Method for producing regular porous cellulose pearls, corresponding cellulose pearls and use thereof

US6670469B1 · kind B1 · utility

Assignee

• Thuringishces Institut fur Textil und Kunststoff-Forschung E.V. · DE

Inventors

• Christine Beyer · Rudolstadt, DE
• Frank Meister · Rudolstadt, DE
• Christoph Michels · Riegelsberg, DE
• Bernd Riedel · Hagneck, CH
• Eberhard Taeger · Rudolstadt, DE

Key dates

• Filing date: Aug 12, 1999
• Grant date: Dec 30, 2003
• Expiry date: Aug 12, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2301/02
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Process for producing regular porous pearl cellulose with a particle size in the range from 2 to 1,000 &mgr;m, comprising the steps:a) a cellulose having a degree of polymerisation in the range from 150 to 2,000 is dissolved in a solvent to form a solution of 0.5 to 25% by mass, b) the cellulose solution is finely divided and dispersed in a dispersant which is immiscible with said solution and has a viscosity in the range from 10 to 80,000 mPa·s, c) the dispersed solution particles are solidified to regular pearl particles by precipitating with a liquid precipitating agent miscible with the solvent (1) after cooling the dispersion to below the melting temperature of the cellulose solution and separating the frozen particles of the cellulose solution from the dispersant or (2) directly in the dispersion, and d) the pearl particles are separated from the liquid mixture of solvent, precipitating agent and possibly dispersant.