Foam-core golf balls

• US 7,452,291 B2
• Filed: 07/27/2005
• Issued: 11/18/2008
• Est. Priority Date: 03/23/2001
• Status: Expired due to Fees

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Hebert, Edmund A., Ladd, Derek A.
• Primary Examiner(s): GORDEN, RAEANN
• Application Number:
  US11/191,087
• Publication Number:
  US 20050261084A1
• Time in Patent Office: 1,210 Days
• Field of Search: 473/377, 473/373, 473/374
• US Class Current: 473/377
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0047 Density; Specific gravity
• CPC Class Codes: A63B 37/0051 Materials other than polybutadienes; Constructional details
• CPC Class Codes: A63B 37/0061 Coefficient of restitution
• CPC Class Codes: A63B 37/0066 Density; Specific gravity
• CPC Class Codes: A63B 37/0082 Density; Specific gravity

Abstract

A golf ball with a controlled moment of inertia and controlled spin rate is disclosed. The increase in moment of inertia is preferably accomplished by a reduction in the specific gravity or weight of the core, e.g., by foaming. Preferably, this reduction is less than about 15% in specific gravity or less than about 25% in weight to minimize the reduction in the coefficient of restitution of the core.

Claims

1. A golf ball comprising a core and a cover, wherein the ball has a moment of inertia greater than 84 g·

cm²;

the core has its specific gravity reduced to less than 1.05, the reduction in specific gravity being less than 15% to minimize the reduction in the coefficient of restitution of the core; and

the core comprises a highly neutralized thermoplastic polymer having a specific gravity of less than 0.95.

2. The golf ball of claim 1, wherein the highly neutralized thermoplastic polymer comprises (a) an ethylene, C_3-8 alpha, beta-ethylenically unsaturated carboxylic acid copolymer, (b) a high molecular weight, monomeric organic acid or salt thereof, (c) a cation source and (d) a thermoplastic elastomer polymer selected from copolyetheresters, copolyetheramides, block styrene polydiene thermoplastic elastomers, elastomeric polyolefins, and thermoplastic polyurethanes.

3. The golf ball of claim 1, wherein the highly neutralized polymer comprises a melt processible thermoplastic composition comprising (a) aliphatic, mono-functional organic acid(s) having fewer than 36 atoms and (b) an ethylene, C_3-8 alpha, beta-ethylenically unsaturated carboxylic acid copolymer(s) and ionomer(s) thereof.

4. The golf ball of claim 1, wherein the highly neutralized polymer comprises (a) a salt of a high molecular weight organic acid and (b) an acid containing copolymer ionomer.

5. The golf ball of claim 4, wherein the highly neutralized polymer further comprises (c) a thermoplastic polymer selected from co-polyesteresters, copolyetheramides, block styrene polydiene thermoplastic elastomers, elastomeric polyolefins, and thermoplastic polyurethanes.

6. The golf ball of claim 1, wherein the specific gravity of the highly neutralized polymer is reduced by the incorporating less than 5% of low specific gravity fillers into the polymer.

7. The golf ball of claim 6, wherein the highly neutralized polymer comprises between 1 and 3% low specific gravity fillers.