JP2010274115A - Polyurea cover for golf balls based on alicyclic isocyanates - Google Patents

Abstract

A golf ball cover having excellent mechanical strength, cutting / shearing resistance, and light stability is realized.
A golf ball having a cover material made from a polyurea composition is realized. In one version, the golf ball 20 includes a polybutadiene core 22 and a cover layer 24 made from a polyurea composition. In other versions, the golf ball 20 includes a polybutadiene core 22, an intermediate casing layer made from an ionomer resin, and an outer cover layer 24 made from a polyurea composition. The polyurea composition is a reaction product of an alicyclic isocyanate and an amine compound. The diisocyanate is selected from 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, and mixtures thereof. The produced cover material is associated with many beneficial properties including improved durability, toughness, and light stability.
[Selection] Figure 1

Description

  The present invention generally relates to golf balls comprising cover materials made from polyurea compositions. More specifically, the polyurea composition is a reaction product of an alicyclic isocyanate, an amine-terminated compound, and an amine curing agent. The produced cover material has many advantages including improved durability, toughness, and light stability.

  Golf ball covers made from polyurethane and polyurea compositions are generally known in the art. In recent years, polyurethane and polyurea cover materials have become more popular because they impart the desired combination of “soft” and “hardness” to golf balls. The “hardness” of the golf ball cover protects the ball from tearing, wear and other damage. In addition, a hard cover ball generally reaches a higher speed when hit with a club. Therefore, such golf balls tend to travel a longer distance and are particularly important for driver shots from tees. On the other hand, the “softness” of a golf ball gives the player a better “feel” when the ball is hit with a club face. The player feels greater control over the ball when the club face collides. Softness allows the player to spin the ball and gives him better control of the flight pattern, which is important for approach shots.

  Basically, the polyurethane composition contains urethane bonds formed by reacting isocyanate groups (—N═C═O) with hydroxyl groups (OH). Polyurethanes are produced by reacting polyisocyanates with polyalcohols (polyols) in the presence of catalysts and other additives. The chain length of the polyurethane prepolymer is extended by reacting it with a hydroxyl-terminated hardener compound.

Polyurea compositions can also be produced, which are distinguished from the polyurethanes described above. In general, polyurea compositions contain urea linkages formed by reacting isocyanate groups (—N═C═O) with amine groups (NH or NH ₂ ). The chain length of the polyurea prepolymer is extended by reacting the prepolymer with an amine curing agent.

  Golf balls with polyurethane and polyurea covers are described in the patent literature. For example, U.S. Pat. No. 5,484,870 (Wu, U.S. Pat. No. 5,677,097) discloses a polyurea composition suitable for molding golf ball covers. The polyurea composition is a reaction product of an organic compound having at least two isocyanate functional groups and an amine curing agent. The molecular equivalent ratio of amine groups to isocyanate groups may vary within a wide range. Coloring agents, UV absorbers, plasticizers, and other additive materials may be included in the composition. U.S. Pat. No. 6,964,621 (Bulpett et al., US Pat. No. 5,677,097) discloses polyurea compositions that can be used in the construction of golf balls. These compositions are prepared from a polyurea prepolymer and a curing agent. According to the '621 patent, the resulting golf balls have improved cut and shear resistance.

  As discussed above, isocyanates with two or more functional groups are fundamental components in the production of polyurethanes and polyureas. Aromatic isocyanates are commonly used for several reasons, including high reactivity and cost benefits. Examples of aromatic isocyanates include, but are not limited to, toluene 2,4-diisocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4'-methylenediphenyl diisocyanate (MDI), 2,4'- Methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (PMDI), p-phenylene diisocyanate (PDI), m-phenylene diisocyanate (PDI), naphthalene 1,5-diisocyanate (NDI), naphthalene 2,40 diisocyanate (NDI) , P-xylene diisocyanate (XDI), and others. Aromatic isocyanates can react with hydroxyl or amine compounds to produce polymers that are durable, tough and have high melting points. The resulting polyurethane or polyurea generally has good mechanical strength and cut / shear resistance. However, one of the drawbacks of using aromatic isocyanates is that the polymer reaction products tend to have poor light stability and are susceptible to discoloration upon exposure to light, particularly ultraviolet (UV) radiation. Since aromatic isocyanates are used as reactants, some aromatic structures are found in the reaction products. UV light causes quinoidation of the benzene ring and causes yellow discoloration. For this reason, UV light stabilizers are added to the formulation, but the cover still exhibits a yellow appearance due to prolonged sunlight exposure. For this reason, golf balls are usually painted with white paint and covered with a transparent coating to protect the appearance of the ball.

  In the second approach, aliphatic isocyanate is used to form the prepolymer. Examples of aliphatic isocyanates include, but are not limited to, isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), and others. Although these aliphatic isocyanates provide polymers with good light stability, such polymers tend to have lower mechanical strength and cut / shear resistance.

