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AssigneeKuraray Co., Ltd.
InventorsShigeki Takada, Ken Yuki, Hitoshi Maruyama, Taku Tanaka, Kazunari Igarashi
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Disclosed herein is a process for suspension polymerization of a vinyl polymer which comprises using as the suspending agent a polyvinyl ester polymer having an ionic group at an end thereof or a polyvinyl alcohol polymer having a degree of hydrolysis of 90 mol % or less which is obtained by hydrolysis of the above polyvinyl ester polymer. According to the above-mentioned process, vinyl polymer granules having a sharp granulometric dispersion, high bulk density, high plasticizer absorption and low vinyl monomer residue are obtained.
A process for suspension polymerization of vinyl chloride which comprises using as the secondary suspending agent a self-emulsifiable vinyl ester polymer having an ionic group at an end thereof or a self-emulsifiable vinyl alcohol polymer having a degree of hydrolysis of 60 mol % or less which is obtained by hydrolysis of said vinyl ester polymer, said ionic group being selected from the group consisting of amino group, ammonium group, carboxyl group and sulfonic group.
A secondary suspending agent for suspension polymerization of vinyl chloride which comprises a self-emulsifiable vinyl ester polymer having an ionic group at an end thereof or a self-emulsifiable vinyl alcohol polymer having a degree of hydrolysis of 60 mol % or less which is obtained by hydrolysis of said vinyl ester polymer, said ionic group being selected from the group consisting of amino group, ammonium group, carboxyl group and sulfonic group.
A secondary suspending agent for suspension polymerization of vinyl chloride which comprises an aqueous dispersion containing as the dispersoid a self-emulsifiable vinyl ester polymer having an ionic group at an end thereof or a self-emulsifiable vinyl alcohol polymer having a degree of hydrolysis of 60 mol % or less which is obtained by hydrolysis of said vinyl ester polymer, said ionic group being selected from the group consisting of amino group, ammonium group, carboxyl group and sulfonic group.
An aqueous dispersion which comprises water as the dispersion-medium and as the dispersoid a self-emulsifiable vinyl ester polymer having an ionic group at an end thereof or a self-emulsifiable vinyl alcohol polymer having a degree of hydrolysis of 60 mol % or less which is obtained by hydrolysis of said vinyl ester polymer, said ionic group being selected from the group consisting of amino group, ammonium group, carboxyl group and sulfonic group.
A self-emulsifiable vinyl alcohol polymer having a carboxylic group at an end thereof, a degree of hydrolysis of 10 to 60 mol % and a degree of polymerization of 50 to 3,000.
Dependencies are inferred from the claim text.