Inorganic fine particle dispersion liquid

Abstract

The present invention provides an inorganic fine particle dispersion liquid which is capable of producing a curable resin composition that has excellent imprint properties and excellent UV resistance after curing. The present invention pertains to an inorganic fine particle dispersion liquid which contains an organic solvent and inorganic fine particles that have an average dispersed particle diameter of 50 nm or less and are surface-treated with an alkoxysilane compound 1 represented by general formula (1) and an alkoxysilane compound 2 represented by general formula (2). (1): (R2)(4-m)-Si-(OR1)m (In general formula (1), m represents an integer of 1 to 3, R1 represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R2 represents a monovalent hydrocarbon group having 1 to 3 carbon atoms.) (2): (R4)(4-n)-Si-(OR3)n (In general formula (2), n represents an integer of 1 to 3, R3 represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R4 represents R5-(OCHR6CH2)k-OR7, R5-OC(=O)C(=CH2)-R6, or R8 (in the formulae, k represents an integer of 1 to 10, R5 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, R6 represents H or CH3, R7 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R8 represents a monovalent hydrocarbon group having 4 to 20 carbon atoms).)

Description

Inorganic fine particle dispersion

[0001] The present invention relates to an inorganic fine particle dispersion.

[0002] In recent years, in order to prevent reflection in displays and improve the light-collecting efficiency of optical lenses, curable resin compositions containing inorganic oxide fine particles exhibiting a high refractive index, such as titanium oxide or zirconium oxide, have been investigated and put to practical use. Such curable resin compositions can be obtained by mixing a dispersion of inorganic oxide fine particles into a curable resin while maintaining the dispersed state.

[0003] Due to miniaturization and simplification of manufacturing processes for optical elements such as microlenses and diffractive optical elements, imprinting methods, which perform microfabrication on the order of submicron or less by pressing a mold against a substrate and transferring the shape of the mold, have been used to pattern curable resin compositions, instead of electron beam lithography, which requires multiple steps such as exposure and development. Such imprinting methods require resin materials with excellent imprintability (ease of processing in the imprinting process).

[0004] Imprinted substrates manufactured by the imprinting method are also being considered for use in AR (Augmented Reality) devices, such as goggle-type devices. Since AR devices are expected to be used outdoors, they may be exposed to ultraviolet (UV) rays for long periods of time. In such cases, the curable resin composition is required to be resistant to loss of optical properties and to not yellow even when exposed to UV rays after curing.

[0005] Patent Documents 1 to 4 describe coating compositions containing surface-treated inorganic fine particles, but do not examine imprint properties and UV resistance.

[0006] JP 2018-24566 A JP 2017-105659 A JP 2015-206019 A JP 2011-201740 A

[0007] An object of the present invention is to provide an inorganic fine particle dispersion that can produce a curable resin composition that has excellent imprint properties and UV resistance after curing.

[0008] The present inventors have found that by using an inorganic fine particle dispersion containing inorganic fine particles having an average dispersed particle diameter of 50 nm or less and surface-treated with an alkoxysilane compound 1 represented by general formula (1) and an alkoxysilane compound 2 represented by general formula (2), and an organic solvent, it is possible to prepare a curable resin composition that is excellent in imprintability and UV resistance after curing, and have completed the present invention.

[0009] That is, the present invention relates to an inorganic fine particle dispersion liquid containing inorganic fine particles having an average dispersed particle diameter of 50 nm or less and surface-treated with an alkoxysilane compound 1 represented by the following general formula (1) and an alkoxysilane compound 2 represented by the following general formula (2), and an organic solvent. (R ２ ) （４－ｍ） -Si-(OR １ ) ｍ (1) [In general formula (1), m represents an integer of 1 to 3, and R １ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ２ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. ４ ) （４－ｎ） -Si-(OR ３ ) ｎ (2) [In general formula (2), n represents an integer of 1 to 3, and R ３ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ４ is R ５ -(OCHR ６ CH ２ ) ｋ -OR ７ , R ５ -OC(=O)C(=CH ２ )-R ６ , or R ８ (wherein k represents an integer of 1 to 10, R ５ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, R ６ is H or CH ３ represents R ７ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ８ represents a monovalent hydrocarbon group having 4 to 20 carbon atoms).

[0010] The viscosity of the inorganic fine particle dispersion was measured at 25° C. using a cone plate with an angle of 1°34′ and a radius of 24 mm at a rotation speed of 50 rpm, and was expressed as η ５０ , the viscosity measured at a rotation speed of 10 rpm is η １０ Then, η ５０ is 30 mPa·s or less, and the viscosity change rate η １０ / η ５０ is preferably 0.9 to 1.5.

[0011] The viscosity of the inorganic fine particle dispersion was measured at 25° C. using a cone plate with an angle of 1°34′ and a radius of 24 mm at a rotation speed of 50 rpm, and was expressed as η ５０ Then, the η of the dispersion one month after preparation ５０ η of the dispersion immediately after preparation ５０ It is preferable that the ratio of 1.5 or less.

[0012] In the inorganic fine particle dispersion, the inorganic fine particles are preferably inorganic oxide fine particles.

[0013] In the inorganic fine particle dispersion, the inorganic oxide fine particles are preferably zirconium oxide, titanium oxide, or metal titanate.

[0014] In the inorganic fine particle dispersion, the mass ratio of the alkoxysilane compound 1 to the alkoxysilane compound 2 is preferably 5:95 to 95:5.

[0015] In the inorganic fine particle dispersion, the total content of the dispersant, the alkoxysilane compound 1, and the alkoxysilane compound 2 is preferably 30 parts by mass or less relative to 100 parts by mass of the inorganic fine particles.

[0016] In the inorganic fine particle dispersion, the mass ratio of the dispersant to the total mass of the alkoxysilane compound 1 and the alkoxysilane compound 2 is preferably 0:100 to 50:50.

[0017] In the inorganic fine particle dispersion, the content of the inorganic fine particles is preferably 15 to 56% by mass.

[0018] The inorganic fine particle dispersion is preferably used for optical purposes.

[0019] The present invention also relates to a curable resin composition containing the inorganic fine particle dispersion and a curable resin.

[0020] In the curable resin composition, it is preferable that the haze value of the cured product obtained by curing the composition to a film thickness of 1 μm is 1% or less.

[0021] The present invention also relates to a cured product of the curable resin composition.

[0022] According to the present invention, it is possible to provide an inorganic fine particle dispersion liquid that can produce a curable resin composition that has excellent imprint properties and excellent UV resistance after curing.

[0023] <<Inorganic Fine Particle Dispersion>> The inorganic fine particle dispersion of the present invention contains inorganic fine particles having an average dispersed particle diameter of 50 nm or less and surface-treated with an alkoxysilane compound 1 represented by general formula (1) and an alkoxysilane compound 2 represented by general formula (2), and an organic solvent.

[0024] <Inorganic Fine Particles> The inorganic fine particles are not particularly limited, but examples thereof include inorganic oxide fine particles such as metal oxides composed of one type of metal element and composite metal oxides composed of two or more types of metal elements.

[0025] Examples of metal oxides composed of one type of metal element include zirconium oxide (ZrO ２ ), titanium oxide (TiO ２ ), silicon oxide (SiO ２ ), aluminum oxide (Al ２ O ３ ), iron oxide (Fe ２ O ３ , FeO, Fe ３ O ４ ), copper oxide (CuO, Cu ２ O), zinc oxide (ZnO), yttrium oxide (Y ２ O ３ ), niobium oxide (Nb ２ O ５ ), molybdenum oxide (MoO ３ ), indium oxide (In ２ O３ , In ２ O), tin oxide (SnO ２ ), tantalum oxide (Ta ２ O ５ ), tungsten oxide (WO ３ , W ２ O ５ ), lead oxide (PbO, PbO ２ ), bismuth oxide (Bi ２ O ３ ), cerium oxide (CeO ２ , Ce ２ O ３ ), antimony oxide (Sb ２ O ５ ), germanium oxide (GeO ２ , GeO), etc. These inorganic fine particles may be used alone or in combination of two or more. Zirconium oxide and titanium oxide are preferred as inorganic fine particles because they are easily available and their optical properties such as refractive index can be easily adjusted.

