Casing layer for polyurethane-covered and polyurea-covered golf balls
View Patent ↗This invention is related to multi-layer golf balls having at least one layer containing a neutralized high acid ionomer linked to a grafted metallocene copolymer, where the golf balls exhibit improved performance characteristics and properties.
1. A golf ball comprising a core, a cover, and a layer disposed between the core and cover, wherein the cover comprises polyurea, and wherein the layer disposed between the core and cover further comprises a blend comprising:
a high acid ionomer comprising greater than 16 percent acid groups by weight of the high acid ionomer, wherein between about 25 and about 70 percent of the acid groups are neutralized by a suitable cationic source;
a metallocene catalyzed polymer comprising at least one grafted moiety, wherein the grafted moiety is selected from the group consisting of maleic anhydride, fumaric anhydride, and itaconic anhydride; and
an unneutralized acid copolymer comprising greater than 16 weight percent acid groups by weight of the unneutralized acid copolymer.
2. The golf ball of claim 1 , wherein between about 30 and about 60 percent of the acid groups in the high acid ionomer are neutralized.
3. The golf ball of claim 1 , wherein the cationic source comprises at least one of the group comprising magnesium, sodium, potassium, cesium, calcium, barium, manganese, copper, zinc, tin, and lithium.
4. The golf ball of claim 1 , wherein the blend comprises about 10 to about 40 pph of the metallocene catalyzed polymer based on the total blend.
5. The golf ball of claim 1 , wherein the blend comprises about 80 to about 64 pph of the high acid ionomer based on the total blend.
6. The golf ball of claim 1 , wherein the blend comprises about 3 to about 4 pph of the unneutralized acid copolymer based on the total blend.
7. The golf ball of claim 1 , wherein the unneutralized acid copolymer has a melt flow index of 60.
8. A golf ball comprising:
a core;
a casing layer disposed about the core, wherein the casing layer comprises a blend comprising:
a high acid ionomer comprising greater than 16 percent acid groups by weight of the high acid ionomer, wherein between about 25 percent and 70 percent of the acid groups are neutralized; and
a metallocene catalyzed polymer comprising at least one grafted moiety; and
an unneutralized acid copolymer comprising greater than 16 weight percent acid groups by weight of the unneutralized acid copolymer;
a cover, wherein the cover is cast from a polyurea material.
9. The golf ball of claim 8 , wherein the high acid ionomer comprises between about 17 and 25 weight percent acid groups.
10. The golf ball of claim 8 , wherein the at least one grafted moiety is selected from the group consisting of maleic anhydride, fumaric anhydride, and itaconic anhydride.
11. The golf ball of claim 8 , wherein the blend comprises about 16 to about 33 pph of the metallocene catalyzed polymer and about 84 to about 67 pph of the high acid ionomer based on the total blend.
12. The golf ball of claim 8 , wherein the blend comprises about 4 percent or less unneutralized acid copolymer by weight of the blend.
13. The golf ball of claim 12 , wherein the blend comprises about 16 to about 33 pph of the metallocene catalyzed polymer and about 80 to about 64 pph of the high acid ionomer based on the total blend based on the total blend.
14. The golf ball of claim 8 , wherein between about 30 and about 60 percent of the acid groups in the high acid ionomer are neutralized.
15. The golf ball of claim 8 , wherein the unneutralized acid copolymer has a melt flow index of 60.
16. A golf ball comprising:
a core;
a casing layer disposed about the core, wherein the casing layer comprises a blend comprising:
a high acid ionomer comprising greater than 16 percent acid groups by weight of the high acid ionomer, wherein between about 25 and about 70 percent of the acid groups are neutralized with a metal cation;
a metallocene catalyzed polymer comprising at least one grafted moiety; and
an acid copolymer comprising greater than 16 weight percent acid groups by weight of the acid copolymer; and
a cover, wherein the cover is cast from a polyurea material.
17. The golf ball of claim 16 , wherein the cover has a hardness of about 30 to about 55 Shore D.
18. The golf ball of claim 16 , wherein the at least one grafted moiety is selected from the group consisting of maleic anhydride, fumaric anhydride or itaconic anhydride.
19. The golf ball of claim 16 , wherein the high acid ionomer is present in the blend in an amount of about84 pph to about 67 pph based on the total blend.
20. The golf ball of claim 19 , wherein the blend comprises about 16 to about 33 pph of the metallocene catalyzed polymer based on the total blend.
21. The golf ball of claim 20 , wherein the blend comprises between about 2 and 4 pph of the acid copolymer based on the total blend.
22. The golf ball of claim 16 , wherein the acid copolymer has a melt flow index of 60.