Golf balls having foam, hollow, or metal center and plasticized thermoplastic core layer
First Claim
1. A golf ball, comprising a core assembly and cover having at least one layer, the core assembly comprising:
- i) an inner core formed from a foamed thermoplastic composition, the inner core having an outer surface hardness (Hinner core surface) and a center hardness (Hinner core center), the Hinner core surface being greater than the Hinner core center to provide a positive hardness gradient, andii) an outer core layer formed from a plasticized non-foamed thermoplastic composition, comprising;
a) an acid copolymer of ethylene and an α
,β
-unsaturated carboxylic acid, optionally including a softening monomer selected from the group consisting of alkyl acrylates and methacrylates;
b) a plasticizer;
c) a cation source present in an amount sufficient to neutralize from about 0 to about 100% of all acid groups present in the composition; and
d) a non-acid polymer, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of greater than 50 wt. %, based on the combined weight of the acid copolymer and the non-acid polymer;
the outer core layer being disposed about the inner core and having an outer surface hardness (Houter surface of OC) and a midpoint hardness (Hmidpoint of OC), the Houter surface of OC being greater than the Hmidpoint of OC to provide a positive hardness gradient,wherein the center hardness of the inner core (Hinner core center) is in the range of about 10 Shore C to about 70 Shore C and the outer surface hardness of the outer core layer (Houter surface of OC) is in the range of about 20 Shore C to about 95 Shore C to provide a positive hardness gradient across the core assembly.
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Accused Products
Abstract
Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) made from a foam or metal-containing composition, or it has a hollow shell construction, and the outer core layer is made of a thermoplastic composition. Preferably, the thermoplastic composition comprises: a) ethylene acid copolymer, b) plasticizer, and c) cation source. A fatty acid ester such as ethyl oleate is preferably used as the plasticizer. The core assembly preferably may have a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency at given compressions.
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Citations
11 Claims
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1. A golf ball, comprising a core assembly and cover having at least one layer, the core assembly comprising:
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i) an inner core formed from a foamed thermoplastic composition, the inner core having an outer surface hardness (Hinner core surface) and a center hardness (Hinner core center), the Hinner core surface being greater than the Hinner core center to provide a positive hardness gradient, and ii) an outer core layer formed from a plasticized non-foamed thermoplastic composition, comprising; a) an acid copolymer of ethylene and an α
,β
-unsaturated carboxylic acid, optionally including a softening monomer selected from the group consisting of alkyl acrylates and methacrylates;b) a plasticizer; c) a cation source present in an amount sufficient to neutralize from about 0 to about 100% of all acid groups present in the composition; and d) a non-acid polymer, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of greater than 50 wt. %, based on the combined weight of the acid copolymer and the non-acid polymer; the outer core layer being disposed about the inner core and having an outer surface hardness (Houter surface of OC) and a midpoint hardness (Hmidpoint of OC), the Houter surface of OC being greater than the Hmidpoint of OC to provide a positive hardness gradient, wherein the center hardness of the inner core (Hinner core center) is in the range of about 10 Shore C to about 70 Shore C and the outer surface hardness of the outer core layer (Houter surface of OC) is in the range of about 20 Shore C to about 95 Shore C to provide a positive hardness gradient across the core assembly. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification