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:
May. 29, 1984
Filed:
Nov. 02, 1981
Charles C Payne, Chicago, IL (US);
Nalco Chemical Company, Oak Brook, IL (US);
Abstract
New alumina coated silica sols are produced by a method which comprises mixing a concentrated deionized silica sol with concentrated solutions of trivalent acid aluminum salts, heating this premix to at least 90.degree. C. for 1-15 minutes to form an alumina reacted silica sol solution, cooling this reacted silica sol solution to form a cooled alumina reacted silica sol solution, diluting with deionized water to about 10 weight percent solids, exposing this diluted alumina reacted silica sol to ultrafiltration through a membrane having a molecular weight cutoff of about 30,000, adding distilled or deionized water to the diluted alumina reacted silica sol during ultrafiltration to wash dissolved salts from this salt solution forming a diluted alumina-coated silica sol having a pH between about 4-5 and a conductivity between about 2,000-4,000 micromhos, concentrating this dilute alumina-coated silica sol to at least 30 weight percent solids, thereby obtaining a stable alumina-coated silica sol.