Photosensitive composition, cured product and method for producing same, display element, and imaging element

Abstract

The purpose of the present invention is to provide: a photosensitive composition which has a high refractive index, has little change in viscosity and resolution even after a certain period of time has elapsed, has excellent storage stability, does not solidify when a coating slit nozzle or the like is used, has good coating properties over time, and has high resolution; a cured film which is formed from the photosensitive composition, and a method for producing the cured film; a display element which is provided with the cured film; and an imaging element which is provided with the cured film. The present invention relates to a photosensitive composition for forming an optical member, the photosensitive composition containing: (A) particles which each have a reactive group, an acidic group that is different from the reactive group, and at least one group that is selected from the group consisting of an oxygen atom-containing or oxygen atom-free alkyl group having 2-30 carbon atoms and an oxygen atom-containing or oxygen atom-free alkylene group having 2-30 carbon atoms; (B) a radically polymerizable compound; and (C) a photoradical generator.

Description

Photosensitive composition, cured product and method for producing the same, display element, and imaging element

[0001] The present invention relates to a photosensitive composition, a cured product and a method for producing the same, a display element, and an imaging element, and more particularly to a technique for forming an optical member for a display element or an imaging element.

[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 imaging elements in imaging devices such as cameras. Solid-state imaging elements are provided with hemispherical condenser lenses (hereinafter also referred to as "microlenses") or intralayer lenses to collect light onto light-receiving elements (photodiodes) and improve sensor sensitivity. Furthermore, display elements such as organic EL elements have adopted a structure in which microlenses are provided on the light-emitting side of each pixel in order to improve light extraction efficiency and adjust the viewing angle (see, for example, Patent Document 1). Lenses for solid-state imaging elements and display elements have also recently been formed by photolithography using photosensitive compositions.

[0003] Known photosensitive compositions include, for example, composite resin compositions comprising inorganic fine particles synthesized by a gas phase method and having an average particle size of 1 to 100 nm, and at least one polycarboxylic acid resin having a fused ring structure selected from the group consisting of indene, tetralin, fluorene, xanthene, anthracene, and benzanthracene (see, for example, Patent Document 2).

[0004] JP 2020-101659 A JP 2011-116943 A

[0005] It is desirable to further increase the refractive index of cured films used in solid-state imaging devices and display devices in order to improve light extraction efficiency. It is known that, in order to form a cured film with a high refractive index, a photosensitive composition in which high refractive index particles are dispersed is used to form the cured film. However, conventionally used photosensitive compositions contain an alkali-soluble resin added for exposure and development, which reduces the refractive index, making it impossible to obtain a sufficient refractive index. Furthermore, the photosensitive composition described in Patent Document 2 also fails to obtain a sufficient refractive index due to the addition of a polycarboxylic acid resin.

[0006] Furthermore, when high refractive index particles are usually added, they are dispersed in the photosensitive composition using a dispersant, but since the dispersant is physically adsorbed on the surface of the high refractive index particles, there are cases where the dispersant is desorbed from the particles. It has now been newly discovered that the desorption of the dispersant causes problems such as the particles agglomerating to form foreign matter, reducing the storage stability of the photosensitive composition and making it impossible to coat after a certain period of time (poor coatability over time).

[0007] The present invention aims to provide a photosensitive composition that has a high refractive index, exhibits excellent storage stability with little change in viscosity or resolution even after a certain period of time, does not solidify when using a coating slit nozzle or the like, has good coatability over time, and has high resolution; a cured film formed from the photosensitive composition and a method for producing the same; a display element including the cured film; and an imaging element including the cured film.

[0008] As a result of extensive research to solve this problem, the present inventors have found that the above object can be achieved by incorporating particles (A) to which a specific group has been introduced by chemical bonding (chemical modification) into a photosensitive composition, and have thus completed the present invention.

[0009] In one embodiment, the present invention relates to a photosensitive composition for forming an optical member, comprising: (A) particles having a reactive group, an acidic group different from the reactive group, and at least one group selected from the group consisting of an oxygen-containing or oxygen-free alkyl group having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group having 2 to 30 carbon atoms; (B) a radical-polymerizable compound; and (C) a photoradical generator.

[0010] In another embodiment, the present invention relates to a method for producing a cured product, the method comprising: applying the photosensitive composition onto a substrate; irradiating the photosensitive composition applied onto the substrate with radiation; developing the photosensitive composition after irradiation with radiation; and heating the developed photosensitive composition at a temperature of 100°C or less to cure it.

[0011] In another embodiment, the present invention relates to a cured product formed by curing the photosensitive composition, and a display element and an imaging element including the cured film.

[0012] In another embodiment, the present invention relates to a photosensitive composition for forming an optical member, comprising: (A1) particles having a reactive group and at least one group selected from the group consisting of an oxygen-containing or oxygen-free alkyl group having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group having 2 to 30 carbon atoms; (B) a radical-polymerizable compound; and (C) a photoradical generator.

[0013] According to the present invention, it is possible to provide a photosensitive composition for forming optical members, which has a high refractive index, excellent storage stability with little change in viscosity or resolution even after a certain period of time, does not solidify when using a coating slit nozzle or the like, has good coatability over time, and has high resolution.

[0014] The reason for this is presumably as follows. When a photosensitive composition in which particles are dispersed using a dispersant is exposed to the atmosphere for a certain period of time, the solvent evaporates, or moisture in the atmosphere disrupts the physical interaction between the particles in the photosensitive composition and the dispersant, promoting particle aggregation. As a result, the viscosity and resolution of the photosensitive composition change significantly after a certain period of time, resulting in poor storage stability and poor long-term coatability. In the present invention, by using particles (A) in which dispersible alkyl or alkylene groups are introduced onto the particle surface by chemical bonding, it is believed that even in the presence of moisture, viscosity increases little and long-term coatability and storage stability are excellent. Furthermore, since the particles (A) have acidic groups such as carboxy groups introduced onto their surface by chemical bonding, it is possible to impart alkali-solubility to the composition. As a result, an alkali-soluble resin is not required, or if used, only a small amount can be added, which is believed to sufficiently increase the refractive index of the cured film. Furthermore, since the particles (A) have reactive groups on their surface, it is believed that inorganic particles can be fixed in cured films and molded articles.

[0015] The method for producing a cured film of the present invention uses a photosensitive composition that has a high refractive index, exhibits excellent storage stability with little change in viscosity or resolution even after a certain period of time, does not solidify when using a coating slit nozzle or the like, has good coatability over time, and has high resolution, so that a high-quality cured film can be produced even after a certain period of time has passed.

[0016] The display element and the imaging element of the present invention are of high quality because they include the cured film.

[0017] One embodiment of the method for forming the particles (A) used in the present invention will be described below.

[0018] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments. In this specification, a numerical range described using "to" means that the numerical values ​​described before and after "to" are included as the lower and upper limits. A "structural unit" refers to a unit that mainly constitutes the main chain structure, and at least two or more units are contained in the main chain structure.

[0019] In this specification, the term "hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. The term "chain hydrocarbon group" refers to a straight-chain hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure in the main chain and is composed only of a chain structure. However, it may be saturated or unsaturated. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. However, it does not necessarily have to be composed only of an alicyclic hydrocarbon structure, and it also includes groups that have a chain structure as part of it. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. However, it does not necessarily have to be composed only of an aromatic ring structure, and it may contain a chain structure or an alicyclic hydrocarbon structure as part of it. The ring structures of the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent consisting of a hydrocarbon structure.

[0020] In this specification, "(meth)acryloyl" means to include "acryloyl" and "methacryloyl", "(meth)acrylic" means to include "acrylic" and "methacrylic", and "(meth)acrylate" means to include "acrylate" and "methacrylate".

[0021] <Photosensitive Composition> The photosensitive composition according to this embodiment (hereinafter also simply referred to as "the composition") includes particles (A), a radical polymerizable compound (B), and a photoradical generator (C), and the particles (A) include a reactive group (X), an acidic group (Y), and at least one group (Z) selected from the group consisting of oxygen-containing or oxygen-free alkyl groups having 2 to 30 carbon atoms and oxygen-containing or oxygen-free alkylene groups having 2 to 30 carbon atoms.

[0022] The photosensitive composition is a photosensitive composition for forming optical elements for display elements such as organic electroluminescent (EL) elements and imaging elements. Optical elements formed from this composition are used, for example, to increase the light extraction efficiency of display elements or to improve sensor sensitivity by collecting light on light-receiving elements (photodiodes) in solid-state imaging devices. The optical element preferably includes a planarizing film or a pattern formed by repeatedly arranging lenses. The lenses constituting the pattern may have a hemispherical, cylindrical, or truncated conical shape. The shape of the lenses as viewed from above may be circular, polygonal, or the like, and each may have a curved surface such as a sphere, or may be a cylindrical or truncated conical shape. The lenses are formed from the photosensitive composition of the present invention, and another transparent material layer, such as a low refractive index material layer, may be formed in the gap between the lenses. The planarizing film is formed on a substrate to planarize the surface of the substrate on which a semiconductor element or the like is formed. The pattern is a microscopic light collector (lens or trapezoidal / rectangular pattern) or interlayer lens provided in a display element or a solid-state imaging element (e.g., a CCD image sensor or a CMOS image sensor). In a display element such as an organic EL element, the pattern is provided in each pixel for the purpose of improving the light extraction efficiency of each pixel and adjusting the viewing angle, and in a solid-state imaging element, the pattern is provided for the purpose of collecting light in a light-receiving element to improve sensor sensitivity. The composition is preferably a photosensitive composition for forming a planarizing film or a photosensitive composition for forming a pattern. Each component contained in the photosensitive composition will be described below.

[0023] <Particles (A)> The particles (A) used in the present invention contain, on their surfaces, a reactive group (X), an acidic group (Y) different from the reactive group, and at least one group (Z) selected from the group consisting of an oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms, although other groups may also be contained. The particles (A) are particles obtained by surface-modifying particles (a) made of a metal oxide or the like, and are particles into which, through surface modification, the reactive group (X), the acidic group (Y), and at least one group (Z) selected from the group consisting of an oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms have been introduced.

[0024] The particles (a) used in the particles (A) can be particles according to the purpose of addition, such as adjusting the refractive index, and in the present invention, it is preferable to use particles that can increase the refractive index of the resulting cured product. The particles may be either inorganic or organic. They may also have a core-shell structure in which a core particle and a shell layer are formed.

[0025] Examples of inorganic particles that form the particles (a) include zirconium oxide (ZrO ２ ), titanium oxide (TiO ２ ), silicon oxide (SiO ２ ) (including silica and hollow silica), aluminum oxide (Al ２ O ３ ), iron oxide (Fe ２ O ３ , FeO, Fe ３ O ４ ), copper oxide (CuO, Cu ２ O), zinc oxide (ZnO), yttrium oxide (Y ２ O ３ ), niobium oxide (Nb ２ O ５ ), molybdenum oxide (MoO ３ ), indium oxide (In ２ O ３ , In ２ O), tin oxide (SnO２ ), tantalum oxide (Ta ２ O ５ ), tungsten oxide (WO ３ , W ２ O ５ ), lead oxide (PbO, PbO ２ ), bismuth oxide (Bi ２ O ３ ), cerium oxide (CeO ２ , Ce ２ O ３ ), antimony oxide (Sb ２ O ５ , Sb ２ O ５ ), germanium oxide (GeO ２ , GeO), and nitrides such as silicon nitride and boron nitride.

[0026] Also usable are titanates such as barium titanate, titanium / silicon composite oxides, and composite oxides composed of two or more metal elements such as yttrium-stabilized zirconia.

