Radiation-sensitive composition, cured product, display element, image sensor, and method for manufacturing the cured product

Abstract

The present invention aims to provide a radiation-sensitive composition capable of forming a cured product with excellent bending resistance at low temperatures, a cured product formed from the radiation-sensitive composition, a method for producing the same, a display element equipped with the cured product, and an image sensor equipped with the cured product. [Solution] The present invention relates to a radiation-sensitive composition for forming optical components, comprising metal oxide particles (A), a polyfunctional polymerizable compound (B) having at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group, and a photoinitiator (E), wherein the viscosity at 25°C is 50 cP or less.

Description

[Technical Field]

[0001] The present invention relates to a radiation-sensitive composition, a cured product, a display element, an image sensor, and a method for manufacturing the cured product. [Background technology]

[0002] Various image sensors, such as CCD (Charge-Coupled Device) image sensors and CMOS (Complementary Metal-Oxide-Semiconductor) image sensors, are used as solid-state image elements in imaging devices such as cameras. Solid-state image elements are equipped with hemispherical focusing lenses (hereinafter also called "microlenses") or intralayer lenses to concentrate light onto the photodiode and improve sensor sensitivity. In addition, in display elements such as organic EL elements, a structure is adopted in which microlenses are provided on the light-emitting side of each pixel for the purpose of improving light extraction efficiency and adjusting the viewing angle. In recent years, lenses for solid-state image elements and organic EL elements have been formed using photolithography technology with radiation-sensitive compositions.

[0003] High refractive index is required for cured materials used in solid-state image sensors and display elements to improve light extraction efficiency. Methods for producing high refractive index cured materials include using a photocurable liquid composition containing metal oxide nanoparticles (see, for example, Patent Document 1) and using a photopolymerizable composition containing a high refractive index monomer, one or more highly flexible monomers, and a photopolymerization initiator (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2022 / 181562 [Patent Document 2] Japanese Patent Publication No. 2023-553373 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, the above-mentioned cured material has been required to be crack-free even when bent at low temperatures (e.g., -20°C) (low-temperature bending resistance).

[0006] Accordingly, the present invention aims to provide a radiation-sensitive composition capable of forming a cured product with excellent bending resistance at low temperatures, a cured product formed from the radiation-sensitive composition and a method for producing the same, a display element equipped with the cured product, and an image sensor equipped with the cured product. [Means for solving the problem]

[0007] The present inventors, after diligent research to solve the above problem, have found that the above objective can be achieved by providing a radiation-sensitive composition comprising metal oxide particles (A), a specific polyfunctional polymerizable compound (B), and a photoinitiator (E), and having a specific viscosity, and have completed the present invention.

[0008] In one embodiment, the present invention is Metal oxide particles (A) and, A polyfunctional polymerizable compound (B) having at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group, It contains a photoinitiator (E), The viscosity at 25°C is 50 cP or less. This invention relates to a radiation-sensitive composition for forming optical components.

[0009] In another embodiment, the present invention is The present invention relates to a cured product obtained by curing the above-mentioned radiation-sensitive composition, a display element equipped with the cured product, and an image sensor.

[0010] In another embodiment, the present invention is The process involves applying the above-mentioned radiation-sensitive composition onto a substrate, A step of irradiating the radiation-sensitive composition applied on the above-mentioned substrate with radiation, It relates to a method for producing a cured product containing .

Effects of the Invention

[0011] The radiation-sensitive composition of the present invention contains metal oxide particles, and contains a polyfunctional polymerizable compound (B) having at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group, and by having a specific viscosity, it can form a cured product excellent in flex resistance at low temperatures.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0013] Hereinafter, matters related to the embodiments will be described in detail. In this specification, a numerical range described using "~" means including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0014] In this specification, "hydrocarbon group" includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Linear hydrocarbon group" means a linear hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure in its main chain and consists only of a linear structure. However, linear hydrocarbon groups may be saturated or unsaturated. "Alicyclic hydrocarbon group" means a hydrocarbon group that contains only the structure of an alicyclic hydrocarbon as its ring structure and does not contain an aromatic ring structure. However, an alicyclic hydrocarbon group does not have to consist only of the structure of an alicyclic hydrocarbon; it may also include a linear structure as part of it. "Aromatic hydrocarbon group" means a hydrocarbon group that contains an aromatic ring structure as its ring structure. However, an aromatic hydrocarbon group does not have to consist only of an aromatic ring structure; it may also include a linear structure or an alicyclic hydrocarbon structure as part of it. The ring structure of an alicyclic hydrocarbon group or an aromatic hydrocarbon group may have substituents consisting of hydrocarbon structures.

[0015] In this specification, "(meth)acryloyl" encompasses "acryloyl" and "methacryloyl," and "(meth)acrylic" encompasses "acrylic" and "methacrylic." "(meth)acrylate" encompasses "acrylate" and "methacrylate."

[0016] ≪Radiation-sensitive composition≫ The radiation-sensitive composition according to this embodiment (hereinafter also simply referred to as "this composition") comprises metal oxide particles (A), a polyfunctional polymerizable compound (B) having at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group, and a photoinitiator (E), and has a viscosity of 50 cP or less at 25°C. This composition can suppress ink clogging even when inkjet coating is performed and is suitable for inkjet coating.

[0017] The above-described radiation-sensitive composition is a radiation-sensitive composition for forming optical components for display elements such as organic EL elements and image sensors. Optical components formed with this composition can, for example, improve the light extraction efficiency in display elements or improve sensor sensitivity by focusing light on a photodiode in a solid-state imaging device. Preferably, the optical component is a pattern formed by repeatedly aligning planarization films or lenses. The shape of the lenses constituting the pattern can be hemispherical, cylindrical, or frustoconical. The shape of the lens as viewed from the top surface can be circular or polygonal, and each may have a curved surface such as a sphere, or a trapezoidal shape such as a columnar or frustoconical. The lenses are formed with the radiation-sensitive composition of the present invention, and other transparent material layers such as a low-refractive index layer may be formed in the gaps between the lenses. The planarization film is formed on a substrate to planarize the surface of a substrate on which semiconductor elements or the like are formed. A pattern is a minute light-collecting element (lens or trapezoidal / rectangular pattern) or interlayer lens provided on a display element or solid-state image sensor (e.g., CCD image sensor, CMOS image sensor). In display elements such as organic EL elements, patterns are provided on each pixel to improve the light extraction efficiency and adjust the viewing angle, while in solid-state image sensors, they are provided to concentrate light on the light-receiving element to improve sensor sensitivity.

[0018] The viscosity of this composition at 25°C is 50 cP or less, preferably 40 cP or less, more preferably 30 cP or less, and even more preferably 28 cP or less. The lower limit of viscosity at 25°C is not particularly limited, but when applied by inkjet, it is preferably 5 cP, and when applied by slit coating, it is preferably 1 cP, and more preferably 3 cP. Having the above viscosity, this composition has good coatability by inkjet, slit coating, etc. In particular, when applied by inkjet, it can exhibit excellent inkjet coatability without ink clogging of the nozzles.

[0019] From the viewpoint of coatability, the surface tension of this composition at 25°C is preferably 30 mN / m or less, more preferably 28 mN / m or less, and even more preferably 27 mN / m or less. The lower limit of the surface tension at 25°C is not particularly limited, but is 20 mN / m.

[0020] The following describes each component contained in the above-mentioned radiation-sensitive composition.

