Abstract: A method of producing silica-based particles includes, when a dispersion liquid of composite oxide particles is prepared by simultaneously adding an aqueous silicate solution and/or an acidic silicic acid solution and an aqueous solution of an alkali-soluble inorganic compound in an alkali aqueous solution or in an alkali aqueous solution with seed particles dispersed therein, if required, the aqueous silicate solution and/or the acidic silicic acid solution and the aqueous solution of alkali-soluble inorganic compound are added so that the molar ratio of MOx/SiO2 are in a range from 0.01 to 2, herein MOx denoting an inorganic oxide other than silica and SiO2 denoting silica to prepare the dispersion liquid of composite oxide particles with an average diameter (Dp1) in a range from 3 to 300 nm.

Abstract: Provided is a silica-based polishing particle which can polish and flatten the surface of a substrate at a sufficient polishing rate with generation of scratches prevented, and successfully prevents generation of particle residues on a substrate after polishing. A silica-based polishing particle with a three-dimensional polycondensation structure containing an alkoxy group, wherein the particle has an average particle diameter (d) of 5 to 300 nm, an aspect ratio of 1.00 or more and 1.20 or less, and a carbon content of 0.005% by mass or more and less than 0.50% by mass.

Abstract: Provided is a silica-based polishing particle, particularly suitable for primary polishing, which provides a high polishing rate on the surface of a substrate and which prevents particle residues on the substrate after polishing, and an abrasive including the silica-based polishing particle. A silica-based polishing particle with a three-dimensional polycondensation structure containing an alkoxy group, wherein the particle has an average particle diameter (d) of 5 to 300 nm, an aspect ratio of more than 1.20 and 5.00 or less, and a carbon content of 0.005% by mass or more and less than 0.50% by mass.

Abstract: Hollow silica-based particles having cavities inside the outer shell having a low refractive index. The method of producing the silica-based particles comprises the following steps (a) and (b): (a) a step in which, when an aqueous silicate solution and/or an acidic silicic acid solution and an aqueous solution of an alkali-soluble inorganic compound are simultaneously added in an alkali aqueous solution to prepare a dispersion liquid of composite oxide particles, an electrolytic salt is added at the molar ratio of a mole number of the electrolytic salt (ME) versus that of SiO2 (MS) [(ME)/(MS)] in the range from 0.1 to 10, and (b) a step of furthermore adding an electrolytic salt, if necessary, to the dispersion liquid of composite oxide particles and then removing at least a portion of elements constituting the composite oxide other than silicon by adding an acid to prepare a dispersion liquid of silica-based particles.

Abstract: Producing a silica particle by inhibiting the generation of incompletely reacted materials such as oligomers which have not been grown to the silica particles having the intended particle size. A dispersion liquid of a silica particle is produced by simultaneously adding, to a liquid substantially consisting of an organic solvent, a liquid containing silane alkoxide and a liquid containing an alkali catalyst and water to cause hydrolysis and polycondensations to produce a silica particle. The variation rate of the mole ratio of the alkali catalyst to silane alkoxide in the reaction system for a period from the start to the end of the reaction relative to the initial mole ratio is 0.90 to 1.10; and the variation rate of the mole ratio of water to silane alkoxide for a period from the start to the end of the reaction relative to the initial mole ratio is 0.90 to 1.10.

Abstract: Provided is a silica-based polishing particle, particularly suitable for primary polishing, which provides a high polishing rate on the surface of a substrate and which prevents particle residues on the substrate after polishing, and an abrasive including the silica-based polishing particle. A silica-based polishing particle with a three-dimensional polycondensation structure containing an alkoxy group, wherein the particle has an average particle diameter (d) of 5 to 300 nm, an aspect ratio of more than 1.20 and 5.00 or less, and a carbon content of 0.005% by mass or more and less than 0.50% by mass.

Abstract: Provided is a silica-based polishing particle which can polish and flatten the surface of a substrate at a sufficient polishing rate with generation of scratches prevented, and successfully prevents generation of particle residues on a substrate after polishing. A silica-based polishing particle with a three-dimensional polycondensation structure containing an alkoxy group, wherein the particle has an average particle diameter (d) of 5 to 300 nm, an aspect ratio of 1.00 or more and 1.20 or less, and a carbon content of 0.005% by mass or more and less than 0.50% by mass.