[0027] As the inorganic particles, zirconium oxide, titanium oxide, and zinc oxide are preferred from the viewpoints of ease of availability, ease of adjusting optical properties such as refractive index, particle stability, etc., and zirconium oxide and titanium oxide are particularly preferred from the viewpoint of high dispersion stability. The inorganic particles may be used alone or in combination of two or more.

[0028] As the organic particles, those that are commonly used in this field can be used as appropriate, and examples thereof include particles of resins such as polyester resins.

[0029] The shape of the particles (a) is not particularly limited, but examples thereof include spherical, granular, plate-like, and columnar shapes.

[0030] The average particle size of the particles (a) is not particularly limited, but from the viewpoint of obtaining a cured film having 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 size of the particles (a) is, for example, 1 nm or more, preferably 2 nm or more. The average particle size in the present invention refers to the D50 particle size (median size, which is the particle size showing the 50% integrated value of the integrated distribution curve) measured by dynamic light scattering, and can be measured, for example, using a MicrotracWave II-EX150 manufactured by MicrotracBell.

[0031] The reactive group (X) is preferably a group selected from the group consisting of a (meth)acryloyl group, a vinyl group, an epoxy group, an epoxycyclohexyl group, a mercapto group, an amino group, an acid anhydride group, an isocyanate group, and a carboxy group, and is more preferably a (meth)acryloyl group. The particles (A) having the reactive group (X) are cured together with the polymer in the photosensitive composition of the present invention, and the inorganic particles are easily fixed in the cured film or molded article. The amino group may be a primary or secondary amino group, but a secondary amino group is preferred from the viewpoint of reaction control.

[0032] Examples of the acidic group (Y) include a carboxy group, a phenolic hydroxyl group, a sulfo group, a sulfonamide group, a phosphate group, a phosphonate group, etc. Among these, from the viewpoint of improving the dispersibility of particles in a solvent and alkaline developability, a carboxy group or a phenolic hydroxyl group is preferred, and a carboxy group is particularly preferred.

[0033] Examples of the oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms include alkyl groups such as an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an eicosyl group.

[0034] Examples of the oxygen-containing alkyl group (Z1) include a group having an —O— or ester bond between carbon atoms of the alkyl group. Furthermore, groups represented by the following formula (4-1) or (4-2) can also be suitably used as the oxygen-containing alkyl group (Z1):

[0035] (In formula (4-1), R ３ is an alkylene group having 2 to 4 carbon atoms. n represents an integer of 1 to 10. When n is 2 or more, multiple R ３ are the same or different. ４ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, provided that the total number of carbon atoms in the group represented by formula (4-1) is 2 to 30. In formula (4-2), R ４１ is an alkylene group having 1 to 4 carbon atoms. ４２ is an alkyl group having 1 to 25 carbon atoms. X is an ester bond. However, the total number of carbon atoms in the group represented by formula (4-2) is 2 to 30.

[0036] Examples of the alkylene group having 2 to 4 carbon atoms include an ethylene group, a propylene group, and a butylene group. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, and a butyl group.

[0037] Examples of alkylene groups having 1 to 4 carbon atoms include methanediyl, ethanediyl, propanediyl, and butanediyl. Examples of alkyl groups having 1 to 25 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl.

[0038] The oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms is preferably an oxygen-free alkyl group having 2 to 30 carbon atoms, more preferably an oxygen-free alkyl group having 8 to 20 carbon atoms, and even more preferably an oxygen-free alkyl group having 8 to 15 carbon atoms.

[0039] Examples of the oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms include an ethanediyl group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, an octanediyl group, a decanediyl group, a tetradecanediyl group, an octadecanediyl group, and an icosanediyl group.

[0040] Examples of the oxygen atom-containing alkylene group (Z2) having 2 to 30 carbon atoms include groups having an —O— or ester bond between carbon atoms of the alkylene group.

[0041] The oxygen-atom-containing or oxygen-atom-free alkylene group (Z2) having 2 to 30 carbon atoms is preferably an oxygen-atom-free alkylene group having 2 to 30 carbon atoms, more preferably an oxygen-atom-free alkylene group having 4 to 20 carbon atoms, and even more preferably an oxygen-atom-free alkylene group having 8 to 15 carbon atoms.

[0042] One end of the alkylene group (Z2) is located on the particle side, and the other end has an arbitrary substituent, and the substituent is preferably the reactive group (X), the acidic group (Y), the acidic group (Y) bonded to the reactive group (X), or the like.

[0043] When an alkylene group (Z2) having 4 or more carbon atoms and a reactive group at its terminal is introduced, the alkyl group (Z1) is not necessarily used in combination because a sufficient dispersibility effect can be obtained. In this case, the alkylene group preferably has 6 or more carbon atoms, more preferably 8 or more carbon atoms.

[0044] The amount of the acidic group (Y) introduced is preferably 1 to 50 mol %, more preferably 5 to 30 mol %, and even more preferably 8 to 20 mol %, relative to 100 mol % of the reactive group (X). When the amount of the acidic group (Y) introduced is within the above range, sufficient alkali solubility can be imparted to the composition, and a binder resin is unnecessary or only a small amount is required, which is preferable because the refractive index of the resulting cured product can be increased. This is also preferable because development adhesion is improved. This is also preferable because development residue is reduced.

[0045] From the viewpoints of crosslinkability, reaction efficiency, refractive index, and dispersibility, the amount of the alkyl group (Z1) introduced is preferably 5 to 80 mol %, more preferably 10 to 50 mol %, and even more preferably 10 to 30 mol %, relative to 100 mol % of the reactive group (X). By setting the amount of the alkyl group (Z1) introduced within the above range, the dispersibility of the particles (a) can be improved, and as a result, the storage stability of the composition can be improved, which is preferable. Furthermore, by setting the amount of the alkyl group (Z1) introduced within the above range, a decrease in the refractive index can be suppressed, which is preferable.

[0046] From the viewpoints of refractive index and dispersibility, the amount of the alkylene group (Z2) introduced is preferably 50 to 150 mol %, more preferably 60 to 120 mol %, and even more preferably 70 to 100 mol %, relative to 100 mol % of the reactive group (X). By setting the amount of the alkylene group (Z2) introduced within this range, the dispersibility of the particles (a) can be improved, and as a result, the storage stability of the composition can be improved, which is preferable. Furthermore, by setting the amount of the alkylene group (Z2) introduced within this range, a decrease in refractive index can be suppressed, which is preferable.

[0047] The combination of at least one group (Z) selected from the group consisting of the reactive group (X), the acidic group (Y), the oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms, and the oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms is not particularly limited, but a combination of X being a (meth)acryloyl group, Y being a carboxy group, and Z being an alkyl group having 8 to 15 carbon atoms, or a combination in which a (meth)acryloyl group (X) is introduced at the end of the alkylene group (Z2) and a carboxy group (Y) is further introduced via the (meth)acryloyl group, is preferred.

[0048] At least one group (Z) selected from the group consisting of the reactive group (X), the acidic group (Y), the oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms, and the oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms is preferably chemically bonded to the particles. Here, "chemically bonded" does not necessarily mean that these groups are directly bonded to the particles, but may be introduced via an organic group or the like. The method for introducing these groups is not particularly limited, but an example of the introduction method will be described below.

[0049] Examples of the introduction method include a method in which a particle into which a reactive group (X) has been previously introduced is reacted with a compound having an acidic group (Y) and a compound having an oxygen atom-containing or oxygen atom-free alkyl group (Z1) having 2 to 30 carbon atoms to introduce the reactive group (X), the acidic group (Y), and the oxygen atom-containing or oxygen atom-free alkyl group (Z1) having 2 to 30 carbon atoms.

[0050] Furthermore, examples of the introduction method include a method in which a particle having an oxygen atom-containing or oxygen atom-free alkylene group (Z2) having 2 to 30 carbon atoms and having a reactive group (X) previously introduced at the end of the alkylene group (Z2) is reacted with a compound having an acidic group (Y), thereby introducing the reactive group (X), the acidic group (Y), and the oxygen atom-containing or oxygen atom-free alkylene group (Z2) having 2 to 30 carbon atoms.

[0051] As the particles into which the reactive group (X) has been previously introduced, it is preferable to use particles having a core-shell structure in which a shell layer having the reactive group (X) is formed on the surface of the inorganic particle. The reactive group (X) in the shell layer can be reacted with a compound having an acidic group (Y) or a compound having an oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms to form particles having the reactive group (X), the acidic group (Y), and the oxygen-containing or oxygen-free alkyl group (Z1) in the shell layer. The alkylene group (Z2) and the reactive group (X) at its terminal in the shell layer can be reacted with a compound having an acidic group (Y) to form particles having the reactive group (X), the acidic group (Y), and the oxygen-containing or oxygen-free alkylene group (Z2) in the shell layer. The components constituting the shell layer are not particularly limited, but a layer formed by a treatment to bond a compound capable of reacting with hydroxyl groups present on the particle surface, such as a coupling agent, is preferred. The shell layer can be formed by dispersing the particles in a solvent, mixing in a coupling agent, and allowing the particles to act. If necessary, the particle surface can be treated with hexamethyldisilazane or the like.

[0052] As a coupling agent that can be used to form the shell layer, a reactive group (X)-containing silane coupling agent or a reactive group (X)-containing titanium coupling agent is preferred. As such a reactive group (X), those listed as the reactive group (X) possessed by the particles can be suitably employed. By using a coupling agent having a reactive group (X) as the coupling agent, the reactive group (X) can be introduced onto the particle surface, and various groups can be introduced by further reacting the reactive group (X) with a compound, which is preferable. The particles (a) are surface-treated with a reactive group (X)-containing coupling agent to form raw material particles (a-1).

[0053] In addition, the reactive group (X)-containing coupling agent can be used in combination with a coupling agent having an acidic group (Y), a coupling agent having an oxygen- or non-oxygen-containing alkyl group (Z1) having 2 to 30 carbon atoms, or a coupling agent having a refractive index-increasing group. The use of these coupling agents in combination is preferred because it allows the introduction of the acidic group (Y), the oxygen- or non-oxygen-containing alkyl group (Z1) having 2 to 30 carbon atoms, or the refractive index-increasing group onto the particle surface. The refractive index-increasing group is preferably R ２ A refractive index-increasing group represented by the following formula can be suitably used.

[0054] Furthermore, as the reactive group (X)-containing coupling agent, a reactive group (X)-containing coupling agent having an oxygen atom-containing or oxygen atom-free alkylene group (Z2) having 2 to 30 carbon atoms between the reactive site of the coupling agent and the reactive group (X) can be used, and a compound having an acidic group (Y) can be introduced thereto.

[0055] Examples of the silane coupling agent include (meth)acryloxysilanes such as 2-(meth)acryloxyethyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 4-(meth)acryloxybutyltrimethoxysilane, 5-(meth)acryloxypentyltrimethoxysilane, 6-(meth)acryloxyhexyltrimethoxysilane, 8-(meth)acryloxyoctyltrimethoxysilane, 10-(meth)acryloxydecanyltrimethoxysilane, 14-(meth)acryloxytetradecanyltrimethoxysilane, 18-(meth)acryloxyoctadecanyltrimethoxysilane, and 20-(meth)acryloxyicosanyltrimethoxysilane; 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 N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride; p-styryltrimethoxysilane; phenyltrimethoxysilane;hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, tridecyltrimethoxysilane, tetradecyltrimethoxysilane, pentadecyltrimethoxysilane, hexadecyltrimethoxysilane, heptadecyltrimethoxysilane, octadecyltrimethoxysilane, nonadecyltrimethoxysilane, trifluoropropyltrimethoxysilane; mercaptosilanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane; 3-trimethoxysilylpropylsuccinic 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); etc.;

[0056] Examples of the titanium coupling agent include titanates such as isopropyl dimethacryl isostearoyl titanate and isopropyl diacryl isostearoyl titanate; and the like.

