Rubber composition for tire tread

Abstract

The invention relates to a rubber composition that can be used as a tire tread having improved adhesion on melting ice, comprising at least one diene elastomer such as natural rubber and / or a polybutadiene, more than 30 pce of a liquid plasticizer, between 50 and 150 pce of a reinforcing filler such as silica or carbon black, and between 2 and 40 pce of microparticles of a water-soluble sulfate of an alkali or alkali earth metal such as a magnesium sulfate, wherein said composition is characterized in that the volumetric microparticle size distribution, measured by laser grading as per ISO Standard 13320-1, satisfies the following relations:50[mu]m(D50(150[mu]m:-0.50(Span(1.50, wherein D50 is the diameter of the median particle corresponding to 50% of the cumulative distribution of particles; Span=(D90-D10) / D50; wherein D10 and D90 are the diameters of the particle corresponding to 10% and to 90%, respectively, of the cumulative particle distribution. The invention also relates to tire treads incorporating such a composition, as well as to said tires themselves.

Description

technical field [0001] The present invention relates to rubber compositions useful as treads for tires, in particular "winter tires" capable of rolling on ground covered with ice or black ice without the provision of studs (also called studless tires). [0002] More particularly, the present invention relates to tire treads that are particularly suitable for rolling under "thawing" conditions generally encountered in the temperature range between -5°C and 0°C. Particular attention should be paid to the fact that in this range, the pressure of the tires during the passage of the vehicle brings the surface of the ice to melt, and the ice is covered with a thin layer of water, which is not conducive to the grip of these tires. Background technique [0003] In order to avoid the detrimental effect of the studs, in particular their strong abrasive action on the pavement of the ground itself and its significantly damaging road behavior on dry road surfaces, tire manufacturers hav...

AI Technical Summary

Problems solved by technology

If the powder is insoluble under the conditions in which the tire is used, the above-mentioned functions (microporosity and creation of channels for draining water) cannot be performed, and the grip cannot be improved

However, the known disadvantages of these solutions are that they are detrimental to the reinforcement of the rubber compositions (and thus to their wear resistance) or to their hysteresis (and thus to their rolling resistance)

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