Multilayer Solid Golf Ball

Abstract

A multilayer solid golf ball maintains performance characteristics after exposure to high ambient temperatures. A core includes a thermoplastic material. The core is surrounded by an intermediate layer comprising a peroxide cross-linked polybutadiene. A single layer or double layer cover with dimples is also provided.

1 . A golf ball comprising:
 a core, said core comprising a thermoplastic material;   an intermediate layer enclosing said core to form an inner ball, said intermediate layer comprising a thermoset material; and   a cover enclosing said inner ball, wherein said golf ball satisfies the following requirements:   (1) said inner ball has a first deflection amount of 2.2 to 3.2 millimeters under a load of 10 to 130 kilograms when said inner ball is kept in an environment of 24 degrees Celsius for at least about eight hours,   (2) said inner ball has a second deflection amount under a load of 10 to 130 kilograms when said inner ball is kept in an environment of about 50 degrees Celsius for at least about 8 hours, and wherein the ratio of the second deflection amount to the first deflection amount is between about 1.05 and about 1.15, and   (3) said core has a coefficient of restitution at 40 meters per second falling between approximately 0.79 and 0.89 and higher than that of said golf ball.   
     
     
         2 . The golf ball of  claim 1 , wherein said core has a diameter of 19 millimeters to 32 millimeters. 
     
     
         3 . The golf ball of  claim 1 , wherein said intermediate layer has a thickness of 3 millimeters to 11 millimeters. 
     
     
         4 . The golf ball of  claim 1 , wherein said intermediate layer has a thickness of 4 millimeters to 10 millimeters. 
     
     
         5 . The golf ball of  claim 1 , wherein said thermoplastic material is selected from the group consisting of ionomer resin, highly neutralized acid polymer composition, polyamide resin, polyester resin, polyurethane resin, and any combinations thereof. 
     
     
         6 . The golf ball of  claim 1 , wherein said cover comprises an inner cover layer enclosing said inner ball and an outer cover layer enclosing said inner cover layer; said outer cover layer having a Shore D hardness lower than that of the inner cover layer. 
     
     
         7 . The golf ball of  claim 6 , wherein said inner cover layer comprises an external surface having a Shore D hardness of 45 to 65; said outer cover layer comprises an external surface having a Shore D hardness of 40 to 60. 
     
     
         8 . A golf ball comprising:
 a core, said core comprising a thermoplastic material;   an intermediate layer enclosing said core to form an inner ball, said intermediate layer comprising a thermoset material; and   a cover enclosing said inner ball and having a plurality of dimples on its outer surface, wherein said golf ball satisfies the following requirements:   (1) said inner ball has a first deflection amount of 2.2 to 3.2 millimeters under a load of 10 to 130 kilograms when said inner ball is kept in an environment of 24 degrees Celsius for at least about 8 hours,   (2) said inner ball has a second deflection amount under a load of 10 to 130 kilograms when said inner ball is kept in an environment of 50 degrees Celsius for at least about 8 hours, and the ratio of the second deflection amount to the first deflection amount is between about 1.05 and about 1.15, and   (3) said core has a coefficient of restitution at forty (40) meters per second falling between approximately 0.79 and 0.89 and higher than that of said golf ball, and   (4) said dimples have a total volume of 550 cubic millimeters to 800 cubic millimeters.   
     
     
         9 . The golf ball of  claim 8 , wherein said dimples have a total number of 250 to 500. 
     
     
         10 . The golf ball of  claim 8 , wherein said dimples have a total number of 300 to 450. 
     
     
         11 . The golf ball of  claim 8 , wherein said dimples have a total volume of 600 cubic millimeters to 800 cubic millimeters. 
     
     
         12 . The golf ball of  claim 8 , wherein said dimples are provided with 3 to 6 kinds of different diameters. 
     
     
         13 . The golf ball of  claim 12 , wherein the number of dimples with the largest diameter is greater than the respective number of any other dimples with smaller diameters. 
     
     
         14 . The golf ball of  claim 8 , wherein said core has a diameter of 19 millimeters to 32 millimeters. 
     
     
         15 . The golf ball of  claim 8 , wherein said intermediate layer has a thickness of 3 millimeters to 11 millimeters. 
     
     
         16 . The golf ball of  claim 8 , wherein said intermediate layer has a thickness of 4 millimeters to 10 millimeters. 
     
     
         17 . The golf ball of  claim 8 , wherein said thermoplastic material is selected from the group consisting of ionomer resin, highly neutralized acid polymer composition, polyamide resin, polyester resin, polyurethane resin, and any combinations thereof. 
     
     
         18 . The golf ball of  claim 8 , wherein said cover comprises an inner cover layer enclosing said inner ball and an outer cover layer enclosing said inner cover layer; said outer cover layer having a Shore D hardness lower than that of the inner cover layer. 
     
     
         19 . The golf ball of  claim 18 , wherein said inner cover layer or outer cover layer comprises a material selected from the group consisting of ionomer resin, highly neutralized acid polymer composition, polyamide resin, polyester resin, thermoplastic polyurethane resin, thermoset polyurethane resin, and any combinations thereof. 
     
     
         20 . The golf ball of  claim 18 , wherein said inner cover layer comprises an external surface having a Shore D hardness of 45 to 65; said outer cover layer comprises an external surface having a Shore D hardness of 40 to 60.