DISPERSION STABILIZER FOR SUSPENSION POLYMERIZATION, AND METHOD FOR PRODUCING VINYL RESIN

摘要

Provided is a dispersion stabilizer for suspension polymerization comprising an aqueous emulsion containing a dispersant (A), a dispersoid (B), a graft polymer (C), and an aqueous medium, wherein the dispersant (A) contains a surfactant, the dispersoid (B) contains a polymer having an ethylenically unsaturated monomer unit, the graft polymer (C) is obtained by graft polymerization of the ethylenically unsaturated monomer with the dispersant (A), a mass ratio [A/(A+B+C)] is 0.001 or more and less than 0.18, a mass ratio [C/(A+B+C)] is 0 or more and less than 0.04, and the total content of the dispersant (A), the dispersoid (B), and the graft polymer (C) is 35 to 70 mass %. A vinyl polymer to be obtained by suspension polymerization of a vinyl compound using the dispersion stabilizer has good plasticizer absorption. Further, the number of fish-eyes that occur when the vinyl polymer is formed is small, and the hue deterioration is also suppressed. Further, the dispersion stabilizer also has excellent handleability.

主权项

1. A dispersion stabilizer for suspension polymerization comprising an aqueous emulsion comprising a dispersant (A), a dispersoid (B), a graft polymer (C), and an aqueous medium,
wherein the dispersant (A) comprises a surfactant, the dispersoid (B) comprises a polymer comprising an ethylenically unsaturated monomer unit, the graft polymer (C) is obtained by graft polymerization of the ethylenically unsaturated monomer with the dispersant (A), a mass ratio [A/(A+B+C)] of the dispersant (A) with respect to a total amount of the dispersant (A), the dispersoid (B), and the graft polymer (C) is 0.001 or more and less than 0.18, a mass ratio [C/(A+B+C)] of the graft polymer (C) with respect to the total amount of the dispersant (A), the dispersoid (B), and the graft polymer (C) is 0 or more and less than 0.04, and a total content of the dispersant (A), the dispersoid (B), and the graft polymer (C) is 35 to 70 mass %.