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:
Oct. 11, 1994
Filed:
Feb. 16, 1993
Applicant:
Inventors:
James T Dew, Jeannette, PA (US);
Larry R Evans, Jeannette, PA (US);
Walter H Waddell, Pittsburgh, PA (US);
Assignee:
PPG Industries, Inc., Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B02C / ;
U.S. Cl.
CPC ...
241 30 ; 241235 ;
Abstract
A statistically large population of particles of amorphous precipitated silica is substantially free of particles of amorphous precipitated silica which are retained on a 20 mesh sieve screen, and is characterized by at least 90 percent by weight of said particles of said population being retained on a 200 mesh sieve screen. Such a population may be produced by cracking amorphous precipitated silica particles between the textured rolls of at least one roll pair.