  It is also known to use alicyclic isocyanates in polyurethane formulations. U.S. Patent Application Publication No. 2007/0265388 (Argyropoulos, U.S. Pat. No. 5,677,097) discloses a polyurethane dispersion prepared by reacting a polyisocyanate with a polyol. The alicyclic diisocyanate used to produce the polyurethane is (i) trans-1,4-bis (isocyanatomethyl) cyclohexane, or (ii) two or more cis-1,3-bis (isocyanatomethyl). ) Selected from isomeric mixtures of cyclohexane, trans-1,3-bis (isocyanatomethyl) cyclohexane, cis-1,4-bis (isocyanatomethyl) cyclohexane, and trans-1,4-bis (isocyanatomethyl) cyclohexane Is done. The isomer mixture contains at least about 5 weight percent trans-1,4-bis (isocyanatomethyl) cyclohexane. The '388 publication states that polyurethane dispersions can also be used in adhesive applications such as wood, fabric, plastic, metal, glass, fiber, medical ointment, automotive interior, leather, and even shoe soles, wood or glass. Disclosure.

  U.S. Patent Application Publication No. 2009/0105013 (Slagel et al., U.S. Pat. No. 6,057,097) discloses a polyurethane / polyurea hybrid that can be cured to form an outer layer and / or an inner layer of a golf ball. In one example, the prepolymer is a product of polycaprolactone glycol reacted with 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, or combinations thereof. The prepolymer may be cured using one or more isomers of diethyltoluenediamine as a curing agent. The '013 publication discloses the synthesis of pure polyurea compositions using reactants, 1,3-bis (isocyanatomethyl) cyclohexane, and / or 1,4-bis (isocyanatomethyl) cyclohexane. Not.

  There continues to be a need for polyurethane and polyurea golf ball cover materials with good mechanical strength and cut / shear resistance, as well as light stability. In particular, it would be beneficial to employ an isocyanate component that imparts such properties to the polymer. The present invention achieves such a golf ball cover material having excellent mechanical strength and cut / shear resistance, as well as light stability.

US Pat. No. 5,484,870 US Pat. No. 6,964,621 US Patent Application Publication No. 2007/0265388 US Patent Application Publication No. 2009/0105013

  The present invention provides a golf ball comprising a cover material made from a polyurea composition, which comprises 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, And reaction products of isocyanates, amine-terminated compounds, and amine curing agents selected from the group consisting of these and mixtures thereof. The resulting polyurea cover material has many advantages, including improved durability, toughness, cut / shear resistance, and light stability. In one version, the golf ball includes a polybutadiene core and an enveloping cover made from the polyurea composition. In another version, the golf ball includes a polybutadiene core, an intermediate casing layer made from an ionomer resin, and a soup outer cover layer made from polyurea and surrounding the casing layer. Golf balls made in accordance with the present invention may have a variety of structures. In one embodiment, the core diameter is about 1.26 to about 1.60 inches, the intermediate layer thickness is in the range of about 0.015 to about 0.120 inches, and the cover thickness is jy 0.020 inches to about 0.050 inches.

  The novel features that characterize the invention are set forth in the appended claims. However, the preferred embodiments of the present invention, together with other objects and attendant advantages, are best understood with reference to the following detailed description taken in conjunction with the accompanying drawings. The drawings are as follows.

1 is a cross-sectional view of a single layer, two piece golf ball having a polyurethane cover made in accordance with the present invention. FIG. 1 is a cross-sectional view of a single layer, two piece golf ball with a polyurea cover made in accordance with the present invention. FIG. 1 is a cross-sectional view of a multi-layered, three-piece golf ball having a polyurethane cover made in accordance with the present invention. 1 is a cross-sectional view of a multi-layered, three-piece golf ball having a polyurethane cover made in accordance with the present invention.

  The present invention relates generally to golf balls comprising cover materials made from polyurethane or hybrid polyurethane / polyurea or polyurea or hybrid polyurea / polyurethane compositions.

[Polyurethane composition]
Basically, the polyurethane composition contains urethane bonds formed by reacting isocyanate groups (—N═C═O) with hydroxyl groups (OH). Polyurethanes are produced by reacting polyisocyanates with polyalcohols (polyols) in the presence of catalysts and other additives. The chain length of the polyurethane prepolymer is extended by reacting it with a hydroxyl-terminated hardener compound. The produced polyurethane polymer has elastic properties based on phase separation of soft and hard segments. Soft segments are formed from polyols and are generally flexible and mobile, while hard segments are formed from isocyanates and chain extenders and are generally hard and non-mobile. The polyurethane composition contains a urethane bond of the general formula:

[Polyurethane / polyurea hybrid composition]
A polyurethane / polyurea hybrid composition is produced when a polyurethane prepolymer is chain extended with an amine-terminated curing agent. Any excess isocyanate groups in the prepolymer react with amine groups in the curing agent to form urea bonds. That is, a polyurethane / polyurea hybrid containing both urethane and urea linkages is produced. The isocyanate may react with the polyol prior to reaction with water, and the isocyanate may react with water prior to reaction with the polyol. Water reacts with isocyanate groups to produce carbamic acid. The relatively unstable carbamic acid then decomposes to form carbon dioxide and amine. The amine then reacts with the isocyanate group to form a urea bond.

