Highly-neutralized acid polymers and their use in golf balls

• US 7,642,319 B2
• Filed: 04/28/2008
• Issued: 01/05/2010
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J.
• Primary Examiner(s): BUTTNER, DAVID J
• Application Number:
  US12/110,418
• Publication Number:
  US 20080207353A1
• Time in Patent Office: 617 Days
• Field of Search: None
• US Class Current: 525/190
• CPC Class Codes: A63B 37/0038 Intermediate layers, e.g. inner cover, outer core, mantle
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0049 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0061 Coefficient of restitution
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: C08K 5/053 Polyhydroxylic alcohols
• 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 33/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof

Abstract

The present invention is directed to a golf ball having at least one layer which includes a polymer composition containing at least 50 wt % of an acid polymer and at least 0.5 wt % of a polylactic acid, wherein the weight percentages are based on the total polymeric weight of the polymer composition. At least 70% of the acid groups of the acid polymer are neutralized by a cation source or a metal salt thereof.

Claims

1. A golf ball having at least one layer formed from a polymer composition, the polymer composition comprising:

at least 50 wt %, based on the total polymeric weight of the polymer composition, of an acid polymer having acid groups, wherein at least 70% of the acid groups are neutralized; and

at least 0.5 wt %, based on the total polymeric weight of the polymer composition, of a polylactic acid.

2. The golf ball of claim 1, wherein at least 90% of the acid groups of the acid polymer are neutralized.

3. The golf ball of claim 1, wherein at least 95% of the acid groups of the acid polymer are neutralized.

4. The golf ball of claim 1, wherein 100% of the acid groups of the acid polymer are neutralized.

5. The golf ball of claim 1, wherein the polymer composition is substantially free of fatty acids and their salts.

6. The golf ball of claim 1, wherein the polymer composition has a melt flow index of from 1.0 g/10 min to 5.0 g/10 min.

7. The golf ball of claim 1, wherein the polymer composition consists essentially of:

at least 50 wt %, based on the total polymeric weight of the polymer composition, of the acid polymer;

at least 0.5 wt %, based on the total polymeric weight of the polymer composition, of the polylactic acid; and

from 0 wt % to 60 wt %, based on the total weight of the polymer composition, of an inorganic additive.

8. The golf ball of claim 1, wherein the golf ball is a multi-layer golf ball, and wherein the polymer composition is present in an intermediate layer.

9. The golf ball of claim 8, wherein the intermediate layer is an inner cover layer having a thickness of from 0.010 in to 0.060 in and a material hardness of from 30 Shore D to 80 Shore D.

10. The golf ball of claim 1, wherein the golf ball comprises a center and a cover, and wherein the polymer composition is present in the center.

11. The golf ball of claim 1, wherein the polymer composition has a flexural modulus of from 5,000 psi to 125,000 psi.

12. The golf ball of claim 1, wherein the polymer composition has a notched izod impact strength of at least 2 ft·

lb/in.

13. A golf ball having at least one layer formed from a polymer composition, the polymer composition consisting essentially of:

at least 50 wt %, based on the total polymeric weight of the polymer composition, of an acid polymer having acid groups, wherein at least 70% of the acid groups are neutralized;

at least 0.5 wt %, based on the total polymeric weight of the polymer composition, of a polylactic acid; and

from 0 wt % to 60 wt %, based on the total weight of the polymer composition, of an inorganic additive;

wherein the polymer composition has a melt flow index of from 1.0 g/10 min to 5.0 g/10 min.

14. The golf ball of claim 13, wherein at least 90% of the acid groups of the acid polymer are neutralized.

15. The golf ball of claim 13, wherein at least 95% of the acid groups of the acid polymer are neutralized.

16. The golf ball of claim 13, wherein 100% of the acid groups of the acid polymer are neutralized.

17. The golf ball of claim 13, wherein the polymer composition has a flexural modulus of from 5,000 psi to 125,000 psi and a notched izod impact strength of at least 2 ft·

lb/in.