Bridgestone Sports Co., Ltd.

Toshihiko Manami

Eiji Takehana

Hiroshi Higuchi

Rinya Takesue

Hiroyuki Nagasawa

Hideo Watanabe

The present invention provides a golf ball composed of a core, an outermost cover layer and one or more intermediate layer therebetween. At least one intermediate layer includes a mixture composed of a base polymer made of, in a specific ratio, (a) a metal ion neutralization product of an olefin-unsaturated carboxylic acid random copolymer and/or a metal ion neutralization product of an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random copolymer, (b) a thermoplastic elastomer selected from the group consisting of thermoplastic polyester elastomers, thermoplastic block copolymers and thermoplastic polyurethanes, and (c) a thermoplastic block copolymer containing end blocks modified by a functional group having reactivity with an ionomer resin, both end blocks being formed of different comonomers. The mixture also includes (e) an organic acid of 18 to 40 carbons or a derivative thereof, and (f) a metal ion source selected from the group consisting of alkali metals, alkaline earth metals and transition metals. The mixture has an optimized difference between the melt viscosities of (b) and (a) as measured under a shear rate of 6,000 secand 240&#xb0; C. in accordance with JIS K-7199. The golf ball of the invention has a flight and control performance acceptable for use by professional golfers and skilled amateurs, and also has an excellent durability to cracking under repeated impact.

Golf ball

The invention provides a golf ball having a core and a cover of one or more layer, wherein at least one layer of the cover is made of a material obtained by molding a mixture composed of (a) 100 parts by weight of a base resin and (b) 1 to 40 parts by weight of a saturated branched-chain fatty acid or a derivative thereof. The golf ball has a soft, pleasant feel on impact and excellent scuff resistance while retaining a good flight performance. Moreover, it exhibits a highly white appearance that undergoes little discoloration.

The present invention provides a golf ball composed of a core, an outermost cover layer and one or more intermediate layer therebetween. At least one intermediate layer includes a mixture composed of a base polymer made of, in a specific ratio, (a) a metal ion neutralization product of an olefin-unsaturated carboxylic acid random copolymer and/or a metal ion neutralization product of an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random copolymer, (b) a thermoplastic elastomer selected from the group consisting of thermoplastic polyester elastomers, thermoplastic block copolymers and thermoplastic polyurethanes, and (c) a thermoplastic block copolymer containing end blocks modified by a functional group having reactivity with an ionomer resin, both end blocks being formed of different comonomers. The mixture also includes (e) an organic acid of 18 to 40 carbons or a derivative thereof, and (f) a metal ion source selected from the group consisting of alkali metals, alkaline earth metals and transition metals. The mixture has an optimized ratio between the melt viscosities of (b) and (a) as measured under a shear rate of 6,000 secand 240&#xb0; C. in accordance with JIS K-7199. The golf ball of the invention has a flight and control performance acceptable for use by professional golfers and skilled amateurs, and also has an excellent durability to cracking under repeated impact.

In a golf ball comprising a core and a cover, at least one layer of the cover is formed of a cover stock composition in which fullerene and/or carbon nanotubes are uniformly dispersed in a thermoplastic resin. The golf ball is prepared by uniformly dispersing fullerene and/or carbon nanotubes in a thermoplastic resin to provide a cover stock composition and forming at least one layer of the cover from the cover stock composition.

Golf ball and making method

In a golf ball having a core and a cover of one or more layer which encloses the core, at least one cover layer is made primarily of a mixture of (A) a thermoplastic resin or thermoplastic elastomer and (B) a polyacetal. The golf ball has an excellent durability to repeated impact, and improved resistance to both scuffing and discoloration.

In a golf ball having a core or a sphere composed of a core enclosed by a cover layer and having also an outermost cover layer which covers a surface of the core or a surface of the sphere, the outermost cover layer is composed primarily of at least one thermoplastic resin or thermoset resin, which resin contains an inorganic composite material prepared by coating glass flakes with a metal or metal oxide. This arrangement provides a highly fashionable golf ball endowed with aesthetic characteristics that are novel and have a visual impact on the golfer.

In a golf ball composed of a core and a cover of one or more layer that encloses the core, at least one layer of the cover is composed of 100 parts by weight of a base resin, 1 to 7 parts by weight of titanium oxide, 0.002 to 0.4 part by weight of a blue pigment, and 0.0006 to 0.5 part by weight of a violet pigment. The weight ratio of the blue pigment to the violet pigment is from 1:99 to 99:1. A sufficient whiteness is imparted to the surface of the ball, and the ball has an excellent resistance to color fading.

The invention provides a golf ball comprising a core and a cover of one or more layers, characterized in that at least one layer which constitutes the cover is formed primarily of a mixture of (A) a thermoplastic resin composition selected from among a thermoplastic block copolymer, polyester base elastomer, polyamide base elastomer and polyolefin, which are modified with functional groups having reactivity with isocyanate, and (B) an isocyanate compound or an isocyanate mixture having at least two isocyanate groups as functional groups in a molecule, and a method for preparing the same. The golf ball has excellent flight performance, feel on impact, and scuff resistance.

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Chichibu, Japan

Toshihiko Manami