GOLF BALL HAVING COLOR-SHIFT EFFECT

Abstract

A golf ball has a core, a cover layer, and a color-shift material incorporated into at least one of the cover layer or a coating applied to the cover layer. The golf ball also has an alignment indicator that provides an intended target strike location on the golf ball. The color-shift material causes the golf ball to exhibit a localized color-shift effect upon application of pressure in the form of a strike by a golf club. The color-shift effect comprises a shift between a first color and a second color and measured as a deltaE of greater than 2 when the change of pressure is within a target range. The color-shift material and the alignment indicator provide feedback regarding an actual strike location relative to the intended target strike location.

Claims

1. A golf ball comprising: a core; a cover layer; a color-shift material incorporated into at least one of the cover layer or a coating applied to the cover layer; and an alignment indicator that provides an intended target strike location on the golf ball; wherein the color-shift material causes the golf ball to exhibit a localized color-shift effect upon application of pressure in the form of a strike by a golf club, wherein the color-shift effect comprises a shift between a first color and a second color and measured as a deltaE of greater than 2 when the change of pressure is within a target range, and wherein the color-shift material and the alignment indicator provide feedback regarding an actual strike location relative to the intended target strike location.

2. The golf ball of claim 1, wherein the alignment indicator is a pattern of ink or paint applied to a layer of the golf ball.

3. The golf ball of claim 1, wherein the alignment indicator maintains its appearance before and after the strike by the golf club.

4. The golf ball of claim 1, wherein the alignment indicator comprises the color-shift material.

5. The golf ball of claim 1, wherein the color-shift effect is reversible.

6. The golf ball of claim 5, wherein the color-shift effect reverses after about a threshold amount of time, wherein the threshold amount of time is greater than 1 minute.

7. The golf ball of claim 1, wherein color-shift material is configured to shift between more than two colors.

8. The golf ball of claim 7, wherein the second color depends on the change in pressure as applied by the strike by a golf club.

9. The golf ball of claim 1, wherein the color-shift material comprises a chromogenic material.

10. The golf ball of claim 1, wherein the shift between the first color and the second color includes a deltaE of greater than 5 when the change of pressure is within a target range.

11. The golf ball of claim 10, wherein the shift between the first color and the second color includes a deltaE of greater than 20 when the change of pressure is within a target range.

12. A golf ball comprising: a core; a cover layer; a color-shift material incorporated into at least one of the cover layer or a coating applied to the cover layer; and wherein the color-shift material causes the golf ball to exhibit a localized color-shift effect upon application of pressure in the form of a strike by a golf club, wherein the color-shift effect comprises a shift between a first color and a second color and measured as a deltaE of greater than 2 when the change of pressure is within a target range, and wherein color-shift material is configured to shift between more than two colors.

13. The golf ball of claim 12, wherein the color-shift depends on the change in pressure as applied by the strike by a golf club.

14. The golf ball of claim 13, wherein the color-shift provides feedback regarding a club head speed of the golf club.

15. The golf ball of claim 12, wherein the color-shift effect is reversible.

16. The golf ball of claim 12, wherein each color of the more than two colors is the result of a color shift between a first color and a second color and measured as a deltaE of greater than 5 when the change of pressure is within a target range.

17. The golf ball of claim 12, wherein each color of the more than two colors is the result of a color shift between a first color and a second color and measured as a deltaE of greater than 20 when the change of pressure is within a target range.

18. The golf ball of claim 12, wherein the color-shift material is configured to shift to any of plurality of colors in a color scale, depending on a club head speed of a golf club striking the golf ball.

19. The golf ball of claim 12, wherein the second color comprises a plurality of colors such that the color-shift effect produces a color gradient appearance.

20. The golf ball of claim 12, wherein the color-shift material comprises a chromogenic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The foregoing and other aspects of the present disclosure are best understood from the following detailed description when read in connection with the accompanying drawings. For the purpose of illustrating the disclosure, there are shown in the drawings embodiments that are presently preferred, it being understood, however, that the disclosure is not limited to the specific instrumentalities disclosed. Included in the drawings are the following Figures:

[0009] FIG. 1 is a cross-sectional view of a two-piece golf ball in accordance with an embodiment of the present disclosure;

[0010] FIG. 2 is a cross-sectional view of a three-piece golf ball in accordance with an embodiment of the present disclosure;

[0011] FIG. 3 is a cross-sectional view of a four-piece golf ball in accordance with an embodiment of the present disclosure;

[0012] FIG. 4 is a cross-sectional view of a five-piece golf ball in accordance with an embodiment of the present disclosure;

[0013] FIG. 5 is a view of a golf ball having a color-shift material in accordance with an embodiment of the present disclosure;

[0014] FIG. 6 is a view of the golf ball of FIG. 5 after a color-shift effect has occurred;

[0015] FIG. 7 is a view of a golf ball having a color-shift material in accordance with another embodiment of the present disclosure;

[0016] FIG. 8 is a view of the golf ball of FIG. 7 after a color-shift effect has occurred;

[0017] FIG. 9 is a view of a golf ball having a color-shift material in accordance with another embodiment of the present disclosure;

[0018] FIG. 10 is a view of the golf ball of FIG. 9 after a color-shift effect has occurred;

[0019] FIG. 11 is a view of a golf ball having a color-shift material in accordance with another embodiment of the present disclosure;

[0020] FIG. 12 is a view of the golf ball of FIG. 11 after a color-shift effect has occurred;

[0021] FIG. 13 is a view of a golf ball having a color-shift material in accordance with another embodiment of the present disclosure;

[0022] FIG. 14 is a view of the golf ball of FIG. 13 after a first color-shift effect has occurred;

[0023] FIG. 15 is a view of the golf ball of FIG. 13 after a second color-shift effect has occurred;

[0024] FIG. 16 is a view of the golf ball of FIG. 13 after a third color-shift effect has occurred;

[0025] FIG. 17 is a view of a golf ball having a color-shift material in accordance with another embodiment of the present disclosure;

[0026] FIG. 18 is a view of a face of a golf club having a color-shift material in accordance with an embodiment of the present disclosure;

[0027] FIG. 19 is a view of the face of a golf club of FIG. 18 after a first color-shift effect has occurred; and

[0028] FIG. 20 is a view of the face of a golf club of FIG. 19 after a second color-shift effect has occurred.

DETAILED DESCRIPTION OF THE INVENTION

[0029] The present disclosure generally relates to golf equipment containing color-shift materials. Disclosed golf equipment may include color-shift materials to provide a feedback response to a golfer. For example, disclosed golf balls or golf clubs may include at least one layer having a color-shift material that changes color based on an impact between a golf club and a golf ball. In at least some embodiments, the color-shift effect is reversible. In some embodiments, the golf equipment includes alignment markings to be observed and used in relation to the color-shift material.

[0030] The color-shift layer of the golf equipment may be configured to transition between two or more colors. In some embodiments, the color-shift layer reversibly changes between two colors. The reversal of the color change may occur over time, a length of which may be calibrated to be best suited to a particular application. In some embodiments, the color-shift layer changes between a plurality of colors, with the color shift being dependent on an input level. For example, a color-shift layer may be calibrated such that the various possible color changes each correspond to a different mechanical force such that the color change can be translated into a golf parameter (i.e., club head speed).

[0031] Disclosed color-shift golf equipment may include color-shift material incorporated into one or more layers. For example, a color-shift material may be incorporated into a layer of a golf ball or an outer face of a golf club. In some golf ball embodiments, the color-shift material may be incorporated into one or more layers that are visible to an observer. For example, the color-shift material may be incorporated into a cover layer or a coating of the golf ball. In other embodiments, the color-shift material may incorporated into a core or intermediate layer. Example materials and constructions for golf ball embodiments are described next, followed by further details for embodiments of other golf equipment (i.e., golf clubs).

Golf Ball EmbodimentsCover Layer

[0032] Golf balls consistent with the present disclosure include an outer cover layer. The outer cover layer includes at least one cover material. The cover material may be a thermoset polyurethane, a cast urethane, or an ionomer material.

[0033] In one embodiment, the cover is formed from a polyurethane, polyurea, or hybrid of polyurethane-polyurea. When used as cover layer materials, polyurethanes and polyureas can be thermoset or thermoplastic. Thermoset materials can be formed into golf ball layers by conventional casting or reaction injection molding techniques. Thermoplastic materials can be formed into golf ball layers by conventional compression or injection molding techniques.

