MX-417, MX-410, MX-302, Cymel 300, 301, 303 manufactured by Nihon Cytex Industry 350, 370, 325, 327, 703, 712, 01, 285, 232, 235, 236, 238, 211, 254, 204, 202, 207, My Coat 506, 508, 212, 715, and the like.

  Among them, an alkoxyalkyl group-containing melamine compound is preferable. Nikalac MW-30M, MW-30, MW-22, MS-21, MX-45, MX-500, MX-520, MX manufactured by Sanwa Chemical Co., Ltd. -43, MX-302, Cymel 300, 301, 303, 350, 285, 232, 235, 236, 238, My Coat 506, 508 manufactured by Nippon Cytex Industries.

  Specific examples of commercially available benzoguanamine compounds include, for example, Nikalac BX-4000, SB-401, BX-37, SB-355, SB-303, SB301, BL-60, SB-255, SB manufactured by Sanwa Chemical Co., Ltd. -203, SB-201, Cymel 1123 manufactured by Nippon Cytex Industries, Ltd., My Coat 105, 106, 1128, and the like.

  Among these, Sanka Chemical's Nikalac BX-4000 and SB-401 and Nippon Cytex Industries' Cymel 1123, which are alkoxyalkyl group-containing benzoguanamine compounds, are preferable.

  Examples of the epoxy compound include bisphenol fluorenediglycidyl ether, biscresol fluorenediglycidyl ether, bisphenoxyethanol fluorenediglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, Methylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether, diglycidyl terephthalate, diglycidyl o-phthalate, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and Polypropy Glycol polyol glycidyl ethers such as diglycidyl ether, may be mentioned polyglycidyl isocyanurate, not necessarily limited thereto.

  As the phenol compound, for example, both a novolac type phenol compound obtained by reacting phenols and aldehydes under an acidic catalyst and a resol type phenol compound obtained by reacting under a basic catalyst can be used. Examples of phenols include orthocresol, paracresol, paraphenylphenol, paranonylphenol, 2,3-xylenol, phenol, metacresol, 3,5-xylenol, resorcinol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol. B, bisphenol E, bisphenol H, bisphenol S and the like. Examples of aldehydes include formaldehyde and acetaldehyde. Phenols and aldehydes may be used singly or in combination of two or more.

  Examples of the isocyanate compound of the blocked isocyanate compound include hexamethylenediisocyanate, isophorone diisocyanate, toluidine isocyanate, diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, bis (4-isocyanatocyclohexyl) methane, tetra Diisocyanates such as methylxylylene diisocyanate, isocyanurates of these diisocyanates, trimethylolpropane adduct type, biuret type, prepolymer having an isocyanate residue (low polymer obtained from diisocyanate and polyol), uretdione having an isocyanate residue, etc. However, the present invention is not necessarily limited to this.

  Examples of the blocking agent for the blocked isocyanate compound include phenol (dissociation temperature of 180 ° C. or higher), ε-caprolactam (dissociation temperature of 160 to 180 ° C.), oxime (dissociation temperature of 130 to 160 ° C.), or active methylene (100 to 120 ° C.). ° C) and the like, but is not necessarily limited thereto. Moreover, it is used individually by 1 type or in combination of 2 or more types.

<Manufacturing method>
The method for producing the resin composition for a light scattering layer of the present invention is not particularly limited, and may be any method that is used for uniformly mixing particles and a resin, and may be any conventionally known method. Absent.

For example, each component constituting the resin composition for a light scattering layer of the present invention is prepared independently, and then mixed or kneaded, previously prepared light scattering particles (B), and if necessary, a metal oxide Examples thereof include a method in which the resin (A) is polymerized under the condition where the fine particles (C) are present and other components are mixed.
From the viewpoint of dispersion stability, uniformly disperse the light scattering particle (B) dispersion, the metal oxide fine particle (C) dispersion, if necessary, the solution in which the resin (A) is dissolved, and other components. A method of mixing is preferred.

"Light scattering layer"
The light scattering layer of the present invention is formed using the above-described resin composition for a light scattering layer of the present invention.
The light scattering layer of the present invention is, for example, coated with a resin composition for a light scattering layer on a light-transmitting substrate such as glass and dried, and the obtained coating film is heated or irradiated with ultraviolet rays or electron beams. It is obtained by applying and curing.
As a coating method, a known method can be used,
For example using lots or wire bars;
In addition, various coating methods such as micro gravure coating, gravure coating, die coating, curtain coating, lip coating, slot coating or spin coating can be used.
When patterning the light scattering layer on the translucent substrate using the resin composition for the light scattering layer, 1) a method of directly patterning on the translucent substrate by a printing method, and 2) by a photolithography method A patterning method can be used.
1) The printing method can be performed by a normal printing method such as flexographic printing, gravure printing, gravure offset printing, offset printing, reverse offset printing, screen printing, letterpress printing, and ink jet printing.
2) In the photolithography method, it is used in the form of a photosensitive resin composition. In that case, 2-1) after directly applying and drying the resin composition for a light scattering layer of the present invention on a translucent substrate, or 2-2) using a solvent on a film substrate (hereinafter referred to as a separate film). After applying the dissolved resin composition, the photosensitive dry film obtained by drying the solvent is attached to the light-transmitting substrate, and then adhered to the light-transmitting substrate and air bubbles by laminating or vacuum laminating. After the light scattering layer is formed by removing and the like, pattern formation is performed by a solution development or alkali development process.
Although the thickness of a light-scattering layer is not specifically limited, Usually, it is preferable that it is 0.5-20 micrometers.

In addition, when the light scattering layer of the present invention is applied to an organic EL device, if the wavelength dependency of the refractive index of the light scattering layer is large, there is a problem that the luminance changes in each color pixel and the white balance is lost. The scattering layer preferably has a small difference in refractive index at each wavelength. Specifically, when the refractive indexes at wavelengths 473 nm, 594 nm, and 633 nm measured by a prism coupler are n (473), n (594), and n (633), respectively, n (473) / n (594), The value of n (633) / n (594) is preferably 0.2 to 2.0, more preferably 0.5 to 1.5, and still more preferably 0.95 to 1.05.

"Organic EL device"
The organic EL device of the present invention includes an organic EL element having a light scattering layer formed from a resin composition for a light scattering layer. The structure of the organic EL element is not particularly limited. As an example of the basic structure, a translucent substrate, at least one organic layer (organic EL layer) including a light emitting layer, a back electrode, and a TFT substrate are provided on the translucent substrate. One example is a bottom emission structure in which layers are sequentially stacked and light is extracted from the anode side. As another example, at least one organic layer (organic EL layer) including a back electrode, a light emitting layer, a translucent electrode, and a sealing layer are sequentially stacked on a TFT substrate, and light is extracted from the cathode side. The structure of top emission can be mentioned. These methods and techniques are described in Keiji Kido, “All about organic EL”, published by Nihon Jitsugyo Shuppansha (published in 2003).

A structure of an organic EL device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a bottom emission structure which is one example of the present embodiment.
The organic EL device 1 of the present embodiment includes at least one including a light scattering layer 12, a light-transmitting first electrode (anode, light-transmitting electrode) 13, and a light-emitting layer on a light-transmitting substrate 11. Two organic layers (organic EL layers) 14 and a second electrode (cathode, back electrode) 15 having light reflectivity are sequentially laminated.
The light scattering layer 12 is a layer formed using the above-described resin composition for a light scattering layer of the present invention.

The organic EL device can be used for an organic EL lighting device or an organic EL display device.
In an active matrix organic EL display device, a plurality of light emitting layers that emit different colors are arrayed in a matrix. Further, a TFT substrate on which a pixel electrode composed of a second electrode (cathode, back electrode) 15 and a TFT (thin film transistor) as a switching element thereof is formed for each dot is provided.

