Golf Balls Containing Multi-Layered Cores With Foam Center and Thermoplastic Outer Layers

A core assembly for a golf ball, comprising:

• i) an inner core layer comprising a foamed composition, the inner core layer having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SGinner), and 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;
• ii) an intermediate core layer comprising a first non-foamed thermoplastic composition, the composition comprising an elastomer selected from the group consisting of polyester-polyether block copolymers, polyether-amide block copolymers, and blends thereof, the intermediate layer being disposed about the inner core and having a thickness in the range of about 0.050 to about 0.400 inches, a specific gravity (SGintermediate), and an outer surface hardness (Houter surface of IC) and an inner surface hardness (Hinner surface of IC), the Houter surface of IC being greater than the Hinner surface of IC to provide a positive hardness gradient;
• and
• iii) an outer core layer comprising a second non-foamed thermoplastic composition, the composition comprising an ethylene acid copolymer containing acid groups such that at least 70% of the acid groups are neutralized, the outer core layer being disposed about the intermediate core layer and having a thickness in the range of about 0.100 to about 0.750 inches, a specific gravity (SGouter), and an outer surface hardness (Houter surface of OC) and an inner surface hardness (Hinner surface of OC), the Houter surface of OC being the same or less than the Hinner surface of OC to provide a zero or negative hardness gradient,
• wherein the SGouter, is greater than the SG inner, and the SGintermediate is greater than the SGinner.

A core assembly for a golf ball, comprising:

• i) an inner core layer comprising a foamed composition, the inner core layer having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SGinner), and 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;
• ii) an intermediate core layer comprising a first non-foamed thermoplastic composition, the composition comprising an elastomer selected from the group consisting of polyester-polyether block copolymers, polyether-amide block copolymers, and blends thereof, the intermediate layer being disposed about the inner core and having a thickness in the range of about 0.050 to about 0.400 inches, a specific gravity (SGintermediate), and an outer surface hardness (Houter surface of IC) and an inner surface hardness (Hinner surface of IC), the Houter surface of IC being the same or less than the Hinner surface of IC to provide a zero or negative hardness gradient;
• and
• iii) an outer core layer comprising a second non-foamed thermoplastic composition, the composition comprising an ethylene acid copolymer containing acid groups such that at least 70% of the acid groups are neutralized, the outer core layer being disposed about the intermediate core layer and having a thickness in the range of about 0.100 to about 0.750 inches, a specific gravity (SGouter), and an outer surface hardness (Houter surface of OC)and an inner surface hardness (Hinner surface of OC), the Houter surface of OC being the same or less than the Hinner surface of OC to provide a zero or negative hardness gradient, p1 wherein the SGouter, is greater than the SGinner, and the SGintermediate is greater than the SGinner.