[0034] In one example, the outer cover layer may be made of a thermoplastic polyurethane composition. In general, polyurethanes contain urethane linkages formed by reacting an isocyanate group (NCO) with a hydroxyl group (OH). The polyurethanes are produced by the reaction of a multi-functional isocyanate (NCORNCO) with a long-chain polyol having terminal hydroxyl groups (OHOH) in the presence of a catalyst and other additives. The chain length of the polyurethane prepolymer is extended by reacting it with short-chain diols (OHROH). The resulting polyurethane has elastomeric properties because of its hard and soft segments, which are covalently bonded together. This phase separation occurs because the mainly non-polar, low melting soft segments are incompatible with the polar, high melting hard segments. The hard segments, which are formed by the reaction of the diisocyanate and low molecular weight chain-extending diol, are relatively stiff and immobile. The soft segments, which are formed by the reaction of the diisocyanate and long chain diol, are relatively flexible and mobile. Because the hard segments are covalently coupled to the soft segments, they inhibit plastic flow of the polymer chains, thus creating elastomeric resiliency.

[0035] By the term, isocyanate compound as used herein, it is meant any aliphatic or aromatic isocyanate containing two or more isocyanate functional groups. The isocyanate compounds can be monomers or monomeric units, because they can be polymerized to produce polymeric isocyanates containing two or more monomeric isocyanate repeat units. The isocyanate compound may have any suitable backbone chain structure including saturated or unsaturated, and linear, branched, or cyclic. These isocyanate compounds also can be referred to as polyisocyanates or multi-functional isocyanates. By the term, polyamine as used herein, it is meant any aliphatic or aromatic compound containing two or more primary or secondary amine functional groups. The polyamine compound may have any suitable backbone chain structure including saturated or unsaturated, and linear, branched, or cyclic. The term polyamine may be used interchangeably with amine-terminated component. These polyamines also can be referred to as amine compounds or multi-functional amines. By the term, polyol as used herein, it is meant any aliphatic or aromatic compound containing two or more hydroxyl functional groups. The term polyol may be used interchangeably with hydroxy-terminated component. By the term, polyimine compound, it is meant it is meant any aliphatic or aromatic compound containing two or more imine functional groups. These polyimines also can be referred to as imine compounds or multi-functional imines.

[0036] Thermoplastic polyurethanes have minimal cross-linking; any bonding in the polymer network is primarily through hydrogen bonding or other physical mechanism. Because of their lower level of cross-linking, thermoplastic polyurethanes are relatively flexible. The cross-linking bonds in thermoplastic polyurethanes can be reversibly broken by increasing temperature such as during molding or extrusion. That is, the thermoplastic material softens when exposed to heat and returns to its original condition when cooled. On the other hand, thermoset polyurethanes become irreversibly set when they are cured. The cross-linking bonds are irreversibly set and are not broken when exposed to heat. Thus, thermoset polyurethanes, which typically have a high level of cross-linking, are relatively rigid.

[0037] Commercially-available examples of suitable thermoplastic polyurethanes that can be used in accordance with this disclosure include TPUs sold under the tradenames of Texin 250, Texin 255, Texin 260, Texin 270, Texin950U, Texin 970U, Texin1049, Texin990DP7-1191, Texin DP7-1202, Texin990R, Texin993, TexinDP7-1049, Texin 3203, Texin 4203, Texin 4206, Texin 4210, Texin 4215, and Texin 3215, each commercially available from Covestro LLC, Pittsburgh PA; Estane 50 DT3, Estane58212, Estane55DT3, Estane58887, EstaneEZ14-23A, EstaneETE 50DT3, each commercially available from Lubrizol Company of Cleveland, Ohio; and ElastollanWY1149, Elastollan1154D53, Elastollan1180A, Elastollan1190A, Elastollan1195A, Elastollan1185AW, Elastollan1175AW, each commercially available from BASF; Desmopan 453, commercially available from Bayer of Pittsburgh, PA, and the E-Series TPUs, such as D 60 E 4024 commercially available from Huntsman Polyurethanes of Germany.

[0038] Aromatic polyurethanes can be prepared in accordance with this disclosure and these materials are preferably formed by reacting an aromatic diisocyanate with a polyol. Suitable aromatic diisocyanates that may be used in accordance with this disclosure include, for example, toluene 2,4-diisocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4-methylene diphenyl diisocyanate (MDI), 2,4-methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (PMDI), p-phenylene diisocyanate (PPDI), m-phenylene diisocyanate (PDI), naphthalene 1,5-diisocyanate (NDI), naphthalene 2,4-diisocyanate (NDI), p-xylene diisocyanate (XDI), and homopolymers and copolymers and blends thereof. The aromatic isocyanates are able to react with the hydroxyl or amine compounds and form a durable and tough polymer having a high melting point. The resulting polyurethane generally has good mechanical strength and cut/shear-resistance.

[0039] Aliphatic polyurethanes also can be prepared in accordance with this disclosure and these materials are preferably formed by reacting an aliphatic diisocyanate with a polyol. Suitable aliphatic diisocyanates that may be used in accordance with this disclosure include, for example, isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), 4,4-dicyclohexylmethane diisocyanate (H.sub.12 MDI), meta-tetramethylxylyene diisocyanate (TMXDI), trans-cyclohexane diisocyanate (CHDI), and homopolymers and copolymers and blends thereof. Particularly suitable multi-functional isocyanates include trimers of HDI or H.sub.12 MDI, oligomers, or other derivatives thereof. The resulting polyurethane generally has good light and thermal stability.

[0040] Any polyol available to one of ordinary skill in the art is suitable for use according to the disclosure. Exemplary polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadiene (including partially/fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In one embodiment, the polyol includes polyether polyol. Examples include, but are not limited to, polytetramethylene ether glycol (PTMEG), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups.

[0041] In another embodiment, polyester polyols are included in the polyurethane material. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly(hexamethylene adipate) glycol; and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In still another embodiment, polycaprolactone polyols are included in the materials of the disclosure. Suitable polycaprolactone polyols include, but are not limited to: 1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylol propane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In yet another embodiment, polycarbonate polyols are included in the polyurethane material of the disclosure. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly(hexamethylene carbonate) glycol. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In one embodiment, the molecular weight of the polyol is from about 200 to about 4000.

[0042] There are two basic techniques that can be used to make the polyurethanes: a) one-shot technique, and b) prepolymer technique. In the one-shot technique, the diisocyanate, polyol, and hydroxyl-terminated chain-extender (curing agent) are reacted in one step. On the other hand, the prepolymer technique involves a first reaction between the diisocyanate and polyol compounds to produce a polyurethane prepolymer, and a subsequent reaction between the prepolymer and hydroxyl-terminated chain-extender. As a result of the reaction between the isocyanate and polyol compounds, there will be some unreacted NCO groups in the polyurethane prepolymer. The prepolymer should have less than 14% unreacted NCO groups. Preferably, the prepolymer has no greater than 8.5% unreacted NCO groups, more preferably from 2.5% to 8%, and most preferably from 5.0% to 8.0% unreacted NCO groups. As the weight percent of unreacted isocyanate groups increases, the hardness of the composition also generally increases.

[0043] Either the one-shot or prepolymer method may be employed to produce the polyurethane compositions of the disclosure. In one embodiment, the one-shot method is used, wherein the isocyanate compound is added to a reaction vessel and then a curative mixture comprising the polyol and curing agent is added to the reaction vessel. The components are mixed together so that the molar ratio of isocyanate groups to hydroxyl groups is preferably in the range of about 1.00:1.00 to about 1.10:1.00. In a second embodiment, the prepolymer method is used. In general, the prepolymer technique provides better control of the chemical reaction. The prepolymer method provides a more homogeneous mixture resulting in a more consistent polymer composition. The one-shot method results in a mixture that is inhomogeneous (more random) and affords the manufacturer less control over the molecular structure of the resultant composition.

[0044] The polyurethane compositions can be formed by chain-extending the polyurethane prepolymer with a single chain-extender or blend of chain-extenders as described further below. As discussed above, the polyurethane prepolymer can be chain-extended by reacting it with a single chain-extender or blend of chain-extenders. In general, the prepolymer can be reacted with hydroxyl-terminated curing agents, amine-terminated curing agents, and mixtures thereof. The curing agents extend the chain length of the prepolymer and build-up its molecular weight. In general, thermoplastic polyurethane compositions are typically formed by reacting the isocyanate blend and polyols at a 1:1 stoichiometric ratio. Thermoset compositions, on the other hand, are cross-linked polymers and are typically produced from the reaction of the isocyanate blend and polyols at normally a 1.05:1 stoichiometric ratio.

