JP2003339913A - Intermediate layer of golf ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball with a novel intermediate layer in order to improve ball characteristics. <P>SOLUTION: The intermediate layer of the golf ball essentially consists of a specific triblock copolymer or its hydrogenated product, and a specific block copolymer or their mixture is used. The drawbacks anticipated by using such layer are not admitted and the intermediate layer imparts the ball characteristics reformed unexpectedly relating to a spin speed, feeling and durability. The layer can be incorporated into a wide range of various kinds of known ball structures. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to golf ball intermediate layers, and more particularly to golf ball intermediate layers made from compositions that optimize ball performance.

[0002]

Golf balls generally include a core and at least one coating layer surrounding the core. Balls can be classified as two-piece, wound, or multi-layer balls. Two-piece balls include a spherical inner core and an outer cover cover layer. Wound balls include a core, a rubber thread that is pulled and wound around the core to a desired diameter, and a cover cover layer, typically of balata rubber material. Multi-layer balls include a core, a cover layer, and one or more intermediate layers.
Two-piece balls generally have good durability and distance when hit, but lack the “feel” -the overall feel to the golfer when hit-and the spin rate Low, this gives you poor control of the ball. Wound balls with balata coating generally have a high spin rate and provide good control and feel, but have a short flight distance and poor durability as compared to two-piece balls. A good way to optimize good speed, spin rate, feel, and durability requirements is
Achieved by a multi-layer structure.

Multilayer balls generally have performance characteristics intermediate between those of two-piece balls and wound balls, that is, the multilayer balls are inferior in distance and durability to two-piece balls, but are superior to wound balls. , And the multi-layer ball shows less feel and spin than the wound ball but better than the two-piece ball. In particular, the use of intermediate layers to improve spin speed often leads to substantial ball speed loss and hence reduced flight distance.
Therefore, without losing the flight distance or durability of the ball,
Efforts have been focused on designing golf ball intermediate layers by creating layers that provide high spin rates. These efforts have yet to reach full success.

Used in any intermediate layer of a multi-layer ball,
The material properties of the composition are important factors in determining the performance of the resulting golf ball. In particular, the composition of the intermediate layer is particularly important and determines the ball speed and spin rate. Various materials with different physical properties have been used in the interlayer to create balls with the most desirable properties possible. Most intermediate layers incorporate soft or hard ionomer resins. Such an ionomer resin is generally an ionic copolymer of an olefin and a metal salt of an unsaturated carboxylic acid, or an ionomer terpolymer having a comonomer in its structure. These resins can change elasticity, flexural modulus, and hardness. Examples of these resins include Wilmington, Dela
Ware's EI DuPont de Nemours & Company manufactures Surlyn (SURLYN), and Irving, Texas's E
Includes resins marketed under the name IOTEK, made by xxonn Mobil. Many interlayers also incorporate an elastic resin in addition to the ionomer layer. The elastic resin used for the cover cover of the golf ball includes various thermoplastic or thermosetting elastomers that can be used. Examples of these elastomers are Philadel
Manufactured at Atofina Chemicals in phia, Pennsylvania, P
Includes resins marketed under the name EBAX. Other materials commonly used for the intermediate layer include EI DuPont de
HYTREL-like polyester elastomers manufactured by Nemours & Company and BF Go from Cleveland, Ohio
Includes thermoplastic urethanes such as ESTANE manufactured by odrich.

Each of the above materials has special properties that provide good golf ball properties when used in the intermediate layer. However, none of these materials can optimize all the important properties of the ball's intermediate layer, and when one of these properties is improved using a particular material, the other properties are often replaced. Make it worse. Therefore, in order to improve the properties of golf balls, some of the above materials are blended to create improved intermediate layers. As mentioned above, ideally the middle layer is
You must give a good spin without sacrificing ball speed. Therefore, ionomers are often combined with elastomers in the interlayer. In fact, most non-wound intermediate layers incorporate ionomer resins. The resulting formulation provides acceptable ball spin and speed. Numerous patents disclose preferred interlayers in which elastomers and ionomer resins are mixed.

