Patent ID: 9567409
Date: 2017-02-14
CPC Classifications: C08F

Claim:
1. A method for preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer, comprising: (a) polymerizing a vinyl aromatic hydrocarbon monomer in a hydrocarbon solvent with an organic lithium compound as a polymerization initiator to prepare a first mix solution comprising a vinyl aromatic hydrocarbon block; and (b) polymerizing a conjugated diene monomer and the vinyl aromatic hydrocarbon block present in the first mix solution of the step (a) by adding the conjugated diene monomer to the first mix solution of the step (a) to form a conjugated diene block on an end of the vinyl aromatic hydrocarbon block and to thereby prepare a second mix solution comprising a vinyl aromatic hydrocarbon block-conjugated diene block, wherein the method further comprises: (c) adding an ion stabilizer to the first mix solution during or after polymerization of the vinyl aromatic hydrocarbon monomer of the step (a) and before adding the conjugated diene monomer of the step (b), (d) adding a coupling agent to the second mix solution of the step (b) and performing a coupling reaction to form a vinyl aromatic hydrocarbon-conjugated diene block copolymer, and (e) adding octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and trisnonylphenyl phosphite to the vinyl aromatic hydrocarbon-conjugated diene block copolymer after performing the coupling reaction, wherein the ion stabilizer is tri-isobutyl aluminum, wherein a molar ratio of the ion stabilizer to the organic lithium compound (number of moles of ion stabilizer/number of moles of organic lithium compound) is 0.05 to 0.2, and wherein the coupling agent is dichlorodimethylsilane.