JP2004188206A - Golf ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball which reduces the spin rate of a driver. <P>SOLUTION: This golf ball has a core, an intermediate layer and a cover. The intermediate layer is formed of a blended material whose bending elasticity is at least approximate 70,000psi, and whose melt flow rate is at least approximate 4g/10-minute. The blended material has at least one ionomer of a high acid. In addition, the thickness of the intermediate layer is less than 0.0635cm (approximate 0.025 inches). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to golf balls, and more particularly, to a composition of a golf ball layer having desirable mechanical properties.

  Spin rate is an important property for both advanced golfers and golfers who play in the past. A higher spin rate allows more skilled players, such as PGA pros and less handicapped players, to have more control over the golf ball. High spin rate golf balls are advantageous for approach shots to the green. It can create a backspin, tweak it, cause the ball to stop on the green, create a sidespin, tweak it, draw or fade the ball, thereby effectively controlling the player's ball control. Improve. For this reason, more skilled players generally prefer high spin rate balls, especially for scoring irons such as 7 irons to sand wedges.

  On the other hand, a player with a distraction is not good at intentionally controlling the spin of the ball, and generally does not like a golf ball with a high spin rate. Such players often fail with slices and hooks. If the club head hits the ball improperly, unintentional side spins will be added to the ball, causing the ball to miss the intended course. The side spin causes the player to lose ball control and to reduce the straight line distance the ball flies. Golf balls with low spin do not tend to get off the line even if the ball does not hit the club face at right angles. A low spin ball will not fix the hook or slice, but will reduce the adverse effects of side spin. For this reason, players with distractions typically prefer low spin rate golf balls.

  The present invention has been made in consideration of the above circumstances, and has as its object to provide a golf ball capable of suppressing a spin rate.

  According to the present invention, in order to achieve the above object, a configuration as described in the claims is adopted.

Hereinafter, the present invention will be described in detail.
The present invention relates to a golf ball having a core, a cover, and an intermediate layer disposed therebetween. The formulation of the intermediate layer comprises a high-acid ionomer having at least about 16% by weight of the carboxylic acid. The high acid ionomer preferably has a melt flow rate of at least about 4 g / 10-min, and the carboxylic acid is neutralized by at least about 10% with the metal cation. The formulation preferably has a flexural modulus of at least about 70000 psi and a melt flow rate of at least about 4 g / 10-min, more preferably a melt flow rate of about 10 g / 10-min to about 100 g / 10-min. Have.

  The diameter of the core may be at least about 1.55 inches, and the thickness of the intermediate layer may be less than about 0.025 inches, preferably about 0.0127 cm. (About 0.005 inches) to about 0.02 inches. The hardness of the on-ball of the mid layer is preferably less than about 70 Shore D, and more preferably less than about 65 Shore D. On the other hand, the hardness of the composition forming the intermediate layer is preferably greater than about 65 Shore D, more preferably at least greater than about 70 Shore D. Further, the formulation may be blended with a modulus-enhancing filler such that the flexural modulus of the filled formulation is substantially greater than that without the filler. Suitable elasticity enhancing fillers are nanoscale or microscale fibers, filaments, flakes, whiskers, wires, tubes or particulates, such as tungsten, tungsten oxide, barium sulfate, carbon black, silica, or titanium oxide. Formed from material.

  The invention also relates to a core / intermediate layer / cover ball configuration wherein the intermediate layer comprises a blend comprising a blend of a first high acid ionomer and a second high acid ionomer. Each high acid ionomer has at least about 16% by weight carboxylic acid and has a melt flow rate of at least about 4 g / 10-min. The resulting formulation has a flexural modulus of at least about 70,000 psi and a melt flow rate of at least about 4 g / 10-min. The first and second high acid ionomers can be neutralized by about 30% to about 100% and have a weight ratio of about 5:95 to about 95: 5. The formulation may have a material hardness of at least about 65 Shore D, and the intermediate layer has an on-ball hardness of about 70 Shore D or less. Preferably, the formulation has a material hardness of at least about 70 Shore D and an on-ball hardness of about 65 Shore D or less. The composition further includes a modulus-enhancing filler such that the composition containing the filler has a substantially higher flexural modulus than the composition without the filler. The thickness of the intermediate layer can be from about 0.005 inch to about 0.02 inch.

  The invention further relates to a multi-layer golf ball having an intermediate layer formed from a formulation comprising a blend of a high acid ionomer and a high flow material. Preferably, the high acid ionomer has a carboxylic acid content of at least about 16% by weight, the high flow material has a melt flow rate of at least about 4 g / 10-min, and the blend has a flexural modulus of at least about 70,000 psi. And its melt flow rate is at least about 4 g / 10-min. The thickness of the intermediate layer is preferably from about 0.005 inches to about 0.02 inches. The high acid ionomer can have a melt flow rate of less than about 4 g / 10-min. The formulation may further include a modulus-enhancing filler, whereby the flexural modulus of the filled formulation is substantially greater than without the filler.

  High flow materials include thermoplastic elastomers, high flow ionomers, non-ionomer olefin / acid copolymers or terpolymers, partially or fully neutralized polymers, polyamides, polyolefins, polyurethanes, polyureas, epoxies, polyesters, polys Including ether esters, polyetheramides, polyamides, metallocene catalyzed polymers, functional styrene-butadiene-elastomers, styrenic block copolymers, acrylonitrile-polybutadiene-styrene copolymers, silicones, or metal salts of fatty acids. Preferably, the high flow ionomer has a carboxylic acid content of at least about 16% by weight and the non-ionomeric olefin / acid copolymer or terpolymer has a carboxylic acid content of about 5% to about 30% by weight. .

  Alternatively, the invention disclosed herein relates to a golf ball interlayer comprising a composition comprising at least one high acid ionomer, wherein the on-ball hardness of the intermediate layer is substantially greater than the material hardness of the composition. And preferably less than the material hardness of the formulation by at least about 5 Shore D, more preferably by at least about 10 Shore D. The high acid ionomer preferably has a melt flow rate of at least about 4 g / 10-min, has at least 16% by weight of carboxylic acid, and has a content of greater than about 30% by weight of the formulation. The material hardness of the formulation is preferably at least about 65 Shore D, more preferably at least about 70 Shore D. The hardness of the mid-layer on-ball is preferably less than about 70 Shore D, more preferably less than about 65 Shore D, and most preferably between about 45 Shore D and about 60 Shore D. Preferably, the melt flow rate of the formulation is at least about 4 g / 10-min and its flexural modulus is at least about 70,000 psi. The formulation may also include a filler for increasing the modulus of elasticity such that the flexural modulus of the formulation containing the filler is substantially greater than without the filler. Additionally or alternatively, at least one high flow material with a melt flow rate greater than about 4 g / 10-min may be added.

