JP6575093B2 - Organic electroluminescence device and organic electroluminescence device - Google Patents

Description

  The present invention relates to an organic electroluminescence (EL) element and an organic electroluminescence (organic EL) device.

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.

The light scattering layer has a function of diffusing and scattering light, and is an organic EL device, an LED device, a quantum dot display, a liquid crystal display, a light emitting element device, a solar cell reflective film, a solar cell sealing material, and a photosensitive resin. It has been developed in the optical field such as a base material. Among these, active research is being conducted on light scattering layers that improve the light extraction efficiency of organic EL devices. (For example, see 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 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, and the characteristics such as the refractive index of the binder.

  Patent Document 4 proposes to improve the light extraction efficiency by providing a flat layer on the light scattering layer. The surface of the light scattering layer is rough due to scattering particles, and if an electrode is provided on the light scattering layer, the surface of the electrode becomes rough, causing shorts and dark spots. Therefore, a flat layer having a high refractive index is placed on the light scattering layer. By providing in, it can be expected to emit light with high efficiency.

JP 2004-296429 A JP 2005-190931 A JP 2009-110930 A JP 2013-114802 A

  In the organic EL device, the flatness of the electrode is an important point that affects the element performance. That is, when a light scattering layer and a flat layer are provided between the electrode and the glass in order to improve the light extraction efficiency, the flatness of the flat layer is particularly important. For example, in the step of patterning the light scattering layer and the flat layer, an alkali development step for photolithography etching is performed. Furthermore, before laminating the translucent electrode thereon, a cleaning process for removing foreign substances is performed. At this time, if the alkali development resistance or chemical resistance of the photosensitive resin composition for using the flat layer is low, the flatness of the flat layer deteriorates, and as a result, film thickness unevenness or unevenness is formed on the translucent electrode formed thereon. Fine protrusions are formed, and a portion where a current is locally large is generated. When the organic EL element is caused to emit light, a short circuit, a dark spot, luminance unevenness, or a reduction in lifetime is caused.

  Further, the patterning property of the light extraction layer composed of the light scattering layer and the flat layer is also an important point. If the cross-sectional shape of the coating end face by the alkali development treatment is reversely tapered, the translucent electrode formed thereon is disconnected, causing dark spots and a reduction in device life.

  The present invention provides an organic EL device having a long life, excellent light emitting appearance, and high light extraction efficiency by a light extraction layer comprising a light scattering layer excellent in patternability and a flat layer excellent in flatness. Objective.

  As a result of diligent studies to solve the above problems, the present inventors have formed a light scattering layer and a flat layer formed from a specific photosensitive resin composition for a light scattering layer and a photosensitive resin composition for a flat layer. It has been found that an organic EL device having a light extraction layer made of can provide an organic EL device having good electrode flatness, long life, excellent light emitting appearance, and high light extraction efficiency.

  That is, the present invention is an organic electroluminescence device having a light extraction layer composed of a light scattering layer and a flat layer, wherein the light scattering layer comprises light scattering particles (A) having an average particle diameter of 200 nm to 500 nm, and alkali-soluble. The flat layer is formed of a photosensitive resin composition for a light scattering layer containing a resin, a photopolymerization initiator, a photopolymerizable monomer, and a leveling agent. It is related with the organic electroluminescent element characterized by being formed with the photosensitive resin composition for flat layers containing a photosensitive monomer and a leveling agent.

  In the present invention, the refractive index of the light scattering layer and the refractive index of the flat layer are both 1.60 or more, and the absolute value of the difference between the refractive index of the light scattering layer and the refractive index of the flat layer is 0 or more. The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is 0.05 or less.

  The present invention also relates to the organic electroluminescence device, wherein the flat layer photosensitive resin composition contains at least one of an oxime ester photopolymerization initiator and an acetophenone photopolymerization initiator.

  Moreover, this invention relates to the said organic electroluminescent element characterized by the photosensitive resin composition for flat layers containing alkali-soluble resin which has an alicyclic structure.

  Moreover, this invention relates to the said organic electroluminescent element characterized by the photosensitive resin composition for flat layers containing a fluorine leveling agent.

  In the present invention, the ratio [I / M] of the content [I] of the amount of the photopolymerization initiator and the content [M] of the photopolymerizable monomer in the photosensitive resin composition for the light scattering layer is 0. The ratio [I / M] of the content weight [I] of the photopolymerization initiator content and the content weight [M] of the photopolymerization monomer in the photosensitive resin composition for flat layer of 1 to 0.5 The organic electroluminescent element is characterized in that is 0.5 or more and 1.5 or less.

  The present invention also relates to the organic electroluminescence element, wherein the flat layer has a thickness of 2 μm or more and 10 μm or less.

  Further, the present invention is characterized in that at least one of the photosensitive resin composition for light scattering layer and the photosensitive resin composition for flat layer further contains a high refractive index organic compound having a refractive index of 1.55 or more. It is related with the said organic electroluminescent element.

  Moreover, this invention relates to the organic electroluminescent apparatus which has the said organic electroluminescent element.

  ADVANTAGE OF THE INVENTION According to this invention, the flatness of a flat layer and by extension, an electrode can be provided, the organic electroluminescent element and apparatus which are excellent in the light emission external appearance with the long lifetime and high light extraction efficiency can be provided. The organic EL device of the present invention can be applied to a lighting device or a display device.

Schematic cross section of bottom emission EL element

  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 organic electroluminescence device of the present invention has a light extraction layer comprising a light scattering layer and a flat layer, and the light scattering layer comprises light scattering particles (A) having an average particle diameter of 200 nm to 500 nm, an alkali-soluble resin. , A photopolymerization initiator, a photopolymerizable monomer, and a photosensitive resin composition for a light scattering layer containing a leveling agent, and a flat layer comprising an alkali-soluble resin, a photopolymerization initiator, and a photopolymerizability It is formed by the photosensitive resin composition for flat layers containing a monomer and a leveling agent.

<Light extraction layer>
The light extraction layer for an electroluminescence element of the present invention comprises a light scattering layer and a flat layer. The layer structure of the light extraction layer is the order of the light scattering layer and the flat layer as viewed from the light transmitting substrate on the light extraction side. If the first electrode is provided as it is on the light scattering layer having poor flatness, the flatness of the electrode is lost and a short circuit occurs when the device emits light. Therefore, it is necessary to further form a flat layer on the light scattering layer.
The refractive index of the light scattering layer forming the light extraction layer and the refractive index of the flat layer are both preferably 1.60 or more, and more preferably 1.65 or more. The light-emitting elements used in organic EL elements and translucent first electrodes often have a refractive index of 1.60 or more, and light emitted from the elements is totally reflected by reducing the difference in refractive index between layers. This is because it can be prevented.
For the same reason, the absolute value of the difference between the refractive index of the light scattering layer and the refractive index of the flat layer is preferably 0 or more and 0.05 or less. More preferably, it is 0 or more and 0.02 or less.

  Further, the light scattering layer and the flat layer of the present invention may be subjected to a surface polishing step and a cleaning step in order to further improve the flatness or to remove the adhered foreign matter.

<Light scattering layer>
The light scattering layer of the present invention is a photosensitive resin composition for a light scattering layer containing light scattering particles having an average particle diameter of 200 nm to 500 nm, an alkali-soluble resin, a photopolymerization initiator, a photopolymerization monomer, and a leveling agent. It is formed by a thing.
The light scattering layer of the present invention is, for example, coated with a photosensitive resin composition for a light scattering layer on a light-transmitting substrate such as glass and dried, and the resulting coating film is heated, or ultraviolet rays, electron beams, etc. Obtained by irradiation 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 a light scattering layer on a light-transmitting substrate using a photosensitive resin composition, 1) patterning directly on the light-transmitting substrate by a printing method, and 2) patterning by a photolithography method. The method to do may 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, the photosensitive resin composition of the present invention can be preferably used. In that case, 2-1) The photosensitive resin composition of the present invention is directly applied to a light-transmitting substrate and dried, or 2-2) dissolved in a solvent on a film base (hereinafter referred to as a separate film). After the photosensitive resin composition is applied, the photosensitive dry film obtained by drying the solvent is attached to the light-transmitting substrate, and then adhered to the light-transmitting substrate by lamination or vacuum lamination. After the light scattering layer is formed by removing bubbles and the like, pattern formation is performed by 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. In particular,
When the refractive indexes at wavelengths of 473 nm, 594 nm, and 633 nm measured by a prism coupler (Prism Coupler 2010 / M manufactured by Metricon) are n (473), n (594), and n (633), respectively, n (473) / The value of n (594), n (633) / n (594) is preferably 0.2 to 2.0, more preferably 0.5 to 1.5, and even more preferably 0. .95 to 1.05 is preferable.

Moreover, when applying the light-scattering layer of this invention to an organic electroluminescent apparatus, it is preferable that surface roughness is small and flatness is favorable. Therefore, the surface roughness Ra is preferably less than 300 angstroms. If it is 300 angstroms or more, the surface roughness of the flat layer may be affected.
The surface roughness Ra can be measured with a stylus-type film thickness meter DECTAC-3 manufactured by ULVAC.

Furthermore, the transmittance of the light scattering layer of the present invention is preferably 40% or more and less than 90%. More preferably, it is 50% or more and 80% or less. If it is less than 40%, the influence of low light transmittance is greater than light extraction by the scattering effect, and it is difficult to obtain a sufficient light extraction effect. Conversely, if it is 90% or more, the scattering effect is too low. In some cases, a sufficient light extraction effect cannot be obtained.
The haze of the light scattering layer is preferably 20 or more and less than 95. More preferably, it is 30 to 80%. If it is 20 or less, the scattering effect is too low, so that it is difficult to obtain a sufficient light extraction effect. Conversely, if it is 95 or more, the scattering effect is too strong, which may lead to a decrease in transmittance.
The transmittance and haze can be measured by a turbidimeter (“NDH-5000” manufactured by Nippon Denshoku Industries Co., Ltd.).

<Flat layer>
The flat layer of the present invention is formed from a photosensitive resin composition for a flat layer containing an alkali-soluble resin, a photopolymerization initiator, a photopolymerization monomer, and a leveling agent.
The flat layer of the present invention is, for example, coated with a photosensitive resin composition on a translucent substrate such as glass and dried, and the obtained coating film is cured by heating or irradiation with ultraviolet rays or electron beams. Can be obtained.
The coating method and patterning method are the same as those of the light scattering layer.
The thickness of the flat layer is preferably 2 μm or more and 10 μm or less. More preferably, it is 3 μm or more and 8 μm or less. If it is 2 μm or more, the effect of flattening the roughness of the surface of the light scattering layer is more easily obtained, and if it is 10 μm or less, the alkali development step is shortened, and the device creation workability is improved.

Moreover, when applying the flat layer of this invention to an organic EL apparatus, it is preferable that surface roughness is small and flatness is favorable. The surface roughness Ra is preferably less than 100 mm. More preferably, it is less than 30 mm. If it is 100 mm or more, the surface roughness of the translucent electrode is deteriorated, which may cause a short circuit of the element.
The surface roughness Ra can be measured with a stylus-type film thickness meter DECTAC-3 manufactured by ULVAC.

Furthermore, the transmittance of the flat layer of the present invention is preferably 90% or more. More preferably, it is 93% or more. If it is less than 90%, the transmittance of the entire light extraction layer may be lowered.
The haze of the flat layer is preferably less than 2. More preferably, it is less than 1. If it is 2 or more, the light scattered by the scattering layer is further scattered, and the light extraction effect of the light scattering layer may not be sufficiently obtained.
The transmittance and haze can be measured by a turbidimeter (“NDH-5000” manufactured by Nippon Denshoku Industries Co., Ltd.).

  Hereinafter, each component which comprises the photosensitive resin composition for forming the light-scattering layer of this invention and a flat layer is explained in full detail.

<< Photosensitive resin composition >>
In the present invention, the photosensitive resin composition for a light scattering layer for forming a light scattering layer is a light scattering particle (A) having an average particle diameter of 200 nm to 500 nm, an alkali-soluble resin, a photopolymerization initiator, and a photopolymerization. And a leveling agent. Moreover, the photosensitive coloring composition for flat layers for forming a flat layer contains alkali-soluble resin, a photoinitiator, a photopolymerizable monomer, and a leveling agent.
Here, when it contains light scattering particles (A), it corresponds to the photosensitive resin composition for light scattering layers, and when it does not contain light scattering particles (A), it is included in the photosensitive resin composition for flat layers. Applicable. In addition, the constituent components other than the light scattering particles (A) may be the same or different in the photosensitive resin composition for the light scattering layer and the photosensitive resin composition for the flat layer.

