Abstract: A golf ball includes a core, and a cover made from a cover material containing an ionomer resin and also barium sulfate and titanium dioxide added in a total amount ranging from 10 to 25 parts by mass on the basis of 100 parts by mass of the ionomer resin. A flexural amount of the core, measured by applying a load of 980 N thereto, is in a range of 4.0 to 5.5 mm. A ratio of a melt-flow rate to a specific gravity (melt-flow rate/specific gravity) of the cover material is in a range of 1.6 or more. A Shore D hardness of the cover is in a range of 55 to 65.

Abstract: In connection with a golf ball comprising a core, an intermediate resin layer, and a cover, the invention provides a mold having a cavity wall defining a spherical cavity, wherein the core is placed in the cavity to define a space for molding the resin layer. The cavity wall is provided with a plurality of radially extending projections, the total cross-sectional area of the projections relative to the cavity wall and the total volume of the projections relative to the space volume are properly controlled.

Abstract: A multi-piece solid golf ball includes a core having a structure with at least two layers and a cover on the core with an outer and inner cover layers. The core has a diameter in the range of 35 to 41 mm. The inner sphere of the core is formed of a rubber material based on polybutadiene and an outer layer is formed of a thermoplastic or rubber based material. The outer cover layer has a Shore D hardness of 40-60 degrees. The inner cover layer has a Shore D hardness of up to 53 degrees and lower than that of the outer cover layer. The ball's carry is comparable to conventional solid golf balls and spin receptivity is approximate to wound golf balls while the ball is durable and offers pleasant feel.

Abstract: A golf ball includes a solid core and a cover of at least one layer; wherein each of a specific gravity of the solid core and a specific gravity of the cover is nearly equal to a value (S) of a relation expression given by S=W/[(&pgr;/6)×D3], where W is a weight of the golf ball and D is a diameter of the golf ball. The golf ball can enhance the durability to increase the carry of the ball with less variations in carry of the ball.

Abstract: A golf ball includes a solid core, an intermediate layer, and a cover in a surface of which a plurality of dimples are formed. The solid core has a center JIS-C hardness of 50-70 and a surface JIS-C hardness of 60-80, and has a diameter of 35-40 mm. The intermediate layer is made from a material mainly containing an ionomer resin, and has a JIS-C hardness of 70-85 and a thickness of 0.5-2 mm. The cover is made from a material mainly containing an ionomer resin, and has a JIS-C hardness of 85 or more and a thickness of 0.5-2 mm. A difference in JIS-C hardness between the intermediate layer and the surface of the solid core is in a range of 15 or less. A different in JIS-C hardness between the cover and the intermediate layer is in a range of 10 or more. The hardnesses of the solid core, the intermediate layer, and the cover satisfy a relationship of (hardness gradient from intermediate layer to cover)/(hardness gradient from core center to intermediate layer)≧6.

Abstract: In a solid golf ball comprising a solid core and a cover, the solid core has a multilayer construction which includes a center core and an outer core of at least one layer that encloses the center core. The center core is formed primarily of a resin and has a diameter from 3 mm to less than 15 mm. The outer core is formed of a rubber composition based on polybutadiene. The center core has a surface hardness which is higher than the hardness of an innermost layer of the outer core. The ball has a high-pitched click and a soft feel.

Abstract: A golf ball including a sold core and a cover is provided. A deformed amount of the solid core, measured by applying a load of 980 N thereto, is in a range of 4.0 to 6.0 mm. A JIS-C hardness of the cover is in a range of 75 to 95. A JIS-C hardness (Sh) of a surface of the core and a JIS-hardness (Ch) of a center portion of the core satisfy a relationship of 1.55×Ch−16≦Sh≦1.55×Ch−10. A JIS-C hardness (Vh) of the cover and a JIS-C hardness (Sh) of the surface of the core satisfy a relationship of 0.9×Vh−70≦Vh−Sh≦0.9×Vh−50. The hardnesses of the center portion of the core, the surface of the core, and the cover become higher in this order. With this configuration, the golf ball can exhibit a high carrying performance, a good controllability, a desirable very soft feeling of hitting, and an excellent durability against continuous hitting.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 1.0 to 3.0 mm. The core is made from a rubber composition mainly containing polybutadiene. The outermost layer is made from a non-ionomer based thermoplastic resin. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. The core has a hardness corresponding to a deflection in a range of 3.5 to 6.5 mm under an applied load of 100 kg.

Abstract: A two-piece golf ball includes a core and a cover having a thickness of 1.0 to 3.0 mm. The core is made from a rubber composition containing a main rubber component which mainly contains polybutadiene. The cover is made from a material mainly containing an ionomer resin in which at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof is dispersedly blended. The core has a hardness corresponding to a deflection in a range of 3.3 to 6.0 mm under an applied load of 100 kg. The cover has a Dulometer D hardness in a range of 55 to 70.

Abstract: A two-piece golf ball includes a core and a cover having a thickness of 0.5 to 2.5 mm. The core is made from a rubber composition mainly containing polybutadiene. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component mainly containing an ionomer resin. The core has a hardness corresponding to a deflection in a range of 3.0 to 5.5 mm under an applied load of 100 kg. The cover has a Dulometer D hardness in a range of 45 to 55.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 0.5 to 2.0 mm. The core is made from a rubber composition mainly containing polybutadiene. The outermost layer is made from a resin material containing an ionomer resin in an amount of 30% by weight or more. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. The hardness of the outermost layer of the at least one intermediate layer is harder than the hardness of a center portion of the core. The hardness of the cover is harder than the hardness of the outermost layer of the at least one intermediate layer.