[0057] These coupling agents may be used alone or in combination of two or more. For example, by using three types of coupling agents in combination, namely, a coupling agent having a reactive group (X), a coupling agent having an acidic group (Y), and a coupling agent having an oxygen atom-containing or oxygen atom-free alkyl group (Z1) having 2 to 30 carbon atoms, it becomes possible to introduce the reactive group (X), the acidic group (Y), and the oxygen atom-containing or oxygen atom-free alkyl group (Z1) to the particle surface in a single operation. Furthermore, by using two types of coupling agents in combination, namely, a reactive group (X)-containing coupling agent having an oxygen atom-containing or oxygen atom-free alkylene group (Z2) having 2 to 30 carbon atoms between the reactive site of the coupling agent and the reactive group (X), and a coupling agent having an acidic group (Y), it becomes possible to introduce the reactive group (X), the acidic group (Y), and the oxygen atom-containing or oxygen atom-free alkylene group (Z2) to the particle surface in a single operation.

[0058] The method for producing raw material particles (a-1) is not particularly limited, and they can be produced by a known method by contacting particles (a) that will become core particles (particles to be treated) with a coupling agent having a reactive group (X) that will serve as a surface coating agent. In this case, the core particles may be produced by a top-down method or a bottom-up method. Furthermore, the core particles may be produced in a gas phase or a liquid phase. For example, core-shell particles can be obtained by contacting core particles with a surface coating agent that will form the shell layer, preferably in the presence of water. Alternatively, core particles and a surface coating agent can be mixed in an organic solvent, preferably in the presence of a dispersant, and then stirred using beads to obtain core-shell particles. The temperature and pressure when contacting the core particles with the surface coating agent can be appropriately set depending on the production method used. When the core particles are brought into contact with the surface coating agent, the ratio of the core particles to the surface coating agent can be, for example, 0.5 to 100 parts by mass of the surface coating agent per 100 parts by mass of the core particles, and it is preferable that the amount of the surface coating agent be 10 to 60 parts by mass per 100 parts by mass of the core particles.

[0059] In the present invention, the alkyl group (Z) having 2 to 30 carbon atoms, which may or may not contain oxygen atoms, can be introduced by reacting a part of the reactive group (X) of the raw material particle (a-1) (particles having a reactive group (X) or particles having a reactive group (X) and an alkylene group (Z2)) with compound 1 represented by the following formula (1) (a compound having an alkyl group (Z) having 2 to 30 carbon atoms, which may or may not contain oxygen atoms).

[0060] (In formula (1), Z １ is an alkyl group (Z) having 2 to 30 carbon atoms and containing or not containing an oxygen atom. １ is a group that reacts with the reactive group (X).

[0061] Said Xc １The reactive group (X) is determined by the type of reactive group (X) possessed by the particle, and is not particularly limited as long as it is a group capable of reacting with the reactive group (X). Examples of the reactive group include a mercapto group, an amino group, an alkylamino group having 1 to 20 carbon atoms, a (meth)acryloyl group, a carboxy group, an isocyanate group, and an epoxy group. Among these, a mercapto group, an amino group, and an alkylamino group having 1 to 20 carbon atoms are preferred, and a mercapto group is more preferred.

[0062] The reactive group (X) and a group (Xc) that reacts with the reactive group (X) １ ) X is a (meth)acryloyl group, Xc １ is a mercapto group, X is a (meth)acryloyl group, Xc １ is an amino group, X is a mercapto group, Xc １ is a (meth)acryloyl group, X is an epoxy group, Xc １ is a carboxy group, X is an epoxy group, Xc １ is a mercapto group, X is an epoxy group, Xc １ is an amino group, X is a vinyl group, Xc １ is a mercapto group, X is an amino group, Xc １ is an isocyanate group, X is an amino group, Xc １ is an epoxy group, X is an amino group, Xc １ Among these, combinations in which X is a (meth)acryloyl group, Xc is a carboxyl group, etc. １ A combination of a mercapto group is preferred, and in this case, examples of the addition reaction include the Michael addition reaction and the thiol-ene reaction, with the Michael addition reaction being preferred.

[0063] Examples of the base used in the Michael addition reaction include trimethylamine, triethylamine, tripropylamine, imidazole, diazabicycloundecene, pyridine, morpholine, piperazine, piperidine, sodium hydroxide, and potassium hydroxide, with triethylamine being preferred.

[0064] Specific examples of the compound 1 represented by the formula (1) include, for example, Xc １ is a mercapto group, examples of thiol compounds include butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol, undecanethiol, dodecanethiol, tridecanethiol, tetradecanethiol, pentadecanethiol, hexadecanethiol, heptadecanethiol, octadecanethiol, nonadecanethiol, 2-ethylhexanethiol, and 2-ethylhexyl thioglycolate; １ is an amino group, amine compounds such as butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, 2-ethylhexylamine, and 3-ethoxypropylamine; １ is an alkylamino group having 1 to 20 carbon atoms, examples thereof include N,N-dimethyl-n-octylamine, N,N-dimethyl-n-decylamine, N,N-dimethyl-n-dodecylamine, dihexylamine, N,N-dimethyl-n-tetradecylamine, dioctylamine, and didecylamine.

[0065] Z according to the compound 1 represented by the formula (1) １ The amount of the compound 1 represented by the formula (1) introduced is the same as the amount of the alkyl group (Z) introduced. Since the entire amount of the compound 1 added is used in the reaction, the amount (molar amount) of the compound 1 introduced is １ The amounts (molar amounts) of these introduced are approximately the same.

[0066] The amount of compound 1 represented by formula (1) added is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the solid content of the raw material particles (a-1).

[0067] Furthermore, an acidic group (Y) can be introduced by reacting a part of the reactive group (X) of the raw material particle (a-1) (particles having a reactive group (X) or particles having a reactive group (X) and an alkylene group (Z2)) with a compound 2 (a compound having an acidic group (Y)) represented by the following formula (2):

[0068] (In formula (2), Y １ is an acidic group. １ is an (m+1)-valent organic group, and m is an integer of 1 to 3. When m is 2 or 3, a plurality of Y １ are the same or different. １ is a group that reacts with the reactive group (X).

[0069] Y １ The acidic group represented by the formula (I) is as described above.

[0070] R １ Among the (m+1)-valent organic groups represented by the formula (I), when m is 1, examples of the divalent organic group include an alkanediyl group having 1 to 10 carbon atoms and an arenediyl group having 6 to 12 carbon atoms, and from the viewpoint of dispersibility, an alkanediyl group is preferred.

[0071] Examples of the alkanediyl group having 1 to 10 carbon atoms include a methanediyl group, an ethanediyl group, a propanediyl group, a butanediyl group, a hexanediyl group, and an octanediyl group.

[0072] Examples of the arenediyl group having 6 to 12 carbon atoms include a benzenediyl group, a toluenediyl group, a naphthalenediyl group, etc. Among these, a benzenediyl group is preferred.

[0073] R １ As the (m+1)-valent organic group represented by the formula (I), a group obtained by removing (m-1) hydrogen atoms from the above divalent organic group can be suitably used.

[0074] Xc １ The group that reacts with the reactive group (X) represented by the formula (1) has the same meaning as that of the reactive group (X) and the group that reacts with the reactive group (X) １) the combinations given in the formula (1) can be suitably adopted.

[0075] Examples of the compound 2 represented by formula (2) include monovalent thiol compounds and monovalent amine compounds, with monovalent thiol compounds being preferred. Specific examples include compounds represented by the following formulae (SH-1) to (SH-12), with the compounds represented by the following formulae (SH-1) and (SH-4) being preferred.

[0076]

[0077] Y by the compound 2 represented by the formula (2) １ The amount of the compound 2 represented by the formula (2) introduced is the same as the amount of the acidic group (Y) introduced. １ The amounts (molar amounts) of these introduced are approximately the same.

[0078] The amount of compound 2 represented by formula (2) added is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the solid content of the raw material particles (a-1).

[0079] An example of a method for forming particles (A) using raw particle (a-1) will be described with reference to FIG. 1. First, inorganic particle 1 (particle (a)) is reacted with a coupling agent having a reactive group (X) to form particle 2 (raw particle (a-1)) that has been surface-treated with the coupling agent containing the reactive group (X). By adding compound 1 or compound 2 to raw particle (a-1), a part of the reactive group (X) of raw particle (a-1) and the group (Xc １ ) react with each other to form particles (A) having, on the particle surface, a reactive group (X), an acidic group (Y), and at least one group (Z) selected from the group consisting of an oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms introduced by chemical bonding.

[0080] In addition to the compound 1 represented by the formula (1) and the compound 2 represented by the formula (2), a compound 3 containing a refractive index-increasing group represented by the following formula (3) may also be reacted.

[0081] (In formula (3), R ２ is a refractive index increasing group. １ is a group that reacts with the reactive group (X).

[0082] The R ２ Examples of the compound include (r1-1) to (r1-12) below.

[0083] (In the above formula, "*" represents Xc １ represents a bond with .)

[0084] R ２ Among the above, (r1-1), (r1-4) and (r1-12) are preferred.

[0085] Xc １ The group that reacts with the reactive group (X) represented by the formula (1) has the same meaning as that of the reactive group (X) and the group that reacts with the reactive group (X) １ ) the combinations given in the formula (1) can be suitably adopted.

[0086] The amount of compound 3 represented by formula (3) added is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the solid content of the raw material particles (a-1).

[0087] The amount of the refractive index-increasing group introduced by the compound represented by formula (3) is preferably 1 to 50 mol %, more preferably 5 to 30 mol %, and even more preferably 8 to 20 mol %, relative to 100 mol % of the reactive group (X). Having the amount of the refractive index-increasing group introduced within this range is preferred because it allows the refractive index of the resulting cured product to be increased. Since the entire amount of compound 3 represented by formula (3) added is subjected to the reaction, the amount (molar amount) of compound 3 charged and the amount (molar amount) of the refractive index-increasing group introduced are approximately the same.

[0088] The shape of the particles (A) is not particularly limited, but examples thereof include spherical, granular, plate-like, and columnar shapes.

[0089] In addition, the average particle diameter of the particles (A) as a whole is not particularly limited, but from the viewpoint of obtaining a cured film 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. In addition, from the viewpoint of dispersion stability, the average particle diameter of the particles (A) is, for example, 1 nm or more, preferably 2 nm or more. If it is larger than 100 nm, light scattering by the particles in a thin film or a molded body becomes severe, and high transparency may not be maintained, which is not preferable. In addition, if it is smaller than 1 nm, the specific surface area of ​​the particles becomes large, the cohesive energy increases, and it may be difficult to maintain dispersion stability, which is not preferable.

[0090] The present composition may contain one type of the particles (A) or a combination of two or more types.

[0091] The lower limit of the content of particles (A) in the composition (total content when multiple types are included) is preferably 50 mass%, more preferably 60 mass%, and even more preferably 70 mass%, based on the total amount of solids (i.e., components other than the solvent) contained in the composition, from the viewpoint of increasing the refractive index of the resulting cured product. Also, the upper limit of the content of particles (A) is preferably 95 mass%, more preferably 90 mass%, based on the total amount of solids contained in the composition, from the viewpoint of ensuring the stability of the dispersion.

