Abstract: An information processing apparatus that estimates a hit feeling of a golf ball, includes a characteristic amount obtainment unit configured to obtain a characteristic amount of a striking sound which an estimation target ball generates as a sound source upon the estimation target ball being struck and an estimation unit configured to estimate a hit feeling of the estimation target ball based on correlation information and the characteristic amount obtained by the characteristic amount obtainment unit. The correlation information indicates correlation, for a plurality of kinds of test balls, between a hit feeling which a testing golfer feels at the time of striking a test ball and a characteristic amount of a striking sound which the test ball generates as a sound source upon the test ball being struck.

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: 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: A golf ball of the present invention includes a core and a cover located outside the core and having a plurality of dimples on a surface thereof A bottom of each of the dimples has a curved shape protruding toward an outside of the golf ball. A depth d of a center protruding portion of the bottom of the dimple is a perpendicular distance between a line S connecting both ends of an outer periphery of the dimple and a highest point of the protruding portion. A volume occupation ratio VR of the dimple is less than 0.75. A relationship between Shore D hardness H of a material of the cover and the depth d (unit: mm) satisfies the following Formula 1: (H-83)/(?300)>d ??(Formula 1).

Abstract: Provided are a golf ball and a resin composition for a cover or topcoat thereof which can suppress the yellowing of the golf ball caused by ultraviolet rays even if a naturally derived substance is used as an ultraviolet absorber, and they are environmentally and human friendly. A resin composition for a cover or topcoat of a golf ball of the present invention contains: a resin for a cover or topcoat; and a plant-derived extract which absorbs ultraviolet rays. The resin composition has a color difference ?E of 10.0 or less in a Lab color system between before and after a color tone change test, the color tone change test being carried out by irradiating a film formed from the resin composition with a xenon lamp. In the golf ball of the present invention, the cover or the topcoat is formed by using the resin composition.

Abstract: In a multi-piece solid golf ball having a core formed of a rubber composition, an intermediate layer formed of a polyurethane material and a cover, the ball satisfies the following condition: surface hardness of ball?surface hardness of intermediate layer-encased sphere. When the ball is struck with a driver at a head speed of 40 m/s, the sum of the time t1 required from contact initiation between the driver and ball for deformation of the ball to reach a maximum value and the time t2 required from the state of maximum ball deformation for the ball and driver clubface to separate is at least 685 microseconds, and the ratio t2/t1 is at least 1.35, and the core has a specific hardness profile. This ball has an excellent flight performance when hit by low or moderate head-speed golfers, is receptive to spin on approach shots and has a good, soft feel at impact.

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 golf club head having a hollow structure is provided. The golf club head includes a face, and a body including at least a crown, a sole, and a hosel chamber. The crown, the sole, and the hosel chamber include laminated layers of a fiber-reinforced resin. The crown includes at least one first rigidity control portion that partially extends in a toe-heel direction. The sole includes at least one second rigidity control portion that extends from a back surface side of the face toward a back end of the body. One of the first rigidity control portion and the second rigidity control portion decreases flexural rigidity in a face-back direction, and the other of the first rigidity control portion and the second rigidity control portion increases flexural rigidity in the face-back direction.

Abstract: In a golf ball having a core composed of one or more layer, the outermost layer of the core is formed of a rubber composition containing a base rubber and an ?,?-unsaturated metal carboxylate, an envelope layer directly encasing the core is formed of a resin composition containing a thermoplastic resin having a structure that includes ?,?-ethylenically unsaturated carboxylic acid copolymerization units, and a surface of the core outermost layer and the envelope layer adjoin each other through an intervening oxazoline group-containing substance. The golf ball has improved adhesion between the rubber-based core and the cover layer that directly encases the core and is formed of an ionomer resin or other ?,?-ethylenically unsaturated carboxylic acid copolymer-containing resin material.

Abstract: In a golf ball having a core and a cover of one or more layer, at least one layer of the cover is formed of a resin composition which includes in a specific weight ratio: (I) a thermoplastic polyurethane resin that uses polytetramethylene glycol having a number-average molecular weight of from 1,900 to 2,100 as the polyol component, (II) a thermoplastic polyurethane resin that uses polytetramethylene glycol having a number-average molecular weight of from 900 to 1,100 as the polyol component, and (III) an aromatic vinyl elastomer. The cover layer formed of this resin composition has a Martens hardness and an elastic work recovery which together satisfy a specific formula. The golf ball has an excellent controllability on approach shots without losing distance on driver shots. In addition, the scuff resistance and moldability are good.

