Process for the production of water-adsorbing cellulose ethers

US4068067A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

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

Key dates

• Filing date: May 6, 1976
• Grant date: Jan 10, 1978
• Expiry date: May 6, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08B15/005
• 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 at least partially water-insoluble cellulose ethers in which cellulose is alkalized in a liquid reaction medium and etherified in a manner such that by etherification only an at least largely water-soluble carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose is produced, and in which the cellulose is reacted in an alkaline reaction medium before, during, or after the etherification with a modification agent reactive with the still free hydroxyl groups of the cellulose anhydro glucose groups, said modification agent having one of the formulae ##STR1## in which R.sub.1 is hydroxyl, an acylamino or esterified carbamino group, and R.sub.2 is hydrogen or a carboxyl group, The improvement comprising effecting alkalization, etherification, and modification in a liquid reaction medium other than isopropyl alcohol.