In a tire, a tread rubber includes a first layer which is grounded on a road surface in an outer peripheral surface thereof, and a second layer which is joined to an inner peripheral surface of the first layer in an outer peripheral surface thereof, the first layer includes a joint portion where rubbers having different elastic modulus are joined, and the second layer is formed by a rubber having a greater elastic modulus than an elastic modulus of at least one of the rubbers constructing the first layer.

A tire includes a tread rubber which is formed by a plurality kinds of rubber having different elastic modulus, the tread rubber is provided with peripheral joint portions where the plurality kinds of rubber having the different elastic modulus is joined in a tire peripheral direction, and a ground end portion of an outside surface of the tread rubber in a tire width direction is formed by the rubber having the greatest elastic modulus among the plurality kinds of rubber constructing the peripheral joint portions.

Disclosed are pneumatic vehicle tires and methods of their production, the tires comprising a tread that has a tread segment arranged radially on the outside, and a material strip that is arranged helically in windings approximately in the circumferential direction, wherein, in the region of the tread segment, the material strip has at least two layers in the longitudinal direction of the material strip, wherein the first layer is formed from a first rubber compound and the second layer is formed from a second rubber compound, and wherein the layers connect the radially outer surface to the radially inner surface of the tread segment. The disclosed pneumatic vehicle tire has lower noise emissions and more uniform wear during driving and is improved in respect of at least one conflict of aims.

A method for forming a composite tread, the method comprising the steps of: forming a coextruded strip of a first compound and a second compound, wherein the first compound is a tread compound, and the second compound is formed from a second compound, wherein the tread is formed from winding the coextruded strip onto the tire building drum while varying the ratio of the first compound to the second compound.

In a tire, a ribbon rubber includes a first inclined portion which is placed at a slant with respect to a tire-circumferential direction from an outer second row of a tire-width direction to an outer first row, a first parallel portion having an end connected to an end of the first inclined portion, the first parallel portion being placed parallel to the tire-circumferential direction to configure the outer first row of the tire-width direction, and an outermost inclined portion having an end connected to an end of the first parallel portion, the outermost inclined portion being placed at a slant with respect to the tire-circumferential direction. The outermost inclined portion is placed along the first inclined portion, and is placed outside of the outer first row from the outer first row of the tire-width direction.

In a tire, a ribbon rubber includes a first inclining portion which inclines with respect to a tire-circumferential direction from an outside second row of a tire-width direction toward an outside first row in a winding direction; and a first parallel portion placed parallel to the tire-circumferential direction to configure the outside first row of the tire-width direction, a winding-start end of the first parallel portion being connected to a winding-finishing end of the first inclining portion, the winding-finishing end of the first parallel portion is placed closer to the winding direction than the winding-finishing end of the first inclining portion, or is placed at the same position as the winding-finishing end.

A manufacturing method of a pneumatic tire comprises a forming step of a tread rubber which includes a two-shot stage of simultaneously winding a first rubber ribbon constructed by a nonconductive rubber, and a second rubber ribbon constructed by a nonconductive rubber. In the two-shot stage, the first rubber ribbon and the second rubber ribbon which are adjacent to each other are spirally wound in such a manner as to come into contact with each other, and a ribbon winding position passes through an L-shaped route. A conductive rubber is partly provided in the first rubber ribbon in the winding process when the ribbon winding position passes through the L-shaped route. A conductive portion which spirally and continuously extends to the tread end from the ground-contacting surface and intermittently appears in the tire meridian cross section is formed by the conductive rubber.

A method for forming a composite tread, the method comprising the steps of forming a coextruded strip of a first compound and a second compound, wherein the first compound is a tread compound, and the second compound is formed from a high-wear compound, wherein the tread is formed from winding the coextruded strip onto the tire building drum while varying the ratio of the first compound to the second compound.