MULTI-LAYER CORE GOLF BALL

• US 20140113748A1
• Filed: 12/31/2013
• Published: 04/24/2014
• Est. Priority Date: 01/10/2008
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Bulpett, David A., Binette, Mark L., Comeau, Brian, Blink, Robert P.
• Granted Patent: US 9,573,022 B2
• Time in Patent Office: Days
• US Class Current: 473/373
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0031 Hardness
• 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 37/0045 Thickness
• CPC Class Codes: A63B 37/0046 Deflection or compression
• CPC Class Codes: A63B 37/0059 Ionomer
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0068 Initial velocity
• 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 37/0087 Deflection or compression
• CPC Class Codes: A63B 37/0096 Spin rate
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005

Abstract

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a layer formed from a highly neutralized polymer composition and a layer formed from a thermoset rubber.

Claims

1. A golf ball comprising:

an inner core layer having a diameter of from 0.500 inches to 1.580 inches and formed from a highly neutralized polymer composition, wherein the highly neutralized polymer composition comprises;

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;

a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof;

an organic acid or salt thereof; and

a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition;

an outer core layer formed from a thermoset rubber composition and having a thickness of from 0.010 inches to 0.300 inches and a surface hardness of 50 Shore C or greater; and

a cover.

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

,β

-unsaturated carboxylic acid does not include a softening monomer, and wherein the acid is selected from acrylic acid and methacrylic acid and is present in the acid copolymer in an amount of from 15 mol % to 30 mol %, based on the total weight of the acid copolymer.

3. The golf ball of claim 2, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of greater than 50 wt %, based on the combined weight of the acid copolymer and the non-acid polymer.

4. The golf ball of claim 3, wherein the non-acid polymer is ethylene-n-butyl acrylate, wherein the n-butyl-acrylate is present in an amount of 20 wt % or greater, based on the total weight of the highly neutralized polymer composition.

5. The golf ball of claim 4, wherein the highly neutralized polymer composition has a solid sphere compression of 40 or less and a coefficient of restitution of 0.820 or greater.

6. The golf ball of claim 2, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of less than 50 wt %, based on the combined weight of the acid copolymer and the non-acid polymer.

7. The golf ball of claim 6, wherein the non-acid polymer is ethylene-n-butyl acrylate, wherein the n-butyl-acrylate is present in an amount of 20 wt % or greater, based on the total weight of the highly neutralized polymer composition.

8. The golf ball of claim 7, wherein the highly neutralized polymer composition has a solid sphere compression of 100 or greater and a coefficient of restitution of 0.860 or greater.

9. The golf ball of claim 1, wherein the organic acid salt is magnesium oleate, and wherein the magnesium oleate is present in an amount of 30 parts or greater, per 100 parts of acid copolymer and non-acid copolymer combined.

10. The golf ball of claim 9, wherein the cation source is present in an amount sufficient to neutralize 110% or greater of all acid groups present in the composition.

11. The golf ball of claim 1, wherein the thickness of the outer core layer is from 0.010 inches to 0.150 inches.

12. The golf ball of claim 1, wherein the thickness of the outer core layer is from 0.070 inches to 0.150 inches.

13. A golf ball comprising:

an inner core layer having a diameter of from 0.500 inches to 1.580 inches and formed from a first thermoset rubber composition;

at least one outer core layer having a thickness of from 0.005 inches to 0.300 inches and a surface hardness of from 50 Shore C to 90 Shore C and formed from a highly neutralized polymer composition, wherein the highly neutralized polymer composition comprises;

a 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;

a non-acid polymer selected from the group consisting of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof;

an organic acid or salt thereof; and

a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition; and

a cover.

14. The golf ball of claim 13, wherein the acid copolymer of ethylene and an α

,β

-unsaturated carboxylic acid does not include a softening monomer, and wherein the acid is selected from acrylic acid and methacrylic acid and is present in the acid copolymer in an amount of from 15 mol % to 30 mol %.

15. The golf ball of claim 14, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of greater than 50 wt %, based on the combined weight of the acid copolymer and the non-acid polymer.

16. The golf ball of claim 15, wherein the non-acid polymer is ethylene-n-butyl acrylate, wherein the n-butyl-acrylate is present in an amount of 20 wt % or greater, based on the total weight of the highly neutralized polymer composition.

17. The golf ball of claim 16, wherein the highly neutralized polymer composition has a solid sphere compression of 40 or less and a coefficient of restitution of 0.820 or greater.

18. The golf ball of claim 14, wherein the non-acid polymer is an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates and is present in an amount of less than 50 wt %, based on the combined weight of the acid copolymer and the non-acid polymer.

19. The golf ball of claim 18, wherein the non-acid polymer is ethylene-n-butyl acrylate, wherein the n-butyl-acrylate is present in an amount of 20 wt % or greater, based on the total weight of the highly neutralized polymer composition.

20. The golf ball of claim 19, wherein the highly neutralized polymer composition has a solid sphere compression of 100 or greater and a coefficient of restitution of 0.860 or greater.

21. The golf ball of claim 13, wherein the organic acid salt is magnesium oleate, and wherein the magnesium oleate is present in an amount of 30 parts or greater, per 100 parts of acid copolymer and non-acid copolymer combined.

22. The golf ball of claim 21, wherein the cation source is present in an amount sufficient to neutralize 110% or greater of all acid groups present in the composition.

23. The golf ball of claim 13, wherein the thickness of the outer core layer is from 0.010 inches to 0.150 inches.

24. The golf ball of claim 13, wherein the thickness of the outer core layer is from 0.070 inches to 0.150 inches.

25. The golf ball of claim 13, wherein the golf ball additionally comprises at least one outer core layer formed from a second thermoset rubber composition and having a thickness of from 0.010 inches to 0.100 inches and a surface hardness of 50 Shore C or greater.