[0045] A catalyst may be employed to promote the reaction between the isocyanate and polyol compounds for producing the prepolymer or between prepolymer and chain-extender during the chain-extending step. Preferably, the catalyst is added to the reactants before producing the prepolymer. Suitable catalysts include, but are not limited to, bismuth catalyst; zinc octoate; stannous octoate; tin catalysts such as bis-butyltin dilaurate, bis-butyltin diacetate, stannous octoate; tin (II) chloride, tin (IV) chloride, bis-butyltin dimethoxide, dimethyl-bis[1-oxonedecyl)oxy]stannane, di-n-octyltin bis-isooctyl mercaptoacetate; amine catalysts such as triethylenediamine, triethylamine, and tributylamine; organic acids such as oleic acid and acetic acid; delayed catalysts; and mixtures thereof. The catalyst is preferably added in an amount sufficient to catalyze the reaction of the components in the reactive mixture. In one embodiment, the catalyst is present in an amount from about 0.001 percent to about 1 percent, and preferably 0.1 to 0.5 percent, by weight of the composition.

[0046] The hydroxyl chain-extending (curing) agents are preferably selected from the group consisting of ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; 2-methyl-1,3-propanediol; 2-methyl-1,4-butanediol; monoethanolamine; diethanolamine; triethanolamine; monoisopropanolamine; diisopropanolamine; dipropylene glycol; polypropylene glycol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol; 2,3-dimethyl-2,3-butanediol; trimethylolpropane; cyclohexyldimethylol; triisopropanolamine; N,N,N,N-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene glycol bis-(aminopropyl) ether; 1,5-pentanediol; 1,6-hexanediol; 1,3-bis-(2-hydroxyethoxy) cyclohexane; 1,4-cyclohexyldimethylol; 1,3-bis-[2-(2-hydroxyethoxy) ethoxy]cyclohexane; 1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy]ethoxy}cyclohexane; trimethylolpropane; polytetramethylene ether glycol (PTMEG), preferably having a molecular weight from about 250 to about 3900; and mixtures thereof.

[0047] Suitable amine chain-extending (curing) agents that can be used in chain-extending the polyurethane prepolymer include, but are not limited to, unsaturated diamines such as 4,4-diamino-diphenylmethane (i.e., 4,4-methylene-dianiline or MDA), m-phenylenediamine, p-phenylenediamine, 1,2- or 1,4-bis(sec-butylamino)benzene, 3,5-diethyl-(2,4- or 2,6-) toluenediamine or DETDA, 3,5-dimethylthio-(2,4- or 2,6-)toluenediamine, 3,5-diethylthio-(2,4- or 2,6-)toluenediamine, 3,3-dimethyl-4,4-diamino-diphenylmethane, 3,3-diethyl-5,5-dimethyl 4,4-diamino-diphenylmethane (i.e., 4,4-methylene-bis(2-ethyl-6-methyl-benezeneamine)), 3,3-dichloro-4,4-diamino-diphenylmethane (i.e., 4,4-methylene-bis(2-chloroaniline) or MOCA), 3,3,5,5-tetraethyl-4,4-diamino-diphenylmethane (i.e., 4,4-methylene-bis(2,6-diethylaniline), 2,2-dichloro-3,3,5,5-tetraethyl-4,4-diamino-diphenylmethane (i.e., 4,4-methylene-bis(3-chloro-2,6-diethyleneaniline) or MCDEA), 3,3-diethyl-5,5-dichloro-4,4-diamino-diphenylmethane, or MDEA), 3,3-dichloro-2,2,6,6-tetraethyl-4,4-diamino-diphenylmethane, 3,3-dichloro-4,4-diamino-diphenylmethane, 4,4-methylene-bis(2,3-dichloroaniline) (i.e., 2,2,3,3-tetrachloro-4,4-diamino-diphenylmethane or MDCA); and mixtures thereof. One particularly suitable amine-terminated chain-extending agent is Ethacure 300 (dimethylthiotoluenediamine or a mixture of 2,6-diamino-3,5-dimethylthiotoluene and 2,4-diamino-3,5-dimethylthiotoluene.) The amine curing agents used as chain extenders normally have a cyclic structure and a low molecular weight (250 or less).

[0048] When the polyurethane prepolymer is reacted with hydroxyl-terminated curing agents during the chain-extending step, as described above, the resulting polyurethane composition contains urethane linkages. On the other hand, when the polyurethane prepolymer is reacted with amine-terminated curing agents during the chain-extending step, any excess isocyanate groups in the prepolymer will react with the amine groups in the curing agent. The resulting polyurethane composition contains urethane and urea linkages and may be referred to as a polyurethane/urea hybrid. The concentration of urethane and urea linkages in the hybrid composition may vary. In general, the hybrid composition may contain a mixture of about 10 to 90% urethane and about 90 to 10% urea linkages.

[0049] More particularly, when the polyurethane prepolymer is reacted with hydroxyl-terminated curing agents during the chain-extending step, as described above, the resulting composition is essentially a pure polyurethane composition containing urethane linkages having the following general structure:

##STR00001##

where x is the chain length, i.e., about 1 or greater, and R and R.sub.1 are straight chain or branched hydrocarbon chain having about 1 to about 20 carbons.

[0050] However, when the polyurethane prepolymer is reacted with an amine-terminated curing agent during the chain-extending step, any excess isocyanate groups in the prepolymer will react with the amine groups in the curing agent and create urea linkages having the following general structure:

##STR00002##

where x is the chain length, i.e., about 1 or greater, and R and R.sub.1 are straight chain or branched hydrocarbon chain having about 1 to about 20 carbons.

[0051] The polyurethane compositions used to form the cover layer may contain other polymer materials including, for example: aliphatic or aromatic polyurethanes, aliphatic or aromatic polyureas, aliphatic or aromatic polyurethane/urea hybrids, olefin-based copolymer ionomer compositions, polyethylene, including, for example, low density polyethylene, linear low density polyethylene, and high density polyethylene; polypropylene; rubber-toughened olefin polymers; acid copolymers, for example, poly(meth)acrylic acid, which do not become part of an ionomeric copolymer; plastomers; flexomers; styrene/butadiene/styrene block copolymers; styrene/ethylene-butylene/styrene block copolymers; dynamically vulcanized elastomers; copolymers of ethylene and vinyl acetates; copolymers of ethylene and methyl acrylates; polyvinyl chloride resins; polyamides, poly(amide-ester) elastomers, and graft copolymers of ionomer and polyamide including, for example, Pebax thermoplastic polyether block amides, available from Arkema Inc; cross-linked trans-polyisoprene and blends thereof; polyester-based thermoplastic elastomers, such as Hytrel, available from DuPont; polyurethane-based thermoplastic elastomers, such as Elastollan, available from BASF; polycarbonate/polyester blends such as Xylex, available from SABIC Innovative Plastics; maleic anhydride-grafted polymers such as Fusabond, available from DuPont; and mixtures of the foregoing materials.

[0052] In addition, the polyurethane compositions may contain fillers, additives, and other ingredients that do not detract from the properties of the final composition. These additional materials include, but are not limited to, catalysts, wetting agents, coloring agents, optical brighteners, cross-linking agents, whitening agents such as titanium dioxide and zinc oxide, ultraviolet (UV) light absorbers, hindered amine light stabilizers, defoaming agents, processing aids, surfactants, and other conventional additives. Other suitable additives include antioxidants, stabilizers, softening agents, plasticizers, including internal and external plasticizers, impact modifiers, foaming agents, density-adjusting fillers, reinforcing materials, compatibilizers, and the like. Some examples of useful fillers include zinc oxide, zinc sulfate, barium carbonate, barium sulfate, calcium oxide, calcium carbonate, clay, tungsten, tungsten carbide, silica, and mixtures thereof. Rubber regrind (recycled core material) and polymeric, ceramic, metal, and glass microspheres also may be used. Generally, the additives will be present in the composition in an amount between about 1 and about 70 weight percent based on total weight of the composition depending upon the desired properties.

