A
polymer composition obtainable by subjecting a particular crosslinkable
polymer composition to dynamic crosslinking. The crosslinkable
polymer composition contains. (a) a block
copolymer comprising two or more polymer blocks of a vinyl aromatic compound and one or more (hydrogenated) polymer blocks of a
conjugated diene; (b) an olefin
copolymer having a density of 0.88 to 0.92 g / cm2 and obtained through copolymerization of
ethylene and an α-olefin having 4 to 12 carbon atoms; (c) a
softening agent; and (d) an
organic peroxide in respective amounts that satisfy the following relational expressions ① to ③:0.66≦Wb / Wa≦4①0≦Wc / (Wa+Wb+Wc)≦0.25②0.001≦Wd / (Wa+Wb+Wc)≦0.01③wherein Wa, Wb, Wc and Wd represent the respective amounts (by
mass) of the components (a), (b), (c) and (d), that are present in the
polymer composition prior to the dynamic crosslinking.The
polymer composition of the present invention is based on a
thermoplastic elastomer that has various improved properties, including moldability, abrasion resistance, scratch resistance,
hydrolysis resistance, softness,
rubber elasticity, grip, shock
absorbance, oil resistance, lightweightness and
mechanical strength, and has these properties in a well-balanced manner.