WO2002081035A1 - Golf ball having very thin outermost cover layer for improved scuff resistance - Google Patents
Golf ball having very thin outermost cover layer for improved scuff resistance Download PDFInfo
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- WO2002081035A1 WO2002081035A1 PCT/US2002/003594 US0203594W WO02081035A1 WO 2002081035 A1 WO2002081035 A1 WO 2002081035A1 US 0203594 W US0203594 W US 0203594W WO 02081035 A1 WO02081035 A1 WO 02081035A1
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- Prior art keywords
- layer
- golf ball
- cover layer
- hardness
- core
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Classifications
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/12—Special coverings, i.e. outer layer material
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0023—Covers
- A63B37/0024—Materials other than ionomers or polyurethane
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0023—Covers
- A63B37/0029—Physical properties
- A63B37/0031—Hardness
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0023—Covers
- A63B37/0029—Physical properties
- A63B37/0033—Thickness
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0038—Intermediate layers, e.g. inner cover, outer core, mantle
- A63B37/004—Physical properties
- A63B37/0043—Hardness
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/0038—Intermediate layers, e.g. inner cover, outer core, mantle
- A63B37/004—Physical properties
- A63B37/0045—Thickness
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/007—Characteristics of the ball as a whole
- A63B37/0072—Characteristics of the ball as a whole with a specified number of layers
- A63B37/0075—Three piece balls, i.e. cover, intermediate layer and core
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- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/007—Characteristics of the ball as a whole
- A63B37/0072—Characteristics of the ball as a whole with a specified number of layers
- A63B37/0076—Multi-piece balls, i.e. having two or more intermediate layers
Definitions
- This invention relates to a golf ball, and particularly, a multi-layer golf ball having a very thin outermost cover layer that improves resistance to scuffing and scratching of the ball.
- golf balls have been categorized in three different groups: one-piece balls, multi-piece (two or more pieces) solid balls, and wound (three-piece) balls.
- the one-piece ball is typically formed from a solid mass of moldable material, which has been cured to develop the necessary degree of hardness. It possesses no significant difference in composition between the interior and exterior of the ball. These balls do not have an enclosing cover.
- One-piece balls are described, for example, in U.S. Patent No. 3,313,545, U.S. Patent No. 3,373,123, and U.S. Patent No. 3,384,612.
- the wound ball is frequently referred to as a three-piece ball since it is made with a vulcanized rubber thread wound under tension around a solid or semi-solid core and thereafter enclosed in a single or multi-layer covering of tough protective material. While for many years the wound ball satisfied the standards of both the U.S.G.A. and most golfers, it has several disadvantages. For example, a wound ball is difficult to manufacture due to the number of production steps required and the careful control, which must be exercised in each stage of manufacture to achieve suitable roundness, velocity, rebound, click, feel, and the like.
- the three-piece wound ball typically has a balata cover, which is relatively soft and flexible. Upon impact, it compresses against the surface of the club producing high spin. Consequently, the soft and flexible balata covers provide an experienced golfer with the ability to apply a spin to control the ball in flight in order to produce a draw or a fade or a backspin, which causes the ball to "bite" or stop abruptly on contact with the green. Moreover, the soft balata cover produces a soft "feel" to the low handicap player. Such playability properties of workability, feel, etc. are particularly important in short iron play with low swing speeds and are exploited significantly by relatively skilled players.
- balata covered balls are easily cut and/or damaged if hit incorrectly.
- golf balls produced with balata or balata containing cover compositions have a relatively short life span.
- balata and its synthetic substitute, transpolyisoprene and resin blends have been essentially replaced as the cover materials of choice by new cover materials comprising ionomeric resins.
- multi-layered golf ball One important development in balancing the playability-durability dilemma found in one-piece and wound balls has been the multi-layered golf ball.
- multi-layered golf balls have cores designed for "driver distance”, mid- layers designed for full iron shots, and covers designed for maximal "feel” and spin in half-shots, chips, and putts.
- U.S. Patent Nos. 4,431 ,193 and 4,919,434 disclose multi-layer golf balls. Multi-layered golf balls attempt to achieve playability with a "soft" -type solid or liquid core, while the multiple layers of the molded covers attempt to maximize the protection of the ball from cutting and scuffing.
- Solid cores are generally made of polybutadiene, while molded covers are generally made from natural balata, synthetic balata, or ionomeric resins.
- lonomeric resins are polymers containing interchain ionic bonding. lonomeric resins are known to have superior toughness, durability, and flight characteristics, and as a result of these characteristics, various ionomeric resins sold by E.I.
- lonomeric resins are generally ionic copolymers of an olefin, such as ethylene, and a metal salt of an unsaturated carboxylic acid, such as acrylic acid, methacrylic acid, or maleic acid.
- Metal ions such as sodium or zinc, are used to neutralize some portion of the acidic group in the copolymer resulting in a thermoplastic elastomer exhibiting enhanced properties, i.e., durability, etc., for golf ball cover construction over balata.
- ionomers are available both from Exxon and DuPont, with a wide range of properties which vary according to the type and amount of metal cations, molecular weight, composition of the base resin (i.e., relative content of ethylene and methacrylic and/or acrylic acid groups) and additive ingredients, such as reinforcement agents.
- a great deal of research continues in developing ionomeric materials for golf balls exhibiting the desired combination of the properties of both playability and durability.
- Various non-ionomeric thermoplastic materials have been used for golf ball covers in order to increase playability, but have been found inferior to ionomers in achieving good cut resistance and travel distance. It would be useful to obtain a golf ball having a cover which incorporates non-ionomeric materials creating favorable playability characteristics, while achieving favorable durability characteristics of a ball having a cover which primarily contains ionomers.
- U.S. Patent No. 4,431 ,193 discloses a multi-layer ball with a hard ionomeric inner cover layer and a soft outer cover layer.
- U.S. Patent No. 4,919,434 discloses a golf ball with a 0.4 - 2.2 mm thick cover made from two thermoplastic cover layers.
- U.S. Patent No. 5,628,699 discloses a wound golf ball with an inner layer having a higher Shore D hardness than the outer layer.
- the outer layer has a thickness of 0.4 to 3.3 mm and has a Shore D hardness of 40 to 55.
- the inner layer is formed of a different ionomer resin from the outer layer and has a Shore D hardness of 55 to 68.
- U.S. Patent No. 5,674,137 discloses a wound golf ball with a cover having a multi-layered structure having a total thickness of 1.0 to 4.0 mm.