Abstract: A water-repellent transparent coating-substrate assembly includes a substrate and a water-repellent transparent coating disposed on a surface of the substrate, the transparent coating including an inorganic oxide fine particle layer containing inorganic oxide fine particles, and an overcoating layer disposed on the inorganic oxide fine particle layer, the surface of the water-repellent transparent coating having irregularities including depressions and protrusions in which the protrusions have an average height (TF) in the range of 30 to 500 nm and an average protrusion interval (pitch width) (WF) in the range of 50 to 1000 nm, the water-repellent transparent coating having a water contact angle in the range of 130 to 180°.

Abstract: A composition for forming a transparent coating film including hollow silica microparticles and a binder is provided. The hollow silica microparticles have an average particle diameter of 5 to 300 nm when measured by the dynamic light scattering method, a specific surface area of 50 to 1500 m2/g, and an outer shell in which cavities are formed. The microparticles lose weight by 1.0 W % or more at a temperature in the range of from 200° C. to 500° C. when measured by the thermogravimetry (TG). A surface charge (QA) of the hollow silica microparticles contained in the compositions for forming a transparent coating film is in the range from 5 to 20 ?eq/g.

Abstract: There is provided an antireflective laminate having a low refractive index and excellent mechanical strength, which comprises a coating layer of an ionizing radiation curing-type resin composition comprising ionizing radiation curing group-containing hollow silica fine particles. The antireflective laminate comprises a light transparent base material and at least a low refractive index layer having a refractive index of not more than 1.45 provided on the light transparent base material, wherein the low refractive index layer comprises an ionizing radiation curing-type resin composition and silica fine particles having an outer shell layer with the interior of the silica fine particles being porous or void, and, for a part or all of the silica fine particles, at least a part of the surface of the silica fine particle has been treated with an ionizing radiation curing group-containing silane coupling agent.

Abstract: Silica particles calcined in a calcination step are supplied in a swirling flow generated by a gas introduced in a disintegration container and disintegrated therein, whereby the silica particles can be easily disintegrated and there can be obtained disintegrated silica particles having both low hygroscopicity and high dispersibility in resin. In addition, the introduction of dehumidified air (gas) during the disintegration reduces hygroscopicity and greatly improves dispersibility in resin. Furthermore, performing heating treatment (calcination) again after the disintegration causes the surface modification of the disintegrated silica particles, greatly improving hygroscopicity and dispersibility in resin. The resin composition obtained in this manner including silica particles provides good injectability and filterability when used for an underfill material for semiconductors and an in-plane spacer or sealing spacer of liquid crystal displays.

Abstract: There is provided an antireflective laminate having a low refractive index and excellent mechanical strength, which comprises a coating layer of an ionizing radiation curing-type resin composition comprising ionizing radiation curing group-containing hollow silica fine particles. The antireflective laminate comprises a light transparent base material and at least a low refractive index layer having a refractive index of not more than 1.45 provided on the light transparent base material, wherein the low refractive index layer comprises an ionizing radiation curing-type resin composition and silica fine particles having an outer shell layer with the interior of the silica fine particles being porous or void, and, for a part or all of the silica fine particles, at least a part of the surface of the silica fine particle has been treated with an ionizing radiation curing group-containing silane coupling agent.

Abstract: A water-repellent transparent coating-substrate assembly includes a substrate and a water-repellent transparent coating disposed on a surface of the substrate, the transparent coating including an inorganic oxide fine particle layer containing inorganic oxide fine particles, and an overcoating layer disposed on the inorganic oxide fine particle layer, the surface of the water-repellent transparent coating having irregularities including depressions and protrusions in which the protrusions have an average height (TF) in the range of 30 to 500 nm and an average protrusion interval (pitch width) (WF) in the range of 50 to 1000 nm, the water-repellent transparent coating having a water contact angle in the range of 130 to 180°.

