Curable composition, cured product, optical material, microlens, diffractive optical element, and surface-treated tio2 particles

Abstract

The present invention provides: a curable composition comprising a compound A that is represented by general formula (1) and has a point group of Cs, and surface-treated metal oxide particles that contain a specific metal element, are surface-treated with a silane coupling agent, and have an average particle diameter of 2-200 nm; a cured product; an optical material; a microlens; a diffractive optical element; and surface-treated TiO2 particles. In the formula, Ra to Rh each represent a hydrogen atom, R1, or R2.　At least one of Ra to Rh is R1, and at least two thereof are each selected from among R1 and R2. R1 is a group represented by one of general formulae (Pol-1) to (Pol-4), and R2 is an alkylsulfanyl group having 1 to 12 carbon atoms. In the formulae, L1 represents an alkylene group having 2 to 6 carbon atoms, and * represents a bond.

Description

Curable compositions, cured products, optical materials, microlenses, diffractive optical elements, and surface-treated TiO2 particles

[0001] The present invention relates to a curable composition, a cured product, an optical material, a microlens, a diffractive optical element, and a surface treatment TiO ２ Regarding particles.

[0002] In recent years, there has been a growing demand for optical components requiring high refractive indices, such as microlenses in micro-OLED (Organic Light Emitting Diode) displays, microlenses for image sensors, and diffractive optical elements in augmented reality (AR) glasses. As a result, research is being conducted on applying resins that exhibit high refractive indices (high refractive index resins) as materials for such optical components. High refractive index resins can be obtained by polymerizing monomers that exhibit high refractive indices (high refractive index monomers), by blending inorganic particles that exhibit high refractive indices (high refractive index inorganic particles) into a resin, or by combining these technologies for high refractive index monomers and high refractive index inorganic particles.

[0003] For example, Patent Document 1 describes a hard coat composition having a refractive index of 1.58 or higher, comprising surface-modified inorganic nanoparticles, an acrylate crosslinking agent, and an aromatic sulfur acrylate monomer. Patent Document 2 describes a printable dispersion comprising a curable composition and metal oxide particles, wherein the metal oxide particles have organic functional groups covalently bonded to their surface, and the organic functional groups are not covalently bonded to any part of the curable composition. Patent Document 3 describes a formulation comprising at least partially capped metal oxide nanocrystals and a matrix comprising at least one monomer, oligomer, or polymer, for example, a formulation comprising less than 5 wt% of a solvent in which at least partially capped metal oxide nanocrystals are dispersed in the matrix, and the metal oxide is zirconium oxide, titanium oxide, hafnium oxide, zinc oxide, tantalum oxide, niobium oxide, or a mixture of at least two of these oxides.

[0004] Special table 2008-527413 Publication Special table 2009-516393 Publication Special table 2022-507821

[0005] Imprint technology is known to be used to fabricate optical components with microstructures on the nano to micrometer order. Imprint technology is a microfabrication technique that transfers a fine pattern to the surface of a material, such as resin, by pressing a mold with a desired fine pattern structure onto the material. There is also a demand for the fabrication of optical components made of high refractive index resins using this imprint technology. Imprint technology consists of the following steps: coating the substrate with material, pressing with the mold pressed onto it, fixing the transferred pattern by light or heat curing, and demolding. The material used for imprinting needs to have low viscosity, similar to ink used in inkjet printing. Furthermore, naphthalene skeleton-containing monomers, known as an example of high refractive index monomers, have high crystallinity due to the naphthalene skeleton, so crystal precipitation becomes a problem when using compositions containing naphthalene skeleton-containing monomers.

[0006] In the example described in Patent Document 1, 2-[7-(2-acryloyloxyethylsulfanyl)-naphthalene-2-ylsulfanyl]-ethyl acrylic acid is used as the aromatic sulfur acrylate monomer. In the example described in Patent Document 2, 2-(naphthalene-2-ylsulfanyl)-ether ester is used as the monomer constituting the curable composition. As a result of our investigations, we have found that while compositions containing naphthalene skeleton-containing monomers and high refractive index inorganic particles as described in Patent Documents 1 and 2 can be made low viscosity and produce a cured product with a high refractive index, crystals may precipitate in the coating film obtained using the composition, which may adversely affect the optical properties required for the resulting cured film.

[0007] An object of the present invention is to provide a curable composition that has a low viscosity in the state of the curable composition before curing reaction, is excellent in suppressing crystal precipitation in the obtained coating film, and can impart a high refractive index to the obtained cured product. Another object of the present invention is to provide a cured product obtained from this curable composition, as well as an optical material, a microlens, and a diffractive optical element including this cured product. Another object of the present invention is to provide surface-treated TiO which is suitable, for example, as metal oxide particles to be contained in the above curable composition, and which can increase the refractive index of the obtained cured product without impairing the light transmittance of the cured product when contained in a curable composition containing a polymerizable compound ２ An object of the present invention is to provide particles and a curable composition containing the same.

[0008] The above object of the present invention has been solved by the following means. <1> A compound represented by the following general formula (1) and having a point group of C ｓ A, and surface-treated metal oxide particles containing at least one metal element selected from Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al and Ce, subjected to surface treatment with a silane coupling agent, and having an average particle diameter of 2 to 200 nm. In the above formula, R ａ to R ｈ each are a hydrogen atom, or the following R １ or R ２ , provided that at least one of R ａ to R ｈ is the following R １ , and at least two of R ａ to R ｈ are groups selected from the following R １ and R ２ . R １ : a group represented by any one of the following general formulas (Pol-1) to (Pol-4); R ２ : an alkylsulfanyl group having 1 to 12 carbon atoms In the above formula, L １∫ represents an alkylene group having 2 to 6 carbon atoms. * represents a bond. <2> The curable composition according to <1>, wherein the surface-treated metal oxide particles contain at least one metal element selected from Ti, Y, Zr, Sn, and Al. <3> The curable composition according to <1> or <2>, wherein the silane coupling agent contains a compound represented by the following general formula (2). In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ４ This represents a (meth)acryloyl group or a group represented by the following general formula (p). In the above formula, R ５ L represents an alkyl group having 1 to 3 carbon atoms. ３ represents an alkylene group having 2 to 6 carbon atoms, and n is 0 to 10. * represents a bond. <4> The curable composition according to <3>, wherein the silane coupling agent contains a compound represented by the following general formula (3). In the above formula, L, R ３ , R ５ and n are L and R, respectively. ３ , R ５ This is synonymous with n. <5> A curable composition according to any one of <1> to <4>, wherein compound A contains a disubstituted compound represented by the following general formula (1-1). In the above formula, R ａ and R ｆ The above R １ or R ２ This shows that R ａ and R ｆ At least one of the above R １ The curable composition according to any one of <1> to <5>, wherein the content of the surface-treated metal oxide particles in the solid content of the curable composition is 45% by mass or more. The curable composition according to any one of <1> to <5>. The metal oxide particles constituting the surface-treated metal oxide particles are Al(OH) ３ TiO coated with ２A curable composition containing particles, as described in any one of <1> to <6>. <8> A polymerizable compound and Al(OH) ３ TiO coated with ２ Surface-treated TiO2 particles with an average particle size of 2 to 200 nm, which are surface-treated with a silane coupling agent represented by the following general formula (3). ２ A curable composition containing particles. In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ５ represents an alkyl group having 1 to 3 carbon atoms. n is 0 to 10. * represents a bond. <9> A cured product obtained from any one of the curable compositions described in <1> to <8>. <10> An optical material containing the cured product described in <9>. <11> A microlens or diffractive optical element containing the cured product described in <9>. <12> Al(OH) ３ TiO coated with ２ Surface-treated TiO2 particles with an average particle size of 2 to 200 nm, which are surface-treated with a silane coupling agent represented by the following general formula (3). ２ particle. In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ５ * indicates an alkyl group having 1 to 3 carbon atoms. n is between 0 and 10. * indicates a bond.

[0009] In the present invention, when there are multiple substituents or linking groups, etc. (hereinafter referred to as substituents, etc.) represented by a specific symbol or formula, or when multiple substituents, etc. are specified simultaneously, unless otherwise specified, each substituent, etc. may be identical or different from one another (regardless of whether the expression "each independently" is used or not, each substituent, etc. may be identical or different from one another). The same applies to the specification of the number of substituents, etc. Furthermore, when multiple substituents, etc. are in close proximity (especially when adjacent), unless otherwise specified, they may be linked to each other to form a ring. Furthermore, unless otherwise specified, a ring, such as an alicyclic ring, aromatic ring, or heterocyclic ring, may be further fused to form a fused ring. In the present invention, unless otherwise specified, with respect to double bonds, if E-type and Z-type double bonds exist in the molecule, either one or a mixture thereof may be used. Furthermore, in the present invention, unless otherwise specified, when a compound has one or more chiral carbons, the stereochemistry of such chiral carbons may independently take the form of either the (R) or (S) isomer. As a result, the compound may be a mixture of optical isomers or stereoisomers such as diastereoisomers, or it may be a racemic mixture. However, when counting the types of compounds such as compound A described later, only the types of structural isomers are counted, and stereoisomers are not counted as different types. Furthermore, in this invention, the designation of compounds and monomers includes those in which a part of the structure has been changed, to the extent that the effects of the present invention are not impaired. In this invention, substituents (the same applies to linking groups and rings) that are not specified as substituted or unsubstituted may have any substituent on the group, to the extent that the desired effects are not impaired. For example, "alkyl group" includes both unsubstituted alkyl groups and substituted alkyl groups. For example, R in general formula (1) ａ ~R ｈ R can be adopted as ２The alkyl group in the C1 to C12 alkylsulfanyl group may have substituents, as will be described later. In the present invention, when the number of carbon atoms of a group is specified, this number of carbon atoms refers to the total number of carbon atoms of the group unless otherwise specified in the present invention or this specification. That is, if the group has further substituents, it refers to the total number of carbon atoms including these substituents.

[0010] In the present invention, when describing content, content ratio, conditions, physical properties, etc., by indicating numerical ranges, if the upper and lower limits of the numerical range are described separately, either upper or lower limit can be appropriately combined to form a specific numerical range. On the other hand, when describing multiple numerical ranges expressed using "~", the upper and lower limits forming the numerical range are not limited to the specific combination of upper and lower limits described before and after "~" as a specific numerical range, but can be a numerical range formed by appropriately combining the upper and lower limits of each numerical range. In the present invention, a numerical range expressed using "~" means a range that includes the values ​​described before and after "~" as the lower and upper limits. In the curable composition of the present invention, unless otherwise specified, each component may be used individually or as a mixture of two or more. The same applies to cured products, optical materials, microlenses, and diffractive optical elements obtained from the curable composition of the present invention. In the present invention, the solid content contained in the curable composition means the components obtained by excluding the dispersion medium (including the solvent) from the total composition of the curable composition.

[0011] In this invention, "(meth)acrylate" refers to either acrylate or methacrylate, or both; "(meth)acrylic acid" refers to either acrylic acid or methacrylic acid, or both; "(meth)acryloyl" refers to either acryloyl or methacryloyl, or both; and "(meth)acryloyl group" refers to either an acryloyl group or a methacryloyl group, or both. Furthermore, "(meth)acrylothioate ester" refers to either acrylic acid S-ester or methacrylic acid S-ester, or both, and means an ester of (meth)acrylic S-acid, which is an S-acid (-C(=O)SH). In this invention, monomers are distinguished from oligomers and polymers by molecular weight, and compounds with a weight-average molecular weight of 1000 or less are called monomers.

