The invention concerns a tyre and a rubber composition for tyre based on at least one isoprene elastomer (for example, natural rubber), one inorganic filler as reinforcing filler (for example, silica), a coupling system binding said reinforcing inorganic filler and the isoprene elastomer, said coupling system comprising in combination: as first coupling agent, a sulphurated silane compound; as second coupling agent, one at least bifunctional organosilicium compound (for example an organosilane or an organosiloxane) capable of being grafted on the elastomer by means of an azo-dicarbonyl functional (-CO-N=N-CO-) group.

Rubber composition for tyre comprising an organosilicium coupling system

The invention concerns a rubber composition for making tyres or semi-finished products for tyres, based on at least one isoprene elastomer, one inorganic filler as reinforcing filler, one polyfunctional organosiloxane coupling agent capable of binding the reinforcing inorganic filler and the isoprene elastomer, comprising per molecule, grafted on its silicon atoms, at least one hydroxyl or hydrolyzable function enabling it to be grafted on the reinforcing inorganic filler and at least one group bearing at least one functional azo-dicarbonyl -CO-N=N-CO- group enabling it to be grafted on the isoprene elastomer.

Rubber Composition for Tire Comprising an Organosiloxane Coupling Agent

A process for preparing, in one step, a diene block copolymer, of which at least one of these blocks is constituted of a polyether, the number-average molecular weight of which is approximately from 100 to 5000 g/mol, and at least one other of these blocks is constituted of a diene elastomer. The process according to the invention allows a high degree of grafting of the polyether to the polymer chains. Also disclosed is a reinforced rubber composition, especially intended for the manufacture of tires, comprising such a block copolymer which is intended to interact with the reinforcing filler. Such a rubber composition has improved hysteresis properties in the vulcanized state, while retaining satisfactory processing properties in the non-vulcanized state.

Process for Preparing a Diene Copolymer Comprising a Polyether Block, Diene Copolymer Comprising a Polyether Block, Reinforced Rubber Composition and Tire

The invention relates to a rubber composition for tyres, comprising at least a diene elastomer, an inorganic reinforcing filler, and a coupling agent linking the inorganic filler and the diene elastomer. The composition is characterised in that the coupling agent is an azo-silane compound having formula (I) (G1)3-a(G2)aSi-Z-NH-C(0)-N=N-C(0)-NH-Z-Si(G1)3-a(G2)a, wherein: - G1, which may be identical or different, each represent a monovalent hydrocarbon group selected from among optionally substituted, linear or branched alkyls having between 1 and 18 carbon atoms, cycloalkyls or aryls, optionally substituted, having between 5 and 18 carbon atoms; - G2, which may be identical or different, each represent a hydroxyl group or a monovalent group taking the form (G3)n-OG1, in which G3 is a divalent linking group comprising between 1 and 18 carbon atoms and containing one or more heteroatoms selected from among O, S, Si and N, and n is a number greater than or equal to 0 and less than or equal to 18; - Z represents a divalent linking group comprising between 1 and 18 carbon atoms; and - a is equal to 1, 2 or 3.

Rubber tyre composition comprising an azo-silane coupling agent

The invention relates to a process for preparing, in one step, a diene block copolymer, of which at least one of these blocks is constituted of a polyether for which the number-average molecular weight is essentially from 100 to 5000 g/mol, and at least another of these blocks is constituted of a diene elastomer. The process according to the invention allows a high degree of grafting of the polyether to the polymer chains. The present invention also relates to a reinforced rubber composition, especially intended for manufacturing tyres, comprising such a block copolymer that is intended to interact with the reinforcing filler. A rubber composition according to the invention has improved hysteresis properties in the vulcanized state, while retaining satisfactory processing properties in the non-vulcanized state.

Process for preparing a diene copolymer having a polyether block, reinforced rubber composition and tyre

The invention concerns a tyre and a rubber composition for tyre or semi-finished product for tyre, based on at least one isoprene elastomer (for example, natural rubber), an inorganic filler as reinforcing filler (for example, silica), a coupling system binding said reinforcing inorganic filler and the isoprene elastomer, said coupling system comprising in combination: a monofunctional covering agent (for example, a polyorganosiloxane oil) capable of binding to the functional sites of the inorganic filler surface; and as coupling agent, an organosilicium compound (for example, an organosilane or an organosiloxane) at least bifunctional graftable on the elastomer by means of a functional azo-dicarbonyl (-CO-N=N-CO-) group.

Rubber composition for tyre comprising an organosilicium coupling agent and an inorganic filler covering agent

The invention relates to a rubber composition which can be used to produce tyres and which is based on at least one diene elastomer, an inorganic reinforcing filler and a coupling agent which is used to join the inorganic filler and the elastomer. The inventive composition is characterised in that the aforementioned inorganic filler comprises a synthetic aluminosilicate having formula (I) Mx Si Aly Oa (OH)b, (H20)c, wherein: M is a cation which is selected from the group comprising K+, Na+, Ca++ and mixtures of said cations; x > 0; y > 0; a ≥ 0; b ≥ 0, c ≥ 0 and a+b > 0, and having the following characteristics: (a) a specific surface area (BET) of between 20 and 300 m2/g; (b) an average particle size in mass (dW) of between 20 and 400 nm; and (c) a deagglomeration speed (α), using ultrasound, which is greater than 5.10-4 µm-1/min. The invention also relates to the use of one such rubber composition for the production of rubber articles, in particular tyres or semi-finished rubber products, such as treads, which are intended for tyres.

Rubber composition for tyres, based on reinforcing aluminosilicate

Rubber materials with well-dispersed fillers and large mechanical reinforcement have been obtained by melt-processing a diene elastomer matrix and tailored nanocellulose powders having both a high specific surface area and a modified interface. Such filler powders with a specific surface area of 180 m2 g−1 and 100 m2 g−1 have been obtained by freeze-drying suspensions of short needle-like cellulose nanocrystals (CNCs) and entangled networks of microfibrillated cellulose (MFC) in tert-butanol/water, respectively. A quantitative and toposelective filler surface esterification was performed using a gas-phase protocol either with palmitoyl chloride (PCl) to obtain a hydrophobic but non-reactive nanocellulose interface, or with 3,3′-dithiopropionic acid chloride (DTACl) to introduce reactive groups that can covalently bind the nanocellulose interface to the dienic matrix in a subsequent vulcanization process. A set of filled materials was prepared varying the filler morphology, interface and volume fraction. Transmission electron microscopy images of ultrathin cryo-sections showed that modified nanocellulose fillers presented a relatively homogeneous distribution up to a volume fraction of 20%. The materials also exhibited a significant modulus increase, while keeping an extensibility in the same range as that of the neat matrix. Strikingly, in the case of the reactive interface, a strong stress-stiffening behavior was evidenced from the upward curvature of the tensile curve, leading to a large increase of the ultimate stress (up to 7 times that of the neat matrix). Taken together, these properties, which have never been previously reported for nanocellulose-filled elastomers, match well the mechanical characteristics of industrial carbon black or silica-loaded elastomers.

Anne Veyland

Papers

Rubber composition for tyre comprising an organosilicium coupling agent and an inorganic filler covering agent

Rubber composition for tyre comprising an organosilicium coupling system

Rubber tyre composition comprising an azo-silane coupling agent

Rubber composition for tyres, based on reinforcing aluminosilicate

Rubber materials from elastomers and nanocellulose powders: filler dispersion and mechanical reinforcement.