Abstract: A first golf ball 2 includes a core 4, a mid layer 6, and a cover 8. The core 4 includes a center 10 and an envelope layer 12. The mid layer 6 includes a metal ion source (C) that can neutralize an ionomer resin. The mid layer 6 has a melt flow rate (190° C., 2.16 kg) of 4 g/10 min or greater. The difference (H3?H1) between the JIS-C hardness H3 of the cover 8 and the JIS-C central hardness H1 of the center 10 is equal to or greater than 45. A second golf ball 22 includes a core 24, a mid layer 28, and a cover 30. The mid layer 28 has a melt flow rate (190° C., 2.16 kg) of 4 g/10 min or greater. Preferably, the mid layer 28 includes a high melt viscosity resin (A), a low melt viscosity ionomer resin (B), and a metal ion source (C1).

Abstract: An object of the invention is to provide a golf ball excellent in the durability at the normal and low temperatures, flight distance, and shot feeling on the shots. Another object of the present invention is to provide a golf ball excellent in a direction stability on the shots. The present invention provides a golf ball comprising: a core consisting of at least one layer; and a cover covering the core and having a thickness ranging from 0.3 mm to 1.0 mm, wherein the cover is formed from a cover composition that contains as a resin component, (A) a highly elastic polyamide resin (B) a metal-neutralized product of binary copolymer and/or ternary copolymer, and (C) a resin having a polar functional group in a specific amount, and wherein the cover composition has a slab hardness ranging from 65 to 75 in Shore D hardness.

Abstract: An object of the present invention is to provide a golf ball excellent in fluidity, adhesion of the paint film, and repulsion. Another object of the present invention is to provide a golf ball which is excellent in durability and low-temperature durability.

Abstract: Golf ball 2 has a center 8, a mid layer 10 and a cover 6. The base polymer of the mid layer 10 includes an ionomer resin as a principal component. The surface hardness H1s of the center 8 is greater than the hardness H2 of the mid layer 10. The Shore D hardness H3 of the cover 6 is equal to or greater than 57. The weight W2 of the mid layer 10 is greater than the weight W3 of the cover 6. The total weight (W2+W3) of the weight W2 of the mid layer 10 and the weight W3 of the cover 6 is 8.4 g or greater and less than 12.0 g. The total volume (V2+V3) of the volume V2 of the mid layer 10 and the volume of the cover 6 is equal to or less than 10.0 cm3.

Abstract: A golf ball containing a core, a reinforcing layer and a cover. The core is formed by a center and a mid layer. The center is formed by a center inner sphere and a center outer layer. The center inner sphere and the center outer layer are obtained through crosslinking of a rubber composition. The base polymer of the mid layer is an ionomer resin. The base polymer of the cover is a thermoplastic polyurethane elastomer. The thickness Tc of the cover is equal to or less than 1.0 mm. The hardness Hc of the cover is 20 or greater and 50 or less. The ratio (D2/D3) of the amount of compressive deformation D2 of the core to the amount of compressive deformation D3 of the golf ball is 0.98 or greater and 1.10 or less.

Abstract: Golf ball 2 has a spherical core 4, a reinforcing layer 6 positioned outside of the core 4 and a cover 8 positioned outside of the reinforcing layer 6. The core 4 has a inner sphere 10, a first mid layer 12 positioned outside of the inner sphere 10, and a second mid layer 14 positioned outside of the first mid layer 12. The principal component of the first mid layer 12 and the second mid layer 14 is an ionomer resin. The principal component of the cover 8 is a thermoplastic polyurethane elastomer. The second mid layer 14 has a hardness Hs which is greater than a hardness Hf of the first mid layer 12 and a hardness Hc of the cover 8. The hardness Hc of the cover 8 is equal to or less than 50. A product (Tc·Hc) of a thickness Tc (mm) and a hardness Hc of the cover 8 is equal to or less than 25.

