Composition containing silica particles, polyorganosiloxane and solvent, and method for producing same

Abstract

[Problem] To provide a composition which exhibits high stability under conditions of high temperature and high salinity and which contains silica particles, a polyorganosiloxane and a solvent. [Solution] Provided is a composition which contains silica particles, a polyorganosiloxane and a solvent. An organosiloxane in the composition is such that the molecular weight of the polyorganosiloxane, as calculated from a maximum peak measured using a mass analysis device, falls within the range 400-4000. The retention time of the composition, as measured using FFF-MALS under certain conditions, is 9.5 min to 25.0 min.

Description

Composition containing silica particles, polyorganosiloxane, and solvent, and method for producing the same

[0001] The present invention relates to a composition containing silica particles, a polyorganosiloxane, and a solvent, and a method for producing the composition.

[0002] Compositions containing silica particles, polyorganosiloxane, and a solvent are liquids in which silica particles are dispersed in a solvent. To improve stability, methods are used to highly disperse the silica particles. One such method is to modify the surface of the silica particles with a silane coupling agent. For example, a method for producing an organic solvent-dispersed silica sol has been disclosed, which includes a step of adding a silicon alkoxide having two or more alkoxide groups bonded to a silicon atom, or a silicon alkoxide having one or more hydroxyl groups bonded to a silicon atom and one or more alkoxide groups bonded to a silicon atom, to a hydrophilic inorganic oxide sol to surface treat the hydrophilic inorganic oxide, and a step of replacing the dispersion medium of the sol with a non-alcoholic organic solvent in the presence of a primary alcohol having 3 to 12 carbon atoms (see, for example, Patent Document 1). As a conventional technique for a composition containing silica particles, polyorganosiloxane, and a solvent, there is disclosed a method for adjusting the refractive index of a coating, which comprises mixing metal oxide particles (A) which may contain silica particles, a matrix-forming resin (B) which may contain polyorganosiloxane, and a solvent (C), and then coating the mixture on a substrate and forming a coating by energy irradiation (for example, Patent Document 2).

[0003] JP 2005-200294 JP 2023-147211

[0004] The above patent documents do not describe the stability of the produced silica sol or composition. The present invention provides a composition containing silica particles, a polyorganosiloxane, and a solvent, which is highly stable even at high temperatures and high salt concentrations. An object of the present invention is to provide a composition with high resin dispersibility (compatibility with resin) by specifying the molecular weight of the organosiloxane in the composition and the range of the diffusion coefficient and electrical mobility of the composition.

[0005] Among the particles in silica sol, there are surface-treated particles that are less susceptible to the effects of pH and salts. These particles ensure stability through interparticle repulsion, which is thought to be due to electrical repulsion between cationic and anionic functional groups. The inventors decided to add an organosiloxane as a silane compound having a functional group to a composition containing silica particles and a solvent in order to surface treat the silica particles. The inventors then prepared a stable composition by selecting the groups contained in the (poly)organosiloxane, the type of solvent, and the production method, thereby completing the present invention. Furthermore, the inventors discovered that a composition with specified retention time, electrical mobility, and molecular weight range of the polyorganosiloxane in the composition measured by FFF-MALS is highly stable, thereby completing the present invention.

[0006] That is, in a first aspect, the present invention provides a composition comprising silica particles, polyorganosiloxane, and a solvent, wherein the solution from which the silica particles have been removed is diluted 10 times with an eluent of water / acetonitrile = 1 / 1, and the sample is continuously introduced (infusion measurement) into a mass spectrometer in ESI ionization positive mode under conditions of a capillary temperature of 275 ° C, a desolvation temperature of 150 ° C, and a flow rate of 30 μL / min, and the molecular weight of the polyorganosiloxane calculated from the maximum peak is in the range of 400 to 4000, and the composition is diluted with pure water to a silica concentration of 2 mass%, and the components of the solution are separated by flow within the channel, resulting in a retention time (t Ｒ In FFF-MALS, which measures the retention time (t Ｒ) is 9.5 min to 25.0 min. As a second aspect, the composition according to the first aspect, in which the silica particles have an average primary particle size of 5 to 100 nm; As a third aspect, the composition according to the first aspect, in which the silica particles have an average particle size of 5 to 200 nm as measured by a dynamic light scattering method; As a fourth aspect, the composition according to the first aspect, in which at least a portion of the silica particles are coated with a silane compound having an organic group, and the organic group is a hydrocarbon group-containing organic group, an epoxy group-containing organic group, a glycidoxy group-containing organic group, an amino group-containing organic group, a hydroxy group-containing organic group, an acryloyl group-containing organic group, or a carboxy group-containing organic group; As a fifth aspect, the composition according to the first aspect, in which the polyorganosiloxane is contained in a product obtained by heating a silane compound having an organic group in an acidic solution; As a sixth aspect, a measurement sample containing N-methylpyrrolidone (NMP) and terephthalic acid standards, the composition, and an electrophoresis buffer is injected into a capillary having both ends applied with a voltage of 30 kV under conditions of 50 mbar for 6 seconds, The migration time is measured using a detector with a UV absorption wavelength set to 195 nm ± 5 nm, the uncorrected electrical mobility defined by formula (2) is calculated, and the electrical mobility of the composition obtained from the apex position of the peak derived from the composition in a CE chart corrected with a standard substance based on the calculated uncorrected electrical mobility is −0.0200 (cm ２ / V·min) or more, ｅｆｆ ×L ｔｏｔ ) / V × (1 / t ｅｐ -1 / t ｅｏ ) Equation (2) In equation (2), μ is the uncorrected electrical mobility (cm ２ / V·min), L ｅｆｆ represents the effective length of the capillary (104 cm), and L ｔｏｔ represents the total length of the capillary (112.5 cm), and t ｅｐ represents the migration time (min) of the composition, and t ｅｏrepresents the migration time (min) of the uncharged standard substance (NMP), and V represents the voltage (V). As a seventh aspect, the composition according to the first aspect, in which the solvent includes water or salt water; As an eighth aspect, the composition according to the first aspect, in which the solvent includes methanol or ethanol; As a ninth aspect, the composition according to the first aspect, in which, in a high-temperature salt resistance test in which the composition is stored at 100°C for 10 hours at a concentration such that the silica concentration is 0.5% by mass in an environment with a salt concentration of 3% by mass or more, a ratio expressed as DLS average particle size after the high-temperature salt resistance test / DLS average particle size before the test is 1.5 or less; As a tenth aspect, the composition according to the first aspect, in which, when a solution obtained by removing silica particles from the composition is diluted 10-fold with an eluent of water / acetonitrile = 1 / 1, and the sample is continuously introduced (infusion measurement) into a mass spectrometer in ESI ionization positive mode under conditions of a capillary temperature of 275°C, a desolvation temperature of 150°C, and a flow rate of 30 μL / min, the mass distribution has a peak derived from at least one monovalent or doubly charged ion in the range of 400 to 1800 m / z; As an eleventh aspect, there is provided a method for producing a composition according to the fourth aspect, in which a mixture containing silica particles and a silane compound having an organic group is heated to 10 to 150°C while being stirred, thereby obtaining a composition containing silica particles at least a portion of which is coated with a silane compound having an organic group and a polyorganosiloxane.

