US 12,291,630 B2
Method for preparing conjugated diene-based polymer
Young Hwan Jeong, Daejeon (KR); Yoo Vin Kim, 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. 17/615,386
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Sep. 23, 2020, PCT No. PCT/KR2020/012872
§ 371(c)(1), (2) Date Nov. 30, 2021,
PCT Pub. No. WO2021/060833, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 10-2019-0119589 (KR), filed on Sep. 27, 2019.
Prior Publication US 2022/0227987 A1, Jul. 21, 2022
Int. Cl. C08L 25/10 (2006.01); C08L 51/00 (2006.01)
CPC C08L 51/003 (2013.01) 15 Claims
 
1. A method for preparing a conjugated diene-based polymer, the method comprising:
injecting 30 to 50 parts by weight of a conjugated diene-based monomer among 100 parts by weight, 0.1 to 5 parts by weight of a dimer acid saponified material, and a polymerization initiator into a reactor in one batch, and initiating polymerization reaction (S1);
injecting the remaining conjugated diene-based monomer and an emulsifier in three or more installments according to a polymerization conversion ratio after initiating the polymerization reaction (S2); and
finishing the polymerization reaction at a point where the polymerization conversion ratio is 90 to 99% (S3),
wherein step S2 comprises:
injecting the conjugated diene-based monomer and the emulsifier at a point where the polymerization conversion ratio is 20 to 35% (S2-1);
injecting the conjugated diene-based monomer and the emulsifier at a point where the polymerization conversion ratio is 45 to 60% (S2-2); and
injecting the conjugated diene-based monomer and the emulsifier at a point where the polymerization conversion ratio is 70 to 80% (S2-3).