# US 6,297,325 B1 · Rubber composition comprised of cis-1,4-polyisoprene and polymeric di-maleamic acid and articles, including tires, having at least one component comprised thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,297,325 B1 - Document ID: US6297325B1 - Status: Granted - Kind: B1 - Application number: 09/513,041 - Filed: 2000-02-25 - Granted: 2001-10-02 - Earliest claimed: 2000-02-25 - Assignees: The Goodyear Tire & Rubber Company - Inventors: Lawson Gibson Wideman; Paul Harry Sandstrom - Web page: https://patentgrep.com/patent/US6297325B1 ## CPC - C08L 51/04: grafted on to rubbers - B60C 1/0016: {Compositions of the tread} - C08F 279/02: on to polymers of conjugated dienes - C08F 290/14: Polymers provided for in subclass C08G - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract This invention relates to rubber compositions comprised of cis-1,4-polyisoprene and a polymeric di-maleamic acid and to articles of manufacture having at least one component comprised thereof, including tires. The polymeric di-maleamic acid has been observed to enhance green strength of such rubber composition. ## Claims ### Claim 1 A rubber composition comprised of cis-1,4-polyisoprene elastomer which contains from about 0.1 to about 20 phr of a polymeric di-maleamic acid and where said cis-1,4-polyisoprene is selected from natural, cis 1,4-polyisoprene rubber, synthetic cis-1,4-polyisoprene rubber or their mixtures; wherein said polymeric di-maleamic acid is characterized as a polyoxypropylene polymer with maleamic acid termination on each end of the polymer and having a molecular weight in a range of about 210 to 10,200. ### Claim 2 (depends on 1) The rubber composition of claim 1 wherein said cis-1,4-polyisoprene elastomer is synthetic cis-1,4-polyisoprene. ### Claim 3 (depends on 1) The rubber composition of claim 1 wherein said cis-1,4-polyisoprene elastomer is a blend of natural and synthetic cis-1,4-polyisoprene. ### Claim 4 (depends on 1) The rubber composition of claim 1 which comprises, based upon 100 parts by weight elastomers (phr), (A) 100 phr of unvulcanized conjugated diene-based elastomers comprised of (1) about 10 to about 90 phr of cis-1,4-polyisoprene elastomer, wherein said cis-1,4-polyisoprene is selected from natural, cis-1,4-polyisoprene rubber, synthetic cis-1,4-polyisoprene rubber or their mixtures, and, correspondingly (2) about 90 to about 10 phr of at least one additional conjugated diene-based elastomer, and (B) about 0.1 to about 20 phr of polymeric di-maleamic acid. ### Claim 5 (depends on 4) The rubber composition of claim 4 wherein said cis-1,4-polyisoprene is comprised of synthetic cis-1,4-polyisoprene. ### Claim 6 (depends on 4) The rubber composition of claim 4 wherein said cis-1,4-polyisoprene elastomer is a blend of natural and synthetic cis-1,4-polyisoprene. ### Claim 7 (depends on 4) The rubber composition of claim 4 wherein said additional diene-based elastomer is selected from homopolymers and copolymers of isoprene, 1,3-butadiene or their mixtures (other than said natural and synthetic cis-1,4-polyisoprene elastomers), copolymers of at least one diene selected from isoprene and 1,3-butadiene with styrene or their mixtures; wherein said polymeric di-maleamic acid is characterized as a polyoxypropylene polymer with maleamic acid termination on each end of the polymer and having a molecular weight in a range of about 210 to 10,200. ### Claim 8 (depends on 4) The rubber composition of claim 4 wherein said additional diene based elastomer is selected from styrene/butadiene copolymer rubbers (aqueous emulsion polymerization derived and organic solvent solution polymerization derived elastomers), isoprene/butadiene copolymer rubbers, styrene/isoprene copolymer rubbers, styrene/isoprene/butadiene terpolymer rubbers, cis-1,4-polybutadiene rubber, high vinyl polybutadiene rubber with a vinyl 1,2- content in a range of about 30 to about 90 percent, emulsion polymerization prepared butadiene/acrylonitrile copolymers, 3,4-polyisoprene rubber or their mixtures. ### Claim 9 (depends on 4) The rubber composition of claim 4 which contains at least two of said additional conjugated diene-based elastomers. ### Claim 10 (depends on 1) The rubber composition of claim 1 which contains particulate reinforcement for said rubber composition wherein said reinforcement is comprised of at least one of rubber reinforcing carbon black and amorphous silica in an amount in a range of about 35 to about 100 phr thereof. ### Claim 11 (depends on 4) The rubber composition of claim 4 which contains particulate reinforcement for said rubber composition wherein said reinforcement is comprised of at least one of rubber reinforcing carbon black and amorphous silica in an amount in a range of about 35 to about 100 phr thereof. ### Claim 12 (depends on 1) An article of manufacture which contains at least one component which is comprised of the rubber composition of claim 1. ### Claim 13 (depends on 4) An article of manufacture which contains at least one component which is comprised of the rubber composition of claim 4. ### Claim 14 (depends on 1) A tire which contains at least one component which is comprised of the rubber composition of claim 1. ### Claim 15 (depends on 4) A tire which contains at least one component which is comprised of the rubber composition of claim 4. ### Claim 16 (depends on 14) The tire of claim 14 where said component is selected from at least one of a tread, sidewall, carcass ply and apex. ### Claim 17 (depends on 15) The tire of claim 15 where said component is selected from at least one of a tread, sidewall, carcass ply and apex. ### Claim 18 (depends on 1) A tire having a tread comprised of the rubber composition of claim 1. ### Claim 19 (depends on 4) A tire having a tread comprised of the rubber composition of claim 4.