Sumitomo Rubber Industries Limited

Sri Sports Limited

Kunio Niwa

Takeshi Ashino

Tetsuo Yamaguchi

Kazuyoshi Shiga

Hiroaki Tanaka

Masanori Taguchi

Takehiko Hyodo

Fumiya Suzuki

Hiroomi Matsushita

Hiroyuki Takeuchi

Koichi Fujisawa

Masaru Kohno

Kohei Mimura

Ichiro Tominaga

Shinichi Nakade

Taketo Matsuki

Toshihiro Horii

Yuko Sakurai

Yuko Kujirai

Ikuko Umezawa

Masao Maekawa

Masaji Hasegawa

Ryohei Hirose

Naoka Sakamoto

Lid for a container

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

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.

A midsole of a shoe has a low elastic part, a high elastic partand an inclined surface. The low elastic partand the high elastic partinclude air bubbles. An ethylene-vinyl acetate copolymer (EVA) is used as a base polymer in the low elastic partand the high elastic part. The inclined surfaceis inclined upward from the inside to the outside. The low elastic partis located to the inside of the inclined surface. The high elastic partis located to the outside of the inclined surface. An inner high elastic partis located to the inside of a low elastic part. The thickness of the low elastic partbecomes gradually larger from the outside to the inside along the inclined surface. The thickness of the high elastic partbecomes gradually larger from the inside to the outside along the inclined surface. The width Wa of the inclined surfacein left and right direction is 5 mm or more and 100 mm or less.

Shoe

In a racket frame, a yoke part is disposed between left and right portions of a bifurcated throat part continuous with a head part and with a shaft part. A ball-hitting face is formed with the yoke part and the head part. The head part and the yoke part have a plurality of string holes formed in penetration therethrough to insert longitudinal and transverse strings therethrough. Longitudinal string holes formed outside left and right sides of the yoke part connected with the left and right portions of the throat part are extended to the throat part to form extended longitudinal string holes open on an outer surface of the throat part.

Racket

A tennis racket frame is composed of a laminate of prepregs each containing carbon fibers serving as a reinforcing fiber thereof. At least one part of layers of the laminate is formed as a hard layer consisting of a prepreg composed of the reinforcing carbon fibers and a hard carbon film (DLC film) formed on the surface of the carbon fibers.

Tennis racket frame

In a tennis racket having a racket frame composed of a fiber reinforced resin, the moment of inertia Ic of the tennis racket in a center direction thereof is set to not less than 13000 g&#xb7;cmnor more than 17000 g&#xb7;cm, the moment of inertia Ig around a center of gravity thereof is set to not less than 80000 g&#xb7;cmnor more than 200000 g&#xb7;cm, and the moments of inertia Ic and Ig are so set as to satisfy a relationship expressed by [30&#xd7;(Ic)&#x2212;(Ig)]/10000&#x2267;31.

Tennis racket

A tennis racket frame (), including a sleeve composed of a fiber reinforced resin, having a weight not less than 180 g nor more than 270 g, when strings are not mounted in a ball-hitting face thereof surrounded with a head part thereof. Supposing that the strings are not mounted in the ball-hitting face, a secondary natural frequency (F) of the racket frame in an in-plane direction thereof is set to not less than 200 Hz nor more than 320 Hz, a secondary natural frequency (F) thereof in an out-of-plane direction thereof is set to not less than 480 Hz nor more than 650 Hz, and F/Fis set to not less than 0.3 nor more than 0.6.

Racket frame

A racket frame () including a laminate having not less than two fiber reinforced resinous layers layered one upon another and one or more modified fiber reinforced resinous layers () each containing a modified resinous composition, as a matrix resin, having a loss factor (=tan &#x3b4;) not less than 0.5 nor more than 3.0, when the loss factor is measured at a temperature of 0&#xb0; C. to 10&#xb0; C. and a frequency of 10 Hz. A weight of the modified fiber reinforced resinous layers () is set to not less than 1% nor more than 10% of a weight of the fiber reinforced resinous layers.

A racket frame ( ) has a pipe-shaped racket-frame body ( ) made of a fiber reinforced resin and composed of a head ( ), a throat part ( ), a shaft part ( ), and a grip part ( ) sequentially arranged and a yoke ( ) connected to the racket-frame body ( ). In this construction, supposing that the head ( ) is a clock face and that the top position of the head ( ) is 12 o'clock, a yoke rigidity value at a central position P , vertical to a ball-hitting face (F), of the yoke ( ) in a longitudinal direction thereof is in a range of 10% to 70% of a face rigidity value which is an average of a rigidity value at a 12 o'clock position (P ) vertical to the ball-hitting face (F) and a rigidity value at a three o'clock position (P ) vertical to the ball-hitting face (F).

Racket with reduced yoke rigidity

A frame body ( ) is formed separately from a yoke ( ) connecting right and left parts of the frame body ( ) to each other. The yoke ( ) and the frame body ( ) are connected to each other by a mechanical connection means, with both ends of the yoke ( ) in contact with the right and left parts of the frame body ( ) in an area of not less than 10 cm (1.6 in ). A shear force generated when the racket frame ( ) deforms is collectively applied to a connection surface of the frame body ( ) and that of the yoke ( ) to increase a vibration-damping performance of the racket frame ( ).

Racket with vibration damping yoke

Disclosed is a structural material excelling in lightness of weight, strength, flexural modulus and other properties, being made from polyamide resin reinforced with continuous fiber and/or long filament reinforcing material. This structural material can be fabricated by a monomer casting method by arranging said fiber reinforcing material preliminarily in a desired shape, putting it into a mold, pouring molten &ohgr;-lactams containing a polymerization catalyst and an initiator into said mold, and heating to obtain polyamide resin.

Growing community of inventors

Hyogo, Japan

Kunio Niwa