[0026] Examples of composite oxides composed of two or more metal elements include barium titanate and strontium titanate (SrTiO ３ Examples of such composite oxides include titanates such as titanium / silicon composite oxides, yttrium-stabilized zirconia, etc. Such composite oxides include not only compounds or solid solutions composed of multi-component elements, but also those having a core-shell structure in which a core metal particle is surrounded by a metal oxide composed of other metal elements, and those having a multi-component dispersed structure in which a single metal oxide particle contains multiple other metal oxide particles dispersed within it. Note that titanium oxide includes not only titanium oxide but also metal titanates containing different elements, such as barium titanate.

[0027] The primary particle diameter of the inorganic fine particles is not particularly limited, but is preferably 1 to 50 nm, more preferably 1 to 25 nm, and even more preferably 5 to 20 nm. If the primary particle diameter is less than 1 nm, the inorganic fine particles have a large specific surface area and high cohesive energy, making it difficult to maintain dispersion stability. On the other hand, if the primary particle diameter exceeds 50 nm, the imprintability of the curable resin composition may be reduced. Here, the primary particle diameter is the particle diameter at 50% of the cumulative number (D50), and can be measured using an electron microscope such as SEM or TEM, or by conversion from the specific surface area.

[0028] The specific surface area of ​​inorganic particles is 250 m ２ / g or less is preferable, and 200m ２ / g or less is more preferable. ２ / g or more is preferable, and 50m ２ / g or more is more preferable. The specific surface area can be measured by a gas adsorption method.

[0029] The inorganic fine particles are surface-treated with an alkoxysilane compound. Such surface-treated inorganic fine particles may be surface-treated in advance with an alkoxysilane compound, or may be those obtained by adding an alkoxysilane or the like to a dispersion liquid and reacting it with the inorganic fine particles. The alkoxysilane compound used for the surface treatment can be the alkoxysilane compound described below.

[0030] The inorganic fine particles may be dispersed in various solvents in advance. The solvent is not particularly limited, but examples thereof include alcohols such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 2-propanol, and butanol; ethers such as tetrahydrofuran and diethyl ether; ethylene glycol ethers such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol monoethyl ether (ethyl cellosolve), and ethylene glycol monobutyl ether (butyl cellosolve); ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol dialkyl ethers such as diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and diethylene glycol ethyl methyl ether; diethylene glycol monomethyl ether; diethylene glycol dimethyl ether; diethylene glycol dibutyl ether; diethylene glycol ethyl methyl ether; diethylene glycol monomethyl ether; diethylene glycol monobutyl ether; diethylene glycol monomethyl ether; diethylene glycol dimethyl ether; diethylene glycol dibutyl ether; diethylene glycol ethyl methyl ether; diethylene glycol monobutyl ether; diethylene glycol mono ... diethylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME); alkylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (ethyl carbitol acetate), diethylene glycol monobutyl ether acetate, and 3-methoxybutyl-1-acetate; aromatic hydrocarbons such as benzene, ethylbenzene, toluene, and xylene; ketones such as acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, acetylacetone, and 4-hydroxy-4-methyl-2-pentanone;Examples of the ester include ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, dimethyl succinate, diethyl succinate, diethyl adipate, diethyl malonate, dibutyl oxalate, and γ-butyrolactone; and amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. Among these, ethylene glycol ethers, alkylene glycol monoalkyl ether acetates, diethylene glycol dialkyl ethers, ketones, and esters are preferred, and propylene glycol monomethyl ether acetate (PGMEA), diethylene glycol monoethyl ether acetate (ethyl carbitol acetate), and propylene glycol monomethyl ether (PGME) are more preferred. These solvents may be used alone or in combination of two or more. The blending ratio of the solvent to the inorganic fine particles is not particularly limited, but is preferably 15:85 to 90:10, and more preferably 30:70 to 80:20.

[0031] The content of inorganic fine particles in the dispersion is preferably 15 to 56% by mass, more preferably 19 to 56% by mass, and even more preferably 25 to 50% by mass. If it is less than 15% by mass, the amount of solvent used will be large, which will place a burden on the environment, and furthermore, the properties of the inorganic fine particles may not be fully obtained, such as a decrease in refractive index. If it exceeds 56% by mass, aggregation tends to occur easily and stability tends to deteriorate. Note that the content of inorganic fine particles does not include the content of alkoxysilane compounds bonded to the surface of the inorganic fine particles.

[0032] <Alkoxysilane Compound> The alkoxysilane compound enhances the affinity between the inorganic fine particles and the curable resin when the dispersion is mixed with the curable resin. In addition, in the present invention, the inorganic fine particles are surface-treated with the alkoxysilane compound 1 and the alkoxysilane compound 2 described below, and therefore a curable resin composition having excellent imprint properties and excellent UV resistance after curing can be provided. When the dispersion of the present invention is placed under acidic or alkaline conditions, the hydroxyl groups present on the surface of the inorganic fine particles react with the alkoxysilane compound, thereby enabling the surface treatment of the inorganic fine particles.

[0033] <Alkoxysilane Compound 1> Alkoxysilane compound 1 is represented by the following general formula (1): (R ２ ) （４－ｍ） -Si-(OR １ ) ｍ (1)

[0034] In general formula (1), m represents an integer of 1 to 3. From the viewpoint of compatibility with resin components, etc., m is preferably an integer of 2 to 3, and more preferably 3.

[0035] In general formula (1), R １ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. １ Examples of the alkyl group include alkyl groups having 1 to 3 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and an isopropyl group. From the viewpoint of reactivity with inorganic fine particles, R １ is preferably a methyl group or an ethyl group, and more preferably a methyl group. In general formula (1), when m is an integer of 2 or more, R １ may be the same as or different from each other.

[0036] In general formula (1), R ２ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. ２ Examples of the alkyl group include alkyl groups having 1 to 3 carbon atoms, such as methyl, ethyl, propyl, and isopropyl groups; and alkenyl groups having 2 to 3 carbon atoms, such as vinyl, allyl, and isoallyl groups. From the viewpoint of UV resistance, R ２is preferably a methyl group or an ethyl group, and more preferably a methyl group. In general formula (1), when 4-m is an integer of 2 or more, R ２ may be the same as or different from each other.

[0037] In the present invention, the hydrocarbon group means a group consisting of only carbon atoms and hydrogen atoms.

[0038] Specific examples of the alkoxysilane compound 1 include alkoxysilanes having an alkyl group such as methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methoxytrimethylsilane, ethyltrimethoxysilane, ethyltriethoxysilane, and propyltrimethoxysilane; and alkoxysilanes having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldimethoxysilane. These may be used alone or in combination of two or more. Among these, from the viewpoint of UV resistance, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, or ethyltriethoxysilane is preferred, and methyltrimethoxysilane or methyltriethoxysilane is more preferred.

[0039] In an inorganic particle dispersion, if the inorganic particles are surface-treated with alkoxysilane compound 1, the UV resistance of the curable resin composition can be improved. When the curable resin composition is exposed to UV, inorganic particles such as titanium oxide are activated by UV, which may cause a reaction that decomposes the resin around the surface of the inorganic particles. Here, if the inorganic particles are surface-treated with alkoxysilane compound 1, it is thought that the activity on the surface of the inorganic particles is suppressed, and the decomposition of the surrounding resin is suppressed, thereby improving UV resistance, but the present invention is not limited to this mechanism. The improvement in UV resistance by alkoxysilane compound 1 is due to the R １ This is presumably due to the fact that the compound is composed of short-chain hydrocarbon groups, but the present invention is not limited to this mechanism.

