UV curable coating for golf balls

Abstract

An UV curable coating for a golf ball or a similar game ball that the UV curable coating is the reaction product of at least one UV-reactive component, a polyfunctional aziridines, and a photo-initiator. The UV curable coating is substantially free of solvent, therefore, contains nearly 100% solids.

What is claimed is:  
     
         1 . A high solids, low-solvent containing outer coating for a golf ball, comprising a UV curable coating which contains (a) at least one UV-reactive component, (b) a polyfunctional aziridine having the formula 
       R—[X—N(CH 2 ) 2 ] m   
       in which R is an organic aliphatic radical or a hydrogen atom, X is an alkylene group which may contain an ester group, an ether group, an amide group or a similar inert group, and m is a number of 2 to 4, and (c) a photo-initiator.  
     
     
         2 . The coating of  claim 1  wherein said UV-reactive component comprises a urethane acrylate oligomer (a) formed by reacting diisocyanate with a hydroxyl group containing acrylate or methacrylate and the product further reacted with polyol or (b) reacting a hydroxyl group containing acrylate or methacrylate with a lactone and reacting the product with an isocyanate.  
     
     
         3 . A golf ball comprising a top coat covering formed from a UV-curable coating comprising at least one UV curable acrylate oligomer, a polyfunctional aziridine, and a photoinitiator.  
     
     
         4 . A coated substrate comprising a polymer as substrate and coated with a UV cured coating comprising (a) at least one UV-reactive component, (b) a polyfunctional aziridine having the formula 
       R—[X—N(CH 2 ) 2 ] m   
       in which R is an organic aliphatic radical or a hydrogen atom, X is an alkylene group which may contain an ester group, an ether group, an amide group or a similar inert group, and m is a number of 2 to 4, and (c) a photo-initiator.  
     
     
         5 . The coated substrate of  claim 3  wherein said UV-reactive component comprises a urethane acrylate oligomer (a) formed by reacting diisocyanate with a hydroxyl group containing acrylate or methacrylate and the product further reacted with polyol or (b) reacting a hydroxyl group containing acrylate or methacrylate with a lactone and reacting the product with an isocyanate.  
     
     
         6 . The golf ball according to  claim 1  wherein UV curable acrylate oligomer has a viscosity within the range of 8,000 centipoise to about 40,000 centipoise.  
     
     
         7 . The golf ball according to  claim 1  wherein the photoinitiator is present in an amount of from 1 to 8 % by weight of the coating.  
     
     
         8 . The golf ball according to  claim 1  wherein the photoinitiator is selected from the group consisting of a benzophenone, benzoin, acetophenone, benzoin methyl ether, Michler's ketone, benzoin butyl ether, xanthone, thioxanthone, propiophenone, fluorenone, carbozole, diethyoxyacetophenone, 2-, 3- and 4- methylacetophenones, 2-, 3-and 4- methoxyacetophenones, 2- and 3-chloroxanthones, 2-, and 3-chlorothioxanthones, 2-acetyl-4-methylphenyl acetate, 2,2′-dimethyoxy-2-phenyl acetophenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, 3- and 4-allyl-acetophenone, p-diacetylbenzene, 3-chloro-2-nonylxanthone, 2-chlorobenzophenone, 4-methoxybenzophenone, 2,2′,4,4′-tetrachlorobenzophenone, 2-chloro-4′-methylbenzophenone, 4-chloro-4′-methylbenzophenone, 3-methylbenzophenone, 4-tert-butyl-benzophenone, isobutyl ether, benzoic acetate, benzil, benzilic acid, amino benzoate, methylene blue, 2,2-diethoxyacetophenone, 9,10-phenanthrenequinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 1-tert-butyl-anthraquinone, 1,4-naphthoquinone, isopropylthioxanthone, 2-chlorothioxanthone, 2-iso-propylthioxanthone, 2methylthioxanthone, 2-decylthioxanthone, 2-dodecyl-thioxanthone, 2-methyl-1-[4-(methyl thio)phenyl)]-2-morpholinopropanone-1, and any combination thereof.  
     
     
         9 . A golf ball comprising a top coat covering substantially the entire golf ball, the top coat formed from a UV-curable coating comprising 30 to 80% by weight on weight of the coating, of at least one UV reactive component, 10 to 60% by weight of a reactive diluent, a polyfunctional aziridine in an amount ranging from 0.1 to 15% by weight of the UV-curable coating, and a photoinitiator in an amount ranging from 0.5 to 15% by weight of the UV-curable coating.  
     
     
         10 . The coated substrate according to  claim 3  wherein the UV reactive component is an oligomer selected from the group consisting of urethane acrylate, epoxy acrylate or polyether acrylate, the polyfunctional aziridine is present in the coating in an amount of from 0.5% to 8% per weight of the coating, and the photoinitiator in an amount of approximately 1 part per weight of the UV-curable coating.  
     
     
         11 . The golf ball according to  claim 6  wherein the UV reactive component comprises a urethane acrylate oligomer at from 40% to 70% by weight of the coating and a reactive diluent in an amount of from 10 to 60 % by weight.