Abstract: A golf ball including a composition having an unsaturated polymer, a cross-linking agent, a peptizer, and an accelerator. The composition can be incorporated into the golf ball's core, intermediate layers, and cover layers, and can provide optimal performance and durability properties. The golf balls incorporating the composition are easy to manufacture.

Abstract: A golf ball 2 has a hollow center 8, a mid layer 10, an inner cover 12 and an outer cover 14. The center 8 is formed by crosslinking a rubber composition. The rubber composition contains a natural rubber as a base polymer. The rubber composition contains sulfur. The mid layer 10 is formed by crosslinking a rubber composition. This rubber composition includes butadiene as a principal component of the base polymer. The center 8 has an inside diameter of 2 mm or greater and 13 mm or less. The center 8 has an outside diameter of 5 mm or greater and 15 mm or less. The center 8 has a surface JIS-C hardness H2 of 25 or greater and 55 or less. A difference (H4?H3) between a surface JIS-C hardness H4 of the mid layer 10 and a JIS-C hardness H3 of an innermost part of the mid layer is equal to or greater than 10.

Abstract: A method and apparatus for printing is provided. The method includes preparing a hollow printing pad having a transfer surface, the printing pad being configured so that when the transfer surface is pushed, the gas in the hollow part is released to the outside of the printing pad; transferring ink or paint in recesses formed on the surface of a printing plate to the transfer surface of the printing pad by applying the ink or paint onto the surface of the printing plate and by pressing the transfer surface of the printing pad against the surface of the printing plate; and transferring the ink or paint to the object to be printed by pressing the transfer surface of the printing pad against the object to be printed until at least the hemispherical portion of the object to be printed is wrapped by the transfer surface of the printing pad.

Abstract: Disclosed are golf balls having soft, resilient bimodal ionomeric covers with improved softness and scuff resistance and methods for their preparation. The soft, resilient bimodal ionomeric covers comprise at least partially neutralized mixtures of carboxylate functionalized terpolymers (molecular weight between about 80,000 and 500,000) with carboxylate functionalized ethylene low copolymers (molecular weight between about 2,000 and 30,000).

Abstract: Elastomeric interpolymers comprising at least two, or more, cyclic olefin monomers that are prepared by ring opening metathesis polymerization, and that are characterized by having no crystallinity, a glass transition temperature (Tg) of less than ?80° C., and a number average molecular weight (Mn) of at least 40 kg/mole, and functionalized products thereof. A ring opening metathesis polymerization process for producing the elastomeric interpolymers having no crystallinity. Uses of the elastomeric interpolymers in applications such as rubber compounds, tires, and the like. Cores of golf balls that are prepared by using metathesis polymerization produced elastomeric interpolymers having 0 to about 30% crystallinity.

Abstract: A polyurea-based curable coating for use with sports equipment, such as golf balls, golf shoes, golf clubs, footballs, billiard balls, baseballs, and the like, of which the coating may be cured over time, with heat, or a combination thereof, providing enhanced adhesion to equipment surfaces, improved abrasion resistance, and increased water resistance.

Abstract: An object of the present invention is to provide a golf ball having high resilience. The present invention provides a golf ball having a constituting member, wherein at least a part of the constituting member is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, the organic sulfur compound being derivatives of thiophenols and disulfide with a strong electron withdrawing substituent.

Abstract: The invention provides a golf ball having a core and one or more cover layer encasing the core, wherein at least one cover layer is formed by injection-molding a single resin composition of primarily (A) a thermoplastic polyurethane and (B) a polyisocyanate compound, and at least some polyisocyanate compound in which all the isocyanate groups on the molecule remain in an unreacted state is present in the resin composition. The golf ball has a high rebound, an excellent spin performance and an excellent scuff resistance, and the cover layer-forming resin composition has excellent flow properties and an excellent cover layer manufacturability.

