Casing layer for polyurethane-covered and polyurea-covered golf balls
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 about 16 percent acid groups by weight of the high acid ionomer, wherein greater than 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
a non-ionomeric acid copolymer comprising from about 17 percent to about 30 percent acid groups by weight of the non-ionomeric acid copolymer.
2. The golf ball of claim 1 , wherein between about 72 and about 99 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 16 to about 33 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 2 to about 4 pph of the non-ionomeric acid copolymer based on the total blend.
7. 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 about 16 percent acid groups by weight of the high acid ionomer, wherein greater than about 70 percent of the acid groups are neutralized;
a metallocene catalyzed polymer comprising at least one grafted moiety; and
a non-ionomeric acid copolymer comprising greater than 16 percent acid groups by weight of the acid copolymer; and
a cover comprising polyurea.
8. The golf ball of claim 7 , wherein the high acid ionomer comprises between about 17 and 25 weight percent acid groups.
9. The golf ball of claim 7 , wherein the at least one grafted moiety is selected from the group consisting of maleic anhydride, fumaric anhydride, and itaconic anhydride.
10. The golf ball of claim 7 , 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.
11. The golf ball of claim 8 , wherein the blend comprises about between about 2 and 4 pph melt flow modifier based on the total blend.
12. The golf ball of claim 11 , 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.
13. The golf ball of claim 7 , wherein between about 75 and about 90 percent of the acid groups in the high acid ionomer are neutralized.
14. 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 between about 17 and 25 percent acid groups by weight of the high acid ionomer, wherein between about 72 percent and about 99 percent of the acid groups are neutralized with a metal cation;
a metallocene catalyzed polymer comprising at least one grafted moiety selected from the group consisting of maleic anhydride, fumaric anhydride, and itaconic anhydride; and
a non-ionomeric acid copolymer comprising greater than 16 percent acid groups by weight of the non-ionomeric acid copolymer; and
a cover cast from a polyurea material.
15. The golf ball of claim 14 , wherein the cover has a hardness of about 30 to about 55 Shore D.
16. The golf ball of claim 14 , wherein the at least one grafted moiety is maleic anhydride.
17. The golf ball of claim 14 , wherein the high acid ionomer is present in the blend in an amount of about 84 pph to about 67 pph based on the total blend.
18. The golf ball of claim 14 , wherein the blend comprises about 16 to about 33 pph of the metallocene catalyzed polymer based on the total blend.
19. The golf ball of claim 14 , wherein the blend comprises between about 2 and 4 pph of the non-ionomeric acid copolymer based on the total blend.
20. The golf ball of claim 1 , wherein the non-ionomeric acid copolymer has a melt flow index of 60.
21. The golf ball of claim 7 , wherein the non-ionomeric acid copolymer has a melt flow index of 60.
22. The golf ball of claim 15 , wherein the non-ionomeric acid copolymer has a melt flow index of 60.