[0021] <Metal oxide particles (A)> The metal oxide particles (A) used in the present invention include, for example, zirconium oxide (ZrO2), titanium oxide (TiO2), silicon oxide (SiO2) (including silica and hollow silica), aluminum oxide (Al2O3), iron oxide (Fe2O3, FeO, Fe3O4), copper oxide (CuO, Cu2O), zinc oxide (ZnO), yttrium oxide (Y2O3), niobium oxide (Nb2O5), molybdenum oxide (MoO3), Examples include indium oxide (In2O3, In2O), tin oxide (SnO2), tantalum oxide (Ta2O5), tungsten oxide (WO3, W2O5), lead oxide (PbO, PbO2), bismuth oxide (Bi2O3), cerium oxide (CeO2, Ce2O3), antimony oxide (Sb2O5, Sb2O5), germanium oxide (GeO2, GeO), and barium titanate (BaTiO3).

[0022] The metal oxide particles (A) described above are preferably zirconium oxide, titanium oxide, zinc oxide, and barium titanate (BaTiO3) from the viewpoint of ease of availability, ease of adjusting optical properties such as refractive index, and particle stability, with zirconium oxide being particularly preferred due to its high dispersion stability. The metal oxide particles (A) described above may be used alone or as a mixture of two or more types.

[0023] The shape of the metal oxide particles (A) is not particularly limited, but examples include spherical, granular, plate-like, columnar, etc.

[0024] The average particle diameter of the metal oxide particles (A) is not particularly limited, but from the viewpoint of obtaining a cured product with high surface flatness and transparency, it is preferably 100 nm or less, more preferably 50 nm or less, and even more preferably 35 nm or less. Furthermore, from the viewpoint of dispersion stability, the average particle diameter of the metal oxide particles (A) is, for example, 1 nm or more, and preferably 2 nm or more. In this invention, the average particle diameter refers to the D50 particle diameter (median diameter, which is the particle diameter that shows the 50% integrated value of the integrated distribution curve) measured by dynamic light scattering, and can be measured, for example, using MicrotracWaveII-EX150 manufactured by MicrotracBell.

[0025] The metal oxide particles (A) may be manufactured by a top-down method or a bottom-up method. Furthermore, the metal oxide particles (A) may be manufactured in the gas phase or in the liquid phase.

[0026] Commercially available metal oxide particles (A) can be used. Specifically, examples include "UEP-100" (manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd.), "PCS" (manufactured by Shin-Nippon Denko Co., Ltd.), and ST-485SA15 (manufactured by Titanium Industry Co., Ltd.).

[0027] The above metal oxide particles (A) may be metal oxide particles coated with a compound having an acidic group or a silane coupling agent, but from the viewpoint of the refractive index of the cured product, uncoated metal oxide particles are preferred. The particles are surface-treated with a coating agent-particle composite containing a compound having an acidic group (hereinafter also referred to as "specific coating agent") (T1) or a surface coating agent containing a silane coupling agent (T2).

[0028] The above surface coating agent (T1) is not particularly limited as long as it contains a compound having an acidic group (specific coating agent). Examples of acidic groups in the specific coating agent include carboxyl groups, phenolic hydroxyl groups, sulfo groups, phosphoric acid groups, and phosphonic acid groups. From the viewpoint of improving particle dispersibility and alkali developability in the medium, carboxyl groups or phenolic hydroxyl groups are preferred among these, and carboxyl groups are particularly preferred. In terms of excellent alkali developability and the ability to suppress development residue, and in the case of inkjet printing, it is preferable to use metal oxide particles selected from the group consisting of zirconium oxide, titanium oxide, barium titanate, and silica, and whose surfaces are coated with a carboxyl group-containing compound, and it is preferable to use zirconium oxide particles whose surfaces are coated with a carboxyl group-containing compound.

[0029] The specific coating agent may be a low-molecular-weight compound (i.e., a compound without a molecular weight distribution) or a polymer. The specific coating agent preferably contains a carboxyl group-containing compound, and more preferably contains a monocarboxylic acid or a carboxyl group-containing polymer as the carboxyl group-containing compound.

[0030] Examples of monocarboxylic acids used as specific coating agents include compounds represented by the following formula (1). R 1 -COOH (1) (In formula (1), R 1 This refers to a monovalent hydrocarbon group or halogenated hydrocarbon group having 4 or more carbon atoms, or a monovalent group having one or more atoms selected from the group consisting of oxygen, sulfur, and nitrogen atoms.

[0031] In the above equation (1), R 1 Examples of monovalent hydrocarbon groups with 4 or more carbon atoms represented by include chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. 1When the monovalent hydrocarbon group represented by is a chain hydrocarbon group or an alicyclic hydrocarbon group, it may be either saturated or unsaturated. When it is a chain hydrocarbon group, it may be either linear or branched. R 1 The monovalent hydrocarbon group represented by is preferably a chain hydrocarbon group among these, and more preferably an alkyl group or an alkenyl group. R 1 The number of carbon atoms of is preferably 6 or more, more preferably 7 or more, from the viewpoint of enhancing the dispersibility of the coated metal oxide particles. Also, from the viewpoint of ease of production of the coated metal oxide particles, the number of carbon atoms of R 1 is preferably 30 or less, more preferably 20 or less. R 1 When is a monovalent halogenated hydrocarbon group having 4 or more carbon atoms, the halogen atoms possessed by R 1 include a fluorine atom, a chlorine atom, and the like.

[0032] R 1 When is a monovalent group having one or more selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom, examples of the monovalent group include a group containing one or more selected from the group consisting of -O-, -S-, and -NH- between carbon-carbon bonds in the hydrocarbon group, and a group in which any hydrogen atom possessed by the hydrocarbon group is substituted with one or more selected from the group consisting of a hydroxyl group, a thiol group, and an amino group. Among these, a group containing -O- between carbon-carbon bonds in the hydrocarbon group is preferable. R 1 When is a monovalent group having one or more selected from the group consisting of an oxygen atom, a sulfur atom, and a nitrogen atom, the number of carbon atoms of R 1 is preferably 2 or more, more preferably 2 to 15, and even more preferably 2 to 8, from the viewpoint of enhancing the dispersibility of the coated metal oxide particles.

[0033] Specific examples of the compound represented by the above formula (1) include R 1Examples of monocarboxylic acids in which the hydrocarbon group is monovalent include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, stearic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, neodecanoic acid, 2-hexyldecanoic acid, naphthenic acid, cyclohexanecarboxylic acid, oleic acid, linoleic acid, and linolenic acid.

[0034] R 1 Examples of monocarboxylic acids in which the monovalent group has one or more atoms selected from the group consisting of oxygen, sulfur, and nitrogen atoms include methoxyacetic acid, ethoxyacetic acid, 3-ethoxypropionic acid, 2-methoxyethoxyacetic acid, glyoxylic acid, pyruvate, hydroxybenzoic acid, thioglycolic acid, 2-[2-(2-methoxyethoxy)]ethoxyacetic acid, oxovaleric acid, asparagine, glutamine, methionine, glycolic acid, lactic acid, 2-hydroxyisobutyric acid, hydroxystearic acid, salicylic acid, and the like.

[0035] As the carboxyl group-containing polymer, a polymer containing structural units having a carboxyl group can be preferably used.