Abstract: Disclosed herein are soft and stiff compositions, i.e., compositions which have a flexural modulus that is greater than the value that is expected based on the composition's hardness. The compositions preferably have a hardness/modulus relationship represented by the formula H?11.889Ln(M)+42, where H is the hardness of the composition, in JIS-C, and M is the flexural modulus of the composition, in ksi; or a softness/stiffness relationship represented by the formula if M<56, then H?8.5218Ln(M)+26.5 if M?56, then H?8.5218Ln(M)+28.5, where H is the hardness of the composition, in Shore D, and M is the flexural modulus of the composition, in ksi.

Abstract: The invention is directed to a golf ball comprising a long-chain branched neodymium-catalyzed polybutadiene having a cis-1,4 content of at least about 96% and a solution viscosity of less than 165 mPa·s, wherein the overall golf ball comprises a COR of at least about 0.780 and an Atti compression of from about 25 to about 120. The invention is also directed to a golf ball comprising a core, a cover and optionally an intermediate layer disposed between the core and the cover; wherein at least one of said core, cover and intermediate layer comprises a polybutadiene composition comprising a long-chain branched neodymium-catalyzed polybutadiene having a cis-1,4 content of at least about 96% and a solution viscosity of less than 165 mPa·s.

Abstract: A phase transition golf ball comprises a phase transition material. The phase transition material may optionally include a microwave susceptor or an induction susceptor. The phase transition material preferably comprises an ethylene acid copolymer, or an ionomer of an ethylene acid copolymer. The performance of the phase transition golf ball, for example its hardness or compression, is adjusted by inducing a complete or partial phase transition in the phase transition material. The extent of the adjustment in performance is correlated with the extent of the phase transition. Preferably, the phase transition is reversible and repeatable and takes place at temperatures that might be achieved through the use of common household appliances. Also preferably, the phase transition material returns to its original state over an extended period, for example hours or days.

Abstract: An object of the present invention is to provide a painted golf ball which is excellent in the gloss and the evenness of the paint thickness as well as the adhesion of the paint film to the golf ball body. The method for producing the golf ball of the present invention comprises applying a two-component curing type urethane-based aqueous paint including an aqueous polyol composition (A) and an aqueous polyisocyanate (B) to a golf ball body in a specific method, wherein (A) the aqueous polyol composition contains (a-1) an aqueous acrylic polyol, (a-2) an aqueous urethane polyol and (a-3) an aqueous urethane resin.

Abstract: A golf putting practice ball having visually contrasting lighter and darker sections and a visually contrasting aiming line going across a lighter color section in a 90 degree angle to the borderline of the lighter and darker color sections, and a visually contrasting mark located on the border of the different color sections of the ball, at a location 90° away from the midpoint of the aiming line, and a weight located in an asymmetric position in relation to the internal center of the ball.

Abstract: The invention relates on one hand to a celluloid-free table-tennis ball, preferably having a diameter of 38.5 to 48 mm, a weight between 2.0 and 4.5 grams, and a shell thickness (approximately) between 0.20 mm and 1.30 mm, where the shell is composed of plastic, whose principal component is an organic non-crosslinked polymer, which in its main chain has not only carbon atoms but also heteroatoms; and on the other hand also to a process of manufacturing a table-tennis ball of this kind, where mostly in a first step two or more shell parts are manufactured, these shell parts are joined in a subsequent step.

Abstract: An object of the present invention is to provide a golf ball having a high resilience with a high spin rate on the approach shots. The present invention provides a golf ball comprising a constituting member that is formed from a polyurethane composition containing a polyurethane elastomer as a resin component, the polyurethane composition satisfying properties of a rebound resilience of 54% or more and a shear loss modulus G? of 5.03×106 Pa or less when measured at the conditions of the temperature of 0° C., the oscillation frequency of 10 Hz, and in a shear mode using a dynamic viscoelasticity measuring apparatus.

