Golf ball with single thermoplastic cover layer of heterogeneous composition

Abstract

The invention relates generally to golf balls, and more specifically, to a golf ball having a single cover layer that is comprised of a blend of two or more distinct resinous materials. The present invention relates to a method of manufacturing a golf ball having a single cover layer of heterogeneous composition. One embodiment of the invention describes a method wherein a core, comprising one or more layers, has pre-molded hemispherical cover cups placed about the core and each cover cup has at least two layers of distinct resinous materials, and the cover cups are heated and compressed such that the resinous materials in the cover cups intermingle with each other to form a single cover layer comprised of a non-distinct blend of the materials.

1 . A golf ball comprised of a core and a cover, wherein the cover has an inner surface and an outer surface and is formed from a mixture of a first material and a second material and a first percent of the first material on the outer surface is greater than a second percent of the second material on the outer surface. 
     
     
         2 . The golf ball of  claim 1 , wherein the first and second materials are blends of two or more thermoplastic materials. 
     
     
         3 . The golf ball of  claim 1 , wherein the outer surface has a first hardness as measured on the surface thereof and the inner surface has a second hardness as measured on the surface thereof that is different from the first hardness. 
     
     
         4 . The golf ball of  claim 1 , wherein the cover has a first thickness, and a second thickness extending from the outer surface to a 50/50 blend point within the cover, and the ratio of the second thickness to the first thickness is proportional to a melt flow of the first material. 
     
     
         5 . The golf ball of  claim 4 , wherein the melt flow of the second material is greater than the melt flow of the first material. 
     
     
         6 . The golf ball of  claim 4 , wherein the melt flow of the first material is greater than the melt flow of the second material, such that as the melt flow of the first material increases with respect to the second material, the blend depth of the second thickness decreases. 
     
     
         7 . The golf ball of  claim 1 , wherein the materials of the cover are comprised of one or more polymers selected from the group consisting of partially or fully neutralized thermoplastic ionomers, a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a polyetherester, a polyesterester, a metallocene polymer, a thermoplastic polyetheramide, a thermoplastic polyester, a thermoplastic polyurethane, a ethylene or propylene based polymer, a methyl acrylate, a methyl methacrylate polymer, a polycarbonate, a polyamide, a polyphenylene oxide, a polyether ketone, a polysulfone, a acrylonitrile butadiene polymer, a acrylic styrene-acrylonitrile polymer, a terphthalate polymer, a ethylene-vinyl alcohol polymer, a tetrafluoroethylene polymer, a reinforced polymer, a urea or hybrids, silicones and silicone copolymers, styrene block copolymers and blends thereof. 
     
     
         8 . The golf ball of  claim 1 , wherein the core is solid and comprised of more than one layer. 
     
     
         9 . The golf ball of  claim 1 , wherein the core is a wound core. 
     
     
         10 . The golf ball of  claim 1 , wherein the core is a dual core. 
     
     
         11 . A golf ball comprised of:
 a core:   a cover comprising of a thermoset polyurethane; and   an intermediate layer between the core and cover;   wherein the intermediate layer comprises an inner surface and an outer surface and is formed from a mixture of a first material and a second material with a first percent of the first material on the outer surface being greater than a second percent of the second material on the outer surface.   
     
     
         12 . The golf ball of  claim 11 , wherein the first and second materials are blends of two or more thermoplastic materials. 
     
     
         13 . The golf ball of  claim 11 , wherein the outer surface has a first hardness as measured on the surface thereof and the inner surface has a second hardness as measured on the surface thereof that is different from the first hardness. 
     
     
         14 . The golf ball of  claim 11 , wherein the intermediate layer has a first thickness, and a second thickness extending from the outer surface to a 50/50 blend point within the cover, and the ratio of the second thickness to the first is proportional to a melt flow of the first material. 
     
     
         15 . The golf ball of  claim 14 , wherein the melt flow of the second material is greater than the melt flow of the first material. 
     
     
         16 . The golf ball of  claim 14 , wherein the melt flow of the first material is greater than the melt flow of the second material, such that as the melt flow of the first material increases with respect to the second material, the blend depth of the second thickness decreases. 
     
     
         17 . The golf ball of  claim 11 , wherein the materials of the intermediate layer are comprised of one or more polymers selected from the group consisting of partially or fully neutralized thermoplastic ionomers, a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a polyetherester, a polyesterester, a metallocene polymer, a thermoplastic polyetheramide, a thermoplastic polyester, a thermoplastic polyurethane, a ethylene or propylene based polymer, a methyl acrylate, a methyl methacrylate polymer, a polycarbonate, a polyamide, a polyphenylene oxide, a polyether ketone, a polysulfone, a acrylonitrile butadiene polymer, a acrylic styrene-acrylonitrile polymer, a terphthalate polymer, a ethylene-vinyl alcohol polymer, a tetrafluoroethylene polymer, a reinforced polymer, a urea or hybrids, silicones and silicone copolymers, styrene block copolymers and blends thereof. 
     
     
         18 . A method of manufacturing a golf ball having a single cover layer of heterogeneous composition, the method comprising:
 providing a core;   placing a mating pair of hemispherical pre-molded cover cups about the core, each cup having at least two layers, each layer consisting of distinct resinous materials; and   heating and compressing the cover cups such that the resinous materials in the cover cups intermingle with each other to form a single cover layer comprised of a non-distinct blend of the materials.   
     
     
         19 . The method of  claim 18 , wherein the heating and compression is done by a conventional one-step golf ball compression molding process. 
     
     
         20 . The method of  claim 18 , wherein the heating is at a temperature between about 300° F. to 600° F. 
     
     
         21 . The method of  claim 18 , wherein the intermingling of the cups may be further promoted by the application ultrasonic energy, electromagnetic energy, or infrared radiation. 
     
     
         22 . The method of  claim 18 , wherein the pre-molded cover cups are made by a method consisting of lamination, co-injection molding, or rotational molding. 
     
     
         23 . The method of  claim 18 , wherein the materials of the layers are comprised of one or more polymers selected from the group consisting of partially or fully neutralized thermoplastic ionomers, a dynamically vulcanized thermoplastic elastomer, a functionalized styrene-butadiene elastomer, a polyetherester, a polyesterester, a metallocene polymer, a thermoplastic polyetheramide, a thermoplastic polyester, a thermoplastic polyurethane, a ethylene or propylene based polymer, a methyl acrylate, a methyl methacrylate polymer, a polycarbonate, a polyamide, a polyphenylene oxide, a polyether ketone, a polysulfone, a acrylonitrile butadiene polymer, a acrylic styrene-acrylonitrile polymer, a terphthalate polymer, a ethylene-vinyl alcohol polymer, a tetrafluoroethylene polymer, a reinforced polymer, a urea or hybrids, silicones and silicone copolymers, styrene block copolymers and blends thereof.