Inorganic particles contain constituents

Abstract

The objective is to provide a composition containing inorganic particles and aromatic monomers, wherein the viscosity of the composition is reduced. [Solution] The present invention provides a composition comprising inorganic particles, an aromatic monomer, and an α,β-unsaturated carboxylic acid, wherein the aromatic monomer has one or more polymerizable unsaturated groups selected from the group consisting of (meth)acryloyl groups, vinyl groups, and allyl groups, and the number of hydrogen atoms bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid is 1 or 0.

Description

[Technical Field]

[0001] This invention relates to a composition containing inorganic particles. [Background technology]

[0002] Compositions containing various inorganic particles can contribute to the enhancement of functionality and performance of various materials, such as optical materials, electronic component materials, magnetic recording materials, catalytic materials, ultraviolet absorbing materials, and dental materials, depending on the function of the inorganic particles. In particular, in optical materials, there is a demand for high-refractive-index compositions for applications such as optical lenses, inkjet resin compositions, nanoimprint resin compositions, microlens arrays, anti-reflective layers used in transparent electrodes, anti-reflective films and anti-reflective agents, surface coatings for optical lenses, organic EL light extraction layers, various hard coating materials, planarization films for thin-film transistors (TFTs), overcoats for color filters, various protective films such as anti-reflective films, and optical filters, insulating films for touch sensors, insulating films for TFTs, photospacers for color filters, and protective films for touch panels.

[0003] For example, Patent Document 1 discloses a composition containing zirconium oxide particles and phenylbenzyl acrylate, and states that the cured product of this composition has a high refractive index. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-104071 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, when applying inorganic particle-containing compositions to optical applications, aromatic monomers with high refractive indices are preferably used as monomers. However, using aromatic monomers can sometimes increase the viscosity of the composition. However, Patent Document 1 does not examine the viscosity of compositions containing inorganic particles and aromatic monomers.

[0006] Therefore, the present invention aims to provide a composition comprising inorganic particles and aromatic monomers, wherein the viscosity of the composition is reduced. [Means for solving the problem]

[0007] The present invention, which has achieved the above objectives, is as follows. [1] comprising inorganic particles, aromatic monomers, and α,β-unsaturated carboxylic acids, The aromatic monomer has one or more polymerizable unsaturated groups selected from the group consisting of (meth)acryloyl groups, vinyl groups, and allyl groups. A composition in which the number of hydrogen atoms bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid is 1 or 0. [2] The composition according to [1], wherein a carboxyl group is not bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid. [3] The composition according to [1] or [2], wherein the α,β-unsaturated carboxylic acid is one or more compounds selected from those represented by the following formulas (z1-1), (z1-2), (z2), and (z3). [ka] [In the formula, R z11 and R z13 R is a hydrocarbon group to which a heteroatom or substituent having a heteroatom may be attached, z12 , R z14 [This is a hydrogen atom or a hydrocarbon group.] [ka] [In formula (z2), ring Z 21is a hydrocarbon ring or heterocyclic ring having a carbon-carbon double bond, which represents a ring to which a hydrocarbon group, a heteroatom or a substituent having a heteroatom may be bonded, and ring Z 22 is ring Z 21 is a hydrocarbon ring or heterocyclic ring that may be fused to ring Z, which represents a ring to which a hydrocarbon group, a heteroatom or a substituent having a heteroatom may be bonded, and the α,β-unsaturated group of the α,β-unsaturated carboxylic acid represented by formula (z2) forms a carbon-carbon double bond within the ring of ring Z 21

Chemical Structure

[0008] According to the present invention, a composition comprising inorganic particles and aromatic monomers, having low viscosity, can be realized. [Modes for carrying out the invention]

[0009] The present invention relates to a composition comprising inorganic particles, an aromatic monomer, and an α,β-unsaturated carboxylic acid, wherein the aromatic monomer has one or more polymerizable unsaturated groups selected from the group consisting of (meth)acryloyl groups, vinyl groups, and allyl groups, and the number of hydrogen atoms bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid is 1 or 0. Compositions containing aromatic monomers tend to have high viscosity due to π-π interactions between the aromatic monomers, but it is believed that by including a predetermined α,β-unsaturated carboxylic acid in the composition, these π-π interactions can be mitigated, thereby reducing the viscosity of the composition.

[0010] <α,β-unsaturated carboxylic acids> The number of hydrogen atoms bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid is 1 or 0. The number of hydrogen atoms bonded to the carbon atom at the α-position of the α,β-unsaturated carboxylic acid may be 1 or 0. If the number is 0, it is preferable that a hydrocarbon group is bonded, and it is preferable that the number of hydrogen atoms bonded to the carbon atom at the α-position is 1.

[0011] The α,β-unsaturated carboxylic acid is preferably one or more selected from the compounds represented by the following formulas (z1-1), (z1-2), (z2), or (z3), more preferably one or more selected from the compounds represented by (z1-1), (z1-2), or (z2), and even more preferably one or more selected from the compounds represented by (z1-1) or (z1-2).

[0012] [ka]

[0013] In the formula, R Z11 and R Z13 R is a hydrocarbon group to which a heteroatom or substituent having a heteroatom may be attached, Z12 , R Z14 It is a hydrogen atom or a hydrocarbon group.

[0014] R Z11 and R Z13 Examples of hydrocarbon groups in this context include aliphatic chain hydrocarbon groups, aliphatic hydrocarbon groups having a cyclic structure, aromatic hydrocarbon groups, and groups that combine aliphatic hydrocarbon groups and aromatic hydrocarbon groups. The aliphatic chain hydrocarbon group is preferably an alkyl group or an alkenyl group, more preferably an alkyl group, and more preferably an alkyl group having 1 to 3 carbon atoms. The aliphatic hydrocarbon group having a cyclic structure is preferably a cycloalkyl group, a cycloalkenyl group, a bicycloalkyl group, or a bicycloalkenyl group, with a bicycloalkenyl group being preferred, and 2,4,5,6,7,7a-hexahydro-1H-indene being even more preferred. Examples of aromatic hydrocarbon groups include phenyl groups and naphthyl groups, with phenyl groups being preferred. The group combining an aliphatic hydrocarbon group and an aromatic hydrocarbon group is preferably an alkylaryl group, an alkenylaryl group, an arylaryl group, or an arylalkyl group, more preferably an arylalkyl group or an alkenylaryl group, and even more preferably a benzyl group or a vinylphenyl group.

[0015] R Z11 and R Z13 The hydrocarbon group in is preferably an aliphatic hydrocarbon group or an aromatic hydrocarbon group, more preferably an alkyl group, a phenyl group, or a naphthyl group, and even more preferably an alkyl group or a phenyl group.

[0016] Examples of heteroatoms bonded to the hydrocarbon group include halogen atoms or oxygen atoms, and it is preferable that they are bonded to the hydrocarbon group as a halogeno group or an oxo group (=O), with the oxo group being more preferable. Examples of substituents having heteroatoms bonded to the hydrocarbon group include formyl group, carboxyl group, alkoxy group, hydroxyl group, sulfonyl group (-S(=O)2), nitro group (-NO2), and methylenedioxy group (-O-CH2-O-), with formyl group, carboxyl group, alkoxy group having 1 to 5 carbon atoms, hydroxyl group, and methylenedioxy group being preferred, and an alkoxy group having 1 to 3 carbon atoms or a hydroxyl group being more preferable. When a divalent group such as a methylenedioxy group is bonded to a hydrocarbon group, the methylenedioxy group is bonded to the hydrocarbon group at two locations (two carbon atoms).

