JPH01212577A - Golf ball having foamed cover - Google Patents

Abstract

PURPOSE: To vary a restitution coefficient of a golf ball consisting of a core and a cover made of foam layers by forming the cover with a specific polymer, and forming at least one layer of foam material inside the outermost shell skin made of non-foam material. CONSTITUTION: The core 6 of this golf ball 2 is a sphere made of highly cross- combined polybutadiene, and has a wound-type core 10 covered with foam material 8. The foam cover stock is formed by blowing natural or synthetic polymer material (thermoplastic material) excluding ion copolymer of olefin with 2-5 carbon atoms and unsaturated mono-carboxylic acid metal salt. Such a blowing agent is used as generates netrogen and can be thermally decomposed. A preferable ratio of the blowing agent to the thermoplastic resin in weight is 0.1-0.5%. The strictly physical character can be changed by controlling the size and distribution of foams, the thickness of the cover and the apparent density of the foam cover material.

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention Golf balls have traditionally included a cover formed from a polymeric material. Regarding this point, Balata
) A traditional pull-7 pole with a cover formed from rubber is noteworthy. The physical properties and especially the feel of the balata rubber cover when struck with a salfclap have become the industry standard.

In recent years, golf balls have begun to include covers made from synthetic polymeric materials such as polyolefins and particularly ionic copolymers of polyethylene, polyurethane, and olefins. Such ionic copolymers of olefins are manufactured by DuPont (E. Engineering, Du FontDo Henou
It was put on the market in the mid-1960s by Co., Ltd., Co., Ltd., Ilmington, P. R.S., and marketed under the trade name Surlyn (5urlyn). The composition of covers based on Surlyn resins has become very popular and is very advantageous in that the resulting covers have excellent cut and abrasion resistance. Although it has a Surlyn resin cover, it is well known in the male Luf world that Lua poles have higher cut resistance than poles with balata covers. These Surlyn-covered pull 7 poles have been widely praised by consumers. Approximately 60% of Luapol sold in the United States in 1976 contains Surlyn Copper. Contains Surlyn Copper, but Luapol is covered by U.S. Patent No. 3,454,2
80 (issued July 8, 1969).

Most of the Surlyn resins manufactured by DuPont are loaded with zinc or sodium ions.

Various types of Surlyn resins with different physical properties are commercially available from Den-4n. The physical properties of various resins are described in readily available DuPont technical reports. The basic Surlyn resins useful as Sol 7 ball cover materials in this invention are Surlyn A1605 and Surlyn A1557.

Mixtures of various Surlyn resins are also very advantageous as cover stock materials. A suitable mixture for use as a cover stock material is listed in U.S. Pat. No. 3.819.
It is described in detail in Specification No. 768 (issued June 25, 1974).

Although Surlyn resin has the great advantage of being resistant to cutting due to abrasion, its use alone or in mixtures has negligible disadvantages as a stock material for male Luapol covers. The reason is that the feel of the pole when struck with a male look rub is very similar to the feel of a traditional balata cover with a lua pole.

When you hit a male lure pole with a Plut's Crab, you will hear a clearly audible sound. This sound is generally called a pull-7 pole click (cJiak).

To reiterate, the click of the Isu-Linker Ruapol is quite different from the click of the Paratakapardelfpol. For some male Rufers, and especially those who have traditionally used Balata-covered female Ruf poles, the click changes and feel changes in Surlyn-covered female Ruf poles are dissatisfying.

Some advanced pull 7ers are able to hit the pole to control the flight of the pole by applying a Kanashi Pax to the lure pole. For the male Rufer, he controls the flight of the male Luapole and the final point of the flight is Kt? It is desirable to be able to apply backspin to the pole in order to control the movement 1A of the pole. For example, if you apply backspin to the flight of the pole, you can stop it exactly when it hits the green (if it were like that, it would bounce forward).

Whether or not Paxzen can be applied to a male Lua Paul is related to the degree of deformation of the Rua Paul that hit the Zolf Paul with Baruk Love. Traditional balata covers tend to deform easily, so it is relatively easy to spin these traditional poles. On the other hand, due to the nature of the cover of Surlyn Copper male lure poles, Balata cover poles are not easily deformed, so it is much more difficult to apply sufficient puckskin to these poles.

The advantages of such control will be explained in detail later.

The standard commonly referred to as the coefficient of restitution is one of the criteria useful for determining the lichenity of a male Luapole. There is a property of the cover stock, Ji, but it has been seen that it has a substantial relationship with the coefficient of restitution of Luapole! kt-Have it, make use of the present invention, and be skilled in the art! It is possible to change the coefficient of repulsion of Luapole, but 1. This is possible, and much more so, when using prior art covers.

A detailed explanation of the nine results of the number of rebound bullets related to the present invention will be given later.

, Balata cover is Rufu Paul! In a competition comparing Surlyn to the oil-covered PULL 7 pole, the i-Yanpean advertisement takes full advantage of the shortcomings of the Surlyn resin Kapersolf pole mentioned above. In general, these advertising campaigns emphasize the difference in feel and the difficulty of applying a Surlyn resin-covered bilf ball. Some advertising campaigns even go so far as to compare Surlyn resin-covered pull-a-balls to stones. By incorporating the present invention into the structure of a golf ball, the cut resistance, abrasion resistance, coefficient of restitution, feel, click and ability to backspin the golf ball are achieved and selectively varied in the first place. be able to. Generally speaking, utilizing the present invention, these physical properties can be varied to an optimum extent by varying the apparent density and distribution of pores in the golf pole cover.

As a result of these changes, those skilled in the art can produce golf balls with the desirable qualities of both balata and Surlyn resin covered Lua balls.