[0092] In the above description, the particle (A) is described as having different reactive groups (X) and acidic groups (Y). However, when the particle (A) has a group that functions as both the reactive group (X) and the acidic group (Y), such as a carboxy group, the particle (A1) may have the reactive group (X) and at least one group (Z) selected from the group consisting of an oxygen-containing or oxygen-free alkyl group (Z1) having 2 to 30 carbon atoms and an oxygen-containing or oxygen-free alkylene group (Z2) having 2 to 30 carbon atoms.

[0093] <Radical polymerizable compound (B)> Examples of the radical polymerizable compound (B) include a monofunctional polymerizable compound (B1) and a polyfunctional polymerizable compound (B2). The radical polymerizable compound (B) is a compound that can generate a polymer by reacting multiple polymerizable compounds (B) with each other when the composition is irradiated with radiation.

[0094] As the monofunctional polymerizable compound (B1), a compound having one radical polymerizable group can be preferably used, for example, (meth)acryloyl group-containing compounds, chain vinyl compounds, aromatic vinyl compounds, maleimide compounds, etc. Specific examples of (meth)acryloyl group-containing compounds include unsaturated carboxylic acids, unsaturated carboxylic anhydrides, (meth)acrylic acid esters having a chain structure, (meth)acrylic acid esters having an alicyclic structure, (meth)acrylic acid esters having an aromatic ring structure, (meth)acrylamide compounds, etc. These compounds can be preferably used in terms of good polymerizability and relatively high plasticity. As the monofunctional polymerizable compound (B1), from the viewpoint of achieving a high refractive index and transparency, (meth)acryloyl group-containing compounds can be preferably used.

[0095] Examples of the unsaturated carboxylic acid include (meth)acrylic acid, crotonic acid, maleic acid, itaconic acid, and fumaric acid; examples of the unsaturated carboxylic acid anhydride include maleic anhydride, itaconic anhydride, and citraconic anhydride.

[0096] Examples of the (meth)acrylic acid ester having a chain structure include (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid polyoxyalkylene esters, (meth)acrylic acid polyoxycarbonyl alkylene esters, and mono(meth)acryloyloxyalkyl esters of dicarboxylic acids.

[0097] Examples of the (meth)acrylic acid alkyl esters 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, and n-stearyl (meth)acrylate; examples of the (meth)acrylic acid hydroxyalkyl esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; examples of the (meth)acrylic acid alkoxyalkyl esters include methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and propoxyethyl (meth)acrylate; Examples of the (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, and 2-ethylhexyloxydiethylene glycol (meth)acrylate; examples of the (meth)acrylic acid polyoxycarbonyl alkylene esters include ω-carboxy-polycaprolactone mono(meth)acrylate; and examples of the mono(meth)acryloyloxyalkyl esters of dicarboxylic acids include mono(2-(meth)acryloyloxyethyl) succinate and mono(2-(meth)acryloyloxyethyl) phthalate.

[0098] Examples of the (meth)acrylic acid ester having an alicyclic structure include cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, 4-hydroxymethylcyclohexyl (meth)acrylate, tricyclo[5.2.1.0](meth)acrylate, and 2-methylcyclohexyl (meth)acrylate. ２，６ ] decan-8-yl, (meth)acrylic acid tricyclo[5.2.1.0 ２，５ ] decan-8-yloxyethyl, isobornyl (meth)acrylate, and the like.

[0099] Examples of the (meth)acrylic acid ester having an 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, and (1,1'-biphenyl-4-yl)methyl (meth)acrylate.

[0100] Examples of the (meth)acrylamide compound include (meth)acryloylmorpholine, N-(2-hydroxyethyl)(meth)acrylamide, N-vinyl-2-pyrrolidone, and N-vinyl-ε-caprolactam.

[0101] Examples of the chain vinyl compounds include propene, butene, pentene, and hexene. Examples of the 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 maleimide compounds include N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, and N-(p-methylphenyl)maleimide.

[0102] Further specific examples of the monofunctional polymerizable compound (B1) include compounds represented by the following formulae (b1-1) to (b1-28).

[0103]

[0104] (In formulas (b1-1) to (b1-28), R ２０ is a hydrogen atom or a methyl group. ２１is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer from 0 to 10.

[0105] As the polyfunctional polymerizable compound (B2), a compound having two or more radically polymerizable groups can be preferably used, and examples thereof include a polyfunctional (meth)acryloyl group-containing compound, a polyfunctional aromatic vinyl compound, and a polyfunctional chain vinyl compound.

[0106] Specific examples of the polyfunctional (meth)acryloyl group-containing compound include bifunctional (meth)acrylic acid esters, trifunctional or higher functional (meth)acrylic acid esters, etc. Specific examples of these include bifunctional (meth)acrylic acid esters such as 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, and tetraethylene glycol di(meth)acrylate.

[0107] Examples of trifunctional or higher functional (meth)acrylic acid esters 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, and succinic acid-modified pentaerythritol. Examples of the acrylic oligomer include tris(meth)acrylate, succinic acid-modified dipentaerythritol penta(meth)acrylate, tris(2-(meth)acryloyloxyethyl) isocyanurate, and carboxy group-containing polybasic acid-modified (meth)acrylic oligomer, as well as polyfunctional urethane acrylate compounds obtained by reacting a compound having a linear alkylene group and an alicyclic structure and having two or more isocyanate groups with a compound having one or more hydroxy groups in the molecule and three, four, or five (meth)acryloyloxy groups.

[0108] Examples of the polyfunctional aromatic vinyl compounds include 1,3-divinylbenzene, 1,4-divinylbenzene, etc. Examples of the polyfunctional chain vinyl compounds include 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, etc.

[0109] Further specific examples of the polyfunctional polymerizable compound (B2) include compounds represented by the following formulas (b2-29) to (b2-53).

[0110]

[0111]

[0112] (In formulas (b2-29) to (b2-53), R ２０ is a hydrogen atom or a methyl group. m and n are each independently an integer of 0 to 10. x, y, and z are each independently an integer of 0 to 3, provided that 1≦x+y+z≦3 is satisfied.

[0113] As the polyfunctional polymerizable compound (B2), from the viewpoints of increasing the refractive index and transparency, among the above, a (meth)acryloyl group-containing compound can be preferably used.

[0114] The radical polymerizable compound (B) may also be a polymerizable compound (B3) having both a radical polymerizable group and a cationically polymerizable group, and is preferably used in combination with the monofunctional polymerizable compound (B1) or the polyfunctional polymerizable compound (B2). Examples of the cationically polymerizable group include an epoxy group, an oxetanyl group, and a vinyl ether group.

[0115] The polymerizable compound (B3) having both a radical polymerizable group and a cationically polymerizable group is preferably a compound having a vinyl group or a (meth)acryloyl group as the radical polymerizable group and an epoxy group or an oxetanyl group as the cationically polymerizable group. Examples of the polymerizable compound (B3) include glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl (meth)acrylate, 3,4-epoxytricyclo[5.2.1.0] ２，６ ] decyl (meth)acrylate, 2-hydroxyethyl methacrylate [3,4-epoxytricyclo(5.2.1.0 ２，６ ) decan-9-yl], methacrylic acid [3,4-epoxytricyclo(5.2.1.0 ２，６ ) decan-9-yl], (3-methyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)(meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, (oxetan-3-yl)methyl (meth)acrylate, 3-(meth)acryloyloxymethyl-3-ethyloxetane, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3-[(4-vinylbenzyl)oxymethyl]-3-ethyloxetane, and the like, with 3-[(4-vinylbenzyl)oxymethyl]-3-ethyloxetane being preferred.

[0116] The present composition may contain one or a combination of two or more of the radical polymerizable compounds (B).

[0117] When the radical polymerizable compound (B) contains both a monofunctional polymerizable compound (B1) and a polyfunctional polymerizable compound (B2), the content of the monofunctional polymerizable compound (B1) is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the monofunctional polymerizable compound (B1) and the polyfunctional polymerizable compound (B2). The content of the monofunctional polymerizable compound (B1) is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on the total amount of the monofunctional polymerizable compound (B1) and the polyfunctional polymerizable compound (B2).

[0118] Furthermore, when the radical polymerizable compound (B) contains the polymerizable compound (B3), the content thereof in the radical polymerizable compound (B) is preferably 50 mass% or less, and more preferably 30 mass% or less.

[0119] The lower limit of the content of the radical polymerizable compound (B) in the composition (the total content when multiple types are contained) is preferably 5 parts by mass, more preferably 10 parts by mass, and even more preferably 20 parts by mass, relative to 100 parts by mass of the particles (A). The upper limit of the content of the radical polymerizable compound (B) is preferably 50 parts by mass, more preferably 45 parts by mass, and even more preferably 35 parts by mass, relative to 100 parts by mass of the particles (A). By setting the content of the radical polymerizable compound (B) in the composition within the above range, the refractive index can be increased, the sensitivity of the composition can be improved, and a cured product with good heat resistance and chemical resistance can be obtained.

[0120] <Photoradical Generator (C)> As the photoradical generator (C), a photoradical polymerization initiator that generates radicals in response to radiation and can initiate polymerization of the radically polymerizable compound (B) can be preferably used. The photopolymerization initiator to be used is not particularly limited, but examples thereof include O-acyloxime compounds, acetophenone compounds, biimidazole compounds, and acylphosphine oxide compounds.

[0121] Examples of O-acyloxime compounds include 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), 1-(9-ethyl-6-benzoyl-9H-carbazol-3-yl)-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-benzoate, ethanone- 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime), ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl}-9H-carbazol-3-yl]-1-(O-acetyloxime), and the like. Commercially available products include, for example, ADEKA ARCLES N-1919T, NCI-831E, NCI-930, and NCI-730 (all manufactured by ADEKA Corporation), and IRGACURE OXE01, OXE2, OXE3, and OXE4 (all manufactured by BASF).

[0122] 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)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-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, and 1-hydroxycyclohexylphenyl ketone. Commercially available products include Irgacure 369, 369E, 379EG, 651, 184, and 907 (all manufactured by BASF).

[0123] Examples of the biimidazole compound 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, and 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole.

[0124] Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0125] The present composition may contain one or a combination of two or more of the above photoradical generators (C).

[0126] The lower limit of the content of the photoradical generator (C) in the composition (the total content when multiple types are contained) is preferably 0.5 parts by mass, more preferably 1 part by mass, relative to 100 parts by mass of the particles (A) contained in the composition. The upper limit of the content of the photoradical generator (C) is preferably 15 parts by mass, more preferably 10 parts by mass, and even more preferably 5 parts by mass, relative to 100 parts by mass of the particles (A) contained in the composition. By setting the content of the photoradical generator (C) within the above range, a photosensitive composition exhibiting good curability and transparency can be obtained.

[0127] The composition may contain components other than the particles (A), the radical polymerizable compound (B), and the photoradical generator (C). Examples of the other components include a surfactant (D), an adhesion aid (E), a photoacid generator (F), a binder resin (G), a dehydrating agent (H), and a solvent (I).

[0128] <Surfactant (D)> The surfactant (D) can be used to improve the coatability of the composition (i.e., to improve wetting and spreading properties and reduce coating unevenness). Examples of the surfactant (D) include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

[0129] Specific examples of the surfactant (D) 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); Fluorad FC430 and FC431 (manufactured by Sumitomo 3M Limited); 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.); and Polyflow No. 75 and No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.); FTX-218 (manufactured by Neos Co., Ltd.); F-Top EF301, EF303, and EF352 (manufactured by Shin-Akita Kasei Co., Ltd.).

