Abstract: A method for producing an active silicic acid solution in which the existing amount of foreign matters as plate-like fine particles is reduced and a method for producing a silica sol in which such foreign matters are reduced. The method fulfills the following condition; the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is measured to be 0% to 30% in accordance with measuring method A, the method including the steps of: preparing an active silicic acid solution by subjecting an alkali silicate aqueous solution having a silica concentration of 0.5% by mass to 10.0% by mass to cation-exchange to remove alkaline components; and filtering the active silicic acid solution through a filter whose removal rate of particles having a primary particle size of 1.0 ?m is 50% or more.

Abstract: A method for producing an active silicic acid solution in which the existing amount of foreign matters as plate-like fine particles is reduced and a method for producing a silica sol in which such foreign matters are reduced. The method fulfills the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is measured to be 0% to 30% in accordance with measuring method A, the method including the steps of: preparing an active silicic acid solution by subjecting an alkali silicate aqueous solution having a silica concentration of 0.5% by mass to 10.0% by mass to cation-exchange to remove alkaline components; and filtering the active silicic acid solution through a filter whose removal rate of particles having a primary particle size of 1.0 ?m is 50% or more.

Abstract: To provide a method for producing an alkali silicate aqueous solution containing a reduced amount of foreign substance of plate-like fine particles and a method for producing a silica sol containing a reduced amount of foreign substance of plate-like fine particles. A method for producing an alkali silicate aqueous solution fulfilling the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is determined to be 0 to 30%. The method for producing an alkali silicate aqueous solution includes the steps of adjusting a silica concentration of an alkali silicate aqueous solution to 0.5 to 10.0% by mass and filtering the alkali silicate aqueous solution through a filter having a removal rate of particles with a primary particle size of 1.0 ?m of 50% or more.

Abstract: A method for producing an active silicic acid solution in which the existing amount of foreign matters as plate-like fine particles is reduced and a method for producing a silica sol in which such foreign matters are reduced. The method fulfills the following condition; the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is measured to be 0% to 30% in accordance with measuring method A, the method including the steps of: preparing an active silicic acid solution by subjecting an alkali silicate aqueous solution having a silica concentration of 0.5% by mass to 10.0% by mass to cation-exchange to remove alkaline components; and filtering the active silicic acid solution through a filter whose removal rate of particles having a primary particle size of 1.0 ?m is 50% or more.

Abstract: To provide a method for producing an alkali silicate aqueous solution containing a reduced amount of foreign substance of plate-like fine particles and a method for producing a silica sol containing a reduced amount of foreign substance of plate-like fine particles. A method for producing an alkali silicate aqueous solution fulfilling the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is determined to be 0 to 30%. The method for producing an alkali silicate aqueous solution includes the steps of adjusting a silica concentration of an alkali silicate aqueous solution to 0.5 to 10.0% by mass and filtering the alkali silicate aqueous solution through a filter having a removal rate of particles with a primary particle size of 1.0 ?m of 50% or more.

Abstract: To provide a method for producing an alkali silicate aqueous solution containing a reduced amount of foreign substance of plate-like fine particles and a method for producing a silica sol containing a reduced amount of foreign substance of plate-like fine particles. A method for producing an alkali silicate aqueous solution fulfilling the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is determined to be 0 to 30%. The method for producing an alkali silicate aqueous solution includes the steps of adjusting a silica concentration of an alkali silicate aqueous solution to 0.5 to 10.0% by mass and filtering the alkali silicate aqueous solution through a filter having a removal rate of particles with a primary particle size of 1.0 ?m of 50% or more.

Abstract: A method for producing an active silicic acid solution in which the existing amount of foreign matters as plate-like fine particles is reduced and a method for producing a silica sol in which such foreign matters are reduced. The method fulfills the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is measured to be 0% to 30% in accordance with measuring method A, the method including the steps of: preparing an active silicic acid solution by subjecting an alkali silicate aqueous solution having a silica concentration of 0.5% by mass to 10.0% by mass to cation-exchange to remove alkaline components; and filtering the active silicic acid solution through a filter whose removal rate of particles having a primary particle size of 1.0 ?m is 50% or more.

