JP2002272880A - Thin-layer-covered multilayer golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball provided with a core which comprises a center and an outer core layer and with a cover which comprises an inner cover layer and a thin outer cover layer. SOLUTION: The golf ball comprises the core 12 and the cover 14 disposed about the core, wherein the core comprises the center and at least one outer core layer 18 adjacent the center, and the cover comprises at least one inner cover layer 22 and the outer cover layer 20, wherein the center 16 has an outer diameter from about 0.953 cm about 3.56 cm (about 0.375 in to about 1.4 in) and the deflection of greater than about 4.5 mm under a load of 100 kg, the outer core layer has an outer diameter from about 3.56 cm to about 4.11 cm (about 1.4 in to about 1.62 in), the inner cover layer has an outer diameter of greater than about 4.01 cm (about 1.58 in) and a material hardness of less than Shore D of about 72 and the outer cover layer has a hardness of greater than Shore D of about 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates generally to golf balls and, more particularly, to multilayer golf balls. In particular, the present invention relates to golf balls having a core including a center and outer core layer, and a cover including an inner cover layer and a thin outer cover layer. The outer cover layer was made from a castable reactive liquid,
Made of thermosetting materials. The core is made of a polybutadiene composition, including a butadiene polymer, having a modulus of elasticity greater than about 40 and a molecular weight greater than about 200,000.

[0002]

BACKGROUND OF THE INVENTION Conventional golf balls are composed of several general sets: (a) solid golf balls comprising one or more layers;
And (b) thread-wound golf balls. Solid golf balls are easy to manufacture and relatively inexpensive,
Includes one-piece balls that have poor playing characteristics and are therefore generally restricted to use as practice balls. Two-piece balls are generally the most popular golf balls for recreational players because they consist of a solid core and a cover and are extremely durable and provide maximum flight distance. Typically, the core is
Made from chemically cross-linked polybutadiene with zinc diacrylate and / or other similar cross-linking agents. These golf balls are generally easy to manufacture, but are considered to have limited playing characteristics. Solid golf balls also include multilayer golf balls composed of a solid core including one or more layers and / or a cover including one or more layers. These balls are said to have an extended range of playing characteristics.

[0003] Wound balls are generally preferred by many players due to their high spin characteristics and soft "feel". Wound golf balls include a solid, hollow or fluid-filled center, typically surrounded by a tensioned elastic material, and a cover. Wound balls are generally more difficult and expensive to manufacture than solid two-piece balls. Various golf balls have a wide range of playing characteristics,
It is devised by manufacturers and the like to give, for example, compression force, speed, "feel" and spin characteristics. These characteristics can be optimized for different competitive abilities. For example, one of the factors that manufacturers typically modify to change the playing characteristics of the golf ball is a polymer composition used to make the center and / or core of the golf ball. One of the most common polymers used is polybutadiene, and more specifically, high cis
-Polybutadiene with isomer concentration.

[0004] The use of polybutadiene having a high cis-isomer concentration provides a golf ball that is very elastic and rigid, especially when combined with a hard cover material. These highly elastic golf balls have a relatively hard "feel" when hit with a club. Golf balls with a soft "feel" made of high cis-polybutadiene
Has low elasticity. In an effort to produce improved golf balls, various other polybutadiene formulations have been produced, as discussed below. U.S. Patent 3,239,228
Discloses a solid golf ball including a core obtained by molding a polybutadiene rubber having a high sulfur content and a cover. The polybutadiene content of this core is 25-1
It is sterically controlled to a configuration of 00% cis and 0-65% trans 1,4-polybutadiene, all of which have the vinyl configuration of polybutadiene. A preferred embodiment of the polybutadiene golf ball core is 35% cis-isomer, 52%
% Trans-isomer and 13% vinyl-polybutadiene. The content of the trans and vinyl components is important for the overall playing characteristics of this polymer blend.
It is not important.

[0005] British Patent No. 1,168,609 discloses a molding composition which can mold an improved golf ball core and which contains cis-polybutadiene as a basic polymer component. The core polymer component typically contains at least 60% cis-polybutadiene, with the balance being trans.
-Or vinyl-type polybutadiene. In a preferred embodiment, the core polybutadiene component comprises 90% cis-
Structure, the remaining 10% of which is trans- or vinyl-
1,4-polybutadiene in shape. U.S. Patent 3,572,72
Nos. 1 and 3,572,722 disclose solid one-piece or two-piece golf balls, which include a core and a cover. The cover material may be a number of materials known to those skilled in the art or a number thereof, including, for example, trans-polybutadiene, the remainder of which is in cis- or vinyl-form, which may be present in at least 90%. Any of the blends can be included.

[0006] British Patent 1,209,032 discloses a two-piece or three-piece golf ball having a core and a cover. The core or cover material can be any crosslinkable material. In particular, the material can be a butadiene or isoprene polymer or copolymer. Preferably, the polymer component is a polybutadiene with a cis content greater than 50% by weight. U.S. Patent No.
No. 3,992,014 discloses a one-piece solid golf ball. The material of this golf ball is typically polybutadiene, having a three-dimensional structure selected to include at least 60% cis-polybutadiene, with the balance being the remainder.
40% are trans-polybutadiene and / or 1,2-polybutadiene (vinyl) isomer. US Patent 4,692,
No. 497 describes golf balls with polybutadiene and α, β
The golf ball material is disclosed as being produced by curing a diene polymer comprising a metal salt of an ethylenically unsaturated acid with at least two radical initiators.

US Pat. No. 4,931,376 discloses a process for making butadiene polymers for use in a variety of applications, including golf ball cover materials. In one aspect of the invention, a mixed polymer resin material containing at least 30% by weight of the trans-polybutadiene polymer is used as a golf ball cover on a two-piece ball. In one preferred embodiment, the golf ball cover material comprises a blend containing 30-90% by weight of a trans-polybutadiene polymer. U.S. Patent No. Has been disclosed. This mixture
About 99.5% by mass to about 95% by mass of cis-1,4-polybutadiene and about 0.5% by mass to about 5% by mass of 1,2-
And polybutadiene.

[0008] US Patent No. 5,252,652 discloses basic rubber,
1,4- having a cis content of preferably at least 40 mol%
Disclosed are one-piece or multi-layer golf ball cores with improved flight properties made from rubber compositions comprising polybutadiene, metal salts of unsaturated carboxylic acids, organic peroxides and organic sulfur compounds and / or metal salts thereof. . The organic sulfur compound and / or metal salt thereof is typically present in an amount of about 0.05 to 2 parts by weight, and the organic peroxide is typically present in an amount of about 0.5 to 3 parts by weight, based on the total polymer component. Present in parts. EP 0,577,058 discloses a golf ball including a core and a cover formed as two separate layers. The inner layer of the cover is molded over the core and made of an ionomer resin. The outer layer of the cover is formed on the inner layer and is made of a blend of natural or synthetic balata and a crosslinkable elastomer, such as polybutadiene. In one embodiment of the outer layer of the cover, the elastomer is 1,4-polybutadiene with at least 40% cis-structure, with the remaining 60% being the trans-isomer of polybutadiene. One preferred embodiment is at least 90%
And more preferably at least 95% of the cis-structure.

US Pat. No. 5,421,580 discloses a wound golf ball including a liquid center contained in a center bag, a layer of rubber thread formed on the liquid center, and a cover of the wound layer and a cover over the liquid center. I have. The cover material may comprise any one of a number of materials or blends thereof known to those skilled in the art, including trans-polybutadiene and / or 1,2-polybutadiene (vinyl), or the cover may be 70-85. The preferred ratio of trans-isomer which can be included so as to have JIS-C hardness is not described. U.S. Patent No. It is produced by vulcanizing a rubber composition. The amount of trans-polybutadiene structure present after vulcanization is 10-30%. Because 3
Its presence in an amount greater than 0% is detrimentally deemed to result in a core that is too soft and has low elasticity and results in poor golf ball performance. The core contains a vulcanizing agent, a filler, an organic peroxide and an organic sulfur compound.

British Patent No. 2,321,021 discloses a solid golf ball having a two-layer cover structure including a core and a cover formed on the core, and having an inner cover layer and an outer cover layer. ing. The outer cover layer is made of a rubber composite containing 0.05 to 5 parts by mass of an organic sulfide compound. The rubber composition for the core is a base rubber, preferably having a cis-isomer content of at least 40% by mass.
Contains 1,4-polybutadiene, crosslinking agents, auxiliary crosslinking agents, organic sulfides and fillers. The crosslinker is typically 0.1.
The organic peroxide is present in an amount of 3 to 5.0 parts by weight, and the co-crosslinking agent is typically a metal salt of an unsaturated fatty acid present in an amount of 10 to 40 parts by weight. The organic sulfide compound is typically present in an amount of 0.05 to 5 parts by weight. U.S. Pat.No. 5,816,944 discloses a solid golf ball having a core and a cover, wherein the core is
The cover has a JIS-C hardness of 50-80, and the cover has a Shore D hardness of 50-60. The core material comprises a vulcanized rubber, such as cis-polybutadiene with a crosslinking agent, an organic peroxide, an organic sulfur compound and / or a metal-containing organic sulfur compound, and a filler.

Furthermore, conventional polymers containing a high percentage of trans-polybutadiene structure, such as Firestone (Firstone)
diene containing 40% cis-isomer and 50% trans-polybutadiene isomer (D
IENE) 35NF and mixtures of high cis- and high trans-polybutadiene isomers, such as Shell Corporati
CARIFLEX BR1220, available from On) and FUREN 88, available from Asahi Chemical Co., respectively, typically do not provide high modulus and are therefore undesirable. A number of patents have been issued in addition to the filling center or core component that affect the performance characteristics of golf balls, including various golf balls, such as wound balls, conventional solid balls, and double cover layers. It is intended to improve the properties of layers and covers used in the manufacture of multilayer balls having a double core layer, and / or balls including a mantle layer provided between the core and the cover. The most common polymers used by manufacturers in golf ball layers and covers are ionomers, such as DE
Wilmington's EI Dupont Dnemours (EI
DuPont de Nemours and Co.) as a commercially available product, such as Surlyn (SURLYN). However, manufacturers have recently considered using alternative polymers such as polyurethane. For example, U.S. Pat. No. 3,147,324 is directed to a method of making a golf ball having a polyurethane cover.

