Patent · US Expired

Method of preparing a cellulose carbamate solution

US6590095B1 · kind B1 · utility

126Cited by

4References

7Claims

0Family size

Assignee

Zimmer A.G. · DE

Inventors

Harry Schleicher · Teltow, DE
Bodo Borrmeister · Potsdam, DE
Hermann Lang

Key dates

Filing date	Dec 2, 1998
Grant date	Jul 8, 2003
Priority date	—
Expiry date	Nov 27, 2019

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08B15/06
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.