[0012] The curable composition of the present invention has low viscosity in the state of the curable composition before the curing reaction, is excellent in suppressing crystal deposition in the resulting coating film, and can also impart a high refractive index to the resulting cured product. The cured product, optical material, microlens, and diffractive optical element of the present invention can exhibit a high refractive index. Surface treatment of TiO ２ The particles are suitable, for example, as metal oxide particles to be included in the above-mentioned curable composition, and by including them in a curable composition containing a polymerizable compound, the refractive index of the resulting cured product can be increased without impairing the light transmittance of the cured product. ２ The curable composition of the present invention, which contains particles, can increase the refractive index of the resulting cured product without impairing its light transmittance.

[0013] Figure 1 is a schematic cross-sectional view illustrating a method for producing a cured product of the present invention using the curable composition of the present invention and imprint technology.

[0014] [Curable Composition] The curable composition of the present invention is represented by the general formula (1) below, and the point group is C ｓThe present invention provides a curable composition comprising compound A and surface-treated metal oxide particles (hereinafter also simply referred to as "surface-treated metal oxide particles (M)") which contain at least one metal element from among Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al, and Ce, are surface-treated with a silane coupling agent, and have an average particle size of 2 to 200 nm. In the present invention, a curable composition means a composition that has curability and from which a cured product (resin) can be obtained by a curing reaction.

[0015] Compound A contained in the curable composition of the present invention is represented by general formula (1), and the substituent R on the naphthalene ring ａ ~R ｈ At least one of them is R １ And R ａ ~R ｈ At least two of are R １ and R ２ A base selected from and whose point group is C ｓ It is a substituted naphthalene compound that has a perpendicular mirror plane. Compound A has at least one R １ (The group represented by any of the general formulas (Pol-1) to (Pol-4) below) is either a (meth)acryloylthiooxy group or a (meth)acryloyloxy group and a sulfur atom L １ A group formed by linking (alkylene groups having 2 to 6 carbon atoms), which compound A may have as a substituent. ２ This is an alkylsulfanil group having 1 to 12 carbon atoms. The curable composition of the present invention contains a substituted naphthalene compound (compound A) having the above-mentioned specific chemical structure and specific point group, and specific surface-treated metal oxide particles (M), thereby having low viscosity in the state of the curable composition before the curing reaction, enabling the resulting cured product to have a higher refractive index, and moreover, even though all of the compounds A exhibit high crystallinity, crystal deposition in the resulting coating film can be suppressed.

[0016] The components contained in the curable composition of the present invention will be described in order below.

[0017] <Compound A> Compound A is represented by the following general formula (1), and the point group is C ｓ It is a compound that is [this compound].

[0018] (Compounds represented by general formula (1))

[0019] In the above formula, R ａ ~R ｈ is either a hydrogen atom, or R as described below. １ Or R ２ This indicates that R ａ ~R ｈ At least one of the following R １ And, R ａ ~R ｈ At least two of the following R １ and R ２ It is a base selected from among them.

[0020] (R １ ) R １ This refers to a group represented by any of the following general formulas (Pol-1) to (Pol-4).

[0021]

[0022] In the above formula, L １ * indicates an alkylene group with 2 to 6 carbon atoms. * indicates a bond.

[0023] L １ The alkylene group having 2 to 6 carbon atoms may be either linear or branched, and the number of carbon atoms in the alkylene group may be 2 to 6, but from the viewpoint of exhibiting a higher refractive index, 2 to 5 is preferred, 2 to 4 is more preferred, and 2 to 3 is even more preferred. １ The minimum number of atoms that form a bond between the sulfur atom and the (meth)acryloyloxy group is preferably 2 to 6, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 2 to 3. As an example of the "minimum number of atoms that form a bond between the sulfur atom and the (meth)acryloyloxy group," in the specific compound (B-4) shown below, the minimum number of atoms that form a bond between S and the acryloyloxy group in the general formula (Pol-3) is 2 (-CH ２ CH ２-) is the result. Examples of the alkylene group mentioned above include 1,1-ethylene group, 1,2-ethylene group, 1,1-propylene group, 1,2-propylene group, 1,3-propylene group, 1,1-butylene group, 1,2-butylene group, 1,3-butylene group, 1,4-butylene group, 1,1-pentylene group, 1,2-pentylene group, 1,3-pentylene group, 1,4-pentylene group, 1,5-pentylene group, 1,1-hexylene group, 1,2-hexylene group, 1,3-hexylene group, 1,4-hexylene group, 1,5-hexylene group, and 1,6-hexylene group, with 1,2-ethylene group, 1,3-propylene group, 1,4-butylene group, 1,5-pentylene group, or 1,6-hexylene group being preferred. The alkylene group described above may have substituents, and examples of alkylene groups having such substituents include halogenated alkylene groups and hydroxyalkylene groups. Examples of halogen atoms constituting the halogenated alkylene group include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0024] (R ２ ) R ２ This represents an alkylsulfanyl group having 1 to 12 carbon atoms. ２In the alkylsulfanyl group having 1 to 12 carbon atoms (-S-alkyl group), the alkyl group may be either linear or branched. The alkyl group only needs to have 1 to 12 carbon atoms, preferably 1 to 7 carbon atoms. From the viewpoint of exhibiting a higher refractive index, 1 to 5 carbon atoms are more preferred, and 1 to 3 carbon atoms are even more preferred. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, 1-methylbutyl group, 3-methylbutyl group, hexyl group, 1-methylpentyl group, 4-methylpentyl group, heptyl group, 1-methylhexyl group, 5-methylhexyl group, 2-ethylhexyl group, octyl group, 1-methylheptyl group, nonyl group, 1-methyloctyl group, nonyl group, decyl group, undecyl group, and dodecyl group, with methyl group or ethyl group being preferred. The alkyl group may have a substituent, and examples of such alkyl groups having a substituent include halogenated alkyl groups and hydroxyalkyl groups. Examples of the halogen atom constituting the halogenated alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R ２ As the alkylsulfanyl group having 1 to 12 carbon atoms, a methylsulfanyl group or an ethylsulfanyl group is preferred.

[0025] In the above compound A, R ａ to R ｈ , at least one of which is the above R １ , therefore, the above compound A is a polymerizable compound having at least one (meth)acryloyl group. R ａ to R ｈ among the 8 groups, the number of groups that are the above R １ only needs to be 1 or more. From the viewpoint of obtaining a good cured product, for example, 1 to 4 groups are preferred, and 1 to 3 groups are more preferred. Also, in the above compound A, R ａ to R ｈ , at least two of which are the above R １ and R ２ is a group selected from. R ａ to R ｈ among the 8 groups, the above R １ and R ２The number of elements selected from these may be two or more, for example, two to six are preferred, two to four are more preferred, and two to three are even more preferred.

[0026] Of compound A, the above R １ and R ２ In a disubstituted compound having two groups selected from (hereinafter referred to as "substituent A"), the position where substituent A is located is R ａ and R ｂ , R ａ and R ｃ , R ａ and R ｄ , R ａ and R ｆ , R ａ and R ｇ , R ａ and R ｈ , R ｂ and R ｃ , or R ｂ and R ｇ Preferably, R ａ and R ｆ This is more preferable. Among compound A, in a trisubstituted compound having three substituents A, the position where substituent A is located is R ａ , R ｃ and R ｆ The combination, R ａ , R ｃ and R ｇ A combination of, or R ｂ , R ｃ and R ｇ The combination is preferable, R ａ , R ｃ and R ｆ The combination is more preferable. Among compound A, in a tetrasubstituted compound having four substituents A, the positions where substituent A is located are R ａ , R ｃ , R ｆ and R ｇ A combination of, or R ａ , R ｃ , R ｆ and R ｈ The combination is preferable, R ａ , R ｃ , R ｆ and R ｇ The combination is more preferable.

[0027] From the viewpoint of having superior effect in suppressing crystal deposition in the coating film, the above compound A preferably contains a disubstituted compound represented by the following general formula (1-1). The point group of the disubstituted compound represented by the following general formula (1-1) is R ａ and R ｆ R １ and R ２ Regardless of which substituent it is, C is always ｓ That is the case.

[0028]

[0029] In the above formula, R ａ and R ｆ This is R in the general formula (1) mentioned above. １ or R ２ This shows that R ａ and R ｆ At least one of them is R １ That is. R １ and R ２ This is R in the general formula (1) mentioned above. １ and R ２ These are synonymous with each other.

[0030] The following lists preferred specific examples of compound A, but the present invention is not limited to these compounds. In the following, Me represents a methyl group, Hex represents an n-hexyl group, and * represents a bond. Point groups are indicated in parentheses below the compound numbers.

[0031]

[0032]

[0033] The molecular weight of compound A is preferably 174 to 945, more preferably 174 to 820, and even more preferably 174 to 730.

[0034] Compound A can be synthesized by conventional methods. For example, it can be synthesized by referring to the synthesis methods described in Japanese Patent Publication No. 2013-155118 (Sumitomo Seika) and Japanese Patent Publication No. Hei 3-170456 (Sumitomo Seika). It can also be synthesized by referring to the methods described in the examples as appropriate.

[0035] The curable composition of the present invention may contain one or more of the above-mentioned compound A, for example, one to five types. From the viewpoint of further improving the effect of suppressing crystal deposition in the coating film, it is preferable that the curable composition of the present invention contains two or more of the above-mentioned compound A, and more preferably three or more types. When the curable composition of the present invention contains two or more of the above-mentioned compound A, the proportion of each compound A in the total amount of the above-mentioned compound A (meaning "the sum of all the above-mentioned compound A contained in the curable composition of the present invention") is not particularly limited, and for example, each can be 5% by mass or more, preferably 7% by mass or more, and more preferably 10% by mass or more. The upper limit is appropriately determined according to how many types of the above-mentioned compound A are contained in the curable composition of the present invention, such that the lower limit of each compound A is 5% by mass or more (preferably 7% by mass or more, more preferably 10% by mass or more).

[0036] The total content of compound A in the solid content of the curable composition of the present invention can be, for example, 5 to 80% by mass, preferably 5 to 70% by mass, more preferably 5 to 60% by mass, and even more preferably 7 to 60% by mass. If two or more types of compound A are contained, it is preferable that the total content be within the above range.

[0037] <Surface-treated metal oxide particles (M)> Surface-treated metal oxide particles (M) contain at least one metal element from among Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al, and Ce, and are surface-treated with a silane coupling agent, with an average particle diameter of 2 to 200 nm.

