# US 4,400,488 A · Composition and method of improving the unvulcanized properties of blends containing reclaimed rubber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,488 A - Document ID: US4400488A - Status: Granted - Kind: A - Application number: 06/372,856 - Filed: 1982-04-28 - Granted: 1983-08-23 - Earliest claimed: 1977-03-21 - Assignees: The Goodyear Tire & Rubber Company - Inventors: Joginder Lal; Sandra J. Walters - Web page: https://patentgrep.com/patent/US4400488A ## CPC - C08L 21/00: Compositions of unspecified rubbers - C08L 17/00: Compositions of reclaimed rubber - C08L 23/20: having four to nine carbon atoms - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - C08L 9/06: Copolymers with styrene - C08L 23/22: Copolymers of isobutene; Butyl rubber; Homopolymers or copolymers of other iso-olefins - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The green strength of compositions containing elastomers and/or up to 100 percent of reclaimed rubber is improved by the addition of crystalline or semi-crystalline butene polymers selected from the group consisting of polybutene and interpolymers made from 1-butene with at least one monomer selected from the group consisting of alpha-olefins, non-conjugated dienes, and non-conjugated polyenes. Although reclaimed rubbers are utilized, an unexpected increase in green strength of an unvulcanized blend is obtained. The reclaimed rubbers utilized in the blend may be those which have been devulcanized by mechanical energy, heat, and/or chemical agents. Additionally and preferably, the rubbers may be reclaimed through the use of microwave energy. Additionally, the unvulcanized properties of compositions containing 100 percent of scrap rubber which has been reclaimed using microwave energy are significantly improved by adding crystalline or semi-crystalline alpha-olefin polymers, such as polyethylene or polypropylene. Unexpected improvements in solvent resistance and molding properties of the uncured blends are also achieved. ## Claims ### Claim 1 A prevulcanization process for producing a reclaimed rubber blend, comprising: improving the green strength of a reclaimed rubber-elastomer blend by obtaining from about 5 parts by weight to about 100 parts by weight of reclaimed rubber, said reclaimed rubber produced by devulcanizing scrap rubber with microwave energy, said reclaimed rubber selected from the group consisting of polychloroprene, chlorobutyl rubber, bromobutyl rubber, butyl rubber, nitrile rubber, nitrile rubber-poly(vinyl chloride) blends having up to 30 percent by weight by poly(vinyl chloride), EPDM, natural or synthetic cis-1,4-polyisoprene, polyalkenylenes, elastomers made from monomers selected from the group consisting of conjugated dienes having from 4 to 10 carbon atoms, interpolymers of said dienes (1) among themselves, or (2) with monomers selected from the group consisting of vinyl substituted hydrocarbon compounds having from 8 to 12 carbon atoms, and combinations thereof; adding to said reclaimed rubber from about 95 parts by weight to about 0 parts by weight of an elastomer, said elastomer selected from the group consisting of natural or synthetic cis-1,4-polyisoprene, polyalkenylenes, elastomers made from monomers selected from the group consisting of conjugated dienes having from 4 to 10 carbon atoms, interpolymers of said dienes (1) among themselves, or (2) with monomers selected from the group consisting of vinyl substituted hydrocarbon compounds having from 8 to 12 carbon atoms; and combinations thereof, the total amount of said reclaimed rubber and said elastomer being 100 parts by weight; adding to said reclaimed rubber and said elastomer a semi-crystalline butene polymer having a number average molecular weight of from about 30,000 to about 500,000, the amount of said butene polymer ranging from about 2 parts by weight to about 30 parts by weight per 100 parts by weight of said elastomer-reclaimed rubber mixture, said butene polymer selected from the group consisting of polybutene and interpolymers made from 1-butene monomer and at least one monomer selected from the group consisting of (a) alpha-olefins having 2 through 16 carbon atoms, (b) non-conjugated dienes having the formula: ##STR10## where R.sub.1, R.sub.2 and R.sub.3 is a hydrogen, a lower alkyl group containing from 1 to 4 carbon atoms, or an aryl group; where R.sub.4 is an aryl group or a lower alkyl group containing from 1 to 9 carbon atoms, and n is an integer having a value of from 1 to 6, and wherein the said R.sub.1 's in the ##STR11## group may be similar or dissimilar, (c) non-conjugated alpha-, omega-polyenes having from 6 to 36 carbon atoms which may or may not contain internal unsaturation, and (d) combinations thereof, said butene in said interpolymers comprises from 99.9 to 65 mole percent of the total monomers; and mixing said elastomer, said reclaimed rubber and said butene polymer to produce an elastomer-reclaimed rubber blend having