- the outer layer has a thickness of 0.4 to 3.0 mm and a particular first hardness.
- the inner layer has a second hardness higher than the first hardness.
- the outer layer is formed of a first ionomer or balata rubber resin having a Shore D hardness of 40 to 55, and the inner layer is formed of a second ionomer or balata rubber resin having a Shore D hardness of 55 to 68.
- the difference in hardness between the first and second resins is at least 5 in Shore D hardness.
- U.S. Patent No. 5,779,562 discloses a multi-core, multi-cover golf ball.
- the cover includes an inner cover layer and an outer cover layer enclosing the inner cover layer.
- the outer cover layer has a Shore D hardness of no more than 55, and the outer cover layer has a Shore D hardness less than the inner cover layer.
- U.S. Patent No. 5,803,831 discloses a multi-layered golf ball having a soft outer cover.
- the golf ball has a thermoplastic inner cover layer with a preferable Shore D hardness of at least 65, and an outer cover layer with a Shore D hardness of 55 or less.
- the durability of the multi-layered golf balls described above suffer with a softer outer layer which increases the likelihood of scuffing, cutting, and scratching.
- Each of the above noted patents disclose an outer layer having a Shore D hardness no greater than 55.
- the above noted patents also disclose that the Shore D hardness of the outer layer is less than the inner cover layer.
- the durability of such golf balls would suffer as less experienced golfers are more prone to scuffs, cuts, and scratches. Therefore, it would be advantageous to have a golf ball with the playability of the golf balls described in the above noted patents while having improved durability, namely scuff, cutting, and scratching resistance.
- the present invention is directed toward a golf ball with a very thin outermost cover layer that provides the ball durability characteristics such as scuff, cutting, and scratch resistance while maintaining desirable playability characteristics when struck with golf clubs.
- the present invention is further directed toward a golf ball which comprises a core and a cover including a very thin outermost cover layer, wherein the outermost cover layer comprises a thermoplastic material, has a thickness of less than about 0.040 inches, a Shore D hardness of at least 56, and a Shore D hardness at least as hard as a layer between the outermost layer and core.
- the present invention is further directed toward a golf ball which comprises a core and a cover including a very thin outermost cover layer disposed about an inner cover layer, wherein the outermost cover layer comprises a thermoplastic material, has a thickness of less than about 0.040 inches, a Shore D hardness of at least 56, and a Shore D hardness at least as hard as the layer below it.
- the present invention provides a golf ball comprising a core, at least one mantle layer including a woven elastomer thread, and a cover including a very thin outermost cover layer, wherein the outermost cover layer comprises a thermoplastic material, has a thickness of less than about 0.040 inches, a Shore D hardness of at least 56, and a Shore D hardness at least as hard as the layer below it.
- Fig. 1 is a partial sectional view of a preferred embodiment golf ball in accordance with the present invention
- Fig. 2 is a partial sectional view of another preferred embodiment golf ball in accordance with the present invention.
- Fig. 3 is a partial sectional view of another preferred embodiment golf ball in accordance with the present invention.
- Fig. 4 is a partial sectional view of yet another preferred embodiment golf ball in accordance with the present invention. It will be appreciated that these drawings are not necessarily to scale and are schematic in nature. Detailed Description of the Preferred Embodiments
- the present invention provides a golf ball, and preferably a multi-layer golf ball, comprising a very thin outermost cover layer that imparts improved scuff or scratch resistance properties to the ball.
- the present invention golf ball comprises a core, optional mantle layer, optional wound layer and/or wound core layer, a cover or cover layer, and an outermost protective layer.
- a multi-layer cover assembly is used for the cover of the present invention golf ball, wherein the outer cover layer of that assembly is formed and provided as described herein, and serves as the outer protective layer.
- a multi-layer cover assembly is formed and provided as described herein, and upon which is disposed, an outer protective layer as described herein.
- the present invention also includes golf ball embodiments utilizing outermost protective layers formed or otherwise disposed upon single cover layers and cover layer assemblies of three or more cover layers.
- the present invention is particularly directed toward a multi-layer golf ball 1 which comprises a core 2, at least one cover layer 3 comprising an outermost cover layer and at least one mantle layer 4 disposed therebetween.
- a golf ball 10 is shown having an inner cover layer 16 and an outer cover layer 18 which comprises an outermost cover layer, disposed about a mantle 14 and core 12.
- the present invention provides a golf ball comprising a wound interior layer, such as shown in Figs. 3 and 4.
- Fig 3 illustrates a preferred embodiment golf ball 20 comprising a core 22, a wound layer 24 disposed about and immediately adjacent to the core 22, a mantle layer 26, and a cover 28 comprising an outermost cover layer.
- the cover 28 may include an inner and outer cover layer as previously described with regard to the preferred embodiment golf ball 10 depicted in Fig. 2.
- Figure 4 illustrates yet another preferred embodiment golf ball 30 comprising a core 32, a mantle layer 34 disposed about and immediately adjacent to the core 32, a wound layer 36 disposed about the mantle and core, and a cover 38.
- the cover 38 may include inner and outer cover layers as previously described with regard to the preferred embodiment golf ball 10.
- the core of the present invention golf ball may comprise a variety of materials, including those conventionally employed as golf ball cores.
- Typical materials for such cores include core compositions having a base rubber, a crosslinking agent, a filler, and a co-crosslinking agent.
- the base rubber typically includes natural or synthetic rubbers.
- a preferred base rubber is 1 ,4-polybutadiene having a cis-structure of at least 40%. Natural rubber, polyisoprene rubber and/or styrene-butadiene rubber may be optionally added to the 1 ,4-polybutadiene.
- the initiator included in the core composition can be any known polymerization initiator which decomposes during the cure cycle.
- the crosslinking agent includes a metal salt such as a zinc salt or a magnesium salt from an unsaturated fatty acid having 3 to 8 carbon atoms such as acrylic or methacrylic acid.
- the filler typically includes materials such as zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate and the like.
- the core is a cross-linked 1 ,4-polybutadiene having a specific gravity greater than 1.2, and, more preferably, about 1.25. The high specific gravity of the core decreases the spin rate of the ball for a lower flight path.
- the PGA compression of the core is preferably greater than 60, and, more preferably, about 65.
- the core of the golf ball is made of a crosslinked unsaturated elastomer and preferably comprises a thermoset rubber such as polybutadiene, but can also be made of other core materials which would provide a sufficient coefficient of restitution (COR).
- the core imparts upon the finished golf ball a COR of at least 0.780, and preferably at least 0.790.
