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. 22, 2000
Filed:
Nov. 16, 1998
Henryk Struszczyk, Zgierz, PL;
Dariusz Wawro, Lodz, PL;
Pawel Starostka, Lodz, PL;
Wlodzimierz Mikolajczyk, Lodz, PL;
Alojzy Urbanowski, Lodz, PL;
Institute of Chemical Fibres, Lodz, PL;
Lurgi Zimmer AG, Frankfurt am Main, DE;
Abstract
Process for producing cellulosic moldings such as fibers, foils, casings and beads from cellulose, wherein (a) the initial cellulose is hydrothermally treated with water in a water/cellulose ratio on a weight basis of at least 1 at a temperature in the range from about 100.degree. to about 200.degree. C. and under a pressure in the range from 0.1 to about 1.5 MPa; (b) the treated cellulose is dissolved in an aqueous solution of alkali hydroxide at a temperature of at least 0.degree. C. to form a homogenous cellulose solution containing from about 5% to about 10% by weight cellulose and at maximum 10% by weight alkali hydroxide, and (c) the alkaline cellulose solution is formed and coagulated by contacting it with an aqueous solution containing 1 to about 30% by weight of an acid. This fully ecological process avoids handling of toxic products or by-products and uses aqueous solvents instead of expensive organic solvents. The cellulose solution is stable for at least 48 hours.