Golf balls comprising highly-neutralized acid polymers

• US 6,756,436 B2
• Filed: 04/09/2002
• Issued: 06/29/2004
• Est. Priority Date: 06/26/2001
• Status: Expired due to Term

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Dalton, Jeffrey L., Sullivan, Michael J., Cavallaro, Christopher, Boehm, Herbert C., Rajagopalan, Murali, Harris, Kevin M.
• Primary Examiner(s): Buttner, David J.
• Application Number:
  US10/118,719
• Publication Number:
  US 20030013549A1
• Time in Patent Office: 812 Days
• Field of Search: 524/322, 524/394, 524/399, 473/354, 473/372, 473/373, 473/374, 473/377
• US Class Current: 524/322
• CPC Class Codes: A63B 37/0004 Surface depressions or protrusions
• CPC Class Codes: A63B 37/0024 Materials other than ionomers or polyurethane
• CPC Class Codes: A63B 37/0026 Balata
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0043 Hardness
• 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 37/0056 Hollow; Gas-filled
• CPC Class Codes: A63B 37/0061 Coefficient of restitution
• CPC Class Codes: A63B 37/0062 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 37/0091 Density distribution amongst the different ball layers
• CPC Class Codes: A63B 37/00922 whereby hardness of the cover is lower than hardness of the intermediate layers
• CPC Class Codes: A63B 37/0097 Layers interlocking by means of protrusions or inserts, lattices or the like
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005
• CPC Class Codes: C08L 2205/02 : containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/08 : Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0876 : Neutralised polymers, i.e. ionomers
• CPC Class Codes: C08L 2666/04 : Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof

Abstract

A golf ball comprising a core comprised of a polymer containing an acid group neutralized by an organic acid or a salt thereof, the organic acid or salt thereof being present in an amount sufficient to neutralize the polymer by at least about 80%, wherein the core has a first Shore D hardness, a compression of no greater than about 80, and a diameter of no less than about 1.53 inches; and a cover comprised of a material having a second Shore D hardness at least 10 points less than the first hardness.

Claims

1. A golf ball comprising:

a single-layer core comprised of a polymer containing an acid group, a base, and an organic acid or a salt thereof, the base and the organic acid or salt thereof being present in sufficient amounts so that the polymer is neutralized by at least about 80%, wherein the core has a first Shore D hardness, a compression of no greater than about 80, and a diameter of no less than about 1.53 inches; and

a cover comprised of a material having a second Shore D hardness at least 10 points less than the first hardness.

2. The golf ball of claim 1, wherein the polymer comprises ionomeric copolymers and terpolymers, ionomer precursors, or mixtures thereof.

3. The golf ball of claim 1, wherein the organic acid is selected from the group consisting of aliphatic organic acids, aromatic organic acids, saturated mono-functional organic acids, unsaturated mono-functional organic acids, and multi-unsaturated mono-functional organic acids.

4. The golf ball of claim 1, wherein the salt of the organic acid comprises barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium, salts of fatty acids comprising stearic, bebenic, erucic, oleic, linoelic, or dimerized derivatives thereof.

5. The golf ball of claim 1, wherein the core further comprises a second polymer component in an amount sufficient to reduce the core compression to less than or equal to about 70.

6. The golf ball of claim 5, wherein the second polymer component has a Shore D hardness of about 40 or greater.

7. The golf ball of claim 5, wherein the second polymer component comprises ionomeric copolymers and terpolymers, ionomer precursors, thermoplastics, thermoplastic elastomers, polybutadiene rubber, balata, grafted metallocene-catalyzed polymers, non-grafted metallocene-catalyzed polymers, single-site polymers, high-crystalline acid polymers, cationic ionomers, or mixtures thereof.

8. The golf ball of claim 1, wherein the base and the organic acid or salt thereof are present in sufficient amounts such that the acid group of the polymer is neutralized by at least about 90%.