PREFERRED MODES FOR CARRYING OUT THE INVENTION In broad terms, the present invention relates to the use of foam as a coverstock for the center of a conventional lure ball. As described later in the detailed description, the foamed coverstocks of the present invention can have a uniform foamed cross-section, a moderate foamed cross-section, and can be included with one or more non-foamed shells. .

Foamed coverstocks can be formed from natural or synthetic polymeric materials, such materials are well known in the art, and generally include blowing agents, nucleating materials, and other additives necessary to create the desired structure. is adjusted.

Thermoplastic materials are generally preferred because they are less expensive and have better processing properties. However, thermosetting resins can be utilized in accordance with the invention as well. Typical but non-limiting desirable properties for resins are good flow, moderate stiffness, high abrasion resistance, high tear strength and especially good demoldability. However, in the present invention, ionic copolymers of olefins and innes having 2 to 5 carbon atoms and unsaturated monocarboxylic metal salts are excluded from the materials. Such ionic copolymers are, for example, zinc or sodium ionic copolymers of ethylene or mixtures thereof. The sodium copolymer is sold by DuPont under the trade name Surlyn 1605, and the zinc copolymer is sold under the trade name Surlyn 1557.

Referring to the figure, it can be seen that No. 1 shows a standard Lua pole structure 2 having a large number of conventional dimples 4. The dimples 4 are molded into the cover material which is the subject of the invention. As used herein, golf pole 2 is meant to include a lure ball, although it generally has a solid center or a wound center.

Referring to FIG. 2, it can be seen that the pull 7 pole 2 has a solid central portion 6 which is in turn covered with a foam cover 8. Referring to FIG. Generally, the central part 6 consists of highly cross-linked polybutadiene spheres. The engineering of manufacturing solid cores such as core 6 is known in the prior art and does not form part of the present invention.

Referring to FIG. 6, it can be seen that this example golf ball 2 has a wound center portion 10f which is in turn covered with a foam cover 8. As shown in FIG. Generally, the center 10 consists of an extended length of elastomeric polymer system wrapped around a central sphere (not shown) to create a sphere of constant size. Techniques for manufacturing balls of the type shown by the wound center 10 are well known in the prior art and do not form part of the present invention.

Sections 4.5 and 6 illustrate three different embodiments of the invention. These three different embodiments are illustrated on a solid center, generally designated 6, but also on a front wound center, such as the third center 10 in FIGS. 4.5 and 6. We believe that the following aspects can be used.

FIG. 4 shows a preferred ai;+n- of the present invention for use in conjunction with a solid center. In this embodiment, the cover 12 is sandwiched between non-foamed shells 16 and 18, with a core of foamed Fi14tfi.

The non-foamed shells 16 and 18 are formed in-situ by various process parameters when molding the cover 12 over the center 6.

Shells 16 and 18 may be varied and formed by a number of techniques. For example, the shells 16 and 18 are formed at various molding temperatures during the initial stages of the injection molding process, and at various other parameters such as melting temperature, injection time, injection rate, injection pressure,
It can be formed by the nozzle shape, gate, gas venting, holding pressure, holding time, injection amount, blowing agent concentration, core material concentration, polymerization composition, casting surface treatment, and casting slippage.

Item 5-5 illustrates a middle embodiment of the invention in which the cover 20 includes an essentially uniform foam structure. In this embodiment as well, the outermost shell 21 of the cover 20 is formed as a non-foamed skin.

The sixth case represents yet another embodiment in which the cover 22 may be molded onto the central portion 6. Inside the outermost non-foamed skin 23 of the cover 22, three foamed layers are formed, including a center layer 24 sandwiched between two layers 2B and 28. Center layer 24 has lower apparent smuggling than layers 26 and 28.

In other words, 126 and 28 are apparently denser than center layer 24. As will be appreciated by those skilled in the art, the apparent density of the cover 22 at the interface between layers 24, 26 and 28 will naturally vary.

The apparent density of each of the layers 24, 26 and 28 can be varied by one skilled in the art by changing the process parameters described above during molding of the cover 22f:on the central part 6.

For purposes of this invention, when expressing density and specific gravity, they are expressed as "apparent density" and "apparent specific gravity." These terms take into account the fact that the coverstock of the present invention is non-uniform, containing a shell and various cell structures.

These terms take into account such variables and indicate the actual density and specific gravity of the average structure.

The solid core used in accordance with the present invention has a diameter of approximately 1.50 mm.
Inches. According to modern thinking, all lure balls are between 1.680 and 1.690 inches in diameter. Therefore, the thickness of the cover of the pole of the present invention is about half the difference between the center size and the finished pole size, or about 0.090 inch. This cover thickness has been found to be generally advantageous and functional when used with the present invention. Of course, it is also possible to use a larger diameter center to reduce the thickness of the cover.

Generally, the thickness of the cover should not be reduced to the point beyond which functional foaming is no longer possible. Although not all parameters of cover thickness have been investigated, it appears that functional foaming generally ceases when cover thicknesses are reduced below t0,060 inches.

It is within the scope of the present invention to utilize a thicker cover than the standard of about 0.90 inches. Thicker covers utilized in this embodiment may be about 0.90 to about 0.125 inches. If a thicker cover is used, the diameter of the center will naturally be smaller accordingly.

As is well understood by those skilled in the art, the diameter of the Wakun V-shaped center is typically larger than that of the solid V-shaped. During the process of applying the cover over the center, the Waun P-type center is compressed with a net, so that the effective size of the resulting center is 1.50 inches as measured with respect to the solid F-type center. becomes the same as

Examples of natural polymeric materials suitable for use in accordance with the present invention are grasshoppers or gutta percha.
raha).

