Abstract: An object of the present invention is to provide a method for manufacturing a golf ball excellent in kneading workability when preparing a core rubber composition containing (d) a carboxylic acid and/or a salt thereof. The present invention provides a method for manufacturing a golf ball comprising the steps of blending (a) a base rubber and at least (b) a carboxylic acid and/or a salt thereof to prepare a first masterbatch; blending (a) a base rubber and at least (c) a crosslinking initiator to prepare a second masterbatch; blending the first masterbatch and second masterbatch to form a core rubber composition; molding the core rubber composition into a spherical core; and forming one or more cover layers covering the spherical core.

Abstract: An object of the present invention is to provide a golf ball having a spherical core with an outer-hard inner-soft structure formed from a rubber composition excellent in kneading workability. Another object of the present invention is to provide a golf ball traveling a great flight distance on driver shots. The present invention provides a golf ball having a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, and (d) a basic metal salt of a fatty acid.

Abstract: A golf ball 2 includes a spherical core 4, a mid layer 6 positioned outside the core 4, and a cover 8 positioned outside the mid layer 6. The core 4 includes a spherical center 10 and an envelope layer 12 positioned outside the center 10. The center 10 has a diameter of 1 mm or greater and 15 mm or less. The center 10 has a JIS-C hardness H1, at its central point, of 20 or greater and 50 or less. The difference (H4?H3) between the JIS-C hardness H4 of the core 4 at its surface and the JIS-C hardness H3 of the envelope layer 12 at its innermost portion is equal to or greater than 10. The cover 8 has a flexural modulus of 300 MPa or greater and 1000 MPa or less, and has a tensile modulus of 400 MPa or greater and 1500 MPa or less.

Abstract: An object of the present invention is to provide a golf ball having an excellent properties like flight distance and low temperature durability. The present invention provides a golf ball comprising: a core consisting of a center and one or more intermediate layers covering the center; and a cover covering the core, wherein at least one piece or one layer of said intermediate layers is formed from a highly elastic intermediate layer composition that contains (A) a highly elastic polyamide resin having a flexural modulus in a range from 700 MPa to 5,000 MPa; (B) a metal-neutralized product of ethylene-(meth)acrylic acid copolymer and (C) a resin having a polar functional group in a specific way.

Abstract: The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover is formed from a cover composition containing a non-petroleum based polyester resin as a resin component (A) and a needle-like and/or fibrous filler (B). The present invention further provide a golf ball comprising a core and a cover covering the core, wherein the cover is formed from a cover composition containing, a non-petroleum based polyester resin (A-1), at least one petroleum based thermoplastic resin (A-2), and a compatibilizer (C) containing at least a (meth)acrylic resin (C-1) having a polar functional group and an olefin resin (C-2) having a polar functional group. According to the present invention, durability, abrasion resistance and repulsion of a golf ball can be improved.

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: 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. The present invention provides a golf ball comprising: a core and a cover covering the core, wherein the cover is formed from a cover composition that contains as a resin component, (A) a specific high melt viscosity ionomer resin being neutralized with at least two metal ions, and (B) a low melt viscosity ionomer resin being neutralized with at least two metal ions, in a ratio of (A) the high melt viscosity ionomer resin/(B) the low melt viscosity ionomer resin being 55 mass % to 99 mass %/45 mass % to 1 mass %.

Abstract: An object of the present invention is to provide a golf ball providing a great distance. The present invention provides a golf ball comprising: a core consisting of a center and one or more intermediate layers covering the center; and a cover covering the core, wherein at least one of said intermediate layers is formed from a high fluidity intermediate layer composition that contains (A) a polyamide resin composition having a flexural modulus in a range from 500 MPa to 4,000 MPa and a melt flow rate (240° C., 2.16 kg) of 5.0 g/10 min or more, and (B) at least one member selected from the group consisting of an ethylene-(meth)acrylic acid binary copolymer, a metal-neutralized product of the binary copolymer, an ethylene-(meth)acrylic acid-(meth)acrylic acid ester ternary copolymer, and a metal-neutralized product of the ternary copolymer.

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 objective of the present invention is to provide a golf ball striking a balance between the flight distance on the driver shots and the approach performance on the approach shots and having the excellent shot feeling and durability.

Abstract: A golf ball 2 includes a spherical core 4, a mid layer 6 positioned outside the core 4, and a cover 8 positioned outside the mid layer 6. The core 4 includes a spherical center 10 and an envelope layer 12 positioned outside the center 10. The center 10 has a diameter of 1 mm or greater and 15 mm or less. The center 10 has a JIS-C hardness H1, at its central point, of 20 or greater and 50 or less. The difference (H4?H3) between the JIS-C hardness H4 of the core 4 at its surface and the JIS-C hardness H3 of the envelope layer 12 at its innermost portion is equal to or greater than 10. The cover 8 has a flexural modulus of 300 MPa or greater and 1000 MPa or less, and has a tensile modulus of 400 MPa or greater and 1500 MPa or less.