[0007] In the composition of the present invention containing silica particles, polyorganosiloxane, and a solvent, if the composition satisfies the following conditions, high stability in the evaluation of high-temperature salt resistance can be obtained. In the composition of the present invention containing silica particles, polyorganosiloxane, and a solvent, if the composition satisfies the following conditions, the composition can be easily made highly concentrated and can have high resin dispersibility (compatibility with resin). - The molecular weight of the polyorganosiloxane is in the range of 400 to 4000, and the retention time (t Ｒ) is 9.5 min to 25.0 min; and the electrical mobility of the composition measured under certain conditions is -0.0200 or more. In other words, if the retention time, electrical mobility, and molecular weight of the polyorganosiloxane in the composition measured by FFF-MALS are within a specific range, a stable composition with high high-temperature salt resistance can be obtained. The present invention has the advantage that it is not necessary to actually conduct a long-term high-temperature salt resistance test to confirm that the composition is stable and has high high-temperature salt resistance. Furthermore, a composition containing silica particles, polyorganosiloxane, and a solvent produced by the production method of the present invention can be used to obtain a stable composition with high high-temperature salt resistance, and can also obtain a composition with high resin dispersibility (compatibility with resin).

[0008] FIG. 1 shows the detection time (retention time + 5 min) measured by FFF-MALS. FIG. 2 shows the electrical mobility measured with a capillary electrophoresis system and corrected with a standard substance. FIG. 3 shows the mass distribution (m / z) measured with a mass spectrometer. FIG. 4 shows the cumulative distribution of volume average particle diameter obtained by DLS average particle diameter measurement. FIG. 5 shows the cumulative distribution of volume average particle diameter obtained by DLS average particle diameter measurement. FIG. 6 shows the cumulative distribution of volume average particle diameter obtained by DLS average particle diameter measurement.

[0009] The present invention relates to a dispersion composition containing silica particles surface-modified with a silane compound having an organic group, and polyorganosiloxanes including organosiloxane monomers, oligomers, and polymers as dispersoids, and a solvent as a dispersion medium.

[0010] <Silica Particles> In the present invention, it is preferable to use a silica sol as the silica particles dispersed in a solvent. The silica sol is not particularly limited, and can be appropriately selected from known silica sols. Commercially available silica sols are usually in the form of a dispersion in which silica particles are dispersed in various solvents. Specific examples of commercially available silica sols include Snowtex (trade name) ST-O, ST-OS, ST-O-40, and ST-OL manufactured by Nissan Chemical Industries, Ltd.; water-dispersed silica sols such as Silicadol 20, 30, and 40 manufactured by Nippon Chemical Industry Co., Ltd.; and organosilica sols such as methanol silica sol, MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-L, IPA-ST-ZL, and EG-ST manufactured by Nissan Chemical Industries, Ltd., but are not limited thereto.

[0011] <Solvent> Examples of the solvent include water, salt water, organic solvents, etc., and mixtures thereof. Examples of the organic solvent include organic solvents such as alcohols, ketones, ethers, esters, amides, and hydrocarbons. Examples of the alcohol include alcohols having 1 to 10 carbon atoms, such as methanol, ethanol, 1-propanol, 2-propanol, butanol, and ethylene glycol. Examples of the ketone include linear or cyclic aliphatic ketones having 3 to 30 carbon atoms, such as methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl amyl ketone, and cyclohexanone. Examples of the ether include linear or cyclic aliphatic ethers having 3 to 30 carbon atoms, such as diethyl ether, tetrahydrofuran, and ethylene glycol monopropyl ether. Examples of esters include linear or cyclic esters having 2 to 30 carbon atoms, such as ethyl acetate, butyl acetate, sec-butyl acetate, methoxybutyl acetate, amyl acetate, n-propyl acetate, i-propyl acetate, ethyl lactate, butyl lactate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, phenyl acetate, phenyl lactate, and phenyl propionate. Examples of amides include aliphatic amides having 3 to 30 carbon atoms, such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, and N-ethylpyrrolidone. Examples of hydrocarbons include linear or cyclic aliphatic or aromatic hydrocarbons having 6 to 30 carbon atoms, such as hexane, heptane, octane, nonane, decane, benzene, toluene, and xylene. In particular, in the present invention, the solvent is preferably water, brine, or alcohol, and more preferably water, brine, methanol, or ethanol. A mixture of two or more solvents selected from the group consisting of water, salt water, methanol and ethanol may also be used.

[0012] <Polyorganosiloxane> The polyorganosiloxane in the composition of the present invention includes silane compounds (including organosiloxane derivatives) having an organic group coated (modified) on silica particles, (bonded silanes), and those (including free silanes and free polyorganosiloxanes) that are dissolved in a solvent without being bonded to silica particles. (Poly)organosiloxane derivatives are also silane compounds having an organic group. The organic group is a hydrocarbon group-containing organic group, an epoxy group-containing organic group, a glycidoxy group-containing organic group, a glycidoxyalkyl group-containing organic group, an amino group-containing organic group, a hydroxy group-containing organic group, an acryloyl group-containing organic group, or a carboxy group-containing organic group.

