Golf ball

Abstract

A golf ball 2 includes a core 4, an inner cover 6 positioned outside the core 4, and an outer cover 8 positioned outside the inner cover 6. The core 4 has a capsule 14, a plurality of separators 16, an electronic unit 18, and a plurality of fillings 20. The capsule 14 has a melting point of not lower than 100° C. A ratio P1 of a volume Vr of the capsule 14 to a volume Vc of the core 4 is not less than 25% and not greater than 75%. The electronic unit 18 is housed in the capsule 14. The electronic unit 18 detects behavior of the golf ball 2.

What is claimed is: 
     
         1 . A golf ball comprising a core and one or more covers positioned outside the core, wherein
 the core has an electronic unit for detecting behavior of the golf ball and a capsule in which the electronic unit is housed and which has a melting point of not lower than 100° C., and   a ratio P 1  of a volume Vr of the capsule to a volume Vc of the core is not less than 25% and not greater than 75%.   
     
     
         2 . The golf ball according to  claim 1 , wherein the core has, in the capsule, a positioning mechanism capable of fixing a position of the electronic unit with respect to the capsule by attaching the electronic unit. 
     
     
         3 . The golf ball according to  claim 2 , wherein the positioning mechanism is a separator fixed to the capsule and partitioning an inside of the capsule. 
     
     
         4 . The golf ball according to  claim 1 , wherein the core has a filling positioned between the capsule and the electronic unit. 
     
     
         5 . The golf ball according to  claim 4 , wherein a base material of the filling is an epoxy resin. 
     
     
         6 . The golf ball according to  claim 4 , wherein the filling includes a matrix and a specific gravity adjusting agent dispersed in the matrix and having a density higher than a density of the matrix. 
     
     
         7 . The golf ball according to  claim 6 , wherein the specific gravity adjusting agent is tungsten powder. 
     
     
         8 . The golf ball according to  claim 1 , wherein the capsule has a Shore D hardness of not less than 30. 
     
     
         9 . The golf ball according to  claim 1 , wherein
 a material of the capsule is a resin composition, and   a base resin of the resin composition is polycarbonate or polyether ether ketone.   
     
     
         10 . The golf ball according to  claim 1 , wherein
 the one or more covers include a cover formed by crosslinking a rubber composition, and   the rubber composition includes
 (1) a base rubber, 
 (2) a co-crosslinking agent, and 
 (3) a crosslinking initiator having a 1-minute half-life temperature of not higher than 170° C. 
   
     
     
         11 . The golf ball according to  claim 1 , wherein
 the one or more covers include a cover whose material is a resin composition, and   a base resin of the resin composition is an ionomer resin or a polyurethane.   
     
     
         12 . The golf ball according to  claim 1 , wherein
 the one or more covers include an inner cover positioned outside the core and an outer cover positioned outside the inner cover,   the inner cover is formed by crosslinking a rubber composition, and   a material of the outer cover is a resin composition.   
     
     
         13 . The golf ball according to  claim 12 , wherein
 the inner cover has a thickness of not less than 1.0 mm,   the inner cover has a Shore D hardness of not greater than 50,   the outer cover has a thickness of not less than 1.0 mm, and   the outer cover has a Shore D hardness of not greater than 50.   
     
     
         14 . A golf ball comprising a core and one or more covers positioned outside the core, wherein
 the core has an electronic unit for detecting behavior of the golf ball, and   any one of the one or more covers has a first hemisphere shell and a second hemisphere shell having a color different from a color of the first hemisphere shell.   
     
     
         15 . The golf ball according to  claim 14 , wherein
 the electronic unit has a sensor, and   an angle of a straight line connecting a center of a circle forming a boundary between the first hemisphere shell and the second hemisphere shell and a center of gravity of the sensor, to the circle, is not less than 70° and not greater than 90°.   
     
     
         16 . The golf ball according to  claim 14 , wherein the core has a capsule having a melting point of not lower than 100° C., and the electronic unit is housed in the capsule. 
     
     
         17 . The golf ball according to  claim 16 , wherein a ratio P 1  of a volume Vr of the capsule to a volume Vc of the core is not less than 25% and not greater than 75%. 
     
     
         18 . The golf ball according to  claim 16 , wherein the core has, in the capsule, a positioning mechanism capable of fixing a position of the electronic unit with respect to the capsule by attaching the electronic unit. 
     
     
         19 . The golf ball according to  claim 18 , wherein the positioning mechanism is a separator fixed to the capsule and partitioning an inside of the capsule. 
     
     
         20 . The golf ball according to  claim 16 , wherein the core has a filling positioned between the capsule and the electronic unit. 
     
     
         21 . The golf ball according to  claim 16 , wherein
 a material of the capsule is a resin composition, and   a base resin of the resin composition is polycarbonate or polyether ether ketone.   
     
     
         22 . The golf ball according to  claim 14 , wherein
 the one or more covers include an inner cover positioned outside the core and an outer cover positioned outside the inner cover,   the inner cover is formed by crosslinking a rubber composition,   the outer cover has the first hemisphere shell and the second hemisphere shell,   a material of the first hemisphere shell is a resin composition, and   a material of the second hemisphere shell is a resin composition different from the resin composition of the first hemisphere shell.   
     
     
         23 . The golf ball according to  claim 22 , wherein the rubber composition includes
 (1) a base rubber,   (2) a co-crosslinking agent, and   (3) a crosslinking initiator having a 1-minute half-life temperature of not higher than 170° C.