  The invention further relates to a golf ball intermediate layer having a thickness of less than about 0.025 inches (0.0635 cm) and comprising a composition comprising at least one high acid ionomer, wherein the intermediate layer comprises It has an on-ball hardness smaller than the material hardness. The thickness of the intermediate layer is preferably between about 0.005 inches and about 0.02 inches. The formulation preferably has a flexural modulus of at least about 70,000 psi and a melt flow rate of at least about 4 g / 10-min.

  The present invention relates to yet another golf ball intermediate layer comprising a blend comprising a blend of at least about 16% by weight of a carboxylic acid content and a thermoplastic elastomer, wherein the material hardness of the intermediate layer is substantially that of the on-ball. Greater than hardness. The thermoplastic elastomer may be an ionomer or a non-ionomer. The blend may also include a modulus-enhancing filler so that the filler-containing blend has a greater flexural modulus than without the filler.

[Definition]
As used herein, the term "flexural modulus" or "modulus" refers to the ratio of stress to strain within the elastic limit (as measured in bending mode) of a material. And is similar to the tensile modulus. This property is used to indicate the bending stiffness of the material. A three-point loading system is applied to the material of a simply supported beam, in the form of a rectangular bar, either molded directly or cut from a sheet or plate. The load is applied to the center point of the beam, and the load tip is pushed by the beam at a constant speed of 2 mm / min. The load deflection curve is plotted using the recorded data. The flexural modulus is equivalent to the angle of the tangent of the stress / strain curve at the curved portion where the beam is not yet deformed. Flexural modulus values are typically reported in Pascals ("Pa") or pounds per square inch (psi), among other units. For standard measurements of flexural modulus, Procedure B of ASTM D6267-98 ("Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electronic Materials-In-Digital Electronics-Internal-Medical-Instrumental-Electrical-In-the-Body").

  As used herein, the term “melt flow rate” (“MFR”) is also known as “melt flow index”, “melt flow”, “melt mass flow rate” or simply “flow rate” And the rate at which the thermoplastic is extruded from the orifice under load. Typically, an extrusion plastometer or rheometer is used, where a predetermined amount of material is forced into the barrel of a melt flow rate device and heated to a temperature specific to the material. Under a load determined by the material, the piston extrudes from a standardized die of a predetermined length and a predetermined diameter. The timed throughput is collected and weighed, and the MFR of the material is calculated in g / 10-min. Standard measurements for MFR include ASTM D1238-01el ("Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plasticometer"). Advantages of high MFR are easy extrusion, high extrusion speed, high flow rate during sealing (heat sealing), and the ability to produce a thin film of a moisture-proof layer. Although the invention is not limited to any theory, relatively high MFR materials have relatively low viscosities. If the viscosity is low, a thin film can be formed by applying the material uniformly and thinly.

  As used herein, the term "material hardness" is the indentation hardness of a non-metallic material in the form of a slab or button and is measured with a durometer. Non-metallic materials include thermoplastic elastomers, sulfurized (thermoset) rubbers, elastomeric materials, cellular materials, gel materials and other rubbers or plastics. The durometer is provided with a spring-loaded indenter, which applies a pushing load to the slab and measures its hardness. Material hardness indirectly affects other material properties such as tensile modulus, resilience, plasticity, compression resistance and elasticity. Standard measurements of material hardness include ASTM D2240-02a ("Standard Test Method for Rubber Property-Durometer Hardness"). The material hardness reported here is expressed in Shore D units.

  As used herein, the term "on-ball hardness" refers to the hardness of a given portion of a golf ball, measured directly on the surface of a golf ball (or other sphere surface), and refers to the material in terms of its properties and values. Completely different from hardness. The differences in value mainly depend on the golf ball elements (ie, center, core, and / or layer) under the portion to be measured, including their structure, size, thickness, material composition. . Therefore, those skilled in the art can easily understand that the on-ball hardness and the material hardness are not correlated and can not be converted.

  As used herein, the term "compression" is also known as "ATTI compression" or "PGA compression" and refers to a point obtained from a compression tester (ATTI Engineering Company, Union city, NJ). Indicated and also known in the art as a scale for determining the relative compression of an object. The compression tester is equipped with a Federal Dial Gauge (Model D81-C), which applies a spring load force to an object such as a golf ball center, a golf ball core, a core with additional layers, or the entire golf ball. Is added. A spring compression of 0.508 cm (0.2 inch) indicates a compression of 100 on the object, and a spring compression of 0.254 cm (0.1 inch) indicates a compression of 0 on the object. Compression is a material property (on-ball property) measured on a golf ball structure, not a property of the material itself.

  As used herein, the term “coefficient of restitution” or “COR” of a golf ball refers to the rebound of the ball relative to the initial input velocity when the ball is launched from an air launcher into a rigid vertical plate. Defined as a ratio of speeds. The faster a golf ball bounces, the greater the COR of the ball and the longer the distance achieved in play is typically longer. The initial speed is about 15.24 m / s (about 50 ft / s) to about 60.96 m / s (about 200 ft / s), and unless otherwise specified, is usually understood as 38.1 m / s (125 ft / s). Is done. Golf balls have different CORs for different initial velocities.

  As used herein, the term “nanoscale” is defined as having at least one dimension less than one micron (length, width, height, diameter, etc.), and the term “microscale” is defined as at least one It is defined as having a dimension of less than 1 mm.

  As used herein, the term "filler" is used to change certain properties of a selected portion of a golf ball, such as density or specific gravity, flexural modulus, tensile modulus, moment of inertia, hardness, abrasion resistance, weatherability. Means any compound or formulation that can be used for

  The term “about,” as used in connection with a number, a larger number, or a range of numbers, is to be understood to refer to all such numbers or all numbers in the range. .

  According to the present invention, a golf ball with a reduced spin rate of the driver can be realized.

  The golf ball of the present invention may have various multilayer structures including at least one core, one cover, and one intermediate layer disposed between the core and the cover. The core may be a single solid mass or may include a center and one or more outer core layers. The center may be one-piece, liquid-filled, gel-filled, or gas-filled. The cover may include one or more inner cover layers and one outer cover layer. Any outer cover layer, intermediate layer or inner cover layer, wound layer, molded layer, adhesive or tie layer, continuous or discontinuous layer, lattice mesh, web or net, layer of uniform or non-uniform thickness , A layer having a plurality of individual elements such as islands and protrusions, a metal layer, or a foam layer.

  The solid core is a thermosetting plastic; a thermosetting rubber such as natural rubber, polybutadiene, polyisoprene, styrene-butadiene and styrene-propylene-diene rubber; a thermoplastic plastic such as ionomer resin, polyamide, and polyester; It can be made from any suitable core material, including plastic elastomers. Suitable thermoplastic elastomers include AtoFina Chemicals Inc. Pebax ™, E.C. I. Includes Hytrel ™ from Du Pont de Nemours and Company, thermoplastic urethanes from various manufacturers, and Kraton ™ from Shell Chemical Company. Suitable castable materials also include materials including urethanes, polyureas, epoxies, silicones. Additionally, suitable core materials include reaction injection molded (RIM) polyurethane or polyurea. The preferred RIM polyurethane is a nucleated version, in which a gas such as nitrogen is agitated into the prepolymer before it is injected into a mold into a closed mold to form a polyurethane layer.

