Curable composition, cured film and method for producing the same, and organic el element

Abstract

The present invention provides a curable composition, a curable film, a method for manufacturing the same, and an organic EL device, wherein a curable film having a wrinkle structure on the film surface can be manufactured by simple operation and with a small amount of exposure. The curable composition contains at least one compound (A) selected from the group consisting of a compound having a (meth)acryloyl group and a (meth)acrylic polymer, a photopolymerization initiator, and an ultraviolet absorber. The curable composition contains 2.5 mass% or more and 20 mass% or less of the photopolymerization initiator and 3 mass% or more and 30 mass% or less of the ultraviolet absorber, based on the total amount of solids of the curable composition. An irregular wrinkle structure is formed on the surface of a cured film obtained by irradiating radiation from above the film formed by coating the curable composition on a substrate and heating it.

Description

Technology Field

[0001] The present invention relates to a curable composition, a curable film and a method for manufacturing the same, and an organic EL device. Background Technology

[0002] Organic electroluminescence devices (organic EL devices) are light-emitting devices having a stacked structure including an anode, an organic light-emitting layer, and a cathode, and are being commercialized for applications such as display devices and lighting devices. Organic EL devices are equipped with insulating cured films, such as planarization films. Planarization films are formed on a substrate for the purpose of flattening the substrate surface by filling in irregularities on the surface of a substrate on which semiconductor devices are formed. In recent years, it has been considered to form planarization films using high-refractive index materials and to improve the brightness of display devices or adjust the viewing angle by combining a high-refractive-index planarization film with a low-refractive-index film.

[0003] In addition, conventionally, to improve the luminous efficiency of an organic EL device, it has been proposed to provide a layer with a refractive index different from that of the electrode on the surface of a substrate (e.g., see Patent Document 1) or to form a lens sheet on top of an organic light-emitting layer (e.g., see Patent Document 2). Furthermore, a display device has been proposed that enables the efficient extraction of light emitted from an organic light-emitting device to the outside of the device by providing a micro-lens on the light-emitting extraction surface side of the organic light-emitting device (e.g., see Patent Document 3).

[0004] Various image sensors, such as CCD (Charge-Coupled Device) image sensors and CMOS (Complementary Metal-Oxide-Semiconductor) image sensors, are used as solid-state imaging elements in imaging devices such as cameras. In solid-state imaging elements, hemispherical condensing lenses (hereinafter also referred to as "micro-lenses") or in-layer lenses are provided to collect light from a light-receiving element (photodiode) and improve sensor sensitivity. Furthermore, in organic EL devices, a structure is adopted in which a micro-lens is provided on the light-emitting side for each pixel for the purpose of improving light extraction efficiency or adjusting the viewing angle (see, for example, Patent Document 4).

[0005] In addition, in recent years, as a technique to increase the extraction efficiency of light emitted from the organic light-emitting layer of an organic EL device and to improve the luminescence efficiency, it has been proposed to use a film having a random wrinkle structure on its surface (see Patent Document 5). Patent Document 5 discloses forming a film having a random wrinkle structure by applying a composition containing a styrene derivative to a substrate and irradiating the applied composition with ultraviolet light. Prior art literature

[0006] Japanese Patent Publication No. 2003-109747, Japanese Patent Publication No. Hei 8-83688, Japanese Patent Publication No. 2012-134128, Japanese Patent Publication No. 2020-101659, U.S. Patent No. 9605347 Specification The problem to be solved

[0007] Cured films having a wrinkled structure have high functionality and are expected to be applied to various uses, including optical components. It is industrially advantageous if such cured films can be produced by a simple process. Furthermore, when applied to organic EL devices, considering the damage to the organic EL device, it is required that the cured film having a wrinkled structure be formed with the smallest possible amount of exposure.

[0008] The present invention has been made in consideration of the above problem, and its main purpose is to provide a curable composition that can produce a curable film having a wrinkled structure on its surface by simple operation and with a small amount of exposure. means of solving the problem

[0009] According to the present invention, the following curable composition, curable film, method for manufacturing the same, and organic EL device are provided.

[0010] [1] A curable composition comprising a compound (A) having a (meth)acryloyl group, a photopolymerization initiator, and an ultraviolet absorber, wherein the photopolymerization initiator is included in an amount of 2.5 mass% or more and 20 mass% or less relative to the total amount of solids of the curable composition, and the ultraviolet absorber is included in an amount of 3 mass% or more and 30 mass% or less relative to the total amount of solids of the curable composition, and an irregular wrinkle structure is expressed on the surface of the cured film obtained by irradiating radiation from above the film formed by applying the curable composition on a substrate and heating.

[0011] [2] A curable composition described in [1] containing a polymer, either as the compound (A) or separately from the compound (A).

[0012] [3] A curable composition described in [2] having a weight average molecular weight of 2,500 or more and 40,000 or less of the polymer.

[0013] [4] A curable composition as described in [2] or [3], wherein the polymer has a carboxyl group.

[0014] [5] A curable composition described in any one of [1] to [4], wherein the compound (A) comprises a nonpolymer having 1 to 6 (meth)acryloyl groups in one molecule.

[0015] [6] A curable composition described in [5] comprising the above compound (A), a nonpolymer having one (meth)acryloyl group in one molecule and a nonpolymer having two to six (meth)acryloyl groups in one molecule.

[0016] [7] 30 mJ / ㎠ A curable composition described in any one of [1] to [6] that partially cures with an exposure amount of 1000 mJ / ㎠ or less.

[0017] [8] A curable composition comprising a polymer, a polymerizable compound (except for the polymer), a photopolymerization initiator, and an ultraviolet absorber, wherein the photopolymerization initiator is included in an amount of 2.5 mass% or more and 20 mass% or less relative to the total amount of solids of the curable composition, and the ultraviolet absorber is included in an amount of 3 mass% or more and 30 mass% or less relative to the total amount of solids of the curable composition, and an irregular wrinkle structure is expressed on the surface of the cured film obtained by irradiating radiation from above and heating the film formed by applying the curable composition on a substrate.

[0018] [9] A curable composition described in any one of [1] to [8] for use with an organic EL device.

[0019]

[10] A cured film formed by a curable composition described in any one of [1] to [8], having an irregular wrinkle structure on the film surface.

[0020]

[11] A method for manufacturing a cured film having an irregular wrinkle structure on the surface of the film, comprising: a forming process in which a curable composition described in any one of [1] to [8] is applied onto a substrate to form a film; an irradiation process in which radiation is irradiated from above onto the film formed on the substrate; and a heating process in which the film is heated after the radiation is irradiated.

[0021]

[12] A method for manufacturing a cured film as described in

[11] , wherein in the above irradiation process, the upper part of the film is cured and the lower part of the film is left uncured, and in the above heating process, the film is heated while the lower part of the film is left uncured.

[0022]

[13] A method for manufacturing a cured film as described in

[11] or

[12] , wherein the heating temperature in the heating process above is 75°C or higher.

[0023]

[14] The amount of exposure in the above irradiation process is 30 mJ / cm² A method for manufacturing a hardened film as described in any one of

[11] to

[13] , having a hardening agent of 1000 mJ / ㎠ or less.

[0024]

[15] A method for manufacturing a curable film as described in any one of

[11] to

[14] , wherein the curable composition is applied onto the substrate by spin coating or slit coating.

[0025]

[16] An organic EL device comprising an organic light-emitting layer and a light extraction layer, wherein the light extraction layer is formed by a curable composition described in any one of [1] to [8] and has an irregular wrinkle structure on the surface of the layer. Effects of the invention

[0026] According to the curable composition of the present invention, a curable film having a wrinkle structure on its surface can be obtained with simple operation and with a small amount of exposure. Brief explanation of the drawing

[0027] Figure 1 is an optical microscope image of the surface of the cured film of Example 13. Specific details for implementing the invention

[0028] The details regarding the embodiments are described in detail below. Additionally, in this specification, a numerical range described using "to" implies that the values ​​described before and after "to" are included as lower and upper limits.

[0029] In this specification, the term "hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group composed solely of a chain structure without including a ring structure. However, the chain hydrocarbon group may be saturated or unsaturated. "Alicyclic hydrocarbon group" refers to a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, the alicyclic hydrocarbon group does not need to be composed solely of an alicyclic hydrocarbon structure and includes having a chain structure in part thereof. "Aromatic hydrocarbon group" refers to a hydrocarbon group that includes an aromatic ring structure as a ring structure. However, the aromatic hydrocarbon group does not need to be composed solely of an aromatic ring structure and may include a chain structure or an alicyclic hydrocarbon structure in part thereof. In addition, the ring structure of the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent containing a hydrocarbon structure. "(Meth)acryl" is a term including "acryl" and "methacryl". "(Meth)acrylo" is a term including "acrylo" and "methacrylo". "(Meth)acrylate" is a term including "acrylate" and "methacrylate".

