US 12,252,564 B2
Method for producing vinyl chloride type polymer
Hiroshi Fukudome, Kamisu (JP); Kazuhiro Kumakura, Kamisu (JP); and Toshihiko Kawakubo, Kamisu (JP)
Assigned to Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Appl. No. 17/620,373
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
PCT Filed Jun. 8, 2020, PCT No. PCT/JP2020/022523
§ 371(c)(1), (2) Date Dec. 17, 2021,
PCT Pub. No. WO2020/255777, PCT Pub. Date Dec. 24, 2020.
Claims priority of application No. 2019-113440 (JP), filed on Jun. 19, 2019.
Prior Publication US 2022/0235159 A1, Jul. 28, 2022
Int. Cl. C08F 214/06 (2006.01); C08F 2/01 (2006.01); C08F 2/20 (2006.01); C08F 114/06 (2006.01); C08L 71/02 (2006.01)
CPC C08F 214/06 (2013.01) [C08F 2/01 (2013.01); C08F 2/20 (2013.01); C08F 114/06 (2013.01); C08L 71/02 (2013.01)] 3 Claims
 
1. A method for producing a vinyl chloride type polymer, the method being to produce the vinyl chloride type polymer by polymerizing a vinyl chloride monomer, or a mixture of a vinyl chloride monomer with a monomer copolymerizable with the vinyl chloride monomer in an aqueous medium by using a polymerization reactor, the method comprising:
charging an aqueous solution of a copolymerized polyether having a weight-average molecular weight of 1,000 to 3,500 with a mole ratio of ethylene oxide to propylene oxide in a range of 10/90 to 60/40 and having an alkyl group or an aryl group at both terminals thereof into the polymerization reactor with an amount of 0.005 to 0.050 parts by weight as the copolymerized polyether relative to 100 parts by weight of the vinyl chloride monomer,
wherein,
the polymerization reactor is equipped with a reflux condenser, and
in the polymerization, the aqueous solution of the copolymerized polyether is added at a polymerization stage with a polymerization rate of 30 to 80%.