[0038] (Metal Oxide Particles (m)) The metal oxide particles before surface treatment with a silane coupling agent (hereinafter referred to as "metal oxide particles (m)") may be any metal oxide particles containing at least one metal element (meaning a metallic element or a metalloid element) from among Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al, and Ce. As a result, the surface-treated metal oxide particles (M) will be particles exhibiting a high refractive index. Note that metal oxide particles (m) means particles of an oxide of at least one metal from among Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al, and Ce. The oxide of at least one metal from Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al, and Ce is not particularly limited. Examples of metal oxides containing one metal element include TiO ２ FeO, Fe ２ O ３ ,Cd ２ O, CuO, Y ２ O ３ , ZrO ２ NbO, Nb ２ O ５ MoO ３ In ２ O ３ , SnO ２ Sb ２ O ３ , HfO ２ Ta ２ O ５ WO ３ , PbO, Pb(II) ２ Pb(IV)O ４ , PbO ２ , Bi ２ O ３ Al ２ O ３ and CEO ２ Examples include composite metal oxides containing two or more metal elements, such as HfO ２ -ZrO ２ and TiO ２ -ZrO ２ Binary metal oxides such as Y-containing ZrO ２ and Sn-containing TiO２ Examples include metal oxides to which metal elements different from the metal elements constituting the metal oxides are added (contained). From the viewpoint of further increasing the refractive index nD of the hardened product, the metal oxide particles (m) preferably contain at least one metal element from Ti, Y, Zr, Sn, and Al, such as TiO ２ , Y ２ O ３ , ZrO ２ , SnO ２ Al ２ O ３ , Hf-ZrO ２ Ti-ZrO ２ , Y-containing ZrO ２ and Sn-containing TiO ２ It is more preferable that the particles be at least one of the following: ZrO ２ and TiO ２ It is even more preferable that the particles be at least one of the following types.

[0039] Also, among the metal oxide particles (m), TiO ２ Particles of metal oxides having photocatalytic activity, such as Al(OH)3, should be treated with other metal compounds that do not have photocatalytic activity to suppress their photocatalytic activity. ３ The surface may be coated with ). Examples of such metal oxide particles (m) include Al(OH) ３ TiO coated with ２ Particles are preferred. When the metal oxide particles (m) are metal oxide particles whose surface is coated with another metal compound that does not have photocatalytic activity, the content of the metal compound coating the surface of the metal oxide particles (m) can be, for example, 0.1 to 25% by mass, preferably 0.1 to 20% by mass, and more preferably 0.1 to 15% by mass.

[0040] (Silane Coupling Agent) The silane coupling agent used for surface treatment of metal oxide particles (m) should be one that reacts with functional groups present on the surface of the metal oxide particles (m) to form chemical bonds and imparts dispersibility of the surface-treated metal oxide particles (M) in the curable composition of the present invention, and furthermore, in the resulting cured product. In other words, in the present invention, surface-treated metal oxide particles that have been surface-treated with a silane coupling agent mean surface-treated metal oxide particles in which an organosilicon compound derived from the silane coupling agent is chemically bonded to the surface of the metal oxide particles (m).

[0041] The silane coupling agent described above can be any compound commonly used to disperse high refractive index metal oxide particles in a composition or resin, without any particular limitations. For example, a compound having a structure in which at least one of a hydroxyl group, an alkoxy group, and a chlorine atom is bonded to a silicon atom can be used. In addition to the structure in which at least one of a hydroxyl group, an alkoxy group, and a chlorine atom is bonded to a silicon atom, the silane coupling agent may also have a radical polymerizable group such as a (meth)acryloyl group, a vinyl group, or an allyl group; a cationic polymerizable group such as a vinyl ether group, an oxyranyl group, or an oxetanyl group; or a functional group such as an amino group, a sulfanyl group, an isocyanate group, or a polyalkylene oxy group. Among these, the silane coupling agent is preferably a compound having at least one of an alkylene oxy structure (excluding the alkoxy group bonded to the silicon atom) and an ester structure (-C(=O)O-) in addition to the structure in which at least one of a hydroxyl group, an alkoxy group, and a chlorine atom is bonded to a silicon atom.

[0042] From the viewpoint of being able to further reduce viscosity and enhance the effect of suppressing crystal deposition in the coating film, the above silane coupling agent preferably contains a compound represented by the following general formula (2).

[0043]

[0044] In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ４ This represents a (meth)acryloyl group or a group represented by the general formula (p) described below.

[0045] The alkylene group having 2 to 6 carbon atoms as L may be either linear or branched, and the number of carbon atoms in the alkylene group is preferably 2 to 5, more preferably 2 to 4, even more preferably 2 to 3, and particularly preferably 3. A specific example of the alkylene group having 2 to 6 carbon atoms as L is L in compound A described above. １ The description relating to specific examples of alkylene groups having 2 to 6 carbon atoms can be applied, and 1,3-propylene groups are preferred.

[0046] R ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. ３ The alkyl group constituting the alkoxy group having 1 to 5 carbon atoms may be either linear or branched, and the number of carbon atoms in the alkoxy group may be 1 to 5, preferably 1 to 3, and more preferably 1 to 2. Examples include methoxy, ethoxy, propyloxy, isopropyloxy, butoxy, and pentyloxy groups, with methoxy or ethoxy groups being preferred. ３ The C1-C3 alkyl group that can be used may be either linear or branched, and the number of carbon atoms is preferably 1-2. Examples include methyl, ethyl, propyl, and isopropyl groups. The three R groups present in the compound represented by general formula (2) ３ Of these, at least one is a carbon-1 to carbon-5 alkoxy group, chlorine atom, or hydroxyl group; preferably at least two are carbon-1 to carbon-5 alkoxy groups, chlorine atoms, or hydroxyl groups; more preferably all three are carbon-1 to carbon-5 alkoxy groups, chlorine atoms, or hydroxyl groups; and even more preferably all three are carbon-1 to carbon-5 alkoxy groups.

[0047] R ４This represents a (meth)acryloyl group or a group represented by the following general formula (p).

[0048]

[0049] In the above formula, R ５ L represents an alkyl group having 1 to 3 carbon atoms. ３ * represents an alkylene group with 2 to 6 carbon atoms, where n is 0 to 10. * indicates a bond.

[0050] R ５ The C1-C3 alkyl group can be either linear or branched, and C1-C2 is preferred. Examples include methyl, ethyl, propyl, and isopropyl groups, with methyl or ethyl groups being preferred.

[0051] L ３ The alkylene group having 2 to 6 carbon atoms may be either linear or branched, and the number of carbon atoms in the alkylene group is preferably 2 to 4, more preferably 2 to 3, and even more preferably 2. ３ A specific example of an alkylene group having 2 to 6 carbon atoms is L in compound A mentioned above. １ The description relating to specific examples of alkylene groups having 2 to 6 carbon atoms can be applied, and 1,2-ethylene groups are preferred.

[0052] n is between 0 and 10, preferably between 1 and 8, more preferably between 1 and 6, and even more preferably between 2 and 4.

[0053] From the viewpoint of further reducing viscosity and further enhancing the effect of suppressing crystal deposition in the coating film, R ４ It is preferable that the group is represented by the above general formula (p). In particular, it is preferable that the silane coupling agent contains a compound represented by the following general formula (3).

[0054]

[0055] In the above formula, L, R ３ , R ５ and n are L and R in the general formula (2) above, respectively. ３ , R ５ This is synonymous with n.

[0056] In particular, the silane coupling agent described above is one in which n is 1 to 6, L is a 1,3-propylene group, and R ３ It is more preferable that the compound contains an alkyloxypoly(ethyleneoxy)propyltrialkoxysilane compound in which the alkoxy group has 1 to 5 carbon atoms.

[0057] Examples of the above silane coupling agents include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, o,m,p-methylphenyltrimethoxysilane, o,m,p-methylphenyltriethoxysilane, o,m,p-ethylphenyltrimethoxysilane, o,m,p-ethylphenyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]-triethoxysilane, methoxytri(ethyleneoxy)propyltrimethoxysilane (METOPTS), methoxytri(ethyleneoxy)propyltriethoxysilane, polyalkylene oxide trimethoxysilane (e.g., Silquest) A-1230 (trade name, available from Momentive), polyalkylene oxide triethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane, 3-(acryloyloxy)propyltriethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane Examples of trialkoxysilane compounds include royloxypropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane.

[0058] The proportion of the compound represented by general formula (2) in the silane coupling agent is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. It is also preferable that all of the silane coupling agent be the compound represented by general formula (2). The same applies to the proportion of the compound represented by general formula (3) in the silane coupling agent and the proportion of the alkyloxypoly(ethyleneoxy)propyltrialkoxysilane compound in the silane coupling agent.

[0059] The content of the silane coupling agent in the surface-treated metal oxide particles (M) is preferably, for example, 1 to 50% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 30% by mass. The content of the metal oxide particles (m) in the surface-treated metal oxide particles (M) is preferably, for example, 50 to 99% by mass, more preferably 60 to 97% by mass, and even more preferably 70 to 95% by mass. In order to adjust the content of the silane coupling agent or the metal oxide particles (m) in the surface-treated metal oxide particles (M) to the above ranges, the blending ratio of the silane coupling agent and the metal oxide particles (m) used when producing the surface-treated metal oxide particles (M) is preferably, for example, silane coupling agent:metal oxide particles (m) = 1 to 50:50 to 99, more preferably 3 to 40:60 to 97, and even more preferably 5 to 30:70 to 95.

[0060] (Average particle size) If the average particle size of the surface-treated metal oxide particles (M) is 2 to 200 nm, the resulting cured product can be given a desired level of light transmittance. From the viewpoint of further improving the light transmittance of the cured product, the average particle size of the surface-treated metal oxide particles (M) is preferably 2 nm or more and less than 100 nm, more preferably 2 nm or more and less than 80 nm, and even more preferably 2 nm or more and less than 50 nm. The average particle size of the surface-treated metal oxide particles (M) is the D50 particle size based on scattered light intensity, calculated by measuring the particle size using the dynamic light scattering method (DLS method) and analyzing it using the Marquadt method. Details are as described in the examples below.

[0061] The total content of surface-treated metal oxide particles (M) in the solid content of the curable composition of the present invention is not particularly limited, but on a mass basis, for example, it may be 20% by mass or more, preferably 30% by mass or more, and more preferably 45% by mass or more from the viewpoint of being able to suppress crystal precipitation in the coating film to a higher level and obtain a cured product exhibiting a higher refractive index. The upper limit can be, for example, 95% by mass or less, and preferably 93% by mass or less. The preferred range can be, for example, 20 to 95% by mass, preferably 30 to 95% by mass, more preferably 45 to 95% by mass, and even more preferably 45 to 93% by mass. Furthermore, the total content of surface-treated metal oxide particles (M) in the solid content of the curable composition of the present invention can be, for example, 5 to 85% by volume, preferably 10 to 85% by volume, more preferably 15 to 85% by volume, and even more preferably 15 to 80% by volume. Furthermore, if two or more types of surface-treated metal oxide particles (M) are contained, it is preferable that the total content, both by mass and by volume, be within the above range.

[0062] As for the surface-treated metal oxide particles (M), from the viewpoint of having superior effect in suppressing crystal deposition in the coating film, the metal oxide particles (m) are Al(OH) ３ TiO coated with ２ Surface-treated metal oxide particles (M) containing particles are preferred. In this case, the silane coupling agent preferably contains the compound represented by the general formula (2), and more preferably contains the compound represented by the general formula (3).

