AQUEOUS POLYMER DISPERSION AND ITS PRODUCTION, FOR ELECTROPHOTOGRAPHIC TRANSFER PAPER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain the subject dispersion useful for electrophotographic transfer paper having high gloss and suitable for use in photographic printing by copolymerization of a specific ethylenically unsaturated monomer mixture in the presence of a specific alkali-soluble polymer neutralized product. SOLUTION: This aqueous polymer dispersion is obtained by the following steps: first, an alkali-soluble polymer is prepared by reaction between (A) 40-70 wt.% of at least two kinds of ethylenically unsaturated carboxylic ester monomers each with a solubility to 20 deg.C water of >=0.5 wt.% and the SP number of the homopolymer of >=7 (Cal/cm3)1/2, being <=0.5 in SP number difference (e.g. methyl acrylate and methyl methacrylate), (B) 5-40 wt.% of an ethylenically unsaturated monomer (e.g. acrylic acid and (C) 0-30 wt.% of another ethylenically unsaturated monomer copolymerizable with the monomer B (e.g. styrene); subsequently, in the presence of the alkali-soluble polymer's neutralized product, a copolymerization is carried out between 70-100 wt.% of the component A and 0-30 wt.% of the component C; the copolymer thus obtained has a glass transition temperature of -10 to 50 deg.C.