- the diameter of the core is determined based upon the desired overall ball diameter, minus the combined thicknesses of the inner and outer cover layers.
- the core typically has a diameter of about 1.0 - 1.6 inches, preferably 1.4 - 1.6 inches, a PGA compression of 80 - 100, and a COR in the range of 0.770 - 0.830.
- Conventional solid cores are typically compression molded from a slug of uncured or lightly cured elastomer composition comprising a high cis content polybutadiene, and a metal salt of an ⁇ , ⁇ , ethylenically unsaturated carboxylic acid such as zinc mono- or di-acrylate or methacrylate.
- the manufacturer may include filler such as small amounts of a metal oxide, e.g., zinc oxide.
- larger amounts of metal oxide other than those that are needed to achieve the desired COR are often included in conventional cores in order to increase the core weight so that the finished ball more closely approaches the U.S.G.A. upper weight limit of 1.620 ounces.
- core composition including compatible rubbers or ionomers, and low molecular weight fatty acids such as stearic acid.
- Free radical initiators such as peroxides are admixed with the core composition so that on the application of heat and pressure, a complex curing cross-linking reaction takes place.
- the core such as core 2 in Fig. 1 , core 12 in Fig. 2, core 22 in Fig. 3, and core 32 in Fig. 4, may be composed of any one or more of the materials herein described.
- the core comprises a center which is liquid-filled or solid around which an elastic thread is wound such as core 22 in Fig. 3, and core 32 in Fig. 4.
- the solid center is typically a homogenous mass of a resilient material such as polybutadiene or a natural rubber.
- the liquid-filled center is typically a thin-walled sphere into which a liquid such as com syrup is injected by means of a hypodermic needle. The sphere is then sealed and frozen to make the center a solid mass.
- the windings for either type of center are provided by an elastic thread, which is stretched and wound about the center to a desired thickness.
- the centers of wound cores have a diameter of about 1.000 to about 1.125 inches.
- the outer diameter of a conventional wound core is about 92% of the overall diameter of the finished ball.
- the outer diameter of wound cores employed in this embodiment of the present invention have an overall diameter of less than 90% of the overall diameter of the finished ball.
- the wound cores have a diameter of about 75-90% of the overall diameter of the finished ball.
- the wound cores of the present invention have an overall diameter of about 85% of the overall diameter of the finished ball.
- the core may comprise more than one layer, i.e., the core may be multi-layered. At least one layer is disposed about the core.
- the multi-layered core may optionally be wound with an elastic thread.
- the mantle layer such as layer 4 in Fig. 1 , layer 14 in Fig. 2, layer 26 in Fig. 3, and layer 34 in Fig. 4, comprises a wide array of materials such as thermoplastic polyester, thermoplastic polyetherester, dynamically vulcanized thermoplastic elastomer, functionalized styrene-butadiene elastomer, thermoplastic polyurethane or metallocene polymer, or blends thereof.
- the mantle layer is a thermoplastic polyetherester.
- Suitable thermoplastic polyetheresters include
- Hytrel® 3078 is the most preferred.
- the mantle layer preferably has a specific gravity greater than 1 and less than 1.2.
- Suitable dynamically vulcanized thermoplastic elastomers include Santoprene®, Sari ink®, Vyram®, Dytron®, and Vistaflex®.
- Santoprene® is the trademark for a dynamically vulcanized PP/EPDM.
- Santoprene® 203-40 is an example of a preferred Santoprene® and is commercially available from Advanced Materials
- Suitable functionalized styrene-butadiene elastomers include Kraton ® FG-1901x and FG-1921x, which are available from the Shell Corporation.
- thermoplastic polyurethane examples include Estane® 58133, Estane® 58134, and Estane® 58144, which are commercially available from the B.F. Goodrich Company.
- Suitable metallocene polymers whose melting points are higher than the cover materials can also be employed in the mantle layer of the present invention.
- the materials for the mantle layer described above may be in the form of a foamed polymeric material.
- suitable metallocene polymers include foams of thermoplastic elastomers based on metallocene single- site catalyst-based foams. Such metallocene-based foam resins are commercially available from Sentinel Products located in Hyannis, Massachusetts.
- the mantle layer may comprise up to 100% by weight a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a thermoplastic polyurethane, a metallocene polymer, or blends thereof.
- the mantle layer comprises Santoprene®, thermoplastic polyurethane, or blends thereof.
- the mantle layer is a blend of a first and a second thermoplastic polymer, wherein the first thermoplastic polymer is a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a thermoplastic polyurethane or ⁇ a metallocene polymer, and the second thermoplastic is a material such as a thermoplastic polyurethane, a thermoplastic polyetherester or polyetheramide, a thermoplastic ionomer resin, a thermoplastic polyester, another dynamically vulcanized elastomer, another functionalized styrene-butadiene elastomer, another metallocene polymer, or blends thereof.
- the first thermoplastic polymer is a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a thermoplastic polyurethane or ⁇ a metallocene polymer
- the second thermoplastic is a
- Suitable thermoplastic polyetheresters for use in this blended embodiment include Hytrel® 3078, Hytrel® G3548W, and Hytrel® G4078W, which are commercially available from DuPont.
- Suitable thermoplastic polyetheramides include Pebax® 2533, Pebax® 3533, and Pebax® 4033, which are available from Elf-Atochem.
- Suitable thermoplastic ionomer resins include any number of olefinic based ionomers including SURLYN® and lotek®, which are commercially available from DuPont and Exxon, respectively.
- the flexural moduli for these ionomers is about 100 kpsi to about 200 kpsi.
- thermoplastic polyesters include polybutylene terephthalate.
- dynamically vulcanized thermoplastic elastomers, functionalized styrene-butadiene elastomers, thermoplastic polyurethane, or metallocene polymers identified above are also useful as the second thermoplastic in such blends.
- the materials of the second thermoplastic described above may be in the form of a foamed polymeric material.
- thermoplastic blends comprise about 1 % to about 99% by weight of a first thermoplastic material, and about 99% to about 1 % by weight of a second thermoplastic material.
- the thermoplastic blend comprises about 5% to about 95% by weight of a first thermoplastic material, and about 5% to about 95% by weight of a second thermoplastic material.
- the first thermoplastic material of the blend is a dynamically vulcanized thermoplastic elastomer, such as Santoprene®.
- golf ball include a ball with more than one mantle layer. If more than one mantle layer is used, the mantle layers do not have to be in contact with one another, i.e., the mantle layers may be disposed between various layers of the golf ball without touching one another.