[0017] R Z12 , R Z14 is a hydrogen atom or a hydrocarbon group, preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.

[0018] Examples of compounds represented by formula (z1-1) or (z1-2) include crotonic acid, isocrotonic acid, cinnamic acid, ferulic acid, 3,5-dimethoxy-4-hydroxycinnamic acid, 4-hydroxycinnamic acid, 2-carboxycinnamic acid, 4-formylcinnamic acid, 3,4-methylenedioxycinnamic acid, 2-hydroxycinnamic acid, 3-hydroxy-4-methoxycinnamic acid, 3-hydroxycinnamic acid, 3,4-dihydroxy-5-methoxycinnamic acid, tigric acid, angelic acid, 1,4-benzenediacrylic acid, 3-benzoylacrylic acid, and hydroxyvalerenic acid, with crotonic acid, cinnamic acid, or ferulic acid being preferred.

[0019] [ka]

[0020] In formula (z2), ring Z 21 This represents a hydrocarbon ring or heterocycle having a carbon-carbon double bond, which may have a hydrocarbon group, a heteroatom, or a substituent having a heteroatom attached to it, and ring Z 22 is ring Z 21 This represents a hydrocarbon ring or heterocycle which may be fused to ring Z, and which may have a hydrocarbon group, a heteroatom, or a substituent having a heteroatom attached to it, and the α,β-unsaturated group of the α,β-unsaturated carboxylic acid represented by formula (z2) is ring Z 21 It forms an intra-ring carbon-carbon double bond.

[0021] Ring Z 21 and ring Z 22 The heterocycle in this material preferably contains one or more atoms selected from N (nitrogen atom), O (oxygen atom), and S (sulfur atom) in its ring structure, and more preferably contains O (oxygen atom). Ring Z 21 Examples of hydrocarbon rings having a carbon-carbon double bond in this context include benzene, cyclopentene, cyclohexene, 1,3-cyclohexadiene, and 1,4-cyclohexadiene, with 1,3-cyclohexadiene and 1,4-cyclohexadiene being preferred. Ring Z 21 Examples of heterocycles having a carbon-carbon double bond in this context include dihydrofuran, furan, dihydropyran, and pyran, with pyran being preferred. Ring Z 22 The hydrocarbon ring in this case is ring Z. 21 In addition to the hydrocarbon rings mentioned above, cyclopentane and cyclohexane are also examples. Ring Z 22 The complex ring in is the ring Z. 21 In addition to the heterocycles mentioned above, examples include tetrahydrofuran and tetrahydropyran, with dihydropyran being preferred.

[0022] Ring Z 21 or ring Z 22 The hydrocarbon ring or heterocycle may have one or more hydrocarbon groups, heteroatoms, and substituents having heteroatoms bonded to it. Ring Z 21 or ring Z 22 The hydrocarbon group that may be bonded is preferably an alkyl group, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. Ring Z 21 or ring Z 22 A heteroatom that may be bonded to R and a substituent having a heteroatom are R Z11 and R Z13 Examples include heteroatoms that may be bonded to the hydrocarbon group, or substituents having heteroatoms, with oxo groups, hydroxyl groups, or carboxyl groups being preferred. Ring Z 21 and ring Z 22 Preferably, one or more of the following groups are bonded to the hydrocarbon ring or heterocycle: a methyl group, an oxo group, a hydroxyl group, or a carboxyl group.

[0023] Examples of compounds represented by formula (z2) include citrinin and 4-oxo-4H-pyran-2,6-dicarboxylic acid.

[0024] [ka]

[0025] In formula (z3), ring Z 31 represents a hydrocarbon ring or heterocycle which may have hydrocarbon groups, heteroatoms, or substituents having heteroatoms attached, and ring Z 32 is ring Z 31 A hydrocarbon ring or heterocycle which may be fused to a ring, and which may have a hydrocarbon group, a heteroatom, or a substituent having a heteroatom attached, where the carbon atom at the β position of the α,β-unsaturated carboxylic acid represented by formula (z3) is ring Z 31 These are the carbon atoms that make up the compound.

[0026] Ring Z 31 , Z 32 Details of the hydrocarbon ring or heterocycle in ring Z are as follows: 22 You can refer to all the explanations of hydrocarbon rings and heterocycles in [the relevant section]. Also, ring Z 31 , Z 32 For hydrocarbon groups, heteroatoms, and substituents having heteroatoms that may be bonded to ring Z, 21 , Z 22 Similar examples that may be combined with these can be listed.

[0027] (4-methylcyclohexylidene)acetic acid is an example of a compound represented by formula (z3).

[0028] The α,β-unsaturated carboxylic acid is not limited in its form as long as it is included in the composition, and may or may not coat the inorganic particles. For example, inorganic particles coated with an α,β-unsaturated carboxylic acid may be mixed with an aromatic monomer and other components as needed, or the inorganic particles and the α,β-unsaturated carboxylic acid may be prepared separately and mixed with an aromatic monomer and other components as needed.

[0029] The content of α,β-unsaturated carboxylic acid is preferably 0.5 to 15% by mass, more preferably 0.8 to 10% by mass, and even more preferably 1 to 7% by mass, based on 100% by mass of the composition. The amount of α,β-unsaturated carboxylic acid per 100 parts by mass of inorganic particles is preferably 1 to 18 parts by mass, more preferably 1.3 to 15 parts by mass, and even more preferably 1.5 to 10 parts by mass. Furthermore, the amount of α,β-unsaturated carboxylic acid per 100 parts by mass of aromatic monomer is preferably 5 to 50 parts by mass, more preferably 8 to 45 parts by mass, and even more preferably 10 to 40 parts by mass.

[0030] <Aromatic monomers> Aromatic monomers are specifically compounds that have one or more aromatic hydrocarbon rings and aromatic heterocycles selected from aromatic hydrocarbon rings and aromatic heterocycles, and one or more polymerizable unsaturated groups selected from (meth)acryloyl groups, vinyl groups, and allyl groups in their molecules.

[0031] Polymerizable unsaturated groups can be directly, or -O-, -S-, and -(CH2) x It is preferable that the aromatic hydrocarbon ring or aromatic heterocycle is bonded via one or more of the following (where x is an integer from 1 to 5): -

[0032] The aromatic hydrocarbon ring is preferably a benzene ring, a naphthalene ring, a fluorene ring in which one or more benzene rings are further fused, or a 9,10-dihydroanthracene ring, and more preferably a benzene ring or a naphthalene ring.

[0033] The aromatic heterocycle is preferably a xanthene ring, a 9H-thioxanthene ring, or a dinaphthothiophene ring.

[0034] The aromatic monomer may consist of one of the preferred embodiments of the aromatic hydrocarbon ring and aromatic heterocycle described above, or it may consist of two or more of these monomers linked directly or via one or more of the -O-, -S-, and - hydrocarbon groups.

[0035] Examples of aromatic monomers include compounds represented by the following formulas (a1) to (a4).

