Process for the production of water adsorbing but water-insoluble cellulose ethers

US3936441A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Arno Holst
• Michael Kostrzewa · Wiesbaden, DE
• Helmut Lask · Wiesbaden, DE

Key dates

• Filing date: Nov 11, 1974
• Grant date: Feb 3, 1976
• Expiry date: Nov 11, 1994

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08B11/00
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

This invention relates to an improvement in the process for the production of water-adsorbing, but largely water-insoluble, cellulose ethers, in which cellulose is alkalized in the presence of alkali hydroxide and isopropanol as a reaction medium and is so reacted with an etherification agent that by etherification only a water-soluble cellulose ether is produced, and in which process the cellulose is reacted with a cross-linking agent which is polyfunctional towards cellulose in an alkaline reaction medium before, during, or after the etherification of the cellulose, the improvement comprising effecting the etherification of cellulose to carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose, or methylhydroxyethyl cellulose, reacting the cellulose with the polyfunctional cross-linking agent in the presence of 0.8 to 7.5 parts by weight of isopropanol, based upon the cellulose weight, and employing as the cross-linking agent acrylamido methylene chloroacetamide, dichloroacetic acid or phosphorus oxychloride or a compound in which at least two groups functional towards cellulose are PA1 The acrylic amino group ##EQU1## the chlorine azomethine group ##E…