[0030] Curable composition

[0031] The curable composition of the present disclosure (hereinafter also referred to as the “present composition”) is designed to induce an irregular wrinkle structure on the surface of a cured film obtained by irradiating radiation from above a film formed by applying the curable composition onto a substrate and heating it. The curable composition of the first embodiment of the present disclosure contains a compound having a (meth)acryloyl group, a photopolymerization initiator, and an ultraviolet absorber. Furthermore, the curable composition of the second embodiment of the present disclosure contains a polymer, a polymerizable compound (except for the polymer), a photopolymerization initiator, and an ultraviolet absorber. Below, each component included in the curable composition of each embodiment and the optionally incorporated component will be described in detail. Additionally, unless specifically stated otherwise, each component may be used alone or in combination of two or more types. For convenience, the curable composition of the first embodiment will also be referred to as the “first composition,” and the curable composition of the second embodiment will also be referred to as the “second composition.”

[0032] [First Embodiment]

[0033] <Compounds having (meth)acryloyl groups>

[0034] A compound having a (meth)acryloyl group (hereinafter also referred to as “Compound (A)”) is incorporated into the first composition as a polymerizable compound that undergoes a polymerization reaction upon radiation irradiation. Examples of radiation include ultraviolet rays, far ultraviolet rays, X-rays, charged particle rays, etc.

[0035] Compound (A) may be a polymer or a nonpolymer. Below, the cases where compound (A) is a polymer and where it is a nonpolymer will be explained separately. Also, below, compound (A) as a polymer will be referred to as “polymer (Ac)”, and compound (A) as a nonpolymer will be referred to as “compound (Am)”.

[0036] ·Regarding the polymer (Ac)

[0037] The polymer (Ac) may have (meth)acryloyl groups at the ends of the main chain or in the side chains. It is preferable for the polymer (Ac) to have (meth)acryloyl groups in the side chains, as this allows for a relatively large amount of (meth)acryloyl groups to be introduced, resulting in a composition with excellent curability, and facilitates the formation of wrinkle structures on the surface of the cured film.

[0038] The main backbone of the polymer (Ac) is not particularly limited as long as (meth)acryloyl groups can be introduced. Examples of the main backbone of the polymer (Ac) include a polymer having ethylenically unsaturated monomers as constituent units (hereinafter also referred to as "addition polymer"), novolak resin, phenol-xylylene glycol condensation resin, cresol-xylylene glycol condensation resin, phenol-dicyclopentadiene condensation resin, polyorganosiloxane, polyamide, polyimide, polybenzoxazole, polyurethane, etc. Examples of polymers having ethylenically unsaturated monomers as constituent units include (meth)acrylic monomers, styrene monomers, maleimide monomers, or polymers containing two or more of these monomers as constituent units. In terms of the ease of obtaining a cured film exhibiting a high refractive index, good patterning characteristics and solvent resistance, ease of controlling the amount of (meth)acryloyl group introduction, and good balance of heat resistance, moisture resistance, low expansion, and cost, the polymer (Ac) is preferably at least one type selected from the group consisting of novolak resin and addition polymer.

[0039] The method of introducing a (meth)acryloyl group into a polymer (Ac) is not particularly limited. Examples include a method of polymerizing using a monomer capable of introducing a (meth)acryloyl group into a polymer side chain; a method of obtaining a polymer having a first reactive group, and then reacting the polymer having the first reactive group with a compound having a (meth)acryloyl group and a second reactive group capable of reacting with the first reactive group; etc. In the latter method, as the first reactive group and the second reactive group, examples include an embodiment in which one reactive group is an oxiranyl group and the other reactive group is a carboxyl group, an amino group, a thiol group, or a hydroxyl group.

[0040] In order to easily obtain a cured film having a wrinkled structure on the surface, it is preferable that the polymer (Ac) includes structural units having (meth)acryloyl groups. In the polymer (Ac), the proportion of structural units having (meth)acryloyl groups is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more with respect to the total amount of structural units having the polymer (Ac).

[0041] It is preferable that the polymer (Ac) has carboxyl groups. By using a polymer having carboxyl groups as the polymer (Ac), the solubility of the polymer (Ac) in an alkaline developer can be increased, and it becomes possible to obtain a cured film having a desired pattern shape. Such a cured film is suitable as an optical material (e.g., a high-refractive index material) for display devices such as organic EL devices or micro LED devices, or for imaging devices. From the perspective of improving the resolution of the cured film, it is preferable that the polymer (Ac) includes structural units having carboxyl groups.

[0042] In the polymer (Ac), the proportion of structural units having carboxyl groups is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more with respect to the total amount of structural units having polymer (Ac). The upper limit of the proportion of structural units having carboxyl groups can be appropriately set according to the main framework of the polymer (Ac) and is not particularly limited. The proportion of structural units having carboxyl groups is, for example, 99 mol% or less with respect to the total amount of structural units having polymer (Ac).

[0043] In order to form a cured film exhibiting a high refractive index and to form a fine wrinkle structure on the surface of the cured film, it is preferable that the glass transition temperature (Tg) of the polymer (Ac) be between -50°C and 150°C. From the above perspective, it is more preferable that the glass transition temperature of the polymer (Ac) be 120°C or lower, and even more preferable that it be 100°C or lower. Furthermore, it is more preferable that the glass transition temperature of the polymer (Ac) be -40°C or higher, and even more preferable that it be -30°C or higher. Additionally, in this specification, the glass transition temperature of the polymer is a value measured by a rigid body pendulum test.

[0044] The weight average molecular weight (Mw) of the polymer (Ac) is preferably in the range of 2,500 to 40,000, as wrinkle structures are easily formed on the film surface. In this regard, the Mw of the polymer (Ac) is more preferably 3,000 or higher, and even more preferably 3,200 or higher. Additionally, the Mw of the polymer (A) is more preferably 35,000 or lower, and even more preferably 30,000 or lower.

[0045] In addition, for the polymer (Ac), the molecular weight distribution (Mw / Mn), indicated by the ratio of the weight-average molecular weight to the number-average molecular weight, is preferably 5.0 or less, and more preferably 4.0 or less. In addition, in this specification, the weight-average molecular weight and the number-average molecular weight (Mn) of the polymer are polystyrene equivalent values ​​measured by gel permeation chromatography (GPC).

[0046] In order to form a wrinkled structure having a finer uneven shape on the film surface, the first composition preferably contains a polymer (Ac). The content of the polymer (Ac) is preferably 5 mass% or more, more preferably 10 mass% or more, and even more preferably 15 mass% or more, with respect to the total amount of solids (i.e., components other than the solvent) in the first composition. Additionally, from the viewpoint of making it easier to form a wrinkled structure on the film surface, the content of the polymer (Ac) is preferably 60 mass% or less, more preferably 50 mass% or less, and even more preferably 45 mass% or less, with respect to the total amount of solids in the first composition.

[0047] ·Regarding the compound (Ad)

[0048] Compound (Ad) is a nonpolymer having (meth)acryloyl groups. The molecular weight of compound (Ad) is preferably 600 or less, more preferably 550 or less, even more preferably 500 or less, and particularly preferably 450 or less. Additionally, from the viewpoint of obtaining a cured product with excellent solvent resistance, the molecular weight of compound (Ad) is preferably 100 or more.

[0049] In the compound (Ad), the number of (meth)acryloyl groups per molecule is not particularly limited. The number of (meth)acryloyl groups in the compound (Ad) is preferably 1 to 10, and more preferably 1 to 6, from the perspective of facilitating the formation of a fine uneven wrinkle structure on the film surface and from the perspective of the ease of obtaining the compound (Ad). The compound (Ad) may be either a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, and may include both monofunctional (meth)acrylate and polyfunctional (meth)acrylate. Furthermore, it is preferable that the compound (Ad) does not have a group different from the (meth)acryloyl group (specifically, a vinylphenyl group and an ethynylphenyl group) as a group containing a polymerizable carbon-carbon unsaturated bond.

[0050] Specific examples of cases where the compound (Ad) is a monofunctional (meth)acrylate include (meth)acrylic acid esters having a chain structure, (meth)acrylic acid esters having a ring structure, (meth)acrylic acid esters having an aromatic ring structure, (meth)acrylic acid esters, (meth)acrylamide compounds, etc.

