JP2002085597A - Multilayered golf ball having thin thermosetting outer layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered golf ball having improved adhesiveness between adjacent composite material layers and a method for manufacturing the same. SOLUTION: The method for manufacturing the multilayered golf ball having the improved boundary adhesiveness includes (a) a process step of forming a core and (b) a process step of forming an intermediate layer on this core, where the intermediate layer has a patterned outside surface molded to an integral type and this patterned outside surface includes plural peaks having a height of about 0.051 to about 0.381 mm (about 2 to about 15 mill) and (c) a process step of casting a cover layer on the intermediate layer by using a liquid reactive material having castability or the reactive product thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

REFERENCE TO RELATED APPLICATIONS The present invention relates to a method and apparatus for improving the adhesion between golf ball layers, filed on January 12, 1998, which is incorporated by reference in US patent application Ser. No. 09 / 005,90.
No. 09 / 324,850, filed Jun. 6, 1999 and relating to a multilayer golf ball having a thin thermosetting resin outer layer, filed on June 3, 1999, the latter of which was filed in 1998.
U.S. Patent Application No. 0, filed December 9, 2015, relating to a method of manufacturing a multilayer golf ball having a thin thermosetting resin outer layer.
This is a divisional application of 9 / 207,690, which was filed on May 27, 1997.
A divisional application of U.S. Patent Application No. 08 / 863,788, filed on date, relating to a multi-layer golf ball having a thin thermosetting resin outer layer, the last of which is a U.S. patent application Ser.
Licensed as 5,885,172.

[0002]

FIELD OF THE INVENTION The present invention relates generally to golf balls, and more particularly to multi-layer golf balls having improved adhesion between adjacent component layers and methods of making such golf balls. Things. In particular, the invention relates to a core, an inner (inner) cover layer and an extremely thin outer layer.
Relates to a golf ball having an (outer) cover layer, wherein the outer cover layer comprises a thermoplastic material formed from a castable reactive liquid, and the inner cover layer comprises a patterned pattern. A high flexural modulus material having the following properties to improve the adhesion between the layers.

[0003]

BACKGROUND OF THE INVENTION Conventional golf balls can be divided into three general types or groups. That is, they can be classified into (1) two-piece balls, (2) wound balls (also known as three-piece balls), and (3) multilayer balls. Differences in playing characteristics resulting from these various types of structures can be extremely important. Balls with a two-piece construction are generally the most reputed for recreational golfers. This is because these balls provide extremely durable balls and also provide the maximum flight distance. The two-piece ball is made of a single solid core, usually made of cross-linked rubber and housed by a cover material. Typically, the solid core is made of polybutadiene, which is chemically cross-linked with zinc diacrylate and / or a similar cross-linking agent.
The cover is a resin marketed by DuPont (DuPont) Surlyn (SURLYN ^TM), or exon (Exxon)
Includes a high toughness and cut resistant blend of one or more materials known as ionomers, such as Iotek ^™, commercially available from US Pat. The core and cover material provide a ball with a "hard" coating that is resistant to cutting and other damage caused by hitting the ball with a golf club.
In addition, such a combination gives the ball a high initial velocity, resulting in a large flight distance. However, due to their hardness, these balls have a relatively low spin rate, which makes it difficult to adjust, especially during shorter approach shots. Therefore, these types of balls are generally considered to be "distance" balls.
Because of the extremely rigid nature of these materials, many two-piece balls have a hard "feel" when struck with a club. Softer cover materials, such as balata and in some cases softer ionomers, have been used in two-piece balls to obtain improved "feel" and higher spin rates.

[0004] Wound balls generally have a solid rubber or liquid-filled center formed by winding a long stretched elastic yarn into a core. The wound core is then covered with a durable cover material, such as Surlyn® or a similar material, or a more flexible cover, such as balata or polyurethane. Wound balls are generally softer than two-piece balls and give higher spin rates, resulting in skilled golfers,
This allows for high control over the flight of the ball and its final position. In particular, it is desirable for a golfer to be able to provide a backspin to the golf ball in order to control the flight of the golf ball and to adjust the movement of the ball when it falls to the ground. For example, a significant backspin will stop the ball when it hits the landing surface, instead of rolling forward. The ability to impart a backspin to a golf ball is related to the degree of deformation of the golf ball cover when hit with a golf club. Spinning wound balls is easier because spinning balls can traditionally deform more than traditional two-piece balls. However, high spin wound balls typically compare to two-piece balls,
Fly a shorter distance on hit. Moreover, because of its more complex construction, wound balls generally require longer hours to manufacture and are more expensive than two-piece balls.

[0005] The United States Golf Association (USGA), in all the games approved by the USGA, when hit with a driver at a speed of 39.6 m / sec, ie 130 ft / sec (hereinafter referred to as "USGA test"),
Rules have been enacted that prohibit the competitive use of golf balls capable of achieving an initial speed exceeding 76.2 m / s or 250 ft / s.
However, manufacturers are allowed a 2% tolerance and are capable of producing golf balls that achieve an initial speed of 77.7 m / s (255 ft / s). Regardless of the shape of the ball, a player generally seeks a golf ball for which the driver achieves the maximum flight distance, which requires a high initial velocity at impact. Therefore, in order to meet market requirements, manufacturers etc.
We are struggling to produce golf balls with an initial speed in the USGA test as close as possible to the maximum value by A, ie 77.7 m / s or 255 m / s. Accordingly, golf ball manufacturers and others continue to seek new ways to provide golf balls that provide maximum performance in both flying distance and spin rate for golfers of all skill levels. More recently, many golf ball manufacturers have developed multilayer golf balls, i.e., having multiple cores, intermediate mantles and / or
Alternatively, a golf ball including a cover layer may be used to reduce some of the undesirable features of conventional two-piece balls, such as its hard feel, and to provide the positive features of these golf balls (such as their high initial speed and distance). ) In an attempt to maintain Further, it is desirable that such a multilayer ball have a "hitting sound and feel" and spin properties close to those of a wound ball.

[0006] Multilayer golf balls can be manufactured utilizing various configurations. For example, a multilayer ball may include two or more cover layers molded around a conventional core, with one or more intermediate layers inserted between the cover and the core. Similarly, a multi-layer ball can be made from a core that includes one or more core layers, and in some cases can include one or more intermediate and / or cover layers.
The multi-layer ball can also include a known wound core, around which at least one intermediate layer and / or at least one cover layer is formed. An example of a multi-layer ball is Altus Newing [Bridgestone
(Bridgestone), Reygrande 2x2 (Bridgestone), Giga (Spalding), Metal Mix (Dunlop), Ultra Tour Balata (Ultra Tour Balata) [Wilson ( Wils
on)]. Typically, the layers of a multi-layer golf ball are manufactured by molding the layer around the core or by molding an intermediate or cover layer prior to it. Conventional techniques for applying such layers include injection molding, compression molding and casting of the layer material around a previously formed core or layer, and the like. Therefore, a crucial feature of the production of multilayer balls is to achieve good adhesion between these various layers. If the adhesion between these layers does not meet predetermined criteria, the performance or durability of the golf ball will be adversely affected. For example, low adhesion may form air pockets between the layers, resulting in separation of the layers if the ball is hit with a club.

