GB2254792A

GB2254792A - Multiple-coat clear coat with optical brightener for golf ball.

Info

Publication number: GB2254792A
Application number: GB9208475A
Authority: GB
Inventors: Raymond A Berard; Maneul R Jerome
Original assignee: Hogan Ben Co
Current assignee: Hogan Ben Co
Priority date: 1991-04-18
Filing date: 1992-04-16
Publication date: 1992-10-21
Also published as: GB9208475D0; JPH06121844A; CA2066143A1

Abstract

A golf ball (24) includes first, second and third clear coats (26, 28, 30) on its cover (14). The second clear coat (28) contains an effective amount of an optical brightener. The first and third clear coats (28, 30) a trace of optical brightener. In a second embodiment of the invention, small quantities of optical brightener are included in the first and third clear coats (26, 30), in amounts less than that which causes degradation of their physical properties. In a further embodiment of the invention, an optical brightener is included in the cover (14) of the golf ball (24). In a still further embodiment of the invention, a paint layer (34) on the cover (14) is coated with first, second and third clear coats. At least two of the paint layer, the first clear coat, the second clear coat and the third clear coat contain an effective amount of an optical brightener and the remainder contain no more than a trace amount of optical brightener. <IMAGE>

Description

MULTIPL COAT CLEAR COAT WITH OPTICAL BRIGHTENER FOR GOLF BALL BACKGROUND OF THE INVENTION The present invention relates to sporting goods and, more particularly to golf balls.

The ancient game of golf uses appropriate high technology to further the enjoyment of the game. The technology used in golf balls is directed to aesthetic and performance factors. The present invention is concerned primarily with aesthetic factors.

The concept of using a material which converts a portion of the naturally occurring ultra violet light into visible light is well known. In the remainder of this disclosure, such a material is known as an optical brightener. Optical brighteners may be colored or colorless. An article containing, or coated with, such an optical brightener appears brighter than it otherwise would. This effect has been used for many years to produce a fluorescent brightly colored appearance on paper or cloth.

One proprietary product of this sort is known as DAY GLO. Most conventional laundry detergents contain a colorless optical brightener to make clothing washed with them appear brighter than they otherwise would. This effect sometimes surprises a wearer of a white shirt, that has been washed with a laundry detergent containing a colorless optical brightener, when the wearer is bathed in ultraviolet light in an otherwise dark room. The shirt fluoresces white, while the remainder of the wearer remains virtually invisible in the dark room.

In the technical field of golf balls, the first use known of optical brighteners is documented in a deposition of the litigation Acushnet Company v Spaulding and Evenflo Companies, Civil Action No. 89-1359- MC in the United States District Court For the District of Massachusetts.

In that deposition, deponent Alfred I. LdRosa stated that, in the Summer of 1972, he substituted a fluorescent orange pigment for the conventional titanium dioxide in the SURLYN ionomer resin covers of approximately 5-10 dozen golf balls. The covers received a protective coating of clear coat. These golf balls were used on public golf courses by Mr. LdRosa and by several acquaintances to whom he gave them. Some of these acquaintances gave supporting affidavits in the law suit. It appears that this technique was never embraced as a product by the employer of the deponent, however, the unrestricted public use in 1972 appears to be confirmed by the affidavits.

U.S. Patent No. 4,798,386,filed in 1988, discloses the use of a generally colorless optical brightener in the cover of a golf ball. It was this patent that constituted the subject matter of the above civil action.

The civil action was ultimately settled.

SURLYN resin may be given a suitable color and brightness by incorporating additives in the resin. Golf balls made with SURLYN covers may contain optical brighteners, and be covered with a layer of clear coat. In some cases, it is more convenient to treat the surface of the SURLYN cover with a layer of paint, followed with a coating of clear coat. In such cases, optical brighteners in the cover are less useful since their effect is almost totally hidden by the paint.

Prior to the introduction of SURLYN ionomeric resin, golf ball covers were conventionally made of balata, a naturally occurring material.