Abstract: The invention provides a rubber composition for golf balls which includes a base rubber, (B) a metal salt of an unsaturated carboxylic acid and/or an unsaturated carboxylic acid and zinc oxide, (C) an organic peroxide, and (D) from 0.1 to 5 parts by weight of a metal salt of a thiol having the general formula (R—S)nM (wherein R is a monovalent hydrocarbon group having from 12 to 30 carbons, exclusive of aromatic groups; n is an integer such as 1, 2 or 3; and M is a metal) per 100 parts by weight of the base rubber. The golf ball-forming rubber composition of the invention is suitable for pressure molding and has an excellent productivity because it does not lower the rate of vulcanization. The golf ball of the invention, which is formed using the composition, is endowed with an excellent rebound.

Abstract: This disclosure relates to golf balls made from a crosslinked thermoplastic polyurethane elastomer. The crosslinked thermoplastic polyurethane elastomer includes crosslinks located in the hard segments, where the crosslinks being the reaction product of unsaturated bonds located in the hard segments as catalyzed by a free radical initiator. The crosslinks may be formed from an unsaturated diol as a chain extender. The unsaturated diol may be trimethylolpropane monoallylether (TMPME). The golf ball may include the crosslinked thermoplastic polyurethane elastomer in the cover layer, in which case the cover layer may exhibit a high degree of scuff resistance.

Abstract: A phase transition golf ball comprises a phase transition material. The phase transition material may optionally include a microwave susceptor or an induction susceptor. The phase transition material preferably comprises an ethylene acid copolymer, or an ionomer of an ethylene acid copolymer. The performance of the phase transition golf ball, for example its hardness or compression, is adjusted by inducing a complete or partial phase transition in the phase transition material. The extent of the adjustment in performance is correlated with the extent of the phase transition. Preferably, the phase transition is reversible and repeatable and takes place at temperatures that might be achieved through the use of common household appliances. Also preferably, the phase transition material returns to its original state over an extended period, for example hours or days.

Abstract: A process for producing a molding having an embedded member which comprises: a first step in which a mold (1) having pins (3) which extend from the outside to the inside of the mold and can be withdrawn outward is heated to a given temperature; a second step in which a member (2) to be embedded is held in a given position within the mold by supporting the member, including an upper part thereof, with the pins (3); a third step in which a thermoplastic resin is packed through a gate (1d) first into that part of the cavity of the mold (1) which is located under the member to be embedded to thereby cause the thermoplastic resin to press the member against the pin (3) located in an upper part of the mold; a fourth step in which the thermoplastic resin is packed into the remaining part of the cavity of the mold (1); and a fifth step in which the pins (3) are withdrawn successively from the lower side of the mold before cooling to a temperature at which the thermoplastic resin solidifies and loses its flowability.

Abstract: A golf ball with a piezoelectric material portion allows golf ball data to be obtained when a golfer hits the golf ball with a golf club. An output from the piezoelectric material generated in response to the impact force of the golf club hitting the golf ball is measured. Based on the measured output, golf ball data can be obtained. The obtained golf ball data may be used by golf club fitting systems, golf ball fitting systems, and golfer profile databases.

Abstract: The invention provides a golf ball material which is a resin mixture composed of (a) a nonionic olefin-unsaturated carboxylic acid copolymer and/or olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 40,000 to 200,000, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of from 2.5 to 10.0 and an unsaturated carboxylic acid content of at least 16 wt %, (b) a nonionic olefin-unsaturated carboxylic acid copolymer and/or olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 40,000 to 200,000, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of from 4.0 to 10.

Abstract: A method for preparing a golf ball with surface indicia such as a letter or image having metallic luster includes the steps of forming an adhesive indicia made of a thermoplastic resin on a golf ball surface, bonding the metal thin-film on a metal thin film-bearing film over the indicia under pressure or heat and pressure, then peeling off the film so as to leave a portion of the metal thin-film having the same shape as the indicia adhering to and laminated with the indicia.