[0040] <Alkoxysilane Compound 2> Alkoxysilane compound 2 is represented by the following general formula (2): (R ４ ) （４－ｎ） -Si-(OR ３ ) ｎ (2)

[0041] In general formula (2), n represents an integer of 1 to 3. From the viewpoint of compatibility with resin components, etc., n is preferably an integer of 2 to 3, and more preferably 3.

[0042] In general formula (2), R ３ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. ３ Examples of the alkyl group include alkyl groups having 1 to 3 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and an isopropyl group. From the viewpoint of reactivity with inorganic fine particles, R ３ is preferably a methyl group or an ethyl group, and more preferably a methyl group. In general formula (2), when n is an integer of 2 or more, R ３ may be the same as or different from each other.

[0043] In general formula (2), R ４ is R ５ -(OCHR ６ CH ２ ) ｋ -OR ７ , R ５ -OC(=O)C(=CH ２ )-R ６ , or R ８ In general formula (2), when 4-n is an integer of 2 or more, R ４ may be the same as or different from each other.

[0044] k represents an integer of 1 to 10. For example, k may be an integer of 1 to 5.

[0045] R ５ represents a divalent hydrocarbon group having 1 to 20 carbon atoms. ５ Examples of R include alkylene groups having 1 to 20 carbon atoms, such as methylene and ethylene groups; divalent hydrocarbon groups having 2 to 20 carbon atoms and having a double bond; and divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms. From the viewpoint of compatibility with resin components, etc., R５ is preferably a divalent hydrocarbon group having 1 to 15 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms.

[0046] R ６ is H or CH ３ Represents.

[0047] R ７ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. ７ Examples of the alkyl group include alkyl groups having 1 to 20 carbon atoms, such as methyl and ethyl groups; alkenyl groups having 2 to 20 carbon atoms; and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms. From the viewpoint of compatibility with resin components, etc., R ７ is preferably a monovalent hydrocarbon group having 1 to 15 carbon atoms, and is preferably an alkyl group having 1 to 10 carbon atoms.

[0048] R ８ represents a monovalent hydrocarbon group having 4 to 20 carbon atoms. ８ Examples of the alkyl group include alkyl groups having 4 to 20 carbon atoms, such as butyl and pentyl groups; alkenyl groups having 4 to 20 carbon atoms, such as butylene and pentylene groups; and monovalent hydrocarbon groups having 6 to 20 carbon atoms. From the viewpoint of compatibility with the resin component, R ８ is preferably a monovalent hydrocarbon group having 4 to 15 carbon atoms, and is preferably an alkyl group having 4 to 10 carbon atoms.

[0049] Specific examples of the alkoxysilane compound 2 include alkoxysilanes having an aliphatic hydrocarbon group such as butyltrimethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, and tributylmethoxysilane; alkoxysilanes having an aromatic hydrocarbon group such as phenyltrimethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane; alkoxysilanes having a (meth)acrylic group such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 8-methacryloxyoctyltrimethoxysilane; and alkoxysilanes having a polyalkyleneoxy group such as alkoxypolyalkyleneoxyalkyltrialkoxysilanes (e.g., methoxytriethyleneoxypropyltrimethoxysilane, methoxy(triethyleneoxy)undecyltrimethoxysilane). These may be used alone or in combination of two or more. Among these, from the viewpoint of imprinting properties, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 8-methacryloxyoctyltrimethoxysilane are preferred, and 8-methacryloxyoctyltrimethoxysilane and the like are more preferred.

[0050] In the inorganic particle dispersion, the imprintability of the curable resin composition can be improved when the inorganic particles are surface-treated with the alkoxysilane compound 2. When the inorganic particles are surface-treated with the alkoxysilane compound 2, the curable resin composition becomes soft after curing, and it is thought that the imprintability is improved by the hardness being suitable for imprinting applications, but the present invention is not limited to this mechanism.

[0051] From the viewpoint of UV resistance, the content of alkoxysilane compound 1 in the inorganic fine particle dispersion is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of inorganic fine particles. The upper limit is not particularly limited, but is preferably 15 parts by mass or less, more preferably 10 parts by mass or less.

[0052] From the viewpoint of imprinting properties, the content of alkoxysilane compound 2 in the inorganic particle dispersion is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of inorganic particles. The upper limit is not particularly limited, but is preferably 30 parts by mass or less, more preferably 20 parts by mass or less.

[0053] From the viewpoints of imprint properties and UV resistance, the mass ratio of alkoxysilane compound 1 to alkoxysilane compound 2 is preferably 5:95 to 95:5, more preferably 10:90 to 90:10, and even more preferably 15:85 to 85:15.

[0054] In the inorganic fine particle dispersion of the present invention, the inorganic fine particles may be surface-treated with, in addition to alkoxysilane compound 1 and alkoxysilane compound 2, an alkoxysilane compound other than alkoxysilane compound 1 and alkoxysilane compound 2. Examples of alkoxysilane compounds other than alkoxysilane compound 1 and alkoxysilane compound 2 include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 2-aminophenyltrimethoxysilane, 3-aminophenyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane, etc. Alkoxysilanes having an amino group include alkoxysilanes having an epoxy group, such as β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.

[0055] In the inorganic fine particle dispersion of the present invention, it is preferable that the alkoxysilane compounds bonded to the surfaces of the inorganic fine particles are not in the form of condensates.

[0056] <Organic Solvent> The organic solvent is not particularly limited, but is preferably non-reactive with each component in the dispersion, and examples thereof include alcohols such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; ethers such as tetrahydrofuran; ethylene glycol ethers such as ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, and ethylene glycol monoethyl ether (ethyl cellosolve); ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol dialkyl ethers such as diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and diethylene glycol ethyl methyl ether; and diethylene glycol monomethyl ether. diethylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc.; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME); alkylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (ethyl carbitol acetate), diethylene glycol monobutyl ether acetate, 3-methoxybutyl-1-acetate, etc.; aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone;Examples of suitable esters include ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, dimethyl succinate, diethyl succinate, diethyl adipate, diethyl malonate, and dibutyl oxalate. Among these, preferred are ethylene glycol ethers, alkylene glycol monoalkyl ether acetates, diethylene glycol dialkyl ethers, ketones, and esters, with propylene glycol monomethyl ether acetate (PGMEA), diethylene glycol monoethyl ether acetate (ethyl carbitol acetate), and propylene glycol monomethyl ether (PGME). These solvents may be used alone or in combination of two or more.

[0057] The solid content of the inorganic fine particle dispersion is not particularly limited, but is preferably 10 to 85% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 75% by mass. Within this range, excellent dispersion stability and imprintability can be achieved, and a sufficient film thickness can be obtained.

[0058] <Dispersant> In order to disperse the inorganic fine particles, a dispersant can be blended in. The dispersant is not particularly limited as long as it can be dispersed in a solvent, and examples thereof include polyacrylic acid-based dispersants, polycarboxylic acid-based dispersants, phosphoric acid-based dispersants, silicone-based dispersants, and organic acids.

[0059] An example of a polyacrylic acid-based dispersant is sodium polyacrylate, and commercially available products thereof include the Aron series (manufactured by Toagosei Co., Ltd.) and the Sharol series (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0060] Examples of polycarboxylic acid-based dispersants include acidic dispersants that are not neutralized with cations and polycarboxylic acid ammonium salts, and commercially available products include AH-103P (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), SN Dispersant 5020, SN Dispersant 5468 (manufactured by San Nopco Ltd.), Poise 532A, Poise 2100 (manufactured by Kao Corporation), Marialim AKM-0531, Marialim AKM-1511-60, Marialim HKM-50A, and Marialim HKM-150A (manufactured by NOF Corporation).

