Method for the continuous production of crosslinked particulate gel-type polymers

• Main Author: FUNK RUEDIGER,HILLEBRECHT ANNEMARIE,STUEVEN UWE,WEISMANTEL MATTHIAS,VAN ESBROECK DOMINICUS,POSSEMIERS KARL J.,DEKAEY RONNY
• Format: Patent
• Language: English
• Published: 05.09.2007
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR PREPARATION OR CHEMICAL WORKING-UP; THEIR RELEVANT APPARATUS; TRANSPORTING; WORKING-UP

In the continuous preparation of finely divided, gel-form, crosslinked polymers (I) by copolymerizing water-soluble mono-ethylenically unsaturated monomers (II) with 0.001-5 mol. % (based on (II)) of monomers (III) containing at least two polymerizable groups in a kneader through which materials are transported axially, (a) the degree of filling of the kneader is at least 71%, (b) (II) contains up to 150 ppm hydroquinone hemi-ether (IV), (c) the polymerization zone temperature is more than 65[deg]C and/or (d) the kneader has back mixing ratio less than 0.33.