Sumitomo Rubber Industries Limited

Dunlop Sports Company Limited

Gifu University

Takehiko Hyodo

Kazuyoshi Shiga

Hiroaki Tanaka

Kunio Niwa

Masanori Taguchi

Fumiya Suzuki

Sho Goji

Akihiro Mine

Toshihiro Tamura

Yuko Kujirai

Hiroshi Hasegawa

Tadashi Uozumi

Kohei Mimura

Asami Nakai

Yumi Kanemitsu

Yasuo Naito

Akio Ohtani

Yuko Sakurai

Yuta Shimane

An adhesive for a tennis ball of the present disclosure includes base rubber and a filler. The base rubber contains, as a main component thereof, liquid rubber having a number average molecular weight of not less than 10,000. The filler has an average nitrogen specific surface area of not less than 40 m/g. A tennis ball of the present disclosure includes a hollow core made of a rubber material. The core includes two hemispherical half cores. The two half cores are adhered to each other by using the adhesive for a tennis ball.

Adhesive for tennis ball

An adhesive for a tennis ball includes base rubber. The base rubber contains, as a main component thereof, liquid rubber having a number average molecular weight of not less than 10,000. The adhesive has a shear viscosity of not greater than 2,000 Pa·s. A tennis ball includes a hollow core made of a rubber material. The core includes two hemispherical half cores. The two half cores are adhered to each other by using the adhesive for a tennis ball.

An aqueous adhesive for rubber includes rubber latex and an ammonium-salt-based vulcanization acceleration aid. An amount of the ammonium-salt-based vulcanization acceleration aid contained in the aqueous adhesive is preferably not less than 0.01% by weight and not greater than 5.0% by weight in terms of solid content. An aqueous adhesive for a ball includes rubber latex as a main component. A content of an inorganic filler in the aqueous adhesive is not greater than 0.1% by weight in terms of solid content. A ballincludes a hollow coreobtained by crosslinking a rubber composition that contains a vulcanizing agent. The coreis formed of two hemispherical half cores. The two half cores are adhered to each other by using the aqueous adhesive for a ball.

Aqueous adhesive for rubber and aqueous adhesive for ball

The aqueous adhesive for a tennis ball includes rubber latex. The rubber latex is a mixture of liquid rubber latex and solid rubber latex. A ratio of liquid rubber to an entire rubber component contained in the rubber latex is greater than 20% by weight and less than 90% by weight in terms of solid content. The tennis ball includes a seam formed of the aqueous adhesive for a tennis ball.

Aqueous adhesive for tennis ball

The aqueous adhesive for a tennis ball includes rubber latex. The rubber latex is a mixture of liquid rubber latex and solid rubber latex. When a solid content in the aqueous adhesive is measured at a temperature of 140° C. by a curelastometer, a torque is not less than 0.26 N·m after 10 minutes from start of heating. The tennis ball includes a seam portion formed of the aqueous adhesive for a tennis ball.

A rubber composition for a hollow ball includes a base rubber and an inorganic filler. A weight reduction rate TGAfrom room temperature to 650&#xb0; C. and a weight reduction rate TGAfrom room temperature to 850&#xb0; C. of the rubber composition are measured under an air atmosphere by thermogravimetry conforming to JIS K0129. The weight reduction rate TGAof the rubber composition is not less than 63% and not greater than 99%. A difference (TGA&#x2212;TGA) between the weight reduction rates TGAand TGAof the rubber composition is not less than 0% and not greater than 7%. A hollow ballincludes a hollow coreformed from the rubber composition.

Rubber composition for hollow ball and hollow ball

A rubber composition for a tennis ball includes a base rubber and a filler having a degree of flatness DL of not less than 50, the degree of flatness DL being obtained by dividing an average particle diameter D(&#x3bc;m) of the filler by an average thickness T (&#x3bc;m) of the filler. An amount of the filler per 100 parts by weight of the base rubber is not less than 1 part by weight and not greater than 150 parts by weight. A gas permeability coefficient GPS and a loss tangent tan &#x3b4;S of the rubber composition and a gas permeability coefficient GPL and a loss tangent tan &#x3b4;L of a rubber composition obtained by replacing the filler with kaolin clay having a degree of flatness DL of 20 satisfy (1): GPL/GPS&#x2265;1.02 and (2): |tan &#x3b4;L&#x2212;tan &#x3b4;S|&#x2264;0.03. A tennis ballincludes a coreformed using the rubber composition.

