Bridgestone Corporation

Yukari Kanda

Kazuaki Someno

Fumiteru Nishiura

Yasuto Yanagisawa

Shigenobu Waragai

Osamaru Matsuo

Provided is a method for producing a mixture, comprising a mixing step for mixing a slurry prepared by dispersing a filler containing carbon black and a rubber liquid prepared by dispersing or the like a rubber component. In the above producing method, the carbon black contained in the slurry has a surface average acidic functional group amount (&#x3bc;eq/m) of 0.40 or more and less than 3.00; a pH of the slurry is 8 or more; the sum total of the solid matter concentrations of the slurry and the rubber liquid is 20% by mass or less; a mixing equipment used has one or more rotors disposed rotatably in a rotation axis direction and one or more stators disposed unrotatably in the rotation axis direction; the rotors and the stators have plural projections which are arranged circularly with the rotation axis set as the center; rings are formed concentrically by the projections in a single stage or a multistage; and the slurry and the rubber liquid are allowed to pass through a space between the rotors and the stators while the rotors rotate, whereby the mixing is carried out to produce the mixture.

Method for producing mixture

Provided is a process for producing a wet masterbatch which, without deteriorating a reinforcing property of a rubber composition and rubber physical properties, micronizes a filler slurry by controlling an amount of functional groups on a filler surface, and improves filler dispersibility in the rubber wet masterbatch and the rubber composition. The process for producing a wet masterbatch comprises: a step of producing a slurry solution having a pH of 8 or more by dispersing carbon black having an average amount of surface acidic functional groups (&#x3bc;eq/m) of 0.15 or more and less than 3.00; a step of producing a mixture by mixing the slurry solution and a rubber latex solution in a liquid phase; and a step of drying the mixture.

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Tokyo, Japan

Yukari Kanda