Multi-layer core golf ball

• US 9,579,546 B2
• Filed: 08/05/2013
• Issued: 02/28/2017
• Est. Priority Date: 08/05/2013
• 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:
  US13/958,854
• Publication Number:
  US 20150038264A1
• Time in Patent Office: 1,303 Days
• Field of Search: 473/376
• US Class Current: 1/1
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• 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 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• 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 37/0092 Hardness distribution amongst different ball layers

Abstract

Golf balls having a very high positive gradient multilayer core are provided. The multilayer core includes an outer core layer and a very soft, low compression inner core layer. The inner core layer is formed from an unfoamed composition and has a center hardness that is at least 40 Shore C points less than the outer surface hardness of the outer core layer.

Claims

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

a solid inner core layer formed from an unfoamed composition and having a diameter of 1.10 inch or less and a center Shore C hardness (H_center) of 15 or less,

one or more optional intermediate core layers, and

an outer core layer having a thickness of 0.200 inches or greater and an outer surface Shore C hardness (H_{outer surface}) of 80 or greater,

wherein H_{outer surface}>

H_center, and H_{outer surface}−

H_center≧

70.

2. The golf ball of claim 1, wherein the core has an overall compression of ≧

70.

3. The golf ball of claim 1, wherein the inner core layer composition is a thermoset composition consisting essentially of:

a base rubber;

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.

4. The golf ball of claim 1, wherein the inner core layer composition is a thermoplastic.