[0051] As a further specific example where the compound (Ad) is a monofunctional (meth)acrylate, examples of (meth)acrylic acid esters containing a chain structure include (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid polyoxyalkylene esters, etc. Examples of (meth)acrylic acid alkyl esters include (meth)acrylic acid methyl, (meth)acrylic acid ethyl, (meth)acrylic acid n-propyl, (meth)acrylic acid isopropyl, (meth)acrylic acid butyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid n-lauryl, (meth)acrylic acid n-stearyl, etc. Examples of (meth)acrylate hydroxyalkyl esters include (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 3-hydroxypropyl, (meth)acrylate 4-hydroxybutyl, etc. Examples of (meth)acrylate alkoxyalkyl esters include (meth)acrylate methoxyethyl, (meth)acrylate ethoxyethyl, (meth)acrylate propoxyethyl, etc. Examples of (meth)acrylic acid polyoxyalkylene esters include (meth)acrylic acid methoxydiethylene glycol, (meth)acrylic acid methoxytetraethylene glycol, (meth)acrylic acid ethoxydiethylene glycol, (meth)acrylic acid methoxydipropylene glycol, (meth)acrylic acid ethoxydipropylene glycol, (meth)acrylic acid 2-ethylhexyloxydiethylene glycol, etc.

[0052] As (meth)acrylic acid esters having a cyclic structure, (meth)acrylic acid cyclohexyl, (meth)acrylic acid 2-methylcyclohexyl, (meth)acrylic acid 4-butylcyclohexyl, (meth)acrylic acid 4-hydroxymethylcyclohexyl, (meth)acrylic acid tricyclo[5.2.1.0 2,6 ]decane-8-yl, (meth)acrylic acid tricyclo[5.2.1.0 2,5Examples include decane-8-yloxyethyl, (meth)acrylate isobornyl, etc. Examples of (meth)acrylic acid esters having an aromatic ring structure include (meth)acrylic acid phenyl, (meth)acrylic acid benzyl, (meth)acrylic acid naphthylmethyl, (meth)acrylic acid naphthylethyl, (meth)acrylic acid phenoxyethyl, (meth)acrylic acid phenylthioethyl, (meth)acrylic acid m-phenoxyphenylmethyl, (meth)acrylic acid p-phenoxyphenylmethyl, (meth)acrylic acid o-phenylphenoxyethyl, (meth)acrylic acid 2-hydroxy-3-phenoxypropyl, (meth)acrylic acid polyethyleneoxynonylphenyl, (meth)acrylic acid (1-naphthyl)methyl, (meth)acrylic acid (2-naphthyl)methyl, (meth)acrylic acid (1,1'-biphenyl-4-yl)methyl, etc. Examples of (meth)acrylamide compounds include (meth)acryloyl morpholine, N-(2-hydroxyethyl)(meth)acrylamide, N-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam, etc.

[0053] Specific examples of cases where the compound (Ad) is a polyfunctional (meth)acrylate include polyfunctional (meth)acrylic acid esters such as difunctional (meth)acrylic acid esters and polyfunctional (meth)acrylic acid esters with three or more functions.

[0054] As further specific examples of polyfunctional (meth)acrylates, difunctional (meth)acrylic acid esters include, for example, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, etc.

[0055] Examples of (meth)acrylic acid esters with three or more functional groups include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, tri(2-(meth)acryloyloxyethyl)phosphate, succinic acid-modified pentaerythritol tri(meth)acrylate, succinic acid-modified dipentaerythritol penta(meth)acrylate, isocyanuric acid tri(2-(meth)acryloyloxyethyl)phosphate, etc. In addition, as a (meth)acrylic acid ester with three or more functions, a polyfunctional urethane acrylate compound obtained by reacting a compound having a straight-chain alkylene group and an alicyclic structure and also having two or more isocyanate groups with a compound having one or more hydroxyl groups in the molecule and also having three, four, or five (meth)acryloyloxy groups may be used. As for the polyfunctional (meth)acrylate, a compound having three or more (meth)acryloyl groups in one molecule may be preferably used, and a compound having three to ten groups may be more preferably used.

[0056] Preferred specific examples of the compound (Ad) include compounds represented by each of the following formulas (C1-1) to (C1-42).

[0057]

[0058]

[0059]

[0060] (Among Equations (C1-1) to (C1-42), R 20 is a hydrogen atom or a methyl group. In the formula, R 20 If this plural exists, the plural R 20☐ is identical or different. m and n are independent integers from 0 to 6. x, y, and z are independent integers from 0 to 3, provided that 1 ≤ x + y + z ≤ 3.

[0061] In order to obtain a composition with excellent curability and to easily obtain a cured film having a wrinkle structure on the film surface, it is preferable that the first composition contains a compound (Ad). In the first composition, the content of the compound (Ad) is preferably 10 mass% or more, more preferably 30 mass% or more, and even more preferably 50 mass% or more, based on the total amount of solids included in the first composition. Furthermore, the content of the compound (Ad) is preferably 90 mass% or less, more preferably 85 mass% or less, and even more preferably 80 mass% or less, based on the total amount of solids included in the first composition. By setting the content of the compound (Ad) to the above range, it is possible to obtain a cured film having a fine wrinkle structure on the film surface while having a composition that exhibits good curability.

[0062] In order to accelerate the curing reaction on the upper part of the film when radiation is irradiated from above the film formed by the curable composition, and to facilitate the formation of a wrinkle structure on the film surface by subsequent heat treatment, the first composition preferably contains a nonpolymer having 2 to 6 (meth)acryloyl groups in one molecule (hereinafter also referred to as "compound (B)"). In addition, in order to form a wrinkle structure having an irregular shape of finer irregularity on the surface of the cured film, the first composition preferably contains a nonpolymer having 1 (meth)acryloyl group in one molecule (hereinafter also referred to as "compound (C)") and compound (B).

[0063] In order to achieve a high refractive index of the cured film formed by the first composition, the first composition preferably contains a monofunctional (meth)acrylate having a ring structure as the compound (C). In particular, it is preferable to contain at least one selected from the group consisting of monofunctional (meth)acrylic acid esters having an alicyclic structure and monofunctional (meth)acrylic acid esters having an aromatic ring structure.

[0064] In the first composition, the content of compound (B) is preferably 5 mass% or more with respect to the total amount of solids included in the first composition, more preferably 10 mass% or more, and even more preferably 20 mass% or more. Additionally, the content of compound (B) is preferably 90 mass% or less with respect to the total amount of solids included in the first composition, more preferably 85 mass% or less, and even more preferably 80 mass% or less.

[0065] In addition, the content of compound (C) is preferably 1 mass% or more with respect to the total amount of solids included in the first composition, more preferably 2 mass% or more, and even more preferably 5 mass% or more. In addition, the content of compound (C) is preferably 80 mass% or less with respect to the total amount of solids included in the first composition, and more preferably 70 mass% or less.

[0066] Compound (A) incorporated into the first composition is preferably composed of compound (B) in that it facilitates the formation of a wrinkle structure on the membrane surface, and is more preferably composed of polymer (Ac) and compound (B). Furthermore, it is even more preferable to include polymer (Ac), compound (B), and compound (C) in that it enables the formation of a wrinkle structure with a finer uneven shape on the membrane surface.

[0067] Photopolymerization Initiator

[0068] As a photopolymerization initiator, a photoradical generator capable of generating radicals in response to radiation and initiating polymerization may be preferably used. The photoradical generator used is not particularly limited. Examples of photoradical generators include O-acyloxime compounds, acetophenone compounds, nonimidazole compounds, and acylphosphine oxide compounds.

[0069] As O-acyloxime compounds, for example, 1,2-octanedion-1-[4-(phenylthio)-2-(O-benzoyloxime)], ethano-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), 1-(9-ethyl-6-benzoyl-9H-carbazole-3-yl)-octane-1-onoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethane-1-onoxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazole-3-yl]-ethane-1-onoxime-O-benzoate, Ethanol-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), Ethanol-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), Ethanol-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), Ethanol-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolalanyl)methoxybenzoyl}-9H-carbazole-3-yl]-1-(O-acetyloxime), Examples include 3-cyclohexyl-1-(6-(2-(benzoylyoxyimino)octanoyl)-9-ethyl-9H-carbazole-3-yl)-propane-1,2-dione-2-(O-benzoylyoxime).

[0070] Examples of acetophenone compounds include α-aminoketone compounds and α-hydroxyketone compounds. Specific examples of these include α-aminoketone compounds such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholine-4-yl-phenyl)-butan-1-one, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one. Examples of α-hydroxyketone compounds include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenylketone, etc.

