Tire with rubber tread of intermedial and lateral zones with path of least electrical resistance

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 black-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 said lateral tread zone 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.