9. The golf ball of claim 1, wherein the base and the organic acid or salt thereof are present in sufficient amounts such that the acid group of the polymer is neutralized by at least about 100%.

10. The golf ball of claim 5, wherein at least one of the polymer or the second polymer component is partially neutralized by a metal cation.

11. The golf ball of claim 1, wherein the core has a diameter of about 1.58 inches or greater.

12. The golf ball of claim 1, wherein the cover is comprised of a castable reactive liquid material.

13. The golf ball of claim 1, wherein the cover is cast or reaction injection molded over the core.

14. The golf ball of claim 1, wherein the cover comprises polyurethane, polyurea, ionomer, metallocene-catalyzed polymer, copolyetheresters, copolyesteresters, polyamide, copolyetheramide, or copolyesteramide.

31. The golf ball of claim 1, wherein the single-layer core further comprises a thermoset rubber.

32. The golf ball of claim 31, wherein the rubber has a resilience index of at least about 40.

33. The golf bail of claim 1, wherein the organic acid or the salt thereof is relatively non-migratory and non-volatile.

34. The golf ball of claim 1, wherein the cover comprises a castable thermoplastic or thermosetting material.

15. A golf ball comprising:

a core comprising a center and an outer layer, the center being comprised of a polymer containing an acid group, a base, and an organic acid or a salt thereof, the base and the organic acid or salt thereof being present in sufficient amounts such that the polymer is fully neutralized, wherein the outer layer has a first Shore D hardness and the core has a compression of less than or equal to about 90 and a diameter of about 1.53 inches or greater; and

a cover being comprised of a castable thermoplastic or thermosetting material having a second Shore D hardness being at least 5 points less than the first hardness.

16. The golf ball of claim 15, wherein the outer layer further comprises a softening copolymer in sufficient weight percentage to reduce the core compression to less than or equal to about 70.

17. The golf ball of claim 15, wherein the core has a diameter of about 1.58 inches or greater.

18. The golf ball of claim 15, wherein at least one of the center and the outer layer comprises a thermoset rubber.

19. The golf bail of claim 15, wherein the cover is cast or reaction injection molded over the core.

20. The golf ball of claim 15, wherein the cover is comprised of a cast polyurethane.

21. The golf ball of claim 15, further comprising an intermediate layer being disposed between the center and the cover and comprised of an ionomer having a Shore D hardness that is at least 10 units greater than the first Shore D hardness.

22. The golf ball of claim 15, wherein the core is surface treated by plasma treatment, corona discharge, chemical treatment or mechanically treated.

23. A golf ball comprising:

a core comprised of a thermoset rubber, a first polymer containing an acid group, a first base, and a first organic acid or salt thereof being present in an amount greater than about 10 weight percent of the first polymer, the core having a diameter of about 0.5 to 1.55 inches;

an intermediate layer disposed about the core, being comprised of a second polymer, a second base, and a second organic acid or salt thereof, the second base and the second organic acid or salt thereof being present in sufficient amounts so that the second polymer is neutralized by at least about 100%; and

a cover disposed about the intermediate layer, the cover having a Shore D hardness of about 55 or less.

24. The golf ball of claim 23, wherein the cover is comprised of a polyurethane or a polyurea.

25. The golf ball of claim 24, wherein the intermediate layer has a Shore D hardness of at least about 62.

26. The golf ball of claim 24, wherein the cover has a thickness f about 0.04 inches or less.

27. The golf ball of claim 24, wherein the core has a compression of about 90 or less and a diameter of at least 1.4 inches.

28. The golf ball of claim 23, wherein the core is further comprised of a thermoplastic structure having a center and projections, the structure comprising the first polymer, the first base, and the first organic acid or salt thereof;

and the thermoset rubber is molded around the projections to form a sphere.

29. The golf ball of claim 28, wherein the first polymer is neutralized by more than about 80%.

30. The golf ball of claim 29, wherein the first polymer is neutralized by more than about 100%.