[0007] The adhesion between the wound core and the cover of a wound ball is due to the slight imperfections formed on the wound non-uniform outer surface formed by overlapping the yarns. It is known to be enhanced. As the cover is molded around the wound core, the cover material flows into these imperfections, resulting in improved adhesion. However, on the contrary, in two-piece and multi-layer balls, the adhesion between the core, cover and / or intermediate layers is greatly reduced due to the relatively smooth outer surface of these layers. Accordingly, a number of methods are known in the art for increasing the adhesion between the various solid layers of a golf ball. For example, U.S. Pat.Nos. 4,229,401 and 4,173,345,
The problems associated with the cover compression molded around the core are mitigated by providing a surface channel of approximately 1.59 mm (1/16 in) deep surrounding the outer surface of the core and passing through the bipolar region of the core. are doing. By providing such channels, by eliminating the entrapment of air between the cover and the core during the compression molding process when the golf ball hits a golf club,
It has been found that separation between the cover and the core can be prevented. Further, to improve the adhesion between the core layer and the cover, and between the intermediate layers including the wound layer, by utilizing protrusions or prongs extending from the outer surface of the core or the intermediate layer. There are numerous patents. For example, U.S. Pat.
No. 52 and 2,229,170 disclose the use of a plurality of uniformly sized protrusions extending from the surface of the core. Such protrusions are devised to provide anchoring means for winding the elastic thread.

[0008] Further, US Patent No. 697,925 discloses a game ball, wherein a metal core is covered by a soft rubber encapsulant, the encapsulant extending to about half its length. It contains a deep "pit". A hard shell material is compression molded around the core / encapsulation, so that the shell material flows into the pits and consequently forms corners, which form the hard shell and the soft shell. Engage with the rubber enclosure. Further, in golf ball technology, the adhesion between the cover and the core of a two-piece golf ball can be improved by roughening the outer surface of the core layer. For example, U.S. Pat. No. 1,558,706 gives a very general description of improving the adhesion of a two-piece ball containing a vulcanized rubber core and a balata shell. Here, the outer surface of the core is roughened by forming corrugations, which correlate with the cover and the core so that when the ball is hit by a club, Works to prevent any movement during The '706 patent discloses the general concept of roughening the core surface to improve adhesion, but this includes details on how to roughen the core surface, Nor does it give any specific description of the properties of the corrugations on the core surface.

Similarly, US Pat. No. 4,367,873 discloses the manufacture of softball and baseball balls comprising a core of PVC foam and a cover made of an ethylene copolymer, wherein the core cover comprises 2.54 cm (1
in) of 1/8 to 1/16. A wound layer is wrapped around the core cover, and a leather outer cover is then placed around the wound. The '837 patent discloses that such corrugations can provide cushioning when the ball is hit and provide a more resilient ball, and possibly the outer leather cover and inner Increases the friction between the cores. One conventional method for improving the adhesion between multilayer golf ball layers is to coat the outer surface of the core, including the core or surrounding intermediate layer, after molding or before forming a subsequent layer thereon. Then, texturing the outer surface manually or by scuffing. Such surface roughening is typically accomplished by polishing the surface with a polisher, such as a Glebar polisher, or in an abrasive medium at various stages of the ball manufacture. By tumbling or grinding. Similarly, the surface can be roughened by spraying the surface of the layer with sand or some other abrasive.

After roughening the surface, it must be washed to remove any free or excess abrasive material. Otherwise, the free or excess abrasive material left on the surface will form air pockets if the next layer is formed thereon. As mentioned above, such air pockets can lead to separation of the layers,
Not desirable. Furthermore, the roughened surface needs to be completely dried before applying the next layer. If the surface is not completely dried, the residual moisture is converted to steam as it forms the next layer around it, forming defects in the interfacial bonding region, which also May lead to separation of Such a post-molding method roughens the outer surface of the layer,
It is difficult to achieve a sufficient pattern depth by these steps. Even after cleaning and drying the treated surface, small particles from the golf ball layer and / or excess abrasive media remain in the interfacial bonding regions between the layers,
The small particles can be easily removed when the ball is hit with a club, forming air pockets between the layers, which can lead to separation of the layers. Similarly, insufficient pattern depth can lead to separation of these layers. Further, such post-molding roughening methods require at least three distinct steps: (1) roughening the surface by polishing, and (2) cleaning the roughened surface. Removal of excess debris and (3) thorough drying of the roughened surface before applying the next layer.

Thus, there is a need for an effective method for improving the interfacial adhesion between golf ball layers,
In this way, the outer surface of a layer is sufficiently deep and provided with a debris-free pattern, while eliminating any post-molding treatment such as polishing, sandblasting, washing and drying. Further, it is intended to improve the properties of known two-piece balls by modifying a typical single layer core and / or single cover layer configuration to provide a multi-layer core and / or cover. Many patents have been issued. The inventions disclosed in these patents aim to improve various golf ball characteristics. For example, there are a number of multilayer ball patents that aim to improve the spin, hitting sound, or feel of a solid ball and maintain the flight distance provided by the solid structure. Various methods of dealing with this core structure have been described in the art. For example, U.S. Pat. No. 5,072,944 discloses a three-piece solid golf ball comprising a center and outer layers made from a rubber composition, preferably a base rubber of polybutadiene. The patent teaches that it is desirable that the central core be softer than the outer layer, where the layers have a hardness (Shore C) of 25-75 and 70-90, respectively. ). U.S. Pat. No. 4,625,964 relates to a solid golf ball having a polybutadiene rubber core having a diameter not exceeding 32 mm and a polybutadiene rubber interlayer having a lower specific gravity than the core material.

US Pat. No. 4,848,770 discloses a non-wound three-piece golf ball that includes a core of highly filled synthetic rubber or polymeric material, an unfilled synthetic rubber intermediate mantle and cover. The core and intermediate mantle have a hardness in the range of 50-95. U.S. Pat.No. 5,002,281 is directed to a three-piece solid golf ball having an inner core having a hardness in the range of 25-70 (Shore C) and a hardness in the range of 80-95 (Shore C). Having an outer shell with C), wherein the specific gravity of the inner core must be greater than 1.0 and equal to or less than the specific gravity of the outer shell, the latter having a specific gravity of less than 1.3. U.S. Pat. No. 5,253,871 relates to a golf ball having a three-piece structure and includes an elastomeric core, an interlayer of a thermoplastic material comprising at least 10% ether block copolymer, preferably blended with an ionomer, and a thermoplastic cover. Some accompanying patents contemplate golf balls with multiple cover layers. For example, U.S. Pat.
Relates to a golf ball having a multi-layer cover, wherein the inner layer is made of a rigid, high flexural modulus ionomer resin;
Also, the outer layer is made of a soft, low flexural modulus ionomer resin, wherein one or both of the layers can include a foamed ionomer resin. Also, U.S. Patent No. 5,314,187 relates to a golf ball having a cover formed of multiple layers, wherein the outer layer is molded over the inner layer and comprises a blend of balata and an elastomer. The inner layer is made of an ionomer resin.

