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. 03, 1989
Filed:
Aug. 10, 1987
Applicant:
Inventors:
S Allen Grimsley, Portsmouth, VA (US);
James C Robinson, Chesapeake, VA (US);
Mark A Schroeder, Norfolk, VA (US);
Assignee:
Hoechst Celanese Corporation, Somerville, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D21C / ;
U.S. Cl.
CPC ...
162 72 ; 162 75 ; 162 76 ; 162160 ;
Abstract
Compositions and a method are disclosed for minimizing brightness reversion of chromophore-containing wood pulps, especially low-cellulose wood pulps, such as groundwood and thermomechanical pulps, which have been reductively bleached or bleached with hydrogen peroxide. Ascorbic acid and palmitoyl ascorbate are particularly effective for preventing such reversion at low levels.