Tire rubber composite and pneumatic tire

Abstract

Provided is a tire rubber composition that has lower rolling resistance, and improved wet performance and abrasion resistance compared to conventional levels. The composition is characterized in that: 2-50 parts by weight of an aromatic modified terpene resin with a softening point of at least 100 DEG C and a total of 60-130 parts by weight of two types of silica, silica X and silica Y, are added to 100 parts by weight of a diene rubber that includes 5-50 wt% of a terminal-modified S-SBR having a vinyl unit content of at least 25 wt% and a glass transition temperature of - 50 DEG C or below; the functional group of the modified S-SBR is reactive with a silanol group; a reinforcing filler comprising of silica X, silica Y and optionally added carbon black includes the silica at a proportion of at least 85 wt%; the specific surface area of silica X as determined by nitrogen absorption is at least 140m<2> / g; the specific surface area of silica Y as determined by nitrogen absorption is 100-140m<2> / g exclusive; and if the respective masses of silica X and silica Y per 100 parts by weight of the diene rubber are expressed as x parts by weight and y parts by weight, the relationship x / 7 < y <=x is satisfied.

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 wear resistance compared to conventional levels. Background technique [0002] In recent years, for pneumatic tires for passenger cars, the marking (marking method) system established by JATMA (Japan Automobile Tire Manufacturers Association, Japan Automobile Tire Manufacturers Association) has been started, and low rolling resistance and wet road grip are required to be improved. horizontally. 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...

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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