摘要 |
Water-soluble copolymers having a K value of from 15 to 120 (determined on the sodium salt according to H. Fikentscher in aqueous solution at 25 DEG C., a pH of 7 and a polymer concentration of the Na salt of 1% by weight) contain, in the polymerized form, (a) from 99.5 to 80 mol % of one or more monoethylenically unsaturated C3-C6-monocarboxylic acids and (b) from 0.5 to 20 mol % of one or more comonomers which possess two or more ethylenically unsaturated, non-conjugated double bonds, are derived from esters and are obtainable by esterification of (b1) monoethylenically unsaturated C3-C6-monocarboxylic acids with (b2) polyhydric alcohols of 2 to 6 carbon atoms, polyalkylene glycols, polyglycerols, polyvinyl alcohol and monohydric, monoethylenically unsaturated C3-C6-alcohols and (c) from 0 to 30 mol % of other water-soluble, monoethylenically unsaturated monomers which are copolymerizable with (a) and (b), the copolymers containing polymer segments which consist of units of the monomers (a) and (c), have a weight average molecular weight of not more than 15,000 and are bonded to one another via units of (b).
|