Golf balls having at least two core layers formed from HNP compositions

• US 8,740,726 B2
• Filed: 12/03/2012
• Issued: 06/03/2014
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Ladd, Derek A., Hebert, Edmund A., Jones, Douglas E.
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US13/692,583
• Publication Number:
  US 20130095956A1
• Time in Patent Office: 547 Days
• Field of Search: 473/376
• US Class Current: 473/376
• CPC Class Codes: A63B 2209/00 Characteristics of used materials
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0049 Flexural modulus; Bending stiffness
• 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 37/0072 with a specified number of layers
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/008 Diameter
• CPC Class Codes: A63B 37/0092 Hardness distribution amongst different ball layers
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005
• CPC Class Codes: C08L 23/0876 Neutralised polymers, i.e. ionomers

Abstract

The present invention is directed to golf balls consisting of a multi-layer core and a cover. The multi-layer core consists of a center and an outer core layer that are both soft relative to a hard rubber intermediate core layer. The outer core layer is preferably thin relative to the center and the outer core layer. The multi-layer core includes at least one layer formed from a relatively soft HNP composition and at least one layer formed from a relatively hard HNP composition.

Claims

1. A golf ball comprising a core and a cover, wherein the core has an overall diameter of from 1.40 inches to 1.60 inches and consists of:

(a) a center having a diameter of from 0.50 inches to 1.50 inches, a surface hardness of 65 Shore C or greater, a center hardness (H), and formed from a highly neutralized polymer composition, the highly neutralized polymer composition having a material hardness of 55 Shore D or less and comprising a highly neutralized ethylene/(meth)acrylic acid/alkyl (meth)acrylate copolymer wherein at least 80% of the acid groups of the acid copolymer are neutralized;

(b) an intermediate core layer having a surface hardness (I) of 40 Shore C or greater; and

(c) an outer core layer having a surface hardness (S) of from 20 Shore C to 70 Shore C and formed from a partially neutralized polymer composition, the partially neutralized polymer composition having a material hardness of 45 Shore D or greater and comprising a partially neutralized ethylene/(meth)acrylic acid copolymer wherein 40% to 100% of the acid groups of the acid copolymer are neutralized;

wherein H<

I and S<

I and H<

S, and wherein S−

H=D, where D is an integer from 1 to 22, and

wherein the material hardness of the highly neutralized composition used to form the center is less than the material hardness of the partially neutralized composition used to form the outer core layer.

2. The golf ball of claim 1, wherein the center has a diameter of from 0.750 inches to 1.500 inches and the center hardness (H) is from 50 Shore C to 60 Shore C;

the intermediate core layer surface hardness (I) is from 80 Shore C to 90 Shore C; and

the outer core layer has a thickness of from 0.010 inches to 0.150 inches and the outer core layer surface hardness (S) is from 50 Shore C to 60 Shore C.

3. The golf ball of claim 1, wherein the outer core layer has a thickness of from 0.030 inches to 0.070 inches.

4. The golf ball of claim 1, wherein the intermediate core layer is formed from a rubber composition.

5. The golf ball of claim 1, wherein the intermediate core layer is formed from a thermoplastic composition.

6. A golf ball comprising a core and a cover, wherein the core has an overall diameter of from 1.40 inches to 1.60 inches and consists of:

(a) a center having a diameter of from 0.50 inches to 1.50 inches, a surface hardness of 65 Shore C or greater, a center hardness (H), and formed from a partially neutralized polymer composition, the partially neutralized polymer composition having a material hardness of 55 Shore D or less and comprising a partially neutralized ethylene/(meth)acrylic acid/alkyl (meth)acrylate copolymer wherein 40% to 100% of the acid groups of the acid copolymer are neutralized;

(b) an intermediate core layer having a surface hardness (I) of 40 Shore C or greater; and

(c) an outer core layer having a surface hardness (S) of from 20 Shore C to 70 Shore C and formed from a highly neutralized polymer composition, the highly neutralized polymer composition having a material hardness of 45 Shore D or greater and comprising a highly neutralized ethylene/(meth)acrylic acid copolymer wherein at least 80% of the acid groups of the acid copolymer are neutralized;

wherein H<

I and S<

I and H<

S, and wherein S−

H=D, where D is an integer from 1 to 22, and

wherein the material hardness of the partially neutralized composition used to form the center is less than the material hardness of the highly neutralized composition used to form the outer core layer.

7. The golf ball of claim 6, wherein the center has a diameter of from 0.750 inches to 1.500 inches and the center hardness (H) is from 50 Shore C to 60 Shore C;

the intermediate core layer surface hardness (I) is from 80 Shore C to 90 Shore C; and

the outer core layer has a thickness of from 0.010 inches to 0.150 inches and the outer core layer surface hardness (S) is from 50 Shore C to 60 Shore C.

8. The golf ball of claim 6, wherein the outer core layer has a thickness of from 0.030 inches to 0.070 inches.

9. The golf ball of claim 6, wherein the intermediate core layer is formed from a rubber composition.

10. The golf ball of claim 6, wherein the intermediate core layer is formed from a thermoplastic composition.