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. 29, 2013
Filed:
Jan. 16, 2011
Applicant:
Thomas Dietz, Haibach, DE;
Inventor:
Thomas Dietz, Haibach, DE;
Assignee:
Evonik Degussa GmbH, Essen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C 9/16 (2006.01); D21C 9/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
The delignification and bleaching of chemical pulp by a bleaching stage, in which the chemical pulp is reacted first with chlorine dioxide and, after reaction of the chlorine dioxide, is further reacted without intermediate washing with hydrogen peroxide in the presence of a molybdate or tungstate, permits the production of chemical pulp having a whiteness of at least 89.5%, having improved stability to yellowing and reduced oxidative damage.