Multi-layer core golf ball

• US 9,943,730 B2
• Filed: 07/28/2016
• Issued: 04/17/2018
• 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., Ladd, Derek A., Comeau, Brian, Goguen, Douglas S.
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US15/221,932
• Publication Number:
  US 20160332035A1
• Time in Patent Office: 628 Days
• Field of Search: 473376
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0005 Protrusions
• 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 37/0043 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 37/0066 Density; Specific gravity
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/0092 Hardness distribution amongst different ball layers
• CPC Class Codes: A63B 37/0097 Layers interlocking by means of protrusions or inserts, lattices or the like

Abstract

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core has a very high positive hardness gradient and comprises at least three layers, including at least one thermoset layer and at least one thermoplastic layer.

Claims

1. A golf ball comprising a core and cover, the core comprising:

a solid inner core layer formed from an unfoamed first thermoset composition and having a diameter of from 0.50 inches to 1.45 inches and a center Shore C hardness (H_center) of 50 or less;

an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.01 inches to 0.20 inches; and

an outer core layer formed from a second thermoset composition and having a thickness of 0.15 inches or greater and an outer surface Shore C hardness (H_{outer surface}) of 70 or greater; and

wherein H_{outer surface}−

H_center≥

60.

2. The golf ball of claim 1, wherein the inner core layer has a compression of <

20.

3. The golf ball of claim 2, wherein the core has an overall compression of ≥

45.

4. The golf ball of claim 1, wherein the inner core layer has a compression of <

10.

5. The golf ball of claim 1, wherein H_center≤

40.

6. A golf ball comprising a core and cover, the core comprising:

a solid inner core layer formed from an unfoamed first thermoset composition and having a diameter of from 0.50 inches to 1.45 inches and a center Shore C hardness (H_center);

an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.01 inches to 0.20 inches; and

an outer core layer formed from a second thermoset composition and having a thickness of 0.15 inches or greater and an outer surface Shore C hardness (H_{outer surface})of 70 or greater; and

wherein H_center≤

30, and wherein H_{outer surface}−

H_center≥

40.

7. The golf ball of claim 6, wherein H_{outer surface}≥

80.

8. The golf ball of claim 6, wherein the thermoset composition of the inner core layer consists essentially of:

polybutadiene;

from 0.1 phr to 2.0 phr of a peroxide;

optionally 5 phr or less of a metal oxide;

optionally 5 phr or less of a metal coagent;

optionally 5 phr or less of a metal carbonate; and

optionally one or more additional components selected from the group consisting of fillers, colorants, and antioxidants.

9. A golf ball comprising a core and cover, the core comprising:

a solid inner core layer formed from an unfoamed first thermoset composition and having a diameter of from 0.25 inches to 1.10 inches and a center Shore C hardness (H_center) of 50 or less;

an intermediate core layer formed from a thermoplastic composition and having a thickness of from 0.01 inches to 0.20 inches; and

an outer core layer formed from a second thermoset composition and having a thickness of 0.10 inches or greater and an outer surface Shore C hardness (H_{outer surface}) of 60 or greater; and

wherein H_{outer surface}−

H_center≥

60.

10. The golf ball of claim 9, wherein the inner core layer has a compression of <

20.

11. The golf ball of claim 10, wherein the core has an overall compression of ≥

45.

12. The golf ball of claim 9, wherein the thermoset composition of the inner core layer consists essentially of:

polybutadiene;

from 0.1 phr to 2.0 phr of a peroxide;

optionally 5 phr or less of a metal oxide;

optionally 5 phr or less of a metal coagent;

optionally 5 phr or less of a metal carbonate; and

optionally one or more additional components selected from the group consisting of fillers, colorants, and antioxidants.