[0012] Since about 1960, polyurethane has been recognized as a useful material for golf ball covers.
Polyurethane is a reaction product of a polyurethane prepolymer and a curing agent. The polyurethane prepolymer is
It is a product formed by the reaction between a polyol and a diisocyanate. The curing agents used previously are typically diamines or glycols. Often, a catalyst is used to facilitate the reaction between the curing agent and the polyurethane prepolymer. Since 1960, various companies have considered the usefulness of polyurethane as a golf ball cover material. U.S. Pat. No. 4,123,061 teaches a golf ball made from a polyurethane prepolymer of a polyether and a curing agent such as a trifunctional polyol, a tetrafunctional polyol or a diamine. US Patent 5,334,67
No. 3 describes the use of two categories of commercially available polyurethanes, thermoset and thermoplastic polyurethanes, for making golf ball covers, and especially polyurethane prepolymers and slowly reacting amine curing agents, and / or A golf ball covered with a thermosetting polyurethane made from a composition comprising a bifunctional glycol is disclosed. This first industrially successful,
Polyurethane-coated golf balls were first commercialized in 1993 and were sold by Titleist ^TM
Professional) ball.

Unlike SURLYN ^™ or ionomer coated golf balls, polyurethane golf ball covers can be formulated to have the soft "feel" of balata coated golf balls. However, polyurethane golf ball covers have heretofore not been able to compete well with Surlyn-coated golf balls in terms of rebound, which is a function of elasticity or initial velocity after impact by a golf club. U.S. Pat.No. 3,989,568,
Any one or two polyurethane prepolymers and
Disclosed are three-component systems using one or two polyols or fast-reacting diamine curing agents. The reagents selected for this system must have different kinetics in two or more competitive reactions. U.S. Pat.No. 4,123,061 was prepared from a polyurethane prepolymer of polyether and a curing agent such as a trifunctional polyol, a tetrafunctional polyol or a rapidly reactive diamine.
A golf ball is disclosed.

US Pat. No. 5,334,673 discloses a golf ball cover made from a composition comprising a polyurethane prepolymer and a slowly reacting polyamine curing agent and / or a difunctional glycol. The resulting golf balls have been found to have improved shear and cut resistance as compared to covers made from balata or Surlyn. U.S. Pat. No. 5,692,974 discloses the use of cationic ionomers in golf ball cover compositions. The patent further relates to a golf ball having a core and cover incorporating a urethane ionomer. Improved resilience and initial rate are achieved by adding an alkylating agent, such as t-butyl chloride, which induces ionic interactions in the polyurethane to produce a cationic ionomer. International patent application WO 98/37929 discloses a composition for golf ball covers, which comprises a diisocyanate /
Blends including polyol prepolymers and curing agents including blends of slowly reacting and rapidly reactive diamines. Shows improved "feel", playing characteristics and durability.

[0015] Conventional polyurethane prepolymers are known to have lower resilience than Surlyn and other ionomer resins. This time, golf ball core,
The use of the polyurethane composition of the present invention in the manufacture of intermediate and mantle layers, and / or covers,
The speed of a golf ball made with this composition is close to the speed observed for (1) Surlyn coated golf balls,
And (2) it has been found that the rate can be increased to a value higher than that seen when another urethane composition is used. Further, it is desirable to combine the polyurethane cover composition with a polybutadiene core material, especially one having an elasticity index greater than about 40. Cores made from these materials have been found to provide exceptionally high elastic properties without loss of performance properties (ie, low compressibility).

[0016] The multilayer core structure allows the moment of inertia of the ball to be easily adjusted through adjustment of the specific gravity of each independent core layer. By using a multi-layer core structure, the ball designer can adjust the ball spin performance when hit by a full shot. With a full shot, the internal structure of the ball has a significant effect on the spin rate of the ball. Thus, the spin rate of the driver and long iron shot can be more precisely adjusted through the use of multilayer core technology. Further, the feel of the ball can be changed by changing the hardness and compressibility of the individual layers, with greater control than is achieved by a single solid core structure. Accordingly, it is desirable to produce a multi-layer golf ball having a low compression ratio and a resiliency equal to or higher than conventional balls. It is also desirable to achieve the same or lower compression ratios and achieve higher resilience without unduly reducing speed.

[0017]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a golf ball in general, and more particularly to provide a multi-layer golf ball. It is an object of the present invention to provide a golf ball having a core, particularly including a center and outer core layer, and a cover including an inner cover layer and a thin outer cover layer.

[0018]

SUMMARY OF THE INVENTION Accordingly, the present invention includes a core and a cover disposed therearound, the core including a center and at least one outer core layer adjacent the center. And the cover includes at least one inner cover layer and an outer cover layer, wherein the center is between about 0.953 cm
The outer core layer has an outer diameter of about 3.56 cm (about 0.375 in to about 1.4 in) and a deflection of more than about 4.5 mm under a load of 100 Kg, and the outer core layer has a flexure of about 3.56 cm to about 4.11 cm (about 1.4 in to about 1.
62 in), and the inner cover layer is about 4.
A golf ball having an outer diameter of greater than about 1.58 in (01 cm) and a material hardness of less than about 72 Shore D; and wherein the outer cover layer has a hardness of greater than about 50 Shore D. . In one embodiment, the outer cover layer has a material hardness of less than about 55 Shore D, and the outer cover layer preferably has a material hardness of less than about 50 Shore D. The inner cover layer should have a material hardness from about 60 to about 70 Shore D, more preferably from about 60 to about 65 Shore D.

In another embodiment, the outer diameter of the inner cover layer is from about 4.04 cm to about 4.22 cm (about 1.59 in to about 1.66 cm).
in) and more preferably about 4.06 cm
About 1.6 in to about 1.64 in. The outer diameter of the center is about 1.27 cm to about 3.18 cm (about 0.5 in.
To about 1.25 in) and more preferably from about 2.29 cm to about 3.05 cm (about 0.9 in to about 1.2 i).
n) Within the range. The outer diameter of the outer core layer is about 3.86
cm to about 4.04 cm (about 1.52 in to about 1.59 in), and more preferably about 3.90 cm to about 4.0 cm.
1 cm (about 1.535 in to about 1.58 in). In yet another aspect, the golf ball has a moment of inertia of less than about 83 g · cm ² . Further, the center preferably has a first hardness, the outer core layer has a second hardness greater than the first hardness, and the inner cover layer has a greater hardness than the second hardness. Has a large third hardness. In a preferred embodiment, the outer cover layer has a fourth hardness less than the third hardness.

In one embodiment, the center has a first specific gravity and the outer core layer has a second specific gravity that differs by less than about 0.1. In one preferred embodiment, the center is solid. Also, the center may be liquid, hollow or filled with air. The present invention also includes a core and a cover disposed therearound, the core including a solid center and an outer core layer adjacent the center, and the cover includes an inner cover layer and an outer cover layer. The center is between about 0.953 cm and
The outer core layer has an outer diameter of about 3.56 cm (about 0.375 in to about 1.4 in) and a deflection of more than about 4.5 mm under a load of 100 Kg, and the outer core layer has a flexure of about 3.56 cm to about 4.11 cm (about 1.4 in to about 1.
62 in), and the inner cover layer is about 4.
A golf ball having an outer diameter greater than about 01 cm (about 1.58 in) and a material hardness less than about 72 Shore D, and the outer cover layer having a hardness greater than about 50 Shore D. Also concerns.

In one embodiment, the outer cover layer comprises about 50
Has a material hardness of less than about 0.89 mm (about 0.035 in). In a preferred embodiment, the center has a first hardness, the outer core layer has a second hardness above the first hardness, and the inner cover layer has the second hardness. With a third hardness that exceeds. Further, the outer cover layer has a fourth hardness less than the third hardness. In another embodiment, the outer diameter of the inner cover layer is from about 4.04 cm to about 4.22 cm.
(About 1.59 in to about 1.66 in), and more preferably about 4.06 cm to about 4.17 cm (about 1.6 in to about 1.64 i).
n) Within the range. The outer diameter of the center is about 1.27 cm to about
3.18 cm (about 0.5 in to about 1.25 in), and preferably about 2.29 cm to about 3.05 cm (about 0.9 in).
in to about 1.2 in). In yet another embodiment, the outer diameter of the outer core layer is from about 3.86 cm to about 4.04 cm (about 4.0 cm).
1.52 in to about 1.59 in). The ball also has a moment of inertia of less than about 83 g · cm ² . In another embodiment, the center has a first specific gravity and the outer core layer has a second specific gravity that differs by less than about 0.1.

Definitions In the context of one or more numerical values or numerical ranges, the term "about" as used herein is understood to mean all such numerical values, including all numerical values within a range. Should. The term `` cis-trans catalyst, '' as used herein, refers to any component or a component thereof that will convert at least a portion of the cis-polybutadiene isomer to the trans-polybutadiene isomer at a given temperature. Means a combination. It should be understood that a combination comprising the cis-isomer, trans-isomer and any vinyl-isomer, measured at any given time, constitutes 100% of the polybutadiene. As used herein, the term "active ingredient" is defined as a particular component of a mixture or blend that is essential for the chemical reaction concerned. As used herein, the term substituted and unsubstituted `` aryl '' group refers to a hydrocarbon ring having a conjugated double bond system, typically comprising a 4n + 2π ring electron system, where n is an integer. means. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, anisyl, tolyl, xylyl, and the like. According to the invention, aryl also comprises a heteroaryl group such as pyrimidine or thiophene. These aryl groups may also be substituted with any number of various functional groups. In addition to the functional groups described herein in connection with carbocyclic groups, the functional groups on the aryl group may include hydroxy and its metal salts, mercapto and its metal salts, halogen, amino, nitro, cyano and amide, ester Carboxyl, silyl, acrylate and metal salts thereof, including acids and metal salts thereof, sulfonyl or sulfonamides, and phosphates and phosphites, and combinations thereof.

