Bridgestone Sports Co., Ltd.

Cashew Co., Ltd.

Hiroto Sasaki

Hiroshi Higuchi

Atsushi Nanba

Nobuyuki Kataoka

Hisashi Yamagishi

Jun Shindo

Takashi Ohira

Susumu Muta

Hideo Watanabe

Yasushi Ichikawa

Atsuki Kasashima

Etsuji Akimaru

Shigeru Noguchi

Shuichi Yamamoto

A golf ball which is formed from a vulcanized rubber compound composed of 100 parts by weight of a rubber base material, 10 to 60 parts by weight of an unsaturated carboxylic acid and/or a metal salt thereof, 0.1 to 5 parts by weight of an organosulfur compound, 5 to 80 parts by weight of an inorganic filler, and 0.1 to 3 parts by weight of an organic peroxide, the rubber base material being composed of a first polybutadiene accounting for 50 to 95 wt % and a second polybutadiene accounting for 5 to 50 wt %, both polybutadiene being synthesized by using a rare earth element-based catalyst, the first polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML1+4 (100&#xb0; C.)) no lower than 50 and the second polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML1+, (100&#xb0; C.)) no higher than 45. The golf ball is characterized by good rebound resilience and good workability with which it is produced.

Golf ball

A golf ball which is formed from a vulcanized rubber compound composed of 100 parts by weight of a rubber base material, 10 to 60 parts by weight of an unsaturated carboxylic acid and/or a metal salt thereof, 0.1 to 5 parts by weight of an organosulfur compound, 5 to 80 parts by weight of an inorganic filler, and 0.1 to 3 parts by weight of an organic peroxide, the rubber base material being composed of a first polybutadiene accounting for 50 to 95 wt % and a second polybutadiene accounting for 5 to 50 wt %, both polybutadiene being synthesized by using a rare earth element-based catalyst, the first polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) no lower than 50 and the second polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) no higher than 45. The golf ball is characterized by good rebound resilience and good workability with which it is produced.

A club shaft composed of a club shaft body and a single- or multi-layered coating film covering said club shaft body, wherein said coating film includes a coating layer having good scratch or scuff resistance and high resilience. The club shaft keeps its good appearance owing to its self-healing ability even though it is damaged during carry in a caddie bag.

Club shaft

A ball composed of a ball body and a single- or multi-layered coating film covering the ball body, wherein the coating film includes a coating layer having good scratch or scuff resistance and high resilience. The ball keeps a good appearance even after repeated hitting because of its good scratch or scuff resistance and its ability to repair scratches automatically with the lapse of time even though it is temporarily damaged.

Ball

A golf ball-which is formed from a crosslinked rubber compound composed of, as essential components, (A) a rubber base material composed of (a) a polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) of 50 to 120, which is synthesized by using a group VIII element catalyst and/or a rare earth element-based catalyst, and (b) a solid isoprene rubber containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) of 70 to 90, with the ratio of (a) to (b) being from 70/30 to 98/2 by weight; (B) an unsaturated carboxylic acid and/or a metal salt thereof; and (C) an organic peroxide. The golf ball is characterized by good rebound resilience and good workability with which it is produced.

A golf ball which is formed from a crosslinked rubber compound composed of, as essential components, (A) a rubber base material composed of (a) a polybutadiene containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) of 50 to 120, which is synthesized by using a group VIII catalyst element and/or a rare earth element-based catalyst, and (b) a solid isoprene rubber containing no less than 60 wt % of cis-1,4 bonds and having a Mooney viscosity (ML(100&#xb0; C.)) of 70 to 90, with the ratio of (a) to (b) being from 96/4 to 99/1 by weight; (B) an unsaturated carboxylic acid and/or a metal salt thereof; and (C) an organic peroxide. The golf ball is characterized by good rebound resilience and good workability with which it is produced.

Disclosed herein is a one-piece golf ball formed by vulcanization from a rubber composition composed of 100 parts by weight of rubber base material, 10 to 40 parts by weight of unsaturated carboxylic acid, 10 to 60 parts by weight of metal oxide, and 0.9 to 5 parts by weight of organic peroxide, said rubber base material containing 60 to 100% by weight based on the weight of a polybutadiene which is synthesized with a catalyst of rare earth element, contains no less than 60% of cis-1,4-linkage, and has a Mooney viscosity (ML(100&#xb0; C.)) no less than 40. This golf ball has good shot feeling and high rebound resilience and is easy to produce by extrusion.

One-piece golf ball

A rubber composition comprising 100 parts by weight of a base rubber containing 5-30% by weight of syndiotactic-1,2-polybutadiene and at least 40% by weight of cis-1,4-polybutadiene, 5-10 parts by weight of an unsaturated carboxylic acid metal salt, up to 2 parts by weight of an inorganic filler, and 10-30% by weight based on the weight of the metal salt of an initiator can be molded and vulcanized into a rubber product having a specific gravity of less than 1 and is suitable for the manufacture of golf balls for practice over water.

Golf ball and rubber composition therefor

A coating composition comprising a two-part curable urethane paint consisting essentially of a polyol and a polyisocyanate, a metal chelating agent having a boiling point of up to 200&deg; C., and an organometallic compound as a curing catalyst is easy to apply to golf balls because of a long pot life and a short curing time.

Golf ball coating composition and coated golf ball

A coating composition for a golf ball which comprises a non-yellowing polyisocyanate and a hydroxyl group-containing polyester obtained by reacting a polyhydric alcohol, at least a part of which has an alicyclic structure in the molecule, with a polybasic acid component, and a golf ball whose body is coated with the above coating composition. When said coating composition is used, a high durability is achieved even when a white enamel coating is omitted from the lower layer part of the coating and the coating step can be shortened.

Coating composition for golf ball and golf ball using the same

A practice golf ball having a multiplicity of dimples formed in its surface has a weight of 46.5-49.0 grams and undergoes a distortion of 2.5-4.0 mm under a constant load of 100 kg. A percent dimple volume Vr is in the range of 0.7%.ltoreq.Vr.ltoreq.1.1% wherein the percent dimple volume Vr is the sum of the volumes of the entire dimples divided by the volume of a phantom sphere given on the assumption that the ball surface is free of dimples. The ball offers a good feel upon shots, follows a low trajectory without substantial shortage of a flight distance, and is thus suited for use in urban golf practice pits of limited space.

Practice golf ball

A practice golf ball having a multiplicity of dimples formed in its surface has a weight of 46.5-49.0 grams and undergoes a distortion of 2.5-4.0 mm under a constant load of 100 kg. Those dimples having a diameter/depth (Dm/Dp) ratio between 10/1 and 15/1 occupy at least 80% of the total number of dimples. The ball offers a good feel upon shots, follows a low trajectory without substantial shortage of a flight distance, and is thus suited for use in urban golf practice pits of limited space.

In a solid golf ball comprising a solid core and a cover, the solid core has a distortion of 3.5-5.0 mm under a load of 100 kg, and the cover based on an ionomer resin has a Shore D hardness of 50.degree.-63.degree. and a 300% modulus of 15-35 MPa. The ball offers a soft feel while maintaining the characteristics of solid golf balls.

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Chichibu, Japan

Hiroto Sasaki