[0013] <Hydrocarbon Group-Containing Organic Group> Examples of the hydrocarbon group-containing organic group include alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkylene groups having 2 to 10 carbon atoms, alkenylene groups having 2 to 10 carbon atoms, and alkynylene groups having 2 to 10 carbon atoms.

[0014] The alkyl group having 1 to 10 carbon atoms may be any of linear, branched, and cyclic alkyl groups, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methylcyclopropyl group, a 2-methylcyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n- Propyl group, 1-ethyl-n-propyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl methyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclohexyl group butyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples of the alkylene group include, but are not limited to, 3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, 2-ethyl-3-methyl-cyclopropyl, hexyl, heptyl, octyl, nonyl, and decyl. Examples of the alkylene group include alkylene groups derived from the alkyl groups described above.

[0015] The alkenyl group having 2 to 10 carbon atoms may be any of linear, branched, and cyclic, and examples thereof include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 2-methyl-3- butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, and 2-methyl-2-pentenyl group, but are not limited to these. Examples of the alkenylene group include alkenylene groups derived from the above-mentioned alkenyl groups.

[0016] The alkynyl group having 2 to 10 carbon atoms may be linear, branched, or cyclic, and includes those in which one or more C-C structures present in the alkyl group are replaced with a C≡C structure, more specific examples thereof include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 2-pentynyl group, a 3-pentynyl group, a 4-pentynyl group, and a 5-hexynyl group. Furthermore, examples of the alkynylene group include alkynylene groups derived from the above-mentioned alkynyl groups.

[0017] <Epoxy Group-Containing Organic Group> Examples of epoxy group-containing organic groups include, but are not limited to, a glycidyl group; a glycidoxy group; glycidoxyalkyl groups such as a 2-glycidoxyethyl group, a 3-glycidoxypropyl group, and a 4-glycidoxybutyl group; epoxycyclohexylalkyl groups such as a 2-(3,4-epoxycyclohexyl)ethyl group and a 3-(3,4-epoxycyclohexyl)propyl group; and oxiranylalkyl groups such as a 3,4-epoxybutyl group (also referred to as a 4-oxiranylbutyl group) and a 7,8-epoxyoctyl group (also referred to as an 8-oxiranyloctyl group).

[0018] <Glycidoxy Group-Containing Organic Group> Examples of the glycidoxy group-containing organic group include, but are not limited to, a glycidoxy group, a glycidoxyalkyl group-containing organic group, and a glycidoxyalkyl group such as a 2-glycidoxyethyl group, a 3-glycidoxypropyl group, and a 4-glycidoxybutyl group.

[0019] <Amino Group-Containing Organic Group> Examples of the amino group-containing organic group include a primary amino group, a secondary amino group, a tertiary amino group, and an organic group containing any of these.

[0020] <Hydroxy Group-Containing Organic Group, Acryloyl Group-Containing Organic Group, or Carboxy Group-Containing Organic Group> The hydroxy group-containing organic group, acryloyl group-containing organic group, and carboxy group-containing organic group are organic groups that contain a hydroxy group, an acryloyl group, or a carboxy group, respectively, and include organic groups in which hydrogen atoms of the hydrocarbon group-containing organic group are substituted with a hydroxy group, an acryloyl group, or a carboxy group.

[0021] <Production Method> While stirring the silica sol, a silane compound (organosiloxane, or (poly)organosiloxane monomer, oligomer, and / or polymer) is added. The mixture of silica sol and silane compound is then heated to 10 to 150°C (reaction temperature). The pH is confirmed to be 1 to 7 (if it is not within the 1 to 7 range, the pH is adjusted with an acid or alkali to fall within that range). The mixture is then maintained at 10 to 150°C for 2 to 10 hours, including the time required for heating, and then cooled. After cooling to room temperature, the mixture is removed and filtered to obtain a composition containing silica particles surface-treated with polyorganosiloxane. By surface-treating the silica particles with polyorganosiloxane, their compatibility with resins is further improved, resulting in improved resin dispersibility. Therefore, a composition with high stability can be obtained, even after storage. Furthermore, filtering the mixture can remove coarse silica particles and coarse free (unbonded) polyorganosiloxane, facilitating the production of a highly concentrated composition. Therefore, a composition with high resin dispersibility (compatibility with resin) and high concentration can be obtained. The reaction temperature can be from 10°C to the boiling point of the solvent, and in the case of an aqueous solvent, the reaction temperature can be in the range of 10°C to 100°C.

[0022] <Acid or alkali used in production> Examples of acids include mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid, and organic acids such as formic acid, oxalic acid, citric acid, acetic acid, lactic acid, malic acid, succinic acid, tartaric acid, butyric acid, fumaric acid, propionic acid, and ascorbic acid. Examples of alkalis include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0023] <Catalyst> Hydrolysis during production can be carried out without or with a catalyst. When a catalyst is used, examples of the hydrolysis catalyst include metal chelate compounds, organic acids, inorganic acids, organic bases, and inorganic bases. Examples of metal chelate compounds used as hydrolysis catalysts include triethoxy mono(acetylacetonato)titanium and triethoxy mono(acetylacetonato)zirconium. Examples of organic acids used as hydrolysis catalysts include acetic acid and oxalic acid. Examples of inorganic acids used as hydrolysis catalysts include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid. Examples of organic bases used as hydrolysis catalysts include pyridine, pyrrole, piperazine, and quaternary ammonium salts. Examples of inorganic bases used as hydrolysis catalysts include ammonia, sodium hydroxide, and potassium hydroxide.

