Rubber composition for tire tread and pneumatic tire using the rubber composition

Abstract

The object of the present invention is to provide a rubber composition for tire treads which has a good vulcanization rate and excellent wet grip and fuel efficiency. As a means of solving the problems of the present invention, there is provided a rubber composition for tire treads containing 40 parts by mass or more of a solution-polymerized SBR diene having a Mw of 900,000 to 1.5 million and a styrene content of 35 to 45%. 100 parts by mass of rubber, compounded with 60 to 110 parts by mass of silicon dioxide satisfying all the conditions of (1) to (4) below, and relative to the silicon dioxide, compounded with fatty acid metal salts (except zinc salts) 2-8 mass % of the mixture formed with fatty acid ester. The conditions for the above silica are: (1) N2SA is 194-225m2 / g. (2) The specific surface area of ​​CTAB is 170-210m2 / g. (3) The relationship between the above-mentioned N2SA and the above-mentioned CTAB specific surface area is that the N2SA / CTAB specific surface area is 0.9 to 1.4. (4) DBP absorption is 190ml / 100g or more.

Description

technical field [0001] The present invention relates to a rubber composition for tire treads and a pneumatic tire using the rubber composition, and more particularly, to a rubber for tire treads having a good vulcanization rate, wet grip and excellent fuel consumption performance Composition and a pneumatic tire using the rubber composition. Background technique [0002] Pneumatic tires are required to have various performances, but a high balance between wet grip and fuel consumption performance is particularly desired. It is known to compound silica into rubber compositions for tires in order to improve these performances. [0003] In addition, if silica with a high specific surface area is used, the number of bonds between silica and rubber increases, and reinforcement improves, which is presumed to improve wet grip performance. However, according to the studies of the present inventors, it has been found that if the specific surface area of ​​silica is increased, the i...

AI Technical Summary

Problems solved by technology

However, according to the studies of the present inventors, the following problem was found: if the specific surface area of ​​silica is increased, the interaction between silicas increases, the dispersibility deteriorates, and the desired effect cannot be obtained.

In addition, there is a problem that if a large amount of silica with a high specific surface area is blended, the vulcanization accelerator will be adsorbed and the vulcanization rate will be slowed down.

Images