As a site where the light scattering layer of the present invention is provided, for example, the following cases can be considered.
In the case of the bottom emission structure, for example, the following cases can be considered.
(1) Translucent substrate / light scattering layer / translucent electrode / organic EL layer / back electrode (2) Light scattering layer / translucent substrate / translucent electrode / organic EL layer / back electrode (3) Light Scattering layer / translucent substrate / light scattering layer / translucent electrode / organic EL layer / back electrode

In the case of the top emission structure, for example, the following cases can be considered.
(4) Substrate / Back electrode / Organic EL layer / Translucent or semi-transparent electrode / Light scattering layer / Protective substrate (5) Substrate / Back electrode / Organic EL layer / Translucent or semi-transparent electrode / Sealing layer / Light scattering layer / Protective substrate (6) Substrate / Back electrode / Organic EL layer / Translucent or semi-transparent electrode / Sealing layer / Protective substrate / Light scattering layer (7) Substrate / Back electrode / Organic EL layer / translucent or semi-transparent electrode / light scattering layer / protective substrate / light scattering layer At this time, an organic EL element including a light scattering layer between the translucent substrate and the translucent electrode is included. Those are more preferable from the viewpoint of light extraction efficiency.

As a manufacturing method of a bottom emission structure, after providing a light-scattering layer on a translucent substrate as mentioned above, a translucent electrode is formed on a light-scattering layer. As a material for the translucent electrode, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used, and a material having a work function of 4 eV or more is preferable.
As a specific example,
Conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO);
Metals such as gold, silver, chromium and nickel;
Other inorganic conductive materials such as copper iodide and copper sulfide;
Organic conductive materials such as polyaniline, polythiophene, PEDOT / PSS, and polypyrrole;
And mixtures or laminates thereof.
A conductive metal oxide is preferable, and ITO is particularly preferable in terms of productivity, high conductivity, translucency, and the like.

Further, in order to control the injection property of electrons or holes into the organic EL layer while maintaining the translucency, it is possible to laminate a metal and ITO to form a translucent electrode. Here, the thickness of the ultrathin metal is preferably 0.1 nm to 20 nm from the viewpoint of maintaining translucency. In addition, as metals here,
Alkali metals (such as Li, Na, and K) and fluorides thereof;
Alkaline earth metals (such as Mg and Ca) and their fluorides;
Gold, silver, lead, aluminum, sodium-potassium alloys, and mixed metals containing them;
Lithium-aluminum alloys and mixed metals containing them;
LiF / Al alloys and mixed metals containing them;
Magnesium-silver alloys and mixed metals containing them;
And rare earth metals such as indium and ytterbium.
Of these, materials having a work function of 4 eV or less are preferable, and aluminum, lithium-aluminum alloys and mixed metals thereof, magnesium-silver alloys and mixed metals thereof, and the like are more preferable.

The film thickness of the translucent electrode can be appropriately selected depending on the material, but is usually preferably about 50 nm to 300 nm.
As a method for forming the translucent electrode, an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (such as a sol-gel method), and a method of applying a dissolved material or a dispersion material are used.
The formed translucent electrode is etched to form a pattern as desired. Furthermore, the driving voltage of the apparatus can be lowered and the light emission efficiency can be increased by washing and other processing. For example, in the case of ITO, UV-ozone treatment is effective.

Next, after providing a translucent electrode on the surface of the light scattering layer as described above, an organic EL layer is formed on the surface of the translucent electrode.
The organic EL layer includes a light emitting layer, and may include a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, or the like. Each of these layers may have other functions.

The material of the hole injection layer and the hole transport layer has either a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. I just need it. Specific examples include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, anilines Examples thereof include copolymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene.

The material of the light emitting layer can inject holes from the anode, hole injection layer, or hole transport layer when an electric field is applied, and can inject electrons from the cathode, electron injection layer, or electron transport layer. Any layer can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of emitting light by providing a recombination field of holes and electrons.
For example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives, perinone derivatives, oxadiazole derivatives, aldazines Derivatives, pyralidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidin compounds, and 8-quinolinol derivative metal complexes or rare earths Various metal complexes represented by complexes;
and,
And polymer compounds such as polythiophene, polyphenylene, and polyphenylene vinylene.

  Specific examples of the light-emitting material that becomes the light-emitting layer are listed below, but are not limited to the following specific examples.

  Blue light emission is obtained by using, for example, perylene, 2,5,8,11-tetra-t-butylperylene (abbreviation: TBP), a 9,10-diphenylanthracene derivative, or the like as a guest material. In addition, styrylarylene derivatives such as 4,4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), 9,10-di-2-naphthylanthracene (abbreviation: DNA), and 9,10-bis It can also be obtained from an anthracene derivative such as (2-naphthyl) -2-tert-butylanthracene (abbreviation: t-BuDNA). A polymer such as poly (9,9-dioctylfluorene) may also be used.

Green light is emitted from coumarin dyes such as coumarin 30 and coumarin 6, bis [2- (2,4-difluorophenyl) pyridinato] picolinatoiridium (abbreviation: FIrpic), and bis (2-phenylpyridinato) acetyl. It can be obtained by using acetonatoiridium (abbreviation: Ir (ppy) (acac)) or the like as a guest material. Also, metals such as tris (8-hydroxyquinoline) aluminum (abbreviation: Alq ₃ ), BAlq, Zn (BTZ), and bis (2-methyl-8-quinolinolato) chlorogallium (abbreviation: Ga (mq) ₂ Cl) It can also be obtained from the complex. A polymer such as poly (p-phenylene vinylene) may also be used.

Light emission from orange to red is caused by rubrene, 4- (dicyanomethylene) -2- [p- (dimethylamino) styryl] -6-methyl-4H-pyran (abbreviation: DCM1), 4- (dicyanomethylene) -2- Methyl-6- (9-julolidyl) ethynyl-4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) styryl] -4H-pyran (abbreviation: BisDCM) Bis [2- (2-thienyl) pyridinato] acetylacetonatoiridium (abbreviation: Ir (thp) ₂ (acac)), and bis (2-phenylquinolinato) acetylacetonatoiridium (abbreviation: Ir (pq) ( acac)) and the like as a guest material. It can also be obtained from a metal complex such as bis (8-quinolinolato) zinc (abbreviation: Znq ₂ ) or bis [2-cinnamoyl-8-quinolinolato] zinc (abbreviation: Znsq ₂ ). A polymer such as poly (2,5-dialkoxy-1,4-phenylenevinylene) may be used.

  White light emission defines the energy level of each layer of the organic EL laminated structure and emits light using tunnel injection (European Patent No. 0390551). A light emitting element is described (Japanese Patent Laid-Open No. 3-230584), a light emitting layer having a two-layer structure is described (Japanese Patent Laid-Open No. 2-220390 and Japanese Patent Laid-Open No. Hei 2-216790), and a light emitting layer Are made of materials having different emission wavelengths (JP-A-4-51491), a blue light emitter (fluorescent peak 380 to 480 nm) and a green light emitter (480 to 580 nm). Laminated and further containing a red phosphor (Japanese Patent Laid-Open No. 6-207170), blue light emitting layer contains blue fluorescent dye, green light emitting layer is red fluorescent It includes an area containing iodine, etc. construction of what (JP-A-7-142169) and the like further containing a green phosphor.

The material for the electron injection layer and the electron transport layer only needs to have a function of injecting electrons from the cathode, a function of transporting electrons, or a function of blocking holes injected from the anode.
As a specific example,
Triazole derivatives, oxazole derivatives, oxadiazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthaleneperylene, etc. A metal complex of a heterocyclic tetracarboxylic anhydride, a silole derivative, a phthalocyanine derivative, and an 8-quinolinol derivative;
Examples thereof include various metal complexes represented by metal complexes having metal phthalocyanine, benzoxazole, and benzothiazole as a ligand.

The thicknesses of the hole injection layer, the hole transport layer, the light emitting layer, the electron injection layer, and the electron transport layer are not particularly limited, but are preferably 10 nm to 500 nm. Each layer may have a single layer structure, or a multilayer structure having the same composition or different compositions.
The formation method of these layers is not particularly limited, but resistance heating evaporation method, electron beam evaporation method, sputtering method, molecular lamination method, coating method (spin coating method, casting method, dip coating method, etc.), A method such as the LB (Langmuir Blodgett) method is used. The resistance heating vapor deposition method and the coating method are preferable.

