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:
Aug. 11, 1998
Filed:
Oct. 06, 1993
Applicant:
Inventor:
Ted Yuan Tsai, Harriman, NY (US);
Assignee:
International Paper Company, Purchase, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 65 ; 162 66 ; 162 89 ;
Abstract
In the bleaching of kraft cellulosic pulps employing a stage in which the pulp is contacted simultaneously with gaseous chlorine and ozone, the improvement in which the pulp at a low to high consistency is initially chlorinated with hypochlorous acid and thereafter is contacted substantially simultaneously with gaseous chlorine and ozone. The pulp so processed exhibits enhanced brightness and good viscosity, and the process produces low quantities of environmentally undesirable chlorinated organics. The bleaching sequence of M(C+Z).sub.g ED is disclosed.