In a golf ball having a core and a cover of one or a plurality of layers that encases the core, the core or at least one layer of the cover is formed of a resin composition which contains from 5 to 250 parts by weight of a mechanoluminescent material that receives mechanical energy and luminesces per 100 parts by weight of a base material which is a rubber material or a resin material. This golf ball has an excellent visibility in that, even under dark conditions, the ball impact site can be clearly confirmed visually at the time of impact. Moreover, the ball is able to maintain a good scuff resistance.

A golf ball 2 includes a spherical core 4, an inner mid layer 6 positioned outside the core 4, an outer mid layer 8 positioned outside the inner mid layer 6, a reinforcing layer 10 positioned outside the outer mid layer 8, and a cover 12 positioned outside the reinforcing layer 10. When distances (%) from a central point of the core 4 to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core 4 to a surface of the core 4 at intervals of 12.5% of a radius of the core 4, are plotted in a graph, R.sup.2 of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95.

Buoyant dimpled golf ball having CoR ≥0.810, specific gravity <1.00 g/cc, initial velocity ≥250 ft/s, first aerodynamic coefficient magnitude between about 0.25 and about 0.30 and first aerodynamic force angle between about 29 degrees and 34 degrees at Reynolds Number of 230000 and spin ratio of 0.085; and second aerodynamic coefficient magnitude between about 0.26 and about 0.31 and second aerodynamic force angle between about 31 degrees and 36 degrees at Reynolds Number of 180000 and spin ratio of 0.101. Golf ball may additionally have third aerodynamic coefficient magnitude between about 0.27 and about 0.32 and third aerodynamic force angle between about 34 degrees and 39 degrees at Reynolds Number of 133000 and spin ratio of 0.133; and fourth aerodynamic coefficient magnitude between about 0.33 and about 0.38 and fourth aerodynamic force angle between about 38 degrees and 43 degrees at Reynolds Number of 89000 and spin ratio of 0.183.

In a method and related system of the invention, each golf ball component is progressed while being coated, without contacting another surface until after curing, and without the margin for error created in prior systems/methods using physical or air stream up-take supports. In one embodiment, a method of the invention comprises the steps of: progressing a golf ball component within an enclosed chamber for a controlled duration of time; at least partially covering the golf ball component with a coating material while the ball is progressed within the enclosed chamber; and at least partially curing the coating material on golf ball component in the chamber. The golf ball component may be in a state of free fall while progressed within the enclosed chamber, and in some embodiments, also during the step of curing the coating material on the golf ball component.

A light-emitting golf ball using a small generator includes a core that is a center point of the golf ball; an inner shell formed to surround the core; an outer shell formed to surround an outer surface of the inner shell and struck by a golf club; a generator positioned on one side of the inner shell and generating a current based on a rotational force caused by a stroke; and a light emitting portion located on one side of the inner shell and providing light so that the golf ball emits light based on the generated current. According to the present disclosure, the golf ball emits light, and thus it is easy to track a trajectory of the golf ball. In addition, it is possible to more easily determine the trajectory and position of the golf ball when the day is cloudy or enters the night.

Golf balls having a single or dual-layered solid core are provided. In one embodiment, the golf ball has dimensions and properties that do not conform to the rules of the United States Golf Association (USGA). For example, the ball weight; ball size; ball spherical symmetry; ball initial velocity; and/or ball overall distance may fall outside of the USGA standards. The dual-layered core can have an inner core comprising a thermoplastic composition and surrounding outer core comprising a thermoset composition. In another embodiment, the dual-layered core has an inner core comprising a thermoplastic composition and outer core comprising a thermoset composition. The thermoplastic composition preferably comprises an ethylene acid copolymer ionomer and plasticizer. The thermoset composition preferably comprises polybutadiene rubber. The ball further includes a cover of at least one layer.

Provided are novel cross-linked polymers and their use in various materials, including packaging films and injection molded articles. These polymers, which comprise certain hydroxyl-containing crosslinking compounds, as well as optionally adjuvants, show improved creep resistance when compared to conventional ethylene acrylic or methacrylic acid copolymers and their ionomers.

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

The present invention relates to a golf ball stamp, and more particularly to, a stamp, which can reduce manufacturing costs due to its simple structure and store ink inside, is easy and convenient to replace the rubber plate that prints a mark on a golf ball, and can print a mark clearly on the rough golf ball surface.

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