[0036] As the surface coating agent (T1), compounds other than those having an acidic group (specific coating agent) (hereinafter also referred to as "other coating agents") may be used in combination with the specific coating agent. Examples of other coating agents include titanium alkoxides, alkoxysilyl group-containing compounds, and unsaturated carbon-carbon bond-containing compounds. Specific examples of these include titanium alkoxides such as titanium tetra-n-butoxide, titanium tetra-t-butoxide, and titanium tetraethoxide. Examples of alkoxysilyl group-containing compounds include vinyltrimethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane. Examples of unsaturated carbon-carbon bond-containing compounds include silane compounds having carbon-carbon unsaturated bonds, which were exemplified as alkoxysilyl group-containing compounds.

[0037] When other coating agents are used in the production of coated metal oxide particles, the proportion of the other coating agent used is, for example, 50% by mass or less, preferably 40% by mass or less, relative to the total amount of surface coating agent used in the production of metal oxide particles.

[0038] The above-mentioned surface coating agent (T2) is not particularly limited, as long as it contains a silane coupling agent.

[0039] Examples of the silane coupling agent mentioned above include: (meth)acryloxysilanes such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxyoctyltrimethoxysilane; Epoxysilanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxyoctyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, dimethylvinylmethoxysilane, vinyltrichlorosilane, dimethylvinylchlorosilane, and 7-octenyltrimethoxysilane; Aminosilanes such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-8-aminooctyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane; Quaternary ammonium salts such as the hydrochloride of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane; p-Styryltrimethoxysilane; Phenylentrimethoxysilane; Hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, trifluoropropyltrimethoxysilane; Mercaptosilanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane; 3-Trimethoxysilylpropyl succinic anhydride; Butadiene polymer-modified silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: X-12-1267B-ES); Benzotriazole group-containing silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: X-12-1214A); Examples include:

[0040] These silane coupling agents may be used individually or in combination of two or more.

[0041] The method for producing coated metal oxide particles is not particularly limited, and they can be produced by contacting core metal oxide particles (particles to be treated) with a surface coating agent (T1) or (T2). In this case, for example, it is preferable to contact the particles to be treated and the surface coating agent in the presence of water. Alternatively, the particles may be obtained by mixing the particles to be treated and the surface coating agent in an organic solvent, preferably in the presence of a dispersant, and then stirring with beads. The temperature and pressure when contacting the particles to be treated and the surface coating agent can be appropriately set according to the production method adopted. When contacting the particles to be treated and the surface coating agent, the ratio of particles to be treated and the surface coating agent can be, for example, 0.5 to 100 parts by mass of surface coating agent per 100 parts by mass of particles to be treated, and preferably 10 to 60 parts by mass of surface coating agent per 100 parts by mass of particles to be treated.

[0042] This composition may contain one or more of the above-mentioned metal oxide particles (A).

[0043] From the viewpoint of achieving a high refractive index in the resulting cured product, the lower limit of the metal oxide particle (A) content in this composition (total content if multiple types are included) is preferably 20% by mass, more preferably 25% by mass, and even more preferably 30% by mass, relative to the total amount of solids (i.e., components other than the solvent) contained in this composition. Furthermore, from the viewpoint of ensuring inkjet coating properties, the upper limit of the metal oxide particle (A) content is preferably 70% by mass, and more preferably 60% by mass, relative to the total amount of solids contained in this composition.

[0044] <Polyfunctional polymerizable compound (B)> The polyfunctional polymerizable compound (B) has at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group.

[0045] Examples of the linear alkanediyl groups having 7 or more carbon atoms mentioned above include heptanediyl group, octanediyl group, nonanediyl group, decanediyl group, undecanediyl group, dodecanediyl group, tridecanediyl group, tetradecanediyl group, pentadecanediyl group, hexadecanediyl group, heptadecanediyl group, octadecanediyl group, nonadecanediyl group, eicosanediyl group, and the like.

[0046] Examples of the polyalkylene oxide group include polyethylene oxide (EO) groups, polypropylene oxide (PO) groups, polybutylene oxide groups, and other alkylene groups having 2 to 4 carbon atoms, or combinations thereof. Among these, polyethylene oxide groups and polypropylene oxide groups are preferred, and polyethylene oxide groups are more preferred. The number of repeating alkylene oxide groups in the polyalkylene oxide group is usually 1 to 300.

[0047] Examples of the above-mentioned alkanetriyl groups having 5 or more carbon atoms include pentanetriyl, hexanetriyl, heptanetriyl, octanetriyl, nonanetriyl, and the alkanetriyl group represented by the following formula (b).

[0048] [ka] (In formula (b), R 2 This is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. a, b, and c are each independent integers between 1 and 10. * represents a bonding operation.

[0049] The above R 2 As the hydrocarbon group having 1 to 10 carbon atoms in R, the monovalent hydrocarbon group having 1 to 20 carbon atoms, as described in formula (2) below, can preferably be selected from those with the corresponding number of carbon atoms. Among these, R 2 An ethyl group is preferred as the component.

[0050] The above a, b, and c are each independent integers from 1 to 10, preferably from 1 to 5, more preferably 1 or 2, and even more preferably 1.

[0051] As the polyfunctional polymerizable compound (B) mentioned above, compounds having two or more radical polymerizable groups can be preferably used, and examples include polyfunctional (meth)acryloyl group-containing compounds and polyfunctional chain-like vinyl compounds.

[0052] Specific examples of the polyfunctional (meth)acryloyl group-containing compounds mentioned above include difunctional (meth)acrylic acid esters and trifunctional or more (meth)acrylic acid esters. Examples of these difunctional (meth)acrylic acid esters include 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate.

[0053] Examples of (meth)acrylic acid esters with three or more functionalities include trimethylolpropane tri(meth)acrylate, trimethylolpropane EO-modified tri(meth)acrylate, and trimethylolpropane PO-modified tri(meth)acrylate.

[0054] Examples of the above-mentioned polyfunctional chain vinyl compounds include 1,12-tridecadiene and 1,13-tetradecadiene.

[0055] Further specific examples of polyfunctional polymerizable compounds (B) include compounds represented by formulas (b-1) to (b-7) below.

[0056] [ka] (In formulas (b-1) to (b-7), R 20 This is either a hydrogen atom or a methyl group. m and n are independent integers between 0 and 10. x, y, and z are each independent integers between 0 and 3, satisfying the condition 1 ≤ x + y + z ≤ 3.

[0057] As for the polyfunctional polymerizable compound (B), from the viewpoint of achieving a high refractive index and transparency, it is preferable to include a compound containing a (meth)acryloyl group among the above. Furthermore, from the viewpoint of bending resistance at low temperatures, a compound that is trifunctional or more and has an ethylene oxide chain or a propylene oxide chain is preferred, and from the viewpoint of balancing bending resistance at low temperatures and inkjet coating properties, a bifunctional (meth)acrylic acid ester having a linear alkanediyl group with 7 or more carbon atoms is more preferred.

[0058] This composition may contain one or more of the above-mentioned polyfunctional polymerizable compounds (B).

[0059] From the viewpoint of bending resistance, the content of the above-mentioned polyfunctional polymerizable compound (B) is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 30% by mass or less, and even more preferably 15% by mass or more and 28% by mass or less, of the total polymerizable compounds in the composition.

