Thermoplastic elastomer compositions

A thermoplastic elastomer composition, comprising;

• a blend of
• from about 10 to about 48 parts by weight of a crystalline 1-olefin polymer, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90.degree. C.,
• from about 90 to about 10 parts by weight of a random styrene-butadiene copolymer rubber, and
• a compound selected from the class consisting of a triblock copolymer, a diblock copolymer, and combinations thereof, the amount of said triblock and said diblock copolymer of combinations theory ranging from about 0.1 to about 80 parts by weight said triblock copolymer and said diblock copolymer made from conjugated dienes having from 4 to 10 carbon atoms and a vinyl substituted aromatic having from 8 to 12 carbon atoms,
• said blend being partially cured and having a melt flow index of at least 1.0 so that a thermoplastic elastomer is formed.

A process for making a thermoplastic elastomer blend composition, comprising the steps of:

• providing a blend of a 1-olefin polymer, a random styrene-butadiene copolymer rubber, and a compound selected from the group consisting of a triblock copolymer, a diblock copolymer, and combinations thereof,
• said blend having from about 10 to about 48 parts by weight of said crystalline 1-olefin polymer, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to about 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90.degree. C.,
• from about 90 to about 10 parts by weight of said random styrene-butadiene copolymer rubber, and
• the amount of said triblock and said diblock copolymer or combinations thereof ranging from about 0.1 to about 80 parts by weight, said triblock copolymer and said diblock copolymer made from conjugated dienes having from 4 to 10 carbon atoms and a vinyl substituted aromatic having from 8 to 12 carbon atoms, and
• heating said blend at a temperature at or above the melting point of said crystalline 1-olefin polymer so that a reprocessable thermoplastic elastomer blend is formed.

A process for making a thermoplastic elastomer blend composition, comprising the steps of:

• providing a blend of a 1-olefin polymer, a random styrene-butadiene copolymer rubber, and a compound selected from the group consisting of a triblock copolymer, a diblock copolymer, and combinations thereof,
• said blend having from about 10 to about 48 parts by weight of said crystalline 1-olefin polymer, said 1-olefin polymer selected from the class consisting of a homopolymer and a copolymer made from 1-olefin monomers having from 2 to about 20 carbon atoms, said homopolymer or said copolymer having a melting point of at least 90.degree. C.,
• from about 90 to about 10 parts by weight of said random styrene-butadiene copolymer rubber, and
• the amount of said triblock and said diblock copolymer or combinations thereof ranging from about 0.1 to about 80 parts by weight, said triblock copolymer and said diblock copolymer made from conjugated dienes having from 4 to 10 carbon atoms and a vinyl substituted aromatic having from 8 to 12 carbon atoms, and
• heating said blend at a temperature at or above the melting point of said 1-olefin polymer, and
• partially curing said blend to have a melt flow index of at least 1.0 so that a reprocessable thermoplastic elastomer blend is produced.