Method for continuously producing cross-linked fine-particle geleous polymerizates

US6710141B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Wilfried Heide · Freinsheim, DE
• Stefan Wickel · Ludwigshafen, DE
• Thomas Daniel · Waldsee, DE
• Joachim Nilges · Ludwigshafen, DE
• Jurgen Hofmann · Spalt, DE

Key dates

• Filing date: May 8, 2002
• Grant date: Mar 23, 2004
• Expiry date: May 16, 2022

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2219/00166
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for continuous production of crosslinked fine particles of polymer gel by copolymerizing a) water-soluble monoethylenically unsaturated monomers, b) from 0.001 to 5 mol % based on the monomers (a) of monomers containing at least two ethylenically unsaturated double bonds, and c) from 0 to 20 mol % based on the monomers (a) of water-insoluble monoethylenically unsaturated monomers in from 20 to 80% by weight aqueous solution in the presence of an initiator at from 0 to 140° C. by feeding the aqueous solution of the monomers together with the initiator and an inert gas continuously into a mixing kneader having at least two axially parallel rotating shafts equipped with a plurality of kneading and transporting elements which convey the substances introduced at the upstream end of the mixing kneader in the axial direction toward the downstream end of the mixer, comprises the fraction of heat being removed by evaporation of water from the reaction mixture being not less than 5% of the heat of reaction and the fraction of heat being removed by product discharge being not less than 25% of the heat of reaction and the rest of the heat being removed via cooling of the reactor …