[0060] From the viewpoint of bending resistance, the lower limit of the content of polyfunctional polymerizable compound (B) in this composition (total content if multiple types are included) is preferably 5% by mass, more preferably 8% by mass, and even more preferably 10% by mass, based on the total amount of solids (i.e., components other than solvents) contained in this composition. Furthermore, the upper limit of the content of polyfunctional polymerizable compound (B) is preferably 50% by mass, more preferably 40% by mass, based on the total amount of solids contained in this composition.

[0061] <Polymerizable compound containing a phosphate group (C)> From the viewpoint of adhesion and resistance to bending at low temperatures, it is preferable that this composition contains a polymerizable compound (C) that contains a phosphate group.

[0062] Examples of polymerizable compounds (C) containing a phosphate group include (meth)acrylate phosphoric acid.

[0063] Examples of the above-mentioned phosphoric acid (meth)acrylate include compounds represented by the following formula (2).

[0064] [ka] (In formula (2), R 11 This is either a hydrogen atom or a methyl group. R 12 It is a divalent organic group. t is an integer between 1 and 6. u is either 1 or 2.

[0065] The above R 12 Examples of divalent organic groups in this context include groups obtained by removing one hydrogen atom from a monovalent organic group.

[0066] Examples of the monovalent organic groups mentioned above include monovalent hydrocarbon groups having 1 to 20 carbon atoms, groups having a divalent heteroatom-containing group between carbon atoms or at the end of the carbon chain of the hydrocarbon group, groups in which some or all of the hydrogen atoms of the hydrocarbon group are replaced with a monovalent heteroatom-containing group, or combinations thereof.

[0067] Examples of the above-mentioned monovalent hydrocarbon groups having 1 to 20 carbon atoms include chain hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

[0068] Examples of monovalent linear hydrocarbon groups having 1 to 20 carbon atoms include monovalent linear or branched saturated hydrocarbon groups having 1 to 20 carbon atoms, or monovalent linear or branched unsaturated hydrocarbon groups having 2 to 20 carbon atoms. Examples of monovalent linear or branched saturated hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, 2-methylpropyl, 1-methylpropyl, t-butyl, n-pentyl, isopentyl, and neopentyl groups. Examples of monovalent linear or branched unsaturated hydrocarbon groups having 2 to 20 carbon atoms include alkenyl groups such as ethenyl, propenyl, and butenyl groups; and alkynyl groups such as ethynyl, propynyl, and butynyl groups.

[0069] Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic or polycyclic saturated hydrocarbon groups, or monocyclic or polycyclic unsaturated hydrocarbon groups. Examples of monocyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic saturated hydrocarbon groups include bridged alicyclic hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups. Examples of monocyclic unsaturated hydrocarbon groups include monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl groups. Examples of polycyclic unsaturated hydrocarbon groups include polycyclic cycloalkenyl groups such as norborneyl, tricyclodecenyl, and tetracyclododecenyl groups. A bridged alicyclic hydrocarbon group is a polycyclic alicyclic hydrocarbon group in which two carbon atoms that are not adjacent to each other are bonded together by a linking group containing one or more carbon atoms.

[0070] Examples of the above-mentioned monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xyl, naphthyl, and anthyl groups; and aralkyl groups such as benzyl, phenethyl, and naphthylmethyl groups.

[0071] Examples of the monovalent heteroatom-containing groups mentioned above include hydroxyl groups, carboxyl groups, sulfanyl groups, cyano groups, nitro groups, halogen atoms, and the like.

[0072] Examples of the above-mentioned divalent heteroatom-containing groups include -CO-, -C(=O)O-, -CS-, -NR'-, -O-, -S-, -SO-, -SO2-, or combinations thereof. R' is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0073] Among these, the above R 12 Preferably, the group is an alkanediyl group having 1 to 10 carbon atoms, or an alkanediyl group having 1 to 10 carbon atoms and containing an ester bond between the carbon-carbon bonds, with methanediyl group, ethanediyl group, propanediyl group, and butanediyl group -CH2CH2OCOCH2CH2CH2CH2CH2- being preferred, and ethanediyl group, propanediyl group, or -CH2CH2OCOCH2CH2CH2CH2CH2- being more preferred.

[0074] The above t is an integer from 1 to 6, preferably an integer from 1 to 3, and more preferably 1 or 2.

[0075] Specific examples of monofunctional polymerizable compounds (C) represented by the above formula (2) are shown below. In the chemical formula, R 11 u is equivalent to equation (2) above.

[0076] [ka]

[0077] As the monofunctional polymerizable compound (C) containing a phosphate group, commercially available products can be used. Specifically, examples include "KAYAMER PM-21" and "KAYAMER PM-2" (both manufactured by Nippon Kayaku Co., Ltd.), "Hosmer M," "Hosmer PE," and "Hosmer PP" (all manufactured by Unichemical Co., Ltd.), and "Light Ester P-1M" (manufactured by Kyoeisha Chemical Co., Ltd.).

[0078] This composition may contain one or more polymerizable compounds (C) containing a phosphate group.

[0079] When polymerizable compound (C) is incorporated into this composition, the lower limit of the polymerizable compound (C) content (total content if multiple types are included) is preferably 0.5% by mass, more preferably 1% by mass, and even more preferably 2% by mass, based on the total amount of solids (i.e., components other than solvents) contained in this composition, from the viewpoint of bending resistance at low temperatures. Furthermore, the upper limit of the polymerizable compound (C) content containing phosphate groups is preferably 10% by mass, more preferably 8% by mass, based on the total amount of solids contained in this composition.

[0080] <Monofunctional polymerizable compounds (D) other than polymerizable compounds (C) containing a phosphate group> This composition may contain monofunctional polymerizable compounds (D) other than polymerizable compound (C) containing a phosphate group.

[0081] As the monofunctional polymerizable compound (D), compounds having one radical polymerizable group can be preferably used, such as (meth)acryloyl group-containing compounds, linear vinyl compounds, aromatic vinyl compounds, and maleimide compounds. Specific examples of (meth)acryloyl group-containing compounds include unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, (meth)acrylic acid esters with a linear structure, (meth)acrylic acid esters with an alicyclic structure, (meth)acrylic acid esters with an aromatic ring structure, and (meth)acrylamide compounds. Among these, (meth)acryloyl group-containing compounds can be preferably used as the monofunctional polymerizable compound (D) from the viewpoint of achieving a high refractive index and transparency.

[0082] Examples of the above unsaturated carboxylic acids include (meth)acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, etc. Examples of the above unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, etc.

[0083] Examples of (meth)acrylic acid esters having the above-mentioned chain structure include alkyl (meth)acrylates, hydroxyalkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, polyoxyalkylene (meth)acrylates, polyoxycarbonylalkylene (meth)acrylates, and mono(meth)acryloyloxyalkyl esters of dicarboxylic acids.

[0084] Examples of the alkyl (meth)acrylates mentioned above include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, etc. Examples of the above-mentioned hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. Examples of the above-mentioned (meth)acrylate alkoxyalkyl esters include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and propoxyethyl (meth)acrylate; Examples of the above (meth)acrylic acid polyoxyalkylene esters include methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, ethoxydipropylene glycol (meth)acrylate, 2-ethylhexyloxydiethylene glycol (meth)acrylate, etc. The above (meth)acrylic acid polyoxycarbonyl alkylene esters include ω-carboxy-polycaprolactone mono(meth)acrylate, etc. Examples of mono(meth)acryloyloxyalkyl esters of the above-mentioned dicarboxylic acids include mono(2-(meth)acryloyloxyethyl) succinate and mono(2-(meth)acryloyloxyethyl) phthalate.

