Patent ID: 6367525
Filing Date: 2002-04-09
Classification: B29D,B60C,Y10S

Abstract:
A vulcanized pneumatic tire comprising; a tread portion including a surface rubber layer, formed from a rubber composition having a specific resistance of 108 &OHgr;Â·cm or more after curing by vulcanization, said surface rubber layer provided at least at a tire radial direction outer side region of tire tread portion, and portions of the tread portion being replaced by a plurality of conductive rubber members formed from a rubber composition whose specific resistance is 106 &OHgr;Â·cm or less, a layer radially beneath said tread portion,wherein each of the conductive rubber members is provided from a tire radial direction outer side surface of the tread portion to a tire radial direction inner surface of the tread portion and is electrically connected to said layer beneath the tread portion, and elongated exposed portions of the respective conductive rubber members at the tire radial direction outer side surface of the surface rubber layer are formed such that a longitudinal direction of the elongated exposed portions extends along a tire circumferential direction, and are disposed discontinuously along the tire circumferential direction to form a row, wherein the tread portion has at least a two layer structure comprising the surface rubber layer which is disposed in an outer portion of the tread portion in the radial direction of said tire and an inner rubber layer which is disposed in an inner portion of the tread portion in the radial direction of said tire and has a specific resistance of 106 &OHgr;Â·cm or less after curing by vulcanization such that the inner rubber layer has a relatively large specific resistance in the range of 106 &OHgr;Â·cm or less after curing by vulcanization, the conductive rubber members have better conductivity than the inner rubber layer, and each conductive rubber member extends through the surface rubber layer and the inner rubber layer with substantially the same thickness as the total thickness of the surface rubber layer and the inner rubber layer.