A golf ball for amateur golfers is endowed with both an excellent flight and a good feel at impact that is soft and solid when hit by the average golfer whose head speed is not very high. The golf ball, which includes a core and a cover, has a compressive deformation A when subjected to a final load of 5 kg from an initial load of 0.2 kg that is 0.21 mm or less, a compressive deformation B when subjected to a final load of 30 kg from an initial load of 5 kg that is from 0.72 to 0.90 mm and a compressive deformation C when subjected to a final load of 60 kg from an initial load of 5 kg that is from 1.55 to 1.80 mm.

Multi-layered golf balls having a dual-layered core and cover of at least one layer are provided. The dual-core construction includes a non-foamed inner core (center) made of a thermoplastic or thermoset composition such as polybutadiene rubber. An outer core layer comprising a foamed composition, such as polyurethane foam, is disposed about the inner core. In one version, the foamed outer core layer is made of a relatively soft foam composition having low flex modulus and density. The foamed outer core layer may specific gravity gradient within the layer, wherein the outer surface specific gravity is greater than the midpoint specific gravity. A cover may be disposed about the core structure. For example, an inner cover made of ethylene acid copolymer ionomer and outer cover made of polyurethane may be used.

An object of the present invention is to provide a golf ball showing a low spin rate on driver shots and a high spin rate on approach shots. The present invention provides a golf ball comprising a spherical center, at least two envelope layers covering the spherical center, and a cover covering the envelope layers, wherein an envelope layer (Es1) formed from a material having a lowest material hardness among a center constituent material and envelope layers constituent materials, is disposed in a region located at a distance from 36.0% to 65.0% of a golf ball radius from a center point of the golf ball.

A golf ball 2 includes a core 4, a cover 8 positioned outside the core 4, and a paint film 10 positioned outside the cover 8. The paint film 10 includes an inner layer 12 and an outer layer 14 positioned outside the inner layer 12. A 10% modulus Mo of the outer layer 14 is lower than a 10% modulus Mi of the inner layer 12. A difference (Mi-Mo) between the modulus Mi and the modulus Mo is not less than 25.0 kgf/cm.sup.2. The cover 8 has a Shore D hardness Hc of not less than 50 and not greater than 65. The cover 8 has a thickness Tc of not less than 0.80 mm and not greater than 1.80 mm.

Multi-layered golf balls having a dual-layered core and cover of at least one layer are provided. The dual-core construction includes a non-foamed inner core (center) made of a thermoplastic or thermoset composition such as polybutadiene rubber. An outer core layer comprising a foamed composition, such as polyurethane foam, is disposed about the inner core. In one version, the foamed outer core layer is made of a relatively soft foam composition having low flex modulus and density. The foamed outer core layer may specific gravity gradient within the layer, wherein the outer surface specific gravity is greater than the midpoint specific gravity. A cover may be disposed about the core structure. For example, an inner cover made of ethylene acid copolymer ionomer and outer cover made of polyurethane may be used.

Multi-layered golf balls having a dual-layered core and cover of at least one layer are provided. The dual-core construction includes a non-foamed inner core (center) made of a thermoplastic or thermoset composition such as polybutadiene rubber. An outer core layer comprising a foamed composition, such as polyurethane foam, is disposed about the inner core. In one version, the foamed outer core layer is made of a relatively soft foam composition having low flex modulus and density. The foamed outer core layer may specific gravity gradient within the layer, wherein the outer surface specific gravity is greater than the midpoint specific gravity. A cover may be disposed about the core structure. For example, an inner cover made of ethylene acid copolymer ionomer and outer cover made of polyurethane may be used.

A golf ball 2 includes a core 4, a cover 8 positioned outside the core 4, and a paint film 10 positioned outside the cover 8. The paint film 10 includes an inner layer 12 and an outer layer 14 positioned outside the inner layer 12. A 10% modulus Mo of the outer layer 14 is lower than a 10% modulus Mi of the inner layer 12. A difference (Mi-Mo) between the modulus Mi and the modulus Mo is not less than 25.0 kgf/cm.sup.2. The cover 8 has a Shore D hardness Hc of not less than 50 and not greater than 65. The cover 8 has a thickness Tc of not less than 0.80 mm and not greater than 1.80 mm.

Multi-layered golf balls having at least one layer made of a polyamide composition containing a transparent polyamide polymer and fatty acid salt are provided. In one preferred version, the polyamide composition consists essentially of a blend of 40 to 99% by weight transparent polyamide and 1 to 60% by weight fatty acid salt. The golf ball includes a core having at least one layer and a cover having at least one layer. The polyamide composition may be used to form any core, cover, or other layer in the golf ball. The polyamide compositions have a good combination of properties including Coefficient of Restitution (COR) and compression.

A golf ball is provided that includes at least two layers of material disposed between a spherical core and a cover layer, wherein the elastic modulus of each is within three orders of magnitude of each adjacent layer or core. The spherical core can be a hollow metal core. This results in a golf ball that is legal for play and capable of drive distances essentially equivalent to those of currently available high performance golf balls, but also provides a golf ball that has less hook and slice during play.

A golf ball 2 includes a core 4, a mid layer 6, a cover 8 and a paint layer 10. The core 4 includes a center 12 and an envelope layer 14. The golf ball 2 satisfies the following mathematical formulas. In the mathematical formulas, Tm represents a thickness of the mid layer, Tcmin represents a minimum thickness of the cover, Tcmax represents a maximum thickness of the cover, and Tp represents a thickness of the paint layer. The golf ball 2 has a large number of dimples 16 on a surface thereof. The number of planes that can divide a pattern of the dimples so that divided patterns are mirror symmetry to each other is one.
Tm>TcmaxTcmin>Tp
(TcmaxTcmin)0.15 mm
0.15(Tp/Tcmin)0.04