Inorganic fine particle dispersion

Abstract

The present invention provides an inorganic fine particle dispersion having a small average dispersed particle size of inorganic fine particles and excellent optical characteristics and moldability while being environmentally friendly due to an increased solids fraction. The present invention relates to an inorganic fine particle dispersion containing inorganic fine particles having an average dispersed particle size of 25 nm or less and an organic solvent, wherein, when the viscosity measured at a rotation speed of 50 rpm at 25℃ using a cone plate having an angle of 1°34' and a radius of 24 mm is taken to be η50 and the viscosity measured at a rotation speed of 10 rpm is taken to be η10, η50 is 30 mPa∙s or less and the viscosity change rate η10 / η50 is 0.9-1.5.

Description

Inorganic fine particle dispersion

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

[0002] In recent years, with the growing attention being paid to the SDGs, there has been an increasing demand for reducing environmental impact, necessitating the reduction of organic solvent emissions during manufacturing processes. Nanoparticle dispersions, in particular, use large amounts of organic solvents to improve compatibility with various compositions, and increasing the solid content and achieving a high solids content is required. High solids content also has the advantage of improving thick-film coating properties. On the other hand, when nanoparticles are highly dispersed at high solids content, there is a significant tendency for viscosity, thixotropy, and the average dispersed particle size of the fine particles to increase, resulting in problems such as poor dischargeability during use and poor surface smoothness and moldability during coating. In particular, when thixotropy is high, for example, when spin coating is performed, coating spread is suppressed at the initial rotation speed, but as the rotation speed gradually increases, coating spread rapidly. This results in uneven spreading rather than uniform spreading, making it difficult to obtain a smooth coating film.

[0003] In particular, nanoimprinting applications present problems such as reduced penetration into fine patterns and reduced extrusion performance of air bubbles. Regarding the average particle size of fine particles, for example, in optical applications, if the average particle size is large, problems such as reduced light transmittance, reduced transparency, and increased light loss occur. In recent years, nanoimprinting applications have been required to create finer patterns, and in order to improve penetration into fine areas, low viscosity, low thixotropy, and ultra-small particle size are required. Ultra-small particle size alone does not achieve satisfactory moldability; it is important to combine low viscosity, low thixotropy, and ultra-small particle size.

[0004] Furthermore, if the solid content is high, the frequency of particle collisions increases, which makes aggregation more likely over time and reduces storage stability. Although this can be improved to some extent by storing in a low-temperature environment, such as freezing, this increases the environmental load in terms of the large amount of electricity consumed, thereby defeating the original purpose. Therefore, a composition that is stable for a long period of time when stored at 25°C is required.

[0005] Patent Documents 1 to 3 all disclose dispersions containing inorganic fine particles and a dispersion medium. However, Patent Document 1 only discloses a dispersion having a high viscosity and a high viscosity change rate. Patent Document 2 does not disclose anything about thixotropy. Patent Document 3 only discloses an inorganic fine particle dispersion in which the dispersed particle diameter of the inorganic fine particles is large.

[0006] JP 2018-119086 A JP 2017-25225 A International Publication No. 2019 / 240154

[0007] An object of the present invention is to provide an inorganic fine particle dispersion liquid having a small average dispersed particle diameter of inorganic fine particles, which has excellent optical properties and moldability while being environmentally friendly due to its high solid content.

[0008] That is, the present invention (1) is an inorganic fine particle dispersion liquid containing inorganic fine particles having an average dispersed particle diameter of 25 nm or less and an organic solvent, and the viscosity 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 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 is an inorganic fine particle dispersion liquid in which the σ is 0.9 to 1.5.

[0009] In the present invention (2), the η of the dispersion one month after preparation ５０ is the η of the dispersion immediately after preparation. ５０ The inorganic fine particle dispersion liquid according to the present invention (1), wherein the ratio of the saturation temperature to the saturation temperature is 1.5 or less.

[0010] The present invention (3) is the inorganic fine particle dispersion according to the present invention (1) or (2), in which the inorganic fine particles are inorganic oxide fine particles.

