| 摘要 |
<p>In a process for the preparation of copolymers which contain monoethylenically unsaturated monocarboxylic acids and dicarboxylic acids as copolymerized monomer units, by copolymerizing the monocarboxylic acids with the dicarboxylic acids or, where appropriate, their inner anhydrides, in an aqueous medium in the presence of a water-soluble initiator, the improvement that a) from 10 to 60% by weight, based on the sum of the monomers, of a monoethylenically unsaturated dicarboxylic acid of 4 to 6 carbon atoms, its alkali metal salt or, where appropriate, its anhydride, b) from 90 to 40% by weight of a monoethylenically unsaturated monocarboxylic acid of 3 to 10 carbon atoms or its alkali metal salt and c) from 0 to 20% by weight of another monoethylenically unsaturated monomer, which is free from carboxyl groups and is copolymerizable with a) and b) are copolymerized in an aqueous medium in the presence of from 0.5 to 5% by weight, based on monomers, of the watersoluble initiator by introducing the dicarboxylic acid, its salt or its anhydride into the aqueous medium, adding the monocarboxylic acid together with the initiator over from 3 to 10 hours, completing the reaction at 60 - 150.degree.C and, where appropriate, hydrolyzing the anhydride groups.</p> |
