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

In a multi-piece solid golf ball having a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and an outermost layer encasing the intermediate layer, the envelope layer-encased sphere, the intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, the intermediate layer and the cover have thicknesses which satisfy a specific relationship, and the core has a hardness profile in which the hardnesses at the core surface, core center, a position 5 mm from the core center, and a position midway between the core surface and center satisfy specific relationships. This golf ball satisfies at a high level the flight and control performances desired for use by professional golfers and skilled amateurs. In particular, it holds down the spin rate on full shots and follows a straight trajectory, thus having a superior flight performance, and moreover is endowed with an excellent scuff resistance.

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.

Multi-piece golf balls containing a dual-layered core and dual-layered cover are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, and a surrounding outer core layer. The core layers may have different hardness gradients. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and combinations and alloys thereof preferably dispersed in a thermoplastic polymeric matrix. The outer core layer is preferably formed from a thermoset composition such as polybutadiene. The multi-layered cores and covers have selective specific gravity relationships between the different layers. This helps provide the ball with good flight distance and spin control. The resulting balls have good resiliency and other playing performance properties.

A golf ball is provided that achieves a satisfactory distance on full shots with an iron, is superior in the short game, and has a good feel at impact and a good durability. The golf ball has a core formed of a rubber composition as one or more layer, an envelope layer formed of a resin material as one or more layer, an intermediate layer formed of a resin material as one layer, and a cover formed of a resin material as one layer having a thickness of not more than 1.0 mm. The layers of the ball have Shore C hardnesses at the respective surfaces thereof which together satisfy certain conditions, and the core and the ball have respective deflections which satisfy certain other conditions.

A golf ball is provided that achieves a satisfactory distance on full shots with a driver and an iron, is superior in the short game, and has a good feel at impact and a good durability. The golf ball has a core formed of a rubber composition as one or more layer, an inner envelope layer formed of a resin material as one or more layer, an outer envelope layer and intermediate layer which are each formed of a resin material as one layer, and a cover formed of a resin material as one layer having a thickness of not more than 1.0 mm. The inner envelope layer-encased sphere, outer envelope layer-encased sphere, intermediate layer-encased sphere and ball have Shore C hardnesses at the respective surfaces thereof which together satisfy certain conditions, and the ball has at least a given deflection under specific loading conditions.

A golf ball includes a single core having an outer surface and a geometric center. The core is formed from a substantially homogenous rubber composition. An inner cover layer is disposed about the core, the inner cover including a high-acid ionomer and having a material hardness of about 66 to 75 Shore D. The high-acid ionomer has an acid content of about 16% or greater. An outer cover layer is disposed about the inner cover layer, the outer cover including a polyurethane and having a material hardness of about 38 Shore D to about 56 Shore D. The core surface hardness is from 0 Shore C to 15 Shore C lower than the geometric center hardness to define a hardness gradient.

A golf ball includes a core and a three-layer cover disposed adjacent the core. The three-layer cover includes an inner cover, an intermediate cover, and an outer cover. The inner cover includes a non-ionomeric E/Y copolymer where E is an olefin and Y is a carboxylic acid. The inner cover has a hardness of about 45 to 68 Shore D. The outer cover includes a castable thermoset polyurethane and has a hardness of about 40 to 62 Shore D. The intermediate cover layer, disposed between the inner and outer cover layers, is formed from a polyamide composition, where the polyamide composition includes a transparent polyamide having a light transmission of about 50% or greater.

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises at least one intermediate core layer formed from a metallic, composite, or inorganic/organic hybrid composition.

In a multi-piece solid golf ball having a core, an intermediate layer encasing the core and a cover which encases the intermediate layer and has numerous dimples on an outside surface thereof, the intermediate layer is formed of a resin material, the cover is formed of a urethane resin material, the core has a diameter of at least 38.0 mm, the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of at least 3.9 mm, the core has a center and a surface such that the value obtained by subtracting the JIS-C hardness at the core center from the JIS-C hardness at the core surface is at least 15, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and the (intermediate layer thickness)/(core diameter) value is from 0.025 to 0.043, the (cover thickness)/(core diameter) value is from 0.014 to 0.027.