Golf Ball EmbodimentsIntermediate Layers

[0053] In one embodiment, an intermediate layer is disposed between the single or multi-layered core and surrounding cover layer. These intermediate layers also can be referred to as casing or mantle or inner cover layers. The intermediate layer can be formed from any materials known in the art, including thermoplastic and thermosetting materials, but preferably is formed of an ionomer composition comprising an ethylene acid copolymer containing acid groups that are at least partially neutralized. Suitable ethylene acid copolymers that may be used to form the intermediate layers are generally referred to as copolymers of ethylene; C.sub.3 to C.sub.8 , -ethylenically unsaturated mono- or dicarboxylic acid; and optional softening monomer. These ethylene acid copolymer ionomers also can be used to form the inner core and outer core layers as described above. In other embodiments, these thermoplastic ionomer compositions can be used to make the golf ball cover.

[0054] Suitable ionomer compositions include partially-neutralized ionomers and highly-neutralized ionomers (HNPs), including ionomers formed from blends of two or more partially-neutralized ionomers, blends of two or more highly-neutralized ionomers, and blends of one or more partially-neutralized ionomers with one or more highly-neutralized ionomers. For purposes of the present disclosure, HNP refers to an acid copolymer after at least 70% of all acid groups present in the composition are neutralized. Ionomers are salts of O/X and O/X/Y-type acid copolymers, wherein O is an -olefin, X is a C.sub.3-C.sub.8 ,-ethylenically unsaturated carboxylic acid, and Y is a softening monomer. O is preferably selected from ethylene and propylene. X is preferably selected from methacrylic acid, acrylic acid, ethacrylic acid, crotonic acid, and itaconic acid. Methacrylic acid and acrylic acid are examples. Y is preferably selected from (meth) acrylate and alkyl (meth) acrylates wherein the alkyl groups have from 1 to 8 carbon atoms, including, but not limited to, n-butyl (meth) acrylate, isobutyl (meth) acrylate, methyl (meth) acrylate, and ethyl (meth) acrylate.

[0055] Some O/X and O/X/Y-type copolymers include, without limitation, ethylene acid copolymers, such as ethylene/(meth)acrylic acid, ethylene/(meth)acrylic acid/maleic anhydride, ethylene/(meth)acrylic acid/maleic acid mono-ester, ethylene/maleic acid, ethylene/maleic acid mono-ester, ethylene/(meth)acrylic acid/n-butyl (meth)acrylate, ethylene/(meth)acrylic acid/iso-butyl (meth)acrylate, ethylene/(meth)acrylic acid/methyl (meth)acrylate, ethylene/(meth)acrylic acid/ethyl (meth)acrylate terpolymers, and the like. The term, copolymer, as used herein, includes polymers having two types of monomers, those having three types of monomers, and those having more than three types of monomers. Some , -ethylenically unsaturated mono- or dicarboxylic acids are (meth) acrylic acid, ethacrylic acid, maleic acid, crotonic acid, fumaric acid, itaconic acid. As used herein, (meth) acrylic acid means methacrylic acid and/or acrylic acid. Likewise, (meth) acrylate means methacrylate and/or acrylate.

[0056] In one example, highly neutralized E/X- and E/X/Y-type acid copolymers, wherein E is ethylene, X is a C.sub.3-C.sub.8 ,-ethylenically unsaturated carboxylic acid, and Y is a softening monomer are used. X is preferably selected from methacrylic acid, acrylic acid, ethacrylic acid, crotonic acid, and itaconic acid. Y is preferably an acrylate selected from alkyl acrylates and aryl acrylates and preferably selected from (meth) acrylate and alkyl (meth) acrylates wherein the alkyl groups have from 1 to 8 carbon atoms, including, but not limited to, n-butyl (meth) acrylate, isobutyl (meth) acrylate, methyl (meth) acrylate, and ethyl (meth) acrylate. Example E/X/Y-type copolymers are those wherein X is (meth) acrylic acid and/or Y is selected from (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, methyl (meth) acrylate, and ethyl (meth) acrylate. Other example E/X/Y-type copolymers are ethylene/(meth) acrylic acid/n-butyl acrylate, ethylene/(meth) acrylic acid/methyl acrylate, and ethylene/(meth) acrylic acid/ethyl acrylate.

[0057] The amount of ethylene in the acid copolymer is typically at least 15 wt. %, preferably at least 25 wt. %, more preferably least 40 wt. %, and even more preferably at least 60 wt. %, based on total weight of the copolymer. The amount of C.sub.3 to C.sub.8 , -ethylenically unsaturated mono- or dicarboxylic acid in the acid copolymer is typically from 1 wt. % to 35 wt. %, preferably from 5 wt. % to 30 wt. %, more preferably from 5 wt. % to 25 wt. %, and even more preferably from 10 wt. % to 20 wt. %, based on total weight of the copolymer. The amount of optional softening comonomer in the acid copolymer is typically from 0 wt. % to 50 wt. %, preferably from 5 wt. % to 40 wt. %, more preferably from 10 wt. % to 35 wt. %, and even more preferably from 20 wt. % to 30 wt. %, based on total weight of the copolymer. Low acid and high acid ionomeric polymers, as well as blends of such ionomers, may be used. In general, low acid ionomers are considered to be those containing 16 wt. % or less of acid moieties, whereas high acid ionomers are considered to be those containing greater than 16 wt. % of acid moieties.

[0058] The various O/X, E/X, O/X/Y, and E/X/Y-type copolymers are at least partially neutralized with a cation source, optionally in the presence of a high molecular weight organic acid, such as those disclosed in U.S. Pat. No. 6,756,436, the entire disclosure of which is hereby incorporated herein by reference. The acid copolymer can be reacted with the optional high molecular weight organic acid and the cation source simultaneously, or prior to the addition of the cation source. Suitable cation sources include, but are not limited to, metal ion sources, such as compounds of alkali metals, alkaline earth metals, transition metals, and rare earth elements; ammonium salts and monoamine salts; and combinations thereof. Some cation sources are compounds of magnesium, sodium, potassium, cesium, calcium, barium, manganese, copper, zinc, lead, tin, aluminum, nickel, chromium, lithium, and rare earth metals.

[0059] Other suitable thermoplastic polymers that may be used to form the intermediate layer include, but are not limited to, the following polymers (including homopolymers, copolymers, and derivatives thereof: (a) polyester, particularly those modified with a compatibilizing group such as sulfonate or phosphonate, including modified poly(ethylene terephthalate), modified poly(butylene terephthalate), modified poly(propylene terephthalate), modified poly(trimethylene terephthalate), modified poly(ethylene naphthenate), and those disclosed in U.S. Pat. Nos. 6,353,050, 6,274,298, and 6,001,930, the entire disclosures of which are hereby incorporated herein by reference, and blends of two or more thereof; (b) polyamides, polyamide-ethers, and polyamide-esters, and those disclosed in U.S. Pat. Nos. 6,187,864, 6,001,930, and 5,981,654, the entire disclosures of which are hereby incorporated herein by reference, and blends of two or more thereof; (c) polyurethanes, polyureas, polyurethane-polyurea hybrids, and blends of two or more thereof; (d) fluoropolymers, such as those disclosed in U.S. Pat. Nos. 5,691,066, 6,747,110 and 7,009,002, the entire disclosures of which are hereby incorporated herein by reference, and blends of two or more thereof; (c) polystyrenes, such as poly(styrene-co-maleic anhydride), acrylonitrile-butadiene-styrene, poly(styrene sulfonate), polyethylene styrene, and blends of two or more thereof; (f) polyvinyl chlorides and grafted polyvinyl chlorides, and blends of two or more thereof; (g) polycarbonates, blends of polycarbonate/acrylonitrile-butadiene-styrene, blends of polycarbonate/polyurethane, blends of polycarbonate/polyester, and blends of two or more thereof; (h) polyethers, such as polyarylene ethers, polyphenylene oxides, block copolymers of alkenyl aromatics with vinyl aromatics and polyamicesters, and blends of two or more thereof; (i) polyimides, polyetherketones, polyamideimides, and blends of two or more thereof; and (j) polycarbonate/polyester copolymers and blends.

Golf Ball EmbodimentsCore Layer(s) and Overall Construction

[0060] The core layers for disclosed golf balls may be made using any suitable conventional technique such as, for example, compression or injection-molding. Typically, the cores are formed by compression molding a slug of uncured or lightly cured rubber material into a spherical structure. Prior to forming the cover layer, the core structure may be surface-treated to increase the adhesion between its outer surface and adjacent layer. Such surface-treatment may include mechanically or chemically-abrading the outer surface of the core. For example, the core may be subjected to corona-discharge, plasma-treatment, silane-dipping, or other treatment methods known to those in the art.

