A dispersion of organic solvent containing colloidal silica particles and zinc cyanurate particles, and a method for producing the same.

Abstract

[Problem] To provide an organic solvent dispersion comprising dispersion particles, which include colloidal silica particles and zinc cyanurate particles, dispersed in an organic solvent in a manner with high dispersion stability, and a production method thereof. [Solution] This production method of an organic solvent dispersion comprising dispersion particles, which include colloidal silica particles and zinc cyanurate particles, dispersed in an organic solvent, involves a dispersion step in which silica particles, zinc cyanurate particles and an organic solvent are mixed and the dispersion particles, which include colloidal silica particles and zinc cyanurate particles, are dispersed in the organic solvent. In this production method of an organic solvent dispersion comprising dispersion particles, which include colloidal silica particles and zinc cyanurate particles, dispersed in an organic solvent, alkoxy groups represented in general formula (1) are bonded to at least part of the surface of said dispersion particles. (In the formula, R1 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-methoxyethyl group, a 1-methoxy-2-propyl group, a 1-ethoxy-2-propyl group, or a phenyl group.)

Description

[Technical Field]

[0001] This invention relates to an organic solvent dispersion in which dispersible particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, and to a method for producing the same. [Background technology]

[0002] Zinc cyanurate is known as a corrosion inhibitor for metal surfaces of ferrous metals, and various methods for producing it have been disclosed. For example, Patent Document 1 discloses a method for producing lead cyanurate and zinc, which are known as corrosion-preventive protective agents for metal surfaces, in which PbO or ZnO and cyanuric acid are mixed into a paste at 100°C to 180°C, and the resulting paste is subjected to a shearing action at 50°C to 250°C. Furthermore, Patent Document 2 discloses a corrosion-preventive coating material for metal surfaces based on zinc salts and / or lead salts of organic compounds, such as barbituric acid and cyanuric acid, which uses zinc salts and / or lead salts of organic compounds. Furthermore, Patent Document 3 describes a particle with an average particle diameter D50 of 80 nm to 900 nm, measured by laser diffraction, and a specific surface area of ​​20 m². 2 / g~100m 2 A method for producing needle-shaped or plate-shaped basic zinc cyanurate particles, characterized by having a density of / g and a ratio of the length of the long axis to the short axis (axial ratio) of 5 to 25, is disclosed by wet dispersion of a mixed slurry containing zinc oxide or basic zinc carbonate, cyanuric acid, and water. Furthermore, Patent Document 4 discloses a method for producing basic zinc cyanurate powder by heating a mixed powder consisting of zinc oxide, cyanuric acid, and water under sealed or open conditions, and also discloses a rust-preventive pigment composition containing this basic zinc cyanurate powder. Furthermore, Patent Document 5 discloses an aqueous dispersion containing colloidal silica particles and zinc cyanurate particles as dispersed particles, a method for producing the same, and a coating composition with a resin emulsion. Furthermore, Patent Document 6 discloses a paint composition in which a dispersion of zinc cyanurate particles and inorganic oxide particles is used as a paint additive and blended with a resin emulsion. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 59-031779 [Patent Document 2] Japanese Patent Application Laid-open No. 54-123145 [Patent Document 3] International Publication No. 2011 / 162353 [Patent Document 4] International Publication No. 2016 / 006585 [Patent Document 5] International Publication No. 2019 / 181966 [Patent Document 6] International Publication No. 2021 / 054471 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] While zinc cyanurate has long been known to provide high corrosion protection to metal surfaces, the zinc cyanurate obtained by the above manufacturing method has needle-shaped or plate-shaped particles and a relatively large particle size. When attempting to disperse it in an organic solvent, it forms a non-uniform slurry, making handling difficult. Furthermore, while the stability of the coating composition tends to improve when a dispersion containing colloidal silica particles and zinc cyanurate particles is formed, the long-term storage stability of the dispersion itself has not been investigated. By using a dispersion of zinc cyanurate particles and inorganic oxide particles as paint additives and combining it with a resin emulsion to create a paint composition, it is possible to form a highly adhesive coating film. However, for organic solvent-based paint compositions, further improvements in handling properties were required.

[0005] The present invention has been made in view of the above circumstances, and aims to provide an organic solvent dispersion in which dispersible particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent in a manner having high dispersion stability, and a method for producing the same. [Means for solving the problem]

[0006] The inventors of the present invention conducted diligent research to solve the above problems and found that by mixing silica particles, zinc cyanurate particles, and an organic solvent, and performing a dispersion step in which the dispersed particles containing silica particles and zinc cyanurate particles are dispersed in the organic solvent, the particle size distribution of the dispersed particles becomes narrower, and an organic solvent dispersion with high dispersion stability can be obtained. Furthermore, they found that by bonding alkoxy groups to at least a portion of the surface of the dispersed particles, high dispersion stability in organic solvents is also achieved, thus completing the present invention.

