	US 12,103,998 B2
	Method of preparing diene-based rubber polymer and method of preparing graft polymer including the diene-based rubber polymer
Chang Hong Bak, Daejeon (KR); Jae Min Suk, Daejeon (KR); Jin Hyoung Lee, Daejeon (KR); Jae Won Heo, Daejeon (KR); and Young Min Kim, Daejeon (KR)
Assigned to LG CHEM, LTD., Seoul (KR)
Appl. No. 17/436,027
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Aug. 24, 2020, PCT No. PCT/KR2020/011255 § 371(c)(1), (2) Date Sep. 2, 2021, PCT Pub. No. WO2021/054630, PCT Pub. Date Mar. 25, 2021.
Claims priority of application No. 10-2019-0116370 (KR), filed on Sep. 20, 2019.
Prior Publication US 2022/0169770 A1, Jun. 2, 2022
Int. Cl. C08F 36/06 (2006.01); C08F 36/00 (2006.01); C08F 279/04 (2006.01)

CPC C08F 279/04 (2013.01) [C08F 36/00 (2013.01); C08F 36/06 (2013.01)]

10 Claims

1. A method of preparing a diene-based rubber polymer, comprising:

adding each of a diene-based monomer, a molecular-weight regulator, an initiator, and an emulsifier to a reactor a first time and carrying out polymerization;

adding a molecular-weight regulator to the reactor a second time when a polymerization conversion rate of 48 to 72% is reached and carrying out polymerization;

adding a diene-based monomer to the reactor a second time when a polymerization conversion rate of 63 to 77% is reached and carrying out polymerization;

adding each of an initiator and an emulsifier to the reactor a second time when a polymerization conversion rate of 68 to 81% is reached and carrying out polymerization; and

adding each of an initiator and an emulsifier to the reactor a third time when a polymerization conversion rate of 85 to 91% was reached and carrying out polymerization.