Provided are a golf ball and a resin composition for a cover or topcoat thereof which can suppress the yellowing of the golf ball caused by ultraviolet rays even if a naturally derived substance is used as an ultraviolet absorber, and they are environmentally and human friendly. A resin composition for a cover or topcoat of a golf ball of the present invention contains: a resin for a cover or topcoat; and a plant-derived extract which absorbs ultraviolet rays. The resin composition has a color difference ΔE of 10.0 or less in a Lab color system between before and after a color tone change test, the color tone change test being carried out by irradiating a film formed from the resin composition with a xenon lamp. In the golf ball of the present invention, the cover or the topcoat is formed by using the resin composition.

Provided are a golf ball which has a surface that sparkles when exposed to ultraviolet rays even if a naturally derived substance is used as a fluorescent material, and it is environmentally and human friendly, and a resin composition for a cover or a topcoat therefor. A resin composition for a cover or a topcoat of a golf ball of the present invention includes: a resin for a cover or a topcoat; and a plant-derived or alga-derived extract which emits light using an absorbed light as an energy source, as a fluorescent material. In the golf ball of the present invention, the cover or the topcoat is formed by using such a resin composition.

A golf ball of the present invention includes a core and a cover located outside the core and having a plurality of dimples on a surface thereof A bottom of each of the dimples has a curved shape protruding toward an outside of the golf ball. A depth d of a center protruding portion of the bottom of the dimple is a perpendicular distance between a line S connecting both ends of an outer periphery of the dimple and a highest point of the protruding portion. A volume occupation ratio VR of the dimple is less than 0.75. A relationship between Shore D hardness H of a material of the cover and the depth d (unit: mm) satisfies the following Formula 1:

(H-83)/(−300)>d   (Formula 1).

A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The main body 4 includes a spherical core 8, a mid layer 10 positioned outside the core 8, and a cover 12 positioned outside the mid layer 10. An indentation depth, measured when the paint layer 6 in a cross-section along a plane passing through a central point of the golf ball 2 is pressed by a force of 30 mgf in a direction perpendicular to the cross-section, is not less than 300 nm and not greater than 3000 nm. The paint layer 6 preferably has a thickness of not less than 5 μm and not greater than 50 μm.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

A thermoplastic polyurethane composition includes a first elastomer, a second elastomer, and a third elastomer. The first elastomer includes a first material and a plurality of fiber elements. The second elastomer includes a second material. The third elastomer includes a third material and an additive. Each of the first, second, and third materials is one of polyester-based thermoplastic polyurethane, polyether-based thermoplastic polyurethane, polycarbonate-based thermoplastic polyurethane, or combinations thereof. A golf ball and a method for making the golf ball are also provided herein.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

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 composed of at least one layer and formed on a surface of the golf ball body, wherein a base resin constituting an outermost layer of the paint film is a polyurethane obtained by a reaction between (A) a polyol composition and (B) a polyisocyanate composition, and a loss modulus (E″) at the temperature of −50° C. obtained by measuring a dynamic viscoelasticity of the polyurethane is 1.00×10.sup.8 Pa or more.