[0085] Examples of (meth)acrylic acid esters having the above alicyclic structure include cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, 4-hydroxymethylcyclohexyl (meth)acrylate, and tricyclo(meth)acrylate [5.2.1.0 2,6 ] Decane-8-yl, (meth)acrylate tricyclo[5.2.1.0 2,5 Examples include decane-8-yloxyethyl and isobolonyl (meth)acrylate.

[0086] Examples of (meth)acrylic acid esters having the above aromatic ring structure include phenyl (meth)acrylate, benzyl (meth)acrylate, naphthylmethyl (meth)acrylate, naphthylethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenylthioethyl (meth)acrylate, m-phenoxyphenylmethyl (meth)acrylate, p-phenoxyphenylmethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, polyethyleneoxynonylphenyl (meth)acrylate, (1-naphthyl)methyl (meth)acrylate, (2-naphthyl)methyl (meth)acrylate, (1,1'-biphenyl-4-yl)methyl (meth)acrylate, and biphenylmethyl (meth)acrylate.

[0087] Examples of the above-mentioned (meth)acrylamide compounds include (meth)acryloylmorpholine, N-(2-hydroxyethyl)(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-vinyl-2-pyrrolidone, and N-vinyl-ε-caprolactam.

[0088] Examples of the above-mentioned chain-like vinyl compounds include propene, butene, pentene, and hexene. Examples of the above-mentioned aromatic vinyl compounds include styrene, methylstyrene, α-methylstyrene, t-butoxystyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid, and vinylnaphthalene. Examples of the above-mentioned maleimide compounds include N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, and N-(p-methylphenyl)maleimide.

[0089] Further specific examples of monofunctional polymerizable compounds (D) include compounds represented by formulas (d-1) to (d-28) below.

[0090] [ka]

[0091] [ka] (In formulas (d-1) to (d-28), R 20 This is either a hydrogen atom or a methyl group. R 21 It is a monovalent hydrocarbon group having 1 to 20 carbon atoms. n is an integer between 0 and 10.

[0092] Among these, (meth)acrylates having aromatic groups are preferred as the monofunctional polymerizable compound (D) from the viewpoint of high refractive index, and (meth)acrylamide compounds are preferred from the viewpoint of surface tension.

[0093] The refractive index of the monofunctional polymerizable compound (D) is not particularly limited, but a higher refractive index is preferable from the viewpoint of obtaining a cured product with a high refractive index. A refractive index of 1.50 or higher is preferred for the monofunctional polymerizable compound (D).

[0094] This composition may contain one or more monofunctional polymerizable compounds (D).

[0095] When a monofunctional polymerizable compound (D) is incorporated into this composition, the lower limit of the content of the monofunctional polymerizable compound (D) (total content if multiple types are included) is preferably 20% by mass, more preferably 30% by mass, and even more preferably 40% by mass, based on the total amount of solids (i.e., components other than the solvent) contained in this composition, from the viewpoint of inkjet coating properties. Furthermore, the upper limit of the content of the monofunctional polymerizable compound (D) is preferably 80% by mass, and more preferably 70% by mass, based on the total amount of solids contained in this composition.

[0096] <Photoinitiator (E)> The photoinitiator (E) is a compound that initiates or promotes the polymerization of the polymerizable compound upon exposure.

[0097] Examples of photoinitiators (E) include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, and bis(4-dimethylaminophenyl) ketone. Ton, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, ethanonon-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(o-acetyloxime), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 4-benzoyl-4'-methyldimethyl sulfide, 4-dimeth Diaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 4-dimethylamino-2-ethylhexylbenzoic acid, 4-dimethylamino-2-isoamylbenzoic acid, benzyl-β-methoxyethyl acetal, benzyl dimethyl ketal, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, o-methyl o-benzoylbenzoate, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 1-chlorothioxanthone Ro-4-propoxythioxanthone, thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzimidal, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)-imidazolyl dimer, benzophenone, 2-chlorobenzophenone, p,p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3-dimethyl-4-methoxybenzophenone, benzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin butyl ether, acetophenone, 2,2 -Diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, p-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, α,α-dichloro-4-phenoxyacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzosverone, pentyl-4-dimethylaminobenzoate T,9-phenylacridin, 1,7-bis-(9-acridinyl)heptane, 1,5-bis-(9-acridinyl)pentane, 1,3-bis-(9-acridinyl)propane, p-methoxytriazine, 2,4,6-tris(trichloromethyl)-s-triazine, 2-methyl-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)- s-triazine, 2-[2-(4-diethylamino-2-methylphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-n-butoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-Bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyl-s-triazine; Ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, etc.; Diacyl peroxides such as isobutyryl peroxide, bis(3,5,5-trimethylhexanoyl) peroxide, etc.; p-menthane hydroperoxide, Examples include hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkylperoxides such as 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane; peroxyketals such as 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane; peroxyesters such as t-butylperoxyneodecanoate and 1,1,3,3-tetramethylperoxyneodecanoate; peroxydicarbonates such as di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate; and azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobisisobutyrate.

[0098] Among the above, acylphosphine initiators such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide are preferred from the viewpoint of transparency.

[0099] Commercially available photoinitiators (E) can also be used. Examples of commercially available products include "Omnirad 907", "Omnirad 369", "Omnirad 379", "Omnirad 184", "Omnirad 819", "Omnirad TPO-X" (manufactured by IGM Resins BV), and "TR-PBG-345" (manufactured by TRONLY).

[0100] This composition may contain one or more photoinitiators (E).

[0101] The lower limit of the photoinitiator (E) content (total content if multiple types are included) is preferably 0.5% by mass, more preferably 1% by mass, and even more preferably 2% by mass, based on the total amount of solids (i.e., components other than the solvent) contained in the composition. The upper limit of the photoinitiator (E) content is preferably 10% by mass, more preferably 8% by mass, based on the total amount of solids contained in the composition.

[0102] <Surfactant (F)> Surfactants (F) can be used to improve the applicability of the composition (wetting spread and reduction of uneven application). Examples of surfactants (F) include fluorinated surfactants, silicone surfactants, and nonionic surfactants. Among these, nonfluorinated surfactants are preferred, and silicone surfactants are more preferred.

[0103] Specific examples of surfactants (F) include fluorine-based surfactants such as Megafac F-171, F-172, F-173, F-251, F-430, F-554, and F-563 (manufactured by DIC Corporation); Florard FC430 and FC431 (manufactured by Sumitomo 3M Co., Ltd.); Asahiguard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106, and S-611 (manufactured by AGC Seimi Chemical Co., Ltd.); Polyflow No. 75 and No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.); FTX-218 (manufactured by Neos Co., Ltd.); and Ftop EF301, EF303, and EF352 (manufactured by Shin Akita Chemical Co., Ltd.).

[0104] Examples of silicone-based surfactants include the following product names: SH200-100cs, SH-28PA, SH-30PA, SH-89PA, SH-190, SH-8400, FLUID, SH-193, SZ-6032, SF-8428, DC-57, DC-190, PAINTAD19, FZ-2101, FZ-77, FZ-2118, L-7001, L-7002 (manufactured by Toray Dow Corning Silicone Co., Ltd.); 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 BIC Chemie Japan Co., Ltd.).

