Infrared heating method for creating cure gradients in golf balls and golf ball cores

Abstract

This invention is directed to a method for creating cure gradients in golf balls and golf ball cores by the application of high temperatures from infrared radiation. The hardness gradients are created in the outer skin wherein the outer 0.001 to 0.040 inches of the core has a different hardness than the rest of the core. The same hardness gradients can be applied to the outer skin of any intermediate or cover layers. The skin can either be harder or softer than the rest of the component. The skins can be compounded by materials that will be reactive at temperatures produced by infrared radiation.

What is claimed is:  
     
         1 . A method of curing a golf ball core comprising of: 
 providing a pre-molded core;    heating the core with high temperature infrared radiation to form an outer skin thereupon; and,    forming a cure gradient in the outer skin.    
     
     
         2 . The method of  claim 1 , wherein the cure gradient formed in the outer skin is between about 0.001 to about 0.04 inches thick.  
     
     
         3 . The method of  claim 1 , wherein the core provided is of a thermosetting composition.  
     
     
         4 . The method of  claim 1 , wherein the heating creates a difference in hardness between the outer skin and a remainder of the core.  
     
     
         5 . The method of  claim 4 , wherein the heating creates an outer skin that is harder than the remainder of the core.  
     
     
         6 . The method of  claim 5 , wherein the outer skin has a Shore D hardness of greater than about 50 and the remainder of the core has a Shore D hardness of at least about 3 points lower.  
     
     
         7 . The method of  claim 5 , wherein the outer skin has a Shore D hardness of greater than about 60 and the remainder of the core has a Shore D hardness of at least about 3 points lower.  
     
     
         8 . The method of  claim 1 , wherein the heating by infrared radiation comprises heating to temperatures from about 350° F. to about 2000° F.  
     
     
         9 . The method of  claim 1 , wherein the heating creates an outer skin that is softer than a remainder of the core.  
     
     
         10 . The method of  claim 9 , wherein the outer skin has a Shore D hardness of greater than about 50 and the remainder of the core has a Shore D hardness of at least about 3 points higher.  
     
     
         11 . The method of  claim 9 , wherein the heating creates a softer outer skin on the core by degrading the core.  
     
     
         12 . The method of  claim 11 , wherein the degrading of the core comprises treating the core with a material that will react upon infrared radiation exposure.  
     
     
         13 . The method of  claim 11 , wherein the degrading of the core comprises compounding the core with a material that will degrade upon exposure to infrared radiation.  
     
     
         14 . A method of curing a golf ball component comprising: 
 providing a pre-molded core;    forming a cover layer about the core;    heating the cover layer with high temperature infrared radiation to form an outer skin thereupon; and,    forming a cure gradient in the outer skin.    
     
     
         15 . The method of  claim 14 , wherein the cure gradient formed in the outer skin is between about 0.001 to about 0.04 inches thick.  
     
     
         16 . The method of  claim 14 , wherein the heating creates a difference in hardness between the outer skin and a remainder of the cover layer.  
     
     
         17 . The method of  claim 16 , wherein the heating creates an outer skin on the cover that is harder than the remainder of the cover layer.  
     
     
         18 . The method of  claim 17 , wherein the outer skin has a Shore D hardness of greater than about 50 and the remainder of the cover layer has a Shore D hardness of at least about 3 points lower.  
     
     
         19 . The method of  claim 16 , wherein the heating creates an outer skin on the cover layer that is softer than the remainder of the cover.  
     
     
         20 . The method of  claim 19 , wherein the heating creates an outer skin having a Shore D hardness of greater than about 50 and the remainder of the cover layer has a Shore D hardness of at least about 3 points higher.  
     
     
         21 . The method of  claim 19 , wherein the heating comprises degrading the cover layer to create an outer skin that is softer than the remainder of the cover layer.  
     
     
         22 . The method of  claim 21 , wherein the degrading of the cover layer comprises treating the cover layer with a material that will react upon infrared radiation exposure.  
     
     
         23 . The method of  claim 21 , wherein the degrading of the cover layer comprises compounding the cover layer with a material that will degrade upon exposure to infrared radiation.  
     
     
         24 . The method of  claim 14 , wherein the cover layer is an inner cover layer.  
     
     
         25 . The method of  claim 14 , wherein the golf ball component further comprises an intermediate layer disposed between the core and the cover layer.