<Light scattering particles (A)>
In the present invention, the photosensitive resin composition containing the light scattering particles (A) is a photosensitive resin composition for a light scattering layer, and is a resin composition for forming a light scattering layer.
It is important that the light scattering particles (A) have an average particle diameter of 200 nm or more and 500 nm or less. By using the light scattering particles (A) having an average particle diameter of 200 nm or more, a sufficient scattering effect can be exhibited and the refractive index of the binder is not affected. Further, by using the light scattering particles (A) having an average particle diameter of 500 nm or less, the scattering angle becomes wide even if the scattering intensity (haze value) is small, so that effective scattering for total reflection is obtained and the extraction efficiency is improved. It is difficult to change the color tone because it becomes higher or the change of the light extraction efficiency due to the wavelength becomes smaller. The average particle diameter of the light scattering particles (A) is more preferably 250 nm to 400 nm.

When the content of particles having a particle diameter of 600 nm or more with respect to the total amount of the light-scattering particles (A) is 20% by volume or less, the change in the light extraction efficiency due to the wavelength becomes small, and the color tone hardly changes. In addition, since the surface roughness of the light scattering layer is reduced, unevenness in the film thickness or protrusions of the translucent electrode is difficult to occur, and unevenness in brightness is unlikely to occur, thereby extending the life. The content of particles of 600 nm or more is more preferably 15% by volume or less.
In addition, about the average particle diameter of light-scattering particle | grains (A), or content of particle | grains with a particle diameter of 600 nm or more, light-scattering particle | grains (A) are previously made into a dispersion body, The resin composition for light-scattering layers is used using the said dispersion body. When obtaining a thing, it is set as content of the light-scattering particle (A) in the resin composition for light-scattering layers with the average particle diameter of the light-scattering particle (A) in the said dispersion.

In the present specification, the “average particle diameter” and “particle diameter” of the light scattering particles (A) 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 size is that the scattering state of the light scattering particles (A) in the composition for the light scattering layer is used even when the scattering particles having the same average primary particle size 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.

As the particle size distribution of the light scattering particles (A), the coefficient of variation is preferably 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.

Examples of the light scattering particles (A) include organic scattering particles such as polyacrylate beads, polymethacrylate beads, acrylic-styrene copolymer beads, melamine resin beads, polycarbonate beads, cross-linked polystyrene beads, polyvinyl chloride beads, And benzoguanamine-melamine formaldehyde condensate beads, trifluoroethyl methacrylate copolymer beads and the like. Examples of inorganic scattering particles include SiO ₂ , ZrO ₂ , and TiO ₂ .
In the present specification, the “refractive index of light scattering particles” means the bulk refractive index of the material constituting the light scattering particles. The refractive index of the bulk material can be measured using an Abbe refractometer or a V block refractometer.

  As the light scattering particles (A), it is preferable to use a dispersion liquid previously dispersed in a solvent. At that time, an additive such as a surfactant for stabilizing the dispersion may be added.

  1-30 weight% is preferable in the solid content of the resin composition for light-scattering layers, and, as for the usage-amount of a light-scattering particle (A), 1-20 weight% is more preferable. If the amount is less than 1% by weight, a sufficient scattering effect may not be exhibited. If the amount exceeds 30% by weight, the particles tend to aggregate and the surface roughness of the light scattering layer may increase.

(Organic scattering particles (A1))
Among the organic scattering particles (A), the organic scattering particles (A1) are preferable because they hardly aggregate in the resin composition.
The average particle size of the organic scattering particles (A1), the content of particles having a particle size of 600 nm or more, and the particle size distribution are polymerization temperature, monomer composition, dispersion medium, stirring conditions, type / amount / addition method of polymerization initiator, emulsifier. It can be adjusted according to the conditions such as type and amount.

The organic scattering particles (A1) are a copolymer using acrylate or methacrylate having a polycyclic structure or an alkyl chain having 4 to 24 carbon atoms. In the present invention, acrylate or methacrylate is abbreviated as (meth) acrylate.
By using a (meth) acrylate having a polycyclic structure or an alkyl chain having 4 or more and 24 or less carbon atoms, it is presumed that the resulting organic scattering particles are likely to be sterically repelled. As a result, aggregation of metal oxide fine particles, which will be described later, is suppressed, and a coating film with good flatness can be formed.
Among the polycyclic structures, it is more preferable to use an acrylate or methacrylate having a bridgehead structure.

Examples of (meth) acrylates having a polycyclic structure include (meth) acrylates having a bridgehead structure, (meth) acrylates having a plurality of cyclic structures continuous in the same plane, and having a plurality of independent cyclic structures (meta) ) Acrylate, and (meth) acrylate having a bridgehead structure is preferably used.
Examples of (meth) acrylates having a bridgehead structure include 2-norbornyl acrylate, 2-norbornyl methacrylate, isobornyl (meth) acrylate, boronyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclo Pentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-[(1 ′, 1 ′, 1′-trifluoro-2 ′-(trifluoromethyl) -2′-hydroxy) propyl] -3 -Norbornyl (meth) acrylate, 3-hydronopoxy-1-propyl (meth) acrylate, adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2 -Adamantyl (meth) acrylate, 2-isopropyl-2-adamantyl (meth) acrylate -To, 2-[(1 ', 1', 1'-trifluoro-2 '-(trifluoromethyl) -2'-hydroxy) propyl] -3-norbornyl (meth) acrylate, (1R, 2S , 4S) -1,7,7-trimethylspiro [bicyclo [2.2.1] heptane-3,2 '(3'H)-[1H] indene] -2-ol (meth) acrylate 1,3,3aα, 4,7,7aα-hexahydro-1,3-dioxo-4β, 7β-epoxyisobenzofuran-4-methanol (meth) acrylate, (1S, 4S) -7-oxa Bicyclo [2.2.1] hept-5-en-2β-yl (meth) acrylate, 1-methyl-1- (1-adamantyl) ethyl (meth) acrylate, 3-hydroxy-1-adamantyl (meth) acrylate 3,5-dihydroxy-1-adama Til (meth) acrylate, 2- (norborna-2-en-5-ylmethyl) -1,1,1,3,3,3-hexafluoro-2-propanol (meth) acrylate, 2- ( Norborna-2-en-5-yl) -1,1,1,3,3,3-hexafluoro-2-propanol (meth) acrylate, 4α, 7α-methano-3a, 4,5 6,7,7a-hexahydro-1H-indene-6-ol (meth) acrylate, and the like. These may be used alone or in combination of two or more, but are not necessarily limited thereto.

  The alkyl chain in the (meth) acrylate having an alkyl chain having 4 to 24 carbon atoms may have a cyclic or branched chain. The alkyl chain preferably has 4 to 16 carbon atoms.

As a (meth) acrylate having an alkyl chain having 4 to 24 carbon atoms,
n-butyl (meth) acrylate, s-butyl (meth) acrylate, 2-methylbutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclopentyl (meth) acrylate, 1,1-dimethylbutyl (Meth) acrylate, 1,1-dimethylpropyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, 3-methylcyclohexyl (meth) acrylate, 4- Methylcyclohexyl (meth) acrylate, 2-methylpentyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 1-methylheptyl (meth) acrylate, 3,3,5-to Methylcyclohexyl (meth) acrylate, 6-methylheptyl (meth) acrylate, n-nonyl (meth) acrylate, 5-methyl-2- (1-methylethyl) cyclohexyl (meth) acrylate, n-undecyl (meth) acrylate, 4- (1,1-dimethylpropyl) cyclohexyl (meth) acrylate, isooctyl (meth) acrylate, 3,5,5-trimethylhexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, lauryl (Meth) acrylate, n-dodecyl (meth) acrylate, spiro [bicyclo [3.2.0] heptane-6,1′-cyclohexane] -7-yl (meth) acrylate, 7-butyl-7-ethylbicyclo [ 3.2.0] Hepta-6 (Meth) acrylate, n-tridecyl (meth) acrylate, cyclododecyl (meth) acrylate, 2-5-dipentylcyclohexyl (meth) acrylate, 4-cyclohexylcyclohexyl (meth) acrylate, [4- (1-methylethyl) Cyclohexyl] methyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cetyl (meth) acrylate, docosyl (meth) ) Acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, and the like, but are not necessarily limited thereto.

  The organic scattering particle (A1) is preferably obtained by polymerizing a (meth) acrylate having a polycyclic structure or an alkyl chain having 4 to 24 carbon atoms with another monomer that can be copolymerized. The total amount of (meth) acrylates having a polycyclic structure or an alkyl chain having 4 to 24 carbon atoms is preferably 1 to 50% by weight, more preferably 3 to 25% by weight, in 100% by weight of the monomer used for %, More preferably 5 to 15% by weight. It is preferable that the amount of (meth) acrylate having a polycyclic structure or an alkyl chain having 4 to 24 carbon atoms is within the above range because the dispersion effect is more effectively exhibited.

  The organic scattering particles (A1) can be obtained by various methods, and can be obtained in a dispersion state. Examples thereof include emulsion polymerization (one embodiment of which is soap-free emulsion polymerization), dispersion polymerization, suspension polymerization, seed polymerization and the like. Among these, emulsion polymerization and dispersion polymerization are preferable because they can form particles having a relatively narrow particle size distribution and contribute to the reduction of wavelength dependency in the present invention. Moreover, the dispersibility by steric repulsion can be provided by setting it as the polymer containing various (meth) acrylates.

<Alkali-soluble resin>
The alkali-soluble resin used for the photosensitive resin composition used for forming the light scattering layer or the flat layer will be described.
The alkali-soluble resin is a resin into which a carboxyl group is introduced in order to exhibit alkali solubility. The method for introducing a functional group is not particularly limited, but a method of modifying a copolymer containing an ethylenically unsaturated monomer having an acid group so that the acid group remains, or an ethylenic group having a hydroxyl group. Examples thereof include a method of modifying a copolymer containing an unsaturated monomer with a polybasic acid anhydride.

  When imparting developability, the acid value of the alkali-soluble resin is preferably 30 mgKOH / g or more and less than 200 mgKOH / g. If the acid value is less than 30 mg KOH / g, sufficient developability cannot be ensured, and if it is 200 mg KOH / g or more, the alkali solubility is too strong and the pattern may be peeled off during alkali development.

  The alkali-soluble resin has a weight average molecular weight (Mw) of 5000 or more, and transmits light emitted from a light emitting layer, for example, light in a predetermined wavelength band such as visible light, near infrared light, or near ultraviolet light. The resin is not particularly limited as long as it has a property. The weight average molecular weight (Mw) is preferably 20000 or less.

  For example, an organic EL device is 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 weight average molecular weight (Mw) of the alkali-soluble resin is 5000 or more, the chemical resistance of the light scattering layer is improved, and the light scattering layer or the translucent electrode is peeled off in the solvent washing step before laminating the organic layer. Can be effectively suppressed / prevented. Further, by using an alkali-soluble resin having a weight average molecular weight (Mw) of 20000 or less, the photosensitive resin composition can have a low viscosity, and the aggregation of the light scattering particles (A) can be suppressed and prevented, and the surface of the light scattering layer Can be made smoother, short-circuits in forming the translucent electrode can be suppressed and prevented, and the life can be extended.

  The “weight 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.

  As the alkali-soluble resin, a curable resin such as light (electromagnetic wave) curable by visible light, ultraviolet light or infrared light, or electron beam curable by electron beam irradiation is preferably used.

  Examples of such resins include, but are not necessarily limited to, ester resins, urethane resins, epoxy resins, acrylic resins, and silicone resins. These can be used singly or as a mixture of two or more at any ratio as required.

The 5% thermal decomposition temperature of the alkali-soluble resin is preferably 200 ° C. or higher.
The “5% pyrolysis temperature” in the present specification indicates a temperature when the weight 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 (E) 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 alkali-soluble resin preferably contains an alicyclic structure in the main chain or side chain from the viewpoint of alkali development resistance. The “alicyclic structure” referred to here is an aliphatic ring, an aromatic ring, and a heterocyclic ring containing an O atom and / or an N atom.
In the present invention, since the photosensitive resin composition for a flat layer contains an alkali-soluble resin having an alicyclic structure, the coating film has excellent alkali development resistance and has excellent flatness. Therefore, it is preferable. As a result, when the organic EL device emits light, it is possible to reduce the occurrence of dark spots, luminance unevenness, or life reduction.

Specifically, as an alkali-soluble resin having an alicyclic structure,
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 preferable from the viewpoint of heat resistance and light resistance.
Further, the refractive index of the acrylic soluble resin of the present invention is preferably 1.55 or more.
Among resins having a refractive index of 1.55 or more, an ester resin having a fluorene skeleton or an acrylic resin having a fluorene skeleton is most preferable from the viewpoint of high transparency.

(Alkali-soluble resin having a fluorene skeleton)
Examples of the alkali-soluble resin having a fluorene skeleton in the present invention include a reaction product of a compound having a fluorene skeleton having active hydrogen and a compound having one group capable of reacting with active hydrogen.
The group capable of reacting with active hydrogen is a carboxyl group, a halogen group, or an isocyanate group. Specifically, (meth) acrylic acid, dicarboxylic acid, (meth) acrylic acid chloride, (meth) acryloyloxyethyl isocyanate And epichlorohydrin).
Specific examples of the compound having a fluorene skeleton having active hydrogen include bisphenolfluorenes, 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxyphenyl] fluorene, 9,9-bis (4 -Glycidyloxyphenyl) fluorene (BPFG), 9,9-bis (4-glycidyloxy-3-methylphenyl) fluorene and the like.

