Golf balls and golf ball components made using three-dimensional (3D) additive manufacturing systems are provided. The golf ball includes at least one three-dimensional piece. Preferably, a continuous liquid interface printing method is used to make the three-dimensional structure. Ultraviolet (UV)-light polymerizable materials are used in the method. The method may be used to make single-piece or multi-piece balls. For example, the ball may include an inner core produced by the liquid interface printing method. An outer core layer may be disposed about the inner core, and a cover comprising inner and outer cover layers may encapsulate the core assembly to form the finished golf ball. The outer core and cover layers may be made using conventional molding technologies or the methods of this invention.

An object of the present invention is to provide a golf ball having excellent approach spin performance under a dry condition and excellent approach spin performance under a condition that there is grass between the golf ball and the club face. 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, wherein the paint film is composed of at least one layer, and an outermost paint film layer located at the outermost layer of the golf ball contains, as a base resin, a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition, (B) the polyol composition contains a urethane polyol as a polyol component, and the outermost paint film layer has a dynamic friction coefficient of from 0.65 to 1.2 measured with a dynamic friction tester under specific conditions.

An object of the present invention is to provide a golf ball having excellent approach spin performance under a dry condition and excellent approach spin performance under a condition that there is grass between the golf ball and the club face. 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, wherein the paint film is composed of at least one layer, and an outermost paint film layer located at the outermost layer of the golf ball contains, as a base resin, a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition, and the outermost paint film layer has a dynamic friction coefficient of from 0.75 to 1.5 measured with a dynamic friction tester under specific conditions.

An object of the present invention is to provide a golf ball having excellent resilience performance. The present invention provides a golf ball comprising a constituent member, wherein at least a part of the constituent member is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, wherein (d) the organic sulfur compound contains at least one member selected from the group consisting of a thiophenol having a halogenated sulfanyl group, a metal salt of a thiophenol having a halogenated sulfanyl group, and a diphenyl disulfide having a halogenated sulfanyl group.

An object of the present invention is to provide a golf ball comprising a paint film having improved abrasion resistance without substantially lowering the spin performance. 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, wherein the paint film contains a resin fine particle in an amount of less than 10 parts by mass with respect to 100 parts by mass of a base resin thereof, the base resin of the paint film is a polyurethane, and the resin fine particle contains a polyrotaxane component having a cyclodextrin, a linear molecule penetrating the cyclic structure of the cyclodextrin in a skewering manner, and a blocking group located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a OC.sub.3H.sub.6O group.

An object of the present invention is to provide a golf ball having excellent shot feeling and durability. The present invention provides a golf ball comprising a constituent member containing a crosslinked rubber component and resin fine particles, wherein the resin fine particles contain a polyrotaxane component having a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a OC.sub.3H.sub.6O group.

A golf ball paint composition includes primarily a urethane paint containing polyol as a base resin and polyisocyanate as a curing agent. The polyisocyanate includes two types of isocyanurate and adduct of hexamethylene diisocyanate and the golf ball paint composition has an elastic work recovery of at least 70%. The paint composition has a high self-repairing ability and is of high quality as a golf ball paint. Golf balls coated with this composition are able to maintain a good durability, in addition to which they have an excellent abrasion resistance and an excellent ball appearance.

A golf ball includes a main body and a paint layer positioned outside the main body. The paint layer includes an inner layer and an outer layer positioned outside the inner layer. When an indentation depth (nm) is measured on a cross-section along a plane passing through a central point of the golf ball when a force of 30 mgf is applied to the cross-section in a direction perpendicular to the cross-section, an indentation depth Di on a cross-section of the inner layer is smaller than an indentation depth Do on a cross-section of the outer layer. A thickness To of the outer layer is larger than a thickness Ti of the inner layer.

A golf ball paint composition includes primarily a urethane paint containing polyol as a base resin and polyisocyanate as a curing agent. Two types of polyester polyol are used as the polyol, and the composition has an elastic work recovery of at least 70%. The paint composition has a high self-repairing ability and is of high quality as a golf ball paint. Golf balls coated with this composition are able to maintain a good durability, in addition to which they have an excellent abrasion resistance and an excellent ball appearance.

In a resin composition for golf balls that includes, as a primary ingredient, a polyurethane or polyurea, letting P1 be the absorbance peak height near a wave number of 697 cm.sup.1 and P2 be the absorbance peak height near a wave number of 1512 cm.sup.1 in the infrared absorption spectrum of the composition measured by ATR/FT-IR spectroscopy, the ratio P1/P2 is from 0.03 to 2.10. When used as a cover material in golf balls having a core and a cover of one or more layer, the resin composition keeps the ball from flying too far on approach shots and also gives the ball a good controllability without sacrificing distance on shots with a driver.