Abstract: A method for producing a wet rubber masterbatch uses a single-screw extruder. The single-screw extruder includes a screw, and an external cylinder in which a slit extended along the length direction of the external cylinder (the screw-shaft direction) is formed in an internal wall surface of the external cylinder, and when the width of the slit is represented by A and the clearance between a crest of the screw and the internal wall surface of the external cylinder is represented by B, the following expression (1) is satisfied: 0<AB(Y)/AB(X)<0.9??(1) wherein AB (Y) is the product of A and B at a downstream side along the screw-shaft direction of the external cylinder, and AB (X) is the product of A and B at an upstream side along the screw-shaft direction of the external cylinder.

Abstract: [PROBLEM] To provide a method for manufacturing a rubber composition that will serve as raw material for vulcanized rubber which excels in tear resistance, wet performance, and ability to achieve reduced heat generation. [SOLUTION MEANS] Manufacture of a tire or of a rubber composition by means of a method comprising an operation in which (a) a wet master batch comprising a first rubber and a first carbon black, (b) a second rubber comprising styrene-butadiene rubber, and (c) a second carbon black are dry-blended together under specific conditions.

Abstract: A method of manufacturing a wet rubber masterbatch includes preparing latex containing magnesium in an amount which is not greater than 150 ppm; and making a liquid mixture that includes a rubber component and carbon black. The latex may include rubber particles for which the 90 vol % particle diameter is not greater than 2 ?m. The liquid mixture can be made by a step (a) in which the latex and a dispersion solvent are mixed; and a step (b) in which a latex solution obtained at step (a) and a slurry containing the carbon black are mixed. The method for manufacturing a wet rubber masterbatch may satisfy: 0.1<b/a<1.0, where a indicates amount (ppm) of magnesium present in latex; and b indicates amount (parts by mass) of carbon black in the liquid mixture for every 100 parts by mass of rubber component in the liquid mixture.

Abstract: A problem which is addressed is the provision of a method for manufacturing a wet rubber masterbatch that will serve as raw material for vulcanized rubber which excels in fatigue resistance, ability to achieve reduced heat generation, and tensile characteristics. A wet rubber masterbatch is manufactured by means of a method comprising an operation in which a latex that has magnesium present therein in an amount which is not greater than 150 ppm is prepared; an operation in which a liquid mixture is made; and an operation in which the liquid mixture is coagulated to obtain a coagulum. The latex comprises rubber particles for which the 90 vol % particle diameter is not greater than 2 ?m. The operation in which the liquid mixture is made comprises a step in which the latex and a dispersion solvent are mixed together.

Abstract: A method for producing a wet rubber masterbatch uses a single-screw extruder. The single-screw extruder includes a screw, and an external cylinder in which a slit extended along the length direction of the external cylinder (the screw-shaft direction) is formed in an internal wall surface of the external cylinder, and when the width of the slit is represented by A and the clearance between a crest of the screw and the internal wall surface of the external cylinder is represented by B, the following expression (1) is satisfied: 0<AB(Y)/AB(X)<0.9??(1) wherein AB (Y) is the product of A and B at a downstream side along the screw-shaft direction of the external cylinder, and AB (X) is the product of A and B at an upstream side along the screw-shaft direction of the external cylinder.

Abstract: [PROBLEM] To provide a method for manufacturing a rubber composition that will serve as raw material for vulcanized rubber which excels in tear resistance, wet performance, and ability to achieve reduced heat generation. [SOLUTION MEANS] Manufacture of a tire or of a rubber composition by means of a method comprising an operation in which (a) a wet master batch comprising a first rubber and a first carbon black, (b) a second rubber comprising styrene-butadiene rubber, and (c) a second carbon black are dry-blended together under specific conditions.