The particular materials that have been disclosed for golf ball compositions include a first polymer block containing an aromatic vinyl compound, a second polymer block containing a conjugated diene compound, and a hydroxyl group located on the block copolymer. Or a hydrogenation product of this triblock copolymer. The hydroxyl groups can be on the end block copolymer or elsewhere in the block copolymer structure. The aromatic vinyl compound is preferably styrene,
It is selected from the group consisting of methylstyrene, 4-propylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, and vinylanthracene. The conjugated diene compound is preferably 1,3-butadiene, isoprene, 2,
It is selected from 3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. The triblock copolymer preferably has a number average molecular weight between about 30,000 and about 1,000,000.
An example of this material in which a triblock copolymer having hydroxyl groups is located in the endblock copolymer is HG-252 by Kuraray of Kurashiki, Japan.
It is sold under the brand name.

This material is based on Akiba et al. (“Akiba'711
Patent ") and are incorporated herein by reference (see, for example, U.S. Patent No. 5,837,049). The Akiba'711 patent discloses compositions incorporating specific triblock polymers and ionomers, and also Both of these disclose and claim a golf ball coated cover composition incorporating an ionomer and a block polymer in a weight ratio ranging from 98: 2 to 50:50. Flexibility and tenacity are imparted to the cover layer of the ball.However, the Akiba'711 patent uses the material in the intermediate layer, or alternatively, a composition that incorporates only the triblock copolymer without ionomer incorporation. It does not discuss the use of things.

The first patent that illustrates the understanding of using specific triblock copolymers in the intermediate layer for golf balls is that of Sano et al., Which is simply in combination with an ionomer or a specific block copolymer, The use of a thermoplastic elastomer having a terminal OH group such as a specific triblock copolymer in the intermediate layer is disclosed (see, for example, Patent Document 2). Similarly, Sasa
The Ki patent discloses and claims a golf ball intermediate layer that incorporates a specific triblock copolymer and a hard ionomer having a specific hardness and flexural modulus (see, for example, US Pat. No. 6,037,049). The hard ionomer is
The result is described as providing a ball having high resilience. To avoid low resilience of the resulting balls, one needs a blend with a hard polymer, such as a hard ionomer, as specified in the Sasaki patent, which is a triblock copolymer. There is nothing inconsistent with previous understanding of its use. Certain triblock copolymers can be used like most elastomers when blended with hard, non-elastomeric materials, such as ionomers of high acid copolymers, to create a satisfactory golf ball intermediate layer. It has been explained. However,
Blending materials to improve properties is not entirely satisfactory as long as the above materials are used. Generally, a non-elastomeric material, such as a copolymer ionomer having a high acid-content copolymer, is
Without blending into the layers, it is difficult to make interlayers that give good properties. Also, the requirement to blend these materials complicates manufacturing possibilities and requires increased monitoring and quality control during the manufacturing process.

[0009]

[Patent Document 1] US Pat. No. 5,693,711

[Patent Document 2] US Pat. No. 5,948,862

[Patent Document 3] US Pat. No. 6,334,820

[0010]

In view of the above considerations, the mid layer of a golf ball is needed to optimize the performance characteristics of many balls without compromising other properties. It is clear that The intermediate layer of the ball should also provide processing and manufacturing methods with little or no difficulty. The present invention fulfills this and other needs and provides additional related advantages.

[0011]

The present invention embodies an intermediate layer of a golf ball, which comprises one or more specific triblock polymers, their triblock copolymers, or specific triblock copolymers. An intermediate layer consisting essentially of the hydrogenation products of block copolymers or mixtures thereof. Each triblock copolymer and their hydrogenation products include: a first polymer block containing an aromatic vinyl compound; a second polymer block containing a conjugated diene compound; and a hydroxyl group located on the block copolymer. ing. Each block copolymer is a hydrogenated diene block copolymer having a polystyrene-reduced number-average molecular weight of 50,000 to 600,000.
Each hydrogenated diene block copolymer is:
(A) an AB block copolymer, A is an alkenyl aromatic compound polymer block, and B is
An alkenyl aromatic compound-A-of a conjugated diene random copolymer block, which is a conjugated diene homopolymer block having a vinyl content of the conjugated diene portion of more than 60%, or a vinyl content of the conjugated diene portion of 15% to 60% B block copolymer or; (b) AB-
C block copolymers, wherein A and B are as defined above, and C is a tapered block of an alkenyl aromatic compound-conjugated diene copolymer,
(C) an ABA block copolymer in which the alkenyl aromatic compound is gradually increasing; A and B are hydrogenation products as defined above. In each block copolymer, the weight ratio of the alkenyl aromatic compound and the conjugated diene is 5/9.
5 to 60/40, and the content of bound alkenylaromatic compound in at least one block A is at least 3% by weight, based on the total monomers, and 2
The total content of bound alkenyl aromatic compounds in one block A or in blocks A and C is 5% to 25
% By weight. Further, in the hydrogenated diene block copolymer, which is a hydrogenation product as described above, at least 80% of the double bond unsaturated portion of the conjugated diene is used.
% Is saturated by hydrogenation.