[0061] Examples of phosphoric acid-based dispersants include polyoxyethylene alkyl ether phosphate esters, and commercially available products include Phosphanol RA-600 and ML-220 (manufactured by Toho Chemical Industry Co., Ltd.) and Disparlon PW-36 (manufactured by Kusumoto Chemicals Co., Ltd.).

[0062] Examples of silicone-based dispersants include modified silicone oil, etc. Commercially available products include ES-5612 (manufactured by DuPont Toray Specialty Materials Co., Ltd.).

[0063] Examples of organic acids include carboxylic acid compounds such as citric acid, stearic acid, oxalic acid, palmitic acid, butyric acid, propionic acid, acetic acid, oleic acid, linoleic acid, and linolenic acid.

[0064] When a dispersant is incorporated, the amount thereof is preferably 0.25 to 30 parts by mass, more preferably 0.25 to 8 parts by mass, even more preferably 0.5 to 7 parts by mass, and most preferably 1 to 5 parts by mass, per 100 parts by mass of inorganic fine particles. If the amount is less than 0.25 parts by mass, the inorganic fine particles may not be sufficiently dispersed. If the amount is more than 30 parts by mass, the light resistance and heat resistance may be reduced when processed into a thin film, molded product, etc., and the properties of the inorganic fine particles may not be fully obtained. Note that, when the main purpose is to suppress a decrease in refractive index and deterioration of film properties (such as high light absorption on the low wavelength side), it is preferable to not include a dispersant, even if this slightly impairs dispersibility.

[0065] The total content of the dispersant, alkoxysilane compound 1, and alkoxysilane compound 2 is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, per 100 parts by mass of inorganic fine particles. If the content exceeds 30 parts by mass, the inorganic fine particles cannot be highly filled, and the desired properties may not be obtained. There is no particular lower limit, but 10 parts by mass or more is preferred. If the content is less than 10 parts by mass, it may be difficult to uniformly disperse the inorganic fine particles.

[0066] The mass ratio of the dispersant to the sum of the masses of alkoxysilane compound 1 and alkoxysilane compound 2 is preferably 0:100 to 50:50, more preferably 0:100 to 35:65, even more preferably 0:100 to 20:80, and most preferably 5:95 to 18:82. If the mass ratio of alkoxysilane compound to dispersant is less than 50, the amount of dispersant will be excessive, which may cause deterioration in properties when processed into a thin film, a molded product, etc.

[0067] <Average Dispersed Particle Diameter of Inorganic Fine Particles> The average dispersed particle diameter of inorganic fine particles in the inorganic fine particle dispersion is 50 nm or less, preferably 10 to 45 nm, and more preferably 20 to 40 nm. When the average dispersed particle diameter of inorganic fine particles is 50 nm or less, the imprintability of the curable resin composition can be improved. Here, the average dispersed particle diameter is the particle diameter (D50) at 50% of the cumulative number measured by dynamic light scattering. The average dispersed particle diameter of inorganic fine particles means the average particle diameter in the dispersion of inorganic fine particles in a state where the particles have been surface-treated with alkoxysilane compound 1 and alkoxysilane compound 2.

[0068] <Viscosity of Inorganic Fine Particle Dispersion> The viscosity η of the inorganic fine particle dispersion was measured at 25° C. using a cone plate with an angle of 1°34′ and a radius of 24 mm at a rotation speed of 50 rpm. ５０ is preferably 30 mPa·s or less, and more preferably 10 mPa·s or less. ５０ The lower limit of the viscosity η is not particularly limited, but can be, for example, 1 mPa·s or more. ５０ When the amount of the acrylic acid falls within the above range, the coating property tends to be improved.

[0069] The viscosity η of the inorganic fine particle dispersion was measured at 25° C. using a cone plate with an angle of 1° 34′ and a radius of 24 mm at a rotation speed of 10 rpm. １０ is preferably 45 mPa·s or less, and more preferably 15 mPa·s or less. １０ The lower limit of the viscosity η is not particularly limited, but can be, for example, 1 mPa·s or more. １０ When the amount of the acrylic acid falls within the above range, the coating property tends to be improved.

[0070] In addition, the viscosity change rate η １０ / η ５０ is preferably 0.9 to 1.5, more preferably 0.9 to 1.3, and even more preferably 0.9 to 1.1. １０ / η ５０ When the viscosity is within the above range, the change in viscosity with respect to the shear rate is small, and the imprintability of the curable resin composition containing the inorganic fine particle dispersion tends to be improved.

[0071] It is preferable that the viscosity and viscosity change rate described above are satisfied at least for the dispersion immediately after preparation, and thereafter, the viscosity η ５０ The viscosity may be more than 30 mPa·s.

[0072] η of the dispersion one month after preparation of the dispersion ５０ η of the dispersion immediately after preparation ５０ The ratio of 1.5 to 1.3 is preferably 1.5 or less, more preferably 1.3 or less, and even more preferably 1.1 or less. If it exceeds 1.5, the dispersion stability will be poor.

[0073] The inorganic fine particle dispersion of the present invention is preferably used for optical purposes.

[0074] <<Curable Resin Composition>> The curable resin composition of the present invention contains the inorganic fine particle dispersion of the present invention and a curable resin. The mass ratio of the total mass of the curable resin, alkoxysilane compound 1, and alkoxysilane compound 2 to the mass of the inorganic fine particles is preferably 10:90 to 50:50, and more preferably 20:80 to 40:60. When it is within the above range, the composition exhibits excellent imprintability and fully satisfies the optical properties required for optical elements.

[0075] The inorganic fine particles are preferably contained in an amount of 40 to 90 mass %, more preferably 50 to 80 mass %, of the solid content of the curable resin composition. When the amount is within this range, the curable resin composition has excellent imprinting properties and satisfies the optical properties required.

[0076] Examples of the curable resin include polysiloxane resins; epoxy resins such as bisphenol A type, bisphenol F type, phenol novolac type, tetrakis(hydroxyphenyl)ethane type or tris(hydroxyphenyl)methane type, which are polyfunctional types having many benzene rings, biphenyl type, triphenolmethane type, naphthalene type, ortho novolac type, dicyclopentadiene type, aminophenol type, fluorene type, and alicyclic epoxy resins, and silicone epoxy resins; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and acrylates. Examples of the epoxy resin include alkyl-modified dipentaerythritol pentaacrylate, ethylene glycol (meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, glycerin tri(meth)acrylate, acrylates such as 9,9-bis(4-(meth)acryloyloxyphenyl)fluorene, aliphatic epoxy compounds such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether, fluorene-containing epoxy compounds such as 9,9-bis(4-glycidyloxyphenyl)fluorene, and melamine. Of these, polysiloxane resins are preferred.

[0077] The amount of the curable resin to be added is preferably 0.01 to 500 parts by mass, more preferably 0.1 to 100 parts by mass, and even more preferably 0.2 to 50 parts by mass, per 100 parts by mass of the inorganic fine particles.

