Nissan Chemical Industries Limited

Brewer Science, Inc.

Other

Kiyomi Ema

Yoshitane Watanabe

Tohru Nishimura

Noriyuki Takakuma

Kouji Yamaguchi

Naoki Kawashita

Yoshiyuki Kashima

Yutaka Ohmori

Terry Lowell Brewer

Isao Ota

Osamu Tanegashima

Ram W Sabnis

Akira Yanagimoto

Takaichi Sugiyama

Yasuhisa Sone

Hisayuki Sato

Ken-ichi Okubi

Edith G Hays

Michael D Stroder

Hirokazu Kato

Hideaki Watanabe

Masayuki Fukuda

Kenji Yamaguchi

Toshio Kasai

Akira Kitajima

Akita Kitajima

Jonathan W Mayo

Robert E Nichols

Michie Kaneko

Hisanobu Urahata

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 &#x3bc;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 &#x3bc;m is 50% or more.

Method for producing purified active silicic acid solution and silica sol

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 &#x3bc;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 &#x3bc;m is 50% or more.

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 &#x3bc;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 &#x3bc;m of 50% or more.

Method for producing purified alkali silicate aqueous solution and silica sol

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&#xb0; 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&#xb0; C. In addition, 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 acidic zirconia sol (C3) and a refractory powder (D) are mixed, the acidic zirconia sol (C3) being obtained by a manufacturing method that includes a step (I), in which an alkaline zirconia sol (A3) and a zirconium salt (B3) are mixed, and a step II, in which the obtained liquid mixture is caused to react at 80 to 250&#xb0; C.

Method for manufacturing slurry and mold for precision casting

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.

Process for producing acidic aqueous alumina sol

A stable silica sol having an SiO 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 D /D of a particle diameter (D nm) measured by a dynamic light scattering method to a mean particle diameter (a particle diameter measured by a nitrogen absorption method: D nm) where D 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.

Moniliform silica sol, process for producing the same, and ink-jet recording medium

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.

Alumina powder, process for producing the same and polishing composition

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 (D /D ) of a particle diameter D nm (as measured by dynamic light scattering method) to a mean particle diameter D (as measured by nitrogen absorption method) of 3 or more, wherein D is between 50 to 800 nm and D 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.

Polishing composition

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.

Antistatic polyester film and process for producing the same

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.

Organic-inorganic composite conductive SOL and process for producing the same

A high optical density, i.e., .gtoreq.3.0, at 1 micron or less film thickness, black matrix is disclosed having improved stability and shelf life as a consequence of admixing Pigment Black 7 and organic dye or dye mixtures on a polyimide polymer vehicle.

High optical density ultra thin organic black matrix system

A process for producing a stable acidic aqueous alumina sol containing 50 to 300 nm of elongate secondary particles which are elongated in only one plane and formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length of one side of 10 to 30 nm when observed through an electron microscope, the process comprises the steps of: (A) adding an alkali to an aqueous alumina sol containing fibrous colloidal particles of an amorphous alumina hydrate to produce a reaction mixture having a pH of 9 to 12, (B) subjecting the reaction mixture obtained in the step (A) to a hydrothermal treatment at a temperature of 110 to 250.degree. C. to produce an aqueous suspension containing an alumina hydrate having a boehmite structure, and (C) desalting the aqueous suspension obtained in the step (B) by adding water and an acid by ultrafiltration to form an acidic aqueous alumina sol having a pH of 3 to 6.

Process for producing an acidic aqueous alumina sol

Reaction product of sulfonated amino resin and amino group-containing

An organic black matrix having high resistivity (.gtoreq.10.sup.11 ohm/square), high optical density (.gtoreq.2.0) at ultra thin film thicknesses (.ltoreq.1.0 microns) for improved STN and TFT pixel display applications is made possible by combining polyimide/dye solutions and mixed metal oxide pigment dispersions at a weight/weight ratio of dye to pigment of 1:15 to 3:15. The need for low resistivity carbon black, as a replacement for sputtered chrome, is negated.

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Tokyo, Japan

Kiyomi Ema