EMULSION POLYMERIZATION METHOD USING REACTIVE EMULSIFYING AGENT, AQUEOUS POLYMER DISPERSION OBTAINED BY SAME, AND POLYMER FILM

摘要

Provided is an emulsion polymerization method wherein emulsion polymerization of a monomer is carried out using a reactive emulsifying agent in an aqueous medium in the presence of a polymerization initiator, said emulsion polymerization method capable of solving problems such as improvement of copolymerization ratio of the reactive emulsifying agent with the monomer, elimination of the foam trouble and further improvement of the water resistance of a coating film. Emulsion polymerization is carried out using: one or more kinds of polymerizable unsaturated monomers (X) which have at least one carbon-carbon double bond in each molecule; one or more kinds of reactive emulsifying agents (Y) which have at least one polymerizable group in each molecule; and one or more kinds of polyfunctional monomers (Z1) which have two or more polymerizable unsaturated groups in each molecule, while having a molecular weight of less than 150 per one functional group, or one or more kinds of hydrophilic monomers (Z2) which have one polymerizable unsaturated group and a hydrophilic group in each molecule, while having an average molecular weight of less than 250. The mass ratio of the total amount of the polyfunctional monomers (Z1) or the hydrophilic monomers (Z2) used therein relative to the total amount of the reactive emulsifying agents (Y) used therein is within the range of Z1/Y = 1/3-1/30 or Z2/Y = 1/1-1/30.