[0061] As discussed above, an inner cover layer or intermediate layer, preferably formed from an ethylene acid copolymer ionomer composition, can be formed between the core or ball sub-assembly and cover layer. The intermediate layer comprising the ionomer composition may be formed using a conventional technique such as, for example, compression or injection-molding. For example, the ionomer composition may be injection-molded or placed in a compression mold to produce half-shells. These shells are placed around the core in a compression mold, and the shells fuse together to form an intermediate layer. Alternatively, the ionomer composition is injection-molded directly onto the core using retractable pin injection-molding.

[0062] In one embodiment, a golf ball of the present disclosure is a one-piece ball where the core and cover form a single integral layer. In another version, shown in FIG. 1, a golf ball of the present disclosure is a two-piece ball 10 comprising a single core layer 12 and a single cover layer 14. As shown in FIG. 2, in one embodiment, the golf ball 20 comprises a core layer 22, an intermediate layer 24, and a cover layer 26. In FIG. 2, the intermediate layer 24 can be considered an outer core layer, an inner cover layer, a mantle or casing layer, or any other layer disposed between the core 22 and the cover layer 26. Referring to FIG. 3, in another embodiment, a four-piece golf ball 30 comprises an inner core layer 32, an outer core layer 34, an intermediate layer 36, and an outer cover layer 38. In FIG. 3, the intermediate layer 36 may be considered a casing or mantle layer, or inner cover layer, or any other layer disposed between the outer core layer 34 and the outer cover of the ball 38. Referring to FIG. 4, in another version, a five-piece golf ball 40 comprises a three-layered core having an inner core layer 42, an intermediate core layer 44, an outer core layer 46, an inner cover layer 48, and an outer cover layer 50. As exemplified herein, a golf ball in accordance with the present disclosure can comprise any combination of any number of core layers, intermediate layers, and cover layers. Furthermore, disclosed embodiments may be described as having one or more coatings. Coatings are typically applied to a cover layer of the golf ball and may be referred to herein as a coating or a coating layer. One of ordinary skill in the art would understand that a coating or coating layer is applied to an outermost layer of a golf ball and would not be considered a piece or layer of a golf ball for characterizing the golf ball as a 2, 3, 4, or 5-piece or layer ball. For example, the two-piece ball 10 would still be considered a two-piece or two-layer golf ball even if one or more additional coating layers were applied to the single cover layer 14.

[0063] The golf balls of this disclosure provide the ball with a variety of advantageous mechanical and playing performance properties as discussed further below. In general, the hardness, diameter, and thickness of the different ball layers may vary depending upon the desired ball construction. If the ball includes an intermediate layer or inner cover layer, the hardness (material) is about 50 Shore D or greater, more preferably about 55 Shore D or greater, and most preferably about 60 Shore D or greater. In one embodiment, the inner cover has a Shore D hardness of about 62 to about 90 Shore D. In one example, the inner cover has a hardness of about 68 Shore D or greater. In addition, the thickness of the inner cover layer is preferably about 0.015 inches to about 0.100 inches, more preferably about 0.020 inches to about 0.080 inches, and most preferably about 0.030 inches to about 0.050 inches.

[0064] The manufacturing methods and molds of this disclosure may be used to mold relatively thin outer covers, for example covers having a thickness of less than 0.075 inches, more preferably 0.050 inches and below, preferably 0.040 inches and below, more preferably 0.030 inches and below, and most preferably 0.025 inches and below.

[0065] More particularly, the outer cover preferably has a thickness within a range having a lower limit of about 0.004 or 0.010 or 0.020 or 0.030 or 0.040 inches and an upper limit of about 0.050 or 0.055 or 0.065 or 0.070 or 0.080 inches. Most preferably, the thickness of the outer cover is about 0.025 inches or less. The outer cover preferably has a surface hardness of 65 Shore D or less, or 55 Shore D or less, or 50 Shore D or less, or 50 Shore D or less, or 45 Shore D or less. Preferably, the outer cover has hardness in the range of about 20 to about 59 Shore D. In one example, the outer cover has hardness in the range of about 25 to about 55 Shore D.

[0066] The United States Golf Association (USGA) has set total weight limits for golf balls. Particularly, the USGA has established a maximum weight of 45.93 g (1.62 ounces) for golf balls. There is no lower weight limit. In addition, the USGA requires that golf balls used in competition have a diameter of at least 1.68 inches. There is no upper limit so many golf balls have an overall diameter falling within the range of about 1.68 to about 1.80 inches. The golf ball diameter is preferably about 1.68 to 1.74 inches, more preferably about 1.68 to 1.70 inches. In accordance with the present disclosure, the weight, diameter, and thickness of the core and cover layers may be adjusted, as needed, so the ball meets USGA specifications of a maximum weight of 1.62 ounces and a minimum diameter of at least 1.68 inches.

Color-Shift Material

[0067] Disclosed embodiments include a color-shift material in at least one layer. In some embodiments, a golf ball includes a chromogenic material, such as a chromogenic polymer. A chromogenic material is a material that exhibits a change in visible optical properties caused by an external stimulus. Chromogenic polymers include but are not limited to thermochromic polymers (external stimulus is temperature), mechanochromic or piezochromic polymers (external stimulus is pressure), electrochromic polymers (external stimulus is voltage), and photochromic polymers (external stimulus is light exposure). Disclosed embodiments include chromogenic cover compositions for golf balls and/or chromogenic coatings.

[0068] An embodiment of the present disclosure includes a coated or uncoated golf ball including a single- or dual-core and a cover layer formed from a chromogenic polymer. In another embodiment, a golf ball includes a cover layer and at least one coating applied to the cover layer, the coating layer including a chromogenic polymer.

[0069] Embodiments of the present disclosure may include a cover layer comprising a chromogenic polymer. The cover material, in addition to being characterized as a chromogenic polymer, may be a thermoset polyurethane, a cast urethane, or an ionomer material. The cover material may be configured to perform a color shift (i.e., exhibit a color-shift effect). In one example, the color shift may be characterized as a shift between opaque colors (e.g., white to black, yellow or orange to red, white to yellow, yellow to black, etc.). In another example, a cover material may be configured to perform a color shift between a transmissive state (transparent/translucent) and opaque (white, yellow, blue, etc.). In another example, a cover material may be configured to perform a color shift between a transmissive state (transparent/translucent) and another transmissive state (transparent/translucent). The term color shift includes a shift between states that may be characterized as having an absence of color (e.g., white, transparent, translucent white, etc.).

[0070] In another embodiment, a golf ball includes a coating layer containing a chromogenic polymer. The golf ball may further include a cover layer beneath the chromogenic coating layer. The cover layer may be white or non-white. The cover layer may be transparent, translucent, or opaque, independent of the chromogenic effect of the coating layer. The chromogenic coating layer may contribute to the appearance of the golf ball. The color-shift effect produced by the chromogenic coating may combine with the color and/or appearance of the underlying cover layer to produce a combined visual effect. For example, the chromogenic coating may color shift from a first color to a second color, that, combined with the underlying coating layer, produces a third color. The chromogenic coating layer may include an isocyanate. The chromogenic coating layer may produce a color shift upon application of an external stimulus, consistent with the disclosed embodiments.

[0071] A chromogenic polymer for use in a golf ball may be selected from one or more known chromogenic compositions. Examples of chromogenic materials are described in a publication entitled First example of non-toxic thermochromic polymer materialbased on a novel mechanism, by Seeboth et al., and a publication entitled Thermochromic PolymersFunction by Design, also by Seeboth et al., both of which are appended to this application and hereby incorporated by reference in their entirety.