[0024] <Amount of Polyorganosiloxane Added and Amount of Polyorganosiloxane Covered on the Surface of Silica Particles> The amount of polyorganosiloxane added to cover the surface of silica particles is set so that the number of silicon atoms in the polyorganosiloxane relative to the surface area of ​​the silica particles is 0.1 / nm ２ ~50.0 pieces / nm ２ , 0.5 pieces / nm ２ ~50.0 pieces / nm ２ , 1.0 pieces / nm ２ ~50.0 pieces / nm ２ , 2.0 pieces / nm ２ ~50.0 pieces / nm ２ , 1.0 pieces / nm ２ ~40.0 pieces / nm ２ , 1.0 pieces / nm ２ ~35.0 pieces / nm ２ , 1.0 pieces / nm ２ ~30.0 pieces / nm ２ , 1.0 pieces / nm ２ ~20.0 pieces / nm ２ , or 2.0 pieces / nm ２ ~20.0 pieces / nm ２ Furthermore, the amount of addition can be 1.0 particles / nm ２ ~47 pieces / nm ２As described in the above production examples, when a silane compound (organosiloxane, or (poly)organosiloxane monomer, oligomer and / or polymer) is added to silica sol, the number of silicon atoms in the silane compound relative to the surface area of ​​the silica particles is taken as the number of silicon atoms in the polyorganosiloxane. The polyorganosiloxane is used as the surface coating amount of the silica particles, and the number of silicon atoms in the polyorganosiloxane relative to the surface area of ​​the silica particles is 0.5 / nm ２ ~10.0 pieces / nm ２ , 0.5-8 pieces / nm ２ , 0.5-6 pieces / nm ２ , or 0.7 to 6 particles / nm ２ It can be said that:

[0025] <Uses> The composition of the present invention can be used for high-salt dispersion medium sols, adhesives, release agents, semiconductor encapsulants, LED encapsulants, paints, film internal additives, hard coating agents, photoresist materials, printing inks, detergents, cleaners, additives for various resins, insulating compositions, rust inhibitors, lubricants, metalworking oils, film coating agents, stripping agents, well treatment agents, and the like.

[0026] [Evaluation of Composition] <Average Primary Particle Diameter> In the present invention, the average primary particle diameter of silica particles in the composition refers to the specific surface area diameter measured by the nitrogen adsorption method (BET method) by measuring the amount of nitrogen gas adsorbed. The specific surface area diameter (average particle diameter (specific surface area diameter) D (nm)) measured by the nitrogen adsorption method (BET method) is calculated based on the specific surface area S (m ２ / g), D (nm) is given by the formula D (nm) = 2720 / S. The average primary particle diameter of the silica particles in the composition, as measured by the BET method, can be in the range of 5 nm to 100 nm, preferably 5 to 80 nm, and more preferably 5 to 50 nm.

[0027] <DLS (Dynamic Light Scattering) Average Particle Diameter> The DLS average particle diameter (average particle diameter by dynamic light scattering) of the silica particles in the composition was measured by diluting the composition with a dispersion solvent and measuring the average particle diameter using a dynamic light scattering particle diameter measuring device, using the parameters of the solvent. The Z-average particle diameter can be used as the DLS average particle diameter. The average particle diameter of the silica particles in the composition, measured by dynamic light scattering, is in the range of 5 nm to 200 nm, preferably 5 to 100 nm, and more preferably 5 to 50 nm.

[0028] <Particle Size Distribution> The particle size distribution of silica particles in the composition can be calculated by evaluating D10, D50, and D90 from the cumulative distribution of volume-average particle sizes obtained by DLS average particle size measurement, and then calculating the formula (D90 - D50) / (D50 - D10). D10, D50, and D90 are the values ​​corresponding to 10%, 50%, and 90% of the cumulative total from the fine particle side. The particle size distribution (D90 - D50) / (D50 - D10) confirms the degree of uniformity of the particle size distribution, with values ​​closer to 1 indicating a more uniform distribution width. The particle size distribution (D90 - D50) / (D50 - D10) of silica particles in the composition can be in the range of 0.3 to 5.0, preferably 0.5 to 3.0. By adjusting the particle size distribution of the silica particles in the composition, (D90-D50) / (D50-D10), to 0.3 to 5.0, the silica particles will have a uniform size, and therefore, when the composition is highly concentrated, floating of fine particles and settling of coarse particles will be less likely to occur, resulting in improved storage stability.

[0029] <Evaluation of Retention Time (Evaluation of Diffusion Coefficient)> Measurement of retention time was carried out by FFF (field flow fractionation). A membrane filter with a pore size of 10 kDa (material: RCamp) was used. A spacer thickness (W) of 350 μm was used. The composition of the present invention was diluted with an eluent of 10 mM sodium phosphate (pH 7.2) to obtain a composition with a silica concentration of 2 mass %. 25 μL of the diluted composition of the present invention was injected into the FFF device. The focus time was set to 5 min and the transition time to 1 min, and the composition was concentrated for 5 min after injection before separation. F ｏｕｔ(Detector Flow) was 0.5 mL / min, F ｃ The diluted composition was eluted at a cross flow rate of 2 mL / min and a channel temperature of 25°C. Multi-angle light scattering (MALS) was used to detect the eluted composition. The retention time (t Ｒ In order to eliminate measurement differences between instruments, the obtained data was measured as the retention time (t Ｒ ) (3.4 min) was used as a standard (to obtain the same value). Bovine serum albumin was detected at a wavelength of 210 nm using a photodiode array detector (trade name SPD-M40, manufactured by Shimadzu Corporation). The bovine serum albumin used was confirmed to have a molecular weight of 66 kDa (measured in Linear mode, Positive, High Masses) using MALDI-TOFMS (trade name RapiflexX, manufactured by Bruker). The retention time of the silica particles in the composition measured by FFF measurement can be 9.5 min to 25 min, 10.0 min to 25 min, 10.5 min to 25 min, 11.0 min to 25 min, 10.0 min to 20 min, or 10.0 min to 15 min. By setting the retention time of silica particles in the composition measured by FFF measurement to 9.5 minutes or more, the silica particle surfaces are sufficiently coated, resulting in good dispersibility in the resin. Furthermore, by setting the retention time of silica particles in the composition measured by FFF measurement to 25 minutes or less, the silica particles have sufficient mobility, allowing them to diffuse in the composition, and even if the composition is highly concentrated, they are less likely to settle or aggregate, thereby maintaining dispersion stability. Note that the retention time (t Ｒ ) can also be used to calculate the diffusion coefficient. For example, the diffusion coefficient (D) is calculated from equation (1): D = W ２ / 6t Ｒ ln(1+F Ｃ / F ｏｕｔ ) Equation (1) In equation (1), D is the diffusion coefficient (m ２ / s), W represents the spacer thickness (μm), F ｃ represents the cross-flow rate (mL / min), F ｏｕｔ represents the detector flow (mL / min), and t Ｒ represents the retention time (min). The diffusion coefficient (D) is 1.0 × 10 －１２ ~6.8 x 10 －１１ , 5.0 × 10 －１２ ~6.8 x 10 －１１ , 1.0×10 －１１ ~6.8 x 10 －１１ , 5.0 × 10 －１２ ~6.5 x 10 －１１ , 5.0 × 10 －１２ ~6.0 x 10 －１１ , or 1.0 × 10 －１１ ~6.0 x 10 －１１ The diffusion coefficient (D) can be set to 1.0 × 10 －１２ ~6.8 x 10 －１１ By doing so, it is possible to obtain sufficient dispersion stability of the silica particles.