Abstract: A golf ball 2 includes a spherical core 4, a mid layer 6 positioned outside the core 4, and a cover 8 positioned outside the mid layer 6. The core 4 includes a spherical center 10 and an envelope layer 12 positioned outside the center 10. The center 10 has a diameter of 1 mm or greater and 15 mm or less. The center 10 has a JIS-C hardness H1, at its central point, of 20 or greater and 50 or less. The difference (H4?H3) between the JIS-C hardness H4 of the core 4 at its surface and the JIS-C hardness H3 of the envelope layer 12 at its innermost portion is equal to or greater than 10. The cover 8 has a flexural modulus of 300 MPa or greater and 1000 MPa or less, and has a tensile modulus of 400 MPa or greater and 1500 MPa or less.

Abstract: An object of the present invention is to provide a resin composition for the golf ball that suppresses the bleed out of the low molecular weight material component, as well as improves the fluidity and repulsion performance. The present invention provides a golf ball forming resin composition comprising as a resin component, (A) a high melt viscosity resin; (B) a low melt viscosity ionomer resin having a melt viscosity (190° C.) ranging from 1 Pa·s to 10 Pa·s measured by a brookfield viscometer, in a ratio of (A) the high melt viscosity resin/(B) the low melt viscosity ionomer resin being 55 mass % to 99 mass %/45 mass % to 1 mass %; and (C) a metal ion source capable of neutralizing carboxyl groups of (A) the high melt viscosity resin and (B) the low melt viscosity ionomer resin, in an amount of from 0.1 part to 10 parts with respect to 100 parts by mass of a sum of (A) the high melt viscosity resin and (B) the low melt viscosity ionomer resin.

Abstract: An object of the invention is to provide a golf ball excellent in the durability at the normal and low temperatures, flight distance, direction stability and shot feeling on the shots. The present invention provides a golf ball comprising: a core consisting of a center having a diameter of 35 mm or less and a surrounding layer covering the center; at least one intermediate layer covering the core, said intermediate layer having a thickness ranging from 0.5 mm to 1.2 mm and a density of 1.10 g/cm3 or more; and a cover covering the intermediate layer and having a thickness ranging from 0.3 mm to 1.0 mm, wherein the cover is formed of a cover composition that has a slab hardness ranging from 65 to 75 in Shore D hardness and contains as a resin component; (A) a polyamide resin composition having a flexural modulus in a range from 700 MPa to 4,000 MPa and a melt flow rate (240° C., 2.16 kg) of 5.

Abstract: 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 ?) between ?20° C. and 0° 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.

Abstract: The present invention is directed to a golf ball having a center, an envelope layer, an intermediate layer and a cover, wherein the intermediate layer has a thickness less than 1.2 mm, the envelope layer has a hardness Hs of 60 or more, the intermediate layer has a hardness Hm from 40 to 60, and the cover has a hardness Hc less than 40 in Shore D hardness, and the hardness Hs, Hm and Hc satisfy a following mathematical expression: Hs>Hm>Hc, and the intermediate layer composition has a flexural modulus from 150 MPa to 450 MPa, a maximum loss factor (tan ?) between ?20° C. and 0° C. of 0.08 or less, a rebound resilience of 55% or more.

Abstract: A golf ball 2 includes a core 4, a mid layer 6, and a cover 8. The difference between: a hardness H(5.0) at a point located at a distance of 5 mm from the central point of the core 4; and a hardness Ho at the central point is 6.0 or greater. The difference between: a hardness H(12.5) at a point located at a distance of 12.5 mm from the central point; and the hardness H(5.0) is 4.0 or less. The difference between a hardness Hs at the surface of the core 4 and the hardness H(12.5) is 10.0 or greater. The difference between the hardness Hs and the hardness Ho is 22.0 or greater. In the core 4, there is no zone in which a hardness decreases from the central point to the surface. A hardness H3 of the cover 8 is greater than a hardness H2 of the mid layer 6. The cover 8 is formed from a resin composition containing a polyamide copolymer including a polymerized fatty acid (a-1), sebacic acid and/or azelaic acid (a-2), and a polyamine component (a-3).

Abstract: An object of the present invention is to provide a golf ball having excellent durability and flight distance. The present invention provides a golf ball comprising: a core consisting of a center and one or more intermediate layers covering the center; and a cover covering the core, wherein, at least one piece or one layer of said intermediate layers is formed from a highly elastic intermediate layer composition that contains a highly elastic resin (A) having a flexural modulus in a range from 700 MPa to 5000 MPa and an ionomer resin (B) having a flexural modulus in a range from 150 MPa to 1000 MPa in an amount ratio ((A)/(B)) of the highly elastic resin (A) to the ionomer resin (B) being (20 mass % to 80 mass %)/(80 mass % to 20 mass %) (the total is 100 mass %).

Abstract: The present invention provides a golf ball having a center and at least one intermediate layer covering the center and a cover, wherein at least one of the intermediate layer is formed from a composition comprising, as a resin component, (A) a polyamide copolymer containing (a-1) a polymerized fatty acid, (a-2) sebacic acid and/or azelaic acid, (a-3) a polyamine component as an essential component, and (B) at least one member selected from (b-1) a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid, (b-2) a metal ion-neutralized product of a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid, (b-3) a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid ester, and (b-4) a metal ion-neutralized product of a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid ester.

Abstract: An object of the present invention is to provide a golf ball which is superior in durability to a golf ball having an ionomer resin cover which has conventionally been used. Another object of the present invention is to provide a golf ball using a non-petroleum based material. The golf ball of the present invention comprises a core and a cover covering the core, wherein at least either the core or the cover includes, as a resin component, a polyester resin containing a non-petroleum based material as a constitutional component.