Although balata has the undesirable property that it is subject to cutting in use, it remains in wide use, especially by professional golfers, because it is believed to provide greater performance than does a golf ball with a SURLYN cover.

Balata has a slightly yellow color, which cannot be corrected by additives. Golfers appear to believe that a golf ball must have a bright white, or slightly bluish white color. Thus, a ball with a balata cover is almost uniformly covered with a layer of an opaque paint to give the golf ball the desired color.

Thus, the technique of adding an optical brightener in the cover is not applicable with a painted SURLYN or balata cover.

It is common to place a coating of a clear lacquer such as, for example, a polyurethane, called a clear coat, over the paint layer to protect the paint layer against abrasion and chipping. U.S. Patent No.

4,865,326adds a colorless optical brightener to the clear coat. This patent is specific in reciting that the clear coat containing the optical brightener must be the outer layer of the golf ball. This permits the optical brightener to receive whatever ultra violet light is in the environment, and thereby give the surface of the golf ball a brighter appearance.

It has been found that the addition of the optical brightener tends to degrade the physical properties of the clear coat. In particular, when the clear coat is the outer layer of the golf ball, the presence of the optical brightener tends to reduce the ability of the clear coat to withstand abrasion and chipping. Indeed, the clear coat containing the optical brightener tends to abrade and chip in a manner similar to the paint layer which it is intended to protect.

U.S. Patent No. 4,802,674 discloses other techniques for adding an optical brightener to a golf ball.

US Patent No. 5,000,458 discloses a golf ball having a two-coat clear coat consisting of a primer coat on the surface of the cover, and a finish coat on the primer coat. The primer coat contains an optical brightener consisting of from about 0.45 to about 2.7 percent by weight of the solids content. The finish coat contains no more than trace amounts, less than about 0.04 percent, optical brightener by weight of solids.

The primer coat may be less than an ideal location for an optical brightener. The purpose of the primer coat is to ensure adhesion of itself, and the succeeding layer of clear coat, to the surface of the cover.

A quantity of optical brightener in the range specified in the patent tends to degrade the ability of the primer to provide suitable adhesion.

OBJECTS AND SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide a technique for providing a brighter appearance to a golf ball which overcomes the drawbacks of the prior art.

The present invention is defined in the appended claims, from one aspect, the invention provides a first layer of a primer clear coat on the surface of a golf ball, the first layer containing no more than trace amounts of an optical brightener, at least a second intermediate layer covering the first layer, the at least a second intermediate layer containing an optical brightener, and a top coat of transparent clear coat containing no more than trace amounts of optical brightener. The top coat of transparent clear coat is the outer layer of the golf ball.

According to a further aspect of the invention there is provided a golf ball containing an effective amount of at least one type of optical brightener in at least two of a cover, a paint layer on the cover, and an intermediate layer of clear coat on the cover or the paint layer.

Briefly stated, the present invention may provide a golf ball having first, second and third clear coats on its cover, counting outward from the cover. The second clear coat contains an effective amount of an optical brightener.

The first and third clear coats contain no more than a nominal amount of optical brightener. In an alternative embodiment of the invention, small quantities of optical brightener are included in the first and third clear coats.

The amounts of optical brightener in the first and third clear coats are less than that which causes degradation of the physical properties of the first and third clear coat.

In a further embodiment of the invention, an optical brightener is included in the cover of the golf ball.

Brightness enhancement from the optical brightener in the cover augments the effect of the optical brightener in the clear coats. In a still further embodiment of the invention, a paint layer on the cover is coated with first, second and third clear coats. At least two of the paint layer, the first clear coat, the second clear coat and the third clear coat contain an effective amount of an optical brightener, the remainder of the paint layer, the first clear coat, the second clear coat and the third clear coat contain no more than a trace amount of optical brightener.