[0036] [ka] In formula (a1), X 1 ha-(CH2) m11 -(O,S) m12 -X 11 X 11 m11 is an integer from 0 to 2, and m12 is 0 or 1. R 11 is a phenoxy group, a phenyl group, or -(CH2) m13 -(O,S) m14 -X 12 X 12m13 is an integer from 0 to 2, and m14 is 0 or 1. q1 is either 0 or 1, n1 is either 0 or 1. Note -(O,S) m12 -is, -(O) m12 - or -(S) m12 - means -(O,S) m14 -What is-(O) m14 - or -(S) m14 -This means that, and below, -(O,S) x Similarly, regarding the description of -, -(O) x - or -(S) x - This means that

[0037] X 1 ha-(CH2) m11 -(O) m12 -X 11 It is preferable that m11 is 1; m12 is 1; X 11 It is preferable that at least one of the following conditions is met: (meth)acryloyl group, preferably all of the following conditions are met, and furthermore X 11 It is preferable that the group is an acryloyl group.

[0038] The compound represented by formula (a1) is either a compound where q1=0 and n1=1, or a compound where q1=1 and R 11 Compounds in which the group is a phenoxy group or a phenyl group are preferred.

[0039] Specific examples of aromatic monomers represented by formula (a1) include phenoxybenzyl (meth)acrylate, naphthylmethyl (meth)acrylate, biphenylmethyl (meth)acrylate, or compounds represented by the following formula, with one or more of phenoxybenzyl acrylate, naphthylmethyl acrylate, and biphenylmethyl acrylate being particularly preferred.

[0040] [ka]

[0041]

Chem.

[0042]

Chem.

[0043] [ka] [Equations (A1-1) to (A1-4) are rings D in a1 and a2, respectively. 1 [Combine with a1 and a2] Ring B 1 This is one of the following formulas (B1-1) to (B1-4):

[0044] [ka] [Equations (B1-1) to (B1-4) are rings D in b1 and b2, respectively. 1 [Combine with b1 and b2] X 25 is, -(CH2) m250 -(O,S) m251 -X 25a X 25a The group can be a (meth)acryloyl group, a vinyl group, or an allyl group, m250 is an integer from 0 to 2, m251 is 0 or 1, and q25 is 0 or 1. X 26 is, -(CH2) m260 -(O,S)m261 -X 26a X 26a is a (meth)acryloyl group, a vinyl group, or an allyl group, m260 is an integer from 0 to 2, m261 is 0 or 1, and q26 is 0 or 1. Equation (a2) contains X 21a , X 22a , X 23a , X 24a , X 25a and X 26a It includes at least one of the following.

[0045] In equation (a2), it is preferable that q25 = q26 = 0, in which case q21 is 1 and R 21 is a group represented by the above formula (a2-1), or -(CH2) m210 -(O,S) m211 -X 21a The fact that; and that q22 is 1 and R 22 is a group represented by the above formula (a2-2), or -(CH2) m220 -(O,S) m221 -X 22a It is preferable that at least one of the following conditions is met:

[0046] Specific examples of compounds represented by formula (a2) include the following:

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] [ka] In formula (a3), X 31 is, -(CH2) m310 -(O,S) m311 -X 31a X 31a m310 is an integer from 0 to 2, and m311 is 0 or 1. q31 is either 0 or 1. X 32 is, -(CH2) m320 -(O,S) m321 -X 32a X 32a m320 is an integer from 0 to 2, and m321 is 0 or 1. q32 is either 0 or 1. The sum of q31 and q32 is 1 or 2. a3 and a4 represent the bonding sites between the tetrahydrothiophene ring and ring A2. b3 and b4 represent the bonding sites between the tetrahydrothiophene ring and ring B2. Ring A 2 This is one of the following formulas (A2-1) to (A2-4):

[0053] [ka] [Equations (A2-1) to (A2-4) bond to a3 and a4 of the tetrahydrothiophene ring, respectively, at a3 and a4.] Ring B 2 This is one of the following formulas (B2-1) to (B2-4).

[0054] [ka] [Equations (B2-1) to (B2-4) bond to b3 and b4 of the tetrahydrothiophene ring, respectively.]

[0055] Specific examples of compounds represented by formula (a3) ​​include the following:

[0056] [ka]

[0057] [ka] In formula (a4), X 41 is, -(CH2) m410 -(O,S) m411 -X 41a X 41a m410 is an integer from 0 to 2, and m411 is 0 or 1. X 42 is, -(CH2) m420 -(O,S) m421 -X 42a X 42a m420 is an integer between 0 and 2, and m421 is 0 or 1.

[0058] A preferred specific example of the aromatic monomer represented by formula (a4) is the compound represented by the following formula.

[0059] [ka]

[0060] The aromatic monomer is also preferably a compound (a5) having a structure in which a (meth)acryloyl group, a vinyl group, or an allyl group is directly bonded to an aromatic hydrocarbon ring (especially a benzene ring), and having a refractive index of 1.64 to 1.70.

[0061] The aromatic monomer is preferably one or more of the compound represented by formula (a1) and compound (a5), more preferably the compound represented by formula (a1), even more preferably one or more of phenoxybenzyl acrylate, naphthyl methyl acrylate, and biphenyl methyl acrylate, and even more preferably biphenyl methyl acrylate.

[0062] The aromatic monomer content is preferably 5 to 40% by mass, preferably 8 to 30% by mass, and preferably 10 to 25% by mass, based on 100% by mass of the composition.

[0063] <Inorganic particles> The inorganic particles can be appropriate depending on the function required of the inorganic particle-containing composition, and are preferably at least one selected from the group consisting of metal particles and metal oxide particles, and more preferably metal oxide particles. Examples of metals constituting the inorganic particles include at least one metal selected from the group consisting of titanium, zirconium, indium, zinc, tin, lanthanum, yttrium, cerium, niobium, and tantalum.

[0064] Examples of the aforementioned metal oxides include single metal oxides composed of one metal element such as titanium oxide, zirconium oxide, indium oxide, zinc oxide, tin oxide, lanthanum oxide, yttrium oxide, cerium oxide, niobium oxide, and tantalum oxide; and oxides composed of two or more metal elements such as indium tin oxide, tin antimony oxide, barium titanate, strontium titanate, and titanite. Furthermore, the inorganic particles may be composed of one of these materials, or of two or more materials.

[0065] The metal oxide particles are preferably single metal oxides, more preferably at least one particle selected from titanium oxide, zirconium oxide, and zinc oxide. Among these, zirconium dioxide particles (ZrO2 particles) are preferred because, in addition to increasing the refractive index with aromatic monomers, using inorganic particles with a high refractive index can further increase the refractive index of the composition.

[0066] The refractive index of the inorganic particles is, for example, 1.60 to 2.72, and by setting it to be above the lower limit, the refractive index of the composition can be made higher. The refractive index of the inorganic particles is preferably 1.65 to 2.50, more preferably 1.70 to 2.20.

[0067] The crystalline structure of inorganic particles can be determined by X-ray diffraction, and is preferably cubic, tetragonal, or monoclinic, although multiple crystalline structures may be present. Note that X-ray diffraction measurements make it difficult to distinguish between cubic and tetragonal inorganic particles, and even if cubic particles are present, their proportion is counted as tetragonal. From the viewpoint of increasing the refractive index, it is preferable that 50% or more of the total crystalline structure be tetragonal and / or cubic. Furthermore, the ratio of the total tetragonal and cubic crystals to monoclinic crystals ((tetragonal + cubic) / monoclinic) is preferably 1.0 to 30, more preferably 1.1 to 20.