In each triblock copolymer,
The aromatic vinyl compound is preferably selected from the group consisting of styrene, methylstyrene, 4-propylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, and vinylanthracene, and the conjugated diene compound is preferably 1,3- It is selected from the group consisting of butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Each triblock copolymer is preferably about 30,000.
It has a number average molecular weight between ˜1,000,000. Preferably, the weight ratio of triblock copolymer to hydrogenated diene block copolymer is 99: 1 to 1: 9.
The range is between nine.

The intermediate layer further includes a filler, a stabilizer, a colorant,
It may contain processing aids, antioxidants, or mixtures thereof. The filler used can be a heavy filler having a specific gravity greater than about 2. The present invention is also embodied in a golf ball that incorporates a core, a cover, and the particular intermediate layer described above, located between the core and the cover. In these golf balls, the core may include an inner core and one or more outer cores surrounding the inner core. The core can also contain a liquid. Golf balls can incorporate one or more layers located between the core and the cover, or layers of rubber thread located between the core and the cover. The ball cover can include a copolymer ionomer, a terpolymer ionomer, or a mixture thereof. The ball cover can also include an elastomeric material.

Preferably, the interlayer of the present invention is about 0.0
Having a thickness between 05 inches and about 0.1 inches,
More preferably between about 0.01 inch and about 0.05 inch, and most preferably between about 0.02 inch and about 0.0 inch.
It has a thickness of between 5 inches. The middle layer is injection molded,
It can be made using compression molding or by powder deposition on a golf ball portion.

The invention also resides in the intermediate layer consisting essentially of the triblock copolymers defined above, wherein the aromatic vinyl is styrene or α-.
It contains methylstyrene and the conjugated diene compound contains isoprene or 1,3-butadiene and preferably has a thickness of about 0.1 inch. The invention also belongs to the intermediate layer, which consists essentially of the block copolymers specified above.

Other features and advantages of the present invention will be apparent from the detailed description of the preferred embodiments which follows.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention belongs to an intermediate layer for a golf ball and comprises one or more specific triblock polymers, hydrogenation products of these triblock copolymers, or specific block copolymers. , Or a mixture of these. Therefore, the intermediate layer is substantially free of non-rubber elastic (particularly ionomer) polymers. The intermediate layer provides excellent golf ball properties without complicating processing.

As stated above, each triblock copolymer is: a first polymer block containing an aromatic vinyl compound; a second polymer block containing a conjugated diene compound; and a hydrogenated block copolymer, or triblock copolymer. The hydroxyl groups located in the product, or a mixture thereof, are incorporated. Preferably,
Aromatic vinyl compounds are styrene, methylstyrene, 4
-Propylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, and vinylanthracene, and the conjugated diene compound is preferably 1,
3-butadiene, isoprene, 2,3-dimethyl-1,
3-butadiene, 1,3-pentadiene, and 1,3-
It is selected from the group consisting of hexadiene. Each triblock copolymer preferably has a number average molecular weight of between about 30,000 and about 1,000,000.

In view of the prior art understanding and disclosure of discussing the use of a particular triblock copolymer in a ball composition, this triblock copolymer has been successfully used as a composition of essentially the entire intermediate layer. It is surprising to find that it can be used. As discussed above, in the prior art understanding of ball making, certain triblock copolymers have been favored only when blended with rather rigid polymers and ionomers, generally with high acid content copolymers. . This particular triblock polymer has been considered necessary because of its softness, making it clearly unsuitable for exclusive use in interlayers. In general, the soft elastomeric material in the ball composition has contributed to improved feel and spin rate of the resulting ball at the expense of ball speed. It has been believed that the addition of ionomers, especially copolymeric ionomers, to these compositions is necessary to produce balls having acceptable speed when struck.

Surprisingly in view of the above, it has been observed that when a composition consisting essentially of a particular triblock copolymer is used in the interlayer, it gives unexpectedly superior ball properties. . Ball layers incorporating only soft elastomers such as certain triblock copolymers will produce balls with unacceptable properties, such as low coefficient of restitution and consequent low ball speed. Despite the general recognition, they exhibit these excellent properties. This recognition is
It is also reflected in the above-discussed patents incorporating soft elastomers blended with hard components. The intermediate layer of the present invention differs significantly from these patents in that it has a high acid
It does not contain hard bulk polymeric materials such as ionomers.

