An object of the present invention is to provide a golf ball having excellent shot feeling while maintaining the resilience performance on driver shots. The present invention provides a golf ball comprising a core and at least one cover covering the core, wherein the core is formed from a core rubber composition containing (a) a base rubber, (b) an α,β-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 monophenol compound having a substituent group only at p-position.

A golf ball includes a core, a mid layer, and a cover. An amount of compressive deformation C3 of the golf ball can be not less than 2.80 mm. The golf ball can satisfy the following mathematical formulas (1) and (2):

C1>(124.8−Hs)/11.5   (1)

C2−C1≥(−1/6*C1+(68−H2)/20+(5−Hd)/ 100)*T2   (2), where

C1 is an amount of compressive deformation (mm) of the core,

C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer,

Hd is Hs−Ho,

Ho is a hardness (Shore C) of a center the core,

Hs is a hardness (Shore C) of a surface of the core,

H2 is a hardness (Shore D) of the mid layer, and

T2 is a thickness (mm) of the mid layer.

A golf ball can include a core, a mid layer, and a cover. The golf ball can satisfy the following mathematical formulas (1), (2), and (3):

C1≤(124.8−Hs)/11.5  (1)

C2−C1≥(−⅙*C1+(68−H2)/20+(5−Hd)/100)*T2  (2)

10≤H2*T2−H3*T3  (3), where

C1 is an amount of compressive deformation (mm) of the core,

C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer,

Hd is Hs−Ho,

Ho is a hardness (Shore C) of a center the core,

Hs is a hardness (Shore C) of a surface of the core,

H2 is a hardness (Shore D) of the mid layer,

H3 is a hardness (Shore D) of the cover,

T2 is a thickness (mm) of the mid layer, and

T3 is a thickness (mm) of the cover.

An object of the present invention is to provide a golf ball having excellent durability. The present invention provides a golf ball comprising a core and at least one cover layer covering the core, wherein the core is formed from a core rubber composition containing (a) a base rubber, (b) an α,β-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 hindered phenol compound, and (b) the co-crosslinking agent and (d) the hindered phenol compound are blended in the core rubber composition such that the following expression (1) is satisfied:
0.04≤HF/B≤0.35  (1) in the formula (1), HF=a number of OH functional group in one molecule of (d) the hindered phenol compound×an amount of (d) the hindered phenol compound (mole) with respect to 100 parts by mass of (a) the base rubber, and B=an amount of (b) the co-crosslinking agent (mole) with respect to 100 parts by mass of (a) the base rubber.

In a multi-piece solid golf ball having a core formed of a rubber composition, an intermediate layer formed of a polyurethane material and a cover, the ball satisfies the following condition: surface hardness of ball≤surface hardness of intermediate layer-encased sphere. When the ball is struck with a driver at a head speed of 40 m/s, the sum of the time t1 required from contact initiation between the driver and ball for deformation of the ball to reach a maximum value and the time t2 required from the state of maximum ball deformation for the ball and driver clubface to separate is at least 685 microseconds, and the ratio t2/t1 is at least 1.35, and the core has a specific hardness profile. This ball has an excellent flight performance when hit by low or moderate head-speed golfers, is receptive to spin on approach shots and has a good, soft feel at impact.

In a golf ball having a core, envelope layer, intermediate layer and cover, the (core diameter)/(ball diameter) value falls within a particular range, the core has a specific hardness profile, and the Shore C hardness relationships among the core center and surface hardnesses and the surface hardnesses of the envelope layer-encased sphere, intermediate layer-encased sphere and ball satisfy the following conditions:

core surface hardness<surface hardness of envelope layer-encased sphere<surface hardness of intermediate layer-encased sphere>ball surface hardness,  (1)

(surface hardness of envelope layer-encased sphere)−(core center hardness)≥28.  (2)

Also, the envelope layer, intermediate layer and cover have respective thicknesses which satisfy the condition:

cover thickness<intermediate layer thickness  (3)

cover thickness<envelope layer thickness  (4)

envelope layer thickness≥0.8 mm.  (5)

This ball enables mid-level and skilled amateur golfers to achieve superior distances on driver shots and on iron shots, and moreover has a soft yet good feel at impact.

A golf ball comprising an electrical component is disclosed herein. The electrical component comprises an integrated circuit having a gyroscope, a magnetometer, and a BLUETOOTH low energy (BTLE) radio, and at least one battery. A body is composed of an epoxy material, and the body encompasses the electrical component.

Multi-layered golf balls having an inner core with a relatively large diameter are provided. In one embodiment, the golf ball comprises an inner core, outer core, and cover. The inner core comprises a thermoset or thermoplastic composition. For example, a blend of polybutadiene rubbers can be used to form the inner core. The outer core layer is relatively thin and comprises a thermoset or thermoplastic composition. The dimensions and compressions of the core layers have specific relationships referred to as the Core Profile. The golf ball further comprises a cover having at least one layer. Ethylene acid copolymer ionomers and polyurethanes, particularly thermoplastic polyurethane, can be used to form the cover.

A golf ball a core, one or more intermediate layers, and one or more cover layers. The core may comprise an inner portion and an outer portion. One or more layers of the golf ball may be formed by the application of ultrasonic welding on two half shells to form. One or more of the layers may be formed by a number of different chemical compositions, and may have varying thicknesses, hardnesses, coefficients of restitution, and PGA compression. The golf ball itself may have varying coefficient of restitution and PGA compression, depending on the layers.

Golf ball comprising a core and a cover, wherein the core includes between 2 and 20 smaller spheres that are surrounded by a second core composition having at least one different physical property than the composition(s) forming the smaller spheres. The smaller spheres can be entirely surrounded by the second core composition; or, at least two smaller adjacent spheres may each be partially surrounded by the second core composition while also being in partial contact with each other.