[0007] In other words, the present invention, in first view, is an organic solvent dispersion in which disperse particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, This invention relates to an organic solvent dispersion in which an alkoxy group represented by general formula (1) is bonded to at least a portion of the surface of the dispersed particles. [ka] (In the formula, R1 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-methoxyethyl group, a 1-methoxy-2-propyl group, a 1-ethoxy-2-propyl group, or a phenyl group.) The second aspect relates to the organic solvent dispersion described in the first aspect, wherein the alkoxy groups are bound to colloidal silica particles contained in the dispersed particles, and are bound at a rate of 0.01 to 10.0 groups per unit surface area of ​​the colloidal silica particles. The third aspect relates to the organic solvent dispersion according to the first or second aspect, wherein the amount of water contained in the dispersion in which the dispersed particles are dispersed in an organic solvent is 5% by mass or less. The fourth aspect relates to an organic solvent dispersion according to any one of the first to third aspects, wherein the organic solvent is at least one or more selected from the group consisting of alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds. The fifth aspect relates to an organic solvent dispersion according to any one of the first to fourth aspects, wherein the dispersed particles containing the colloidal silica particles and zinc cyanurate particles satisfy the following conditions (a) and (b). (a) The average particle size obtained by laser diffraction is 50 nm to 100 nm, (b) In particle size distribution measurement by laser diffraction, if the particle sizes at which the cumulative frequency reaches 10%, 50%, and 90% are D10, D50, and D90, respectively, then D50 / D10 is 1.10 or greater and less than 1.60, and D90 / D50 is 1.10 or greater and less than 1.60. The sixth aspect relates to a method for producing an organic solvent dispersion in which dispersible particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, comprising a dispersion step of mixing silica particles, zinc cyanurate particles, and an organic solvent, and dispersing the dispersed particles containing silica particles and zinc cyanurate particles in the organic solvent. The seventh aspect relates to a method for producing an organic solvent dispersion as described in the sixth aspect, wherein the mixture of silica particles, zinc cyanurate particles, and an organic solvent is a mixture of silica sol and zinc cyanurate particles using an organic solvent as a dispersion medium. The eighth aspect relates to a method for producing the organic solvent dispersion described in the seventh aspect, wherein the water content of the silica sol is 5% by mass or less. The ninth aspect relates to a method for producing an organic solvent dispersion according to the seventh or eighth aspect, wherein the dispersion medium for the silica sol is at least one or more selected from the group consisting of alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds. As a tenth aspect, the present invention relates to a method for producing an organic solvent dispersion liquid according to any one of the seventh to ninth aspects, wherein the silica sol is an alcohol-dispersed silica sol or an organic solvent-dispersed silica sol obtained by substituting the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, and the organic solvent is at least one or two or more selected from the group consisting of ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds. As an eleventh aspect, the present invention relates to a method for producing an organic solvent dispersion liquid according to any one of the seventh to tenth aspects, wherein the silica sol is an alcohol-dispersed silica sol having at least one or two or more alcohols selected from the group consisting of methanol, ethanol, propanol, butanol, isopropyl alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether as a dispersion medium, or an organic solvent-dispersed silica sol obtained by substituting the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, and the organic solvent is at least one or two or more selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, γ-butyrolactone, ethyl acetate, butyl acetate, toluene, xylene, n-pentane, n-hexane, cyclohexane, N,N-dimethylformamide, and N-methylpyrrolidone. As a twelfth aspect, the present invention relates to a method for producing an organic solvent dispersion liquid according to any one of the sixth to eleventh aspects, wherein an alkoxy group represented by the general formula (1) is bonded to at least a part of the surface of the dispersed particles containing the colloidal silica particles and zinc cyanurate particles. [Chemical formula] (In the formula, R1 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-methoxyethyl group, a 1-methoxy-2-propyl group, a 1-ethoxy-2-propyl group, or a phenyl group.) From the 13th perspective, it relates to the method for producing an organic solvent dispersion liquid according to the 12th perspective, in which the alkoxy group is bonded to colloidal silica particles contained in the dispersed particles, and is bonded at a ratio of 0.01 to 10.0 per unit surface area of the colloidal silica particles. From the 14th perspective, it relates to the method for producing an organic solvent dispersion liquid according to any one of the 6th to 13th perspectives, in which the dispersed particles containing colloidal silica particles and zinc cyanurate particles obtained by the dispersion step satisfy the following (a) and (b). (a) The average particle diameter by the laser diffraction method is 50 nm to 100 nm, (b) In the measurement of the particle size distribution by the laser diffraction method, when the particle diameters at which the frequency integration becomes 10%, 50%, and 90% are D10, D50, and D90 respectively, D50 / D10 is 1.10 or more and less than 1.60, and D90 / D50 is 1.10 or more and less than 1.60. From the 15th perspective, it relates to the method for producing an organic solvent dispersion liquid according to the 9th perspective, in which the dispersion medium of the silica sol is at least one or two or more selected from the group consisting of methanol, ethanol, propanol, butanol, isopropyl alcohol, methyl ethyl ketone, and methyl isobutyl ketone. From the 16th perspective, it relates to the method for producing an organic solvent dispersion liquid according to any one of the 6th to 15th perspectives, in which the average primary particle diameter of the silica particles is 5 nm to 500 nm. From the 17th perspective, it relates to the method for producing an organic solvent dispersion liquid according to any one of the 6th to 16th perspectives, in which the average length of the long axis of the zinc cyanurate particles by transmission electron microscope observation is 50 nm to 1000 nm, and the average length of the short axis is 10 nm to 300 nm, and the ratio of the length of the long axis to the short axis is 2 to 25. From the 18th perspective, it relates to the method for producing an organic solvent dispersion liquid according to any one of the 6th to 17th perspectives, in which in the dispersion step, the silica particles and the zinc cyanurate particles are dispersed at a mass ratio of 1:0.01 to 100. The 19th aspect relates to a method for producing an organic solvent dispersion according to any one of the 6th to 18th aspects, wherein in the dispersion step, the total solid content of colloidal silica particles and zinc cyanurate particles is 0.1% by mass to 50% by mass. The 20th aspect relates to a method for producing an organic solvent dispersion according to any one of the 6th to 19th aspects, wherein the dispersion step is carried out in a liquid-based disperser. The 21st aspect relates to a method for producing an organic solvent dispersion according to the 20th aspect, wherein the liquid dispersion machine is a high-speed rotary shear type stirrer, a colloidal mill, a high-pressure jet type disperser, an ultrasonic disperser, a container-driven mill, or a media stirring mill. The 22nd aspect relates to a method for producing an organic solvent dispersion according to the 21st aspect, wherein the media stirring mill is of the circulating or batch type. [Effects of the Invention]