- the cover layer of the present invention golf balls comprises at least one layer of a thermoplastic or thermosetting material.
- the cover layer is shown in Fig. 1 as layer 3, in Fig. 2, as layers 16 and 18, in Fig. 3 as layer 28, and in Fig. 4 as layer 38.
- Any number of a wide variety of cover materials may be used in the present invention golf balls.
- the preferred conventional cover materials are ionomer resins and low modulus ionomers obtained by providing a cross metallic bond to polymers of monoolefins with at least one member selected from the group consisting of unsaturated mono- or di-carboxylic acids having 3 to 12 carbon atoms and esters thereof.
- the polymers contain 1 to 50% by weight of the unsaturated mono- or di-carboxylic acid and/or ester thereof. More particularly, low modulus ionomers, such as acid-containing ethylene copolymer ionomers, include E/X/Y copolymers. E is ethylene. X is a softening comonomer such as acrylate or methacrylate present in 0-50, preferably 0-25, and most preferably 0-2, weight percent of the polymer.
- Y is acrylic or methacrylic acid present in 5-35, preferably 10-35, and most preferably 15-20, weight percent of the polymer, wherein the acid moiety is neutralized 1-90%, preferably at least 40%, and most preferably at least about 60%, to form an ionomer by a cation.
- suitable cations include lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc or aluminum, or a combination of such cations.
- Preferred cations include lithium, sodium, magnesium, and zinc.
- Specific acid-containing ethylene copolymers include ethylene/acrylic acid, ethylene/methacrylic acid, ethylene/acrylic acid/n- butyl acrylate, ethylene/methacrylic acid/n-butyl acrylate, ethylene/methacrylic acid/iso-butyl acrylate, ethylene/acrylic acid/iso-butyl acrylate, ethylene/methacrylic acid/n-butyl methacrylate, ethylene/acrylic acid/methyl methacrylate, ethylene/acrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl methacrylate, and ethylene/acrylic acid/n-butyl methacrylate.
- Preferred acid-containing ethylene copolymers include ethylene/methacrylic acid, ethylene/acrylic acid, ethylene/methacrylic acid/n-butyl acrylate, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/methyl acrylate and ethylene/acrylic acid/methyl acrylate copolymers.
- the most preferred acid-containing ethylene copolymers are ethylene/methacrylic acid, ethylene/acrylic acid, ethylene/(meth) acrylic acid n-butyl acrylate, ethylene/(meth) acrylic acid/ethyl acrylate, and ethylene. (meth) acrylic acid/methyl acrylate copolymers.
- ionomer resins are commercially available from DuPont Co. under the tradename SURLYN®.
- the presently preferred cover material is a 50/50 blend of SURLYN® 8140 and SURLYN® 7940, which are high acid sodium and standard lithium SURLYN®, respectively. This cover material has a flex modulus of about 85 kpsi and a specific gravity of about 0.95.
- Another preferred cover is comprised of a 50/50 blend of SURLYN® 8140 and SURLYN® SEP671 , which is a lithium SURLYN® having about 19% methacrylic acid.
- This material has a flex modulus of about 105 kpsi.
- the flex modulus of the cover is greater than 80 kpsi.
- the preferred cover has a hardness of about 70 Shore D.
- the high flex modulus of the cover provides increased initial velocity and a low spin rate.
- a multi-layer cover is utilized, such as shown in Fig. 2.
- the inner layer 16 of the cover is either a thermoplastic material such as a thermoplastic elastomer, a thermoplastic rubber, a thermoset rubber, or a thermoset elastomer material.
- a thermoplastic material such as a thermoplastic elastomer, a thermoplastic rubber, a thermoset rubber, or a thermoset elastomer material.
- Additional examples of materials suitable for use as the inner cover layer include polyether or polyester thermoplastic urethanes as well as thermoset polyurethanes.
- a preferable thermoplastic material is a thermoplastic urethane with a melting point of about 178° to about 205° F.
- a preferable thermoset material is a rubber-based, castable urethane.
- the outer layer 18 of the cover is either a thermoplastic plastic material such as an elastomer or a thermoplastic rubber, or a thermosetting material.
- Suitable materials for the outer layer include urethanes, ionomers with a low modulus and other "dead” but durable materials such as EPDM and butyl rubber. Additionally, the present invention also contemplates the use of a polymeric foam material, such as the metal locene-based foamed resin described above, as the material for either the outer cover layer or the inner cover layer, but preferably not both layers. In one embodiment of the present invention, it is preferable that the thermoplastic or thermosetting materials of the outer layer have a melting point or heat of reaction (cure) temperature less than the melting point or heat of reaction (cure) temperature of the materials of the inner layer.
- cure melting point or heat of reaction
- the inner and outer cover layers of this embodiment of the invention can be molded about the core and mantle layers through a variety of conventional molding methods.
- the cover layers can be compression molded, retractable pin injection molded, fixed pin injection molded, cast around the core and mantle or a combination thereof.
- the materials of the outer layer are characterized in that they have thermal properties such that no flow of the inner layer material occurs during the molding of the outer cover layer about the inner layer, regardless of the process employed to mold the layers.
- the covers of the present invention golf balls may comprise thermoplastic or engineering plastics such as ethylene or propylene based homopolymers and copolymers including functional monomers such as acrylic and methacrylic acid and fully or partially neutralized ionomers and their blends, methyl acrylate, methyl methacrylate homopolymers and copolymers, imidized, amino group containing polymers, polycarbonate, reinforced polyamides, polyphenylene oxide, high impact polystyrene, polyether ketone, polysulfone, poly(phenylene sulfide), reinforced engineering plastics, acrylonitrile-butadiene, acrylic-styrene-acrylonitrile, poly(ethylene terephthalate), poly(butylene terephthalate), poly (ethylene-vinyl alcohol), poly(tetrafluorethylene) and their copolymers including functional comonomers and blends thereof.
- functional monomers such as acrylic and methacrylic acid and fully or partially neutralized ionomers
- the inner cover layer comprises an ionomer with an average weight percent (wt %) acid content of about 15 or less which is at least 10% neutralized.
- the inner cover layer such as layer 16 shown in Fig.
- ionomers 2 constitutes a blend of two types of ionomers in which one component of the blend is an ethylene-acrylic acid or ethylene-methacrylic acid copolymer containing at least 15 wt% acid groups which are at least partially neutralized with a cation, and the other type of ionomer is a terpolymer of ethylene, acrylic acid or methacrylic acid and a softening termonomer such as butyl acrylate or methyl acrylate, resulting in an overall wt % acid content of about 15 or less.