  However, it is necessary that an alkali-soluble group such as a carboxylic acid group or a hydroxyl group is contained in the terminal group of the main chain or side chain of the resin.

  The molecular weight (weight average molecular weight) of the alkali-soluble resin having a fluorene skeleton may be, for example, 5,000 to 50,000, preferably 5,000 to 35,000, and more preferably about 10,000 to 20,000.

(1) Polyester resin having a fluorene skeleton (including unsaturated polyester resin)
A polyester-based resin having a fluorene skeleton can be obtained by a reaction between a diol component composed of at least the bisphenol fluorenes (9,9-bis (monohydroxyphenyl) fluorenes) and a dicarboxylic acid component. Resins include polyacrylate resins using aromatic dicarboxylic acids as polymerization components, in addition to saturated or unsaturated polyester resins.

The diol component of the polyester resin may be configured by combining the bisphenol fluorenes and other diols. Examples of such diols include alkylene glycols (for example, linear chains such as ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, tetramethylene glycol, hexanediol, neopentyl glycol, octanediol, and decanediol. Or branched C _2-12 alkylene glycol), (poly) oxyalkylene glycol (for example, di to tetra C2-4 alkylene glycol such as diethylene glycol, triethylene glycol, dipropylene glycol, etc.), alicyclic diol ( For example, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxycyclohexyl) propane and its alkylene oxide adduct (2,2-bis ( -(2-hydroxyethoxy) cyclohexyl) propane), etc.), aromatic diols (for example, biphenol, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), bisphenol AD, bisphenol F and their alkylene oxides (C _2-3 alkylene oxide) adducts (such as 2,2-bis (4- (2-hydroxyethoxy) phenyl) propane) and xylylene glycol). These diols may be used alone or in combination of two or more.

Preferred diols are linear or branched C _2-10 alkylene glycols, particularly C _2-6 alkylene glycols (eg, linear or branched chain such as ethylene glycol, propylene glycol, 1,4-butanediol). C _2-4 alkylene glycol). As the diol, at least ethylene glycol is often used. When such diols (for example, ethylene glycol) are used, the polymerization reactivity can be enhanced and flexibility can be imparted to the resin.

  The ratio (molar ratio) between the bisphenol fluorenes and the diols is, for example, the former / the latter = 100/0 to 50/50, preferably 100/0 to 75/25 (for example, 100/0 to 70/30). More preferably, it may be about 100/0 to 90/10 (for example, 100/0 to 80/20).

  If necessary, the diol component may be used in combination with polyols such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and the 9,9-bis (di or trihydroxyphenyl) fluorenes.

Examples of the dicarboxylic acid component constituting the polyester-based resin include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and derivatives capable of forming esters thereof [for example, acid anhydrides; acid halides (acid chlorides, etc.); Lower alkyl esters (such as C _1-2 alkyl esters)] and the like. These dicarboxylic acids can be used alone or in combination of two or more.

Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dicarboxylic acid, dodecane dicarboxylic acid, hexadecane dicarboxylic acid and other saturated C _3-20 aliphatic dicarboxylic acids. Acids (preferably saturated C _3-14 aliphatic dicarboxylic acids, etc.); unsaturated C _4-20 aliphatic dicarboxylic acids (preferably unsaturated C _4-14 aliphatics, such as maleic acid, fumaric acid, citraconic acid, mesaconic acid) Dicarboxylic acid and the like); derivatives of these that can form esters.
In the unsaturated polyester resin, the ratio of the aliphatic unsaturated dicarboxylic acid (maleic acid or its acid anhydride) is, for example, 10 to 100 mol%, preferably 30 to 100 mol%, based on the entire dicarboxylic acid component. More preferably, it may be about 50 to 100 mol% (for example, 75 to 100 mol%).

Examples of the alicyclic dicarboxylic acid include saturated alicyclic dicarboxylic acids (cyclopentane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid, cycloheptane dicarboxylic acid, etc. C _3-10 cycloalkane-dicarboxylic acid), unsaturated alicyclic dicarboxylic acid (C _3-10 cycloalkene-dicarboxylic acid such as 1,2-cyclohexene dicarboxylic acid, 1,3-cyclohexene dicarboxylic acid, etc.); Cyclic alkane dicarboxylic acids (di- or tricyclo C _7-10 alkane-dicarboxylic acid such as bornane dicarboxylic acid, norbornane dicarboxylic acid, adamantane dicarboxylic acid), polycyclic alkene dicarboxylic acids (bornene dicarboxylic acid, norbornene dicarboxylic acid, etc. di- or tricyclic C _7-10 A Ken - dicarboxylic acid), etc. These esters can form derivatives can be exemplified.

Aromatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid (2,6-naphthalenedicarboxylic acid, etc.), 4,4'-diphenyldicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, 4 , 4′-diphenylmethane dicarboxylic acid, aromatic C _8-16 dicarboxylic acid such as 4,4′-diphenyl ketone dicarboxylic acid; and ester-forming derivatives thereof.

  The dicarboxylic acid may be used in combination with a polyvalent carboxylic acid such as trimellitic acid or pyromellitic acid, if necessary.

The dicarboxylic acid component is usually at least one selected from aliphatic dicarboxylic acids and alicyclic dicarboxylic acids, in particular, aliphatic dicarboxylic acids (saturated aliphatic dicarboxylic acids or derivatives capable of forming esters thereof, particularly adipic acid, Saturated C _3-14 aliphatic dicarboxylic acids such as suberic acid and sebacic acid) and alicyclic dicarboxylic acids (C _5-10 cycloalkane dicarboxylic acids such as cyclohexane dicarboxylic acid) are preferred.

  In the polyarylate-based resin, a dicarboxylic acid component containing at least an aromatic dicarboxylic acid is used, and the aromatic dicarboxylic acid may be used in combination with another dicarboxylic acid (aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid). Good. The ratio of the aromatic dicarboxylic acid to the other dicarboxylic acid is, for example, the former / the latter (molar ratio) = 100/0 to 10/90, preferably 100/0 to 30/70, more preferably 100/0 to 50. It may be about / 50.

In the polyester resin, the ratio (molar ratio) between the dicarboxylic acid component and the diol component (such as bisphenolfluorenes and diols) is usually the former / the latter = 1.5 / 1 to 0.7 / 1, preferably 1. It may be about 2/1 to 0.8 / 1 (particularly 1.1 / 1 to 0.9 / 1).
The terminal group of the polyester resin may be a hydroxy group or a carboxyl group, but it needs to be an alkali-soluble group. Thereby, alkali solubility is provided.

  The polyester-based resin can be produced by subjecting a diol component composed of bisphenolfluorenes and the dicarboxylic acid component to a condensation reaction by a conventional method such as a direct polymerization method (direct esterification method) or a transesterification method. .

As specific examples of the unsaturated polyester resin, for example, a compound represented by the following chemical formula (10):
Chemical formula (10)

A compound represented by the following general formula (11):
Formula (11)

[Wherein, R ¹⁰ represents oxygen, a carbonyl group, a tetrafluoroethylene group, or a single bond. ]

  It is obtained by copolymerizing pyromellitic anhydride and at least one selected from terephthalic acid and acid chlorides thereof.

(2) Acrylic resin having a fluorene skeleton A (meth) acrylic monomer can be obtained by a reaction between a bisphenolfluorene and an acrylic polymerizable monomer having a carboxyl group. The (meth) acrylic monomer can be used alone or copolymerized with other acrylic polymerizable monomers to form an acrylic resin.
As the acrylic polymerizable monomer having a carboxyl group, an unsaturated monocarboxylic acid, in particular, (meth) acrylic acid can be used. Cinnamic acid, crotonic acid, sorbic acid, maleic acid monoalkyl ester (monomethyl malate, etc.) ) Etc. may be used. Furthermore, as long as it reacts with active hydrogen, it may be a reactive derivative such as an acid chloride or a C _1-2 alkyl ester instead of an unsaturated carboxylic acid. These monomers may be used alone or in combination of two or more.

  The amount of the unsaturated monocarboxylic acid used is 0.5 to 1.2 mol, preferably 0.7 to 1.1 mol, more preferably 0.8 to 1 mol, based on 1 mol of the hydroxy group of the bisphenol fluorene. It may be about a mole. Such an acrylic resin is often an oligomer (resin precursor).

The acrylic resin in the form of an oligomer may be polymerized with a copolymerizable monomer as necessary to form an acrylic copolymer. Examples of copolymerizable monomers include carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (meth) acrylic acid C _1-6 alkyl such as methyl (meth) acrylate Examples include esters; vinyl cyanides such as (meth) acrylonitrile; aromatic vinyl monomers such as styrene; vinyl carboxylic acid esters such as vinyl acetate; α-olefins such as ethylene and propylene. These copolymerizable monomers can be used alone or in combination of two or more.

  The alkali-soluble resin preferably has an ethylenically unsaturated double bond and / or a crosslinkable group, whereby heat resistance and chemical resistance are improved. The terminal group of the alkaline resin may be a hydroxy group or a carboxyl group, but it must be an alkali-soluble group. Thereby, alkali solubility is provided.

Examples of the ethylenically unsaturated double bond 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 alkali-soluble resin 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) to 1600 (g / mol). When the double bond equivalent of the alkali-soluble resin is 400 (g / mol) or more, curing shrinkage of the resin can be suppressed, and a fine crack or peeling is hardly generated in the translucent electrode. On the other hand, when the double bond equivalent is 1600 (g / mol) or less, the crosslinking density is increased, the etching resistance is improved, and the light scattering layer or the translucent electrode is peeled off in the solvent washing step before the organic layer lamination. Can be suppressed / prevented.

There is no restriction | limiting in particular as a method of obtaining resin which has an ethylenically unsaturated double bond suitable as alkali-soluble resin in the photosensitive resin composition of this invention.
Examples of the alkali-soluble resin having an ethylenically unsaturated double bond include an ethylenically unsaturated monomer having an acid (carboxyl) group and other ethylenically unsaturated monomers such as a hydroxyl group, an epoxy group, and an isocyanate. It can be obtained by polymerizing an unsaturated monomer component containing an ethylenically unsaturated monomer having one or more functional groups selected from the group. Alternatively, a method may be mentioned in which the functional group in the copolymer obtained here is modified with a functional group capable of reacting with the functional group and an ethylenically unsaturated monomer having an ethylenically unsaturated double bond.
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 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;
And polybasic acid anhydrides such as tetrahydrophthalic anhydride, phthalic anhydride, hexahydrophthalic anhydride, succinic anhydride, and maleic anhydride.
Among these, (meth) acrylic acid is particularly preferable.

(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, but are not necessarily limited thereto.

(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. Although it is mentioned, it is not necessarily limited to these. Among these, glycidyl (meth) acrylate is 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, but are not necessarily limited thereto. It is not something.

  The other ethylenically unsaturated monomer component constituting the alkali-soluble resin is not particularly limited as long as it has an ethylenically unsaturated group, and examples thereof include (meth) acrylic acid esters, N-vinylpyrrolidone. Styrenes, acrylamides, other vinyl compounds, and macromonomers, but are not necessarily limited thereto.

Among these, as described above, it is preferable to copolymerize an ethylenically unsaturated monomer that introduces an alicyclic structure into the main chain or side chain of the alkali-soluble resin.
As an ethylenically unsaturated monomer that introduces an alicyclic structure into the main chain,
Cyclic dienes such as indene, benzofuran, norbornene, and cyclohexene;
and,
Intramolecular cyclization reaction proceeds during copolymerization with methacrylic acid esters such as vinylcyclopropane and the like, and the like and the like are included, but it is not necessarily limited to these. It is not a thing.
As an ethylenically unsaturated monomer that introduces an alicyclic structure 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, but are not necessarily limited thereto.
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 that introduces the alicyclic structure into the main chain or the side chain is not particularly limited, but is 5 to 50 with respect to 100% by weight of the total of the monomers constituting the alkali-soluble resin. % By weight is preferred. When the amount of the ethylenically unsaturated monomer that introduces the alicyclic structure into the main chain or the side chain is within the above range, the polymerization and the molecular weight can be easily controlled, and the etchant resistance can be secured.

Other copolymerizable ethylenically unsaturated monomers other than ethylenically unsaturated monomers containing an alicyclic structure in the main chain or side chain include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (Meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, etc. (Meth) acrylic acid 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;
However, it is not necessarily limited to these.
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 alkali-soluble resin can be controlled by the type and blending of the ethylenically unsaturated monomer used for copolymerization and modification. The weight average molecular weight (Mw) can be controlled by the polymerization conditions such as the type and amount of the polymerization initiator.

