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:
Nov. 11, 1997
Filed:
Jun. 09, 1995
Applicant:
Inventors:
Marco Solinas, Vancouver, CA;
Thomas Howard Murphy, Burnaby, CA;
Adriaan Reinhard van Heiningen, New Brunswick, CA;
Yonghao Ni, Fredericton, CA;
Assignee:
MacMillan Bloedel Limited, Vancouver, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 65 ; 162 77 ; 162 78 ;
Abstract
A bleached pulp having a high viscosity for a given permanganate number is formed by pretreating never dried pulp with an organic solvent medium to produce a treated pulp composed of said never dried pulp in the medium and then bleaching that treated pulp using ozone at a pH of 1.5-5 to provide a bleached pulp while reducing the viscosity loss during the ozone bleaching step significantly compared to that what would occur if the medium used in the ozone bleaching were water.