Bridgestone Corporation

Other

Kazuhiro Yanagisawa

Shunji Araki

Hiroshi Yamada

Toshihiro Tadaki

Tomohisa Konno

Masaaki Tsuchihashi

Tetsuo Takano

Isao Nishi

Hajime Kondo

Yoshiyuki Udagawa

Uchu Mukai

Kazuaki Someno

Shinichi Motofusa

The present invention provides a rubber composition and a pneumatic tire using the rubber composition. The rubber composition which comprises: a rubber component comprising a styrene-butadiene copolymer rubber or a blend of the styrene-butadiene copolymer rubber and another conjugated diene base rubber with the styrene-butadiene copolymer rubber being 70% by weight or more of the entire blend, and the entire content of styrene is 30 to 40% by weight of the entire rubber component; silica in an amount of 10 to 60 parts by weight per 100 parts by weight of the rubber component; a specific silane coupling agent, i.e., a bis (alkoxysilylalkyl)polysulfide having a polysulfide chain in which the distribution of sulfur is specified, in an amount of 1 to 20% by weight of the amount of silica; and carbon black, the sum of the amount of silica and carbon black being 60 to 130 parts by weight per 100 parts by weight of the rubber component. The pneumatic tire has excellent wet skid resistance, excellent grip performance on a dry road surface, and excellent abrasion resistance.

Rubber composition and pneumatic tire using said rubber composition

The present invention provides a natural rubber masterbatch effective in achieving a tread rubber composition which is suitable for heavy-duty tires for rough roads and which is effective in greatly enhancing the abrasion resistance of the tires without impairing the low heat build-up of the tires, a method of producing the natural rubber masterbatch, a rubber composition prepared using the natural rubber masterbatch, and a tire. In a mixing step of mixing a natural rubber latex with a slurry containing water and a carbon black dispersed therein, 10 to 100 weight parts of the carbon black is mixed with 100 weight parts of a natural rubber component in the natural rubber latex. The carbon black satisfies the following conditions: (1) NSA is 120 to 180 m/g; (2) the relationship between 24M4DBP and NSA is represented by the inequality 15&#x2266;24M4DBP&#x2212;0.375NSA&#x2266;38; and (3) the Dst of aggregates of the carbon black is represented by the inequality Dst&#x2266;65 nm and the ratio (&#x394;D50/Dst) of the &#x394;D50 of the carbon black aggregates to the Dst thereof is represented by the inequality &#x394;D50/Dst&#x2266;0.70.

Natural rubber masterbatch and method of producing the same

A natural rubber wet masterbatch rubber composition comprising a mixture of a natural rubber latex with a slurry solution containing a carbon black dispersed therein, which satisfies the followings: (1) a CATB specific surface area (m/g) in the range of 60&#x3c;CTAB&#x3c;110, (2) a 24M4DBP (m/100 g) in the range of 55&#x3c;24M4DBP&#x3c;75, (3) a CATB specific surface area and a tint strength (TINT) having the relationship of TINT&#x3e;0.41&#xd7;CTAB+81, and (4) a compounding amount of 10 to 100 parts by mass relative to 100 parts by mass of natural rubber. The natural rubber wet masterbatch rubber composition can be suitably used for improving the resistance to fracture and to crack propagation of a tire, a steel coating rubber for a rubber product for industrial use, and the like.

Rubber composition

The natural rubber master batch of the present invention is prepared by mixing a natural rubber latex having its amide linkages cleaved and an aqueous slurry having a filler dispersed in water. Alternatively, the natural rubber master batch is prepared by a method including a step for mixing a natural rubber latex and an aqueous slurry containing dispersed fillers having a specific particle size distribution and a limited range of 24M4DBP absorption. The natural rubber composition of the present invention is prepared by compounding natural rubber, which contains non-rubber components prepared by cleaving amide linkages of natural rubber latex, with silica and/or a particular inorganic filler.

Natural rubber master batch, production method thereof, and natural rubber composition

A rubber composition comprises a polar group-containing diene polymer synthesized through an emulsion polymerization as a rubber component, and an inorganic filler represented by a formula of mM.xSiO .zH O wherein M is a metal selected from the group consisting of aluminum, magnesium, titanium and calcium, an oxide or a hydroxide of such a metal or an hydrate thereof, m is an integer of 1 to 5, x is an integer of 0 to 10, y is an integer of 2 to 5 and z is an integer of 0 to 10.

The present invention provides a rubber composition and a pneumatic tire using the rubber composition. A rubber composition which comprises: a blend rubber of a copolymer and other diene base rubbers, the copolymer being obtained by copolymerization of 1,3-butadiene and an aromatic vinylmonomer using an organic lithium compound as an initiator, the glass transition point of the copolymer being &minus;50&deg; C. or more, and the blend rubber comprising the copolymer in an amount of 20 parts by weight or more and the other diene base rubbers in an amount of 80 parts by weight or less per 100 parts by weight of the blend rubber; silica filler in an amount of 10 to 80 parts by weight per 100 parts by weight of the blend rubber; carbon black in an amount of 20 to 80 parts by weight per 100 parts by weight of the blend rubber; and a specific silane coupling agent, i.e., a bis (alkoxysilylalkyl) polysulfide having a polysulfide chain in which the distribution of sulfur is specified, in an amount of 1 to 20% by weight of the amount of silica. The pneumatic tire has excellent wet skid resistance, low rolling resistance, and abrasion resistance.