Examples of synthetic polymeric materials suitable for use in accordance with the present invention include the following.

Photopolymerization and copolymerized compounds, such as (1) the polymerization of vinyl chloride, polyvinyl chloride and unsaturated polymerizable compounds such as vinyl esters, (2) (3) polyurethanes, such as polyurethanes made from polyols and organic polyisocyanates;
4) fs 7amides such as polyhexamethylene adipamide, (5) & restyrene, high impact polystyrene, styrene acrylonitrile copolymer and Al1 (acrylonitrile, butadiene and styrene copolymer),
(6) Acrylic resins such as methyl methacrylate, acrylonitrile and styrene copolymers, (7)
Thermoplastic polymers such as urethane, ethylene and blown copolymers, transpolyisozolene, styrene and cispolycitadiene block copolymers, etc.
8) Polyphenylene oxide resin or [noryl (N
oryl) A mixture with high-impact polystyrene referred to under the trade name of J. The foregoing list is not intended to be exhaustive, but merely indicates the wide range of polymerized materials that can be utilized in the present invention. Mixtures of the aforementioned materials can also be used.

Additional substances can be added to the cover composition within the scope of the present invention to the extent that they do not adversely affect the basic freshness of the cover composition according to the present invention. Such substances are colorants, including dyes and pigments, excipients and similar additives. Additives such as anti-weighting agents, antistatic agents and stabilizers are also added. The upper limit for additives is usually about 5 percent by weight of the product.

The male Luer ball cover material phase of the present invention can be applied to the center by any standard method. For example, the cover material can be injection molded directly around a previously formed center part, or the cover material of the invention can be used to inject half shells of the cover (h
(alf day hall) You can also build two. These half shells are then placed in a center tm roll and fused together to form the completed golf pole. Although completed, the molding technology used to fully manufacture the lure ball is also not an essential part of the invention. However, although the cover composition of the present invention has been completed, many standard manufacturing methods for making lure balls can be utilized. The technique utilized must, of course, provide sufficient blade physical conditions to enable foaming.

As briefly mentioned above, the cover material of the present invention is applied in a conventional manner onto a standard center. Either solid or wound centers can be used in accordance with the present invention. With respect to the wound center, the thread-like material is wrapped around either a solid F core or a liquid-filled spherical shell. The thread-like threads wrapped around this small core are either thread-like or tape-like. Regarding poles with solid centers, these generally consist of a sphere with a center made of a resilient polymeric material. Since this core material is not an essential part of the present invention, a detailed explanation of the core material is not considered necessary. However, it can be said that the cover material of the present invention can be utilized in conjunction with any standard golf pole center.

As mentioned above, the Luapole cover of the present invention can be used as a means of changing or adjusting the coefficient of restitution. In general, the repulsion force of a golf pole represents the elasticity of the pole in question, and therefore, the distance the pole moves when hit with a look love! 1lIt-shown. Although both the center and the cover contribute to the coefficient of restitution, for the purposes of this invention:
We only deal with the coefficient of restitution that is affected by the cover material. Coefficient of restitution is generally measured by applying a completed golf pole to a hard surface at a constant speed. Measure again the velocity of the pole as it rebounds from that surface.

The ratio of the rebound F speed to the initial speed is the restitution coefficient. The coefficient of restitution is directly related to the resiliency of the golf pole and how much the golf pole moves when struck with a look rub, holding other variables constant.

The elasticity of golf poles is determined by a test called the initial velocity test, generally conducted by the United Eighttates
It is regulated by the G'olf Association. In this test, you will be hit with a rotating club face like a golf pole. The peripheral speed of the rotating club face is approximately 146 feet/second. The velocity of the pole struck by the club face is measured as it passes through two screens of light located in front of the club face.

The maximum allowable limit for a golf pole when measured using this method is:
225 feet/second at 75°F'. This upper limit standard value of 225 feet/second is approximately 0 in terms of coefficient of restitution.
．． It corresponds to 795.

With respect to the above-mentioned coefficient of restitution criteria, the cover material of the present invention is particularly advantageous, having a solid center which with the present invention is very close to the maximum limit of 0.795! You can make lure balls. According to the first pass of the present invention, 0.79
After forming the center which exceeds the limit of 5, the coefficient of restitution is set to 0.
This objective is achieved by providing a cover to the center to lower the diameter.

The ability and extent to which the coefficient of restitution can be varied will be shown in the Examples below. From the data of these examples, it can be seen that changing the stock material of the cover from a solid type material to a foam material changes the coefficient of repulsion of the Luapol. It is true that it is desirable to approach the maximum value of the coefficient of restitution mentioned above without exceeding it, but in addition to approaching the specified maximum limit value, m1lt
Whether L is false is a matter of speculation. The data in question sufficiently demonstrate that it is possible to vary the coefficient of restitution of a given Luapol using the present invention. Tolerance of dedine may exist in the male luapole system provided by the use of the present gAt-, but such tolerance of dedine did not exist in the prior art.

The foam covers of the present invention are formed by foaming the polymer@shell in situ during the operation of forming the cover over the core. A wide range of foaming agents can be used for the rounding. Examples of suitable organic blowing agents are azobisformamide F1, apbisinzotyronitrile, diazoaminopenzene, N,
N-dimethyl-N.

N-jetroterephthalamide, N,N-dinitrodipentamethylene-tetramine, penzenesulfonyl-ruhi F
radip, benzene-1,3-disulfonyl hydrazide,
Diphenylsulfone-3,3-disulfonylhydrazi
, a, 4'-oxy V-sbenzenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, halicum azodicarboxylate, butylamine nitrile, nitrourine 1,
)+7 hydrazinotriazine, phenylmethyl-urethane-p-sulfone, diF, and inorganic blowing agents such as anthonium bicarbonate and sodium bicarbonate.