[0063] In relation to the above, the present invention provides in one aspect the following curable composition invention: a polymerizable compound and Al(OH) ３ TiO coated with ２ Surface-treated TiO particles with an average particle size of 2 to 200 nm, which are surface-treated with a silane coupling agent represented by the above general formula (3). ２ Particles (hereinafter referred to as "surface-treated TiO ２ A curable composition containing particles (hereinafter referred to as "the curable composition (I) of the present invention"). Surface treatment TiO in the curable composition (I) of the present invention.２ The particles (T) are those described in the curable composition of the present invention above, namely Al(OH) ３ TiO coated with ２ Particles, surface-treated with a silane coupling agent represented by the above general formula (3), with an average particle size of 2 to 200 nm, surface-treated TiO ２ The particles are the same, and the preferred form is also the same. Furthermore, the polymerizable compound in the curable composition (I) of the present invention is not particularly limited as long as it is a compound containing a polymerizable group, for example, compound A described above and other monomers described later. Surface treatment TiO ２ Because the particles (T) have good dispersibility, they can exist with excellent dispersibility not only in the above-mentioned compound A, but also in compositions containing polymerizable compounds like compound A, such as other monomers described later. Therefore, the curable composition (I) of the present invention can enhance the light transmittance of the resulting cured product.

[0064] The curable composition of the present invention preferably satisfies at least one of the following (i) to (v), more preferably at least two, even more preferably at least three, particularly preferably at least four, and most preferably all of them. The following (i) to (v) are as described in the corresponding descriptions for Compounds A to B above, and the descriptions relating to preferred ranges can also be applied to each. (i) The surface-treated metal oxide particles (M) contain at least one metal element from Ti, Y, Zr, Sn, and Al. (ii) The silane coupling agent contains a compound represented by general formula (2), preferably a compound represented by general formula (3). (iii) Compound A contains a disubstituted compound represented by general formula (1-1). (iv) The content of surface-treated metal oxide particles (M) in the solid content of the curable composition is 45% by mass or more. (v) The metal oxide particles (m) constituting the surface-treated metal oxide particles (M) are Al(OH) ３ TiO coated with ２ The particles include, preferably, surface-treated metal oxide particles (M) and Al(OH) ３TiO coated with ２ Particles, surface-treated with a silane coupling agent represented by general formula (3), with an average particle size of 2 to 200 nm, and surface-treated TiO ２ Contains particles.

[0065] <Other Components> In addition to the compound A and surface-treated metal oxide particles (M) described above, the curable composition of the present invention may further contain other components. Examples of other components include monomers other than the compound A described above (hereinafter referred to as "other monomers") and photoradical polymerization initiators.

[0066] (Other Monomers) In addition to compound A described above, the curable composition of the present invention may also contain other monomers, such as (meth)acryloyl group-containing compounds (excluding compound A). By including other monomers, it becomes possible, for example, to adjust the stress relaxation function of the cured product obtained from the curable composition of the present invention when the cured product undergoes thermal changes. Examples of (meth)acryloyl group-containing compounds include monofunctional mono(meth)acrylic acid ester compounds, difunctional di(meth)acrylic acid ester compounds, and polyfunctional (meth)acrylic acid ester compounds with three or more functions, depending on the number of (meth)acryloyl groups which are functional groups. Note that these (meth)acrylic acid ester compounds may also be (meth)acrylothio acid ester compounds.

[0067] Specific examples of mono(meth)acrylic acid ester compounds include isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, iso Cutyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 1-ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethyldiglycol (meth)acrylate, cyclic trimethylolpropane formal mono(meth)acrylate, imide (meth) Acrylate, isoamyl (meth)acrylate, ethoxylated succinate (meth)acrylate, trifluoroethyl (meth)acrylate, ω-carboxypolycaprolactone mono(meth)acrylate, cyclohexyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, diethylene glycol monobutyl ether (meth)acrylate, lauryl (meth)acrylate, isodecyl (meth)acrylate, octyl / decyl (meth)acrylate, tridecyl (meth)acrylate Sulfate, caprolactone (meth)acrylate, ethoxylated (4) nonylphenol (meth)acrylate, methoxypolyethylene glycol (350) mono(meth)acrylate, methoxypolyethylene glycol (550) mono(meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, methylphenoxyethyl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, tribromophenyl (meth)acrylate, ethoxylated tribromophenyl (meth)acrylate,Examples include 2-phenoxyethyl (meth)acrylate, ethylene oxide adducts of 2-phenoxyethyl (meth)acrylate, propylene oxide adducts of 2-phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 3-(meth)acryloyloxymethylcyclohexene oxide. Specific product names and sources of mono(meth)acrylic acid ester compounds include ethoxylated orthophenylphenol acrylate (NK Ester A-LEN-10, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) and m-phenoxybenzyl acrylate (Light Acrylate POB-A, manufactured by Kyoeisha Chemical Co., Ltd.).

[0068] Specific examples of di(meth)acrylic acid ester compounds include di(meth)acrylates of diols and di(meth)acrylates of (poly)alkylene glycols. Specific product names and sources for di(meth)acrylic acid ester compounds include 1,6-hexanediol diacrylate (NK Ester A-HD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; Light Acrylate 1,6HX-A, manufactured by Kyoeisha Chemical Co., Ltd.), 1,9-nonanediol diacrylate (NK Ester A-NOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; Light Acrylate 1,9ND-A, manufactured by Kyoeisha Chemical Co., Ltd.), and 1,10-decanediol diacrylate (NK Ester A-DOD-N (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), neopentyl glycol diacrylate (NK Ester A-NPG (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); light acrylate NP-A (manufactured by Kyoeisha Chemical Co., Ltd.), ethylene glycol diacrylate (SR206NS (manufactured by Arkema)), polyethylene glycol diacrylate (NK Ester A-400 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)), polypropylene glycol diacrylate (NK Ester APG-400 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) (Manufactured by Chemical Industry Co., Ltd.), tricyclodecanedimethanol diacrylate (also known as dimethylol-tricyclodecanediacrylate) (NK Ester A-DCP, manufactured by Shin Nakamura Chemical Industry Co., Ltd.; Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.), 1,3-butanediol dimethacrylate (NK Ester BG, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 1,4-butanediol dimethacrylate (NK Ester BD, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 1,6-hexanediol dimethacrylate Examples include relate (NK Ester HD-N, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 1,9-nonanediol dimethacrylate (NK Ester NOD-N, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 1,10-decanediol dimethacrylate (NK Ester DOD-N, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 1,12-dodecanediol dimethacrylate (SR262, manufactured by Sartomer Co., Ltd.), neopentyl glycol dimethacrylate (NK Ester NPG, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), etc.

[0069] Specific product names and sources for polyfunctional (meth)acrylic acid ester compounds include trimethylolpropane triacrylate (NK Ester A-TMPT, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.; Light Acrylate TMP-A, manufactured by Kyoeisha Chemical Co., Ltd.), ethoxylated trimethylolpropane triacrylate (NK Ester A-TMPT-EO, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), ethoxylated glycerin triacrylate (NK Ester A-GLY-6E, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), propoxylated glycerin triacrylate (NK Ester A-GLY-3P, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), and other trifunctional (meth)acrylic acid ester compounds; Examples include tetrafunctional (meth)acrylic acid ester compounds such as pentaerythritol tetraacrylate (NK Ester A-TMMT, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), ethoxylated pentaerythritol tetraacrylate (NK Ester ATM-4E, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), and ditrimethylolpropane tetraacrylate (NK Ester AD-TMP-L, manufactured by Shin Nakamura Chemical Industry Co., Ltd.); pentafunctional (meth)acrylic acid ester compounds such as dipentaerythritol pentaacrylate (M-402, manufactured by Toagosei Co., Ltd.); and hexafunctional (meth)acrylic acid ester compounds such as dipentaerythritol hexaacrylate (GM66G0H, manufactured by Kokusei Chemical Co., Ltd.).

[0070] Furthermore, the curable composition of the present invention may also contain, within the range of achieving the effects of the present invention, other monomers represented by the general formula (1) above, and R ａ ~R ｈ At least one of the above R １ It is also possible to include compounds that do not fall under compound A among the compounds described above. Represented by the general formula (1) above, R ａ ~R ｈ At least one of the above R １ In a compound, a compound that does not fall under compound A is, for example, a compound whose point group is C ２ｖ or C ２ｈ The compound is R ａ ~R ｈ One of them is R １ And the remaining seven are hydrogen atoms, or R １ and R ２ Examples of compounds with substituents that do not fall under the above category include those compounds.

[0071] Furthermore, the following (meth)acrylic acid ester compounds and (meth)acrylicthio acid ester compounds are also preferred. However, the present invention is not limited to these compounds.

[0072]

[0073] There are no particular restrictions on how the above (meth)acrylic acid ester compounds can be obtained; they may be obtained commercially or synthesized by conventional methods.

[0074] If the curable composition of the present invention contains other monomers, the content of other monomers in the solid content of the curable composition of the present invention can be, for example, 1 to 40% by mass, preferably 1 to 35% by mass, more preferably 1 to 30% by mass, even more preferably 1 to 25% by mass, and particularly preferably 1 to 20% by mass. If the curable composition of the present invention contains other monomers, the curable composition of the present invention may contain two or more types of other monomers. If two or more types of other monomers are contained, it is preferable that the total content is within the above range.

[0075] (Photoradical polymerization initiator) The curable composition of the present invention preferably contains a photoradical polymerization initiator. The curable composition of the present invention can produce a cured product exhibiting a high refractive index by photopolymerization due to the action of the photoradical polymerization initiator. As the photoradical polymerization initiator, compounds commonly used as photoradical polymerization initiators can be used as appropriate according to the photopolymerization (photocuring) conditions described later, and specifically the following compounds can be used. For example, 1,2-diphenylethanedione, methylphenylglyoxylate; bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,4,4-trimethylpentylphosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate (also known as (2,4,6-trimethylbenzoyl)ethoxylphenylphosphine oxide), etc., α-acylphosphine α-hydroxyketone compounds such as 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropan-1-one; benzyl ketal compounds such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-aminoketone compounds such as 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone;Examples of oxime ester compounds include 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyl oxime) (available from BASF Japan as Irgacure OXE01 (trade name)), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone=O-acetyloxime (available from BASF Japan as Irgacure OXE02 (trade name)), Irgacure OXE03 and Irgacure OXE04 (all trade names, available from BASF Japan), and ADEKA Arculus N-1919T, ADEKA Arculus NCI-831E, ADEKA Arculus NCI-930 and ADEKA Arculus NCI-730 (all trade names, available from ADEKA).

[0076] In particular, the present invention uses 1-hydroxycyclohexylphenyl ketone (available from BASF Japan as Irgacure 184 (trade name)), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (available from BASF Japan as Irgacure 819 (trade name)), (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (available from BASF Japan as Irgacure TPO (trade name)), 2,2-dimethoxy-1,2-diphenylethane-1-one (available from BASF Japan as Irgacure 651 (trade name)), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylpropan-1-one, and 2-methyl Preferably, one of the following photoradical polymerization initiators may be used: ru-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, ethylphenyl(2,4,6-trimethylbenzoyl)phosphinate (available from BASF Japan as Irgacure TPO-L (trade name)), or ADEKA Arclus NCI-831E (trade name, available from ADEKA), 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyl oxime) (available from BASF Japan as Irgacure OXE01 (trade name)), or 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone=O-acetyloxime (available from BASF Japan as Irgacure OXE02 (trade name)). The photoradical polymerization initiator may contain one or more types.

