Sumitomo Rubber Industries Limited

Tatsuya Miyazaki

Ryuichi Tokimune

Masanobu Nakamura

Soh Ishino

Tsuyoshi Tsuchida

Hirokazu Ishida

Toshiaki Sakaki

Kiyoshi Ueyoko

Yuka Yokoyama

Ryo Mashita

Toshifumi Haba

Keiji Takagi

Sumiko Miyazaki

Naoya Hashimoto

Hirotoshi Otsuki

Kouji Kawaguchi

According to the rubber composition for a tire tread comprising a diene-based rubber component, and, based on 100 parts by mass of the diene-based rubber component, 0.5 to 6.0 parts by mass of a branched alkane of 40 to 70 carbon atoms, 0.05 to 3.5 parts by mass of a linear alkane of 45 or more carbon atoms and 1 to 35 parts by mass of aluminum hydroxide, and a tire comprising tread composed of the rubber composition for a tire tread of the present invention, a rubber composition for a tire tread capable of improving initial wet grip performance can be provided, thereby providing a tire having such improved initial wet grip performance.

Rubber composition for tire tread and tire

The present invention provides a tread rubber composition that is excellent in wet grip performance during the initial phase of running and tensile properties, and a pneumatic tire including the tread rubber composition. The present invention relates to a tread rubber composition containing: a diene rubber; silica; and sulfur and/or a sulfur-containing compound, the tread rubber composition satisfying the following relationships (1) to (3):EB/M300&#x2265;50&#x2003;&#x2003;(1);M100&#x2265;1.7 MPa&#x2003;&#x2003;(2); andEB&#x2265;500%&#x2003;&#x2003;(3).

Rubber composition for tread, and pneumatic tire

The present invention provides a rubber composition which has excellent processability owing to its low rubber viscosity during kneading, despite containing a white filler, and which further has excellent fuel economy and excellent abrasion resistance. Also provided is a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition including: a rubber component, a white filler, and a compound represented by the formula (1) below, wherein X represents &#x2014;CONH&#x2014; or &#x2014;COO&#x2014;; Rrepresents a C7-C23 alkyl group or a C7-C23 alkenyl group; Rrepresents a C1-C3 alkylene group; and Rand Reach independently represent a hydrogen atom, a C1-C3 alkyl group, or a C1-C3 hydroxyalkyl group, and at least one of Ror Ris the hydroxyalkyl group. 

Rubber composition and pneumatic tire

Provided is a rubber composition having improved initial dry grip performance, durability of dry grip performance, and chipping resistance (elongation at break). The rubber composition includes: a diene polymer; carbon black and/or silica; and a sulfur-containing oligomer having a weight average molecular weight of 4,000 or more, determined by GPC in chloroform solvent using polystyrene standard oligomers.

Provided are a rubber composition that achieves a balanced improvement in grip performance during the initial to late phases of running and abrasion resistance, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition containing a rubber component, sulfur, and a molten mixture of a solid resin and a plasticizer, the solid resin having an SP value of 9.2 to 13 and/or a softening point of 130&#xb0; C. or higher, the plasticizer including at least one compound selected from the group consisting of phosphoric acid esters, phthalic acid esters, aliphatic polybasic acid esters, trimellitic acid esters, acetic acid esters, and ricinoleic acid esters, the solid resin being present in an amount of 1 part by mass or more per 100 parts by mass of the rubber component.

An object of the present invention is to provide a rubber composition which is excellent in cord adhesiveness, steering stability and elongation at break. The present invention relates to a rubber composition for coating a steel cord comprising not less than 0.12 part by mass of zinc benzoate and/or zinc t-butylbenzoate, 0.03 to 0.30 part by mass of fatty acid cobalt salt in terms of cobalt element, and less than 0.5 part by mass in total of a fatty acid having 16 to 22 carbon atoms and a fatty acid derived from the fatty acid cobalt salt which has 16 to 22 carbon atoms based on 100 parts by mass of a rubber component, and a tire having a breaker and/or a carcass obtained by use of the rubber composition for coating a steel cord.

Rubber composition for coating steel cord and tire

Provided are a rubber composition for outer layers of tires with which it is possible to reduce the amount of phosphorus used, and further to improve initial grip performance and grip performance during the middle phase of running while maintaining or improving good abrasion resistance, thereby achieving a balanced improvement in these properties, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for outer layers of tires, containing a rubber component, a plasticizer, a resin having a softening point of 30&#xb0; C. or higher, and sulfur, the plasticizer including an aliphatic polybasic acid ester having a freezing point of &#x2212;50 to &#x2212;10&#xb0; C., the rubber composition containing, per 100 parts by mass of the rubber component, 0.5 to 50 parts by mass of the aliphatic polybasic acid ester and 2 parts by mass or more of the resin.

Rubber composition for use in outer layer of tire, and pneumatic tire

The purpose of the present invention is to provide a rubber composition in which a rubber viscosity during kneading is low and processability is good though the rubber composition comprises a white filler, and fuel efficiency and abrasion resistance are good. A rubber composition comprising a rubber component, a white filler and a compound represented by the following formula (1), where Rrepresents an alkyl group or alkenyl group having 8 to 14 carbon atoms, the alkyl group or alkenyl group may be linear, branched or cyclic, and Rrepresents a hydroxyalkyl group or a hydroxyalkyl group having an oxyalkylene unit.