[0078] <Polysiloxane Resin> The polysiloxane resin may be, for example, a polysiloxane resin represented by the following general formula (R ９ SiO ３／２ ) ａ (R １０ ２ SiO ２／２ ) ｂ (R １１ ３ SiO １／２ ) ｃ (SiO ４／２ ) ｄ (In the general formula, R ９ , R １０ , R １１ are each independently a hydrogen atom, a hydroxyl group, an alkoxy group, a hydrocarbon group having 1 to 12 carbon atoms, or a substituent having 1 to 12 carbon atoms and one or more crosslinkable functional groups, and R ９ , R １０ , R １１ When there are a plurality of each of R ９ , R １０ , R １１ at least one of the groups is a substituent having 1 to 12 carbon atoms and having one or more crosslinkable functional groups, and a, b, c, and d are numbers that satisfy the conditions 0.001≦a≦1.00, 0≦b≦0.999, 0≦c≦0.30, 0≦d≦0.30, and a+b+c+d=1.0.

[0079] R ９ , R １０ , R １１ are each independently a hydrogen atom, a hydroxyl group, an alkoxy group, a hydrocarbon group having 1 to 12 carbon atoms, or a substituent having 1 to 12 carbon atoms and one or more crosslinkable functional groups. A hydrocarbon group is a group consisting of carbon and hydrogen, and examples thereof include an aliphatic hydrocarbon group and an aromatic hydrocarbon group. A substituent having 1 to 12 carbon atoms and one or more crosslinkable functional groups is a hydrocarbon group having 1 to 12 carbon atoms in which one or more hydrogen atoms have been substituted with a crosslinkable functional group. Here, the number of carbon atoms in the hydrocarbon group is preferably 1 to 6. R９ , R １０ , R １１ When there are a plurality of R, they may be different. ９ , R １０ , R １１ At least one of the groups must be a substituent having 1 to 12 carbon atoms and having one or more crosslinkable functional groups. Examples of the crosslinkable functional groups include a (meth)acrylic group, a (meth)acryloxy group, a vinyl group, and an epoxy group.

[0080] a is preferably 0.1 to 1, b is preferably 0 to 0.7, c is preferably 0 to 0.2, and d is preferably 0 to 0.1. Within the above ranges, a composition having good compatibility with the inorganic fine particle dispersion and good curability can be obtained.

[0081] The method for producing the polysiloxane resin is not particularly limited, but it can be obtained, for example, by hydrolysis and condensation reaction of alkoxysilane.

[0082] (Alkoxysilane used in producing polysiloxane resin) The alkoxysilane may be a compound represented by the following formula (a): SiR ４ (a) In formula (a), each of the four R's is hydrogen, a hydroxyl group, an alkoxy group, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and at least one of the four R's is an alkoxy group. The alkoxy group, the aliphatic hydrocarbon group, and the aromatic hydrocarbon group may each have a substituent.

[0083] When one of the four R's is an alkoxy group, it is called a monoalkoxysilane; when two R's are alkoxy groups, it is called a dialkoxysilane; when three R's are alkoxy groups, it is called a trialkoxysilane; and when four R's are alkoxy groups, it is called a tetraalkoxysilane. The alkoxysilane used in the production of the polysiloxane resin may be any of monoalkoxysilane, dialkoxysilane, trialkoxysilane, and tetraalkoxysilane.

[0084] Examples of alkoxy groups include C1-4 alkoxy groups such as methoxy and ethoxy. Examples of aliphatic hydrocarbon groups include C1-20 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, and t-butyl. Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, tolyl, and xylyl; and aralkyl groups such as benzyl.

[0085] Examples of the substituents that the aliphatic hydrocarbon group and aromatic hydrocarbon group may have include crosslinkable functional groups such as a (meth)acrylic group, a (meth)acryloxy group, a vinyl group, and an epoxy group, a primary amino group, a thiol group, and a styryl group.

[0086] Examples of alkoxysilanes include alkoxysilanes having an aliphatic hydrocarbon group such as methyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and methoxytrimethylsilane; alkoxysilanes having an aromatic hydrocarbon group such as phenyltrimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and methylphenyldiethoxysilane; alkoxysilanes having an amino group such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 2-aminophenyltrimethoxysilane, 3-aminophenyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylmethoxysilane, and 3-aminopropyldimethylethoxysilane; and 3-methacryloxypropyl Alkoxysilanes having a (meth)acrylic group such as vinyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane; alkoxysilanes having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane; alkoxysilanes having an epoxy group such as β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane.

[0087] In the hydrolysis and condensation reactions, an alkoxysilane having a crosslinkable functional group can be used in combination with an alkoxysilane not having a crosslinkable functional group, if necessary. Alternatively, hydrolyzable silanes such as dimethylsilanediol, diisopropylsilanediol, diisobutylsilanediol, di-n-propylsilanediol, di-n-butylsilanediol, di-t-butylsilanediol, phenylmethylsilanediol, dicyclohexylsilanediol, ethylsilanetriol, and diphenylsilanediol may be used in combination.

[0088] (Hydrolysis and Condensation Reaction) The hydrolysis and condensation reaction can be carried out under temperature and time conditions of preferably 30 to 120°C for 1 to 24 hours, more preferably 40 to 90°C for 2 to 12 hours, and even more preferably 45 to 80°C for 3 to 8 hours.

[0089] The alkoxy groups in the alkoxysilane form siloxane bonds through hydrolysis and condensation reactions to produce a polysiloxane resin, but some unreacted alkoxy groups and hydroxyl groups formed by hydrolysis of the alkoxy groups may remain in the polysiloxane resin.

[0090] The hydrolysis and condensation reactions may be carried out using a catalyst, and examples of such catalysts include basic catalysts and acidic catalysts. Examples of basic catalysts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, potassium t-butoxide, sodium bicarbonate, sodium carbonate, barium hydroxide, sodium hydroxide, and potassium hydroxide. Among these, tetramethylammonium hydroxide, potassium t-butoxide, sodium bicarbonate, sodium carbonate, barium hydroxide, sodium hydroxide, and potassium hydroxide are preferred due to their high catalytic activity. Examples of acidic catalysts include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, phosphoric acid, boric acid, trifluoroacetic acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid.

[0091] A solvent can be used for the hydrolysis and condensation reaction, if necessary. Examples of such solvents include water; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran (THF); glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol monobutyl ether; alkylene glycol monoalkyl ether acetates such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, propylene glycol methyl ether acetate (PGMEA), and 3-methoxybutyl-1-acetate; aromatic hydrocarbons such as toluene and xylene; and ketones such as methyl ethyl ketone, methyl isobutyl ketone (MIBK), methyl amyl ketone, and cyclohexanone. Preferred are ketones, alkylene glycol monoalkyl ether acetates, and aromatic hydrocarbons. These solvents may be used alone or in combination of two or more.

[0092] The amount of the solvent to be added is preferably 50 to 500 parts by mass, more preferably 100 to 400 parts by mass, per 100 parts by mass of the alkoxysilane.

[0093] The weight-average molecular weight of the polysiloxane resin is not particularly limited, but is preferably 1,000 to 5,000, and more preferably 1,300 to 3,700. Within the above range, the resin tends to have excellent curing properties, optical properties, and imprintability. Here, the weight-average molecular weight is measured by gel permeation chromatography (GPC) and calculated in terms of standard polystyrene.

[0094] The amount of polysiloxane resin is preferably 0.01 to 500 parts by mass, more preferably 0.1 to 100 parts by mass, and even more preferably 0.2 to 50 parts by mass, relative to 100 parts by mass of inorganic fine particles. The amount of polysiloxane resin is preferably 10 to 100% by mass, more preferably 30 to 100% by mass, and even more preferably 50 to 100% by mass, of all curable resins.

[0095] The curable resin composition may contain other components in addition to the components described above, such as thermoplastic resins such as acrylic resins, polyester resins, urethane resins, and polyolefin resins, polymerization initiators, leveling agents, surfactants, photosensitizers, antifoaming agents, neutralizing agents, antioxidants, mold release agents, ultraviolet absorbers, and solvents.

