Abstract: In a golf ball for professional golfers and skilled amateurs which has a single-layer core, a cover and at least one intermediate layer therebetween, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) and the ball have a surface hardness relationship therebetween which satisfies the condition: (surface hardness of intermediate layer-encased sphere)>(surface hardness of ball). Moreover, the core has a diameter of from 35.5 to 39.5 mm and a unique hardness profile that satisfies certain specific conditions. This ball is endowed with both an excellent flight performance and a good durability to repeated impact.
Abstract: A golf ball having a single-layer rubber core, a single-layer resin cover and one intermediate layer therebetween satisfies the following conditions: (Shore C hardness at surface of intermediate layer-encased sphere)>(Shore C hardness at ball surface), 14?(Atti compression of core)?38, (Atti compression of core)/(Shore C hardness at core surface?Shore C hardness at core center)?1.1, and 600?(Shore C hardness at surface of intermediate layer-encased sphere)×(specific gravity of intermediate layer material)×[volume (cm3) of intermediate layer material]. This ball has a superior distance performance on full shots with an iron and a high spin performance in the short game, imparts a very soft feel and possesses an excellent durability to cracking on repeated impact. The ball is intended to satisfy the needs of primarily skilled amateur golfers who handle iron shots skillfully.
Abstract: A foam composition that includes a polymer material such as polyurethane or polyurea and a leachable water-soluble fine powder is provided. This composition can be used in a relatively simple process to obtain a foam body (porous body) that is uniform only at the surface or uniform throughout. The foam body can be suitably used as a golf ball member in golf balls required to have good controllability on approach shots. Also provided is a method for producing a foam member, which method includes the steps of molding the foam composition to obtain a solid molded body, and then leaching out and removing the water-soluble fine powder so as to obtain a foam-molded body.
Abstract: A golf club head having a hollow structure includes a face, a sole, and a crown. The face includes a front surface and a back surface that face away from each other. The front surface is a ball-striking surface. The sole includes an abutment structure. The abutment structure includes a metallic sole fixation member fixed to the sole, an elastic member, and a metallic pin member connected to the metallic sole fixation member through the elastic member.
Abstract: A rubber composition for a golf ball core includes (a) a conjugated diene polymer, (b) a copolymer of a conjugated diene compound and a non-conjugated olefin, and (c) an organic peroxide. Golf balls having at least one core layer formed of such a rubber composition and a cover of one or more layers encasing the core exhibit improved durability to cracking on repeated impact while maintaining the basic properties required of golf balls, such as flight and spin controllability on approach shots.
Abstract: A rubber composition for a golf ball core includes (a) a conjugated diene polymer, (b) a multi-component copolymer having conjugated diene units, non-conjugated olefin units and aromatic vinyl units, and (c) an organic peroxide. The conjugated diene units include butadiene units, the non-conjugated olefin units include ethylene units, and the aromatic vinyl units include styrene units. The content of conjugated diene units with respect to the multi-component copolymer is at least 5 wt %. Golf balls having at least one core layer formed of such a rubber composition and a cover of one or more layers encasing the core exhibit improved durability to cracking on repeated impact while maintaining the basic properties required of golf balls, such as flight and spin controllability on approach shots.
Abstract: The invention provides a distance golf ball endowed with a good flight performance when struck with a driver or an iron by an ordinary amateur golfer, a good durability to repeated impact and a soft feel. The ball is a multi-piece solid golf ball having a core, an intermediate layer and a cover, wherein the core is formed as one or more layer of a rubber composition, the intermediate layer is formed primarily of an ionomer resin, the intermediate layer and the cover are both single layers, each containing an inorganic granular filler, and the ball satisfies the following conditions: surface hardness of ball > surface hardness of sphere consisting of core encased by intermediate layer (intermediate layer-encased sphere), Shore D hardness at surface of ball - Shore D hardness at center of core ? 37, specific gravity of cover > specific gravity of intermediate layer.