[Polyurea composition]
In general, polyurea compositions contain urea linkages formed by reacting isocyanate groups (—N═C═O) with amine groups (NH or NH ₂ ). The chain length of the polyurea prepolymer is extended by reacting the prepolymer with an amine curing agent. The produced polyurea has elastic properties due to the soft and hard segments, which are covalently bonded to each other. Soft, amorphous, low-melting segments are formed from polyamines and are relatively soft and mobile, while hard, high-melting segments are formed from isocyanates and chain extenders and are relatively hard , Non-migrating. The polyurea composition contains urea linkages of the general formula:

[Polyurea / polyurethane hybrid composition]
A polyurea / polyurethane hybrid composition is produced when a polyurea prepolymer (described above) is chain extended with a hydroxyl-terminated curing agent. Any excess isocyanate groups in the prepolymer react with hydroxyl groups in the curing agent to form urethane bonds. That is, a polyurea / polyurethane hybrid is produced.

  In a preferred embodiment, a pure polyurea composition is prepared as described above. That is, the composition contains only urea bonds. An amine-terminated curing agent is used in the reaction to produce a pure polyurea composition. However, it should be noted that polyurea / polyurethane hybrid compositions can also be prepared according to the present invention as described above. Such a hybrid composition can be made if the polyurea prepolymer is cured with a hydroxyl-terminated curing agent. Any excess isocyanate in the polyurea prepolymer reacts with hydroxyl groups in the curing agent to form urethane bonds. The produced polyurea / polyurethane hybrid composition contains both urea and urethane linkages.

  More specifically, in one preferred version of the ball cover, the polymer matrix comprising the ball cover contains 100% by weight of the polyurea composition of the present invention. In other versions, the polymer matrix of the ball cover is a polyurea / polyurethane hybrid blend. The blend comprises from about 10 to about 90% by weight polyurea composition and from about 90% to about 10% polyurethane composition. In yet another embodiment, the polymer matrix constituting the ball cover comprises 100% by weight of the polyurethane composition of the present invention. A polymer matrix comprising a polyurea / polyurethane hybrid blend can also be prepared. The blend may comprise from about 10 to about 90% by weight polyurethane composition and from about 90% to about 10% polyurea composition. Alternatively, the ball cover may be made from a blend of about 10 to about 90% by weight of the polyurea composition and about 90% to about 10% of other polymers such as vinyl resins, polyesters, polyamides, and polyolefins. .

[Isocyanate compound]
As discussed above, the polyurea composition is an elastic material that is the reaction product of an isocyanate component and an amine-terminated polymer resin. Many isocyanate compounds are known in the art. Surprisingly, isocyanates selected from the group consisting of 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, and mixtures thereof have the most favorable properties for this invention. It was found to be imparted to the produced polyurea composition. The diisocyanate compound has the following general structure.

  It has been found that the isocyanate compounds of this invention react with amine-terminated compounds to produce polyureas with high mechanical strength and high integrity. Furthermore, this isocyanate compound realizes a polyurea composition with improved light stability. This isocyanate compound can realize a polymer having beneficial mechanical properties normally found in polymers produced using aromatic isocyanate compounds. At the same time, the polymer has good light stability, which is characteristic of polymers made using aliphatic isocyanates.

[Amine-terminated compounds]
In forming the urea prepolymer of this invention, any suitable amine-terminated compound may be reacted with the above-described isocyanate compounds according to this invention. Such amine-terminated compounds include, for example, amine-terminated hydrocarbons, amine-terminated polyethers, amine-terminated polyesters, amine-terminated polycarbonates, amine-terminated polycaprolactones, and mixtures thereof. The molecular weight of the amine terminated compound is generally in the range of about 100 to about 10,000. Suitable polyetheramines include, but are not limited to, methyldiethanolamine; polyoxyalkylene diamines such as polytetramethylene ether diamine, polyoxypropylene triamine, polyoxyethylene diamine, and polyoxypropylene diamine; poly (ethylene oxide capped oxypropylene ) Ether diamines; propylene oxide based triamines; triethylene glycol diamines; glycerin based triamines; and mixtures thereof. In one example, the polyetheramine used to produce the prepolymer is Jeffamine D2000 (Huntsman). Additional amine-terminated compounds are also useful in forming the polyurea prepolymers of this invention, which include, but are not limited to, poly (acrylonitrile-co-butadiene); liquid or wax solid form poly (1,4-butanediol) bis (4-aminobenzoate); linear or branched polyethyleneimine; low or high molecular weight polyethyleneimine with an average molecular weight of about 500 to about 30,000; poly with an average molecular weight of about 200 to about 5000 (Propylene glycol) bis (2-aminopropyl ether); polytetrahydrofuran bis (3-aminopropyl) terminated with an average molecular weight of about 200 to about 2000; and mixtures thereof (Aldrich Co). Preferably, the amine-terminated compound is a copolymer of polytetramethylene oxide and polypropylene oxide (Hutsman).