- one component of the blend is an ethylene-acrylic acid or ethylene-methacrylic acid copolymer containing at least 15 wt% acid groups which are at least partially neutralized with a cation
- the other type of ionomer is a terpolymer of ethylene, acrylic acid or methacrylic acid and a softening termonomer such as butyl acrylate or methyl acrylate,
- the outer cover layer may also comprise an ionomer.
- the out ⁇ r layer such as layer 18 in Fig. 2, can contain a single type of ionomer or a blend of two or more types of ionomers.
- a hardening and/or softening modifier can be added.
- the outer cover layer is harder than the inner cover layer, and has a Shore D hardness of about 60 or more, more preferably 65 or more and most preferably 68 or more (ASTM D-2240).
- the outer cover layer contains an ionomer having at least 16 weight % acid groups, which are at least partially neutralized.
- the thicknesses for the inner and outer cover layers are as follows.
- the inner and outer layers together form a cover having a thickness of about 0.090 to about 0.250 inches, more preferably about 0.10 to about 0.20 inches, and most preferably about 0.11 to about 0.15 inches.
- the inner cover layer has a thickness of about 0.025 to about 0.200 inches, and more preferably from about 0.050 to about 0.100 inches.
- the outer cover layer preferably has a thickness of about 0.025 to 0.200 inches, or more preferably from about 0.050 to about 0.100 inches.
- the ratio of the diameter of the ball to the thickness of the cover i.e., the sum of the thickness of the inner cover layer and the outer cover layer, is no more than about 19:1 , preferably no more than about 17:1 , and more preferably no more than about 15:1.
- the hardness of the inner and outer cover layers, and the compositions and thicknesses of these layers are appropriate to result in a golf ball having a COR of at least .780, more preferably at least .790 and most preferably at least .800.
- the golf ball of the invention has an overall PGA compression of from about 30 to about 110, more preferably from about 50 to about 107, and most preferably from about 60 to about 90.
- the spin rate of the golf balls is no more than about 8000 revolutions per minute (rpm) when struck with a 9-iron under conditions of launch angle, ball speed and tee position which produce a spin rate of about 7100 rpm for a two-piece hard covered ball (1994 Top-Flite XL) and a spin rate of about 9700 rpm for a thread wound balata covered ball (1994 Titleist Tour 100) using the same club.
- This relatively low spin rate provides the advantage of less sideways spin for improved accuracy and less backspin for improved rolling distance.
- the inner cover layer preferably comprises an ionomer having an average wt % acid content of about 15 or less which is at least 10% neutralized.
- the inner cover layer such as layer 16 in Fig. 2, includes a blend of hard and soft ionomer resins including but not limited to those described in U.S. Patent Nos. 4,884,814 and 5,120,791 , both of which are incorporated herein by reference.
- a blend of a high modulus ionomer (i.e., a hard ionomer) and a low modulus ionomer (i.e., a soft ionomer) in a mixture can be used.
- a high modulus ionomer is one which has a flexural modulus of about 15,000 - 70,000 psi or more as measured under ASTM method D-790.
- the hardness of this type of ionomer is at least 50 on the Shore D scale as measured in accordance with ASTM method D-2240.
- a low modulus ionomer which can be blended with the high modulus ionomer to form an inner layer, should have a flexural modulus of about 1 ,000 to about 15,000 psi (ASTM D-790), and a hardness of about 20 to about 40 on the Shore D scale (ASTM D-2240).
- the hard ionomer resins used in blends to form the inner cover layer include ionic copolymers which are the, e.g., sodium, zinc, magnesium, calcium, manganese, nickel, potassium or lithium, etc., salt, or blend thereof, of the reaction product of an olefin having from 2 to 8 carbon atoms and an unsaturated monocarboxylic acid having from 3 to 8 carbon atoms and which result in a ball having the desired combination of COR, compression, and inner cover layer hardness.
- the carboxylic acid groups of the copolymer may be totally or partially, that is from about 10 to about 100%, neutralized.
- the hard ionomeric resins typically are copolymers of ethylene with acrylic and/or methacrylic acid. Two or more hard ionomer resins can be blended.
- the metal cation salts utilized in the invention are preferably those salts which provide the metal cations capable of neutralizing, to various extents, the carboxylic acid groups of the high acid copolymer. These include acetate, oxide or hydroxide salts of, e.g., lithium, calcium, zinc, sodium, potassium, nickel, magnesium, and manganese, etc.
- lithium ion sources are lithium hydroxide monohydrate, lithium hydroxide, lithium oxide and lithium acetate.
- Sources for the calcium ion include calcium hydroxide, calcium acetate and calcium oxide.
- Suitable zinc ion sources are zinc acetate dihydrate and zinc acetate, a blend of zinc oxide and acetic acid.
- Examples of sodium ion sources are sodium hydroxide and sodium acetate.
- Sources for the potassium ion include potassium hydroxide and potassium acetate.
- Suitable nickel ion sources are nickel acetate, nickel oxide and nickel hydroxide.
- Sources of magnesium include magnesium oxide, magnesium hydroxide and magnesium acetate.
- Sources of manganese include manganese acetate and manganese oxide.
- the metal cation neutralized high acid ionomer resins can be produced by reacting the high acid base copolymer with various amounts of the metal cation salts above the crystalline melting point of the copolymer, such as at a temperature from about 200 °F to about 500° F, preferably from about 250 °F to about 350° F under high shear conditions at a pressure of from about 10 psi to 10,000 psi. Other blending techniques may also be used.
- the amount of metal cation salt utilized to produce the new metal cation neutralized high acid based ionomer resins is the quantity which provides a sufficient amount of the metal cations to neutralize the desired percentage of the carboxylic acid groups in the high acid copolymer.
- the extent of neutralization is generally from about 10% to about 90%.
- Examples of commercially available hard ionomeric resins which can be used in a blend to form the inner cover layer include the hard sodium ionic copolymer sold under the trademark SURLYN® 8940 and the hard zinc ionic copolymer sold under the trademark SURLYN® 9910.
- SURLYN® 8940 is a copolymer of ethylene with methacrylic acid with about 15 weight % acid which is about 29% neutralized with sodium ions. This resin has an average melt flow index of about 2.8.
- SURLYN® 9910 is a copolymer of ethylene and methacrylic acid with about 15 weight % acid which is about 58% neutralized with zinc ions. The average melt flow index of SURLYN® 9910 is about 0.7.