  The alkali-soluble resin can be imparted with any physical properties depending on the type and blending of the ethylenically unsaturated monomer to be used.

In the synthesis of the alkali-soluble resin, 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. 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. Preferably, the polymerization temperature is 40 to 150 ° C., and the polymerization concentration is 5 to 50. More preferably, the polymerization temperature is 60 to 130 ° C., and the polymerization concentration is 10 to 40%.
Polymerization concentration (%) = [total weight of monomer components / (total weight of monomer components + solvent weight)] × 100

As the polymerization initiator used for the synthesis of the alkali-soluble resin, organic peroxides and azo compounds 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 weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

Examples of the solvent used for the synthesis of the alkali-soluble resin include water, water-miscible organic solvents, acetate esters, 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 methoxypropyl acetate.
Examples of ketones include cyclohexanone and methyl isobutyl ketone.

<Photopolymerization initiator>
In the photosensitive resin composition of the present invention, a photopolymerization initiator is added in order to form a light scattering layer and a flat layer by photolithography as an alkali development type photosensitive resin composition.

Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane Acetophenone-based photopolymerization initiators such as -1-one;
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:
And imidazole-based photopolymerization initiators are used, but are not necessarily limited thereto.
These can be used alone or in admixture of two or more.

  Specific examples of commercially available photopolymerization initiators include Irgacure 369, Irgacure 907, Irgacure OXE01, and Irgacure OXE02 manufactured by BASF. However, it is not necessarily limited to these.

  Especially, in the photosensitive coloring composition for flat layers, it is preferable to contain at least 1 sort (s) among an oxime ester type photoinitiator and an acetophenone type photoinitiator. Since the sensitivity is high, the alkali development resistance is high, and the flatness of the flat layer can be further increased. Furthermore, 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (o-benzoyloxime) is more preferable because alkali development resistance is further increased.

The photopolymerization initiator is preferably used in an amount of 1 to 10% by weight in 100% by weight of the solid content of the light scattering layer resin composition. It is preferably used in an amount of ˜20% by weight.
Furthermore, the ratio [I / M] of the content [I] of the photopolymerization initiator content and the content [M] of the photopolymerizable monomer in the light scattering layer resin composition is 0.1 or more and 0.5 or less. The ratio [I / M] of the content [I] of the photopolymerization initiator content and the content [M] of the photopolymerizable monomer in the photosensitive coloring composition for the flat layer is 0.5 or more and 1 Most preferably, it should be 5 or less. The reason will be described later.

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

<Photopolymerizable monomer>
The photopolymerizable monomer used for the photosensitive resin composition of the present invention will be described.
The photopolymerizable monomer has an ethylenically unsaturated double bond, and preferably has a weight average molecular weight (Mw) of 200 or more and less than 5000. In order to improve alkali development resistance, it is particularly preferable that the double bond equivalent of the photopolymerizable monomer is 80 g / mol or more and 140 g / mol or less.
A resin having an ethylenically unsaturated double bond and an alkali-soluble functional group and having a weight average molecular weight (Mw) of 5000 or more is regarded as an alkali-soluble resin.

Examples of the photopolymerizable monomer 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 (meth) acrylate, Tri (meth) acrylates such as 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 bifunctional or higher functional 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, but are not necessarily limited thereto. It is not something.
These may be used singly or in combination of two or more at any ratio as necessary.

  Commercially available products include M-350 (trimethylolpropane ethylene oxide modified triacrylate), M-450 (pentaerythritol tri and tetraacrylate), M-402 (dipentaerythritol penta and hexaacrylate) (manufactured by Toa Gosei Co., Ltd.), Biscoat # 802 (tripentaerythritol octaacrylate (Osaka Organic Chemical Co., Ltd.), Kayarad DPCA30, Kayarad DPCA60 (caprolactone-modified dipentaerythritol hexaacrylate) (manufactured by Nippon Kayaku Co., Ltd.) and the like are mentioned. It is not limited to.

As content of a photopolymerizable monomer, it is preferable to use in the quantity of 5 to 40 weight% in 100 weight% of solid content of the resin composition for light scattering layers. In this case, when the amount of the photopolymerizable monomer is less than 5% by weight, it is difficult to obtain the effect of imparting alkali development resistance. When the amount is more than 40% by weight, the amount of light scattering particles is relatively reduced, which is sufficient. In some cases, scattering characteristics cannot be obtained. More preferably, it is 10 to 35% by weight. In 100 weight% of solid content of the resin composition for light-scattering layers, it is preferable to use in the quantity of 5-40 weight%. In this case, when the amount of the photopolymerizable monomer is less than 5% by weight, the effect of imparting alkali development resistance cannot be obtained. Development characteristics cannot be obtained. More preferably, it is 10 to 30% by weight.
Furthermore, the ratio [I / M] of the content [I] of the amount of the photopolymerization initiator and the content [M] of the photopolymerizable monomer in the photosensitive resin composition for the light scattering layer is 0.1 or more and 0. 0.5 or less, more preferably 0.1 or more and 0.3 or less.
The ratio [I / M] of the content [I] of the photopolymerization initiator content and the content [M] of the photopolymerizable monomer in the photosensitive resin composition for the flat layer is 0.5 or more and 1.5. Or less, more preferably 0.6 or more and 1.4 or less.
By being in this range, the cross-sectional shape of the light scattering layer and the flat layer becomes smooth, and it is difficult for a problem that a crack is generated in the organic EL element formed on the electrode to shorten its life. Further, in the above composition, the hardened portion by exposure is always wider in the flat layer than in the light scattering layer, and there is no concern that the light scattering layer is exposed even if the same exposure mask is used.

The photopolymerizable monomer in the present invention preferably has a refractive index of 1.55 or more. More preferably, the refractive index is 1.60 or more.
Among the photopolymerizable monomers having a refractive index of 1.55 or more, a photopolymerizable monomer containing a fluorene skeleton is most preferable.

(Photopolymerizable monomer having a fluorene skeleton)
The photopolymerizable monomer contained in the photosensitive resin composition of the present invention is a photopolymerizable monomer having a fluorene skeleton having a refractive index of 1.55 or more. This is preferable because the refractive index can be increased and the transmittance and flatness of the flat layer can be improved. As a secondary effect, the amount of inorganic fine particles used can be reduced in order to increase the refractive index of the flat layer, so that EL element damage due to moisture release from the inorganic fine particles can be reduced.

Examples of the photopolymerizable monomer containing a fluorene skeleton include compounds represented by the following general formula (I).
General formula (1)

[In General Formula (1), R ¹ represents a hydrogen atom, a hydroxyl group, a phenyl group, a tolyl group, an amino group, a carboxy group, or an alkyl group represented by — (CH ₂ ) _n CH ₃ ;
R ² is -C (A) = CH ₂ , -CO-C (A) = CH ₂ ,-(B) -O-CO-C (A) = CH ₂ ,-(B) -C (A) = _{CH 2, -O- (B) -O} -CO-C (A) = CH 2, -O- (B) -C (A) = CH 2, -SH, - (B) -CO-C (A ) = CH ₂ , —O— (B) —CO—C (A) ═CH ₂ ,
Indicate
(A) is —H or —CH ₃ ;
(B) is (CH ₂ ) _n , (OCH ₂ CH ₂ ) _n , (OCH ₂ CH ₂ CH ₂ ) _n , (OCH ₂ CH (OH) CH ₂ ) _n, or (OCOCH ₂ CH ₂ CH ₂ CH ₂ ) _n ,
R ³ represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
j, k and m are each independently an integer of 0 to 4, j + k is an integer of 0 to 5, and n is an integer of 1 to 20. ]

The substitution position of R ² is not particularly limited, and may be o-, m-, or p-position with respect to fluorene, but m- and / or p-position is preferred.

(A) is —H or —CH ₃ , and (A) is preferably —H from the viewpoint of developability.
(B) is (CH ₂ ) _n , (OCH ₂ CH ₂ ) _n , (OCH ₂ CH ₂ CH ₂ ) _n , (OCH ₂ CH (OH) CH ₂ ) _n, or (OCOCH ₂ CH ₂ CH ₂ CH ₂ ) _n , R ⁴ is a hydrogen atom, a cyano group, a halogen atom or an alkyl group, and (B) is (OCH ₂ CH ₂ ) _n , (OCH ₂ CH ₂ CH ₂ ) _n , ( OCH ₂ CH (OH) CH ₂ ) is preferred.

However, in R ³ , (B) is (OCH ₂ CH ₂ CH ₂ ) _n , (OCH ₂ CH ₂ CH ₂ ) _n , (OCH ₂ CH (OH) CH ₂ ) _n, or (OCOCH ₂ CH ₂ CH ₂ CH ₂ ) for _{n, -O- (B) -O-} CO-C (a) = CH 2, -O- (B) -C (a) = CH 2, -O- (B) -CO-C ( a) = as CH ₂ etc., -O- (B) - and it does not become.

  Monomers having a fluorene skeleton represented by the general formula (1) include 9,9-bis ((meth) acryloyloxy-branched alkoxy-di to tetraalkylphenyl) fluorenes, 9,9-bis ((meta ) Acryloyloxy-poly branched alkoxy-dialkylphenyl) fluorenes and the like.

9,9-bis ((meth) acryloyloxy-branched alkoxy-di to tetraalkylphenyl) fluorenes include, for example, 9,9-bis ((meth) acryloyloxy-branched C3-4 alkoxy-dialkylphenyl) fluorene. Class {eg, 9,9-bis [4
-(2- (meth) acryloyloxypropoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (2- (meth) acryloyloxypropoxy) -2,5-dimethylphenyl] fluorene, 9 , 9-bis [4- (2- (meth) acryloyloxypropoxy) -2,6-dimethylphenyl] fluorene, 9,9-bis [3- (2- (meth) acryloyloxypropoxy) -2,4- Dimethylphenyl] fluorene, 9,9-
9,9-bis ((meth) acryloyloxy-branched C3-4alkoxy-diC1-4alkylphenyl) such as bis [2- (2- (meth) acryloyloxypropoxy) -3,4-dimethylphenyl] fluorene Fluorene, preferably 9,9-bis (2- (meth)
9, such as acryloyloxypropoxy-diC1-4alkylphenyl) fluorene}
9-bis ((meth) acryloyloxy-branched alkoxy-dialkylphenyl) fluorenes are included.

The 9,9-bis ((meth) acryloyloxy-polybranched alkoxy-di to tetraalkylphenyl) fluorenes include, for example, 9,9-bis ((meth) acryloyloxy-dibranched C3-4 alkoxy-dialkylphenyl). ) Fluorenes {for example, 9,9-bis ((meth) acryloyl such as 9,9-bis {4- [2- (2- (meth) acryloyloxypropoxy) propoxy] -3,5-dimethylphenyl} fluorene) Oxy-dibranched C3-4alkoxy-diC1-4alkylphenyl) fluorene, preferably 9,9-bis [2- (2- (meth) acryloyloxypropoxy) propoxy-diC1-4alkylphenyl] fluorene} and the like 9,9-bis ((meth) acryloyloxy-dibranched alkoxy-dialkylpheny ), And the like fluorenes.

  Commercially available products can be used as the monomer having a fluorene skeleton represented by the general formula (1). Specifically, NK ester A-BPEF, NK ester A-BPEF-4E (Shin Nakamura Chemical Co., Ltd.) Product), ASF-400 (manufactured by Nippon Steel Chemical Co., Ltd.), Ogsol EA-0200 (manufactured by Osaka Gas Chemical Company), and the like.

  The content of the monomer having a fluorene skeleton represented by the general formula (1) is preferably 5% by weight or more and less than 40% by weight in a total solid content of 100% by weight of the photosensitive resin composition. When the content is less than 5% by weight, sufficient sensitivity, resistance to developability, and high refractive index are difficult to obtain. On the other hand, when the content is 40% by weight or more, the balance between the refractive index and the developability is deteriorated.

<Leveling agent>
In the photosensitive resin composition of the present invention, a leveling agent is added in order to improve the leveling property of the composition on the transparent substrate. Examples of the leveling agent include dimethylsiloxane having a polyether structure or a polyester structure in the main chain, dimethylsiloxane having a polyester structure in the main chain, and a fluorine leveling agent containing fluorine. Especially, it is preferable that the photosensitive resin composition for flat layers contains a fluorine leveling agent. This is because the flatness of the flat layer is further improved and the light emission unevenness of the element is reduced.