Abstract: The present invention provides a golf ball composed of a core and a cover having an outside surface on which are formed a plurality of dimples. Letting BV and CV be the initial velocity (m/s) of, respectively, the ball and the core as measured by a method using an initial velocity measuring apparatus of the same type as a USGA drum rotation-type initial velocity instrument and letting BE and CE be the deflection (mm) of, respectively, the ball and the core when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf), the core initial velocity CV is from 70.0 to 78.0 m/s and the ball satisfies the formula ?1.0?(BV/BE)?(CV/CE)?3.0. The golf ball of the invention has a flight distance that can be reduced compared with official golf balls currently in use, yet has the same good feel on impact and excellent controllability, scuff resistance and durability to repeated impact as a game ball.

Abstract: A method of orienting a spherical object comprising the steps of acquiring an image of a spherical object at an imaging station; analyzing the image with a first computer to determine an analysis; transferring the object from the imaging station to orienting stations using a transfer mechanism; and orienting the object to a predetermined orientation according to the analysis; wherein the orienting stations comprise first, second, and third stations each rotating the object about a single axis; the first, second, and third stations collectively orienting the object by rotation about alternately perpendicular axes. In one embodiment, at least one of the orienting stations is at least partially mounted onto the transfer mechanism. In another embodiment, the transfer mechanism is a compliant object carrier that is movable translationally and substantially immovable rotationally. In an alternate embodiment, the ball is orientated with a gimbaled mechanism. An object orienter is also disclosed.

Abstract: A golf ball that, in the process of spherical grinding after forming, can maintain the dimple shape and achieve the designed dimple surface occupation ratio. A mold for forming a golf ball of the present invention has at least two body parts, a cavity being formed within the mold by the joining of the at least two body parts, the body part comprising a cavity wall surface which has a spherical surface shape with the center thereof being at the center of the cavity and dimple-forming protrusions provided on the cavity wall surface, the dimple-forming protrusions being connected to the cavity wall surface at an angle of about 60 or more degrees in a region from about 3 ?m to about 20 ?m from the cavity wall surface.

Abstract: The invention provides a golf ball mold that is composed of a plurality of mold parts which removably mate to form a cavity having an inner wall with a plurality of dimple-forming protrusions thereon, wherein a non-circular resin injection port is formed between a plurality of mutually adjoining dimple-forming protrusions which include dimple-forming protrusions that lie across a parting line of the mold. Also provided is a golf ball molded using such a mold, and a golf ball manufacturing method which uses such a mold. By using the golf ball mold of the invention, even when manufacturing golf balls with a high dimple surface coverage on which the dimples are tightly arranged particularly up to the vicinity of the resin injection port, imbalances in the resin injection pressure and flow rate during injection molding are suppressed, enabling golf balls to be manufactured without production problems such as molding defects, scorching, core deformation and core eccentricity.

Abstract: Provided is a method for increasing the melt flow of a composition comprising a mixture of high molecular weight carboxylate functionalized ethylene copolymers (Mw between 80,000 and 500,000 Da) with low molecular weight carboxylate functionalized ethylene copolymers (Mw between 2,000 and 30,000 Da), wherein the carboxylic acid groups are at least partially neutralized to form salts containing zinc cations. The method comprises melt mixing the composition with ionomers containing cations other than zinc. Also disclosed are trimodal compositions comprising high molecular weight terpolymers, high molecular weight dipolymers and low molecular weight dipolymers wherein the carboxylic acid groups are at least partially neutralized to salts containing zinc cations and non-zinc cations. The compositions are used in films, multilayer structures and other articles of manufacture.

Abstract: A cross-sectional shape of each of dimples 8 of a golf ball 2 is a wave-like curve. The wave-like curve has two first curves 14, two second curves 16, two third curves 18, and one fourth curve 20. Each first curve 14 and each third curve 18 are upwardly convex. Each second curve 16 and the fourth curve 20 are downwardly convex. Each first curve 14 is connoted to a land 10 at an edge Ed. Each second curve 16 is connected to the first curve 14 at a first inflexion point 22. Each third curve 18 is connected to the second curve 16 at a second inflexion point 24. The fourth curve 20 is connected to the third curves 18 at third inflexion points 26. In the wave-like curve, the upwardly convex curves 14 and 18 and the downwardly convex curves 16 and 20 are alternately arranged.

