Golf balls having foam inner core and thermoset outer core layer

• US 9,302,156 B2
• Filed: 04/29/2013
• Issued: 04/05/2016
• Est. Priority Date: 04/29/2013
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Ladd, Derek A., Binnette, Mark L., Comeau, Brian, Michalewich, Michael, Ricci, Shawn
• Primary Examiner(s): Gorden, Raeann
• Application Number:
  US13/872,354
• Publication Number:
  US 20140323244A1
• Time in Patent Office: 1,072 Days
• Field of Search: 473/377
• US Class Current: 1/1
• CPC Class Codes: A63B 2037/065 Foam
• CPC Class Codes: A63B 37/0038 Intermediate layers, e.g. inner cover, outer core, mantle
• 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 37/0058 Polyurethane
• CPC Class Codes: A63B 37/006 Physical properties
• 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 37/0075 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 37/0091 Density distribution amongst the different ball layers
• CPC Class Codes: A63B 37/06 Elastic cores
• CPC Class Codes: A63B 45/00 Apparatus or methods for manufacturing balls working of plastics or substances in a plastic state B29

Abstract

Multi-piece golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a foam composition, preferably foamed polyurethane. The outer core layer is preferably formed from a non-foamed thermoset composition such as polybutadiene rubber. Preferably, the specific gravity (density) of the foam inner core is less than the density of the outer core layer. The ball further includes a cover of at least one layer and may include at least one casing layer. The core structure and resulting ball have relatively good resiliency.

Claims

1. A core assembly for a golf ball, comprising:

i) an inner core layer comprising a foamed composition, the inner core layer having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SG_inner), and an outer surface hardness (H_{inner core surface}) and a center hardness (H_{inner core center}), wherein the H_{inner core center} is in the range of about 30 Shore C to about 78 Shore C and the H_{inner core surface} is in the range of about 46 Shore C to about 95 Shore C, the H_{inner core surface} being greater than the H_{inner core center} to provide a positive hardness gradient; and

ii) an outer core layer comprising a thermoset material, the outer core layer being disposed about the inner core layer and having a thickness in the range of about 0.100 to about 0.750 inches, a specific gravity (SG_outer), and an outer surface hardness (H_{outer surface of OC}) and an inner surface hardness (H_{inner surface of OC}), the H_{outer surface of OC} being greater than the H_{inner surface of OC} to provide a positive hardness gradient, wherein the SG_outer, is greater than the SG_inner.

2. The core assembly of claim 1, wherein the inner core comprises a foamed polyurethane composition.

3. The core assembly of claim 2, wherein the foamed polyurethane composition is prepared from a mixture comprising polyisocyanate, polyol, and curing agent compounds, and blowing agent, the polyisocyanate being selected from the group consisting of toluene 2,4-dilsocyanate (TDI), toluene 2,6-diisocyanate (TDI), 4,4′

-methylene diphenyl dilsocyanate (MDI), 2,4′

-methylene diphenyl diisocyanate (MDI), polymeric methylene diphenyl diisocyanate (PMDI), p-phenylene diisocyanate (PPDI), m-phenylene diisocyanate (PDI), naphthalene 1,5-diisocynate (NDI), naphthalene 2,4-diisocyanate (NDI), p-xylene diisocyanate (XDI), and homopolymers and copolymers and blends thereof.

4. The core assembly of claim 2, wherein the foamed polyurethane composition is prepared from a mixture comprising polyisocyanate, polyol, and curing agent compounds, and blowing agent, the polyisocyanate being selected from the group consisting of isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), 4,4′

-dicyclohexylmethane diisocyanate (“

H₁₂ MDI”

), meta-tetramethylxylyene diisocyanate (TMXDI), trans-cyclohexane diisocyanate (CHDI), and homopolymers and copolymers and blends thereof.

5. The core assembly of claim 2, wherein the foamed polyurethane composition is prepared from a mixture comprising polyisocyanate, polyol, and curing agent compounds, and blowing agent, the polyol being selected from the group consisting of polyisocyanate polytetramethylene ether glycol (PTMEG), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof.

6. The core assembly of claim 2, wherein the foamed polyurethane composition is prepared by adding water to a mixture of polyisocyanate, polyol, and curing agent compounds, and catalyst, the water being added in a sufficient amount to cause the mixture to foam.

7. The core assembly of claim 6, wherein the catalyst is selected from the group consisting of zinc and tin-based catalysts and mixtures thereof.

8. The core assembly of claim 1, wherein the inner core has a diameter in the range of about 0.100 to about 0.500 inches and specific gravity in the range of about 0.25 to about 1.25 g/cc.

9. The core assembly of claim 1, wherein the inner core has a diameter in the range of about 0.40 to about 0.80 inches and specific gravity in the range of about 0.30 to about 0.95 g/cc.

10. The core assembly of claim 1, wherein the outer core layer comprises at least one thermoset rubber material selected from the group consisting of polybutadiene, ethylene-propylene rubber, ethylene-propylene-diene rubber, polyisoprene, styrene-butadiene rubber, polyalkenamers, butyl rubber, halobutyl rubber, polystyrene elastomers, copolymers of isobutylene and p-alkylstyrene, halogenated copolymers of isobutylene and p-alkylstyrene, copolymers of butadiene with acrylonitrile, polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber, and mixtures thereof.

11. The core assembly of claim 10, wherein the rubber material is polybutadiene.

12. The core assembly of claim 1, wherein the outer core layer has a thickness in the range of about 0.250 to about 0.750 inches and specific gravity in the range of about 0.60 to about 2.90 g/cc.