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:
Dec. 30, 2014
Filed:
Oct. 10, 2007
Magnus Björklund, Ôstersund, SE;
Thomas Christopher Greschik, Göteborg, SE;
Håkan Fägersten, Kode, SE;
Magnus Björklund, Ôstersund, SE;
Thomas Christopher Greschik, Göteborg, SE;
Håkan Fägersten, Kode, SE;
Akzo Nobel N.V., Arnhem, NL;
Abstract
The present invention relates to a process of bleaching pulp derived from an alkaline pulping process having a hexenuronic acid content prior to the final bleaching stage from about 1 to about 80 mmol/kg dry pulp, said process comprising three chlorine dioxide stages D0, D1, and D2, wherein the chlorine dioxide charges based on the total chlorine dioxide charge in a) D0 is from about 40 to about 60%; b) D1 is from about 30 to about 55%; c) D2 is from about 4 to about 20%, and wherein the final chlorine dioxide stage D2 is performed at a pH from about 2 to about 4.5. The invention also relates to a bleached pulp obtainable by the process.