Finally, a back electrode is formed on the surface of the organic EL layer.
The back electrode which is a negative electrode supplies electrons to an electron injection layer, an electron transport layer, a light emitting layer, or the like, and is selected in consideration of adhesion to an adjacent layer, ionization potential, stability, and the like.
The back electrode preferably has light reflectivity.
As a material for the back electrode, metals, alloys, conductive metal oxides, other conductive compounds, and mixtures thereof can be used.
As a specific example,
Alkali metals (such as Li, Na, and K) and fluorides thereof;
Alkaline earth metals (such as Mg and Ca) and their fluorides;
Gold, silver, lead, aluminum, sodium-potassium alloys, and mixed metals containing them;
Lithium-aluminum alloys and mixed metals containing them;
LiF / Al alloys and mixed metals containing them;
Magnesium-silver alloys and mixed metals containing them;
And rare earth metals such as indium and ytterbium.
A material having a work function of 4 eV or less is preferable, and aluminum, a lithium-aluminum alloy and a mixed metal thereof, a magnesium-silver alloy and a mixed metal thereof, and the like are more preferable.
Further, in order to control the injection property of electrons or holes into the organic layer while maintaining the light reflectivity, the back electrode material and ITO can be laminated to form the back electrode.

Although the film thickness of a back electrode can be suitably selected with material, 100 nm-1 micrometer are preferable normally. For the production of the back electrode, methods such as electron beam vapor deposition, sputtering, resistance heating vapor deposition, and coating are used. A metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. It is possible to deposit a plurality of metals at the same time to form an alloy electrode, or a previously prepared alloy may be deposited.

As a manufacturing method of the top emission structure, there is a method in which a back electrode, an organic EL layer, a translucent electrode, and a light scattering layer are sequentially laminated on a substrate such as a TFT. The back electrode, organic EL layer, translucent electrode, light scattering layer material, lamination method, and the like described here may be the same as those described in the bottom emission manufacturing method.

In addition, in order to improve the stability of the organic EL element against temperature, humidity, atmosphere, etc., a protective layer may be provided on the element surface or between layers, or the whole element may be covered or sealed with a resin or the like. . In particular, when covering or sealing the entire device, a molten glass, a photocurable resin that is cured by light, or the like is preferably used.

  The current applied to the organic EL element having the light scattering layer of the present invention is usually a direct current, but a pulse current or an alternating current may be used. The current value and the voltage value are not particularly limited as long as the element is within a range not destroying the element. However, considering the power consumption and life of the element, it is desirable to efficiently emit light with as little electrical energy as possible.

The driving method of the organic EL element having the light scattering layer of the present invention can be driven not only by the passive matrix method but also by the active matrix method. These methods and techniques are described in Shinji Kido, “All about organic EL”, published by Nihon Jitsugyo Shuppansha (published in 2003).

  The light emitted from the organic EL layer by applying a voltage between the translucent electrode and the back electrode of the organic EL device formed as described above is transmitted from the translucent electrode through the light scattering layer. Further, the light is transmitted through the translucent substrate and taken out. When the light emitted from the organic EL layer passes through the light scattering layer, the light is scattered and the directivity is changed, so that the totally reflected light is prevented from being guided.

The organic EL device having the light scattering layer of the present invention can be applied in various forms.
For example, the organic EL device comprising the light scattering layer of the present invention can be used as a full color display device.
The main methods of the full color method include a three-color painting method, a color conversion method, and a color filter method. In the three-color coating method, an evaporation method using a shadow mask, an ink jet method, and a printing method can be used. In addition, Special Table 2002-53482, S.I. T.A. Lee, et al. Proceedings of SID'02, p. 784 (2002) can also be used. The laser thermal transfer method (also referred to as Laser Induced Thermal Imaging, LITI method) can also be used. In the color conversion method, a light emitting layer that emits color light is used to convert green and red, which have wavelengths longer than colors, through a color conversion (CCM) layer in which fluorescent dyes are dispersed. The color filter method is a method of extracting light of three primary colors through a color filter for liquid crystal using a white light emitting organic EL light emitting element. In addition to these three primary colors, a part of white light is extracted and used for light emission. As a result, the luminous efficiency of the entire device can be increased.

Furthermore, the organic EL element having the light scattering layer of the present invention may adopt a microcavity structure. This is because the organic EL element has a structure in which the light emitting layer is sandwiched between the anode and the cathode, and the emitted light causes multiple interference between the anode and the cathode, but the reflectance and transmission of the anode and the cathode. This is a technology that actively uses the multiple interference effect and controls the emission wavelength extracted from the device by appropriately selecting the optical characteristics such as the rate and the film thickness of the organic layer sandwiched between them. . Thereby, it is also possible to improve the emission chromaticity. For the mechanism of this multiple interference effect, see J.A. Yamada et al., AM-LCD Digest of Technical Papers, OD-2, p. 77-80 (2002).

The organic EL element having the light scattering layer of the present invention may adopt a multi-photon emission element structure. Multi-photon emission is an element structure in which a plurality of light emitting units including at least one light emitting layer are stacked so as to be connected in series via a charge generation layer (see, for example, Japanese Patent No. 3933593). According to such an element structure, light emission from a plurality of light emitting layers can be obtained simultaneously with the same amount of current as that of one unit element, so that current efficiency and external quantum efficiency equivalent to the number of light emitting units can be obtained. .

  As described above, the organic EL device having the light scattering layer of the present invention is used as a flat panel display such as a wall-mounted television or various flat light emitters, and further as a light source such as a copying machine or a printer, a liquid crystal display or an instrument. Application to a light source such as a light source, a display board, a marker lamp, etc. is conceivable.

  EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. Unless otherwise specified, “part” represents “part by mass” and “%” represents mass%.

  First, 5% thermal decomposition temperature of resin (A), mass average molecular weight (Mw) of resin (A) and silane compound (E), double bond of resin (A) and ethylenically unsaturated monomer (D) The measurement method of the equivalent, the acid value of the resin (A), and the particle diameter of the light scattering particles (B) and the metal oxide fine particles (C) will be described.

(5% thermal decomposition temperature)
As 5% thermal decomposition temperature, using a differential thermothermal gravimetric simultaneous measurement apparatus EXSTER TG / DTA6300 manufactured by Seiko Instruments Inc., measured at a heating rate of 10 ° C./min in an air stream of 200 ml / min, The temperature at which the mass of the resin sample was 95% before the temperature increase was determined.

(Mass average molecular weight (Mw))
The mass average molecular weight (Mw) was measured using gel permeation chromatography GPC-101 manufactured by Showa Denko K.K. Using THF (tetrahydrofuran) as a solvent, the molecular weight in terms of polystyrene was determined.

(Double bond equivalent)
Double bond equivalent is a measure of the amount of double bonds contained in a molecule. If the compounds have the same molecular weight, the amount of double bonds introduced increases as the double bond equivalent value decreases. .
The double bond equivalent was calculated by the following formula.
[Double bond equivalent] = [molecular weight of monomer component having double bond] / [mass ratio of monomer component having double bond to all monomers in molecule]

(Acid value)
The acid value (JIS acid value) was determined by the following method.
1 g of a sample was dissolved in a titration solvent in which xylene and dimethylformamide were mixed at a mass ratio of 1: 1. Titration was performed using a 0.1 mol / L potassium hydroxide solution (solvent is ethanol) by potentiometric titration. The acid value was calculated from the following formula from the titration amount up to the end point of the potassium hydroxide solution with the inflection point on the titration curve as the end point.
A = (BC) × f × D / S
(The symbols in the formula are as follows.
A: Acid value (mgKOH / g), B: Addition amount (mL) of potassium hydroxide solution in this test, C: Addition amount (mL) of potassium hydroxide solution in blank test (measured without using measurement sample) , F: factor of potassium hydroxide solution, D: concentration conversion value = 5.611 mg / mL (equivalent amount of potassium hydroxide of 1 mL of 0.1 mol / L potassium hydroxide solution), S: sample (g))

(Particle size)
The particle size was measured using “Nanotrack UPA” manufactured by Nikkiso Co., Ltd. A few drops of the light scattering particle dispersion liquid whose solid content mass% concentration was adjusted to 20% were poured into a cell filled with the same solvent as the dispersion liquid, and the measurement was performed at a concentration at which the signal level reached the optimum value.

