Sumitomo Rubber Industries Limited

Ai Matsuura

Takayuki Hattori

Lucksanaporn Tarachiwin

Hathainat Kum-Ourm

Kenichi Uesaka

Takao Wada

Michio Hirayama

Kamalin Kanyawararak

Yasuhisa Minagawa

Naoya Ichikawa

Toshiaki Sakaki

Kazuo Hochi

Yoshiaki Miyamoto

Hiroshi Ito

Sumiko Miyazaki

Atsuko Ochi

Takehiro Kitaura

Masatoshi Kobayashi

Jun Okamoto

Noa Kaneko

Hironori Inamoto

Tomohiro Hosokawa

The invention provides natural rubbers having improved processability and/or abrasion resistance, rubber compositions containing the natural rubbers, and pneumatic tires formed from the rubber compositions. The invention relates to a natural rubber which shows aH-NMR spectrum where the sum of peak intensities at about 4.17, 3.94, 3.84, 3.73, 3.50, and 3.41 ppm, normalized to 10,000 for the peak intensity at about 5.11 ppm, is 8.0 or less.

Natural rubber, rubber composition and pneumatic tire

The present invention aims to provide rubber compositions for tires that contain a natural rubber achieving a balanced improvement in abrasion resistance, breaking performance, and processability to achieve a balanced improvement in abrasion resistance, breaking performance, and processability, and also provide pneumatic tires containing such rubber compositions for tires. Included is a rubber composition for tires comprising a modified natural rubber prepared by treating natural rubber latex with a proteolytic enzyme, and then treating the treated natural rubber latex with a lipolytic enzyme and/or a phospholipid degrading enzyme. Also included is a rubber composition for tires, comprising a modified natural rubber prepared by centrifuging natural rubber latex to recover a latex fraction comprising latex particles having an average particle size of 0.25 &#x3bc;m or less.

Rubber composition for tires and pneumatic tire

The present invention provides a method for producing natural rubber with which the odors of solid natural rubber is easily reduced, and further which does not degrade physical properties such as heat aging resistance. The present invention relates to a method for producing natural rubber, the method including a sheeting step including sheeting a non-deproteinized solid natural rubber to form a natural rubber sheet, the natural rubber sheet having a moisture content of 20% or less.

Method for producing natural rubber

The present invention aims to provide a composite including a rubber component in which surface-treated silica with a small particle size is uniformly dispersed, and a method for producing the composite. The present invention also aims to provide a rubber composition including the composite, the rubber composition capable of achieving both fuel efficiency and abrasion resistance while having excellent processability. The present invention also aims to provide a pneumatic tire including the rubber composition. The present invention relates to a composite formed from a compound latex prepared by mixing a natural rubber latex and a dispersion of surface-treated silica formed from a water glass, the surface-treated silica having an average particle size of not more than 100 nm and having a chemically-treated surface.

Composite and method for producing the same, rubber composition, and pneumatic tire

It is an object of the present invention to provide a tire rubber composition excellent in performances such as silica dispersibility and processability. The present invention relates to a tire rubber composition, comprising: a rubber component that contains an epoxidized natural rubber; silica; and a silane coupling agent, wherein the amount of the epoxidized natural rubber in 100% by mass of the rubber component is 15% by mass or more, the silica has a CTAB specific surface area of 180 m/g or more and a BET specific surface area of 185 m/g or more, and the silane coupling agent contains a mercapto group.

Tire rubber composition and pneumatic tire

The present invention has its object to provide a rubber composition for a tread which can prevent reversion and can also achieve environmental performance (excellent rolling resistance, response to depletion of oil resources, attention to COemission), wet grip performance, dry grip performance, handling stability, and durability (abrasion resistance, crack resistance) in a well-balanced manner. The present invention also aims to provide a pneumatic tire using the rubber composition for the tread thereof. The rubber composition for a tread includes a rubber component containing 35% by mass or more of an epoxidized natural rubber; and a white filler, wherein a total sulfur content is less than 1.75% by mass, and a crosslink density is 7.0&#xd7;10mol/cmor more.

Rubber composition for tread and pneumatic tire

It is an object of the present invention to provide a tire rubber composition and a pneumatic tire produced using the rubber composition, which improve mechanical strength, abrasion resistance, rolling resistance, wet grip performance, and dry grip performance in good balance. The present invention relates to a tire rubber composition comprising: a rubber component that contains a modified diene rubber; and a silica component that contains a silica surface-treated with a silane coupling agent, wherein the amount of the modified diene rubber in 100% by mass of the rubber component is 15% by mass or more, and the dispersion ratio of the silica component is 70% or higher.

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

It is an object of the present invention to provide a tire rubber composition excellent in performances such as silica dispersibility and processability. The present invention relates to a tire rubber composition, comprising: a rubber component; silica; and a silane coupling agent, wherein the silica has a CTAB specific surface area of 180 m/g or more and a BET specific surface area of 185 m/g or more, and the silane coupling agent is a copolymer comprising units A represented by formula (1) and units B represented by formula (2), and the proportion of the units B is 1 to 70 mol % of the total molar amount of the units A and the units B. 

The present invention provides a rubber composition capable of reducing rolling resistance, and improving abrasion resistance, wet skid performance, and steering stability. A tire having a tread and/or a sidewall using the rubber composition is also provided. The rubber composition of the present invention comprises not less than 10 parts by weight of the silica (1) having an average primary particle diameter of not less than 22 nm and not less than 5 parts by weight of the silica (2) having an average primary particle diameter smaller than 22 nm based on 100 parts by weight of a rubber component, wherein the total amount of the silica (1) and the silica (2) is 15 to 150 parts by weight. The tire of the present invention is prepared by using the rubber composition.

Rubber composition and tire having tread and/or sidewall using same

An acrylic resin glove is made of a film having a crosslinked structure, formed of an acrylic resin emulsion, and an internal surface treating agent for an acrylic resin glove, is composed of an acrylic resin emulsion, and at least one organic filler selected from the group consisting of methacrylic resin micro-particles, polyolefinic resin micro-particles and cellulose beads, each having an average particle diameter within a range from 3 to 10 &mgr;m, the content of said organic filler being within a range from 2 to 8% by weight based on the total weight. The acrylic resin glove is superior in fitting and detaching properties and in washing resistance while maintaining required mechanical characteristics. The internal surface treating agent is used to obtain an acrylic resin glove having the above-described characteristics by forming a film of this treating agent on the internal surface of the acrylic resin glove, thereby to improve the lubricity of the internal surface of the glove.

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Kobe, Japan

Ai Matsuura