[0105] 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, and polyethylene glycol distearate.

[0106] This composition may contain one or more of the above-mentioned surfactants (F).

[0107] When a surfactant (F) is incorporated into this composition, the content ratio of surfactant (F) (total content ratio if multiple types are included) is preferably 0.01 to 1.5% by mass, more preferably 0.05 to 1.0% by mass, and even more preferably 0.1 to 0.8% by mass, based on the total amount of solids (i.e., components other than the solvent) contained in this composition.

[0108] This composition may contain metal oxide particles (A), a polyfunctional polymerizable compound (B), and a photoinitiator (E), as well as optional polymerizable compounds containing phosphate groups (C), monofunctional polymerizable compounds (D), and surfactants (F), and may also contain other components. Other components include adhesion aids, dispersants, polymerization inhibitors, antioxidants, sensitizers, softeners, plasticizers, UV absorbers, and organic solvents. The proportions of these components are appropriately selected according to each component, within a range that does not impair the effects of this disclosure.

[0109] This composition may contain an organic solvent, but when used for inkjet coating, the solvent content is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, relative to the total amount of the composition. It may also be used without a solvent. On the other hand, in the case of other coating methods such as slit coating, the viscosity may be adjusted to a suitable level by adding a solvent as appropriate.

[0110] ≪Method for manufacturing hardened products≫ A cured product can be manufactured using the radiation-sensitive composition prepared as described above. This composition is particularly suitable as a cured film material that can be formed by exposing a film formed with the radiation-sensitive composition to light.

[0111] The cured product of this disclosure may be manufactured, for example, by a method comprising the following steps (I) and (II), and, if a pattern is to be formed, by a method comprising step (III) as necessary. (I) Step of applying the composition onto the substrate. (II) A step of irradiating the composition coated on the substrate with radiation. (III) A process of developing the composition after irradiation with radiation. The following describes each step (steps (I) to (III)) of the manufacturing method disclosed herein.

[0112] <Process (I): Coating process> Step (I) is a step of forming a coating film on a substrate by applying the composition onto the substrate. Examples of substrates include glass substrates, silicon wafers, plastic substrates, plastic films, and substrates on which a colored resist, overcoat, anti-reflective film, various metal thin films, sealing films, etc., are formed on their surface. Examples of plastic substrates and plastic films include resin substrates and films made of plastics such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethersulfone, polycarbonate, and polyimide. Various elements (for example, light-receiving elements such as photodiodes and light-emitting elements such as organic light-emitting diodes) may be pre-installed on these substrates.

[0113] As for the application method of this composition, suitable methods such as spraying, roll coating, rotary coating (spin coating), slit die coating, bar coating, and inkjet coating can be used. Of these, spin coating, bar coating, slit die coating, and inkjet coating are preferred application methods.

[0114] After applying this composition to a substrate, a preheating process (pre-bake) may be performed to prevent dripping and other purposes. The pre-bake conditions can be appropriately set depending on the type and usage ratio of each component. For example, the pre-bake conditions can be 60 to 100°C for 30 seconds to 10 minutes. From the viewpoint of applicability to organic EL elements, the pre-bake temperature is preferably 60 to 90°C.

[0115] <Process (II): Exposure process> Step (II) is a step in which at least a portion of the coating film formed in step (I) is irradiated with radiation. This radiation irradiation causes a curing reaction to proceed in the exposed area. Furthermore, if a pattern is to be formed, the radiation irradiation of the coating film in step (II) can be carried out through a mask. The mask may be a multi-tone mask such as a halftone mask or a graytone mask.

[0116] In this step, a cured film is obtained by irradiating the coated film formed in step (I) above with radiation to expose the coated film. The thickness of the formed cured film is preferably 0.1 to 30 μm, and more preferably 0.5 to 10 μm.

[0117] Examples of radiation used to irradiate the coating include ultraviolet light, far ultraviolet light, X-rays, and charged particle beams. Examples of ultraviolet light 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. Of these, ultraviolet light is preferred for irradiating the coating, and ultraviolet light with a wavelength of 200 nm to 400 nm is more preferred. Examples of light sources used include LED lamps, low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, and excimer lasers. The radiation exposure dose is 300 J / m². 2 ~50,000 J / m 2 (30~5,000 mJ / cm 2 ) is preferable.

[0118] <Step (III): Development step> Step (III) is an optional step, and may be included as needed when forming a pattern. Step (III) is a step in which a pattern is formed on the substrate by developing the coating film that has been irradiated with radiation in step (II). This developing step removes the unexposed parts of the coating film formed on the substrate, and a pattern consisting of exposed parts can be formed on the substrate.

[0119] Examples of developers include aqueous solutions of alkalis (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, and 1,5-diazabicyclo[4.3.0]-5-nonane. Alternatively, aqueous solutions obtained by adding an appropriate amount of water-soluble organic solvents such as methanol or ethanol, or a surfactant, to an aqueous solution of alkali, or by adding a small amount of various organic solvents capable of dissolving this composition, may be used as a developer.

[0120] As for the development method, appropriate methods such as the liquid-filling method, dipping method, agitation immersion method, and shower method can be employed. The development time should be adjusted as appropriate depending on the composition of this composition. For example, the development time is 20 seconds to 120 seconds.

[0121] The manufacturing method of the present disclosure may optionally include a step (IV) of heating the pattern. The heat treatment in step (IV) is preferable because it further promotes hardening, resulting in a cured product exhibiting good heat resistance and chemical resistance. The heat treatment can be carried out, for example, using a heating device such as an oven or a hot plate. When obtaining microlenses as cured products, hemispherical microlenses may be obtained by thermal flow of the pattern through the heat treatment in step (IV).

[0122] The heating temperature in step (IV) is not particularly limited, but from the viewpoint of enabling application to organic EL elements, it is preferably 100°C or lower, more preferably 95°C or lower, and even more preferably 90°C or lower. Furthermore, from the viewpoint of obtaining a cured product with high heat resistance and chemical resistance, the heating temperature in step (IV) is preferably 60°C or higher, and more preferably 80°C or higher. The heating time can be set appropriately depending on the type of heating device, etc. For example, when heating is performed using a hot plate, the heating time is, for example, 5 to 60 minutes. When heating is performed using an oven, the heating time is, for example, 10 to 90 minutes. In step (IV), a step bake method in which multiple heat treatments are performed may be used.

[0123] The manufacturing method of the present disclosure may further include, as an optional step, a step of irradiating the cured product with radiation before or after the heating step in step (IV) (hereinafter also referred to as the "post-exposure step"). By irradiating with radiation in the post-exposure step (hereinafter also referred to as the "post-exposure step"), heat resistance, chemical resistance, etc., can be further improved, and a more reliable cured product can be obtained. The type of radiation and exposure conditions in post-exposure can be the same as those in step (II). The wavelength of the irradiation light, irradiation amount, light source, etc., during post-exposure may be the same as or different from those in step (II).

[0124] ≪Cured product≫ The cured product of the present invention can be formed by curing the above-mentioned radiation-sensitive composition. According to this composition, a cured product with a high refractive index and excellent bending resistance at low temperatures can be obtained.

[0125] As for the refractive index of the cured product, a cured product with a refractive index of 1.60 or higher at a wavelength of 589 nm can be obtained. Furthermore, with this composition, a cured product with a high refractive index, preferably 1.64 or higher at a wavelength of 589 nm, can also be obtained.