[Polyol compound]
When forming the polyurethane prepolymer, any polyol compound may be reacted with the above-described isocyanate compound according to the present invention. Examples of polyols are not limited to this,
Polyether polyols, hydroxyl-terminated polybutadiene (including partially or fully hydrogenated derivatives) polyester polyols, polycaprolactone polyols, and polycarbonate polyols. Particularly preferred are polytetramethylene ether glycol ("PTMEG"), polyethylene propylene glycol, polyoxypropylene glycol, and combinations thereof. The hydrocarbon chain has saturated or unsaturated bonds and may have substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of this invention comprises PTMEG. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol, polybutadiene adipate glycol, polyethylene propylene adipate glycol, ortho-phthalate-1,6-hexanediol, and combinations thereof. The hydrocarbon chain has saturated or unsaturated bonds and may have substituted or unsubstituted aromatic and cyclic groups. Polycaprolactone polyols include but are not limited to 1,6-hexanediol initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylolpropane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol initiated polycaprolactone, And combinations thereof. The hydrocarbon chain has saturated or unsaturated bonds and may have substituted or unsubstituted aromatic and cyclic groups. Suitable polycarbonates include polyphthalate carbonate. The hydrocarbon chain has saturated or unsaturated bonds and may have substituted or unsubstituted aromatic and cyclic groups.

[Manufacturing process]
There are two basic methods that can be employed to produce the polyurea composition of this invention: a) a one-shot method, and b) a prepolymer method. In the one-shot method, the isocyanate, amine-terminated compound, and amine-terminated curing agent are reacted in one step. On the other hand, in the prepolymer method, a first reaction is performed between an isocyanate and an amine-terminated compound to generate a polyurea prepolymer, and the next reaction is performed between the prepolymer and an amine-terminated curing agent. . As a result of the reaction between the isocyanate and the amine-terminated polycaprolactone, some unreacted NCO groups remain in the polyurea prepolymer. The prepolymer should contain less than 14% NCO groups. Preferably, the prepolymer is accompanied by no more than 8.5% unreacted NCO groups, more preferably from 2.5% to 8%, 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 generally increases. Although the polyurea composition of this invention can be produced using either a one-shot method or a prepolymer method, the prepolymer method is preferred because the prepolymer method can better control the chemical reaction. The prepolymer method results in a more uniform mixture resulting in a more consistent polymer composition. The one-shot method results in a non-uniform (more random) mixture and gives the manufacturer less control over the molecular structure of the product composition.

In the casting process, a polyurea composition can be produced by chain extending the polyurea prepolymer with a single curing agent or blend of curing agents as described below. The composition of this invention may be selected from both castable thermoplastic or thermoset materials. Thermoplastic polyureas are typically made by reacting isocyanate and amine-terminated compounds, each having two (or less) functional groups, in a 1: 1 stoichiometric ratio. For example, the prepolymer is cured with a second diamine to produce a non-crosslinked thermoplastic composition. On the other hand, thermosetting compositions are cross-linked polymers, typically made from the reaction of isocyanate and amine-terminated compounds, where each component comprises two (or more) functional groups, Usually, the theoretical amount ratio is 1.05: 1. For example, the prepolymer is cured with a first or second diamine to produce a crosslinked thermoset polyurea. In general, thermosetting polyurea compositions are easier to prepare than thermoplastic polyureas.

