Abstract: 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 a 1H-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.

Abstract: 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 a 1H-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.

Abstract: 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 ?m or less.

Abstract: 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.

Abstract: 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 ?m or less.

Abstract: 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 ?m or less.

Abstract: 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.

Abstract: 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 ?m or less.

Abstract: 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.

Abstract: 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 m2/g or more and a BET specific surface area of 185 m2/g or more, and the silane coupling agent contains a mercapto group.

Abstract: 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.

Abstract: 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 CO2 emission), 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 7.0×10?5 mol/cm3 or more.

Abstract: 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.

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

Abstract: 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 m2/g or more and a BET specific surface area of 185 m2/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.

Abstract: The present invention provides a tire rubber composition which has good silica dispersibility and improves in terms of the reinforcement, the abrasion resistance, the mechanical strength, the rolling resistance, the wet grip performance, and the handling stability on a dry road surface in a balanced manner; and provides a pneumatic tire produced using the tire rubber composition. The present invention relates to a tire rubber composition, comprising: a rubber component; a first silica; and a second silica, wherein the first silica has a CTAB specific surface area of 180 m2/g or more, a BET specific surface area of 185 m2/g or more, and an aggregate size of 45 nm or more, and the second silica has a CTAB specific surface area of 95 m2/g or less, and a BET specific surface area of 100 m2/g or less.

Abstract: 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.

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

Abstract: 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 m2/g or more and a BET specific surface area of 185 m2/g or more, and the silane coupling agent contains a mercapto group.

Abstract: 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 m2/g or more and a BET specific surface area of 185 m2/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.