  A preferred formulation for a solid core includes a base rubber, a crosslinker, and an initiator. The base rubber is typically a natural or synthetic rubber. Preferred base rubbers are 1,4-polybutadiene having less than about 90% cis bonds, having a Mooney viscosity of less than about 30, having a molecular weight of less than about 100,000, and having a polydispersity of less than about 4. It is. Mooney viscosity measurements are made according to ASTM D1646-00 ("Standard Test Methods for Rubber-Viscosity, Stress Relaxation, and Pre-Vulcanization Characteristics (Mooney Visometer) defined"). Examples of preferred polybutadiene rubbers include Buna ™ CB22 and CB23 from Bayer, Ubepol ™ 360L and 150L from Ube Industries, and Cariflex ™ BCP820 and BCP824 from Shel Chemical. Blends of two or more such polybutadienes having a Mooney viscosity of about 20 to about 150 are preferred for solid cores. Polybutadiene may also be blended with natural rubber, polyisoprene rubber, and / or other elastomers known in the art as styrene-butadiene rubber to modify the properties of the core.

  Crosslinkers suitable for polybutadiene-based solid cores include metal salts of unsaturated fatty acids having 3 to 8 carbon atoms, such as diacrylates, dimethacrylates, and monomethacrylates. Here, the metal can be magnesium, calcium, zinc, aluminum, sodium, lithium, or nickel. Preferred acrylates are zinc acrylate, zinc diacrylate (ZDA), zinc methacrylate, zinc dimethacrylate and blends thereof. Zinc diacrylate is preferred in terms of increasing the initial velocity of the golf ball, but the present invention is not limited to this. The crosslinker is typically present in an amount of less than about 10 parts per hundred parts of the base polymer (10 pph; parts per hundred parts), preferably from about 20 to about 40 pph based on the base polymer. .

  Polymerization initiators for promoting cross-linking action in the core are well known in the art and may be any known free radical initiator or blends thereof that decompose during the cure cycle. Preferred free radical initiators include organic peroxide compounds such as dicumyl peroxide; 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane; α, α-bis (t-butylperoxy) 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane; di-t-butyl peroxide; and blends thereof. Other examples include, but are not limited to, Varox ™ 231XL and DCP-R from AtoFina, Perkadox ™ BC and 14, from Akzo Nobel, and Elastochem ™ DCP-70 from Rhein Chemie. In these pure forms, the initiator is present in an amount of at least about 0.25 ppm, based on the base polymer, and is preferably between about 0.5 pph and about 2.5 pph. One skilled in the art will readily understand that the amount is adjusted depending on the activity and concentration of the initiator.

  In the polybutadiene-based solid core of the present invention, it is preferable to mix a halogenated organic sulfur compound such as a halogenated thiophenol or a metal salt thereof in order to further enhance the flexibility and resilience of the core. A halogenated thiophenol, preferably pentachlorothiophenol (PCTP) or zinc pentachlorothiophenol (ZnPCTP), partially functions as a cis-trans catalyst to convert the cis-1,4 bond of polybutadiene to trans-1,4. Convert to join. The use of halogenated organosulfur compounds such as PCTP and ZnPCTP in golf balls to produce soft and fast cores is disclosed in US patent application Ser. No. 09/951963. PCTP is available from the Struktol Company, USA under Struktol ™, and ZnPCTP is available from eChinaChem. The organosulfur halide compound is present in an amount of at least about 2 ppm, and more preferably, is present in an amount between about 2.3 pph and about 5 pph.

  The solid core may also include fillers to adjust the hardness, strength, modulus, weight, density and / or specific gravity of the core. Preferred fillers include metal or alloy powders, metal oxide strands, ceramics, particulates, carbonaceous materials, polymeric materials, glass microspheres, organic and / or inorganic fibers, and the like, and blends thereof. These fillers may be integral or perforated. Specific fillers for the core include tungsten powder, tungsten carbide, zinc oxide, tin oxide, tungsten oxide, barium sulfate, zinc sulfate, barium carbonate, calcium carbonate, solid zinc, silica and clay arrays, and ligrinds (typically Specifically, a recycled core material which is crushed into particles of about 30 mesh) is included.

  Other additional additives for golf balls are well known in the art and are incorporated into the core to achieve its particular purpose and desired effect. Such additives include antioxidants which prevent premature crosslinking or any molecular destruction of the rubber compound, accelerators which accelerate the polymerization reaction, processing accelerator oils which affect fluid or mixing properties, foaming agents, cis-trans Includes catalysts, adhesives, binders, free radical stabilizers, radical scavengers, scorch (early vulcanization) inhibitors, and blends thereof.

  The solid core diameter of the golf ball of the present invention is preferably at least about 1.3 inches, more preferably at least about 1.5 inches, and most preferably at least about 1.55 inches (3.937 cm). ). In one embodiment, the diameter of the solid core is from about 1.58 inches to about 1.62 inches. The compression (compression value) of the core is from about 20 to about 120, more preferably from about 30 to about 110, and most preferably from about 40 to about 100. In one embodiment, the core may have a compression of less than about 20, and may be fairly soft. The core must be highly resilient, and the COR will be greater than about 0.8 at 38.1 m / s (125 ft / s). Preferably, conventional techniques and techniques having a COR of greater than about 0.81, most preferably greater than 0.815 can be used to produce a solid core from the substrate formulations disclosed herein.

  In a preferred embodiment of the present invention, the intermediate layer may be a part of the core as the outer core layer, or may be a part of the cover as the inner cover layer. The intermediate layer may be a continuous layer formed from a formulation that includes at least one high acid ionomer. Preferably, the intermediate layer formulation has a flexural modulus of at least about 70,000 psi and an MFR of at least about 4 g / 10-min. The thickness of the intermediate layer is preferably about 0.025 inches, more preferably between about 0.005 inches and about 0.02 inches. Yes, and most preferably between about 0.01 inch and about 0.015 inch. The intermediate layer is preferably located near the cover, and more preferably is located adjacent to the cover. Most preferably, the intermediate layer is an inner cover layer adjacent to the outer cover layer. The flexural modulus of the formulation for the interlayer is preferably from about 70,000 psi to about 150,000 psi, more preferably from about 80,000 psi to about 130,000 psi, and most preferably from 850000 psi to about 110,000 psi. The MFL of the formulation is preferably from about 4 g / 10-min to about 500 g / 10-min, more preferably from about 10 g / 10-min to about 100 g / 10-min, most preferably from about 10 g / 10-min to about 100 g / 10-min. From 10 g / 10-min to about 75 g / 10-min. The material hardness of the formulation is also preferably at least about 65 Shore D, more preferably greater than about 70 Shore D, and most preferably greater than about 75 Shore D. At the same time, the on-ball hardness of the intermediate layer is preferably less than about 70 Shore D, more preferably less than about 65 Shore D, and most preferably between about 45 Shore D and about 60 Shore D. In another preferred embodiment, the material hardness of the formulation for the middle layer is substantially greater than the on-ball hardness of the middle layer, preferably at least about 5 Shore D, more preferably at least about 10 Shore D. Shore D is big.

