Multi-layer-core golf ball having highly neutralized polymer outer core layer

• US 8,221,267 B2
• Filed: 09/21/2011
• Issued: 07/17/2012
• Est. Priority Date: 06/26/2001
• Status: Expired due to Fees

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Rajagopalan, Murali, Sullivan, Michael J.
• Primary Examiner(s): SELLERS, ROBERT E
• Application Number:
  US13/238,747
• Publication Number:
  US 20120010023A1
• Time in Patent Office: 300 Days
• Field of Search: None
• US Class Current: 473/373
• CPC Class Codes: A63B 37/0004 Surface depressions or protrusions
• CPC Class Codes: A63B 37/0027 Polyurea
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0034 Deflection or compression
• CPC Class Codes: A63B 37/0037 Flexural modulus; Bending stiffness
• 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 37/0049 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0051 Materials other than polybutadienes; Constructional details
• CPC Class Codes: A63B 37/0056 Hollow; Gas-filled
• CPC Class Codes: A63B 37/0061 Coefficient of restitution
• CPC Class Codes: A63B 37/00622 Surface hardness
• 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 37/0067 Weight; Mass
• CPC Class Codes: A63B 37/0069 Flexural modulus; Bending stiffness
• 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 37/0078 : Coefficient of restitution
• CPC Class Codes: A63B 37/008 : Diameter
• CPC Class Codes: A63B 37/0083 : Weight; Mass
• CPC Class Codes: A63B 37/0087 : Deflection or compression
• CPC Class Codes: A63B 37/0091 : Density distribution amongst the different ball 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
• CPC Class Codes: A63B 37/02 : Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005
• CPC Class Codes: C08L 2205/02 : containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/08 : Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0869 : Acids or derivatives thereof
• CPC Class Codes: C08L 23/0876 : Neutralised polymers, i.e. ionomers
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 : Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof

Abstract

A golf ball including an inner core layer formed from a thermoset rubber composition and having a first surface hardness; a thermoplastic outer core layer having a second surface hardness, an inner surface hardness, and being formed from a copolymer of ethylene and an α,β-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer; an inner cover layer; and an outer cover layer; wherein the first surface hardness is less than the second surface hardness by at least 5 Shore C and less than the inner surface hardness by at least 5 Shore C.

Claims

1. A golf ball comprising:

an inner core layer comprising a first rubber composition and having a first surface hardness;

an intermediate core layer comprising a second rubber composition;

a thermoplastic outer core layer having a second surface hardness, an inner surface hardness, and comprising a copolymer of ethylene and an α

,β

-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer;

an inner cover layer; and

an outer cover layer;

wherein the first surface hardness is less than the second surface hardness by at least 5 Shore C and less than the inner surface hardness by at least 5 Shore C.

2. The golf ball of claim 1, wherein the inner core has a diameter of 0.80 inches to 1.40 inches and a compression of 30 or less, and the outer core layer has flexural modulus of 50,000 psi to 70,000 psi and a thickness of 0.040 inches or greater, and the outer cover layer comprises castable thermoset polyurethane or polyurea having a hardness of from 45 Shore D to 60 Shore D and a thickness from 0.020 inches to 0.040 inches.

3. The golf ball of claim 1, wherein a core resulting from a combination of the inner core layer, the intermediate core layer, and the thermoplastic outer core layer has a compression of 60 or greater.

4. The golf ball of claim 3, wherein the core has a diameter of 1.500 inches or less.

5. The golf ball of claim 4, wherein the outer core layer has a thickness of 0.090 inches or greater.

6. The golf ball of claim 1, wherein the inner core has a first elastic modulus and the outer core layer has a second elastic modulus less than the first.

7. The golf ball of claim 1, wherein the inner core has a first specific gravity and the outer core layer has a second specific gravity less than the first.

8. The golf ball of claim 1, wherein the inner core has a first Bashore resilience and the outer core layer has a second Bashore resilience less than the first.

9. The golf ball of claim 1, wherein the first surface hardness is less than the second surface hardness by at least 7 Shore C and less than the inner surface hardness by at least 7 Shore C.