Bridgestone Sports Co., Ltd.

Dic Covestro Ppolymer Ltd

Hiroyuki Nagasawa

Hiroshi Higuchi

Rinya Takesue

Katsunobu Mochizuki

Hideo Watanabe

Junji Umezawa

Yoshinori Egashira

Eiji Takehana

Daisuke Arai

Atsushi Nanba

Nobuyuki Kataoka

Yoshihiro Yamana

Hidekazu Saito

Satoshi Matsuda

Hiroki Kimura

Motoki Aoyagi

Jun Shindo

Toru Ogawana

Kanae Tajima

Junji Hayashi

Yasushi Ichikawa

Kae Iizuka

Toshihiko Manami

Yoko Furuta

Masahiro Yamabe

Yasuharu Kawaguchi

Kazufumi Tabata

Takashi Akutagawa

Naoki Shirakawa

The invention provides a golf ball having a core and a cover of one or more layer encasing the core, wherein, letting HU-A and HU-B be respectively the Martens hardnesses measured at positions 100 &#x3bc;m and 200 &#x3bc;m inward from a surface of an outermost layer of the cover and toward a center of the core, and letting HU-C be the Martens hardness measured at a position 100 &#x3bc;m from an inner side of the outermost cover layer and toward the surface, HU-A or HU-B is harder than HU-C.

Golf ball

In a golf ball having a core and a cover of one or more layer encasing the core, an outermost layer of the cover is molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof, and the surface of the cover is treated with a polyisocyanate compound that is free of organic solvent. A method of manufacturing the golf ball is also described. Such golf balls are endowed with an excellent spin performance and scuff resistance, in addition to which productivity of the golf balls is high.

Golf ball and method of manufacture

The invention provides a method of manufacturing a golf ball having a core and a cover of one or more layer over the core, wherein an outermost layer of the cover is molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof. The method includes at least the following steps (1) and (2):

Golf ball manufacturing method

A method of manufacturing golf balls having a core and a cover of at least one layer encasing the core includes, when molding the cover, blending a thermal antioxidant into the cover stock in a plurality of divided portions. This method is able to minimize deterioration and discoloration of the cover stock, enabling golf balls of stable quality to be obtained. In addition, it is able to facilitate the use of reclaimed material, enabling environmentally and economically efficient production to be carried out.

The invention provides a golf ball having a core and a cover of one or more layer encasing the core, wherein the cover has an outermost layer molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof and, letting the absorbance peak heights near a wave number of 1512 cmmeasured by the attenuated total reflectance method in Fourier transform infrared absorption spectroscopy (FT-IR/ATR spectroscopy) at an outside portion and an inside portion of the outermost cover layer be respectively Pand P, the value P-Pis at least 0.02.

The invention provides a golf ball having a core encased by a cover of one or more layer, which cover is formed of a material composed primarily of a thermoplastic polyurethane material and containing also a lubricant composed primarily of a montanic acid ester. Paint film adhesion is not adversely affected even when the mold temperature during injection-molding of the golf ball is raised to 60&#xb0; C. or above.

In a colored golf ball having a core, a cover of two or more layers encasing the core, and a coat of paint applied to a surface of an outermost layer of the cover, the outermost cover layer is formed of a resin composition which includes (a) a thermoplastic resin, (b) a fluorescent color-containing color pigment and/or dye, and (c) titanium oxide. A layer adjoining an inner side of the outermost layer is formed of a resin composition containing a resin. The colored golf ball has an excellent rebound and weatherability, and also is endowed with a high brightness and a sense of quality and elegance.

Colored golf ball

In a colored golf ball having a core, a cover of at least one layer encasing the core, and a layer of paint applied to a surface of an outermost layer of the cover, the outermost cover layer and/or the paint layer is colored with a fluorescent dye, and the golf ball itself has a color tone which satisfies specific ranges in the Lab color system. The ball is endowed with an excellent spin performance and durability, an appearance characterized by outstanding visibility, stylishness and elegance, and an excellent weather resistance.

In a colored golf ball having a core, a cover of at least one layer encasing the core, and a layer of paint applied to a surface of an outermost layer of the cover, the outermost cover layer and/or the paint layer is colored with a fluorescent dye and titanium oxide, and the golf ball itself has a color tone which satisfies specific ranges in the Lab color system. The ball is endowed with an excellent spin performance and durability, an appearance characterized by outstanding visibility, stylishness and elegance, and an excellent weather resistance.

The invention provides a multi-piece solid golf ball composed of a solid core, a cover, at least one intermediate layer situated therebetween, and a plurality of dimples on a surface of the ball. The diameter of the solid core, the deflection of the core when compressed under a final load of 130 kgf from an initial load of 10 kgf, the hardness at the center of the core, the hardness in a region 5 mm to 10 mm from the center of the core, the hardness 15 mm from the center of the core, and the surface hardness are set within specific ranges. The intermediate layer is composed primarily of a material obtained by mixing under applied heat a specific resin composition. The golf ball of the invention has an excellent flight performance, feel, controllability and scuff resistance.

Multi-piece solid golf ball

The invention provides a multi-piece solid golf ball composed of a solid core, a cover, at least one intermediate layer situated therebetween, and a plurality of dimples on a surface of the ball. The diameter of the solid core, the deflection of the core when compressed under a final load of 130 kgf from an initial load of 10 kgf, the hardness at the center of the core, the hardness in a region 5 mm to 10 mm from the center of the core, the hardness 15 mm from the center of the core, and the surface hardness are set within specific ranges. The intermediate layer is composed primarily of a material obtained by mixing under applied heat a specific resin composition and the cover is formed primarily of polyurethane. And, the number of dimples and the trajectory volume TVT are set within specific ranges. The golf ball of the invention has an excellent flight performance, feel, controllability and scuff resistance.

The invention provides a multi-piece solid golf ball composed of a solid core, a cover, at least one intermediate layer interposed therebetween, and a plurality of dimples on a surface of the ball. The diameter of the solid core, the deflection of the core when compressed under a final load of 130 kgf from an initial load of 10 kgf, the hardness at the center of the core, the hardness in a region 5 mm to a region 10 mm from the center of the core, the hardness in a region 15 mm from the center of the core, and the surface hardness are set within specific ranges. The intermediate layer is composed primarily of a material obtained by mixing under applied heat a specific resin composition.

Growing community of inventors

Chichibu, Japan

Hiroyuki Nagasawa