[0068] The average primary particle diameter of the inorganic particles is preferably 1 to 50 nm, more preferably 5 to 30 nm, and even more preferably 5 to 20 nm. If the inorganic particles are coated with a coating agent, the average primary particle diameter of the coated inorganic particles is indicated. When the average primary particle diameter of the inorganic particles is within the above range, the transparency of the composition is further enhanced. The average primary particle diameter can be determined by observing the inorganic particles under magnification using an electron microscope such as a transmission electron microscope (TEM), field emission transmission electron microscope (FE-TEM), or field emission scanning electron microscope (FE-SEM), randomly selecting 100 particles, measuring their lengths along their long axes, and calculating the arithmetic mean.

[0069] The crystallite size of the inorganic particles is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less, and is usually 1 nm or more. The smaller the crystallite size, the higher the light transmittance of the composition can be. The crystallite size can be determined by X-ray diffraction.

[0070] The inorganic particle content is preferably 60 to 90% by mass, more preferably 65 to 88% by mass, and even more preferably 70 to 86% by mass, based on 100% by mass of the solid content of the composition. According to the composition of the present invention, even if inorganic particles are included at a high concentration, the increase in viscosity can be suppressed.

[0071] <Coating agent> Inorganic particles are preferably coated with a coating agent. Inorganic particles coated with a coating agent can be easily dispersed in the composition.

[0072] The amount of coating agent is preferably 0.5 to 25% by mass, more preferably 3 to 25% by mass, even more preferably 5 to 20% by mass, and even more preferably 10 to 20% by mass, based on 100% by mass of inorganic particles coated with the coating agent.

[0073] Examples of the coating agent include hydroxy compounds, carboxylic acid compounds, phosphate esters, and silane coupling agents.

[0074] The aforementioned hydroxy compound is a compound having a hydroxyl group (-OH group). Examples of the aforementioned hydroxy compound include Praxel 205, 205U, 205UT, 205H, 208, 210, 210CP, 210B, 212, 212CP, 212UA, 220, 220CPB, 220CPT, 220UA, 230, 240, 210N, 220N, 230N, 303, 305, 305T, 308, 309, 312, 320, 410, L Examples include 212AL, L220AL, L320AL, 220EB, 220EC, T2205T, P3403, CD210, CD220, CD205PL, CD220PL, FA1, FA1DDM, FA2D, FA5, FA10L, FM1, FM1D, FM2D, FM3, FM4, FM5, FM6, HEMAC1, and H1P (manufactured by Daicel Corporation). Among these, hydroxy compounds containing a (meth)acryloyl group are preferred.

[0075] The carboxylic acid compound is a compound having a carboxyl group (-COOH group). As the carboxylic acid compound, you may use the α,β-unsaturated carboxylic acid described above (i.e., an α,β-unsaturated carboxylic acid in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0), or you may use other carboxylic acid compounds, or you may use both. Examples of carboxylic acid compounds other than the α,β-unsaturated carboxylic acids described above include, specifically, Linear saturated aliphatic monocarboxylic acids such as butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, palmitic acid, and stearic acid, as well as isovaleric acid, 3,3-dimethylbutyric acid, 3,3-diethylbutyric acid, 3-methylvaleric acid, isononanoic acid, 4-methylvaleric acid, 4-methyloctanoic acid, isobutyric acid, 2-methylbutyric acid, 2-ethylbutyric acid, 2-ethylhexanoic acid, 2-methylvaleric acid, 2-methylhexanoic acid, 2- Saturated aliphatic carboxylic acids, including branched-chain saturated aliphatic monocarboxylic acids such as methylheptanoic acid, 2-propylbutyric acid, 2-hexylvaleric acid, 2-hexyldecanoic acid, 2-heptylundecanoic acid, 2-methylhexadecanoic acid, pivalic acid, 2,2-dimethylbutyric acid, 2,2-dimethylvaleric acid, 2,2-diethylbutyric acid, 2,2-dimethylhexanoic acid, and neodecanoic acid, as well as saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid; Alicyclic hydrocarbon group-containing carboxylic acids, including monocarboxylic acids containing alicyclic hydrocarbon groups such as naphthenic acid, and dicarboxylic acids containing alicyclic hydrocarbon groups such as cyclohexanedicarboxylic acid; Unsaturated carboxylic acids including unsaturated monocarboxylic acids such as (meth)acrylic acid, oleic acid, linoleic acid, linolenic acid, and 2-hexenoic acid; unsaturated dicarboxylic acids such as itaconic acid; and unsaturated carboxylic acids containing (meth)acryloyl groups such as 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, and ω-carboxy-polycaprolactone mono(meth)acrylate; Ether-containing carboxylic acids such as methoxyacetic acid, ethoxyacetic acid, 3-ethoxypropionic acid, 2-methoxyethoxyacetic acid, and 2-methoxyethoxyethoxyacetic acid; Hydroxy group-containing carboxylic acids, including monocarboxylic acids containing hydroxyl groups such as lactic acid, hydroxystearic acid, glycolic acid, DL-lactic acid, 2-hydroxyisobutyric acid, dimethylolpropionic acid, hydroxypivalic acid, 3-hydroxypropionic acid, DL-2-hydroxybutyric acid, DL-3-hydroxybutyric acid, 2-hydroxy-2-methylbutyric acid, β-hydroxyisovaleric acid, 2,2-bis(hydroxymethyl)butyric acid, and 4-hydroxycyclohexanecarboxylic acid, as well as polycarboxylic acids containing hydroxyl groups such as malic acid and citric acid; Carbonyl group-containing carboxylic acids such as pyruvate, levulinic acid, 2-oxovaleric acid, β-methyllevulinic acid, and α-methyllevulinic acid; Sulfide bond-containing carboxylic acids such as phenylthioacetic acid; Amino group-containing carboxylic acids, including amino group-containing monocarboxylic acids such as glycine, alanine, 2-methylalanine, cysteine, serine, threonine, valine, leucine, isoleucine, methionine, and lysine, and amino group-containing dicarboxylic acids such as aspartic acid and glutamic acid; Cyano group-containing carboxylic acids such as cyanoacetic acid; Examples include heterocyclic compounds substituted with carboxyl groups such as proline; and so on.

[0076] The carboxylic acid compound preferably contains at least a secondary carboxylic acid. Inorganic particles coated with a secondary carboxylic acid have good affinity for aromatic monomers and can exhibit better dispersibility even when the concentration of inorganic particles in the composition is high.

[0077] The term "secondary carboxylic acid" refers to a carboxylic acid in which the carbon bonded to the carboxyl group (-COOH group) is a secondary carbon. The secondary carboxylic acid is preferably a monocarboxylic acid, more preferably a saturated or unsaturated aliphatic monocarboxylic acid, and even more preferably a saturated aliphatic monocarboxylic acid.

[0078] The secondary carboxylic acid preferably has 4 to 30 carbon atoms, more preferably 6 to 20, and even more preferably 7 to 16.

[0079] Examples of secondary carboxylic acids include isobutyric acid, 2-methylbutyric acid, 2-ethylbutyric acid, 2-ethylhexanoic acid, 2-methylvaleric acid, 2-methylhexanoic acid, 2-methylheptanoic acid, 2-propylbutyric acid, 2-hexylvaleric acid, 2-hexyldecanoic acid, 2-heptylundecanoic acid, and 2-methylhexadecanoic acid. 2-ethylhexanoic acid, 2-methylvaleric acid, 2-methylhexanoic acid, 2-methylheptanoic acid, 2-propylbutyric acid, 2-hexylvaleric acid, and 2-hexyldecanoic acid are preferred, 2-ethylhexanoic acid and 2-hexyldecanoic acid are more preferred, and 2-ethylhexanoic acid is even more preferred.