- Iotek 4000 Iotek 4010, lotek ⁇ OOO, Iotek 8020, Iotek 8030, Iotek 7010 and lotek 7030 which are sold by Exxon Corporation. It is to be understood that the above examples are for illustrative purposes and are by no means intended to be limiting.
- Non-limiting examples of soft ionomers to be blended with the above- described hard ionomers to form the inner cover layer of the inventive golf ball comprise sodium, zinc magnesium, calcium, manganese, nickel, potassium or lithium, etc. salts of a terpolymer of an olefin having from about 2 to 8 carbon atoms, acrylic acid or methacrylic acid, and a softening comonomer which is an unsaturated monomer of the acrylate ester class having from 1 to 21 carbon atoms.
- the soft ionomer is preferably an ionomer made from an acrylic acid-based polymer and an unsaturated monomer of the acrylate ester class.
- the soft (low modulus) ionomers have a hardness from about 20 to 40 as measured on the Shore D scale and a flexural modulus from about 1,000 to about 15,000, as measured in accordance with ASTM method D-790.
- Certain ethylene-acrylic acid-based soft ionomer resins developed by the Exxon Corporation under the designation "lotek 7510" may be combined with known hard ionomers such as those indicated above to produce the inner cover.
- the combination produces higher CORs at equal or lower levels of hardness, higher melt flow (which corresponds to improved, more efficient molding, i.e., fewer rejects) as well as significant cost savings versus the outer layer of multi-layer balls produced by other known hard-soft ionomer blends as a result of the lower overall raw materials costs and improved yields.
- lotek 7520, SURLYN® 8320 and SURLYN® 8120 also can be used. It has been determined that when hard-soft ionomer blends are used for the inner cover layer, good results are achieved when the relative combination is in a range of about 90 to about 10 % hard ionomer and about 10 to about 90 % soft ionomer.
- the results are improved by adjusting the range to about 75 to 25% hard ionomer and 25 to 75% soft ionomer. Even better results are noted at relative ranges of about 60 to 40% hard ionomer resin and about 40 to 60% soft ionomer resin.
- the outer cover layer such as layer 18 shown in Fig. 2 of the golf ball is harder than the inner cover layer, such as inner cover layer 16 of Fig. 2, and generally, but not necessarily, has a different chemical composition than the inner cover layer.
- the outer cover layer preferably comprises a high acid ionomer resin or high acid ionomer blend in which more than 10 weight % of the acid groups are neutralized.
- the outer cover layer is formed from a blend of two or more high acid ionomer resins that are neutralized to different extents using different metal cations. Softening modifiers can be used to achieve the desired Shore D hardness of the outer cover layer.
- the preferred high acid ionomers which can be used in formulating the outer cover layer of the golf ball are ionic copolymers which are the metal salts of the reaction product of an olefin having from about 2 to 8 carbon atoms and an unsaturated monocarboxylic acid having from about 3 to 8 carbon atoms.
- sodium, zinc, magnesium, manganese, potassium, calcium, nickel and lithium can be used as the neutralizing cation.
- the ionomeric resins are copolymers of ethylene with either acrylic or methacrylic acid.
- an additional comonomer such as an acrylate ester, e.g., iso-n- butylacrylate, etc.
- the carboxylic acid groups of the copolymer are partially neutralized by the metal ions, i.e., from about 10 to about 75% or more preferably from about 30 to about 70%.
- Each of the high acid ionomer resins which may be included in the outer cover layer composition preferably contains more than 16% by weight of a carboxylic acid, preferably 17 to about 25% by weight of a carboxylic acid, and most preferably from about 18.5 to about 21.5% by weight of a carboxylic acid.
- Examples of commercially available high acid methacrylic acid-based ionomers which can be used in accordance with the invention include SURLYN® AD-8422 (sodium cation), SURLYN® 8162 (zinc cation), SURLYN® SEP-513-1 (zinc cation), and SURLYN® SEP-503-2 (magnesium cation). According to DuPont, all of these ionomers contain from about 18.5 to about 21% by weight methacrylic acid.
- high acid acrylic acid-based ionomers which can be used in the present invention also include the Escor® or lotek High Acid Ethylene Ionomers produced by Exxon, including lotek Ex-959 and lotek EX-960. Furthermore, a number of other high acid ionomers neutralized to various extent by different types of metal cations, including manganese, lithium, potassium, calcium and nickel and several new high acid ionomers and/or high acid ionomer blends other than sodium, zinc and magnesium are now available for golf ball cover production. As indicated above, softening comonomers can be included in the ionomeric inner and/or outer cover layers.
- Non-limiting examples of a softening comonomer include vinyl esters of aliphatic carboxylic acids wherein the, acids have 2 to 10 carbon atoms, vinyl ethers wherein the alkyl group contains 1 to 10 carbon atoms, and alkyl acrylates or methacrylates wherein the alkyl group contains 1 to 10 carbon atoms.
- Suitable softening comonomers include vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, or the like.
- Examples of a number of copolymers suitable for use to produce the high acid ionomers used in the present invention include, but are not limited to, high acid embodiments of an ethylene/acrylic acid copolymer, an ethylene/methacrylic acid copolymer, an ethylene/itaconic acid copolymer, an ethylene/maleic acid copolymer, an ethylene/methacrylic acid/vinyl acetate copolymer, an ethylene/acrylic acid/vinyl alcohol copolymer, an ethylene/ acrylic acid/vinyl alcohol copolymer, etc.
- the base copolymer broadly contains greater than 16% by weight unsaturated carboxylic acid, from about 30 to about 83% by weight ethylene and from 0 to about 40% by weight of a softening comonomer.
- the copolymer contains about 20% by weight unsaturated carboxylic acid and about 80% by weight ethylene. Most preferably, the copolymer contains about 20% acrylic acid with the remainder being ethylene.
- the inner cover layer and/or outer cover layer optionally may include hardening or softening modifiers, non-limiting examples of which include a metal stearate, such as zinc stearate, or another fatty acid salt, as described in commonly assigned U.S. Patent Nos. 5,306,760 and 5,312,857, both of which are herein incorporated by reference.
- a metal stearate such as zinc stearate
- another fatty acid salt as described in commonly assigned U.S. Patent Nos. 5,306,760 and 5,312,857, both of which are herein incorporated by reference.
- One purpose of the metal stearate or other fatty acid salt is to reduce the cost of production of the ball without affecting overall performance of the finished ball.
