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. 24, 2005
Filed:
Jan. 31, 2002
Cristian Libanati, Silver Spring, MD (US);
James George Miller, Ellicott City, MD (US);
Sandra Joan Kempske, Towson, MD (US);
Cristian Libanati, Silver Spring, MD (US);
James George Miller, Ellicott City, MD (US);
Sandra Joan Kempske, Towson, MD (US);
W.R. Grace & Co.-Conn., Columbia, MD (US);
Abstract
A silica gel abrasive having good cleaning and low abrasion is prepared by combining at least two silica gels before adjusting the pH of the abrasive to a pH in the range of 3-6. One of the gels is washed at relatively lower temperature compared to the wash temperature of a second gel. The two gels are then milled and dried to a median particle size in the range of 5 to 12 microns. The volatiles content of the gel combination is in the range of 20-40% by weight. The resulting mixtures have low abrasion as measured by Einlehner, e.g., in the range of 0.5 to 3 when measured using a brass screen. A dentifrice composition comprising 10 to 25% of the abrasive has a PCR of at least 80 and can obtain PCR's greater than 100.