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: A method of manufacturing golf balls having a core and a cover of at least one layer encasing the core includes the steps of producing a core by molding and vulcanizing a rubber composition containing (A) a base rubber, (B) an ?,?-unsaturated carboxylic acid and/or a metal salt thereof, and (C) an organic peroxide; and heat-treating the core for 1 to 24 hours at between 175 and 300° C. Golf balls which undergo little energy loss and have a high initial velocity can be obtained by this method.

Abstract: In a golf ball having a core, a cover and at least one intermediate layer therebetween, the cover is formed of a rubber composition which includes a diene rubber, methacrylic acid, a metal oxide and an organic peroxide. The cover has a specific Poisson's ratio, Shore D hardness and thickness. At least one intermediate layer has a specific Shore D hardness and thickness. This golf ball, even with the use of a rubber cover, compares favorably with balls having conventional resin covers, both in that it can achieve a lower spin rate on shots with a driver (W #1) and thus has an excellent flight performance and also in that it can improve controllability in the short game.

Abstract: In a golf ball having a core of at least one layer and a cover of one or more layer encasing the core, at least one layer of the cover is formed of a resin composition that includes (I) a polyurethane or a polyurea and (II) an aromatic vinyl elastomer which together satisfy certain specific conditions. The golf ball has an excellent controllability on approach shots and is also able to maintain a good scuff resistance.

Abstract: A method for manufacturing a golf ball having a core, an intermediate layer and a cover that is formed of a resin material composed primarily of a polyurethane resin and has a thickness of 0.1 mm to 0.7 mm by injection molding the cover using a vertically separating two-part injection mold having specific gate and support pin configurations. This method enables a relatively soft urethane resin cover that is thin and of high quality to be formed, and has a good golf ball productivity.

Abstract: In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the envelope layer is formed into two layers—an inner envelope layer and an outer envelope layer. The inner envelope layer-encased sphere, outer envelope layer-encased sphere, intermediate layer-encased sphere and ball have respective surface hardness that satisfy a specific relationship. The inner envelope layer or outer envelope layer is formed primarily of one or more elastomer, and further the core has a particular hardness profile. This ball has an excellent flight when struck by golfers whose head speeds are not that fast and has a good, soft feel at impact, thus making it highly suitable for 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 envelope layer thickness.

Abstract: In a golf ball comprising a core, a cover layer, an intermediate layer between the core and the cover layer, the cover layer is formed of a resin material composed primarily of polyurethane or polyurea, a sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a lightness (Li value) in the L*a*b* color space of at least 25 on its surface, and the cover layer has a visible light transmittance of at least 0.6%. The golf ball has a surface with a distinctive aesthetic appearance and retains both a good spin performance and a good scuff resistance, making it useful as a ball for professional and skilled amateur golfers.

Abstract: In a multi-piece solid golf ball having a core, an intermediate layer encasing the core and a cover which encases the intermediate layer and has numerous dimples on an outside surface thereof, the core is formed of a rubber composition including the specific ingredient compounding ingredients, the intermediate layer is formed of a resin material, the cover is formed of a urethane resin material, the core has a diameter of at least 38.0 mm, the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of at least 3.9 mm, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and the (intermediate layer thickness)/(core diameter) value is from 0.025 to 0.043, the (cover thickness)/(core diameter) value is from 0.014 to 0.027.

Abstract: In a golf ball having a core, envelope layer, intermediate layer and cover, the core has a specific hardness profile, the resin materials making up either or both of the envelope layer and the intermediate layer contain a high-acid ionomer, and the Shore C hardness relationships among the core center, surface of the envelope-encased layer and surface of the intermediate layer-encased sphere satisfy the following conditions: surface hardness of envelope layer-encased sphere<surface hardness of intermediate layer-encased sphere,??(1) surface hardness of intermediate layer-encased sphere?center hardness of core?40.??(2) This ball achieves a good distance on shots with utility and iron clubs, is receptive to spin in the short game, and has a soft feel at impact on all shots, making it useful to amateur golfers.