US Pat. No. 4,919,434 is directed to a golf ball having a cover that includes an inner layer and an outer layer, each of which includes a thermoplastic resin, the layers comprising a material that can be melt bonded to each other. It is preferred to include. Both British Patent Applications GB 2,291,817 and GB 2,291,812 are directed to thread wound golf balls with improved flight distance, which golf balls include a double cover layer, wherein the inner cover layer is Has a higher hardness than its outer cover layer. These references teach that the cover layer can be made of a balata or ionomer resin and should have a combined thickness of less than 4 mm. UK Patent Application GB 2,278,609 discloses a multilayer golf ball that provides high flight distance without sacrificing playability or durability, the golf ball comprising a core, an inner cover layer and an outer cover layer. Wherein the inner cover layer comprises a highly acidic ionomer and the outer cover layer comprises a soft or non-ionomeric thermoplastic elastomer. However, none of these patents have an extremely thin thermoset outer layer made from a castable reactive liquid, as described herein, and have a "stepped" like golf ball of the present invention. It does not disclose a multilayer ball that provides a golf ball exhibiting excellent performance.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention in general to provide a golf ball, and more particularly, to a multi-layer golf ball having improved adhesion between adjacent component layers, and An object of the present invention is to provide a method for manufacturing such a golf ball. In particular, it is an object of the present invention to provide a golf ball having a core, an inner cover layer and an extremely thin outer cover layer, wherein the outer cover layer is formed from a castable reactive liquid. The inner cover layer includes a thermoplastic material, and the inner cover layer includes a high flexural modulus material having a textured pattern to improve adhesion between the layers.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a multi-layer golf ball having improved adhesion between adjacent component layers and a method of making such a golf ball. The cover of such a golf ball is composed of an inner layer and a cast outer layer. The present invention is further directed to a multi-layer golf ball that generally includes a core, an inner cover layer, and a very thin (i.e., <0.05 in) outer cover layer, wherein the inner cover layer has a high flexural modulus. The outer cover layer includes a thermosetting material formed from a reactive liquid material having castability. In one particular embodiment, the present invention is directed to a multi-layer golf ball comprising a core, an inner cover layer and a very thin outer cover layer, wherein a) the core comprises a solid or liquid-filled center, A length of elastic yarn wrapped around it, b) the inner cover layer comprises a high flexural modulus material, and c) the outer cover layer comprises a castable reactive Including a thermosetting material formed from a liquid material.

The present invention also relates to a method for improving the interfacial adhesion between golf balls, and particularly to multilayer golf balls, and to golf balls produced by such a method. In particular, the present invention is directed to a golf ball having improved interfacial adhesion between the layers forming the ball, wherein the ball includes at least a cover and a core. The ball includes a textured pattern on the outer surface of the core, the pattern having a height of about 2 to 15 mils and a plurality of peaks having a draft of less than about 10 degrees. including. A cover material covers the patterned core to form a two-piece ball. In another embodiment, the present invention further comprises a golf ball comprising more than one layer to the cover, wherein the inner layer is integrally formed with its outermost layer, With attached surface profile. The inner layer is formed by placing a core into a mold cavity, where the cavity has a patterned pattern on its inner surface. The pattern has a plurality of depressions having a depth in the range of about 2 to 15 mils and a draft of less than about 10 degrees. The inner layer is preferably injection molded or compression molded to form the inner layer with a patterned surface profile on its outermost surface, the surface profile comprising:
A corresponding image of the pattern of the mold cavity,
And includes a plurality of peaks having a height ranging from about 0.051 to 0.38 mm (about 2 to 15 mils). An outer cover material is then cast over the patterned intermediate layer.

The present invention also contemplates a golf ball comprising at least a cover, a core, and optionally one or more intermediate layers disposed between the cover and the core, wherein the core and / or at least One intermediate layer has a patterned surface profile integrally formed on its outermost layer. This patterned surface profile is approximately 0.051-0.38 mm (approx.
2 to 15 mils) in height.
This textured surface profile can be a repeating pattern, or it can be a random pattern of peaks. Such patterns can have regular geometric or irregular shaped peaks.
The outer cover layer is cast over the core or intermediate layer and has a thickness of less than about 1.27 mm (about 0.05 in). Further, the present invention is also directed to a mold for molding a golf ball, wherein the mold includes a cavity having a patterned pattern on an inner surface thereof, wherein the patterned pattern is about It includes a plurality of depressions having a depth in the range of about 2 to 15 mils and preferably having a draft of less than about 10 degrees.

[0018]

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, it has been found that golf balls having the construction claimed herein exhibit "gradual performance" when hit with various clubs. More specifically, the term “graded performance” as used herein
The golf ball claimed herein has the advantage of a traditional hard-covered two-piece ball in terms of distance when hit with a club having high club head speed and low loft angle, Simultaneously, when hit with a club having a low head speed and a high loft angle, it means having the same high spin and feel characteristics as a wound ball with a traditional soft coating. Thus, golf balls having the configurations claimed herein provide the golf ball industry with "the best of both worlds" balls. That is,
The present invention also provides a golf ball that provides a maximum flight distance with a low spin for long shots (eg, by a driver) and a high spin and high controllability (eg, for short shots). The present invention is also directed to a method and apparatus for producing a golf ball having improved interfacial adhesion between layers, and to a golf ball produced by such a method. Compared to,
To improve such interfacial adhesion, a streamlined,
Give a more effective way. More specifically, as noted above, the prior art describes several complex methods for increasing the adhesion of various layers of a golf ball. Such a method can be used to create channels (1/16 of 2.54 cm) in the outer surface of the inner layer.
Forming (1/16 of 1 in) or more), forming deep pits extending through half of the inner layer,
Or forming a complex group of protrusions and anchoring a subsequently applied layer to this inner layer. In addition, the surface of the golf ball core or inner layer may be fringing
Alternatively, it is also known to roughen the surface by exposing the surface to a polishing medium. However, all of these methods require many labor intensive and time consuming steps and / or provide lower adhesion as compared to the golf balls of the present invention.