[0072] Chromogenic polymers of the present disclosure may include one or more of the following chemical compositions that may contribute to a chromogenic effect: poly(lactic acid) (PLA); polystyrene (PS); poly(N-isopropylacrylamide) (PNIPAM); polyether; poly(ethylene terephthalate glycol); poly(ethylene terephthalate); poly(methyl methacrylate); poly(methylmethacrylate-co-butylmethacrylate); poly(butyl methacrylate); poly(ethylene-co-norbornene); poly(ethylene glycol) (PEG); poly(methylmethacrylate) (PMMA); poly(methacrylic acid); poly(ethylacrylate); poly(N,N-diethylacrylamide); poly[styrene-block-poly(methacrylic acid); poly(styrene-b-isoprene) (PS-b-PI); poly(dodecylglyceryl itaconate) (PDGI); poly(acrylamide) (PAAm); poly(acrylic acid) (PAAc); poly(p-methyl styrene) (PpMS); poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-PAAc); poly(N-isopropylacrylamide-co-glycidylmethacrylate) (PNIPAM-co-PGMA); poly(N,N-diethylacrylamide-co-N-ethylacrylamide-co-2-hydroxyethyl methacrylate; poly(N-isopropylacrylamide-co-acrylic acid); N,N-methylenebisacrylamide; poly(ethylene glycol) ethyl ether methacrylate; poly(ethylene glycol) methyl ether methacrylate; poly(benzylmethacrylate) (PBMA); 4-acryloylaminoazobenzene; N-isopropyl-acrylamide; Nafion (a perfluorosulfonate ion exchange polymer); safranin-O; phenolphthalein; methylene blue; borax; poly(1-vinyl-3-ethylimidazolium)bis-(trifluoromethanesulfonimide); N-isopropylacrylamide; glycidyl methacrylate; N,N-methylene-bis-acrylamide; cresol red-3-(N,N-dimethyl-N-dodecylammonio) propanesulfonate; 1,4-bis(-cyano-4-octadecyloxystyryl)-2,5-dimethoxybenzene (Cyano OPV I); 2-(4-[2-(4-ethoxy-phenyl)-vinyl]-phenyl)-3-(4-(2-(4-[2-(4-ethoxy-phenyl)-vinyl]-phenyl)-2-isocyano-vinyl)-2,5-bis-octyloxy-phenyl]-acrylonitrile (Cyano OPV II); 1,4-bis(-cyano-4-methoxystyryl)-benzene (Cyano OPV III); 4,4-bis(2-benzoxazolyl)stilbene (BBS); N,N-bis(2-(1-piperazino)ethyl]-3,4,9,10-perylenetetracarboxylic acid diimide dichloride (PZPER); N,N-bis-(R)-(1-phenylethyl)-perylene-3,4,9,10-tetracarboxyldiimide (R-Pery); anthocyanidin; cyanidin; pelargonidin chloride; cyanidin chloride; delphinidin chloride; dodecyl gallate; hexadecanoic acid; 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile.

[0073] In one embodiment, a golf ball layer may include a chromogenic polymer having the following chemical composition: PLA; cyanidin chloride; dodecyl gallate; and hexadecanoic acid.

[0074] An embodiment of the present disclosure includes a coated golf ball including a single or dual core and a cover layer formed from a chromogenic thermoplastic polyurethane. The TPU cover has a first polyurethane coating layer and a second polyurethane coating layer disposed about the first polyurethane coating layer. In an embodiment, the first polyurethane coating layer includes unreacted isocyanate groups and has an isocyanate index of at least about 120. The first polyurethane coating layer has an isocyanate index of at least about 150, possibly, at least about 200, and most at least about 250.

[0075] The first polyurethane coating layer typically includes an aliphatic isocyanate and/or an aromatic isocyanate. One preferred isocyanate may be 4,4-methylene diphenyl diisocyanate. If an aromatic and aliphatic isocyanate are present, the aromatic isocyanate and the aliphatic isocyanate are present in a ratio of about 2:1. The first and second polyurethane coating layers may be applied in a variety of manners know in the art, but are applied by spray-coating. In another preferred embodiment, the second polyurethane coating layer has an isocyanate index of less than about 96.

[0076] Another chromogenic polymer golf ball of the disclosure includes a core, a cover layer formed from a thermoplastic polyurethane, a first polyurethane coating layer including an aromatic isocyanate, and a second polyurethane coating layer disposed about the first polyurethane coating layer. The first polyurethane coating layer contains unreacted isocyanate groups and has an isocyanate index of at least about 120. The second polyurethane coating layer has an isocyanate index of less than about 96. The isocyanate comprises 4,4-methylene diphenyl diisocyanate, 2,4-methylene diphenyl diisocyanate, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 4,4-dicyclohexylmethane diisocyanate, p-phenylene diisocyanate, or isophorone diisocyanate. The first polyurethane coating layer may also be substantially free of aliphatic isocyanate.

[0077] Additional examples of color-shift materials include triaryl imidazole dimmers of Bis-2,4,5-triaryl imidazoles having one or more substituents groups selected from aryl groups such as phenyl, p-tolyl, p-chlorophenyl, p-anisyl; 1,3,3-trimethylspiro(indoline-2,3-[3H]naphtho [2,1-b] [1,4]oxazine; 2,2,4,4,5,5-hexaphenyl bisimidazole; 2,2,4,4,5,5-hexa-p-tolyl-bisimidazole; 2,2,4,4,5,5-hexa-p-chlorophenyl bisimidazole; 2,2-di-p-chlorophenyl-4,4, 5,5-tetraphenyl bisimidazole; 2,2-di-p-anisyl-4,4,5,5-tetraphenyl bisimidazole; 2,2-di-p-tolyl-4,4,5,5-tetraphenyl bisimidazole; 2-phenyl phenanthroimidazole dimers; bistetraaryl pyrrole; bistetra phenyl pyrrole; bianthrones; 2,2,4,4-tetramethyl bianthrone; xanthylidene anthrone; dixanthylene; helianthrone; mesonaphthobianthrone; anils; conjugated polymers; polysilenes; heterocyclic compounds; betaine derivatives such as pyridinium N-phenoxide betaine dyes; coordination compounds; metal cluster compounds; organometallic complexes of copper (II).

Color-Shift Effect

[0078] Disclosed embodiments include a color-shift material configured to exhibit a color-shift effect. A color-shift effect is a visual change in an appearance state of the golf ball. The visual change may be a change in color (e.g., hue, brightness, saturation, tint, etc.), or, in some embodiments, a change in opacity of a material that alters the appearance. The color-shift effect may be localized in that it occurs only or predominantly at a location on the surface of the golf ball where the golf club makes contact. The localized response enables visual identification of the strike made by the golf club. Some embodiments may include an alignment marking that identifies a target strike location such that the actual strike location can be assessed for accuracy relative to a desired outcome.

[0079] According to disclosed embodiments, a color-shift effect may be permanent, semi-permanent, or reversible. In embodiments in which the color-shift effect is reversible, the color-shift may be reversible over time or upon exposure to simulating conditions, such as heat, cooling, light, water, or the like. The color-shift effect may be automatically reversed after a threshold time, which may depend in part on the color-shift material. For example, the color-shift material may relax or cool at ambient temperature to return to an initial appearance state. In some embodiments, the reversal may occur after a short amount of time (e.g., less than 30 seconds, less than 1 minute, less than 2 4) so that the ball can be quickly reused in an indoor hitting environment (e.g., golf simulator). In other embodiments, the reversal may occur after a longer amount of time (e.g., more than 3 minutes, more than 5 minutes, more than 10 minutes) so that the ball retains the color shift long enough that a user can travel to a location of the golf ball after it has been hit in an outdoor hitting environment (e.g., on a golf course). In these embodiments, a material that returns to an original color after relaxation (e.g., of stress, elevated temperature) of the material that was stressed by the club impact may be selected.

[0080] According to a disclosed embodiment, a golf ball having at least one chromogenic polymer layer experiences a threshold color-shift effect upon application of an external stimulus within a target range. A threshold color-shift effect may be quantified using colorimetry. Colorimetry measurements may include, for example, spectral measurements (e.g., the appearance of a color through a light measurement), kinetic measurements (e.g., a determination of a halftime of color change in a manner known in the art), or other quality measurements. In some embodiments, colorimetry measurements may use a color coordinate system, such as those known in relation to the CIELAB color space (e.g., L*, a*, b*, C* and h, which measure lightness (L*), chroma (C*), hue angle from 0o to 360 (h), (a*) value (represents the degree of redness (positive a*) and greenness (negative a*) and (b*) value (represents the degree of yellowness (positive b*) and blueness (negative b*)). A change in color may be understood as a threshold deviation in a color coordinate (e.g., average deltas (change in) lightness (DeltaL*cmc), chroma (DeltaC*cmc), hue (deltaH*cmc) and distance between two colors (DeltaE*cmc) may be derived using color coordinate measurements. For example, a color-shift may be considered to exceed a threshold when a deltaE*cmc (referred to herein as deltaE) measurement exceeds a predetermined threshold. Colorimetry measurements on a golf ball may be made by using, for example, a Gretag Macbeth CE 7000A spectrophotometer under illuminant D65, with a 10 standard observer.

