Multi-layer cover golf ball having non-ionomeric intermediate cover layer
A golf ball includes a core and a cover disposed about the core. The cover includes a thermoplastic inner cover layer having a hardness between 55 Shore D and 60 Shore D, an outer cover layer having a hardness between 55 Shore D and 60 Shore D, and a non-ionomeric thermoplastic intermediate cover layer disposed between the inner and outer cover layer. The intermediate layer has a hardness greater than the inner cover layer and the outer cover layer. The inner cover is formed from a partially- or fully-neutralized ionomer, the intermediate layer from a non-ionomer, and the cover outer cover layer from a polyurea formed from the reaction product of a prepolymer comprising an isocyanate and an amine-terminated polytetramethylene ether glycol, and an amine-terminated curing agent.
1. A golf ball comprising a core and a cover disposed adjacent the core, the cover comprising a thermoplastic inner cover layer disposed about the core and having a hardness between 55 Shore D and 60 Shore D; an outer cover layer having a hardness between 55 Shore D and 60 Shore D; and a non-ionomeric thermoplastic intermediate cover layer disposed between the inner and outer cover layers and having a hardness greater than the inner cover layer and the outer cover layer;
wherein the inner cover comprises a partially- or fully-neutralized ionomer, the intermediate layer consists essentially of a non-ionomer and has a hardness greater than the inner cover layer hardness and greater than the outer cover layer hardness by at least 10 Shore D, and the cover outer cover layer comprises a polyurea formed from the reaction product of a prepolymer comprising an isocyanate and an amine-terminated polytetramethylene ether glycol and an amine-terminated curing agent.
2. The golf ball of claim 1 , wherein the intermediate layer hardness is 75 Shore D or greater.
3. The golf ball of claim 2 , wherein the intermediate layer hardness is from 80 Shore D to 90 Shore D.
4. The golf ball of claim 1 , wherein the amine-terminated polytetramethylene ether glycol is end-capped with one or more propylene glycol units to form a copolymer.
5. The golf ball of claim 1 , wherein the core comprises a center and at least one outer core layer.
6. The golf ball of claim 1 , wherein the center is a solid layer formed from a single homogeneous composition.
7. The golf ball of claim 1 , wherein the amine-terminated PTMEG has a molecular weight of 1000 to 4000.
8. The golf ball of claim 7 , wherein the amine-terminated PTMEG has a molecular weight of 2000 to 3000.
9. The golf ball of claim 1 , wherein the thermoplastic inner cover layer further comprises polyolefins, metallocenes, polyesters, polyamides, thermoplastic elastomers, copolyether-amides, copolyether-esters, or mixtures thereof.
10. The golf ball of claim 1 , wherein a combination of the inner cover, the intermediate cover, and the outer cover have a total thickness of 0.125 inches or less.
11. The golf ball of claim 10 , wherein the total thickness is 0.115 inches or less.
12. The golf ball of claim 1 , wherein the outer cover layer hardness is less than the inner cover layer hardness.
13. A golf ball comprising a core and a cover disposed adjacent the core, the cover comprising a thermoplastic inner cover layer disposed about the core and having a hardness between 55 Shore D and 60 Shore D; an outer cover layer having a hardness between 55 Shore D and 60 Shore D; and a non-ionomeric thermoplastic intermediate cover layer disposed between the inner and outer cover layers and having a hardness greater than the inner cover layer and the outer cover layer;
wherein the inner cover comprises a partially- or fully-neutralized ionomer, the intermediate layer consists essentially of a non-ionomer and has a hardness of 80 Shore D to 90 Shore D, and the cover outer cover layer comprises a polyurea formed from the reaction product of a prepolymer comprising an isocyanate and an amine-terminated polytetramethylene ether glycol and an amine-terminated curing agent.