An object of the present invention is to provide a golf ball having a decreased spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) a compound represented by the formula (1) as a co-crosslinking agent, and (c) a crosslinking initiator,
(R.sup.1COO)M(OCOR.sup.2)m  (1) in the formula (1), M represents a metal atom, m represents 1 or 2, R.sup.1 and R.sup.2 are different from each other, represent an alkenyl group having 2 to 30 carbon atoms or an alkynyl group having 2 to 30 carbon atoms and have a carbon-carbon double bond or a carbon-carbon triple bond at an α-position carbon atom bonding to the carbonyl group, and when m is 2, two of R.sup.2 may be identical to or different from each other.

A cue ball used for practice and play in pool or billiards. The cue ball is made with a plurality of concentric sphere layers or shells starting with a centermost opaque ball, followed by two or three spheres of differently colored semi-transparent polymer resins; then an outermost clear layer of polymer.

A cue ball used for practice and play in pool or billiards. The cue ball is made with a plurality of concentric sphere layers or shells starting with a centermost opaque ball, followed by two or three spheres of differently colored semi-transparent polymer resins; then an outermost clear layer of polymer.

A lightweight spherical baseball like training ball has a hollow polyethylene plastic core adhered to a stitched white colored synthetic leather cover with a thin layer of adhesive. The lightweight ball has raised seams and measures in circumference similar to the ball circumference size mandated by Major League Baseball or softball rules whereby the ball is suitable for baseball and softball training and playing variations of the game of baseball or softball in confined areas.

A lightweight spherical baseball like training ball has a hollow polyethylene plastic core adhered to a stitched white colored synthetic leather cover with a thin layer of adhesive. The lightweight ball has raised seams and measures in circumference similar to the ball circumference size mandated by Major League Baseball or softball rules whereby the ball is suitable for baseball and softball training and playing variations of the game of baseball or softball in confined areas.

An object of the present invention is to provide a golf ball traveling a great distance on driver shots and on iron shots. The present invention provides a golf ball comprising a spherical core including an inner layer and an outer layer, and a cover, wherein a difference (H.sub.X+1−H.sub.X−1) between a hardness (H.sub.X+1) at a point outwardly away in a radial direction from a boundary between the inner layer and the outer layer of the spherical core by 1 mm and a hardness (H.sub.X−1) at a point inwardly away in the radial direction from the boundary between the inner layer and the outer layer of the spherical core by 1 mm is 0 or more in Shore C hardness, a surface hardness (H.sub.X+Y) of the spherical core is more than 65 in Shore C hardness, an angle α of a hardness gradient of the inner layer is 0° or more, a difference (α−β) between the angle α and an angle β of a hardness gradient of the outer layer is 0° or more, a thickness of the cover is 3 mm or less, a difference (Hc−H.sub.x+y) between a hardness (Hc) of the cover and the surface hardness (H.sub.X+Y) of the spherical core is 2 or more in Shore C hardness, and the cover has a highest hardness among the constituent members of the golf ball.

Multi-piece golf balls containing a multi-layered core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, an intermediate core layer, and a surrounding outer core layer. The layers of the core structure may have different hardness gradients. In one preferred embodiment, each core layer has a positive hardness gradient. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof. The intermediate core layer is preferably formed from a first thermoset composition such as polybutadiene rubber, and the outer core layer is preferably formed from a second thermoset composition. The resulting ball has high resiliency and good spin control.

A golf ball includes a core, a mid layer, and a cover. The core includes an inner core, a mid core, and an outer core. The mid layer includes an inner mid layer and an outer mid layer. A hardness H(C) is equal to or greater than a hardness H(B). A hardness H(E) is equal to or greater than a hardness H(D). An angle α is calculated by (Formula 1). An angle β is calculated by (Formula 2). The angle α is 0° or greater. A difference (α−β) is 0° or greater. A hardness Hm2 of the outer mid layer is greater than a hardness Hm1 of the inner mid layer.
α=(180°/π)*atan [{H(D)−H(C)}/Y]  (Formula 1)
β=(180°/π)*atan [{H(F)−H(E)}/Z]  (Formula 2)

A golf ball comprising a core comprising an inner core center and an outer core layer disposed over the inner core center. The inner core center has a deflection of greater than 0.210 inch under a load of 100 kilograms, and the entire the core has a deflection ranging from 0.130 inch to 0.105 inch under a load of 100 kilograms. A mantle layer is disposed over the core and a cover is disposed over the mantle.

Golf ball consisting of an inner part comprising at least an elastomeric polymer and a reinforcing agent comprising graphene nano-platelets in which at least 90% of the nano-platelets has a lateral size (x, y) from 50 to 50,000 nm and a thickness (z) from 0.34 to 45 nm, and a C/O ratio ≥100:1.