Also, in addition to the above specific triblock copolymers, additional types of specific block copolymers can be used in the ball interlayer, either alone or in combination with the specific triblock copolymers, are improved. It has been found to produce an intermediate layer with different properties. This particular block copolymer is described in US Pat. Nos. 5,191,024 and 5,30, both to Shibata et al.
No. 6,779 ("Shibata'024" and "Shibat, respectively"
a'779 ”patent) and is hereby incorporated by reference.

Each particular block copolymer in the interlayers of the present invention is a hydrogenated diene block copolymer having a polystyrene-reduced number-average molecular weight of 50,000 to 600,000. Each particular block copolymer is; (i) an AB block copolymer, wherein A is an alkenyl aromatic compound polymer block and B is (1) a vinyl content of the conjugated diene moiety greater than 60% ('024 (Described in patent) conjugated diene homopolymer block, or (2) 15% ~
It has a vinyl content of the conjugated diene moiety of 60% ('779
A block copolymer of alkenyl aromatic compound-conjugated diene random copolymer blocks; or (ii) an ABC block copolymer, wherein A and B are as defined above, and C is an alkenyl aromatic compound. −
A tapered block of a conjugated diene copolymer, wherein the proportion of alkenyl aromatic compound is gradually increased, or (iii) A and B are ABA block copolymers as defined above. It is either. In the particular block copolymer, the weight ratio of alkenyl aromatic compound to conjugated diene is 5 / 95-6.
It is 0/40. In the specific block copolymer, the content of the bound alkenyl aromatic compound in at least one block A is at least 3% by weight,
And two blocks A, or blocks A and C
The total content of bound alkenyl aromatic compounds therein is 3% to 50% by weight, based on the total monomers. In certain block copolymers, which are hydrogenation products as described above, at least 80% of the double bond unsaturated moieties of the conjugated diene are saturated by hydrogenation.

An intermediate layer included within the scope of the present invention is one or more of the above specified triblock copolymers or hydrogenated products thereof, one or more of the above specified block copolymers, or these. It consists essentially of a mixture of compounds. A preferred mixture is 99: 1
It has a weight ratio of the particular triblock copolymer to the particular block copolymer in the range between 1:99.

The suitability of the particular block copolymer alone in the interlayer is surprising, as it is too soft without incorporation with a harder material such as the copolymer ionomer, like certain triblock copolymers. It is an elastomer material that is considered to be unsuitable for use in the intermediate layer. Similarly, it has been found that, when a layer consisting essentially of a particular triblock copolymer and / or a particular block copolymer is used for the intermediate layer, it surprisingly gives good ball properties.

In addition to the specific triblock copolymers and / or the specific block copolymers, the interlayers of the present invention also include colorants, stabilizers, antioxidants, processing aids, fillers, or mold release agents. However, it may contain small amounts of materials that are generally added to the ball composition. Compositions within the scope of the present invention may also incorporate inorganic fillers such as titanium dioxide, calcium carbonate, zinc sulfide, or zinc oxide. Golf ball formulations, and ball compositions within the scope of the present invention, have a greater density than zinc oxide, barium sulfate, tungsten, or a base polymer resin to provide additional density, preferably greater than about 2. Additional fillers can be selected, such as any other metal powder with a high specific gravity. Any organic or inorganic fiber, continuous or discontinuous, can also be included in the composition. The intermediate layer of the present invention can be used in balls of various designs, including balls with solid, liquid, or multilayer cores, with or without rolled layers. Any of these ball structures
Intermediate layers can be incorporated that consist essentially of certain triblock copolymers and / or block copolymers.

The preferred thickness of the intermediate layer of the present invention is about 0.
It is between 005 inches and about 0.1 inches, more preferably between about 0.01 inches and about 0.05 inches, and most preferably between about 0.02 inches and about 0.05 inches. The intermediate layer of the present invention can be made using a variety of methods. 1) injection molding of the whole layer, 2) injection molding of half the cup and compression molding of the whole layer;
The method includes compression molding from a sheet material, or 3) a method of coating the ball portion with a powder containing the material.