Abstract: A golf ball including a composition having an unsaturated polymer, a cross-linking agent, a peptizer, and an accelerator. The composition can be incorporated into the golf ball's core, intermediate layers, and cover layers, and can provide optimal performance and durability properties. The golf balls incorporating the composition are easy to manufacture.

Abstract: A golf ball including a core and a cover layer, wherein the golf ball has a weight of about 1.39 oz to about 1.62 oz, and at a Reynolds number of about 207,000 and a non-dimensional spin ratio of about 0.095, the golf ball has a lift-to-weight ratio of greater than about 1.7 and a drag-to-weight ratio of greater than about 2.7.

Abstract: The present invention provides an ionomer composition for a golf ball providing a golf ball which is excellent in abrasion-resistance, durability and resilience, and a golf ball using the same. The ionomer composition for a golf ball of the present invention comprises a polymer containing at least following component as a constituent component: first component: an olefin monomer having 2 to 8 carbon atoms; second component: an unsaturated carboxylic acid having 2 to 18 carbon atoms; and third component: a diene or a diene polymer, wherein at least 10 mole % of the carboxyl group in the polymer is neutralized with an inorganic metal compound.

Abstract: A polyurea-based curable coating for use with sports equipment, such as golf balls, golf shoes, golf clubs, footballs, billiard balls, baseballs, and the like, of which the coating may be cured over time, with heat, or a combination thereof, providing enhanced adhesion to equipment surfaces, improved abrasion resistance, and increased water resistance.

Abstract: An object of the present invention is to provide a novel golf ball material that controls the spin rate on the approach shots while suppressing the change in the spin rate on the driver shots. Another object of the present invention is to provide a golf ball which produces a high spin rate on the approach shots and a low spin rate on the driver shots. The present invention provides a golf ball resin composition comprising: a polyurethane having a polyol component having a number average molecular weight from 200 to 1,500 as a constituting component.

Abstract: The invention provides a molded and crosslinked rubber material for golf balls which is obtained by molding and crosslinking a rubber composition containing rubber and rubber compounding ingredients, including a base rubber, a filler and an organic peroxide, into a spherical body of one or more layers. A monomer is impregnated into the molded and crosslinked rubber material, and one or both of the following chemical reactions is induced: (i) chemical reaction of the monomer with the rubber and/or a rubber compounding ingredient, (ii) chemical reaction of the monomer itself. The depth of impregnation by the monomer from a surface of the molded and crosslinked rubber material to the interior thereof is at least 0.3 mm. The invention also provides a method for manufacturing such a molded and crosslinked rubber material for golf balls.

Abstract: The present invention is directed to a two-piece golf ball having a core and a cover, wherein the core comprises at least one unsaturated polymer, at least one cross-linking agent, at least one co-cross-linking agent, and at least one peptizer (comprising one or more organic sulfur compounds, or one or more metal or non-metal salts of an organic sulfur compound), and optionally at least one weight adjusting filler. The improved two-piece balls have optimal velocity and distance performance, as well as excellent shot feel, the called “long and soft” combination. The balls also demonstrate excellent durability properties, and ease of manufacture.

Abstract: A golf ball material composed of (A) an ionomer, (B) a resin composition which includes one or more selected from the group consisting of diene polymers, thermoplastic polymers and thermoset polymers, and (C) an acid group-bearing thermoplastic resin composition is prepared by melt-mixing components B and C so as to form a resin composition of components B and C, then melt-mixing this resin composition with component A while injecting water under pressure. The golf ball material has a good thermal stability, flow and processability, and can be used to produce high-performance golf balls endowed with durability, scuff resistance and optimal hardness without a loss of rebound.