  Suitable materials for the interlayer of the present invention include high acid ionomers, high flow ionomers, and blends thereof. The high acid ionomer is an ionic copolymer or terpolymer of an olefin having about 2 to 8 carbon atoms and a carboxylic acid having about 3 to 8 carbon atoms, wherein the acid content is at least about 16% by weight. . Preferably, the carboxylic acid content in the ionomer is from about 17% to about 25% by weight, more preferably, from about 18% to about 22% by weight. The carboxylic acid may be an unsaturated monocarboxylic acid such as acrylic acid, crotonic acid, maleic acid, fumaric acid, or itaconic acid. At least about 10% by weight of the carboxylic acid groups are neutralized by metal cations such as sodium, lithium, zinc, magnesium. Preferably, the carboxylic acid groups are neutralized to between about 30% and about 100%. Examples of high acid ionomers include copolymers of ethylene and acrylic or methacrylic acid. Additionally, a softening comonomer is included to form an ion terpolymer. The comonomer includes a vinyl ester of an aliphatic carboxylic acid having 2 to 10 carbon atoms in an acid, an alkyl ether having 1 to 10 carbon atoms in an alkyl group, and an alkyl acrylate having 1 to 10 carbon atoms in an alkyl group. Or an alkylalkyl acrylate such as an alkyl methacrylate having 1 to 10 carbon atoms in the alkyl group. Examples of this comonomer include vinyl acetate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, iso-butyl acrylate, n-butyl acrylate, butyl methacrylate, and the like.

  High acid ionomers are commercially available from several manufacturers. For example, ionic copolymers of ethylene and methacrylic acid are described in E.I. I. Manufactured by DuPont de Nemours & Company as Surlyn ™, ionic copolymers and terpolymers of ethylene and acrylic acid are manufactured by ExxonMobil Chemical as Escor ™ and Iotek ™, and filler modified poly (ethylene-methacrylic acid). The ionomer is produced by DuPont as Bexloy ™, and the ionic polyethylene copolymer is A.I. Schulman Inc. And polyolefin ionomers are commercially available from Diamond & Network Polymers, Inc. It is manufactured by. Examples of high acid ionomers include Surlyn ™ 6120, 8140, 8150, 9120, 9150 and high flow ionomers under development. Preferably, the high acid ionomer has an acid content of at least about 5.5 mole percent, a flexural modulus of at least about 50,000 psi, a Shore D hardness of at least about 60, and a Vicat softening. The point is at least about 50 ° F (10 ° C), the melting point is about 80 ° F (26.66 ° C), and the freezing point is about 55 ° F (12.77 ° C). ) Less than.

  Because the interlayer is thin, the formulation of the interlayer should have a substantially higher MFR and be easier to process. Certain high acid ionomers, such as Surlyn® 8150 and 9150, are also high flow ionomers with high MFRs of greater than about 4 g / 10-min. High acid, high flow ionomers can be used alone or in mixtures to produce the interlayers of the present invention. The total amount of ionomer in the formulation is preferably greater than about 30% by weight. In one embodiment, the interlayer formulation comprises at least one high acid, high flow ionomer, such as Surlyn® 8150 or 9150. Including. In other embodiments, the formulation comprises a blend of at least two high acid, high flow ionomers, such as Surlyn® 8150 or 9150. The weight ratio between the two ionomers is preferably from about 5:95 to about 95: 5, more preferably from about 25:75 to about 75:25, and most preferably about 50:50. is there. To incorporate other high acid ionomers in the middle layer with low flow (MFR less than 4 g / 10-min, typically between about 0.5 g / 10-min and about 4 g / 10-min) Preferably, a predetermined amount of high flow material is mixed. Preferred high flow materials have an MFR greater than about 4 g / 10-min, and more preferably have an MFR greater than about 10 g / 10-min. Suitable high flow materials are thermoplastic elastomers, including any of the high flow ionomers described above, as well as olefin / acid copolymers and terpolymers, partially or fully neutralized polymers , Polyamide, polyolefin, polyurethane, polyurea, castable or thermoplastic polyurethane or polyurea from RIM, epoxy, polyester, polyetherester such as Hytrel ™ from Dupont, Pebax from AtoFina, functionalized Styrene-butadiene elastomers, styrenic block copolymers such as Kraton ™ from Shell Chemicals, acrylonitrile-butadiene-styrene copolymer (“ABS”), silicones, metal salts of fatty acids, It includes de.

  In yet another embodiment, the blend for the intermediate layer comprises a high acid, low flow, non-ionomer copolymer and a high flow material. Preferred high flow materials include non-ionomer copolymers of olefins having about 2 to 8 carbon atoms, carboxylic acids having about 3 to 8 carbon atoms, and non-ionomer copolymers of olefins, softening comonomers and carboxylic acids. A polymer and the acid content is from about 5% to about 30% by weight. Examples of such thermoplastic elastomers are copolymers of ethylene and acrylic or methacrylic acid, and terpolymers of ethylene, methyl acrylate and acrylic acid, such as Nucrel ™ from DuPont and Escor ™ from Exxon Mobil. And Primacor ™ from Dow Chemicals. These olefin / acid copolymers and terpolymers not only have MFR as high as about 500 g / 10-min, but are also chemically compatible with high acid ionomers.

  Alternatively, the high flow material may be any of those described above. Other materials applicable to the blending of the intermediate layer include U.S. Patent Nos. 6,149,535, 6,152,834, 6,025,442, 5,919,100, 5,885,172, 5,824,740, 5,692,974, 5,567,772 and U.S. Pat. Includes any of the center, core, coating or cover materials disclosed in applications 10/160827, 10/118719, 09/960208 and 09 / 85,252. These are as described in this patent document. Also, a loaded thin film, a "prepreg" or a densified loaded film described in U.S. Patent No. 6,060,411 for golf balls is suitable for the intermediate layer. See also the above-mentioned patent documents for these. Such films are available from Cytec, Anaheim, Calif. Or Bryte, San Jose, Calif. These high flow materials are chemically modified by the functional groups to gain compatibility with the high acid ionomer and allow for mixing with the high acid ionomer. Suitable compatibilization agents can be used for the above purposes.

