Multi-layer core golf ball

• US 8,262,511 B2
• Filed: 12/02/2009
• Issued: 09/11/2012
• Est. Priority Date: 01/10/2008
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Comeau, Brian, Goguen, Douglas S.
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US12/629,581
• Publication Number:
  US 20100075779A1
• Time in Patent Office: 1,014 Days
• Field of Search: 473/376, 473/373, 473/374
• 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 37/0035 Density; Specific gravity
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0047 Density; Specific gravity
• CPC Class Codes: A63B 37/00621 Centre hardness
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0066 Density; Specific gravity
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers

Abstract

Golf balls consisting of a multi-layer core and a cover are disclosed. The multi-layer core comprises a soft thermoset rubber center, a stiff thermoplastic intermediate core layer, and a thin thermoset rubber outer core layer. The maximum hardness of the core is a point or region located at a distance of from 0.1 mm to 8.0 mm measured radially inward from the outer surface of the core. The maximum core hardness is preferably at least 10% greater than the outer surface hardness of the core.

Claims

1. A golf ball comprising:

a core consisting of;

a center formed from a first diene rubber composition and having a diameter of from 1.000 inches to 1.580 inches, a center hardness of from 40 Shore C to 70 Shore C, and a surface hardness (SH_center) of from 50 Shore C to 85 Shore C;

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

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 an outer surface hardness (SH_outer) of 80 Shore C or greater;

wherein SH_outer is greater than SH_center;

wherein the core has a maximum hardness (SH_peak) located at a distance of from 0.25 mm to 5.00 mm measured radially inward from the outer surface of the core; and

wherein SH_peak is 10% or more higher than SH_outer; and

a cover layer having a thickness of from 0.010 inches to 0.050 inches and formed from a composition having a material hardness of less than 60 Shore D.

2. The golf ball of claim 1, wherein SH_peak is 20% or more higher than SH_outer.

3. The golf ball of claim 1, wherein SH_peak is located at a distance of from 0.50 mm to 5.00 mm measure radially inward from the outer surface of the core.

4. The golf ball of claim 1, wherein SH_peak is located at a distance of from 0.50 mm to 2.50 mm measure radially inward from the outer surface of the core.

5. The golf ball of claim 1, wherein SH_peak is 20% or more higher than SH_outer, and wherein SH_peak is located at a distance of from 0.50 mm to 5.00 mm measure radially inward from the outer surface of the core.

6. The golf ball of claim 1, wherein the difference between SH_outer and SH_center is 5 Shore C units or greater.

7. The golf ball of claim 1, wherein the difference between SH_outer and SH_center is 10 Shore C units or greater.

8. The golf ball of claim 1, wherein the center has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the center is from 10 to 45.

9. The golf ball of claim 1, wherein the center has a diameter of from 1.300 inches to 1.490 inches, the intermediate core layer has a thickness of from 0.020 inches to 0.070 inches, and the outer core layer has a thickness of from 0.030 inches to 0.040 inches.

10. The golf ball of claim 1, wherein the surface hardness of the intermediate core layer is 65 Shore D or greater.

11. The golf ball of claim 1, wherein the surface hardness of the intermediate core layer is 70 Shore D or greater.

12. The golf ball of claim 1, wherein SH_outer is 85 Shore C or greater.

13. The golf ball of claim 1, wherein the thermoplastic composition of the intermediate core layer is selected from the group consisting of partially- and fully-neutralized ionomers, and blends of two or more thereof.

14. A golf ball comprising:

a core consisting of;

a center formed from a first diene rubber composition and having a diameter of from 1.400 inches to 1.550 inches, a center hardness of from 45 Shore C to 70 Shore C, and a surface hardness (SH_center) of from 55 Shore C to 85 Shore C;

an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.020 inches to 0.070 inches and an outer surface hardness of 65 Shore D or greater; and

an outer core layer formed from a second diene rubber composition and having a thickness of from 0.020 inches to 0.050 inches and an outer surface hardness (SH_outer) of 85 Shore C or greater;

wherein SH_outer is greater than SH_center;

wherein the core has a maximum hardness (SH_peak) located at a distance of from 0.50 mm to 5.00 mm measured radially inward from the outer surface of the core; and

wherein SH_peak is 10% or more higher than SH_outer; and

a cover layer having a thickness of from 0.010 inches to 0.050 inches and formed from a composition having a material hardness of less than 60 Shore D, wherein the cover layer composition is selected from polyurethanes, polyureas, and polyurethane-urea hybrids.

15. The golf ball of claim 14, wherein SH_peak is 20% or more higher than SH_outer.

16. The golf ball of claim 14, wherein SH_peak is located at a distance of from 0.50 mm to 2.50 mm measure radially inward from the outer surface of the core.

17. The golf ball of claim 14, wherein SH_peak is 20% or more higher than SH_outer, and wherein SH_peak is located at a distance of from 0.50 mm to 2.50 mm measure radially inward from the outer surface of the core.

18. The golf ball of claim 14, wherein the difference between SH_outer and SH_center is 5 Shore C units or greater.

19. The golf ball of claim 14, wherein the difference between SH_outer and SH_center is 10 Shore C units or greater.

20. The golf ball of claim 14, wherein the center has a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the center is from 10 to 45.