TIRE WITH RUBBER TREAD OF INTERMEDIAL AND LATERAL ZONES WITH PATH OF LEAST ELECTRICAL RESISTANCE

摘要

The invention relates to a tire having a rubber tread of a circumferentially zoned tread. The tread zones are comprised of three circumferential load bearing zones, with each zone containing a portion of the running surface of the tread, comprised of a silica-rich intermedial rubber zone positioned between and extending beneath two carbon black-rich lateral tread zones. The tread configuration contains an underlying carbon black-rich base rubber layer. The intermedial and stratified lateral zones are comprised of rubber compositions having differentiated rebound physical properties. A path of least electrical resistance extends from a lateral carbon black-rich rubber tread zone to the carbon black-rich tread base layer by an extension of a lateral tread zone or by an intermediate carbon black-rich rubber bridge.

主权项

1. A tire is provided having a circumferential rubber tread composed of a cap/base configuration comprised of an outer tread cap rubber layer with a lug and groove configuration with the outer portions of the tread lugs providing the running surface of the tread, and a tread base rubber layer underlying the outer tread cap rubber layer;
wherein the outer tread cap rubber layer is composed of three circumferential load bearing zones comprised of a silica-rich intermedial tread zone rubber layer positioned between and extending beneath two carbon black-rich lateral tread zone rubber layers to thereby underlie the lateral tread zone rubber layers and overlay the carbon back-rich tread base rubber layer; wherein outer tread lug surfaces of the intermedial tread zone rubber layer and the lateral tread zone rubber layers comprise the running surface of the tread; wherein rubber composition of the intermedial tread zone rubber layer has a 100° C. hot rebound property greater than the 100° C. hot rebound property of the rubber composition of the stratified lateral tread rubber layers, wherein a path of least electrical resistance extends from said carbon black-rich lateral rubber tread zone to the carbon black-rich tread base rubber layer by an extension of a lateral tread zone layer which extends to and joins said tread base rubber layer or by an intermediate carbon black-rich rubber bridge which extends between and joins said lateral tread zone rubber layer and said tread base rubber layer, wherein the silica-rich rubber composition of the intermedial tread zone rubber layer contains at least 40 phr of precipitated silica and a maximum of 30 phr of rubber reinforcing carbon black and is therefore relatively electrical resistive, wherein the rubber reinforcing carbon black-rich rubber compositions of the lateral tread zone rubber layer, tread base rubber layer and rubber bridge contains at least 40 phr of rubber reinforcing carbon black.