As used herein, the term "Atti compression ratio"
Is NJ Union City's Atchi Engineering Co., Ltd.
Defined as the deflection of an object or material relative to the calibrated spring deflection measured using an Atti Compression Gauge, commercially available from (Atti Engineering Corp.). Atchi compression ratio is
It is typically used to measure the compressibility of a golf ball. Use this attach gauge to measure approximately 4.27 cm (1.680
When measuring cores with diameters less than (in), use metal or other suitable shims to reduce the diameter of the object to be measured to approximately 4.27.
It should be understood that cm (1.680 in) is used. As used herein, substituted and unsubstituted "carbocycle" means a cyclic carbon-containing compound, examples of which include, but are not limited to, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl and the like. Such cyclic groups may also contain various substituents, wherein one or more hydrogen atoms have been replaced by a functional group. Such functional groups include those described above and lower alkyl groups having 1-28 carbon atoms. These cyclic groups of the present invention can further include heteroatoms.

The term “coefficient of restitution” used herein for a golf ball refers to the value obtained when the ball hits a rigid plate.
It is defined as the ratio of rebound speed to inbound speed. This inbound speed is about 38.13 m / s
(125 ft / s). As used herein, “Group VIA component” or “Group VIA element” refers to a sulfur component,
A component including a selenium component or a tellurium component or a combination thereof is meant. As used herein, the term "sulfur component" means a component that is elemental sulfur, polymeric sulfur, or a combination thereof. Further, “elemental sulfur” means a cyclic structure of S8, and “polymeric sulfur”
It is to be understood that a structure containing at least one additional sulfur relative to the elemental sulfur is meant. As used herein, the term "fluid" includes a liquid, paste, gel, gas, or any combination thereof.

As used herein, the term "molecular weight" is defined as the absolute weight average molecular weight. This molecular weight is measured by the following method: Approximately 20 mg of polymer is added to 10 mL
In tetrahydrofuran (THF). This dissolution is
Depending on the molecular weight and distribution of the polymer, it can take several days at room temperature. One liter of THF is filtered and degassed before being placed in a high performance liquid chromatography (HPLC) vessel. The flow rate of this HPLC is set at 1 mL / min through a Viscogel column. This non-fluid mixed bed column model GM with ID 7.8 mm and length 300 mm
HHR-H is from TX Houston's Viscotek C
orp.). The THF flow rate is set at 1 mL / min for at least 1 hour before starting analysis of the sample or until a stable detector baseline is achieved. During purging of this column and detector, the Viscotek TDA Model 300 triple detector should be set at 40 ° C. This detector is also available from Viscotec. These three detectors (i.e., refractive index, differential pressure and light scattering) and the column should be in thermal equilibrium, and the detectors were purged, zeroed and applied to the instrument. The system for calibration should be prepared according to the instructions.

Next, 100 μL aliquots of the sample solution can be injected into the instrument, and the molecular weight of each sample can be determined using Viscotec triple detector software.
Can be calculated. When measuring the molecular weight of the polybutadiene material, a dn / dc of 0.130 should always be used. It is to be understood that this device and these methods will provide the molecular weight values described and claimed herein, and that other devices or methods will not necessarily provide values equivalent to those used herein. Should. As used herein, the term "multilayer" means at least two layers and also has a ball with a liquid center, a wound ball, a ball with a hollow center, and at least two intermediate layers and / or an inner or outer cover. Include the ball. As used herein, the term "thermoset" refers to an irreversible solid polymer that is the product of the reaction of two or more prepolymer precursor materials.

As used herein, the term "parts by weight", also known as "phr", is defined as parts by weight of a particular component present in a mixture per 100 parts by weight of total polymer components. Mathematically, this can be expressed as the mass of a component divided by the total mass of the polymer and multiplied by a factor of 100. As used herein, the term "substantially free" refers to less than about 5% by weight, preferably less than about 3% by weight, more preferably less than about 1% by weight and most preferably about 0.01% by weight.
It means less than mass%. The term "elasticity index" used here
Is defined as the difference in loss tangent measured at 10 cpm and 1000 cpm divided by 990 (frequency span) and multiplied by 100,000 (a convenient unit for normalization). This loss tangent is measured using RPA 2000, manufactured by Alpha Technologies of OH Akron. This RPA 20
00 is a temperature of 100 ° C using an arc of 0.5 degree,
Set the range from 2.5 to 1000 cpm. An average of six loss tangent measurements is obtained at each frequency and this average is used to calculate the elasticity index. The calculation of the elasticity index is as follows: elasticity index = 100,000 · [(loss tangent at 10 cpm) − (loss tangent at 1000 cpm)] / 990

[0028]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, a golf ball 10 of the present invention includes a core 12 and a cover 14 surrounding the core. Preferably, the core 12 includes a center 16 and an outer core layer 18, and the cover 14 includes an outer cover layer.
20 and an inner cover layer 22. The golf ball core of the present invention can have any of various configurations. For example,
The core of the golf ball may include a known center and may be surrounded by an intermediate mantle or outer core layer provided between the center and the inner cover layer. The core can be a single layer or can include multiple layers. The innermost part of this core is
It can be a solid or a liquid-filled sphere. Like the core, this intermediate mantle or outer core layer can also include multiple layers. The core may also include a solid or liquid-filled center around which a number of threads of tensioned elastic material are wound.

[0029] Materials for the solid core include compositions comprising the basic rubber, crosslinker, filler and co-crosslinker or initiator. The base rubber (base rubber) typically includes natural or synthetic rubber. A preferred base rubber is 1,4-polybutadiene having at least 40% cis-structure. Most preferably, the base rubber comprises a high Mooney viscosity rubber. Desirably, the polybutadiene may also be a mixture with other elastomers known in the art, such as natural rubber, polyisoprene rubber and / or styrene-butadiene rubber, to improve the properties of the core. The crosslinking agent may be a metal salt of an unsaturated fatty acid, such as acrylic acid or methacrylic acid, having 3 to 8 carbon atoms.
And zinc or magnesium salts of unsaturated fatty acids having the formula Suitable crosslinkers include diacrylate, dimethacrylate and monomethacrylate metal salts, where the metal is magnesium, calcium, zinc, aluminum,
Sodium, lithium or nickel.

One aspect of the present invention is directed to a multi-layer golf ball including a solid center surrounded by at least one additional solid outer core layer. At least one of the outer core layers comprises a high Mooney viscosity rubber and about 20 to about 40 ph.
r, preferably about 30 to about 38 phr and most preferably about 3
Produced from a composition based on elastic rubber, containing a crosslinking agent present in an amount of 7 phr. The term used here, "ph
It is to be understood that "r" is a value for rubber by weight. The center of the ball has an elastic high Mooney viscosity rubber component and a crosslinker of about 15
A solid comprising a crosslinker present in an amount of from about 30 to about 30 phr, preferably about 19 to about 25 phr and most preferably about 20 to 24 phr.

The initiator decomposes during the cure cycle;
It can be any known polymerization initiator. Suitable initiators are peroxide compounds such as dicumyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, aa bis (t-butylperoxy) diisopropylbenzene, 2 , 5-dimethyl-2,5-di (t-butylperoxy) hexane or di-t-butyl peroxide and mixtures thereof. As used herein, the term "filler" includes any compound or composition that can be used to alter the density and other properties of the core. Fillers are typically tungsten, zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate regrind (3
Regenerated core material ground to 0 mesh particles), and materials such as high Mooney viscosity rubber regrind. The present invention also provides a core and cover, such as a solid, hollow or fluid-filled center,
A multi-layer golf ball also includes an outer core layer, and inner and outer cover layers disposed about the center. At least one of the center or intermediate layers includes a reaction product, which includes a cis-trans catalyst, an elastic polymer component including polybutadiene, a source of free radicals, and an optional crosslinker, filler, or both.

The present invention also relates to a method for converting a cis-isomer of the polybutadiene elastomeric polymer component to its trans-isomer during a molding cycle and for producing a golf ball. Various combinations of polymers, cis-trans catalysts, fillers, crosslinkers and free radical sources can be used. High molecular weight polybutadiene, preferably having a cis-isomer content greater than about 90%, is added to the golf ball at any point during the molding cycle to obtain a highly elastic and low compressive center or interlayer. Alternatively, the trans-isomer content is increased in a part thereof, or preferably, the golf ball is converted so as to increase the trans-isomer content in substantially all or a part of the golf ball. More preferably, the cis-polybutadiene isomer is present in an amount greater than about 95% of the total polybutadiene isomer content. While not intending to be bound by any particular theory, it is desirable that the initial polybutadiene and the reaction product have a small amount of the 1,2-polybutadiene isomer (vinyl-polybutadiene). Typically, the vinyl-
The polybutadiene isomer content is less than about 7%. Preferably, the vinyl-polybutadiene isomer content is
Less than about 4%. More preferably, the vinyl-polybutadiene isomer content is less than about 2%. Without intending to be bound by any particular theory, the resulting kinetics of the combined cis- and trans-polybutadiene skeletons may result in lower modulus and higher modulus of the reaction product and the golf ball containing it. It is thought to provide resilience.

To obtain a polymer reaction product exhibiting the above high resilience and low modulus (low compression) properties which are desirable and advantageous for the playing characteristics of golf balls, high molecular weight cis-1, Preferably, 4-polybutadiene can be converted to its trans-isomer during its molding cycle. This polybutadiene material is
It typically has a molecular weight in excess of about 200,000. Preferably, the molecular weight of the polybutadiene is greater than about 250,000, more preferably between about 300,000 and 500,000. Not intending to be bound by any particular theory,
It is believed that the cis-trans catalyst component, in combination with the free radical source, acts to convert a proportion of the polybutadiene polymer component from its cis-form to the trans-form. This cis-trans conversion includes organic sulfur or metal-containing organic sulfur compounds, sulfur or metal free, substituted or unsubstituted aromatic organic compounds, inorganic sulfide compounds, aromatic organometallic compounds,
Or the presence of a cis-trans conversion catalyst, such as a mixture thereof. The cis-trans conversion catalyst component can include one or more other cis-trans conversion catalysts described herein.

