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1. (WO2018124242) VINYL POLYMER PRODUCTION METHOD

Pub. No.:    WO/2018/124242    International Application No.:    PCT/JP2017/047106
Publication Date: Fri Jul 06 01:59:59 CEST 2018 International Filing Date: Thu Dec 28 00:59:59 CET 2017
IPC: C08F 2/20
B01F 17/52
C08F 8/14
C08F 16/06
C08K 5/13
C08L 29/04
Applicants: KURARAY CO., LTD.
株式会社クラレ
Inventors: FUKUHARA, Tadahito
福原 忠仁
Title: VINYL POLYMER PRODUCTION METHOD
Abstract:
This production method of a vinyl polymer formed by suspension polymerization of a vinyl compound in the presence of a suspension polymerization dispersion stabilizer. The dispersion stabilizer contains a composition (C), which contains a modified polyvinyl alcohol (A) and a compound (B), and a polyvinyl alcohol (E); in side chains, the modified polyvinyl alcohol (A) has double bonds derived from unsaturated carboxylic acid or a derivative thereof, and the compound (B) is a compound having 2 or more hydroxy groups bonded to a covalent double bond. The modified polyvinyl alcohol (A) and the polyvinyl alcohol (E) have different saponification and viscosity average polymerization degrees. The content of the compound (B) in the composition (C) is greater than or equal to 0.001 and less than 5 parts by mass per 100 parts by mass of the modified polyvinyl alcohol (A), and the mass ratio (C/E) of the composition (C) and the polyvinyl alcohol (E) is 50/50 to 90/10. By this means, during suspension polymerization of the vinyl compound, it is possible to obtain high polymerization stability and to suppress coloration and fisheye of the obtained polymer.