GOLF BALL HAVING A HOLLOW CENTER
Golf balls including a spherical inner core shell layer formed from a thermoset or thermoplastic composition are provided. The shell layer has an outer surface, an inner surface, and an inner diameter to define a hollow center. A thermoset or thermoplastic outer core layer is formed about the shell layer and optional intermediate layer(s) disposed between the shell layer and the outer core layer. A cover is formed about the outer core layer.
1 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a thermoset rubber composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a first thermoplastic composition; and
optionally an intermediate core layer formed from a second thermoplastic composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 3 Shore C to 25 Shore C;
wherein at least one of the first thermoplastic composition and the second thermoplastic composition is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
2 . The golf ball of claim 1 , wherein the diameter of the golf ball is 1.80 inches or greater.
3 . The golf ball of claim 1 , wherein the diameter of the golf ball is 2.00 inches or greater.
4 . The golf ball of claim 1 , wherein the shell layer composition is foamed.
5 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a first thermoset rubber composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a thermoplastic composition; and
optionally an intermediate core layer formed from a second thermoset composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 3 Shore C to 25 Shore C;
wherein the thermoplastic composition of the outer core layer is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
6 . The golf ball of claim 5 , wherein the diameter of the golf ball is 1.80 inches or greater.
7 . The golf ball of claim 5 , wherein the diameter of the golf ball is 2.00 inches or greater.
8 . The golf ball of claim 5 , wherein the shell layer composition is foamed.
9 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a thermoplastic composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a first thermoset composition; and
optionally an intermediate core layer formed from a second thermoset composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 0 Shore C to 5 Shore C; and
wherein the thermoplastic composition of the shell layer is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
10 . The golf ball of claim 9 , wherein the diameter of the golf ball is 1.80 inches or greater.
11 . The golf ball of claim 9 , wherein the diameter of the golf ball is 2.00 inches or greater.
12 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a first thermoplastic composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a thermoset composition; and
optionally an intermediate core layer formed from a second thermoplastic composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 0 Shore C to 5 Shore C; and
wherein at least one of the first thermoplastic composition and the second thermoplastic composition is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
13 . The golf ball of claim 12 , wherein the diameter of the golf ball is 1.80 inches or greater.
14 . The golf ball of claim 12 , wherein the diameter of the golf ball is 2.00 inches or greater.
15 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a first thermoplastic composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a second thermoplastic composition; and
optionally an intermediate core layer formed from a third thermoplastic composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 0 Shore C to 5 Shore C; and
wherein at least one of the first thermoplastic composition, the second thermoplastic composition, and the third thermoplastic composition is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
16 . The golf ball of claim 15 , wherein the diameter of the golf ball is 1.80 inches or greater.
17 . The golf ball of claim 15 , wherein the diameter of the golf ball is 2.00 inches or greater.
18 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a first thermoplastic composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a second thermoplastic composition; and
optionally an intermediate core layer formed from a thermoset composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 0 Shore C to 5 Shore C; and
wherein at least one of the first thermoplastic composition and the second thermoplastic composition is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
19 . The golf ball of claim 18 , wherein the diameter of the golf ball is 1.80 inches or greater.
20 . The golf ball of claim 18 , wherein the diameter of the golf ball is 2.00 inches or greater.
21 . A golf ball comprising a core and a cover, the core comprising:
a spherical inner core shell layer formed from a first thermoset rubber composition, the shell layer having an outer surface, an inner surface, and an inner diameter to define a hollow center;
an outer core layer formed from a second thermoset composition; and
an intermediate core layer formed from a thermoplastic composition and disposed between the shell layer and the outer core layer;
wherein the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 10 Shore C to 25 Shore C; and
wherein the thermoplastic composition of the intermediate core layer is a highly neutralized polymer composition comprising:
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;
an organic acid or salt thereof;
a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and
optionally a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof; and
wherein the golf ball has a diameter of 1.70 inches or greater.
22 . The golf ball of claim 21 , wherein the diameter of the golf ball is 1.80 inches or greater.
23 . The golf ball of claim 21 , wherein the diameter of the golf ball is 2.00 inches or greater.
24 . The golf ball of claim 21 , wherein the shell layer composition is foamed.