Golf ball including a blend of highly neutralized acid polymers and method of manufacture

Patent metadata

Field	Value
Publication number	US-9597548-B2
Application number	US-201514796815-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Jul 29, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A golf ball having an inner core layer, an outer core layer enclosing the inner core layer, and a cover layer enclosing the outer core layer. The inner core layer includes a blend of a first highly neutralized acid polymer having a first Vicat softening temperature and a first specific gravity, a second highly neutralized acid polymer having a second Vicat softening temperature and a second specific gravity, and an ionomer-based masterbatch comprising an additive and an ionomer resin having a third Vicat softening temperature and a third specific gravity. The absolute values of the differences among the Vicat softening temperatures is no more than about 15° C. and the absolute value of the difference between the specific gravities is no more than about 0.015. The cover layer may include an inner cover layer enclosing the outer core layer and an outer layer enclosing the inner cover layer.

First claim

What is claimed is:

1. A golf ball comprising an inner core layer comprising a blend comprising a first highly neutralized acid polymer having a first Vicat softening temperature and a first specific gravity, a second highly neutralized acid polymer having a second Vicat softening temperature and a second specific gravity, and an ionomer-based masterbatch comprising an additive and an ionomer resin having a third Vicat softening temperature, an outer core layer having a thickness between about 5 mm and about 9 mm essentially enclosing the inner core layer and comprising thermoset material, and a cover layer essentially enclosing the outer core layer, wherein the absolute values of the differences among the Vicat softening temperatures is no more than about 15° C. and the absolute value of the difference between the specific gravities is no more than about 0.015;
further comprising an intermediate layer situated between the outer core layer and the cover layer;
wherein the cover layer comprises a crosslinked thermoplastic polyurethane elastomer including crosslinks formed from allyl groups, and the crosslinked thermoplastic polyurethane elastomer is a reaction product formed from reacting an organic isocyanate with a mixture of the following reactants:
(a) a diol having 2 primary hydroxyl groups and at least 1 pendent unsaturation having the following formula:

in which R 1 is a substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted alkyl-aryl group, which may optionally include an ether or ester group, or an unsaturated bond in any main chain or side chain of any group, or is H; R 2 is a substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, or substituted or unsubstituted alkyl-aryl group, which may optionally include an ether or ester group, and R 2 includes an allyl group; and x and y are integers independently having any value from 1 to 10;
(b) a chain extender having at least two reaction sites with isocyanates and having a molecular weight of less than about 450;
(c) a long chain polyol having a molecular weight of between about 500 and about 4,000; and
(d) a sufficient amount of free radical initiator, so as to be capable of generating free radicals that induce crosslinking structures in the hard segments by free radical initiation.

2. A golf ball according to claim 1 , wherein the ionomer resin has a third specific gravity and the additive is a filler having a specific gravity greater than the first, second, and third specific gravities.

3. A golf ball according to claim 2 , wherein the specific gravity of the filler is greater than the sum of the first, second, and third specific gravities.

4. A golf ball according to claim 3 , wherein the specific gravity of the filler is greater than about 3.

5. A golf ball according to claim 1 , wherein the additive is a filler selected from the group consisting of zinc oxide, titanium dioxide, tin oxide, calcium oxide, magnesium oxide, barium sulfate, zinc sulfate, zinc carbonate, barium carbonate, tungsten powder, and molybdenum powder, and blends thereof.

6. A golf ball according to claim 1 , wherein the ionomer-based masterbatch comprises at least about 55 wt percent additive.

7. A golf ball according to claim 1 , wherein the inner core layer has a diameter of from 21 mm to 28 mm.

8. A golf ball according to claim 1 , wherein the first Vicat softening temperature is between about 48° C. and about 65° C., the second Vicat softening temperature is between about 48° C. and about 65° C., and the third Vicat softening temperature is between about 48° C. and about 65° C.

9. A golf ball according to claim 1 , wherein the absolute value of the differences among the Vicat softening temperatures is less than about 5° C.

10. A golf ball according to claim 8 , wherein the inner core layer has a surface Shore D hardness of from about 45 to about 55.

11. A golf ball according to claim 8 , wherein the outer core layer has a surface Shore D hardness of from about 50 to about 60 and is higher than the surface hardness of the inner core layer.

12. A golf ball according to claim 1 , wherein the inner core layer has a Shore D cross-sectional hardness of from 45 to 55 at any single point on a cross-section obtained by cutting the inner core layer in half, and has a Shore D cross-sectional hardness difference between any two points on the cross-section of within ±6.

13. A golf ball according to claim 1 , wherein the sphere comprising the inner core layer enclosed by the outer core layer has a coefficient of restitution of at least about 0.8.

14. A golf ball according to claim 1 , wherein the intermediate layer has a surface Shore D hardness of at least about 60 and the cover layer has a surface Shore D hardness of from about 45 to about 60.

15. A golf ball according to claim 1 , wherein the intermediate layer comprises a thermoplastic material comprising at least one of an ionomer resin, a highly neutralized acid polymer, a polyamide resin, a polyurethane resin, and a polyester resin.

16. A golf ball according to claim 1 , wherein the unsaturated diol (a) is trimethylolpropane monoallylether.

17. A golf ball according to claim 1 , wherein the cover layer has a flexural modulus of less than 1,000 psi.

18. A golf ball according to claim 1 , wherein the intermediate layer is an inner cover layer.

Assignees

• Nike Inc

Inventors

• Ishii Hideyuki
• Ichikawa Yasushi
• Chou Chien-Hsin
• Liu Chen-Tai
• Molinari Arthur Parker

Classifications

• A63B37/0062

  Hardness · CPC title

• A63B37/0063

  Hardness gradient · CPC title

• A63B37/0041

  Coefficient of restitution · CPC title

• A63B37/0064

  Diameter · CPC title

• C08G18/7671

  containing only one alkylene bisphenyl group · CPC title