[0030] <Evaluation of Electrical Mobility> A capillary electrophoresis system was used to measure electrical mobility. A capillary (model number G1600-64311) with an inner diameter of 75 μm, a total length of 112.5 cm, and an effective length of 104 cm was used. 10 mg each of N-methylpyrrolidone (NMP) and terephthalic acid was weighed out, and 20 mL of 5 mM sodium tetraborate (pH 9.3) was added as the electrophoresis running buffer. The mixture was stirred for 30 seconds with a vortex mixer to dissolve the mixture. The electrophoresis standard substance was then adjusted to 50 mL with the electrophoresis running buffer (NMP = terephthalic acid = 200 ppm). A CE (capillary electrophoresis) measurement vial was filled with the composition, 5 mM sodium tetraborate (electrophoresis running buffer), and standard substance in a ratio of 50 μL, 450 μL, and 20 μL. The mixture was then stirred for approximately 10 seconds with a vortex mixer to prepare the measurement sample. Prior to measurement, the electrophoresis solution was passed through the capillary at a pressure of 915 mbar for 20 minutes to perform preconditioning. Subsequently, before and after each sample measurement, the capillary was washed by passing ethanol (Junsei Chemical Co., Ltd., special grade reagent) for 180 seconds, 0.1 M aqueous sodium hydroxide solution (Fujifilm Wako Pure Chemical Industries, Ltd., for volumetric analysis) for 360 seconds, ultrapure water (trade name Milli-Q) for 300 seconds, and the electrophoresis solution for 300 seconds, in this order, at a pressure of 915 mbar. The measurement sample was injected into the capillary at 50 mbar for 6 seconds (pressure injection method), and a voltage of 30 kV was applied to both ends of the capillary to separate the components contained in the composition by electrophoresis. Components separated by electrophoresis were detected using a PDA (photodiode array) detector, with a UV absorption wavelength of 195 nm ± 5 nm. After measurement with a PDA detector, the uncorrected electrical mobility (cm) was calculated from the migration time (min) using equation (2). ２ Furthermore, to eliminate the influence of different devices, the electrical mobility (-0.00277 cm) of terephthalic acid, a standard substance (stable sample), was calculated for each composition. ２ The CE chart (Fig. 2) was prepared by correcting the values ​​so that μ = (L ｅｆｆ ×L ｔｏｔ ) / V × (1 / t ｅｐ -1 / t ｅｏ ) Equation (2) μ: uncorrected electrical mobility (cm２ / V·min) L ｅｆｆ : Effective length of capillary (104 cm) L ｔｏｔ t: total length of capillary (112.5 cm) ｅｐ t: Migration time of the composition (min) ｅｏ : Migration time (min) of uncharged standard substance (NMP) V: Voltage (V)

[0031] <Measurement of polyorganosiloxane molecular weight> As a pretreatment for measuring the polyorganosiloxane molecular weight, 10 g of the composition was placed in a centrifugal filter unit (trade name Amicon Ultra-15, molecular weight cutoff 100 kJ, manufactured by Merck Ltd.) and centrifuged for 60 minutes at a centrifugal acceleration of 10,000 G in a centrifugal separator (high-speed refrigerated centrifuge, trade name Supreme 21, manufactured by TOMY Corporation)) to remove silica particles from the composition, and a filtrate containing polyorganosiloxane was recovered. The molecular weight of the polyorganosiloxane contained in the recovered filtrate was measured using a mass spectrometer. The filtrate containing polyorganosiloxane was diluted 10 times (v / v) with an eluent of pure water / acetonitrile = 1 / 1 (v / v) to prepare a sample. Then, by infusion measurement, a sample was introduced into a mass spectrometer under conditions of a flow rate of 30 μL / min, a capillary temperature of 275 ° C, and a desolvation temperature of 150 ° C, and the molecular weight was measured. The measurement mode of the mass spectrometer was ESI ionization positive mode, and polyorganosiloxane was detected. Then, from the mass-to-charge ratio (m / z) obtained from the obtained mass spectrum and the charge (z) obtained from the spacing of the isotope peaks, the molecular weight (m) of the polyorganosiloxane was calculated as mass-to-charge ratio (m / z) × charge (z) = molecular weight (m).

[0032] [High-Temperature Salt Resistance Test] <Preparation of Brine Test Sample> After placing a magnetic stirrer in a 200 mL polystyrene bottle, the composition prepared in the Example or Comparative Example, pure water, and a brine solution with a salt concentration of 6% by mass were added in this order while stirring with the magnetic stirrer, so that the silica concentration derived from the composition was 0.5% by mass and the salt concentration was 4% by mass, and the mixture was stirred for 1 hour. This was used as a brine test sample to evaluate the heat resistance and high-temperature salt resistance when the silica dispersion was adjusted to a silica concentration of 0.5% by mass under a salt concentration of 4% by mass. The pH, electrical conductivity, and DLS average particle size of the aqueous silica sol (silica particles) in the sample were evaluated for the obtained brine test sample.