Abstract: An object of the present invention is to provide a golf ball comprising a core consisting of a center and at least one intermediate layer covering the center, and a cover covering the core, wherein the cover is made from a cover composition containing, as a resin component, a thermoplastic polyurethane (A) and a polyisocyanate mixture (B) in which a urethane prepolymer (b-1) having at least two isocyanate groups is dispersed in a thermoplastic resin (b-2) which does not substantially react with an isocyanate group; and wherein the cover composition has a slab hardness of more than 60 and not more than 75 in Shore D hardness, and at least one piece or one layer of the intermediate layer is formed from a low hardness intermediate layer composition which has a slab hardness of 40 or less in Shore D hardness.

Abstract: An object of the present invention is to provide a golf ball comprising a core and a cover, wherein the cover is made from a cover composition containing, as a resin component, a thermoplastic polyurethane (A) and a polyisocyanate mixture (B) in which a polyisocyanate (b-1) having at least three isocyanate groups is dispersed in a thermoplastic resin (b-2) which does not substantially react with an isocyanate group; and wherein the cover composition has a slab hardness of more than 60 and not more than 75 in Shore D hardness, and the cover has the thickness of 2.5 mm or less.

Abstract: An object of the present invention is to provide a golf ball comprising a core and a cover, wherein the cover is made from a cover composition containing, as a resin component, a thermoplastic polyurethane (A) and a polyisocyanate mixture (B) in which a urethane prepolymer (b-1) having at least two isocyanate groups is dispersed in a thermoplastic resin (b-2) which does not substantially react with an isocyanate group; and wherein the cover composition has a slab hardness of more than 60 and not more than 75, and the cover has a thickness of 2.5 mm or less.

Abstract: Golf ball 2 has spherical main body 4, mark layer 6 and paint layer 8. The main body 4 has spherical core 10, and cover 12 provided to cover this core 10. The cover 12 does not include titanium oxide. The cover 12 includes a fluorescent colorant. The main body 4 has a chroma saturation of equal to or greater than 25. The paint layer 8 is constituted with a resin composition. This resin composition includes composite particles. The composite particle has a nucleus, and a coat layer provided to coat this nucleus. The nucleus is constituted with mica, while the coat layer is constituted with titanium oxide. The amount of the composite particles is 2 parts by weight or greater and 30 parts by weight or less per 100 parts by weight of the base resin of the paint layer 8.

Abstract: Golf ball 2 has spherical core 4, cover 6 positioned outside the core 4, mark layer 8 and paint layer 10. The resin composition of the cover 6 includes composite particles. The composite particle has a nucleus and a coat layer. The nucleus is constituted with aluminum oxide. The coat layer is constituted with titanium oxide. The composite particles are flaky. The amount of the composite particles is 0.1 parts by weight or more and 15 parts by weight or less per 100 parts by weight of the base resin of the cover 6. The composite particles may be also dispersed in the paint layer 10. The amount of the composite particles in the paint layer 10 is 1 part by weight or more and 30 parts by weight or less per 100 parts by weight of the base resin of the paint layer 10.

Abstract: The object of the present invention is to provide a golf ball having excellent luster and durability. The golf ball of the present invention comprises a golf ball body and a paint film covering the golf ball body, wherein the golf ball body and the paint film contains a luster material having a particle size of 5 ?m to 100 ?m.

Abstract: The object of the present invention is to provide a golf ball having a lasting scent. The golf ball of the present invention is a golf ball comprises a paint film on a surface of the golf ball body, wherein the paint film comprises a microcapsule encapsulating a perfume material. Employment of such a structure inhibits a release of the perfume material component in the paint film during storage of a golf ball, since it is included in the microcapsule. When in use, a film material of the microcapsule is gradually broken by hitting the golf ball, so that the perfume material included in the capsule is gradually released.

Abstract: Golf ball 2 has a spherical core 4, a reinforcing layer 6 positioned outside of the core 4 and a cover 8 positioned outside of the reinforcing layer 6. The core 4 has a inner sphere 10, a first mid layer 12 positioned outside of the inner sphere 10, and a second mid layer 14 positioned outside of the first mid layer 12. The principal component of the first mid layer 12 and the second mid layer 14 is an ionomer resin. The principal component of the cover 8 is a thermoplastic polyurethane elastomer. The second mid layer 14 has a hardness Hs which is greater than a hardness Hf of the first mid layer 12 and a hardness Hc of the cover 8. The hardness Hc of the cover 8 is equal to or less than 50. A product (Tc·Hc) of a thickness Tc (mm) and a hardness Hc of the cover 8 is equal to or less than 25.