Suitable amine-terminated curing agents that can be employed to chain extend the polyurea prepolymers of this invention include, but are not limited to, unsaturated diamines such as 4,4′-diaminodiphenylmethane (ie, 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-diphenylmeta (Ie, 4,4′-methylene-bis (2-ethyl-6-methyl-benzeneamino), 3,3′-dichloro-4,4′-diaminodiphenylmethane (ie, 4,4′-methylene-bis (2 -Chloroaniline) or "MOCA"), 3,3'5,5'-tetraethyl-4,4'-diamino-diphenylmethane (ie 4,4'-methylene-bis (2,6-diethylaniline)), 2 2,2′-dichloro-3,3′5,5′-tetraethyl-4,4′-diamino-diphenylmethane (ie, 4,4′-methylene-bis (3-chloro-2,6-diethyleneaniline) or “MCDEA” "), 3,3'-diethyl-5,5'-dichloro-4,4'-diaminodiphenylmethane or" MDEA ", 3,3'-dichloro-2,2 ', 6,6'-tetraethyl-4, 4'- Amino-diphenylmethane, 3,3′-dichloro-4,4′-diamino-diphenylmethane, 4,4′-methylene-bis (2,3-dichloroaniline) (ie, 2,2 ′, 3,3′-tetra) Chloro-4,4′-diaminodiphenylmethane or “MDCA”, 4,4′-bis (sec-butylamino) -diphenylmethane, N, N′-dialkylamino-diphenylmethane, trimethylene glycol-di (p-aminobenzoate) Polyethylene glycol-di (p-aminobenzoate), polytetramethylene glycol-di (p-aminobenzoate); saturated amines such as ethylenediamine, 1,3-propylenediamine, 2-methyl-pentamethylenediamine, hexamethylenediamine 2,2,4- and 2,4,4-trimethyl- , 6-exandiamine, imino-bis (propylamine), imido-bis (propylamine), methylimino-bis (propylamine) (ie N- (3-aminopropyl) -N-methyl-1,3-propane) Diamine), 1,4-bis (3-aminoproxy) butane (ie 3,3 ′-[1,4-butanediylbis- (oxy) bis] -1-propanamine), diethylene glycol-bis (propylamine) (ie Diethylene glycol-di (aminopropyl) ether), 4,7,10-trioxatridecane-1,13-diamine, 1-methyl-2,6-diamino-cyclohexane, 1,4-diamino-cyclohexane, poly (oxy Ethylene-oxypropylene) diamine, 1,3- or 1,4-bis (methylamino) Cyclohexane, isophoronediamine, 1,2- or 1,4-bis (sec-butylamino) -cyclohexane, N, N′-diisopropyl-isophoronediamine, 4,4′-diamino-dicyclohexylmethane, 3,3′-dimethyl -4,4'-diamino-dicyclohexylmethane, 3,3'-diethyl-4,4'-diamino-dicyclohexylmethane, N, N'-dialkylamino-dicyclohexylmethane, polyoxyethylenediamine, 3,3'-diethyl- 5,5′-dimethyl-4,4′-diamino-dicyclohexylmethane, polyoxypropyldiamine, 3,3′-diethyl-5,5′-dichloro-4,4′-diamino-dicyclohexylmethane, polytetramethylene ether Diamine, 3,3 ′, 5,5′-tetraethyl-4,4′-diamino Dicyclohexylmethane (ie, 4,4′-methylene-bis (2,6-diethylaminocyclohexane)), 3,3′-dichloro-4,4′-diamino-dicyclohexylmethane, 2,2′-dichloro-3,3 ', 5,5'-tetraethyl-4,4'-diamino-dicyclohexylmethane, (ethylene oxide) -capped polyoxypropylene ether diamine, 2,2', 3,3'-tetrachloro-4,4'- Diamino-dicyclohexylmethane, 4,4′-bis (sec-butylamino) dicyclohexylmethane; triamines such as diethylenetriamine, dipropylenetriamine, (propylene oxide) based triamines (ie, polyoxypropylenetriamine), N- (2 -Aminoethyl-1,3-propylenediamine That is, N ₃ -amine), N- (aminopropyl) ethylenediamine, N- (aminopropylbutylenediamine, N- (aminoethyl) hexamethylenediamine, N- (aminopropyl) hexamethylenediamine, trimethylolpropane-based triamine Glycerin-based triamines (all saturated); tetraamines such as N, N′-bis (3-aminopropyl) ethylenediamine (ie, N ₄ amine), trimethylenetetraamine, (both saturated); and other polyamines For example, tetraethylenepentamine (saturated) is included. The amine curing agent used as a chain extender usually has a cyclic structure and has a low molecular weight (250 or less).

  As discussed above, in some cases it may be desirable to produce a polyurea / polyurethane hybrid composition. Under such circumstances, the curing agent employed in the reaction of the polyurea prepolymer may be selected from the group consisting of a hydroxyl-terminated curing agent and a mixture of amine-terminated and hydroxyl-terminated curing agents. Chain extenders or crosslinkers extend the prepolymer chain and increase its molecular weight.

  The hydroxyl terminated curing agent is preferably selected from the following group: The group consists of ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; 2-methyl-1,3-propanediol; 2-methyl-1,4-butanediol; monoethanolamine; diethanolamine; triethanolamine; 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; triisopropanol; N, N, N ′, N′-tetra- (2-hydroxylpropyl) -ethylenediamine; diethylene glycol bis- (a 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, preferably about 250 to about 3900. Having a molecular weight; and mixtures thereof.

  Additional materials known in the art may be added to the polyurea composition. These additional materials include, but are not limited to, catalysts, wetting agents, color formers, optical brighteners, crosslinking agents, whitening agents such as titanium dioxide and zinc oxide, ultraviolet (UV) light absorbers, hindered amine light. Includes stabilizers, defoamers, processing aids, surfactants, and other conventional additives. For example, a wetting additive may be added to disperse the pigment more efficiently. Antioxidants, stabilizers, softeners, plasticizers including internal and external plasticizers, impact modifiers, foaming agents, density adjusting fillers, tougheners, and compatibilizers are also well known in the art You may add only the quantity. Generally, additives are present in the composition in the range of about 1 to about 70 weight percent, based on the full charge of the composition, depending on the desired properties.