[0071] Examples of nonimidazole compounds include 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, etc.

[0072] Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.

[0073] The content of the photopolymerization initiator in the first composition is 2.5 to 20 mass% relative to the total amount of solids included in the first composition. If the content of the photopolymerization initiator is less than 2.5 mass%, when radiation is irradiated from above the coating film formed by the curable composition, the curing reaction at the top of the coating film does not proceed sufficiently, and as a result, there is a tendency not to obtain a cured film having a wrinkle structure on the surface of the film. Furthermore, if the content of the photopolymerization initiator exceeds 20 mass%, when radiation is irradiated from above the coating film formed by the curable composition, the curing reaction proceeds to the core of the coating film, and in this case as well, there is a tendency not to obtain a cured film having a wrinkle structure on the surface of the film. In order to obtain a cured film having a wrinkle structure on the surface of the film, the content of the photopolymerization initiator is preferably 3 mass% or more, more preferably 4 mass% or more, and even more preferably 5 mass% or more relative to the total amount of solids of the first composition. In addition, the content of the photopolymerization initiator is preferably 18 mass% or less with respect to the total amount of solids of the first composition, and more preferably 16 mass% or less.

[0074] The content of the photopolymerization initiator is preferably 1 part by mass or more and 2 parts by mass or more per 100 parts by mass of compound (A). In addition, the content of the photopolymerization initiator is preferably 50 parts by mass or less and 40 parts by mass or less per 100 parts by mass of compound (A).

[0075] UV absorber

[0076] As an ultraviolet absorber, a material capable of absorbing ultraviolet rays (preferably ultraviolet rays of 290 nm to 400 nm) may be preferably used. Specific examples of ultraviolet absorbers include azomethine compounds, indole compounds, triazine compounds, benzotriazole compounds, melocyanine compounds, oxazole compounds, naphthylimide compounds, oxadiazole compounds, oxazine compounds, oxazolidine compounds, anthracene compounds, benzophenone compounds, cyanoacrylate compounds, etc.

[0077] Specific examples of ultraviolet absorbers include, for example, triazine-based compounds such as 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)phenol, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-butyloxyphenyl)-6-(2,4-bis-butyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyroxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, etc.;

[0078] As benzotriazole compounds, 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-tert-octylphenol], 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, etc.;

[0079] Examples of benzophenone compounds include 4,4'-bis(diethylamino)benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, etc.

[0080] In addition, specific examples of commercially available UV absorbers include, for instance, AdekaStab LA-24, LA-29, LA-31, LA-32, LA-36, LA-46, LA-F70, and 1413 (all manufactured by ADEKA), Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 329, Tinuvin 360, Tinuvin 1577 ED, Tinuvin 1600, Chimassorb 81, Tinuvin PS, Tinuvin 99-2, Tinuvin 384-2, Tinuvin 900, Tinuvin 928, Tinuvin 1130, Tinuvin 970, Tinuvin 400, Tinuvin 405, Tinuvin 460, Tinuvin 477, Tinuvin 479, and Tinuvin B Examples include 75, UVA-903KT, UVA-935LH, UVA-805 (all manufactured by BASF Japan); OUV-004, OUV-006, OUV-012, OUV-014, OUV-015, OUV-018 (all manufactured by Fujifilm Wako Junyaku); etc.

[0081] The content of the ultraviolet absorber in the first composition is 3 to 30 mass% relative to the total amount of solids included in the first composition. If the content of the ultraviolet absorber is less than 3 mass%, when radiation is irradiated from above the coating film formed by the curable composition, the curing reaction at the upper part of the coating film does not proceed sufficiently, and there is a tendency not to form a wrinkle structure on the surface of the cured film. Furthermore, if the content of the ultraviolet absorber exceeds 30 mass%, the curing reaction proceeds to the core of the coating film upon radiation irradiation, and in this case, there is also a tendency not to form a wrinkle structure on the surface of the cured film. To obtain a cured film having a wrinkle structure on its surface, the content of the ultraviolet absorber is preferably 4 mass% or more relative to the total amount of solids of the first composition, and more preferably 5 mass% or more. Additionally, the content of the ultraviolet absorber is preferably 25 mass% or less relative to the total amount of solids of the first composition, and more preferably 20 mass% or less.

[0082] Other ingredients

[0083] The first composition may further contain, in addition to the above-described compound (A), photopolymerization initiator, and ultraviolet absorber, a component different from the compound (A), photopolymerization initiator, and ultraviolet absorber (hereinafter also referred to as "other component"). Examples of other components include a polymer not having (meth)acryloyl groups (hereinafter also referred to as "other polymer"), a surfactant, a solvent, etc.

[0084] · Other polymers

[0085] Other polymers do not need to have (meth)acryloyl groups, and their main framework is not particularly limited. Specific examples of the main framework of other polymers include a main framework similar to that exemplified as the main framework of polymer (Ac). Among these, at least one type selected from the group consisting of addition polymers, novolak resins, polyamides, polyimides, polybenzoxazoles, and polyurethanes may be preferably used.

[0086] From the perspective of improving the patternability of the first composition, it is preferable that the other polymer has a carboxyl group. From the perspective of improving the resolution of the cured film obtained using the first composition, it is preferable that the other polymer includes a structural unit having a carboxyl group. When the other polymer includes a structural unit having a carboxyl group, the proportion of the structural unit having a carboxyl group is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more with respect to the total amount of the structural unit having the other polymer. In addition, in the other polymer, the proportion of the structural unit having a carboxyl group is, for example, 99 mol% or less with respect to the total amount of the structural unit having the other polymer.

[0087] It is preferable that the glass transition temperature (Tg) of the other polymer be between -50°C and 150°C. In order to form a cured film exhibiting a high refractive index while forming a fine wrinkle structure on the surface of the cured film, it is more preferable that the glass transition temperature of the other polymer be 120°C or lower, and even more preferable that it be 100°C or lower. Furthermore, it is more preferable that the glass transition temperature of the other polymer be -40°C or higher, and even more preferable that it be -30°C or higher.

[0088] The weight-average molecular weight (Mw) of the other polymer is preferably in the range of 2,500 to 40,000, as wrinkle structures are prone to forming on the film surface. In this regard, the Mw of the other polymer is more preferably 3,000 or higher, and even more preferably 3,200 or higher. Additionally, the Mw of the other polymer is more preferably 35,000 or lower, and even more preferably 30,000 or lower. The molecular weight distribution (Mw / Mn) of the other polymer is preferably 5.0 or lower, and even more preferably 4.0 or lower.

[0089] When other polymers are included in the first composition, the content of other polymers is preferably 2 mass% or more, more preferably 5 mass% or more, and even more preferably 10 mass% or more, based on the total amount of solids included in the first composition. In addition, the content of other polymers is preferably 70 mass% or less, more preferably 60 mass% or less, and even more preferably 50 mass% or less, based on the total amount of solids included in the first composition.

[0090] In order to obtain a cured film having a wrinkle structure on its surface with a finer uneven shape, it is preferable that the first composition contains a polymer. The first composition may contain a polymer as compound (A), or may contain a polymer separately from compound (A). That is, the polymer contained in the first composition may be polymer (Ac), other polymers, or both polymer (Ac) and other polymers.

[0091] When the first composition contains a polymer, the polymer content is preferably 2 mass% or more, more preferably 5 mass% or more, and even more preferably 10 mass% or more, with respect to the total amount of solids included in the first composition. In addition, the polymer content is preferably 70 mass% or less, more preferably 60 mass% or less, and even more preferably 50 mass% or less, with respect to the total amount of solids included in the first composition.

[0092] · Surfactants

[0093] A surfactant may be used to further improve the applicability of the first composition (specifically, to reduce smudging or uneven application). Examples of surfactants include fluorine-based surfactants (including fluorine-containing nonionic surfactants), silicone-based surfactants, and nonionic surfactants.

[0094] Specific examples of surfactants include fluorine-based surfactants, hereinafter referred to by trade names, such as Megapak F-171, F-172, F-173, F-251, F-430, F-554, F-563 (manufactured by DIC); Fluorad FC430, FC431 (manufactured by Sumitomo 3M); Asahi Guard AG710, Suplon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106, S-611 (manufactured by AGC Seimi Chemical); Polyflow No. 75, No. 95 (manufactured by Kyoesha Chemical); FTX-218 (manufactured by Neos); Examples include F-Top EF301, EF303, and EF352 (manufactured by Shin-Akita Kasei Co., Ltd.).

