1,2-polybutadiene, thermoplastic elastomer composition and polymer composition

A thermoplastic elastomer composition, which comprises

• (a) a thermoplastic elastomer selected from the group consisting of an aromatic vinyl-based thermoplastic elastomer, an urethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a vinyl chloride-based thermoplastic elastomer and a fluorine-based thermoplastic elastomer, and
• (b) a 1,2-polybutadiene having
• 1) a 1,2-bond content in the butadiene unit of 70% by weight or more,
• 2) a melting point in the range of 50 to 140° C.,
• 3) a viscosity η in the range of 400 to 1200 poise when measured with a slit die rheometer at a shear rate of 5113 sec−1 at 120° C.
• 4) a viscosity η in the range of 300 to 1000 poise when measured with a slit die rheometer at a shear rate of 5113 sec−1 at 150° C.,
• 5) a viscosity η in the range of 200 to 800 poise when measured with a slit die rheometer at a shear rate of 5113 sec−1 at 180° C., and
• 6) a total halogen content of 30 ppm or less.