Abstract: In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the core is formed of one or more layer of a rubber composition; the envelope layer, intermediate layer and cover are each formed of a single layer of resin material; the hardness relationship among the layers satisfies the following two conditions: material hardness of cover>material hardness of intermediate layer, and material hardness of envelope layer?surface hardness of core; the ball additionally satisfies the condition: envelope layer thickness (mm)×envelope layer material hardness (Shore D hardness) cover thickness (mm)×cover material hardness (Shore D hardness); and the core and ball have optimized deflections when subjected to a specific loading. This ball serves as a distance ball which enables a superior distance to be achieved on full shots with a driver and with irons.
Abstract: In a golf ball having a core, a cover, at least one intermediate layer therebetween, and a coating layer on the cover, the cover is formed of a transparent or translucent resin composition and the intermediate layer is formed of a resin composition. The sphere consisting of the core encased by the intermediate layer has specific lightness and chroma values in the Lab color space. The coating layer is composed of one or more layer, at least one of which contains an effect pigment having polarizing properties. Markings are provided inside of the coating layer and have a specific L value. During use, the ball retains a visual to familiarity close to that of a white ball. Up close, it is clearly discernible from a white ball; from a distance, it appears white and is highly visible.
Abstract: A method for producing a golf ball of the present invention includes the steps of: forming a first coating film on a surface of a covering having a plurality of dimples; and forming a second coating film on a surface of the first coating film. The second coating film is formed of a second coating material composition containing a polyurethane coating material and a solvent having a boiling point of 80° C. or less. An elastic recovery rate of the second coating film is 50% or more. In the golf ball of the present invention obtained by the method, an edge ratio which is a ratio of a film thickness of the second coating film in an edge portion of the dimple to a film thickness of the second coating film in a central portion of the dimple is 50% or more.
Abstract: The present invention provides a golf ball comprising a core of one or more layers and a cover of one or more layers which encases the core, wherein at least one layer of the cover is formed of the resin composition comprising (a?) a polyester resin and (b) an amine-containing polymer having a branched structure. In the golf ball of the present invention, the adhesion property between the core and each cover layer adjacent to the core can be improved and the excellent durability can be obtained.
Abstract: The present invention provides the rubber composition for a golf ball comprising (a) a base rubber, (b) a co-crosslinking agent which is an ?,?-unsaturated carboxylic acid or a metal salt thereof or both, (c) a crosslinking initiator, and (d) an alcohol, wherein the amount of component (d) is from 0.1 to 10 parts by weight per 100 parts by weight of the base rubber (a) and the compounding ratio between component (b) and component (c) is set to at least 60 of E value that is represented by “E=the molar amount of component (b)/the molar amount of the active oxygen of component (c), and a golf ball using the rubber composition, in order to achieve the object that good durability of the golf ball to impact is maintained.
Abstract: The golf club head includes a face portion, a plurality of score lines formed in the face portion and extending in a toe-heel direction, and a plurality of convex portions formed in the face portion, projecting from reference plane which includes edges of each of the plurality of score lines, and extending in the toe-heel direction. The plurality of convex portions include a first convex portion and a second convex portion formed between adjacent score lines. A projecting height of the first convex portion and/or a width in an orthogonal direction of the toe-heel direction of the first convex portion is larger than that of the second convex portion.
Abstract: In a golf ball having a core and a cover of one or more layer, the core is formed of a material molded under heat from a rubber composition containing (a) a base rubber, (b) water and/or a lower alcohol having a specific molecular weight, (c) an ?,?-unsaturated carboxylic acid and/or a metal salt thereof, and (d) an organic peroxide. The base rubber (a) is a rubber obtained by mixing together (a-1) a polybutadiene and (a-2) an unneutralized ethylene-unsaturated carboxylic acid copolymer, and subsequently neutralizing the copolymer with (a-3) a metal oxide. Component (a-2) has a specific acid content and accounts for a specific portion of the combined amount of components (a-1) and (a-2). The core surface and center have a specific JIS-C hardness difference therebetween. This ball achieves both a lower spin rate and excellent durability while maintaining a high rebound.
