Sumitomo Rubber Industries Limited

Nippon Paper Industries Co., Ltd.

Sumiko Miyazaki

Kenya Watanabe

Ryo Miyamori

Takeshi Nakayama

Tatsuya Miyazaki

Takeshi Fujii

Toshiaki Sakaki

Naoya Ichikawa

Takahiro Mabuchi

Ai Matsuura

Daisuke Sato

Takafumi Kawasaki

Kanta Ando

Tomohiro Hosokawa

The present invention provides a method for producing a masterbatch and related products which enhance the dispersibility of fillers in rubber to improve rubber physical properties such as tensile strength, rigidity, and fuel economy. Provided is a method for producing a masterbatch, including: step (1) of mixing a rubber latex having a zeta potential of &#x2212;100 to &#x2212;20 mV with a filler dispersion having a zeta potential of &#x2212;90 to &#x2212;10 mV to prepare a latex compound; and step (2) of adjusting a zeta potential of the latex compound prepared in step (1) to &#x2212;30 to 0 mV.

Method for producing masterbatch

The present invention provides, inter alia, a method for producing a masterbatch in which the dispersibility of microfibrillated plant fibers is further increased to obtain excellent processability and improved rubber properties such as fuel economy, tensile strength, and elongation at break. The present invention relates to a method for producing a masterbatch, the method including step (I) of mixing a rubber latex with microfibrillated plant fibers oxidized with an N-oxyl compound to obtain a mixture, and coagulating the mixture by adjusting its pH to 2 to 6.

Method for producing master batch, master batch obtained by said production method, rubber composition for tire, and pneumatic tire

The present invention provides a method for producing a masterbatch and related products which enhance the dispersibility of fillers in rubber to improve the balance of tensile strength, rigidity, and fuel economy. Provided is a method for producing a masterbatch, including a step of mixing a rubber latex having a zeta potential of &#x2212;100 to &#x2212;20 mV with a filler dispersion having a zeta potential of 10 to 90 mV, and preparing a latex compound having a zeta potential of &#x2212;20 to 0 mV.

Provided is a pneumatic tire including a sidewall that has a good balance of excellent handling stability, rolling resistance, and durability and further has excellent flex crack growth resistance. The sidewall is formed from a modified cellulose fiber-containing rubber composition that is allowed to simultaneously achieve excellent rigidity, excellent tensile properties, and low energy loss by improving the dispersibility of the cellulose fiber in rubber. The present invention relates to a pneumatic tire including a sidewall formed from a modified cellulose fiber-containing rubber composition, the modified cellulose fiber-containing rubber composition containing a modified cellulose fiber (A) obtained by adding a C15 or higher cyclic polybasic acid anhydride (a) containing a hydrophobic group to a cellulose fiber through esterification, a dispersing polymer (B) having a softening point of 135&#xb0; C. or lower, and a rubber component (C).

Pneumatic tire and run-flat tire

Provided are a modified cellulose fiber-containing rubber composition and rubber composition for tires that are allowed to simultaneously achieve excellent rigidity, excellent tensile properties, and low energy loss by improving the dispersibility of the cellulose fiber in rubber, as well as a pneumatic tire formed from the rubber composition, having excellent handling stability, excellent rolling resistance properties, and excellent durability. The present invention relates to a modified cellulose fiber-containing rubber composition containing: a modified cellulose fiber (A) obtained by adding a C15 or higher cyclic polybasic acid anhydride (a) containing a hydrophobic group to a cellulose fiber through esterification; a dispersing polymer (B) having a softening point of 135&#xb0; C. or lower; and a rubber component (C).

Rubber composition, rubber composition for tires, and pneumatic tire

Provided are a rubber composition that is environmentally friendly and achieves both excellent breaking properties and low energy loss, and a tire that includes a component prepared using the same and is environmentally friendly and excellent in rolling resistance properties and durability. The present invention provides a rubber composition containing a rubber component, a specific chemically modified microfibrillated cellulose, and carbon black.

Rubber composition and tire

The present invention provides a method for producing epoxidized natural rubber with high productivity and at low cost, a rubber composition for a tire containing the epoxidized natural rubber, and a pneumatic tire formed from the rubber composition for a tire. The present invention relates to a method for producing epoxidized natural rubber, the method including: step (1) of reacting an acid anhydride with hydrogen peroxide to prepare an organic peracid; and step (2) of epoxidizing natural rubber latex with the obtained organic peracid.

Method for producing epoxidized natural rubber, rubber composition for tires, and pneumatic tire

Provided are a rubber composition in which microfibrillated plant fibers are sufficiently uniformly dispersed to improve tire performance requirements in a balanced manner, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition formed from a masterbatch containing a rubber latex and microfibrillated plant fibers, the masterbatch being obtained by stirring the microfibrillated plant fibers in a solvent with a circulation type or continuous homogenizer and mixing the resulting microfibrillated plant fiber solution with the rubber latex and a cationic polymer, the microfibrillated plant fibers having a mean fiber length of 10 to 150 &#x3bc;m, the microfibrillated plant fiber solution containing 0.1 to 2.0% by mass of the microfibrillated plant fibers, and the amount of the cationic polymer being 0.01 to 5 parts by mass per 100 parts by mass of the rubber component of the rubber latex.

Rubber composition and pneumatic tire

The present invention relates to a natural rubber that contains 200 ppm or less of phosphorus.

Natural rubber and method for producing the same, rubber composition and pneumatic tire using the same, modified natural rubber and method for producing the same, and rubber composition for tread or for covering carcass cord and pneumatic tire using the same

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Kobe, Japan

Sumiko Miyazaki