Balls incorporating the intermediate layers of the present invention can have a wide variety of suitable coated covers. Various ionomers known to be used for ball covers,
Certain triblock copolymers, as well as non-ionomer resins, or combinations thereof, have been successfully used as part of the coating cover composition. Non-limiting examples of suitable ionomer coated cover materials include copolymer ionomers and terpolymer ionomers, or mixtures thereof. The ionomer of the copolymer is obtained by neutralizing at least a part of carboxyl groups in a copolymer of an α-olefin and an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms with a metal ion. You can Suitable α-
Olefins include ethylene, propylene, 1-butene, and 1-hexene. Examples of suitable unsaturated carboxylic acids include acrylic, methacrylic, ethacrylic, alphachloroacrylic, croton, malein, fumaric and itaconic acid. The ionomers of the copolymers have varying acid content and degree of acid neutralization, such as lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, or combinations of these cations. , Ionomers neutralized by monovalent or divalent cations.

Terpolymer ionomers suitable as cover materials include α-olefins, and α, β-unsaturated carboxylic acids having 3 to 8 carbon atoms, and α, β-unsaturations having 2 to 22 carbon atoms. Of saturated carboxylates,
At least a part of the carboxyl groups in the terpolymer,
It can be obtained by neutralizing with metal ions.
Suitable examples of alpha-olefins include ethylene, propylene, 1-butene, and 1-hexene. Examples of suitable unsaturated carboxylic acids include acrylic, methacrylic, ethacrylic, alphachloroacrylic, croton,
Includes maleic acid, fumaric, and itaconic acid. Terpolymer ionomers have various acid contents and degrees of acid neutralization: lithium, sodium, potassium, magnesium, calcium, barium, lead, tin,
Included are ionomers neutralized with monovalent or divalent cations such as zinc, aluminum, or combinations of these cations.

With a ball incorporating an intermediate layer within the scope of the present invention, a suitable non-coating cover material used as
Examples of ionomer polymers include, but are not limited to, thermoplastic elastomers, thermosetting elastomers, thermoplastic rubbers, thermoplastic vulcanizates, polycarbonates, polyolefins, polyamides, copolymer polyamides, polyesters, polyurethanes. , Polyarylate, polyacrylate, polyphenyl ether, modified-polyphenyl ether, high-impact polystyrene, diallyl phthalate polymer, metallocene catalyst polymer, acrylonitrile-styrene-butadiene (A
BS), styrene-acrylonitrile (SAN) (including olefin-modified SAN and acrylonitrile styrene acrylonitrile), styrene-maleic anhydride (S /
MA) polymer, styrene copolymer, styrene terpolymer, cellulose polymer, liquid crystal polymer (LC
P), ethylene-propylene-diene-monomer (EP
DM), ethylene vinyl acetate (EVA) and polysiloxane. Suitable polyamides are:
1) Dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohexyldicarboxylic acid, and ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, or decamethylenediamine , 1,
Polycondensation with 4-cyclohexyldiamine or diamine such as m-xylylenediamine, 2) Ring-opening polymerization of cyclic lactam such as ε-caprolactam or ω-laurolactam; 6-aminocaproic acid, 9-aminononanoic acid , A resin obtained by polycondensation of an aminocarboxylic acid such as 11-aminoudecanoic acid or 12-aminododecanoic acid, or 3) copolymerization of a cyclic lactam with a dicarboxylic acid and a diamine. Specific examples of suitable polyamides are nylon 6; nylon 4,6; nylon 6,
6; nylon 6,9; nylon 6,10; nylon 6,
12; Nylon 11; Nylon 12; Copolymerized nylon;
Nylon 6 / 6,6; Nylon 6/6, T; Nylon 6,6 / 6,10; and Nylon MXD6.

Within the scope of the present invention, examples of suitable non-ionomeric polymers for use as coated cover materials with golf balls incorporating intermediate layers are Pittsfie.
ld, a trademark sold by GE Plastics of Massachusetts
LEXAN, VALOX, NORYL, and NORYL GTX, Philadelphia,
CRIST for sale at ATOFINA Chemicals in Pennsylvania
EMS-CHEMIE of AMID and RILSAN, Sumter, South Carolina
GRILAMID, Wilmington, Delaware's E.
ZYTE for sale by I. DuPont de Nemours & Co.
L, TENITE sold by Eastman Chemical Company of Kingsport, Tennessee, EXXPOL sold by Exxon Mobil of Houston, Texas, and BF Goodri of Cleveland, Ohio.
Includes ESTANE sold on ch.

Balls incorporating intermediate layers within the scope of this invention also incorporate core compositions known for their use in golf balls. Examples of suitable core formulations include dicumyl peroxide or sulfur-
Polybutadiene c containing a reaction product of zinc oxide and zinc diacrylate in addition to a cross-linking agent such as a compound containing
It contains thermoplastic elastomers, such as is-1,4 type crosslinked diene elastomers.