[0033] <Evaluation of High-Temperature Salt Resistance> 65 g of the brine test sample was placed in a 120 mL sealable Teflon (registered trademark) container, sealed, and then the Teflon (registered trademark) container was placed in a dryer at 100°C. After being held at 100°C for a predetermined time (10 hours), the container was cooled to room temperature (approximately 20°C), and the brine test sample's appearance, pH, electrical conductivity, and DLS average particle size of the aqueous silica sol (silica particles) in the sample were evaluated. The high-temperature salt resistance was evaluated by determining the high-temperature salt resistance (see <Determination of High-Temperature Salt Resistance> below) based on the measurement results of the DLS average particle size of the aqueous silica sol (silica particles) in the sample held at 100°C for a predetermined time (10 hours) and cooled to room temperature (approximately 20°C), as well as by evaluating the appearance.

[0034] <Judgment of high-temperature salt resistance> A: The ratio of the DLS average particle size after the high-temperature salt resistance test to the DLS average particle size before the test was 1.1 or less. B: The ratio of the DLS average particle size after the high-temperature salt resistance test to the DLS average particle size before the test was more than 1.1 and 1.5 or less. C: The ratio of the DLS average particle size after the high-temperature salt resistance test to the DLS average particle size before the test was more than 1.5 and 2.4 or less. D: The ratio of the DLS average particle size after the high-temperature salt resistance test to the DLS average particle size before the test was more than 2.4 and 20.0 or less. E: The ratio of the DLS average particle size after the high-temperature salt resistance test to the DLS average particle size before the test was more than 20.0 or the product was cloudy and solid-liquid separation occurred. The high-temperature salt resistance test result indicated that A was the most favorable, followed by B, C, D, and E in that order.

[0035] (Evaluation of the amount of polyorganosiloxane surface coating) <Removal of unbound polyorganosiloxane and organic solvent> 2 g of a composition containing silica particles and 4 g of pure water were placed in a 15 ml centrifugal filter unit (trade name: Amicon Ultra-15, Merck Ltd.), and centrifuged for 20 minutes at a centrifugal force of 2770 G. After centrifugation, the liquid discharged to the bottom of the unit was discarded, and the same mass of pure water as the discarded liquid was added to the concentrated composition on the filter to redisperse it, and then centrifuged again for 20 minutes at a rotation speed of 2770 G. The process after the centrifugation described above was repeated a total of four times to obtain polyorganosiloxane-coated silica particles from which unbound polyorganosiloxane and organic solvent had been removed.

[0036] <Measurement of carbon content> The polyorganosiloxane-coated silica particles from which unbonded polyorganosiloxane and organic solvent had been removed were heated and dried at 100 ° C. and pulverized in a mortar to obtain silica powder. The carbon content of the obtained silica powder was measured using an organic trace element metal analyzer, and the surface coating amount was calculated from the obtained carbon content using the following formula.

[0037] The present invention will be described in further detail below based on synthesis examples, examples, and comparative examples, but it should be understood that the present invention is not limited to these examples in any way.

[0038] <Measurement Apparatus> The physical property analysis of the compositions prepared in the Examples and Comparative Examples and the brine test sample described below was carried out using the following apparatuses. Retention time: FFF (product name: FFF System, manufactured by PostNova) and MALS (multi-angle light scattering detector, product name: Dawn Heleos II, manufactured by Wyatt Technology) were used. Electrical mobility: A capillary electrophoresis system (product name: Agilent 7100 Capillary Electrophoresis System, manufactured by Agilent Technologies, Inc.) was used. DLS average particle size (dynamic light scattering particle size): A dynamic light scattering particle size measurement device (product name: Zetasizer Nano, manufactured by the Malvern Division of Spectris Co., Ltd.) was used. pH: A pH meter (manufactured by DKK-TOA Corporation) was used. Electrical conductivity: An electrical conductivity meter (manufactured by DKK-TOA Corporation) was used. Viscosity: A BMII viscometer (manufactured by Tokyo Keiki Co., Ltd.) was used. - Surface coating amount: An organic trace element analyzer (trade name CHNS / O Analyzer, manufactured by PerkinElmer Japan Co., Ltd.) or a TN measuring device (trade name TN-2100V Total Nitrogen Analyzer, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used. - Si-NMR: A trade name Advanced Neo (manufactured by Bruker Corporation) was used. - Nitrogen gas adsorption amount: A trade name Monosorb (manufactured by Quantachrome Instruments) was used. - Polyorganosiloxane molecular weight: A mass spectrometer (trade name Orbitrap Fusion, manufactured by Thermo Fisher Scientific) was used.

