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:
Jul. 04, 2000
Filed:
Nov. 05, 1996
Kevin J Snowden, Milledgeville, GA (US);
Kuan-Ting Wu, Yunlin, TW;
Jose M Rodriguez, Eatonton, GA (US);
Imerys Pigments, Inc., Roswell, GA (US);
Abstract
An improved form of calcium carbonate which is acid resistant to enable its use as a filler material in the making of neutral to weakly acidic paper, and a process for producing this acid-resistant calcium carbonate is provided. This acid-resistant calcium carbonate composition comprises calcium carbonate and at least about 0.1% to about 25% based on the dry weight of the calcium carbonate, of sodium silicate, together with at least 0.1% to about 25 percent, based on the dry weight of the calcium carbonate, of a weak acid, such as phosphoric acid, formic acid, fluoroboric acid, polyacrylic acid, or alum, or a mixture of weak acids, such as phosphoric acid and polyacrylic acid.