Patent · US Expired

Process for producing extractive-material-reduced cellulose

US4814440A · kind A · utility

1Cited by

1References

12Claims

0Family size

Assignee

Akzo N.V. · NL

Inventors

Joachim Behnke · Miltenberg, DE
Helmut Schulze · Großwallstadt, DE
Ernst Berg · Dormagen, DE
Michael Pelger · Wuppertal, DE

Key dates

Filing date	Oct 1, 1987
Grant date	Mar 21, 1989
Priority date	—
Expiry date	Oct 1, 2007

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21H11/12
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

The invention relates to a process for obtaining extractive-material-reduced cellulose with a low LAL reaction, wherein cotton linters or wood pulps, subsequent to the customary digesting treatment, are subjected for 1 to 10 hours to hydraulic washing with water, lye with a concentration of less than 5 g/l alkali content, or with a diluted acid containing less than 5 g/l acid at temperatures of 120.degree. to 180.degree. C. and under a pressure of 2 to 20 bar. The resulting cellulose is used for the manufacture of hemodialysis and/or hemofiltration membranes in the form of flat membranes, tubular membranes or hollow filaments by regeneration of a cellulose solution containing the extractive-material-reduced cellulose with a low LAL reaction. The regeneration may be effected from solutions of cellulose cuoxam, cellulose xanthate, or solutions of cellulose in tertiary amine oxide or in an LiCl-containing solvent.

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