The golf ball of the present invention comprises a multi-layer cover, a core and optionally at least one intermediate layer (eg, a mantle layer, an inner cover layer or an outer cover) inserted between the outer cover layer and the core. Layer), wherein the core,
The outer surface of either or both of the intermediate layers has a textured surface profile integrally formed thereon. The golf ball of the present invention has a patterned surface profile.
When including one or more layers with (eg, a patterned core and a patterned intermediate layer), the surface profile may include the same or different patterns. The patterned surface profile used in the present invention has an outermost surface on the core, the intermediate layer, or both,
Includes a plurality of integrally molded peaks. As used herein, the term "peak" refers to a raised area extending from the surface of the core and / or intermediate layer. In selecting an appropriate surface profile to be formed on the outer surface of the golf ball layer, several parameters need to be considered. These parameters include peak height, peak shape and pattern density. Preferably, these parameters are chosen to maximize the surface area available for interfacial bonding between the textured surface profile and subsequently applied layers.

The peak of the textured surface profile is about
0.051 to 0.38 mm (about 2 to 15 mils), preferably about 0.051 to about 0.
254 mm (about 2 to about 10 mils), more preferably about 0.076 to about 0.17
8 mm (about 3 to about 7 mil) and most preferably about 0.101 to 0.12
It has a height of 7mm (about 4-5 mils). If all of these peaks had a height of less than about 2 mils, it was found that the adhesion between the layers was not adequately improved. Similarly, if the height of the recess exceeds about 15 mils, removing the core or interlayer from the mold cavity has proven extremely difficult. The peaks can have the same height, or the peaks can have a lower height than the peak with the highest height. Further, these peaks may include single points, such as those having a regular shape extending in a pyramid or cone. Alternatively, the peaks can have an irregular or jagged shape, which provides an additional surface area for interfacial bonding with a subsequently applied layer. The peaks that form the surface profile can also have substantially the same width, or can have a wide range. As used herein, the term `` peak density '' refers to the percentage of the surface area of the outer surface of the layer covered by peaks having the surface profile, as shown in FIGS.1A-1E and 2A-2D. %)
Means For optimal results, the peak density is preferably from about 45% to about 75% of the surface area of the outer surface, and the peak density is more preferably about 45% of the surface area of the outer surface. 50% to about 70%, and most preferably about 60%.

As shown in FIGS. 1A-1E and 2A-2D, the surface profile used in the present invention can be of various shapes and / or
Or it can include a very wide variety of random or repeating patterns of peaks with heights. For example,
As shown in FIGS. 2A-2D, the textured surface profile can, in another embodiment, include a repeating pattern of irregularly shaped peaks. Further, FIG.
As shown in 1E, the textured surface profile can include a random pattern of non-uniform shaped peaks. Many of the textured surface profiles that are suitable for use in the present invention have previously illustrated only other applications (i.e., other than golf balls), such as a wide range of plastic and metal industrial products, e.g., few applications. Then the computer,
Housings for photocopiers and electronics, various furniture, and various office products and accessories.
Used in decorative and ornamental surface finishes. However, according to the present invention, surprisingly, such a textured surface profile is integrally formed on the outermost surface of the core and / or intermediate layer of the golf ball by molding the textured surface with the textured surface. Between the later layer formed on the surface,
It has been found that high interfacial adhesion is provided. Since the patterned pattern on the inner surface of the mold cavity corresponds to the patterned surface profile integrally molded on the outer surface of the inner golf ball component,
Certain features of the peak, such as peak height, shape and pattern density, of the surface profile must be taken into account when selecting a corresponding patterned pattern for the inner surface of the mold. .

Further, an additional parameter to be considered in selecting a pattern for the surface of the mold cavity is the draft of the depression formed in the mold. The term "draft" is well known in the molding arts. This is a measure of the angle at which the sidewalls of the depression vary from vertical.
If the draft angle is too small, it is difficult to remove the molded piece from the mold. However, in the present invention, when the draft is too large, the peak formed on the surface of the golf ball layer does not provide sufficient interfacial adhesion. Therefore, in order to obtain sufficient interfacial adhesion and sufficient releasability from the mold cavity, the draft of the pattern depression formed in the mold is less than about 10 degrees, preferably It should be between about 2 degrees and about 10 degrees, more preferably between about 4 and about 8 degrees, and most preferably about 6.5 degrees. The textured surface profile may be applied to the outer surface of the core and / or intermediate layer during the molding process used in forming the core and / or intermediate layer. It is formed by integrally molding with. The textured surface profile is formed on the outer surface of the core and / or interlayer using a modified mold cavity. Typically, the conventional mold cavities used to form the core and / or intermediate layers are:
It had a substantially smooth inner surface to facilitate removal of molded articles from the cavity. However, the inner surface of the mold cavity used in the present invention has a patterned pattern on its surface, with a corresponding patterned surface on the outer surface of the layered structure formed therein. Suitable for generating profiles. As shown in FIGS. 3A and 3B, the depression in the patterned pattern is
Have D. This pattern can have dimples of various depths, but almost all of them have a depth of about 0.051 to about 0.38 mm (2 to
About 15 mils), preferably about 0.051 to about 0.254 mm (about 2 to about 10 mils), more preferably about 0.076 to about 0.178 mm (about 3 to about 7 mils)
And should most preferably have a depth of about 4 to about 5 mils.

As shown in FIG. 3A, the depressions of the patterned pattern can have a regular shape and a substantially smooth bottom. However, as shown in FIG.3B, the depressions in the patterned pattern have an irregular shape with a rough bottom, thus providing an additional surface area for interfacial bonding with a subsequently applied layer. Can be. The depressions forming the pattern can all have substantially the same width, or they can have a variety of different widths. As used herein, the term "indentation density" refers to the percentage (%) of the surface area of the inner surface of the mold cavity that is covered by the indentations of the patterned pattern. For optimal results, the density of the depressions is preferably from about 45% to about 75% of the surface area of the inner surface of the mold cavity,
This recess density is more preferably from about 50% to about 70% and most preferably about 60%. After giving the cavity a predetermined pattern, the core and / or intermediate layer forming material is introduced into the cavity using any known molding method, for example, injection molding or compression molding. The resulting construct (i.e., the core or core with an intermediate layer formed thereon) includes a textured surface profile integrally molded on its outermost surface. This surface profile is a "negative image" of the pattern on the mold inner surface. The surface profile has a height of about 0.051 to about 0.38 mm (about 2 to 15 mils) and about 4
Includes multiple peaks with a peak density of 5 to about 75%. Next, the construct is removed from the mold and without any other surface conditioning steps such as polishing, washing or drying,
It is possible to proceed directly to the next manufacturing stage.

A particularly preferred pattern is a pattern (Pattern).
n) No. 11050 as Mold-Tech (a division of Roehlen Industries)
Is available as a commercial product from
Includes a random pattern of non-uniform depressions having a depression density of about 4 to about 5 mils, a depression density of about 60%, and a draft of about 5-6 degrees. The methods claimed herein can be used to improve the interfacial adhesion between any adjacent layers of a golf ball construction. Accordingly, the method of the present invention can be used to produce multilayer golf balls or known two-piece balls, including a cover, a core, and at least one intermediate layer provided between the cover and the core. For example, a two-piece ball with a cover and a core can be made by compression molding and casting, where the core blend has a depth of about 0.051 to about 0.38 mm (about 2-15 mils) and less than about 10 degrees. It is introduced into a mold cavity having an interior surface with a patterned pattern including a plurality of depressions having draft angles. A core having a corresponding patterned surface profile is formed, the profile being formed integrally with the outer surface of the core, from about 0.051 to about 0.38 mm (about 2 mm).
1515 mils). The core is removed from the patterned mold cavity and a multilayer cover is subsequently applied around the patterned core, as described in more detail below. The textured surface profile of the core promotes adhesion between the core and the cover.