[0011] The present invention (4) is the inorganic fine particle dispersion according to the present invention (3), in which the inorganic oxide fine particles are zirconium oxide, titanium oxide, or a metal titanate.

[0012] The present invention (5) is the inorganic fine particle dispersion according to any one of the present inventions (1) to (4), wherein the inorganic fine particles contain inorganic fine particles whose surfaces have been treated with an alkoxysilane compound.

[0013] The present invention (6) is the inorganic fine particle dispersion according to the present invention (5), wherein the content of the dispersant and the alkoxysilane compound is 40 parts by mass or less per 100 parts by mass of the inorganic fine particles.

[0014] The present invention (7) is the inorganic fine particle dispersion according to the present invention (6), wherein the mixing ratio of the dispersant to the alkoxysilane compound is 0:100 to 50:50.

[0015] The present invention (8) is a method for preparing a silane compound having the formula: ２ ４－ｍ -Si-(OR １ ) ｍ (wherein m represents an integer of 1 to 3, R １ represents a monovalent hydrocarbon group having 1 to 5 carbon atoms, and R ２ is R ４ -(OCHR ３ CH ２ ) ｎ -OR ５ , R ４ -OC(=O)C(=CH ２ )-R ３ , or R ５ (wherein n represents 1 to 10, R ３ is H or CH ３ represents R ４ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, R ５ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. ) The inorganic fine particle dispersion liquid according to any one of the present inventions (5) to (7), wherein the compound is represented by

[0016] The present invention (9) is the inorganic fine particle dispersion according to any one of the present inventions (1) to (8), wherein the content of the inorganic fine particles is 15 to 56% by mass.

[0017] The present invention (10) is an inorganic fine particle dispersion liquid according to any one of the present inventions (1) to (9), which is used for optical purposes.

[0018] The present invention (11) is a curable resin composition containing the inorganic fine particle dispersion according to any one of the present inventions (1) to (10) and a curable resin.

[0019] The present invention (12) is the curable resin composition according to the present invention (11), wherein the haze value of a cured product of the curable resin composition having a film thickness of 1 μm is 1% or less.

[0020] The present invention (13) is a cured product obtained by curing the curable resin composition according to the present invention (11) or (12).

[0021] According to the present invention, an inorganic particle dispersion liquid can be provided which has a high solid content, yet has a small average dispersed particle diameter of inorganic particles, low viscosity, and low thixotropy, and is therefore environmentally friendly and has excellent optical properties and moldability.

[0022] <<Inorganic Fine Particle Dispersion>> The inorganic fine particle dispersion of the present invention is an inorganic fine particle dispersion containing inorganic fine particles having an average dispersed particle diameter of 25 nm or less and an organic solvent, and has a viscosity of η 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 , 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 0.9 to 1.5.

[0023] <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.

[0024] 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 O ３ , 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 oxides may be used alone or in combination of two or more. Zirconium oxide and titanium oxide are preferred inorganic oxides because they are easily available and their optical properties such as refractive index can be easily adjusted.

[0025] Examples of composite metal oxides composed of two or more metal elements include barium titanate and strontium titanate (SrTiO ３ Examples of such composite metal oxides include titanates such as titanium / silicon composite oxides, yttrium-stabilized zirconia, etc. Such composite metal 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.

[0026] The primary particle diameter of the inorganic fine particles is preferably 1 to 25 nm, more preferably 5 to 20 nm. If the diameter is less than 1 nm, the inorganic fine particles have a large specific surface area and high cohesive energy, which may make it difficult to maintain dispersion stability. On the other hand, if the diameter exceeds 25 nm, the inorganic fine particles in the thin film or molded body may cause severe light scattering, making it difficult to maintain high transparency. Here, the primary particle diameter can be measured using an electron microscope such as SEM or TEM, or by conversion from the specific surface area.

[0027] 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.

[0028] In view of dispersion stability, inorganic fine particles are preferably surface-treated with alkoxysilane compound.Such surface-treated inorganic fine particles may be surface-treated in advance with alkoxysilane compound, or may be those that are added to dispersion liquid and reacted with inorganic fine particles.As the alkoxysilane compound used for surface treatment, the alkoxysilane compound described below can be used.