improved green strength before vulcanization. ### Claim 2 (depends on 1) A process according to claim 1, wherein the melting temperature of said butene polymer ranges from about 55.degree. C. to about 125.degree. C. and wherein the inherent viscosity of said butene polymer is from about 0.5 dl/g to about 10.0 dl/g. ### Claim 3 (depends on 2) A process according to claim 2, wherein the amount of said microwave reclaimed rubber ranges from about 40 to about 100 parts by weight and wherein the amount of said elastomer ranges from about 60 to about 0 parts by weight. ### Claim 4 (depends on 3) A process according to claim 3, wherein said butene polymers are selected from the group consisting of polybutene, a copolymer of 1-butene and ethylene, a copolymer of 1-butene and propylene, a copolymer of 1-octene, a terpolymer of 1-butene, 1-octene, and 1,7-octadiene, and a terpolymer of 1-butene, 1-hexene and 1-octene. ### Claim 5 (depends on 4) A process according to claim 4, wherein said reclaimed rubber is selected from the group consisting of polychloroprene, chlorobutyl rubber, bromobutyl rubber, nitrile rubber-poly(vinyl chloride) blends having up to 30 percent by weight of poly (vinyl chloride), butyl rubber, nitrile rubber, EPDM, natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, a copolymer of butadiene and styrene, and combinations thereof. ### Claim 6 (depends on 5) A process according to claim 5, wherein said elastomer is selected from the group consisting of natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, and a copolymer of butadiene and styrene. ### Claim 7 (depends on 6) A process according to claim 6, wherein said reclaimed rubber is made from stock selected from the group consisting of tires, tire carcass, tire tread, belts, inner tubes, hoses, curing bladders, and combinations thereof. ### Claim 8 (depends on 6) A process according to claim 6 wherein said butene polymer is added to said reclaimed rubber immediately following microwave devulcanization. ### Claim 9 (depends on 5, 6, 7) A process according to claims 5, 6, 7, or 8, wherein the amount of said reclaimed rubber is 100 parts by weight. ### Claim 10 (depends on 6) A process according to claim 6, wherein a portion of said reclaimed rubber has been made by devulcanizing vulcanized rubber using mechanical energy, heat, or chemical agents, and wherein the amount of said nonmicrowave reclaimed rubber ranges from about 5 parts by weight to about 60 parts by weight, and wherein the amount of said microwave reclaim ranges from 95 parts by weight to 40 parts by weight. ### Claim 11 (depends on 10) A process according to claim 10, wherein said nonmicrowave reclaimed rubber is selected from the group consisting of polychloroprene, chlorobutyl rubber, bromobutyl rubber, butyl rubber, nitrile rubber, EPDM, natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, a copolymer of butadiene and styrene, and combinations thereof, the amount of said reclaimed rubber ranging from about 10 parts by weight to about 50 parts by weight, and the amount of said elastomer ranges from about 90 parts by weight to about 50 parts by weight. ### Claim 12 An elastomeric prevulcanization blend composition having improved green strength, comprising: from about 5 parts by weight to about 100 parts by weight of reclaimed rubber, said reclaimed rubber produced by devulcanizing scrap rubber with using microwave energy, said reclaimed rubber selected from the group consisting of polychloroprene, chlorobutyl rubber, bromobutyl rubber, butyl rubber, EPDM, nitrile rubber, nitrile rubber-poly (vinyl chloride) blends having up to 30 percent by weight of poly(vinyl chloride), natural or synthetic cis-1,4-polyisoprene, polyalkenylenes, elastomers made from monomers selected from the group consisting of conjugated dienes having from 4 to 10 carbon atoms, interpolymers of said dienes (1) among themselves, or (2) with monomers selected from the group consisting of vinyl substituted hydrocarbon compounds having from 8 to 12 carbon atoms; and combinations thereof; from about 95 parts by weight to about 0 parts by weight of an elastomer, said elastomer selected from the group consisting of natural or synthetic cis-1,4-polyisoprene, polyalkenylenes, elastomers made from monomers selected from the group consisting of conjugated dienes having from 4 to 10 carbon atoms, interpolymers of said dienes (1) among themselves, or (2) with monomers selected from the group consisting of vinyl substituted hydrocarbon compounds having from 8 to 12 carbon atoms; and combinations thereof, the total amount by weight of said reclaimed rubber and said elastomer being 100 parts by weight; from about 2 to about 30 parts by weight per 100 parts by weight of said elastomer-reclaimed rubber blend of a butene polymer, said butene polymer selected from the group consisting of polybutene and interpolymers made from 1-butene monomers and at least one monomer selected from the group consisting