Rubber composition for tennis ball and tennis ball

A rubber composition for a tennis ball includes a base rubber and a high-flatness filler. The high-flatness filler has an average particle diameter Dof not less than 1 &#x3bc;m and not greater than 50 &#x3bc;m. A degree of flatness DL is not less than 40 and not greater than 200. An amount of the high-flatness filler per 100 parts by weight of the base rubber is not less than 5 parts by weight and not greater than 100 parts by weight. A ratio (E2/E1) of a tensile elastic modulus E2 in a tensile strain range from 70% to 100% to a tensile elastic modulus E1 in a tensile strain range from 10% to 30%, of a vulcanized rubber obtained by vulcanizing the rubber composition, is not less than 0.60 and less than 1.00. The tennis ball includes a hollow core formed from the rubber composition.

Rubber composition for tennis ball

A rubber composition for a hollow ball includes a base rubber, an inorganic filler composed of a large number of flat particles, and a carbon-based filler. As to the carbon-based filler, a degree of flatness DLc obtained by dividing an average particle diameter D(&#x3bc;m) by an average thickness Tc (&#x3bc;m) is not less than 50. A weight ratio Mc/Mi is not less than 0.01 and not greater than 1.00. The rubber composition is obtained by a production method including: a first step of mixing the base rubber and the carbon-based filler to obtain a master batch; and a second step of adding the large number of flat particles that form the inorganic filler, to the master batch to orient the large number of flat particles. The hollow ballincludes a coreformed from the rubber composition.

To provide a lightweight shaft having excellent strength, a shaft has one or a plurality of fiber reinforced resin layers. At least one of the fiber reinforced resin layers is produced by a filament winding method in which one or a plurality of fiber bundles are wound while tension is applied thereto. The fiber bundles each include a plurality of filaments. The tension applied to the fiber bundles is not less than 0.04 (gf) per filament. The tension is great. Preferably, at least one of the fiber reinforced resin layers is produced by a multi-filament winding method in which a plurality of the fiber bundles are simultaneously wound while being arranged side by side. Preferably, fibers forming the filaments are carbon fibers. Preferably, a resin composition included in each fiber reinforced resin layer is an epoxy resin composition.

Golf club shaft

An object of the present invention is to provide a golf club shaft having excellent strength. The present invention provides a golf club shaft made of a fiber-reinforced epoxy resin material comprising a cured product of an epoxy resin composition and a reinforcing fiber, wherein the epoxy resin composition comprises at least one selected from the group consisting of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin and a novolac type epoxy resin, and a tetraglycidyl type epoxy resin as an epoxy resin component, and the cured product of the epoxy resin composition has a swelling ratio in a range from 20 mass % to 44 mass % in methyl ethyl ketone.

A rubber composition contains a higher ethylene content EPDM and a lower ethylene content EPDM as a rubber component. The proportion of the higher ethylene content EPDM is 30 to 80 mass % based on the overall amount of the rubber component. The rubber composition is less susceptible to reduction in friction coefficient &#x3bc; and has a proper hardness, a smaller permanent elongation and an excellent abrasion resistance after crosslinking. Therefore, the rubber composition is suitable for a sheet conveying roller and an image forming apparatus incorporating the sheet conveying roller.

Rubber composition, sheet conveying roller, and image forming apparatus

A sheet feeding member is provided, which is made of a thermoplastic elastomer composition comprising: a base polymer including a polyurethane thermoplastic elastomer and a polyester thermoplastic elastomer; and at least one ion conductive agent selected from the group consisting of a quaternary ammonium salt and a lithium salt/polyol, wherein the ion conductive agent is present in a proportion of 0.2 to 4 parts by mass based on 100 parts by mass of the base polymer in the thermoplastic elastomer composition.

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Kobe, Japan

Takehiko Hyodo