US 11,884,760 B2
Production method for branched conjugated diene-based polymer, production method for rubber composition, production method for tire, branched conjugated diene-based polymer, and branched conjugated diene-based polymer composition
Shinichi Sekikawa, Tokyo (JP); Kenta Hisamura, Tokyo (JP); Syogo Sumitani, Tokyo (JP); and Yoshifumi Araki, Tokyo (JP)
Assigned to Asahi Kasei Kabushiki Kaisha, Tokyo (JP)
Filed by Asahi Kasei Kabushiki Kaisha, Tokyo (JP)
Filed on Dec. 9, 2020, as Appl. No. 17/116,014.
Claims priority of application No. 2019-224387 (JP), filed on Dec. 12, 2019; application No. 2020-047421 (JP), filed on Mar. 18, 2020; and application No. 2020-202847 (JP), filed on Dec. 7, 2020.
Prior Publication US 2021/0189039 A1, Jun. 24, 2021
Int. Cl. C08F 236/06 (2006.01); C08K 3/04 (2006.01); C08K 3/36 (2006.01); C08J 3/20 (2006.01)
CPC C08F 236/06 (2013.01) [C08J 3/203 (2013.01); C08K 3/04 (2013.01); C08K 3/36 (2013.01); C08J 2347/00 (2013.01)] 12 Claims
 
1. A production method for a branched conjugated diene-based polymer, comprising the following sequential steps:
(i) a polymerizing step of obtaining a conjugated diene-based polymer having an active end by polymerizing or copolymerizing a conjugated diene compound, or a conjugated diene compound and an aromatic vinyl compound with an organic lithium-based compound used as a polymerization initiator;
(ii) a branching step of introducing a branch structure by reacting a styrene derivative as a branching agent with the active end of the conjugated diene-based polymer, wherein the active end reacts with a vinyl group and a functional group of the styrene derivative, respectively, and the active end reacted with the vinyl group polymerizes with the conjugated diene compound and/or the aromatic vinyl compound while retaining a polymerization activity;
(iii) adding a second conjugated diene compound and/or a second aromatic vinyl compound to a reaction system during and/or after the branching step such that the second conjugated diene compound and/or the second aromatic vinyl compound reacts with the active end of the conjugated diene-based polymer; and
(iv) a reaction step of reacting a coupling agent containing silicon and a sulfur atom with the active end of the conjugated diene-based polymer resulting from the branching step.