[0080] Examples of the phosphate esters include (meth)acryloyl group-containing phosphate esters such as 2-(meth)acryloyloxyethyl acid phosphate, 2-(meth)acryloyloxypropyl acid phosphate, 3-(meth)acryloyloxypropyl acid phosphate, and 2-(meth)acryloyloxyethylphenyl acid phosphate; (poly)alkylene glycol monoalkyl ether phosphate esters such as triethylene glycol monomethyl ether phosphate and dipropylene glycol monomethyl ether phosphate; alkyl phosphate esters such as methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, n-octyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, and oleyl acid phosphate; and the like. Furthermore, commercially available phosphate esters can be used as appropriate, such as DISPERBYK-110, 111, 180 (manufactured by Bic Chemie Japan), Prysurf A125C, A212C, A208B, A208F, A208N, A219B, and AL (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Among these, (meth)acryloyl group-containing phosphate esters are preferred as phosphate esters.

[0081] Examples of the silane coupling agent include (meth)acryloxy group-containing silane coupling agents such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane.

[0082] These coating agents can be used individually or in combination of two or more.

[0083] The coating agent preferably contains a carboxylic acid compound other than an α,β-unsaturated carboxylic acid (particularly a secondary carboxylic acid) in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0. It is more preferably that the coating agent contains a carboxylic acid compound other than an α,β-unsaturated carboxylic acid in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0, along with at least one of a phosphate ester and a hydroxy compound. It is even more preferably that the coating agent contains at least one of a phosphate ester and a hydroxy compound along with a secondary carboxylic acid. In any of these preferred embodiments, it is also preferable that the coating agent further contains an α,β-unsaturated carboxylic acid in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0.

[0084] The total proportion of carboxylic acid compounds other than α,β-unsaturated carboxylic acids having 1 or 0 hydrogen atoms bonded to the β-carbon atom, phosphate esters, hydroxy compounds, and silane coupling agents in 100 mol% of the coating agent is preferably 20 to 100 mol%, more preferably 30 to 80 mol%, and even more preferably 40 to 60 mol%. It is more preferable that the total proportion of carboxylic acid compounds other than α,β-unsaturated carboxylic acids having 1 or 0 hydrogen atoms bonded to the β-carbon atom, phosphate esters, and hydroxy compounds in 100 mol% of the coating agent is within the aforementioned range.

[0085] The proportion of carboxylic acid compounds other than α,β-unsaturated carboxylic acids (especially secondary carboxylic acids) in 100 mol% of the coating agent, in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0, is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, and even more preferably 15 to 35 mol%.

[0086] The proportion of phosphate ester in 100 mol% of the coating agent is preferably 10 to 80 mol%, more preferably 15 to 75 mol%, and even more preferably 20 to 70 mol%.

[0087] The proportion of the hydroxy compound in 100 mol% of the coating agent is preferably 10 to 80 mol%, more preferably 15 to 75 mol%, and even more preferably 20 to 70 mol%.

[0088] The total amount of phosphate ester, hydroxy compound, and silane coupling agent relative to the amount of secondary carboxylic acid is preferably 0.5 to 10.0, more preferably 0.8 to 6.0, and even more preferably 1.0 to 4.0 in molar ratio. It is even more preferable that the molar ratio of the amount of phosphate ester and hydroxy compound relative to the amount of secondary carboxylic acid is within the above range.

[0089] <Composition> The composition of the present invention comprises inorganic particles, an aromatic monomer, and an α,β-unsaturated carboxylic acid in which the number of hydrogen atoms bonded to the carbon atom at the β position is 1 or 0. By including the α,β-unsaturated carboxylic acid, it is possible to suppress the increase in viscosity of the composition while using an aromatic monomer with a high refractive index, thereby achieving both a high refractive index and low viscosity.

[0090] The refractive index of the composition at a temperature of 20°C is preferably 1.680 to 1.800, more preferably 1.700 to 1.780, and even more preferably 1.710 to 1.760.

[0091] The viscosity of the composition at a temperature of 40°C is preferably less than 6000 mPa·s, more preferably 500 mPa·s or more and less than 6000 mPa·s, even more preferably 1000 to 5700 mPa·s, even more preferably 1000 to 5400 mPa·s, and particularly preferably 1000 to 3000 mPa·s.

[0092] Furthermore, in a preferred embodiment, the dispersibility of inorganic particles can be improved, and transparency can also be improved. The total light transmittance of the composition is preferably 50% or more, and although there is no particular upper limit, it may be, for example, 98% or less.

[0093] The refractive index, viscosity, and total light transmittance of the composition can be measured according to the methods described in the examples below.

[0094] The composition may also contain monomers other than aromatic monomers, polymerization initiators, solvents, polymers (resins), high refractive index additives, or other additives. The content of components other than inorganic particles, aromatic monomers, and α,β-unsaturated carboxylic acids having 1 or 0 hydrogen atoms bonded to the β-carbon in 100% by mass of the composition is, for example, 0 to 10% by mass, preferably 0 to 5% by mass, and more preferably 0 to 3% by mass.

[0095] <Monomers other than aromatic monomers> Examples of monomers other than aromatic monomers include monofunctional monomers having one polymerizable double bond or crosslinkable monomers having two or more polymerizable double bonds, and one or more of these can be used in combination.

[0096] Other monofunctional monomers besides aromatic monomers include: Alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; alkylene glycol mono(meth)acrylates such as methoxypolyethylene glycol (meth)acrylate; glycidyl (meth)acrylate Examples include (meth)acrylic acid esters having a glycidyl group such as acrylate; (meth)acrylic acid esters having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, Praxel FA1, FA1DDM, FA2D, FA5, FA10L, FM1, FM1D, FM2D, FM3, FM4, FM5, FM6, HEMAC1 (manufactured by Daicel Corporation); and carboxyl group-containing monomers such as (meth)acrylic acid.

[0097] Examples of crosslinkable monomers other than aromatic monomers include crosslinkable (meth)acrylic acid esters such as alkylene glycol poly(meth)acrylates including ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and tetramethylene glycol di(meth)acrylate; 2-(2-vinyloxyethoxy)ethyl (meth)acrylate; urethane acrylate oligomers (for example, the Shiko® series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), the CN series (manufactured by Sartomer Co., Ltd.), the Unidick® series (manufactured by DIC Corporation), the Kayarad® UX series (manufactured by Nippon Kayaku Co., Ltd.), etc.).

[0098] <Polymerization initiator> As polymerization initiators, known radical polymerization initiators can be used, and it is particularly preferable to use photoradical polymerization initiators. Examples of photoradical polymerization initiators include alkylphenones such as acetophenone, 3-methylacetophenone, benzyldimethylketal, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-hydroxycyclohexylphenyl ketone; benzophenones including benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ethers such as benzoin propyl ether and benzoin ethyl ether; thioxanthones such as 4-isopropylthioxanthone; xanthones, fluorenone, camphorquinone, benzaldehyde, and anthraquinone. Polymerization initiators can be used individually or in combination of two or more.

[0099] The content of the polymerization initiator is not particularly limited, but is preferably 1 to 10 parts by mass, and more preferably 2 to 5 parts by mass, per 100 parts by mass of aromatic monomer.