[0096] As the polymerization initiator, a photoradical polymerization initiator, a thermal radical polymerization initiator, etc. can be used. These polymerization initiators may be used alone, or two or more polymerization initiators, for example, two or more photoradical polymerization initiators or two or more thermal radical polymerization initiators, may be used in combination, or a photoradical polymerization initiator and a thermal radical polymerization initiator may be used in combination.

[0097] Examples of the photoradical polymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0098] Examples of the thermal radical polymerization initiator include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, 1,3-bis(t-butylperoxyisopropyl)benzene, 1,1-bis(t-butylperoxy)valerate, benzoyl peroxide, t-butyl peroxybenzoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and m-toluyl peroxide.

[0099] The amount of the polymerization initiator to be added is preferably 0.1 to 25 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the component having a crosslinkable functional group.

[0100] The leveling agent is not particularly limited, and examples thereof include siloxane-based compounds such as polyether-modified polydimethylsiloxane, polyether-modified siloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, polyether-modified acrylic group-containing polydimethylsiloxane, polyester-modified acrylic group-containing polydimethylsiloxane, perfluoropolydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, and perfluoropolyester-modified polydimethylsiloxane; fluorine-based compounds such as perfluoroalkylcarboxylic acid and perfluoroalkylpolyoxyethyleneethanol; polyether compounds such as polyoxyethylene alkylphenyl ether, propylene oxide polymer, ethylene oxide polymer; carboxylic acids such as coconut oil fatty acid amine salts, gum rosin; ester compounds such as castor oil sulfates, phosphate esters, alkyl ether sulfates, sorbitan fatty acid esters, sulfonate esters, succinate esters; sulfonate compounds such as alkylarylsulfonic acid amine salts, dioctyl sodium sulfosuccinate; phosphate compounds such as sodium lauryl phosphate; amide compounds such as coconut oil fatty acid ethanolamide; and acrylic compounds.

[0101] When a leveling agent is used, the amount of the leveling agent added is preferably 0.001 to 5 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.05 to 0.5 mass %, based on the solid content of the curable resin composition.

[0102] The viscosity of the curable resin composition containing the inorganic fine particle dispersion of the present invention, the curable resin, and the like is not particularly limited, but is preferably 0.1 to 100 mPa s, and more preferably 3.0 to 50 mPa s. When it is within the above range, excellent coating properties are obtained.

[0103] The lower the haze value of the cured product of the curable resin composition, the better the optical properties, and the haze value is preferably 1% or less, and more preferably 0.2% or less. Here, the haze value of the cured product is measured using a cured product of the curable resin composition having a film thickness of 1 μm.

[0104] The curable resin composition can be produced by adding a curable resin such as a polysiloxane resin and, if necessary, optional components such as a polymerization initiator and a leveling agent to the inorganic fine particle dispersion of the present invention and mixing them.

[0105] When the curable resin composition is used for imprinting, an imprint substrate can be produced by a method including a step of applying the curable resin composition to a substrate and a step of patterning the composition by nanoimprinting. A step of curing the coating film obtained by patterning may also be provided.

[0106] In the method for manufacturing an imprint substrate, a light-transmitting material is selected for at least one of the substrate and / or the master substrate. The material of the substrate is not particularly limited and can be selected depending on the application. Examples include quartz, glass, ceramic materials, vapor-deposited films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, and Fe, paper, SOG (spin-on-glass), TFT array substrates, PDP electrode plates, conductive substrates such as ITO, insulating substrates, semiconductor substrates such as silicone, silicone nitride, polysilicone, silicone oxide, and amorphous silicone, and polymer substrates such as polyethylene, polypropylene, polyester, polyethylene naphthalate, polycarbonate, polyimide, cycloolefin, polystyrene, polytetrafluoroethylene, PMMA, and ABS resin. The shape of the substrate is also not particularly limited and may be plate-shaped or roll-shaped. As mentioned above, the substrate can be either light-transmitting or non-light-transmitting depending on the combination with the master, etc.

[0107] The method for applying the curable resin composition to a substrate is not particularly limited, and examples thereof include bar coating, spin coating, spray coating, dip coating, nozzle coating, gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, curtain coating, knife coating, transfer roll coating, squeeze coating, impregnation coating, kiss coating, calendar coating, extrusion coating, and inkjet coating.

[0108] The thickness of the coating film is not particularly limited, but is preferably 0.005 to 100 μm, more preferably 0.05 to 40 μm, and even more preferably 0.1 to 20 μm. Within the above range, the film has excellent imprintability and maintains sufficient optical properties.

[0109] In nanoimprinting, a patterned master (transfer imprint stamp) is pressed against a substrate coated with a curable resin, and the imprinting resin composition is cured by light or heat to transfer a fine structure pattern. After curing, the master is removed to produce an imprint substrate.

[0110] The material of the master is not particularly limited. For example, examples of light-transmitting masters include silicone, glass, quartz, PMMA, polycarbonate resin, and other light-transmitting resins, transparent metal vapor-deposited films, flexible films such as polydimethylsiloxane, photocured films, and metal films. Non-light-transmitting masters are not particularly limited, but may be any material having a predetermined strength. Specific examples include ceramic materials, vapor-deposited films, magnetic films, reflective films, metal substrates such as Ni, Cu, Cr, and Fe, and substrates such as SiC, silicone, silicon nitride, polysilicone, silicon oxide, and amorphous silicone, and are not particularly limited. The shape of the mold is also not particularly limited, and may be either a plate-shaped mold or a roll-shaped mold. Furthermore, using a flexible resin mold facilitates film imprinting using a roll-to-roll method.

[0111] The pressing pressure is not particularly limited, but is preferably 0.001 to 10 MPa, more preferably 0.01 to 5 MPa. The pressing time is not particularly limited, but is preferably 0.1 to 30 minutes, more preferably 0.5 to 10 minutes.

[0112] The pattern of the master is not particularly limited, but examples thereof include a wiring pattern, a line and space pattern, a moth-eye pattern, and a pattern consisting of protrusions or depressions in the shape of a cylinder, a cone, a truncated cone, a polygonal prism (e.g., a square prism), a polygonal pyramid (e.g., a square pyramid), or a polygonal pyramid truncated cone (e.g., a square pyramid).

[0113] The master plate may be subjected to a release treatment to improve the releasability between the resin composition and the master plate surface. The release treatment method is not particularly limited, and examples thereof include treatment with a silicone-based, fluorine-based, or nonionic surfactant, a silane coupling agent, or fluorine-containing diamond-like carbon.

[0114] After the coating step, a solvent drying step may be carried out depending on the curable resin composition. In particular, when a solvent with a high boiling point is used, a drying step may be carried out in order to obtain a smooth coating film or to reduce shrinkage after pattern formation by nanoimprinting.

[0115] The curing method of the curable resin composition is not particularly limited, and either photocuring or thermal curing can be applied. In the thermal curing method, the heating temperature is not particularly limited, but is preferably 60 to 300°C, and more preferably 100 to 250°C. A heating temperature of less than 60°C may result in insufficient curing, and a heating temperature of more than 300°C may damage the shape of the substrate depending on the material of the substrate. The heating time is also not particularly limited, but is preferably 5 to 300 seconds, and more preferably 10 to 180 seconds. A heating time of less than 5 seconds may result in insufficient curing, and a heating time of more than 300 seconds may damage the shape of the substrate depending on the material of the substrate. In addition, the time required for the process is long, which is undesirable from the viewpoint of productivity.

[0116] The photocuring method is not particularly limited, but in the curing of the curable resin composition, the irradiation dose of light in the step of irradiating the pattern forming layer with light may be sufficiently greater than the irradiation dose required for curing. The irradiation dose required for curing is appropriately determined by examining the consumption of unsaturated bonds in the curable resin composition and the tackiness of the cured film, and is, for example, 5 mJ / cm. ２ ~2000mJ / cm ２ The substrate temperature during light irradiation is usually room temperature, but light irradiation may be performed while heating in order to enhance reactivity.