Abstract: A multilayer core molding method includes: an upstream process of obtaining an intermediate molded body 33; and a downstream process of performing molding using a downstream process molding apparatus 2, and wherein the downstream process includes: an intermediate molded body arrangement step of arranging the intermediate molded body on the intermediate plate cavity surface or the first downstream process mold cavity surface; and a first vulcanization step, performed after the intermediate molded body arrangement step, of vulcanization-molding the intermediate molded body until it is substantially or completely vulcanized, in a state in which at least the first downstream process mold and the intermediate plate are closed against each other.
Abstract: A golf ball is provided which suppresses twisting due to external forces while maintaining sufficient deflection at the time of impact, reduces the spin rate without lowering ball rebound, and is thus able to effectively increase the distance traveled by the ball, particularly on shots with a driver. In the golf ball, which includes a core and a cover, the core has a core body made of a first polybutadiene rubber and having a surface with a plurality of groves or holes thereon, which grooves or holes are filled with a second polybutadiene rubber of a differing composition from the first polybutadiene rubber. The polybutadiene rubber-filled groove portions or hole portions have a higher surface hardness than the core body.
Abstract: A golf ball is provided that achieves a satisfactory distance on full shots with an iron, is superior in the short game, and has a good feel at impact and a good durability. The golf ball has a core formed of a rubber composition as one or more layer, an envelope layer formed of a resin material as one or more layer, an intermediate layer formed of a resin material as one layer, and a cover formed of a resin material as one layer having a thickness of not more than 1.0 mm. The layers of the ball have Shore C hardnesses at the respective surfaces thereof which together satisfy certain specific conditions, the core and the ball have respective deflections which satisfy certain conditions and the core has a specific internal hardness profile.
Abstract: In a golf ball having a core, an envelope layer, an intermediate layer and a cover, the difference between the center hardness and the surface hardness of the core is set in a specific range, the intermediate layer is formed of a resin material that includes a high-acid ionomer, the Shore C hardness relationships among the core center and the surfaces of the envelope-encased layer and the intermediate layer-encased sphere satisfy specific conditions; and the ball has a deflection when compressed under a given load which is at least 2.7 mm. This ball achieves a good distance on shots with a driver, utility club or iron, is receptive to spin in the short game, and has a soft feel at impact on all shots, making it useful to amateur golfers.
Abstract: In a golf ball having a core, envelope layer, intermediate layer and cover, the (core diameter)/(ball diameter) value falls within a particular range, the core has a specific hardness profile, and the Shore C hardness relationships among the core center and surface hardnesses and the surface hardnesses of the envelope layer-encased sphere, intermediate layer-encased sphere and ball satisfy the following conditions: core surface hardness<surface hardness of envelope layer-encased sphere<surface hardness of intermediate layer-encased sphere>ball surface hardness,??(1) (surface hardness of envelope layer-encased sphere)?(core center hardness)?28.??(2) Also, the envelope layer, intermediate layer and cover have respective thicknesses which satisfy the condition: cover thickness<intermediate layer thickness??(3) cover thickness<envelope layer thickness??(4) envelope layer thickness?0.8 mm.
Abstract: A multilayer core molding method for molding a multilayer core of a golf ball includes an upstream process; and a downstream process, wherein the intermediate molded body includes: an inner core; and an unvulcanized or semi-vulcanized first outer core material, and the downstream process molding apparatus includes: a first downstream process mold including a substantially hemispherical first downstream process mold cavity surface; a second downstream process mold including a substantially hemispherical second downstream process mold cavity surface; and an intermediate plate including a substantially hemispherical intermediate plate cavity surface, and a substantially hemispherical intermediate plate projecting surface, and wherein the downstream process includes: a second outer core arrangement step; an intermediate molded body arrangement; and a preparatory molding step.