[0095] Examples of silicone-based surfactants include, from the following product names: SH200-100cs, SH28PA, SH30PA, SH89PA, SH190, SH8400, SH193, SZ6032, SF8428, DC57, DC190, PAINTAD19, FZ-2101, FZ-77, FZ-2118, L-7001, L-7002 (manufactured by Toray Dow Corning); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); BYK-300, BYK-306, BYK-310, BYK-330, BYK-335, BYK-341, BYK-344, BYK-370, BYK-340, BYK-345 (manufactured by Big Chem Japan).

[0096] Examples of nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, etc.

[0097] When a surfactant is incorporated into the first composition, the content of the surfactant is preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the total amount of polymerizable compounds included in the first composition, more preferably 0.02 to 2 parts by mass, and even more preferably 0.1 to 1.0 parts by mass.

[0098] ·solvent

[0099] A solvent may be added to the first composition for purposes such as dissolving each component incorporated into the first composition. As the solvent used, an organic solvent that can dissolve or disperse each component incorporated into the first composition and does not react with each component may be preferably used. Specifically, examples include alcohols, ketones, esters, ethers, aromatic hydrocarbons, and amides.

[0100] Specific examples of these include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and methyl-3-methoxypropionate. Examples of ethers include polyoxyethylene lauryl ether, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, and diethylene glycol methyl ethyl ether. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of amides include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.

[0101] Other components, in addition to the above, may include, for example, sensitizers, softeners, plasticizers, adhesion aids, etc. The content of these components in the first composition is appropriately selected according to each component within a range that does not impair the effects of the present disclosure.

[0102] When a substance having fluorine atoms (hereinafter also referred to as a "fluorine-containing component") is contained in the first composition, it may interfere with the formation of a wrinkle structure. Therefore, it is desirable that the content of the fluorine-containing component in the first composition be as low as possible. Specifically, the content of the fluorine-containing component in the first composition is preferably 10 mass% or less with respect to the total amount of solids included in the first composition, more preferably 5 mass% or less, even more preferably 1 mass% or less, and even more preferably 0.5 mass% or less.

[0103] The solid content concentration of the first composition (i.e., the ratio of the total mass of components other than the solvent in the curable composition to the total mass of the curable composition) is appropriately selected considering viscosity, volatility, etc. The solid content concentration of the first composition is preferably in the range of 3 to 60 mass%. If the solid content concentration is 3 mass% or more, when the first composition is applied to a substrate, a sufficient film thickness of the coating film can be secured, and a wrinkle structure can be easily formed on the film surface. In addition, if the solid content concentration is 60 mass% or less, the film thickness of the coating film does not become excessively thick, and the viscosity of the first composition can be appropriately increased, thereby securing good coating properties. The solid content concentration in the first composition is more preferably 5 to 55 mass%, and even more preferably 10 to 50 mass%.

[0104] The first composition can be prepared by mixing a compound (A), a photopolymerization initiator and an ultraviolet absorber, and other components that are formulated as needed. The composition obtained by mixing each component may be filtered, for example, through a filter with a hole diameter of 0.5 μm or less.

[0105] The first composition obtained in this manner can form an irregular wrinkle structure on the surface by partially curing it with a relatively small amount of exposure and then performing a heat treatment, which offers significant process advantages. Specifically, it is preferable to partially cure the first composition with an exposure amount of 30 to 1000 mJ / cm², and more preferable to partially cure it with an exposure amount of 30 to 500 mJ / cm². Furthermore, "partial curing" as used herein refers to a condition where, when radiation is irradiated from above onto a coating film formed from the first composition, the upper part of the coating film is cured while the lower part of the coating film remains uncured. The upper part of the coating film refers, for example, to a depth of about 5 μm from the surface of the coating film.

[0106] [Second Embodiment]

[0107] The curable composition of the second embodiment (the second composition) contains a polymer, a polymerizable compound (except for the polymer), a photopolymerization initiator, and an ultraviolet absorber.

[0108] Polymer

[0109] The main framework of the polymer is not particularly limited. Specific examples of the main framework of the polymer include a main framework similar to that exemplified as the main framework of the polymer (Ac). Among these, at least one polymer selected from the group consisting of addition polymers, novolak resins, polyamides, polyimides, polybenzoxazoles, and polyurethanes may be preferably used. Specific examples of the polymer incorporated in this embodiment include the polymer (Ac) exemplified in the description of the first embodiment and other polymers.

[0110] In terms of imparting good patternability to the cured film formed by the second composition, it is preferable for the polymer to have carboxyl groups, and more preferable for it to include structural units having carboxyl groups. In the polymer, the proportion of structural units having carboxyl groups is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more with respect to the total amount of structural units having polymer. In addition, the proportion of structural units having carboxyl groups in the polymer is, for example, 99 mol% or less with respect to the total amount of structural units having polymer.

[0111] The glass transition temperature (Tg) of the polymer is preferably between -50°C and 150°C. In order to form a cured film exhibiting a high refractive index while forming a fine wrinkle structure on the surface of the cured film, the glass transition temperature of the polymer is more preferably 120°C or lower, and even more preferably 100°C or lower. Furthermore, the glass transition temperature of the polymer is more preferably -40°C or higher, and even more preferably -30°C or higher.

[0112] The weight-average molecular weight (Mw) of the polymer is preferably in the range of 2,500 to 40,000, as wrinkle structures are prone to forming on the film surface. In this regard, the Mw of the polymer is more preferably 3,000 or higher, and even more preferably 3,200 or higher. Additionally, the Mw of the polymer is more preferably 35,000 or lower, and even more preferably 30,000 or lower. The molecular weight distribution (Mw / Mn) of the polymer is preferably 5.0 or lower, and even more preferably 4.0 or lower.

[0113] In the second composition, the polymer content is preferably 2 mass% or more, more preferably 5 mass% or more, and even more preferably 10 mass% or more, based on the total amount of solids included in the second composition. Additionally, the polymer content is preferably 70 mass% or less, more preferably 60 mass% or less, and even more preferably 50 mass% or less, based on the total amount of solids included in the second composition.

[0114] Polymerizable Compounds

[0115] The polymerizable compound included in the second composition is a nonpolymer and may be a monofunctional compound having one polymerizable group in one molecule, or a polyfunctional compound having two or more polymerizable groups. Examples of polymerizable groups include ethylenically unsaturated groups, oxiranyl groups, oxetanyl groups, N-alkoxymethylamino groups, etc. Among these, ethylenically unsaturated groups are preferred due to their high polymerization, and vinyl group-containing groups such as (meth)acryloyl groups, vinyl groups, and vinylphenyl groups are preferred. The number of polymerizable groups in one molecule of the polymerizable compound is preferably 1 to 10, and more preferably 1 to 6.

[0116] In order to obtain a curable composition in which an irregular wrinkle structure is easily formed on the surface of a film, it is preferable that the second composition contains a polyfunctional compound having 2 to 6 polymerizable groups in one molecule. In addition, in order to form a wrinkle structure having a finer irregular shape on the surface of the cured film, it is preferable that the second composition contains a monofunctional compound having 1 polymerizable group in one molecule and a polyfunctional compound having 2 to 6 polymerizable groups in one molecule.

[0117] In the second composition, the preferred range of the content of a polyfunctional compound having 2 to 6 polymerizable groups per molecule is the same as the description of compound (B) in the first composition. In addition, in the second composition, the preferred range of the content of a monofunctional compound having 1 polymerizable group per molecule is the same as the description of compound (C) in the first composition.

[0118] <Photopolymerization initiator, UV absorber>

[0119] Specific examples and preferred examples of the photopolymerization initiator and ultraviolet absorber included in the second composition, and their contents, may be described by reference in the first embodiment.

[0120] The second composition may contain additional components different from the polymer, polymerizable compound, photopolymerization initiator, and ultraviolet absorber. Examples of such components include surfactants and solvents. Specific examples of these components include compounds similar to those exemplified in the description of the first composition. Furthermore, regarding details such as the solid content concentration and physical properties of the second composition, the description of the first composition may be referenced.

[0121] Cured film and method of manufacturing the same

[0122] The cured film of the present disclosure (hereinafter also referred to as the “present cured film”) is formed by the curable composition prepared as described above and has an irregular wrinkle structure on the film surface. Here, “irregular wrinkle structure” refers to a case where no clear regularity is observed in the wrinkles, such as when the wrinkles formed on the film surface are curved or the length of the wrinkles is random. It is preferable that the present cured film has periodic wrinkles on the film surface in which concave and convex portions appear repeatedly. The present cured film can be manufactured by a method comprising the following forming process, irradiation process, and heating process using the present composition.

[0123] Formation process: A process of forming a film by applying the composition onto a substrate.

