The present invention provides a golf ball including a two-layer core having an inner layer core and an outer layer core, an intermediate layer, and a cover, in which a large number of dimples are formed on an outer surface of the cover, and a relationship between a surface hardness of an intermediate layer-encased sphere and a ball surface hardness satisfies the following condition:

(ball surface hardness)< (surface hardness of intermediate layer-encased sphere) (where hardness means Shore D hardness).

Further, a value obtained by subtracting a center hardness of the entire core from a surface hardness of the entire core is at least 25 on the Shore C hardness scale, and a lift coefficient and a drag coefficient at a predetermined Reynolds number and spin rate of the dimples are set within a predetermined range.

An ultra-low compression golf ball is disclosed herein. The core preferably has a PGA compression less than 30. The mantle layer and cover have approximately the same thickness. The cover comprises a thermoplastic polyurethane material and has a specific gravity greater than the core and mantle layer. The golf ball has a PGA compression less than 75 and a COR of at least 0.780.

A unique method of embedding an RFID chip into the core of a golf ball and using it in the application of a limited flight range ball for use in a range setup that can receive and monitor RFID signals is disclosed herein. The density of the core material is adjusted in relation to the mass of the RFID chip. The golf ball with an embedded RFID chip conforms to a mass limitation of the USGA.

A golf ball 2 has a large number of dimples 8 on a surface thereof. A trajectory of the golf ball 2 is divided into first to fourth segments. An average CD1 of drag coefficients CD and an average CL1 of lift coefficients CL in the first segment are equal to or less than 0.225 and 0.180, respectively. An average CD2 of drag coefficients CD and an average CL2 of lift coefficients CL in the second segment are equal to or less than 0.250 and 0.220, respectively. An average CD3 of drag coefficients CD and an average CL3 of lift coefficients CL in the third segment are equal to or greater than 0.260 and 0.220, respectively. An average CD4 of drag coefficients CD and an average CL4 of lift coefficients CL in the fourth segment are equal to or greater than 0.250 and 0.200, respectively.

An object of the present invention is to provide a golf ball showing an increased spin rate on approach shots under a wet condition while maintaining a spin rate on approach shots under a dry condition. 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 paint film has a multi-layered construction composed of two or more layers, and a difference (M.sub.outM.sub.in) between a 10% elastic modulus (M.sub.out) of an outermost layer of the paint film and a 10% elastic modulus (M.sub.in) of an innermost layer of the paint film is 25 kgf/cm.sup.2 or more.

An object of the present invention is to provide a golf ball showing increased controllability on approach shots for less than 40 yards and showing excellent shot feeling. In the inventive golf ball, the paint film is formed from a curing type paint composition including: a base material containing a polyrotaxane, and a curing agent containing a polyisocyanate, and wherein the polyrotaxane has a cyclodextrin, a linear molecule included in a cyclic structure of the cyclodextrin in a manner of piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both ends of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via OC.sub.3H.sub.6O group.

An object of the present invention is to provide a golf ball showing increased controllability on approach shots for less than 40 yards and showing excellent shot feeling. In the inventive golf ball, the paint film is formed from a curing type paint composition including: a base material containing a polyrotaxane, and a curing agent containing a polyisocyanate, and wherein the polyrotaxane has a cyclodextrin, a linear molecule included in a cyclic structure of the cyclodextrin in a manner of piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both ends of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via OC.sub.3H.sub.6O group.

An ultra-low compression golf ball is disclosed herein. The core preferably has a PGA compression less than 30. The mantle layer and cover have approximately the same thickness. The cover comprises a thermoplastic polyurethane material and has a specific gravity greater than the core and mantle layer. The golf ball has a PGA compression less than 75 and a COR of at least 0.780.

The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

An object of the present invention is to provide a golf ball showing an increased spin rate on approach shots under a wet condition while maintaining a spin rate on approach shots under a dry condition. 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 paint film has a multi-layered construction composed of two or more layers, and a difference (M.sub.inM.sub.out) between a 10% elastic modulus (M.sub.in) of an innermost layer of the paint film and a 10% elastic modulus (M.sub.out) of an outermost layer of the paint film is 25 kgf/cm.sup.2 or more.