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. 23, 2007
Filed:
Feb. 04, 2004
Thomas Qiuxiong HU, Vancouver, CA;
Brian R. James, Vancouver, CA;
Dominggus Yawalata, Vancouver, CA;
Maria B. Ezhova, Vancouver, CA;
Thomas Qiuxiong Hu, Vancouver, CA;
Brian R. James, Vancouver, CA;
Dominggus Yawalata, Vancouver, CA;
Maria B. Ezhova, Vancouver, CA;
FPInnovations, Pointe Claire, Québec, CA;
University of British Columbia, Vancouver, British Columbia, CA;
Abstract
A method for the bleaching and brightness stabilization of lignocellulosic materials is described. The method involves the treatment of lignocellulosic materials, in particular, (a) wood pulps such as thermomechanical pulps (TMP) and chemithermomechanical pulps (CTMP), and (b) papers made from wood pulps, with a water-soluble phosphine or a phosphonium compound preferably containing at least one phosphorus hydroxyalkyl bond/linkage, for example a phosphorus hydroxymethyl bond/linkage (P—CHOH). One example of such a water-soluble phosphine is the commercially available, tris(hydroxymethyl)phosphine (THP), P(CHOH). One example of such a phosphonium compound is the commercially available, tetrakis(hydroxymethyl)phosphonium chloride (THPC), [P(CHOH)]Cl.