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:
Jul. 27, 1999
Filed:
Jan. 15, 1997
Applicant:
Inventors:
David Victor Avila, Ottawa, CA;
Juan Cesar Scaiano, Ottawa, CA;
Assignee:
University of Ottawa, Ottawa, CA;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
D21H / ;
U.S. Cl.
CPC ...
162160 ; 162158 ; 162173 ; 162135 ; 1621816 ; 1621818 ; 10616301 ;
Abstract
The present invention relates to a method for the inhibition of photo-yellowing in paper rich in lignin by treatment of pulp or paper rich in lignin with a compound containing hydroxy functionalities that are capable of forming a ketal with a carbonyl group in an acidic environment. In a preferred embodiment the acidic environment is provided by the presence of an acidic clay or an acidic zeolite.