[0008] The manufacturing method of the present invention allows for the production of an organic solvent dispersion in which dispersed particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent in a state of high dispersion stability, without the formation of precipitates even when left for a long period of time. Furthermore, the organic solvent dispersion obtained by this manufacturing method has the effect of being easy to handle when manufacturing compositions such as paints. In addition, since the zinc cyanurate particles are uniformly dispersed in the composition and coating film, it is expected that the corrosion-preventive and other functions inherent to zinc cyanurate will be fully exhibited. Furthermore, the organic solvent dispersion of the present invention maintains high dispersion stability even in organic solvents because alkoxy groups are bonded to at least a portion of the surface of the dispersed particles, resulting in the effect of preventing the formation of precipitates even when left standing for a long period of time. [Modes for carrying out the invention]

[0009] The present invention relates to a method for producing an organic solvent dispersion in which dispersible particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, comprising a dispersion step of mixing silica particles, zinc cyanurate particles, and an organic solvent to disperse the dispersed particles containing silica particles and zinc cyanurate particles in the organic solvent. The present invention also relates to an organic solvent dispersion in which an alkoxy group represented by the general formula (1) is bonded to at least a part of the surface of the dispersed particles including colloidal silica particles and zinc cyanurate particles.

[0010] The silica particles can be used in any form, such as silica powder or silica sol with an organic solvent as a dispersion medium. Here, the silica powder refers to a powder of SiO2, which can be produced by known methods, such as liquid phase methods (hydrolysis method, sol-gel method, hydrothermal method, coprecipitation method, freeze drying method, etc.), gas phase methods (melting method, spray drying method, gas phase reaction method (combustion hydrolysis, etc.), etc.). In addition, colloidal silica particles can be produced by known methods (for example, ion exchange method, peptization method, hydrolysis method, reaction method, etc.) and dried for use.

[0011] The silica powder can have, for example, a specific surface area of 1 m 2 / g to 800 m 2 / g, and examples include powders having a specific surface area of 10 m 2 / g to 700 m 2 / g, 30 m 2 / g to 500 m 2 / g, 40 m 2 / g to 300 m 2 / g.

[0012] Commercially available silica powders can be used, and examples include, but are not limited to, the following. For example, AEROSIL (registered trademark) series manufactured by Nippon Aerosil Co., Ltd., Cab-O-SIL (registered trademark) series manufactured by Cabot Corporation, Sylysia (registered trademark) series manufactured by Fuji Silysia Chemical Ltd., Rheolosil (registered trademark) series manufactured by Tokuyama Corporation, Excellica (registered trademark) series, HDK (registered trademark) series manufactured by Asahi Kasei Wacker Silicone Co., Ltd., etc.

[0013] Silica sols using organic solvents as dispersion media can be used in the form of organic solvent dispersion sols in which colloidal silica particles are dispersed in an organic solvent. Silica sols can be prepared by replacing the organic solvent in a water-dispersed silica sol, produced by known methods (e.g., ion exchange, papular lysis, hydrolysis, reaction (oxidation)), with an organic solvent using evaporation methods such as a rotary evaporator. Alternatively, silica powder can be dispersed in an organic solvent to produce an organic solvent dispersion sol. The silica sol can be used with a water content of 5% by mass or less, 3% by mass or less, or 2% by mass or less.

[0014] The silica sol can be in the range of 0.1% to 50% by mass, 1.0% to 40% by mass, or 5.0% to 40% by mass.

[0015] As the dispersion medium for silica sol, at least one or more organic solvents selected from the group consisting of alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds can be used. Examples of these organic solvents include alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and γ-butyl lactone; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; esters such as ethyl acetate and butyl acetate; hydrocarbons such as toluene, xylene, n-pentane, n-hexane, and cyclohexane; and nitrogen-containing organic compounds such as N,N-dimethylformamide and N-methylpyrrolidone. These may be used individually or in combination of two or more. Furthermore, the organic solvent used in the above dispersion step and the organic solvent used as the dispersion medium for the silica sol may be the same or different.

[0016] The silica sol is an alcohol-dispersed silica sol, or an organic solvent-dispersed silica sol obtained by replacing the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, wherein the organic solvent is a ketone, an ether, an ester, a hydrocarbon, or a nitrogen-containing organic compound.

[0017] The aforementioned alcohol-dispersed silica sol is an alcohol-dispersed sol using methanol, ethanol, propanol, butanol, isopropyl alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether as the dispersion medium.

[0018] The organic solvent-dispersed silica sol obtained by replacing the dispersion medium of the alcohol-dispersed silica sol with an organic solvent is an organic solvent-dispersed sol using methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, γ-butyl lactone, ethyl acetate, butyl acetate, toluene, xylene, n-pentane, n-hexane, cyclohexane, N,N-dimethylformamide, and N-methylpyrrolidone as the dispersion medium.