[0124] Irradiation process: A process of irradiating a film formed on a substrate with radiation from above.

[0125] Heating process: A process of heating the film after irradiation.

[0126] Below, each process in the method for manufacturing the cured film is described.

[0127] Formation Process

[0128] In the forming process, a coating film is formed on a substrate by applying the present composition onto the substrate. Examples of substrates include glass substrates, silicon wafers, plastic substrates, plastic films, and substrates having a coloring resist, overcoat, anti-reflective film, various metal thin films, sealing films, etc. formed on their surfaces. Examples of plastic substrates and plastic films include resin substrates and films comprising plastics such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethersulfone, polycarbonate, and polyimide. Various elements (e.g., light-receiving elements such as photodiodes or light-emitting elements such as organic light-emitting diodes) may be pre-installed on these substrates.

[0129] As a method for applying the present composition, suitable methods such as spraying, roll coating, spin coating, slit die coating, bar coating, and inkjet coating may be employed. It is preferable to apply the present composition onto a substrate by spin coating or slit coating, as this allows the cured film to be formed with simpler operation.

[0130] After applying the composition onto a substrate, a preheating treatment (pre-baking) of the composition may be performed for purposes such as preventing dripping. The conditions for pre-baking can be appropriately set according to the type or usage ratio of each component. For example, the conditions for pre-baking can be set to 60 to 100°C for 30 seconds to 10 minutes. The pre-baking temperature is preferably 60 to 90°C from the perspective of making the cured film applicable as a component of an organic EL device. The film thickness of the formed coating is preferably 0.1 to 20 μm, and more preferably 0.5 to 15 μm.

[0131] <Investigation Process>

[0132] In the irradiation process, radiation is irradiated from above onto the film formed on the substrate by the formation process. By doing so, a curing reaction can be carried out in the exposed portion of the film.

[0133] Examples of radiation irradiated onto the coating film include ultraviolet rays, far-ultraviolet rays, X-rays, and charged particle beams. Examples of ultraviolet rays include g-rays (wavelength 436 nm), i-rays (wavelength 365 nm), and KrF excimer laser light (wavelength 248 nm). Examples of X-rays include synchrotron radiation. Examples of charged particle beams include electron beams. Among these, ultraviolet rays are preferred for the radiation irradiated onto the coating film, and ultraviolet rays with a wavelength of 200 to 380 nm are more preferred. Examples of light sources used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, UV-LED lamps, xenon lamps, and excimer lasers.

[0134] In this irradiation process, it is desirable to adjust the exposure amount so that a portion of the film formed on the substrate is cured when viewed in the depth direction. More specifically, in the irradiation process, radiation is applied so that the upper part of the film formed on the substrate is cured and the lower part remains uncured. In the method for manufacturing the cured film, it is believed that by heating the film in this partially uncured state in the subsequent heating process, the upper part of the film where the curing reaction has proceeded shrinks, and an irregular wrinkle structure can be formed on the film surface. From the perspective of obtaining a film in a partially uncured state after exposure treatment of the film, the radiation exposure amount to the film on the substrate is preferably 30 to 1000 mJ / cm², and more preferably 30 to 500 mJ / cm². Furthermore, from the perspective of suppressing the occurrence of non-uniformity of the wrinkle structure on the film surface, it is desirable to irradiate from a direction perpendicular to the substrate surface.

[0135] Heating Process

[0136] In the heating process, the film is heated after exposure by the irradiation process. This allows for the appearance of an irregular wrinkle structure on the film surface. Additionally, this heat treatment promotes the curing of uncured areas, thereby obtaining a cured film exhibiting good heat resistance and chemical resistance. The heat treatment can be performed using a heating device, such as an oven or a hot plate.

[0137] In the heating process, the heating temperature is preferably 60°C or higher, more preferably 75°C or higher, and even more preferably 80°C or higher, from the perspective of promoting the curing reaction of the uncured portion to obtain a cured film with high heat resistance and chemical resistance, and from the perspective of softening the film to facilitate the formation of a wrinkle structure due to shrinkage. Additionally, the heating temperature is preferably 250°C or lower, and more preferably 230°C or lower. When applied to organic EL devices, the heating temperature is preferably 100°C or lower, more preferably 95°C or lower, and even more preferably 90°C or lower. The heating time can be appropriately set depending on the type of heating device, etc. For example, when heating is performed by a hot plate, the heating time is, for example, 5 to 60 minutes. Also, when heating is performed by an oven, the heating time is, for example, 10 to 90 minutes. In the heating process, a step bake method in which multiple heating treatments are performed may be used.

[0138] Other Processes

[0139] The present composition may be used as a negative-type pattern-forming material in which a pattern is formed by exposing a film to light through a mask during an irradiation process and dissolving the unexposed portion in an alkaline developer. In this case, it is preferable to further include the development process described below.

[0140] ·Development process

[0141] In the development process, a pattern is formed on a substrate by developing a coating film irradiated with radiation by an irradiation process. Through this development process, unexposed portions of the coating film formed on the substrate are removed, thereby forming a pattern including exposed portions on the substrate.

[0142] As a developer, examples include aqueous solutions of alkali (basic compounds) such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane, etc. Additionally, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to an aqueous alkali solution, or by adding a small amount of various organic solvents capable of dissolving the present composition, may be used as a developer.

[0143] As a development method, appropriate methods such as the liquid pooling method, dipping method, shaking immersion method, and shower method may be employed. The development time can be appropriately adjusted according to the composition of the present composition. The development time is, for example, 20 seconds to 120 seconds.

[0144] · Post-exposure process

[0145] The present manufacturing method may additionally include, as an optional process, a process of irradiating radiation onto a cured film before or after heating by a heating process (hereinafter also referred to as a "post-exposure process"). By irradiating radiation in the post-exposure process (hereinafter also referred to as "post-exposure"), the heat resistance and chemical resistance of the cured film can be further improved, and reliability can be further enhanced. Regarding the type of radiation and exposure conditions in post-exposure, conditions similar to those of the irradiation process may be adopted. Furthermore, conditions such as the wavelength of the irradiated light, the irradiation dose, and the light source during post-exposure may be the same as or different from those of the irradiation process.

[0146] The cured film obtained using the present composition preferably has fine wrinkles (wrinkles) on the film surface formed by a periodic uneven shape as a wrinkle structure. From the perspective of obtaining a cured film exhibiting a high refractive index, the width of the wrinkles on the film surface is preferably 120 μm or less, and more preferably 70 μm or less. Here, the width of the wrinkles is a value indicated by the average value of the width of the concave portions in the uneven shape of the film surface, measured at a total of 5 points by observing the film from above using an optical microscope.

[0147] In addition, to obtain a cured film having a wrinkled structure on the film surface using the present composition, this can be done by, for example, adjusting at least one of the amount of photopolymerization initiator, the amount of ultraviolet absorber, and the amount and type of crosslinking agent in the composition, or by changing curing conditions such as the amount of exposure and at least one of the heating temperature after exposure.

[0148] <Physical properties of the hardened film>

[0149] · Glass transition temperature

[0150] It is preferable that the glass transition temperature (Tg) of the cured film obtained using the present composition be 30°C or higher and 150°C or lower. If the Tg of the cured film is within the above range, it is suitable in that the cured film has appropriate hardness and a wrinkle structure is easily formed on the film surface. The Tg of the cured film obtained from the present composition is more preferably 35°C or higher, and even more preferably 40°C or higher. Furthermore, the Tg of the cured film obtained from the present composition is more preferably 145°C or lower, and even more preferably 140°C or lower. Additionally, in this specification, the glass transition temperature of the cured film is a value measured by a rigid body pendulum test.

[0151] · Refractive index

[0152] The cured film formed by the present composition exhibits a high refractive index in that it contains a relatively large amount of a polymerization initiator and an ultraviolet absorber. Specifically, by applying and curing the present composition onto a substrate, a cured film having a refractive index of 1.5 or higher at a wavelength of 550 nm can be obtained. It is preferable that the refractive index of the cured film formed using the present composition at a wavelength of 550 nm be 1.5 to 1.7.

[0153] Use of Curable Compositions and Curable Films, and Organic EL Devices

[0154] The present cured film having an irregular wrinkle structure on the film surface is suitable as a material for forming optical members for display devices or imaging devices, such as organic EL devices or micro LED devices.

