An object of the present invention is to provide a novel golf ball having excellent spin performance on approach shots. The present invention provides a golf ball comprising a golf ball body, and a paint film formed on a surface of the golf ball body and composed of at least one layer, wherein a base resin constituting an outermost layer of the paint film includes a polyurethane, and the polyurethane has a loss elastic modulus (E″) of 0.2×10.sup.8 Pa or more at −50° C. and a loss tangent (tan δ) having a peak temperature of 0° C. or less, obtained by measuring dynamic viscoelasticity of the polyurethane under specific conditions.

A description is provided herein of an apparatus comprising a golf ball having embedded electronic components that can measure how far said ball has rolled and its velocity during a putt across a putting surface. Elements of the ball fabrication are described which allow light to be transmitted to interrogation devices which respond depending on the orientation of the ball relative to external light sources. A correlation of light received at various parts of the ball provide an event signal which is interpreted by an on-board processor. Determination of current distance and speed is continuously calculated during the roll of the putted ball. Data is relayed to a secondary device capable of displaying the information to a golfer during putting practice sessions. This will help the golfer to train how hard to hit a putt so that it will roll a known distance.

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 golf ball comprising layers that have from 0.05% to 70% by weight of a radio-opaque filler, and wherein the concentration of the radio-opaque filler is measurably different in each layer is disclosed herein. The radio-opaque filler is preferably a compound based on barium, bismuth, tungsten, iodine, or reduced iron.

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 according to the present invention comprises: a core having a diameter of 37-39 mm and a first density; a mantle which surrounds the core, includes amorphous alloy powder, and has a thickness of 0.8-1.2 mm and a second density; and a cover which surrounds the mantle and has a thickness of 1-1.4 mm and a third density.

It has been found that carboxylic acid functionalized high cis-1,4-polybutadiene rubber which is comprised of polybutadiene rubber chains having a cis-1,4-microstructure content of at least 90 percent has much better interaction with metal salts of α,β-ethylenically unsaturated carboxylic acids, such as zinc diacrylate or zinc dimethacrylate. This results in such rubber compositions being stiff while still exhibiting a lower level of hysteresis. These characteristics are beneficial when used in manufacturing tire apex compositions, in manufacturing golf ball cores, and in a wide variety of other applications. Such rubber compositions can be used as substitutes for thermoplastic elastomers in many applications.

Golf ball having a generally spherical surface and comprising a plurality of dimples separated by a land area formed on the ball surface, wherein the plurality of dimples includes at least one non-spherical dimple having a non-axially symmetric plan shape and a defined point of maximum dimple depth, wherein: (i) each dimple cross-section of the non-spherical dimple consists of two arcs, each arc extending from the defined point of maximum dimple depth to a point at the land area of the golf ball; and (ii) every point on the perimeter of the non-spherical dimple is located at a radial angle, θ, about a unit circle, where 0≤θ≤2π, and the edge angle value of the non-spherical dimple at any given point on the perimeter is defined by the solution of an edge angle function f(θ), wherein f(θ) is a non-periodic, continuous, differentiable function.

Golf ball comprising a core, an outer layer and at least one adhesion promoting coating disposed between each of the core and the outer layer; the core comprising a rubber composition comprising at least one zinc-containing and/or magnesium-containing component; the outer layer comprising at least one ionomer; and the adhesion promoting coating comprising a waterborne dispersion comprised of at least one ethylene acid copolymer having an acid content of at least 15% by weight wherein the copolymer is at least partially neutralized with one or more neutralizing agent; wherein at least one neutralizing agent is selected from ammonia compounds and/or amine compounds. In a specific embodiment, the at least one neutralizing agent comprises i) mono and/or divalent metal compounds and ii) ammonia compounds and/or amine compounds.

The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.