[0130] Examples of silicone surfactants include, by trade name, 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, and L-7002 (manufactured by Toray Dow Corning Silicone Co., Ltd.); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); and BYK-300, 306, 310, 330, 335, 341, 344, 370, 340, and 345 (manufactured by BYK Japan Co., Ltd.).

[0131] 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.

[0132] The present composition may contain one or more of the surfactants (D) described above.

[0133] When a surfactant (D) is blended in the present composition, the content of the surfactant (D) (the total content when multiple types of surfactants are included) is preferably 0.01 parts by mass or more and 1.5 parts by mass or less, and more preferably 0.02 parts by mass or more and 1.2 parts by mass or less, relative to 100 parts by mass of the particles (A) contained in the present composition.

[0134] <Adhesion Aid (E)> The adhesion aid (E) is a component that improves the adhesion between the obtained cured film and the substrate. As the adhesion aid (E), a functional silane coupling agent having a reactive functional group such as a carboxy group, a methacryloyl group, a vinyl group, an isocyanate group, or an oxiranyl group is preferred.

[0135] Examples of the functional silane coupling agent include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0136] The present composition may contain one or a combination of two or more of the adhesion aids (E).

[0137] When the present composition contains an adhesion aid (E), the content ratio of the adhesion aid (E) (the total content ratio when multiple types of adhesion aids (E) are contained) is preferably 1 part by mass or more and 15 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less, per 100 parts by mass of the particles (A) contained in the present composition.

[0138] <Photoacid Generator (F)> The photoacid generator (F) refers to a compound that generates an acid upon irradiation with light or other radiation. Examples of radiation include ultraviolet light, far ultraviolet light, X-rays, and charged particle beams. The generation of this acid can initiate cationic polymerization of a cationically polymerizable compound. Therefore, when the radical polymerizable compound (B) contains a polymerizable compound (B3), it is preferable that the radical polymerizable compound (B) contains a photoacid generator (F).

[0139] Examples of the photoacid generator (F) include oxime sulfonate compounds, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, sulfonate ester compounds, carboxylate ester compounds, and onium salts. Specific examples of these compounds include those described in JP-A-2020-026515. Among these, onium salts are preferred.

[0140] Examples of the onium salts include diphenyliodonium salts, triphenylsulfonium salts, sulfonium salts, benzothiazonium salts, and tetrahydrothiophenium salts. Examples of diphenyliodonium salts include diphenyliodonium tetrafluoroborate. Examples of triphenylsulfonium salts include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium tetrakis(pentafluorophenyl)borate. Among these, triphenylsulfonium hexafluoroantimonate is preferred.

[0141] The present composition may contain one or more of the above photoacid generators (F) in combination.

[0142] When the composition contains a photoacid generator (F), the lower limit of the content of the photoacid generator (F) (the total content when multiple types are contained) is preferably 0.5 parts by mass, more preferably 1 part by mass, relative to 100 parts by mass of the particles (A) contained in the composition. The upper limit of the content of the photoacid generator (F) is preferably 10 parts by mass, more preferably 5 parts by mass, relative to 100 parts by mass of the particles (A) contained in the composition. By setting the content of the photoacid generator (F) within the above range, a photosensitive composition exhibiting good curability can be obtained.

[0143] <Binder Resin (G)> The binder resin (G) is preferably a polymer having an acidic group. Examples of the acidic group include a carboxy group, a phenolic hydroxyl group, and a fluorinated hydroxyalkyl group. The binder resin is preferably an alkali-soluble resin. Here, "alkali-soluble" refers to a polymer that can be dissolved or swelled in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) at 25°C. The fluorinated hydroxyalkyl group refers to a group in which any hydrogen atom bonded to a carbon in a hydroxyalkyl group is substituted with a fluorine atom.

[0144] As the binder resin (G), a polymer having an ethylenically unsaturated monomer as a structural unit can be preferably used. Examples of the ethylenically unsaturated monomer constituting the polymer include the same compounds as those exemplified as the monofunctional polymerizable compound (B1), and preferably contain a carboxyl group-containing compound. In this case, the binder resin (G) preferably contains structural units derived from the carboxyl group-containing compound in an amount of 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on the total structural units constituting the binder resin (G).

[0145] When the binder resin (G) is a polymer containing an ethylenically unsaturated monomer as a constituent unit, the polymer can be produced, for example, by a known method such as radical polymerization using the above-mentioned ethylenically unsaturated monomer in an appropriate solvent in the presence of a polymerization initiator. Examples of the polymerization initiator include azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(isobutyrate) dimethyl. The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass per 100 parts by mass of the total amount of monomers used in the reaction. Examples of the polymerization solvent include alcohols, ethers, ketones, esters, and hydrocarbons, and specific examples include those listed as solvent (I) below. The amount of the polymerization solvent used is preferably such that the total amount of the monomers used in the reaction is 0.1 to 60% by mass relative to the total amount of the reaction solution. In the polymerization, the reaction temperature is usually 30° C. to 180° C. The reaction time varies depending on the types of polymerization initiator and monomer and the reaction temperature, but is usually 0.5 to 10 hours.

[0146] Examples of the binder resin (G) include polymers containing ethylenically unsaturated monomers as structural units, as well as phenolic hydroxyl group-containing polymers such as novolak resins, phenol-xylylene glycol condensation resins, cresol-xylylene glycol condensation resins, and phenol-dicyclopentadiene condensation resins. Furthermore, alkali-soluble polyorganosiloxanes, alkali-soluble polyimides, alkali-soluble polybenzoxazoles, and the like may also be used as the binder resin (G). Specific examples of alkali-soluble polyorganosiloxanes include the polymers described in WO 2017 / 188047 and WO 2017 / 169763. Specific examples of alkali-soluble polyimides and polybenzoxazoles include the polymers described in WO 2017 / 169763 and WO 2017 / 159876.

[0147] By including the binder resin (G) in the present composition, it is possible to improve the alkaline developability, but the refractive index of the obtained cured product tends to decrease, and the surface flatness tends to decrease. In the present invention, as described above, the particles (A) have acidic groups (Y) and can improve the alkaline developability, so the binder resin (G) does not need to be included, and if it is included, it may be in a small amount.

[0148] The present composition may contain one or more of the above binder resins (G).

[0149] When the composition contains a binder resin (G), the content of the binder resin (G) (the total content when multiple types are contained) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of the particles (A) contained in the composition. From the viewpoint of refractive index, it is preferable that the composition does not contain a binder resin (G).

[0150] <Dehydrating Agent (H)> The dehydrating agent (H) that can be used in the present composition is not particularly limited, but preferably contains an orthoester compound. An orthoester compound is a compound having three groups "-OR １１ ” (However, R １１is a monovalent hydrocarbon group) bonded to the same carbon atom, and is a compound represented by the general formula: R １２ -C(OR １１ ) ３ where R １２ is a hydrogen atom or a monovalent organic group. The orthoester compound is hydrolyzed to an ester. By incorporating such an orthoester compound into the photosensitive composition, the water absorption action of the orthoester compound can further improve the long-term coatability and storage stability of the photosensitive composition, which is preferable. In addition, the orthoester compound is preferred because it is stable and hydrophobic in alkaline developers and has little effect on exposed areas (for example, on sensitivity).

[0151] The group "-OR" contained in the orthoester compound １１ Examples of the group "-OR" include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, a tert-butoxy group, an n-pentoxy group, a phenoxy group, and a methylphenyloxy group. １１ " is preferably an alkoxy group, more preferably an alkoxy group having 1 to 4 carbon atoms. １１ " are the same or different groups.

[0152] R １２ Examples of R include a hydrogen atom, a monovalent chain hydrocarbon group, a halogenated chain hydrocarbon group in which at least one hydrogen atom of the chain hydrocarbon group is substituted with a halogen atom, and a monovalent aromatic ring group. １２ is preferably a hydrogen atom, a monovalent chain hydrocarbon group, or a monovalent aromatic ring group, and specific examples thereof include a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.

[0153] Among the above orthoester compounds, the compound represented by the following formula (5) can be preferably used: １２１ -C-(OR １１１ ) ３ ...(5) (In formula (5), R１１１ is an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R １２１ is a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 4 carbon atoms, or a monovalent aromatic ring group having 6 to 12 carbon atoms. １１１ are the same or different.)

[0154] In the formula (5), R １１１ The alkyl group of R may be linear or branched. １１１ is preferably a methyl group, an ethyl group or a phenyl group, more preferably a methyl group or an ethyl group.

[0155] R １２１ The chain hydrocarbon group R is preferably a chain or branched alkyl group having 1 to 4 carbon atoms. １２１ Examples of the aromatic ring group of R include a phenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, and a naphthyl group. In addition, the chain hydrocarbon group or aromatic ring group may have at least one hydrogen atom substituted with a halogen atom. １２１ is preferably a monovalent aromatic ring group, and particularly preferably a phenyl group, in that it is highly effective in improving coating properties over time and storage stability.

[0156] Specific examples of the orthoester compound include triethyl orthochloroacetate, trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, triisopropyl orthoformate, tributyl orthoformate, diethylphenyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, triethyl orthodichloroacetate, trimethyl orthobutyrate, triethyl orthobutyrate, trimethyl orthopropionate, triethyl orthopropionate, trimethyl orthovalerate, triethyl orthovalerate, trimethyl orthoisobutyrate, orthoisobutyrate, Among these, one or more selected from the group consisting of methyl orthoacetate, triethyl orthoacetate, trimethyl orthobenzoate, and triethyl orthobenzoate are preferred, one or more selected from the group consisting of triethyl orthoacetate, trimethyl orthobenzoate, and triethyl orthobenzoate are more preferred, and one or more selected from the group consisting of trimethyl orthobenzoate and triethyl orthobenzoate are even more preferred.

[0157] As the orthoester compound, a compound having an aromatic ring group can be preferably used from the viewpoint of long-term coating property and storage stability. Specific examples of the compound having an aromatic ring group include those represented by the formula (5) where R １１１ and R １２１ In particular, compounds in which at least one group is an aromatic ring-containing group are exemplified.

[0158] Specific examples of orthoester compounds having an aromatic ring group include trimethyl orthobenzoate, triethyl orthobenzoate, diethylphenyl orthoformate, etc. Among these, trimethyl orthobenzoate and triethyl orthobenzoate are particularly preferred because of their high effect of improving coating properties over time and storage stability.

[0159] The boiling point of the orthoester compound is not particularly limited, but is preferably 105° C. or higher at 1 atmosphere, more preferably 110° C. or higher, and even more preferably 115° C. or higher. Note that when the boiling point of the orthoester compound is high, even if the photosensitive composition is allowed to remain in a coating device or the like for a certain period of time, the orthoester compound can be prevented from volatilizing during that period, and the effect of incorporating the orthoester compound can be maintained, which is preferable.

[0160] Specific examples of orthoester compounds having a boiling point of 105°C or higher at 1 atmosphere include triethyl orthoformate (boiling point 145°C), tripropyl orthoformate (boiling point 198°C), tributyl orthoformate (boiling point 247°C), trimethyl orthoacetate (boiling point 108°C), triethyl orthoacetate (boiling point 145°C), triethyl orthodichloroacetate (boiling point 195°C), trimethyl orthobutyrate (boiling point 146°C), trimethyl orthopropionate (boiling point 128°C), triethyl orthopropionate (boiling point 158°C), trimethyl orthovalerate (boiling point 164°C), trimethyl orthobenzoate (boiling point 115°C), and triethyl orthobenzoate (boiling point 240°C). Of these, trimethyl orthobenzoate (boiling point 115°C / 3.3 kPa) and triethyl orthobenzoate (boiling point 240°C) are preferred. In this specification, the boiling point is a value at 1 atmosphere.

