Abstract: A golf ball including an inner core layer formed from a first thermoset rubber composition and having a diameter of about 1.25 to 1.58 inches; an outer core layer formed from a second thermoset rubber composition; and an intermediate core layer disposed between the inner core layer and outer core layer. The intermediate core layer is formed from a thermoplastic composition having a first melt flow index at 280° C. under a 10-kg load of less than about 35 g/10 min and has a thickness of about 0.005 inches to 0.10 inches and a surface hardness of greater than about 60 Shore D. A cover layer having a thickness of about 0.01 to 0.05 inches and a surface hardness of about 60 Shore D or less is formed around the core.

Abstract: A golf ball includes a single core formed from a substantially homogenous rubber composition, an inner cover disposed about the core, and an outer cover. The inner cover includes an ionomeric material and has a hardness of about 60 Shore D or greater. The outer cover layer is disposed about the inner cover layer, is formed from a castable polyurea or polyurethane, and has a material hardness of about 60 Shore D or less. The outer surface of the core has a trans content of about 12% or less and a hardness of about 71 to 88 Shore C, the geometric center of the core has a trans content of about 10% or less and a hardness of about 70 to 80 Shore C, and the core surface hardness is greater than the geometric center hardness by about 1 to 10 Shore C to define a shallow positive hardness gradient.

Abstract: A golf ball including a core and a cover disposed about the core. The cover includes a thermoplastic inner cover layer having a hardness between 55 and 60 Shore D; an outer cover layer having a hardness between 55 and 60 Shore D; and a stiff 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. The inner cover layer is formed from a non-ionomeric composition including a non-ionomeric stiffening polymer and at least one E/Y copolymer or E/X/Y terpolymer, where E is an olefin, Y is a carboxylic acid, and X is a softening comonomer. The intermediate cover layer is formed from a stiff thermoplastic polyurethane or polyurea composition and the cover outer cover layer is formed from a thermoset polyurethane, a polyurea, or a urethane-urea blend.

Abstract: A golf ball includes a core and a cover disposed adjacent the core. The cover includes a thermoplastic inner cover layer having a hardness between 55 and 60 Shore D; an outer cover layer having a hardness between 55 and 60 Shore D; and a non-ionomeric thermoplastic polyurethane or polyurea intermediate cover layer disposed between the inner and outer cover layers. The intermediate cover layer has a hardness greater than the inner cover layer hardness and the outer cover layer hardness. The inner cover is formed from a partially- or fully-neutralized ionomer and the outer cover layer is formed from a polyurethane, a polyurea, or a urethane-urea blend.

Abstract: A golf ball including a thermoplastic core having an outer diameter of 1.51 inches to 1.59 inches; an outer cover layer; and an inner cover layer between the core and the outer cover layer. The thermoplastic core has been exposed to a gradient-initiating solution comprising a solvent, free radical initiator, and a reactive co-agent comprising a metal salt of an acrylic or methacrylic acid, a mono- or multi-functional acrylate or methacrylate, or having the chemical structure where R=linear, branched, or aromatic C1-C14 and n=1-5, such that the hardness of the outer surface is different than the hardness of the geometric center to define a positive or negative hardness gradient of 5 Shore C or greater.

Abstract: A golf ball including an inner core layer formed from a thermoset rubber composition and having a first surface hardness; a thermoplastic outer core layer having a second surface hardness, an inner surface hardness, and being formed from a copolymer of ethylene and an ?,?-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer; an inner cover layer; and an outer cover layer; wherein the first surface hardness is less than the second surface hardness by at least 5 Shore C and less than the inner surface hardness by at least 5 Shore C.

Abstract: A golf ball including a unitary core having a volume, an outer surface, a geometric center, and an outermost transition volume adjacent to the outer surface, the core being formed from a substantially homogenous composition; and a cover layer including ionomer, metallocene-catalyzed polymer, polyester, polyamide, non-ionomeric thermoplastic elastomer, copolyether-ester, copolyether-amide, polycarbonate, polybutadiene, polyisoprene, or polystyrene block copolymer. The outermost transition volume is disposed between the core outer surface and the geometric center, the transition volume has an outer portion congruent with the core outer surface, and comprises the outermost 45% of the core volume or less. Both a hardness of the core outer surface and a hardness within the outermost transition volume are less than the hardness of the geometric center to define a negative hardness gradient.