Further, multi-layer golf balls can also be manufactured by the claimed method of the present invention. The outer surface of one of the layers of the multi-layer construction is integrally molded with about 0.05
It can have a patterned surface profile that includes a plurality of peaks having a height of about 1 to about 0.38 mm (about 2 to 15 mils).
Each of the outer layer surfaces can have the same surface profile or different surface profiles. Alternatively,
Only selected layers of the construct can have a patterned surface profile integrally molded therewith. In a non-limiting example, the golf ball core can be molded utilizing a compression molding process, or can be an elastomer wrapped around a liquid or solid center. The core is then placed in the mold cavity. The cavity includes a textured pattern on its inner surface. The interlayer blend is then injection molded around the core in the mold cavity to form an intermediate layer, wherein the outer surface of the intermediate layer is integrally molded with the pattern. Includes surface profile with After forming the intermediate layer, a cover is cast around the construct, as described in more detail below. Alternatively, the cavity for molding the core may include a patterned pattern on its inner surface to form a core having a corresponding patterned surface profile. The patterned core is then placed in a second mold cavity, also having a patterned inner surface. An interlayer material blend is then introduced into the second mold cavity to form a construct that includes an interlayer having a patterned surface profile on an outer surface. Subsequently, a cover is cast around the construct, as described more fully below.

Without being bound by any particular theory, such as obtained by an 8-iron or wedge,
In connection with low club head speeds and high loft shots, the stiffness of the ball surface has a greater effect on the flight characteristics of the ball than on the overall configuration of the ball. Thus,
If all other parameters are the same, a ball with a soft surface will have a higher spin rate than a ball with a hard surface. However, conversely, when a ball is hit due to a high club head speed and a low loft angle, such as with a driver, the overall configuration of the ball depends on the flight characteristics of the ball rather than on the hardness of the ball surface. It is considered to have a significant effect. Thus, according to the present invention, when a golf ball having a low spin structure is manufactured, and an extremely thin layer made of a relatively soft thermosetting material is added, which is manufactured from a reactive liquid having castability, A golf ball with “gradual performance” from a driver to a wedge can be manufactured. As used herein, the term "thermoset" material means an irreversible solid polymer that is the reaction product of two or more prepolymer precursor materials. The use of a multi-layer cover allows the ball to have "graded performance" when hit with various clubs. The thickness of the outer cover layer is important for the "gradual performance" of the golf ball of the present invention. If the outer cover layer is too thick, the cover layer is not the cover surface property,
It will contribute to in-flight properties related to the overall configuration of the ball. However, if this outer cover layer is too thin, it will not be sufficiently durable to withstand repeated impacts by the golfer's club. Specifically, the outer cover layer is less than about 1.27 mm (about 0.05 in), preferably about
It must have a thickness of about 0.508 to about 1.02 mm (about 0.02 to about 0.04 in). Most preferably, this thickness is about 0.762 mm (about 0.062 mm).
3in).

This outer cover layer provides a relatively soft thermoset to reproduce soft feel and high spin playing characteristics when the ball of the present invention is used in pitching and other "short game" shots. Manufactured from materials. In particular, the outer cover layer should have a Shore D hardness of from about 30 to about 60. In a very flexible embodiment, the cover has a Shore D hardness of 35-50 and most preferably 40-45. In another embodiment, the cover comprises 50-6
It has a Shore D hardness in the range of 0. Further, the material for the outer cover layer needs to have a certain degree of abrasion resistance so that it can be advantageously used as a golf ball cover. The outer cover layer of the present invention can include any suitable thermosetting material. It is made from a castable reactive liquid material. Preferred materials for the outer cover layer are:
Includes, but is not limited to, castable urethanes and polyurethanes, thermoset urethane ionomers and thermoset urethane epoxies. An example of a suitable polyurethane ionomer is the name "golf ball cover," June 7, 1995.
Pending U.S. Patent Application 08 / 482,519, filed on date
It is described in. The entire disclosure of this patent application is the reference of the present invention. Thermoset polyurethanes and urethanes are particularly preferred for the outer cover layer of the balls of the present invention. Polyurethane is a reaction product of a polyurethane prepolymer and a curing agent. The polyurethane prepolymer is a product formed by the reaction of a polyol with a diisocyanate. The curing agent is typically either a diamine or a glycol. Often, a catalyst is used to facilitate the reaction between the curing agent and the polyurethane prepolymer.

Conventionally, thermoset polyurethanes have been prepared from diisocyanates such as 2,4-toluene diisocyanate (TDI) or methylene bis- (4-cyclohexyl isocyanate) (HM
DI) and a polyol cured with a polyamine such as methylene dianiline (MDA), or a trifunctional glycol such as trimethylolpropane, or N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine It is prepared using a tetrafunctional glycol. However, the present invention
It is not limited to only these particular types of thermosetting polyurethanes. Quite the contrary, any suitable castable polyurethane can be used to form the outer cover layer of the present invention. In a preferred embodiment, the inner cover layer of the present invention is made of a rigid, high flexural modulus, elastic material, which when hit for long range shots (e.g., with a driver or long iron). In addition, it contributes to the low spin and flight distance characteristics of the ball claimed in the present invention. Specifically, the inner cover layer material has a Shore D hardness of about 65-80, preferably about 69-74 and most preferably about 70-72. Further, as defined herein, the term "high flexural modulus" refers to at least about 447.9 MPa (about 65,
000 psi), preferably from about 70,000 psi to about 82.3 MPa.
The flexural modulus (as measured by ASTM 790) is 26.8 MPa (about 120,000 psi) and most preferably at least about 516.8 MPa (about 75,000 psi). The thickness of the inner cover layer is
It can range from about 0.020 to about 0.045 in, preferably about 0.030 to about 0.040 in, and most preferably about 0.035 in.
In another embodiment, the inner cover layer material comprises about 62-7
It has a Shore D hardness of 0, preferably about 65-68. In this embodiment, the flexural modulus of the material is at least about
344.5 MPa (about 50,000 psi), preferably about 379 to about 482.3 MP
a (about 55,000 to about 70,000 psi) and most preferably about 41
It can be from 3.4 to about 447.9 MPa (about 60,000 to about 65,000 psi). The thickness of the inner cover layer is about 0.508 to about 1.143 mm (about
20 to about 0.045 in), preferably about 0.762 to about 1.016 mm (about 0.03 in.
0 to about 0.040 in) and most preferably about 0.889 mm (about 0.035 in.
in).