of (a) alpha-olefins having 2 through 16 carbon atoms and (b) non-conjugated dienes having the formula: ##STR12## where R.sub.1, R.sub.2, and R.sub.3 is a hydrogen, a lower alkyl group containing from 1 to 4 carbon atoms, or an aryl group; wherein R.sub.4 is an aryl group or a lower alkyl group containing from 1 to 9 carbon atoms, and n is an integer having a value of from 1 to 6, and wherein the said R.sub.1 's in the ##STR13## group may by similar or dissimilar; and (c) non-conjugated alpha-, omega-polyenes having from 6 to 36 carbon atoms which may or may not contain internal unsaturation, and (d) combinations thereof, said butene in said interpolymers comprises from 99.9 to 65 mole percent of the total monomers. ### Claim 13 (depends on 12) An elastomeric composition according to claim 12, wherein the melting temperature of said butene polymer ranges from about 55.degree. C. to about 125.degree. C. and wherein the inherent viscosity of said butene polymer is from about 0.5 dl/g to about 10.0 dl/g. ### Claim 14 (depends on 13) An elastomeric composition according to claim 13, wherein the amount of said reclaimed rubber ranges from about 40 to about 100 parts by weight and wherein the amount of said elastomer ranges from about 60 to about 0 parts by weight. ### Claim 15 (depends on 14) An elastomeric composition according to claim 14, wherein said butene polymers are selected from the group consisting of polybutene, a copolymer of 1-butene and ethylene, a copolymer of 1-butene and propylene, a copolymer of 1-butene and 1-hexene, a copolymer of 1-butene and 1-octene, a terpolymer of 1-butene, 1-octene, and 1,7-octadiene, and a terpolymer of 1-butene, 1-hexene and 1-octene. ### Claim 16 (depends on 15) An elastomer composition according to claim 15, wherein said reclaimed rubber is selected from the group consisting of polychloroprene, chlorobutyl rubber, bromobutyl rubber, nitrile rubber-poly(vinyl chloride) blends having up to 30 percent by weight of poly(vinyl chloride), butyl rubber, nitrile rubber, EPDM, natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, a copolymer of butadiene and styrene, and combinations thereof. ### Claim 17 (depends on 16) An elastomer composition according to claim 16, wherein said elastomer is selected from the group consisting of natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, and a copolymer of butadiene and styrene. ### Claim 18 (depends on 17) An elastomeric composition according to claim 17, wherein the amount of butene in said butene interpolymer ranges from about 95 to about 70 mole percent of the total monomers, wherein the amount of said butene polymer ranges from about 3 parts by weight to about 27 parts by weight per 100 parts by weight of said reclaimed rubber-elastomer mixture, and wherein said inherent viscosity of said butene polymer ranges from about 1.0 to about 6.0 dl./g., and wherein the molecular weight of said butene polymer ranges from about 50,000 to about 300,000. ### Claim 19 (depends on 17) An elastomeric composition according to claim 17, wherein a portion of said reclaimed rubber has been devulcanized using mechanical energy, heat, and chemical agents, and wherein the amount of said nonmicrowave reclaimed rubber ranges from about 5 parts by weight to about 60 parts by weight, and wherein the amount of said microwave reclaim ranges from 95 parts by weight to 40 parts by weight. ### Claim 20 (depends on 19) An elastomeric composition according to claim 19, wherein said nonmicrowave reclaimed rubber is selected from the group consisting of olychloroprene, chlorobutyl rubber, bromobutyl rubber, butyl rubber, nitrile rubber, EPDM, natural or synthetic cis-1,4-polyisoprene, cis-1,4-polybutadiene, 1,2-polybutadiene, a copolymer of butadiene and styrene, and combinations thereof, the amount of said reclaimed rubber ranging from about 10 parts by weight to about 50 parts by weight, and the amount of said elastomer ranges from about 90 parts by weight to about 50 parts by weight. ### Claim 21 (depends on 17) An elastomer composition according to claim 17, wherein said reclaimed rubber is made from stock selected from the group consisting of tires, tire carcass, tire tread, belts, inner tubes, hoses, curing bladders, and combinations thereof. ### Claim 22 (depends on 16, 17) An elastomeric composition according to claim 16, 17, or 21, wherein the amount of reclaimed rubber is 100 parts by weight. ### Claim 23 (depends on 6) A process according to claim 6, wherein the amount of butene in said butene interpolymer ranges from about 95 to about 70 mole percent of the total monomers, wherein the amount of said butene polymer ranges from about 3 parts to about 27 parts by weight per 100 parts by weight of said reclaimed rubber-elastomer blend, and wherein said inherent viscosity of said butene polymer ranges from about 1.0 to about 6.0 dl./g., and wherein the molecular weight of said butene polymer ranges from about 50,000 to about 300,000.