[Production Examples 1-24, Examples 1-110, Comparative Examples 1-24]

(1) Preparation of resin (A) solution (Production Example 1)
Step 1:
In a reaction vessel equipped with a stirrer, a thermometer, a dropping device, a reflux condenser, and a gas introduction tube, 100 parts of PGMEA (propyleneglycol monomethyl ether acetate) was added as a solvent. The container was heated to 80 ° C. while injecting nitrogen gas. While maintaining this temperature, 5.0 parts of styrene (St), 15.9 parts of cyclohexyl methacrylate (CHMA), 31.7 parts of methacrylic acid (MAA), and 3.0 of 2,2′-azobisisobutyronitrile. Part of the mixture was added dropwise over 1 hour to carry out the polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 70 ° C. for 3 hours, and then 0.5 parts of azobisisobutyronitrile dissolved in 40 parts of PGMEA was added, followed by stirring at the same temperature for 3 hours. A polymer was obtained.
Step 2:
Next, dry air was introduced into the reaction vessel, and 50.0 parts of glycidyl methacrylate (GMA), 37.0 parts of PGMEA, 0.6 part of dimethylbenzylamine, and 0.1 part of methoquinone were charged, and then at the same temperature for 10 hours. And stirring was continued. After cooling to room temperature, the resin solution (A-1) having a solid content of 35% by mass was obtained by diluting with PGMEA.
Table 1 shows main reaction conditions (prepared composition and reaction temperature) and evaluation results of the obtained resin.

(Production Examples 2 to 10)
Resin solutions (A-2) to (A-10) were obtained in the same manner as in Production Example 1, except that the reaction conditions (charge composition and reaction temperature) were changed to those shown in Table 1.

Each abbreviation in Table 1 is as follows.
PGMEA: propylene glycol monomethyl ether acetate,
DCPMA: dicyclopentanyl methacrylate,
CHMA: cyclohexyl methacrylate,
St: Styrene,
M-110: paracumylphenol ethylene oxide modified acrylate,
HEMA: hydroxyethyl methacrylate,
MAA: methacrylic acid,
GMA: glycidyl methacrylate,
MMA: methyl methacrylate.
The unit of the blending amount in Table 1 is “part”.

(2) Preparation of light scattering particles (B) dispersion

(Production Example 11)
In a mixed solvent of 66 g of methanol and 24 g of water in an N ₂ atmosphere, 4.5 g of methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 5 g of trifluoroethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), and allyl methacrylate (Wako Pure Chemical Industries, Ltd.) 0.5 g) was polymerized at 60 ° C. for 8 hours using 0.025 g of 2,2′-azobis (2-amidinopropane) dihydrochloride (W-50 Pure Chemicals, V-50). Then, 123 g of PGMEA was added, methanol and water were removed by stripping, and a light scattering particle dispersion (B-1) (acrylic resin particle dispersion) was produced.
Composition of light scattering particle dispersion (B-1), disperser, primary particle diameter of particles, particle diameter in dispersion, particle content of particle diameter of 600 nm or more with respect to total amount of particles in dispersion, and dispersion Table 2 shows the coefficient of variation of the particles inside.

(Production Examples 12-17)
Light scattering particle dispersions (B-2) to (B-7) were prepared in the same manner as in Production Example 11 except that the composition was changed to that shown in Table 2. Table 2 shows the primary particle size of each particle, the particle size in the dispersion, the content of particles having a particle size of 600 nm or more with respect to the total amount of particles in the dispersion, and the coefficient of variation of the particles in the dispersion.

(Production Example 18)
Step 1: Production of Dispersant (T-1) In a four-necked flask equipped with a stirrer, a reflux condenser, a dry air introduction tube, and a thermometer, biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Corporation) ) 80.0 parts, pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD PET-30), 250.0 parts, hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) 0.16 parts, And 141.2 parts of cyclohexanone was charged and the temperature was raised to 85 ° C. Next, 1.65 parts of 1,8-diazabicyclo [5.4.0] -7-undecene (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a catalyst, and the mixture was stirred at 85 ° C. for 8 hours. Thereafter, 77.3 parts of glycidyl methacrylate (manufactured by Dow Chemical Japan Co., Ltd.) and 33.9 parts of cyclohexanone were added, and then dimethylbenzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) 2.65 as a catalyst. The mixture was stirred at 85 ° C. for 6 hours and cooled to room temperature to complete the reaction.
The obtained reaction solution was light yellow and transparent and had a solid content of 70% by mass. The reaction product had a weight average molecular weight (Mw) of about 3130.
Step 2: Production of dispersion To 10 g of titanium oxide (TiO ₂ ) particles having an average primary particle size of 250 nm, 87.2 g of methyl isobutyl ketone as a dispersion medium and 2.8 g of the dispersant (T-1) were added. . Using zirconia beads (1.25 mm) as a medium, dispersion treatment was carried out with dynomill for 1 hour to prepare a light scattering particle dispersion (B-8) (titanium oxide particle dispersion).
Composition of light scattering particle dispersion (B-8), disperser, particle primary particle diameter, particle diameter in dispersion, particle content of particle diameter of 600 nm or more with respect to total amount of particles in dispersion, and dispersion Table 2 shows the coefficient of variation of the particles inside.

(Production Examples 19 to 20)
Light scattering particle dispersions (B-9) to (B-10) were produced in the same manner as in Step 2 of Production Example 11, except that the formulation and the disperser shown in Table 2 were respectively changed.
The evaluation results are shown in Table 2.

Each abbreviation in Table 2 is as follows.
Titanium oxide 1: Taipei CR-97 manufactured by Ishihara Sangyo Co., Ltd.
Titanium oxide 2: Ipehara Sangyo Co., Ltd.
Silica: Nippon Shokubai Co., Ltd. Sea Hoster KE-S30,
Melamine resin: Nippon Shokubai Eposter S6,
BYK-111: BYK-111 manufactured by Big Chemie.

(3) Preparation of metal oxide fine particle (C) dispersion (Production Example 21)
10 g of titanium oxide (TiO ₂ ) fine particles having an average primary particle diameter of 15 nm, 84.3 g of PGMEA (propylene glycol monomethyl ether acetate) as a dispersion medium, and the dispersant obtained in Step 1 of Production Example 1-11 as a dispersant 5.7 g of (T1-1) was added. A two-stage dispersion treatment was performed on the obtained liquid. As pre-dispersion, zirconia beads (average diameter: 1.25 mm) were used as media and dispersed for 1 hour with a paint shaker. As this dispersion, zirconia beads (average diameter: 0.1 mm) were used as media, and the dispersion was carried out for 7 hours with a disperser UAM-015 manufactured by Kotobuki Industries Co., Ltd. As described above, a metal oxide fine particle dispersion (C1) (titanium oxide fine particle dispersion) was produced. The average particle diameter of the titanium oxide fine particles in the dispersion was 80 nm.

(4) Preparation of silane compound (E) (Production Example 22)
A flask equipped with a cooling tube was prepared as a reaction tank, and 100 g of 3-isocyanatopropyltriethoxysilane (“KBE-9007” manufactured by Shin-Etsu Chemical Co., Ltd.) and 50 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were well stirred and mixed. Prepared and purged with nitrogen. Then, it heated with the oil bath, stirring, and raised the temperature of the reaction tank to 60 degreeC. After the reaction vessel temperature was stabilized at 60 ° C., the mixture was further stirred for 8 hours. After confirming the completion of the reaction by FT-IR spectrum, the temperature of the reaction vessel was lowered to room temperature to obtain 130 g of an ethanol solution of (3-carbamateethyl) propyltriethoxysilane having a solid content of 79% by mass.
A 100 mL four-necked flask equipped with a Dimroth type cooling condenser, a Dean Stark, a stirrer, and a thermometer was sufficiently substituted with nitrogen. 100 g of the ethanol solution of (3-carbamateethyl) propyltriethoxysilane obtained above, 25 mL of ethanol, and 0.06 g of sodium acetate were charged, and 1.3 g of water was slowly added. The mixture was aged at 30 to 40 ° C. for 1 hour under normal pressure and then aged for 3 hours under reflux. After aging, the solvent was gradually extracted at normal pressure, and when the kettle temperature reached 105 ° C., the heating was stopped and the system was cooled. The obtained solution was filtered and dried at 120 ° C. under reduced pressure for 1 hour to obtain a silane compound (E-1) which is a transparent oily product. The mass average molecular weight (Mw) was about 5,500.

(Production Example 23)
Prepare a flask with a cooling tube as a reaction vessel, and add 100 g of 3-isocyanatopropyltriethoxysilane (“KBE-9007” manufactured by Shin-Etsu Chemical Co., Ltd.) and 100 g of 2,8-ethyl-1-tetradecanol. A stirred mixture was prepared and purged with nitrogen. Then, it heated with the oil bath, stirring, and raised the temperature of the reaction tank to 60 degreeC. After the temperature of the reaction vessel was stabilized at 60 ° C., the mixture was further stirred for 10 hours. After confirming the completion of the reaction by FT-IR spectrum, the temperature of the reaction vessel was lowered to room temperature and taken out into a nitrogen-substituted container to obtain a silane compound (E-2). The mass average molecular weight (Mw) was about 520.