The inner cover layer can be made from a wide range of elastic materials. Preferred inner cover materials are rigid, high flexural modulus ionomer resins and blends thereof. These ionomers are at least one selected from the group consisting of unsaturated mono- or di-carboxylic acids having 3 to 12 carbon atoms and esters thereof.
It is obtained by providing cross-metal bonds (the polymer comprises 1 to 50% by weight of the unsaturated mono- or di-carboxylic acids and / or esters thereof). More specifically,
Such an acid-containing ethylene copolymer ionomer component is present in an amount of 5-35 (preferably at least about 15, more preferably at least about 15-35, and most preferably at least about 16-20) weight percent of the polymer. , And copolymers of ethylene and acrylic or methacrylic acid. Wherein the acid moiety is 1-90% (preferably at least 40%, most preferably at least about 60%) neutralized to provide lithium *, sodium *, potassium, magnesium *, calcium, barium,
By cations such as lead, tin, zinc * or aluminum (*: preferred) or a combination of these cations,
Form ionomers. Specific acid-containing ethylene copolymers include ethylene / acrylic acid, ethylene / methacrylic acid,
Ethylene / acrylic acid / n-butyl acrylate, ethylene /
Methacrylic acid / n-butyl acrylate, ethylene / methacrylic acid / isobutyl acrylate, ethylene / acrylic acid /
Isobutyl acrylate, ethylene / methacrylic acid / n-butyl methacrylate, ethylene / acrylic acid / methyl methacrylate, ethylene / acrylic acid / methyl acrylate,
Ethylene / methacrylic acid / methyl acrylate, ethylene /
Methacrylic acid / methyl methacrylate and ethylene /
Contains acrylic acid / n-butyl methacrylate. Preferred acids
-Containing ethylene copolymers include ethylene / methacrylic acid, ethylene / acrylic acid, ethylene / methacrylic acid / n-butyl acrylate, ethylene / acrylic acid / n-butyl acrylate, ethylene / methacrylic acid / methyl acrylate and ethylene / acrylic acid / methyl Including acrylate copolymer. Most preferred acid-containing ethylene copolymers are ethylene / methacrylic acid, ethylene / acrylic acid, ethylene / (meth) acrylic acid / n-butyl acrylate, ethylene / (meth)
Includes acrylic acid / ethyl acrylate and ethylene / (meth) acrylic acid / methyl acrylate copolymer.

Methods for making the ionomer are well known in the art, for example, as described in US Pat. No. 3,262,272. Such ionomer resins are commercially available from DuPont under the name Surlyn® and from Exxon under the trade name Iotec®. Some particularly suitable Surlyns include Surlyn 8140 (Na) and Surlyn 8546 (Li), which have a methacrylic acid content of about 19%. However, the material for the inner cover layer is not limited to an ionomer resin. Instead, the present invention provides for virtually all highly elastic materials that are compatible with the other materials of the golf ball.
It can be used as the inner cover layer. Examples of other suitable inner cover materials are thermoplastic or thermoset polyurethanes,
Thermoplastic or thermoset polyetheresters or polyetheramides, thermoplastic or thermoset polyesters, mechanically vulcanized elastomers, functionalized styrene
Butadiene elastomers, metallocene polymers or blends thereof. Suitable thermoplastic polyetheresters are Hytrel (Hy
Includes materials commercially available from DuPont under the trade name trel ^™ ). Suitable thermoplastic polyetheramides include materials available from Elf-Atochem under the trade name Pebax ^™ . Other suitable materials for the inner cover layer include nylon and acrylonitrile-butadiene-styrene copolymer (ABS).

The golf ball core of the present invention can include any of a variety of configurations. For example, the core of the golf ball can include a known center portion, which is surrounded by an intermediate layer disposed between the center portion and the cover layer. The core may be a single layer or may include multiple layers. The innermost part of the core may be solid, or it may be a liquid-filled sphere. Like the core, the intermediate layer can include multiple layers. The core may also include a solid or liquid-filled center around which a very long stretched elastic yarn is wrapped. The material for the solid core includes a composition containing a base rubber, a crosslinker, a filler, and an auxiliary crosslinker or initiator.
The base rubber typically comprises a natural or synthetic rubber.
The preferred base rubber is 1,4-polybutadiene containing at least 40% cis-structure. If desired, the polybutadiene can be mixed with other elastomers known in the art, such as natural rubber, polyisoprene rubber and / or styrene-butadiene rubber to improve the properties of the core. The crosslinking agent includes a metal salt of an unsaturated fatty acid, for example, a zinc salt or a magnesium salt of an unsaturated fatty acid having 3 to 8 carbon atoms such as acrylic acid or methacrylic acid. Suitable crosslinkers include diacrylate, dimethacrylate and monomethacrylate metal salts, where the metal is magnesium, calcium, zinc, aluminum, sodium, lithium or nickel.

The initiator decomposes during the cure cycle;
It can be any known polymerization initiator. Suitable initiators are peroxide compounds such as dicumyl peroxide, 1,1-dioxide
(t-butylperoxy) -3,3,5-trimethylcyclohexane, aabis (t-butylperoxy) -diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane Or di-t-butyl peroxide and mixtures thereof. Prior art golf balls typically contain 5 to 50 pph zinc oxide in a diacrylate-peroxide core system. However, this zinc oxide can be replaced with calcium oxide in a diacrylate-peroxide system to obtain a suitable core composition. As used herein, the term "filler" includes any compound or composition that can be used to alter the density and other properties of the core. Fillers typically include materials such as zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, regrind (regenerated core material ground to 30 mesh size). According to one aspect of the invention, the core includes a liquid-filled or solid, central portion wound with an elastic thread. The solid center is typically a homogeneous mass of an elastic material, such as polybutadiene or natural rubber. The liquid-filled center is a thin-walled sphere, typically made of a thermoplastic or thermoset material, into which liquids such as corn syrup and water are injected by means of a needle. The sphere is then sealed. Typically, the core is frozen into a solid mass before winding. The center winding of either type is realized by a stretched elastic yarn, and the elastic yarn is wound around the core with a predetermined thickness.

With the inner cover layer of the golf ball of the present invention, the overall outer diameter (OD) of the core (including the center and any mantle layer or thread) is about 4.01 to 4.04.
About 4.17 cm (about 1.58 to about 1.64 in), preferably about 4.06 to about 4.1
4 cm (about 1.60 to about 1.63 in), and most preferably about 4.11 cm
(About 1.62in). The multi-layer golf ball can have an overall diameter of any size. The United States Golf Association (USGA) standard specifies that the minimum size of a competitive golf ball is about 4.27 cm (1.6
Although it is limited to a value exceeding 8 in), there is no regulation on the maximum diameter. In addition, golf balls of any size can be used for recreational games. The preferred diameter of the golf balls of the present invention is from about 4.27 cm to about 4.57 cm (about 1.68 to about 1.80 in). The most preferred diameter is about 4.27 cm to about 4.37 cm (about 1.68 to about 4.68 cm).
1.72in). The most preferred diameter is from about 4.27cm to about 4.29cm
(About 1.68 to about 1.69 in). The core and inner cover of the golf ball of the present invention can be manufactured by any known method utilized in the golf ball art. For example, a solid core can be injection molded or compression molded. Similarly, the center of the bobbin used in the present invention can be manufactured by known means. The inner cover layer and optional mantle layer can then be injection molded or compression molded around the core.

