POLYMER COMPOSITION, CROSS-LINKED BODY, AND TIRE
A polymer composition includes a conjugated diene-based polymer (A) and a filler having a Mohs hardness of 5 or more (B), where the conjugated diene-based polymer (A) contains a polymer (A1) satisfying expression (i) when a composition ratio (molar ratio) of a structural unit represented by formula (1), a structural unit represented by formula (2), a structural unit represented by formula (3) and a structural unit represented by formula (4) in the polymer is p, q, r and s, respectively. 0.75≤( p +(0.5× r ))/( p+q +(0.5× r )+ s )≤0.95 Expression (i)
1 . A polymer composition comprising:
a conjugated diene-based polymer (A); and
a filler having a Mohs hardness of 5 or more (B), wherein
the conjugated diene-based polymer (A) comprises a polymer (A1) satisfying an expression (i) when a composition ratio (molar ratio) of a structural unit represented by formula (1), a structural unit represented by formula (2), a structural unit represented by formula (3) and a structural unit represented by formula (4) in the polymer is p, q, r and s, respectively:
0.75≤( p +(0.5 ×r ))/( p+q +(0.5 ×r )+ s )≤0.95 Expression (i)
2 . The polymer composition according to claim 1 , wherein a proportion of the polymer (A1) in the conjugated diene-based polymer (A) is 50% by mass or more.
3 . The polymer composition according to claim 1 , wherein the polymer (A1) has a glass transition temperature of −40° C. or lower.
4 . The polymer composition according to claim 1 , wherein the polymer (A1) has a weight average molecular weight (Mw) in terms of polystyrene measured by a gel permeation chromatograph of 1.0×10 5 to 2.0×10 6 .
5 . The polymer composition according to claim 1 , wherein the filler (B) is at least one selected from the group consisting of alumina, silicon carbide, boron carbide and diamond.
6 . The polymer composition according to claim 1 , further comprising a component (C), wherein the component (C) is at least one selected from the group consisting of a foaming agent, thermally microcapsules, and thermally expandable graphite.
7 . The polymer composition according to claim 1 , further comprising at least one selected from the group consisting of silica and carbon black.
8 . The polymer composition according to claim 1 , further comprising a crosslinking agent.
9 . A cross-linked product obtained by employing the polymer composition according to claim 1 .
10 . A tire in which one or both of a tread and a sidewall are formed using the polymer composition according to claim 1 .