  The intermediate layer may also be added with an elasticity-enhancing filler to impart the above-mentioned desirable physical and mechanical properties to the intermediate layer, particularly a high flexural modulus. In fact, it has been verified that the addition of certain fillers substantially increases the flexural modulus of the formulation. Suitable fillers for the intermediate layer include, for example, metal (or metal alloy) powders, metal oxides and salts, particulates, carbonaceous materials, and the like, or blends thereof. Examples of useful metal (metal alloy) powders include, but are not limited to, bismuth powder, boron, brass powder, bronze powder, cobalt powder, copper powder, inconel (trademark; nickel, chromium, iron alloy) powder , Iron metal powder, molybdenum powder, nickel powder, stainless steel powder, titanium metal powder, zirconium oxide powder, aluminum flake, tungsten metal powder, beryllium metal powder, zinc metal powder, or tin metal powder. Examples of metal oxides include, but are not limited to, zinc oxide, iron oxide, aluminum oxide, titanium dioxide, magnesium oxide, zirconium oxide and tungsten trioxide. Examples of particulate, carbonaceous materials include, but are not limited to, graphite and carbon black. Examples of useful fillers include, but are not limited to, graphite fibers, precipitated hydrated silica, clay, talc, glass fibers, aramid fibers, mica, calcium metasilicate, barium sulfate, zinc sulfate, silicate, diatomaceous earth, Includes calcium carbonate, magnesium carbonate, regrind (recycled cured center material ground and mixed to a 30 mesh particle size), manganese powder, and magnesium powder. Preferably, the modulus enhancing filler comprises tungsten, tungsten oxide, barium sulfate, carbon black, silica, titanium oxide, or a blend thereof. The filler is preferably in the form of nanoscale or microscale fibers, filaments, flakes, whiskers, tubes or particulates. The filler is present in the intermediate layer in an amount sufficient to substantially increase the flexural modulus of the formulation. Preferably, the amount of filler in the formulation is from about 5% to about 70% by weight, more preferably, from about 10% to about 50% by weight. Of course, using an appropriate amount of filler, the weight of the golf ball is adapted to the United States Golf Association (“USGA”) upper limit of 45.92 g (1.62 oz).

  The intermediate layer of the present invention and its formulations are beneficial to any and all golf ball constructions and can be applied to any portion of the ball, including the core and cover. For example, the formulation may be used to form an intermediate layer in a multi-layer golf ball having a cover thickness greater than 0.05 inches, an inner cover layer in a multi-layer golf ball having two or more cover layers, or two or more thermosetting layers. An outer core layer sandwiched can be created. The formulation can be applied as a liquid, dispersion, lacquer, paste, gel, melt, or solid half-shell. The intermediate layer is formed around the core or inside the cover by compression molding, injection molding, RIM, lamination, casting, spraying, dipping, powder coating, other means of deposition, or a combination of these methods. Is done. Because the interlayer is thin, preferred production methods include RIM, thin-wall injection molding, injection compression molding, liquid spray coating, powder spray coating, and the like.

  When the layers are injection molded, it is important that less of the compound material be placed around the underlying golf ball element, for example, the core. This is because the small space between the mold and the core does not allow the material to flow properly. The core may "explode" if you do. Because the material is injected at high pressure, it compresses the core and the core breaks along the parting line. To avoid an "explosion", the injection molding process is modified to first mold a preform layer from the compound material that is about twice the thickness of the desired intermediate layer. Preferably, the thickness of the preform layer is between about 0.01 inch and about 0.05 inch. The preform layer is then compression molded to reduce its thickness to produce the desired intermediate layer. Due to the high melting point of the material, retractable pin molding can be used in combination with runners and gates of sufficient diameter to allow more material to be used. Alternatively, the preform produced from the injection molded half shell may be thinned by polishing or multi-step progressive compression molding. Equipment for polishing includes a centerless grinder or a tumbling grinder. For golf balls in which the outer cover layer is not a non-urethane compound, the intermediate layer and the outer cover layer may be co-injection molded.

  The golf ball cover interfaces the ball with clubs and other objects, such as trees, cart tracks, and grass. Desirable properties for the cover include high abrasion resistance, high tear strength, and high resilience. In general, the cover must have good performance characteristics and sufficient strength for durability. The cover may include one or more layers, including an inner cover layer and an outer cover layer. The cover can be comprised of the following homopolymer or copolymer materials that can be used alone or in conjunction with one another.

(1) Non-ionomer acid polymers, such as copolymers of olefins and carboxylic acids or terpolymers of olefins and softening comonomers with carboxylic acids. Here, the olefin has 2 to 8 carbon atoms and the carboxylic acid has 3 to 8 carbon atoms. Carboxylic acid groups include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, or itaconic acid. Examples of the softening comonomer include a vinyl ester of an aliphatic carboxylic acid having 2 to 10 carbon atoms of an acid, an alkyl ether having 1 to 10 carbon atoms of an alkyl group, and an alkyl ether having 1 to 10 carbon atoms of an alkyl group. Acrylates or alkylalkyl acrylates having 1 to 10 carbon atoms in the alkyl group are included. Preferred non-ionomeric acid polymers include E.C. I. And Nucor ™ from DuPont de Nemours & Company and Escor ™ from ExxonMobil. These are terpolymers of ethylene and methacrylic acid or acrylic acid partially neutralized. Preferably, these ionomers contain at least about 10% by weight carboxylic acid, more preferably about 16% by weight.

(2) An ionomer such as an ionic version of the copolymer or terpolymer listed in column (1) above. In particular, the carboxylic acid groups are partially or completely neutralized by cations. Preferred ionomers include E. coli. I. Includes Surlyn ™ from DuPont de Nemours & Company and Iotek ™ from ExxonMobil Chemical. These are copolymers or terpolymers of ethylene and methacrylic or acrylic acid partially or completely neutralized with zinc, sodium, lithium, magnesium, potassium, calcium, manganese, nickel and the like.

(3) Polyolefins, such as polyolefins, polyethylene, polypropylene, polybutylene, and copolymers such as ethylene methyl acrylate, ethylene ethyl acrylate, ethylene vinyl acetate, and copolymers and homopolymers produced using single-site catalysts such as metallocene. .

(4) Polyurethanes such as polyurethanes made from polyols and diisocyanates or polyisocyanates. This includes thermoplastic polyurethanes, thermoset polyurethanes and polyurethane ionomers.

(5) Polyureas such as thermoplastic polyureas, thermosetting polyureas, and polyurea ionomers. This includes those described in US Pat. Nos. 5,484,870, 10/072395 and 10 / 228,311.

(6) Vinyl resins such as those produced by polymerization of vinyl chloride, or vinyl resins produced by copolymerization of vinyl chloride with vinyl acetate, acrylic ester or vinylidene chloride.

(7) Polyamides such as those made from poly (hexamethylene adipamide) and other diamines and dibasic acids, and amino acids such as those made from poly (caprolactam), and polyamides and SURLYN, polyethylene, ethylene copolymers, Blends with ethyl-propylene-nonconjugated diene terpolymers and the like.

(8) Acrylic resins and blends of these resins with polyvinyl chloride, elastomers, and the like.

(9) Natural rubber such as sulfided synthetic rubber or sulfided balata rubber.