[0126] The cured product is preferably one in which no cracks are observed after 100,000 folds when a test specimen, formed by depositing a 20 μm film thickness on a 50 μm polyimide substrate, is subjected to a bending test at -20°C with a radius of curvature R = 1.5 mm, and is particularly preferably one in which no cracks are observed after 200,000 folds.

[0127] The above-mentioned cured material is suitable as an optical component for display elements or image sensors. The optical component is preferably a component that improves the light extraction efficiency in a display element (an optical path adjusting component that adjusts the path of light) or an optical path adjusting component that adjusts the path of light in order to focus it on a light-receiving element (photodiode) in an image sensor such as a camera.

[0128] Furthermore, the cured product can be suitably used as a sealant or insulating film for various display elements.

[0129] ≪Display Elements≫ The display element of the present invention comprises a cured product formed from the above-mentioned radiation-sensitive composition. Examples of display elements include liquid crystal display elements, organic EL display elements, and micro-LED (Light Emitting Diode) display elements.

[0130] Image sensor The image sensor of the present invention comprises a cured product formed from the above-mentioned radiation-sensitive composition. The cured product of the present invention is preferably used as an optical path adjusting member to adjust the path of light in order to focus light onto a light-receiving element (photodiode) in an image sensor such as a camera. [Examples]

[0131] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following, "parts" and "%" refer to mass unless otherwise specified.

[0132] (Preparation Example 1: Synthesis of metal oxide particles (A-2)) To tetrahydrofuran (THF) as an organic solvent, an amount of (A-1) (zirconia particles, product name: UEP-100, manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd. (solid content concentration: 100%)) with a primary particle size of 15 nm was added to the dispersion (a-2) in an amount equal to 40% by mass, and methacryloyloxypropyltrimethoxysilane as a silane-based surface treatment agent was added in an amount equal to 5% by mass to the dispersion (a-2). After this, a mixture was prepared using a stirring rod. After sufficient stirring, 0.05 mm zirconia beads were added in an amount equal to twice the mass of the mixture, and a metal oxide particle dispersion (a-2) with a zirconia content of 40% by mass was obtained using a paint shaker. Here, as a phosphate ester dispersant, Prysurf AL (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added in an amount such that the mass ratio of (A-1) to (A-1) in dispersion (a-2) is (A-1):Prysurf AL = 40:1.8, and as a fatty acid dispersant, HIPLAAD ED401 (manufactured by Kusumoto Kasei Co., Ltd.) is added in an amount such that the mass ratio of (A-1) to (A-1) in dispersion (a-2) is (A-1):HIPLAAD An amount of ED401 in a ratio of 40:1.2, and an amount of biphenyl methyl acrylate (D-1) as an acrylate monomer (dispersion monomer) in a mass ratio of (A-1):(D-1)=40:25 in the dispersion (a-2), were added. After filtering out the undispersed bulk metal oxide particles using a 1 μm syringe filter, the pressure was reduced to remove tetrahydrofuran (THF) to produce a metal oxide particle dispersion in which 48 parts by weight of coated metal oxide particles (A-2) containing a dispersant were dispersed in 25 parts by weight of dispersion monomer (D-1). As a result, a dispersion containing (A-1) particles: 55% by mass, methacryloyloxypropyltrimethoxysilane: 6.8% by mass, Prysurf AL: 2.5% by mass, HIPLAAD ED401: 1.7% by mass, and biphenyl methyl acrylate (D-1): 34% by mass was obtained.

[0133] (Preparation Example 2: Synthesis of metal oxide particles (A-3)) 2.67 g of zirconium oxynitrate and 100 g of water were placed in a glass container and dissolved. Then, while stirring, 100 g of a 1.2% by mass aqueous sodium hydroxide solution was gradually added and reacted to obtain a slurry containing zirconium oxyhydroxide at a concentration of 0.7% by mass. Next, 28 g of decanoic acid was added to this slurry, and the mixture was stirred for about 5 minutes while maintaining a temperature of 70°C in an oil bath. After standing for about 1 hour to separate the oil phase and aqueous phase, only the oil phase was collected to obtain 30 g of a dispersion (referred to as dispersion A3) containing zirconium decanoate at a concentration of 15% by mass.

[0134] Next, 2.0 g of dispersion A3 and 0.06 g of water were mixed in a high-pressure reaction vessel, and hydrothermal treatment was performed at 300°C for 10 minutes using an electric furnace. After that, the high-pressure reaction vessel was allowed to cool to room temperature, 3.0 g of hexane was added, and the contents of the high-pressure reaction vessel were transferred to a glass container. After standing for a while, the oil phase and aqueous phase were separated, and only the oil phase was collected and vacuum dried to obtain a paste-like solid. 1.0 g of methanol was added to the obtained solid and stirred thoroughly, then centrifuged, the precipitate was collected and dried to obtain 0.3 g of white powder (A-3). The average particle size of this white powder was 5 nm. Furthermore, when the white powder was dispersed in 0.13 g of benzyl acrylate (D-3) to obtain a metal oxide particle dispersion in which 30 parts by weight of (A-3) was dispersed in 13 parts by weight of dispersed monomer (D-3), the average particle size of the aggregated particles in the metal oxide particle dispersion was 5 nm.

[0135] [Preparation of radiation-sensitive resin composition] The raw materials used in the preparation of each radiation-sensitive resin composition are shown below.

[0136] (A) Component: Metal oxide particles A-1: Zirconia particles, product name: UEP-100, average primary particle size: 15 nm, manufactured by Daiichi Rare Elements Chemical Industry Co., Ltd. (solid content concentration: 100%) • A-2: Metal oxide particles obtained in Preparation Example 1 (A-2) • A-3: Metal oxide particles obtained in Preparation Example 2 (A-3)

[0137] (B) Component: Polyfunctional polymerizable compound • B-1: Polyethylene glycol diacrylate, Product name: M-240, Manufactured by Toagosei Co., Ltd. • B-2: 1,9-nonanediol diacrylate, Product name: Viscoat #260, Manufactured by Osaka Organic Chemical Industry Co., Ltd. • B-3: Trimethylolpropane triacrylate, Product name: Light Acrylate TMP-A, manufactured by Kyoeisha Chemical Co., Ltd. • B-4: Trimethylolpropane EO-modified triacrylate (trifunctional), product name: Miramer M3130, manufactured by Miwon.

[0138] (C) Component: Phosphoric acid group-containing polymerizable compound C-1:2-Methacryloyloxyethyl caproate acid phosphate, Product name: KAYAMER PM-21, Manufactured by Nippon Kayaku Co., Ltd. • C-2: Acid phosphooxypropylene glycol monomethacrylate, product name: Fosmer PP, weight-average molecular weight: 460, manufactured by Unichemical Co., Ltd. • C-3: Acid phosphooxyethylene glycol monomethacrylate, product name: Fosmer PE, weight-average molecular weight: 360, manufactured by Unichemical Co., Ltd. C-4:2-Methachlorooxyethyl acid phosphate, Product name: Light Ester P-1M, Weight-average molecular weight: 228, Manufactured by Kyoeisha Chemical Co., Ltd.

