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:
Jul. 08, 2003
Filed:
Dec. 02, 1998
Applicant:
Inventors:
Assignee:
Zimmer A.G., Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08B 3/00 ; C07H 1/00 ;
U.S. Cl.
CPC ...
C08B 3/00 ; C07H 1/00 ;
Abstract
The present invention concerns a method of preparing a cellulose carbamate solution by dissolving cellulose carbamate in sodium hydroxide solution at temperatures of <10° C., wherein an 8% to 15% cellulose carbamate solution with a sodium hydroxide concentration of 7% to 12% is prepared in a first step, and then the solution is adjusted to a sodium hydroxide concentration of <9% by diluting with dilute sodium hydroxide solution and/or water in a second step, with the provision that the weight ratio of cellulose carbamate to sodium hydroxide in both steps is >1.