Patent ID: 9717955
Date: 2017-08-01
CPC Classifications: A63B

Claim:
1. A golf ball comprising a core formed by crosslinking a rubber composition including a base rubber and from 0.05 parts by weight to 3.0 parts by weight of 2-naphthalenethiol based upon 100 parts by weight of said base rubber, a mid layer positioned outside the core, and a cover positioned outside the mid layer, wherein a difference between: a JIS-C hardness H(5.0) at a point which is located at a distance of 5 mm from a central point of the core; and a JIS-C hardness Ho at the central point is equal to or greater than 6.0, a difference between: a JIS-C hardness H(12.5) at a point which is located at a distance of 12.5 mm from the central point; and the JIS-C hardness H(5.0) is equal to or less than 3.0, a difference between a JIS-C hardness Hs at a surface of the core and the JIS-C hardness H(12.5) is equal to or greater than 10.0, the JIS-C hardness H(12.5) is smaller than the average value of the JIS-C hardness H(10) at a point which is located at a distance of 10.0 mm from the central point of the core and the JIS-C hardness H(15) at a point which is located at a distance of 15.0 mm from the central point of the core, a difference between the JIS-C hardness Hs and the JIS-C hardness Ho is equal to or greater than 22.0, a difference between the JIS-C hardness H(5.0) and the JIS-C hardness Ho is smaller than a difference between the JIS-C hardness Hs and the JIS-C hardness H(12.5), wherein a difference between the JIS-C hardness H(12.5) and the JIS-C hardness H(5.0) is equal to or less than 1.5, and a difference between the JIS-C hardness Hs and the JIS-C hardness H(12.5) is equal to or greater than 13.0, there is no zone in which a hardness decreases from the central point toward the surface, the mid layer is constituted with a resin composition, and the base polymer of the mid layer include an ionomer resin as a principal component, and a Shore D hardness H3 of the cover is greater than a Shore D hardness H2 of the mid layer.