(10) thermoplastics, such as urethane; olefinic thermoplastic rubbers, such as blends of polyolefins with ethylene-propylene-non-conjugated diene terpolymers; block copolymers of styrene and butadiene; thermoplastic block copolymers, such as Kraton® from Shell Chemical A) rubber; isopropylene or ethylene-butadiene rubber; or co-polyether-amides, such as Pebax from AtoFina (commercially available).

(11) Polyphenylene oxide resin or a blend of polyphenylene oxide and high impact polystyrene. This is, for example, Noryl ™ from the General Electric Company.

(12) Thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / glycol modified and elastomers. This includes E. I. Includes Hytel (TM) from DuPont de Neumours & Company and Lomod (TM) from General Electric Company.

(13) Blends and alloys. This includes acrylonitrile butadiene styrene, polybutylene terephthalate, polyethylene terephthalate, styrene maleic anhydride, polyethylene, polycarbonates with elastomers, and acrylonitrile butadiene styrene or polyvinyl chloride with ethylene vinyl acetate or other elastomers, polyethylene, propylene, polyacetal. , Nylon, polyester, blends of cellulose ester and thermoplastic rubber, and the like.

  Both cover layers can be made from polymers containing α, β-unsaturated carboxylic acid groups or salts thereof that are highly neutralized by cations. The acid portion of a highly neutralized ionomer, typically an ionomer based on ethylene, is preferably greater than about 70%, more preferably greater than about 90%, and most preferably at least about 100% neutralized. ing. Highly neutralized ionomers can also be blended with the second polymer component, which can be neutralized if the component contains acid groups. The second polymer component may be partially or completely neutralized, preferably an ionomer copolymer and an ionomer terpolymer, an ionomer precursor, a thermoplastic, a polyamide, a polycarbonate, a polyester, a polyurethane, a polyurea, Includes thermoplastic elastomers, polybutadiene rubber, balata, metallocene catalyzed polymers (grafted and ungrafted), single site polymers, highly crystalline acid polymers, cationic ionomers, and the like.

  The cover layer and any other layers of the golf ball of the present invention can be formed from a polyurethane type material, and preferably, the outer cover layer can be formed. Suitable polyurethanes include, but are not limited to, thermoset polyurethanes, thermoplastic polyurethanes, polyurethane ionomers, polyurethane ureas, polyurea urethanes, polyurethane epoxies, including at least one polyisocyanate, A reaction product of a polyol and at least one curing agent is included.

  Any polyisocyanate available to one of skill in the art can be utilized in this invention. Examples of polyisocyanates include, but are not limited to: 4,4'-diphenylmethane diisocyanate ("MDI"); polymer MDI; carbodiimide-modified liquid MDI; 4,4'-dicyclohexylmethane diisocyanate ("HMDI"); p-phenylene diisocyanate ("PPDI"); Phenylene diisocyanate ("MPDI"); 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; triisocyanate of HDI; triisocyanate of 2,4,4-trimethyl-1,6-hexane diisocyanate ("TMDI"); tetracene diisocyanate; Isocyanate; anthracene diisocyanate; it includes, and mixtures thereof; uretdione of hexamethylene diisocyanate; the isocyanurate of toluene diisocyanate. Preferably, the polyisocyanate comprises MDI, PPDI, TDI, or a mixture thereof. As used herein, the term "MDI" refers to 4,4'-diphenylmethane diisocyanate, polymeric MDI, carbodiimide modified liquid MDI, and mixtures thereof, and the diisocyanate used is referred to as "low free monomer". Those skilled in the art will readily understand that what can be done is an isocyanate group having a low amount of "free" monomer, typically less than about 0.1%. Will. Examples of "low free monomer" diisocyanates include, but are not limited to, low free monomer MDI, low free monomer TDI, and low free monomer PPDI. It is necessary that at least one polyisocyanate has less than about 14% unreacted NCO groups. Preferably, the at least one polyisocyanate has no more than about 7.5%, more preferably, less than about 7.0% NCO. It is well understood in the art that polyurethane hardness is related to the percentage of unreacted NCO groups.

  Any polyol available to one of skill in the art is suitable for use in accordance with the present invention. Examples of polyols include, but are not limited to: That is, polyether polyols, hydroxy-terminated polybutadienes (including partially / fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In one preferred embodiment, the polyol comprises a polyether polyol. For example, 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 of the present invention comprises PTMEG. Suitable polyester polyols include, but are not limited to: That is, polyethylene adipate glycol; polybutylene adipate glycol; polyethylene propylene adipate glycol; o-phthalate-1,6-hexanediol; poly (hexamethylene adipate) glycol; and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. Suitable polycaprolactone polyols include, but are not limited to: That is, 1,6-hexanediol-initiated polycaprolactone, diethylene glycol-initiated polycaprolactone, trimethylolpropane-initiated polycaprolactone, neopentyl glycol-initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, PTMEG-initiated polycaprolactone, and these. It is a mixture. The hydrocarbon chain can have saturated or unsaturated, or substituted or unsubstituted aromatic and cyclic groups. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate and poly (hexamethylene carbonate) glycol. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups.

  Curing agents for the polyurethanes of the present invention include hydroxy-terminated curing agents and amine curing agents. Suitable hydroxy-terminated curing agents may be diols, triols or tetraols, including ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; low molecular weight polytetramethylene ether glycol; (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. Is included. Preferred hydroxy-terminal curing agents are 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, and mixtures thereof.

  Amine curing agents, including primary and secondary amines, are also optimal for use in polyurethane cover and layers. Specific amine curing agents include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers, such as 3,5 -Diethyltoluene-2,6-diamine; 4,4'-bis- (sec-butylamino) -diphenylmethane; 1,4-bis- (sec-butylamino) -benzene, 4,4'-methylene-bis- (2-chloroaniline); 4,4′-methylene-bis- (3-chloro-2,6-diethylaniline) (“MCDEA”); polytetramethylene oxide-di-p-aminobenzoate; N, N ′ -Dialkyldiaminodiphenylmethane; p, p'-methylenedianiline ("MDA"); m-phenylenediamine ("MPDA"); 4,4 ' Methylene-bis- (2-chloroaniline) ("MOCA"); 4,4'-methylene-bis- (2,6-diethylaniline) ("MDEA"); 4,4'-methylene-bis- (2 , 3-dichloroaniline) ("MDCA"); 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane; 2,2'-3,3'-tetrachlorodiaminodiphenylmethane; tri Methylene glycol di-p-aminobenzoate; and mixtures thereof. A preferred polyamine curing agent is 3,5-dimethylthio-2,4-toluenediamine and its isomers, such as Ethacure ™ 300 from Albermarle Corporation.

  Both hydroxy-terminated and amine-terminated hardeners can include one or more saturated, unsaturated, aromatic, and cyclic groups. Further, the hydroxy-terminated and amine curing agents can include one or more halogen groups. The polyurethane composition can be made by a blend or mixture of curing agents. However, if desired, the polyurethane composition can be made with a single curing agent.