[0100] The total content of inorganic particles, aromatic monomers, α,β-unsaturated carboxylic acids, monomers other than aromatic monomers, and polymerization initiators in 100% by mass of the solid components in the composition is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 97% by mass or more, and may be 100% by mass.

[0101] <Solvent> Examples of solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, 1-methoxy-2-propanol, and ethylene glycol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate and propyl acetate; ethers such as ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and propylene glycol monomethyl ether; modified ethers such as propylene glycol monomethyl ether acetate (especially ether-modified and / or ester-modified alkylene glycols); hydrocarbons such as benzene, toluene, xylene, ethylbenzene, hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, and mineral spirits; halogenated hydrocarbons such as dichloromethane and chloroform; amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; water; and oils such as mineral oil, vegetable oil, wax oil, and silicone oil. These can be used individually or in combination of two or more. From a handling standpoint, solvents with a boiling point of approximately 40°C or higher and 250°C or lower at atmospheric pressure (1013 hPa) are preferred.

[0102] <Polymer (resin)> As polymers (resins), one or more types can be used, and examples include polyamides such as 6-nylon, 66-nylon, and 12-nylon; polyimides; polyurethanes; polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyvinyl chlorides; polyvinylidene chlorides; polyvinyl acetates; polystyrenes; (meth)acrylic resin polymers; ABS resins; fluororesins; phenol-formaldehyde resins; phenolic resins such as cresol-formaldehyde resins; epoxy resins; urea resins; melamine resins; amino resins such as guanamine resins; polyvinyl butyral resins; polyurethane resins; ethylene-vinyl acetate copolymer resins; ethylene-(meth)acrylic acid ester copolymer resins, and other soft and hard resins.

[0103] <High refractive index additive> One or more high refractive index additives can be used, and examples include compounds with the following structures.

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] <Other additives> Other additives include surfactants, curing agents, curing accelerators, colorants, internal release agents, coupling agents, reactive diluents, plasticizers, stabilizers, flame retardant aids, crosslinking agents, low shrinkage agents, polymerization inhibitors, antioxidants, UV absorbers, defoaming agents, leveling agents, thixotropes, and thickeners.

[0108] The compositions of the present invention can be applied to a variety of applications, such as resist applications, optical applications, ink applications, coating applications, and adhesive applications. Specifically, they are suitably used in optical lenses, inkjet resin compositions, nanoimprint resin compositions, microlens arrays, anti-reflective layers used in transparent electrodes, anti-reflective films and anti-reflective agents, surface coatings for optical lenses, organic EL light extraction layers, various hard coating materials, planarization films for TFTs, overcoats for color filters, various protective films such as anti-reflective films, and optical materials such as optical filters, insulating films for touch sensors, insulating films for TFTs, photospacers for color filters, and protective films for touch panels. [Examples]

[0109] The present invention will be described in more detail below with reference to examples. The present invention is not limited by the following examples, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit described below, and all such modifications are included within the technical scope of the present invention.

[0110] The physical properties and characteristics disclosed in the examples and comparative examples were measured by the following methods.

[0111] (1) Analysis of the crystal structure The crystal structure of zirconium oxide particles was analyzed using an X-ray diffractometer (Rigaku Corporation, RINT-TTRIII). The measurement conditions were as follows: X-ray source: CuKα (0.154nm) X-ray output settings: 50kV, 300mA Sampling width: 0.0200° Scan speed: 10.0000° / min Measurement range: 10~75° Measurement temperature: 25℃

[0112] (2) Determination of the proportion of tetragonal and monoclinic crystals Based on values ​​calculated using an X-ray diffractometer (Rigaku Corporation, RINT-TTRIII), the proportion of tetragonal and monoclinic crystals was quantified using the reference intensity ratio method (RIP method) with calculation software (Rigaku Corporation, PDXL) (peak assignment was also done according to the specifications of the calculation software). Note that in this measurement, it is difficult to distinguish between tetragonal and cubic crystals, and even if cubic crystals are present, their proportion is counted as that of tetragonal crystals.

[0113] (3) Calculation of crystallite size by X-ray diffraction analysis The crystallite size of the zirconium oxide particles was calculated using calculation software (PDXL, Rigaku Corporation) based on the full width at half maximum of the 30° peak, which was analyzed and calculated using an X-ray diffractometer (RINT-TTRIII, Rigaku Corporation).

[0114] (4) Measurement of average primary particle size using an electron microscope The average primary particle diameter of coated zirconium oxide particles was measured by observation using an ultra-high-resolution field emission scanning electron microscope (Hitachi High-Technologies Corporation, S-4800). Coated zirconium oxide particles were observed at a magnification of 150,000x, and the length along the long axis of each particle was measured for any 100 particles. The average value of these measurements was defined as the average primary particle diameter.

[0115] (5) Measurement of organic content Using a TG-DTA (thermogravimetric-indicative thermal analysis) apparatus, coated zirconium oxide particles were heated from room temperature to 800°C at a rate of 10°C / min in an air atmosphere, and the weight (mass) loss rate of the particles was measured. This weight (mass) loss rate was defined as the organic content of the coated zirconium oxide particles.

[0116] (6) Viscosity evaluation of monomer dispersion The viscosity of the monomer dispersion of zirconium oxide particles was measured using a viscometer (TV-100EH viscometer manufactured by Toki Sangyo Co., Ltd.) under the following conditions. Set temperature: 40℃ Sample volume: 0.2 mL Preheat time: 5 minutes Measurement time: 5 minutes Cone rotor: 3° × R9.7

[0117] (7) Measurement of refractive index of monomer dispersion The refractive index of the monomer dispersion of coated zirconium oxide particles was measured using an ATAGO DR-M4 multi-wavelength Abbe refractometer (measurement temperature 20°C, interference filter wavelength 589(D)nm).

[0118] (8) Measurement of total light transmittance The total light transmittance of the zirconium oxide particle dispersion was measured using a turbidimeter (NDH7000, manufactured by Nippon Denshoku Industries Co., Ltd.). A quartz cell with a path length of 1 cm was used. Based on the total light transmittance values, the following evaluations were performed. ○: 50% or more, ×: less than 50%

[0119] [Production Example 1: Production of coated zirconium oxide nanoparticles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid (coated ZrO2 particles 1)] In a separable flask equipped with a stirrer, thermometer, and condenser, 50 parts by mass of basic zirconium carbonate (SZBC, manufactured by Saint-Gobain ZirPro (Handan) Co., Ltd; ZrO2 content 41.1% by mass, moisture content 40.2% by mass), 74 parts by mass of mineral spirits as solvents, and 2.5 parts by mass of 2-ethylhexanoic acid were added and stirred at room temperature for 5 to 10 minutes (Step (1)). Then, the flask was immersed in an oil bath and stirred while the internal temperature was raised to 85°C. After that, the internal temperature was maintained at 85°C to 90°C and stirring was continued for 3 hours (Step (2)). Subsequently, 24 parts by mass of 2-ethylhexanoic acid were added and the oil bath temperature was adjusted to maintain the internal temperature at 100 to 130°C for 4 hours to react the basic zirconium carbonate with 2-ethylhexanoic acid (Step (3)). The reaction product was a white slurry at the start of the reaction, but at the end of the reaction it had become a translucent, cloudy liquid. When the reaction solution was cooled to room temperature, it separated into two layers, with the upper layer being the mineral spirit layer. The upper layer was filtered, and a small amount of mineral spirit was added to adjust the Zr concentration to approximately 12% by mass (step (4)).