(Production Example 24)
A flask equipped with a cooling tube was prepared as a reaction tank, and 100 g of 3-isocyanatopropyltriethoxysilane (“KBE-9007” manufactured by Shin-Etsu Chemical Co., Ltd.) and 100 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were well stirred and mixed. Prepared and purged with nitrogen. Then, it heated with the oil bath, stirring, and raised the temperature of the reaction tank to 60 degreeC. After the temperature of the reaction vessel stabilized at 60 ° C., the mixture was further stirred for 6 hours. After confirming the completion of the reaction by FT-IR spectrum, the temperature of the reaction vessel was lowered to room temperature and taken out into a nitrogen-substituted container to obtain a silane compound (E-3). The weight average molecular weight (Mw) was about 280.

(5) Preparation of resin composition for light scattering layer (Example 1)
10.30 g of the resin (A-4) obtained above and metal oxide fine particle dispersion (C-1) 31.30 g with respect to 10.00 g of the light scattering particle dispersion (B-1) obtained above. 85 g and 48.14 g of organic solvent PGMEA were added and stirred and mixed to be uniform. The mixture was filtered through a filter having a mesh diameter of 5 μm to prepare a resin composition for a light scattering layer. The mass ratio of the solid content in this composition is resin (A-4): light scattering particles (B-1) (including a dispersant for dispersing light scattering particles): metal oxide fine particles (C) ( (Including a dispersing agent for dispersing light scattering particles) = 40: 10: 50.
Table 3 shows the composition.

(Examples 2-50, Comparative Examples 1-4)
A resin composition for a light scattering layer was obtained in the same manner as in Example 1 except that the composition shown in Table 3 was used.

Each abbreviation in Table 3 is as follows.
V # 802: Biscoat # 802 manufactured by Osaka Organic Chemical Industry Co., Ltd.
DPCA60: Cayarad DPCA60 manufactured by Sartomer,
M402: Aronix M402 manufactured by Toagosei Co., Ltd.
KBM-573: Shin-Etsu Silicone KBM-573,
Irg907: Irgacure 907 manufactured by BASF,
OXE01: BASF Irgacure OXE01,
OXE02: BASF Irgacure OXE02,
BYK330: BYK330 manufactured by Big Chemie.

(Examples 51 to 110, Comparative Examples 7 to 24)
A resin composition for a light scattering layer was obtained in the same manner as in Example 1 except that the blending compositions shown in Table 4, Table 5, and Table 6 were used.

The abbreviations in Table 4, Table 5, and Table 6 are as follows.
Thermally reactive compound (G)
MX-43: Alkoxyalkyl group-containing melamine compound manufactured by Sanwa Chemical Co., Ltd. NIKALAC MX-43
MX-417: a melamine compound containing an imino group and a methylol group manufactured by Sanwa Chemical Co., Ltd. Nicalak MX-417
SB-401: Alkoxyalkyl group-containing benzoguanamine compound manufactured by Sanwa Chemical Co., Ltd. Nicalak SB-401
BL-60: Imino group / methylol group-containing benzoguanamine compound manufactured by Sanwa Chemical Co., Ltd. Nicarac BL-60
BL-4265: isocyanate compound manufactured by Bayer, Death Module BL-4265
EPPN-201: Epoxy compound EPPN-201 manufactured by Nippon Kayaku Co., Ltd.

(6) Evaluation The obtained resin composition for light scattering layers was evaluated by the following apparatus or method.
(The refractive index of the binder material and the refractive index difference between the binder material and the light scattering particles (B))
The binder material was applied to a PEN (polyethylene naphthalate) film using a spin coater so that the finished film thickness was 2.0 μm. Next, the obtained coated substrate was held on a hot plate heated to 110 ° C. for 2 minutes, and then subjected to ultraviolet exposure at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. . The coated substrate was heated at 200 ° C. for 30 minutes and allowed to cool, and the refractive index (n1) of the binder material was measured with an Abbe refractometer in accordance with Japanese Industrial Standards: JIS K7142 “Plastic Refractive Index Measuring Method”. The difference between the refractive index (n1) of the binder material and the refractive index (n2) of the light scattering particles was determined using the following values for the refractive index (n2) of the light scattering particles.
-Refractive index of inorganic particles: It is the refractive index of the literature value in the bulk.
-Refractive index of organic particles: Theoretical refractive index (nD) calculated from the following formula.
Theoretical refractive index (nD) = W1 × n1 + W2 × n2 +... + Wm × nm
n1: Refractive index of homopolymer of monomer A n2: Refractive index of homopolymer of monomer B nm: Refractive index of homopolymer of monomer C W1: Copolymerization ratio of monomer A (monomer Mass ratio based on the total amount of
W2: Copolymerization ratio of monomer B (mass ratio based on the total amount of monomers)
Wm: Copolymerization ratio of monomer C (mass ratio based on the total amount of monomers)

Evaluation was made based on the following criteria.
-Refractive index of the binder material 1.65 or more: good (○),
Less than 1.65: Possible (△)
-Refractive index difference between the binder material and the light scattering particles (B) 0.1 ≦ | n1-n2 |: “Good (◯)”,
0.1> | n1-n2 |: “impossible (×)”

(Visible light transmittance of light scattering layer)
The finished film thickness after heating the resin composition for light scattering layer to a glass substrate of 100 mm × 100 mm and 0.7 mm thickness (Corning glass “Eagle 2000”) at 230 ° C. for 20 minutes using a spin coater is 2. It apply | coated so that it might be set to 0 micrometer. Next, the obtained coated substrate was held on a hot plate heated to 110 ° C. for 2 minutes, and then subjected to ultraviolet exposure at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. . The coated substrate was heated at 230 ° C. for 20 minutes and allowed to cool, and then the transmittance at a wavelength of 400 nm of the obtained coating film was determined using a microspectrophotometer (“OSP-SP100” manufactured by Olympus Optical Co., Ltd.). Evaluation was made based on the following criteria.
Transmittance of 80% or higher: Good (○),
Transmittance less than 80%: Possible (△)

(Heat resistance; measurement of transmittance after additional baking)
A resin composition-coated substrate for a light scattering layer obtained by the same method as that prepared for transmittance measurement was heated at 300 ° C. for 20 minutes, allowed to cool, and then a microspectrophotometer (“OSP-SP100” manufactured by Olympus Optical Co., Ltd.) Was used to determine the transmittance of the obtained coating film at a wavelength of 400 nm. Evaluation was made based on the following criteria.
Transmittance of 80% or higher: Good (○),
Transmittance less than 80%: Possible (△)

(Evaluation of EL device with bottom emission structure (light extraction efficiency, light emission appearance (dark spots, unevenness), wavelength dependence))
Using the ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90: 10 (mass ratio)) on the resin composition-coated substrate for the light scattering layer obtained by the same method as that prepared for the measurement of transmittance, An ITO film having a thickness of 150 nm was formed by a DC sputtering method to obtain a translucent electrode (anode).
The ITO film was etched using a photoresist to form a pattern so that the light emission area was 5 mm × 5 mm. After ultrasonic cleaning, ozone cleaning was performed using a low-pressure ultraviolet lamp. Next, organic EL layers were sequentially formed on the ITO surface by vacuum deposition as follows.
First, CuPc was formed to a thickness of 15 nm as a hole injection layer. Next, α-NPD was formed to a thickness of 50 nm as a hole transport layer. Next, the red light emitting layer shown in Table 8 was formed to a thickness of 40 nm, and the electron injection layer shown in Table 8 was formed to a thickness of 30 nm.
Thereafter, Mg and Ag were co-evaporated to form MgAg with a thickness of 100 nm, and from the viewpoint of preventing MgAg oxidation, 50 nm of Ag was further formed thereon to form a back electrode (cathode).
After taking out from the vacuum deposition apparatus, an ultraviolet curable epoxy resin was dropped onto the cathode electrode side, and a slide glass was placed thereon, the epoxy resin was cured using a high-pressure ultraviolet lamp, and the device was sealed.
In the same manner as described above, the light emitting layer and the electron injection layer shown in Table 7 were used to produce blue, green, and white light emitting elements, respectively.
Separately, an EL element was obtained by the same method as above except that a glass substrate on which a light scattering layer was not formed was used as a base material for evaluation.