[0019] The dispersed particles, comprising the alcohol-dispersed silica sol, or the organic solvent-dispersed silica sol obtained by replacing the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, and zinc cyanurate particles, have an alkoxy group represented by general formula (1) bonded to at least a portion of their surface. [ka] (In the formula, R1 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-methoxyethyl group, a 1-methoxy-2-propyl group, a 1-ethoxy-2-propyl group, or a phenyl group.)

[0020] The aforementioned alkoxy group is formed by the reversible reaction of silanol groups (Si-OH groups) on the surface of colloidal silica particles with alcohols. For example, when R1 is a methyl group, it is formed by the reversible reaction of silanol groups on the surface of colloidal silica particles with methanol. The alkoxy group is preferably such that R1 is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a 1-methoxy-2-propyl group. By having such alkoxy groups bonded to at least a portion of the surface of the colloidal silica particles, the dispersed particles containing the colloidal silica particles and zinc cyanurate particles exhibit good dispersion stability in organic solvents, and the formation of precipitates can be suppressed even during long-term storage.

[0021] The amount of alkoxy groups bonded to the surface of colloidal silica particles is determined by the unit surface area (nm) of the colloidal silica particles. 2 The number is 0.05 to 10.0 per ) unit. Preferably, it is 0.05 to 7.0 units, or 0.1 to 7.0 units. The amount of alkoxy groups bound to the surface of colloidal silica particles can be determined by gas chromatography or other methods. The surface area of ​​the colloidal silica particles can be measured by nitrogen gas adsorption (BET) method.

[0022] The average primary particle size of colloidal silica particles contained in silica sol can be measured by nitrogen gas adsorption (BET) method. B The specific surface area (nm) is measured by the BET method. 2 / g to, (D B This is the primary particle diameter calculated using the formula nm) = 2720 / S, and represents the particle diameter converted to spherical silica particles. This value falls within the range of an average particle diameter of 5 nm to 500 nm, or 5 nm to 200 nm, or 5 nm to 100 nm.

[0023] Furthermore, at least a portion of the surface of the colloidal silica particles contained in the silica sol may be modified with an organosilicon compound or its hydrolysate. Surface modification with an organosilicon compound makes the colloidal surface hydrophobic, which improves its dispersibility in water-insoluble organic solvents. The particles, for example, have a structure in which the organosilicon compound is bonded to the hydroxyl groups on the surface of the colloidal silica particles.

[0024] The organosilicon compounds used can be known organosilicon compounds or silane compounds known as silane coupling agents, and the type can be appropriately selected depending on the application and the type of solvent. Specific examples of the above silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethylditriethoxysilane, 3-glycidoxypropyltriethoxysilane, p-vinylphenyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyl Examples include methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-[methoxy-poly(ethyleneoxy)propyl]trimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, and 3-isocyanatepropyltriethoxysilane. Specific examples of the above-mentioned silanes include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, and hexamethyldisilazane.

[0025] A silica sol dispersed in an organic solvent can be a commercially available product, and examples include, but are not limited to, the following. For example, you can use OrganoSilicaSol, manufactured by Nissan Chemical Corporation, under the trade name OrganoSilicaSol.

[0026] Zinc cyanurate particles can be used that have a needle-like or plate-like elongated particle shape, and have a molar ratio of (zinc oxide) / (cyanuric acid) of 1.0 to 5.0. These zinc cyanurate particles can be manufactured by two methods: a liquid-phase reaction method in which the raw materials are dispersed in water in a slurry state, and a solid-phase reaction method in which the raw materials are in a powder state. For example, in the solid-phase reaction method, the above-mentioned zinc cyanurate particles can be manufactured by heat-treating a mixed powder consisting of zinc oxide, cyanuric acid, and water, with a sieve residue of less than 1% by mass on a mesh size of 1,000 μm, a molar ratio of zinc oxide to cyanuric acid of 2 to 3, and a water content of 9% to 18% by mass of the mixed powder, in a sealed or open state at 30°C to 300°C.

[0027] The average length of the major and minor axes of the primary particles of the zinc cyanurate particles described above can be measured by transmission electron microscopy. The average length of the major axis of the primary particles can be 50 nm to 1000 nm, 100 nm to 800 nm, or 200 nm to 700 nm, and the average length of the minor axis can be 10 nm to 300 nm, 30 nm to 200 nm, or 30 nm to 100 nm. The ratio of the length of the major axis to the length of the minor axis (major axis / minor axis) can be 2 to 25, 2 to 10, or 2 to 5.

[0028] Furthermore, zinc cyanurate particles can be dispersed in pure water, either the particles themselves or a dispersion containing them. The average particle size of the zinc cyanurate particles in the aqueous dispersion can then be measured using a laser diffraction particle size distribution analyzer (for example, Shimadzu Corporation, product name SALD-7500nano). The average particle size measured by the laser diffraction method can be 100 nm to 5000 nm, 500 nm to 3000 nm, or 800 nm to 3000 nm.

[0029] Furthermore, the specific surface area of ​​zinc cyanurate particles is, for example, 10 m². 2 / g~100m 2 You can use something that is / g.

[0030] Zinc cyanurate particles can be commercially available, and examples include, but are not limited to, the following. For example, you can use Starfine, manufactured by Nissan Chemical Corporation.

[0031] Organic solvents used when mixing silica particles and zinc cyanurate particles include alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds. Examples of these solvents include alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and γ-butyl lactone; ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; esters such as ethyl acetate and butyl acetate; hydrocarbons such as toluene, xylene, n-pentane, n-hexane, and cyclohexane; and nitrogen-containing organic compounds such as N,N-dimethylformamide and N-methylpyrrolidone. These can be used individually or in combination of two or more.