Abstract: A golf ball including a composition having an unsaturated polymer, a cross-linking agent, a peptizer, and an accelerator. The composition can be incorporated into the golf ball's core, intermediate layers, and cover layers, and can provide optimal performance and durability properties. The golf balls incorporating the composition are easy to manufacture.

Abstract: The invention provides a golf ball material composed of (i) a non-ionomeric thermoplastic resin, (ii) an ionomeric resin and/or an acid-containing polymer which is the base resin of an ionomeric resin, and (iii) at least one compound selected from among N,N-dialkylaminoalkyl(meth)acrylamide, N,N-dialkylaminoalkyl(meth)acrylate and derivatives thereof. Methods for preparing such a material, and a golf ball which includes as a component therein a molded part made of the golf ball material are also provided. The golf ball material has a good thermal stability, flow and processability, and can thus be used to obtain high-performance golf balls having an excellent rebound resilience, an outstanding durability and a good flexibility.

Abstract: There are provided a mold for forming a golf ball, which allows a dimple formed near the equator of golf ball corresponding to the partition surface of upper and lower molds to be formed so as to have the same shape as that of a dimple formed in other regions, and a golf ball manufactured using this mold. The mold for forming a golf ball in accordance with the present invention includes at least two body parts, a cavity is formed within the mold by the joining of the at least two body parts, and in at least one of the body parts, a groove for forming a projecting land part which is ground after the formation of the golf ball is provided in a cavity wall surface adjacent to the whole circumference of a parting line formed by the joining.

Abstract: Disclosed are a ball for use in a sporting activity, and a tracking system for tracking the ball. The ball comprises a microchip embedded in the ball. The microchip is adapted to transmit an information specific to a location of the ball to the tracking system. The tracking system is configured to locate the ball based on the information specific to the spatial location of the ball.

Abstract: A transmitter tag for a ball, the tag comprises a transmitter configured to issue a signal for location of the ball, a power source for powering the transmitter, activation means operable for activating the transmitter when the ball is in use, and deactivation means operable for remote manual deactivation of the transmitter after the ball is located.

Abstract: A golf ball-forming composition, golf balls prepared from the composition and the process for preparing thereof. The golf ball-forming composition is composed of the following: polyvinyl alcohol resin 5-80 wt %; filler 0-90 wt %, natural high polymer material 0-60 wt %, and plasticizer 5-50 wt %. The filler is the common filler known by the skilled person in the art; the natural high polymer material is celluloses or amyloses; the plasticizer is the common substances used by the skilled person in the art. The golf ball-forming composition is water soluble and biodegradable. The water soluble and biodegradable golf ball has a hollow inside, and has a surface which is disposed with at least one through hole communicated with the hollow. When the golf ball is hit into water, water will enter the hollow via the through hole, thereby increases the contact area between water and the ball and accelerates the dissolution of the ball, so that the ball may eventually completely biodegraded in the environment.

Abstract: A method for coating golf ball components is provided and includes the step of adhering a thin layer of a non-ionomeric polyolefin powder to the interior surfaces of a golf ball mold. The polyolefin powder is adhered to the mold using electrostatic, tribostatic or fluidized bed processes. The golf ball component is placed within the mold, and a sufficient amount of heat and pressure is applied to the mold so that the thin layer of non-ionomeric polyolefin powder fuses to the golf ball component.

Abstract: The invention provides a colored golf ball composed of a core, a cover having a plurality of dimples formed on an outside surface thereof, and an inside layer in contact with the cover. The ball satisfies the following conditions: (i) a color difference ?E* between the inside layer and the ball of at least 30; (ii) the inside layer has a lightness L* value, expressed in the L*a*b* color system based on JIS Z8729, of at least 82 and a chroma C, defined as (a*2+b*2)1/2, of at most 10; (iii) the ball has a lightness L* value of at least 50; (iv) the lightness L* value of the ball?the lightness L* value of the inside layer; (v) the inside layer has a transparency which is up to 10% in terms of total transmittance and up to 1.0% in terms of parallel transmittance; and (vi) the cover has a transparency which is at least 50% in terms of total transmittance and at least 1.0% in terms of parallel transmittance.

