MULTI-LAYERED CORES FOR GOLF BALLS CONTAINING IONOMER AND NON-IONOMER LAYERS
Multi-piece golf balls having a solid core of at least one layer and cover of at least one layer are provided. At least one of the core layers comprises a thermoplastic ionomer composition and at least one of the core layers comprises a thermoplastic non-ionomer composition. Preferably, the ionomer composition is a highly neutralized ethylene acid copolymer. Preferably, the non-ionomer composition is a thermoplastic elastomer selected from polyester-polyether block copolymers, polyether-amide block copolymers, and blends thereof. The resulting ball has high resiliency and rebounding properties.
1 . A golf ball, comprising:
a) an inner core layer formed from a non-ionomer composition comprising a thermoplastic elastomer selected from the group consisting of: polyester-polyether block copolymers, polyether-amide block copolymers, and blends thereof;
b) an outer core layer formed from an ionomer composition comprising an ethylene acid copolymer and containing acid groups such that greater than 70% of the acid groups are neutralized; and
c) a cover having at least one layer.
2 . The golf ball of claim 1 , wherein the non-ionomer composition is relatively flexible having a flex modulus of 1,000 to 50,000 psi and the ionomer composition is relatively stiff having a flex modulus of 20,000 psi to 150,000 psi, the flex modulus of the non-ionomer composition being less than the flex modulus of the ionomer composition.
3 . The golf ball of claim 2 , wherein the modulus of the non-ionomer elastomer composition is at least 10% less than the modulus of the ionomer composition.
4 . The golf ball of claim 1 , wherein the non-ionomer composition is relatively stiff having a flex modulus of 20,000 psi to 150,000 psi and the ionomer composition is relatively flexible having a flex modulus of 1,000 to 50,000 psi, the flex modulus of the non-ionomer composition being greater than the flex modulus of the ionomer composition.
5 . The golf ball of claim 4 , wherein the modulus of the non-ionomer composition is at least 10% greater than the modulus of the ionomer composition.
6 . The golf ball of claim 1 , wherein the center of the inner core and surface of the outer core layer each has a hardness, and the surface hardness of the outer core layer is greater than the center hardness of the inner core.
7 . The golf ball of claim 6 , wherein the center hardness of the inner core is about 25 Shore D units or greater and the surface hardness of the outer core is about 45 Shore D units or greater.
8 . The golf ball of claim 6 , wherein the center hardness of the inner core is in the range of about 25 to about 82 Shore D units and the surface hardness of the outer core is in the range of about 30 to about 87 Shore C units.
9 . The golf ball of claim 1 , wherein the center of the inner core and surface of the outer core layer each has a hardness, and the center hardness of the inner core is greater than the surface hardness of the outer core layer.
10 . The golf ball of claim 1 , wherein the cover is a single layer having a thickness of about 0.015 to about 0.090 inches and is formed from a thermoplastic or thermoset material.
11 . The golf ball of claim 1 , wherein the cover comprises two or more layers and has an overall thickness of about 0.020 to about 0.110 inches and wherein each cover layer is formed from a thermoplastic or thermoset material.
12 . The golf ball of claim 1 , wherein the cover comprises an inner cover layer and outer cover layer, the outer cover having a Shore D hardness of less than 65, the hardness of the outer cover being less than the hardness of the inner cover.
13 . The golf ball of claim 1 , wherein the cover is formed from a composition comprising a polymer selected from the group consisting of ethylene acid copolymer ionomers; polyesters; polyamides; polyamide-ethers, polyamide-esters; polyurethanes, polyureas; fluoropolymers; polystyrenes; polypropylenes and polyethylenes; polyvinyl chlorides; polyvinyl acetates; polycarbonates; polyvinyl alcohols; polyethers; polyimides, polyetherketones, polyamideimides; and mixtures thereof.
14 . The golf ball of claim 1 , wherein the inner core has a diameter in the range of about 0.050 to about 1.40 inches.
15 . The golf ball of claim 1 , wherein the outer core layer has a thickness in the range of about 0.020 to about 0.560 inches.
16 . The golf ball of claim 1 , wherein the dual-core core has an overall compression in the range of about 50 to about 130.
17 . The golf ball of claim 16 , wherein the dual-core has an overall compression in the range of about 70 to about 110.
18 . A golf ball, comprising:
a) an inner core layer formed from an ionomer composition comprising an ethylene acid copolymer and containing acid groups such that greater than 70% of the acid groups are neutralized;
b) an outer core layer formed from a non-ionomer composition comprising a thermoplastic elastomer selected from the group consisting of polyester-polyether block copolymers, polyether-amide block copolymers, and blends thereof; and
c) a cover having at least one layer.
19 . The golf ball of claim 18 , wherein the ionomer composition is relatively stiff having a flex modulus of 20,000 psi to 150,000 psi and the non-ionomer composition is relatively flexible having s a flex modulus of 1,000 to 50,000 psi.
20 . The golf ball of claim 19 , wherein the modulus of the ionomer composition is at least 10% greater than the modulus of the non-ionomer composition.
21 . The golf ball of claim 18 , wherein the ionomer composition is relatively flexible having a flex modulus of 1,000 to 50,000 psi and the non-ionomer composition is relatively stiff having a flex modulus of 20,000 to 150,000 psi.
22 . The golf ball of claim 21 , wherein the modulus of the ionomer composition is at least 10% less than the modulus of the non-ionomer composition.
23 . The golf ball of claim 18 , wherein the center of the inner core and surface of the outer core layer each has a hardness, and the surface hardness of the outer core layer is greater than the center hardness of the inner core.
24 . The golf ball of claim 23 , wherein the center hardness of the inner core is about 20 Shore D units or greater and the surface hardness of the outer core is about 25 Shore D units or greater.
25 . The golf ball of claim 23 , wherein the center hardness of the inner core is in the range of about 20 to about 82 Shore D units and the surface hardness of the outer core is in the range of about 25 to about 87 Shore C units.
26 . The golf ball of claim 18 , wherein the center of the inner core and surface of the outer core layer each has a hardness, and the center hardness of the inner core is greater than the surface hardness of the outer core layer.
27 . The golf ball of claim 18 , wherein the cover is a single layer having a thickness of about 0.015 to about 0.090 inches and is formed from a thermoplastic or thermoset material.
28 . The golf ball of claim 18 , wherein the cover comprises two or more layers and has an overall thickness of about 0.020 to about 0.110 inches and wherein each cover layer is formed from a thermoplastic or thermoset material.
29 . The golf ball of claim 18 , wherein the dual-core core has an overall compression in the range of about 50 to about 130.
30 . The golf ball of claim 29 , wherein the dual-core has an overall compression in the range of about 70 to about 110.