[0032] When mixing silica particles, zinc cyanurate particles, and an organic solvent, the ratio of silica particles to zinc cyanurate particles by mass can be, for example, 1:0.01 to 100, 1:0.1 to 10, or 1:1 to 10.

[0033] Furthermore, the concentration of the total solid content (solid content of dispersed particles) of silica particles and zinc cyanurate particles can be, for example, 0.1% to 50% by mass, or 0.1% to 30% by mass, or 0.1% to 20% by mass, or 0.1% to 10% by mass. When using silica sol, the mass of colloidal silica particles contained in the silica sol can be used as the mass of the silica particles.

[0034] A liquid-based disperser can be used in the dispersion step of dispersing dispersed particles in an organic solvent. Liquid dispersion machines can perform operations to create a state in which a substance is dispersed in a liquid medium in particulate form, or to reduce the primary particle size of a substance in a liquid medium. Liquid dispersion machines can be classified according to the external force used to disperse aggregates, and examples include high-speed rotary shear agitators, colloidal mills, roll mills, high-pressure jet dispersers, ultrasonic dispersers, container-driven mills, and media-stirring mills. High-speed rotary shear agitators can be used in the above dispersion process by appropriately setting the agitator blades and rotation speed. Examples of container-driven mills include rotary mills, vibratory mills, and planetary mills. Examples of media-stirring mills include circulating or batch-type devices. These devices can be commercially available, and examples include, but are not limited to, the following. As media stirring mills, for example, ball mills, bead mills, and sand mills such as the Sand Grinder (manufactured by AIMEX Co., Ltd.), Apex Mill (manufactured by Hiroshima Metal & Machinery Co., Ltd. (formerly Kotobuki Kogyo Co., Ltd.)), Attrita (manufactured by Nippon Coke Industries Co., Ltd.), and Pearl Mill (manufactured by Ashizawa Fine Tech Co., Ltd.) can be used. The material and size of the dispersion media, as well as the rotation speed and reaction time of the device for stirring the dispersion media, should be adjusted as appropriate according to the type and viscosity of the organic solvent.

[0035] In the method for producing an organic solvent dispersion of the present invention, the dispersion step does not include a solvent substitution step. Therefore, for example, the method does not include a method for producing an organic solvent dispersion by substituting an organic solvent in an aqueous solvent dispersion in which dispersed particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an aqueous solvent. Furthermore, the solvent substitution step does not include, for example, a step of substituting the organic solvent in the organic solvent dispersion with another organic solvent.

[0036] Dispersed particles, obtained by a dispersion process in which dispersed particles are dispersed in an organic solvent, include colloidal silica particles and zinc cyanurate particles. These dispersed particles, or the dispersion containing these particles, can be dispersed in various solvents, and the average particle size and particle size distribution in the organic solvent can be measured using a laser diffraction particle size analyzer (for example, Shimadzu Corporation, product name SALD-7500nano).

[0037] The average particle diameter obtained by laser diffraction can be 50 nm to 1700 nm, 50 nm to 1200 nm, or 50 nm to 800 nm. Preferably, it is 50 nm to 100 nm.

[0038] In particle size distribution measurement using laser diffraction, the particle sizes at which the cumulative frequency reaches 10%, 50%, and 90% are defined as D10, D50, and D90, respectively, and each particle size is measured. From the measurement results, D50 / D10 and D90 / D50 are calculated. D50 / D10 can be 1.10 or more but less than 1.60, or 1.10 or more but less than 1.50, or 1.10 or more but less than 1.46. D90 / D50 can be 1.10 or more but less than 1.60, or 1.10 or more but less than 1.55, or 1.10 or more but less than 1.50. In this invention, by ensuring that the dispersed particles satisfy the above average particle size range and the above D50 / D10 and D90 / D50 requirements, an organic solvent dispersion with good dispersion stability can be obtained, enabling long-term storage.

[0039] In the particle size distribution measurement described above, a distribution curve can be drawn with particle size on the horizontal axis and relative particle quantity (frequency) on the vertical axis. Dispersed particles, including colloidal silica particles and zinc cyanurate particles, obtained by a dispersion process in which dispersed particles are dispersed in an organic solvent, preferably have a single peak in their distribution curve from the viewpoint of the dispersion stability of the organic solvent dispersion. Furthermore, if there is one or more peaks in the particle size region larger than the most frequent particle size (mode diameter), there is a concern that the dispersion stability of the organic solvent dispersion will decrease and that the dispersed particles will become localized in the coating film.

[0040] The amount of water contained in the dispersion of the above-mentioned dispersed particles in an organic solvent can be 5% by mass or less. Preferably, it can be 3% by mass or less, or 1% by mass or less. By keeping it within this range, an organic solvent dispersion with good dispersion stability is obtained, allowing for long-term storage.