Specific examples of dimethylsiloxane having a polyester structure in the main chain include BYK-310 and BYK-370 manufactured by BYK Chemie. Specific examples of dimethylsiloxane having a polyester structure in the main chain include BYK-323, BYK-330, and BYK-348. Examples of the fluorine leveling agent containing fluorine include Megafac F-444 manufactured by DIC.
In addition, as a bonding form of the polyalkylene oxide unit with dimethylpolysiloxane, a pendant type in which the polyalkylene oxide unit is bonded to the repeating unit of dimethylpolysiloxane, a terminal modified type bonded to the terminal of the dimethylpolysiloxane, and dimethylpolysiloxane Any of linear block copolymer types in which they are alternately and repeatedly bonded may be used. Dimethylpolysiloxane having a polyalkylene oxide unit is commercially available from Toray Dow Corning Co., Ltd., for example, FZ-2110, FZ-2122, FZ-2130, FZ-2166, FZ-2191, FZ-2203, FZ. -2207 can be used in combination of a plurality of these leveling agents. In general, the leveling agent is preferably used in an amount of 0.003 to 0.5% by weight in a total of 100% by weight of the photosensitive resin composition.

  Particularly preferable as a leveling agent is a kind of so-called surfactant having a hydrophobic group and a hydrophilic group in the molecule, and when it is added to a photosensitive resin composition, it has a hydrophilic group but has low solubility in water. The surface tension reducing ability is low, and those that increase the surface flatness of the flat layer can be preferably used. Thereby, the flatness of the translucent electrode provided on the flat layer is improved, and the life of the EL element is improved.

  An anionic, cationic, nonionic or amphoteric surfactant can be supplementarily added to the leveling agent. Two or more kinds of surfactants may be mixed and used. Anionic surfactants added to the leveling agent as auxiliary agents include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzene sulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkyl naphthalene sulfonate, alkyl diphenyl ether disulfonic acid Sodium, lauryl sulfate monoethanolamine, lauryl sulfate triethanolamine, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate Examples include esters.

  Examples of the chaotic surfactant that is supplementarily added to the leveling agent include alkyl quaternary ammonium salts and their ethylene oxide adducts. Nonionic surfactants added to the leveling agent as auxiliary agents include polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostearate And amphoteric surfactants such as alkyl dimethylamino acetic acid betaine and alkylimidazolines, and fluorine-based and silicone-based surfactants.

<Silane compound>
The photosensitive resin composition of the present invention can contain a silane compound. By including the silane compound used in the present invention, the adhesion between the translucent substrate or translucent electrode and the light scattering layer or the flat layer is improved.

  The weight average molecular weight (Mw) of the silane compound used in the present invention is preferably 100 or more and less than 5000. When the weight average molecular weight (Mw) of the silane compound is less than 100, sufficient adhesion may not be obtained, and when it is 5000 or more, the etchant resistance deteriorates, which may not be preferable.

As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid Xylpropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (Meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3 -Aminopropyl Limethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3- Dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, (3-carbamate ethyl) Propyltriethoxysilane, (3-carbamateethyl) propyltrimethoxysilane, (3-carbamateethyl) propyltripropoxysilane, (3-carbamatepropyl) propyltriethoxysilane, (3-carbamatepropyl) propyltrimethoxysilane , (3-carbamatepropyl) propyltripropoxysilane, (3-carbamatebutyl) propyltriethoxysilane, (3-carbamatebutyl) propyltrimethoxysilane, (3-carbamatebutyl) propyltripropoxysilane, (3- Carbamatebutyl) butyltripropoxysilane, (3-carbamatebutyl) propylmethyldiethoxysilane, (3-carbamatepentyl) propyltriethoxysilane, (3-carbamatehexyl) pro Pyrtriethoxysilane, (3-carbamate octyl) pentyl riboxysilane, (3-carbamateethyl) propylsilyltrichloride, (3-carbamateethyl) propyltrimethylsilane, (3-carbamateethyl) propyldimethylsilane, (3- Carbamateethyl) propyltributylsilane, (3-carbamateethyl) ethyl-p-xylenetriethoxysilane, (3-carbamateethyl) -p-phenylenetriethoxysilane, (3-carbamateethyl) propyltriethoxysilane, (3- Carbamateethyl) propyltrimethoxysilane, (3-carbamateethyl) propyltripropoxysilane, (3-carbamatepropyl) propyltriethoxysilane, (3-carbamatepropyl) propiyl Rutrimethoxysilane, (3-carbamatepropyl) propyltripropoxysilane, (3-carbamatebutyl) propyltriethoxysilane, (3-carbamatebutyl) propyltrimethoxysilane, (3-carbamatebutyl) propyltripropoxysilane, (3-carbamatebutyl) butyltripropoxysilane, (3-carbamatebutyl) propylmethyldiethoxysilane, (3-carbamatepentyl) propyltriethoxysilane, (3-carbamatehexyl) propyltriethoxysilane, (3-carbamate Octyl) pentyl riboxysilane, (3-carbamateethyl) propylsilyltrichloride, (3-carbamateethyl) propyltrimethylsilane, (3-carbamateethyl) propyldimethyl Silane, (3-carbamateethyl) propyltributylsilane, (3-carbamateethyl) ethyl-p-xylenetriethoxysilane, (3-carbamateethyl) -p-phenylenetriethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy Propyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyl diethoxy silane, 3-glycidoxypropyl epoxysilanes such as triethoxy silane,
3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, etc. Although it is mentioned, it is not necessarily limited to these.

These silane coupling agents can be used alone or in admixture of two or more at any ratio as required.
The silane coupling agent may be a silanol compound produced by hydrolysis of the above compound or a polyorganosiloxane compound condensed with them.

  From the viewpoint of reactivity with the resin contained in the binder composition, 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone “KBM-403”), 3- (meth) acryloxypropyltrimethoxysilane (Shin-Etsu Silicone “ KBM-503 "), N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Silicone" KBM-573 "), (3-carbamateethyl) propyltriethoxysilane, or (3-carbamateethyl) propyltrimethoxysilane is preferred. 3-glycidoxypropyltrimethoxysilane is particularly preferred.

  The amount of the silane compound used in the photosensitive resin composition of the present invention is preferably 3% by weight or more and less than 50% by weight in a solid content of 100% by weight of the photosensitive resin composition, and 10 to 40% by weight. Is more preferable. If it is less than 3% by weight, sufficient adhesion cannot be obtained, and if it exceeds 50% by weight, the transmittance may decrease.

<Organic solvent>
The photosensitive resin composition of the present invention can contain an organic solvent.
Examples of the organic solvent include 1,2,3-trichloropropane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, 1,4-dioxane, 2-heptanone, 2- Methyl-1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, ethyl 3-ethoxypropionate, 3-methyl-1,3-butane Diol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m-diethylbenzene, m-di Chlorobenzene, N, N-dimethylacetamide, N, N-dimethylformamide, n-butyl Lucol, n-butylbenzene, n-propyl acetate, N-methylpyrrolidone, o-xylene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert -Butylbenzene, γ-butyrolactone, isobutyl alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene Glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monopropylene Ether, ethylene glycol monohexyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol Monomethyl ether, cyclohexanol, cyclohexanol acetate, cyclohexanone, cyclopentanone, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl Ether, dipropylene glycol monobutyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene Glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, methoxypropyl acetate, propylene glycol monomethyl ether propionate, benzyl alcohol, methyl isobutyl T-methylcyclohexanol, n-amyl acetate, n-butyl acetate, isoamyl acetate, isobutyl acetate, propyl acetate, dibasic acid ester, ethanol, n-propanol, iso-propanol, n-butanol, 2-butanol, n- Examples include octanol and n-hexanol.
These organic solvents can be used individually by 1 type or in mixture of 2 or more types by arbitrary ratios as needed.

  Of these organic solvents, methoxypropyl acetate is preferred from the viewpoints of solubility and drying properties. By including methoxypropyl acetate, a coating film having excellent transparency after drying can be obtained.

  Further, in consideration of the drying property of the solvent, it is preferable to include a high boiling point solvent of 160 ° C. or higher in die coating or printing method, for example, 3-methoxy-3-methyl-1-butanol (bp 174 ° C.), 1, 3 -Butanediol (bp 203 ° C.), 3-methyl-1,3-butanediol (bp 203 ° C.), 2-methyl-1,3-propanediol (bp 213 ° C.), diisobutyl ketone (bp 168.1 ° C.), ethylene glycol mono Butyl ether (bp 171.2 ° C.), ethylene glycol monohexyl ether (bp 208.1 ° C.), ethylene glycol monobutyl ether acetate (bp 191.5 ° C.), ethylene glycol dibutyl ether (bp 203.3 ° C.), diethylene glycol monomethyl ether (bp 194.0) ℃), Jie Ren glycol monoethyl ether (bp 202.0 ° C.), diethylene glycol diethyl ether (bp 188.4 ° C.), diethylene glycol monoisopropyl ether (bp 207.3 ° C.), propylene glycol monobutyl ether (bp 170.2 ° C.), propylene glycol diacetate (bp 190 0.0 ° C.), dipropylene glycol monomethyl ether (bp 187.2 ° C.), dipropylene glycol monoethyl ether (bp 197.8 ° C.), dipropylene glycol monopropyl ether (bp 212.0 ° C.), dipropylene glycol dimethyl ether (bp 175 ° C.) ), Tripropylene glycol monomethyl ether (bp 206.3 ° C.), ethyl 3-ethoxypropionate (bp 169.7 ° C.), 3-methoxy Tyl acetate (bp 172.5 ° C.), 3-methoxy-3-methylbutyl acetate (bp 188 ° C.), γ-butyrolactone (bp 204 ° C.), N, N-dimethylacetamide (bp 166.1 ° C.), N-methylpyrrolidone (bp 202 ° C), p-chlorotoluene (bp162.0 ° C), o-diethylbenzene (bp183.4 ° C), m-diethylbenzene (bp181.1 ° C), p-diethylbenzene (bp183.8 ° C), o-dichlorobenzene (bp180) 0.5 ° C), m-dichlorobenzene (bp 173.0 ° C), n-butylbenzene (bp183.3 ° C), sec-butylbenzene (bp178.3 ° C), tert-butylbenzene (bp169.1 ° C), cyclo Hexanol (bp 161.1 ° C.), cyclohexyl acetate (b 173 ° C.), and methyl cyclohexanol (bp174 ℃) and the like. The high boiling point solvent of 160 ° C. or higher is preferably 5 to 50% by weight based on the total amount of the solvent.

  An organic solvent can be used in the quantity of 100-5000 weight part with respect to the solid content total 100 weight part of the photosensitive resin composition of this invention.

<Thermal reactive compound>
In the photosensitive resin composition of the present invention, a heat-reactive compound can be further added 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 include a melamine compound, a benzoguanamine compound, a carbodiimide compound, an epoxy compound, an oxetane compound, a phenol compound, a benzoxazine compound, a blocked carboxylic acid compound, a blocked isocyanate compound, and a silane coupling agent. 1 type (s) or 2 or more types selected from can be used. Particularly preferred is a thermoreactive compound 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, etc. It is not necessarily limited to these.

  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, Scimel 1123 manufactured by Nippon Cytex Industries, Ltd., My Coat 105, 106, 1128, and the like, but are not necessarily limited thereto.

  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.

<Metal oxide fine particles>
The photosensitive resin composition for light scattering layers and the photosensitive resin composition for flat layers may contain metal oxide fine particles. By including metal oxide fine particles, the refractive index can be adjusted.
The metal oxide fine particles used in the present invention desirably have a refractive index of 1.8 to 2.8 in the visible light region. Use of such metal oxide fine particles is preferable because the refractive index of the light scattering layer and the flat layer can be increased.
In the present specification, the “refractive index of metal oxide fine particles” 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, titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), hafnium oxide (HfO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), At least one material selected from the group consisting of tantalum pentoxide (Ta ₂ O ₅ ), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), indium tin oxide (ITO), and zinc oxide (ZnO) Although the particle | grains which consist of are mentioned, It is not necessarily limited to these.

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 is preferably 100 nm or less. By defining the average primary particle size to 100 nm or less, a transparent composition 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, 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 addition amount of the metal oxide fine particles is preferably 5% by weight or more and less than 50% by weight, more preferably 10 to 45% by weight, in the total solid content of 100% by weight in the photosensitive resin composition. When the addition amount is less than 5% by weight, it is difficult to obtain the effect of adjusting the refractive index. On the other hand, when it exceeds 50% by weight, problems such as a decrease in transmittance due to light scattering may occur.

(Metal oxide fine particle dispersion)
The metal oxide fine particle dispersion in the present invention is preferably prepared by a method using a disperser, using a dispersant that matches the surface state of the metal oxide fine particles. 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”), an ultrasonic disperser, and the like.
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.

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

<Antioxidant>
The photosensitive resin composition of the present invention can contain an antioxidant. The antioxidant can suppress a decrease in transmittance due to yellowing or the like due to the heating process. Therefore, by including an antioxidant, yellowing during the heating step can be prevented, and a coating film having a high transmittance can be obtained.

