Sri Sports Limited

Dunlop Sports Company Limited

Sumitomo Rubber Industries Limited

Yoshiko Matsuyama

Takahiro Sajima

Keiji Ohama

Kazuhiko Isogawa

Toshiyuki Tarao

Kosuke Tachibana

Kazuyoshi Shiga

Masatoshi Yokota

Seiichiro Endo

Hirotaka Nakamura

Satoko Okabe

Kohei Mimura

Hirokazu Okamoto

Kazuo Yagi

A golf ball according to the present invention includes a spherical core, a cover member including at least one layer that covers the core, and at least one coating layer that covers the cover member constituting an outermost layer. A plurality of dimples are formed in the cover member constituting the outermost layer. Roughness is formed on the surface of the coating layer. A maximum height Rz and an arithmetic average roughness Ra of the surface of the coating layer satisfy a relationship Rz&#x2265;Ra&#xd7;6.0. The coating layer contains a lustrous material.

Golf ball

An object of the present invention is to provide a golf ball showing improved durability by improving adhesion to a constituent member comprising a polyurethane in the golf ball. The present invention provides a golf ball comprising a center and n envelope layers (n is a natural number of 1 or more) covering the center, wherein at least one envelope layer is a polyurethane envelope layer comprising a polyurethane as a principal component, and the polyurethane envelope layer and a constituent member adjacent to the polyurethane envelope layer are adhered with an adhesive resin composition, and wherein the adhesive resin composition comprises a base material including a urethane polyol and an epoxy resin, and a curing agent including a polyamine compound, and a content of the urethane polyol in the base material is 5 mass % or more and less than 40 mass %.

An object of the present invention is to provide a golf ball showing excellent shot feeling and stain resistance. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein a base resin constituting the paint film includes a polyurethane obtained by a reaction between a polyol composition and a polyisocyanate composition, a molar ratio (NCO/OH) of an isocyanate group (NCO group) in the polyisocyanate composition to a hydroxyl group (OH group) in the polyol composition is 0.6 or more, and the paint film has an elastic modulus of 300 MPa or less.

An object of the present invention is to provide a golf ball showing both striking a good balance between the visibility and the weather resistance. The present invention provides a golf ball comprising a golf ball body and two or more paint film layers formed on a surface of the golf ball body, wherein the paint film layers comprises a first paint film layer containing an inorganic fluorescent agent but substantially not containing an ultraviolet absorber, and a second paint film layer containing an ultraviolet absorber but substantially not containing an inorganic fluorescent agent; and the second paint film layer is disposed inside the first paint film layer.

A golf ballincludes a core, a mid layerpositioned outside the core, a reinforcing layerpositioned outside the mid layer, and a coverpositioned outside the reinforcing layer. The coreis obtained by a rubber composition being crosslinked. The rubber composition includes a base rubber, a co-crosslinking agent, a crosslinking initiator, and a carboxylate. The co-crosslinking agent is: (1) an &#x3b1;, &#x3b2;-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or (2) a metal salt of an &#x3b1;, &#x3b2;-unsaturated carboxylic acid having 3 to 8 carbon atoms. The amount of the carboxylate is equal to or greater than 1.0 parts by weight but less than 40 parts by weight per 100 parts by weight of the base rubber. A hardness of the mid layeris greater than a hardness of the cover

A golf ballincludes a core, a mid layer, and a cover. The coreincludes a centerand an envelope layer. The ratio of the volume Ve of the coreto the volume of a phantom sphere of the golf ballis equal to greater than 76%. The ratio (Co/Ce) of an amount of compressive deformation Co of the centerto an amount of compressive deformation Ce of the coreis greater than 2.0 but less than 3.0. The ratio (Vo/Ve) of the volume Vo of the centerto the volume Ve of the coreis equal to or greater than 0.01 but equal to or less than 0.13.

Golf ballhas spherical core, coversituated on the external side of the core, and paint layersituated on the external side of the cover. The coverhas a Shore D hardness of no greater than 61. The paint layerhas a Martens hardness of no greater than 2.0 mgf/&#x3bc;m. The base polymer of the paint layeris a polyurethane obtained by a reaction of a polyol with a polyisocyanate. The polyisocyanate contains a buret-modified form of hexamethylene diisocyanate. The coverhas a thickness of 0.3 mm or greater and 1.0 mm or less. The paint layerhas a thickness of 5 &#x3bc;m or greater and 40 &#x3bc;m or less.

