| 摘要 |
PURPOSE:To prepare the title aqueous dispersion useful as an agent for improving the water absorption of synthetic resins, by reacting a powdery acrylonitrile polymer having acidic groups and crosslinked structure, with an alkali, thereby introducing a salt-form carboxyl groups to the polymer. CONSTITUTION:A powdery acrylonitrile copolymer or its aqueous emulsion, having particle diameter of <= 1mu, containing acidic groups and crosslinked structure, and obtained by the copolymerization of acrylonitrile with one or more other ethylenic unsaturated compound, is made to react with an alkali metal hydroxide. At least 0.1m-mol/g of salt-form carboxyl groups of formula -COOX (X is alkali metal or ammonium) are introduced into the copolymer, to afford an aqueous dispersion of microhydrogel composed of hydrogel having particle size of <= 1mu (at absolute dryness) and a water swelling of >= 3cc/g, and dispersed homogeneously in an aqueous medium.
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