According to another embodiment of the invention, there is provided a golf ball comprising: a core, a cover molded over the core, a first layer of a clear coat on the cover, the first layer containing less than 0.45 percent optical brightener by weight of solids therein, a second layer of clear coat on the first layer, the second layer of clear coat containing from about 0.3 to about 2.7 percent of an optical brightener by weight of solids, a third layer of clear coat on the second layer, the third layer containing less than about 0.3 percent optical brightener by weight of solids therein, whereby the third layer is effective to protect the second layer against damage in use.

According to another aspect of the invention, there is provided a golf ball comprising: a core, a cover on the core, an effective amount of an optical brightener in the cover, a first layer of a clear coat on the cover, a second layer of a clear coat on the first layer, a third layer of an optical brightener on the second layer, and at least two of the cover, the first layer, the second layer, and the third layer containing optical brighteners.

According to another aspect of the invention, there is provided a golf ball comprising: a core, a cover, a first layer of a clear coat on the cover, a second layer of a clear coat on the first layer, a third layer of a clear coat on the second layer, the second layer containing at least first, second and third sublayers, counting outward from the first layer, the first and third sublayers containing an effective amount of an optical brightener, and the first layer, the second sublayer and the third layer containing no more than 0.3 percent of an optical brightener.

According to another aspect of the invention, there is provided a golf ball comprising: a core, a cover on the core, a paint layer on the cover, at least one layer of a clear coat on the paint layer, and the paint layer containing from about 0.3 to about 10 percent optical brightener by weight of solids therein.

According to another aspect of the invention, there is provided a golf ball comprising: a core, a cover on the core, a paint layer on the cover, at least first, second and third layers on the paint layer, counting outward from the paint layer, at least two of the paint layer, the first layer, the second layer and the third layer contain from about 0.3 to about 10 percent optical brightener by weight of solids therein, and a remainder of the paint layer, the second layer and the third layer containing no more than about 0.3 percent optical brightener by weight of solids therein.

The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.

BRIEF DESCRIPIION OF THE DRAWINGS Fig. 1 shows a cross section of a golf ball containing an optical brightener in its cover, and one containing an optical brightener in an outer layer of clear coat, according to the prior art.

Fig. 2 shows a cross section of a golf ball according to the prior art.

Fig. 3 shows a partial cross section of a golf ball according to an embodiment of the invention.

Fig. 4 shows a partial cross section of a golf ball according to a further embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to Fig. 1, there is shown, generally at 10, a golf ball 10 according to U.S. Patent No. 4,798,386recited in the description of the background of the invention. A core 12 is surrounded by a cover 14 molded in place over core 12.

Core 12 may be of any conventional type including wound or molded. Cover 14 is any conventional type such as, for example, balata rubber or SURLYN plastic resin.

In the deposition identified in the background of the invention, cover 14 contains an effective percentage of a colored optical brightener.

To the best of the ability of the inventor to ascertain, the brightener-containing cover of U.S. Patent No. 4,798,386is substantially the same as cover 14 discussed in the deposition, except that, instead of using a brightly colored optical brightener, the patent uses a colorless optical brightener. As is conventional, a transparent clear coat 16 is deposited cover 14. Clear coat 16 is a conventional material such as, for example polyurethane, conventionally used to resist abrasion and wear of cover 14, as well as a paint layer (not shown) which may be coated on cover 14 beneath clear coat 16.

Still referring to Fig. 1, U.S. Patent No. 4,865,326, instead of including an optical brightener in cover 14, an optical brightener is included in clear coat 16 in an amount from about 0.3% to about 1.0 percent. The foregoing percentages are by weight of solids in clear coat 16. The disclosure of this patent is incorporated herein by reference, and may be referred to for a list of optical brighteners, their optical properties, and techniques for application.

As noted above, it is generally the purpose of the clear coat to prevent abrasion, chipping and cracking of cover 14, or a paint layer (not shown) between cover 14 and clear coat 16. The presence of the optical brightener in clear coat 16 increases its susceptibility to abrasion, chipping and cracking, and thereby subverts the original purpose of adding this layer to golf ball 10.

