Patent ID: 8063146

Claim:
A thermoplastic elastomer composition obtained by dynamic crosslinking with an extruder, the thermoplastic elastomer composition comprising: (A) 10 to 60 parts by weight of a propylene-based polymer; (B) 1 to 30 parts by weight of a propylene/1-butene random copolymer; and (C) 89 to 10 parts by weight of an ethylene/α-olefin/non-conjugated polyene copolymer composed of ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, the total of the components (A) (B) and (C) being 100 parts by weight, and the propylene/1-butene random copolymer (B) satisfying the following conditions (1), (2), (3) and (4): (1) including a propylene-derived unit in an amount of from 60 to 90 mol % and a 1-butene-derived unit in an amount of from 12 to 35 mol %; (2) having a triad isotacticity as determined from 13 C-NMR spectrum measurement of from 85% to 99%; (3) having a molecular weight distribution (Mw/Mn) as determined from gel permeation chromatography (GPC) of from 1 to 3; and (4) having an intrinsic viscosity (η) as measured at 135° C. in decalin of from 0.7 to 12 dl/g.