Abstract: A process for manufacturing a rubber composition which comprises more than 50 phr of a diene elastomer rich in ethylene units, a reinforcing filler comprising a carbon black and a vulcanization system comprising sulfur, a sulfenamide as primary accelerator and a thiuram polysulfide or a mixture of a thiuram polysulfide and a guanidine as secondary accelerator is provided. The process comprises mixing the highly saturated diene elastomer, the reinforcing filler and the secondary accelerator by kneading at a temperature above 110?C, in the absence of the sulfur and the primary accelerator, and incorporating the sulfur and the primary accelerator into the rubber composition by kneading at a temperature below 110° C. The process makes it possible to reduce the hysteresis of the vulcanized rubber compositions.

Abstract: A radial tire intended to be fitted to a heavy vehicle of construction plant type, and more particularly to the tread thereof. The tread of such a tire is desensitized to attack by indenting bodies that are likely to cause cracks at the cut bottom, in particular in the case of a tread with a high volumetric void ratio and a high degree of surface siping. Such a tire has a degree of surface siping TL of the tread at least equal to 3 m/m2, a number of cycles to failure NR of the elastomeric compound of the tread, at least present at the cut bottom, at least equal to 60000 cycles, and a ratio C between the number of cycles to failure NR of the elastomeric compound and the degree of surface siping TL at least equal to 20000 cycles/(m/m2).

Abstract: A rubber composition based on a reinforcing filler and on an elastomeric matrix comprising a highly saturated diene elastomer, comprising units of the following categories A, B, C, D and E, or units of these same categories A, B, C, D and E comprising, for at least one of the categories B, C, D and E, a mixture of at least two different units of the same category which differ from one another through the nature of their side groups Ri: and where R1, R2, R3 and R4, which are identical or different, denote a hydrogen atom, a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; R5 denotes a hydrogen atom or a methyl radical; R6 denotes a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; m, n, o, p and q are numbers ranging from 0 to 100.

Abstract: The present invention relates to a rubber composition based on a reinforcing filler and on an elastomer matrix comprising a highly saturated diene elastomer comprising at least five distinct units of A, B, C, D and E distributed randomly within the elastomer at respective molar fractions of m %, n %, o %, p % and q %, where m+n+o+p+q=100; m?50; n+o+p+q?10; and 15?p+q?2. This rubber composition enables a satisfactory degree of stiffness to be reached while maintaining hysteresis properties acceptable for use in the manufacture of tires for running vehicles.

Abstract: The present invention relates to a tire tread comprising a rubber composition which improves the compromise between wear and durability of the tire, especially a tire intended to run off-road. The composition comprises: from more than 50 to 100 phr of a polyisoprene matrix, the polyisoprene matrix containing an epoxidized polyisoprene having a molar degree of epoxidation ranging from 5% to less than 50%, a carbon black and a silica, the weight of carbon black being greater than 50% of the total weight of carbon black and silica, from 0 to less than 2 phr of a coupling agent, and a crosslinking system. The epoxidized polyisoprene is an epoxidized natural rubber or an epoxidized synthetic polyisoprene having a molar content of 1,4-cis bonds of at least 90% before epoxidation, or a mixture thereof, and, if the epoxidized polyisoprene is an epoxidized polyisoprene having a molar degree of epoxidation of from 5% to 25%, the rubber composition contains more than 50 phr of epoxidized polyisoprene.

Abstract: The present invention relates to a rubber composition which improves the compromise between stiffness in the cured state and the hysteresis of the composition. The rubber composition comprises from 0 to less than 20 phr of a butyl rubber, from more than 50 to 100 phr of a polyisoprene matrix, the polyisoprene matrix containing an epoxidized polyisoprene having a molar degree of epoxidation ranging from 5% to less than 50%, a carbon black and a silica, the weight of carbon black being greater than 50% of the total weight of carbon black and silica, from 0 to less than 2 phr of a coupling agent, and a crosslinking system. The epoxidized polyisoprene is an epoxidized natural rubber or an epoxidized synthetic polyisoprene having a molar content of 1,4-cis bonds of at least 90% before epoxidation, or a mixture thereof, and, if the epoxidized polyisoprene is an epoxidized polyisoprene having a molar degree of epoxidation of from 5% to 25%, the rubber composition contains more than 50 phr of epoxidized polyisoprene.

Abstract: The present invention relates to a rubber composition based on a reinforcing filler and on an elastomer matrix comprising a highly saturated diene elastomer comprising at least five distinct units of A, B, C, D and E distributed randomly within the elastomer at respective molar fractions of m %, n %, o %, p % and q %, where m+n+o+p+q=100; m?50; n+o+p+q?10; and 15?p+q?2. This rubber composition enables a satisfactory degree of stiffness to be reached while maintaining hysteresis properties acceptable for use in the manufacture of tires for running vehicles.

Abstract: A rubber composition based on a reinforcing filler and on an elastomeric matrix comprising a highly saturated diene elastomer, comprising units of the following categories A, B, C, D and E, or units of these same categories A, B, C, D and E comprising, for at least one of the categories B, C, D and E, a mixture of at least two different units of the same category which differ from one another through the nature of their side groups Ri: and where R1, R2, R3 and R4, which are identical or different, denote a hydrogen atom, a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; R5 denotes a hydrogen atom or a methyl radical; R6 denotes a methyl radical or a phenyl radical which is substituted or unsubstituted in the ortho, meta or para position by a methyl radical; m, n, o, p and q are numbers ranging from 0 to 100.

Abstract: Rubber composition based on at least one reinforcing filler comprising a reinforcing inorganic filler, one plasticizing system composed of at least one plasticizing hydrocarbon resin and one liquid plasticizer, one elastomer which is a copolymer at least of isoprene and styrene bearing at least one SiOR functional group, R being hydrogen or a C1-C10 alkyl, C5-C18 cycloalkyl, C6-C18 aryl or C7-C18 aralkyl radical, and one coupling agent for bonding the inorganic filler to the elastomer. A tire, the tread of which comprises such a composition exhibits an improved wet grip.

Abstract: A tire inner liner having a rubber composition based on at least one butyl rubber, a reinforcing filler, graphite and a plasticizing system. The plasticizing system comprises a hydrocarbon plasticizing resin, the glass transition temperature Tg of which is above 20° C. and the softening point of which is below 170° C. A process for producing such a composition for a tire inner liner comprises incorporating into a diene elastomer, in a mixer: a reinforcing filler, graphite, and a plasticizing system, by thermomechanically mixing all the ingredients, one or more times, until a maximum temperature between 110° C. and 190° C. is reached; cooling the mixture down to a temperature below 100° C.; then incorporating a crosslinking system; and mixing everything until a maximum temperature below 110° C. is reached.

Abstract: A tire inner liner having a rubber composition based on at least one butyl rubber, a reinforcing filler and a plasticizing system. The composition also includes graphite and the plasticizing system comprises a hydrocarbon plasticizing resin, the glass transition temperature Tg of which is above 20° C. and the softening point of which is below 170° C. A process is disclosed for producing such a composition for a tire inner liner. The process comprises the following steps: incorporating into a diene elastomer, in a mixer: a reinforcing filler, graphite, and a plasticizing system, by thermomechanically mixing all the ingredients, one or more times, until a maximum temperature between 110° C. and 190° C. is reached; cooling the mixture down to a temperature below 100° C.; then incorporating a crosslinking system; and mixing everything until a maximum temperature below 110° C. is reached.