Kuraray Co., Ltd.

Kuraray Europe Gmbh

Samuel Michel

Masato Nakamae

Masaki Kato

Tadahito Fukuhara

Yosuke Kumaki

Robert Walter Fuss

Akira Tsuboi

Dirk Hartmann

Eva Dudek

Robert Fuss

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.

Dispersion stabilizer for suspension polymerization, and method for producing vinyl resin

A dispersion stabilizer in the present invention contains an aqueous emulsion (a) obtained by dispersing a polymer (A) having an ethylenically unsaturated monomer unit in an aqueous medium, a PVA (B) having a degree of saponification of 65 mol % or more and less than 82 mol % and a viscosity-average degree of polymerization of 250 or more and less than 1500, and a PVA (C) having a degree of saponification of 82 mol % or more and less than 98 mol % and a viscosity-average degree of polymerization of 1500 or more and less than 4000. The dispersion stabilizer contains: 7 to 51 mass % of the polymer (A); 40 to 84 mass % of the PVA (B); and 9 to 53 mass % of the PVA (C), with respect to a total amount of the polymer (A), the PVA (B), and the PVA (C). A vinyl resin satisfying required performance can be obtained using the dispersion stabilizer.

Vinyl resin production method

A polyvinyl chloride resin composition contains: from 0.005 to 5 parts by weight of a polyvinyl alcohol having a viscosity average degree of polymerization of from 100 to 3000 and having a ratio Mw/Mn of a weight average molecular weight Mw to a number average molecular weight Mn of from 2.2 to 4.9; and from 0.01 to 5 parts by weight of a zinc compound, based on 100 parts by weight of a polyvinyl chloride resin. A polyvinyl chloride resin composition is thereby provided that enables to obtain a shaped article thereof excellent in thermal stability while being shaped and less colored.

Polyvinyl chloride resin compositions and manufacturing method therefor

Thermoplastically processable PVC mixtures having enhanced stability are prepared by incorporating at least one stabilizer containing metal ions and a modified polyvinyl alcohol co-stabilizer.

Polyvinyl alcohol as co-stabilizer for PVC

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Hattersheim am Main, Germany

Samuel Michel