Blowing agents generally function by thermal decomposition, which generates gas in situ, which is absorbed by the melt. When the pressure is removed, the melt expands and foams. In addition to this operation, it is commercially practiced to inject gases such as nitrogen, trichloromonofluoromethane, pentane, carbon 2alide, etc. into the melt under pressure. When the gas is absorbed and the pressure is removed again, the melt expands and foams.

A preferred embodiment of the invention uses a thermally decomposable, nitrogen-producing blowing agent.

It will be appreciated that the proportion of blowing agent used according to the invention is
The physical and chemical properties of the blowing agent used will vary depending on the desired apparent density of the resulting Bill 7 ball copper. According to a preferred embodiment of the invention, FiaeJ I! fP
a @Used at 0.1 to 0.5% based on the weight of the thermoplastic resin. Pia@JM? is the trade name used for a blowing agent which is essentially azodicarbonamide F. Fi
aeJ I! fPA is 8obin OhemiaaJ
g.

Engineering nc, (8obin Park%Boston%
Available from Massachusetts %02201).

The apparent density of the foamed female lure ball cover according to the invention can also be varied by injection technology.

The injection technology in question is well within the skill of those skilled in the art.<3! However, there are various variables that can be easily solved, such as advance time, injection speed, shot dimensions, gate dimensions, vent holes in the mold, injection pressure, etc.
Including holding pressure, etc.

Depending on the nature of the blowing agent used, the present invention! Although single cell or interconnected cell structures can be made for the luer ball cover, a single cell structure is preferred. In either case, the outermost shell should be a non-foamed skin.

As mentioned above, the 1/h pole cover of the present invention can be used in a number of ways with a suitable centerpiece.

According to a preferred object of the invention, a male Luer ball cover is used for the core by injection molding. A preferred injection molding technique involves preparing a master patch of molding powder of defined composition.

This masterbatch is dry mixed and includes one or more polymeric materials, a colorant, 1. It contains antioxidants, foaming agents, etc. Of course, the blowing agent only decomposes once.]
Mix in polymer vI size at low temperature. Next, this master patch is made into a pellet. Next, place the center of the Ruapor in the deaf.

The above masterbatch is placed in a T-injection molding mode and the resulting melt is injected into the mold, thus foaming the polymeric material and spreading the flow to adhere to the core. This molding process creates dimples on the cover. The resulting delua ball is cooled and the luapol is essentially completed.

Another important aspect of the present invention is that the use of foam coverstock material reduces the net cost of the male lure shark coat. Good quality polymeric materials suitable for use in Luapole coverstock materials are relatively expensive. The method of the present invention maximizes the utilization of golf ball cover stock materials.

In other words, if one bond of material is used, a lot of Delua can be made. If we look at the invention properly from a cost perspective, it is cheaper to make the Pilfpol cover from a foamed polymeric material in which the cells contain foaming gas than to make the cover from a non-foamed material. The cost is said to be lower if you include the cost of the polymer material! It is clear that the features are very advantageous.

The synthetic golf ball cover provided by the present invention is also advantageous in that the apparent specific gravity of the cover stock is lower than the specific gravity of a pole covered with a non-foamed material. According to a broad aspect of the invention, the synthetic coverstock including the non-foamed shell can have an apparent specific gravity of about 0.65 to about 1.50. The preferred range of this apparent specific gravity is about 0.6
5 to about 1.25, and the most preferred apparent specific gravity is about 0.
．． 75 to about 0.80. In order to make a comparison, these specific gravity must be compared to the specific gravity of the foamed material. 5 This variation in specific gravity can be obtained by changing the foam structure of the Luapol cover.

For reference, Surlyn resins using Zoruapol according to the prior art have a specific gravity of 0.940 to 0.965.

The physical properties and flight flaws of the male luapol are influenced to some extent by the weight distribution of the resulting finished luapol. In some instances it is desirable to concentrate the weight as close as possible to the center of gravity of the pole.

Considering this fact, the present invention, which concentrates a greater proportion of the total weight in the center of the pole compared to conventional poles with non-foamed covers, has a natural advantage in pole design. Ru.

Additionally, and for the first time, it appears that the Sol 7 ball manufacturer can modify the dynamics and flight characteristics of the resulting pull-a-pole by varying the density of the coverstock material. Due to this weight distribution, the rotational inertia to be overcome is small, so it is possible to give a larger spin to the male lure ball when hitting it with a club. Prior to the present invention, such a concept had not been realized.

In addition to the above-mentioned advantages resulting from the state of gravity distribution, the pull-apole obtained by the present invention has a different high-speed and low-velocity impact compared to similar poles with non-foamed covers.
-The present invention is very advantageous in that it has W properties.

Upon high-velocity impact, the cover distorts and the cover contacts the clubface with a substantially larger contact surface than a pole with a non-foamed cover. As a result, you can control the pole better, allowing you to perform important ball operations during play, such as backspin, drawwing, and phasing. The energy required to warp the cover at high speed is less than with conventional covers. Therefore, more energy is directly applied to the inner core material at impact, increasing the flight of the pull-a-ball.

On the other hand, this same foam cover pole has a different low speed impact 4! This is useful for putting. In low-velocity impacts, foam covers produce the same dissipating effect as parametrically covered poles, so in low-velocity impacts, foam-covered balls require greater impact force than conventional poles to move the same distance. It is well known that the probability of failure in a putt can be greatly reduced if more force is required to move the pole a certain distance within the putting range.

