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:
Jan. 31, 1995
Filed:
Mar. 09, 1992
Alex Berg, Schwabisch-Hall, DE;
Wim Janssen, Murrhardt, DE;
Stefan Balle, Schwabisch Gmund, DE;
Rudolf G Kunz, deceased, late of Nurtingen, DE;
Wolfdieter Klein, Recklinghausen, DE;
Acetocell GmbH & Co. KG, Gschwend, DE;
Abstract
In a three-stage process for the delignification of cellulose-containing raw materials, pulping is initially performed with a solution of concentrated aqueous acetic acid at an elevated temperature and under an elevated pressure. The resultant acetic acid-moist pulp is treated in a second stage with the aforementioned pulping solution with the addition of nitric acid and is then washed or extracted with water or with the pulping solution. In a third treatment stage, the thus-obtained acetic acid-moist pulp is treated with an ozone-containing gas.