The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 15, 2000
Filed:
May. 26, 1998
Keiko Yoshitake, Funabashi, JP;
Takafumi Yokoyama, Funabashi, JP;
Nissan Chemicals Industries, Ltd., Tokyo, JP;
Abstract
A process of producing a hydrophobic organosilica sol which comprises aging a reaction mixture at 0 to 100.degree. C. in the state that an alkali present in the reaction mixture is removed or is neutralized with an acid in an equivalent amount or more, thereby forming a silylation-treated silica sol having a hydrophobic colloidal silica dispersed therein, the reaction mixture comprising: (a) a hydrophilic colloidal silica having a specific surface area of 5.5 to 550 m.sup.2 /g in SiO.sub.2 concentration of 5 to 55% by weight, (b) a silylating agent of a disiloxane compound and/or monoalkoxysilane compound in a millimolar ratio of 0.03 to 2 in terms of Si atom per 100 m.sup.2 of a surface of the hydrophilic colloidal silica, and (c) a medium, as a residue thereof, comprising a mixed solvent comprising a hydrophobic organic solvent having a solubility of water of 0.1 to 12% by weight and an alcohol having 1 to 3 carbon atoms in a weight ratio of 0.05 to 20 to the hydrophobic organic solvent, and water in an amount of 15% by weight or less based on the weight of the medium.