About each light emitting element obtained using the light-emitting body of Table 7, a forward current of 10 mA / cm ^{2 was} applied at room temperature, and the appearance of light emission (dark spots, unevenness) was observed. Further, the front luminance was measured with a spectral radiance meter “CS-2000” manufactured by Konica Minolta Sensing Co., Ltd., and the white light emitting element was obtained based on the front luminance of the EL element produced with the substrate on which the light scattering layer was not formed. The improvement rate of the front luminance was calculated. In addition, the wavelength dependence of the light scattering layer is determined by the difference in front luminance in the light emitting device using the red, blue, and green light emitting layers in Table 4, and the change in the shape of the emission spectrum in the light emitting device using the white light emitting layer. Evaluation was based on the presence or absence. The emission spectrum was measured using MCPD-9800 manufactured by Otsuka Electronics Co., Ltd. Evaluation was made based on the following criteria.
・ Luminescent appearance (dark spots, unevenness)
Dark spots and unevenness are not observed: Good (○),
Dark spots and unevenness are slightly observed: Yes (△),
Dark spots and unevenness are observed: Impossible (×)
・ Light extraction efficiency Front brightness improvement ratio 1.5 times or more: Excellent (◎),
Front brightness improvement rate of 1.2 times to less than 1.5 times: good (○),
Front brightness improvement rate less than 1.2 times: Possible (△)
・ Wavelength dependence The difference in front brightness improvement ratio of red, blue, and green is less than 10% and the spectral shape of white does not change: Good (○)
The difference in the value of the front luminance improvement rate for each of red, blue, and green is 10% or more and less than 20%, and the white spectrum shape is not changed: Yes (△),
The difference between the values of the front luminance improvement ratios of red, blue, and green is 20% or more and the white spectrum shape is changed: Impossible (×)

  The evaluation results are shown in Table 8.

As the light scattering particles (B), the average particle size in the resin composition for the light scattering layer is 200 nm or more and 600 nm or less, and the content of particles having a particle size of 600 nm or more with respect to the total amount of the light scattering particles is 20% by volume or less. In Comparative Examples 1 to 3 using particles that did not satisfy the condition, the emission appearance was deteriorated or wavelength dependency was observed. Moreover, in the comparative example 4, since the difference in refractive index between the binder refractive index and the light scattering particles (B) was smaller than 0.1, the extraction efficiency was low.
In Examples 1 to 50, the light extraction efficiency is high, the light emission appearance (dark spots, unevenness) is good, the wavelength dependency of the light extraction efficiency improvement rate is small, and complicated processes such as color separation for each color are required. An unnecessary organic EL element was realized.
As compared with Examples 4 and 5 having a binder refractive index of less than 1.65, in other Examples having a binder refractive index of 1.65 or more, it was found that the extraction efficiency was large and the wavelength dependency was extremely reduced.

The other physical property evaluation methods are shown below.
(Measurement of adhesion to glass and ITO)
About the resin composition coating substrate for light scattering layers obtained by the same method as that prepared for the measurement of transmittance, the adhesion of the coating film is evaluated by an adhesion (cross-cut method) test according to JISK5600-5-6. The number of peels in 25 grids was counted.
As the substrate, Corning glass “Eagle 2000” and Geomatek ITO film were used.
Evaluation was made based on the following criteria.
Number of cross-cuts peeled 0: Excellent (◎)
The number of peeling of the grid is less than 1 (edge peeling: level at which the border of the grid cuts off): good (○),
The number of peeling of the grid is 1 or more and 3 or less: Yes (○ △),
The number of peeling of the grid is 3 or more and 5 or less: possible (△),
More than 5 grids peeled: Impossible (×)

(ITO etchant resistance)
A coating film was formed on the ITO substrate by the same method as that prepared for measuring transmittance. The obtained resin composition-coated substrate for light scattering layer was immersed in a solution of nitric acid / hydrochloric acid / water = 0.1 / 1/1 (mass ratio) at 40 ° C. for 5 minutes, washed with pure water, and then 24 hours. I left it alone. The obtained substrate was evaluated for the adhesion of the coating film by an adhesion (cross-cut method) test according to JIS K5600-5-6, and the number of peels in 25 grids was counted.
As the substrate, an ITO film manufactured by Geomatek Co. was used.
Evaluation was made based on the following criteria.
Number of cross-cuts peeled 0: Excellent (◎)
The number of peeling of the grid is less than 1 (edge peeling: level at which the border of the grid cuts off): good (○),
Number of cross-cuts 1 to 3: Yes (△),
More than 3 grids peeled: Impossible (×)

(chemical resistance)
The light scattering layer resin composition-coated substrate obtained by the same method as that prepared for transmittance measurement was immersed in acetone or isopropyl alcohol and ultrasonically cleaned at 25 ° C. for 10 minutes, respectively. The obtained substrate was evaluated for the adhesion of the coating film by an adhesion (cross-cut method) test according to JIS K5600-5-6, and the number of peels in 25 grids was counted.
Evaluation was made based on the following criteria.
Number of cross-cuts peeled 0: Excellent (◎)
The number of peeling of the grid is less than 1 (edge peeling: level at which the border of the grid cuts off): good (○),
Number of cross-cuts 1 to 3: Yes (△),
More than 3 grids peeled: Impossible (×)

(Flatness)
About the resin composition application | coating board | substrate for light-scattering layers obtained by the same method as what was produced for the measurement of the transmittance | permeability, the surface roughness of the coating film was measured with the stylus-type film thickness meter DECTAC-3 made from ULVAC. .
Evaluation was made based on the following criteria.
Surface roughness less than 100 mm: Excellent (◎),
Surface roughness of 100 mm or more and less than 200 mm: good (◯),
Surface roughness of 200 to 300 mm: possible (△),
Surface roughness greater than 300 mm: Impossible (×)

(Development speed)
The resin composition for a light scattering layer was applied to a glass substrate by a spin coat method so that the dry film thickness was 2.0 μm and dried. After exposing this coated substrate at 60 mJ / cm ² through a mask pattern with a high-pressure mercury lamp, spray development at a pressure of 0.25 MPa using a 0.04 mass% potassium hydroxide aqueous solution (developer temperature 26 ° C.), The time until the coating film was dissolved and the substrate surface was exposed (development dissolution time) was measured.
Evaluation was made based on the following criteria.
Development time less than 20 seconds: Excellent (○),
Development time 20 seconds or more and less than 60 seconds: good (△),
Development time 60 seconds or more: Impossible (×)

  Table 9 shows the evaluation results.

  As shown in Table 9, in Examples 29 to 50 to which the silane compound (E) was added, a coating film excellent in adhesion, etchant resistance, and chemical resistance was obtained.

<Evaluation of organic EL device with top emission structure and coating type structure (light extraction efficiency, light emission appearance (dark spot, unevenness)), wavelength dependence>
(Top emission structure A)
An aluminum film is formed by vacuum deposition on a glass substrate that is ultrasonically cleaned with isopropyl alcohol and then dried with dry nitrogen gas under a condition of a thickness of 100 nm, and then an ITO ceramic target (In ₂ O ₃ : SnO _2). = 90% by mass: 10% by mass), an ITO film having a thickness of 20 nm is formed by a DC sputtering method, patterned to have a light emitting area of 5 mm × 5 mm, and a back surface made of a laminate of aluminum and ITO An electrode (anode) was formed. Next, without taking out from the vacuum, organic EL layers were sequentially formed on the ITO surface by vacuum deposition as follows. First, α-NPD was formed to a thickness of 40 nm as a hole injection / hole transport layer. Next, H1 and Ir-1 listed in Table 7 were adjusted to a deposition rate of 100: 6 and formed to a thickness of 30 nm. Next, BAlq was formed to a thickness of 10 nm as a hole blocking layer. Further, Alq3 was formed to a thickness of 20 nm as an electron transport layer. Next, magnesium is formed to a thickness of 2 nm by vacuum deposition, and further, a thickness of 100 nm is formed by DC sputtering from an ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90 mass%: 10 mass%). The ITO film was formed to form a translucent electrode (cathode) made of a laminate of magnesium and ITO. Finally, the glass substrate and the resin composition-coated substrates for light scattering layers of Examples 29 to 50 and Comparative Example 4 prepared for measuring transmittance were used as sealing substrates, and epoxy photocuring was used as a sealing material around them. A mold adhesive was applied, which was brought into close contact with the scattering film side of the substrate, and irradiated with UV light from the glass substrate side to be cured and sealed. What was sealed only with the glass substrate is referred to as Comparative Example 5.