[0041] Furthermore, surfactants may be added during the dispersion process to improve dispersibility in organic solvents. Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Examples of anionic surfactants include carboxylates, sulfonates, sulfate esters, and phosphate esters. Examples of cationic surfactants include amine salts and quaternary ammonium salts. Examples of amphoteric surfactants include carboxylates, amine acids, and betaines. Examples of nonionic surfactants include esters, ethers, and ester-ethers. [Examples]

[0042] The present invention will be described in detail with reference to the following embodiments, but the present invention is not limited to these embodiments. Silica sol and zinc cyanurate particles were prepared using the following procedure. (1) The following silica sol was prepared. • Methanol-dispersed silica sol (manufactured by Nissan Chemical Corporation, average primary particle size 12 nm, solid content 30.5% by mass, BET method) • Methyl ethyl ketone (MEK) dispersed silica sol (manufactured by Nissan Chemical Corporation, average primary particle size 12 nm, solid content 30.8% by mass, BET method) • Propylene glycol monomethyl ether (PGME) dispersed silica sol (manufactured by Nissan Chemical Corporation, average primary particle size 12 nm by BET method, solid content 30.5% by mass) • Water-dispersible silica sol (manufactured by Nissan Chemical Corporation, product name Snowtex-N40, average primary particle size 21.4 nm by BET method, solid content 40.4% by mass) (2) The following zinc cyanurate particles were prepared. • Zinc cyanurate particles: Manufactured by Nissan Chemical Corporation, trade name Starfine (registered trademark) (average particle diameter 1.7 μm measured by laser diffraction, average major axis of primary particles 400 nm to 600 nm, minor axis 50 nm to 70 nm observed by transmission electron microscope, major axis / minor axis ratio 5.7 to 12, specific surface area 15 m²) 2 (molecular ratio of 2.5 based on (zinc oxide) / (cyanuric acid) / g) (3) The pH of the organic solvent dispersion was measured by the following method. An organic solvent dispersion and pure water were mixed in equal amounts, and the pH was measured at 20°C using a pH meter (manufactured by Toa DTK Co., Ltd.). (4) The average particle size of dispersed particles in the organic solvent dispersion was measured by laser diffraction. A dispersion containing colloidal silica particles and zinc cyanurate particles was diluted with pure water and then measured using a Shimadzu Corporation SALD-7500nano. Here, the refractive index was substituted with [1.70-0.2i]. (5) The Ostwald viscosity of the organic solvent dispersion was measured according to the following method. The viscometer was measured in a constant temperature bath at 25°C using an Ostwald viscometer (manufactured by Shibata Scientific Co., Ltd.). (6) The dispersion stability (settling) of the organic solvent dispersion was evaluated according to the following method. The obtained organic solvent dispersion was placed in a 100 mL polypropylene container at a rate of 105 g, left at room temperature for 3 months, and the presence or absence of sediment at the bottom of the container was checked. If no sediment was present, the dispersion stability was evaluated as "good," and if sediment was present, the dispersion stability was evaluated as "poor." (7) The amount of water contained in the solvent of the organic solvent dispersion was measured according to the following method. The water content was measured using the Karl Fischer titration method with a Karl Fischer moisture meter (manufactured by Kyoto Electronics Manufacturing Co., Ltd.). The water content of the solvent in the aqueous dispersion was defined as 100%. (8) The amount of alkoxy groups bonded to the surface of silica particles was measured according to the following method. (8.1) Place 3 mL of silica sol dispersed in an organic solvent into a 30 mL centrifuge tube, and add 20 mL of toluene. (8.2) After centrifuging (5000 rpm x 30 minutes), remove the supernatant liquid. (8.3) Add 4 mL of acetone to redissolve the gel, then add 10 mL of toluene and 4 mL of hexane, and perform centrifugation (5000 rpm × 30 minutes). (8.4) Repeat steps (8.2) through (8.3). (8.5) After vacuum drying the obtained gel at 60°C, the resulting powder is ground in a mortar and pestle and dried at 150°C for 2 hours. 0.2 g of the powder obtained above was mixed and dissolved in 10 mL of 0.05 N sodium hydroxide aqueous solution, and the amount of alcohol was measured by gas chromatography to determine the amount of alkoxy groups bound to the surface. The amount of alkoxy groups obtained is calculated using the surface area value of silica particles obtained by nitrogen adsorption, and the unit surface area (nm) of the silica particles is calculated. 2 The number was calculated per unit.

[0043] [Example 1] 34.3 g of methanol-dispersed silica sol and 60.2 g of methanol were placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a stirrer equipped with turbine blades to prepare a mixed slurry (SiO2 concentration 10.0% by mass, zinc cyanurate concentration 10.0% by mass). Next, 105 g of the mixed slurry and 180 g of glass beads with a diameter of 0.5 mm to 0.7 mm were placed in a 250 mL polypropylene container, and the container was placed on a ball mill turntable set to a rotation speed of 150 rpm and wet-milled for 30 hours to obtain a methanol dispersion. The obtained methanol dispersion had a solid content (silica + zinc cyanurate) concentration of 20% by mass, a pH of 6.6, an average particle size of 68 nm measured by laser diffraction, and a viscosity of 1.0 mPa·s. The dispersion stability was evaluated. The results are shown in Table 1.

[0044] [Example 2] 34.3 g of MEK-dispersed silica sol and 60.2 g of MEK were placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (SiO2 concentration 10.0% by mass, zinc cyanurate concentration 10.0% by mass). Next, 105 g of the mixed slurry and 180 g of glass beads with a diameter of 0.5-0.7 mm were placed in a 250 mL polypropylene container, and the container was placed on a ball mill turntable set to a rotation speed of 150 rpm and wet-milled for 30 hours to obtain a MEK dispersion. The obtained MEK dispersion had a solid content (silica + zinc cyanurate) concentration of 20% by mass, a pH of 6.6, an average particle size of 70 nm measured by laser diffraction, and a viscosity of 1.3 mPa·s. The results of the dispersion stability evaluation are shown in Table 1.