[Ball structure]
The polyurethane and polyurea cover materials of this invention can be employed in any type of ball structure known in the art. Such golf ball designs include, for example, single pieces, two pieces, three pieces, and four pieces. The core, intermediate casing, and cover may be single or multi-layer structures. Referring to FIG. 1, there is shown a multilayer (two-piece) golf ball (20) comprising a solid core (22) and a polyurethane cover (24) of the present invention. FIG. 1A shows another version of a multilayer (two-piece) golf ball (20a) comprising a solid core (22a) and a polyurethane cover (24a). 1 and 1A, the cover material (24, 24a) surrounds and encapsulates the core segments (22, 22a), respectively. 2 and 2A, a multi-layer (three-piece) golf ball (30, 30a) is shown. In FIG. 2, the ball (30) has a solid core (32), an intermediate layer (32), and a polyurethane cover (36). On the other hand, in FIG. 2A, the ball (30a) is manufactured with a polyurea cover (34). The ball (30a) of FIG. 2A includes a solid core (32a) and an enclosing intermediate casing layer (34a) made of ionomer.

[Core segment]
The core of a golf ball can be solid, quasi-solid, fluid filled, or hollow, and the core can be a single piece or multi-piece structure. As shown in FIGS. 1-2A, the cores (22, 22a, 32, and 32a) are solid structures. Wood materials known in the art may be employed in the manufacture of the core, and these materials are thermosetting compositions such as rubber, styrene butadiene, polybutadiene, isoprene, polyisoprene, transisoprene; thermoplastic compositions For example, ionomer resins, polyamides or polyesters; and thermoplastic and thermoset polyurethanes and polyurea elastomers. In one embodiment, the core is a single piece made from a natural or synthetic rubber composition, such as polybutadiene. More specifically, the material for the solid core is typically made from a composition comprising a base rubber, a filler, an initiator, and a crosslinker. The base rubber is usually natural or synthetic rubber, such as polybutadiene rubber. In one embodiment, the base rubber is 1,4-polybutadiene with at least 40% cis-structure. The polybutadiene may be blended with other elastomers such as natural rubber, polyisoprene rubber, styrene-butadiene rubber, and / or other polybutadiene. Another suitable rubber that can be employed in the core is trans-polybutadiene. The polybutadiene isomer is produced by converting the cis-isomer of polybutadiene to the trans-isomer in a molding cycle. Soft and fast agents such as pentachlorothiophenol (PCTP) or ZnPCTP may be blended into the polybutadiene. These compounds also act as cis-to-trans catalysts, and can convert cis-1,4 bonds in polybutadiene into trans bonds. The filler materials described above can be added to the core composition to modify specific gravity, density, hardness, weight, elasticity, elasticity, compression, and other properties. Note that a multi-piece core (not shown) can be constructed if desired. That is, there may be more than one core portion or piece. The inner core portion may be made from a first base rubber material and the outer core portion surrounding the inner core portion may be made from a second base rubber material. Each core piece may be made from the same or different rubber materials described above. Crosslinkers and fillers may be added to the rubber material that builds each core piece.

[Middle layer]
Referring to FIGS. 2 and 2A, the golf ball (30, 30a) may include an intermediate or casing layer (34, 34a) that is comprised of an inner core (32, 32a) and an outer cover (36, 36a). Positioned between. The lying intermediate layer (34, 34a) surrounds and wraps around the core (32, 32a). The intermediate layer may be made of any suitable material known in the art, including thermoplastic and thermoset materials. Suitable thermoplastic materials for producing the intermediate core layer include, but are not limited to, partially and fully neutralized ionomers, ionomer and polyamide graft copolymers, and the following non-ionomer polymers: Non-ionomers, including polymers and copolymers, and derivatives thereof compatible with at least one grafted or copolymerized functional group such as maleic anhydride, amine, epoxy, isocyanate, hydroxyl, sulfonate, phosphonate, etc. Polymers are polyesters; polyamides; polyamide-ethers and polyamide-esters; polyurethanes, polyureas, and polyurethane-polyurea hybrids; fluoropolymers; non-ionomeric acid polymers such as E / Y And E / X / Y-type copolymers, where E is an olefin (eg, ethylene), Y is a carboxylic acid, and X is a softening comonomer, eg, a vinyl estate of an aliphatic carboxylic acid, and an alkyl acrylate Metallocene catalyst polymers; polystyrene; polypropylene and polyethylene; polyvinyl chloride and grafted polyvinyl chloride; polyvinyl acetate; polycarbonates including polycarbonate / acrylonitrile-butadiene styrene blends, polycarbonate / polyurethane blends, and polycarbonate / polyester blends; polyvinyl alcohol; polyethers; A mixture of any two or more of polyimide, polyetherketone, polyamideimide; and the thermoplastic polymers described above Including things. Examples of commercially available thermoplastic materials suitable for forming the intermediate core layer include, but are not limited to, Pebax ™ thermoplastic polyether block amide, commercially available from Arkema Inc; (Trademark) ionomer resin, Hytre (TM) thermoplastic polyester elastomer, DuPont HPF 1000 and ionomer materials sold under the trademark HPG2000, all of which I. Commercially available from DuPont; Iotek ™ ionomer available commercially from ExxonMobil Chemical; ionomer of Amplify ™ IO ethylene acrylic acid copolymer commercially available from The Dow Chemical Company; A. Clarix ionomer resin commercially available from Schulman Inc; Elastollan ™ polyurethane blend-based thermoplastic elastomer commercially available from BASF; and Xylex ™ commercially available from SABIC Innovative Plastics. Contains a polycarbonate / polyester blend. The filler described above may be added to the intermediate layer composition to modify specific gravity, density, hardness, weight, elastic modulus, elasticity, compression, and other properties.