Referring now to Fig. 2, a golf ball 18 is shown according to the above-referenced 5,000,458patent. Golf ball 18 includes a core 12 having a cover 14, molded thereon. A primer coat 20 of clear coat containing an optical brightener, is coated on cover 14. A further clear coat 22 is coated over the surface of primer coat 20. The thicknesses of primer coat 20 and clear coat 22 are exaggerated for purposes of illustration.

The amount of optical brightener in primer coat 20 is from about 0.45 to about 2.7 percent by weight of solids in primer coat 20. Clear coat 22 contains no more than a trace amount of optical brightener.

The presence of clear coat 22 restores the surface protection originally sought from the use of a clear surface coating. However, the presence of optical brightener in primer coat 20 may degrade the physical properties of this coat.

I have discovered that it is not necessary to place optical brighteners in primer coat 20 or clear coat 22. This helps avoid the wear problem when optical brighteners are in clear coat 22, and the degradation of physical properties when optical brighteners are in primer coat 20.

Referring now to Fig. 3, a golf ball 24 is shown, according to an embodiment of the invention. A core 12 has upon it a cover 14, which may be of any suitable material such as, for example, balata or SURLYN.

A primer coat 26, of any suitable coating material such as, for example, any of the materials disclosed in the referenced patents, is applied to the surface of cover 14. Primer coat 26 contains less than about 0.45 percent optical brightener, by weight of solids in primer coat 26.

A clear coat 28 of any suitable material contains an effective amount of an optical brightener. The type of optical brightener may be chosen from among those disclosed in the above-referenced patents, whose disclosures are herein incorporated by reference. The amount of optical brightener in clear coat 28 is from about 0.3 to about 3 percent by weight of solids in clear coat 28.

A top coat 30 covers clear coat 28. Top coat 30 contains less than about 0.3 percent optical brightener, by weight of solids in top coat 30, whereby the desirable protective properties of top coat 30 is retained.

In some applications, I have found that it is advantageous to use more than three clear-coat layers. With more than three clear-coat layers, each coat may be thinner. Each of the thinner layers tends to adhere more firmly to the layer beneath it. Thus, clear coat 28, containing optical brighteners, instead of being a single coat, may be two or more subcoats, for a total of four or more layers of clear coat. The two or more subcoats containing optical brighteners may contain the same amount of optical brighteners, or they may contain different amounts of optical brighteners. In addition, the subcoats containing optical brighteners may contain different kinds of optical brighteners.

In one embodiment of the invention, clear coat 28 consists of, counting outward from primer coat 26, first, second and third subcoats.

Top coat 30 is placed over the third subcoat. The first and third subcoats contain optical brighteners, and the second subcoat, between the first and third subcoats, contains less than about 0.3 percent optical brighteners by weight of solids in the second subcoat. Since a multilayer structure of this sort is well known to those skilled in the art, illustration, and further description thereof is considered unnecessary.

Although it is believed that substantially more than 0.3 percent of optical brightener by weight of solids causes degradation in physical properties, when used in top coat 30, it is further believed that a smaller amount of optical brightener in top coat 30 may not do substantial harm.

Consequently, if additional optical brightener is desirable, it is possible to add a small amount of optical brightener, less than 0.3 percent by weight of solids, to top coat 30. In this manner, a contribution to the optical brightener in clear coat 28 may be enhanced by a small contribution of optical brightener in top coat 30, without degrading the mechanical properties of clear coat 22.

Similarly, a small contribution from an optical brightener in primer coat 26, less than about 0.45 percent by weight of solids, may enhance the optical brightness contribution from other layers.

It is also within the contemplation of the invention that cover 14 may contain at least some optical brightener, substantially as described in U.S. Patent No. 4,798,386,whose brightness may be augmented by the optical brightener in clear coat 20. In this way, the amount of optical brightener required in the cover in the '386 patent may be reduced, because of the augmentation of the optical brightness in clear coat 20.

This overcomes at least part of the economic disadvantage of the large amounts of optical brightener needed in the '386 patent, without sacrificing the desirable brightness of the finished golf ball 18.