Examples of these controls in low velocity impacts are as follows. If a pole, such as a pole with unfoamed Surlyn copper, bounces on the putter face, the chances of failure are very high. On the other hand, failure in movement of a pole where the energy required to impart movement to the pole is high is minimized.

Another important advantage of this low velocity impact property in putting is that as a result of the absorption of energy as described above, the golfer's ball that is t-away from the putter face begins to truly rotate sooner than a pole with a non-foamed cover.

Prior art poles with non-foamed covers tend to skid before starting true rotation on the green due to the inability of the covers to absorb the energy of low velocity impacts.

It should be noted that the exact physical properties described above with respect to the present invention can be varied by adjusting the cell size, its distribution, cover thickness, and changes in the apparent density of the foam cover material. be. Because of the interaction described above between the pole of the present invention and the Cladef Ace, excellent control and feel can be achieved.

Skilled as a result of this control and feel! The V-ear allows you to draw and fade at will, and when approaching the green, the more backspin allows the ripple to bite into the grass better and stop.

The ease of control of the pull 7 pole of the present invention when struck with a golf club, with its desirable high velocity and low deflection)! 7, 8, and 9 depending on whether or not the characteristics can be obtained. In the tests described in FIGS. 7 and g8, impact is performed by sending a sample drop into a pull-a-ball launcher that drives a pole into a steel plate. To create a trace of the problem, cover the surface of the steel plate with carbon-type transfer paper. The purpose of the high speed impact tests in Figures 7 and 8 is the same.

In Figure 5g7, trace C was made with ballm. Paul A
is a Surlyn-covered filter with a centerpiece described below and a lure shark coat sold under the trade name 'rOP-FLXTI. This pole cover is described in U.S. Pat. No. 5,819,768 (1974).
℃ according to the method published on June 25, 2013). The traces in Figure 7 made by Zapur BK are that the cover stock is T.
It was made with Paul, which is nearly identical in all respects to the Girum used to make IIi Trace C, except that it is foamed using iced II'A blowing agent 0.396. The obtained T-Luapole has the structure shown in Fig. 2 and *4.

It is easy to see that the trace is larger than trace C.

! ! (Trace C is 1.020 inches, while trace C is 1.020 inches.
). Therefore, according to the above theory, the distortion of the surface of pole B due to the steel plate is determined by the surface of the ball.
is much larger than the distortion. In addition to the distortion of the surface of Pull B, which is larger than the ball, the traces of the tinsol pattern on Pole B are unclear, and the traces of the tinsol pattern on Pull A are not clear, so Paul B seems to be wetted out to a greater extent. I understand that. Therefore, greater control can be conveyed to Paul.

In FIG. 8i, the keel J and rBJ shown at 91 in FIG. 7 are launched at 80 feet/second according to the test procedure of FIG. Pole rBJ forms a trace rlJ with a diameter of 0.789 inches.

Pole "A," forms a trace rFJ with a diameter of 0.750 inches. As can be seen from the difference in the diameters of these marks, pole rBJ deformed more significantly than pole rAJ during this test operation.

FIG. 9 relates to the low speed impact characteristics of the male Luapole of the present invention. As shown in this figure, the above-described pole "mu" and rBJ in connection with FIG. 7 were utilized in this test.

These balls are dropped from a height of 100 inches onto a steel plate. Paul "Mu" company diameter 0.416 inch trace rGJ
was formed. Pole rBJ formed a trace rHJ with a diameter of 0.422 inches. Due to the difference in these diameters, trace rH
It can further be seen that the ball rBJ of J is significantly more likely to wet out than the ball rAJ of the trace rGJ. In addition to the traces rGJ and "H" for this test, it should also be noted that the rebound height of ball rAJ in this test was 76 inches and the rebound height of ball rBJ was 76 inches. This difference in rebound r further indicates that the balls of the present invention have a softer feel on the face of a golf club. I think this test is similar to the batting shot at the Ile 7 course.

Regarding the tests of FIGS. 7, 8, and 9, it should be noted that these tests were performed on balls with identical centers to achieve maximum uniformity. However, this is not possible or practical in the manufacture of commercially available balls.

This is because in reality the Zail rBJ cover is significantly lighter than the Ball rAJ cover. From a practical standpoint,
Because of this difference in page amount, the center portion of the ball rBJ is adjusted to be heavier to compensate for the difference in cover ■ amount. If this adjustment is actually made, Figures 7, 8 and 9
In the figure, the difference between the six traces of the ball rAJ and rBJ is considered to be larger than the difference mentioned above because the ball rBJ has a larger mass and thus has a larger kinetic energy toward the impact.

Table 1 below shows data from hitting tests conducted on the balls of the present invention in comparison to standard commercially available balls. In the batting test, the ball rOJ was ranked ``Top I
Two standard commercially available poles sold under the Fllte J trade name. Zail rBJ is a ball made in accordance with the present invention. Ball rOJ has a coefficient of restitution of 0.79
It is 5. Ball rBJ has a coefficient of restitution of 0.782.

Regarding the data in Table 1, ball r, which is the ball of the present invention,
BJ has a better carry than Ball rOJ at 145 feet/second. At 160 feet/second, ball rOJ has a slightly better carry than ball rBJ. The advantageous carry of ball rBJ at 145 feet/second is considered to be particularly significant in view of the advantageous properties of the ball of the present invention listed above as a reflection of ball rBJ.

