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:
Aug. 05, 1997
Filed:
Nov. 16, 1995
Alan J Brown, Vancouver, WA (US);
Columbia River Carbonates, Woodland, WA (US);
Abstract
A method is disclosed for producing bulking and opacifying pigments for filling paper by the selective aggregation of fine particles in an anionically or cationically dispersed slurry, such that an aggregated structure is formed which contains within it a labyrinth of internal voids or pores. The aqueous slurry is formed at one to thirty percent solids. A low molecular weight agent of opposite ionic charge is then added to the slurry to selectively aggregate the fine particles present. The resultant aggregates are of larger mean particle size than the feed material and contain little or no fine and colloidal particles. The net charge present on the aggregated particles is lower than that of the feed material.