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. 27, 1998
Filed:
Feb. 13, 1996
David Depasquale, Nanaimo, CA;
Bruce Evans, Bethlehem, PA (US);
Allied Colloids Limited, , GB;
Mineral Technologies, Inc., Bethlehem, PA (US);
Abstract
Filled paper is made by adding a cationising amount of cationic polymer to a slurry of precipitated calcium carbonate, mixing this slurry into a cellulosic suspension and forming a thin stock, adding anionic particulate material to the suspension before or after the slurry, mixing a polymeric retention aid into the thin stock which includes the precipitated calcium carbonate and the anionic particulate material, draining the thin stock on a screen to form a sheet and drying the sheet. A suitable slurry for this purpose is a slurry of 5 to 70% by weight precipitated calcium carbonate and cationic polymer selected from 0.1 to 1% cationic starch and 0.01 to 0.3% of a high charge density, relatively low molecular weight, cationic polymer.