Regarding the data in Table 1, it should be noted that a club speed of 145 feet/second is average but high for the ability to hit the lure's 7 course. A club speed of 145 feet/second is perfect for advanced lures, such as those with a 4 or 5 handicap! Equivalent to lure. On the other hand, in terms of relative importance, the 160 feet/second test is not a meaningful comparison of the average golfer's abilities since most golfers do not reach club speeds of 160 feet/second. I don't think so.

It is particularly noteworthy that ball rBJ travels approximately the same distance as ball rOJ since the coefficient of ball rBJ is significantly less than that of ball rOJ. This fact is believed to demonstrate the particularly advantageous properties of the ball of the invention. This is because clearly more energy from the golf club head is transferred through the cover to the core and significantly less energy is absorbed by the cover. This advantage results in a specified coefficient of restitution of 0.795, which is correlated to initial velocity as determined by the United States Delua Association (U8GA).
It may be possible to create beer that travels further while still fully complying with the above.

It should be noted that the American Co9 Lua Association recently added new rules regarding the total distance the ball can travel. According to this rule, a ball hit by a machine under specified conditions cannot travel farther than 280 yards plus 8 inches. This prescribed distance of 280 yards is covered by humans! This rule is not believed to be restrictive with respect to the balls of the present invention since it exceeds the limits on which a lure ball can be hit. I mention this rule because I want the above data to be evaluated from the correct perspective.

Hitting Method The total flight distance test for a driver and a 5-iron is as follows. 1 wood (6 each of poles rBJ and rOJ) at a club head speed of 145 ft/sec.
(screwdriver) and fire six times each. Next 6 each? - Fire the ball three times each using a 5-iron at 145 feet/second. Repeat this procedure at 160 feet/second. Batting c) Lu Temper Corporation (
1623 Euclid Avenue, Cleveland, Ohio) True Temper Percussion Apparatus (1623 Euclid Avenue, Cleveland, Ohio)
I went in miles/hour. All distances are in yards.

Table 1: "I used to scan the golf sample components in Ho Honor"
"consisting of" means the presence or absence of other ingredients in the composition described therein in such amounts as to substantially interfere with its properties and characteristics.
It is meant to exclude but permit the presence of other ingredients in amounts that do not adversely affect the properties and characteristics described above.

Ho + 1) In the first verse, ``Tsuo't out'' is used to explain the deformation of the Lua pole when it comes into contact with the Irtu club. This is a spherical T lure
Is it possible for the surface to be flatter and non-deformable? It means the extent to which the face is shaped like a woman.

The present invention will be explained below with reference to Examples. These examples are intended to illustrate the invention and are not intended to limit the invention. □Example' Unless otherwise specified in the examples described below, do you have a solid center? - The center of the hole is all 1.50 inches in diameter. I used the third type of center. The coefficient of restitution at center A is 0.78±o, o i o
・The compression is 85±10vGA. Center B coefficient of depression and repulsion is 0.765±0.010 and compression is 60±1Q P
It is GA. Center C has a repulsion coefficient of 0.790±0.01
0, and the compression is 100±10PGm.

These cores consist of highly cross-linked polybutadiene (essentially 1)C') whose main cross-linking agents are peroxides and heavy metal organic salts.

In the example, when using a wound type center, the center has a diameter of 1.560±j, o 1o inches, and a pressure of -90±.
At 10 pem, the coefficient of repulsion is 0.825±0015. Here, the center of the wound shape is made in the usual way with a diameter of 1.12 mm.
It is manufactured by wrapping a rubbery thread containing high capacity polyisoprene to the compression and size described above over a 5 inch solid core of high modulus polybutadiene.

In all examples except Example 1) and Example 12 below, the cover was manufactured using injection molding techniques (first placing the center part in the mold).
Each of the 6 centers was applied by pouring the coverstock material into the mold by flowing the coverstock material around the previously placed center. The temperature of the core and mold is about 70'P.

The circulation time of the injection molding process is such that sufficient time is allowed for the material to harden around the previously placed center. Generally, the circulation time is about 30 to 50 seconds depending on the mold cooling rate. It will be appreciated by those skilled in the art that the circulation time will vary depending on the nature of the polymeric material used as the foamed coverstock material and especially its melting point.

Here, "compression" means that the compression for the pole and ball components is calculated using the Riele model (Rtθh1θModel)1t
501A-1/ type device, and the deformation during one-foot impact under a constant load was measured. Throughout these tests, the constant load was 200 pounds. The data obtained from the above test is then converted into a PGA using the simple formula
Convert to compression. In other words, if you subtract the Liele display from 160, you get PGA.

Here, "PGA compression" has the same meaning as is widely used as a standard in the industry. In this test one record is taken from each of the 12 samples and the average of the test is defined as its compression.

When determining durability data for a barrel test, 12 poles are fired into a hexagonal steel container at room temperature at 135 feet per second from a 100-round air cannon; First strike the corrugated metal plate across 15 inches to create a corrugation on the top of the iron, then bounce off the remaining sides.

When checking the low temperature crack resistance of a golf ball,
121) A pole of g is fired five times from a mechanical air cannon with a coefficient of repulsion as shown below. The muzzle velocity of the tested pole is 165 feet/second.

This pole is fired at a steel plate placed perpendicular to its axis of flight. This steel plate is placed 10 feet from the muzzle. Before launching, the pole is conditioned for 16 hours below zero.

When determining cutting test data, this test is carried out with the lower % of the pole held in a fixed position by a retaining force horn, with a production volume 16601 having a blunt edge blade similar to the main edge of an iron club. was allowed to fall freely from a height of 36 inches.

