Continuous processing equipment is suitable for use in the preparation of elastomeric compositions from end-of-life tire crumb or other vulcanized rubber starting materials. A reactor includes an outer barrel, a first shaft and a second shaft, and one or more piezoelectric transducer-driven acoustic horns arranged along the outer barrel and penetrating the outer barrel through a series of vibration-isolated ports which traverse a jacket of the outer barrel.

A rubber composition manufacturing method comprises an operation in which at least rubber, silica, and silane coupling agent are kneaded in an internal kneader at not less than a temperature lower limit for a coupling reaction between the silica and the silane coupling agent to proceed. For at least a portion of time during which that operation is being carried out, a compressed gas is delivered to the kneading chamber while the ram is in a nonpressing state.

A rubber composition manufacturing method comprises: an operation in which at least amine antioxidant, zinc oxide, silane coupling agent, silica, and rubber comprising modified polymer are fed into an internal kneader; and an operation in which kneading is carried out at the internal kneader while kneading temperature is controlled so as to suppress occurrence of a coupling reaction between the silica and the silane coupling agent, and so as to suppress occurrence of a bonding reaction between the silica and the modified polymer.

A process for producing tyres including building a green tyre having two bead structures. Each bead structure includes a bead filler. The bead filler or another rigid component of the green tyre includes a final elastomeric compound produced by the following: feeding elastomeric polymer and reinforcement filler to a first batch mixing device; mixing and dispersing the reinforcement filler in the elastomeric polymer and unloading the obtained elastomeric compound; feeding the obtained elastomeric compound, along with at least 5 phr of reinforcement resin, to a continuous mixing device of intermeshing and co-rotating twin-screw or multi-screw type or of planetary type; mixing the reinforcement resin in the elastomeric compound and unloading the obtained elastomeric compound; and feeding the obtained elastomeric compound along with the components capable of facilitating the cross-linking to a second batch mixing device and mixing to obtain the final elastomeric compound. The first and second batch mixing device have two counterrotating rotors.

A bladder for tire vulcanizing containing a crosslinked fluoroelastomer obtained by peroxide-crosslinking a fluoroelastomer composition including a peroxide-crosslinkable fluoroelastomer (A), a carbon black (B), and a peroxide cross-linking agent (C), wherein the crosslinked fluoroelastomer has a hardness at 25° C. of 60 to 90, a number of foreign particles selected from the group consisting of lumps of carbon and carbon grit having an aspect ratio of 1.1 or less and a Heywood diameter of 5 μm or more present on a fracture surface obtained by tensile fracture of the crosslinked fluoroelastomer at 170° C. is 10/mm.sup.2 or less, and the fluoroelastomer (A) includes a vinylidene fluoride (VdF) fluoroelastomer.

A high performance tire includes a tread produced by a process including vulcanizing a rubber composition including a rubber component, a carbon black component, and a plasticizer component. The rubber component includes styrene butadiene rubber in content in the range of 60 to 100 mass % with respect to 100 mass % of the rubber component, the carbon black component includes carbon black having DBP oil absorption of 130 cm.sup.3/100 g or more and nitrogen adsorption specific surface area in the range of 100 to 125 m.sup.2/g, and the carbon black has content in the range of 100 to 180 parts by mass and the plasticizer component has content in the range of 120 to 250 parts by mass with respect to 100 parts by mass of the rubber component such that the contents of the carbon black and plasticizer components satisfy (the carbon black component content)/(the plasticizer component content)≦0.9.

The present invention relates to water and solvent-free polymers, in particular water and solvent-free synthetic rubber products like non-halogenated and halogenated butyl rubber products as well as a process for the production thereof. The invention further relates to a device suitable to accomplish said process.

A continuous process for making a pressure-sensitive adhesive is disclosed. A mixture comprising natural rubber having a Mooney viscosity of 85 to 100, a tackifier, a filler, and 0.1 to 5 wt. % of an added C.sub.12-C.sub.24 fatty acid based on the amount of mixture is masticated in a first section of a single- or twin-screw extruder. Mastication of the mixture continues in at least one subsequent extruder section in the presence of additional tackifier. The product is a homogeneous, reduced-viscosity pressure-sensitive adhesive. The minor proportion of added C.sub.12-C.sub.24 fatty acid aids mastication of the rubber and enables high throughput without addition of peptizers. Duct tapes made from the adhesives display improved adhesion to steel, better adhesion bond strength, and enhanced seven-day clean removability from even difficult substrates such as marble or ceramic tile.

A pneumatic tire includes an inner liner including a vulcanized rubber composition such that a number of voids each having a volume of 4.19 μm.sup.3 or more per 8,000,000 μm.sup.3 in the vulcanized rubber composition is 2 or less in an environment of 60° C. under an atmospheric pressure, and that the vulcanized rubber composition has an air permeation coefficient of 0.95×10.sup.−10 cm.sup.3.Math.cm/(cm.sup.2.Math.s.Math.cmHg) or less when measured using a differential pressure method in the environment of 60° C.

A method for manufacturing a tire rubber composition includes kneading a rubber component, a silane coupling agent and silica such that a content of the silica exceeds 50 parts by mass with respect to 100 parts by mass of the rubber component, adding a vulcanization accelerator to a kneading mixture including the rubber component, the silane coupling agent and the silica, kneading the vulcanization accelerator and the kneading mixture including the rubber component, the silane coupling agent and the silica, adding a vulcanization agent to a resulting mixture including the rubber component, the silane coupling agent, the silica and the vulcanization accelerator, and kneading the vulcanization agent and the resulting mixture including the rubber component, the silane coupling agent, the silica and the vulcanization accelerator such that a kneaded material obtained by the kneading of the vulcanization agent and the resulting mixture has a gel fraction of 30% or less.