[0081] In disclosed embodiments, a golf ball may have a first appearance associated with first CIELAB coordinates (e.g., L.sub.1*, a.sub.1*, b.sub.1*, C.sub.1*, h.sub.1). As a result of a color-shift material and an associated color-shift effect, the golf ball may also include at least a portion that has a second color appearance associated with second CIELAB coordinates L.sub.2*, a.sub.2*, b.sub.2*, C.sub.2*, h.sub.2. A difference between the first appearance and the second appearance may be calculated as deltaE, which is determined using the CIELAB coordinates of the colors associated with the appearances (e.g., L.sub.1*, a.sub.1*, b.sub.1*, C.sub.1*, h.sub.1 and L.sub.2*, a.sub.2*, b.sub.2*, C.sub.2*, h.sub.2).

[0082] In some embodiments, a predetermined threshold color shift occurs when deltaE exceeds 2 (considered to be a color change perceptible at a glance). In other embodiments, a threshold color shift occurs when deltaE exceeds 10 (colors are clearly and quickly differentiated as observed). Other deltaE thresholds are possible, such as 3, 5, 20, or 50.

[0083] In some embodiments, a predetermined threshold for a color shift may depend on the type of external stimulus that causes the color shift. For example, a color shift threshold for a change based on temperature may be different than a color shift threshold for a change based on pressure. For each external stimulus, there is a target range for producing the threshold color shift. In other words, a golf ball including a chromogenic polymer layer exhibits a chromogenic effect when the golf ball experiences an external stimulus within a target range (for that stimulus) and, as a result, produces a color shift that exceeds a threshold for that target range. For example, a thermochromic polymer layer in a golf ball may exhibit a color shift if a change in temperature of 5 F. produces a deltaE color shift of at least 2. In another example, a mechanochromic polymer layer in a golf ball may exhibit a color shift if a change in pressure of 1 Bar produces a deltaE color shift of at least 10.

[0084] Disclosed embodiments may include color-shift effects that are localized to an area of a golf ball layer that receives an external stimulus. For example, upon application of pressure in the form of a strike of a golf club as a result of a golf swing, only a portion of the golf ball that is hit by the golf club may exhibit the color-shift effects. This effect may advantageously enable a golfer to observe the location that the golf ball was struck by the golf club. In other embodiments, the color-shift effect may spread to the entire chromogenic layer. For instance, a golfer may strike a golf ball, causing the entire golf ball to change colors. In another example, a golf ball may exhibit a color shift due to exposure to the sun (temperature and/or light), thereby making the golf ball more identifiable and/or findable during a round of play.

[0085] In another embodiment, a golf ball having a color-shift material is configured to produce a color gradient in response to the external stimulus, such as a strike by a golf club. The color gradient appears with greater intensity in a center area of impact that the surrounding region. These embodiments may provide a visualization of the quality of the strike with the golf club, enabling the golfer to identify glancing blows or off-center hits.

Examples

[0086] Golf equipment consistent with disclosed embodiments includes color-shift material (e.g., chromogenic materials) that produces color-shift effect(s). The color-shift effect(s) may enhance a performance parameter of the golf ball, such as identification, alignment, visibility, swing feedback, etc. For example, a golf ball including a color-shift material may exhibit a visible color change at a location of impact by a golf club, thereby providing a golfer with feedback on their swing and how the golf ball was struck. Some disclosed embodiments include golf balls and other golf equipment incorporating piezochromic and/or mechanochromic chromogenic materials as the color-shift material based on pressure applied by the contact between the ball and club. Other embodiments may include a thermochromic color-shift material, which changes color upon a golf club strike due to localized heating of the material (e.g., via friction, pressure, etc.) by the golf club.

[0087] FIG. 5 is an embodiment of a golf ball 100 including a color-shift material. The color-shift material may be incorporated into, for example, a cover layer and/or a coating of the golf ball 100 such that the color-shift material is visible to an observer (e.g., a golfer). According to a disclosed embodiment, the golf ball 100 is configured to transition between at least two visual appearances because of the color-shift material. FIG. 5 is an exemplary depiction of a first visual appearance, in which the golf ball has a generally uniform appearance in the region shown. The golf ball 100 has a generally uniform appearance as a first color. A generally uniform appearance includes a continuous and consistent single color, or shades or hues of a single color. Appearances in which repeated or consistent patterns of more than one color, shade, or hue may also be considered uniform (e.g., a checkerboard appearance). The generally uniform appearance may be broken up by other visual elements, such as printed elements (e.g., sidestamps, play numbers, nameplates, or other features described herein). In some embodiments, the golf ball 100 may be a generally lighter color or white as the first visual appearance.

[0088] FIG. 6 depicts the golf ball 100 exhibiting a second visual appearance after a color-shift effect has occurred. The golf ball 100 includes a color-shift area 102. The color-shift area 102 is a region within the area shown in FIG. 5 that has shifted in color as a result of an external stimulus, such as an object (e.g., a golf club) contacting that particular region of the golf ball 100. The color-shift area 102 may be a distinctly different appearance in comparison to the first appearance such that the color-shift area 102 is evident to an observer. For example, the color-shift area 102 may include a deltaE value of more than 2, more than 3, more than 5, more than 10, more than 20, or more than 50. For example, the color-shift effect shown in FIGS. 5-6 may be a color change from green to blue.

[0089] FIGS. 7 and 8 include a golf ball 110 that is similar to the golf ball 100, including an initial first appearance (FIG. 7) and a second appearance (FIG. 8) after a color-shift effect occurs as a result of an external stimulus (e.g., club strike). The golf ball 110 includes a first area 112 including a color-shift material and a second area 114 that does not include the color-shift material. The areas 112, 114 are portions of a surface of the golf ball 110. The color-shift material in the first area 112 is configured to shift in color as a result of being exposed to an external stimulus. FIG. 8 depicts an exemplary color-shift area 116 within the first area 112. The color-shift area 116 is a different color than the first area 112 (e.g., the entire first area 112 prior to the shift, as well as any unchanged area after the shift).

[0090] The golf ball 110 includes a first area 112 that covers 20-50% of a surface area of the golf ball, although other ranges are possible. The first area 112 is circular, but other shapes are contemplated by this disclosure. In an exemplary embodiment, the color shift effect within the first area 112 from a first color to a second color within the color-shift area 116 may include a deltaE value of more than 2, more than 3, more than 5, more than 10, more than 20, or more than 50. The color-shift effect in FIGS. 7-8 may be a color change from orange to blue. The second area 114, which does not include a color-shift material, may be a different third color, such as white or yellow.

[0091] The embodiment of FIGS. 7-8 depicts an example golf ball that includes a partial color-shift area on the surface, thereby providing an implied target area for a golfer to attempt to strike the golf ball. For example, the golf ball 110 may be placed in a position on the ground with the first area 112 facing a direction away from the intended shot target with an orientation. After the swing, the golfer is able to compare the color-shift area 116 to the first area 112 to determine how the actual strike location to the target strike location (i.e., determine whether the color-shift area 116 is centered within the first area 112). In this way, the first area 112 is an alignment indicator that provides context to a golf shot using the golf ball 110.

[0092] In some embodiments, a golf ball or other golf equipment may include an alignment indicator that is visible on a surface. For example, a golf ball may have a pad-stamped or inkjet-printed alignment indicator that is used to provide a target strike location that can be positioned such that a golfer attempts to make contact at a center of the alignment indicator. FIGS. 9-12 include examples of embodiments including alignment indicators in addition to color-shift materials. FIGS. 9 and 10 include a golf ball 120 having an alignment indicator 122 and FIGS. 11 and 12 include a golf ball 130 having an alignment indicator 132. The alignment indicator 122 is a crosshair shape and the alignment indicator 132 is a circle, although other shapes or patterns are possible (e.g., square, rectangle, bullseye, etc.). The alignment indicators 122, 132 may be pad printed using conventional ink on a surface of the golf balls 120, 130. The alignment indicators 122, 132 may comprise ink or paint that is not a color-shift material. In other embodiments, the alignment indicator may be a color-shift material.

[0093] The golf balls 120, 130 include a layer comprising a color-shift material that is visible to a user. For example, the golf balls 120, 130 may include a cover layer having a color-shift material that is configured to shift in color as a result of an external stimulus (e.g., contact with a golf club). The alignment indicators 122, 132 may be printed on top of the color-shifting cover layers such that the surface area of the ink or paint making up the alignment indicators 122, 132 covers the color-shift effect. FIG. 9 includes the golf ball 120 and the alignment indicator 122 and a color-shift area 124. The color-shift area 124 is generally centered relative to the alignment indicator 122, representing a close relationship between a target strike location and an actual location. FIG. 10, on the other hand, includes a color-shift area 126 that is off-center relative to the alignment indicator 122, representing an off-target strike when comparing the actual and target strike locations. FIGS. 11 and 12 similarly include a color-shift area 134 that indicates a centered strike and a color-shift area 136 that indicates an off-target strike.

