Continuous process for producing water-soluble hydroxyalkyl cellulose and related ethers

US4310663A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Josef Hilbig · Taunusstein, DE
• Arno Holst
• Hans Kunkler · Wiesbaden, DE
• Klaus Stolting · Wiesbaden, DE
• Wolfgang Schminke · Wiesbaden, DE

Key dates

• Filing date: Jun 4, 1980
• Grant date: Jan 12, 1982
• Expiry date: Jun 4, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08B17/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A continuous process for manufacturing water-soluble hydroxyalkyl cellulose, and water-soluble mixed ethers based on hydroxyalkyl cellulose, comprising producing a slurry comprising (by weight) 1 part cellulose, 0.02 to 0.6 parts alkali metal hydroxide, 5 to 10 parts inert organic solvent, and 0.4 to 2.5 parts water; continuously feeding the slurry to a first elevated pressure reactor and mixing the slurry therein with at least one normally gaseous etherifying agent which has been liquified under pressure; maintaining the slurry at a temperature up to 40.degree. C., and a gauge pressure up to 3 bars, for 15 to 90 minutes, to give a degree of substitution from 0.2 to 1.0; continuously circulating the slurry in the first reactor in a loop through a homogenizing device to form a homogenized slurry; continuously feeding the homogenized slurry through a tubular reactor having a conveying device, an inlet, and first and second parts, and reacting the homogenized slurry in the tubular reactor for 70 to 180 minutes at a temperature from 30.degree. to 120.degree. C., under a gauge pressure of up to 10 bars, continuously transferring the reacted slurry into a cooling device; and subsequently…