Abstract: A process for the manufacture of a tread band for pneumatic tyres, wherein the blocks thereof comprise different rubber portions characterized by a different hysteresis loss. The process comprises a shredding step, wherein from a first and from a second rubber tread compound a plurality of fragments is manufactured with dimensions of between 6 and 30 mesh; a mixing step, wherein the fragments from the first and second compound are mixed together in order to obtain a mixture wherein said fragments are distributed in a random manner and retain their chemical/physical individuality; and an extrusion step, wherein the mixture from the preceding step is extruded for the manufacture of the tread band. The first and second compounds have different dynamic properties in terms of: dynamic modulus at 30° C., tand at 0° C., tand at 30° C. and tand at 60° C.

Abstract: A process for the manufacture of a tread band, wherein the blocks thereof comprise different portions having differing hysteresis losses. The process comprises a step for the extrusion of a preliminary tread band consisting of a first rubber compound and an injection step, wherein the preliminary tread band, once extruded, is subjected to the action of at least one injector arranged such as to penetrate into the layer of the preliminary tread band and to release a second rubber compound, which is distributed within the layer consisting of said first compound, maintaining exposed a surface that is suitable for defining a portion of the ground-contacting surface of the resulting tread band.

Abstract: A tubeless tyre (1) comprising a tread (2), a carcass (3) defining an inner cavity (4), an innerliner (5) designed to ensure that the air contained in the inner cavity (4) of the carcass (3) remains under pressure, a sealant layer (6) arranged in said inner cavity (4) in contact with the innerliner (5), and a sound-absorbing layer (7), which is also arranged in said inner cavity (4). The tyre comprises a support structure (8) housed inside said inner cavity (4) and designed to support said sound-absorbing layer (7), always keeping it separate from the sealant layer (6). The support structure (8) comprises a spacing portion (9) having an end in contact with said innerliner (5) and partially immersed in said sealant layer (6) and a support portion (10), on which the sound-absorbing layer (7) is fixed.

Abstract: Rotational cast polyurethane composition prepared from a prepolymer composition comprising: a) an isocyanate-terminated polyurethane prepolymer; and b) a curative agent comprising i) a polyol; ii) an aromatic diamine; iii) a thixotropic aliphatic amine; and iv) a thixotropic colloidal additive, wherein the prepolymer comprises a product produce by the reaction of a polyol with an organic diisocyanate monomer comprising 4,4?-diisocyanato diphenylmethane (MDI), and which prepolymer comprises less than 1.0% by weight of free MDI monomer, based on the toal weight of the prepolymer, exhibits a range of enhanced physical properties compared to those obtained from prepolymers comprising a higher level of free MDI monomer.

Abstract: Rotational cast polyurethane composition prepared from a prepolymer composition comprising: a) an isocyanate-terminated polyurethane prepolymer; and b) a curative agent comprising i) a polyol; ii) an aromatic diamine; iii) a thixotropic aliphatic amine; and iv) a thixotropic colloidal additive, wherein the prepolymer comprises a product produce by the reaction of a polyol with an organic diisocyanate monomer comprising 4,4?-diisocyanato diphenylmethane (MDI), and which prepolymer comprises less than 1.0% by weight of free MDI monomer, based on the total weight of the prepolymer, exhibits a range of enhanced physical properties compared to those obtained from prepolymers comprising a higher level of free MDI monomer.

Abstract: Rotational cast polyurethane composition prepared from a prepolymer composition comprising: a) an isocyanate-terminated polyurethane prepolymer; and b) a curative agent comprising i) a polyol; ii) an aromatic diamine; iii) a thixotropic aliphatic amine; and iv) a thixotropic colloidal additive, wherein the prepolymer comprises a product produce by the reaction of a polyol with an organic diisocyanate monomer comprising 4,4?-diisocyanato diphenylmethane (MDI), and which prepolymer comprises less than 1.0% by weight of free MDI monomer, based on the total weight of the prepolymer, exhibits a range of enhanced physical properties compared to those obtained from prepolymers comprising a higher level of free MDI monomer.

Abstract: Rotational cast polyurethane composition prepared from a prepolymer composition comprising: a) an isocyanate-terminated polyurethane prepolymer; and b) a curative agent comprising i) a polyol; ii) an aromatic diamine; iii) a thixotropic aliphatic amine; and iv) a thixotropic colloidal additive, wherein the prepolymer comprises a product produce by the reaction of a polyol with an organic diisocyanate monomer comprising 4,4?-diisocyanato diphenylmethane (MDI), and which prepolymer comprises less than 1.0% by weight of free MDI monomer, based on the toal weight of the prepolymer, exhibits a range of enhanced physical properties compared to those obtained from prepolymers comprising a higher level of free MDI monomer.