[0155] When an optical member for an organic EL device is formed by the present composition, the optical member is suitable as a light path adjusting member for adjusting the path of light emitted from an organic light-emitting layer. An organic EL device is a device capable of extracting energy as light, which is obtained by recombining holes and electrons in the organic light-emitting layer, for example, between a pair of electrodes, a cathode and an anode, when a voltage is applied between the electrodes, holes from the anode and electrons from the cathode are injected into the organic light-emitting layer. Since the refractive index of the material used in the organic light-emitting layer is relatively high and the difference in refractive index with adjacent layers is large, the generated light undergoes total internal reflection at the interface with the substrate and is trapped within the organic light-emitting layer, resulting in a decrease in luminous efficiency. Generally, in organic electroluminescent devices, it is known that among the light generated within the organic light-emitting layer, about 20% of the light can be emitted outside the device, about 30% of the light reaches the substrate but cannot be emitted from the substrate, and about 50% of the light cannot reach the substrate and is trapped in the organic light-emitting layer or electrodes.

[0156] As a method for improving the luminous efficiency of an organic EL device, there is a method of improving the light extraction efficiency by scattering light by providing a layer with a refractive index different from that of the electrode (hereinafter also referred to as "this refractive index layer") on the surface of a substrate or by forming a lens-shaped cured material (micro lens) on top of an organic light-emitting layer. According to the present composition, a cured film exhibiting a high refractive index can be obtained by having an uneven shape on the film surface, and thus the cured film obtained by the present composition can be used as a substitute for the aforementioned this refractive index layer or micro lens.

[0157] In addition, a layer for improving the light extraction efficiency of the device (hereinafter also referred to as a "light extraction layer") can be formed by the present composition. The light extraction layer is being considered as an optical component for various device devices having an organic EL device or an LED device, specifically for lighting or displays (organic EL displays, quantum dot displays, liquid crystal displays, etc.). For example, in the case of an organic EL device, the light extraction layer is provided in a location even closer to a sealing layer adjacent to an organic light-emitting layer.

[0158] In that low-temperature curing also enables the formation of a high-refractive-index cured film through simple operation, the present composition is suitable as a material for forming a light extraction layer of an organic EL device (particularly for lighting or displays). That is, according to the present disclosure, an organic EL device having an organic light-emitting layer and a light extraction layer, wherein the light extraction layer is formed by the present composition and has an irregular wrinkle structure on the surface of the layer, and an organic EL device having said organic EL device can be obtained. Furthermore, said organic EL device is useful as an organic EL lighting device or an organic EL display device.

[0159] When an optical member for a display element is formed by the present composition, the optical member can be used as a light path adjusting member for adjusting the path of light emitted from a light-emitting diode. In addition, when an optical member for a solid-state imaging element is formed by the present composition, the optical member is suitable as a light path adjusting member for adjusting the path of light to concentrate it on a light-receiving element (photodiode) equipped with an imaging device such as a camera.

[0160] Examples

[0161] The present invention will be described in more detail below in the examples, but the present invention is not limited to the following examples. Furthermore, "parts" and "%" in the examples and comparative examples are based on mass unless otherwise specified. In the present example, the weight-average molecular weight (Mw), number-average molecular weight (Mn), non-volatile content, and acid value of the polymer were measured by the following methods.

[0162] [Weight Average Molecular Weight (Mw) and Number Average Molecular Weight (Mn)]

[0163] The Mw and Mn of the polymer are polystyrene equivalent values ​​measured by the following methods and conditions.

[0164] · Measurement method: Gel permeation chromatography (GPC) method

[0165] · Device: GPC-101 manufactured by Showa Denko Co., Ltd.

[0166] · GPC Column: Combining GPC-KF-801, GPC-KF-802, GPC-KF-803, and GPC-KF-804 manufactured by Shimadzu GLC Corp.

[0167] · Mobile phase: Tetrahydrofuran

[0168] · Column temperature: 40℃

[0169] · Flow rate: 1.0 mL / min

[0170] · Sample concentration: 1.0 mass%

[0171] · Sample injection volume: 100μL

[0172] · Detector: Parallax Refractometer

[0173] · Standard material: Monodisperse polystyrene

[0174] [Non-volatile]

[0175] 1 g of polymer solution was accurately weighed, transferred to an aluminum dish that had been pre-adjusted to a constant weight state, and heated on a hot plate at 180°C for 1 hour. After cooling to room temperature, the container was weighed again, and the mass after drying was recorded. The non-volatile content (%) was calculated from the mass change before and after drying using the following formula.

[0176] Non-volatile content (%) = (Mass after drying / Mass of sample before drying) × 100

[0177] [Measurement of Acid Value]

[0178] 1 g of the sample (polymer) was dissolved in a titration solvent mixed with xylene and dimethylformamide (volume ratio 1:1). It was titrated with a 0.1 mol / L potassium hydroxide-ethanol solution by potentiometric titration. The inflection point on the titration curve was set as the endpoint, and the acid value was calculated from the titration volume of the potassium hydroxide solution up to the endpoint. The acid value was calculated by substituting each obtained measurement value into the following formula.

[0179] A=(BC)×f×D / S

[0180] A: Acid value (mgKOH / g)

[0181] B: Amount of potassium hydroxide solution added in this test (mL)

[0182] C: Amount of potassium hydroxide solution added in a blank test (measurement without using a sample) (mL)

[0183] f: Factor of potassium hydroxide solution

[0184] D: Concentration converted value 5.611 mg / mL

[0185] (0.1 mol / LKOH equivalent of 1 mL of potassium hydroxide)

[0186] S: Sample (g)

[0187] 1. Synthesis of Polymers

[0188] [Synthesization Example 1: Synthesis of Polymer (A1)]

[0189] 220 parts of cresol novolak-type epoxy resin (manufactured by DIC Co., Ltd., trade name: Epiclone N-695, epoxy equivalent: 220) were placed in a 4-neck flask equipped with a stirrer and a reflux condenser, and 214 parts of diethylene glycol monoethyl ether acetate were added and heated to melt. Subsequently, 0.1 parts of hydroquinone as a polymerization inhibitor and 2.0 parts of dimethylbenzylamine as a reaction catalyst were added. This mixture was heated to 95 to 105°C, 72 parts of acrylic acid were slowly added dropwise, and the reaction was carried out for 16 hours. The reaction product was cooled to 80 to 90°C, 106 parts of 1,2,3,4-tetrahydrophthalic anhydride were added, and the reaction was carried out for 8 hours. After cooling, the mixture was removed to obtain polymer (A1). The polymer (A1) had a non-volatile content of 65 mass%, an acid value of 85 mgKOH / g of solids, and a weight average molecular weight Mw of about 3,500.

[0190]

[0191] [Synthesization Example 2: Synthesis of Polymer (A2)]

[0192] 15 parts of 2,2'-azobis(2-methylpropionic acid)dimethyl and 200 parts of diethylene glycol ethylmethyl ether were added to a reaction apparatus equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen inlet. Subsequently, 35 parts of benzyl methacrylate, 15 parts of styrene, 25 parts of phenylmaleimide, 10 parts of glycerin monomethacrylate, and 15 parts of methacrylic acid were added, and nitrogen was applied. While gently stirring the solution in the flask, the temperature of the solution was raised to 80°C and maintained at this temperature for 5 hours to obtain a polymer solution containing polymer (A2). The solid content of this polymer solution was 34.5 mass%, the Mw of polymer (A2) was 11,000, and the molecular weight distribution (Mw / Mn) was 2.2.

[0193] 2. Preparation and Evaluation of Curable Compositions

[0194] The abbreviations of the raw materials used in the preparation of the curable composition are as follows.

[0195] <(Met)Acrylic Compounds>

[0196] · Polymer (A)

[0197] A1, A2: Polymers obtained by Synthesis Examples 1 and 2 above

[0198] · Polyfunctional (meth)acrylates

[0199] B1: Dipentaerythritol penta / hexaacrylate (product name "Aronix M-400", manufactured by Doa Gose Co.)

[0200] B2: Trimethylolpropane polypropylene glycol triacrylate (product name "Aronics M-321", manufactured by Doa Gose Co.)

[0201] B3: Trimethylolpropane triacrylate

[0202] · Monofunctional (meth)acrylate

[0203] C1: Benzyl acrylate

[0204] Polymerization Initiator

[0205] D1: Product name "Irgacure OXE02", manufactured by BASF

[0206] D2: Product name "Irgacure OXE01", manufactured by BASF

[0207] UV absorber

[0208] E1: 4,4'-Bis(diethylamino)benzophenone

[0209] E2: Product name "Tinuvin PS", manufactured by BASF

[0210] E3: Product name "OUV-015", Fujifilm Wako Junyakusai

[0211] Others

[0212] F1: Tetraethyleneglycolbis(4-ethynyl-2,3,5,6-tetrafluorophenyl)ether

[0213] Compound (F1) was synthesized with reference to U.S. Patent No. 9605347 and Finely Formed, Kinetically Modulated Wrinkle Structures in UV-Crosslinkable Liquid Prepolymers (Volume 36 Issue 22 Macromolecular Rapid Communications pages:2019-2019).