[0094] Disclosed examples may include a color shift between a first color and a second color. Other embodiments of the present disclosure may include color-shift effects between more than two colors. For example, some embodiments may include a color shift between at least 3 colors, at least 4 colors, or at least 5 colors. The multi-color-shift effect may be implemented using a single color-shift material or multiple color-shift materials incorporated into a layer of a golf ball or other golf equipment (e.g., club face).

[0095] FIG. 13 includes a golf ball 140 including a color-shift material configured to exhibit a multi-color-shift effect. The golf ball 140 includes a surface 142, wherein a layer that makes up a visible portion of the surface 142 includes a color-shift material. The golf ball 140 in FIG. 13 includes a first appearance. In FIG. 13, the first appearance includes a generally uniform appearance as a white golf ball. Other first appearances (e.g., other initial colors) are also contemplated by this disclosure.

[0096] FIG. 14 depicts the golf ball 140 having a second appearance including a first color-shift area 144 as a result of a first color-shift effect. The first appearance and the second appearance may be similar to the appearances shown and described in relation to FIGS. 5 and 6. For example, the first color-shift may be exhibited based on contact with a golf club during a golf shot. FIG. 15 depicts the golf ball 140 having a third appearance including a second color-shift area 146 as a result of a second color shift effect. FIG. 16 depicts the golf ball 140 having a fourth appearance including a third color-shift area 148 as a result of a third color-shift effect. The second, third, and fourth appearances are all different colors relative to the color associated with the first appearance. The color of each different appearance may be different from each other color (or at least different from the initial color) by at deltaE value of more than 2, more than 3, more than 5, more than 10, more than 20, or more than 50. In at least some embodiments, each color-shift effect is reversible, such that the golf ball 140 is configured to return to the first appearance after a threshold amount of time has passed.

[0097] In an exemplary embodiment, the golf ball 140 is configured to shift from the first appearance directly to any of the second, third, or fourth appearances, depending on a parameter of the external stimulus applied to the golf ball 140. For example, the color-shift effect associated with the golf ball 140 may be dependent on a club head speed of a golf club that contacts the golf ball 140. In general, a faster club head speed will apply a greater force to the golf ball 140 than a slower club head speed (with the same club).

[0098] The color-shift material(s) present in a layer of the golf ball 140 may be tailored such that the color-shift effect is calibrated to different club head speed levels. For example, the first appearance may be associated with an appearance before the golf ball 140 is struck by a golf club. The second appearance may be associated with an appearance after the golf ball 140 is struck by a golf club with a club head speed range of 50-75 mph. The third appearance may be associated with an appearance after the golf ball 140 is struck with a golf club with a club head speed range of 75-100 mph. The fourth appearance may be associated with an appearance after the golf ball 140 is struck by a golf club with a club head speed range of 100-125 mph. As a result, the golf ball 140 provides feedback to a user about club head speed after a golf shot.

[0099] Other embodiments may include a plurality of possible appearances that depend on the club head speed of a golf club that strikes the golf ball. For example, a variety of colors (e.g., 5 or more, 10 or more, 15 or more) or a color scale (e.g., cool to warm color scale, grayscale, etc.) may be used as to translate a color-shift effect into a more precisely associated club head speed value or small range. For instance, in some embodiments, a user may hit the golf ball 140 with a golf club, view the subsequent color-shift effect, and use a calibration tool, such as a look-up table or software program, to translate the color-shift effect into a club head speed associated with the golf shot. As shown in FIGS. 14-16, the sizes of the color-shift areas 142, 144, 146 may be variable. In some embodiments, the size of the color-shift area may be used to further calculate a club head speed due to greater ball compression and more pressure applied to the surface of the golf ball.

[0100] Other embodiments may include golf balls having color-shift materials that exhibit a multi-color shift simultaneously. FIG. 17 is a golf ball 150 exhibiting a color-shift effect in a color-shift area 152 in the form of a color gradient that radiates from a center region to outer regions in a localized portion of the golf ball 150. The color-shift area 152 may be the result of a color-shift that occurs to transition directly from a generally uniform initial appearance (e.g., appearance shown in FIG. 13) to the appearance in FIG. 17. The color gradient appearance shown in FIG. 17 may be the result of a golf club strike as an external stimulus. The different colors of the color gradient may be a result of different force and/or pressure being applied to the golf ball at different areas at the moment of impact. The different colors within the color-shift area 152 provide helpful feedback regarding the golf swing. For example, the gradient shape may provide information regarding a club path or club face orientation. The golf ball 150 may include an alignment indicator (e.g., FIGS. 7-12) to further enable a comparison between a target strike and an actual strike with a golf club.

[0101] Disclosed embodiments are applicable to golf balls, but may also include other golf equipment, such as golf clubs. For example, a color-shift material may be incorporated into a material layer of a face of a golf club. FIG. 18 includes a golf club face 200. The golf club face 200 is shown as a driver face, but other embodiments may include the face of a wood, hybrid, iron, wedge, or putter. The color-shift material may be incorporated into an outer face layer (i.e., a metal or composite) layer of the club face 200. In other embodiments, the color-shift material may be incorporated into a coating material applied to the club face 200. In still other embodiments, the color-shift material may be incorporated into a tape or paper layer configured to be applied to the club face 200. The color-shift material of the golf club face 200 may be any of the color-shift materials (i.e., chromogenic materials) described in this disclosure. For example, the color-shift material of the club face 200 may be a piezochromic and/or mechanochromic material configured to exhibit a color-shift effect upon application of pressure to the club face 200.

[0102] FIG. 18 includes a first appearance of the club face 200. The first appearance is a generally uniform appearance (e.g., a single color or consistent pattern). FIG. 19 is a view of the club face 200 after a color-shift effect has occurred. The club face 200 includes a color-shift area 202. The color-shift area 202 includes a color that is different than the first appearance color by a deltaE value of more than 2, more than 3, more than 5, more than 10, more than 20, or more than 50. As a result, a user can clearly observe the location on the club face 200 where a golf ball was struck. This feedback is helpful to evaluating the effectiveness of a golfer's swing. In at least some embodiments, the color-shift effect is reversible, enabling the club face 200 to return to the first appearance after a threshold amount of time. The threshold amount of time may be set to be, for example, a short amount of time (e.g., 10 seconds, 20 seconds, 30 seconds, etc.) such that the user can observe the color shift and quickly use the golf club to take another golf swing that will exhibit a color-shift effect.

[0103] In some embodiments, the color-shift material of the club face 200 may be configured to color shift among a plurality of different colors. Similar to the golf ball 140, the color-shift effect of the club face 200 may be dependent on a parameter of the external stimulus, such as club head speed. A faster club head speed may result in a different color-shift effect than an otherwise slower club head speed. FIG. 20 includes a third appearance of the club face 200 with a second color-shift area 204 that is different than the color of the color-shift area 202 in FIG. 19. The color-shift effect may be calibrated such that a club head speed value or small range can be calculated based on an observed color-shift effect after a golf swing.

[0104] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art of this disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well known functions or constructions may not be described in detail for brevity or clarity.

[0105] The terms about and approximately shall generally mean an acceptable degree of error or variation for the quantity measured given the nature or precision of the measurements. Numerical quantities given in this description are approximate unless stated otherwise, meaning that the term about or approximately can be inferred when not expressly stated.

[0106] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms a, an and the are intended to include the plural forms as well (i.e., at least one of whatever the article modifies), unless the context clearly indicates otherwise.

[0107] The terms first, second, and the like are used to describe various features or elements, but these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the disclosure. Likewise, terms like top and bottom; front and back; and left and right are used to distinguish certain features or elements from each other, but it is expressly contemplated that a top could be a bottom, and vice versa.

[0108] The golf balls described and claimed herein are not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the disclosure. Any equivalent embodiments are intended to be within the scope of this disclosure. Indeed, various modifications of the device in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. All patents and patent applications cited in the foregoing text are expressly incorporated herein by reference in their entirety. Any section headings herein are provided only for consistency with the suggestions of 37 C.F.R. 1.77 or otherwise to provide organizational queues. These headings shall not limit or characterize the invention(s) set forth herein.