Multi-layer golf ball

Abstract

A multi-layer golf ball includes a core formed from an ionomer, an intermediate layer surrounding the core, and a cover surrounding the intermediate layer. The core has a material hardness measured on the JIS-C scale of from about 34 to about 70, and has an outer surface that includes a plurality of land portions aligned on a common sphere, and a plurality of grooves separating the respective land portions and extending radially inward from the sphere. The common sphere has a diameter of from about 22 mm to about 32 mm. The intermediate layer is formed from a rubber material and has a radial thickness measured from the common sphere of from about 4.0 mm to about 9.0 mm. Additionally, the core has a 10-130 kg compression deformation of from about 3.5 to about 5.5 mm.

What is claimed is: 
     
         1 . A multi-layer golf ball comprising:
 a core formed from an ionomer that has a material hardness measured on the JIS-C scale of from about 34 to about 70, the core having an outer surface with a varying radial dimension and including:
 a plurality of surface features extending from a common sphere having a diameter of from about 22 mm to about 32 mm, wherein each of the plurality of surface features selected from a protrusion and a depression; and 
   an intermediate layer surrounding the core and having a radially inward surface that is bonded to the outer surface of the core across the entire outer surface, the intermediate layer formed from a rubber material and having a radial thickness measured from the common sphere of from about 4.0 mm to about 9.0 mm;   a cover surrounding the intermediate layer and defining an outermost portion of the ball, the cover including an ionomer resin, polyethylene, a polyester resin, or a mixture thereof; and   wherein the core has a 10-130 kg compression deformation of from about 3.5 to about 5.5 mm.   
     
     
         2 . The golf ball of  claim 1 , wherein the core and the intermediate layer define an intermediate ball, and wherein the intermediate ball has a 10-130 kg compression deformation of greater than about 3.0, but less than the 10-130 kg compression deformation of the core alone. 
     
     
         3 . The golf ball of  claim 1 , wherein a radius of the common sphere, multiplied by a total surface area of the core, and divided by a total volume of the core is from about 3.1 to about 3.8. 
     
     
         4 . The golf ball of  claim 1 , wherein the maximum radial height the plurality of surface features, measured from the common sphere, is from about 0.2 mm to about 2.0 mm. 
     
     
         5 . The golf ball of  claim 4 , wherein each surface feature of the plurality of surface features has a maximum radial height measured from the common sphere that is substantially the same. 
     
     
         6 . The golf ball of  claim 1 , wherein the rubber material includes: a main rubber containing a polybutadiene; an unsaturated carboxylic acid and/or a metal salt thereof; and an organic peroxide 
     
     
         7 . The golf ball of  claim 1 , wherein the intermediate layer is bonded to the core through an adhesive layer. 
     
     
         8 . The golf ball of  claim 1 , wherein at least 80% of the plurality of surface features are protrusions that have a perimeter that is a quadrilateral. 
     
     
         9 . The golf ball of  claim 1 , wherein the total number of surface features is between 100 and 300. 
     
     
         10 . A multi-layer golf ball comprising:
 a core formed from an ionomer that has a material hardness measured on the JIS-C scale of from about 34 to about 70, the core having an outer surface that includes:
 between 100 and 300 land portions aligned on a common sphere; 
 a plurality of grooves separating the respective land portions and extending radially inward from the sphere; and 
 wherein the sphere has a diameter between 22 mm and 32 mm; 
   an intermediate layer surrounding the core and having a radially inward surface that is bonded to the outer surface of the core across the entire outer surface, the intermediate layer having radial thickness extending from the common sphere of between 4.0 mm and 9.0 mm;   a cover surrounding the intermediate layer and defining an outermost portion of the ball, the cover including an ionomer resin, polyethylene, a polyester resin, or a mixture thereof; and   wherein the core has a 10-130 kg compression deformation of from about 3.5 to about 5.5 mm.   
     
     
         11 . The golf ball of  claim 10 , wherein the core and the intermediate layer define an intermediate ball, and wherein the intermediate ball has a 10-130 kg compression deformation of greater than about 3.0, but less than the 10-130 kg compression deformation of the core alone. 
     
     
         12 . The golf ball of  claim 10 , wherein a radius of the common sphere, multiplied by a total surface area of the core, and divided by a total volume of the core is from about 3.1 to about 3.8. 
     
     
         13 . The golf ball of  claim 10 , wherein the maximum depth of the plurality of grooves, measured from the common sphere, is from about 0.2 mm to about 2.0 mm. 
     
     
         14 . The golf ball of  claim 13 , wherein each groove of the plurality of grooves has a maximum depth measured in a radial direction relative to the common sphere that is substantially the same. 
     
     
         15 . The golf ball of  claim 10 , wherein the rubber material includes: a main rubber containing a polybutadiene; an unsaturated carboxylic acid and/or a metal salt thereof; and an organic peroxide 
     
     
         16 . The golf ball of  claim 10 , wherein the intermediate layer is bonded to the core through an adhesive layer. 
     
     
         17 . The golf ball of  claim 10 , wherein each groove of the plurality of grooves has a depth measured in a radial direction relative to the common sphere, and a width measured in a tangential direction relative to the common sphere; and
 wherein each groove of the first and second set of grooves has a width/depth ratio of between 2 and 8.