Abstract: A multi-piece golf ball includes a core having a diameter of 30 to 40 mm, at least one intermediate layer including the outermost layer having a thickness of 0.5 to 2.0 mm, and a cover having a thickness of 0.5 to 2.0 mm. The core is made from a rubber composition mainly containing polybutadiene. The outermost layer is made from a resin material containing an ionomer resin in an amount of 30% by weight or more. The cover is made from a material obtained by dispersedly blending at least one kind of silicone powder selected from a silicone rubber powder, a silicon resin powder, and a composite powder thereof, in a main resin component containing an ionomer resin in an amount of 50% by weight or more. The hardness of said cover is smaller than the hardness of said outermost layer of said at least one intermediate layer and is larger than the hardness of a center portion of said core. The multi-piece golf ball is excellent in resilience, durability, feel of hitting, and controllability.

Abstract: A multi-piece solid golf ball comprises a core having a structure consisting of at least two layers and a cover on the core consisting of outer and inner cover layers. The outer cover layer has a Shore D hardness of 40-60 degrees. The inner cover layer has a Shore D hardness of up to 53 degrees and lower than that of the outer cover layer. The ball's carry is comparable to conventional solid golf balls and spin receptivity is approximate to wound golf balls while the ball is durable and offers pleasant feel.

Abstract: A golf ball includes a core and a cover made from a cover material mainly containing an ionomer resin and also an inorganic filler having a specific gravity of 3.50 or more in an amount of 10 to 25 parts by mass on the basis of 100 parts by mass of the ionomer resin. A flexural amount of the core, measured by applying a load of 980 N thereto, is in a range of 4.7 to 5.3 mm. A specific gravity of the cover material is in a range of 1.050 to 1.100, a thickness of the cover is in a range of 1.5 to 2.0 mm, and a Shore D hardness of the cover is in a range of 57 to 63. A weight of the golf ball is in a range of 45.0 to 46.0 g, and a flexural amount of the golf ball, measured by applying a load of 980 N thereto, is in a range of 3.7 to 4.3 mm. A weight (W) of the golf ball and an inertia moment (MI) thereof satisfy a relationship of 1.53×W+13.32≦MI≦1.61×W+11.02.

Abstract: A golf ball includes at least a core, an inner cover, and an outer cover. The inner and outer covers are of different colors. A portion of the inner cover penetrates the outer cover and is exposed to the outside on the surface of the golf ball. The exposed portion constitutes a mark portion on the surface of the golf ball. Further, an auxiliary layer is provided in contact with the inner cover. The auxiliary layer has a color different from those of the inner and outer covers and has an end surface which is exposed to the outside on the surface of the golf ball within the mark portion. Either the inner cover or the auxiliary layer completely covers the core.

Abstract: A golf ball includes a core made from a rubber composition containing polybutadiene as a main rubber component and also an organic sulfur compound; and a cover made from a cover material mainly containing an ionomer resin composed of an Li ion neutralized type ionomer resin and a Mg ion neutralized ionomer resin, and also an inorganic filler having a specific gravity of 3.50 or more. A flexural amount of the core, measured by applying a load of 980 N thereto, is in a range of 4.0 to 5.5 mm. A specific gravity of the cover material is in a range of 1.020 to 1.110, and a Shore D hardness of the cover is in a range of 55 to 65. Such golf ball exhibits high durability and very high resilience.

Abstract: A golf ball includes a solid core, and a cover having one layer or two or more layers provided to directly cover the solid core or cover the solid core via an intermediate layer. At least one layer of the cover is taken as a high hardness cover layer which is made from a base resin containing an inorganic filler in an amount of 5 to 40 parts by weight on the basis of 100 parts by weight of the base resin and which has a Shore D hardness in a range of 66 to 80. With this configuration, the golf ball can exhibit a high carrying performance, a desirable very soft feeling of hitting, and an excellent durability against continuous hitting.

Abstract: A golf ball including a sold core and a cover is provided. A deformed amount of the solid core, measured by applying a load of 980 N thereto, is in a range of 4.0 to 6.0 mm. A JIS-C hardness of the cover is in a range of 75 to 95. A JIS-C hardness (Sh) of a surface of the core and a JIS-hardness (Ch) of a center portion of the core satisfy a relationship of 1.55×Ch−16≦Sh≦1.55×Ch−10. A JIS-C hardness (Vh) of the cover and a JIS-C hardness (Sh) of the surface of the core satisfy a relationship of 0.9×Vh−70≦Vh−Sh≦0.9×Vh−50. The hardnesses of the center portion of the core, the surface of the core, and the cover become higher in this order. With this configuration, the golf ball can exhibit a high carrying performance, a good controllability, a desirable very soft feeling of hitting, and an excellent durability against continuous hitting.

Abstract: A golf ball includes a solid core and a cover of at least one layer; wherein each of a specific gravity of the solid core and a specific gravity of the cover is nearly equal to a value (S) of a relation expression given by S=W/[(&pgr;/6)×D3], where W is a weight of the golf ball and D is a diameter of the golf ball. The golf ball can enhance the durability to increase the carry of the ball with less variations in carry of the ball.

Abstract: A multilayer solid golf ball comprising a core and a cover of four layers is characterized in that the core undergoes a deflection of 2.5-5.5 mm under an applied load of 100 kg, the difference in hardness between a first layer of the cover enclosing the core and a second layer of the cover enclosing the first layer is at least 5 Shore D hardness units, the second layer has a Shore D hardness of up to 52, a third layer of the cover enclosing the second layer is harder than the second layer and a fourth layer of the cover enclosing the third layer.