The rubber composition of the present invention comprises a rubber component which is a blend rubber of a copolymer rubber and other diene based rubbers or the copolymer rubber alone, the copolymer rubber having a glass transition temperature of &minus;60&deg; C. or higher, a styrene content of 15 to 30% by weight and a vinyl content of 40 to 70% of a butadiene portion and the blend rubber comprising 55 parts by weight or more of the copolymer rubber and 45 parts by weight or less of the other diene based rubbers in 100 parts by weight of the rubber component; 20 to 100 parts by weight of silica per 100 parts by weight of the rubber component; 0 to 100 parts by weight of carbon black per 100 parts by weight of the rubber component, a ratio by weight of the amount of the silica to the amount of the carbon black being 1:1 to 1:0; and, in an amount of 1 to 20% by weight of the amount of silica, a specific silane coupling agent which is a bis(alkoxysilylalkyl) polysulfide having a specific polysulfide structure with a specific distribution of sulfur. The obtained rubber composition has excellent workability. The pneumatic tire using this rubber composition shows improved uniformity and abrasion resistance.

Rubber composition and pneumatic tire using the same rubber composition

A rubber composition prepared by blending 15 to 85 parts by weight of silica per 100 parts by weight of a rubber component comprising natural rubber and/or diene base synthetic rubber and 1 to 15% by weight of a dispersion-improving agent based on the amount of the silica described above. Further, a rubber composition prepared by blending 20 to 60 parts by weight of silica and 30 to 80 parts by weight of carbon black having a cetyl trimethylammonium bromide-adsorbing amount (CTAB) of 120 m,/g or more and a dibutyl phthalate-absorbing amount (DBP) of 120 ml/100 g or more per 100 parts by weight of a rubber component comprising natural rubber and/or diene base synthetic rubber, and 3 to 15% by weight of a dispersion-improving agent based on the amount of the silica described above, wherein the total amount of silica and carbon black is 50 to 120 parts by weight. A specific nitrogen-containing carbonyl compound or silicone oil is used as a dispersion-improving agent.

Rubber compositions

The present invention provides a rubber composition and a pneumatic tire using the rubber composition. The rubber composition which comprises: a rubber component comprising a styrene-butadiene copolymer rubber or a blend of the styrene-butadiene copolymer rubber and another conjugated diene base rubber with the styrene-butadiene copolymer rubber being 70% by weight or more of the entire blend, and the entire content of styrene is 30 to 40% by weight of the entire rubber component; silica in an amount of 10 to 60 parts by weight per 100 parts by weight of the rubber component; a specific silane coupling agent, i.e., a bis(alkoxysilylalkyl)polysulfide having a polysulfide chain in which the distribution of sulfur is specified, in an amount of 1 to 20% by weight of the amount of silica; and carbon black, the sum of the amount of silica and carbon black being 60 to 130 parts by weight per 100 parts by weight of the rubber component. The pneumatic tire has excellent wet skid resistance, excellent grip performance on a dry road surface, and excellent abrasion resistance.

The present invention provides a rubber composition and a pneumatic tire using the rubber composition. A rubber composition comprises silica in an amount of 10 to 85 parts by weight per 100 parts by weight of natural rubber and/or diene synthetic rubbers. A polysulfide silane coupling agent having a specific distribution of sulfur reacts with a trivalent phosphorus compound such that a content of high polysulfide in the polysulfide silane coupling agent is reduced. The rubber composition further comprises 1 to 20% by weight, based on an amount of the silica, of the polysulfide silane coupling agent having a specific distribution of sulfur such that a content of high polysulfide component is small. The pneumatic tire has an excellent low heat buildup property.

Rubber composition using a silane coupling agent having a specific

The present invention provides a rubber composition and a pneumatic tire using the rubber composition. The rubber composition comprises a diene base rubber comprising at least 15% by weight of a polybutadiene rubber, silica in an amount of 10 to 80 parts by weight per 100 parts by weight of the diene base rubber and, in an amount of 1 to 20% by weight of the amount of silica, a specific silane coupling agent, i.e., a bis (alkoxysilylalkyl) polysulfide having a polysulfide chain in which the distribution of sulfur is specified. After curing, the cured rubber composition includes closed cells. Therefore, the rubber composition has a good processability at the time of manufacturing of a tire and a pneumatic tire using the same has excellent snow/ice grip performance and abrasion resistance.

A pneumatic tire having improved rolling resistance and wear resistance comprises a tread made from a rubber composition containing a partially hydrophobizated silica subjected to a surface treatment with an organosilicon compound so as to have specified hydrophobization ratio and apparent density.

Pneumatic tires

The present invention provides a rubber composition comprising natural rubber and/or diene synthetic rubbers, silica in an amount of 10 to 85 parts by weight per 100 parts by weight of the rubber, a specific silane coupling agent, i.e., a bis-(alkoxysilylalkyl) polysulfide having a polysulfide structure in which the distribution of sulfur is specified, in an amount of 1 to 20% by weight of the amount of silica, and provides a pneumatic tire manufactured by using the rubber composition. The pneumatic tire has excellent low heat buildup property, low rolling resistance, and reinforcing property.

Growing community of inventors

Tokyo, Japan

Kazuhiro Yanagisawa