The invention relates to a sulfur-crosslinkable rubber mixture comprising a rubber blend composed of at least one solution-polymerized diene polymer A of high molecular weight and at least one solution-polymerized polymer B of low molecular weight, wherein at least one of polymers A and B has been functionalized at the chain end and/or along the polymer chain and/or at a coupling site with at least one group selected from epoxy groups, hydroxyl groups, carboxyl groups, silane sulfide groups, amino groups, siloxane groups, organosilicon groups, phthalocyanine groups and amino group-containing alkoxysilyl groups, 30 to 300 phr of at least one silica and 1 to 20 phf of at least one substance of formula I) as silane coupling agent
(R.sup.1R.sup.2R.sup.3)Si—S.sub.4—Si(R.sup.3R.sup.2R.sup.1)  II)
where R.sup.1, R.sup.2, R.sup.3 in the structure may be the same or different and may be selected from linear or branched alkoxy, cycloalkoxy, alkyl, cycloalkyl or aryl groups having 1 to 20 carbon atoms.

A composite resin molded body includes a base compound resin and a molten-kneaded mixture which contains an organic fibrous filler, and a dispersing agent. In the composite resin molded body, a content of the organic fibrous filler is at least 5 mass % and at most 70 mass %, and a proportion T of the organic fibrous filler carbonized in the composite resin molded body is equal to or less than 0.1.

An acoustic lens for an ultrasonic probe includes a vulcanization-molded article of a rubber composition including a first silicone rubber composition having a plasticity number of 100 or less, and a second silicone rubber composition having a plasticity number of 150 or more and 300 or less.

A method for manufacturing a raw blank of a tyre includes using a calender to produce a ply. The calender includes two rollers with a gap situated therebetween. A ply that includes a first rubber material is formed in the gap of the calender, with a bead of the first rubber material being formed upstream of the gap. The bead and the gap of the calender are fed with a second rubber material, different from the first rubber material, to form at least one insert in the ply.

A method for manufacturing a rubber composition includes kneading a rubber component, an inorganic filler and a thioester-based silane coupling agent, and adding a vulcanizing agent and one or more compounds selected from the group of an imide compound and an N-oxyl compound to a mixture of the rubber component, the inorganic filler, and the thioester-based silane coupling agent such that the vulcanizing agent and the imide compound and/or the N-oxyl compound are kneaded with the mixture including the rubber component, the inorganic filler, and the thioester-based silane coupling agent.

A production method comprising: (a) a step of melt-mixing a base resin containing a chlorinated polyethylene; an organic peroxide, an inorganic filler, and a silane coupling agent, in specific ratios, at a temperature equal to or higher than a decomposition temperature of the organic peroxide, to prepare a silane master batch; (b) a step of mixing the silane master batch obtained in the step (a) with a silanol condensation catalyst, and then forming the resultant mixture; and conducting at least one of the melt-mixing in the step (a) and the mixing in the step (b) is performed in the coexistence of a chloroprene rubber or a polyvinyl chloride; a heat-resistant chlorine-containing crosslinked resin formed body produced by the method, a silane master batch, a mixture and formed body thereof, and a heat-resistant product.

The present invention provides a method for producing a rubber composition containing a rubber component (A) which contains a copolymer of a conjugated diene compound and an aromatic vinyl compound, in which the conjugated diene compound amount in the copolymer is 50% by mass or more and 73% by mass or less and the molecular weight at the peak top of the molecular weight distribution of the polystyrene-equivalent number-average molecular weight of the copolymer as measured through gel permeation chromatography is 100,000 or more and 600,000 or less, a filler containing an inorganic filler (B), a silane coupling agent (C) and at least one accelerator (D) selected from guanidines, sulfenamides, thiazoles, thiurams, thioureas, dithiocarbamates and xanthates, wherein the rubber composition is kneaded in plural stages, and in the first stage (X) of kneading, the rubber component (A), all or a part of the inorganic filler (B), all or a part of the silane coupling agent (C) and the accelerator (D) are added and kneaded. The production method can produce a rubber composition excellent in low-heat-generation property and abrasion resistance.

A process for recovery and devulcanization of vulcanized rubber is provided. The process takes place in a plant including a mill for grinding vulcanized rubber into particles, a twin-screw extruder provided with a device for forced feeding of vulcanized rubber particles and a thermostatting device, a single-screw extruder arranged downstream of the twin-screw extruder and equipped with a thermostatting device, a filter for devulcanized rubber and an extrusion die shaped like a slot, from the which devulcanized rubber comes out in the form of a strip or sheet, and a cooling device for the devulcanized rubber strip or sheet. The twin-screw extruder operates at a temperature between 35 and 450° C., with a rotation speed of the screws between 15 and 600 rpm, and a torque density between 11 and 18 Nm/cm.sup.3, so that the shear rate remains constant for the entire longitudinal extension of the twin-screw extruder.

A method of mixing a rubber composition includes a carbon introduction step and a uniform dispersion step. In the carbon introduction step, on the basis of a deviation between a rate of temperature increase of the rubber mixture (R) and a target value, at least one of a ram pressure (Pr) and a rotational speed (N) of the mixing rotor (2) is PID controlled so that the ultimate temperature of the rubber mixture (R) at the conclusion of the step is within a tolerance range. In the uniform dispersion step, the ram pressure (Pr) or the rotational speed (N) of the mixing rotor (2) is adjusted to reduce a deviation between a value based on successively detected data associated with a predetermined control target and a target value.

A kneader internal inspection device according to the present invention suspends and supports a photographing unit, which is arranged in an interior of a kneader and which photographs the interior, so as to be vertically movable in the interior of the kneader. Therefore, such a kneader internal inspection device is capable of easily inspecting the interior of the kneader.