[0034] In one embodiment, the at least one organic sulfur compound is substantially free of metals. This typically results in a metal content of less than about 10% by weight, preferably about 3% by weight.
It means less than 1% by weight, more preferably less than about 1% by weight and most preferably only trace amounts, for example less than about 0.01% by weight. As used herein when referring to the present invention, the term "organosulfur compound" or "organosulfur component" means at least one of the following compounds: 4,4'-diphenyl disulfide, 4,4'- Ditolyl disulfide, 2,2'-benzamide diphenyl disulfide, bis (2-aminophenyl) disulfide, bis (4-aminophenyl) disulfide, bis (3-aminophenyl) disulfide, 2,2'-bis (3-amino (Naphthyl) disulfide, 2,2'-bis (4-aminonaphthyl) disulfide, 2,2'-bis (5-aminonaphthyl) disulfide, 2,2'-bis (6-aminonaphthyl) disulfide, 2,2 ' -Bis (7-aminonaphthyl) disulfide,
2,2'-bis (8-aminonaphthyl) disulfide, 1,1-bis
(3-aminonaphthyl) disulfide, 1,1-bis (4-aminonaphthyl) disulfide, 1,1-bis (5-aminonaphthyl)
Disulfide, 1,1-bis (6-aminonaphthyl) disulfide, 1,1-bis (7-aminonaphthyl) disulfide, 1,1-bis (8-aminonaphthyl) disulfide, 1,2′-diamino-1,
2'-dithiodinaphthalene, 2,3'-diamino-1,2'-dithiodinaphthalene, bis (4-chlorophenyl) disulfide, bis (2-chlorophenyl) disulfide, bis (3-chlorophenyl) disulfide, bis (4 -Bromophenyl) disulfide, bis (2-bromophenyl) disulfide, bis (3
-Bromophenyl) disulfide, bis (4-fluorophenyl) disulfide, bis (4-iodophenyl) disulfide, bis (2,5-dichlorophenyl) disulfide, bis
(3,5-dichlorophenyl) disulfide, bis (2,4-dichlorophenyl) disulfide, bis (2,6-dichlorophenyl) disulfide, bis (2,5-dibromophenyl) disulfide, bis (3,5-dibromophenyl) disulfide , Bis (2-chloro-5-bromophenyl) disulfide, bis (2,
4,6-trichlorophenyl) disulfide, bis (2,3,4,5,
6-pentachlorophenyl) disulfide, bis (4-cyanophenyl) disulfide, bis (2-cyanophenyl) disulfide, bis (4-nitrophenyl) disulfide, bis
(2-nitrophenyl) disulfide, 2,2'-dithiobenzoic acid ethyl ester, 2,2'-dithiobenzoic acid methyl ester, 2,2'-dithiobenzoic acid, 4,4'-dithiobenzoic acid ethyl ester, Bis (4-acetylphenyl) disulfide, bis (2-acetylphenyl) disulfide, bis (4-formylphenyl) disulfide, bis (4-carbamoylphenyl) disulfide, 1,1′-dinaphthyl disulfide, 2,2 ′
-Dinaphthyl disulfide, 1,2'-dinaphthyl disulfide, 2,2'-bis (1-chlorodinaphthyl) disulfide, 2,
2'-bis (1-bromodinaphthyl) disulfide, 1,1'-bis
(2-chloronaphthyl) disulfide, 2,2′-bis (1-cyanodinaphthyl) disulfide, 2,2′-bis (1-acetyldinaphthyl) disulfide, and the like, or a mixture thereof.

Preferred organic sulfur components include 4,4'-diphenyl disulfide, 4,4'-ditolyl disulfide, 2,2'-benzamide diphenyl disulfide or mixtures thereof. More preferred organic sulfur components include 4,4'-ditolyl disulfide. When present, the organosulfur cis-trans catalyst contains at least about 12% trans-polybutadiene isomer, typically greater than about 32% trans-polybutadiene isomer, based on the total elastic polymer component. As such, it is preferably present in an amount sufficient to produce the reaction product. Suitable metal-containing organosulfur components include, but are not limited to, cadmium, copper, lead and tellurium analogs of diethyldithiocarbamate, diamyldithiocarbamate, and dimethyldithiocarbamate or mixtures thereof. Suitable substituted or unsubstituted aromatic organic components that do not contain sulfur or metals include, but are not limited to, 4,4'-diphenylacetylene, azobenzene, or mixtures thereof. The aromatic organic groups are preferably in the range C ₆ -C ₂₀ , and more preferably C ₆ -C ₁₀ . Suitable inorganic sulfide components include, but are not limited to, titanium sulfide, manganese sulfide, and similar sulfides of iron, calcium, cobalt, molybdenum, tungsten, copper, selenium, yttrium, zinc, tin and bismuth. The cis-trans conversion catalyst may also be a mixture of an organic sulfur component and an inorganic sulfide component.

The cis-trans conversion catalyst may also include a Group VIA element, as defined herein. Elemental sulfur and polymeric sulfur are commercially available, for example, from Elastochem, Inc. of OH Chardon. Examples of sulfur catalyst compounds are PB (RM-S) -80 elemental sulfur and PB (CR
ST) -65 containing polymer sulfur. The tellurium catalyst, trade name TELOY, and the selenium catalyst, trade name VANDEX, are each commercially available from RT Vanderbilt. The cis-trans conversion catalyst comprises
Preferably it is present in an amount of about 0.1 to 10 parts per 100 parts of the total elastic polymer component. More preferably, the cis-trans conversion catalyst comprises from about 0.1 to 5 per 100 parts of the total elastic polymer component.
Present in parts. Most preferably, the cis-trans conversion catalyst comprises from about 0.1 to 100 parts per hundred total elastomeric polymer components.
Present in 8 parts. This cis-trans conversion catalyst is
Typically, the enriched trans-polybutadiene isomer content is increased to about 5-7, based on the total elastic polymer component.
It is present in an amount sufficient to produce the reaction product such that it contains 0% trans-polybutadiene.

The measurement of the trans-isomer content of polybutadiene can be achieved as follows. Standards for calibration are prepared using at least two polybutadiene rubber samples with known trans-isomer content, eg, high and low content samples. These samples alone were used such that the resulting calibration curve contained at least about 13 equally spaced points.
Or to create a stepped sample with a trans-polybutadiene content of at least about 1.5% to 50%,
Alternatively, they are mixed and used together to determine the range of unknown quantities. A commercially available Fourier Transform Infrared (FTIR) spectrometer equipped with a Photoacoustic (PAS) cell is used for each standard.
PAS spectra were obtained. Here, the following device parameters were used. Scan at 2.5 KHz (optical speed of 0.16 cm / sec), use 1.2 KHz electronic filter, set the undersampling ratio to 2 (set the number of laser signals to zero before sample collection), The sensitivity is set to 1, and a minimum of 128 scans are performed at a resolution of 4 cm ^-1 over the range of 375 to 4000 cm ^-1 (co-add).

The cis-, trans- and vinyl-polybutadiene peaks are typically found in the PAS spectrum within the range of 600-1100 cm ^-1 . Each transformer
-The area under the polybutadiene peak can be integrated. By determining the ratio of each peak area to the total area of the three isomers, it is possible to obtain a calibration curve showing the fraction of the trans-polybutadiene area versus the actual trans-polybutadiene content. The obtained correlation coefficient (R ² ) of this calibration curve needs to be at least 0.95. By filling the PAS cell with a freshly cut, non-contaminated surface-free sample containing no foreign materials such as mold release agents, using the above parameters, the points of interest (e.g., core Obtain a PAS spectrum for the unknown core material (at the surface or center). The unknown trans-polybutadiene area fraction is analyzed to determine the actual trans-isomer content from the calibration curve.

In one known situation, when barium sulfate is involved, the above method for testing trans-isomer content may be less accurate. Accordingly, an additional or alternative method for testing the trans-isomer content of polybutadiene is as follows. The calibration standard should consist of at least two polybutadienes of known trans-isomer content.
(Eg, of high and low trans-polybutadiene content). The resulting calibration curve is at least about 1
These samples can be used alone or to create a stepped sample with a trans-polybutadiene content of at least about 1.5% to 50%, including three equally spaced points, or a range of unknown quantities. And used together to determine Using a Fourier-transform Raman (FT-Raman) spectrometer equipped with a near-infrared laser, obtain the Stokes Raman spectrum of each standard using the following instrument parameters: Excessive heating or generation of fluorescence Laser power sufficient to obtain a good signal-to-noise ratio (S / N) that does not result (typically about 400-800 mW is appropriate); resolution: 2 cm ^-1 ; Raman shift Spectral range: about 400-4000 cm ^-1 ; and at least 300 scans are performed.

A calibration curve can be generated from the data obtained above using chemometric methods and software, such as PLS Plus / IQ available from Galactic Industries Corp. of NH Salem. Available calibration curves are SNV (detrend) optical path length correction, mean center data preparatio
n) and a 5-point SG second derivative over the spectral range of about 1600-1700 cm ^-1 was used to obtain this software using the resulting PLS-1 curve. The correction coefficient (R2) of the obtained calibration curve must be at least 0.95. A Raman spectrum of the core material is obtained using the device at the point of interest of the sample (eg, at the surface or center of the golf ball core). This sample needs to be free of foreign substances such as a release agent. Using the PLS calibration curve, the spectrum of the sample is analyzed to determine the trans-polybutadiene isomer content of the sample.

A source of free radicals, often referred to as free radical initiators, is required in the compositions and methods of the present invention. The source of free radicals is typically a peroxide, preferably an organic peroxide. Suitable sources of free radicals are di-t-amyl peroxide, di (2-t-butylperoxyisopropyl) benzene peroxide, 1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, dicumyl peroxide, di
-t-butyl peroxide, 2,5-di- (t-butylperoxy)
-2,5-dimethylhexane, n-butyl-4,4-bis (t-butylperoxy) valerate, lauryl peroxide, benzoyl peroxide, t-butylhydroxy peroxide, etc., and any mixtures thereof . This peroxide typically has about 0.1 per 100 parts of total elastic polymer component.
Parts, preferably from about 0.1 to 15 parts per 100 parts of the total elastic polymer component, and more preferably from about 0.2 to 5 parts per 100 parts of the total elastic polymer component. It is noted that the presence of some cis-trans conversion catalysts according to the present invention may require large amounts of free radical sources, e.g., as described herein, as compared to conventional crosslinking reactions. It should be understood by those skilled in the art. Alternatively or additionally, the free radical source can be one or more electron beams, UV or gamma rays, X-rays or any other high energy radiation source that can generate free radicals. Furthermore, it should be understood that heating facilitates the initiation of free radical generation.

