Highly neutralized acid polymer compositions having a low moisture vapor transmission rate and their use in golf balls
The present invention is directed to a golf ball having at least one layer formed from a moisture resistant composition having a moisture vapor transmission rate of 12.5 g·mil/100 in 2 /day or less, a melt flow index of 1.0 g/10 min or higher, and comprising a highly neutralized acid polymer. Golf balls of the present invention include one-piece, two-piece, multi-layer, and wound golf balls. The composition may be present in any one or more of a core layer, a cover layer, or an intermediate layer.
1 . A golf ball having at least one layer formed from a moisture resistant composition having a moisture vapor transmission rate (MVTR) of 12.5 g·mil/100 in 2 /day or less, a melt flow index of 1.0 g/10 min or higher, and comprising a highly neutralized acid polymer, wherein the highly neutralized acid polymer comprises from 0 wt % to 19 wt % of a softening monomer, based on the total weight of the polymer.
2 . The golf ball of claim 1 , wherein the golf ball core has a diameter of from 1.50 inches to 1.62 inches.
3 . The golf ball of claim 2 , wherein the cover has a thickness of from 0.025 inches to 0.090 inches and is formed from the moisture resistant composition.
4 . The golf ball of claim 1 , wherein the moisture resistant composition has a melt flow index of from 1.0 to 4.0 g/10 min.
5 . The golf ball of claim 1 , wherein the acid polymer is an ethylene/(meth)acrylic acid polymer comprising an alkyl(meth)acrylate in an amount of from 0 wt % to 19wt %, based on the total weight of the polymer.
6 . The golf ball of claim 5 , wherein the moisture resistant composition further comprises an organic acid salt selected from zinc stearate and calcium stearate.
7 . The golf ball of claim 6 , wherein 80% or more of the acid groups present in the moisture resistant composition are neutralized to salts.
8 . The golf ball of claim 7 , wherein 50% or more of the acid groups present in the moisture resistant composition are neutralized to salts having calcium and/or zinc counterions.
9 . A golf ball having at least one layer formed from a moisture resistant composition having a moisture vapor transmission rate (MVTR) of 12.5 g·mil/100 in 2 /day or less, a melt flow index of 1.0 g/10 min or higher, and comprising a highly neutralized acid polymer, wherein the highly neutralized acid polymer comprises from 20 wt % to 50 wt % of a softening monomer, based on the total weight of the polymer.
10 . The golf ball of claim 1 , wherein the golf ball core has a diameter of from 1.50 inches to 1.62 inches and is formed from the moisture resistant composition
11 . The golf ball of claim 9 , wherein the acid polymer is an ethylene/(meth)acrylic acid polymer comprising an alkyl(meth)acrylate in an amount of from 20 wt % to 50 wt %, based on the total weight of the polymer.
12 . The golf ball of claim 11 , wherein the moisture resistant composition further comprises an organic acid salt selected from zinc stearate and calcium stearate.
13 . The golf ball of claim 12 , wherein 80% or more of the acid groups present in the moisture resistant composition are neutralized to salts.
14 . The golf ball of claim 13 , wherein 50% or more of the acid groups present in the moisture resistant composition are neutralized to salts having calcium and/or zinc counterions.
15 . A multi-layer golf ball comprising a core having a diameter of 1.50 inches, an inner cover layer having a thickness of from 0.025 inches to 0.060 inches, and an outer cover layer having a thickness of from 0.025 inches to 0.060 inches, wherein at least one of the core, the inner cover layer, and the outer cover layer is formed from a moisture resistant composition having a moisture vapor transmission rate (MVTR) of 12.5 g·mil/100 in 2 /day or less, a melt flow index of 1.0 g/10 min or higher, and comprising a highly neutralized acid polymer.
16 . The golf ball of claim 15 , wherein the core is formed from the moisture resistant composition, and wherein the acid polymer is an ethylene/(meth)acrylic acid polymer comprising an alkyl(meth)acrylate in an amount of from 20 wt % to 50 wt %, based on the total weight of the polymer.
17 . The golf ball of claim 15 , wherein the inner cover layer is formed from the moisture resistant composition, and wherein the acid polymer is an ethylene/(meth)acrylic acid polymer comprising an alkyl(meth)acrylate in an amount of from 0 wt % to 19 wt %, based on the total weight of the polymer.
18 . The golf ball of claim 17 , wherein the moisture resistant composition further comprises an organic acid salt selected from zinc stearate and calcium stearate.
19 . The golf ball of claim 18 , wherein 80% or more of the acid groups present in the moisture resistant composition are neutralized to salts.
20 . The golf ball of claim 19 , wherein 50% or more of the acid groups present in the moisture resistant composition are neutralized to salts having calcium and/or zinc counterions.