Golf ball with softer feel and higher iron spin
A golf ball comprising: (a) a core; (b) at least one mantle layer adjacent to the core; (c) an inner cover layer adjacent to the mantle layer; and (d) an outer cover layer adjacent to the inner cover layer, wherein the inner cover layer has a material Shore D hardness that is at least 3 less than the material Shore D hardness of the outer cover layer, and the inner cover layer has a thickness of less than 0.050 in.
1. A four-piece ball comprising:
(a) a core comprising a pyridine peptizer;
(b) a mantle layer adjacent to the core, wherein the mantle layer comprises a mixture of an ethylene/methacrylic acid copolymer ionomer in which the methacrylic acid groups have been partially neutralized with sodium ions and an ethylene/methacrylic acid copolymer ionomer in which the methacrylic acid groups have been partially neutralized with zinc ions, and the mantle layer has a material Shore D hardness of 45 to 75 and a thickness of at least 0.030 in.;
(c) an inner cover layer adjacent to the mantle layer, wherein the inner cover layer has a material Shore D hardness of 42 and comprises a polyurethane made from a polytetramethylene ether glycol terminated toluene diisocyanate prepolymer, and the inner cover layer has a thickness of less than or equal to 0.020 in.; and
(d) an outer cover layer adjacent to the inner cover layer, wherein the outer cover layer is selected from a thermoset polyurethane or a thermoset polyurea and the outer cover layer has a material Shore D hardness of 30 to 70, and the outer cover layer has a thickness of at least 0.030 in.,
and wherein the inner cover layer has a material Shore D hardness that is at least 3 units less than the material Shore D hardness of the outer cover layer.
2. The golf ball of claim 1 , wherein the inner cover layer has a material Shore D hardness that is at least 8 units less than the material Shore D hardness of the outer cover layer.
3. The golf ball of claim 1 , wherein the mantle layer has a thickness of at least 0.050 in.
4. The golf ball of claim 1 , wherein the mantle layer has a thickness of 0.035 to 0.080 in.
5. The golf ball of claim 1 , wherein the mantle layer comprises 50% ethylene/methacrylic acid copolymer ionomer in which the methacrylic acid groups have been partially neutralized with sodium ions and 50% ethylene/methacrylic acid copolymer ionomer in which the methacrylic acid groups have been partially neutralized with zinc ions.