Abstract: Golf ball 2 has a core 4, a reinforcing layer 6 and a cover 8. The core 4 is formed by a center 10 and a mid layer 12. The center is formed by a center inner sphere 14 and a center outer layer 16. The center inner sphere 14 and the center outer layer 16 are obtained through crosslinking of a rubber composition. Base polymer of the mid layer 12 is an ionomer resin. Base polymer of the cover 8 is a thermoplastic polyurethane elastomer. A thickness Tc of the cover 8 is equal to or less than 1.0 mm. A hardness Hc of the cover is 20 or greater and 50 or less. A ratio (D2/D3) of an amount of compressive deformation D2 of the core to an amount of compressive deformation D3 of the golf ball 2 is 0.98 or greater and 1.10 or less.

Abstract: Golf ball 2 has a spherical center 10, a mid layer 12 covering this center 10, a reinforcing layer 6 covering this mid layer 12, and a cover 8 covering this reinforcing layer 6. Base polymer of the mid layer 12 is an ionomer resin. Base polymer of the cover 8 is a thermoplastic polyurethane elastomer. The cover 8 has a thickness Tc of equal to or less than 1.2 mm, and particularly equal to or less than 0.8 mm. The difference (Ho?Hc) between the central hardness Ho of the center 10 and the hardness Hc of the cover 8 is 1 or greater and 30 or less. The cover 8 has a hardness Hc of 15 or greater and 40 or less. The product (Tc·Hc) of the thickness Tc (mm) of the cover 8 and the hardness Hc of the cover 8 is equal to or less than 25.

Abstract: A method of producing a golf ball with uniform thickness by, eliminating defective air between the cover and the core, an insufficient thickness of the cover and an uneven thickness of the cover wherein in the step of heat and compression molding to cover the core or an intermediate layer with shells molded from a cover material mainly composed of a thermoplastic resin, if the mold has a temperature of T1° C. and the half shells start to flow at a temperature of T2° C., T1 minus T2 is set within a range of ?3° C. to +10° C.

Abstract: A golf ball is provided which contains a core and a cover. In the forming of the cover, two half shells made from a thermoplastic resinous composition are used to cover the core, the composite is put in a spherical mold, then, the mold is clamped. Thereafter, the thermoplastic resin where it is heated and pressurized at a pressure of 5 kgf/cm2 to 50 kgf/cm2, and the excess thermoplastic resin composition flows out of the spherical cavity. Subsequently, the thermoplastic resin composition is heated in the spherical cavity and is pressurized at a pressure of 70 kgf/cm2 or more whereby the cover is formed. The total volume of the two half shells is 105% to 120% of the volume of the cover.

Abstract: Half shell 10 has a bowl-like shape, and is composed of a thermoplastic resin composition. The half shell 10 has a top part 11 and a side part 12. The thickness Tt of the top part 11 is less than the thickness Ts of the side part 12. The difference (Ts?Tt) between both thicknesses is 0.02 mm or greater and 0.30 mm or less. Two half shells 10 and a core covered by the half shells 10 are placed into a mold comprising an upper portion and a lower portion both of which having a semi hemispherical cavity. Upon clamping, the thermoplastic resin composition is compressed while being heated, resulting in outflow of the excess thermoplastic resin composition from the cavity. A cover is formed having the nominal thickness of 0.3 mm or greater and 1.0 mm or less with remained thermoplastic resin composition.

Abstract: There is provided a method of producing a golf ball, eliminating defective air between the cover and the core, an insufficient thickness of the cover and an uneven thickness of the cover to provide the cover with a uniform thickness. In the method at the step of heat and compression molding to cover the core or an intermediate layer with half shells molded from a cover material mainly composed of a thermoplastic resin, if the mold has a temperature of T1° C. and the half shells start to flow at a temperature of T2° C., T1 minus T2 is set within a range of −3° C. to +10° C.