[0161] The dehydrating agent (H) may contain one or a combination of two or more of the above-mentioned orthoester compounds, or may contain a known dehydrating agent other than an orthoester compound, but preferably consists solely of an orthoester compound.

[0162] When the composition contains a dehydrating agent (H), the lower limit of the content of the dehydrating agent (H) is preferably 1 part by mass, more preferably 3 parts by mass, and even more preferably 5 parts by mass, relative to 100 parts by mass of the particles (A) contained in the composition. The upper limit of the content of the dehydrating agent (H) is preferably 40 parts by mass, more preferably 30 parts by mass, and even more preferably 25 parts by mass, relative to 100 parts by mass of the particles (A) contained in the composition. By setting the content of the dehydrating agent (H) within the above range, a photosensitive composition having excellent long-term coatability and storage stability can be obtained, which is preferable.

[0163] <Solvent (I)> The present composition may be a liquid composition in which the particles (A), the radical polymerizable compound (B), the photoradical generator (C), and other components blended as necessary are dissolved or dispersed in a solvent. As the solvent (I), an organic solvent that dissolves the particles (A), the radical polymerizable compound (B), and the photoradical generator (C) and does not react with each component is preferred.

[0164] Specific examples of the solvent (I) include alcohols such as methanol, ethanol, isopropanol, butanol, octanol, and diacetone alcohol; esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, 3-methoxybutyl acetate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate; ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, ethylene diglycol ethyl methyl ether, dimethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol ethyl methyl ether; amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. Of these, the solvent (I) preferably contains at least one selected from the group consisting of alcohols, ethers, and esters, and more preferably contains at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 3-methoxybutyl acetate, diethylene glycol ethyl methyl ether, diacetone alcohol, and dipropylene glycol methyl ether acetate.

[0165] From the viewpoint of long-term coating properties, the solvent (I) preferably contains a solvent having a high boiling point (for example, 160° C. or higher).

[0166] In addition to the above, other components include, for example, dispersants, polymerization inhibitors, antioxidants, sensitizers, softeners, plasticizers, ultraviolet absorbers, etc. The blending ratio of these components is appropriately selected depending on each component within a range that does not impair the effects of the present disclosure.

[0167] <Dispersant> Furthermore, if necessary, a dispersant of a type that does not affect the effects of the present invention or a dispersant in an amount that does not affect the effects of the present invention may be added.

[0168] Examples of the dispersant include polyacrylic acid dispersants, polycarboxylic acid dispersants, phosphoric acid dispersants, and silicon dispersants.

[0169] When the composition contains a dispersant, the amount of dispersant added is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and most preferably no dispersant, per 100 parts by mass of the particles (A) contained in the composition. If the amount is more than 5 parts by mass, the storage stability and long-term coatability of the resulting cured product may be reduced. In order to disperse particles in a resin, a large amount of dispersant may be required depending on the resin or particles. However, in the present invention, a dispersant is not used, and even if a dispersant is used, a very small amount of dispersant, such as 5 parts by mass or less, can be used to uniformly disperse a large amount of particles.

[0170] The composition can be obtained by mixing the particles (A), the radical polymerizable compound (B), the photoradical generator (C), and other optional components in a predetermined ratio. The composition obtained by mixing the components may be filtered, for example, through a filter having a pore size of 0.5 μm or less.

[0171] The solids concentration of the composition (i.e., the ratio of the total mass of components other than the solvent in the photosensitive composition to the total mass of the photosensitive composition) is appropriately selected taking into consideration viscosity, volatility, and the like. The solids concentration of the composition is preferably in the range of 3 to 60 mass%. A solids concentration of 3 mass% or more is preferred in that a sufficient coating thickness can be ensured when the composition is applied to a substrate. Furthermore, a solids concentration of 60 mass% or less is preferred in that the coating thickness does not become too large, and furthermore, the viscosity of the composition can be appropriately increased, ensuring good coatability. The solids concentration of the composition is more preferably 5 to 55 mass%, and even more preferably 10 to 50 mass%.

[0172] <<Method for Producing a Cured Product>> A cured product can be produced by using the photosensitive composition prepared as described above. This composition is particularly suitable as a negative pattern-forming material in which a pattern (i.e., the portion formed by the photosensitive composition) is obtained by exposing a portion of a film formed by the photosensitive composition to light and dissolving the unexposed portion in an alkaline developer, and then curing the pattern by heat treatment.

[0173] The cured product of the present disclosure is produced, for example, by a method including the following steps (I) to (IV): (I) a step of applying the present composition onto a substrate; (II) a step of irradiating the present composition applied onto the substrate with radiation; (III) a step of developing the present composition after irradiation; and (IV) a step of heating the present composition after development at a temperature of 100°C or less to cure it. Each step (steps (I) to (IV)) in the production method of the present disclosure will be described below.

[0174] <Step (I): Coating Step> Step (I) is a step of forming a coating film on a substrate by coating the present composition on the substrate. Examples of the substrate include glass substrates, silicon wafers, plastic substrates, plastic films, and substrates having colored resists, overcoats, anti-reflection films, various metal thin films, sealing films, etc. formed on their surfaces. 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. These substrates may be previously provided with various elements (for example, light-receiving elements such as photodiodes, and light-emitting elements such as organic light-emitting diodes).

[0175] The composition can be applied by any suitable method, such as spraying, roll coating, rotary coating (spin coating), slit die coating, bar coating, ink jetting, etc. Of these, spin coating, bar coating, and slit die coating are preferred.

[0176] After the composition is applied to a substrate, the composition may be preheated (prebaked) for the purpose of preventing dripping, etc. The prebaking conditions can be appropriately set depending on the type and use ratio of each component. The prebaking conditions can be, for example, 60 to 100°C for about 30 seconds to 10 minutes. From the viewpoint of applicability to organic EL devices, the prebaking temperature is preferably 60 to 90°C. The thickness of the coating film formed after prebaking is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm.

[0177] <Step (II): Exposure Step> Step (II) is a step of irradiating at least a portion of the coating film formed in step (I) with radiation. This radiation exposure causes a curing reaction to proceed in the exposed area. In step (II), the radiation exposure to the coating film is usually carried out through a mask. The mask may be a multi-tone mask such as a halftone mask or a graytone mask.

[0178] Examples of radiation to be irradiated onto the coating film include ultraviolet rays, far ultraviolet rays, X-rays, charged particle rays, etc. Examples of ultraviolet rays include g-rays (wavelength 436 nm), i-rays (wavelength 365 nm), KrF excimer laser light (wavelength 248 nm), etc. Examples of X-rays include synchrotron radiation, etc. Examples of charged particle rays include electron beams, etc. Among these, ultraviolet rays are preferred as the radiation to be irradiated onto the coating film, and ultraviolet rays with a wavelength of 200 nm or more and 380 nm or less are more preferred. Examples of light sources to be used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, excimer lasers, etc. The radiation exposure dose is 500 J / m ２ ~5,000 J / m ２ (50~500mJ / cm ２ ) is preferred.

[0179] <Step (III): Development Step> Step (III) is a step of forming a pattern on the substrate by developing the coating film irradiated with radiation in step (II). This development step removes unexposed areas of the coating film formed on the substrate, allowing a pattern consisting of exposed areas to be formed on the substrate.

[0180] Examples of the developer 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, 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 the developer.

[0181] As the developing method, for example, a suitable method such as a puddle method, a dipping method, a swing immersion method, a shower method, etc. can be used. The developing time may be adjusted appropriately depending on the composition of the present composition. The developing time is, for example, 20 to 120 seconds.

[0182] <Step (IV): Heating Step> Step (IV) is a step of heating the developed pattern at 100°C or less. The heat treatment in step (IV) further promotes curing, and a cured product exhibiting good heat resistance and chemical resistance can be obtained. The heat treatment can be performed using a heating device such as an oven or a hot plate. When obtaining microlenses as the cured product, hemispherical microlenses may be obtained by thermally flowing the developed pattern through the heat treatment in step (IV).

[0183] The heating temperature in step (IV) is 100°C or lower, preferably 95°C or lower, and more preferably 90°C or lower, from the viewpoint of enabling application to organic EL devices. 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 appropriately set 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. Furthermore, 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 heating treatment is performed multiple times may be used.

[0184] 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 a "post-exposure step"). Irradiation with radiation in the post-exposure step (hereinafter also referred to as "post-exposure") can further improve heat resistance, chemical resistance, etc., and produce a cured product with higher reliability. The type of radiation and exposure conditions in the post-exposure can be the same as those in step (II). The conditions for the post-exposure, such as the wavelength and dose of irradiation light and the light source, may be the same as or different from those in step (II).

[0185] <<Cured Film>> The cured film of the present invention can be formed by curing the photosensitive composition. This composition can provide a cured product with a high refractive index, specifically, a cured product with a refractive index of 1.70 or more at a wavelength of 589 nm. This composition can also provide a cured film with a high refractive index, preferably 1.73 or more, more preferably 1.80 or more, and even more preferably 1.82 or more at a wavelength of 589 nm.

[0186] The present composition has high solubility in an alkaline developer and excellent storage stability and long-term application properties. Therefore, by subjecting the composition to exposure treatment and development treatment, a cured product having a desired pattern shape can be obtained, and the same cured product can be obtained even after a certain period of time has passed.

[0187] The cured film is suitable as an optical member for a display element or an imaging element. The optical member is preferably a member for improving the light extraction efficiency in a display element (a light path adjusting member for adjusting the path of light) or a light path adjusting member for adjusting the path of light to focus it on a light receiving element (photodiode) provided in an imaging element such as a camera.

[0188] The cured film can also be suitably used as a sealant or insulating film for use in various display elements. When a composition that does not necessarily contain an acidic group is used, the cured film can also be suitably used as a composition for inkjet printing or a composition for imprints.

[0189] <Display element> The display element of the present invention includes a cured film formed from the photosensitive composition. Examples of the display element include a liquid crystal display element, an organic EL display element, and a micro LED (Light Emitting Diode) display element.

[0190] The imaging element of the present invention includes a cured film formed from the photosensitive composition described above. The cured film of the present invention is preferably used as an optical path adjusting member that adjusts the path of light to focus it on a light receiving element (photodiode) included in the imaging element of a camera or the like.

[0191] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified. In these examples, the weight average molecular weight (Mw) of the polymer (binder resin) was measured by the following method.

[0192] [Weight-average molecular weight (Mw)] The Mw of a polymer (binder resin) is a polystyrene-equivalent value measured by the following method and conditions: Measurement method: gel permeation chromatography (GPC) method Apparatus: GPC-101 manufactured by Showa Denko K.K. GPC column: GPC-KF-801, GPC-KF-802, GPC-KF-803, and GPC-KF-804 manufactured by Shimadzu GLC Corporation combined together Mobile phase: tetrahydrofuran Column temperature: 40°C Flow rate: 1.0 mL / min Sample concentration: 1.0 mass% Sample injection amount: 100 μL Detector: differential refractometer Standard material: monodisperse polystyrene

[0193] [Average Particle Diameter] The average particle diameter of the particles is the D50 particle diameter (median diameter, which is the particle diameter showing the 50% integrated value of the integrated distribution curve) measured by dynamic light scattering, and was measured using MicrotracWave II-EX150 manufactured by MicrotracBell.

