| abstract |
PURPOSE:To obtain a reagent having good storage stability, by compounding calcium bromide in a mixture of an alkyl acrylate derivative, an acrylic acid derivative, a vinyl monomer having a sulfonic acid group and a polyfunctional internal crosslinking monomer. CONSTITUTION:As monomer components, not only 0.1-30wt% of an acrylic acid derivative having a carboxyl group represented by R<3>CH=CR<4>COOH [wherein R<3> is H, a lower alkyl group or a carboxyl group, R<4> is H or lower alkyl group and, when R<3> is H or a lower alkyl group, R<4> may be a carbo-(lower) alkoxy group] and 0.1-20wt% of a vinyl monomer having a sulfonic acid group but also 1-20wt% of a polyfunctional internal crosslinking monomer are used in addition to 30-98.9wt% of an alkyl acrylate derivative represented by a general formula CHz=CR<1>COOR<2> (wherein R<1> is H or an alkyl group and R<2> is an 1-8C alkyl group). Further, calcium bromide is compounded as an additive to make it possible to perform stable emulsion copolymerization without generating a floc even if no emulsifier is especially used. |