Rubber composition and tire

Abstract

As a rubber composition capable of greatly improving on-ice performance while suppressing a decrease in abrasion resistance of a tire, the present invention provides a rubber composition characterizedby the following: containing silica and at least three types of diene-based polymers that form a plurality of mutually incompatible polymer phases; in that a diene-based polymer (B), which is blendedat a quantity of 10 mass% or more relative to the total quantity of the diene-based polymers and which does not have the lowest or the highest glass transition temperature (Tg) among the diene-basedpolymers, is modified by a silicon atom-containing compound, and satisfies the relationship represented by the formula St+Vi / 2 <= 33 [in the formula, St is the content (mass%) of bonded styrene in thediene-based polymer (B) and Vi is the quantity (mass%) of vinyl bonds in the conjugated diene compound portion of the diene-based polymer (B)]; and in that the blending quantity of the silica is 25 parts by mass or more relative to a total of 100 parts by mass of the diene-based polymers.

Description

technical field [0001] The present invention relates to rubber compositions and tires. Background technique [0002] Studless tires having relatively soft tread rubber have traditionally been used as tires for safe running on ice as well as on dry roads. It is known that the performance on ice of a tire is improved when the tread rubber of the tire is made relatively soft. However, tires with soft tread rubber generally have the problem that the tires exhibit poor wear resistance on dry roads. In short, the tire's on-ice performance and wear resistance cannot be simultaneously improved in a compatible manner. [0003] Examples of known techniques for improving the on-ice performance of tires include blending organic fibers, glass fibers, etc., with a rubber composition for a tread of a tire, so that the organic fibers, glass fibers, etc. scrape icy road surfaces and Improves tire performance on ice. However, such organic fibers, glass fibers, etc., which do not exhibit i...

AI Technical Summary

Problems solved by technology

However, tires with soft tread rubber generally have the problem that the tires exhibit poor abrasion resistance on dry roads

However, such organic fibers or glass fibers, etc., which do not exhibit interaction with rubber, rather function as an origin of breakage, and tend to deteriorate the fracture resistance (abrasion resistance) of the tread rubber

It is therefore difficult to blend a satisfactory amount of organic fibers or glass fibers etc. with the rubber composition

That is, it is difficult to improve the on-ice performance of the tire in a satisfactory manner by adding organic fibers or glass fibers or the like to its tread rubber

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