Golf balls having metal-containing plasticized thermoplastic inner cores and thermoplastic outer cores

• US 10,150,010 B2
• Filed: 12/22/2016
• Issued: 12/11/2018
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Binette, Mark L.
• Primary Examiner(s): HUNTER, ALVIN A
• Application Number:
  US15/387,922
• Publication Number:
  US 20170189764A1
• Time in Patent Office: 719 Days
• Field of Search: 473351-378
• CPC Class Codes: A63B 37/0024 Materials other than ionomers or polyurethane
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0044 Hardness gradient
• 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 37/0054 Substantially rigid, e.g. metal
• 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 37/0066 Density; Specific gravity
• CPC Class Codes: A63B 37/0074 Two piece balls, i.e. cover and core
• 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 37/0091 Density distribution amongst the different ball layers
• CPC Class Codes: A63B 37/0092 Hardness distribution amongst different ball layers
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: C08K 5/098 : Metal salts of carboxylic acids
• CPC Class Codes: C08K 5/101 : of monocarboxylic acids
• CPC Class Codes: C08L 23/0876 : Neutralised polymers, i.e. ionomers

Abstract

Multi-piece golf balls containing a dual-layered core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, and a surrounding outer core layer. The layers of the core structure may have different hardness gradients. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof preferably dispersed in a plasticized thermoplastic polymeric matrix. Different plasticizer such as fatty acid esters may be used. The outer core layer also is preferably formed from a thermoplastic composition such as an ethylene acid copolymer ionomer resin. The resulting ball has high resiliency and good spin.

Claims

1. A golf ball, comprising:

i) an inner core layer comprising a first thermoplastic composition, the inner core having an outer surface hardness (H_{inner core surface}) and a center hardness (H_{inner core center}), the H_{inner core surface} being greater than the H_{inner core center} to provide a positive hardness gradient, the first thermoplastic composition comprising;

a) an acid copolymer of ethylene and an α

,β

-unsaturated carboxylic acid, optionally including a softening monomer selected from the group consisting of alkyl acrylates and methacrylates;

b) a plasticizer;

c) a cation source present in an amount sufficient to neutralize from about 0 to about 100% of all acid groups present in the composition; and

d) a metal material wherein the thermoplastic composition comprises about 1 to about 60% by weight metal material; and

ii) an outer core layer comprising a second thermoplastic composition, the outer core layer being disposed about the inner core layer and having an outer surface hardness (H_{outer surface of OC}) and a midpoint hardness (H_{midpoint of OC}), the H_{outer surface of OC} being greater than the H_{midpoint of OC} to provide a positive hardness gradient,

wherein the center hardness of the inner core (H_{inner core center}) is in the range of about 10 Shore C to about 70 Shore C and the outer surface hardness of the outer core layer (H_{outer surface of OC}) is in the range of about 20 Shore C to about 95 Shore C to provide a positive hardness gradient across the core assembly; and

iii) a cover having at least one layer disposed about the outer core layer.

2. The golf ball of claim 1, wherein the inner core layer has a specific gravity in the range of about 1.60 to about 6.25 and the outer core layer has a specific gravity in the range of about 0.60 to about 4.10 g/cc.

3. The golf ball of claim 2, wherein the inner core has a diameter in the range of about 0.100 to about 1.100 inches and a specific gravity (SG_inner), and the outer core layer has a thickness in the range of about 0.200 to about 1.200 inches, and a specific gravity (SG_outer), wherein the is greater than the SG_outer.

4. The golf ball of claim 1, wherein the metal material of the inner core is a metal selected from the group consisting of copper, steel, brass, tungsten, titanium, aluminum, magnesium, molybdenum, cobalt, nickel, iron tin, bronze, silver, gold, and platinum, and alloys and combinations thereof.

5. The claim 1, wherein the first and second thermoplastic compositions comprise a thermoplastic material selected from the group consisting of ethylene acid copolymer ionomers;

polyesters;

polyamides;

polyamide-ethers, polyamide-esters;

polyurethanes, polyureas;

fluoropolymers;

polystyrenes;

polypropylenes and polyethylenes;

polyvinyl chlorides;

polyvinyl acetates;

polycarbonates;

polyvinyl alcohols;

polyethers;

polyimides, polyetherketones, polyamideimides; and

mixtures thereof.

6. The golf ball of claim 1, wherein the first thermoplastic composition comprises about 3 to about 50% by weight plasticizer.

7. The golf ball of claim 6, wherein the plasticizer is a fatty acid ester.

8. The golf ball of claim 7, wherein the plasticizer is an alkyl oleate.

9. The golf ball of claim 8, wherein the plasticizer is ethyl oleate.

10. The golf ball of claim 1, wherein the acid copolymer of ethylene and an α

,β

-unsaturated carboxylic add contains add groups such that 70% or less of the add groups are neutralized.

11. The golf ball of claim 1, wherein the add copolymer of ethylene, and an α

,β

-unsaturated carboxylic add contains add groups such that greater than 70% of the add groups are neutralized.

12. The golf ball of claim 11, wherein 90% or greater of the acid groups are neutralized.

13. The Rolf ball of claim 1, wherein the cation source is a metal cation salt.

14. The golf ball of claim 1, wherein the ethylene add copolymer is selected from the group consisting of ethylene/(meth)acrylic acid/ft-butyl acrylate;

ethylene/(meth)acrylic acid/ethyl-acrylate;

ethylene/(meth)acrylic acid/methyl acrylate;

ethylene/(meth)acrylic acid/n-butyl acrylate; and

ethylene/(meth)acrylic acid/isobutyl acrylate copolymers.

15. The Rolf ball of claim 1, wherein the H_{inner core center} is in the range of about 10 Shore C to about 70 Shore C and the H_{inner core surface} is in the range of about 15 Shore C to about 90 Shore C.

16. The golf ball of claim 1, wherein the H_{midpoint of OC} is in the range of about 20 Shore C to about 8 Shore C and the H_{outer surface of OC} is in the range of about 25 Shore C to about 95 Shore C.

17. The golf ball of claim 1, wherein the center hardness of the inner core (H_{inner core center}) is in the range of about 30 Shore C to about 65 Shore C and the outer surface hardness of the outer core layer (H_{outer surface of OC}) is m the range of about 35 Shore C t about 85 Shore C provide a positive hardness gradient across the core assembly.