[0117] The light used to cure the curable resin composition is not particularly limited, and examples thereof include light or radiation with wavelengths in the high-energy ionizing radiation, near ultraviolet, far ultraviolet, visible, and infrared regions. As a source of high-energy ionizing radiation, for example, an electron beam accelerated by an accelerator such as a Cockcroft accelerator, Handegraaff accelerator, linear accelerator, betatron, or cyclotron is industrially the most convenient and economical. However, other radiation sources such as gamma rays, X-rays, alpha rays, neutron beams, and proton beams emitted from radioisotopes or nuclear reactors can also be used. Examples of ultraviolet light sources include ultraviolet fluorescent lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, carbon arc lamps, and sun lamps. Examples of radiation include microwaves and EUV. Furthermore, LEDs, semiconductor laser light, and laser light used in semiconductor microfabrication, such as 248 nm KrF excimer laser light and 193 nm ArF excimer laser, can also be suitably used in the present invention. These lights may be monochrome lights or lights with a plurality of different wavelengths (mixed lights).

[0118] After patterning by nanoimprinting and removing the original, a curing step may be carried out as necessary.

[0119] The imprint substrate is characterized by having a substrate and a convex portion or a concave portion made of a cured product of the curable resin composition.

[0120] The imprinted substrate can be suitably used in the form of an optical coating film, optical member, or molded article for optical devices, semiconductor devices, display devices, etc. Specific examples include organic electroluminescence (EL), touch panels, touch sensors, liquid crystal displays, XR (Extended Reality / Cross Reality) devices such as AR devices, CMOS, solar cells, transistors, light-emitting diodes, memories, ICs, LSIs, CPUs, RFIDs, CCDs, printed wiring boards, semiconductor mounting substrates, optical waveguides, optical filters, anti-reflection films, lenses, prisms, mirrors, lasers, resonators, PDPs, electronic paper, MEMS, etc.

[0121] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. Hereinafter, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0122] The various chemicals used in the examples and comparative examples are collectively described below. (1) Inorganic fine particle titanium oxide (manufactured by Teika Corporation, MT100HD, average primary particle diameter 15 nm) Zirconium oxide (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., UEP-50, average primary particle diameter 15 nm, specific surface area 40 to 60 m ２ / g) (2) Dispersant: Phosphate ester dispersant (manufactured by Kusumoto Chemical Co., Ltd., trade name: Disparlon PW-36) (3) Alkoxysilane compound 1: Methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-13) (4) Alkoxysilane compound 2: Butyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) 8-Methacryloxyoctyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-5803) (5) Solvent: Propylene glycol monomethyl ether acetate PGMEA (manufactured by Daicel Corporation, MMPGAC) (6) Polymerization initiator: Photoradical polymerization initiator (manufactured by IGM Resins, Omnirad 127) (7) Leveling agent: Silicone leveling agent (manufactured by BYK Japan Co., Ltd., BYK-331)

[0123] Synthesis Example 1: 3-Methacryloxypropylmethyldimethoxysilane and phenyltrimethoxysilane were mixed in a molar ratio of 70:30, diluted to 50% by weight with MIBK, and 3 equivalents of water based on the total amount of alkoxysilanes were added. A 20% by weight aqueous solution of sodium hydroxide was added dropwise in an amount of 0.05 equivalents based on the total amount of alkoxysilanes, and the mixture was heated at 60°C for 3 hours. A separation step of adding and removing water from the reaction solution was carried out three times, and sodium sulfate was added for dehydration. The mixture was then concentrated using an evaporator to obtain a polysiloxane resin. The molecular weight of the obtained polysiloxane resin was measured by GPC, and the weight average molecular weight was found to be 2,700.

[0124] Examples 1 to 5 and Comparative Examples 1 to 3: Inorganic fine particles, alkoxysilane compound 1, alkoxysilane compound 2, dispersant, and solvent were mixed in the amounts shown in Table 1. The resulting mixture was then dispersed using a media-type disperser (paint shaker) to obtain an inorganic fine particle dispersion. The treatment conditions for the paint shaker were: total mixture charge mass 100 g, bead diameter 100 μm, frequency 60 Hz, and dispersion time 180 minutes.

[0125] To the obtained inorganic fine particle dispersion, the polysiloxane resin prepared in Synthesis Example 1, Omnirad 127 as a polymerization initiator, and BYK-331 as a leveling agent were blended in the blending amounts shown in Table 1, and the mixture was stirred at room temperature to prepare a curable resin composition.

[0126] The obtained dispersion was used to evaluate the physical properties related to the average dispersed particle size and viscosity by the following methods. The obtained curable resin was also used to evaluate the imprint property, UV resistance, and haze value by the following methods. The evaluation results are shown in Table 1.

[0127] <Average Dispersed Particle Diameter of Inorganic Fine Particles> The inorganic fine particle dispersion was diluted with a dispersion medium so that the particle concentration became 1% by mass, and the average particle diameter was measured using a Zetasizer Nano ZS manufactured by Malvern.

[0128] <Viscosity and Viscosity Change Rate> The obtained inorganic fine particle dispersion was measured for viscosity η at 25° C. and rotation speeds of 10 rpm and 50 rpm using a viscometer (B-type viscometer, manufactured by Toki Sangyo Co., Ltd.) using a cone plate with an angle of 1°34′ and a radius of 24 mm. １０ , η ５０ The viscosity change rate η was also calculated from these viscosities. １０ / η ５０ The η measured by the above method was calculated. ５０ and η １０ / η ５０ The η of the inorganic fine particle dispersion after one month from the preparation is shown in Table 1. ５０ was measured in the same manner as above. The results were used as the η ５０ The storage stability was evaluated according to the following criteria, and the results are shown in Table 1. Good: η of the dispersion one month after preparation ５０ η of the dispersion immediately after preparation ５０The ratio of η to η of the dispersion one month after preparation is 1.5 or less. ５０ η of the dispersion immediately after preparation ５０ The ratio to is greater than 1.5.

[0129] The obtained curable resin composition was applied to a 0.7 mm white glass substrate by spin coating, and the solvent was dried at 80° C. for 2 minutes to obtain a 3 μm thick coating film. Next, a polydimethylsiloxane master plate on which an L / S pattern with a width of 400 nm and a depth of 500 nm was formed was pressed at room temperature at a pressure of 10 bar, and 1000 mJ / cm was applied using an Eitre 3 (manufactured by Obducat). ２ After curing at 4°C, the pattern was removed to obtain a cured product. The transferred pattern was observed with an SEM, and the imprintability was evaluated on a four-point scale according to the following criteria. The results are shown in Table 1. ○: The pattern was transferred cleanly, and the imprintability was good. △: The pattern was transferred, but chipping and / or deformation was observed. ×: All or most of the pattern peeled off from the substrate when released. XX: The mold did not penetrate in the depth direction, and the pattern was not transferred.

[0130] <UV Resistance> The obtained curable resin composition was applied to a 0.7 mm white glass substrate by spin coating, the solvent was dried at 80°C for 2 minutes, and the coating was then dried at 500 mJ / cm ２ Next, to test the UV resistance, a UV irradiation device (manufactured by Jasco International Co., Ltd., device name: SOLARBOX1500e, set illuminance: 250 W / m) was used. ２２ The film was irradiated with UV light (wavelength: 300 to 800 nm) for 24 hours. The film thickness was measured before and after irradiation, and the film shrinkage rate (%) after UV light irradiation was calculated by comparing the film thickness before UV light irradiation with that before UV light irradiation. The film shrinkage rate is shown in Table 1 as UV resistance.

