PROCESS FOR PREPARING RUBBER SHEET AND TREAD AND STUDLESS TIRE USING SAME

摘要

The present invention provides a studless tire excellent in performance on ice and snow in which digging friction is improved without losing adhesion friction. The studless tire has a tread comprising specific short fiber or plate-like material dispersed in dime rubber so as to be oriented in the tread thickness direction, wherein when measured at 25.degree.C the tread has a complex elastic modulus E1 in the tread thickness direction, and the sheet has a complex elastic modulus E.alpha. in the extrusion direction and a complex elastic modulus E.beta. in a 90.degree. direction from the extrusion direction, when the rubber composition is made into 2 mm sheets with a roller and these moduli fulfill the following equation, 60 .ltoreq. (E1-E.beta.)/(E.alpha.-E.beta.).times. 100 .ltoreq. 100 and the tread has a specific tread rubber hardness. The tire is obtained using a tread prepared by extruding a rubber composition containing dime rubber and specific short fiber or plate-type material in a tube shape, thereby orienting the short fiber in the circumferential direction of the tube shaped rubber, then cutting the obtained rubber sheet parallel to the extrusion direction, rotating each piece 90.degree. and laminating.