A crosslinking agent is added to increase the hardness of the reaction product. Suitable crosslinking agents include metal salts of one or more unsaturated fatty acids or monocarboxylic acids, such as zinc, calcium or magnesium acrylate salts and the like, and mixtures thereof. Preferred acrylates include zinc acrylate, zinc diacrylate, zinc methacrylate, and zinc dimethacrylate and mixtures thereof. The crosslinker must be present in an amount sufficient to crosslink some of the polymer chains in the elastomeric polymer component.
For example, a given composition can be obtained by adjusting the amount of a crosslinking agent. This can be achieved in a manner well known to those skilled in the art, for example, by varying the type and amount of crosslinker. The crosslinker is typically present in an amount greater than about 0.1% of the elastomeric polymer component, preferably about 10-40% of the elastomeric polymer component, more preferably about 10% of the elastomeric polymer component.
It is present in amounts up to 30%. If organic sulfur is selected as the cis-trans conversion catalyst, zinc diacrylate is selected as the crosslinker and is present in an amount less than about 25 phr.

The filler added to one or more portions of the golf ball typically has rheological and mixing properties, specific gravity.
(E.g., density-modifying fillers), and include processing aids or compounds that affect modulus of elasticity, tear strength, reinforcing properties, and the like. These fillers are generally inorganic and suitable fillers include a number of metals or metal oxides, such as zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate, calcium carbonate, barium carbonate, clay, tungsten,
Includes tungsten carbide, a series of silicas, and mixtures thereof. Fillers can also include various blowing agents, which one of skill in the art can readily select.
Polymer, ceramic, metal and glass microspheres can be solid, hollow, and filled or unfilled.
Also typically, a filler is added to one or more portions of the golf ball according to the present invention to adjust its density to meet uniform golf ball criteria. Fillers can be used to alter the mass of at least one additional layer for the central or special ball. This is because, for example, a low-swing-speed player prefers a low-mass ball.

In accordance with the present invention, these polymers, free radical initiators, fillers and any other materials used in forming the golf ball center or any portion of the core are known to those skilled in the art. The mixture can be obtained by any type of mixing. Suitable types of mixing include single pass and multiple pass mixing, and the like.
The crosslinker and any other optional additives used to improve the properties of the golf ball center or additional layers can likewise be incorporated by any mixing method. Single pass mixing, in which the components are added sequentially, is preferred. This is because this type of mixing increases the efficiency of the method and reduces its cost. A preferred mixing cycle is a single step in which the polymer, cis-trans conversion catalyst, filler, zinc diacrylate and peroxide are added sequentially. Suitable mixing devices are well known to those skilled in the art,
Such an apparatus can be a Banbury mixer, a two roll mill or a twin screw extruder. Typically, conventional mixing speeds for compounding the polymer are used,
This rate must be high enough to ensure a substantially uniform dispersion of these components.

On the other hand, this speed must not be too high. This is because high mixing speeds tend to cut the polymer to be mixed, and in particular may unduly reduce the molecular weight of the elastic polymer component. Thus, the rate needs to be low enough to avoid high shear, which could lose a given high molecular weight portion of the polymer component. Also, mixing speeds that are too high can undesirably result in the generation of enough heat to initiate crosslinking before the preform is molded and mounted around the core. The mixing temperature depends on the type of polymer component and, more importantly, the type of free radical initiator. For example, if di (2-t-butyl-peroxyisopropyl) benzene is used as the free radical initiator, the safe mixing of these components requires about 80-125 ° C, preferably about 88-110 ° C. C. and more preferably a mixing temperature of about 90-100.degree. C. is suitable. It is further important that the mixing temperature be kept below the decomposition temperature of the peroxide. For example, if dicumyl peroxide was selected as the peroxide, the temperature would be about 93.3 ° C.
(200 ° F). Suitable mixing speeds and temperatures are well known to those skilled in the art or can be readily determined without undue experimentation.

The mixture can be subjected to, for example, compression or injection molding to obtain a hemispherical shell for forming the central solid sphere or intermediate layer. Subjecting the polymer mixture to a molding cycle where heat and pressure are applied;
Meanwhile, the mixture is confined in a mold. The shape of the mold cavity depends on the portion of the golf ball to be molded.
This compression and heat liberates free radicals by decomposing one or more peroxides, which simultaneously initiates the cis-trans conversion and crosslinking. The temperature and time of the molding cycle are selected based on the type of peroxide and cis-trans conversion catalyst selected. This molding cycle is performed at a single temperature for a certain period of time.
A single step of molding the mixture can be included. An example of a single step molding cycle for a mixture containing dicumyl peroxide would be to maintain the polymer mixture at about 171 ° C. (340 ° F.) for 15 minutes. The molding cycle also includes a two-step process wherein the polymer mixture is maintained in the mold at a first temperature for a first time period, and then to a second, typically higher, temperature. For a second period. An example of a two-stage molding cycle is to maintain the mold at about 143 ° C (290 ° F) for 40 minutes, then raise the mold to about 171 ° C (340 ° F) and maintain at this temperature for 20 minutes Things. In a preferred embodiment of the present invention, a one-stage cure cycle is used. The one-step method is effective and efficient, reducing the time and cost of the two-step method. In accordance with the present invention, the elastic polymer components used in making the golf ball center or any portion of the core of the present invention include polybutadiene, cis-trans conversion catalyst, additional polymer, free radical initiator, filler and optional The other materials are combined to produce a golf ball by an injection molding method, which is also well known to those skilled in the art. The cure time depends on the various materials selected, but a particularly suitable cure time is about 5-18 minutes, preferably about 8-15 minutes, and more preferably about 10-12 minutes. One skilled in the art can easily adjust the cure time up or down based on the particular materials used and the discussion herein.

The cured elastomeric polymer component, which contains a greater amount of trans-polybutadiene than the uncured elastomeric polymer component, is molded into an article, wherein the points inside have a first hardness and The surface has a second hardness, wherein the second hardness is different from the first hardness and is 10% higher than the first hardness. Preferably, the article is a sphere and the point is the center point of the article. In another embodiment, the second hardness is different from the first hardness and is 20% higher than the first hardness. The cured article includes a first amount of trans-polybutadiene at an internal location and a second amount of trans-polybutadiene at a surface location;
Wherein the first amount is at least about 6% greater than the second amount.
Small, preferably at least about 10% less than the second amount
Small, and more preferably at least about 20% less than the second amount. The interior location is preferably a central location and the article is preferably a sphere. Preferably, the compression ratio of the golf ball core, or a portion of the core, prepared according to the present invention is less than about 50, and more preferably less than about 25.

[0048] The cover provides an interface between the ball and the club. Desirable properties for this cover include, among other things, good formability, high abrasion resistance, high tear strength,
High resilience and good release properties. The cover is typically thick enough to provide sufficient strength, good performance characteristics and durability. Preferably, this cover is about
Less than 0.254 cm (about 0.1 in), more preferably about 0.127 cm
(About 0.05 in) and most preferably from about 0.051 to about 0.10
It has a thickness of 2 cm (about 0.02 to about 0.04 in). The present invention is particularly directed to a multi-layer golf ball that includes a core, an inner cover layer, and an outer cover layer. In this embodiment, preferably, at least one of the inner cover layer and the outer cover layer is less than about 0.127 cm (about 0.05 in), more preferably about 0.051 to about 0.102 cm (about 0.02 to about 0.12 cm).
0.04 in). Most preferably, this thickness of any layer is about 0.03 cm (about 0.03 in).

When the golf ball of the present invention includes an intermediate layer, for example, an inner cover layer, this layer can include any material known to those skilled in the art, including thermoplastic and thermoset materials. The intermediate layer may be of any suitable material, such as from EI Dupont Dnemours, Inc. of DE Wilmington, under the trademark Surlyn, or Exxon.
It can include ionic copolymers of ethylene and an unsaturated monocarboxylic acid, etc., available from the company as IOTEK or ESCOR. These are copolymers or terpolymers of ethylene and methacrylic or acrylic acid, partially zinc, sodium, lithium, magnesium, potassium, calcium,
Neutralized with salts such as manganese and nickel, where these salts are olefins having 2 to 8 carbon atoms,
It is a reaction product with 3 to 8 unsaturated monocarboxylic acids. The carboxylic acid groups of the copolymer are completely or partially neutralized and may include methacrylic acid, crotonic acid, maleic acid, fumaric acid or itaconic acid. The golf ball can include one or more homopolymer or copolymer inner cover layer materials, also listed below:

(1) vinyl resins, such as those produced by the polymerization of vinyl chloride or copolymerization of vinyl chloride with vinyl acetate, acrylate or vinylidene chloride;
(2) polyolefins such as polyethylene, polypropylene, polybutylene and copolymers such as ethylene
-Copolymers and homopolymers produced using methacrylates, ethylene-ethyl acrylate, ethylene-vinyl acetate, ethylene-methacrylic acid or ethylene-acrylic acid or propylene-acrylic acid and single-site or metallocene catalysts, (3) Polyurethanes, such as those prepared from polyols and diisocyanates or polyisocyanates and US Pat. No. 5,334,67
No. 3, (4) Polyureas, such as those described in U.S. Pat.No. 5,484,870, (5) Polyamides, such as poly (hexamethylene adipamide prepared from diamines and dibasic acids ) And other polyamides and amino acids, such as poly (caprolactam), and blends of polyamides with Surlyn, polyethylene, ethylene copolymers, ethyl-propylene-nonconjugated diene terpolymers, such as acrylic resins and Blends of these resins with polyvinyl chloride, elastomers, etc.

