Bridgestone Sports Co., Ltd.

Fujifilm Corporation

Nippon Shokubai Co., Ltd.

Nihon Joryu Kogyo Co., Ltd.

Hiroshi Higuchi

Hisashi Yamagishi

Junji Hayashi

Atsushi Nanba

Yasushi Ichikawa

Junji Umezawa

Hiroyuki Nagasawa

Daisuke Arai

Nobuyuki Kataoka

Akira Kawata

Yasumasa Shimizu

Rinya Takesue

Kae Iizuka

Toru Ogawana

Hirotaka Shimosaka

Hiroto Sasaki

Shunichi Kashiwagi

Katsunori Sato

Yoshinori Egashira

Akira Kimura

Hirotaka Shinohara

Tadatoshi Yamada

Motoki Aoyagi

Takashi Ohira

Yuichiro Ozawa

Naoki Miyakoshi

Tooru Ogawana

Hideo Watanabe

Atsuki Kasashima

Jun Shindo

Kunitoshi Ishihara

Nobuhiko Matsumura

Toshihiko Manami

Motoki Furuyama

Tasuku Takita

Kazuhiko Nakamura

Shojiro Kaita

Atsushi Nakamura

Tsuyoshi Nakajima

Takuma Nakagawa

Manabu Hasegawa

Yoshinori Saito

Yasuo Wakatsuki

Kazufumi Tabata

Keiji Kobayashi

Masataka Imoto

The invention provides a golf ball having a core and a cover of at least one layer. The core has a cross-sectional hardness which, letting (H) be a JIS-C hardness at a position 14 mm in from a surface toward a center of the core, (H) be a JIS-C hardness at a position 8 mm in from the surface toward the center of the core, (H) be a JIS-C hardness at a position 6 mm in from the surface toward the center of the core, and (H) be a JIS-C hardness at a position 4 mm in from the surface toward the center of the core, satisfies the formulas (1) H&#x3c;70, (2) H&#x3c;72, (3) H&#x3c;75, and (3) H&#x2212;H&#x3e;8.

Golf ball

The invention provides a multi-piece solid golf ball having a solid core encased by a cover of one, two or more layers, which ball has specific hardness relationships among various areas on a core cross-section obtained by cutting the solid core in half. The golf ball has both a reduced spin rate and a good initial velocity on shots, particularly when struck in a high head-speed range, and thus is able to achieve an increased distance. A good feel on impact can also be obtained.

Multi-piece solid golf ball

The invention provides a multi-piece solid golf ball having a solid core encased by a cover of one, two or more layers, which ball has specific hardness relationships among various areas on a core cross-section obtained by cutting the solid core in half. The golf ball has a reduced spin rate on shots with a driver (W#1) and thus is able to achieve an increased distance. A good feel on impact can also be obtained.

The invention provides a solid golf ball having a core and a cover. The core is formed of a rubber composition containing a base rubber, a co-crosslinking agent, a crosslinking initiator and a metal oxide. The base rubber contains polybutadiene, a styrene-butadiene rubber and, optionally, an isoprene rubber. The co-crosslinking agent is methacrylic acid, and the rubber composition includes a specific waste material in the form of a powder. The core deflection and the cover material are optimized. Utilizing a waste material in a solid golf ball conserves resources and thus is beneficial to the global environment. Even during prolonged use, the golf ball maintains its basic performance attributes (feel, flight, durability) at a high level.

Solid golf ball

The invention provides a solid golf ball having a core and a cover. The core is formed of a rubber composition containing a base rubber, a co-crosslinking agent, a crosslinking initiator and a metal oxide. The co-crosslinking agent is methacrylic acid, and the rubber composition includes a specific waste material in the form of a powder. The core deflection and the cover material are optimized. Utilizing a waste material in a solid golf ball conserves resources and thus is beneficial to the global environment. Even during prolonged use, the golf ball maintains its basic performance attributes (feel, flight, durability) at a high level.

A multi-piece solid golf ball composed of a solid core having an inner core layer and an outer core layer encased by a cover including at least an inner cover layer and an outer cover layer. The inner core layer has a JIS-C cross-sectional hardness of from 60 to 83 at any single point on a cross-section, and has a cross-sectional hardness difference between any two points on the cross-section of within &#xb1;5. The ball has specific relationships between the hardness of the inner core layer 1 mm inside a boundary between the inner core layer and the outer core layer, the hardness of the outer core layer 1 mm outside the boundary, and the surface hardness of the outer core layer. And, the outer cover layer has the specific thickness and Shore D hardness, which is higher than that of the inner cover layer.