However, since it is extremely thin [less than about 1.27 mm (0.05 in)], in order to apply a cover material,
It is not possible to form the outer cover layer of the ball of the present invention using known injection molding or compression molding techniques commonly used in the field of golf balls. These known ball molding methods cannot uniformly apply such a thin outer cover layer to a solid spherical surface. In this way, it has been found by the present invention that the use of a castable, reactive liquid material applied in the liquid state can form a very thin outer cover layer on a golf ball. Specifically, it has been found that a castable, reactive liquid that reacts to form a thermoset material provides a predetermined, very thin outer cover layer. The castable, reactive liquid material utilized to form the thermoset material can be applied on the core or inner cover layer using various coating techniques well known in the art. . One example of a suitable casting technique is "Method and Apparatus for Forming a Polyurethane Cover on a Golf Ball".
U.S. Patent No. 5,7, filed May 2, 1995, entitled
No. 33,428. The entire disclosure of this patent is incorporated herein by reference.

As shown in FIGS. 4 and 6, the cover 8
Around the core 4 and the middle layer 6, the mold parts 51a, b, c and 59
It is formed by mixing and introducing a reactive liquid material having castability into a, b, and c. After mixing, an exothermic reaction starts,
And continue. It is important to measure the viscosity over time. This is because subsequent filling of each mold part, introduction of the core and intermediate layer to one mold part and closing of the mold achieve centering of the cover part and uniform thickness. This is because the time for creating a cover to be held can be adjusted. The core and the intermediate layer 14 are
A suitable viscosity range of the curable urethane mixture for introducing urea is approximately 2000-30000 cps, or an output voltage of 60 mv on a vibrating needle cure meter.
It is measured to be in the range of 9898 mv, and the preferred range is 8000 to 15000 cps (see FIG. 7). The time at which a given viscosity range occurs for mold engagement (gel time) is measured from the time of initial introduction of the mixture into the upper mold parts 51a, b, c. The cover material used in the method of the present invention is a castable polyurethane which is a reaction product of a polyurethane prepolymer and a curing agent. Mixing of the prepolymer with the curing agent to initiate the formation of the cover
This is done by feeding weighed amounts of hardener and prepolymer via lines 63 and 64 in a motorized mixer containing 61. Upper preheated mold part 51
Fill pins a and b and move into holes in each mold, pins 72 and 7
Use 3 to place in the fixing device. The reactants are left in the upper mold parts 51a, b, c for 50-80 seconds, and the core and intermediate layer 14 are lowered into the gelling reaction mixture at a controlled rate. Thereafter, the lower mold part 59a, b, c or series of lower mold parts contains the same amount of mixture introduced into its cavity 58.

The ball cup 46 supports the ball core and the intermediate layer 14 under reduced pressure (or partial vacuum) in a house (not shown). After gelling for 50-80 seconds, the mold part 5
When arranging the core and the intermediate layer 14 in 1a, b, and c, the vacuum is released so that the core and the intermediate layer 14 can be taken out. The mold parts 51a, b, c, including the core and intermediate layer 14 and the solidified cover part 80 thereon, are removed from the centering device, inverted (see FIG. 6) and the other mold part 59
Engage with a, b, c. The latter comprises a selected amount of the reactive polyurethane prepolymer and the curing agent introduced therein before a suitable time beforehand and initiates gelation. Similarly, U.S. Patent No.
No. 6,297 and U.S. Pat.No. 5,334,6 to Wu
No. 73 both disclose suitable techniques that can be used to apply the castable reactive liquids used in the present invention. The entire disclosures of these patents are incorporated by reference for the present invention.
However, the method of the present invention is not limited to using these techniques.

[0037]

The following examples of multilayer golf balls made according to the present invention are given for purposes of illustrating the present invention. However, it is to be understood that this example is given for illustrative purposes only, and is not intended to limit the invention in any way to the examples specifically described herein. Examples The following examples are given for illustrative purposes only. It should be understood that this example does not limit the invention in any way. This is because various modifications of the present invention are possible without departing from the spirit and scope of the present invention. The golf ball of the present invention is manufactured including a cover, a core, and an intermediate layer disposed between the cover and the core. Here, the intermediate layer has a patterned pattern integrally formed on the outer surface thereof. Solid cores were manufactured by molding the core blend composition using known compression molding techniques. The core can also be manufactured using known thread wound core structures or known two-piece core structures using methods well known in the art. The wound core structure may be a solid rubber-based center or a liquid-filled center wound with a length of elastic yarn. Known solid core structures preferably comprise a cis 1,4-polybutadiene rubber, which is cross-linked by a metal salt of an unsaturated fatty acid, such as zinc diacrylate. The core blend composition of this example is as follows:

[0038]

[Table 1]

The core is pulverized using a gray bar pulverizer to have an appropriate outer diameter. The ground core is then washed, dried, and placed into a retractable pin-type injection mold cavity. The cavity has an improved interior surface to provide a patterned pattern to the cavity. In particular, the inner surface of the mold cavity is modified to have a pattern available from Mold-Tech (a division of Lauren Industries) as Pattern No. 11050. This includes a random pattern of non-uniform depressions having a depth of about 4.5 mils, a draft of about 6.5 degrees, and a depression density of about 60%. The core is then coated using conventional injection molding or compression molding techniques to form an interlayer or inner cover layer of an ionomer having a methacrylic acid content of preferably about 15 to 16% by weight or more. To form The ionomer is preferably Surlyn 7940 (lithium), Surlyn 8940 (sodium) or a blend thereof, most preferably a 50/50 blend. The outer cover layer is provided in U.S. Patent Nos. 5,006,297 and 5,006,297.
It can be manufactured according to the method shown in US Pat. No. 334,673 and can be subjected to additional finishing steps to obtain the finished ball. A particularly desirable material for making the outer cover layer is a castable urethane having a Shore D hardness of about 40 to about 60, most preferably a Shore D hardness of about 52 to about 60. The castable urethane preferably comprises p-phenylenediisocyanate ("PPDI") as a starting material, as described in US patent application Ser. No. 09 / 311,591. This US patent application is the reference of the present invention.

