The present invention relates to a method for the preparation of a synthetic rubber blend, wherein the blend comprises a high molecular weight polydiene (A) and a low molecular weight polydiene (B). The present invention further relates to a synthetic rubber blend obtainable according to the method described herein; as well as to rubber compositions comprising the blend; and articles, such as tires.

A tire comprises a tread portion having a tread surface and buttress surfaces. The buttress surfaces have inclinations such that the tread edges shift axially outwards as the tread portion is worn off. The tread rubber includes a radially outermost first rubber layer and a radially inner second rubber layer. The loss tangent δ2 of the second rubber layer is larger than the loss tangent δ1 of the first rubber layer. One of or each of the buttress surfaces is provided with an outer lateral groove. The outer lateral groove is located axially outside the tread edge when the tire is new, and when the tread portion is worn off and the tread edge shifts axially outward, the outer lateral groove is at least partially located axially inward of the tread edge.

A tire (1) in which at least one of the said tread pattern blocks (51) comprises a circumferential reinforcing element (52) positioned axially on the inside relative to the said at least one groove (71) when working from the outside towards the inside and axially close to the said circumferential groove, the circumferential reinforcing element (52) is made of a rubber compound having a dynamic shear modulus G* at least twice as high as the dynamic shear modulus G* of the rubber compound of the rest of the blocks of the tread, the circumferential reinforcing element (52) extends radially from the radially exterior surface of the said crown reinforcement (6) towards the surface of the said tread with an axial width which decreases progressively with increasing radial proximity to the outside, and in which the said circumferential reinforcing element (52) partially forms the axially internal lateral face (7i) of the said at least one of the said tread pattern blocks (51).

Described are articles including treads and/or other tire components that are formed at least in part by rubber compositions having solid agglomerated material comprising disaggregated carbon nanotubes. Such rubber compositions include a diene rubber component and a solid agglomerated material comprising disaggregated carbon nanotubes that consist of a continuous network of carbon nanotubes that contains 1) voids and 2) aggregates of carbon nanotubes having a mean size d.sub.50 of less than 5 μm, the voids and the aggregates together in an amount that is less than 60% of a predetermined surface area, as determined by electron microscopy imagery analysis, the remainder being the disaggregated carbon nanotubes in the continuous network that do not comprise a clearly defined shape.

A run-flat tire includes a belt reinforcing layer outward of a belt layer in a tire radial direction and reinforcing rubber in sidewall portions. Where a center region is a region of a tread portion in which a center land portion corresponding to a land portion included in land portions in a tread portion and located closest to a tire equatorial plane is positioned, the belt reinforcing layer includes a center reinforcing portion in which more pieces of the belt reinforcing layer are layered at a position of the center region than at positions other than the position of the center region, and in the belt reinforcing layer, a width Wc of the center reinforcing portion in a tire lateral direction with respect to a thickness Gr of the side reinforcing rubber at a tire maximum width position is within a range of 0.5 Gr≤Wc≤2.0 Gr.

Provided is a tire for a motorcycle having an improved turning stability on wet road surface, the tire comprises a tread composed of a rubber composition, which comes into contact with a road surface, wherein Hs being a rubber hardness and M300 being a tensile stress (MPa) at 300% elongation of the rubber composition of the tread satisfy Equations 1, 2, and 3:
60≤Hs≤80,  Equation 1:
2≤M300≤12, and  Equation 2:
(M300−2)/(Hs−60)≤0.75.  Equation 3:

Heavy goods vehicle tire, having a crown portion covered radially on the outside by a tread, this tread having at least two cut-outs, the central portion of the tread having a width Lc of between 35% and 70%, the crown portion comprising a reinforcement having at least two working layers having reinforcing elements, these reinforcing elements consisting of UHT-grade threads, having a mechanical breaking strength R satisfying the following relation: R≥(4180−2130×D), where D is the diameter of the thread expressed in millimetres, this tread being formed of at least two layers of superimposed material, the material forming the first layer with a breaking elongation of more than 600% at a temperature of 60° C., this tread being such that, in the central portion, the cavity ratio per unit volume is not more than 10% and the surface cavity ratio as new is not more than 10%.

A tire has a tread 5 which includes grooves 7, the side faces 72 of which are undercut, and includes at least one circumferential reinforcing element 8-1 arranged axially relative to said undercut side face 72 at a distance “d” of between 0 and 15% of the axial width L51 of the tread block 51, at least extending radially from the inside towards the outside from a radial level situated above the wear limit level and to a radial height equal to 5% of the thickness “p” of the tread.

A composition for seeded polymerization includes: a seed copolymer which has a compound having dithioate, a mercaptan compound, a first aromatic vinyl monomer, and a first conjugated diene monomer, and has an average particle diameter of 10-30 nm; a second aromatic vinyl monomer; and a second conjugated diene monomer.

A tire comprises a tread portion. The tread portion is provided with a sipe. The sipe comprises four sipe segments: a first sipe segment, a second sipe segment, a third sipe segment, and a fourth sipe segment. At least one of the first sipe segment and the third sipe segment comprises an oscillated portion which extends in the radial direction of the tire, while oscillating in a lateral direction orthogonal to the length direction of the sipe in a cross section of the sipe orthogonal to the length direction. Each of the first sipe segment and the third sipe segment comprises the oscillated portion including an oscillating-start portion, and the oscillating-start portion of the first sipe segment is inclined with respect to the tire radial direction in the same direction as the oscillating-start portion of the third sipe segment.