Rubber composition

Provided is a rubber composition for tires which can prevent discoloration and improve ozone resistance while maintaining or improving good elongation at break, and further can be produced with high efficiency. Also provided are a pneumatic tire formed from the same, and a method for producing the same. Included is a rubber composition for tires, including: a rubber component; a phenylenediamine antioxidant; and a masterbatch, the masterbatch containing a specific nonionic surfactant and a silica having a BET value of 40-250 m/g at a mass ratio of 1:5 to 1:0.15, the rubber component containing a diene rubber in an amount of 70-100% by mass per 100% by mass of the rubber component, the rubber composition including, per 100 parts by mass of the rubber component, 1.0-10.0 parts by mass of the phenylenediamine antioxidant and 0.1-5.0 parts by mass of the nonionic surfactant introduced in the form of the masterbatch.

Rubber composition for tire, pneumatic tire, and method for manufacturing rubber composition for tire

Provided is a pneumatic tire including a tread formed from a rubber composition highly improving wet-grip performance, dry-grip performance, and durability while maintaining a good balance therebetween. A pneumatic tire including a tread formed from a rubber composition, the composition containing 90% by mass or more of a diene rubber per 100% by mass of the rubber component, the composition further containing a hydrogenated terpene aromatic resin obtained by hydrogenation of double bonds of a terpene aromatic resin, the hydrogenated terpene aromatic resin having a degree of hydrogenation of double bonds of 5-100% and a hydroxyl value of 20 mg KOH/g or less, the hydrogenated terpene aromatic resin being present in an amount of 1-50 parts by mass per 100 parts by mass of the diene rubber, the composition further containing specific inorganic filler in an amount of 1-70 parts by mass per 100 parts by mass of the diene rubber.

Pneumatic tire

Provided is a rubber composition for base tread which can improve steering stability, rolling resistance and durability without deteriorating extrusion processability, comprising 1.8 to 3.5 parts by mass of sulfur and 36 to 60 parts by mass of filler for reinforcement comprising not less than 7 parts by mass of silica based on 100 parts by mass of a rubber component comprising: (a) not less than 0% by mass and not more than 20% by mass of (a1) a polybutadiene rubber comprising 2.5 to 20% by mass of 1,2-syndiotactic polybutadiene crystal and/or (a2) a butadiene rubber synthesized with a rare earth containing catalyst; (b) more than 5% by mass and not more than 60% by mass of (b1) a predetermined tin-modified polybutadiene rubber and/or (b2) a modified butadiene rubber modified with a predetermined compound; and (c) 40 to 75% by mass of a diene rubber other than (a) and (b).

Rubber composition for base tread

Provided is a pneumatic tire including a tread formed from a predetermined rubber composition to achieve greatly improved abrasion resistance while maintaining good wet-grip performance and good durability. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing predetermined amounts of a specific oil-extended polybutadiene rubber, of an isoprene-based diene rubber and/or a styrene-butadiene rubber, of a specific carbon black, and of stearic acid, the oil-extended polybutadiene rubber being synthesized using a rare earth catalyst, the rubber composition having an amount of process oil of a predetermined value or less.

The present invention provides a modified natural rubber having a good balance of improved fuel economy, heat-aging resistance, processability, and breaking resistance, and a method for producing such a rubber. The present invention also provides a tire rubber composition and a pneumatic tire which are prepared using the modified natural rubber. The present invention relates to a highly purified, modified natural rubber whose pH is adjusted to 2 to 7.

Modified natural rubber, process for producing same, rubber composition for tire, and pneumatic tire

Provided is a pneumatic tire including a tread formed from a specified rubber composition, thereby achieving a balanced improvement in fuel economy, wet-grip performance, and abrasion resistance while simultaneously having excellent durability. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing: an oil-extended BR having a cis content of 95 mol % or more, a vinyl content of 1 mol % or less, and a weight average molecular weight of 530,000 or more; a SBR having a bound styrene content of 30-50% by mass and a weight average molecular weight of 700,000 or more; silica; and carbon black, the oil-extended BR being synthesized using a rare earth catalyst, the rubber composition containing, based on 100% by mass of rubber solids, 10-67% by mass of the BR component contained in the oil-extended BR and 10-50% by mass of the SBR.

Provided are: a rubber composition for treads which contains a diene rubber in the rubber component and can simultaneously achieve blowing resistance during dry running, wet grip performance and abrasion resistance; and a pneumatic tire including a tread formed from the rubber composition for treads. The rubber composition contains: a diene rubber including styrene-butadiene rubber; zinc dithiophosphate; an inorganic filler including at least one selected from the group consisting of: a compound of the formula: mM.xSiO.zHO wherein M represents at least one metal selected from the group consisting of Al, Mg, Ti, Ca, and Zr, or an oxide or hydroxide of the metal, m represents an integer of 1-5, x represents an integer of 0-10, y represents an integer of 2-5, and z represents an integer of 0-10; magnesium sulfate; and silicon carbide, and having a BET value of 5-120 m/g and a linseed oil absorption of 30-80 mL/100 g; and sulfur, wherein, per 100 parts by mass of the diene rubber, there are 0.2-15 parts by mass of the zinc dithiophosphate, 1-70 parts by mass of the inorganic filler, and less than 2.5 parts by mass of zinc oxide.

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Kobe, Japan

Tatsuya Miyazaki