Process for the continuous preparation of cross-linked gelatinous polymers with a small particle size

摘要

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.