In the most preferred core, intermediate layer and cover combination, the core has an outer diameter of about 1.54 inches or more, and the outer diameter of the intermediate layer is about 1.62 inches or more. ) And the cover has a thickness of about 1.02 mm (about 0.04 in) or less. It is believed that golf balls made in accordance with the present invention will improve the adhesion between the golf ball layers. Furthermore, balls with a thin cover layer, cast on a harder intermediate layer, have been compared to conventional "high performance" golf balls (eg, TourBalata [Titleist]). When hit with a driver, it shows a much lower spin rate (and thus a longer overall distance), but when hit with an 8-iron and / or `` about 50 yards '' wedge, It is believed that they will have very similar or higher spin rates, thus proving "step-by-step performance" from the driver to the wedge in the golf balls of the present invention. Obviously, the illustrative embodiments of the present invention described herein meet the above objectives, but it should be understood that various modifications and other embodiments can be devised by those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and embodiments as fall within the spirit and scope of the invention.

[Brief description of the drawings]

FIG. 1A illustrates some non-limiting examples of random patterned surface profiles suitable for use in the present invention.

FIG. 1B illustrates some non-limiting examples of random patterned surface profiles suitable for use in the present invention.

FIG. 1C illustrates some non-limiting examples of random textured surface profiles suitable for use in the present invention.

FIG. 1D illustrates some non-limiting examples of random textured surface profiles suitable for use in the present invention.

FIG. 1E illustrates some non-limiting examples of random patterned surface profiles suitable for use in the present invention.

FIG. 2A illustrates a non-limiting example of a uniform patterned surface profile suitable for use in the present invention.

FIG. 2B shows a non-limiting example of a uniform patterned surface profile suitable for use in the present invention.

FIG. 2C illustrates a non-limiting example of a uniform patterned surface profile suitable for use in the present invention.

FIG. 2D illustrates a non-limiting example of a uniform patterned surface profile suitable for use in the present invention.

FIG. 3A is an enlarged view showing a single depression of a patterned mold cavity pattern used in the present invention.

FIG. 3B is an enlarged view showing a single depression of the patterned mold cavity pattern used in the present invention.

FIG. 4 shows a core 4, an inner cover layer 6, and an outer cover layer 8.
FIG. 3 is a cross-sectional view of a golf ball 2 including:

FIG. 5 is a partial side view of the cover casting device.

FIG. 6 shows a device for mixing and dispensing polyurethane and shows one inverted mold part before engaging with a second mold part.

FIG. 7: Voltage vs. c for the appropriate viscosity of curable urethane
It is the graph which plotted ps.

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) // B29K 75:00 B29K 75:00 B29L 31:54 B29L 31:54 (72) Inventor William E. Morgan United States of America Rhode Island 02806 Burlington Meadow Circle 8 (72) Inventor Christopher Cavalaro, Massachusetts, USA 02347 Lakeville, Birchland Road 17 (72) Inventor Jeffrey El Dalton, Massachusetts, USA 02747 North Dartmouth Sleepy Hollow Road 14 F-term (reference) 4F204 AA42 AB03 AD05 AD24 AG19 AH61 EA03 EA04 EB01 EB12 EB23 EK17

Claims (19)

[Claims] 1. A method of manufacturing a multilayer golf ball having improved interfacial adhesion, comprising: (a) forming a core; (b) forming an intermediate layer on the core. The intermediate layer has a patterned outer surface integrally molded, the patterned outer surface having a height of about 0.051 mm to about 0.381 mm (about 2 to about 15 mils). (C) casting the cover layer on the intermediate layer with a liquid reactive substance or a reactive product thereof having castability. 2. The peak on the patterned outer surface is from about 4 degrees to about 8
3. The method of claim 1, wherein the method has a draft angle within a range. 3. The peak of the patterned outer surface is from about 0.076 to about 0.076.
Claims having a height in the range of about 0.178 mm (about 3 to about 7 mils).
Method according to 1. 4. The method of claim 1, wherein the textured outer surface has a peak density in a range from about 45% to about 75%. 5. The method of claim 1, wherein the textured outer surface comprises a random pattern of irregularly shaped peaks. 6. The patterned outer surface has a regular shape,
2. The method of claim 1, having a repetitive peak pattern. 7. The step of forming the core further comprises a second integrally molded textured outer surface, wherein the second textured outer surface is from about 0.051 mm to about 0.381 mm (about 2 mm). The method of claim 1, comprising a plurality of peaks having a height in the range of about 15 mils to about 15 mils. 8. The method of claim 7, wherein said first and second patterned outer surfaces are comprised of substantially the same pattern. 9. The method of claim 7, wherein said second textured outer surface peak has a draft in the range of about 4 degrees to about 8 degrees. 10. The first and second patterned outer surfaces,
8. The method of claim 7, having a height in the range of about 0.076 to about 0.178 mm (about 3 to about 7 mils). 11. The first and second patterned outer surfaces comprise:
Claims having a peak density in the range of about 45 to about 75%.
Method according to 7. 12. The method of claim 7, wherein said second textured outer surface comprises a random pattern of irregularly shaped peaks. 13. The method of claim 7, wherein said second pattern comprises a repetitive pattern of regularly shaped depressions. 14. A multi-layer ball comprising a cover, a core and at least one intermediate layer interposed between the cover and the core, wherein the multilayer ball has improved interfacial adhesion between the layers.
A method of manufacturing a multi-layer golf ball, comprising: (a) forming a golf ball core; (b) forming a patterned pattern on an inner surface of a mold cavity; The pattern is about 0.051mm to about
(C) placing the core in the mold cavity; and (d) placing the core in the mold cavity. Forming an intermediate layer having a first Shore D hardness on the core in the tee, wherein the intermediate layer has a textured surface profile integrally molded on an outer surface thereof; The surface profile is a corresponding image of the pattern and includes a plurality of peaks having a height in a range from about 0.051 mm to about 0.381 mm (about 2 to about 15 mils); Second Shore D smaller than one Shore D hardness
Casting a cover layer having hardness and a thickness of less than about 1.27 mm (0.05 inch) with the castable liquid reactive material or reactive product thereof onto the intermediate layer. The above method, comprising: 15. A golf ball having improved interfacial adhesion comprising a cover, a core and at least one intermediate layer therebetween, wherein the intermediate layer is integrally molded with an outermost layer of the ball. Having a patterned surface profile,
The textured surface profile includes a plurality of peaks extending from the outermost layer, wherein the peaks are about 0.051 mm to about 0.381 mm (about 2 mm).
~ 15 mils) in height,
The above golf ball. 16. The patterned surface profile may be between about 45 and 45.
17. The golf ball of claim 15, having a peak density of about 75%. 17. The method of claim 1, wherein the cover is formed from a castable liquid reactive material or reactive product thereof.
5. The golf ball according to 5. 18. The golf ball of claim 15, wherein the plurality of peaks in the surface profile have a height in a range from about 0.076 mm to about 0.178 mm (about 3 to about 7 mils). 19. The golf ball according to claim 15, wherein the cover has a lower Shore D hardness than the intermediate layer.