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

• US 8,221,265 B2
• Filed: 09/04/2009
• 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:
  US12/554,010
• Publication Number:
  US 20090325732A1
• Time in Patent Office: 1,047 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 having an Atti compression of 30 or less and formed from a first rubber composition and having a first surface hardness; an outer core layer including a second rubber composition; a thermoplastic layer having a second surface hardness, an inner surface hardness, and comprising a copolymer of ethylene and an α,β-unsaturated carboxylic acid, and sufficient amount of an organic acid or a salt of the organic acid and a cation source to neutralize the acid groups of the copolymer by about 80% or greater; an inner cover layer having a hardness of about 40 Shore D to 70 Shore D; and an outer cover layer. The first surface hardness is less than the second surface hardness by at least 5 Shore C.

Claims

1. A golf ball comprising:

an inner core layer having an Atti compression of 30 or less, comprising a first rubber composition, and having a first surface hardness;

an outer core layer comprising a second rubber composition;

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

,β

-unsaturated carboxylic acid, and sufficient amount of an organic acid or a salt of the organic acid and a cation source to neutralize the acid groups of the copolymer by about 80% or greater;

an inner cover layer having a hardness of about 40 Shore D to about 70 Shore D; and

an outer cover layer;

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

2. The golf ball of claim 1, wherein a combination of the inner core and outer core form a solid core having a diameter of 0.80 inches to 1.40 inches, and the outer cover layer comprises castable thermoset polyurethane or polyurea having a hardness of about 45 Shore D to 60 Shore D and a thickness of 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 outer core layer, and the thermoplastic intermediate layer has an Atti compression of about 60 or greater.

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

5. The golf ball of claim 4, wherein the first surface hardness is less than the second surface hardness by at least 10 Shore C.

6. The golf ball of claim 1, wherein the organic acid or salt of the organic acid and cation source neutralize the acid groups of the copolymer by about 90% or greater.

7. The golf ball of claim 6, wherein the organic acid or salt of the organic acid and cation source neutralize the acid groups of the copolymer by about 100%.