Abstract: To provide a method for producing an alkali silicate aqueous solution containing a reduced amount of foreign substance of plate-like fine particles and a method for producing a silica sol containing a reduced amount of foreign substance of plate-like fine particles. A method for producing an alkali silicate aqueous solution fulfilling the following condition: the existing amount of plate-like fine particles having a length of one side of 0.2 to 4.0 ?m and a thickness of 1 to 100 nm is determined to be 0 to 30%. The method for producing an alkali silicate aqueous solution includes the steps of adjusting a silica concentration of an alkali silicate aqueous solution to 0.5 to 10.0% by mass and filtering the alkali silicate aqueous solution through a filter having a removal rate of particles with a primary particle size of 1.0 ?m of 50% or more.

Abstract: A manufacturing method for a slurry for the production of a precision casting mold that includes a zirconia sol and a refractory powder, and a manufacturing method for a precision casting mold that uses the slurry is provided. The present invention relates to a manufacturing method for a slurry for the production of a precision casting mold for a metal that includes a step in which an alkaline zirconia sol (A1) and a refractory powder (D) are mixed, the alkaline zirconia sol (A1) being obtained by a manufacturing method that includes a step (i), in which a zirconium salt (B1) is heated at 60 to 110° C. in an aqueous medium that includes a carbonate of quaternary ammonium, and a step (ii), in which a hydrothermal treatment is carried out at 100 to 250° C.

Abstract: A process for producing a stable acidic aqueous alumina sol containing columnar secondary particles having a length of 50 to 400 nm which are formed by face-to-face coagulation of rectangular plate-like primary particles having a length of one side of 10 to 40 nm and a thickness of 2.5 to 10 nm when observed through an electron microscope, by use of an aqueous alkali aluminate solution and liquid or gaseous carbon dioxide as starting materials. The obtained acidic aqueous alumina sol has a low viscosity and is stable for salts. The dried gel obtained from the sol is characterized in that the gel structure thereof is rigid even though it is porous.

Abstract: A manufacturing method for a slurry for the production of a precision casting mold that includes a zirconia sol and a refractory powder, and a manufacturing method for a precision casting mold that uses the slurry is provided. The present invention relates to a manufacturing method for a slurry for the production of a precision casting mold for a metal that includes a step in which an alkaline zirconia sol (A1) and a refractory powder (D) are mixed, the alkaline zirconia sol (A1) being obtained by a manufacturing method that includes a step (i), in which a zirconium salt (B1) is heated at 60 to 110° C. in an aqueous medium that includes a carbonate of quaternary ammonium, and a step (ii), in which a hydrothermal treatment is carried out at 100 to 250° C.

Abstract: A process for producing a stable acidic aqueous alumina sol containing columnar secondary particles having a length of 50 to 400 nm which are formed by face-to-face coagulation of rectangular plate-like primary particles having a length of one side of 10 to 40 nm and a thickness of 2.5 to 10 nm when observed through an electron microscope, by use of an aqueous alkali aluminate solution and liquid or gaseous carbon dioxide as starting materials. The obtained acidic aqueous alumina sol has a low viscosity and is stable for salts. The dried gel obtained from the sol is characterized in that the gel structure thereof is rigid even though it is porous.

Abstract: A spin coatable, photosensitive black matrix coating having high surface resistivity and exhibiting an optical density greater than 3 at film thicknesses of ≦1 micron has been developed for flat panel display applications where a chrome/chrome oxide black matrix is usually employed. It possesses excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic processes excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic process, thereby reducing the cost of processing in relation to chrome/chrome oxide black matrix fabrication processes.

Abstract: A stable silica sol having an SiO2 concentration of 1 to 50% by weight and containing liquid-medium dispersed moniliform colloidal silica particles each having 3 or more as a ratio of D1/D2 of a particle diameter (D1 nm) measured by a dynamic light scattering method to a mean particle diameter (a particle diameter measured by a nitrogen absorption method: D2 nm) where D1 is 50 to 500 nm, and which are comprised by spherical colloidal silica particles having a mean particle diameter of 10 to 80 nm and metal oxide-containing silica bonding these spherical-colloidal silica particles, and in which the spherical colloidal silica particles link in rows in only one plane, process for producing such and a coating composition for ink receiving layers containing such a silica sol and an ink jet recording medium.

