US 11,952,442 B2
Method for preparing vinyl chloride-based polymer
Jin Hyuck Ju, Daejeon (KR); Hyun Min Lee, Daejeon (KR); Hyun Kyou Ha, Daejeon (KR); Kun Ji Kim, Daejeon (KR); Kwang Jin Lee, Daejeon (KR); Yang Jun Jeon, Daejeon (KR); and Jae Hyun Park, Daejeon (KR)
Assigned to LG CHEM, LTD., Seoul (KR)
Appl. No. 17/251,589
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Oct. 28, 2019, PCT No. PCT/KR2019/014268
§ 371(c)(1), (2) Date Dec. 11, 2020,
PCT Pub. No. WO2020/091340, PCT Pub. Date May 7, 2020.
Claims priority of application No. 10-2018-0129864 (KR), filed on Oct. 29, 2018.
Prior Publication US 2021/0253751 A1, Aug. 19, 2021
Int. Cl. C08F 14/06 (2006.01); C08F 2/18 (2006.01); C08F 2/22 (2006.01); C08F 2/44 (2006.01); C08K 3/26 (2006.01); C08K 3/30 (2006.01)
CPC C08F 14/06 (2013.01) [C08F 2/18 (2013.01); C08F 2/22 (2013.01); C08F 2/44 (2013.01); C08K 3/26 (2013.01); C08K 3/30 (2013.01); C08K 2003/262 (2013.01); C08K 2003/265 (2013.01); C08K 2003/267 (2013.01)] 5 Claims
 
1. A method for preparing a vinyl chloride-based polymer, the method comprising:
a step of injecting an ionizable normal salt and polymerizing a vinyl chloride monomer in the presence of one or more emulsifiers and a polymerization initiator,
wherein the ionizable normal salt comprises a carbonate metal salt or a sulfite metal salt, wherein the ionizable normal salt is continuously injected in an amount of 70 to 1200 ppm based on the total weight of the vinyl chloride monomer when a polymerization conversion rate is in a range of 0% to 20%,
wherein when the polymerization conversion rate being 0% is a point where polymerization reaction begins immediately after initiating the polymerization of the vinyl chloride monomer,
wherein the polymerization is performed by the steps comprising:
injecting supplementary materials comprising an emulsifier and water to a reactor;
applying vacuum to the reactor and then injecting the polymerization initiator and the vinyl chloride monomer; and
continuously injecting the ionizable normal salt to the reactor after the inner temperature of the reactor reaches 30 to 70° C.