Multi-layer golf ball providing improved speed

Abstract

The present invention is directed to a multi-layer golf ball comprising at least one core or core layer, at least one intermediate layer, and at least one cover layer. The core has a diameter of about 1.20 to about 1.56 in. and a PGA compression of about 40 to about 90. The intermediate layer comprises a modified ionomeric polymer, and it has a thickness of about 0.01 to about 0.10 in. and a Shore D hardness of about 30 to about 70. The cover layer has a Shore D hardness of about 40 to about 75. The multi-layer golf balls of the present invention provide high driver ball speed and / or a high Coefficient of Restitution, while maintaining excellent shot feel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Priority is claimed under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 60 / 572,432, filed on May 19, 2004, entitled “Multi-Layer Golf Ball Providing Improved Speed,” by Dean A. Snell, Hyun Jin Kim and Eric Loper, which application is incorporated by reference herein.BACKGROUND OF THE INVENTION [0002] This invention relates generally to golf balls, and, more specifically, to multi-layer golf balls. In particular, this invention relates to a golf ball having a core, at least one intermediate layer, and at least one cover layer, wherein the intermediate layer comprises an ionomer, or ionomer blend, and further comprises at least one fatty acid or metal salt thereof. The multi-layer golf balls of the present invention provide a higher ball speed and / or a higher coefficient of restitution (“C.O.R.”) than do analogous balls having an identical core and cover layer, but an intermediate layer made from the identical ionomers or ...

AI Technical Summary

Benefits of technology

[0018] The present invention is embodied in a multi-piece golf ball having a core, an intermediate layer, and a cover layer, wherein the ball provides a high driver ball speed and / or a high Coefficient of Restitution (“C.O.R.”), while maintaining excellent shot feel. More particularly, the intermediate layer of the ball comprises a modified ionomeric polymer that comprises a special blend composition and / or a special bimodal polymer blend composition. The special blend composition comprises: (1) ethylene, (2) 5 to 25 weight percent (meth)acrylic acid (based on the total weight of (1), (2), and (3)), (3) 0 to 40 weight percent of a C1 to C8-alkyl acrylate (based on the total weight of (1), (2), and (3)), and (4) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer), of a fatty acid or one or more metal salts of the fatty acid. The special bimodal polymer blend composition comprises (1) a high molecular weight component having molecular weight of about 80,000 to about 500,000 and comprising one or more ethylene / α,β-ethylenically unsaturated C3-8 carboxylic acid copolymers and / or one or more ethylene / alkyl(meth)acrylate / (meth)acrylic acid terpolymers; the high molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and a mixture of any these, and / or (2) a low molecular weight component having a molecular weight of about from about 2,000 to about 30,000 and comprising one or more ethylene / α,β-ethylenically unsaturated C3-8 carboxylic acid copolymers and / or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers; the low molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and a mixture of any these, and (3) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of the fatty acid. At least about 40 percent of the acid groups present in the modified ionomeric polymer are neutralized with zinc, sodium, lithium, calcium, or magnesium ions, or a combination thereof.

Problems solved by technology

Moreover, because wound balls generally have a more complex structure, they generally require a longer time to manufacture and are more expensive to produce than are two-piece balls.

Further, such a combination imparts a high initial velocity to the ball, which results in increased distance.

Due to their hardness, however, these two-piece balls have a relatively low spin rate, which makes them difficult to control, particularly on relatively short approach shots.

Because the materials of two-piece balls are very rigid, the balls typically have a hard “feel” when struck by a club.

However, the patents fail to disclose any major effects on ball properties, and fail to disclose that the compositions are useful for parts of a golf ball other than the cover.

However, there is no disclosure of any ball construction parameters required to produce specific performance properties such as driver velocity or driver spin for three-piece balls.

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