[0194] <Preparation of Particle Dispersion> [Synthesis Example 1] Particle Dispersion (A-1) A propylene glycol monomethyl ether acetate (PGMEA) dispersion of titanium oxide (referred to as (a-1)) having a solids concentration of 20% and an average particle size of 33 nm was obtained using a method similar to that of Production Example 1 of Japanese Patent No. 5505726. Specifically, it was prepared as follows. (Preparation of Vapor-Phase Titanium Oxide Dispersion) 100 g of Super Titania F-2 (vapor-phase oxidation method) manufactured by Resonac (formerly Showa Denko K.K.) and 50 g of 3-methacryloyloxypropyltrimethoxysilane (KMB-503 manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with 2000 g of propylene glycol monomethyl ether acetate (PGMEA), and the mixture was dispersed for 5 hours using zirconia beads as a medium in a paint shaker (manufactured by Red Devil Co., Ltd.) to obtain a titanium oxide dispersion. Furthermore, this dispersion was heated at 60 to 70°C for 3 hours to perform a surface treatment, and then the solvent was partially removed by concentration under reduced pressure to obtain a titanium oxide dispersion (a-1) (hereinafter also referred to as raw material dispersion (a-1)) having a solid content of 20 mass% and an average particle size of 33 nm.

[0195] A 300 mL three-neck flask equipped with a stirrer, a condenser, and a thermometer was charged with 100 g of the raw material dispersion (a-1), 0.47 g of β-mercaptopropionic acid (BMPA), 0.60 g of 1-mercaptodecane (C12SH), 0.89 g of triethylamine, and 21 mg of 4-methoxyphenol, and the mixture was stirred at 90 ° C. for 12 hours. After completion of the reaction, the mixture was washed once with a 1 M aqueous hydrochloric acid solution and three times with water, and then PGMEA was added and solvent replacement by vacuum concentration was performed twice to obtain a dispersion (A-1) with a solids concentration of 50% by mass. The particles in the resulting dispersion (A-1) had methacryloyl groups derived from 3-methacryloyloxypropyltrimethoxysilane, carboxy groups derived from BMPA, and alkyl groups derived from C12SH.

[0196] [Synthesis Examples 2 to 4] Particle Dispersions (A-2) to (A-4) Similar to Synthesis Example 1, a modification reaction was carried out using the compositions shown in Table 1, and all were finished as PGMEA dispersions with a solid content concentration of 50 mass %. These were designated dispersions (A-2) to (A-4), respectively.

[0197] Synthesis Example 5 Particle Dispersion (A-5) A dispersion (a-2) (hereinafter also referred to as raw material dispersion (a-2)) was obtained in the same manner as in Synthesis Example 1, except that the amount of 3-methacryloyloxypropyltrimethoxysilane (KMB-503, manufactured by Shin-Etsu Chemical Co., Ltd.) used in Synthesis Example 1 was changed to 30 g.

[0198] 100 g of the dispersion (a-2), 0.42 g of β-mercaptopropionic acid (BMPA), 0.40 g of 1-mercaptodecane (C12SH), 0.89 g of triethylamine, and 21 mg of 4-methoxyphenol were added to a 300 mL three-neck flask equipped with a stirrer, a condenser, and a thermometer, and the mixture was stirred for 12 hours at 90° C. After completion of the reaction, the mixture was washed once with a 1 M aqueous hydrochloric acid solution and three times with water, and then PGMEA was added and solvent replacement by concentration under reduced pressure was performed twice to obtain a dispersion (A-5) with a solids concentration of 50% by mass.

[0199]

[0200] The abbreviations in Table 1 are as follows: (a-1): Titanium oxide dispersion liquid (a-1) obtained in Synthesis Example 1 (a-2): Titanium oxide dispersion liquid (a-2) obtained in Synthesis Example 5 BMPA: β-mercaptopropionic acid C10SH: 1-decanethiol C12SH: 1-dodecanethiol BTZ: 2-mercaptobenzothiazole

[0201] Comparative Synthesis Example 1 Barium titanate particle dispersion (r-1) dispersion containing dispersant To a perfluoroalkoxyalkane (PFA) container, 100 parts by mass of barium titanate (Sigma-Aldrich, primary particle diameter less than 100 nm), 11 parts by mass of MARBON AC-F3 (polyoxyethylene secondary alkyl ether) manufactured by Matsumoto Yushi Seiyaku Co., Ltd., and 192 parts by mass of propylene glycol monomethyl ether were added, and 900 parts by mass of zirconia beads (manufactured by Nikkato Corporation) having a particle size of 0.1 mm were added, and the mixture was shaken for 1 hour using a paint conditioner (manufactured by REDDEVIL Co., Ltd.) to disperse the barium titanate nanoparticles in propylene glycol monomethyl ether. The zirconia beads were then removed to obtain a barium titanate particle dispersion (r-1). The average particle size of the particles in the barium titanate particle dispersion (r-1) was 50 nm.

[0202] Synthesis of Binder Resin (G-1) [Synthesis Example 6] A flask equipped with a condenser and a stirrer was charged with 100 parts by mass of propylene glycol monomethyl ether acetate and purged with nitrogen. The flask was heated to 80°C, and a mixed solution of 100 parts by mass of propylene glycol monomethyl ether acetate, 15 parts by mass of methacrylic acid, 15 parts by mass of styrene, 5 parts by mass of benzyl methacrylate, 15 parts by mass of 2-hydroxyethyl methacrylate, 23 parts by mass of 2-ethylhexyl methacrylate, 12 parts by mass of N-phenylmaleimide, 15 parts by mass of mono(2-acryloyloxyethyl) succinate, and 6 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile) was added dropwise over 1 hour at the same temperature. The temperature was maintained and polymerization was carried out for 2 hours. Thereafter, the temperature of the reaction solution was raised to 100°C, and polymerization was carried out for another 1 hour to obtain a binder resin solution (solids concentration: 33% by mass). The resulting binder resin solution had an Mw of 12,200. This binder resin solution is referred to as "binder resin (G-1)."

[0203] Synthesis Example 7 Synthesis of Raw Material Dispersion 100 g of zirconium oxide nanoparticles (product name: UEP-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., primary particle size: 11 nm), 50 g of vinyltrimethoxysilane (VTMS), and 900 g of methyl ethyl ketone were mixed and dispersed for 5 hours in a paint shaker (manufactured by Red Devil Co., Ltd.) using zirconia beads as a medium, to obtain a zirconium oxide dispersion. Furthermore, this dispersion was heated at 60 to 70°C for 3 hours. After completion of the reaction, the mixture was concentrated to obtain a raw material dispersion (a-3) (hereinafter also referred to as raw material dispersion (a-3)) having a solids concentration of 20% by mass.

[0204] Synthesis Examples 8 to 10: Synthesis of raw material dispersions Raw material dispersions (a-4) to (a-6) were obtained using the compositions shown in Table 2 in the same manner as in Synthesis Example 7.

[0205] Synthesis Example 11 Synthesis of Raw Material Dispersion A raw material dispersion (a-7) (solid content concentration: 20% by mass, methyl ethyl ketone solution) was obtained in the same manner as in Synthesis Example 7, except that TTO-51(A) (ultrafine particle titanium oxide, particle size: 10 to 30 nm) manufactured by Ishihara Sangyo Kaisha, Ltd. was used as the particles as shown in Table 2.

[0206] Synthesis Example 12 Synthesis of Raw Material Dispersion 286 g of a titanium oxide nanoparticle dispersion (product name: NS405, manufactured by Teika Corporation, solid content concentration: 35% by mass, PGMEA solution, particle size: 20 nm), 1814 g of propylene glycol monomethyl ether (PGME), 0.15 g of 4-methoxyphenol, and 50.0 g of KBM5803 were added and stirred at room temperature for 5 hours and at 70° C. for 3 hours. After completion of the reaction, the mixture was concentrated to obtain a dispersion (a-8) with a solid content concentration of 20% by mass.

[0207] Synthesis Examples 13 to 15: Synthesis of raw material dispersions Raw material dispersions (a-9) to (a-11) were obtained using the compositions shown in Table 2 in the same manner as in Synthesis Example 12.

[0208]

[0209] The abbreviations in Table 2 are as follows: UEP100: Zirconium oxide nanoparticles (trade name: UEP-100, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., primary particle size: 11 nm) TTO-51(A): Ultrafine particle titanium oxide (trade name: TTO-51(A), manufactured by Ishihara Sangyo Kaisha, Ltd., particle size: 30 nm) NS405: Titanium oxide nanoparticle dispersion (trade name: NS405, manufactured by Teika Corporation, solid content concentration: 35%, PGMEA solution, particle size: 20 nm)

[0210] Synthesis Example 16 Synthesis of Surface-Modified Particles: Method A To a 300 mL three-neck flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen inlet tube, 100 g of (a-3) obtained in Synthesis Example 7 above, 0.99 g of thiosalicylic acid (TSA), 0.70 g of 2-ethylhexylthiol (2EHT), and 0.14 g of 2,2′-azobis(isobutyronitrile) were added and stirred for 4 hours at 80° C. After completion of the reaction, the mixture was poured into 1 L of hexane, and the precipitate that formed was filtered and dried in vacuo to obtain a powder of surface-modified particles (A-6).

[0211] [Synthesis Examples 17 to 21, 24] Synthesis of surface-modified particles: Method A Powders of surface-modified particles (A-7) to (A-11) and (A-14) were obtained using the compositions shown in Table 3 and in the same manner as in Synthesis Example 12.

[0212] Synthesis Example 22 Synthesis of Surface-Modified Particles: Method B 100 g of (a-6) obtained in Synthesis Example 10 above, 0.41 g of mercaptotriazole (MTRZ), and 0.44 g of 2-ethylhexyl-3-mercaptopropionic acid (2EHT-BMPA) were added to a 300 mL three-neck flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen inlet tube, and the mixture was stirred at room temperature for 12 hours. After completion of the reaction, the mixture was poured into 1 L of hexane, and the precipitate that formed was filtered and vacuum dried to obtain a powder of surface-modified particles (A-12).

[0213] Synthesis Example 23 Synthesis of Surface-Modified Particles: Method B Using the composition shown in Table 3, a powder of surface-modified particles (A-13) was obtained in the same manner as in Synthesis Example 22.

[0214] Synthesis Example 25 Synthesis of Surface-Modified Particles: Method C 100 g of the raw material dispersion (a-8), 0.48 g of β-mercaptopropionic acid (BMPA), 0.89 g of triethylamine, and 21 mg of 4-methoxyphenol were added to a 300 mL three-neck flask equipped with a stirrer, a condenser, and a thermometer, and the mixture was stirred for 12 hours at 90° C. After completion of the reaction, PGMEA was added, and the mixture was washed once with a 1 M aqueous hydrochloric acid solution and three times with water. After concentration under reduced pressure, the mixture was poured into hexane, and the precipitate that formed was filtered and dried under vacuum, yielding a powder of surface-modified particles (A-15).

[0215] [Synthesis Examples 26 to 29]: Method C Using the compositions shown in Table 3, powders of surface-modified particles (A-16) to (A-19) were obtained in the same manner as in Synthesis Example 25.

[0216]

[0217] The abbreviations in Table 3 are as follows: (a-3) to (a-11): Dispersions (a-1) to (a-11) obtained in Synthesis Examples 7 to 15. MTRZ: mercaptotriazole BMPA: β-mercaptopropionic acid

[0218] <Preparation of Photosensitive Composition> The types and abbreviations of the particles (A), radical polymerizable compound (B), photoradical generator (C), surfactant (D), adhesion aid (E), and binder resin (G) used in the preparation of the photosensitive composition are shown below.