[0029] 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, 2-propanol, and butanol, esters such as ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, ethyl carbitol acetate (diethylene glycol monoethyl ether acetate), and γ-butyrolactone, ethers such as diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and propylene glycol monomethyl ether (PGME), ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, and amides such as dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more. The blending ratio of the solvent to the metal oxide fine particles is not particularly limited, but is preferably 15:85 to 90:10, and more preferably 30:70 to 80:20.

[0030] 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 further, 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 will easily occur and stability will tend to be poor.

[0031] <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.

[0032] 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.

[0033] <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.

[0034] 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.).

[0035] 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).

[0036] 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.).

[0037] Examples of silicone-based dispersants include modified silicone oil, etc. Commercially available products include ES-5612 (manufactured by DuPont Toray Specialty Materials Co., Ltd.).

[0038] 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.

[0039] 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.

[0040] When a curable resin composition is produced using a polysiloxane resin as the curable resin, an alkoxysilane compound can be blended to enhance the affinity between the inorganic fine particles and the curable resin when the dispersion is mixed with the curable resin. When the dispersion is kept under acidic or alkaline conditions, the hydroxyl groups present on the surfaces of the inorganic fine particles react with the alkoxysilane compound, thereby performing surface treatment on the inorganic fine particles.

[0041] <Alkoxysilane Compound> The alkoxysilane compound includes R ２ ４－ｍ -Si-(OR １ ) ｍ (wherein m represents an integer of 1 to 3, R １ represents a monovalent hydrocarbon group having 1 to 5 carbon atoms, and R ２ is R ４ -(OCHR ３ CH ２ ) ｎ -OR ５ , R ４ -OC(=O)C(=CH ２ )-R ３ , or R ５ (wherein n represents 1 to 10, R ３ is H or CH ３ represents R ４ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms; R ５ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. ) Compounds represented by ) are preferred.

[0042] Specific examples of the alkoxysilane compound include 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, p-styryltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, 7-octenyltrimethoxysilane, and 8-methacryloxyoctyltrimethoxysilane. Examples of the dialkoxysilane include trialkoxysilanes such as 8-glycidoxyoctyltrimethoxysilane, methyltrimethoxysilane, 2-(acetoxy(polyethyleneoxy)propyl)triethoxysilane, and alkoxypolyalkyleneoxyalkyltrialkoxysilanes (e.g., methoxy(triethyleneoxy)undecyltrimethoxysilane); and dialkoxysilanes such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, dimethyldimethoxysilane, and diphenyldimethoxysilane. These may be used alone or in combination of two or more. Of these, trialkoxysilanes are preferred, and 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, and methoxy(triethyleneoxy)undecyltrimethoxysilane are more preferred.

[0043] The amount of the alkoxysilane compound is preferably 4 to 50 parts by mass, more preferably 6 to 38 parts by mass, and even more preferably 8 to 30 parts by mass, per 100 parts by mass of inorganic fine particles. If the amount is less than 4 parts by mass, it may be difficult to uniformly disperse the inorganic fine particles, and if it exceeds 50 parts by mass, it may be impossible to highly fill the inorganic oxide fine particles, and the desired properties may not be obtained.

[0044] The total amount of the dispersant and the alkoxysilane compound is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of inorganic fine particles. If the amount exceeds 40 parts by mass, the inorganic oxide fine particles cannot be highly loaded, 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 amount is less than 10 parts by mass, it may be difficult to uniformly disperse the inorganic fine particles. Note that the dispersant is an optional component, and if no dispersant is added, the total amount of the dispersant and the alkoxysilane compound will be the amount of the alkoxysilane compound.

[0045] The mixing ratio of the dispersant to the alkoxysilane compound is preferably 0:100 to 50:50, more preferably 0:100 to 35:65, even more preferably 0:100 to 20:80, and even more preferably 5:95 to 18:82. If the mass ratio of the alkoxysilane compound to the 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.