- polar-group modified rubbers can be blended with ionomers as described, for example, in commonly assigned U.S. Patent Nos.
- thermoplastic elastomers which act as hardening or softening agents, include polyurethane, a polyester elastomer such as that sold by DuPont as Hytrel®, a polyester polyurethane such as B.F. Goodrich Company's Estane® polyester polyurethane X-4517, and a polyether amide such as that sold by Elf Atochem S.A. under the name Pebax®.
- a plastomer such as that sold by Exxon under the name ExactTM, e.g., ExactTM 4049 can be included.
- Various plasticizers and processing aids also can be used. It may also be preferred to apply a conventional clear coat on the cover layer.
- the inner cover layer as defined in this application can be formed from two or more layers which, taken together, meet the requirements of softness, thickness and compression of the layer or layers which are defined herein as the inner cover layer.
- the outer cover layer can be formed from two or more layers which, taken together, meet the requirements of hardness, thickness and compression of the layer or layers which are defined herein as the outer cover layer.
- one or more additional, very thin ionomeric or non-ionomeric layers can be added on either side of the inner cover layer as long as the objectives of the invention are achieved.
- a thin outermost cover layer of a scuff resistant and/or scratch resistant material is disposed on the outer surface of a golf ball.
- this thin outermost cover layer is disposed on the outer surface of the cover 3 of the golf ball 1 illustrated in Fig. 1 ; on the outer surface of the outer cover layer 18 of the golf ball
- the outer layer of a multi-layer cover assembly is formed, as described herein, to serve as the outermost protective layer.
- the outer cover layer 18 of the multi-layer cover assembly illustrated in Fig. 2 may be formed to serve as the outermost protective layer.
- the noted very thin protective outermost layer has a maximum thickness such that the layer does not detract from the playability, i.e., spin, feel, etc., of the golf ball, as compared to the ball if not having this layer.
- the thickness of this outermost layer is preferably less than about 0.040 inches, more preferably less than about 0.025 inches, and most preferably less than about 0.020 inches.
- the minimum thickness for this outermost cover layer is that thickness at which the layer provides an effective degree of scuff and/or scratch resistance for the golf ball.
- compositions include ionomer blends such as Spalding Blends No. 1 and 2, set forth below.
- compositions and combinations of materials described in the disclosure for the cover above can be used to form the outermost cover layer as long as the objectives of the present invention are met.
- the properties of the outer layer may be further improved by electron beam or gamma radiation treatment, as described in U.S. Patent No. 5,891 ,973, herein incorporated by reference.
- the hardness of the outermost cover layer also dictates the golf ball's durability and playability.
- the Shore D hardness of the outer cover layer is at least 56, more preferably at least 60, and most preferably at least 62.
- the maximal Shore D hardness is one which provides maximum durability without decreasing the playability properties of the golf ball.
- the Shore D hardness of the outermost cover layer is greater than the Shore D hardness of the layer below it.
- thermoset polybutadiene golf ball cores having a conventional composition, a PGA compression of 93, a COR of 0.782 and a diameter of 1.47 inches were molded in a conventional manner.
- the resulting covered cores had a PGA compression of 94 and a COR of 0.789.
- An outer layer formed from a blend of two hard acrylic acid based ionomers and designated as ionomer 2 was injection molded over the inner layer.
- the outer layer had a thickness of 0.055 inches and a Shore D hardness of 68.
- the balls were primed and clear coated in a uniform manner.
- the balls with the two-part cover had an average PGA compression of about 99, and a COR of about 0.803.
- the spin rate of the balls was determined by striking the balls with a 9-iron under conditions of launch angle, ball speed, and tee position, which produced a spin rate of about 7100 rpm for a two-piece hard covered ball (1994 Top-Flite XL), and a spin rate of about 9700 rpm for a thread wound balata covered ball (1994 Titleist Tour 100) using the same club.
- the properties of the ball are shown in Table 1.
- the resulting ball is predicted to have a PGA compression of about 90 (softened), a COR of 0.803 (unchanged), a spin rate of 8000 (increased), and a scuff resistance that is excellent and at least as good as compared to the thicker cover version.
- Comparative Example 1 The procedure of Comparative Example 1 was repeated using three different combinations of inner and outer cover layer materials at the same cover layer thicknesses. The results are shown on Table 1.
- the ball configuration was the same as Comparative Example 3 except that the outer cover layer thickness was reduced to 0.025 inches.
- the resulting ball is predicted to have a PGA compression of 90 (softer feel), a COR of
- a golf ball core made of a blend of polybutadiene, zinc diacrylate, zinc dimethacrylate, and conventional additives, and having a diameter of 1.43 inches was obtained.
- the core had a COR of 0.763.
- the core was coated with a polyolefin material in a thickness of 0.058 inches.
- the polyolefin material was a butene comonomer with a melt index of 4.5 dg/min and is available under the unregistered trademark EXACTTM 4049 (Exxon Chemical Company, Houston, Texas).
- An outer cover layer formed from a blend of ionomers designated as ionomer 1 was used for the cover of the ball and was injection molded over the inner cover layer in a thickness of 0.090 inches.
- the outer cover layer had a Shore D hardness of 68 (ASTM D-2240).
- the resulting golf ball was primed and top coated using conventional materials.
- the resulting ball had a coefficient of restitution of 0.796, and a PGA compression 79.
- the properties of the core, cover layers, and overall golf ball are shown on Table 2.
- Comparative Example 5 The procedure of Comparative Example 5 was repeated using different combinations of inner cover layer thickness and core size and composition. The same types of inner and outer cover layer materials were used in Comparative Examples 6-9 as were used in Comparative Example 5. The results are shown on Table 2.
- the ball configuration was the same as Comparative Example 8 except that the outer cover layer thickness was reduced to 0.025 inches.
- the ball configuration was the same as Comparative Example 9 except that the outer cover layer thickness is reduced to 0.025 inches.
- Three golf balls labeled Comparative Examples 10, 11 , and 12, respectively, were formed with the same core composition.
- the three golf balls contained no mantle layer.
- Each ball was molded with a different cover.
- the outer cover layer of Comparative Example 10 was made from
- the outer cover layer of Comparative Example 11 was made from 57.6 parts lotek 7510, 33 parts lotek 8000, and 9.4 parts White MB.
- the outer cover layer of Comparative Example 12 was made from 35 parts Surlyn ® 8140, 57.5 parts Surlyn ® 6120, and 12.5 parts
- a "Guillotine Cut Test” was performed on the golf balls by holding the ball firmly in a cavity to expose the top half of the ball.
