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:
May. 03, 2016
Filed:
Mar. 29, 2013
Weyerhaeuser Nr Company, Federal Way, WA (US);
S. Ananda Weerawarna, Seattle, WA (US);
Weyerhaeuser NR Company, Federal Way, WA (US);
Abstract
Carboxylated, mercerized cellulose fiber having at least 12 meq/100 g of carboxyl substitution at the C-6 position of the anhydroglucose units, which includes at least 20% cellulose II, may be produced by catalytically carboxylating mercerized cellulose fiber in at least two catalytic carboxylation stages in a continuous series in which the pH is adjusted, and a primary oxoammonium salt catalyst (or precursor thereof) and secondary oxidant is added, at the beginning of each stage. Optionally, the carboxylated, mercerized cellulose may be made substantially free of aldehyde groups by means of a stabilizing step following the final carboxylation stage, in which aldehyde groups present in the fibers are converted to carboxyl groups.