[0046] The average dispersed particle size of the inorganic fine particles in the inorganic fine particle dispersion is 25 nm or less, preferably 10 to 25 nm. If it exceeds 25 nm, the resulting cured product, such as a thin film or molded article, may become cloudy. To achieve a size of less than 10 nm, particles with a small primary particle size must be used, which may make dispersion difficult. Here, the average particle size can be measured using devices such as dynamic light scattering and laser diffraction.

[0047] 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 The viscosity η is 30 mPa·s or less, preferably 10 mPa·s or less. The viscosity η is 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, more preferably 15 mPa·s or less. １０ / η ５０is 0.9 to 1.5, preferably 0.9 to 1.3, and more preferably 0.9 to 1.1. It is preferable that the viscosity and viscosity change rate of the dispersion immediately after preparation satisfy these viscosity and viscosity change rates. ５０ The viscosity may be more than 30 mPa·s.

[0048] η of the dispersion one month after preparation of the dispersion ５０ is the η of the dispersion immediately after preparation ５０ When the ratio exceeds 1.5, the dispersion stability is poor.

[0049] <<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 and the alkoxysilane compound 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.

[0050] 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.

[0051] 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.

[0052] The amount of the curable resin to be added is preferably 0.01 to 500 parts by mass, more preferably 0.1 to 300 parts by mass, and even more preferably 0.2 to 200 parts by mass, per 100 parts by mass of the inorganic fine particles.

[0053] <Polysiloxane Resin> The polysiloxane resin is a polysiloxane resin represented by the following general formula (R１ SiO ３／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ３ ３ SiO １／２ ) ｃ (SiO ４／２ ) ｄ (In the general formula, R １ , R ２ , R ３ 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 １ , R ２ , R ３ When there are a plurality of each of R １ , R ２ , R ３ 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.

[0054] R １ , R ２ , R ３ 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. R １ , R ２ , R ３ When there are a plurality of R, they may be different. １ , R ２ , R ３At 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.

[0055] 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.

[0056] 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.

[0057] <Alkoxysilane> 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] (Hydrolysis and Condensation Reaction) The hydrolysis and condensation reaction can be carried out under temperature and time conditions of preferably 30 to 120°C and 1 to 24 hours, more preferably 40 to 90°C and 2 to 12 hours, and even more preferably 45 to 80°C and 3 to 8 hours.

[0064] The alkoxy groups in the alkoxysilane form siloxane bonds through the hydrolysis and condensation reaction 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] The amount of polysiloxane resin is preferably 0.01 to 500 parts by mass, more preferably 0.1 to 300 parts by mass, and even more preferably 0.2 to 200 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] When the curable resin composition is used for imprinting, an imprinted 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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).

[0088] 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.

[0089] After the coating step, a solvent drying step may be carried out depending on the 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.

[0090] 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.

[0091] The photocuring method is not particularly limited, but the irradiation dose of light in the step of irradiating the pattern forming layer with light in the method for producing the curable resin composition may be sufficiently larger 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. For example, it may be 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.

[0092] 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).

[0093] After patterning by nanoimprinting and removing the original, a curing step may be carried out as necessary.

[0094] 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.

[0095] 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 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, and MEMS.

[0096] The present invention will be described below with reference to examples, but is not limited to the following examples. Hereinafter, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0097] The various chemicals used in the examples and comparative examples are collectively described below. (1) Inorganic oxide fine particles: 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) Titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P-75, average primary particle diameter 18 nm, specific surface area 75 m ２ / g) Titanium oxide (Sakai Chemical Industry Co., Ltd., SSP-25, average primary particle diameter 9 nm, specific surface area 270 m ２ / g or more) (2) Dispersant: Polyether phosphate ester dispersant (Kusumoto Chemicals Co., Ltd., PW-36) (3) Alkoxysilane compound (CH ３ O) ３ SiC １１ H ２２ (OCH ２ CH ２ ) ３ OCH ３ (manufactured by Azmax Corporation, SIM-6493.7) 3-Methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503) 3-Acryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-5103) (4) Solvent Propylene glycol monomethyl ether acetate PGMEA (manufactured by Daicel Corporation, MMPGAC) Propylene glycol monomethyl ether (manufactured by Daicel Corporation, PGME) Ethyl carbitol acetate (manufactured by Daicel Corporation, ECA) (5) Polymerization initiator Photoradical polymerization initiator (manufactured by IGM Resins, Omnirad 127) (6) Leveling agent Silicone leveling agent (manufactured by BYK Japan KK, BYK-331)

[0098] 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.