[0077] When a photoradical polymerization initiator is included, the content of the photoradical polymerization initiator in the solid content of the curable composition of the present invention is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 3.0% by mass, and even more preferably 0.1 to 3.0% by mass.

[0078] To the extent that it does not contradict the spirit of the present invention, the curable composition of the present invention may contain polymers or monomers other than the components described above, leveling agents (surface modifiers), inorganic particles other than the surface-treated metal oxide particles (M) described above, dispersants, plasticizers, heat stabilizers, mold release agents, dispersion media, etc. These components can be appropriately included depending on the application of the curable composition of the present invention. Examples of dispersion media include solvents described in the method for preparing the curable composition described later. When the curable composition of the present invention contains a dispersion media, the solid content in the curable composition of the present invention can be, for example, 0.1 to 50% by mass, preferably 1 to 45% by mass, more preferably 2 to 35% by mass, and even more preferably 5 to 30% by mass. Examples of leveling agents include silicone-based surfactants, fluorine-based surfactants, and acrylic-based surfactants described in paragraphs 0044 to 0046 of Japanese Patent Publication No. 2024-500396.

[0079] The curable composition of the present invention, while maintaining the composition (type and ratio) of solids in the curable composition, can be measured using a composition in which the solvent in the curable composition is PGMEA (propylene glycol monomethyl ether acetate) and its content is 20% by mass. The viscosity at 25°C can be 20,000 mPa·s or less, preferably 8,000 mPa·s or less. The viscosity of the above measurement composition is measured using a rheometer (for example, trade name: HAAKE RheoStress 6000, manufactured by Thermo Fisher Scientific) at a shear rate of 10 s². －１ This is the viscosity measured at 25°C, and details are as described in the examples below. When the viscosity of the above measurement composition is 20,000 mPa·s or less, the curable composition of the present invention can be made into a low-viscosity composition with a viscosity of approximately 80,000 mPa·s or less at 25°C by adjusting the solid content concentration, thereby improving the handling properties when forming the cured product.

[0080] The curable composition of the present invention can be used in the production of cured products that require a high refractive index. In particular, the curable composition of the present invention has low viscosity and excellent effect in suppressing crystal precipitation during coating film formation, so it can be preferably used as an imprinting material, for example, in nanoimprinting, to produce cured products that exhibit a high refractive index.

[0081] [Method for preparing the curable composition] The method for preparing the curable composition of the present invention is not particularly limited, and it is sufficient to prepare it so that the above-mentioned compound A and surface-treated metal oxide particles (M) are included in the curable composition of the present invention. It is preferable to prepare the surface-treated metal oxide particles (M) by pre-treating the surface of the above-mentioned metal oxide particles (m) with the above-mentioned silane coupling agent, and then mix with the above-mentioned compound A to prepare the curable composition of the present invention. The surface treatment of the metal oxide particles (m) with the silane coupling agent can be carried out by a conventional method, for example, by preparing a hydrolysis solution of the silane coupling agent, and then mixing and dispersing it with the metal oxide particles (m). Zirconia nanobeads may be used during the mixing and dispersion process and removed after the dispersion process. The curable composition of the present invention can be diluted using a solvent to achieve a desired solid content concentration. Suitable solvents include those in which compound A dissolves, such as hydrocarbon solvents like aromatic hydrocarbon solvents such as toluene, halogenated hydrocarbon solvents like chlorinated hydrocarbon solvents such as methylene chloride and chloroform, alcohol solvents such as methanol and ethanol, ether solvents such as cyclic ether solvents such as tetrahydrofuran, epihalohydrin solvents such as epichlorohydrin, glycol ether acetate solvents such as (poly)alkylene glycol monoalkyl ether acetate such as propylene glycol monomethyl ether acetate (PGMEA), ester solvents such as ethyl acetate, amide solvents such as N,N-dimethylformamide, and urea solvents. Furthermore, the solvent used in the preparation of the curable composition can be removed by conventional methods such as heating and / or distillation under reduced pressure to achieve the desired solid content concentration. The photoradical polymerization initiator and other monomers mentioned above may be added simultaneously with the preparation of the mixture of compound A and surface-treated metal oxide particles (M), or they may be added separately and mixed.

[0082] [Cured Product] The cured product of the present invention is a cured product obtained from the curable composition of the present invention, and is a cured product obtained by curing a curable composition containing the above compound A and the above surface-treated metal oxide particles (M). The cured product of the present invention is obtained by the polymerization reaction of monomers containing the above compound A proceeding and curing. The cured product of the present invention may contain unreacted monomers (for example, the above compound A, other monomers, etc.). As described above, the cured product of the present invention can exhibit a high refractive index.

[0083] The refractive index of the cured product of the present invention can be evaluated using the refractive index (nD) at a wavelength of 589 nm at 25°C (in the present invention, this is also simply referred to as "refractive index nD of the cured product"). The refractive index nD of the cured product of the present invention can be 1.7 or higher, preferably 1.8 or higher, and more preferably 1.9 or higher. There is no particular upper limit to the refractive index nD of the cured product of the present invention, but it is practical to be 2.1 or lower. The above refractive index nD of the cured product is a value measured using a spectroscopic ellipsometer (for example, RC2 (product name), manufactured by J.A. Woolam Japan Co., Ltd.), and specifically, a measurement sample (cured product) can be prepared and measured according to the description in the examples below. When forming the cured product, a heating step may be used instead of the ultraviolet irradiation step described in the examples below, or both the heating step and the ultraviolet irradiation step may be used. Furthermore, JIS (Japanese Industrial Standards) B 7090:1999 Optics and optical instruments - Reference wavelengths (ISO 7944:1998 Optics and optical instruments - Reference wavelengths) may be referenced as appropriate.

[0084] The transmittance index of the cured product of the present invention at a wavelength of 400 nm can be 93% or higher, preferably 94% or higher, and more preferably 95% or higher. The transmittance index of the cured product at a wavelength of 400 nm is a value calculated by applying the transmittance (T) and reflectance (R) at a wavelength of 400 nm, measured for a cured product with a thickness of 1 μm using a UV-Vis spectrophotometer with an integrating sphere (for example, Shimadzu Corporation, product name: UV-2700iplus), to the following formula. Specifically, a measurement sample (cured film) can be prepared and measured according to the examples described below. Transmittance index at a wavelength of 400 nm = {T / (1 - R)} × 100% If the above transmittance index at a wavelength of 400 nm is 93% or higher, the cured product of the present invention can exhibit the desired light transmittance at wavelengths of 380 to 800 nm.

[0085] The shape and thickness of the cured product of the present invention can be appropriately adjusted according to the shape to which the cured product of the present invention is applied.

[0086] [Method for Manufacturing Cured Products] The cured products of the present invention can be manufactured by a method that includes a step of photocuring the above-described curable composition. When photocuring is performed, it is preferable to include the above-described photoradical polymerization initiator in the curable composition. The conditions for photocuring can preferably be those described below regarding the conditions for photopolymerization (photocuring).

[0087] One embodiment of the method for producing a cured product of the present invention is to press the curable composition of the present invention against a mold and light-cur it to obtain a cured product with the pattern of the mold transferred to it. From the viewpoint of release properties, the mold is preferably one that has been surface-treated with chromium nitride. As for the surface treatment of the mold with chromium nitride, for example, the description of chromium nitride treatment in paragraph

[0108] of International Publication No. 2019 / 044863 can be applied as is, except that "metal mold" is read as "mold".

[0088] Figure 1 is a schematic cross-sectional view illustrating a method for manufacturing a cured product of the present invention using the curable composition of the present invention and imprint technology. The size, shape, and thickness of the substrate 3, the size, shape, transfer pattern, and thickness of the mold 5, and the amount of curable composition 1 used can be appropriately adjusted to obtain a cured product 7 having the desired size, shape, transferred pattern, and thickness. As shown in Figure 1, (a) first, the curable composition 1 is sandwiched between the mold 5 and the substrate 3; (b) the curable composition 1 is pressed into the mold 5 and photocured by ultraviolet irradiation (UV irradiation) to produce a cured product 7 with the pattern of the mold 5 transferred to it; and (c) the obtained cured product 7 and substrate 3 are released (peeled) from the mold 5 to produce the cured product 7. The ultraviolet irradiation is not particularly limited as long as the curable composition 1 is cured, and the irradiation may be applied from either side of the mold 5 or the substrate 3. It is preferable that the substrate 3 is transparent and that the irradiation is performed from the substrate 3 side. Furthermore, the resulting cured product 7 may be used in a form integrated with the substrate 3, or the substrate 3 may be peeled off and the cured product 7 may be used separately. The description of the transparent substrate in the diffractive optical element described later can preferably be applied to the substrate 3.

[0089] Another preferred embodiment of the method for producing the cured product of the present invention is a method in which a coating film is formed using the curable composition of the present invention, and then photocured to obtain the cured product.

[0090] [Applications of the Cured Product] The cured product of the present invention can be used in a variety of applications and exhibits a high refractive index, making it particularly suitable for use in optical materials. In particular, the curable composition of the present invention used to obtain the cured product has low viscosity and excellent suppression of crystal precipitation during coating film formation, allowing for the production of cured products with diverse microstructure patterns ranging from nanometers to several hundred micrometers using imprint technology, etc., and is therefore preferably used in microlenses for micro-OLED (Organic Light Emitting Diode) displays, microlenses for image sensors, diffractive optical elements (preferably diffractive optical elements for waveguides) in augmented reality glasses (AR glasses), and the like.

[0091] [Diffractive Optical Element] The diffractive optical element of the present invention includes a cured product of the present invention, and preferably includes a surface having a diffraction grating shape formed with the cured product of the present invention, and is formed by curing the curable composition of the present invention. The diffractive optical element of the present invention preferably has a maximum thickness of 0.05 μm to 100 μm. The maximum thickness is more preferably 0.1 μm to 50 μm, and even more preferably 0.2 μm to 30 μm. The step difference (griddle thickness) of the diffraction grating shape (periodic structure) of the diffractive optical element is preferably 0.05 μm to 100 μm, more preferably 0.05 μm to 50 μm, and even more preferably 0.1 μm to 30 μm. Furthermore, the pitch of the diffraction grating shape of the diffractive optical element may be between 0.05 μm and 1 mm, and is also preferably 0.05 μm to 100 μm, and preferably varies within the same diffractive optical element according to the required optical aberration.

[0092] A diffractive optical element can be manufactured, for example, by the following procedure: A curable composition is sandwiched between the surface of a mold, such as a die, which has a surface processed into a diffraction grating shape, and a transparent substrate. After this, the curable composition may be pressed and stretched to a desired extent. While sandwiched, the curable composition is cured by irradiating it with light from the transparent substrate side. After that, the cured product is released from the mold, such as a die. After release, ultraviolet light may be irradiated from the side opposite to the transparent substrate.

[0093] Examples of the transparent substrates mentioned above include flat glass such as BK glass, and flat transparent resins (such as (meth)acrylic resin, polycarbonate resin, and polyethylene terephthalate resin). The surface of the transparent substrate may be subjected to surface treatment such as ozone treatment. The transparent substrate used in the above manufacturing may be included in the diffractive optical element as is, or it may be peeled off.