Abstract: A method of producing hollow silica microparticles that suppress whitening of a transparent coating film and show excellent abrasion resistance and adhesiveness. The method includes preparation of an organosol in which hollow silica microparticles are dispersed with the silica concentration of 1 to 70 W % and addition of a silane compound and an alkali catalyst to the organosol at a temperature in the range from 30° C. to 300° C. to react the silane compound to the hollow silica microparticles under the condition where a quantity of water against the added silica (the hollow silica microparticles) is in the range from 0.1 to 50 W %.

Abstract: A method of producing silica-based particles includes, when a dispersion liquid of composite oxide particles is prepared by simultaneously adding an aqueous silicate solution and/or an acidic silicic acid solution and an aqueous solution of an alkali-soluble inorganic compound in an alkali aqueous solution or in an alkali aqueous solution with seed particles dispersed therein, if required, the aqueous silicate solution and/or the acidic silicic acid solution and the aqueous solution of alkali-soluble inorganic compound are added so that the molar ratio of MOx/SiO2 are in a range from 0.01 to 2, herein MOx denoting an inorganic oxide other than silica and SiO2 denoting silica to prepare the dispersion liquid of composite oxide particles with an average diameter (Dp1) in a range from 3 to 300 nm.

Abstract: Modified zirconia fine particles which are stable in an acidic region as well as in an alkaline region, and which may be readily adjusted in refractive index in a predetermined range are disclosed. Also disclosed is a substrate with a hard coat film excellent in adhesiveness with the substrate, abrasion resistance, scratch strength, pencil hardness and the like without interference fringes and a coating solution which may form the hard coat film. The substrate with a hard coat film is composed of composite oxide particles formed on at least one surface of the substrate and a matrix component, wherein the composite oxide particles are composite oxide particles having a core-shell structure composed of a core formed from zirconium oxide and a shell formed from antimony pentoxide and/or silica.

Abstract: Hollow silica microparticles suppress whitening of a transparent coating film and show excellent abrasion resistance and adhesiveness. The microparticles having the average particle diameter of 5 to 300 nm and the specific surface area of 50 to 1500 m2/g, and also having an outer shell in which cavities are formed. The microparticles lose the weight by 1.0 W % or more at a temperature range from 200° C. to 500° C. when measured by the thermogravimetry (TG), and the microparticles have a positive DTA peak at the temperature range when measured by the differential thermogravimetric analysis (DTA).

Abstract: The present invention provides modified zirconia fine particles which are stable in an acidic region as well as in an alkaline region, and which may be readily adjusted in refractive index in a predetermined range. The present invention further provides a substrate with a hard coat film excellent in adhesiveness with the substrate, abrasion resistance, scratch strength, pencil hardness and the like without interference fringes and a coating solution which may form the hard coat film. The substrate with a hard coat film is composed of composite oxide particles formed on at least one surface of the substrate and a matrix component, wherein the composite oxide particles are composite oxide particles having a core-shell structure composed of a core formed from zirconium oxide and a shell formed from antimony pentoxide and/or silica.

Abstract: Hollow silica-based particles having cavities inside the outer shell having a low refractive index. The method of producing the silica-based particles comprises the following steps (a) and (b): (a) a step in which, when an aqueous silicate solution and/or an acidic silicic acid solution and an aqueous solution of an alkali-soluble inorganic compound are simultaneously added in an alkali aqueous solution to prepare a dispersion liquid of composite oxide particles, an electrolytic salt is added at the molar ratio of a mole number of the electrolytic salt (ME) versus that of SiO2 (MS) [(ME)/(MS)] in the range from 0.1 to 10, and (b) a step of furthermore adding an electrolytic salt, if necessary, to the dispersion liquid of composite oxide particles and then removing at least a portion of elements constituting the composite oxide other than silicon by adding an acid to prepare a dispersion liquid of silica-based particles.

Abstract: Silica-based particles coated with antimony oxide with a low refractive index and having conductivity are provided. The silica-based particles coated with antimony oxide comprise porous or hollow silica-based particles with antimony oxide coated thereon. A refractive index of the silica-based particles coated with antimony oxide is in the range from 1.35 to 1.60 with the volume resistivity value in the range from 10 to 5000 ?/cm and the average particle diameter in the range from 5 to 300 nm, and the thickness of the antimony oxide coating layer is in the range from 0.5 to 30 nm.