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:
Nov. 05, 1991
Filed:
Mar. 02, 1990
Applicant:
Inventors:
Jameel Menashi, Lexington, MA (US);
Kenneth C Koehlert, Champaigne, IL (US);
Assignee:
Cabot Corporation, Waltham, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ; C01B / ;
U.S. Cl.
CPC ...
501 12 ; 501 54 ; 501154 ; 423335 ; 423338 ; 65 211 ; 65 214 ;
Abstract
A process for making non-porous, dense, silica partices having a diameter of about 3 to 1000 microns, a nitrogen B.E.T. surface area less than about 1 m.sup.2 /g, a total impurity content of less than about 50 ppm and a metal impurity content content of less than about 15 ppm from an aqueous dispersion of fumed silica. The particles are converted into porous particles and sintered in an atmosphere having a water partial pressure of from about 0.2 to about 0.8 atmosphere for temperatures below about 1200.degree. C.