[0120] 42.4 parts by mass of the zirconium 2-ethylhexanoate-mineral spirit solution obtained in step (4) were mixed with 7.3 parts by mass of pure water and charged into an autoclave equipped with a thermometer and stirrer, and the atmosphere in the reactor was replaced with nitrogen gas. Then, the internal temperature was heated to 190°C and the reaction was carried out for 9 hours, and then the internal temperature was raised to 195°C and the reaction was carried out for 8 hours to synthesize zirconium oxide nanoparticles. The pressure in the container when the reaction was carried out at 190°C was 1.2 MPa, and the pressure in the container when the reaction was carried out at 195°C was 1.40 MPa. The solution after the reaction was removed, the resulting precipitate was filtered and washed with acetone, and then dried under reduced pressure to obtain zirconium oxide nanoparticles (coated ZrO2 particles 1).

[0121] The crystal structure of the obtained coated ZrO2 particles 1 was confirmed according to the above-described "(1) Analysis of Crystal Structure" and "(2) Determination of the Ratio of Tetragonal and Monoclinic Crystals." Diffraction lines attributed to tetragonal and monoclinic crystals were detected. From the intensity of the diffraction lines, the ratio of tetragonal to monoclinic crystals was determined to be 92 / 8, and the crystallite size calculated by "(3) Calculation of Crystallite Size by X-ray Diffraction Analysis" was 5 nm. Furthermore, the average particle size (number-mean primary particle size) of the coated ZrO2 particles 1, measured by "(4) Measurement of Average Primary Particle Size by Electron Microscopy," was 18 nm. In addition, analysis of the obtained coated ZrO2 particles 1 by infrared absorption spectroscopy revealed absorption originating from CH and absorption originating from COOH. These absorptions are thought to be due to 2-ethylhexanoic acid and / or carboxylates derived from 2-ethylhexanoic acid coating the coated ZrO2 particles 1.

[0122] The organic content of coated ZrO2 particles 1, measured according to "(5) Measurement of Organic Content" described above, was 12% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid coating coated ZrO2 particles 1 constituted 12% by mass of the entire coated ZrO2 particles 1.

[0123] [Production Example 2: Production of zirconium oxide particles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, crotonic acid, and 2-methacryloyloxyethyl acid phosphate (coated ZrO2 particles 2)] The coated ZrO2 particles 1 (10 parts by mass) obtained in Production Example 1 above, crotonic acid (1.5 parts by mass), and 2-methacryloyloxyethyl acid phosphate (0.5 parts by mass) were stirred and mixed in toluene (12 parts by mass) until uniformly dispersed. Next, n-hexane (36 parts by mass) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 parts by mass), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum-dried at room temperature to prepare zirconium oxide particles (coated ZrO2 particles 2) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, crotonic acid, and 2-methacryloyloxyethyl acid phosphate.

[0124] The obtained coated ZrO2 particles 2 were dispersed in deuterated chloroform to prepare the measurement sample. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid, crotonic acid, and 2-methacryloyloxyethyl acid phosphate was 21:57:22.

[0125] The organic content of coated ZrO2 particles 2, measured according to "(5) Measurement of Organic Content" above, was 14% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate, crotonic acid, and 2-methacryloyloxyethyl acid phosphate, which coat coated ZrO2 particles 2, account for 14% by mass of the total coated ZrO2 particles 2.

[0126] [Production Example 3: Production of zirconium oxide particles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-methacryloyloxyethyl acid phosphate (coated ZrO2 particles 3)] The coated ZrO2 particles 1 (10 parts by mass) obtained in the above Production Example 1 and 2-methacryloyloxyethyl acid phosphate (1.0 part by mass) were stirred and mixed in propylene glycol monomethyl ether acetate (12 parts by mass, hereinafter referred to as "PGMEA") until uniformly dispersed. Next, n-hexane (36 parts by mass) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 parts by mass), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum-dried at room temperature to prepare zirconium oxide particles (coated ZrO2 particles 3) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid and 2-methacryloyloxyethyl acid phosphate.

[0127] The obtained coated ZrO2 particles 3 were dispersed in deuterated chloroform to prepare the measurement sample. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid to 2-methacryloyloxyethyl acid phosphate was 31:69.

[0128] The organic content of coated ZrO2 particles 3, measured according to "(5) Measurement of Organic Content" above, was 12% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, and 2-methacryloyloxyethyl acid phosphate, which coat coated ZrO2 particles 3, constitute 12% by mass of the total coated ZrO2 particles 3.

[0129] [Production Example 4: Production of zirconium oxide particles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, propionic acid, and 2-methacryloyloxyethyl acid phosphate (coated ZrO2 particles 4)] The coated ZrO2 particles 1 (10 parts by mass) obtained in Production Example 1 above, propionic acid (1.5 parts by mass), and 2-methacryloyloxyethyl acid phosphate (0.5 parts by mass) were stirred and mixed in toluene (12 parts by mass) until uniformly dispersed. Next, n-hexane (36 parts by mass) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 parts by mass), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum-dried at room temperature to prepare zirconium oxide particles (coated ZrO2 particles 4) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, propionic acid, and 2-methacryloyloxyethyl acid phosphate.

[0130] The obtained coated ZrO2 particles 4 were dispersed in deuterated chloroform to prepare the sample for measurement. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid, propionic acid, and 2-methacryloyloxyethyl acid phosphate was 22:56:22.

[0131] The organic content of coated ZrO2 particles 4, measured according to "(5) Measurement of Organic Content" above, was 14% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate, propionic acid, and 2-methacryloyloxyethyl acid phosphate, which coat coated ZrO2 particles 4, account for 14% by mass of the total coated ZrO2 particles 4.

[0132] The obtained coated ZrO2 particles 4 were dispersed in deuterated chloroform to prepare the sample for measurement. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid, propionic acid, and 2-methacryloyloxyethyl acid phosphate was 20:55:25.

[0133] [Production Example 5: Production of zirconium oxide particles coated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, crotonic acid, and Praxel FA2D (coated ZrO2 particles 5)] The coated ZrO2 particles 1 (10 parts by mass) obtained in the above Production Example 1, crotonic acid (1.5 parts by mass), and Praxel FA2D (manufactured by Daicel Corporation, a hydroxy compound containing an acryloyl group) (0.5 parts by mass) were stirred and mixed in toluene (12 parts by mass) until uniformly dispersed. Next, n-hexane (36 parts by mass) was added to agglomerate the dispersed particles and make the solution cloudy, and the agglomerated particles were separated from the cloudy liquid using filter paper. Subsequently, the separated agglomerated particles were added to n-hexane (36 parts by mass), stirred for 10 minutes, and the agglomerated particles were separated using filter paper. The resulting particles were vacuum dried at room temperature to prepare zirconium oxide particles (coated ZrO2 particles 5) surface-treated with 2-ethylhexanoic acid and / or carboxylate derived from 2-ethylhexanoic acid, crotonic acid, and Praxel FA2D.

[0134] The obtained coated ZrO2 particles 5 were dispersed in deuterated chloroform to prepare the measurement sample. 1 Analysis was performed using 1H-NMR. The results showed that the molar ratio of carboxylate derived from 2-ethylhexanoic acid and / or 2-ethylhexanoic acid, crotonic acid, and Praxel FA2D was 21:58:21.