[0131] <Haze Value> The obtained curable resin composition was applied onto a 0.7 mm white glass substrate by spin coating, and the solvent was dried at 80°C for 2 minutes. ２The total light transmittance and haze value of the resulting coating film were measured using a haze computer (HGM-2B, manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7150.

[0132]

[0133] As shown in Table 1, the inorganic microparticle dispersions of Comparative Examples 1 and 3 did not contain alkoxysilane compound 1, and therefore the UV resistance of the coating film after curing was insufficient. The inorganic microparticle dispersion of Comparative Example 2 did not contain alkoxysilane compound 2 and had an average dispersed particle diameter of more than 50 nm, and therefore the imprintability of the curable resin composition was insufficient. Furthermore, the storage stability of the inorganic microparticle dispersions of Comparative Examples 2 and 3 was insufficient. On the other hand, the inorganic microparticle dispersions of Examples 1 to 5 provided curable resin compositions with excellent imprintability and UV resistance.

[0134] The present invention may include, for example, the following aspects: <1> An inorganic fine particle dispersion liquid containing inorganic fine particles having an average dispersed particle diameter of 50 nm or less and surface-treated with an alkoxysilane compound 1 represented by the following general formula (1) and an alkoxysilane compound 2 represented by the following general formula (2), and an organic solvent. (R ２ ) （４－ｍ） -Si-(OR １ ) ｍ (1) [In general formula (1), m represents an integer of 1 to 3, and R １ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ２ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. ４ ) （４－ｎ） -Si-(OR ３ ) ｎ (2) [In general formula (2), n represents an integer of 1 to 3, and R ３ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ４ is R ５ -(OCHR ６ CH ２ ) ｋ -OR ７ , R ５ -OC(=O)C(=CH ２ )-R ６ , or R ８(wherein k represents an integer of 1 to 10, R ５ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, R ６ is H or CH ３ represents R ７ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ８ represents a monovalent hydrocarbon group having 4 to 20 carbon atoms).

[0135] <2> At 25°C, using a cone plate with an angle of 1°34' and a radius of 24 mm, the viscosity measured at a rotation speed of 50 rpm is η ５０ , the viscosity measured at a rotation speed of 10 rpm is η １０ Then, η ５０ is 30 mPa·s or less, and the viscosity change rate η １０ / η ５０ Item 2. The inorganic fine particle dispersion according to Item 1, wherein the σ is 0.9 to 1.5.

[0136] <3> At 25°C, using a cone plate with an angle of 1°34' and a radius of 24 mm, the viscosity measured at a rotation speed of 50 rpm is η ５０ Then, the η of the dispersion one month after preparation ５０ η of the dispersion immediately after preparation ５０ 3. The inorganic fine particle dispersion according to item 1 or 2, wherein the ratio of

[0137] <4> The inorganic fine particle dispersion according to any one of items 1 to 3, wherein the inorganic fine particles are inorganic oxide fine particles.

[0138] <5> The inorganic fine particle dispersion according to item 4, wherein the inorganic oxide fine particles are zirconium oxide, titanium oxide, or a metal titanate.

[0139] <6> The inorganic fine particle dispersion liquid according to any one of items 1 to 5, wherein the mass ratio of the alkoxysilane compound 1 to the alkoxysilane compound 2 is 5:95 to 95:5.

[0140] <7> The inorganic fine particle dispersion according to any one of items 1 to 6, wherein the total content of the dispersant, the alkoxysilane compound 1, and the alkoxysilane compound 2 is 30 parts by mass or less relative to 100 parts by mass of the inorganic fine particles.

[0141] <8> The inorganic fine particle dispersion according to any one of items 1 to 7, wherein the mass ratio of the dispersant to the total mass of the alkoxysilane compound 1 and the alkoxysilane compound 2 is 0:100 to 50:50.

[0142] <9> The inorganic fine particle dispersion liquid according to any one of items 1 to 8, wherein the content of the inorganic fine particles is 15 to 56% by mass.

[0143] <10> The inorganic fine particle dispersion liquid according to any one of items 1 to 9, which is used for optical purposes.

[0144] <11> A curable resin composition comprising the inorganic fine particle dispersion liquid according to any one of items 1 to 10 and a curable resin.

[0145] <12> The curable resin composition according to item 11, wherein the haze value of a cured product cured to a film thickness of 1 μm is 1% or less.

[0146] <13> A cured product of the curable resin composition according to item 11 or 12.

Claims

1. An inorganic fine particle dispersion liquid containing inorganic fine particles having an average dispersed particle diameter of 50 nm or less and surface-treated with an alkoxysilane compound 1 represented by the following general formula (1) and an alkoxysilane compound 2 represented by the following general formula (2), and an organic solvent. (R ２ ) （４－ｍ） -Si-(OR １ ) ｍ (1) [In general formula (1), m represents an integer of 1 to 3, and R １ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ２ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms. ４ ) （４－ｎ） -Si-(OR ３ ) ｎ (2) [In general formula (2), n represents an integer of 1 to 3, and R ３ represents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ４ is R ５ -(OCHR ６ CH ２ ) ｋ -OR ７ , R ５ -OC(=O)C(=CH ２ )-R ６ , or R ８ (wherein k represents an integer of 1 to 10, R ５ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, R ６ is H or CH ３ represents R ７ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ８ represents a monovalent hydrocarbon group having 4 to 20 carbon atoms).

2. At 25°C, using a cone plate with an angle of 1°34' and a radius of 24 mm, the viscosity measured at a rotation speed of 50 rpm is η ５０ , the viscosity measured at a rotation speed of 10 rpm is η １０ Then, η ５０ is 30 mPa·s or less, and the viscosity change rate η １０ / η ５０ 2. The inorganic fine particle dispersion according to claim 1, wherein the σ is 0.9 to 1.

5.

3. At 25°C, using a cone plate with an angle of 1°34' and a radius of 24 mm, the viscosity measured at a rotation speed of 50 rpm is η ５０ Then, the η of the dispersion one month after preparation ５０ η of the dispersion immediately after preparation ５０ 3. The inorganic fine particle dispersion according to claim 1, wherein the ratio of the total amount of the inorganic fine particle to the total amount of the inorganic fine particle dispersion ... is 1.5 or less.

4. The inorganic fine particle dispersion according to any one of claims 1 to 3, wherein the inorganic fine particles are inorganic oxide fine particles.

5. The inorganic fine particle dispersion according to claim 4, wherein the inorganic oxide fine particles are zirconium oxide, titanium oxide, or a metal titanate.

6. The inorganic fine particle dispersion according to any one of claims 1 to 5, wherein the mass ratio of said alkoxysilane compound 1 to said alkoxysilane compound 2 is 5:95 to 95:

5.

7. An inorganic fine particle dispersion liquid according to any one of claims 1 to 6, wherein the total content of the dispersant, the alkoxysilane compound 1, and the alkoxysilane compound 2 is 30 parts by mass or less per 100 parts by mass of the inorganic fine particles.

8. An inorganic fine particle dispersion liquid according to any one of claims 1 to 7, wherein the mass ratio of the dispersant to the total mass of the alkoxysilane compound 1 and the alkoxysilane compound 2 is 0:100 to 50:

50.

9. The inorganic fine particle dispersion according to any one of claims 1 to 8, wherein the content of the inorganic fine particles is 15 to 56% by mass.

10. The inorganic fine particle dispersion according to any one of claims 1 to 9, which is used for optical purposes.

11. A curable resin composition comprising the inorganic fine particle dispersion according to any one of claims 1 to 10 and a curable resin.

12. The curable resin composition according to claim 11, wherein the haze value of the cured product when cured to a film thickness of 1 μm is 1% or less.

13. A cured product of the curable resin composition according to claim 11 or 12.

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