(Top emission structure B)
On a glass substrate that has been ultrasonically cleaned with isopropyl alcohol and then dried with dry nitrogen gas, aluminum is deposited by vacuum deposition under a thickness of 100 nm, and then lithium fluoride is deposited by vacuum deposition. Then, a lithium fluoride film having a thickness of 0.5 nm was formed and patterned so as to have a light emission area of 5 mm × 5 mm to form a back electrode (cathode) made of a laminate of aluminum and lithium fluoride. Subsequently, without taking out from a vacuum, the organic EL layer was sequentially formed on the lithium fluoride surface by a vacuum deposition method as follows. First, Alq3 was formed to a thickness of 20 nm as an electron transport layer. Next, BAlq was formed to a thickness of 10 nm as a hole blocking layer. Next, H1 and Ir-1 listed in Table 7 were adjusted to a deposition rate of 100: 6 and formed to a thickness of 30 nm. Next, α-NPD was formed to a thickness of 40 nm as a hole injection / hole transport layer. Next, an ITO film having a thickness of 150 nm is formed by a DC sputtering method from an ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90% by mass: 10% by mass), and an ITO translucent electrode (anode) is formed. did. Finally, the glass substrate and the resin composition-coated substrates for light scattering layers of Examples 29 to 50 and Comparative Example 4 prepared for measuring transmittance were used as sealing substrates, and epoxy photocuring was used as a sealing material around them. A mold adhesive was applied, which was brought into close contact with the scattering film side of the substrate, and irradiated with UV light from the glass substrate side to be cured and sealed. What was sealed only with the glass substrate is referred to as Comparative Example 5.

(Coating structure)
On the resin composition coated substrate for light scattering layer of Examples 29 to 50 and Comparative Example 4 obtained by the same method as that prepared for the measurement of transmittance, ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90). An ITO film having a thickness of 150 nm was formed by a DC sputtering method to obtain a light-transmitting electrode (anode). Separately from this, an ITO film was formed directly on the glass substrate in the same manner as described above without forming a light scattering layer, thereby obtaining a translucent electrode (anode). Thereafter, the ITO film was etched using a photoresist with respect to both the translucent electrodes to form a pattern so that the light emission area was 5 mm × 5 mm. After ultrasonic cleaning, ozone cleaning was performed using a low-pressure ultraviolet lamp. PEDOT / PSS (poly (3,4-ethylenedioxy) -2,5-thiophene / polystyrene sulfonic acid, BAYTRON P VP CH8000 manufactured by Bayer) manufactured on a cleaned glass plate with an ITO electrode by a spin coating method A hole injection layer having a thickness of 40 nm was obtained. Subsequently, PVK (Poly (9-vinylcarbazole), manufactured by Sigma-Aldrich) was 60%, and Ir-2 listed in Table 8 was 3% and ETM-1 was 37% in mass ratio of 2.0 wt% in total. Then, it was dissolved in toluene so that a light emitting layer having a thickness of 70 nm was obtained by a spin coating method. Furthermore, after depositing 20 nm of Ca thereon, 200 nm of Al was deposited to form an electrode to obtain an organic EL device. Finally, an ultraviolet curable epoxy resin was dropped on the cathode electrode side, and a glass slide was placed thereon, the epoxy resin was cured using a high pressure ultraviolet lamp, and the device was sealed. A glass substrate is used as Comparative Example 6.

The light emitting appearance, light emission efficiency, and wavelength dependency of the obtained light emitting device were measured by the above methods.
The results are listed in Table 12.

As shown in Table 12, the same results as those of the bottom emission type were obtained in both the top emission structure and the coating type structure.

<Evaluation as photosensitive dry film>
The resin composition for light scattering layer used in Examples 29 to 50 and Comparative Examples 1, 2, and 4 was uniformly applied to a dry film thickness of 2 μm on a 12 μPET film (S-12 manufactured by Toray DuPont Co., Ltd.). After coating and drying at 100 ° C. for 5 minutes, the mixture was cooled to room temperature, and a biaxially stretched polypropylene film (OPP film) was laminated on the light scattering layer resin composition side to obtain a photosensitive dry film. The OPP film was peeled off from the photosensitive dry film, and vacuum laminated to a glass substrate (Corning Glass Eagle 2000). The vacuum lamination conditions were a heating temperature of 60 ° C., a vacuum time of 60 seconds, a vacuum ultimate pressure of 2 hPa, a pressure of 0.4 MPa, and a pressurization time of 60 seconds.
Next, ultraviolet exposure was performed with an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. Further, the obtained substrate was heated at 230 ° C. for 20 minutes and allowed to cool to obtain a light scattering layer. About the obtained light-scattering layer, element preparation and evaluation were performed in the same manner as described above, visible light transmittance and heat resistance of the light-scattering layer; measurement of transmittance after additional baking, evaluation of bottom emission type EL elements (light extraction) Efficiency, luminous appearance (dark spot, unevenness, wavelength dependence)), adhesion to glass and ITO, ITO etchant resistance, chemical resistance, and flatness were evaluated. Examples 29 to 50, Comparative Example 1 The results obtained in 2 and 4 were similar.

<Evaluation of resin composition for light scattering layer by various printing processes>
(A) Reverse offset printing (reverse offset printability)
Using the thin film printing apparatus shown in FIG. 2, the anilox roll was appropriately applied to the light scattering layer resin compositions of Examples 51 to 70 and Comparative Examples 7 to 12 on a glass substrate so that the dry coating thickness was 2 μm. While exchanging, a straight line having a line width of 100 μm was continuously printed, and a linear shape was observed.
: Continuous printing 30 plates or more can print a linear pattern continuously.
X: The linear pattern is distorted in about 30 continuous printings.

(Flatness)
Using the thin film printing apparatus shown in FIG. 2, the finished film thickness after heating the light scattering layer resin compositions of Examples 51 to 70 and Comparative Examples 7 to 12 at 230 ° C. for 20 minutes is 2 μm on a glass substrate. As described above, printing was performed while appropriately replacing the anilox roll, and a 100 mm × 100 mm square light scattering layer was formed on the glass substrate. Next, it was kept on a hot plate heated to 110 ° C. for 2 minutes. Thereafter, Examples 51 to 64 and Comparative Examples 7 to 9 were subjected to ultraviolet exposure at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. The coated substrate was heated at 230 ° C. for 20 minutes to obtain a light scattering layer. In Examples 65 to 70 and Comparative Examples 10 to 12, the coated substrate was heated as it was at 230 ° C. for 20 minutes without exposure to obtain a light scattering layer. About the obtained light-scattering layer, preparation and evaluation of the bottom emission type organic EL element were performed similarly to the above.
The evaluation results are shown in Table 14.
Other evaluation results are shown in Table 13 and Table 14. The evaluation method was performed in the same manner as in Example 1.

(B) Flexographic printing (flexographic printability)
The second unit of the CI 6-color flexo printing machine (Windmoeller & Hoelscher KG's “SOLOFLEX” (CI 6-color press)) is equipped with a flexographic plate (DSF version) with a 100 micron line and space pattern, and 165-line anilox The light scattering layer resin compositions of Examples 71 to 90 and Comparative Examples 13 to 18 were sequentially printed on a glass substrate using a roll (cell capacity 26.5 cm 2 / m 3) so that the dry coating thickness was 2 μm. Whether or not the resin composition for the light scattering layer was continuously transferred from the anilox roll to the plate was visually determined.
Good transferability: ○
Metastatic defect: ×

(Flatness)
A 165-line anilox roll with a 100 mm x 100 mm square pattern mounted on the second unit of a CI 6-color flexographic printing machine ("SOLOFLEX" (CI 6-color press manufactured by Windmoeller & Hoelscher KG)) Light scattering of Examples 71 to 90 and Comparative Examples 13 to 18 so that the finished film thickness after heating at 230 ° C. for 20 minutes on a glass substrate using (cell capacity 26.5 cm ² / m ³ ) is 2.0 μm. The resin compositions for the layers were sequentially printed, and then held for 2 minutes on a hot plate heated to 110 ° C. Thereafter, the resin compositions for the light scattering layers of Examples 71 to 84 and Comparative Examples 13 to 15 were used. Then, UV exposure was performed using an ultrahigh pressure mercury lamp at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² . A light scattering layer was obtained by heating at 0 ° C. for 20 minutes, and the coated substrate was heated at 230 ° C. for 20 minutes without exposing the resin compositions for light scattering layers of Examples 85 to 90 and Comparative Examples 16 to 18. In the same manner as described above, a bottom emission type organic EL device was prepared and evaluated.
The evaluation results are shown in Table 16.
Other evaluation results are shown in Table 15 and Table 16. The evaluation method was performed in the same manner as in Example 1.

