Multi-layer core golf ball

• US 8,337,332 B2
• Filed: 10/24/2011
• Issued: 12/25/2012
• Est. Priority Date: 01/10/2008
• Status: Expired due to Fees

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Ladd, Derek A., Comeau, Brian, Goguen, Douglas S.
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US13/279,668
• Publication Number:
  US 20120040777A1
• Time in Patent Office: 428 Days
• Field of Search: 473/376
• US Class Current: 473/376
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• 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 37/00621 Centre hardness
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0063 Hardness gradient
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005

Abstract

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a thermoset rubber inner core, a thermoplastic first intermediate core layer, a thermoplastic second intermediate core layer, and a thermoset rubber outer core layer.

Claims

1. A golf ball comprising:

an inner core layer formed from a first thermoset rubber composition and having a diameter of from 1.000 inches to 1.580 inches, a center hardness of from 40 Shore C to 65 Shore C, and a surface hardness of from 50 Shore C to 85 Shore C;

a first intermediate core layer formed from a first thermoplastic composition and having a thickness of from 0.005 inches to 0.100 inches and a surface hardness of greater than 60 Shore D;

a second intermediate core layer formed from a second thermoplastic composition and having a thickness of from 0.005 inches to 0.100 inches;

an outer core layer formed from a second thermoset rubber composition and having a thickness of from 0.010 inches to 0.100 inches and a surface hardness of 50 Shore C or greater; and

a cover layer having a thickness of from 0.010 inches to 0.050 inches and a surface hardness of 65 Shore D or less;

wherein one or more of the inner core layer, the first intermediate core layer, the second intermediate core layer, and the outer core layer has a specific gravity of greater than 1.25 g/cc; and

wherein the inner core layer has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the inner core layer is from 10 to 45.

2. The golf ball of claim 1, wherein the diameter of the inner core layer is from 1.400 inches to 1.500 inches.

3. The golf ball of claim 1, wherein the surface hardness of the outer core layer is greater than the surface hardness of the inner core layer.

4. The golf ball of claim 1, wherein the surface hardness of the inner core layer is from 70 Shore C to 85 Shore C.

5. The golf ball of claim 4, wherein the surface hardness of the outer core layer is greater than 85 Shore C.

6. The golf ball of claim 1, wherein the inner core layer has a compression of from 40 to 60.

7. The golf ball of claim 1, wherein the first and second thermoplastic compositions are independently selected from the group consisting of partially- and fully-neutralized ionomers optionally blended with a maleic anhydride-grafted non-ionomeric polymer, polyesters, polyamides, polyethers, and blends of two or more thereof.

8. The golf ball of claim 1, wherein the first intermediate core layer is formed from an ionomer composition comprising a blend of two or more ionomers, and wherein the second intermediate core layer is formed from a composition selected from the group consisting of polyesters, polyamides, polyethers, and blends of two or more thereof.

9. The golf ball of claim 1, wherein the inner core layer is formed from a first polybutadiene composition;

the first intermediate core layer is formed from an ionomer composition;

the second intermediate core layer is formed from a composition selected from the group consisting of polyesters, polyamides, polyethers, and blends of two or more thereof;

the outer core layer is formed from a second polybutadiene composition; and

the cover layer is formed from a composition selected from the group consisting of polyurethanes, polyureas, and copolymers and blends thereof.

10. The golf ball of claim 9, wherein the second polybutadiene composition comprises from 1 phr to 100 phr of a stiffening agent.

11. A golf ball comprising:

an inner core layer formed from a first diene rubber composition and having a diameter of from 1.300 inches to 1.500 inches, a center hardness of from 40 Shore C to 65 Shore C, and a surface hardness of from 70 Shore C to 85 Shore C;

a first intermediate core layer formed from an ionomer composition and having a thickness of from 0.005 inches to 0.100 inches and a surface hardness of greater than 60 Shore D;

a second intermediate core layer formed from a composition selected from the group consisting of polyesters, polyamides, polyethers, and blends of two or more thereof, and having a thickness of from 0.005 inches to 0.100 inches;

an outer core layer formed from a second diene rubber composition and having a thickness of from 0.010 inches to 0.100 inches and a surface hardness of 80 Shore C or greater; and

a cover layer formed from a polyurethane, a polyurea, or a copolymer or blend thereof, and having a thickness of from 0.010 inches to 0.050 inches and a surface hardness of 65 Shore D or less;

wherein the surface hardness of the outer core layer is greater than the surface hardness of the inner core layer;

wherein one or more of the inner core layer, the first intermediate core layer, the second intermediate core layer, and the outer core layer has a specific gravity of greater than 1.25 g/cc; and

wherein the inner core layer has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the inner core layer is from 10 to 45.

12. A golf ball consisting essentially of:

an inner core layer formed from a first diene rubber composition and having a diameter of from 1.400 inches to 1.500 inches, a center hardness of from 50 Shore C to 65 Shore C, and a surface hardness of from 70 Shore C to 85 Shore C;

a first intermediate core layer formed from an ionomer composition and having a thickness of from 0.005 inches to 0.100 inches and a surface hardness of greater than 60 Shore D;

a second intermediate core layer formed from a composition selected from the group consisting of polyesters, polyamides, polyethers, and blends of two or more thereof, and having a thickness of from 0.005 inches to 0.100 inches;

an outer core layer formed from a second diene rubber composition and having a thickness of from 0.010 inches to 0.100 inches and a surface hardness of greater than 85 Shore C; and

a cover layer formed from a polyurethane, a polyurea, or a copolymer or blend thereof, and having a thickness of from 0.010 inches to 0.050 inches and a surface hardness of 65 Shore D or less;

wherein one or more of the inner core layer, the first intermediate core layer, the second intermediate core layer, and the outer core layer has a specific gravity of greater than 1.25 g/cc; and

wherein the inner core layer has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the inner core layer is from 10 to 45.