  The ionomeric resin may be blended with a nonionic thermoplastic resin. Suitable nonionic thermoplastic resins include, but are not limited to, polyurethanes, poly-ether-esters, poly-amide-ethers, poly-ether-ureas, thermoplastic polyether block amides (eg, commercially available from Arkema Inc. Pebax ™ block copolymer), styrene-butadiene-styrene block copolymer, styrene (ethylene-butylene) -styrene block copolymer, polyamide, polyester, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene- (Methacrylate) acrylate, polyethylene- (methacrylic acid) acrylic acid, polymers functionalized by maleic anhydride grafting; I. Including commercially available Fusbond ™ functionalized polymers from DuPont, epoxidized functionalized polymers, elastomers (eg, ethylene propylene diene monomer rubber, metallocene catalyzed polyolefins), and ground powders of thermoplastic elastomers.

  Although golf balls made in accordance with the present invention can be of any size, the USGA requires that the competition golf ball has a diameter of at least 1.68 inches and a weight of 1.62 ounces or less. In play other than USGA competition, the golf ball may be smaller in diameter or heavier. Preferably, the golf ball diameter ranges from about 1.68 to about 1.80 inches. The core diameter is generally in the range of about 1.26 to about 1.60 inches. In one embodiment, the diameter of the single piece core is about 1.57 inches. The hardness of the core varies depending on the desired characteristics of the ball. Generally, the hardness of the core ranges from about 30 to about 65 Shore D, more preferably from about 35 to about 60 Shore D. The compression of the core portion is generally in the range of about 70 to about 110, more preferably in the range of about 80 to about 100. As shown in FIGS. 1-2A, the core segment generally comprises a substantial portion of the ball, for example, the core may comprise at least 95% or more of the ball structure.

  FIGS. 2 and 2A each show a golf ball with an intermediate casing layer (34, 34a), and various materials can be employed, so the thickness range of the intermediate layer may vary. In general, however, the thickness of the intermediate layer is in the range of about 0.015 to about 0.120 inches, and preferably in the range of about 0.020 to about 0.060 inches. A plurality of intermediate layers may be disposed between the inner core and the outer cover. Preferably, the overall diameter of the core and all intermediate layers is from about 90 percent to about 98 percent of the overall diameter of the finished ball. As shown in FIGS. 1 and 2 and described above, the cover material (24, 36) is made from the polyurethane composition of the present invention. In FIGS. 1A and 2A, the cover material (24a, 36a) is made from the polyurea composition of this invention. With polyurethane and polyurea covers, good mechanical strength and durability are imparted to the ball along with play performance characteristics. The thickness of the cover layer can vary, but is generally in the range of about 0.015 to about 0.090 inches, preferably about 0.020 to about 0.050 inches, more preferably about 0.020 to about 0.035 inches.

  The golf ball of the present invention may include layers having the same or different hardness values. Surface hardness and material hardness are important properties considered in ball design and structure. Test methods for measuring surface hardness and material hardness are further described below. A uniform hardness may be employed across the various layers of the golf ball, and there may be a hardness gradient across each layer. For example, the hardness of the core may vary, but is generally in the range of about 30 to about 65 Shore D, more preferably in the range of about 35 to about 60 Shore D. The hardness of the intermediate layer of the present invention may also vary depending on the individual structure of the ball. In one embodiment, the intermediate layer has a hardness of about 30 to about 75 Shore D. As with the core and interlayer, the cover hardness may vary, but generally it is in the range of about 30-65 Shore D. In some examples, the core is contemplated to be softer than the intermediate layer. For example, the hardness of the core may be in the range of about 40 to about 55 Shore D and the hardness of the intermediate layer may be in the range of about 60 to 75 Shore D. Further, in some examples, it is contemplated that the outer cover layer is softer than the intermediate layer. Therefore, the intermediate layer has a hardness in the range of about 60 to about 75 Shore D, and the cover material has a hardness in the range of about 20 to about 55 Shore D.

  The golf ball of the present invention may be constructed using any suitable technique known in the art. These methods generally include compression molding, flip molding, injection molding, retractable pin injection molding, reactive injection molding (RIM), liquid injection molding (LIM), casting, vacuum forming, powder coating, flow coating. , Spin coating, dipping, spraying, etc.