[0045] [Example 3] 34.4 g of PGME-dispersed silica sol and 60.1 g of PGME were placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (SiO2 concentration 10.0% by mass, zinc cyanurate concentration 10.0% by mass). Next, 105 g of the mixed slurry and 180 g of glass beads with a diameter of 0.5-0.7 mm were placed in a 250 mL polypropylene container, and the container was placed on a ball mill turntable set to a rotation speed of 150 rpm and wet-milled for 30 hours to obtain a PGME dispersion. The obtained PGME dispersion had a solid content (silica + zinc cyanurate) concentration of 20% by mass, a pH of 6.2, an average particle size of 144 nm measured by laser diffraction, and a viscosity of 5.8 mPa·s. The results of the dispersion stability evaluation are shown in Table 1.

[0046] [Comparative Example 1] A mixed slurry (zinc cyanurate concentration 10.0% by mass, pH 7.0) was prepared by adding 10.5 g of zinc cyanurate particles to a 250 mL polypropylene container and stirring with a turbine blade stirrer. The average particle size of the obtained mixed slurry was measured by laser diffraction and was 1754 nm. The dispersion stability was evaluated. The results are shown in Table 1.

[0047] [Comparative Example 2] 125 g of aqueous silica sol and 325 g of pure water were placed in a 500 mL polypropylene container, and 50 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (SiO2 concentration 10.0% by mass, zinc cyanurate concentration 10.0% by mass). Next, 150 g of the mixed slurry and 180 g of glass beads with a diameter of 0.7-1.0 mm were placed in a 250 mL polypropylene container, and the container was placed on a ball mill turntable set to a rotation speed of 165 rpm and wet-milled for 30 hours to obtain an aqueous dispersion. The obtained aqueous dispersion had a solid content (silica + zinc cyanurate) concentration of 20% by mass, a pH of 8.1, an average particle size of 141 nm measured by laser diffraction, and a viscosity of 8.3 mPa·s. The dispersion stability was evaluated. The results are shown in Table 1.

[0048] [Comparative Example 3] 94.5 g of methanol was placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (zinc cyanurate concentration 10.0 mass%). Next, 180 g of glass beads with a diameter of 0.7-1.0 mm was added, and the container was placed on a ball mill turntable set to a rotation speed of 165 rpm and wet-milled for 30 hours to obtain a methanol dispersion. The solid content (zinc cyanurate) concentration of the obtained methanol dispersion was 10 mass%, pH 7.0, and the average particle size measured by laser diffraction was 1047 nm. The dispersion stability was evaluated. The results are shown in Table 1.

[0049] [Comparative Example 4] 94.5 g of MEK was placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (zinc cyanurate concentration 10.0 mass%). Next, 180 g of glass beads with a diameter of 0.7-1.0 mm was added, and the container was placed on a ball mill turntable set to a rotation speed of 165 rpm and wet-milled for 30 hours to obtain a MEK dispersion. The solid content (zinc cyanurate) concentration of the obtained MEK dispersion was 10 mass%, pH 6.9, and the average particle size measured by laser diffraction was 1810 nm. The dispersion stability was evaluated. The results are shown in Table 1.

[0050] [Comparative Example 5] 94.5 g of PGME was placed in a 250 mL polypropylene container, and 10.5 g of zinc cyanurate particles were added while stirring with a turbine blade-equipped stirrer to prepare a mixed slurry (zinc cyanurate concentration 10.0 mass%). Next, 180 g of glass beads with a diameter of 0.7-1.0 mm was added, and the container was placed on a ball mill turntable set to a rotation speed of 165 rpm and wet-milled for 30 hours to obtain a PGME dispersion. The solid content (zinc cyanurate) concentration of the obtained PGME dispersion was 10 mass%, pH 6.6, and the average particle size measured by laser diffraction was 177 nm. The dispersion stability was evaluated. The results are shown in Table 1.

[0051] [Table 1]

[0052] As shown in Table 1, the organic solvent dispersions obtained by the production methods of the present invention shown in Examples 1 to 3 were confirmed to exhibit good dispersion stability. On the other hand, the dispersion stability of the organic solvent dispersion of Comparative Example 1, which did not contain colloidal silica particles, was poor, and sedimentation occurred, making viscosity measurement impossible. Furthermore, the dispersion stability of the aqueous dispersion of Comparative Example 2 was also confirmed to be poor. In addition, although the organic solvent dispersions of Comparative Examples 3 to 5 were manufactured through a dispersion process in which zinc cyanurate particles were dispersed in an organic solvent, their dispersion stability was confirmed to be poor because they did not contain colloidal silica particles, demonstrating the superiority of the present invention.

Claims

1. An organic solvent dispersion in which disperse particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, An organic solvent dispersion in which an alkoxy group represented by general formula (1) is bonded to at least a portion of the surface of the dispersed particles. 【Chemistry 1】 (In the formula, R １ (This represents a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-methoxyethyl group, 1-methoxy-2-propyl group, 1-ethoxy-2-propyl group, or phenyl group.)

2. The organic solvent dispersion according to claim 1, wherein the alkoxy groups are bonded to colloidal silica particles contained in the dispersed particles, and the bonded groups are arranged in a ratio of 0.01 to 10.0 groups per 1 nm² of surface area of ​​the colloidal silica particles.

3. The organic solvent dispersion according to claim 1 or claim 2, wherein the amount of water contained in the dispersion of the dispersed particles in the organic solvent is 5% by mass or less.

