| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a golf ball having a great flight distance on driver shots. <P>SOLUTION: The golf ball has a spherical core 4 and at least one cover layer 12 covering the spherical core 4. When JIS-C hardness, which is measured at nine points obtained by dividing a radius of the spherical core into equal parts having 12.5% intervals therebetween, is plotted against a distance from a core center, R<SP POS="POST">2</SP>of a linear approximation curve obtained from the least square method is 0.95 or higher, and a hardness difference between core surface hardness and core center hardness is 15 or higher in JIS-C hardness. <P>COPYRIGHT: (C)2012,JPO&INPIT |
