Rubber wet master batch producing method, rubber wet master batch, and rubber composition containing rubber wet master batch

A method for producing a rubber wet master batch obtained by using at least a filler, a dispersing solvent, and a rubber latex solution as raw materials, comprising:

• a coagulating step of mixing a slurry solution containing the filler and the dispersing solvent with the rubber latex solution, and coagulating the mixture, thereby producing a filler-containing rubber coagulation;
• and
• a heating step of using a uniaxial extruder to heat the filler-containing rubber coagulation to a temperature of 180 to 200° C., thereby dehydrating, drying and plasticizing the filler-containing rubber coagulation through a single step,
• wherein:
• the uniaxial extruder is an extruder having a screw, and an outer cylinder having an inner wall surface in which a slit is formed to be extended along the longitudinal direction of the outer cylinder (screw axial direction);
• and at least one portion of the inner wall surface of the outer cylinder is subjected to blasting treatment.