4. The organic solvent dispersion according to any one of claims 1 to 3, wherein the organic solvent is at least one or more selected from the group consisting of alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds.

5. The organic solvent dispersion according to any one of claims 1 to 4, wherein the dispersed particles, which include the colloidal silica particles and zinc cyanurate particles, satisfy the following (a) and (b). (a) The average particle size obtained by laser diffraction is 50 nm to 100 nm, (b) In particle size distribution measurement by laser diffraction, when the particle sizes at which the cumulative frequency reaches 10%, 50%, and 90% are D10, D50, and D90, respectively, D50 / D10 is 1.10 or more and less than 1.60, and D90 / D50 is 1.10 or more and less than 1.

60.

6. A method for producing an organic solvent dispersion in which dispersible particles containing colloidal silica particles and zinc cyanurate particles are dispersed in an organic solvent, comprising a dispersion step of mixing silica particles, zinc cyanurate particles, and an organic solvent, and dispersing the dispersed particles containing silica particles and zinc cyanurate particles in the organic solvent, A method for producing an organic solvent dispersion in which an alkoxy group represented by general formula (1) is bonded to at least a portion of the surface of dispersed particles containing the colloidal silica particles and zinc cyanurate particles. 【Chemistry 2】 (In the formula, R 1 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-methoxyethyl group, a 1-methoxy-2-propyl group, a 1-ethoxy-2-propyl group, or a phenyl group.)

7. A method for producing an organic solvent dispersion according to claim 6, wherein the mixing of silica particles, zinc cyanurate particles, and an organic solvent is a mixture of silica sol and zinc cyanurate particles using the organic solvent as a dispersion medium.

8. A method for producing an organic solvent dispersion according to claim 7, wherein the water content of the silica sol is 5% by mass or less.

9. The method for producing an organic solvent dispersion according to claim 7 or claim 8, wherein the dispersion medium for the silica sol is at least one or more selected from the group consisting of alcohols, ketones, ethers, esters, hydrocarbons, and nitrogen-containing organic compounds.

10. A method for producing an organic solvent dispersion according to any one of claims 7 to 9, wherein the silica sol is an alcohol-dispersed silica sol, or an organic solvent-dispersed silica sol obtained by replacing the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, and the organic solvent is at least one or more selected from the group consisting of ketones, ethers, esters, hydrocarbons and nitrogen-containing organic compounds.

11. A method for producing an organic solvent dispersion according to any one of claims 7 to 10, wherein the silica sol is an alcohol-dispersed silica sol in which at least one or more alcohols selected from the group consisting of methanol, ethanol, propanol, butanol, isopropyl alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether are used as the dispersion medium, or an organic solvent-dispersed silica sol obtained by substituting the dispersion medium of the alcohol-dispersed silica sol with an organic solvent, wherein the organic solvent is at least one or more selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, γ-butyl lactone, ethyl acetate, butyl acetate, toluene, xylene, n-pentane, n-hexane, cyclohexane, N,N-dimethylformamide, and N-methylpyrrolidone.

12. The alkoxy groups are bonded to colloidal silica particles contained in the dispersed particles, with a ratio of 0.01 to 10.0 groups per 1 nm² of surface area of ​​the colloidal silica particles. A method for producing an organic solvent dispersion according to claim 6.

13. A method for producing an organic solvent dispersion according to any one of claims 6 to 12, wherein the dispersed particles obtained by the dispersion step, which include colloidal silica particles and zinc cyanurate particles, satisfy the following (a) and (b). (a) The average particle size obtained by laser diffraction is 50 nm to 100 nm, (b) In particle size distribution measurement by laser diffraction, when the particle sizes at which the cumulative frequency reaches 10%, 50%, and 90% are D10, D50, and D90, respectively, D50 / D10 is 1.10 or more and less than 1.60, and D90 / D50 is 1.10 or more and less than 1.

60.

14. The method for producing an organic solvent dispersion according to claim 9, wherein the dispersion medium for the silica sol is at least one or more selected from the group consisting of methanol, ethanol, propanol, butanol, isopropyl alcohol, methyl ethyl ketone, and methyl isobutyl ketone.

15. A method for producing an organic solvent dispersion according to any one of claims 6 to 14, wherein the average primary particle diameter of the silica particles is 5 nm to 500 nm.

16. A method for producing an organic solvent dispersion according to any one of claims 6 to 15, wherein the average length of the long axis of the zinc cyanurate particles observed by transmission electron microscopy is 50 nm to 1000 nm, the average length of the short axis is 10 nm to 300 nm, and the ratio of the lengths of the long axis to the short axis is 2 to 25.

17. A method for producing an organic solvent dispersion according to any one of claims 6 to 16, wherein in the dispersion step, silica particles and zinc cyanurate particles are dispersed in a mass ratio of 1:0.01 to 100.

18. A method for producing an organic solvent dispersion according to any one of claims 6 to 17, wherein in the dispersion step, the total solid content of colloidal silica particles and zinc cyanurate particles is 0.1% by mass to 50% by mass.

19. A method for producing an organic solvent dispersion according to any one of claims 6 to 18, wherein the dispersion step is carried out in a liquid-submerged disperser.

20. The method for producing an organic solvent dispersion according to claim 19, wherein the liquid dispersion machine is a high-speed rotary shear type agitator, a colloidal mill, a high-pressure jet type dispersion machine, an ultrasonic dispersion machine, a container-driven mill, or a media stirring mill.

21. The method for producing an organic solvent dispersion according to claim 20, wherein the media stirring mill is of the circulating or batch type.

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