[0039] <Preparation of Composition> (Comparative Example 1) 1000 g of aqueous silica sol (Snowtex (trade name) ST-O, manufactured by Nissan Chemical Industries, Ltd., silica concentration = 20.5 mass%, BET average particle size 11.7 nm, DLS average particle size 18.6 nm) and a magnetic stirrer were placed in a 2000 mL glass recovery flask, and the number of silicon atoms in the polyorganosiloxane was adjusted to 0.5 / nm with respect to the surface area of ​​the silica particles (also referred to as silica) in the aqueous silica sol while stirring with the magnetic stirrer. ２9.4 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Evonik, trade name Dynasilane GLYMO, hereinafter also referred to as "GPS") was added so that the pH was 0.05. Next, a cooling pipe through which tap water was flowing was installed at the top of the recovery flask, and the mixture of aqueous silica sol and GPS was heated to 60°C while refluxing. The mixture was held at 60°C for 4 hours, including the time required for heating, and then cooled. After cooling to room temperature, the mixture was removed, and 1009.4 g of a composition containing silica particles surface-treated with polyorganosiloxane was obtained. Note that the pH was measured before heating and was found to be in the range of 1 to 7, so the pH was not adjusted and the next step was carried out. The same applies to Examples 1 to 6. The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Comparative Example 1 were evaluated. The retention time of the composition of Comparative Example 1 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Comparative Example 1 was evaluated according to <Evaluation of Electrical Mobility>. The molecular weight of the polyorganosiloxane in the composition of Comparative Example 1 was evaluated according to <Evaluation of Polyorganosiloxane Molecular Weight>. A brine test sample was prepared according to <Preparation of Brine Test Sample>, and the high-temperature salt resistance of the sample was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0040] Example 1 The number of silicon atoms in the polyorganosiloxane was 2.0 / nm relative to the surface area of ​​silica in the aqueous silica sol (Nissan Chemical Industries, Ltd., Snowtex (trade name) ST-O, average particle size by BET method: 11.7 nm, average particle size by DLS: 18.6 nm). ２The same procedure as in Comparative Example 1 was repeated, except that 37.4 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Evonik, trade name Dynasilan GLYMO) was added so that the total mass of the mixture was 1037.4 g, and the mixture was heated to 60°C and filtered through a filter (trade name Bolding Cross Nylon Mesh N-No. 460S). The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Example 1 were evaluated. The retention time of the composition of Example 1 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Example 1 was evaluated according to <Evaluation of Electrical Mobility>. The polyorganosiloxane molecular weight in the composition of Example 1 was evaluated according to (Evaluation of Polyorganosiloxane Molecular Weight). Brine test samples were prepared according to <Preparation of Brine Test Samples>, and the high-temperature salt resistance of the samples was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0041] Example 2 The number of silicon atoms in the polyorganosiloxane was 4.0 / nm relative to the surface area of ​​silica in the aqueous silica sol (Snowtex (trade name) ST-O, manufactured by Nissan Chemical Industries, Ltd., average particle size by BET method: 11.7 nm, average particle size by DLS: 18.6 nm). ２ The same procedure as in Comparative Example 1 was repeated to obtain 1,074.8 g of a composition of Example 2, except that 74.8 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Evonik, trade name: Dynasilan GLYMO) was added so that the temperature became 70°C, and the resulting mixture was heated to 60°C and filtered through a filter (trade name: Bolding Cross Nylon Mesh N-No. 460S). The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Example 2 were evaluated. The retention time of the composition of Example 2 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Example 2 was evaluated according to <Evaluation of Electrical Mobility>. Brine test samples were prepared according to <Preparation of Brine Test Samples>, and the high-temperature salt resistance of the samples was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0042] Example 3 The number of silicon atoms in the polyorganosiloxane was 8.0 / nm relative to the surface area of ​​silica in the aqueous silica sol (Snowtex (trade name) ST-O, manufactured by Nissan Chemical Industries, Ltd., average particle size by BET method: 11.7 nm, average particle size by DLS: 18.6 nm). ２ The same procedure as in Comparative Example 1 was repeated to obtain 1,149.7 g of a composition of Example 3. The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Example 3 were evaluated. The retention time of the composition of Example 3 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Example 3 was evaluated according to <Evaluation of Electrical Mobility>. The polyorganosiloxane molecular weight in the composition of Example 3 was evaluated according to (Evaluation of Polyorganosiloxane Molecular Weight). Brine test samples were prepared according to <Preparation of Brine Test Samples>, and the high-temperature salt resistance of the samples was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0043] Example 4 The number of silicon atoms in the polyorganosiloxane was 30.8 / nm relative to the surface area of ​​silica in the aqueous silica sol (Nissan Chemical Industries, Ltd., Snowtex (trade name) ST-O, BET average particle size 11.7 nm, DLS average particle size 18.6 nm). ２ The same procedure as in Comparative Example 1 was repeated, except that 576.2 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Evonik, trade name: Dynasilan GLYMO) was added so that the viscosity became 100% by mass, and the mixture was heated at 60°C and filtered through a filter (trade name: Bolding Cross Nylon Mesh N-No. 460S), to obtain 1,576.2 g of the composition of Example 4. The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Example 4 were evaluated. The retention time of the composition of Example 4 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Example 4 was evaluated according to <Evaluation of Electrical Mobility>. Brine test samples were prepared according to <Preparation of Brine Test Samples>, and the high-temperature salt resistance of the samples was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0044] Example 5 The number of silicon atoms in the polyorganosiloxane was 46.2 / nm relative to the surface area of ​​silica in the aqueous silica sol (Snowtex (trade name) ST-O, manufactured by Nissan Chemical Industries, Ltd., average particle size by BET method: 11.7 nm, average particle size by DLS: 18.6 nm). ２ The same procedure as in Comparative Example 1 was repeated to obtain 1,864.4 g of a composition of Example 5, except that 864.4 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Evonik, trade name: Dynasilan GLYMO) was added so that the solution became 100% by mass, and the mixture was heated at 60°C and filtered through a filter (trade name: Bolding Cross Nylon Mesh N-No. 460S). The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Example 5 were evaluated. The retention time of the composition of Example 5 was evaluated according to <Evaluation of Retention Time>. The electrical mobility of the composition of Example 5 was evaluated according to <Evaluation of Electrical Mobility>. A brine test sample was prepared according to <Preparation of Brine Test Sample>, and the high-temperature salt resistance of the sample was evaluated according to <Evaluation of High-Temperature Salt Resistance>.

[0045] (Comparative Example 2) An aqueous silica sol (Snowtex (trade name) ST-O, manufactured by Nissan Chemical Industries, Ltd.) was used as the composition (aqueous silica sol) of Comparative Example 2. The pH, electrical conductivity, viscosity, and DLS average particle size of the composition of Comparative Example 2 were evaluated. The retention time of the composition of Comparative Example 2 was evaluated according to <Evaluation of retention time>. The electrical mobility of the composition of Comparative Example 2 was evaluated according to <Evaluation of electrical mobility>. A brine test sample was prepared according to <Preparation of brine test sample>, and the room temperature salt resistance of the sample was evaluated according to <Evaluation of high-temperature salt resistance>.

[0046] Tables 1 and 2 show the compositions (component concentrations), polyorganosiloxane molecular weights, and salt resistance test results for the compositions of the examples and comparative examples, while Table 3 shows the evaluation results of the retention time and electrical mobility for the compositions of the examples and comparative examples. Figures 1 and 2 show the evaluation results of the retention time and electrical mobility for the compositions of the examples and comparative examples. Figure 3 shows the measurement results of the molecular weight of the polyorganosiloxane contained in the compositions of the examples. Figures 4 to 6 show the measurement results of the particle size distribution of silica particles in the compositions of Examples 1 to 3.