A multi-piece solid golf ball composed of a solid core having an inner core layer and an outer core layer encased by a cover including at least an inner cover layer and an outer cover layer. The inner core layer has a JIS-C cross-sectional hardness of from 60 to 83 at any single point on a cross-section, and has a cross-sectional hardness difference between any two points on the cross-section of within &#xb1;5. The ball has specific relationships between the hardness of the inner core layer 1 mm inside a boundary between the inner core layer and the outer core layer, the hardness of the outer core layer 1 mm outside the boundary, and the surface hardness of the outer core layer. And, the outer cover layer has the specific Shore D hardness, which is lower than that of the inner cover layer.

A multi-piece solid golf ball composed of a solid core having an inner core layer and an outer core layer encased by a cover including at least an inner cover layer and an outer cover layer. The inner core layer has a JIS-C cross-sectional hardness of from 60 to 83 at any single point on a cross-section, and has a cross-sectional hardness difference between any two points on the cross-section of within &#xb1;5. The ball has specific relationships between the hardness of the inner core layer 1 mm inside a boundary between the inner core layer and the outer core layer, the hardness of the outer core layer 1 mm outside the boundary, and the surface hardness of the outer core layer. And, the difference in Shore D hardness between the inner cover layer and the outer cover layer is within &#xb1;5.

A multi-piece solid golf ball composed of a solid core having an inner core layer and an outer core layer encased by a cover of one or more layer. The inner core layer has a JIS-C cross-sectional hardness of from 60 to 83 at any single point on a cross-section obtained by cutting the inner core layer in half, and has a cross-sectional hardness difference between any two points on the cross-section of within &#xb1;5. The ball has specific relationships between the hardness of the inner core layer 1 mm inside a boundary between the inner core layer and the outer core layer, the hardness of the outer core layer 1 mm outside the boundary, and the surface hardness of the outer core layer.

A multi-piece solid golf ball composed of a solid core having an inner core layer and an outer core layer encased by a cover of one or more layer. The inner core layer has a JIS-C cross-sectional hardness of from 60 to 83 at any single point on a cross-section, and has a cross-sectional hardness difference between any two points on the cross-section of within &#xb1;5. The ball has specific relationships between the hardness of the inner core layer 1 mm inside a boundary between the inner core layer and the outer core layer, the hardness of the outer core layer 1 mm outside the boundary, and the surface hardness of the outer core layer.

A multi-piece solid golf ball has a solid core, an envelope layer that encloses the solid core, an intermediate layer that encloses the envelope layer, and a cover that encloses the intermediate layer and has a plurality of dimples on a surface thereof. The diameter of the solid core, the center hardness, surface hardness and hardness difference between the center and surface of the solid core, the thickness and surface hardness of the envelope layer, and the thickness and surface hardness of the intermediate layer are each optimized within specific ranges. Moreover, the intermediate layer is formed so as to be harder than the envelope layer and the cover. In addition, the thickness and surface hardness of the cover, and the combined thickness of the envelope layer, intermediate layer and cover are each optimized within specific ranges.

The invention provides a multi-piece solid golf ball having a core of at least one layer, a cover of at least two layers which includes an inner cover layer and an outermost cover layer, and a plurality of dimples formed on a surface of the ball. The thickness and Shore D hardness of the outermost cover layer are set in specific ranges, the thickness and Shore D hardness of the inner cover layer are set in specific ranges, and the ball surface has, as expressed in the Lab color system defined by JIS Z-8730, a lightness L value of at least 89, an a value of at least 2 but not more than 10, and a b value of &#x2212;20 or above. The multi-piece solid golf ball of the invention increases the reddish coloring of a white golf ball, thereby enhancing the stylishness of the ball and improving the way the ball looks and feels to the golfer when it is played.

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.

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 encased by a cover of one or more layer, which solid core has an inner core layer and an outer core layer. The inner core layer is formed primarily of a specific, highly neutralized, ionomeric resin composition, has a diameter of from 10 to 38 mm, and has a cross-sectional hardness difference of within &#xb1;5 between any two points on a cross-section formed by cutting the inner core layer in half. The outer core layer is formed of a rubber composition made primarily of polybutadiene rubber. The solid core has a diameter of from 30 to 42 mm. The sum of the hardnesses at the center of the inner core layer and at the surface of the outer core layer is set to a value in a range of from 130 to 170. Such a golf ball is able to achieve an increased distance.

Growing community of inventors

Chichibu, Japan

Hiroshi Higuchi