In a multi-piece solid golf ball made up of, successively, a core, an intermediate layer and a cover having numerous dimples on the surface thereof, the intermediate layer is formed of a resin material and the cover is formed of a urethane resin material, each having a specific respective Shore D hardness. The ball has a specific (intermediate layer thickness)/(core diameter) value and a specific (cover thickness)/(core diameter) value, and the core has a specific deflection and has a specific hardness profile from a center to a surface thereof. This golf ball provides an increased distance and has both a soft feel when played and a high durability to repeated impact.

An object of the present invention is to provide a golf ball having excellent spin performance on approach shots under a dry condition and excellent spin performance on approach shots under the condition that there is grass between the golf ball and the club face. The present invention provides golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film has a multi-layered construction composed of two or more layers, a ratio (M1/E1) of a 10% elastic modulus (kgf/cm.sup.2) (M1) of an innermost layer of the paint film to a maximum elongation (%) (E1) of the innermost layer of the paint film is 10 or more and 50 or less, and the ratio (M1/E1) of the innermost layer of the paint film is greater than a ratio (M2/E2) of a 10% elastic modulus (kgf/cm.sup.2) (M2) of an outermost layer of the paint film to a maximum elongation (%) (E2) of the outermost layer of the paint film.

A golf ball comprising: (a) a core; (b) an inner mantle layer; (c) an intermediate mantle layer; (d) an outer mantle layer; and (e) at least one cover layer; wherein the core has a PGA compression of less than 70, and the core/inner mantle layer/intermediate mantle layer combined construct has a PGA compression of at least 30.

A multi-piece solid golf ball having a two-layer core with an inner core layer and an outer core layer and having a cover of at least two layers including an intermediate layer and an outer layer with numerous dimples on the surface is characterized in that the hardest cover layer has a specific material hardness and the ball has a specific value obtained by subtracting the surface hardness of the overall core from the surface hardness of the hardest cover layer, a specific deflection, and a specific value obtained by subtracting the initial velocity of the inner core layer from the initial velocity of the sphere consisting of the inner core layer encased by the outer core layer. This golf ball enables relatively low head speed golfers to achieve a good distance on full shots with drivers and iron clubs and also provides a soft, comfortable feel at impact.

Golf balls having a multi-layered core made of a foamed composition are provided. The core assembly preferably includes a foam inner core (center) and surrounding outer core layer. Preferably, a polyurethane foam composition is used to form the foam center. The core layers have different hardness gradients and specific gravity values. The foamed inner core assembly includes a geometric center, outer surface (skin), and thermal barrier layer that helps protect the foamed center region from the negative effects of high temperatures used during the ball-manufacturing process. Non-foamed thermoset materials such as polybutadiene rubber may be used to form the thermal barrier layer. The foam cores have good resiliency, thermal stability, and durability over a wide temperature range. The ball further includes a cover that may be multi-layered.

A method and system for determining concentricity of a multiple layer golf ball are disclosed herein. One or more images of a golf ball are generated using an X-ray source, a camera or a digital detector, and an image intensifier. An edge detection algorithm is preferably utilized. The method also includes calculating Y,Z center coordinates of the a best fit diameter or ellipse of the inner edge layer and outer edge layer of the multiple layer golf ball.

The golf ball includes a core, an intermediate layer, and a cover, in which the core is formed of a rubber composition into a single layer or a plurality of layers, the intermediate layer and the cover are both formed of a single-layer resin composition, and a relationship between an initial velocity of the core, an initial velocity of a sphere (intermediate layer-encased sphere) in which the core is encased with the intermediate layer, and an initial velocity of a sphere (ball) in which the intermediate layer-encased sphere is encased with the cover satisfies the following two conditions:

(initial velocity of ball)<(initial velocity of intermediate layer-encased sphere)

0.60?(initial velocity of intermediate layer-encased sphere)?(initial velocity of core)?1.00 (m/s). and the specific deflection is 3.00 mm or less, and a specific gravity of the intermediate layer is 1.05 or more.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

An object of the present invention is to provide a golf ball that can strike a good balance in approach performance under a rough condition and a wet condition while maintaining a flight distance on driver shots. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the golf ball body has a spherical core, an intermediate layer covering the spherical core, and a cover covering the intermediate layer, and the paint film has a multi-layered construction composed of two or more layers, wherein a 10% elastic modulus (Pi10) of an innermost layer of the paint film is greater than a 10% elastic modulus (Po10) of an outermost layer of the paint film and a 10% elastic modulus (C10) of a material constituting the cover, and a thickness (Ti) of the innermost layer of the paint film is greater than a thickness (To) of the outermost layer of the paint film, a 10% elastic modulus (M10) of a material constituting the intermediate layer is greater than the 10% elastic modulus (C10) of the material constituting the cover, and a difference (Po10C10) between the 10% elastic modulus (Po10) of the outermost layer of the paint film and the 10% elastic modulus (C10) of the material constituting the cover is 4.0 kgf/cm.sup.2 or more and 50 kgf/cm.sup.2 or less, and a Shore D hardness (Hc) of the material constituting the cover is 40 or less.

A golf ball comprising: (a) a core; (b) an inner mantle layer; (c) an intermediate mantle layer; (d) an outer mantle layer; and (e) at least one cover layer; wherein the core has a PGA compression of less than 70, and the core/inner mantle layer/intermediate mantle layer combined construct has a PGA compression of at least 30.