[0047]

[0048] In the CE chart corrected with the standard substance, the electrical mobility of the composition obtained from the apex position (maximum value) of the peak derived from the composition of the example was −0.0200 (cm ２ / V·min) or more. The upper limit is 0 (cm ２ / V·min) or less, and ２ / V·min) or less, and ２ The molecular weight of the polyorganosiloxane calculated from the maximum peak shown in Table 3 is preferably in the range of 400 to 4000, more preferably in the range of 400 to 3000, and even more preferably in the range of 400 to 2000.

[0049] <Compatibility Test with Resin> 50 g of the composition of Example 3 or the aqueous silica sol of Comparative Example 2 was weighed into a 120 ml polystyrene bottle. 50 g of an acrylic resin emulsion (manufactured by DIC Corporation, product name: Boncoat 40-418EF) or an ethylene-vinyl acetate-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtech Co., Ltd., product name: Sumikaflex 830) was added thereto, and the mixture was hand-shaken for 30 seconds to obtain a homogeneous resin emulsion composition (no visual phase separation). The stability of the resin emulsion composition was evaluated by comparing the viscosity at the initial stage of mixing with that after 48 hours at 20°C. A ratio of (viscosity after 48 hours at 20°C) / (viscosity at the initial stage of mixing) of 0.8 to 20, 0.8 to 10, or 0.8 to 5 indicated good stability. A ratio of less than 0.8, more than 20, or gelation of the composition indicated poor stability.

[0050] The viscosity measurement results of the resin emulsion compositions are shown in Table 4. The aqueous sol of Comparative Example 2 was incompatible with any of the resin emulsions and gelled immediately after mixing, resulting in an unstable resin emulsion composition. On the other hand, the composition of Example 3 was found to be a stable resin emulsion composition that did not gel immediately after mixing with any of the resin emulsions and did not increase in viscosity even after 48 hours.

[0051]

[0052] Table 5 shows the measurement results of the particle size distribution (D90 - D50) / (D50 - D10) of the silica particles in the compositions of Examples 1 to 5. The compositions of Examples 1 to 5 had a (D90 - D50) / (D50 - D10) ratio of 0.6 to 2.5, and contained silica particles with a good particle size distribution, and were thus able to be obtained as compositions with high storage stability in which floating of fine particles and settling of coarse particles were unlikely to occur.

[0053]

Claims

1. A composition comprising silica particles, polyorganosiloxane, and a solvent, wherein the solution from which the silica particles have been removed from the composition is diluted 10-fold with an eluent of water / acetonitrile = 1 / 1, and the sample is continuously introduced (infusion measurement) into a mass spectrometer in ESI ionization positive mode under conditions of a capillary temperature of 275 ° C, a desolvation temperature of 150 ° C, and a flow rate of 30 μL / min, and the molecular weight of the polyorganosiloxane calculated from the maximum peak is in the range of 400 to 4000, and the composition is diluted with pure water to a silica concentration of 2 mass%, and the components of the solution are separated by the flow in the channel at a temperature of 20 ° C., and the retention time (t Ｒ In FFF-MALS, which measures retention time (t Ｒ ) is 9.5 min to 25.0 min.

2. The composition according to claim 1, wherein the silica particles have an average primary particle size of 5 to 100 nm.

3. The composition according to claim 1, wherein the silica particles have an average particle size of 5 to 200 nm as measured by dynamic light scattering.

4. The composition according to claim 1, wherein the silica particles are at least partially coated with a silane compound having an organic group, and the organic group is a hydrocarbon group-containing organic group, an epoxy group-containing organic group, a glycidoxy group-containing organic group, an amino group-containing organic group, a hydroxyl group-containing organic group, an acryloyl group-containing organic group, or a carboxyl group-containing organic group.

5. The composition according to claim 1, wherein the polyorganosiloxane is contained in a product obtained by heating a silane compound having an organic group in an acidic liquid.

6. A measurement sample containing standard substances of N-methylpyrrolidone (NMP) and terephthalic acid, the composition, and an electrophoretic solution is injected into a capillary having both ends applied with a voltage of 30 kV under the condition of 50 mbar for 6 seconds, the electrophoretic time is measured using a detector with a UV absorption wavelength set to 195 nm ± 5 nm, the uncorrected electric mobility defined by formula (2) is calculated, and the electric mobility of the composition obtained from the apex position of the peak derived from the composition in a CE chart corrected with the standard substances based on the calculated uncorrected electric mobility is -0.0200 (cm ２ The composition according to claim 1, wherein μ=(L / V·min) or more. ｅｆｆ ×L ｔｏｔ ) / V × (1 / t ｅｐ -1 / t ｅｏ In formula (2), μ is the uncorrected electrical mobility (cm ２ / V min), L ｅｆｆ represents the effective length of the capillary (104 cm), L ｔｏｔ represents the total length of the capillary (112.5 cm), and t ｅｐ represents the migration time of the composition (min), t ｅｏ represents the migration time (min) of the uncharged standard substance (NMP), and V represents the voltage (V).

7. The composition of claim 1, wherein the solvent comprises water or salt water.

8. The composition of claim 1, wherein the solvent comprises methanol or ethanol.

9. The composition according to claim 1, wherein in a high-temperature salt resistance test in which the composition is stored at 100°C for 10 hours in an environment with a salt concentration of 3% by mass or more and a silica concentration of 0.5% by mass, the ratio expressed as DLS average particle size after the high-temperature salt resistance test / DLS average particle size before the test is 1.5 or less.

10. The composition according to claim 1, wherein when the solution from which silica particles have been removed from the composition is diluted 10-fold with an eluent of water / acetonitrile = 1 / 1, and the resulting sample is continuously introduced (infusion measurement) into a mass spectrometer in ESI ionization positive mode under conditions of a capillary temperature of 275°C, a desolvation temperature of 150°C, and a flow rate of 30 μL / min, the composition has a mass distribution having at least one peak derived from a singly or doubly charged ion in the range of 400 to 1800 m / z.

11. A method for producing the composition according to claim 4, comprising heating a mixture containing silica particles and a silane compound having an organic group to 10 to 150°C with stirring to obtain a composition containing silica particles, at least a portion of which is coated with a silane compound having an organic group, and polyorganosiloxane.