Patent ID: 11884767
Assignee: BRIDGESTONE CORPORATION
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 6:
7. A method of preparing a vulcanizable composition including a high 1,4-cis block copolymer of polybutadiene and polyisoprene comprising:
(i) forming a polymerization mixture that includes a pseudo-living polymer by combining a first monomer and a lanthanide-based catalyst, where the lanthanide-based catalyst comprises
(a) a lanthanide-containing compound,
(b) an aluminoxane,
(c) an organoaluminum compound defined by the formula AlRnX3-n where each R is individually a hydrocarbon group or a substituted hydrocarbon group, each X is individually a hydrogen atom, a carboxylate group, an alkoxide group, or an aryloxide group, and where n is an integer of 1 to 3, and
(d) a halogen-containing compound;

(ii) adding a second monomer to the polymerization mixture that includes a pseudo-living polybutadiene polymer, to obtain the high 1,4-cis block copolymer of polybutadiene and polyisoprene;
(iii) mixing the high 1,4-cis block copolymer of polybutadiene and polyisoprene with a filler and a curing agent to form the vulcanizable composition, wherein the high 1,4-cis block copolymer of polybutadiene and polyisoprene is between 50% and 100% by weight of a total rubber component of the vulcanizable composition; and, where the first monomer is either 1,3-butadiene or isoprene and where the second monomer is not the same as the first monomer and is either 1,3-butadiene or isoprene.