[0094] By using the curable composition of the present invention as the imprinting material, pressing a mold having a desired pattern of nanometers to several hundred micrometers into the material, and then photocuring the mold, a cured product of the present invention with the mold pattern transferred onto it can be produced, and then demolded to create a diffraction grating shape. Regarding the photocuring conditions, the descriptions in the above-mentioned method for producing the cured product and the descriptions regarding the photopolymerization (photocuring) conditions described later can be applied. Aside from the above, the commonly used descriptions of imprinting can be adopted without particular restriction; for example, one can refer to the Nanoimprint Technology Handbook (edited by the Nanoimprint Technology Research Group of the Japan Society of Applied Physics, Ohmsha Publishing, December 1, 2019).

[0095] The following conditions are preferable for photopolymerization (photocuring). The light used for irradiating the curable composition is preferably ultraviolet light or visible light, and more preferably ultraviolet light. For example, metal halide lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, germicidal lamps, xenon lamps, and LED (Light Emitting Diode) light source lamps are suitably used. The irradiance of the ultraviolet light used for irradiating the curable composition is 1 to 100 mW / cm². ２ Preferably, 1 to 75 mW / cm² ２ More preferably, 5 to 50 mW / cm² ２ This is even more preferable. Multiple exposures with ultraviolet light of different illuminances may be performed. The amount of ultraviolet light exposure should be 0.4 to 10 J / cm². ２ Preferably, 0.5 to 5 J / cm ２ More preferably, 1 to 3 J / cm ２This is even more preferable. The atmosphere during light irradiation is preferably an air or inert gas purged atmosphere, and more preferably an atmosphere in which the air has been purged with nitrogen until the oxygen concentration is 1% or less.

[0096] The present invention will be described in more detail below based on examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. In the following, room temperature means 25°C unless otherwise specified. All processes from the preparation of the curable composition to the production of cured products or evaluation tests were carried out in an environment using yellow light as illumination.

[0097] [Synthesis Example] Compound A and the comparative compound were synthesized as follows.

[0098] [Synthesis Example 1: Synthesis of Compound (A-9)]

[0099] 5.00 g (22.3 mmol) of 1,3,6-naphthalenethiol and 75 mL of N,N-dimethylacetamide (DMAc) were mixed while cooling to an internal temperature (liquid temperature) of 0°C. 8.77 g (69.1 mmol) of 3-chloropropionyl chloride (3CPC) was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then the mixture was heated to an internal temperature (liquid temperature) of 25°C. After stirring for 1 hour, the mixture was cooled to 0°C and triethylamine (Et) was added. ３ 13.98 g (138.2 mmol) of compound (N) was added dropwise, ensuring the liquid temperature did not exceed 7°C. The mixture was then heated to an internal temperature of 25°C. After stirring for 1 hour, 150 mL of ethyl acetate and 150 mL of 1N hydrochloric acid were added for washing and separation. Next, 80 mL of 5% sodium bicarbonate aqueous solution was added and stirred, followed by washing and separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain an oily composition. This was then purified by column chromatography using hexane and ethyl acetate to obtain 6.2 g of compound (A-9). Yield: 72%. Compound (A-9) １ H-NMR (300MHz, CDCl ３): δ (ppm) 5.8-5.9 (m, 3H), 6.3-6.6 (m, 6H), 7.6-7.7 (m, 1H), 7.80 (s, 1H), 8.01 (s, 1H), 8.07 (s, 1H), 8.20 (d, 1H)

[0100] [Synthesis Example 2: Synthesis of Compound (A-4)]

[0101] 5.00 g (26.0 mmol) of 1,6-naphthalenedithiol and 60 mL of N,N-dimethylacetamide (DMAc) were mixed and cooled until the internal temperature (liquid temperature) reached 0°C. 6.93 g (54.6 mmol) of 3-chloropropionyl chloride (3CPC) was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then the mixture was heated until the internal temperature (liquid temperature) reached 25°C. After stirring for 1 hour, the mixture was cooled to 0°C and triethylamine (Et) was added. ３ N) 11.05 g (109.2 mmol) was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then heated to an internal temperature (liquid temperature) of 25°C. After stirring for 1 hour, 150 mL of ethyl acetate and 150 mL of 1N hydrochloric acid were added for washing and separation. Next, 80 mL of 5% sodium bicarbonate aqueous solution was added and stirred, followed by washing and separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain an oily composition, which was then purified by hexane / ethyl acetate column chromatography to obtain 6.3 g of compound (A-4). Yield 81%. Compound (A-4) １ H-NMR (300MHz, CDCl ３ ): δ (ppm) 5.8-5.9 (m, 2H), 6.3-6.6 (m, 4H), 7.6-7.7 (m, 2H), 7.78 (d, 1H), 7.96 (d, 1H), 8.05 (s, 1H), 8.21 (d, 1H)

[0102] [Synthesis Example 3: Synthesis of Compounds (A-38) and (A-46)]

[0103] <Synthesis of compounds (A-38A) and (A-46A)> Under a nitrogen atmosphere, 10 g (52.0 mmol) of 1,6-naphthalenedithiol, 4.68 g (52.0 mmol) of dimethyl carbonate (DMC), and 30 mL of N,N-dimethylacetamide (DMAc) were mixed. Then, 8.62 g (52.0 mmol) of potassium carbonate was added, and the mixture was heated to an internal temperature (liquid temperature) of 50°C. After stirring for 3 hours, 100 mL of ethyl acetate and 100 mL of 2N hydrochloric acid were added for washing and separation. Next, 100 mL of 2N hydrochloric acid was added again for washing and separation. 100 mL of 15% sodium chloride aqueous solution was added and stirred, then washed and separated. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain 14 g of an oily composition containing compound (A-38A) and compound (A-46A). Yield 90%.

[0104] <Synthesis of compounds (A-38) and (A-46)> 14.0 g (67.8 mmol) of a mixture containing the above compounds (A-38A) and (A-46A) was mixed with 3 mL of N,N-dimethylacetamide (DMAc) while being cooled to an internal temperature (liquid temperature) of 0°C. 9.91 g (78.0 mmol) of 3-chloropropionyl chloride (3CPC) was added dropwise so that the liquid temperature did not exceed 7°C, and then the mixture was heated to an internal temperature (liquid temperature) of 25°C. After stirring for 1 hour, it was cooled to 0°C and triethylamine (Et) was added. ３ N) 16.5 g (163 mmol) was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then heated until the internal temperature (liquid temperature) reached 25°C. After stirring for 1 hour, 56 mL of ethyl acetate and 98 mL of 1N hydrochloric acid were added for washing and separation. Next, another 56 mL of 1N hydrochloric acid was added for washing and separation. Then, 56 mL of 5% sodium bicarbonate aqueous solution was added and stirred, followed by washing and separation. After dehydration with magnesium sulfate, filtration, and concentration, the mixture was purified by column chromatography to isolate compounds (A-38) and (A-46). Compound (A-38): yield 20%, Compound (A-46): yield 25%. Compound (A-38) １ H-NMR (300MHz, CDCl ３): δ (ppm) 2.58 (s, 3H), 5.8-5.9 (m, 1H), 6.3-6.6 (m, 2H), 7.4-7.6 (m, 2H), 7.6-7.7 (m, 2H), 7.85 (d, 1H), 8.03 (d, 1H) Compound (A-46) １ H-NMR (300MHz, CDCl ３ ): δ (ppm) 2.58 (s, 3H), 5.8-5.9 (m, 1H), 6.3-6.6 (m, 2H), 7.4-7.6 (m, 3H), 7.6-7.7 (m, 1H), 7.98 (s, 1H), 8.33 (d, 1H)

[0105] Furthermore, all of the compounds obtained by the above synthesis examples were crystalline.

[0106] [Synthesis Example 4: Synthesis of Compound (B-4)]

[0107] <Synthesis of Compound (B-4A)> Under a nitrogen atmosphere, 13.0 g (67.6 mmol) of 1,6-naphthalenedithiol, 17.7 g (141.9 mmol) of 2-bromoethanol, and 49.4 mL of N,N-dimethylacetamide (DMAc) were mixed while adding potassium carbonate (K ２ CO ３ 23.4 g (169.0 mmol) was added, and the mixture was heated to an internal temperature (liquid temperature) of 50°C. After stirring for 1 hour, 130 mL of ethyl acetate and 130 mL of 2N hydrochloric acid were added, and the mixture was washed and separated. Next, 130 mL of water was added and the mixture was stirred, followed by washing and separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain an oily composition, which was then purified by column chromatography to obtain 17.9 g of compound (B-4A). Yield: 94%.

[0108] <Synthesis of Compound (B-4)> Compound (B-4A) 5.00 g (17.8 mmol), triethylamine (Et ３3.97 g (39.2 mmol) of N acryloyl chloride was mixed with 60 mL of dichloromethane while cooling until the internal temperature (liquid temperature) reached 0°C. 3.39 g (37.4 mmol) of acryloyl chloride was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then the mixture was heated until the internal temperature (liquid temperature) reached 25°C. After stirring for 1 hour, 100 mL of 1N hydrochloric acid was added, followed by washing and liquid-liquid separation. Next, 100 mL of 5% sodium bicarbonate aqueous solution was added and stirred, followed by washing and liquid-liquid separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain an oily composition, which was then purified by column chromatography using hexane and ethyl acetate to obtain 5.5 g of compound (B-4). Yield: 79%. Compound (B-4) １ H-NMR (300MHz, CDCl ３ ): δ (ppm) 3.2-3.3 (m, 4H), 4.3-4.4 (m, 4H), 5.8-5.9 (m, 2H), 6.1-6.2 (m, 2H), 6.3 -6.4 (m, 2H), 7.41 (m, 1H), 7.52 (d, 1H), 7.6-7.7 (m, 2H), 7.83 (s, 1H), 8.36 (d, 1H)

[0109] [Synthesis Example 5: Synthesis of Compound (A-17)] Compound (A-17) was synthesized by referring to the synthesis of 16NDSHMA described in Example 2 of International Publication No. 2023 / 058449.

[0110] [Synthesis Example 6: Synthesis of Compound (B-46) and Compound (B-54)]

[0111] <Synthesis of Compounds (B-46A) and (B-54A)> Under a nitrogen atmosphere, 10 g (52.0 mmol) of 1,6-naphthalenedithiol, 8.58 g (52.0 mmol) of 6-bromohexane, and 30 mL of N,N-dimethylacetamide (DMAc) were mixed. Then, 8.62 g (52.0 mmol) of potassium carbonate was added, and the mixture was heated to an internal temperature (liquid temperature) of 50°C. After stirring for 3 hours, 100 mL of ethyl acetate and 100 mL of 2N hydrochloric acid were added, and the mixture was washed and separated. Next, another 100 mL of 2N hydrochloric acid was added, and the mixture was washed and separated. 100 mL of 15% sodium chloride aqueous solution was added and stirred, then the mixture was washed and separated. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain 15 g of an oily composition containing compound (B-46A) and compound (B-54A). Yield 90%.