(7) thermoplastic resin, for example, urethane; olefinic thermoplastic rubber, for example, a blend of polyolefin and ethylene-propylene-non-conjugated diene terpolymer; styrene and butadiene, isoprene or ethylene
-Block copolymer with butylene rubber; or copoly
(Ether-amide), such as Pebax (PE) marketed by ELF Atochem of PA
BAX), (8) Polyphenylene oxide resin or MA Pittsfield's General Electric
blends of polyphenylene oxide and high impact polystyrene, such as those sold under the trademark NORYL by Ctric Company; (9) thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / modified Glycols and elastomers marketed under the trademark HYTREL by EI Dupont-Donnemores of Wilmington, and by the General Electric Company of Pittsfield, MA under the trademark LOMOD, (10) Polycarbonate with acrylonitrile-butadiene-styrene, polybutylene terephthalate, polyethylene terephthalate, styrene-maleic anhydride, polyethylene, elastomer, etc., and polyvinyl chloride with acrylonitrile-butadiene- Styrene or ethylene, - a blend of blends and alloys of vinyl acetate or other elastomers, and (11) and a thermoplastic rubber, polyethylene, polypropylene, polyacetal, nylon, polyesters, cellulose esters and the like.

Preferably, the optional intermediate layer comprises a polymer, for example a homopolymer based on ethylene, propylene, butene-1 or hexene-1 and containing functional groups such as acrylic acid and methacrylic acid. Or copolymers and fully or partially neutralized ionomer resins and blends thereof, methyl acrylate, methyl methacrylate homopolymers and copolymers, imidized amino-containing polymers, polycarbonates, reinforced polyamides, polyphenylene oxides, impact resistance Polystyrene, polyetherketone, polysulfone,
Poly (phenylene sulfide), acrylonitrile-butadiene, acrylic acid-styrene-acrylonitrile, poly
(Ethylene terephthalate), poly (butylene terephthalate), poly (ethylene vinyl alcohol), poly (tetrafluoroethylene) and copolymers thereof containing functional comonomers, and blends thereof. Suitable cover compositions also include polyether or polyester thermoplastic urethanes, thermoset polyurethanes, low modulus ionomers such as E / X / Y terpolymers, where E is ethylene, and X is about 0-50% by weight. A softening comonomer based on acrylate or methacrylate present in an amount of
And Y is acrylic acid or methacrylic acid present in an amount of about 5-35% by weight). More preferably, in low spin rate embodiments designed to achieve maximum flight distance, the acrylic acid or methacrylic acid has about 16-35 mass
%, Making the ionomer a high modulus ionomer. In a high spin embodiment, the inner cover layer contains an ionomer, wherein the acid is present in an amount of about 10-15% by weight and includes a softening comonomer. Preferably, the cover comprises a polyurethane composition containing the reaction product of at least one polyisocyanate, polyol and at least one curing agent.

[0053] Any polyisocyanate available to one of skill in the art is suitable for use in the present invention. Examples of polyisocyanates are 4,4'-diphenylmethane diisocyanate (MDI), polymer MDI, carbodiimide-modified liquid MD
I, 4,4'-dicyclohexylmethane diisocyanate (H12
MDI), p-phenylene diisocyanate (PPDI), toluene diisocyanate (TDI), 3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI),
Naphthalene diisocyanate (NDI), xylene diisocyanate (XDI), p-tetramethyl xylene diisocyanate (p-TMXDI), m-tetramethyl xylene diisocyanate (m-TMXDI), ethylene diisocyanate, propylene-1,2-diisocyanate, tetramethylene- 1,4-diisocyanate, cyclohexyl diisocyanate, 1,6-hexamethylene-diisocyanate (HDI), dodecane-1,12-
Diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-isocyanato-3,3,5-
Trimethyl-5-isocyanatomethylcyclohexane, methylcyclohexylene diisocyanate, HDI triisocyanate, 2,4,4-trimethyl-1,6-hexane diisocyanate (TMDI), tetracene diisocyanate, naphthalene diisocyanate, anthracene diisocyanate, and these Including but not limited to mixtures. Polyisocyanates are known to those skilled in the art as one or more isocyanate groups such as di-, tri- and tetra-isocyanates. Preferably, the polyisocyanate comprises MDI, PPDI, TDI or a mixture thereof, and more preferably the polyisocyanate comprises MDI. As used herein, the term `` MDI '' includes 4,4′-diphenylmethane diisocyanate, polymeric MDI, carbodiimide-modified liquid MDI, and mixtures thereof, and the diisocyanate further used is As will be appreciated by those skilled in the art, it should be understood that the "free monomer" can be "low free monomer" and has a low level of "free" monomeric isocyanate groups, typically less than about 0.1% free monomer groups. It is. Examples of "low free monomer" include, but are not limited to, low free monomer MDI, low free monomer TDI and low free monomer PPDI.

[0054] The at least one polyisocyanate should have less than about 14% unreacted NCO groups.
Preferably, the at least one polyisocyanate should have no more than about 7.5% NCO groups, and more preferably, should have less than about 7.0% NCO groups. Any polyol available to those skilled in the art is suitable for use in the present invention. Examples of polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadienes (including partially / fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols.
In one preferred aspect, the polyol comprises a 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. Preferably, the polyol used in the present invention comprises PTMEG.

[0055] In another embodiment, a polyester polyol is included in the polyurethane material of the present invention. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol, polybutylene adipate glycol, polyethylene propylene adipate glycol, o-phthalate-1,6-hexanediol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In another embodiment, a polycaprolactone polyol is included in the materials of the present invention. Suitable polycaprolactone polyols are
1,6-hexanediol-initiated polycaprolactone, diethylene glycol-initiated polycaprolactone, trimethylolpropane-initiated polycaprolactone, neopentyl glycol-initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone and mixtures thereof But not limited to these. The hydrocarbon chain is
It can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In yet another embodiment, the polycarbonate polyol is included in a polyurethane material of the present invention. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate. 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 about 200
It is in the range of ~ 4000.

Polyamine curing agents are also suitable for use in the polyurethane compositions of the present invention, and have been found to improve the cut, shear and impact resistance of the resulting balls. Preferred polyamine curing agents are 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers, for example, 3,5-diethyltoluene-2, 6,4-diamine; 4,4'-bis (sec-butylamino) -diphenylmethane; 1,4-bis (sec-butylamino) -benzene, 4,4'-methylene-bis (2-chloroaniline); 4'-methylene-bis (3-
Chloro-2,6-diethylaniline); polytetramethylene oxide-di-p-aminobenzoate; N, N'-dialkyldiaminodiphenylmethane; p, p'-methylenedianiline (MD
A), m-phenylenediamine (MPDA); 4,4'-methylenebis
(2-chloroaniline) (MOCA); 4,4'-methylenebis (2,6-diethylaniline); 4,4'-diamino-3,3'-diethyl-5,5'-
Dimethyldiphenylmethane; 2,2 ', 3,3'-tetrachlorodiaminodiphenylmethane;4,4'-methylenebis (3-chloro
-2,6-diethylaniline); trimethylene glycol di-p
-Aminobenzoates; and mixtures thereof, but is not limited thereto. Preferably, the curing agent of the present invention is 3,5-dimethylthio-2,4-toluenediamine and its isomers, such as Albermar, LA Baton Rouge.
Includes ETHACURE 300, which is commercially available from (Albermarle Corporation). Suitable polyamine curing agents include primary and secondary amines and preferably have a molecular weight in the range of about 64 to about 2000.

At least one of diols, triols, tetraols or hydroxy-terminated curing agents can be added to the polyurethane composition described above. Suitable diol, triol and tetraol groups are ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, low molecular weight polytetramethylene ether glycol, 1,3-bis (2-hydroxyethoxy) benzene, 1,3-
Bis [2- (2-hydroxyethoxy) ethoxy] benzene, 1,
3-bis {2- [2- (2-hydroxyethoxy) ethoxy] ethoxy} benzene, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, resorcinol-di- (β-
Hydroxyethyl) ether, hydroquinone-di- (β-hydroxyethyl) ether, and mixtures thereof. Preferred hydroxy-terminated curing agents include ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, and mixtures thereof.
Preferably, the hydroxy-terminated curing agent is about 48-
It has a molecular weight in the range of 2000. As used herein, molecular weight is to be understood as being the absolute weight average molecular weight and as such will be understood by those skilled in the art.

Both the hydroxy-terminated curing agent and the amine curing agent can contain one or more saturated or unsaturated aromatic and cyclic groups. Further, these hydroxy-terminated and amine curing agents can contain one or more halogen atoms. The polyurethane composition of the present invention can be manufactured using a blend or mixture of curing agents. However, if desired, the polyurethane compositions of the present invention can be made with a single curing agent. Any method known to those skilled in the art can be utilized to combine the polyisocyanates, polyols and curing agents of the present invention. One commonly used method, known in the art as the one-shot method, involves simultaneously mixing the polyisocyanate, polyol and curing agent. This method gives a heterogeneous (more random) mixture and gives the manufacturer less control over the molecular structure of the resulting composition. A preferred mixing method is known as a prepolymer method.
In this method, the polyisocyanate and the polyol are separately mixed before adding the curing agent. This method gives a more homogeneous mixture and consequently a more consistent polymer composition.

The optional filler component can be selected to provide additional density to the blend of the components. The choice of such a filler will depend on the given golf ball type (ie, one-piece, two-piece multi-component, or thread wound). Examples of useful fillers are zinc oxide,
Includes barium sulfate, calcium oxide, calcium carbonate and silica, and other well-known corresponding salts and oxides thereof. Additives, including nanoparticles, glass spheres, and various metals such as titanium and tungsten, can be added to the polyurethane compositions of the present invention in the amounts required for their well-known purposes. Additional components that can be added to the polyurethane composition of the present invention include UV stabilizers, and other dyes, as well as optical brighteners and fluorescent pigments and dyes. Such ancillary components may be added in any amount that will achieve its predetermined purpose. It has been found by the present invention that the use of a castable and reactive material, applied as a fluid, can form an extremely thin outer cover layer on a golf ball because of the extremely thin features. Specifically, it has been found that castable and reactive liquids that react to form a urethane elastomeric material provide the desired very thin outer cover layer.

