Two-piece solid golf ball

A two-piece solid golf ball made up of a solid core and a cover wherein said solid core is formed from a rubber composition composed of (A) 100 parts by weight of rubber base material containing 60 to 100 wt % of polybutadiene synthesized by using a catalyst of rare earth element and contains no less than 60% of cis-1,4-linkage, (B) 0.1 to 0.8 parts by weight of more than one organic peroxide compound, (C) 10 to 60 parts by weight of an unsaturated carboxylic acid and/or a metal salt thereof, (D) 0.1 to 5 parts by weight of an organic sulfur compound, and (E) 5 to 80 parts by weight of an inorganic filler and said solid core deforms by 3.0 to 5.5 mm under a load of 980 N (100 kgf) and has a diameter of 37 to 42 mm, and said cover is formed mainly from (F) a thermoplastic polyurethane material and has a thickness of 0.5 to 2.5 mm and a Shore D hardness of 50 to 70, and said two-piece solid golf ball made up of a solid core and a cover deforms by 3.0 to 5.0 mm under a load of 980 N (100 kgf).

A two-piece solid golf ball made up of a solid core and a cover wherein said solid core is formed from a rubber composition composed of (A) 100 parts by weight of rubber base material containing 60 to 100 wt % of polybutadiene synthesized by using a catalyst of rare earth element and contains no less than 60% of cis-1,4-linkage, (B) 0.1 to 0.8 parts by weight of organic peroxide compound, (C) an unsaturated carboxylic acid and/or a metal salt thereof, (D) an organic sulfur compound, and (E) an inorganic filler and said solid core deforms by 3.0 to 5.5 mm under a load of 980 N (100 kgf) and has a diameter of 37 to 42 mm, and said cover is formed mainly from (F) a thermoplastic polyurethane material composed of (M) a thermoplastic polyurethane and (N) an isocyanate mixture, said isocyanate mixture as component (N) being composed of (N-1) an isocyanate compound having two or more isocyanate groups as functional groups in one molecule and (N-2) a thermoplastic resin which does not substantially react with said isocyanate groups, with the (N-1) being dispersed in the (N-2) and has a thickness of 0.5 to 2.5 mm and a Shore D hardness of 50 to 70, and said two-piece solid golf ball made up of a solid core and a cover deforms by 3.0 to 5.0 mm under a load of 980 N (100 kgf).

A two-piece solid golf ball made up of a solid core and a cover wherein said solid core is formed from a rubber composition composed of (A) 100 parts by weight of rubber base material containing 60 to 100 wt% of polybutadiene synthesized by using a catalyst of rare earth element and contains no less than 60% of cis-1,4-linkage, (B) 0.1 to 0.8 parts by weight of organic peroxide compound, (C) an unsaturated carboxylic acid and/or a metal salt thereof, (D) an organic sulfur compound, and (E) an inorganic filler and said solid core deforms by 3.0 to 5.5 mm under a load of 980 N (100 kgf) and has a diameter of 37 to 42 mm, and said cover is formed mainly from (F) a thermoplastic polyurethane material and has a thickness of 0.5 to 2.5 mm and a Shore D hardness of 50 to 70, and said two-piece solid golf ball made up of a solid core and a cover deforms by 3.0 to 5.0 mm under a load of 980 N (100 kgf), wherein the cover has a coating film on the surface thereof, said coating film being formed from a golf ball coating composition containing a hydroxyl group-containing polyester obtained by reaction between a polyhydric alcohol and a polybasic acid and also containing a non-yellowing polyisocyanate, said polyhydric alcohol having at least partly an alicyclic structure in the molecule.