EXAMPLE Multilayer golf balls were made to test the performance of intermediate layers within the scope of the present invention. Each type was 2 dozen, and the balls were marked Type 1-4. Type 1
~ 3 balls have a core with a diameter of 1.48 inches,
And incorporating an intermediate layer having a thickness of 0.1 inches,
Type 4 balls, on the other hand, incorporated a core having a diameter of 1.58 inches. All ball cores had a compressive force of 75. Type 1 balls incorporate an intermediate layer within the scope of the invention, which is wholly above HG-.
It consists of a triblock copolymer commercially available as 252. Types 2 and 3 balls incorporate an intermediate layer that falls within the scope of the prior art. These interlayers contain a blend of SURLYN 9120, SURLYN 8140, and PEBAX 3533. Type 4 balls were prepared as comparative balls, with no interlayer incorporated and showing typical two-piece balls.

A coated cover layer having a thickness of 0.05 inch was provided on all balls. Type 1, 2 and 4
Ball had a coated cover containing an ionomer formulation having a Shore D hardness of 62. Type 3 balls had a cover containing an ionomer formulation having a Shore D hardness of 57. The percent composition of the intermediate layer and the hardness of the cover material are shown in the table below.

[0034]

Testing In addition to the balls described above, several golf balls widely available on the market were tested under the same index. These balls are from Acushnet of Fairhaven, Massachusetts.
HP Tour, Greenville, South Carolina
Revolution and Bea manufactured by MaxFli Golf
Includes Tour Accuracy made by Nike in verton, Oregon.

All balls were tested for spin rate and speed when hit with an 8-iron, and speed when hit with a driver. The balls were also tested for ball compressibility and Shore D scale surface hardness (as distinguished from the cover material hardness shown in Table 1). As discussed above, a high spin rate when hit with a short iron is desirable because it improves control of the ball when hit. Higher ball speeds are desirable because they result in greater distance traveled by the ball. Low PGA compression gives improved ball feel and feel. In addition to these properties, the balls were also tested for shear-cut resistance using a pitching wedge to strike the ball at a controlled speed. Three balls of each type were used in this test. Each ball,
Numerical scores were assigned from 1 (no visible damage) to 5 (substantially dislodged material), and these scores were averaged for each ball type to give the number of shear cut resistances below. It was

Result The test results are shown in Table 2 below.

[0038]

Discussion 1. Comparison of Type 1 and 2 Balls As noted above, Type 1 balls incorporate intermediate layers within the scope of the present invention. Type 2 balls represent the same prior art balls as Type 1 balls except that they incorporated a conventional interlayer containing a copolymeric ionomer and a polyetheramide elastomer.

It is generally believed that the golf ball speed of a multi-layer ball increases with increasing content of the high acid copolymeric ionomer in the ball interlayer composition. Therefore, Type 1 balls without the inclusion of ionomer material in their middle layer will have 30% in their mantle.
It was expected that it would exhibit a lower ball speed than the Type 2 ball, which is incorporating the copolymer ionomer of However, as the data show, the Type 1 balls actually showed comparable driver and 8 iron speeds to the Type 2 balls. Despite the high speed, Type 1 balls also
It showed a substantially higher spin rate with 8 irons. These data show that when a type 1 ball is hit with the same force, it travels about the same distance as a type 2 ball,
And again it shows to show good control when hit with 8 irons.

In addition to good ball speed and spin characteristics, Type 1 balls have lower PGA compression than Type 2 balls and exhibit a better "feel" when struck. In addition, the type 1 ball exhibited substantially excellent shear cut resistance. In general, the exclusive use of triblock copolymers in the mid-layer imparts overall superior properties to golf balls. These results are unexpected, based on previous understanding of soft elastomers such as triblock copolymers, and the known performance properties of interlayers.

2. Comparison of Type 1 and 3 Balls Type 3 balls show prior art balls similar to Type 2 except that the percentage of terpolymer ionomer in the ball cover is higher. Increasing the content of terpolymer ionomer in the coated cover of a multi-layer ball reduces the hardness of the cover and reduces the feel of the ball at the expense of other aspects of ball performance such as ball speed and shear cut resistance. Is a known method in an attempt to improve and improve the spin rate. In this case, the ball speeds of Type 1 and Type 3 balls are essentially the same. However, the spin rate actually shown for Type 3 is much lower than for Type 1 balls. Also, although Type 3 balls exhibit lower PGA compression than Type 2 balls, they have higher P than Type 1 balls.
It showed GA compression. Furthermore, the shear cut resistance for Type 3 balls is significantly worse than for Type 1 and even worse than Type 2 balls. These data indicate that it is far superior to using the intermediate layer of the present invention to improve the ball cover composition as it is commonly tried in improving the properties of golf balls. Shows.