  The antioxidant in the present invention may be a compound having an ultraviolet absorption function, a radical scavenging function, or a peroxide decomposition function. Specifically, as an antioxidant, hindered phenols, hindered amines, phosphorus , Sulfur, benzotriazole, benzophenone, hydroxylamine, salicylate, and triazine compounds, and known ultraviolet absorbers, antioxidants, and the like can be used. Among these antioxidants, phenol-based antioxidants, phosphorus-based antioxidants and sulfur-based antioxidants are preferable from the viewpoint of achieving both transmittance and sensitivity of the coating film. Among phenol-based compounds, hindered phenol-based antioxidants having high steric hindrance are particularly preferable.

[Phenolic antioxidant]
For example, 2,6-di-t-butyl-4-ethylphenol, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3 , 5-triazine, 2,2-thio-diethylenebis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, N, N'-hexamethylenebis (3,5-di- t-butyl-4-hydroxy-hydrocinnamide), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -Isocyanurate, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-methoxyphenol, triethylene glycol- Bis {3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate}, 1,6-hexanediol-bis {3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate}, pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) Examples include propionate and 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxyphenyl) benzene. .

Among them, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythritol tetrakis [3- (3 5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-t- A hindered phenolic antioxidant selected from the group consisting of butyl-4-hydroxybenzylphosphonate-diethyl ester and tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate is: It is preferable from the viewpoint of photocurability.
Specific examples of the hindered phenol antioxidant include Yoshinox BHT (= 2,6-di-t-butyl-4-methylphenol), Tominox TT (= tetrakis- [methylene-3- (3,5 ′). -Di-t-butyl-4'-hydroxyphenyl) propionate] methane), Yoshinox SR, Yoshinox BB, Yoshinox 2246G, Yoshinox 425, Yoshinox 250, Yoshinox 930, Tominox SS, Tominox 917, GSY-314 (or more, Manufactured by API Corporation), IRGANOX245, IRGANOX259, IRGANOX565, IRGANOX1010, IRGANOX1035, IRGANOX1076, IRGANOX1098, IRGANOX1135, IRGANOX107 , IRGANOX 1425WL, IRGANOX 1222, IRGANOX 1330 (above, manufactured by BASF Japan Ltd.), ADK STAB AO-70, ADK STAB AO-50, ADK STAB AO-330, ADK STAB AO-20, ADK STAB AO-30, ADK STAB AO-80 (Asahi Denka) (Manufactured by Kogyo Co., Ltd.), Sumizer BM, Sumizer GM, Sumizer GP, Sumizer GS, Sumizer GA-80, Sumizer BP-101, Sumizer BP-76, and Sumizer BP-101 (manufactured by Sumitomo Chemical Co., Ltd.).

[Amine antioxidant]
Examples of hindered amine-based antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) -1,6-hexamethylenediamine, 2-methyl-2- (2,2,6,6-tetramethyl-4 -Piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) (1,2,3, 4-butanetetracarboxylate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl} {(2,2,6,6 -Tetramethyl-4-piperidi ) Imino} hexamethyl {(2,2,6,6-tetramethyl-4-piperidyl) imino}], poly [(6-morpholino-1,3,5-triazine-2,4-diyl) {(2, 2,6,6-tetramethyl-4-piperidyl) imino} hexamethine {(2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate and 1- (2-hydroxyethyl)- Polycondensate with 4-hydroxy-2,2,6,6-tetramethylpiperidine, N, N′-4,7-tetrakis [4,6-bis {N-butyl-N- (1,2,2 , 6,6-pentamethyl-4-piperidyl) amino} -1,3,5-triazin-2-yl] -4,7-diazadecane-1,10-diamine, etc. Other oligomer type having a hindered amine structure as well as Rimmer type of compounds and the like can also be used.

  Specific examples of the hindered amine-based antioxidant include Sanol LS-770, Sanol LS-765, Sanol LS-622LD, Kimasorp 944 (Sankyo Co., Ltd.), CYASORB UV-3346 (San Chemical Co., Ltd.), Knock rack 224, knock rack CD, Uvasil 299-299LM (above, Ouchi Shinsei Chemical Industry Co., Ltd.), MARK LA-63, MARKLA-68 (above, Asahi Denka Kogyo Co., Ltd.), TINUVIN 144, TINUVIN 312 (above, BASF・ Made by Japan).

[Phosphorus antioxidant]
Although what is marketed can be used as phosphorus antioxidant, Tris [2,4-di- (tert) -butylphenyl] phosphinetris [2-[[2,4,8,10-tetrakis ( 1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphin-6-yl] oxy] ethyl] amine, tris [2-[(4,6,9,11- Tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphin-2-yl) oxy] ethyl] amine, ethylbisphosphite (2,4-ditert-butyl-6-) Methylphenyl), and at least one compound selected from the group consisting of these is preferable, and one or more of these can be used.
Specific examples of phosphorus-based antioxidants include IRGAFOS168, IRGAFOS12, IRGAFOS38, IRGAFOSEPQ, (manufactured by BASF Japan Ltd.), Sumizer Z-16 (manufactured by Sumitomo Chemical Co., Ltd.), ADK STAB PEP-4C, ADK STAB PEP-8F, ADK STAB PEP-8, ADK STAB PEP-45, ADK STAB PEP-11C, ADK STAB PEP-24G, ADK STAB PEP-36, ADK STAB HP-10, ADK STAB P, ADK STAB C, ADK STAB QL, ADK STAB 135A, ADK STAB 1178, ADK STAB 1500, ADK STAB 1500, ADK STAB 3010, ADK STAB 522A, ADK STAB TPP (above, manufactured by Asahi Denka Kogyo Co., Ltd.), GSY-202 (above, AP Aiko Ltd. poration), SANKOHCA (Sanko Co., Ltd.), JPH1200, JP302, JPM313, JP304, JP308, JPP100, JP333E, JP318E, JP312 (manufactured by API Corporation) and the like.

[Sulfur antioxidants]
A sulfur-based antioxidant is an antioxidant containing sulfur in the molecule. As such a sulfur-containing antioxidant, commercially available ones can be used, but dioctadecyl 3,3′-thiodipropanoate, dimyristyl-3,3′-thiodipropionate, dipalmityl-3,3′- Thiodipropionate, distearyl-3,3′-thiodipropionate, 4,4′-thiobis-3-methyl-6-tert-butylphenol, thiodiethylenebis [3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propionate], and is preferably at least one compound selected from the group consisting of these, and one or more of these may be used.
Specific examples of sulfur-based antioxidants include IRGANOXPS800FD, IRGANOXPS802FD (above, manufactured by BASF Japan Ltd.), Adekastab AO-503, Adekastab AO-412S (above, made by Asahi Denka Kogyo Co., Ltd.), Sumizer ZPL-R, Sumizer TPM, Sumilizer Sumitizer TP-D, Sumitizer TL, Sumitizer MB (above, manufactured by Sumitomo Chemical Co., Ltd.), DLTP “Yoshitomi”, DSTP “Yoshitomi”, DMTP “Yoshitomi”, DTTP “Yoshitomi” (above, manufactured by API Corporation).

  As the benzotriazole-based antioxidant, oligomer-type and polymer-type compounds having a benzotriazole structure can be used.

  Specific examples of the benzotriazole antioxidants include Tomisorp 600 (manufactured by Yoshitomi Fine Chemical), TINUVIN 326, TINUVIN 327, TINUVIN P, TINUVIN 328 (above, manufactured by BASF Japan Ltd.), VIOSORB583, VIOSORB590 (manufactured by Kyodo Yakuhin). .

  As the benzophenone-based antioxidant, oligomer type and polymer type compounds having a benzophenone structure can be used.

  Examples of the benzophenone antioxidant include 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4 -Octadecyloxybenzophenone, 2,2'dihydroxy-4-methoxybenzophenone, 2,2'dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4 -Methoxy-5 sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-chlorobenzophenone, LA-51 (manufactured by Asahi Denka Kogyo Co., Ltd.) and the like. In addition, oligomer type and polymer type compounds having a benzophenone structure can also be used.

  Specific examples of the benzophenone antioxidant include Tomisorp 800 (manufactured by API Corporation) and LA-51 (manufactured by Asahi Denka Kogyo Co., Ltd.).

  Examples of the triazine antioxidant include 2,4-bis (allyl) -6- (2-hydroxyphenyl) 1,3,5-triazine. In addition, oligomer-type and polymer-type compounds having a triazine structure can also be used.

  Specific examples of the triazine antioxidant include CYASORB UV-1164 (manufactured by Sun Chemical Co., Ltd.).

  Specifically, a compound such as IRGASTABFS042 (above, manufactured by BASF Japan Ltd.) can be used as the hydroxylamine-based antioxidant.

  Examples of the salicylate ester antioxidant include phenyl salicylate, p-octylphenyl salicylate, p-tertbutylphenyl salicylate, and the like. In addition, oligomer-type and polymer-type compounds having a salicylate structure can also be used.

  These antioxidants can be used singly or in combination of two or more at any ratio as required.

  The content of the antioxidant is preferably 0.1 wt% or more and less than 4 wt% in the total solid content of 100 wt% of the photosensitive resin composition. When the amount is less than 0.1% by weight, it is difficult to obtain a yellowing prevention effect due to insufficient antioxidant, and when the amount is more than 4% by weight, the radicals generated at the time of UV exposure are captured. Curing of the composition may be insufficient.

<Other materials>
The photosensitive resin composition of the present invention includes a monofunctional monomer, a heat stabilizer, a light stabilizer, an antistatic agent, a surfactant, a storage stabilizer, a reactive diluent, and a light stabilizer as necessary. Etc. can also be included.

<Method for producing photosensitive resin composition>
The method for producing the photosensitive resin composition of the present invention is not particularly limited, and the light scattering particles (A), the alkali-soluble resin, the photopolymerization initiator, the photopolymerizable monomer, and the leveling agent are uniformly mixed. Any known method that is usually used can be used.

  For example, each component constituting the photosensitive resin composition of the present invention is independently prepared, and thereafter mixed or kneaded, light scattering particles (A) prepared in advance, alkali-soluble resin, photopolymerization initiator, Examples include a method in which a photopolymerizable monomer and a leveling agent are mixed at once, and other components are added as necessary.

《Organic electroluminescence device》
The organic electroluminescence device of the present invention has a light extraction layer composed of a light scattering layer and a flat layer. The structure of the organic electroluminescence element is not particularly limited, but as an example of the basic structure, at least one organic layer (organic EL layer) including a light extraction layer, a transparent electrode, and a light emitting layer on a transparent substrate, a back surface A structure called bottom emission in which electrodes and a TFT substrate are sequentially laminated and light is extracted from the anode side can be mentioned. As another example, on the TFT substrate, a back electrode, at least one organic layer (organic EL layer) including a light emitting layer, a translucent electrode, a light extraction layer, and a sealing layer are sequentially laminated, and the cathode side A structure called top emission that extracts light from the surface. These methods and techniques are described in Shinji 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 in detail 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 according to the present embodiment includes a light scattering layer 12, a flat layer 16, a light-transmitting first electrode (anode, light-transmitting electrode) 13, and a light-emitting element on a light-transmitting substrate 11. At least one organic layer (organic EL layer) 14 including a layer and a second electrode (cathode, back electrode) 15 having light reflectivity are sequentially stacked.
The light scattering layer 12 and the flat layer 16 are light extraction layers formed using the above-described photosensitive resin composition of the present invention.

《Organic electroluminescence device》
The organic electroluminescence device of the present invention has an organic electroluminescence element and 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 and the flat layer of the present invention are 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 / flat layer / translucent electrode / organic EL layer / back electrode (2) Light scattering layer / translucent substrate / light scattering layer / flat layer / translucent electrode / Organic EL layer / Back electrode (3) Prism lens layer / Translucent substrate / Light scattering layer / Flat 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 translucent electrode / Flat layer / Light scattering layer / Protective substrate (5) Substrate / Back electrode / Organic EL layer / Translucent or translucent Electrode / sealing layer / flat layer / light scattering layer / protective substrate (6) substrate / back electrode / organic EL layer / translucent or semi-transparent electrode / flat layer / light scattering layer / protective substrate / light scattering Layer (7) Substrate / Back electrode / Organic EL layer / Translucent or semi-transparent electrode / Flat layer / Light scattering layer / Protective substrate / Prism lens layer

  At this time, it is more preferable from the viewpoints of light extraction efficiency and life to include an organic EL element having a light scattering layer and a flat layer (light extraction layer) between the light transmissive substrate and the light transmissive electrode.

  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 and a flat layer (light extraction layer).

  As the translucent substrate, a non-flexible substrate or a flexible substrate can be used. For example, non-flexible substrates such as glass substrates, hard resin substrates, wafers, printed substrates, various cards, resin sheets, etc. may be used. For example, polyethylene terephthalate (PET), polyamide, polyolefin, polyethylene naphthalate (PEN) Flexible substrates such as polycarbonate, polyacrylate, polymethacrylate, polyurethane acrylate, polyethersulfone, polyimide, polysilsesquioxane, polynorbornene, polyetherimide, polyarylate, amorphous cyclopolyolefin, cellulose triacetate, etc. It may be used. In the case where the substrate is made of a resin, the resins exemplified above may be appropriately mixed and used as the resin to be used. Further, those having a heat resistance of preferably 100 ° C. or higher, particularly preferably 150 ° C. or higher are appropriate.

