| 摘要 |
Water-soluble copolymers having a K value of from 15 to 120 (determined according to H. Fikentscher in an aqueous solution of their sodium salt at 25.degree.C, a pH of 7 and a polymer concentration of the Na salt of 1% by weight) contain, in polymerized form, a) not less than 80 mol % of one or more monoethylenically unsaturated C3-C6-monocarboxylic acids, b) from 0.5 to 20 mol % of a comonomer which possesses two or more ethylenically unsaturated, non-conjugated double bonds and one or more -CO-OX groups and/or their salt with an alkali metal, ammonium or alkaline earth metal base, and, if required, c) not more than 10 mol % of one or more comonomers which differ from b) and possess two or more ethylenically unsaturated, non-conjugated double bonds, and the said copolymers are prepared by copolymerization of the monomers a), b) and, if required, c) in aqueous solution and are used for coating seed.
|
