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<envelope layer-encased sphere surface hardness<intermediate layer-encased sphere surface hardness>ball surface hardness,

(envelope layer-encased sphere surface hardness)−(core center hardness)≥28, and

(intermediate layer-encased sphere surface hardness)−(core center hardness)≥39.

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

cover thickness<intermediate layer thickness≤envelope layer thickness.

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

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:

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

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

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

(3) cover thickness<intermediate layer thickness.

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 3-axis magnetometer inside a golf ball to detect the impact location on golf club heads that contain ferrous materials is disclosed herein. Key aspects of a golf shot are determined from within the golf ball itself. A magnetometer, preferably running at 85 Hz, inside a golf ball is able to measure spins of 5000 RPM. An integrated circuit comprises 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 integrated circuit.

A golf ball with a core comprising polybutadiene and graphene with an embedded IC is disclosed herein. The golf ball preferably has a single core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an inner core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an outer core comprising polybutadiene and graphene.

A golf ball with a core comprising polybutadiene and graphene is disclosed herein. The golf ball has a single core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an inner core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an outer core comprising polybutadiene and graphene.

In a golf ball having a core, an envelope layer, an intermediate layer and a cover, the difference between the center hardness and the surface hardness of the core is set in a specific range, the intermediate layer is formed of a resin material that includes a high-acid ionomer, the Shore C hardness relationships among the core center and the surfaces of the envelope-encased layer and the intermediate layer-encased sphere satisfy specific conditions; and the ball has a deflection when compressed under a given load which is at least 2.7 mm. This ball achieves a good distance on shots with a driver, utility club or iron, is receptive to spin in the short game, and has a soft feel at impact on all shots, making it useful to amateur golfers.

In a golf ball for professional golfers and skilled amateurs which has a single-layer core, a cover and at least one intermediate layer therebetween, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) and the ball have a surface hardness relationship therebetween which satisfies the condition:

(surface hardness of intermediate layer-encased sphere)>(surface hardness of ball).

Moreover, the core has a diameter of from 35.5 to 39.5 mm and a unique hardness profile that satisfies certain specific conditions. This ball is endowed with both an excellent flight performance and a good durability to repeated impact.

A golf ball having a single-layer rubber core, a single-layer resin cover and one intermediate layer therebetween satisfies the following conditions:

(Shore C hardness at surface of intermediate layer-encased sphere)>(Shore C hardness at ball surface),

14≤(Atti compression of core)≤38,

(Atti compression of core)/(Shore C hardness at core surface−Shore C hardness at core center)≤1.1, and

600≤(Shore C hardness at surface of intermediate layer-encased sphere)×(specific gravity of intermediate layer material)×[volume (cm.sup.3) of intermediate layer material].

This ball has a superior distance performance on full shots with an iron and a high spin performance in the short game, imparts a very soft feel and possesses an excellent durability to cracking on repeated impact. The ball is intended to satisfy the needs of primarily skilled amateur golfers who handle iron shots skillfully.

The present invention provides methods for producing molded golf balls and the resultant balls. The methods of this invention involve producing foamed polyurethane covers and these methods help reduce dimple distortions and other surface imperfections. These golf balls contain an inner core and outer foamed polyurethane cover. One or more intermediate layers can be disposed between the core and cover. In one embodiment, a castable liquid polyurethane composition containing a foaming agent is dispensed into mold cavities, which are then pressed together to form a foam cover for the ball.

A golf ball with improved durability is disclosed herein. The golf ball has a core comprising a polybutadiene material and methyl methacrylate, butadiene, styrene (MBS) with a weight percentage of MBS ranging from 0.5 to 5 weight percent of the core.