| 摘要 |
PURPOSE:To obtain a porous polymer having high bulk density and excellent free flowability and removability of monomer, by adding a specific partially saponified polyvinyl alcohol and a hydroxypropyl methylcellulose to vinyl chloride and carrying out suspension polymerization of the monomer. CONSTITUTION:Vinyl chloride or a vinyl monomer mixture composed mainly of vinyl chloride (e.g. a mixture containing vinyl acetate, acrylic acid, etc., as the other component) is added with (A) a partially saponified polyvinyl alcohol having an average polymerization degree of 150-600 and a saponification degree of 2-55mol% and (B) a hydroxypropyl methylcellulose having a methoxy group substitution degree of 19-30% and a hydroxypropoxy group substitution degree of 4-15% and the monomer is subjected to suspension polymerization. The sum of the components A and B is 0.01-0.5wt% based on charged monomers and the weight ratio of A/B is preferably 1/10-2/1.
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