[0139] (D) Component: Monofunctional polymerizable compound • D-1: Biphenyl methyl acrylate, product name: Miramer M1192, manufactured by Miwon. • D-2: Benzyl methacrylate, product name: BZMA, manufactured by Mitsubishi Gas Chemical Company, Inc. • D-3: Benzyl acrylate, Product name: Viscoat #160, Manufactured by Osaka Organic Chemical Industry Co., Ltd. • D-4: N,N-dimethylacrylamide, Product name: DMAA, manufactured by KJ Chemicals Co., Ltd. • D-5: N,N-diethylacrylamide, Product name: DEAA, manufactured by KJ Chemicals Co., Ltd.

[0140] (E) Component: Photoinitiator • E-1: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, product name: Omnirad 819, manufactured by IGM Resins BV. • E-2: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, product name: Omnirad TPO-X, manufactured by IGM Resins BV.

[0141] (F) Ingredients: Surfactants • F-1: Polyether-modified silicone additive, product name: DOWSIL™ SH28 Paint Additive, manufactured by Toray Dow Corning Corporation.

[0142] (Example 1) Preparation of a radiation-sensitive composition A radiation-sensitive composition was prepared by blending (A) (A-1) 35 parts by mass, (B) (B-1) 15 parts by mass, (C) (C-1) 2.5 parts by mass, (D) (D-1) 23 parts by mass, (D-3) 21.2 parts by mass, (E) (E-1) 3 parts by mass, and (F) (F-1) 0.3 parts by mass.

[0143] (Examples 2-22, Comparative Examples 1-3) Radiation-sensitive compositions for Examples 2-22 and Comparative Examples 1-3 were prepared in the same manner as in Example 1, except that the components used were of the types and in quantities shown in Table 1. In Table 1, "-" indicates that the corresponding component was not used.

[0144] In Examples 2 and 3, the amounts of (A-2) and (A-3) in Table 1 refer to the amounts of coated particles (A-2) and (A-3) in the dispersions obtained in Preparation Examples 1 and 2, and do not include the compounds (D-1) and (D-3) as dispersion monomers. Also, the amount of monofunctional polymerizable compound (D) in Examples 2 and 3 includes the amounts of compounds (D-1) and (D-3) as dispersion monomers in the dispersions obtained in Preparation Examples 1 and 2.

[0145] [evaluation] The radiation-sensitive compositions obtained above were evaluated for viscosity, surface tension, inkjet coating properties, refractive index of the cured product, and -20°C bending test according to the following method.

[0146] <Viscosity of radiation-sensitive composition> The viscosity of the obtained radiation-sensitive composition at 25°C was measured using an E-type viscometer (TVE-25, manufactured by Toki Sangyo Co., Ltd.).

[0147] <Surface tension of radiation-sensitive compositions> The surface tension of the obtained radiation-sensitive composition at 25°C was measured using an automatic surface tension meter (DY-300, manufactured by Kyowa Interface Science Co., Ltd.).

[0148] <Inkjet coating properties> The obtained radiation-sensitive composition was placed in an ink cartridge DMC-11610 (Fujifilm Dimatrix), the nozzle temperature was set to a predetermined level, the ejection state was adjusted, and then the cartridge was left for 30 minutes with the ink filled. The ability to eject the ink was then checked and evaluated according to the following evaluation criteria. A: Dispensing was possible and surface formation was achieved at nozzle temperatures of 35-50°C. B: At nozzle temperatures of 35-50°C, areas where dispensing was impossible occurred, resulting in an inability to form a surface.

[0149] <Refractive index of hardened material> The refractive index of the cured product was determined by applying the obtained radiation-sensitive composition to the surface of a glass substrate to a thickness of 20 μm using a bar coater, and measuring it at 2000 mJ / cm² using 395 nm LED light in a nitrogen-purged container. 2The samples were cured with the specified light intensity, and the refractive index at a wavelength of 589 nm was measured using a prism coupler (Metricon, 2010) at a pressing pressure of 20 psi (137.9 kPa). The following evaluation criteria were used. A: When the measured refractive index of the cured material is 1.64 or higher. B: When the measured refractive index of the cured material is 1.60 or higher but less than 1.64. C: When the measured refractive index of the cured material is less than 1.60

[0150] <-20℃ bending test> The obtained radiation-sensitive composition was applied to a 50 μm polyimide film to a thickness of 20 μm using a bar coater, and then exposed to 2000 mJ / cm² of 395 nm LED light in a nitrogen-purged container. 2 The film was cured with the specified light intensity. The resulting film was subjected to a bending test at -20°C with a radius of curvature R=1.5 mm. It was evaluated according to the following criteria. A: No cracks were observed even after being bent more than 200,000 times. B: Cracks occurred after more than 100,000 but less than 200,000 bending cycles. C: The crack occurred in less than 100,000 uses.

[0151] [Table 1]

[0152] As shown in Table 1, Examples 1 to 22 were able to form cured products with excellent inkjet coating properties, refractive index of the cured product, and performance in the -20°C bending test. On the other hand, the comparative examples were inferior to the examples in inkjet coating properties, refractive index of the cured product, and performance in the -20°C bending test.

Claims

1. Metal oxide particles (A) and A polyfunctional polymerizable compound (B) having at least one group selected from the group consisting of a linear alkanediyl group having 7 or more carbon atoms, an alkanetriyl group having 5 or more carbon atoms, and a polyalkylene oxide group, A photoinitiator (E) is included, The viscosity at 25°C is 50 cP or less. Radiation-sensitive composition for forming optical members.

2. The radiation-sensitive composition according to claim 1, wherein the content of the polyfunctional polymerizable compound (B) is 5% by mass or more and 30% by mass or less of the total polymerizable compounds in the radiation-sensitive composition.

3. The radiation-sensitive composition according to claim 1, wherein the polyfunctional polymerizable compound (B) is a compound that is trifunctional or more and has an ethylene oxide chain or a propylene oxide chain.

4. The radiation-sensitive composition according to claim 1, further comprising a polymerizable compound (C) containing a phosphate group.

5. The radiation-sensitive composition according to claim 1, further comprising a monofunctional polymerizable compound (D) other than a polymerizable compound (C) containing a phosphate group.

6. The radiation-sensitive composition according to claim 5, wherein the monofunctional polymerizable compound (D) is a (meth)acrylate having an aromatic group.

7. The radiation-sensitive composition according to claim 1, further comprising a non-fluorinated surfactant.

8. The radiation-sensitive composition according to claim 1, wherein the surface tension value at 25°C is 30 mN / m or less.

9. The radiation-sensitive composition according to claim 1, wherein the refractive index of the cured product obtained by curing the above-mentioned radiation-sensitive composition is 1.60 or higher at a wavelength of 589 nm.

10. The radiation-sensitive composition according to claim 1, wherein a test specimen, formed by depositing a film with a thickness of 20 μm on a 50 μm polyimide substrate, is subjected to a bending test at -20°C with a radius of curvature R = 1.5 mm, and no cracks are observed even after 100,000 bending cycles.

11. The above-mentioned optical component is a component that improves the light extraction efficiency in a display element, as described in claim 1, for the radiation-sensitive composition.

12. A cured product obtained by curing a radiation-sensitive composition according to any one of claims 1 to 11.

13. A display element comprising the cured product described in claim 12.

14. An image sensor comprising the cured material described in claim 12.

15. A step of applying the radiation-sensitive composition according to any one of claims 1 to 11 onto a substrate, A step of irradiating a radiation-sensitive composition applied to the above substrate with radiation, A method for producing a cured product, including the following:

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