  One of the polyurethane production methods well known to those skilled in the art is the prepolymer method. In this method, a polyurethane prepolymer is produced by reacting at least one polyol with at least one isocyanate. The prepolymer is then cured with a diol or secondary amine curing agent to produce a thermoplastic polyurethane, or with a triol or tetraol curing agent to produce a thermoset polyurethane. The choice of curing agent is critical because some diol-cured urethane elastomers do not produce the urethane elastomers that have the impact resistance required by golf ball covers. Blends of diol-cured urethane elastomer blends with amine curing agents result in thermoset urethanes having improved impact and cut resistance. Other suitable thermoplastic polyurethane resins include those disclosed in US Pat. No. 6,235,830.

  In one preferred embodiment of the present invention, the cover layer, preferably the outer cover layer, is formed using a saturated (aliphatic and cycloaliphatic) polyurethane formed from a saturated polyisocyanate, a saturated polyol, and a saturated curing agent. As used herein, the term “saturated” refers to a compound or material that is substantially free of aromatic moieties or aromatic moieties. Saturated polyisocyanates include, but are not limited to, ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; 1,6-hexamethylene diisocyanate ("HDI"); 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4 -Diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; IPDI (isophorone diisocyanate); methylcyclohexylenediene Isocyanate; HDI triisocyanate include TMDI. Most preferred saturated diisocyanates are 4,4'-dicyclohexylmethane diisocyanate and IPDI.

  Saturated polyols include, but are not limited to, polyether polyols, such as polytetramethylene ether glycol and poly (oxypropylene) glycol. Suitable saturated polyester polyols include polyethylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, polycarbonate polyols and polyoxypropylene diols capped with ethylene oxide. Saturated polycaprolactone polyols useful in this invention include diethylene glycol initiated polycaprolactone, 1,4-butanediol initiated polycaprolactone, 1,6-hexanediol initiated polycaprolactone; trimethylolpropane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone. , PTMEG-initiated polycaprolactone. The most preferred saturated polyols are PTMEG and PTMEG initiated polycaprolactone.

  Suitable saturated curing agents include 1,4-butanediol, ethylene glycol, diethylene glycol, polytetramethylene ether glycol, propylene glycol; trimethanolpropane; tetra- (2-hydroxypropyl) -ethylenediamine; isomers of cyclohexyldimethylol and Mixtures of isomers, isomers of cyclohexanebis (methylamine) and mixtures of isomers; triisopropanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 4,4′-dicyclohexylmethanediamine, 2,2,4-trimethyl -1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine; diethylene glycol di- (aminopropyl) A 4,4′-bis- (sec-butylamino) -dicyclohexylmethane; 1,2-bis- (sec-butylamino) cyclohexane; 1,4-bis- (sec-butylamino) cyclohexane; isophoronediamine; Hexamethylenediamine, propylenediamine, 1-methyl-2,4-cyclohexyldiamine, 1-methyl-2,6-cyclohexyldiamine, 1,3-diaminopropane, dimethylaminopropylamine, diethylaminopropylamine, imido-bis-propyl Includes amines, isomers of diaminocyclohexane and mixtures of isomers, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, and diisopropanolamine. Most preferred saturated curing agents are 1,4-butanediol, 1,4-cyclohexyldimethylol and 4,4'-bis- (sec-butylamino) -dicyclohexylmethane.

  Preferably, the saturated polyurethane comprises from about 1% to 100%, and preferably from about 10% to about 75%, by weight of the cover or layer formulation. The thermosetting polyurethane can be cast, can be reaction injection molded, can be sprayed, can be applied to a laminated foam, and can be a known method. Thermoplastic polyurethanes can be processed using a number of compression or injection techniques.

  Additives commonly used in golf ball cores, covers and layers can be blended with any of the formulations described herein to make up any portion of the golf ball. Additives include catalysts, surfactants, foaming agents for foam, stabilizers, metals, antioxidants, colorants including pigment pigments and dye dyes, optical brighteners, fillers for adjusting density or modulus, viscosity Includes modifiers, release aids, plasticizers, processing aid oils, compatibility aids, dispersibility aids, UV absorbers, hindered amine light stabilizers, and others. The pigment may be a phosphor or an autofluorescent, luminous, or chemiluminescent, including white pigments such as titanium oxide and zinc oxide. Suitable catalysts based on polyurethanes include, but are not limited to, bismuth catalyst, oleic acid, triethylenediamine (Dabco®-33LV), di-butyltin dilaurate (Dabco®-T12) and acetic acid. Is included. The most preferred catalyst is di-butyltin dilaurate (Dabco ™ -T12). Dabco ™ material is manufactured by Air Products and Chemicals. Suitable UV absorbers and light stabilizers include Tinuvin ™ 213, 328, 622, 765 and 770. Tinuvin ™ product is available from Ciba-Geigy. These additives can be added in any amount that achieves their intended purpose.

  Any method known to those skilled in the art can be used to produce the polyurethane-based cover of the present invention. The one-shot method involves mixing a polyisocyanate, a polyol and a curing agent at the same time and is practical, but the resulting mixture is non-uniform and difficult to control. The preferred mixing method is known as the prepolymer method. In this method, the polyisocyanate and the polyol are separately mixed before adding the curing agent. This method results in a more uniform mixture and, as a result, a more consistent polymer composition. Other suitable methods of making the layers of the present invention include reaction injection molding ("RIM"), liquid injection molding ("LIM"), injection compression molding, and thermoplastic polyurethanes that can be injection molded by pre-reacting the components. And then injection molding, or a combination thereof. , All of which are known to those skilled in the art.

  According to the present invention, when a castable reactive material such as a urethane elastomer is used in fluid form, a very thin layer, such as an outer cover layer suitable for golf balls, can be obtained. Specific application techniques include spraying, dipping, spin cording, or flow coating.

  The flexural modulus of the outer cover layer comprising the above-described formulation is preferably from about 500 psi to about 15,000 psi, as measured according to ASTM D6272-98. The thickness of the outer cover layer is preferably less than about 0.05 inches and thin, more preferably less than about 0.03 inches. Alternatively, the thickness of the cover is between about 0.05 inches to about 0.2 inches, and more specifically, between about 0.05 inches to about 0.09 inches. The on-ball hardness of the outer cover layer is optional, but is typically less than about 70 Shore D. The material hardness of the outer cover layer formulation is preferably less than about 70 Shore D. The resulting golf ball includes a core, an intermediate layer and a cover, as described above, and preferably has a COR of at least about 0.8, and more preferably has a COR of at least about 0.81. The golf ball preferably has an ATTI compression of at least about 30, more preferably has an ATTI compression of about 50 to about 120, and most preferably has an ATTI compression of about 55 to about 85. The overall diameter of the golf ball is preferably at least about 1.68 inches, the size of the smallest size indicated by the United States Golf Association. More preferably. The overall diameter of the golf ball is from about 1.68 inches to about 1.76 inches. The dimple coverage on the outermost surface of the golf ball is greater than about 60%, preferably greater than about 80%. Preferred dimple patterns are those disclosed in U.S. Patent Nos. 6,358,131 and 5,957,786. The golf ball also achieves improved aerodynamic properties, such as lift and drag. See US patent application Ser. No. 10 / 096,852.