Abstract: A golf ball comprising an inner core having an outer surface and a geometric center and being formed from a substantially homogenous composition such that the geometric center has a hardness of 56 to 80 Shore C and the outer surface has a hardness of 50 to 75 Shore C. An outer core layer is disposed about the inner core and has an outer surface having a hardness of 85 to 98 Shore C and an inner surface having a hardness of 68 to 78 Shore C and being formed from a second substantially homogenous rubber composition. A cover layer is disposed about the outer core layer. The hardness of the second outer surface is greater than the hardness of the inner surface to define a positive hardness gradient of +7 to +30 Shore C, and the hardness of the first outer surface is lower than the hardness of the geometric center to define a negative hardness gradient of ?1 to ?15 Shore C.

Abstract: A golf ball including a core and a cover disposed adjacent the core, the cover including an ionomeric thermoplastic inner cover layer disposed about the core and having a hardness of 55 Shore D to 60 Shore D; a castable thermoset polyurethane 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, the non-ionomeric intermediate cover layer being formed of a polyester/polycarbonate blend and having a hardness greater than both the inner and outer cover layers; wherein the inner cover layer has a first thickness, the outer cover layer has a second thickness, and the intermediate cover layer has a third thickness less than the first or second thickness by at least 20%.

Abstract: A golf ball including an inner core layer having an Atti compression of 30 or less and formed from a first rubber composition and having a first surface hardness; an outer core layer including a second rubber composition; a thermoplastic layer having a second surface hardness, an inner surface hardness, and comprising a copolymer of ethylene and an ?,?-unsaturated carboxylic acid, and sufficient amount of an organic acid or a salt of the organic acid and a cation source to neutralize the acid groups of the copolymer by about 80% or greater; an inner cover layer having a hardness of about 40 Shore D to 70 Shore D; and an outer cover layer. The first surface hardness is less than the second surface hardness by at least 5 Shore C.

Abstract: A golf ball including a unitary core having a volume, an outer surface, a geometric center, and an outermost transition volume adjacent to the outer surface, the core being formed from a substantially homogenous composition; and a cover layer including ionomer, metallocene-catalyzed polymer, polyester, polyamide, non-ionomeric thermoplastic elastomer, copolyether-ester, copolyether-amide, polycarbonate, polybutadiene, polyisoprene, or polystyrene block copolymer. The outermost transition volume is disposed between the core outer surface and the geometric center, the transition volume has an outer portion congruent with the core outer surface, and comprises the outermost 45% of the core volume or less. Both a hardness of the core outer surface and a hardness within the outermost transition volume are less than the hardness of the geometric center to define a negative hardness gradient.

Abstract: A golf ball including an inner core layer formed from a thermoset rubber composition and having a first surface hardness; a thermoplastic outer core layer having a second surface hardness, an inner surface hardness, and being formed from a copolymer of ethylene and an ?,?-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer; an inner cover layer; and an outer cover layer; wherein the first surface hardness is less than the second surface hardness by at least 5 Shore C and less than the inner surface hardness by at least 5 Shore C.

Abstract: A golf ball including a core and a cover disposed about the core. The cover includes a thermoplastic inner cover layer having a hardness between 55 and 60 Shore D; an outer cover layer having a hardness between 55 and 60 Shore D; and a stiff 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. The inner cover layer is formed from a non-ionomeric composition including a non-ionomeric stiffening polymer and at least one E/Y copolymer or E/X/Y terpolymer, where E is an olefin, Y is a carboxylic acid, and X is a softening comonomer. The intermediate cover layer is formed from a stiff thermoplastic polyurethane or polyurea composition and the cover outer cover layer is formed from a thermoset polyurethane, a polyurea, or a urethane-urea blend.