[0219] <(A) Particles> A-1 to A-5: Particle dispersions (A-1) to (A-5) obtained in Synthesis Examples 1 to 5 A-6 to A-19: Powders of particles (A-6) to (A-19) obtained in Synthesis Examples 16 to 29 a-1: Titanium oxide dispersion (a-1) obtained in Synthesis Example 1 r-1: Barium titanate particle dispersion (r-1) obtained in Comparative Synthesis Example 1 <(B) Radical Polymerizable Compound> B-1: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.) B-2: 3-phenoxybenzyl acrylate (trade name: Light Acrylate POB-A, manufactured by Kyoeisha Chemical Co., Ltd.) <(C) Photoradical Generator> C-1: NCI-930 (trade name, manufactured by ADEKA Corporation) <(D) Surfactant> D-1: Polyether-modified silicone additive (trade name: DOWSIL™ SH28 Paint Additive, manufactured by Dow Corning Toray Co., Ltd.) <(E) Adhesion aid> E-1: 3-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: KMB-503) <(G) Binder resin> G-1: Binder resin (G-1) obtained in Synthesis Example 6

[0220] [Example 1] Preparation of Photosensitive Composition

[0047] 100.0 parts by mass (solids content equivalent) of particle dispersion (A-1) as dispersion (A), 10.0 parts by mass of polymerizable compound (B-1) as polymerizable compound (B-2), 15.0 parts by mass of polymerizable compound (B-2), 4.0 parts by mass of (C-1) as photoradical generator (C), 0.05 parts by mass of (D-1) as surfactant (D), 5 parts by mass of (E-1) as adhesion aid (E), and a solvent (PGMEA) were added to a solids concentration of 35.0 mass%, followed by stirring and dissolution. The mixture was then filtered through a membrane filter with a pore size of 0.2 μm to prepare the photosensitive composition of Example 1.

[0221] [Examples 2 to 5, Comparative Examples 1 to 4] Preparation of Photosensitive Compositions The dispersion, polymerizable compound, photoradical generator, surfactant, adhesion aid, solvent, and binder resin were mixed in the ratios shown in Table 4, and the photosensitive compositions of Examples 2 to 5 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1. In Table 4, "-" indicates that the corresponding component was not used. In Table 4, the amounts of dispersion and binder resin added are expressed as amounts (solids equivalent) excluding the solvent.

[0222]

[0223] [Examples 6 to 19] Preparation and evaluation of photosensitive compositions The photosensitive compositions of Examples 6 to 19 were prepared in the same manner as in Example 1 by mixing the dispersion, polymerizable compound, photoradical generator, surfactant, adhesion aid, and solvent in the ratios shown in Table 5. In Table 5, "-" indicates that the corresponding component was not used. In Table 5, the amount of dispersion added is the amount (solids equivalent) excluding the solvent.

[0224]

[0225] <Refractive index evaluation method> The photosensitive composition was applied to an alkali-free glass substrate using a spinner, and then prebaked on a hot plate at 85°C for 60 seconds to form a coating film with a thickness of 3.0 µm. Next, the obtained coating film was irradiated with 100 mJ / cm using a high-pressure mercury lamp (SUSS). ２ The film was then post-baked in an oven at 85°C for 60 minutes to form a cured film. The refractive index of the resulting cured film at 589 nm was measured using a prism coupler and evaluated according to the following criteria: ⊚: n≧1.73 ◯: 1.73>n≧1.70 Δ: 1.70>n≧1.65 ×: n<1.65

[0226] <Method for evaluating application properties over time (syringe clogging)> A 10 mL clear syringe (PSY-10E, manufactured by Musashi Engineering Co., Ltd.) was fitted with a SUS needle (SNA-20G-B, manufactured by Musashi Engineering Co., Ltd., inner diameter × needle outer diameter (φmm): 0.61 × 0.91). 5 g of each of the photosensitive compositions obtained in the Examples and Comparative Examples was placed in the clear syringe, which was then quickly capped with a syringe head cap (HC-10C, manufactured by Musashi Engineering Co., Ltd.). The photosensitive composition came out of the SUS needle but stopped after about 20 seconds. The clear syringe was left to stand, and after a certain period of time, the syringe head cap was removed. If the photosensitive composition passed through, it was judged as "no syringe clogging"; if the photosensitive composition did not pass through, it was judged as "syringe clogging." Evaluation was performed according to the following criteria: A: Syringe clogging did not occur even after 100 minutes or more had passed. B: The syringe did not clog in less than 80 minutes, but clogged after 80 to 100 minutes. C: The syringe did not clog in less than 60 minutes, but clogged after 60 to 80 minutes. D: The syringe did not clog in less than 20 minutes, but clogged after 20 to 60 minutes. E: Clogged after less than 20 minutes.

[0227] <Evaluation of Storage Stability (Rate of Viscosity Change)> The viscosity of each of the photosensitive compositions obtained in the Examples and Comparative Examples was measured immediately after preparation using an E-type viscometer (initial viscosity). The photosensitive compositions were then stored at 25°C for one month, and the viscosity was measured again (viscosity after storage). The rate of viscosity change was calculated using the following formula and evaluated according to the following criteria.

[0228] A: Viscosity change rate is less than 2% B: Viscosity change rate is 2% or more but less than 5% C: Viscosity change rate is 5% or more but less than 10% D: Viscosity change rate is 10% or more

[0229] <Resolution Evaluation> (Resolution Evaluation Method) Each of the photosensitive compositions obtained in the Examples and Comparative Examples was applied onto a 6-inch glass wafer using a spinner, and then prebaked on a hot plate at 85°C for 60 seconds to form a coating film with a thickness of 3.0 µm. Using a high-pressure mercury lamp (SUSS), the wafer was irradiated with a cumulative dose of 100 mJ / cm through a photomask with a 20 µm hole. ２ The wafer was exposed to light so that the exposure temperature was 100°C, and puddle development was carried out using a 2.38% aqueous TMAH solution (developer temperature: 25°C) for 60 seconds, followed by rinsing with water. The substrate was heated in a clean oven at 85°C for 60 minutes to form a cured film on the 6-inch glass wafer. The residue of the resulting cured film was confirmed using an optical microscope, and the resolution was evaluated. ⊚: Unexposed areas can be resolved without residue while being dissolved in the developer. ◯: Unexposed areas can be resolved without residue while being peeled off with the developer. △: Some residue remains. ×: Resolution is not possible.

[0230] <Evaluation of Storage Stability (Change in Resolution)> The resolution of each of the photosensitive compositions obtained in the Examples and Comparative Examples was measured immediately after preparation according to the following method (initial resolution). The photosensitive compositions were then stored at 25°C for one month, and the resolution was measured again (resolution after storage). The change in resolution was calculated using the following formula and evaluated according to the following evaluation criteria: Resolution change (μm) = (initial resolution) - (resolution after storage) (Resolution Evaluation Method) Each photosensitive composition was applied to a 6-inch glass wafer using a spinner, and then prebaked on a hot plate at 85°C for 60 seconds to form a coating film with a thickness of 3.0 μm. Using a high-pressure mercury lamp (SUSS), a cumulative irradiation dose of 100 mJ / cm was measured through a photomask with a 20 μm hole. ２ The substrate was exposed to light so that the image was clear, and puddle development was carried out using a 2.38% TMAH aqueous solution (developer temperature: 25°C) for 60 seconds, followed by rinsing with water. The substrate was heated in a clean oven at 85°C for 60 minutes to form a cured film on the 6-inch glass wafer. The bottom width inside the resulting hole was confirmed using an optical microscope to evaluate the resolution. A: Resolution change of less than 1 μm B: Resolution change of 1 μm or more but less than 3 μm C: Resolution change of 3 μm or more but less than 5 μm D: Resolution change of 5 μm or more

[0231] As shown in Tables 4 and 5, the photosensitive compositions of Examples 1 to 19 were evaluated as being good in terms of long-term application properties, storage stability, and resolution. In contrast, the comparative examples were poor in all evaluations, and in particular, patterns could not be formed in Comparative Examples 1 and 3. Furthermore, as can be seen from the examples, in the present invention, the surface treatment of particles is carried out by chemical reaction. Therefore, particles that have been powdered can be easily redispersed in the resist solution. Conventional particles tend to aggregate when powdered, which can cause foreign matter, so the fact that this problem has been resolved is a groundbreaking achievement.

[0232] 1 Inorganic particles 2 Raw material particles (a-1) 3 Particles (A)

Claims

1. A photosensitive composition for forming an optical member, comprising: (A) particles having a reactive group, an acidic group different from the reactive group, at least one group selected from the group consisting of an oxygen atom-containing or oxygen atom-free alkyl group having 2 to 30 carbon atoms, and an oxygen atom-containing or oxygen atom-free alkylene group having 2 to 30 carbon atoms; (B) a radically polymerizable compound; and (C) a photo radical generator.

2. The photosensitive composition according to claim 1, wherein the reactive group is a group selected from the group consisting of a (meth)acryloyl group, a vinyl group, an epoxy group, an epoxy cyclohexyl group, a mercapto group, an amino group, an acid anhydride group, an isocyanate group, and a carboxy group.

3. The photosensitive composition according to claim 2, wherein the reactive group is a (meth)acryloyl group.

4. The photosensitive composition according to claim 1, wherein the particle (A) is a particle obtained by reacting a particle having a reactive group with a compound represented by the following formula (1) with a part of the reactive groups. (In formula (1), Z １ is an oxygen atom-containing or oxygen atom-free alkyl group having 2 to 30 carbon atoms. Xc １ is a group that reacts with the reactive group.) 5. The photosensitive composition according to claim 1, wherein the particle (A) is a particle obtained by reacting a part of the reactive groups of a particle having reactive groups with a compound represented by the following formula (2). (In formula (2), Y １ is an acidic group. R １ is a (m + 1)-valent organic group. m is an integer from 1 to 3. When m is 2 or 3, a plurality of Y １ are the same as or different from each other. Xc １ is a group that reacts with the reactive group.) 6. The Y １ is a carboxy group or a phenolic hydroxyl group, and the photosensitive composition according to claim 5.

7. The photosensitive composition according to claim 1, wherein the particles (A) are particles obtained by surface-modifying particles made of a metal oxide, and the metal oxide is a compound selected from the group consisting of titanium oxide, zirconium oxide, and zinc oxide.

8. The photosensitive composition according to claim 1, wherein the radically polymerizable compound (B) is a compound having a (meth)acryloyl group.

9. The photosensitive composition according to claim 1, further comprising a dispersant in an amount of 5 parts by mass or less based on 100 parts by mass of the particles (A), or not containing a dispersant.

10. The photosensitive composition according to claim 1, wherein the optical member is a member for improving the light extraction efficiency in a display element.

11. A cured product obtained by curing the photosensitive composition according to any one of claims 1 to 10.

12. A method for producing a cured product, comprising: a step of applying the photosensitive composition according to any one of claims 1 to 10 onto a substrate; a step of irradiating the photosensitive composition applied onto the substrate with radiation; a step of developing the photosensitive composition after irradiation with radiation; and a step of heating and curing the photosensitive composition after development at a temperature of 100°C or lower.

13. A display element comprising the cured product according to claim 11.

14. An imaging element comprising the cured product according to claim 11.

15. A photosensitive composition for forming an optical member, comprising: particles having a reactive group and at least one group selected from the group consisting of an oxygen atom-containing or oxygen atom-non-containing alkyl group having 2 to 30 carbon atoms and an oxygen atom-containing or oxygen atom-non-containing alkylene group having 2 to 30 carbon atoms; (B) a radically polymerizable compound; and (C) a photo radical generator.

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