Tire with tread having an outer cap layer and underlying transition layer containing corncob granules

摘要

The invention relates to a tire having a lug and groove configured rubber tread having an outer rubber cap layer with a running surface and an underlying specialized transition rubber layer. The transition layer rubber is specialized in a sense of containing corncob granules. In one embodiment, the transition layer rubber may also contain at least one of partially depolymerized rubber, particulate pre-cured rubber and coal dust. The outer tread cap layer is comprised of ground-contacting tread lugs with the tread running surface and associated tread grooves positioned between said tread lugs. The tread grooves may extend radially inward through the outer tread cap layer and into the transition tread layer. The rubber tread configuration may also optionally also include a tread base rubber layer underlying the transition rubber layer. The corncob granules may be colored with a suitable colorant of non-black color so that the transition rubber layer might be used as a treadwear indicator (or tread depth indicator), depending somewhat upon the thickness of the transition rubber layer.