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. 14, 1997
Filed:
Apr. 11, 1995
Alan J Brown, Vancouver, WA (US);
Columbia River Carbonates, Woodland, WA (US);
Abstract
A process is provided for the selective aggregation of the fine and ultrafine particles present in an anionically or cationically dispersed mineral pigment slurry, such that an aggregated structure is formed which contains within it a labyrinth of internal voids or pores, which collectively function as light scattering centers. The aggregates are formed from an assemblage of fine mineral particles, interconnected or bonded together with small quantities of a cationic or anionic polymer or agent of low molecular weight. 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. These mineral aggregates are then of a suitable size and surface charge to be retained well in a fiber web by a combination of filtration retention and adsorption retention, and provide added bulk and opacity to the finished sheet of paper. The high solids, aggregated, products of this invention can also be used to enhance the optical properties, smoothness, printing properties and surface coverage of coated paper and paper board.