[0112] <Synthesis of Compound (B-46B) and Compound (B-54B)> Under a nitrogen atmosphere, 17.4 g (63.0 mmol) of the above composition containing Compound (B-46A) and Compound (B-46B), 8.66 g (69.3 mmol) of 2-bromoethanol, and 49.4 mL of N,N-dimethylacetamide (DMAc) were mixed while adding potassium carbonate (K ２ CO ３ 10.5 g (75.6 mmol) was added, and the mixture was heated to an internal temperature (liquid temperature) of 50°C. After stirring for 1 hour, 130 mL of ethyl acetate and 130 mL of 2N hydrochloric acid were added, and the mixture was washed and separated. Next, 130 mL of water was added and stirred, followed by washing and separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain 17.7 g of an oily composition containing compound (B-46B) and compound (B-54B). Yield: 88%.

[0113] <Synthesis of Compound (B-46) and Compound (B-54)> 6.40 g (20.0 mmol) of the above composition containing Compound (B-46B) and Compound (B-54B), triethylamine (Et ３2.22 g (22.0 mmol) of compound (N) was mixed with 60 mL of dichloromethane while cooling until the internal temperature (liquid temperature) reached 0°C. 1.90 g (21.0 mmol) of acryloyl chloride was added dropwise, ensuring the liquid temperature did not exceed 7°C, and then the mixture was heated until the internal temperature (liquid temperature) reached 25°C. After stirring for 1 hour, 100 mL of 1N hydrochloric acid was added, followed by washing and liquid-liquid separation. Next, 100 mL of 5% sodium bicarbonate aqueous solution was added and stirred, followed by washing and liquid-liquid separation. Dehydration with magnesium sulfate, filtration, and concentration were performed to obtain an oily composition, which was then purified by column chromatography using hexane and ethyl acetate to obtain 1.3 g of compound (B-46) and 1 g of compound (B-54). Compound (B-46) １ H-NMR (300MHz, CDCl ３ ): δ (ppm) 1.1-1.2 (m, 3H), 1.3-1.8 (m, 8H), 2.9-3.3 (m, 4H), 4.3-4.4 (m, 2H), 5.8-5. 9 (m, 1H), 6.1-6.2 (m, 1H), 6.3-6.4 (m, 1H), 7.3-7.7 (m, 4H), 7.83 (s, 1H), 8.19 (d, 1H) Compound (B-54) １ H-NMR (300MHz, CDCl ３ ): δ (ppm) 1.1-1.2 (m, 3H), 1.3-1.8 (m, 8H), 2.9-3.3 (m, 4H), 4.3-4.4 (m, 2H), 5 .8-5.9 (m, 1H), 6.1-6.2 (m, 1H), 6.3-6.4 (m, 1H), 7.3-7.7 (m, 5H), 8.33 (d, 1H)

[0114] [Synthesis Example 7: Synthesis of Comparative Compound (C-1)] Comparative compound (C-1), described below, was synthesized by referring to the synthesis of compound 11 described in Example 12 of Japanese Patent Publication No. 2008-527413. [Synthesis Example 8: Synthesis of Comparative Compound (C-3)] Comparative compound (C-3), described below, was synthesized by referring to the synthesis of acrylic acid 2-(naphthalene-2-ylsulfanyl)-ether ester (NSEA) described in Preparation Example C of Examples of Japanese Patent Publication No. 2009-516393. [Synthesis Example 9: Synthesis of Comparative Compound (C-4)] Comparative compound (C-4), described below, was synthesized in the same manner as in Synthesis Example 2 above, except that 1,6-naphthalenedithiol was replaced with 2,6-naphthalenedithiol (yield 77%).

[0115] [Preparation of dispersion of surface-treated metal oxide particles (M)] (Surface-treated TiO ２ Preparation of particle dispersion No. D1) 1.23 g of the silane coupling agent KBM-5103 (trade name, manufactured by Shin-Etsu Silicone Co., Ltd., (3-acryloyloxy)propyltrimethoxysilane) was mixed with 0.23 g of water, 0.09 g of acetic acid, and 1.04 g of ethanol, and then stirred at room temperature for 30 minutes to prepare a hydrolyzed silane coupling agent solution. Next, 8.80 g of titanium oxide particles (trade name: TTO-51(A), manufactured by Ishihara Sangyo Co., Ltd.) as metal oxide particles (m), 26.1 g of PGMEA (propylene glycol monomethyl ether acetate), and 75 g of zirconia nanobeads (bead diameter 50 μm) were added and stirred at room temperature at 1200 rpm (rotations per minute) for 6 hours to disperse the mixture. After that, the zirconia nanobeads were removed and the surface was treated with TiO ２ A particle dispersion No. D1 was prepared. Surface treatment TiO ２ The solid content concentration of particle dispersion No. D1 was 24% by mass. (Surface-treated metal oxide (TiO) ２ , ZrO ２ or HfO ２ ) Preparation of particle dispersions No. D2 to D6) Surface treatment TiO ２ In the preparation of particle dispersion No. D1, the silane coupling agent and metal oxide particles (m) listed in Table A below were blended in the composition ratios listed in Table A, except that the above surface treatment TiO ２ Prepare the particle dispersion No. D1 in the same manner as the surface treatment metal oxide (TiO ２ , ZrO ２ or HfO ２ Dispersions of particles No. D2 to D6 were prepared. Surface treated metal oxide (TiO ２ , ZrO ２ or HfO ２ The solid content concentration of the particle dispersions No. D2 to D6 was 24% by mass in all cases.

[0116]

[0117] <Note to the table> The wt% listed in the "Amount" column for each component means mass%.

[0118] (Metal oxide particles (m)) TiO ２ (Al(OH) ３ Coating): TTO-51(A) (product name), manufactured by Ishihara Sangyo Co., Ltd., Al(OH) ３ TiO coated with ２ Particles, particle size 30nm ZrO ２ (Uncoated): XF201 (product name), manufactured by Xfnano, ZrO without surface coating ２ Particles, particle size 30nm HfO ２ (Uncoated): Nano Hafniumdioxide, manufactured by Huawei Jingcheng, uncoated HfO ２ Particles, particle size 40nm TiO ２ (Uncoated): Aeroxyde TiO2 P25 (product name), manufactured by Evonik, uncoated TiO2 ２ Particles, particle size 30nm

[0119] (Silane coupling agent) KBM-5103: Trade name, manufactured by Shin-Etsu Silicone Co., Ltd., 3-(acryloyloxy)propyltrimethoxysilane MTEOPTMS: Manufactured by Gelest, methoxytri(ethyleneoxy)propyltrimethoxysilane Silquest A-1230: Silquest A-1230 (trade name), manufactured by Momentive, polyalkylene oxide trimethoxysilane, not a compound represented by general formula (2) as it does not have L in general formula (2).

[0120] [Preparation of Curable Composition] (Preparation of Curable Composition No. 101) Dispersion of surface-treated metal oxide particles No. D1, compound A-9, and photopolymerization initiator Irgacure 819 (trade name, manufactured by BASF Japan) were blended so that the surface-treated metal oxide particles (M), compound A, and photopolymerization initiator were in the composition ratios shown in Table 1-1 below. The mixture was then diluted with PGMEA (propylene glycol monomethyl ether acetate) to a solid content concentration of 10% by mass to prepare curable composition No. 101.

[0121] (Preparation of curable compositions No. 102-118, c11-c15 and r16) Curable compositions No. 102-118, c11-c15 and r16 were prepared in the same manner as in the preparation of curable composition No. 101, except that the dispersion of surface-treated metal oxide particles, compound A or comparative compound, and photopolymerization initiator described in Tables 1-1 to 1-4 (hereinafter collectively referred to as "Table 1") were blended in the composition ratios described in Table 1. Curable compositions No. 101-118 are the curable compositions of the present invention, curable compositions No. c11-c15 are curable compositions for comparison, and curable composition No. r16 is a curable composition as a reference example.

[0122] For the curable compositions, the refractive index nD, viscosity (containing 20% ​​by mass of PGMEA), the effect of suppressing crystal deposition in the coating film, and the transmittance of the cured film were evaluated as follows. Furthermore, the particle size of the dispersion of surface-treated metal oxide particles was measured as follows. The results are summarized in Table 1.

[0123] [Evaluation 1: Particle Size Measurement] A dispersion of surface-treated metal oxide particles prepared above was mixed with 2.5 mL of PGMEA as a solvent to prepare a dispersion for measurement. Using a nanoparticle size measurement system (manufactured by Otsuka Electronics Co., Ltd., product name: nanoSAQLA), particle size measurement was performed by dynamic light scattering (DLS) and analysis by Marquadt. The D50 particle size (hereinafter abbreviated as "D50") based on scattered light intensity was determined and evaluated according to the following criteria. - Particle Size Evaluation - A: 2 nm ≤ D50 < 50 nm B: 50 nm ≤ D50 < 80 nm C: 80 nm ≤ D50 < 100 nm D: 100 nm < D50

[0124] [Evaluation 2: Refractive Index Measurement] (1) Preparation of Cured Product The curable composition prepared above was spin-coated onto a silicon substrate to a cured film thickness of 300 nm. Then, using a UV irradiation device (EXECURE 3000 (product name), manufactured by HOYA CANDEO OPTRONICS), nitrogen (N) was used to reduce the oxygen concentration to 1% or less. ２ Under the substituted atmosphere, the integrated light intensity was 1.2 J / cm². ２ , illuminance 5mW / cm ２A cured product was prepared by irradiating it with UV (ultraviolet) light under the following conditions. (2) Measurement of refractive index Using the cured product prepared under the above conditions, the refractive index (refractive index nD of the cured product) at a wavelength of 589 nm was measured at 25°C using a spectroscopic ellipsometer (RC2 (product name), manufactured by J.A. Woolam Japan Co., Ltd.) and evaluated according to the following criteria. - Criteria for evaluation of the refractive index nD of the cured product - A: 1.9 ≤ nD B: 1.8 ≤ nD < 1.9 C: 1.7 ≤ nD < 1.8 D: nD < 1.7

[0125] [Evaluation 3: Viscosity Evaluation Test] For the curable composition prepared above, a sample was prepared by removing the solvent by vacuum distillation so that the solvent in the curable composition was PGMEA and its content was 20% by mass. The sample was then evaluated using a rheometer (Thermo Fisher Scientific, trade name: HAAKE RheoStress 6000) at 25°C and a shear rate of 10 s. －１ The viscosity (η) was measured and evaluated according to the following criteria: - Evaluation criteria for viscosity (containing 20% ​​by mass of PGMEA) - A: η ≤ 8000 mPa·s B: 8000 mPa·s < η ≤ 20000 mPa·s C: 20000 mPa·s < η ≤ 40000 mPa·s D: 40000 mPa·s < η

[0126] [Evaluation 4: Evaluation of the effect of suppressing crystal deposition in the coating film] The curable composition prepared above was spin-coated onto a circular glass substrate with a diameter of 30 mm so that the film thickness after drying was 1 μm. The obtained coating film was left to stand at room temperature (25°C) for 10 minutes, and then exposed to nitrogen (N) using a UV irradiation device (EXECURE 3000 (product name), manufactured by HOYA CANDEO OPTRONICS) to reduce the oxygen concentration to 1% or less. ２ Under the substituted atmosphere, the integrated light intensity was 1.2 J / cm². ２ , illuminance 5mW / cm ２The coating was cured by UV (ultraviolet) irradiation under the specified conditions. After curing, the coating film (sample) was observed using a microscope at a magnification of 20x, in a 15 mm x 15 mm area, to identify point-like defects in the sample. The crystal deposition suppression effect in the coating film was evaluated according to the following criteria. The point-like defects in the sample are microcrystals that occur after spin coating and are presumed to be caused by the high crystallinity of compound A. - Criteria for evaluation of crystal deposition suppression effect in the coating film - AA: 0 to 2 point-like defects were observed in the sample. A: 3 to 4 point-like defects were observed in the sample. B: 5 to 7 point-like defects were observed in the sample. C: 8 to 10 point-like defects were observed in the sample. D: 11 or more point-like defects were observed in the sample.