[0135] The organic content of coated ZrO2 particles 5, measured according to "(5) Measurement of Organic Content" above, was 14% by mass. Therefore, it was found that 2-ethylhexanoic acid and / or carboxylate, crotonic acid, and Praxel FA2D, which coat the coated ZrO2 particles 5, constitute 14% by mass of the entire coated ZrO2 particles 5.

[0136] [Example 1: Preparation of Zirconium Oxide Particle Monomer Dispersion 1] Coated ZrO2 particles 2 (172 parts by mass) obtained in Production Example 2 and 3-phenoxybenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 1.

[0137] [Example 2: Preparation of Zirconium Oxide Particle Monomer Dispersion 2] A coated zirconium oxide particle dispersion 2 was obtained in the same manner as in Example 1, except that methyl 1-naphthyl acrylate was used instead of phenoxybenzyl acrylate.

[0138] [Example 3: Preparation of Zirconium Oxide Particle Monomer Dispersion 3] Coated ZrO2 particles 5 (172 parts by mass) obtained in Production Example 5 and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 3.

[0139] [Example 4: Preparation of Zirconium Oxide Particle Monomer Dispersion 4] Coated ZrO2 particles 2 (172 parts by mass) obtained in Production Example 2, crotonic acid (0.6 parts by mass), and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 4.

[0140] [Example 5: Preparation of Zirconium Oxide Particle Monomer Dispersion 5] Coated ZrO2 particles 3 (172 parts by mass) obtained in Production Example 3, cinnamic acid (3.4 parts by mass), and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 5.

[0141] [Example 6: Preparation of Zirconium Oxide Particle Monomer Dispersion 6] A coated zirconium oxide particle dispersion 6 was obtained in the same manner as in Example 1, except that ReX-2 (manufactured by Shikoku Chemicals Co., Ltd.), a styrene monomer, was used instead of 3-phenoxybenzyl acrylic acid.

[0142] [Example 7: Preparation of Zirconium Oxide Particle Monomer Dispersion 7] Coated ZrO2 particles 3 (172 parts by mass) obtained in Production Example 3, ferulic acid (3.4 parts by mass), and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 7.

[0143] [Comparative Example 1: Preparation of Zirconium Oxide Particle Monomer Dispersion 8] Coated ZrO2 particles 4 (172 parts by mass) obtained in Production Example 4 and 3-phenoxybenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 8.

[0144] [Comparative Example 2: Preparation of Zirconium Oxide Particle Monomer Dispersion 9] A coated zirconium oxide particle dispersion 9 was obtained in the same manner as in Comparative Example 1, except that 1-naphthylmethyl acrylate was used instead of 3-phenoxybenzyl acrylate.

[0145] [Comparative Example 3: Preparation of Zirconium Oxide Particle Monomer Dispersion 10] A coated zirconium oxide particle dispersion 10 was obtained in the same manner as in Comparative Example 1, except that 4-phenylbenzyl acrylate was used instead of 3-phenoxybenzyl acrylate.

[0146] [Comparative Example 4: Preparation of Zirconium Oxide Particle Monomer Dispersion 11] Coated ZrO2 particles 3 (172 parts by mass) obtained in Production Example 3, acrylic acid (3.4 parts by mass), and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain a coated zirconium oxide particle dispersion 11.

[0147] [Comparative Example 5: Preparation of Zirconium Oxide Particle Monomer Dispersion 12] Coated ZrO2 particles 3 (172 parts by mass) obtained in Production Example 3, methacrylic acid (3.4 parts by mass), and 4-phenylbenzyl acrylate (28 parts by mass) were blended and uniformly stirred to obtain coated zirconium oxide particle dispersion 12.

[0148] Table 1 shows the results of evaluating the viscosity, refractive index, and total light transmittance of dispersions 1 to 12 obtained in Examples 1 to 7 and Comparative Examples 1 to 5, according to "(6) Viscosity evaluation of monomer dispersions," "(7) Refractive index measurement of monomer dispersions," and "(8) Measurement of total light transmittance."

[0149] [Table 1]

Claims

1. It contains inorganic particles, aromatic monomers, and α,β-unsaturated carboxylic acids. The aromatic monomer has one or more polymerizable unsaturated groups selected from the group consisting of (meth)acryloyl groups, vinyl groups, and allyl groups. A composition in which the number of hydrogen atoms bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid is 1 or 0.

2. The composition according to claim 1, wherein a carboxyl group is not bonded to the carbon atom at the β position of the α,β-unsaturated carboxylic acid.

3. The composition according to claim 1 or 2, wherein the α,β-unsaturated carboxylic acid is one or more compounds selected from those represented by the following formulas (z1-1), (z1-2), (z2), and (z3). 【Chemistry 1】 [In the formula, R ｚ１１ and R ｚ１３ R is a hydrocarbon group to which a heteroatom or a substituent having a heteroatom may be attached, ｚ１２ , R ｚ１４ [This is a hydrogen atom or a hydrocarbon group.] 【Chemistry 2】 [In formula (z2), ring Z ２１ This represents a hydrocarbon ring or heterocycle having a carbon-carbon double bond, which may have hydrocarbon groups, heteroatoms, or substituents having heteroatoms attached, and ring Z ２２ is ring Z ２１ This represents a hydrocarbon ring or heterocycle which may be fused to a ring and which may have a hydrocarbon group, a heteroatom, or a substituent having a heteroatom attached to it, and the α,β-unsaturated group of the α,β-unsaturated carboxylic acid represented by formula (z2) is on ring Z ２１ It forms an intraring carbon-carbon double bond. 【Transformation 3】 [In formula (z3), ring Z ３１ represents a hydrocarbon ring or a heterocyclic ring, which may be bonded with a hydrocarbon group, a heteroatom or a substituent having a heteroatom. Ring Z ３２ is a hydrocarbon ring or a heterocyclic ring which may be fused to ring Z ３１ and represents a ring which may be bonded with a hydrocarbon group, a heteroatom or a substituent having a heteroatom. The carbon atom at the β-position of the α,β-unsaturated carboxylic acid represented by formula (z3) is a carbon atom constituting ring Z ３１ .]

4. The aforementioned aromatic monomer is a compound having one or more aromatic hydrocarbon rings and aromatic heterocycles selected from within its molecule. The aromatic hydrocarbon ring is a benzene ring, a naphthalene ring, a fluorene ring in which one or more benzene rings are further fused, or a 9,10-dihydroanthracene ring. The composition according to claim 1 or 2, wherein the aromatic heterocycle is a xanthene ring, a 9H-thioxanthene ring, or a dinaphthothiophene ring.

5. The composition according to claim 1 or 2, wherein the inorganic particles comprise at least one metallic element selected from the group consisting of titanium, zirconium, indium, zinc, tin, lanthanum, yttrium, cerium, niobium, and tantalum.

6. The composition according to claim 1 or 2, wherein the inorganic particles are coated with a coating agent.

7. The composition according to claim 6, wherein the coating agent comprises at least one selected from the group consisting of hydroxy compounds, carboxylic acid compounds, phosphate esters, and silane coupling agents.

8. The composition according to claim 1 or 2, wherein the content of the inorganic particles is 60% by mass or more of 100% by mass of the solid content of the composition.

9. The composition according to claim 1 or 2, wherein the average primary particle diameter of the inorganic particles is 1 nm or more and 50 nm or less.

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