The invention relates to a tyre (100) for vehicle wheels comprising at least one structural element comprising a vulcanized elastomeric material obtained by vulcanizing a vulcanizable elastomeric composition comprising at least one vulcanizable diene elastomeric polymer and at least one composite reinforcing filler, a process for producing a tyre (100) comprising the composite reinforcing filler, a masterbatch comprising the composite reinforcing filler and a process for producing the same, as well as a process for producing the composite reinforcing filler.

The present invention relates to a tyre for vehicle wheels comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric composition comprising a predispersion of natural rubber and lignin obtained by co-precipitation from latex, where said lignin has a concentration of phenolic groups higher than 2 mmol per gram of lignin, and where said predispersion comprises an amount of said lignin such as to provide, in said crosslinkable elastomeric composition, a concentration of lignin equal to or lower than about 25 phr.

The present invention provides a rubber composition which has excellent processability owing to its low rubber viscosity during kneading, despite containing a white filler, and which further has excellent fuel economy and excellent abrasion resistance. Also provided is a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition including: a rubber component, a white filler, and a compound represented by the formula (1) below, wherein X represents CONH or COO; R.sup.1 represents a C7-C23 alkyl group or a C7-C23 alkenyl group; R.sup.2 represents a C1-C3 alkylene group; and R.sup.3 and R.sup.4 each independently represent a hydrogen atom, a C1-C3 alkyl group, or a C1-C3 hydroxyalkyl group, and at least one of R.sup.3 or R.sup.4 is the hydroxyalkyl group. ##STR00001##

A reinforced product, which can be used especially for reinforcing a finished rubber article, comprises one or more textile or metallic reinforcing thread(s), said thread(s) being covered with a sheath comprising a thermoplastic polymer composition, the sheathed thread(s) being themselves embedded in a rubber composition referred to as coating rubber, characterized in that this coating rubber is a composition based on at least one diene elastomer, a reinforcing filler, and a sulfur-based vulcanization system, which system comprises a vulcanization accelerator having a vulcanization initiation time, referred to as t0, of less than 3.5 minutes, preferably of less than or equal to 3 minutes.

A rubber composition based on one or more diene elastomer(s), on at least one reinforcing filler, on at least one coupling agent, on at least one chemical crosslinking system, wherein the reinforcing filler comprises silica in the form of essentially spherical nanoparticles, the specific surface area of this silica ranging from 30 m.sup.2/g to 250 m.sup.2/g. Also disclosed is a process for producing such a composition and also semi-finished or finished articles comprising at least one such composition.

Provided is an additive for imparting low heat build-up to a rubber component, wherein the additive includes a tetrazine compound represented by general formula (1):

##STR00001##

(wherein X.sup.1 and X.sup.2 are the same or different and represent a hydrogen atom or an alkyl, alkylthio, aralkyl, aryl, arylthio, heterocyclic, or amino group; and each of these groups may have one or more substituents), or a salt thereof.

A rubber composition comprises at least one phenol-aldehyde resin based: on at least one derivative of an aromatic polyphenol comprising at least one aromatic ring bearing at least two OZ groups in the meta position relative to one another, the two positions ortho to at least one of the OZ groups being unsubstituted, Z being other than hydrogen, and on at least one aldehyde.

An aromatic polyphenol derivative which comprises at least one aromatic ring bearing at least two OZ groups in the meta position relative to one another, the two positions ortho to at least one of the OZ groups being unsubstituted, is used for the manufacture of a phenol-aldehyde resin for reinforcing a rubber composition. Each OZ group represents an O((CO)(R.sub.1)) group with R.sub.1 representing a hydrocarbon-based radical or a substituted hydrocarbon-based radical.

A tire includes a circular tire frame including a resinous material. The resinous material includes a thermoplastic elastomer including a hard segment (HS) and a soft segment (SS), and 55% or more of molecular chain terminals of the thermoplastic elastomer are hard segments (HS).

Provided is a pneumatic tire which prevents accumulation of static electricity during travelling, which inhibits the tire from rising in an electric resistance with the passage of time, and which is reduced in a rolling resistance of the tire and excellent in durability thereof. In the pneumatic tire described above, a conductive rubber is arranged for a ply coating rubber of one surface, and a non-conductive rubber is arranged for the ply coating rubber of the other surface; assuming that the respective thicknesses thereof are T1 and T2, a carcass ply has a ply in which T1/T2 satisfies 0.2T1/T20.9; and the conductive ply coating rubber is arranged at a tread side, and the non-conductive ply coating rubber is arranged at an inner liner side.