Rubber composition for tire, pneumatic tire

Abstract

A rubber composition for tires comprises: per 100 parts by weight of diene rubber containing from 5 to 50 wt. % of terminally modified S-SBR, from 2 to 50 parts by weight of an aromatic modified terpene resin having a softening point of 100° C. or higher. A total content of 60 to 130 parts by weight of two types of silica, that is silica X and silica Y. A functional group of the modified S-SBR has reactivity with a silanol group. A proportion of the silica relative to a total amount of a reinforcing filler containing the silica X, the silica Y, and an optionally compounded carbon black is 85 wt. % or greater. A nitrogen adsorption specific surface area of the silica X is 140 m2 / g or greater; a nitrogen adsorption specific surface area of the silica Y is greater than 100 m2 / g and less than 140 m2 / g.

Description

technical field [0001] The present invention relates to a rubber composition for tires and a pneumatic tire having low rolling resistance, improved wet grip and abrasion resistance compared to conventional levels. Background technique [0002] In recent years, the marking (marking method) system established by JATMA (Japan Automobile Tire Manufacturers Association, Japan Automobile Tire Manufacturers Association) has started for pneumatic tires for passenger cars, and requires low rolling resistance and wet road grip to coexist at a higher level. In particular, the level of demand for wet grip is very high, and a pneumatic tire satisfying the wet grip class a based on the marking system has not yet been developed. In addition, at the same time, in order to prolong the life of the tire, it is required to improve wear resistance. [0003] Conventionally, in order to improve the balance between low rolling resistance and wet grip, it has been known to incorporate silica into a...

AI Technical Summary

Problems solved by technology

However, silica has a silanol group on its surface, which is easy to aggregate, and because it lacks affinity with diene rubber, there are cases where the dispersibility becomes insufficient. The problem of sufficiently obtaining the effect of improving the dynamic viscoelastic properties such as the loss tangent (tan δ) of the rubber composition

In addition, silica may be less reinforcing than carbon black and may have insufficient wear resistance, and if the dispersibility is poor, there is a problem that the wear resistance will further decrease.

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