[0214] [Example 1]

[0215] (1) Preparation of a curable composition

[0216] 71 parts by mass of polyfunctional (meth)acrylate (B1), 14 parts by mass of polymerization initiator (D1), 14 parts by mass of ultraviolet absorber (E1), and 0.2 parts by mass of surfactant (NEOS "FTX-218") were mixed, and propylene glycol monomethyl ether acetate (PGMEA) was added to make the solid content concentration 30% by mass, and then the components were dissolved by stirring. Subsequently, the resulting mixture was filtered through a membrane filter with a pore diameter of 0.2 μm to prepare a curable composition.

[0217] (2) Evaluation of wrinkle formation

[0218] On an alkali-free glass substrate, the curable composition prepared in (1) above was applied using a spinner, and then pre-baked on a hot plate at 85°C for 2 minutes to form a film with a thickness of 6 μm. Subsequently, the obtained film was irradiated from above with an exposure amount of 200 mJ / cm² using a UV-LED lamp (illumination at 365 nm: approximately 150 mW / cm²). Subsequently, a cured film was formed by post-baking in an oven at 85°C for 60 minutes. The obtained cured film was observed with an optical microscope, and the presence or absence of wrinkles on the film surface and the condition of the wrinkles were evaluated. The evaluation of the wrinkle condition was performed using an indicator of whether the wrinkles were irregular or periodic, with concave and convex parts appearing repeatedly. Specifically, if no clear regularity was observed in the wrinkles, such as when the wrinkles were curved or the length of the wrinkles was random, it was determined to be irregular wrinkles. In addition, when the wrinkles were periodic, the concave portion of the wrinkles and the width of the concave portion were determined by the average value of a total of 5 measurements. The evaluation was performed according to the following criteria. As a result, this example received a good (○) evaluation.

[0219] ◎ (Excellent): Periodic and irregular wrinkles are formed, and the wrinkle period is 70㎛ or less

[0220] ○ (Good): Periodic and irregular wrinkles are formed, and the wrinkle period exceeds 70㎛.

[0221] × (Defective): No wrinkles

[0222] [Examples 2 to 19, Comparative Examples 1 to 3]

[0223] A curable composition was prepared in the same manner as in Example 1, except that the type and amount of raw materials were changed as described in Table 1. In addition, a curable film was formed using each curable composition, and the presence or absence of wrinkles on the film surface and the condition of the wrinkles were evaluated according to the same criteria as in Example 1. When forming the curable film, the procedure was carried out in the same manner as in Example 1, except that the film thickness, exposure amount, and post-bake temperature were changed as shown in Table 1. The evaluation results are shown in Table 1.

[0224]

[0225] As shown in Table 1, according to the curable compositions of Examples 1 to 19, a cured film having an irregular fine wrinkle structure on the film surface could be obtained. In addition, all of the cured films formed by the curable compositions of Examples 1 to 19 had a periodic wrinkle structure on the film surface. In contrast, when the curable compositions of Comparative Examples 1 to 3 were used, no wrinkle structure was formed on the film surface.

[0226] In addition, as Reference Example 1, a curable composition having the same composition as Comparative Example 3 was used to manufacture a cured film by changing the exposure amount from 100 mJ / cm² to 4000 mJ / cm², and a cured film having a wrinkle structure was obtained. In this regard, the curable composition of Comparative Example 3 requires a large amount of exposure to the film to form a wrinkle structure, so it can be said that productivity is low.

[0227] [Evaluation of Effects Based on Wrinkle Structure]

[0228] A curable composition of Example 13 was applied using a spinner onto an alkali-free glass substrate having an ITO film, and then pre-baked on a hot plate at 85°C for 2 minutes to form a film with a thickness of 6 μm. Subsequently, the obtained film was irradiated from above using a UV-LED lamp (illumination at 365 nm: approximately 150 mW / cm²) at an exposure amount of 200 mJ / cm². Subsequently, a cured film having a periodic and irregular fine wrinkle structure on the film surface was formed by post-baking in an oven at 85°C for 60 minutes (see FIG. 1).

[0229] A glass substrate with a hardened film formed thereon was installed on a white backlight illumination device, and the light from the backlight transmitted through the wrinkle structure was measured at an inclination of 60 degrees to calculate the relative luminance. In addition, as a comparison subject, a sample was prepared in which a hardened film was formed on a glass substrate by the same procedure except that no post-baking was performed, and the relative luminance was measured in the same manner. In this comparison sample, no wrinkles were formed on the film surface. When comparing the relative luminances of both, the relative luminance of the sample with the wrinkle structure was 108 compared to the relative luminance of 100 of the comparison sample.

[0230] For the curable compositions of Examples 1 to 12 and 14 to 19, the effect of the wrinkle structure was evaluated in the same way as the curable composition of Example 13, and, in the same way as Example 13, the relative brightness was high compared to the sample of comparison.

Claims

Claim 1 A curable composition comprising a compound (A) having a (meth)acryloyl group, a photopolymerization initiator, and an ultraviolet absorber, wherein the photopolymerization initiator is included in an amount of 2.5 mass% or more and 20 mass% or less relative to the total amount of solids of the curable composition, and the ultraviolet absorber is included in an amount of 3 mass% or more and 30 mass% or less relative to the total amount of solids of the curable composition, and an irregular wrinkle structure is expressed on the surface of a cured film obtained by irradiating radiation from above a film formed by applying the curable composition on a substrate and heating. Claim 2 A curable composition according to claim 1, containing a polymer as the compound (A) or separately from the compound (A). Claim 3 A curable composition according to paragraph 2, wherein the weight average molecular weight of the polymer is 2,500 or more and 40,000 or less. Claim 4 In paragraph 2, a curable composition in which the polymer has a carboxyl group. Claim 5 A curable composition according to claim 1, wherein the compound (A) comprises a nonpolymer having 1 to 6 (meth)acryloyl groups in one molecule. Claim 6 A curable composition according to claim 5, wherein the compound (A) comprises a nonpolymer having one (meth)acryloyl group in one molecule and a nonpolymer having two to six (meth)acryloyl groups in one molecule. Claim 7 In paragraph 1, 30 mJ / ㎠ A curable composition that partially cures with an exposure amount of 1000 mJ / ㎠ or less. Claim 8 A curable composition comprising a polymer, a polymerizable compound (excluding the polymer), a photopolymerization initiator, and an ultraviolet absorber, wherein the photopolymerization initiator is included in an amount of 2.5 mass% or more and 20 mass% or less relative to the total amount of solids of the curable composition, and the ultraviolet absorber is included in an amount of 3 mass% or more and 30 mass% or less relative to the total amount of solids of the curable composition, and an irregular wrinkle structure is expressed on the surface of a cured film obtained by irradiating radiation from above a film formed by applying the curable composition on a substrate and heating. Claim 9 A curable composition for an organic EL device, in any one of claims 1 to 8. Claim 10 A cured film formed by a curable composition described in any one of claims 1 to 8, having an irregular wrinkle structure on the film surface. Claim 11 A method for manufacturing a cured film having an irregular wrinkle structure on the surface of the film, comprising: a forming process in which a curable composition described in any one of claims 1 to 8 is applied onto a substrate to form a film; an irradiation process in which radiation is irradiated from above onto the film formed on the substrate; and a heating process in which the film is heated after the radiation is irradiated. Claim 12 A method for manufacturing a cured film according to claim 11, wherein in the above irradiation process, the radiation is irradiated so that the upper part of the film is cured and the lower part of the film remains uncured, and in the above heating process, the film is heated while the lower part of the film remains uncured. Claim 13 A method for manufacturing a cured film according to claim 11, wherein the heating temperature in the heating process is 75°C or higher. Claim 14 In Clause 11, the exposure amount in the above irradiation process is 30 mJ / cm² A method for manufacturing a hardened film having a hardness of at least 1000 mJ / ㎠ and less than or equal to 1000 mJ / ㎠. Claim 15 A method for manufacturing a curable film according to claim 11, wherein the curable composition is applied onto the substrate by spin coating or slit coating. Claim 16 An organic EL device comprising an organic light-emitting layer and a light extraction layer, wherein the light extraction layer is formed by a curable composition described in any one of claims 1 to 8 and has an irregular wrinkle structure on the surface of the layer.

Images