| 摘要 |
PURPOSE:The titled copolymer, containing specific unsaturated carboxylic acids as an anionic component and capable of exhibiting improved effect on dry paper strengthening by using together with aluminum sulfate, etc., when forming sheets of paper. CONSTITUTION:A copolymer, obtained by copolymerizing an anionic component consisting of two or more alpha,beta-unsaturated carboxylic acids (salts) and containing at least one of alpha,beta-unsaturated dicarboxylic acid (salt) with acrylamide in the presence of a water-soluble radical polymerization initiator, e.g. sodium persulfate, by an aqueous solution polymerization method. Maleic acid, etc., may be preferred for the above-mentioned alpha,beta-unsaturated dicarboxylic acid. 0.05-4wt%, expressed in terms of solid based on the dry weight of pulp, above- mentioned copolymer is preferably added to an aqueous dispersion of the pulp in using the above-mentioned copolymer. |