  More specifically, the core of the golf ball may be formed using compression molding or injection molding. As mentioned above, suitable core materials are thermosetting materials such as rubber, styrene butadiene, polybutadiene, isoprene, polyisoprene, trans-isoprene, and thermoplastic materials such as ionomer resins, polyamides or polyesters. including. The intermediate layer may also be manufactured using known methods such as, for example, retractable pin injection molding or compression molding. The intermediate layer may be made from commercially available ionomer resins as described above.

  This intermediate casing layer is coated with a cover material using a reactive injection molding or casting process. In the casting process, a polyurea mixture is injected into the cavity of the upper molding member. This first molding opposition involves a hemispherical structure. Next, the corresponding cavity of the lower molding member is filled with the polyurea mixture. This second molded half also has a hemispherical structure. The cavity is typically preheated. The ball cup holds the golf ball (the core and the casing layer disposed on the upper side) by vacuum. After the polyurea mixture in the first molded half reaches a quasi-gel or gel state, the pressure is removed and the golf ball is lowered and moved into the upper molded half containing the polyurea mixture. Next, the first molded half is inverted and engaged with the second molded half containing the polyurea mixture, and this polyurea mixture is also in a quasi-gel or gel state. The polyurea mixture in the engaged molded member forms a golf ball cover. The engaged first and second molded halves containing the polyurea mixture and the golf ball center may then be heated so that the mixture hardens and hardens. Next, the golf ball is removed from the molding die. The ball may be heated or cooled if necessary.

  The polyurethane and polyurea compositions of this invention impart many useful properties and characteristics to golf ball covers. In particular, this cover material has good mechanical strength and cut / shear resistance and light stability. The polyurethane and polyurea help to increase the weather resistance of the golf ball. It can be seen that the golf ball of the present invention exhibits great resistance to yellowing and discoloration and is quite different from golf balls constructed without the use of polyurethane and polyurea cover materials.

  It should be noted that a golf ball with a polyurea cover as described and illustrated herein is merely an example of an existing preferred embodiment of the present invention. It should be understood that various modifications and other embodiments can be devised by those skilled in the art without departing from the spirit and scope of the invention. It should be noted that all such embodiments are covered by the appended claims.

20, 20a, 30, 30a Golf balls 22, 22a, 32, 32a Solid cores 24, 24a, 36, 36a Cover layers 34, 34a Intermediate casing layer

Claims (20)

The core,
Various compounds having an isocyanate selected from the group consisting of 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, and mixtures thereof, an amine-terminated compound, and an amine crosslinking agent A golf ball having a polyurea cover material produced by reaction of components.   The golf ball according to claim 1, wherein the isocyanate is 1,3-bis (isocyanatomethyl) cyclohexane.   The golf ball according to claim 1, wherein the isocyanate is 1,4-bis (isocyanatomethyl) cyclohexane.   The golf ball of claim 1, wherein the core comprises polybutadiene.   The curing agent is 4,4′-diaminodiphenylmethane; 3,5-diethyl- (2,4- or 2,6-) toluenediamine; 3,5-dimethylthio- (2,4- or 2,6-) 3,5-diethylthio- (2,4- or 2,6-) toluenediamine; 2,2′-dichloro-3,3′5,5′-tetraethyl-4,4′-diamino-diphenylmethane; 2. An amine-terminated curing agent selected from the group consisting of polytetramethylene glycol-di (p-aminobenzoate); 4,4′-bis (sec-butylamino) -diphenylmethane; and mixtures thereof. The golf ball described.   The golf ball according to claim 1, wherein the polyurea cover material further contains a pigment and a filler.   The golf ball of claim 1, wherein the core has a diameter of about 1.26 to about 1.60 inches.   The golf ball of claim 1, wherein the cover has a thickness of about 0.015 to about 0.090 inches.   The golf ball of claim 7, wherein the cover has a thickness of about 0.020 to about 0.050 inch.   The golf ball of claim 8, wherein the cover has a thickness of about 0.020 to about 0.035 inches.   The golf ball of claim 1, wherein the core has a surface hardness of about 30 to about 65 Shore D.   The golf ball of claim 1, wherein the cover has a material hardness of about 30 to about 65 Shore D.   The golf ball of claim 12, wherein the cover has a material hardness of about 35 to about 55 Shore D. The core,
An intermediate casing layer covering the core;
Various compounds having an isocyanate selected from the group consisting of 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, and mixtures thereof, an amine-terminated compound, and an amine crosslinking agent A golf ball having a polyurea cover material produced by reaction of components.   The golf ball according to claim 14, wherein the isocyanate is 1,3-bis (isocyanatomethyl) cyclohexane.   The golf ball according to claim 14, wherein the isocyanate is 1,4-bis (isocyanatomethyl) cyclohexane.   The golf ball of claim 14, wherein the core comprises polybutadiene.   The golf ball of claim 14, wherein the polyurea cover material further includes a pigment and a filler.   The golf ball according to claim 14, wherein the intermediate layer includes an ionomer resin.   The golf ball of claim 14, wherein the intermediate layer comprises a blend of an ionomer resin and a non-ionomer resin.

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