3. Comparison of Type 1 and 4 Balls Type 4 balls have a two-piece; The core is slightly larger than that of the Type 1 ball; essentially, the portion of the Type 1 ball containing the core and the intermediate layer is the core of the Type 4 ball.

As already discussed, the two-piece ball
At the expense of reduced spin and reduced "feel"
It is known to provide better ball speed and durability than comparable multilayer balls. This reduction in spin and feel is generally increased by using a soft mantle. Therefore, it is expected that the Type 4 balls will exhibit substantially higher ball speed than the Type 1 balls incorporating the soft HG-252 interlayer. As expected, Type 1 balls incorporating intermediate layers within the scope of the present invention demonstrate superior 8-iron spin rates to two-piece Type 4 balls. However, Type 4 balls only show slightly higher ball speeds than Type 1 balls,
And, it showed poor shear cut resistance as compared to the type 1 ball. Type 1 balls also show much lower PGA compression than Type 4 balls, indicating that Type 1 balls have a much better "feel". The data show that the use of the interlayers of the present invention can overcome the conventional drawbacks of multi-layer balls incorporating prior art interlayers.

4. Comparison of Type 1 and Commercially Available Balls Commercially available balls correspond to a wide range of prior art, each having a two-piece, multi-layer, or wound construction. Type 1 balls exhibited higher spin speeds, comparable ball speeds, and much better durability than commercial balls. Type 1 PGA compression was lower than all balls except the HP Tour ball which had the lowest spin rate. In general, Type 1 balls exhibit combined performance characteristics that are superior to commercially available balls. Especially, the type 1 ball is HP Tou
r, better ball speed than two-piece ball,
It showed spin speed and shear cut resistance. Type 1 balls exhibited superior ball spin speed and shear cut resistance over balls with wound cores and thermoset polyurethane covers, Revolution. Finally, Type 1 balls exhibited better spin speed, ball speed, and significant shear cut resistance than balls with thermoplastic polyurethane covers, Tour Accuracy.

Generally, a high spin rate when hit with a short iron, a long flight distance when hit, and a low PGA
It is difficult to make a golf ball that combines compression, soft hitting feel, and good durability. A Type 1 ball incorporating an intermediate layer within the scope of the present invention exhibited all of these. As discussed above, these performances contradict conventional understanding of the effectiveness of the sole use of soft elastomers, such as certain triblock copolymers, and maximize the desired ball performance. Indicates that the intermediate layer of the present invention is beneficial.

Although the invention has been disclosed in detail with reference to only the preferred embodiments, those skilled in the art will recognize that additional golf ball intermediate layers can be made without departing from the scope of the invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hyun Jin Kim             Carl, United States of America             Subad, Veronica Court 1277

Claims (23)