  Specifically, as such a flexible substrate, an amorphous cyclopolyolefin resin film (for example, ZEONEX (registered trademark) or ZEONOR (registered trademark) of Nippon Zeon Corporation, ARTON of JSR Corporation, etc.), polycarbonate film (for example, , Pure ace of Teijin Chemicals Ltd.), polyethylene terephthalate film (for example, manufactured by Teijin Chemicals Ltd.), cellulose triacetate film (for example, Konica Katak KC4UX, KC8UX, etc. of Konica Minolta Opto), polyethylene naphthalate A commercial product of a film (for example, Teonex (registered trademark) of Teijin DuPont Film Co., Ltd.) can be mentioned.

However, since organic EL elements and electrodes are deteriorated by a very small amount of moisture, when a flexible substrate is used, an organic and inorganic multilayer stack is provided on the surface of the substrate in order to provide a water vapor barrier property at an extremely high glass level. It is necessary to provide a film.
In the present invention, it is preferable to use a glass substrate from the viewpoints of heat resistance and water vapor barrier properties.

  Further, on the light extraction side of the translucent substrate, if necessary, antifouling coating, hard coating, antistatic coating, antireflection coating, etc. can be performed with an arbitrary composition. Furthermore, in order to prevent total reflection of light at the light-transmitting substrate and the air interface, surface fine processing such as a scattering sheet, a prism sheet, a microlens, or a pyramid shape can be performed.

  Furthermore, a refractive index adjustment layer may be provided between the light-transmitting substrate and the light scattering layer, or between the light scattering layer and the flat layer. By providing the refractive index adjustment layer, the difference in refractive index between the layers can be relaxed, and the reflection of light at the interface of each layer can be reduced. Between the translucent substrate and the light scattering layer, the refractive index may be intermediate between the translucent substrate and the light scattering layer, but a low refractive index layer such as aero silica gel may be provided.

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 nanoparticles, silver nanowires, copper, chromium, and nickel;
Other inorganic conductive materials such as copper iodide and copper sulfide;
Organic conductive materials such as polyaniline, polythiophene, PEDOT / PSS, carbon nanotubes, carbon nanowires, fullerene derivatives, 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 and the flat layer (light extraction 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. In addition, 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 may be any material that has 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, a light scattering layer, and a flat layer (light extraction layer) are sequentially laminated on a substrate such as a TFT. The back electrode, organic EL layer, translucent electrode, light scattering layer, flat layer (light extraction layer) material, lamination method, etc. described here are the same as those described in the bottom emission manufacturing method. be able to.

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. . There is no restriction | limiting in particular in the sealing process method of an organic EL element, Any conventionally well-known method is employable.
For example, a method of molding with acrylic resin (Japanese Patent Laid-Open No. 3-37991), a method of putting together with P ₂ O ₅ in an airtight case and blocking from the outside air (Japanese Patent Laid-Open No. 3-261091), a metal oxide, etc. A method of providing a protective film and then making it airtight using a glass plate or the like (JP-A-4-212284), a method of providing a plasma polymerization film and a photocurable resin layer (JP-A-5-36475), fluorination A method of holding in an inert liquid made of carbon (JP-A-4-363890, etc.), a method of holding in a silicone oil after providing a polymer protective film (JP-A-5-36475), an inorganic oxide A method of adhering a glass plate coated with polyvinyl alcohol on a protective film such as an epoxy resin (Japanese Patent Laid-Open No. 5-89959), in liquid paraffin or silicone oil Method (Japanese Unexamined Patent Publication No. 5-129080) to contain, a method using an ultraviolet curable resin (JP-A-5-182759 etc.) and the like, is not intended to be limited thereto.
In particular, when the entire device is covered or sealed, a molten glass or a photocurable resin that is cured by light is preferable.

  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 and the flat layer (light extraction 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).

  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 to the light scattering layer and the flat layer ( The light is extracted through the light-transmitting substrate. 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 comprising the light scattering layer and the flat layer (light extraction layer) of the present invention can be applied in various forms.
For example, the organic EL device comprising the light scattering layer and the flat layer of the present invention can also 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 including the light scattering layer and the flat 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 device having the light scattering layer and the flat layer of the present invention may adopt a multi-photon emission device 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 and the flat layer of the present invention is used as a flat panel display such as a wall-mounted TV, various flat light emitters, a light source such as a copying machine or a printer, a liquid crystal Applications to light sources such as displays and instruments, display boards, and indicator lights are 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, “parts” represents “parts by weight” and “%” represents% by weight.

  First, the measurement method of the average particle diameter of light-scattering particle | grains, the double bond equivalent of resin, a weight average molecular weight (Mw), and an acid value is demonstrated.

(Average particle size of light scattering particles)
The average particle size was measured using “Nanotrack UPA” manufactured by Nikkiso Co., Ltd.

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

(Weight average molecular weight of resin (Mw))
The weight 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.

(Resin 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 weight 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))

<Preparation of Light Scattering Particle (A) Dispersion>
(Light scattering particle dispersion (A-1))
Under N ₂ atmosphere, 50 g of trifluoroethyl methacrylate, 40 g of methyl methacrylate, 5 g of allyl methacrylate, and 5 g of adamantyl acrylate were added and stirred in 560 g of water, the temperature was raised to 80 ° C., and 2,2′-azobis (2 -Amidinopropane) An aqueous solution obtained by dissolving 0.167 g of dihydrochloride (hereinafter referred to as "V-50") in a very small amount of water was added all at once and polymerized at 80 ° C for 8 hours. After polymerization, methoxypropyl acetate was added, water was removed by stripping, and a light scattering particle dispersion (A-1) (acrylic resin particle dispersion) adjusted to a solid content of 20% by weight was prepared.
The average particle diameter of the light scattering particles in the obtained light scattering particle dispersion (A-1) is 310 nm, the content of the particles of 600 nm or more with respect to the total amount of the light scattering particles is 9%, the variation coefficient is 8%, and the refractive index. Was 1.46.

(Light scattering particle dispersion (A-2 to 4))
The light scattering particle dispersion liquids (A-2 to 4) are obtained in the same manner as the light scattering particle dispersion liquid (A-1) except that the preparation composition is changed to the composition shown in Table 1 and the blending amount (g). It was. Table 1 shows the average particle diameter of the obtained light scattering particle dispersion, the content of particles of 600 nm or more, the coefficient of variation, and the refractive index with respect to the total amount of the light scattering particles.

<Preparation of dispersant for dispersing metal oxide fine particles>
(Dispersant for dispersing metal oxide fine particles)
In a 4-neck flask equipped with a stirrer, reflux condenser, dry air inlet tube, and thermometer, 80.0 parts of biphenyltetracarboxylic dianhydride, pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd., product) Name: KAYARAD PET-30) 250.0 parts, hydroquinone 0.16 parts, and cyclohexanone 141.2 parts were charged, and the temperature was raised to 85 ° C. Next, 1.65 parts of 1,8-diazabicyclo [5.4.0] -7-undecene was added as a catalyst and reacted at 85 ° C. for 8 hours. After confirming that the peaks of acid anhydride groups, that is, peaks near 1780 cm ⁻¹ and 1850 cm ^−1, disappeared by IR measurement of the reaction product, the reaction product was cooled to stop the reaction. At this point, the acid value of the reaction product was measured by a conventional method and found to be 93 mgKOH / g. Subsequently, 77.3 parts of glycidyl methacrylate and 33.9 parts of cyclohexanone were added to this solution, and then 2.65 parts of dimethylbenzylamine was added as a catalyst, followed by reaction at 85 ° C. for 6 hours. The acid value of the reaction product was measured periodically while continuing the reaction temperature. When the acid value of the reaction product became 7 mgKOH / g or less, it was cooled to room temperature to obtain a dispersant solution having a solid content of 70% by weight. . The acid value was 5 mgKOH / g, and the weight average molecular weight (Mw) was 3130.

<Production of metal oxide fine particle dispersion>
(Metal oxide fine particle dispersion (F-1))
To 10 g of titanium oxide (TiO ₂ ) fine particles having an average primary particle diameter of 15 nm, 84.3 g of methoxypropyl acetate as a dispersion medium, and 5.7 g of the dispersant solution obtained in Production Example 201 (about 3.99 g of the dispersant) Included). 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 (F-1) (titanium dioxide fine particle dispersion) was produced. The average particle diameter of the titanium oxide fine particles in the dispersion was 80 nm. The dispersion contains 50% non-volatile components, titanium oxide contained in 100% non-volatile components is about 71.5%, and the dispersant is about 28.5%.

<Preparation of resin solution>
(Alkali-soluble resin solution (B-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 methoxypropyl acetate as a solvent was placed. The container was heated to 80 ° C. while injecting nitrogen gas. Maintaining this temperature, 15 parts of hydroxyethyl methacrylate (HEMA), 24.0 parts of methyl methacrylate (MMA), 36.6 parts of methacrylic acid (MAA), and 3 parts of 2,2′-azobisisobutyronitrile The mixture was added dropwise over 1 hour to conduct a 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 methoxypropyl acetate was added, and then stirring was continued at the same temperature for 3 hours. Thus, a copolymer was obtained.
Step 2:
Next, dry air was introduced into the reaction vessel, 30 parts of glycidyl methacrylate (GMA) was charged, and stirring was continued at the same temperature for 10 hours. After cooling to room temperature, it was diluted with methoxypropyl acetate to obtain an alkali-soluble resin solution (B-1) having a solid content of 35% by weight. Table 2 shows main reaction conditions (prepared composition and reaction temperature) and evaluation results of the obtained resin.

(Alkali-soluble resin solution (B-2 to 5), other resin (BX-1))
The alkali soluble resin solution (B- 2-5) and other resins (BX-1) were obtained.
The refractive indexes of (B-1 to 5) and (BX-1) were all 1.50.

(Alkali-soluble resin solution (B-6))
Step 1:
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a gas introduction tube, 100 parts of methoxypropyl acetate as a solvent was placed. The container was heated to 80 ° C. while injecting nitrogen gas. While maintaining this temperature, 100 parts of a 50% PGMEA solution of 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxyphenyl] fluorene (ASF-400) was added, and while introducing dry air, 80 A mixture of 17 parts of methacrylic acid and 4 parts of 2,2′-azobisisobutyronitrile was dropped over 1 hour at the same temperature to carry out a polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, and then added with 0.5 part of 2,2′-azobisisobutyronitrile dissolved in 40 parts of PGMEA, and then stirred at the same temperature for 3 hours. To obtain a copolymer.
Step 2:
Next, dry air was introduced into the reaction vessel, 10 parts of tetrahydrophthalic anhydride was charged, and stirring was continued at the same temperature for 10 hours. After cooling to room temperature, by diluting with PGMEA, an alkali-soluble resin solution (B-6) having a refractive index of 40% solid content of 1.62 and containing an ethylenically unsaturated group and a carboxyl group was obtained. The weight average molecular weight was 8000.

Each abbreviation in Table 2 is as follows.
PGMEA: methoxypropyl acetate,
DCPMA: dicyclopentanyl methacrylate,
CHMA: cyclohexyl methacrylate,
St: Styrene,
M-110: paracumylphenol ethylene oxide modified acrylate,
ASF-400: 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxyphenyl] fluorene (solid content ratio 50%)
HEMA: hydroxyethyl methacrylate,
MAA: methacrylic acid,
GMA: glycidyl methacrylate,
MMA: methyl methacrylate.

<Preparation of photosensitive resin composition for light scattering layer>
(Photosensitive resin composition for light scattering layer (SR-1))
5. Light scattering particle dispersion (A-1) 20 parts, alkali-soluble resin (B-4) 8.9 parts, photopolymerization initiator “Irgacure 907” 0.2 parts, photopolymerizable monomer “DPCA30” 6 parts, 0.01 part of a leveling agent “BYK330”, 11.9 parts of metal oxide fine particle dispersion (F-1) and 52.4 parts of methoxypropyl acetate were added and stirred and mixed to be uniform. It filtered with the filter of mesh diameter 5micrometer, and produced the resin composition (SR-1) for light scattering layers.

(Photosensitive resin composition for light scattering layer (SR-2 to 10))
Except for the composition shown in Table 3 and the blending amount (parts by weight), in the same manner as the light scattering layer resin composition (SR-1), the light scattering layer photosensitive resin composition (SR-2 to 2). 10) was obtained.

Each abbreviation in Table 3 is as follows.
<Photopolymerizable monomer>
DPCA30: Kayrad DPCA30 (refractive index: 1.48) manufactured by Sartomer
A-BPEF: NK ester A-BPEF (refractive index 1.62) manufactured by Nakamura Chemical Co., Ltd.
<Photopolymerization initiator>
・ Irg907: Irgacure 907 manufactured by BASF
<Leveling agent>
BYK330: BYK330 manufactured by Big Chemie.