[0099] Examples 1 to 7 and Comparative Examples 1 to 3: Inorganic fine particles, an alkoxysilane compound, a dispersant, and a 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 mass of the mixture charged: 100 g, bead diameter: 100 μm, frequency: 60 Hz, and dispersion time: 180 minutes.

[0100] 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.

[0101] 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 imprintability and haze value by the following methods. The evaluation results are shown in Table 1.

[0102] <Average Dispersed Particle Diameter of 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.

[0103] <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 ５０The viscosity change rate η was also calculated from these viscosities. １０ / η ５０ asked for.

[0104] 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.

[0105] <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. ２ The 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.

[0106]

[0107] As shown in Table 1, the inorganic fine particle dispersion of Comparative Example 1 had a large average dispersed particle diameter of the inorganic fine particles, and the imprinting properties and optical properties based on haze of the curable resin composition were insufficient. ５０ In the inorganic fine particle dispersion of Comparative Example 3, η ５０ and viscosity change rate η １０ / η ５０On the other hand, in the inorganic fine particle dispersions of Examples 1 to 7, the dispersed particle diameter η ５０ , viscosity change rate η １０ / η ５０ The viscosity change rate one month after preparation was also small, and the curable resin composition was excellent in imprintability and optical properties.

Claims

1. An inorganic fine particle dispersion liquid containing inorganic fine particles having an average dispersed particle diameter of 25 nm or less and an organic solvent, wherein the viscosity 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 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 / ５０ The inorganic fine particle dispersion liquid has a viscosity of 0.9 to 1.

5.

2. η of the dispersion one month after preparation ５０ is the η of the dispersion immediately after preparation. ５０ 2. The inorganic fine particle dispersion according to claim 1, wherein the ratio of the molecular weight of the inorganic fine particle dispersion to the molecular weight of the inorganic fine particle dispersion is 1.5 or less.

3. The inorganic fine particle dispersion according to claim 1 or 2, wherein the inorganic fine particles are inorganic oxide fine particles.

4. The inorganic fine particle dispersion according to claim 3, wherein the inorganic oxide fine particles are zirconium oxide, titanium oxide, or a metal titanate.

5. The inorganic fine particle dispersion according to any one of claims 1 to 4, wherein the inorganic fine particles include inorganic fine particles whose surfaces have been treated with an alkoxysilane compound.

6. The inorganic fine particle dispersion according to claim 5, wherein the content of the dispersant and the alkoxysilane compound is 40 parts by mass or less per 100 parts by mass of the inorganic fine particles.

7. The inorganic fine particle dispersion according to claim 6, wherein the mixing ratio of said dispersant to said alkoxysilane compound is 0:100 to 50:

50.

8. The alkoxysilane compound is R ２ ４－ｍ -Si-(OR １ ) ｍ (In the formula, m represents an integer of 1 to 3, R １ represents a monovalent hydrocarbon group having 1 to 5 carbon atoms; R ２ is R ４ - (OCHR ３ CH ２ ) ｎ -OR ５ , R ４ -OC(=O)C(=CH ２ )-R ３ , or R ５ (In the formula, n represents 1 to 10, R ３ is H or CH ３ represents R ４ represents a divalent hydrocarbon group having 1 to 20 carbon atoms; R ５ 8. The inorganic fine particle dispersion according to claim 5, wherein the compound is a compound represented by the formula:

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 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 a cured product of the curable resin composition having a film thickness of 1 μm is 1% or less.

13. A cured product obtained by curing the curable resin composition according to claim 11 or 12.

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