[Claims] 1. One or more triblock copolymers; hydrogenation products of one or more triblock copolymers; one or more hydrogenated diene block copolymers; or mixtures thereof. An intermediate layer of a golf ball consisting essentially of: (i) a first polymer block containing an aromatic vinyl compound, (ii) a second polymer containing a conjugated diene compound. Block, and (iii) a hydroxyl group located in the block copolymer, each hydrogenated diene block having 50,000 to 60
Having a polystyrene-equivalent number-average molecular weight of 10,000 and (i) an AB block copolymer, A being a polymer block of an alkenyl aromatic compound, and B being (1) a conjugated diene homopolymer block. Wherein the conjugated diene moiety has a vinyl content of more than 60%, or (2) the alkenyl aromatic compound-conjugated diene random copolymer block, wherein the conjugated diene moiety has a vinyl content of 15 to 60. %, Or (ii) an ABC block copolymer, wherein A and B are as defined above, and C is a tapered block of an alkenyl aromatic compound-conjugated diene copolymer. , Alkenyl aromatic compounds are gradually increasing, or (iii) A and B are as defined above, A-B-A
A hydrogenated product of a block copolymer, wherein in each hydrogenated diene block copolymer, the weight ratio of alkenyl aromatic compound and conjugated diene is 5 /
95-60 / 40, the content of bound alkenylaromatic compounds in at least one block A is at least 3% by weight, in two blocks A or in blocks A and C The total content of bound alkenyl aromatic compounds is 5% to 25%, based on total monomers, and at least 80% of the double bond unsaturated portion of the conjugated diene.
Is a golf ball mid layer that is saturated with hydrogen. 2. A golf ball intermediate as defined in claim 1, wherein the aromatic vinyl compound is selected from the group consisting of styrene, methylstyrene, 4-propylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, and vinylanthracene. layer. 3. The conjugated diene compound is selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. A golf ball intermediate layer as defined in Item 1. 4. Each of the one or more triblock copolymers comprises from about 30,000 to about 1,000,000.
The golf ball intermediate layer defined in claim 1, having a number average molecular weight between 0. 5. The weight ratio of triblock copolymer to hydrogenated diene block copolymer is from 99: 1 to 1:99.
A golf ball intermediate layer as defined in claim 1 having a range between. 6. The mid layer of a golf ball as defined in claim 1, further comprising a filler, stabilizer, colorant, processing aid, antioxidant, or mixture thereof. 7. The golf ball intermediate layer defined in claim 6, wherein the filler has a specific gravity of greater than about 2. 8. A golf ball containing a core, a cover and an intermediate layer as defined in claim 1 located between the core and the cover. 9. The golf ball defined in claim 8, wherein the core comprises an inner core and one or more outer cores surrounding the inner core. 10. The golf ball defined in claim 8, wherein the core contains a liquid. 11. The golf ball defined in claim 8, further comprising one or more layers located between the core and the cover. 12. The golf ball defined in claim 8, further comprising a layer of rubber thread located between the core and the cover. 13. The golf ball defined in claim 8, wherein the cover comprises a copolymeric ionomer, a terpolymeric ionomer, or a mixture thereof. 14. The golf ball defined in claim 8, wherein the cover contains an elastomeric material. 15. The golf ball intermediate layer defined in claim 1, wherein the intermediate layer has a thickness between about 0.005 inches and about 0.1 inches. 16. The intermediate layer comprises from about 0.01 inch to about 0.1 inch.
16. The golf ball intermediate layer defined in claim 15, having a thickness between 05 inches. 17. The intermediate layer comprises from about 0.02 inch to about 0.02 inch.
The golf ball intermediate layer as defined in claim 16, having a thickness between 05 inches. 18. The golf ball intermediate layer defined in claim 1, wherein the intermediate layer is made using injection molding. 19. The golf ball intermediate layer defined in claim 1, wherein the intermediate layer is made using compression molding. 20. The golf ball intermediate layer defined in claim 1, wherein the intermediate layer is made by depositing a powdered material on a portion of the golf ball. 21. A triblock copolymer comprising: (a) a first polymer block containing styrene or α-methylstyrene, (b) a second polymer block containing isoprene or 1,3-butadiene, and (c ) A golf ball intermediate layer consisting essentially of a triblock copolymer having hydroxyl groups located in the block copolymer, or the hydrogenation products of the triblock copolymer, or mixtures thereof. 22. The golf ball intermediate layer defined in claim 21, wherein the intermediate layer has a thickness of about 0.1 inch. 23. A golf ball midlayer consisting essentially of one or more hydrogenated diene block copolymers, each hydrogenated diene block copolymer having a polystyrene equivalent weight of 50,000 to 600,000. Having a number-average molecular weight, and (i) an AB block copolymer, A being a polymer block of an alkenyl aromatic compound, and B being (1) a conjugated diene homopolymer block of a conjugated diene moiety. A vinyl content of greater than 60%, or (2) an alkenyl aromatic compound-conjugated diene random copolymer block wherein the conjugated diene moiety has a vinyl content of 15-60%, or (Ii) an ABC block copolymer, wherein A and B are as defined above, and C is an alkenyl aromatic A tapered block of a compound-conjugated diene copolymer, wherein the proportion of alkenyl aromatic compounds is gradually increased, or (iii) A and B are ABA block copolymers as defined above, Hydrogenation products of the above, wherein in each hydrogenated diene block copolymer, the weight ratio of alkenyl aromatic compound and conjugated diene is 5 /
95-60 / 40, the content of bound alkenyl aromatic compounds in at least one block A is at least 3% by weight, in two blocks A or in blocks A and C The total content of bonded alkenyl aromatic compounds in
5% to 25%, based on total monomer, and at least 80% of the double bond unsaturated portion of the conjugated diene is
Golf ball mid layer saturated with hydrogen.