The coefficient of restitution data below was obtained by firing a pole from an air gun at a muzzle velocity of 12° (12i1) at a muzzle velocity of 5 ft/sec toward a steel plate placed 10 feet from the muzzle, and the initial device and rebound of the pole. This was obtained by measuring the speed at which the The ratio of the return speed to this initial speed is the determined coefficient of repulsion. The results are reported as the average of the poles thus tested.

If low speed rebound data is determined, test 1
The rebound height of a golf ball dropped from a height of 100 inches onto two solid steel plates is measured and the average of the test results is reported.

In these data, unless otherwise specified, parts are weight parts. In the production of the golf balls in question, the specified polymeric book cover material was dry mixed with the specified blowing agent and poured into the extruder section of an injection molding process in a conventional manner.

1) For specific data where results are available for 1 il pole, these data represent data for multiple poles tested according to each method of operation.

Test results for these poles in question can be found at TOP-PL
Compare this to a golf pole with a standard Surlyn cover with a solid center sold under the trade name TIC. This shark has a PGA compression of 100 and a coefficient of repulsion of 0.9.
0, low speed rebound is 74 inches, 12 out of 12 poles passed the cold crack and durability tests, and 2iIiI out of 12 poles passed the cut test and 12 out of 12 poles passed the cut test and 12 out of 12 poles passed the cut test and Paul passed the barrel test.

Test results are also available at Acughnet Company
, lJewBedford, Massachuse
Titieist Pr from tts.

e- with a standard balata cover with a wound center sold under the trade name 'rrajectory.
Also compare with This pole has a compression of 64 and a hard hitting range of 25.
5 yards, coefficient of restitution 0.80 and slow rebound 68
Inches. Of the 121-balls, 12 meters failed the barrel test. 121) Ili's Giel Junior High School 1
21) 1 passed the low temperature crack resistance test and 12 pieces 9
] Two pieces failed the cutting test.

Regarding the products described by trade name in the examples below,
The following is a summary of all the information known to the inventor.

1Picel IPA Denatured 1-1 AIP H
aake X*kA amide (Azodi 8aaalebr
ook, NJ calzanamide) Martiah MF polyolefin m and MOrtbe
rn1069H1-1 Azobisformamide Petr
OOhemiaa1 (azo 2 carbon amide) 1 part 131)nton, a mixture with MA NOrteOh MP i Q 59 H will be referred to as blowing agent master patch B in the following examples.

Example 1 In this example, center@a was utilized and the coverstock was made by dry mixing the ingredients in Table 2.

Polyethylene Pro-F'ax852!1*
49.25 Foaming agent masterbatch B
, 1.5*Wilmington, Praue, USA%H
erculea lfi! , construction materials.

The compression of the ball awaiting the foam cover was 105. The appearance of the resulting ball was that of a normal golf ball. 2 IM out of 2 tll balls passed the cutting test, but these balls were larger than the Surlyn Kaco 9 Ruff Pole sold under the trade name TOP-PL TKJ.The coefficient of restitution was 0. 754. In the low velocity rebound test, the ball rebounded 64 inches. During the coefficient of restitution test, the cover of the 7g1A ball cracked out of 12. Marry at the average value for poles that did not occur.

Example 2 This example uses the center mD and the following. The cover stock is made by dry mixing the ingredients of batter 2.

The compression of one bottle with a foam cover was 95.

The cutting test was 21) 21 out of 10 poles! It passed, and scratches similar to those in Example 8 were observed. The coefficient of restitution was 0.759. In the low-velocity rebound test, the ball rebounded 65 inches. During the coefficient of restitution test, 6 out of 12 jar covers cracked.

The value of 0.739 is the average value for poles that did not crack.

In the example in , center 0 was used. The coverstock was made by dry mixing the ingredients in Table 3.

′　6　　.

High density polyethylene 98.5 Blowing agent Master Para 1,000 Bt5 The appearance of the resulting golf pole was that of a normal golf ball. Compression of poles with foam covers is 1). It was 0. The cutting test is 21)i
2 out of 1 poles passed, and scratches similar to those in Example 8 were observed. The coefficient of restitution was t), 719. In a low-velocity rebound test, the pole rebounded 66 inches.

During the coefficient of restitution test, cracks appeared in the cover of 10 of the 12 poles. The value of 0.719 is the average value for mail that did not crack.

Example 4 A golf rule was created using the center rim using the same operations as in Example 6. The appearance of the resulting pole was that of a normal golf ball. The compression of the jar with foam cover is 100
Met. The result of the cutting test is Example 84! : It was the same. The coefficient of restitution was 0.726. In a low-velocity rebound test, the ball rebounded 66 inches. During the coefficient of restitution test, a crack appeared in the cover of 91)1 out of 121)fi.

The value of 0.726 is the average value for balls that did not crack.

Example 5 In this example, center area C was used. The cover stock is shown in Table 4.
Made by dry mixing the ingredients.

Table 4 Part Polyolefin Mixed Thermoplastic Go 7 98.5 Blowing Agent Masterbatch B1.5 Uniroyal, New York, NY, USA
It is sold under the product name ``rpu1900J'' by Kogyo nc.

The compression of the resulting tube awaiting the foam cover was 85. Paul's appearance was that of a normal Paul.

Two balls (92 balls) passed the cutting test, and scratches similar to those in Example 1 were observed. The coefficient of restitution was 0.756.

In a low-velocity rebound test, the pole rebounded 61 inches.

Example 6 A golf ball was made using the same procedure as in Example 5, except for the center portion. The appearance of the resulting golf ball was that of a normal golf ball. Pole compression was 65.

The results of the cutting test were the same as in Example 1 above. The coefficient of restitution was 0.773.

In the low speed rebound test, the dart rebounded 66 inches.

Example 7 In this example, center area C was used. The cover stock is shown in Table 5.
Made by dry mixing the ingredients.