- a guillotine blade weighing 5 pounds and having inner and outer blade edge angles of 90° and 60°, respectively, and a cutting edge of three sixty-fourths inch radius was dropped from a height of 3.5 feet to strike the ball at a point one-half inch off the top center point.
- the guillotine blade was guided during the drop by means of a substantially friction- free vertical track. The drops were repeated until ball failure occurred, ball failure defined as permanent damage evidenced by a crack or by removal of a segment from the ball surface.
- a multi-layered golf ball was made with the same core as the golf balls found in Comparative Examples 10-12.
- the inner cover layer of the multi- layered ball is constructed by molding lotek 7510, having a Shore D hardness of about 45, over the core using a 1.68" injection mold.
- the composition of the mantle layer of the multi-layered golf ball is the same as the outer cover layer of Comparative Example 10 except for the addition of White MB to the outer cover layer composition of Comparative Example 10.
- the core and inner cover were glebarred to a size of approximately 1.645", thus leaving a mantle thickness of about 0.050".
- the mantle could have been molded either by compression or injection molding in the proper size cavities to yield the desired mantle size and thickness.
- a very thin, hard layer of ionomer made from 35 parts by weight Surlyn ® 8140, 57.5 parts Surlyn ® 6120, and 12.5 parts White MB, having a Shore D hardness of 70-71 , was compression molded over the soft mantle.
- the outer cover layer of the multi-layered golf ball was the same composition as the outer cover layer of Comparative Example 12.
- the outer cover thickness for the multi-layered golf ball is about 0.020".
- a Guillotine Cut Test was then performed on the ball.
- the outer cover layer of the multi-layered golf ball has a Shore D hardness of 70, while the inner cover layer has a Shore D hardness of about 45.
- the overall Shore D hardness measured on the ball was 57, roughly in between the Shore D hardness measurements of the inner and outer cover layers.
- the multi-layered golf ball was faster and better for cut resistance compared to Comparative Examples 10 and 11.
- Comparative Example 12 did have a higher guillotine resistance than the multi-layered golf ball, but this result was expected due to the high cover hardness and compression as well as greater overall thickness of the outer cover layer.
- the configuration for the multi-layered golf ball was the same as Example 5 except that the inner cover layer was made from 60 parts by weight lotek 7510, 33 parts lotek 8000, and 7 parts 7030.
- the Shore D hardness of the outer cover layer was 70, while the Shore D hardness of the inner cover layer was about 54.
- the overall Shore D hardness of the cover was about 60, roughly halfway between the inner and outer cover layer hardness.
- the guillotine results of the multi-layered ball were much better than those found in Comparative Examples 10 and 11.
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Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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GB0320668A GB2393130A (en) | 2001-02-06 | 2002-02-05 | Golf ball having very thin outermost cover layer for improved scuff resistance |
CA002437167A CA2437167A1 (en) | 2001-02-06 | 2002-02-06 | Golf ball having very thin outermost cover layer for improved scuff resistance |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US09/777,595 | 2001-02-06 | ||
US09/777,595 US20020147057A1 (en) | 2001-02-06 | 2001-02-06 | Golf ball having very thin outermost cover layer for improved scuff resistance |
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WO2002081035A1 true WO2002081035A1 (en) | 2002-10-17 |
WO2002081035A8 WO2002081035A8 (en) | 2004-04-29 |
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Application Number | Title | Priority Date | Filing Date |
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PCT/US2002/003594 WO2002081035A1 (en) | 2001-02-06 | 2002-02-06 | Golf ball having very thin outermost cover layer for improved scuff resistance |
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US (1) | US20020147057A1 (en) |
CA (1) | CA2437167A1 (en) |
GB (1) | GB2393130A (en) |
WO (1) | WO2002081035A1 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
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US7358305B2 (en) * | 1995-06-07 | 2008-04-15 | Acushnet Company | Golf balls containing impact modified non-ionic thermoplastic polycarbonate/polyester copolymers or blends |
US7247676B2 (en) * | 1997-05-27 | 2007-07-24 | Acushnet Company | For golf balls with non-ionomer casing layer |
US7005479B2 (en) * | 1997-05-27 | 2006-02-28 | Acushnet Company | Golf ball with rigid intermediate layer |
US7300364B2 (en) * | 2004-02-06 | 2007-11-27 | Acushnet Company | Multi-layer golf ball having velocity gradient from faster center to slower cover |
US8747716B2 (en) | 2011-04-18 | 2014-06-10 | Acushnet Company | Process for manufacturing golf balls having a multi-layered covers |
US10500444B2 (en) * | 2012-04-20 | 2019-12-10 | Acushnet Company | Golf balls incorporating thermoplastic blend(s) of ionomer(s), thermoplastic polymer(s), and PEPA |
US10500443B2 (en) * | 2017-11-15 | 2019-12-10 | Acushnet Company | Golf balls incorporating thermoplastic blend(s) of ionomer(s), thermoplastic polymer(s), and polymethyl methacrylate-based polymer(s) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4919434A (en) * | 1986-05-23 | 1990-04-24 | Bridgestone Corporation | Golf ball |
US5810678A (en) * | 1995-06-07 | 1998-09-22 | Acushnet Company | Multilayer golf ball |
US5947842A (en) * | 1995-06-07 | 1999-09-07 | Acushnet Company | Multi-layer low-spin golf ball |
-
2001
- 2001-02-06 US US09/777,595 patent/US20020147057A1/en not_active Abandoned
-
2002
- 2002-02-05 GB GB0320668A patent/GB2393130A/en not_active Withdrawn
- 2002-02-06 CA CA002437167A patent/CA2437167A1/en not_active Abandoned
- 2002-02-06 WO PCT/US2002/003594 patent/WO2002081035A1/en not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4919434A (en) * | 1986-05-23 | 1990-04-24 | Bridgestone Corporation | Golf ball |
US5810678A (en) * | 1995-06-07 | 1998-09-22 | Acushnet Company | Multilayer golf ball |
US5947842A (en) * | 1995-06-07 | 1999-09-07 | Acushnet Company | Multi-layer low-spin golf ball |
Also Published As
Publication number | Publication date |
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GB0320668D0 (en) | 2003-10-01 |
US20020147057A1 (en) | 2002-10-10 |
GB2393130A (en) | 2004-03-24 |
WO2002081035A8 (en) | 2004-04-29 |
CA2437167A1 (en) | 2002-10-17 |
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