Patent ID: 7122090

Claim:
A process for preparing a studless tire having a tread comprising a rubber sheet having a thickness of at most 20 mm, which comprises: extruding a rubber composition containing 2 to 50 parts by weight of short fiber or plate-like material having a Moh's hardness of 3–7 based on 100 parts by weight of diene rubber in a tube shape, thereby orienting said short fiber or plate-like material in the circumferential direction of said tube shaped rubber composition; cutting said tube shaped rubber composition at one point in a sidewall thereof in the extrusion direction to obtain a rubber sheet having a complex elastic modulus Ea in the extrusion direction and complex elastic modulus Eb in the 90° direction from the extrusion direction measured at 25° C. which fulfill the following equation: 1.1 ≦Eb/Ea; cutting said rubber sheet parallel to the extrusion direction to obtain pieces; rotating each piece 90° and laminating the rotated pieces together to form a tread having a thickness of at most 20 mm; and forming a studless tire having said tread.