The castable and reactive liquid used to form the urethane elastomeric material utilizes various coating techniques well known in the art, such as spraying, dipping, spinning or flowing. Can be applied on the inner core layer.
One example of a suitable coating technique is "Method and Apparatus for Forming Polyurethane Covers on Golf Balls"
Apparatus For Forming Polyurethane Cover On A Gol
f Ball) ", filed on May 2, 1995, which is incorporated herein by reference, and which is hereby incorporated by reference in its entirety. The cover is formed around the inner cover layer, preferably by mixing and introducing the material into a mold section. By tracking the viscosity over time, filling each mold part, introducing the core into one mold part, and closing the mold, the centering of the melted core cover part is performed. It is important to be able to define a suitable time to ensure overall uniformity. Having determined the viscosity range of the curing urethane mix suitable for introducing the core into the mold part, it is approximately in the range of about 2000 cP to about 30,000 cP, with a preferred range being: It is in the range of about 8000 cP to about 15,000 cP.

To begin production of the cover, the mixture of the prepolymer and the curing agent is fed into a running mixer including a mixing head by feeding weighed curing agent and prepolymer along a line. Do with. The top is filled with preheated mold parts and placed in the fixture using pins that move through holes in each mold. After allowing the reaction material to dwell in the upper mold section for about 40 to about 80 seconds, the core is charged into the gelled reaction mixture at a controlled rate. At a later point in time, the lower mold section or series of lower mold sections will contain a similar amount of the mixture introduced into its cavity. The ball cup holds the ball core by the reduced pressure (partial vacuum) in the hose. After gelling for about 40 to about 80 seconds, at the location of the coated core in the mold section, the vacuum is released and the core is removed. These mold parts having a core and a solidified cover part,
Remove from the centering fixture, invert and combine at an appropriate early point with other mold parts containing the reactive polyurethane prepolymer and curing agent in amounts selected to initiate gelation. Similarly, also Brown
U.S. Pat. No. 5,006,297 and Wu U.S. Pat. No. 5,334,673 both disclose suitable molding techniques that can be used with the castable and reactive liquids used in the present invention. Further, U.S. Patent Nos. 6,180,040 and 6,1
No. 80,722 discloses a method of making a double core golf ball. The entire disclosures of these patents are incorporated by reference for the present invention. However, the method of the present invention is not limited to using these techniques.

Depending on the desired properties, the balls produced according to the present invention may have, as compared to balls of conventional construction,
Substantially the same or high resilience or coefficient of restitution
(COR) and indicates a decrease in compressibility or modulus. Further, the balls made according to the present invention exhibit substantially higher resilience or COR without increasing the compressibility as compared to balls having conventional structures. Another measure of this resilience is "loss tangent" or tan δ, which is obtained by measuring the dynamic stiffness of an object. Loss tangents and terminology related to such dynamic properties are typically described in ASTM D4092-90. Thus, a low loss tangent indicates a high resilience and thus a high resilience. A low loss tangent converts most of the energy imparted to the golf ball from the golf club into mechanical energy, the rate of firing, resulting in a high flight distance. The stiffness or compression stiffness of a golf ball can be measured, for example, by dynamic stiffness. Higher dynamic stiffness indicates higher compression stiffness.
To produce a golf ball with a given compression stiffness, the dynamic stiffness of the crosslinked reaction product must be less than about 50,000 N / m at -50 ° C. Preferably, the dynamic stiffness is between about 10,000 and 40,000 at -50 ° C.
N / m, more preferably this dynamic stiffness is -50
In the range of about 20,000-30,000 N / m at ° C.

The resulting golf ball typically has a diameter of about 0.7
, Preferably greater than about 0.75 and more preferably greater than about 0.78. The golf ball also typically has at least about 40, preferably about 50-12
It has an etch compression of 0, and more preferably about 60-100. The golf ball polybutadiene material of the present invention typically has a flexural modulus in the range of about 500-300,000 psi, preferably about 2000-200,000 psi. The golf ball polybutadiene material typically has at least about 15 Shore A, preferably about 30-80 Shore A, and more preferably about 50-60 Shore A.
With hardness. The specific gravity of the center composition is typically about 0.
Greater than 7 and preferably greater than about 1.0. The center and the outer core layer can have the same or different specific gravity values. In one embodiment, the center and the outer core layer have different specific gravity values. However, it is preferred that the specific gravity of the outer core layer and the center differ by less than 0.1.

[0064] The center composition should include at least one rubber material having an elasticity index of at least about 40. Preferably, the elasticity index is at least about 50. Polymers that produce elastic golf balls and are consequently suitable for the present invention include, but are not limited to, CB23, CB22, BR60 and 1207G. To clarify how to calculate the elasticity index, for example, the elasticity index for CB23 is calculated as follows: elasticity index of CB23 = 100,000 · [(0.954) (0.407)] / 990; C
Elasticity Index of B23 = 55 The molding methods and compositions for the golf ball portion described above typically result in a gradient in material properties. The methods used in the prior art generally utilize hardness to quantify these gradients. Hardness is a qualitative measure of the static modulus and does not represent the modulus of the material at the rate of deformation associated with golf ball applications, ie, impact from a club. As is well known to those having skill in the polymer sciences, another deformation rate can be evaluated using the principle of time-temperature superposition. For golf ball parts containing polybutadiene,
A 1-Hz swing at a temperature in the range of 0 ° C. to −50 ° C. is considered to be qualitatively equivalent to the impact rate of the golf ball. Therefore, the performance of the golf ball at a temperature of preferably −20 ° C. to −50 ° C. can be predicted by using the loss tangent and the dynamic rigidity at 0 ° C. to −50 ° C.

In addition, the vulcanized rubber, such as polybutadiene, in golf balls prepared according to the present invention typically comprises from about 40 to about 80, more preferably from about 45 to about 60, and most preferably from about 45 to about 55. It has a Mooney viscosity in the range.
Mooney viscosity is typically measured according to ASTM D-1646. When making golf balls according to the present invention, they will typically have a dimple coverage of greater than about 60%, preferably greater than about 65%, and most preferably greater than about 75%. The flexural modulus of the golf ball cover, measured according to ASTM method D6272-98, Procedure B, typically exceeds about 3.445 MPa (about 500 psi), and preferably is about
It is in the range of 3.445-1033 MPa (about 500-150,000 psi). As discussed herein, the outer cover layer is preferably made of a relatively flexible polyurethane material. In particular,
The material for this outer cover layer is preferably less than about 60 Shore D, more preferably less than about 5 as measured by ASTM-2240.
It should have a material hardness of less than 5 Shore D and most preferably less than about 50 Shore D. The hardness of the outer cover layer, measured on the golf ball, is preferably greater than about 50. The inner cover layer is preferably less than 72 Shore D, more preferably less than about 70 Shore D and most preferably about 6 Shore D.
Has a material hardness of less than 8 Shore D. Preferably, the center, the outer core layer and the inner cover layer each have a different hardness, and more preferably the hardness increases stepwise from the center to the outer cover layer, i.e. The outer core layer is harder than the center and the inner cover layer is harder than the outer core layer.

The overall outer diameter (OD) of the center is preferably from about 0.953 cm to about 3.56 cm (about 0.375 in to about 1.4 in),
More preferably, from about 1.27 cm to about 3.18 cm (about 0.5 in to about 1.
25 in) and most preferably from about 2.29 cm to about 3.05 cm (about
0.9 in to about 1.2 in). OD of the outer core layer
Is about 3.56 cm to about 4.11 cm (about 1.4 in to about 1.62 in), more preferably about 3.86 cm to about 4.04 cm (about 1.52 in to about 1.5 in.
9 in) and most preferably from about 3.90 cm to about 4.01 cm (about
1.535 in to about 1.58 in). The OD of the inner cover layer of the golf ball according to the present invention is about 4.01 cm (about
1.58 in), more preferably from about 4.04 cm to about 4.2
2 cm (about 1.59 in to about 1.66 in) and most preferably about
It is in the range of about 1.6 inches to about 1.64 inches. The multilayer golf ball of the present invention can have an overall diameter (total diameter) of any size. However, the United States Golf Association (USG)
The standard A) specifies the minimum size of a golf ball for competition.
Limited to 4.267 cm (1.680 in). There is no regulation on the maximum diameter. However, for entertainment competitions, golf balls of any size can be used. The preferred diameter of current golf balls is from about 4.267 cm to about 4.572 cm (about
1.680 in to about 1.800 in). Its more preferred diameter is about 4.267 cm to about 4.470 cm (about 1.680 in to about 1.760 i
n). Its most preferred diameter is from about 4.267 cm to about 4.42
0 cm (about 1.680 in to about 1.740 in).

Golf balls of the present invention should have a moment of inertia (MOI) of less than about 83 and preferably less than about 82. This MOI is typically manufactured by Inertia Dynamics of CT Collinsville, Model No.MOI-005-104 Moment of Inertia Instrument (Moment of Inertia Instrument)
Measure in t). This device is integrated into the PC for connection via the COMM port, and the MOI instrument software
(MOI Instrument Software) Operate using version # 1.2. Golf balls of the present invention should have a center deformation of greater than about 4.5 mm under a load of 100 Kg. Preferably, this central deformation is greater than about 4.8 mm under a load of 100 Kg, and more preferably greater than about 5.0 mm. The data for this variant is available from Mono Research Laboratories (Mono Resear
ch Labs.), Stable Microsystems, Materials Master (Stable Micro Systems)
Measured using a Systems, MaterialsMaster) (No. MT-LQ) device. This MT-LQ has a 500 kg load cell,
The measurement of the deformation starts when a 60 g load is placed on the device. Prior to the deformation measurement, the surface plate is calibrated. After calibration, the operator places the sphere to be measured on the surface of the bottom platen. Raise the upper platen of the device to about 2.54 cm / min (1 in / mi
n) Move down at a crosshead speed of When the surface of the upper platen contacts the sphere and the compression force reaches 60 g (starting force), the displacement is measured as a function of the force, where the force is an independent variable on the x-axis . The apparatus determines a predetermined number of data points / minute, which gives a plot of displacement versus force, from which the displacement of the sphere at a load of 100 Kg is determined.

