Nippon Gohsei Kagaku Kogyo Kabushiki Kaisha

Kizo Ohnishi

Motokazu Maruhashi

Yoshio Ebina

A dispersing stabilizer including (A) a polyvinyl alcohol resin containing oxyalkylene groups and having a surface tension of 35 to 55 dyne/cm at 20.degree. C. as a 1% by weight aqueous solution, or said resin and (B) a water-soluble polymer or a polyvinyl alcohol resin having a low degree of hydrolysis and a low degree of polymerization. When using the dispersing stabilizer of the present invention, both of a porosity and a bulk density of a polyvinyl resin particle can be improved at the same time, and, in addition, a distribution of particle size and a uniformity of porosity can be further improved.

Dispersing stabilizer

A dispersing stabilizer for suspension polymerization of vinyl compounds comprising (A) a water-soluble protective colloid and (B) a carbonyl group-containing polyvinyl alcohol having an average degree of hydrolysis of 10 to 90% by mole; the absorbance of a 0.1% by weight aqueous solution of the component (B) being not less than 0.18 at a wavelength of 280 m.mu.. Suspension polymerization of vinyl chloride can be conducted by using the stabilizer without adhesion of scale to a polymerization vessel, and also particles of the obtained vinyl chloride resins have a high porosity and uniform size.

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Hirakata, Japan

Kizo Ohnishi