Process for producing particulate, water-soluble cellulose derivatives using a superheated gas mixture containing steam

US7259257B2 · kind B2 · utility

Assignee

• Wolff Walsrode AG · DE

Inventors

• Hartwig Schlesiger · Bad Fallingbostel, DE
• Martin Morning · Bad Fallingbostel, DE
• Gunter Weber · Linden, DE
• Volker Eckhardt · Walsrode, DE
• Gerd Sonnenberg · Walsrode, DE
• Rene Kiesewetter · Bad Fallingbostel, DE

Key dates

• Filing date: Feb 16, 2001
• Grant date: Aug 21, 2007
• Expiry date: Apr 3, 2024

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2301/08
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a new, particularly economical process for preparing particulate water-soluble cellulose derivatives. The process involves forming a feed composition of swollen and/or dissolved cellulose derivative, and water. The feed composition is contacted with a superheated gas mixture, in a sieve-free high rotational speed gas jet impact mill, and the cellulose derivative of the feed composition is converted into a solid state form of finely particulate particles. The superheated gas mixture, with which the feed composition is contacted, is selected from: (i) a superheated gaseous mixture of steam and an inert gas; and (ii) a superheated gas mixture of steam and air. The superheated gas mixture has a steam content of 40 wt. % to 99 wt. %, based on the total weight of the superheated gas mixture.