Abstract: Golf balls and methods and systems for manufacturing golf balls. In one exemplary embodiment, a portion of a golf ball comprises a core material having a void, a semiconductor component disposed at least partially in the void, and a filler material in the void and surrounding the semiconductor component, the filler material being placed in the void in a liquid state and occupying a first volume in the liquid state and the filler material transforming into a solid state which occupies substantially the first volume. Methods for manufacturing golf balls and fixtures and apparatuses for manufacturing golf balls are also described.

Abstract: The invention provides a golf ball mold composed of a plurality of mold parts which removably mate to form a hollow interior spherical cavity having a cavity wall with a plurality of dimple-forming protrusions thereon and which have a parting surface that is formed in a convex shape and a concave shape matching the convex shape. All or some of the dimple-forming protrusions are formed at positions at least about 0.03 mm away from an outside edge of a convex portion of the parting surface. The mold eliminates the possibility that molding flash projecting out from the parting surface of the mold will enter the dimples, as a result of which the dimples are not affected by the trimming of flash. Golf balls manufactured with such a mold are able to effectively manifest the aerodynamic performance of dimples tightly and uniformly arranged on the surface of the ball.

Abstract: A molded rubber material for a golf ball is obtained by molding and vulcanizing a rubber composition composed of (a) a diene rubber, (b) an ?,?-unsaturated carboxylic acid and/or a metal salt thereof, (c) an organic peroxide, and (d) an inorganic oxide. The inorganic oxide is prepared by a plasma process, a laser process or flame synthesis, has an average particle size of at most 200 nm, and is added in an amount of at least 1 wt % based on the zinc acrylate. The molded rubber material has a high hardness, a good resilience, and excellent durability.

Abstract: The invention provides a golf ball having a ball component made of a material molded under heat from a rubber composition of (a) a base rubber which includes a polybutadiene of at least 40% cis-1,4 structure, (b) an unsaturated carboxylic acid and/or a metal salt thereof, (c) an organic peroxide, and (d) a halogenated thiophenol, and/or a metal salt thereof, which is prepared by reacting starting materials in a polar solvent then washing with water and drying. The golf ball of the invention uses as a ball component a material of exceptional resilience which is obtained by molding a rubber composition under applied heat. As a result, the ball as a whole has an excellent rebound.

Abstract: The object is to provide a rubber composition for a high-strength golf ball which has a high hardness, high resiliency, excellent processability and improved filler dispersibility, by adjusting each of the Mooney viscosity, the molecular weight distribution and the n value (the rate-dependent index for Mooney viscosity) of a high-cis-polybutadiene rubber using a cobalt catalyst to a value falling within a specific range. The rubber composition comprises 100 parts by weight of a high-cis-polybutadiene synthesized using a cobalt catalyst and 10 to 50 parts by weight of a co-crosslinking agent, wherein the high-cis-polybutadiene satisfies the following requirements (a) to (c): (a) the Mooney viscosity (ML) is 40 to 55; (b) the molecular weight distribution [a weight average molecular weight MW)/a number average molecular weight (Mn)] is 3.0 to 4.2; and (c) the rate-dependent index of Mooney viscosity (n value) is 2.3 to 3.0.

Abstract: There are provided a golf ball molding die capable of manufacturing a golf ball having a satisfactory surface condition, and a golf ball manufactured by using the die. The present golf ball molding die comprises at least two die bodies within which a cavity for molding a golf ball is formed by jointing of the die bodies; and a pin accommodating hole provided in at least one of the die bodies, and is characterized in that at least one groove communicating directly with the cavity is provided in the wall surface of the pin accommodating hole.