(C) Gravure printing (gravure printability)
The resin composition for light scattering layers of Examples 71 to 90 and Comparative Examples 13 to 18 was used with a corrosive plate having a plate depth of 30 microns using a gravure proofing machine, and the dry coating thickness was 2 μm on the glass substrate. Thus, continuous printing of a straight line having a line width of 100 μm was performed, and the linear shape was observed.
: Continuous printing 30 plates or more can print a linear pattern continuously.
X: The linear pattern is distorted in about 30 continuous printings.

(Flatness)
The finished film after heating the resin composition for light scattering layers of Examples 71 to 90 and Comparative Examples 13 to 18 on a glass substrate at 230 ° C. for 20 minutes using a gravure proofing machine and using a corrosion plate having a plate depth of 30 microns. Printing was sequentially performed so that the thickness was 2.0 μm. Next, it was kept on a hot plate heated to 110 ° C. for 2 minutes. Thereafter, the resin compositions for light scattering layers of Examples 71 to 84 and Comparative Examples 13 to 15 were subjected to ultraviolet exposure at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. . The coated substrate was heated at 230 ° C. for 20 minutes to obtain a light scattering layer. The light scattering layer resin compositions of Examples 85 to 90 and Comparative Examples 15 to 18 were not exposed, and the coated substrate was heated as it was at 230 ° C. for 20 minutes to obtain a light scattering layer. About the obtained light-scattering layer, preparation and evaluation of the bottom emission type organic EL element were performed similarly to the above.
The evaluation results are shown in Table 18.
Other evaluation results are shown in Table 17 and Table 18. The evaluation method was performed in the same manner as in Example 1.

(D) Inkjet (IJ) printing (IJ printability)
The inks obtained in Examples 91 to 110 and Comparative Examples 18 to 24 were ejected onto a PET substrate with an inkjet printer having a piezo head capable of changing the frequency of 4 to 10 KHz, and the printing state was visually observed. The discharge stability was evaluated based on the standard.
○: Continuous printing and intermittent printing can be performed accurately at a predetermined position.
X: A defect occurs in the middle or printing cannot be performed at a predetermined position.

(Flatness)
The resin composition for light scattering layers obtained in Examples 91 to 110 and Comparative Examples 19 to 24 is a square pattern of 100 mm × 100 mm on a glass substrate with an inkjet printer having a piezo head capable of changing the frequency of 4 to 10 KHz. Were sequentially printed so that the finished film thickness after heating at 230 ° C. for 20 minutes was 2.0 μm. Next, it was kept on a hot plate heated to 110 ° C. for 2 minutes. Thereafter, Examples 91 to 104 and Comparative Examples 13 to 15 were subjected to ultraviolet exposure at an illuminance of 20 mW / cm ² and an exposure amount of 50 mJ / cm ² using an ultrahigh pressure mercury lamp. The coated substrate was heated at 230 ° C. for 20 minutes to obtain a light scattering layer. In Examples 105 to 110 and Comparative Examples 16 to 18, the coated substrate was heated as it was at 230 ° C. for 20 minutes without exposure to obtain a light scattering layer. About the obtained light-scattering layer, preparation and evaluation of the bottom emission type organic EL element were performed similarly to the above.
The evaluation results are shown in Table 20.
Other evaluation results are shown in Table 19 and Table 20. The evaluation method was performed in the same manner as in Example 1.

From the results of Examples 51 to 110, the light scattering layer formed of the resin composition for a light scattering layer of the present invention can be formed by various printing methods such as reverse offset printing, flexographic printing, gravure printing, and ink jet printing. The same results were obtained as when processed and developed with a spin coater.

DESCRIPTION OF SYMBOLS 1 Organic electroluminescent apparatus 11 Translucent board | substrate 12 Light-scattering layer 13 Translucent electrode 14 At least 1 organic layer (organic EL layer) containing a light emitting layer
15 Back electrode 21 Dispenser 22 Doctor 23 Anilox roll 24 Plate cylinder 25 Letterpress 26 Silicone rubber blanket cylinder 27 Substrate 28 Printing table 29 Coloring composition

Claims (15)

A resin composition for a light scattering layer used for forming a light scattering layer of an organic electroluminescence device,
It consists of a binder material containing at least one resin (A) and light scattering particles (B),
Light scattering particles (B)
A trifluoroethyl methacrylate polymer, wherein the content of trifluoroethyl methacrylate is 60% by weight to 100% by weight in 100% by weight of the monomer constituting the polymer,
The average particle size in the resin composition for light scattering layer is 200 nm or more and 600 nm or less,
And,
The content of particles having a particle diameter of 600 nm or more with respect to the total amount of the light scattering particles (B) is 20% by volume or less,
A resin composition for a light scattering layer, wherein a difference in refractive index between the binder material and the light scattering particles (B) is 0.1 or more.   The resin composition for a light scattering layer according to claim 1, wherein the binder material has a refractive index of 1.65 or more.   The resin composition for a light scattering layer according to claim 1, wherein the binder material further contains metal oxide fine particles (C) having an average primary particle diameter of 100 nm or less. The resin composition for a light scattering layer according to claim 3, wherein the metal oxide fine particles (C) include at least one metal oxide fine particle selected from the group consisting of ZrO ₂ and TiO ₂ . The resin composition for a light scattering layer according to claim 1, wherein the coefficient of variation of the light scattering particles (B) is 30% or less.   The resin composition for light scattering layers according to claim 1, wherein the resin (A) has a double bond equivalent of 400 g / mol or more and 1600 g / mol or less. The resin composition for a light scattering layer according to claim 1, wherein the resin (A) contains a cyclic skeleton in the main chain and / or side chain. The resin composition for a light scattering layer according to claim 1, wherein the resin (A) contains an alkali-soluble group.   The resin composition for a light scattering layer according to claim 1, wherein the binder material further contains an ethylenically unsaturated monomer (D) having a double bond equivalent of 80 g / mol or more and 140 g / mol or less. The resin composition for a light scattering layer according to claim 1, wherein the binder material further contains a silane compound (E) represented by the following general formula (1) having a urethane skeleton or an amide skeleton.
[In General Formula (1), R ¹ is an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a carbon number. An aralkyl group having 7 to 30 carbon atoms or an alkaryl group having 7 to 30 carbon atoms is represented.
X represents an alkylene group having 1 to 20 carbon atoms, an arylene group having 1 to 20 carbon atoms, or an alkyleneoxy group having 1 to 20 carbon atoms.
R ² _, R ³ and R ⁴ are each independently an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Represents an aralkyl group having 7 to 30 carbon atoms, an alkaryl group having 7 to 30 carbon atoms, a siloxane group having a substituent, a halogen atom, a hydroxy group, or a hydrogen atom. ] The silane compound (E) has a mass average molecular weight (Mw) of 200 or more and 5000 or less, and a content in the total solid content of 100% by mass of the resin composition for a light scattering layer is 3% by mass or more and 50% by mass or less. The resin composition for light scattering layers according to claim 10 .   The resin composition for a light scattering layer according to claim 1, wherein the binder material further contains an oxime ester photopolymerization initiator (F).   The light-scattering layer formed using the resin composition for light-scattering layers of Claim 1. A light-scattering layer according to claim 13, a first electrode having a light-transmitting property, at least one organic layer including a light-emitting layer, and a second electrode having a light-reflecting property are provided on a light-transmitting substrate. Organic electroluminescence device stacked sequentially. The organic electroluminescence device according to claim 14, which is a lighting device or a display device.