  The formulations for the intermediate layer of golf balls disclosed herein can be used in sporting goods in general. In particular, the composition can be applied to various game balls, golf club shafts, golf club inserts, golf shoe parts, and the like.

  The present invention is further described by the following examples. However, it should be understood that this example does not limit the invention.

Table 1 shows the physical and performance characteristics of Sample 1 golf ball using the preferred structure and material formulations of the present invention. As a comparison, a ProV1 (trademark) golf ball of Axinet Company (trademark) is used. The objects of comparison are the core, the subassembly (core and middle layer) and the finished ball (core, middle layer and cover). The interlayer of Sample 1 has a thickness of about 0.015 inches and is a 50:50 weight ratio blend of Surlyn® 8150 and 9150. At the core, subassembly, and finished ball level, Sample 1 consistently has a lower compression value and a higher coefficient of restitution than ProV1. According to the 1-wk and 2-wk aging tests, the golf ball of Sample 1 has very high weather resistance.

A comparison of the golf ball of Sample 1 with ProV1 ™ and Pinnacle ™ LS (both from Axinet Company) is shown in Table 2 below. Samples and regular balls show corresponding initial speeds for different clubs. Advantageously, the golf club of Sample 1 produces substantially less spin per driver than ProV1 by at least about 12%. At the professional level (167 ft / s), the spin reduction is about 13%, with the standard driver (160 ft / s) the spin reduction is about 12.4%, and the average level (140 ft / s) In this case, the reduction rate is the largest, about 14.5%. The spin reduction effect of Sample 1 decreases with short irons and wedge shots. For the 8-iron, full wedge, and half wedge, the spin reductions are 11.7%, 6.2%, and 5.3%, respectively.

Samples AJ were made according to the present invention, each with a 1.59 inch diameter PBD core (CB-23 and ZDA from Bayer), a 58 Shore D hardness polyurethane cover, and a 0.015 inch thickness. An intermediate layer having the formulation shown in Table 3 was provided. A 75 compression core is higher in ZDA than a 50 compression core. The intermediate layer includes various grades of Surlyn ™ and various levels of tungsten oxide as a high density filler. Table 4 shows the spin rates of Samples A-J for each standard driver ("D"), 8 iron ("I"), and half wedge ("W"), as well as Axinet Company's Titest ™ ProV1 and Pinnacle ™. ) Shown in comparison with GoldLS.

Table 5 shows the flight distance (flight) of Samples AJ for each standard driver in comparison with ordinary golf balls such as ProV1 and PinnacleGoldLS. The numerical values listed here are the trajectory, carry distance, roll distance, total distance, lateral distance, and landing area. Five out of ten samples outperform ProV1 in carry distance, and seven out of ten samples outperform ProV1 in total distance.

  For details of the contents of the above-listed US patents and US patent applications, refer to them.

  The invention described above and set forth in the claims is not limited to the scope of the specific embodiments disclosed herein, it is to be understood that these embodiments are merely illustrative of various aspects of the invention. It is clear from the intention. It is obvious that any alternatives and various modifications apparent to those skilled in the art without departing from the spirit of the present invention are included in the technical scope of the present invention. Such modifications are, of course, also included in the claims.

Claims (20)

Core and
Cover and
An intermediate layer disposed between the core and the cover, the intermediate layer being formed from a formulation containing at least one high acid ionomer;
A golf ball, wherein the hardness of the on-ball of the intermediate layer is less than the material hardness of the composition by at least about 5 Shore D.   The golf ball of claim 1, wherein the hardness of the on-ball of the intermediate layer is less than the material hardness of the formulation by at least about 10 Shore D.   The golf ball of claim 1, wherein said material hardness is at least about 65 Shore D.   4. The golf ball according to claim 3, wherein said material hardness is at least about 70 Shore D.   The golf ball of claim 1, wherein the on-layer hardness of the mid layer is less than about 65 Shore D.   6. The golf ball of claim 5, wherein said on-ball hardness is from about 45 Shore D to about 60 Shore D.   The golf ball of claim 1, wherein the melt flow rate of the composition is at least about 4 g / 10-min.   2. The composition of claim 1, further comprising a flexural modulus enhancing filler, wherein the flexural modulus of the composition containing the filler is substantially greater than the flexural modulus of the composition without the filler. Golf ball.   The golf ball of claim 1 wherein the composition has a flexural modulus of at least about 70000 psi.   2. The golf ball of claim 1, wherein the high acid ionomer comprises at least about 16% by weight carboxylic acid.   The golf ball of claim 1 wherein the high acid ionomer has a melt flow rate of at least about 4 g / 10-min.   The golf ball of claim 1, wherein the composition further comprises at least one high flow material, the melt flow rate of which is greater than about 4 g / 10-min.   The high flow materials include thermoplastic elastomers, high flow ionomers, non-ionomer olefin / acid copolymers or terpolymers, partially or fully neutralized polymers, polyamides, polyolefins, polyurethanes, polyureas, epoxies, polyesters, 13. The golf ball of claim 12, comprising a polyetherester, polyetheramide, polyamide, metallocene catalyzed polymer, functional styrene-butadiene elastomer, styrenic block copolymer, acrylonitrile-butadiene-styrene copolymer, silicone, or a metal salt of a fatty acid.   The golf ball of claim 1, wherein the at least one ionomer comprises about 30% by weight of the composition. Core and
Cover and
An intermediate layer having a thickness of less than about 0.025 inches (0.0635 cm) and disposed between the core and the cover, the intermediate layer being formed from a formulation containing at least one high acid ionomer. And having
A golf ball, wherein the hardness of the on-ball of the intermediate layer is substantially less than the material hardness of the composition.   16. The golf ball of claim 15, wherein the thickness of the intermediate layer is from about 0.005 inch to about 0.02 inch.   16. The golf ball of claim 15, wherein the composition has a flexural modulus of at least about 70000 psi and the composition has a melt flow rate of at least about 4 g / 10-min. Core and
Cover and
An intermediate layer disposed between the core and the cover, wherein the thermoplastic elastomer comprises a high acid ionomer containing at least about 16% by weight of fresh carboxylic acid from a formulation containing at least one high acid ionomer. Produced from a blend comprising the blend,
A golf ball, wherein the hardness of the on-ball of the intermediate layer is substantially less than the material hardness of the composition.   19. The golf ball according to claim 18, wherein the thermoplastic elastomer is an ionomer or a non-ionomer.   19. The composition of claim 18, wherein the composition further comprises a flexural modulus enhancing filler, whereby the flexural modulus of the composition containing the filler is substantially greater than the flexural modulus of the composition without the filler. Golf ball.