Golf ball and method of improving golf ball performance

Abstract

Golf balls having an outermost layer, which outermost layer has been subjected to impregnation treatment with an isocyanate and/or isothiocyanate-containing olefin compound but has not been topcoated, exhibit at least one improved golf ball attribute, such as scuff resistance or spin performance, compared with similar golf balls that have not been impregnation treated.

1 . A golf ball comprising an outermost layer, wherein the outermost layer is impregnation treated with an isocyanate and/or isothiocyanate-containing olefin compound and is not topcoated. 
   
   
       2 . The golf ball of  claim 1 , wherein the outermost layer is formed of a thermoplastic and/or thermoset polymer. 
   
   
       3 . The golf ball of  claim 1 , wherein the isocyanate and/or isothiocyanate-containing olefin compound in the impregnation-treated outermost layer is subjected to thermal polymerization, photopolymerization and/or addition reaction with functional groups. 
   
   
       4 . The golf ball of  claim 3 , wherein the olefin moiety of the isocyanate and/or isothiocyanate-containing olefin compound is at least one olefin group selected from the group consisting of acrylic, methacrylic, allyl and vinyl groups, and exhibits photopolymerizability on exposure to ultraviolet light and/or thermal polymerizability. 
   
   
       5 . The golf ball of  claim 3 , wherein the isocyanate moiety of the isocyanate-containing olefin compound has an isocyanate group and/or an isocyanate group-capped derivative, and exhibits addition reactivity with at least one functional group selected from the group consisting of amide, urethane, primary amino, secondary amino, hydroxyl and carboxyl groups. 
   
   
       6 . The golf ball of  claim 3 , wherein the isothiocyanate moiety of the isothiocyanate-containing olefin compound has an isothiocyanate group and/or an isothiocyanate group-capped derivative, and exhibits addition reactivity with at least one functional group selected from the group consisting of amide, urethane, primary amino, secondary amino, hydroxyl and carboxyl groups. 
   
   
       7 . The golf ball of  claim 3 , wherein the isocyanate and/or isothiocyanate-containing olefin compound has a melting point of not above 80° C. 
   
   
       8 . The golf ball of  claim 1 , wherein the impregnation layer formed by impregnation of the outermost layer with the isocyanate and/or isothiocyanate-containing olefin compound has a thickness in a range of from about 5 μm to about 900 μm. 
   
   
       9 . The golf ball of  claim 1 , wherein the impregnated layer formed by impregnating the outermost layer with the isocyanate and/or isothiocyanate-containing olefin compound has a surface hardness which is from about 1 to about 10 Shore D hardness units higher than the surface hardness of the outermost layer prior to impregnation treatment. 
   
   
       10 . The golf ball of  claim 1  which is selected from the group consisting of one-piece golf balls, two-piece solid golf balls composed of a core and a cover encasing the core, and multi-piece solid golf balls composed of a core of at least one layer, one or more intermediate layer encasing the core, and a cover of at least one layer encasing the intermediate layer. 
   
   
       11 . A method of modifying a golf ball having an outermost layer, the method comprising the step of impregnating the outermost layer with an isocyanate and/or isothiocyanate-containing olefin compound but not topcoating the outermost layer. 
   
   
       12 . The golf ball modifying method of  claim 11 , wherein the step of impregnating the outermost layer with an isocyanate and/or isothiocyanate-containing olefin compound is carried out at an impregnation temperature which does not exceed the melting point and/or softening point of the polymer material in the outermost layer, and an impregnation time in a range of from about 15 seconds to about 100 hours. 
   
   
       13 . The golf ball modifying method of  claim 12  which additionally comprises, following the step of impregnating the outermost layer with an isocyanate and/or isothiocyanate-containing olefin compound, the step of photopolymerizing by exposure to ultraviolet light and/or the step of thermal polymerizing by heat treatment. 
   
   
       14 . The golf ball modifying method of  claim 13 , wherein the step of photopolymerizing by exposure to ultraviolet light is carried out at an ultraviolet irradiation temperature in a range of from about 0° C. to about 100° C. and for an ultraviolet irradiation time in a range of from about 5 seconds to about 50 hours. 
   
   
       15 . The golf ball modifying method of  claim 14 , wherein the step of thermal polymerizing by heat treatment is carried out after the step of photopolymerizing by exposure to ultraviolet light, at a heat treatment temperature in a range of from about 25° C. to about 100° C., and for a heat treatment time in a range of from about 5 seconds to about 50 hours. 
   
   
       16 . The golf ball modifying method of  claim 12  wherein, following the step of impregnating the outermost layer with an isocyanate and/or isothiocyanate-containing olefin compound, the golf ball is left to stand for at least 200 hours without carrying out a photopolymerization step by exposure to ultraviolet light or a thermal polymerization step by heat treatment.