Rubber composition and tire

Abstract

An object of the present invention is to provide a rubber composition which can prevent mold contamination while maintaining abrasion resistance and wet grip performance, and a tire which has a tread composed of the rubber composition. The rubber composition of the present invention comprises a predetermined amount of at least one selected from the group consisting of stearic acid, a metal salt of saturated fatty acid and a specific mold release agent, a specific resin, silica and a silane coupling agent, based on a diene rubber component, where an amount of an unreacted silane coupling agent in the rubber composition before vulcanization is within a predetermined range.

Description

technical field [0001] The present invention relates to a rubber composition and a tire including a tread made of the rubber composition. Background technique [0002] As a method of improving the wet grip performance and rolling resistance of rubber compositions, increasing the amount of silica, tackifying resins, antiaging agents and the like has been carried out. In addition, as a method of improving wear resistance, high molecular polymers and / or particulate fillers have been mixed and used, but crack resistance tends to deteriorate. Therefore, in order to prevent deterioration of crack resistance, it is necessary to increase the amount of antiaging agent used. [0003] However, there is a problem that these agents bloom on the surface of the green tire and form a sticky coating, and the sticky coating and / or other pieces of rubber (cut pore whiskers, torn spews) Rubber coating, etc.) sticks and deposits in the mould, thus causing the mold to become easily contaminated...

AI Technical Summary

Problems solved by technology

[0003] However, there is a problem that these agents bloom on the surface of the green tire and form a sticky coating, and the sticky coating and / or other pieces of rubber (cut pore whiskers, torn spews) Rubber coating, etc.) sticks and deposits in the mould, thus causing the mold to become easily contaminated, increasing the frequency of mold cleaning and severely reducing productivity

In addition, if the contaminated mold continues to be used, the color and glossiness of the surface of the rubber composition (such as a tire) will become uneven, and if the mold is further used, unevenness will be felt on the surface of the rubber composition

[0004] In particular, there is a problem that molds are prone to contamination due to silica-rich formulations, but recently due to an increase in the amount of adhesion-imparting resins, molds are prone to further contamination

In addition, although it is known that a silane coupling agent can be used in combination to improve the dispersibility of silica, it is known that if the amount of kneading is small and / or the kneading time is short, or degassing treatment is not performed (when using Banbury During the kneading process of the internal mixer, ethanol or water is discharged into the container for a few seconds to facilitate the coupling reaction), the silane coupling agent remains in the kneaded product as an unreacted monomer even after the kneading is completed

If the ratio of the unreacted silane coupling agent remaining is high, there are problems that raw rubber sticks excessively to the processing rollers to cause very dangerous operation and deterioration of production efficiency; Attaches to the mold, whereby the mold becomes susceptible to contamination

However, this rubber composition is intended to prevent tread groove cracks on the shoulder main groove, and does not disclose techniques for reducing the unreacted ratio of the silane coupling agent and preventing mold contamination

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