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AssigneesSumitomo Chemical Company, Limited, Sumitomo Rubber Industries, Ltd.
InventorsHiroyoshi Takao, Keisaku Yamamoto, Akio Imai, Nobuyuki Yoshida, Hiroshi Furukawa, Yuichi Saito, Akio Okumura
Estimating the term…
A diene rubber composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of at least 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.01 to 2.0, said composition having an average intrinsic viscosity of at least 1.8. Since this composition has an excellent wet grip and rolling resistance property and moreover has excellent processability, it is employed as tire tread rubber.
A diene rubber composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of 2.5 to 5, a Mw/Mn value of not more than 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.1 to 0.7 and a glass transition point of not lower than -50.degree. C., said composition having an average intrinsic viscosity of at least 1.8.
A tire wherein a diene rubber composition having an average intrinsic viscosity of at least 1.8 is employed, said composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of 2.5 to 5, a Mw/Mn value of not more than 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.1 to 0.7 and a glass transition point of not lower than -50.degree. C.
Dependencies are inferred from the claim text.