A golf ballincludes a core, a mid layer, a reinforcing layer, and a cover. A hardness Hm of the mid layeris greater than a hardness Hc of the cover. A difference (Hm&#x2212;Hc) is greater than 28. A hardness Hs2 at a surface of a sphere consisting of the coreand the mid layeris greater than a hardness Hs3 at a surface of the golf ball. A difference (Hs2&#x2212;Hs3) is less than 5. A thickness Tm of the mid layeris larger than a thickness Tc of the cover. A ratio (Tm/Tc) is greater than 3.0 and less than 5.0. A diameter of the coreis equal to or greater than 38.2 mm. The hardness Hc of the coveris equal to or less than 37.

An object of the present invention is to provide a golf ball having an improved controllability and shot feeling while maintaining a flight distance on driver shots. The present invention provides a golf ball having a core, an intermediate layer disposed around the core, and a cover disposed around the intermediate layer, wherein the core has a center and an envelope layer disposed around the center, and has a specific hardness distribution, and the intermediate layer is formed from an intermediate layer composition comprising, as a resin component, (A) a modified polyester elastomer and (B) a binary ionomer resin, and having a flexural modulus ranging from 150 MPa to 450 MPa, a maximum loss factor (tan &#x3b4;) between &#x2212;20&#xb0; C. and 0&#xb0; C. of 0.08 or less, a repulsive modulus of 55% or more, and a slab hardness ranging from 60 to 90 in JIS-hardness.

A coreof a golf ballincludes a centerand an envelope layerpositioned outside the center. The ratio of the volume of the coreto the volume of a phantom sphere of the golf ballis equal to or greater than 78%. The difference (He&#x2212;Ho) between a JIS-C hardness He at the surface of the coreand a JIS-C hardness Ho at the central point of the coreis equal to or greater than 15 but equal to or less than 40. The difference (H&#x2212;Ho) between a JIS-C hardness Hat a point Pthat is located radially outward of the boundary between the centerand the envelope layerand whose distance from the boundary is 1 mm and the JIS-C hardness Ho is equal to or greater than 0 but equal to or less than 2.

A golf ballincludes a core, a mid layer, and a cover. The coreincludes a centerand an envelope layer. The ratio (Do/De) of an amount of compressive deformation Do of the centerto an amount of compressive deformation De of the coreis equal to or greater than 1.5 but equal to or less than 2.5. The ratio (Do/Dc) of the amount of compressive deformation Do of the centerto an amount of compressive deformation Dc of the golf ballis equal to or greater than 1.8. The diameter of the centeris equal to or less than 20 mm. The difference (He&#x2212;Ho) between a surface hardness He of the coreand a central hardness Ho of the centeris equal to or less than 40.

A golf ballincludes a spherical core, a mid layeroutside the core, and a coveroutside the mid layer. The coreincludes a spherical centerand an envelope layeroutside the center. At all points P included in a zone that extends over a distance range from equal to or greater than 1 mm to equal to or less than 15 mm from the central point of the core, the following mathematical formula is satisfied.&#x2212;5&#x3c;2&#x2212;1&#x3c;5 In the mathematical formula, Hindicates the JIS-C hardness at a point Plocated radially inward of each point P at a distance of 1 mm from the point P, and Hindicates the JIS-C hardness at a point Plocated radially outward of each point P at a distance of 1 mm from the point P.

A golf ballincludes a core, a mid layer, and a cover. The coreincludes a centerand an envelope layer. The ratio of the volume Ve of the coreto the volume of a phantom sphere of the golf ballis equal to greater than 76%. The ratio (Co/Do) of an amount of compressive deformation Co of the centerto the diameter Do of the centeris equal to or greater than 0.085 but equal to or less than 0.130. The ratio (Ce/De) of an amount of compressive deformation Ce of the coreto the diameter De of the coreis equal to or greater than 0.015 but equal to or less than 0.020.

Golf ball wherein, at all points Pa included in zone 'A' away from the central point of its core at a distance of &#x2267;1 mm and &#x3c;5 mm, this mathematical expression is satisfied: Ha&#x2212;Ha&#x3c;5, wherein Haand Haeach represents hardness at a point located respectively inside a point Pa and outside the point Pa. Also, at any point Pb included in zone 'B' away from the central point of its core at a distance of &#x2267;5 mm and &#x2266;10 mm, this mathematical expression is satisfied: Hb&#x2212;Hb&#x2267;5, wherein Hband Hbeach represents hardness at a point located respectively inside a point Pb and outside the point Pb. This hardness distribution provides a golf ball with reduced energy loss when hit with a driver, and with excellent control performance when hit with a short iron.

Growing community of inventors

Kobe, Japan

Yoshiko Matsuyama