Referring now to Fig. 4, a golf ball 32 includes a core 12 on which a suitable cover 14 is installed, as in prior embodiments. A paint layer 34 is applied over cover 14. As is conventional, paint layer 34 is considered to be a primer coat.

A first layer of clear coat 36 is applied over paint layer 34. A top coat 38 of clear coat is applied over clear coat 36.

At least one of clear coat 36 and paint layer 34 contains an effective amount of about 0.3 to about 10 percent optical brightener by weight of solids therein. Top coat 38 contains no more than about 0.3 percent of optical brightener by weight of solids therein.

In the preferred embodiment, both clear coat 36 and paint layer 34 contain at least 0.3 percent optical brightener by weight of solids therein. The amounts and types of optical brightener used in clear coat 36 and paint layer 34 may be the same, or may be different.

Clear coat 36 may include two or more subcoats (not specifically shown in Fig. 4). One or more of the subcoats may contain an optical brightener. When more than one subcoat contains an optical brightener, the amounts and types of optical brightener in the subcoats may be the same, or they may be different.

Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope prwpirif of the invention as defined in the appended claims.

Claims

1. A golf ball comprising a first layer of a primer clear coat on the surface of a golf ball, the first layer containing no more than trace amounts of an optical brightener, at least a second intermediate layer covering the first layer, the at least a second intermediate layer containing an optical brightener, and a top coat of transparent clear coat containing no more than trace amounts of optical brightener.

2. A golf ball comprising an effective amount of at least one type of optical brightener in at least two of a cover, a paint layer on the cover, and an intermediate layer of clear coat on the cover or the paint layer.

3. A golf ball comprising: a core; a cover molded over said core; a first layer of a clear coat on said cover; said first layer containing less than 0.45 percent optical brightener by weight of solids therein; a second layer cf clear coat on said first layer; said second layer of clear coat containing from about 0.3 to about 2.7 percent of an optical brightener by weight of solids; a third layer of clear coat on said second layer; said third layer containing less than about 0.3 percent optical brightener by weight of solids therein, whereby said third layer is effective to protect said second layer against damage in use.

4. A golf ball according to claim ,wherein said optical brightener comprises from about 0.3 to about 1.0 of said second layer by weight of solids therein.

5. A golf ball according to claim 3' wherein said second and third layers both include an identical resin material, and wherein only said second layer contains more than about 0.3 percent optical brightener by weight of solids therein.

6. A golf ball according to claim 35 further comprising an optical brightener in said cover.

7. A golf ball comprising: a core; a cover on said core; an effective amount of an optical brightener in said cover; a first layer of a clear coat on said cover; a second layer of a clear coat on said first layer; a third layer of an optical brightener on said second layer; and at least two of said cover, said first layer, said second layer, and said third layer containing optical brighteners.

8 A golf ball comprising: a core; a cover; a first layer of a clear coat on said cover; a second layer of a clear coat on said first layer; a third layer of a clear coat on said second layer; said second layer containing at least first, second and third sublayers, counting outward from said first layer; said first and third sublayers containing an effective amount of an optical brightener; and said first layer, said second sublayer and said third layer containing no more than 0.3 percent of an optical brightener.

9, A golf ball comprising: a core; a cover on said core; a paint layer on said cover; at least one layer of a clear coat on said paint layer; and said paint layer containing from about 0.3 to about 10 percent optical brightener by weight of solids therein.

10. A golf ball according to claim 9, wherein: said at least one layer of clear coat includes at least first and second layers of clear coat; and at least two of said paint layer and said first and second layers of clear coat contain from about 0.3 to about 10 percent optical brightener by weight of solids therein.

11. A golf ball comprising: a core; a cover on said core; a paint layer on said cover; at least first, second and third layers on said paint layer, counting outward from said paint layer; at least two of said paint layer, said first layer, said second layer and said third layer contain from about 0.3 to about 10 percent optical brightener by weight of solids therein; and a remainder of said paint layer, said second layer and said third layer containing no more than about 0.3 percent optical brightener by weight of solids therein.

12. A golf ball substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings.