# US 5,346,962 A · Elastomers having reduced hysteresis prepared with vinyl imidazole > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,962 A - Document ID: US5346962A - Status: Granted - Kind: A - Application number: 08/145,128 - Filed: 1993-11-03 - Granted: 1994-09-13 - Earliest claimed: 1993-11-03 - Assignees: Bridgestone/Firestone, Inc. - Inventors: William L. Hergenrother; Martin E. Morrow - Web page: https://patentgrep.com/patent/US5346962A ## CPC - C08F 290/048: {Polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00} - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract A tire treadstock elastomer having reduced hysteresis is prepared by (1) preparing a living polymer by anionic polymerization of a conjugated diene or copolymerization of a conjugated diene with a monovinyl aromatic hydrocarbon, (2) endcapping the living polymer with at least one equivalent, preferably 3 to 15 equivalents, of a 1-vinylimidazole or 1-vinylbenzimidazole, preferably 1-vinylimidazole; (3) quenching and recovering the endcapped polymer and (4) curing the endcapped polymer using a conventional rubber curing recipe to form an elastomer having reduced hysteresis. This elastomer either alone or blended with a conventional treadstock rubber may form a tire treadstock. ## Claims ### Claim 1 An endcapped polymer prepared by reacting a living polymer having at least one functional site with at least about one equivalent of an endcapping agent, said endcapping agent being a vinyl substituted imidazole or vinyl substituted benzimidazole, wherein said living polymer is formed by polymerization of a monomer or mixture thereof in solution in the present of a polymerization initiator, said monomer or mixture thereof being selected from the group consisting of conjugated dienes having from 4 to about 12 carbon atoms and mixtures of one or more said conjugated dienes with one or more monovinyl aromatic monomers having from 8 to about 18 carbon atoms. ### Claim 2 (depends on 1) An endcapped polymer according to claim 1 wherein said living polymer is a polymer of butadiene or a copolymer of butadiene and styrene. ### Claim 3 (depends on 1) An endcapped polymer according to claim 1 wherein said polymerization initiator is a lithium alkyl or a trialkyl tin lithium. ### Claim 4 (depends on 3) An endcapped polymer according to claim 3 wherein said polymerization initiator is n-butylithium. ### Claim 5 (depends on 3) An endcapped polymer according to claim 3 wherein said polymerization initiator is tributyltin lithium. ### Claim 6 (depends on 1) An endcapped polymer according to claim 1 wherein said solution further comprises a solvent selected from the group consisting of hexane, cyclohexane and benzene. ### Claim 7 (depends on 1) An endcapped polymer according to claim 1 wherein said endcapping agent is 1-vinylimidazole. ### Claim 8 (depends on 1) An endcapped polymer according to claim 1 wherein the amount of said endcapping agent is from about 3 to about 15 equivalents. ### Claim 9 An endcapped polymer comprising; (a) a polymer backbone, said backbone being a polymer of one or more conjugated dienes having from 4 to about 12 carbon atoms or a copolymer of one or more conjugated dienes having from 4 to about 12 carbon atoms with one or more monovinyl aromatic monomers having from 8 to about 18 carbon atoms; and (b) an end group, said end group being a vinyl imidazolyl or vinyl benzimidazotyl group or short chain polymer thereof. ### Claim 10 (depends on 9) An endcapped polymer according to claim 9 wherein said end group is a short chain polymer of 1-vinylimidazole having an average chain length of about 3 to about 15 monomer units. ### Claim 11 A process for preparing an endcapped polymer which comprises reacting a living polymer having at least one functional site with at least one equivalent of an endcapping agent, said endcapping agent being a vinyl substituted imidazole or vinyl substituted benzimidazole, wherein said living polymer is formed by polymerization of a monomer or mixture thereof in solution in the presence of a polymerization initiator, said monomer or mixture thereof being selected from the group consisting of conjugated dienes having 4 to about 12 carbon atoms and mixtures of one or more said conjugated dienes with one or more monovinyl aromatic monomers having from 8 to about 18 carbon atoms. ### Claim 12 (depends on 11) A process according to claim 11 wherein said living polymer is a polymer of butadiene or a copolymer of butadiene and styrene. ### Claim 13 (depends on 11) A process according to claim 11 wherein said solution further comprises a solvent selected from the group consisting of hexane, cyclohexane and benzene. ### Claim 14 (depends on 11) A process according to claim 11 wherein said polymerization initiator is a lithium alkyl or a trialkyl tin lithium. ### Claim 15 (depends on 14) A process according to claim 14 wherein said polymerization initiator is n-butyl lithium. ### Claim 16 (depends on 14) A process according to claim 14 wherein said polymerization initiator is tributyltin lithium. ### Claim 17 (depends on 11) A process according to claim 11 wherein said endcapping agent is 1-vinylimidazole. ### Claim 18 (depends on 1) A process according to claim 1 wherein the amount of said endcapping agent is from about 3 to about 15 equivalents. ### Claim 19 (depends on 11) A process according to claim 11 wherein said endcapping agent forms a short chain polymeric end block on reaction with said living polymer.