Table 5 Obe thermoplastic polyester elastomer 997Fi
cel xpAO, 3 [Hytrel 5526 J
It is sold under the name.

The resulting pole with foam cover had a compression of 100. Paul's appearance was that of a normal Paul.

The coefficient of restitution was 0,778. In the low-velocity rebound test, the pole rebounded 69 inches. The pole passed the cut test and exhibited flaws similar to those in Example 1 above.

Example 8 A golf pole was made using the center piece using the same procedure as in Example 7. The resulting pole had the appearance of a normal golf pole. Pole compression is 85, coefficient of restitution is 0.785
Met. In the low-velocity rebound test, Paul scored a 71.
Inches bounced. The pole passed the cut test and exhibited flaws similar to those in Example 1 above.

Example 9 In this example, center C was used. Cover stock is shown in Table 6.
Made by dry mixing the ingredients.

Narrow 6 Part Thermoplastic Polyurethane/997 ptcelzpAO, 5 Books B, F, Goodri, AkrOn, Ohio, USA
ch Co.

It is sold under the name "fjatane 58133 J".

The resulting appearance of the pole was met with a normal sieve.

Paul passed the judgment test. The compression of the pole with foam cover was 95. The coefficient of restitution was 0.750. In a low-velocity rebound test, the pole rebounded 66 inches.

Example 10 Use the same cover as in Example 9 and make a &-ru by the same operation. The size of the center portion is reduced to 1.53. f
A coating is applied to the rolled core to protect it from the high temperatures experienced during molding of l5tane 58153J. The appearance of the obtained pole was that of a normal pole.

The compression of the jar was 80, and the coefficient of restitution was 0.750.

In a low-velocity rebound test, the pole rebounded 66 inches. Paul passed the cutting test.

Example 1) A center C modified to a compression of 85 and a diameter of 1.59 inches was utilized. Ann Ar, Michigan, USA
A liquid thermoset polyurethane foam, sold under the name Reyn-o-8OLRU 6709 J by Hoover Universal of bor, is cured in the center circumference 9 to form the cover stock. Paul passed the cutting test. The compression of the jar was 95, and the coefficient of restitution was 0.785. In the low-velocity rebound test, Paul rebounded 7 inches.

Example 12 In this example, the center area was used and the cover was made easier around the center area by the operation in Example 1). Paul passed the cutting test. The compression of the zipper is 85° and the coefficient of restitution is 0.76.
I was disappointed in the quantity. Paul scored a 66 in the low-velocity rebound test.
Inches bounced.

Example 13 In this example, Center C was used to dry mix the ingredients in Table 7 to make a coverstock.

Table 7 Polyzoropi v> Pro-IFax*6525 24
．． 625 Polyzolopine Pro4ax*8523 7
3.875 Foam Master Patch B 155 The resulting pole compression line 95 with foam cover was manufactured by Heraulea of Prownia Wilmington. Zaru's appearance was that of a normal pole. 21)1
'D M - 2iIm passed the disconnection test, but '
Of the Surrin power bar sold under the name TOP-IPL TI J! The wound was larger than that of Luagir. The coefficient of restitution of the pole was 0.730. In a low-velocity rebound test, the pole rebounded 58 inches. In contrast to the results of Example 1, none of the poles cracked during the coefficient of restitution test.

Example 14 In this example, center C was used. Cover stock is Table 8
Made by dry mixing the ingredients.

Table 8 High density polyethylene (Shore hardness 59-D) 98.
5 Foaming Agent Masterbatch B1.5 The appearance of the obtained tlua ball was that of a normal pill azaple. The compression of the pole with foam cover was 98.

21)! 2m of the poles passed the cutting test, and the same - as in Example 13 was observed. The coefficient of restitution was 0.715. In a low-velocity rebound test, the pole rebounded 65 inches. During the coefficient of restitution test, two of the twelve pole covers cracked. The value of 0.715 is the average value for poles that did not crack. This example and Example 5 above demonstrate that the present invention is applicable to polyethylene and that cracking can be prevented or suppressed by selecting a polyethylene of appropriate weatherability.

[Brief explanation of the drawing]

Figure 1 is normal! A front view of the lure ball. - FIG. 2 shows a core pole according to the invention with a foam cover on a solid core, corresponding to the cross-sectional view taken along the line 2--2 in FIG. FIG. 6 is a cross-sectional view similar to FIG. 2 of a Goler ball of the present invention having a foam cover over a wound center. FIGS. 4, 5, and 6 are partially enlarged sectional views showing examples of various foamed states of the cover. FIG. 7, FIG. 8, and FIG. 9 are explanatory diagrams showing the excellent impact characteristics of the pull 7 pole according to the present invention. FIG. 10 and FIG. 1) show actual results according to the present invention! It is a mirror photograph showing an example of a cross section of a Luaza pull cover. -PIG, 1

Claims (5)

[Claims] (1) Consisting of a center portion and a cover having a foam layer, the cover is formed from a polymer other than an ionic copolymer of an olefin having 2 to 5 carbon atoms and an unsaturated monocarboxylic acid metal salt. A golf ball, characterized in that at least one foam layer is formed inside a non-foaming outermost shell skin. (2) Foam layer is 0.1 to 0.5% based on the weight of the cover
This is due to the pyrolytic blowing agent added in the amount of
1) The golf ball according to item 1). (3) The center part is solid type (1) or (2)
). (4) The center is wound-shaped (1) or (2)
). (5) The golf ball according to any one of (1) to (4) above, wherein the cover is formed from a polymer selected from the group consisting of polyurethane resins and polyolefin resins.