[0127] [Evaluation 5: Transmittance evaluation of cured film] The curable composition prepared above was spin-coated onto a glass substrate to a film thickness of 1 μm after drying. The resulting coating was left to stand at room temperature (25°C) for 10 minutes, and then exposed to nitrogen (N) using a UV irradiation device (EXECURE 3000 (product name), manufactured by HOYA CANDEO OPTRONICS) to reduce the oxygen concentration to 1% or less. ２ Under the substituted atmosphere, the integrated light intensity was 1.2 J / cm². ２ , illuminance 5mW / cm ２The samples were cured by UV (ultraviolet) irradiation under the specified conditions. Using a UV-Vis spectrophotometer with an integrating sphere (Shimadzu Corporation, product name: UV-2700iplus), baseline measurements were performed with a standard white plate made of compressed barium sulfate powder. Then, the cured sample was placed on the light inlet side, and the transmittance (T) at a wavelength of 400 nm was measured. Next, the standard white plate on the cured sample side was removed, and the cured film surface of the cured sample was positioned facing the integrating sphere, and the reflectance (R) at a wavelength of 400 nm was measured. The obtained values ​​were applied to the following formula to calculate the transmittance index at a wavelength of 400 nm, and evaluated according to the following criteria. Transmittance index at a wavelength of 400 nm = {T / (1 - R)} × 100% - Evaluation criteria for the transmittance index of the cured film at a wavelength of 400 nm - A: 95% ≤ Transmittance index at a wavelength of 400 nm B: 94% ≤ Transmittance index at a wavelength of 400 nm < 95% C: 93% ≤ Transmittance index at a wavelength of 400 nm < 94% D: Transmittance index at a wavelength of 400 nm < 93%

[0128]

[0129]

[0130]

[0131]

[0132] The wt% listed in the "Amount" column for each component means the content (mass%) of each component in the solid content of the curable composition. The "Amount (mass%)" for surface-treated metal oxide particles (M) means the amount (mass%) added on a mass basis in the solid content of the curable composition, and the "Amount (volume%)" for surface-treated metal oxide particles (M) means the amount (volume%) added on a volume basis in the solid content of the curable composition. Compound A in No. 104 is composed of A-4, A-46, and A-38, each with a content ratio of 33.3 mass% (100 / 3 mass%). Compound A in No. 115 is composed of B-4, B-46, and B-54, each with a content ratio of 33.3 mass% (100 / 3 mass%). The components in the table are as follows.

[0133] (Dispersion of surface-treated metal oxide particles) D1 to D6: These are the dispersions of surface-treated metal oxide particles No. D1 to D6 listed in Table A. TiO ２ (Al(OH) ３ Coating), ZrO ２ (Uncoated), HfO ２ (Uncoated) and TiO ２ "(Uncoated)" is equivalent to the terms listed in Table A. KBM-5103, MTEOPTMS, and Silquest A-1230 listed in the Silane Coupling Agent column are equivalent to the terms listed in Table A.

[0134] (Compound A)

[0135] (Comparative compound)

[0136] When compound A and the comparative compound are represented by general formula (1), the point group is indicated below the number of each compound. For comparative compound (C-1), the point group is C ２ｖ In this respect, comparative compound (C-2) is not a compound represented by general formula (1), and comparative compound (C-3) is R １ and R ２ In that it has only one group selected from the group, the comparative compound (C-4) has point group C ２ｈ In this respect, none of them are compound A as defined in the present invention. For comparison, POB-A (trade name, manufactured by Kyoeisha Chemical Co., Ltd., m-phenoxybenzyl acrylate) was used as comparative compound (C-2).

[0137] (Photopolymerization initiator) Irg819: Irgacre 819 (trade name, manufactured by BASF Japan, available as Omnirad 819 (trade name, manufactured by IGM Resins B.V.)), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0138] From the results in Table 1, the following can be seen: Although the curable compositions No. c11 and c12 used for comparison are compounds represented by general formula (1), their point group is C ２ｖIt is not a curable composition of the present invention in that it contains comparative compound (C-1) and surface-treated metal oxide particles (M). Also, curable composition No. c15 for comparison and curable composition No. r16 as a reference example are compounds represented by general formula (1), but their point group is C ２ｈ It is not a curable composition of the present invention in that it contains a comparative compound (C-4) and surface-treated metal oxide particles (M). These comparative curable compositions No. c11, c12 and c15, and curable composition No. r16 as a reference example, were inferior in that they could not sufficiently suppress crystal precipitation in the coating film. Comparative curable composition No. c13 is not a curable composition of the present invention in that it contains a comparative compound (C-2) that is not a compound represented by general formula (1) and surface-treated metal oxide particles (M). This comparative curable composition No. c13 was inferior in that it could not achieve the desired level of low viscosity. Comparative curable composition No. c14 contains R in general formula (1) １ and R ２The comparative compound (C-3), which has only one group selected from the above and is not a compound represented by general formula (1), contains surface-treated metal oxide particles (M), and is therefore not a curable composition of the present invention. Curable composition No. c14 for this comparison was inferior as it did not sufficiently suppress crystal precipitation in the coating film. In contrast, curable compositions No. 101 to 118 of the present invention exhibited a desired level of low viscosity in the composition (liquid), had excellent effect in suppressing crystal precipitation in the coating film, and the resulting cured products all had a high refractive index nD of 1.7 or higher, which was excellent. Furthermore, when the surface-treated metal oxide particles (M) contained at least one metal element from Ti, Y, Zr, Sn, and Al, the refractive index nD of the cured product was further increased (No. 105 compared to No. 106, and Nos. 111 and 116 compared to No. 112). When the silane coupling agent contains a compound represented by general formula (2), preferably a compound represented by general formula (3), the viscosity of the composition (liquid) can be kept lower, and crystal precipitation in the coating film can be suppressed to a higher degree (No. 118 compared to No. 117, No. 103 compared to No. 118). When compound A contains a disubstituted compound represented by general formula (1-1), crystal precipitation in the coating film can be suppressed to a higher degree (No. 103, 104, 109, 110 and 115 compared to No. 102). When the content of surface-treated metal oxide particles (M) in the solid content of the curable composition is 45% by mass or more, the refractive index nD of the cured product can be increased, and crystal precipitation in the coating film can be suppressed to a higher degree (No. 101 and 107 compared to No. 108, and No. 113 compared to No. 114). ３ TiO coated with ２ When particles were present, crystal precipitation in the coating film was suppressed to a higher degree (No. 103 compared to No. 116). Also, Al(OH) ３ TiO coated with ２ Particles, surface-treated with a silane coupling agent represented by general formula (3), with an average particle size of 2 to 200 nm, and surface-treated TiO ２The particles are not limited to compound A, but can exist with excellent dispersibility in curable compositions containing polymerizable compounds other than compound A, such as comparative compound (C-4), and are thought to enhance the light transmittance of the cured product (No. 103 compared to No. 116, No. r16 compared to No. c15).

[0139] Although we have described the present invention along with its embodiments, we do not intend to limit our invention in any detail of the description unless specifically designated, and we believe that it should be interpreted broadly without contradicting the spirit and scope of the invention as set forth in the appended claims.

[0140] This application claims priority based on Japanese Patent Application No. 2025-052716, filed in Japan on 26 March 2025, the contents of which are incorporated herein by reference as part of this specification.

[0141] 1. Curable composition 3. Substrate 5. Mold 7. Cured product

Claims

1. A curable composition comprising: a compound A which is represented by the following general formula (1) and has a point group C ｓ , and surface-treated metal oxide particles that contain at least one metal element selected from the group consisting of Ti, Fe, Cu, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Al and Ce, are subjected to a surface treatment with a silane coupling agent, and have an average particle diameter of 2 to 200 nm. In the above formula, R ａ to R ｈ are each a hydrogen atom, or the following R １ or R ２ , with the proviso that at least one of R ａ to R ｈ is the following R １ , and at least two of R ａ to R ｈ are groups selected from the following R １ and R ２ . R １ : a group represented by any one of the following general formulas (Pol-1) to (Pol-4); R ２ : an alkylsulfanyl group having 1 to 12 carbon atoms In the above formula, L １ represents an alkylene group having 2 to 6 carbon atoms, and * represents a bonding site.

2. The curable composition according to claim 1, wherein the surface-treated metal oxide particles contain at least one metal element selected from Ti, Y, Zr, Sn, and Al.

3. The curable composition according to claim 1, wherein the silane coupling agent comprises a compound represented by the following general formula (2). In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ４ This represents a (meth)acryloyl group or a group represented by the following general formula (p). In the above formula, R ５ L represents an alkyl group having 1 to 3 carbon atoms. ３ * represents an alkylene group with 2 to 6 carbon atoms, where n is 0 to 10. * indicates a bond.

4. The curable composition according to claim 3, wherein the silane coupling agent comprises a compound represented by the following general formula (3). In the above formula, L, R ３ , R ５ and n are L and R respectively. ３ , R ５ This is synonymous with n.

5. The curable composition according to claim 1, wherein compound A comprises a disubstituted compound represented by the following general formula (1-1). In the above formula, R ａ and R ｆ This is the aforementioned R １ or R ２ This shows that R ａ and R ｆ At least one of the R １ That is the case.

6. The curable composition according to claim 1, wherein the content of the surface-treated metal oxide particles in the solid content of the curable composition is 45% by mass or more.

7. The metal oxide particles constituting the surface-treated metal oxide particles are Al(OH) ３ TiO coated with ２ A curable composition according to claim 1, comprising particles.

8. Polymerizable compounds and Al(OH) ３ TiO coated with ２ Surface-treated TiO2 particles with an average particle size of 2 to 200 nm, which are surface-treated with a silane coupling agent represented by the following general formula (3). ２ A curable composition containing particles. In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ５ * indicates an alkyl group having 1 to 3 carbon atoms. n is between 0 and 10. * indicates a bond.

9. A cured product obtained from the curable composition according to any one of claims 1 to 8.

10. An optical material comprising the cured product described in claim 9.

11. A microlens or diffractive optical element comprising the cured product described in claim 9.

12. Al(OH) ３ TiO coated with ２ Surface-treated TiO2 particles with an average particle size of 2 to 200 nm, which are surface-treated with a silane coupling agent represented by the following general formula (3). ２ particle. In the above formula, L represents an alkylene group having 2 to 6 carbon atoms. ３ R represents an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, a hydroxyl group, or an alkyl group having 1 to 3 carbon atoms. However, R ３ At least one of these is an alkoxy group having 1 to 5 carbon atoms, a chlorine atom, or a hydroxyl group. ５ * indicates an alkyl group having 1 to 3 carbon atoms. n is between 0 and 10. * indicates a bond.

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