[0068]

EXAMPLES Two types of golf balls were manufactured according to the present invention, each of which is shown in Table 1 below in VDC45 and VDC48.
It was named. These VDC golf balls include a core, the core comprising a solid center having a diameter of about 2.54 cm (1.0 in) and an outer core layer having a thickness of about 0.699 cm (0.275 in).
The outer diameter of this core was about 3.94 cm (1.55 in). This core was covered with an inner cover layer of about 0.889 mm (0.035 in) thickness and an outer cover layer of about 0.762 mm (0.030 in) thickness to produce a golf ball having an outer diameter of about 4.27 cm (1.68 in). Control golf balls were manufactured according to conventional techniques. This control golf ball has a diameter of about 3.94 cm.
Manufactured from a solid core (1.550 in), an inner cover layer of about 0.889 mm (0.035 in) thickness and an outer cover layer of about 0.762 mm (0.030 in) thickness, the outer diameter of the resulting golf ball is
It was about 4.27 cm (1.68 in). Table 1 below shows the composition of the central portion of each of these golf balls.

[0069]

[Table 1] 1: DCP-70 is a dicumyl peroxide on a pelletized binder, OH Chardon's Elastchem
ochem, Inc.). 2: Akzo Nobel Chemicals of IL Chicago
Peroxide mixture on filler, commercially available from Chemicals Inc.).

The composition of the outer core layer of the two VDC balls was high Mooney viscosity CB23 polybutadiene, zinc diacrylate, zinc oxide, DCP-70, Kurary TP 25
1, including Varox 231XL and a colored dispersion.
The inner cover layer had the same configuration as both of these VDC balls and the control ball. The inner cover layer is a 50/50 Na / Li of Surlyn® 8945 and Surlyn 7940.
It was a blend. The outer cover layer of the VDC45 ball is
Polyurethane Sp. Cured with Ethacure 300 (18.7%), commercially available from Albemarle Corp.
PMS1088 prepolymer (77.8%), commercially available from Ecialties Co.), and Harvic Chemical (Harwi
ch Chemical) as a commercially available white dispersion
(3.5%). The outer cover layer of the VDC48 ball is a commercially available EtaCure 300 from Albemarle.
(16%) cured, commercially available from Uniroyal, Vibrathane B-625 prepolymer (80.5%; NCO: 6.1-6.6%), and commercially available from Herbic Chemical White dispersion (3.5
%)including. These VDC balls were manufactured in two different configurations, one having an outer cover layer having a material Shore D hardness of about 45, and the second having an outer cover layer having a material Shore D hardness of about 48. Had layers. These VDC balls were tested for various golf ball properties, such as ball compressibility, center hardness (internal and surface), core layer hardness, internal cover layer hardness, cover hardness, and identical properties. Was compared with a control ball tested.

[0071]

[Table 2] 1: Hardness was measured directly on the golf ball (compared to material hardness).

The pop-out (firing) angle and the spin
Various golf clubs were measured for the C ball and the control ball. Table 3 below shows data on each ball classified into each club type.

[0073]

[Table 3] (1): ball speed: 167 mph; launch angle: 9 °; spin speed: 3500 rpm; club: driver; club head:
975D; Loft: 7.5 °; Shaft: Graphite Design YS9-X (2): Ball speed: 160 mph; Launch angle: 9.5 °; Spin speed: 3000 rpm; Club: Driver; Club head: 975D; Loft: 8.5 °; Shaft: X100 (3): Ball speed: 115 mph; Launch angle: 18.5 °; Spin speed: 9000 rpm; Club: 8-iron; Club head: DCI black; Loft: 40 °; Shaft: X100 (4): Ball Speed: 95 mph; launch angle: 24 °; spin speed: 10400 rpm; club: wedge; club head: D
CI Black; Loft: 46 °; Shaft: X100

From the data shown in Table 3, it is clear that the golf balls of the present invention reduce driver spin for both professional and standard drivers. Those skilled in the art will be well aware that reducing driver spin to optimize flight increases the distance from the tee. If this reduction is too large, spinning the 8-iron will make the approach shot into the green difficult to control, while spinning the wedge will cause the approach shot to stay in place on the green,
This is especially important if the competitor is pitching or chipping on the green. The invention described and claimed herein is not limited in scope by the specific embodiments described herein. As these embodiments are illustrative of some aspects of the present invention. All equivalent aspects are intended to fall within the scope of the present invention. Indeed, various modifications of the invention in addition to those described and shown herein will become apparent to those skilled in the art from the foregoing description. Such modifications fall within the scope of the appended claims.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a golf ball having a dual cover and a dual core according to the present invention.

[Explanation of symbols]

10. Golf ball; 12 Core; 14 Cover
16 center: 18 outer core layer; 20 outer cover layer; 22 inner cover layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryan B. Bosanco Massachusetts, United States 02739 Matapoisset Ocean de Live 3 (72) Inventor Edmund A. Hebert United States Massachusetts 02719 Fairhaven Ivy Lane 7

Claims (28)

[Claims] 1. A core comprising a core and a cover provided therearound, wherein the core comprises a center and at least one outer core layer adjacent to the center, and wherein the cover comprises at least one layer. An inner cover layer and an outer cover layer, wherein (a) the center is about 0.953 cm to about 3.56 cm (about 0.375 in.
About 1.4 in) outside diameter and 100 Kg load
(B) the outer core layer is about 3.56 cm to about 4.11 cm (about 1.4 in.
(C) the inner cover layer has an outer diameter of greater than about 1.58 in and a material hardness of less than about 72 Shore D; and (d) a golf ball, wherein the outer cover layer has a hardness of greater than about 50 Shore D. 2. The golf ball of claim 1, wherein the outer cover layer has a material hardness of less than about 55 Shore D. 3. The golf ball of claim 2, wherein the outer cover layer has a material hardness of less than about 50 Shore D. 4. The internal cover layer has a material hardness of about 60 to about
2. The golf ball according to claim 1, wherein the golf ball is in a range of 70 Shore D. 5. The material hardness of the inner cover layer is from about 60 to about
5. The golf ball according to claim 4, wherein the golf ball falls within a range of 65 Shore D. 6. The outer diameter of the inner cover layer is about 4.04 cm.
The golf ball of claim 1, wherein the golf ball is within a range of about 4.22 cm (about 1.59 in to about 1.66 in). 7. The inner cover layer has an outer diameter of about 4.06 cm.
About 4.17 cm (about 1.6 in to about 1.64 in)
7. The golf ball according to claim 6, wherein 8. The center having an outer diameter of about 1.27 cm to about 3.18 cm.
The golf ball of claim 1, wherein the golf ball is within a range of about 0.5 in to about 1.25 in. 9. The outer diameter of the center is between about 2.29 cm and about 3.05 cm.
9. The golf ball according to claim 8, wherein the golf ball is in a range from about 0.9 in to about 1.2 in. 10. The outer core layer has an outer diameter of about 3.86 cm.
The golf ball of claim 1, wherein the golf ball is within a range of about 4.04 cm (about 1.52 in to about 1.59 in). 11. The outer core layer has an outer diameter of about 3.90 cm.
11. The golf ball of claim 10, wherein the golf ball is within a range of about 1.535 inches to about 1.58 inches. 12. The golf ball of claim 1, wherein the golf ball has a moment of inertia of less than about 83 g · cm ² . 13. The center has a first hardness, the outer core layer has a second hardness exceeding the first hardness, and the inner cover layer has the second hardness. 2. The golf ball of claim 1, having a third hardness that exceeds. 14. The golf ball of claim 13, wherein the outer cover layer has a fourth hardness less than the third hardness. 15. The golf ball of claim 1, wherein the center has a first specific gravity and the outer core layer has a second specific gravity that differs by less than about 0.1. 16. The golf ball according to claim 1, wherein said center is solid. 17. The golf ball of claim 1, wherein the center is liquid, hollow, or filled with air. 18. A core including a core and a cover disposed therearound, wherein the core includes a solid center and an outer core layer adjacent to the center, and wherein the cover comprises an inner cover layer and an outer cover layer. (A) the center is from about 0.953 cm to about 3.56 cm (about 0.375 in.
About 1.4 in) outside diameter and 100 Kg load
(B) the outer core layer is about 3.56 cm to about 4.11 cm (about 1.4 in.
(C) the inner cover layer has an outer diameter of greater than about 1.58 in and a material hardness of less than about 72 Shore D; and (d) a golf ball, wherein the outer cover layer has a hardness of greater than about 50 Shore D. 19. The golf ball of claim 18, wherein the outer cover layer has a material hardness of less than about 50 and a thickness of less than about 0.035 in. 20. The center has a first hardness, the outer core layer has a second hardness exceeding the first hardness, and the inner cover layer has the second hardness. 20. The golf ball of claim 18, having a third hardness that exceeds. 21. The golf ball of claim 20, wherein the outer cover layer has a fourth hardness less than the third hardness. 22. The outer diameter of the inner cover layer is about 4.04 cm.
19. The golf ball of claim 18, wherein the golf ball is within a range of about 1.59 inches to about 1.66 inches. 23. The outer diameter of the inner cover layer is about 4.06 cm.
23. The golf ball of claim 22, wherein the golf ball is between about 1.6 inches and about 1.64 inches. 24. The outer diameter of the center is between about 1.27 cm and about 3.18.
1 cm (about 0.5 in to about 1.25 in).
8. The golf ball according to 8. 25. The outer diameter of the center is between about 2.29 cm and about 3.05 cm.
25 cm (about 0.9 in to about 1.2 in).
The golf ball as described. 26. The outer core layer has an outer diameter of about 3.86 cm.
19. The golf ball of claim 18, wherein the golf ball is in a range of about 1.5 inches to about 1.5 inches. 27. The golf ball of claim 18, wherein the golf ball has a moment of inertia of less than about 83 g · cm ² . 28. The golf ball of claim 18, wherein the center has a first specific gravity and the outer core layer has a second specific gravity that differs by less than about 0.1.