Abstract: A spin coatable, photosensitive black matrix coating having high surface resistivity and exhibiting an optical density greater than 3 at film thicknesses of ≦1 micron has been developed for flat panel display applications where a chrome/chrome oxide black matrix is usually employed. It possesses excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic processes excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic process, thereby reducing the cost of processing in relation to chrome/chrome oxide black matrix fabrication processes.

Abstract: A spin coatable, photosensitive black matrix coating having high surface resistivity and exhibiting an optical density greater than 3 at film thicknesses of ≦1 micron has been developed for flat panel display applications where a chrome/chrome oxide black matrix is usually employed. It possesses excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic processes excellent thermal, light, and chemical stability and good shelf life. It is deposited and patterned by a simple photolithographic process, thereby reducing the cost of processing in relation to chrome/chrome oxide black matrix fabrication processes.

Abstract: Production of an alumina powder characterized by having a single or multiple crystal structure selected from the group consisting of &ggr;, &dgr; and &thgr;-forms, a primary particle size of 10 to 50 nm, a mean secondary particle size of 100 to 500 nm, and a granular primary particle shape, or an alumina powder characterized by having an a-form crystal structure, a primary particle size of 60 to 150 nm, a mean secondary particle size of 200 to 500 nm, and a granular primary particle shape, using as a raw material an alumina hydrate comprising rectangular plate-like primary particles having a boehmite structure and having a length of one side of 10 to 50 nm; and preparation of a polishing composition comprising the alumina powder, water and a polishing accelerator.

Abstract: The present invention relates to a polishing composition for polishing alumina disks, polishing substrates having silica surfaces and semiconductor wafers, comprising a stable aqueous silica sol containing moniliform colloidal silica particles having a ratio (D1/D2) of a particle diameter D1 nm (as measured by dynamic light scattering method) to a mean particle diameter D2 (as measured by nitrogen absorption method) of 3 or more, wherein D1 is between 50 to 800 nm and D2 is between 10 to 120 nm, said moniliform colloidal silica particles being composed of spherical colloidal silica particles and a metal oxide-containing silica bond which bonds these spherical colloidal silica particles together, wherein the spherical colloidal silica particles are linked together in rows in only one plane by observation through an electron microscope, and further wherein said polishing composition contains 0.5 to 50% by weight of said moniliform colloidal silica particles.

Abstract: An antistatic polyester film having the excellent antistatic property and improved appearance of a coating layer, and a process for producing the same are disclosed. The antistatic polyester film comprises a polyester film having formed on at least one surface thereof an antistatic coating layer obtained by coating a coating liquid containing an organic-inorganic composite conductive sol (A) comprising colloidal particles of conductive oxide, having a primary particle size of 5 to 50 nm, and colloidal particles of a conductive polymer. This antistatic polyester film has excellent antistatic property, particularly excellent antistatic property under the low humidity environment, and therefore is useful in magnetic cards, magnetic disks, printing materials, graphic materials, photosensitive materials and the like.

Abstract: An organic-inorganic composite conductive sol, and a process for producing the same are disclosed. The organic-inorganic composite conductive sol comprises colloidal particles having a primary partical size of 5 to 50 nm of conductive oxide such as colloidal particles of conductive zinc antimonate, colloidal particles of conductive indium antimonate or a mixture thereof, and colloidal particles having a primary particle size of 2 to 10 nm of conductive polymer such as polythiophene or polythiophene derivative. The composite conductive sol is suitable for use in various fields such as transparent antistatic materials, transparent ultraviolet absorbing materials, transparent heat absorbing materials, transparent resistant materials, high refractive index hard coat agents and anti-reflecting agents of resins, plastics, glasses, papers, magnetic tapes, and the like.