# US 9,434,804 B2 · Branched conjugated diene copolymer, rubber composition and pneumatic tire > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,434,804 B2 - Document ID: US9434804B2 - Status: Granted - Kind: B2 - Application number: 14/370,323 - Filed: 2013-01-22 - Published: 2014-12-18 - Granted: 2016-09-06 - Earliest claimed: 2012-02-02 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: Kensuke Washizu - Web page: https://patentgrep.com/patent/US9434804B2 ## CPC - C08F 236/06: Butadiene - B60C 1/0016: {Compositions of the tread} - C08F 236/045: {conjugated hydrocarbons other than butadiene or isoprene} - C08F 236/08: Isoprene - C08F 236/22: the radical having three or more carbon-to-carbon double bonds - C08L 47/00: Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds; Compositions of derivatives of such polymers (C08L45/00 takes precedence; of conjugated diene rubbers C08L9/00 - C08L21/00) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract There is provided a branched conjugated diene copolymer prepared by copolymerizing 1 to 99% by weight of a branched conjugated diene compound (1): wherein R1 is an aliphatic hydrocarbon having 6 to 11 carbon atoms, and 99 to 1% by weight of a conjugated diene compound (2): wherein R2 and R3 are the same or different and each is a hydrogen atom, or the like. The branched conjugated diene copolymer is useful as a rubber component of a rubber composition for a tire enhancing both of abrasion resistance and grip performance to a high level and exhibiting excellent processability. ## Claims ### Claim 1 A branched conjugated diene copolymer prepared by copolymerizing monomers consisting of a branched conjugated diene compound and a conjugated diene compound, wherein a copolymerization ratio of the branched conjugated diene compound is 1 to 40% by weight, a copolymerization ratio of the conjugated diene compound is 99 to 60% by weight, the branched conjugated diene compound is farnesene, the conjugated diene compound is 1,3-butadiene, and the branched conjugated diene copolymer has a weight-average molecular weight in a range of 3,000 to 3,000,000 and a number-average molecular weight in a range of 3,000 to 3,000,000 such that Mw/Mn is 20.0 or less, where Mw represents the weight-average molecular weight and Mn represents the number-average molecular weight. ### Claim 2 (depends on 1) The branched conjugated diene copolymer of claim 1, wherein the copolymerization ratio of the branched conjugated diene compound is 2.5 to 40% by weight, and the copolymerization ratio of the conjugated diene compound is 60 to 97.5% by weight. ### Claim 3 (depends on 1) The branched conjugated diene copolymer of claim 1, which is low in a Mooney viscosity ML1+4 (130° C.) compared with a polymer which has the same weight-average molecular weight and in which the branched conjugated diene compound is replaced by the conjugated diene compound. ### Claim 4 (depends on 1) A rubber composition comprising the branched conjugated diene copolymer of claim 1. ### Claim 5 (depends on 4) A pneumatic tire comprising the rubber composition of claim 4. ### Claim 6 A pneumatic tire, comprising: a rubber composition comprising a branched conjugated diene copolymer prepared by copolymerizing monomers consisting of a branched conjugated diene compound and a conjugated diene compound, wherein a copolymerization ratio of the branched conjugated diene compound is 1 to 99% by weight, a copolymerization ratio of the conjugated diene compound is 99 to 1% by weight, the branched conjugated diene compound is farnesene, the conjugated diene compound is 1,3-butadiene, and the branched conjugated diene copolymer has a weight-average molecular weight in a range of 3,000 to 3,000,000 and a number-average molecular weight in a range of 3,000 to 3,000,000 such that Mw/Mn is 20.0 or less, where Mw represents the weight-average molecular weight and Mn represents the number-average molecular weight. ### Claim 7 (depends on 6) The pneumatic tire of claim 6, wherein the rubber composition has the copolymerization ratio of the branched conjugated diene compound in a range of 2.5 to 75% by weight, and the copolymerization ratio of the conjugated diene compound in a range of 25 to 97.5% by weight. ### Claim 8 (depends on 6) The pneumatic tire of claim 6, wherein the branched conjugated diene copolymer is low in a Mooney viscosity ML1+4 (130° C.) compared with a polymer which has the same weight-average molecular weight and in which the branched conjugated diene compound is replaced by the conjugated diene compound. ### Claim 9 (depends on 2) A rubber composition comprising the branched conjugated diene copolymer of claim 2. ### Claim 10 (depends on 9) A pneumatic tire comprising the rubber composition of claim 9. ### Claim 11 (depends on 3) A rubber composition comprising the branched conjugated diene copolymer of claim 3. ### Claim 12 (depends on 11) A pneumatic tire comprising the rubber composition of claim 11. ### Claim 13 (depends on 2) The branched conjugated diene copolymer of claim 2, which is low in a Mooney viscosity ML1+4 (130° C.) compared with a polymer which has the same weight-average molecular weight and in which the branched conjugated diene compound is replaced by the conjugated diene compound. ### Claim 14 (depends on 13) A rubber composition comprising the branched conjugated diene copolymer of claim 13. ### Claim 15 (depends on 14) A pneumatic tire comprising the rubber composition of claim 14. ### Claim 16 (depends on 7) The pneumatic tire of claim 7, wherein the branched conjugated diene copolymer is low in a Mooney viscosity ML1+4 (130° C.) compared with a polymer which has the same weight-average molecular weight and in which the branched conjugated diene compound is replaced by the conjugated diene compound. ### Claim 17 (depends on 6) The pneumatic tire of claim 6, wherein the rubber composition has the copolymerization ratio of the branched conjugated diene compound in a range of 1 to 75% by weight, and the copolymerization ratio of the conjugated diene compound in a range of 25 to 99% by weight. ### Claim 18 (depends on 1) The branched conjugated diene copolymer of claim 1, wherein the copolymerization ratio of the branched conjugated diene compound is 5 to 40% by weight, and the copolymerization ratio of the conjugated diene compound is 60 to 95% by weight. ### Claim 19 (depends on 18) A rubber composition comprising the branched conjugated diene copolymer of claim 18. ### Claim 20 (depends on 19) A pneumatic tire comprising the rubber composition of claim 19.