Tyres, esp. improved all-weather tyres - have tread in the form of many blocks made of cellular rubber contg. short fibres oriented in a specified way

摘要

Pneumatic tyres (I) are claimed, in which the tread has a large no. of blocks consisting of cellular rubber (II) contg. dispersed short fibres, (II) contains a polymer with Tg -60 to -20degC (III) and a urea-based additive mixed with less than the equiv. amt. of foaming agent. (II) has mean cell surface area X = 100-5000 microns2, with coefft. of variation K = 0.5-0.8, over a cross-section of the tread, and cell density 1-4% in the tread, and contains a large no. of short fibres oriented so as to extend circumferentially inside the tread, along the road contact surface and side walls of each tread block. The fibres have mean dia. above 1 micron and mean length 100-5000 microns; (III) is high-styrene SBR, high-vinyl (butadiene) SBR, high-vinyl BR, or butyl rubber, and amt. of (III) is 30-70 pts. wt. to 100 pts. wt. total (II). USE/ADVANTAGE - The invention provides tyres, esp. spikeless all-weather tyres for motor vehicles, with improved performance in all weather conditions and improved braking performance on ice- and snow-covered roads. (11pp Dwg.No.3/3)