Abstract: A golf ball including a thermoplastic inner core and a thermoset outer core layer is described. The inner core has a surface hardness of 43 to about 65 Shore D and a center hardness of about 30 to 43 Shore D that is less than the surface hardness to define a positive hardness gradient. A cover includes an inner and outer cover layer. The thermoplastic inner core is formed from a highly-neutralized ionomer comprising a copolymer of ethylene and an ?,?-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer by 80% or greater. The outer core layer includes a polybutadiene rubber and has a surface hardness greater than an interior hardness by about 6 to 11 Shore D points to define a shallow positive hardness gradient.

Abstract: A golf ball having a core, a cover layer, and an optional intermediate layer disposed between the core and the cover layer is disclosed and described. One or more of the core, the cover layer, or the intermediate layer is formed of a highly neutralized polymer blend of an acid copolymer and a metallocene-catalyzed copolymer, an olefinic block copolymer, a sufficient amount of a suitable cation source and a fatty acid or salt of a fatty acid. The highly neutralized polymer blend is neutralized from 80% to 100% while still retaining processability. Further, the core can have a diameter of 0.5 inches to about 1.62 inches and an Atti compression less than or equal to 105. The cover layer can have a material hardness between about 30 and 70 Shore D.

Abstract: A golf ball comprising an inner core having an outer surface and a geometric center and being formed from a substantially homogenous rubber composition, the rubber composition comprising a base rubber and a resorcinol such that the geometric center has a hardness of 50 to 60 Shore C and the outer surface has a hardness of 85 to 95 Shore C. An outer core layer is disposed about the inner core and has an outer surface having a hardness of 50 to 75 Shore C, an inner surface having a hardness of 51 to 76 Shore C, and is formed from a substantially homogenous composition. A cover layer is disposed about the outer core layer. The hardness of the inner core outer surface is greater than the hardness of the geometric center to define a positive hardness gradient of greater than 20 Shore C, and the hardness of the outer core outer surface is lower than the hardness of its inner surface to define a negative hardness gradient of ?1 to ?5 Shore C.

Abstract: A golf ball including a core having an outer surface and a geometric center and being formed from a substantially homogenous composition throughout, the core having a diameter of 1.20 inches or less, a compression of 45 or less, and a coefficient of restitution of 0.780 or greater. An outer cover having a thickness of 0.04 inches or less and having a material Shore D hardness of 55 or less is present along with an intermediate layer disposed between the core and the outer cover. The intermediate layer has a thickness of 0.14 inches or greater and a Shore D hardness of 60 to 70. The outer surface of the core has a first hardness and the geometric center of the core has a second hardness, the first hardness being substantially the same as or lower than the second hardness to define a “negative” hardness gradient.

Abstract: A golf ball includes a single core formed from a substantially homogenous rubber composition, an inner cover disposed about the core, and an outer cover. The inner cover includes an ionomeric material and has a hardness of about 60 Shore D or greater. The outer cover layer is disposed about the inner cover layer, is formed from a castable polyurea or polyurethane, and has a material hardness of about 60 Shore D or less. The outer surface of the core has a trans content of about 12% or less and a hardness of about 71 to 88 Shore C, the geometric center of the core has a trans content of about 10% or less and a hardness of about 70 to 80 Shore C, and the core surface hardness is greater than the geometric center hardness by about 1 to 10 Shore C to define a shallow positive hardness gradient.

Abstract: A golf ball including an inner core layer formed from a thermoset rubber composition and having a first surface hardness; a thermoplastic outer core layer having a second surface hardness, an inner surface hardness, and being formed from a copolymer of ethylene and an ?,?-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer; an inner cover layer; and an outer cover layer; wherein the first surface hardness is substantially the same as the second surface hardness and the inner surface hardness.

Abstract: A golf ball including an inner core having a geometric center and a first outer surface, the inner core being formed from a first substantially homogenous rubber composition, and an outer core layer formed from a second substantially homogenous rubber composition, the outer core layer having a second outer surface. An inner cover layer is formed over the core and includes an ionomeric material. An outer cover layer is formed over the inner cover layer and includes a castable polyurea or a castable polyurethane. The first outer surface has a hardness of up to about 20 Shore C less than a hardness at the geometric center to define a negative hardness gradient inner core and the second outer surface has a hardness of up to 18 Shore C greater than the geometric center hardness to define a positive gradient outer core layer and a shallow positive hardness gradient core.