<Preparation of photosensitive resin composition for flat layer>
(Photosensitive resin composition for flat layer (OC-1))
Alkaline-soluble resin (B-5) 43.9 parts, photopolymerization initiator "Irgacure 819" 0.6 parts, photopolymerizable monomer "DPCA30" 4 parts, leveling agent "BYK330" 0.01 parts, methoxypropyl 51.5 parts of acetate was added and stirred and mixed to be uniform. It filtered with the filter of mesh diameter 5micrometer, and produced the photosensitive resin composition (OC-1) for flat layers.

(Photosensitive resin composition for flat layer (OC-2 to 20))
Except for the composition shown in Table 4 and the blending amount (parts by weight), the flat layer photosensitive resin composition (OC-2 to 2) was the same as the flat layer photosensitive resin composition (OC-1). 20) was obtained.

Each abbreviation in Table 4 is as follows.
[Photopolymerizable monomer]
DPCA30: Kayrad DPCA30 (refractive index: 1.48) manufactured by Sartomer
A-BPEF: NK ester A-BPEF (refractive index 1.62) manufactured by Nakamura Chemical Co., Ltd.
[Photopolymerization initiator]
・ Irg907: Irgacure 907 manufactured by BASF
・ Irg819: Irgacure 819 manufactured by BASF
・ Irg369: Irgacure 369 manufactured by BASF
OXE01: BASF Irgacure OXE01
OXE02: BASF's Irgacure OXE02
[Leveling agent]
BYK330: BYK330 manufactured by Big Chemie.
・ F-444: DIC Mega Fuck F-444

<Preparation of light extraction layer>
Example 1
Using the photosensitive resin composition for a light scattering layer and the photosensitive resin composition for a flat layer, it was applied on a translucent substrate under the following conditions to produce a light extraction layer.
First, a 0.7 mm thick glass substrate (Corning Glass “Eagle 2000”) was prepared using a spin coater for the photosensitive resin composition (SR-1) for the light scattering layer, so that the finished film thickness was 1.0 μm. It was applied to. 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. . Thereafter, spraying is performed at a pressure of 0.25 MPa using a 0.04 wt% aqueous potassium hydroxide solution (developer temperature 26 ° C.) to dissolve the unexposed portion of the resin coating film, and the area is 5.5 mm × 5. A pattern was formed to be 5 mm. Further, the coated substrate was heated at 200 ° C. for 30 minutes and allowed to cool to produce a light scattering layer.
On the light scattering layer, the photosensitive resin composition for flat layer (OC-1) is applied so that the final film thickness is 1.0 μm, and drying, exposure, development, and baking are performed in the same manner as the light scattering layer. A flat layer was produced, and the light extraction layer 1 was obtained.

(Examples 2 to 23, Comparative Examples 1 to 3)
The light extraction layer 2 was the same as the light extraction layer 1 except that the type and thickness of the photosensitive resin composition for the light scattering layer or the photosensitive resin composition for the flat layer were changed as shown in Table 5. ~ 26 was obtained.

(Measurement of refractive index)
Refractive index was applied to the light scattering layer photosensitive resin composition or the flat layer photosensitive composition on the PEN (polyethylene naphthalate) film in the same manner as the evaluation substrate prepared on the glass. In accordance with Japanese Industrial Standards: JIS K7142 “Plastic Refractive Index Measurement Method”, measurement was performed with an Abbe refractometer.

(8) Evaluation Table 6 shows the evaluation results.
However, since the photosensitive composition for light scattering layer (SR-9) and the photosensitive composition for flat layer (OC-19) could not be developed with an alkali, they were evaluated without patterning.

(Light extraction efficiency I)
On the obtained light extraction layer substrate, an ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90: 10 (weight ratio)) was used to form an ITO film having a thickness of 150 nm by DC sputtering. Next, Alq3 shown in Table 8 was formed to a thickness of 150 nm on the ITO surface by vacuum deposition. The substrate was taken out from the vacuum deposition base, placed on a UV irradiator with a wavelength of 365 nm, and the front luminance was measured with a luminance meter “LS-100” manufactured by Konica Minolta. The front luminance improvement rate (extraction efficiency I) was calculated based on the front luminance created with the substrate on which the light scattering layer and the flat layer were not formed.

-Light extraction efficiency Front brightness improvement ratio of 2.4 times or more: Excellent (◎),
Front luminance improvement rate 1.5 times or more and less than 2.4 times: good (◯),
Front brightness improvement rate less than 1.31.5 times: Possible (△)
Front brightness improvement rate less than 1.3 times: Possible (×)

(Evaluation of EL device with bottom emission structure (light extraction efficiency II, light emission appearance (dark spot, unevenness), life)
An ITO ceramic target (In ₂ O ₃ : SnO ₂ = 90: 10 (weight ratio)) is formed on the obtained light extraction layer substrate, and an ITO film having a thickness of 150 nm is formed by a DC sputtering method. An electrode (anode) was used.
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 6 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).
In a nitrogen glove box connected to a vacuum deposition apparatus, a photo-curable resin (30Y-437 manufactured by ThreeBond Co., Ltd.) is applied to the outer periphery of the glass substrate with a width of about 1 mm, and a moisture getter sheet (Dynic) Set up). On this, the said organic EL element main body was bonded together so that the organic layer formation surface might oppose a desiccant sheet. Then, only the area | region where the photocurable resin was apply | coated was irradiated with ultraviolet light, the resin was hardened, and the element was sealed.
In the same manner as described above, a light emitting layer and an electron injection layer shown in Table 8 were used to produce blue, green, and white light emitting elements, respectively.
Separately, an organic EL device was obtained by the same method as above except that a glass substrate on which a light scattering layer and a flat layer were not formed was used as a base material for evaluation.

About each light emitting element obtained using the light-emitting body of Table 8, a forward current of 10 mA / cm ^{2 was} applied at room temperature, and the appearance of light emission (dark spots, unevenness) was observed. In addition, the front luminance was measured with a spectral radiance meter “CS-2000” manufactured by Konica Minolta Sensing Co., Ltd., and white light emission was obtained based on the front luminance of the organic EL device produced on the substrate on which the light scattering layer was not formed. The improvement rate (extraction efficiency II) of the front luminance of the element was calculated. In addition, for the lifetime, the device was turned on at a luminance of 100 cd / m ² and a lighting acceleration test was performed at a temperature of 105 ° C. The time until the screen brightness is halved is defined as the lifetime.

Evaluation was made based on the following criteria.
・ Light extraction efficiency II
Front brightness improvement rate 1.5 times or more: Excellent (◎),
Front brightness improvement rate 1.2 times or more and less than 1.5 times: good (○),
Front luminance improvement rate 1.1 times or more and less than 1.2 times: possible (△)
Front brightness improvement rate less than 1.1 times: Impossible (×)

・ Luminescent appearance (dark spots, unevenness)
Dark spots and unevenness are not observed: Excellent (◎),
Dark spots and unevenness are slightly observed: good (○),
Dark spots and unevenness are somewhat observed: Yes (△),
A lot of dark spots and unevenness are observed: Impossible (×)

・ Life Luminance half-life 600 hours or more: Excellent (◎),
Luminance half-life 300 hours or more and less than 600 hours: Good (◯),
Luminance half-life 100 hours or more and less than 300 hours: Possible (△)
Luminance half-life less than 100 hours: Impossible (x)

(Taper angle of cross-sectional shape of flat layer)
The cross-sectional shape of the pattern film of the flat layer is examined with a scanning electron microscope (manufactured by Hitachi, Ltd., “S-4200”), and the taper angle of the cross-sectional shape (the bottom of the cross-sectional shape of the pattern and the edge portion) The angle formed by the tangent.) Was measured.

Taper angle less than 30 degrees: Excellent (O),
Taper angle 30 degrees or more and less than 50 degrees: Possible (△)
Taper angle 50 degrees or more: Impossible (×)

(Flatness)
About the light extraction layer, the surface roughness of the coating film was measured with a stylus-type film thickness meter DECTAC-3 manufactured by ULVAC. Evaluation was made based on the following criteria.

Surface roughness less than 10 mm: Excellent (◎),
Surface roughness of 10 mm or more and less than 30 mm: good (◯),
Surface roughness of 30 mm to 100 mm: possible (△),
Surface roughness greater than 100 mm: Impossible (×)

  From the results of Table 7, the light scattering containing the light scattering particles (A) having an average particle diameter of 200 nm to 500 nm, an alkali-soluble resin, a photopolymerization initiator, a photopolymerizable monomer, and a leveling agent according to the present invention. Formed by a photosensitive resin composition for a flat layer containing a light-scattering layer formed from a photosensitive resin composition for layers and an alkali-soluble resin, a photopolymerization initiator, a photopolymerizable monomer, and a leveling agent. The light extraction layer having the flat layer was excellent in light extraction efficiency, light emission appearance, and life. In particular, the type of photopolymerization initiator used in the flat layer and the ratio I / M between the photopolymerization initiator amount (I) and the photopolymerizable monomer amount (M) are made constant so that the flat layer is flat. And the cross-sectional shape are improved, and more excellent light emission characteristics are obtained.

  In Comparative Example 1 using the light scattering particles (A-4) having a large particle diameter, the light extraction efficiency is poor, and even when a flat layer is formed, the flatness is poor, and light emission unevenness and dark spots occur. . Further, in Comparative Example 2 having no alkali-soluble resin, neither the light scattering layer nor the flat layer can be patterned, so that the sealing is not completed completely and the life is short and dark spots are generated. The same applies to the case where either one of the films cannot be patterned. Further, in Comparative Example 3 in which neither the light scattering layer nor the flat layer contained a leveling agent, the flatness was poor and the life and the light emitting appearance were poor.

  From these results, the organic electroluminescence device having the light extraction layer composed of the light scattering layer and the flat layer of the present invention has the light extraction layer composed of the light scattering layer excellent in patternability and the flat layer excellent in flatness. It has been confirmed that an organic EL device having a long life, excellent light emitting appearance, and high light extraction efficiency can be provided.

DESCRIPTION OF SYMBOLS 1 Organic electroluminescent apparatus 11 Translucent board | substrate 12 Light scattering layer 13 Flat layer 14 Translucent electrode 15 At least 1 organic layer (organic EL layer) containing a light emitting layer
16 Back electrode

Claims (8)

An organic electroluminescence element having a light extraction layer composed of a light scattering layer and a flat layer, wherein the organic electroluminescence element has a light-transmitting substrate, and the area of the light-transmitting substrate is larger than the area of the light-transmitting substrate. A small light scattering layer and a flat layer are patterned in the order of a light scattering layer and a flat layer. The light scattering layer comprises light scattering particles (A) having an average particle diameter of 200 nm to 500 nm, alkali-soluble resin, and photopolymerization. The flat layer is formed of a photosensitive resin composition for a light scattering layer containing an initiator, a photopolymerizable monomer, and a leveling agent. And a photosensitive resin composition for a flat layer containing a leveling agent, and the film thickness of the flat layer is 2 μm or more and 10 μm or less, the bottom of the cross-sectional shape of the flat layer pattern , and the edge Taper angle and the tangent of the di-section is an angle that state, and are less than 50 degrees, the weight content of the photopolymerization initiator quantity in the light scattering layer for the photosensitive resin composition [I] and the photopolymerizable monomer The ratio [I / M] of the content weight [M] is 0.1 or more and 0.5 or less, and the content weight [I] of the photopolymerization initiator amount in the photosensitive resin composition for the flat layer and the photopolymerizable monomer the ratio of the weight content of the dimer [M] [I / M] is an organic electroluminescent device, characterized in der Rukoto 0.5 to 1.5. The refractive index of the light scattering layer and the refractive index of the flat layer are both 1.60 or more, and the absolute value of the difference between the refractive index of the light scattering layer and the refractive index of the flat layer is from 0 to 0.05. The organic electroluminescence element according to claim 1. The organic electroluminescence device according to claim 1 or 2, wherein the photosensitive resin composition for a flat layer contains at least one of an oxime ester photopolymerization initiator and an acetophenone photopolymerization initiator. The photosensitive resin composition for flat layers contains alkali-soluble resin which has alicyclic structure, The organic electroluminescent element of any one of Claims 1-3 characterized by the above-mentioned. The photosensitive resin composition for flat layers contains a fluorine leveling agent, The organic electroluminescent element of any one of Claims 1-4 characterized by the above-mentioned. The surface roughness of the flat layer, claim 1-5 organic electroluminescence device according to any one of the preceding, wherein the at 100Å or less. The refractive index of at least one of the alkali-soluble resin and the photopolymerizable monomer contained in the photosensitive resin composition for light scattering layer and the photosensitive resin composition for flat layer is 1.55 or more. The organic electroluminescent element of any one of Claims 1-6 . Claim 1-7 The organic electroluminescent device having an organic electroluminescent element according to any one.