The object of the present invention is to provide a golf ball which is even more excellent in abrasion-resistance, durability and moldability by using a polyurethane ionomer having a novel structure as a base resin of a cover. The golf ball of the present invention has a cover, and the cover comprises, as a base resin, a polyurethane ionomer containing a polycarbonate polyol as a constitutional component.
1. A golf ball comprising a cover, the cover comprising, as a base resin, a polyurethane ionomer containing a polycarbonate polyol and a component containing an acidic group as a constitutional components, wherein
the polycarbonate polyol has a repeating unit (A) as a repeating constitutional unit and a repeating unit (B) having a different structure from that of the repeating unit (A), and a molar ratio of (A)/(B) is 30/70 to 70/30, the repeating unit (A) represented by a following formula (I) and the repeating unit (B) represented by a following formula (II):
wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from a diol having 4 to 6 carbon atoms; and
wherein R 2 is a bivalent residue obtained by removing two hydroxyl groups from a diol having 4 to 6 carbon atoms, and
the component containing an acidic group is derived from dimethylol propionic acid, dimethylol butanoic acid, dihydroxypropionic acid, or dihydroxysuccinic acid, and
a rate of content of the component containing an acidic group in the polyurethane ionomer is from 0.27 mass % to 4.5 mass %.
2. The golf ball according to claim 1 , wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol.
3. The golf ball according to claim 1 , wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,4-butanediol, and R 2 is a bivalent residue obtained by removing two hydroxyl groups from 1,6-hexanediol.
4. The golf ball according to claim 1 , wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,5-pentanediol, and R 2 is a bivalent residue obtained by removing two hydroxyl groups from 1,6-hexanediol.
5. The golf ball according to claim 1 , wherein the rate of content of the component containing an acidic group in the polyurethane ionomer is 1.4 mass % or more.
6. A golf ball comprising a cover, the cover comprising, as a base resin, a polyurethane ionomer containing a polycarbonate polyol and a component containing an acidic group as a constitutional components, wherein the polycarbonate polyol has a repeating unit (A) as a repeating constitutional unit and a repeating unit (B) having a different structure from that of the repeating unit (A), and a molar ratio of (A)/(B) is 30/70 to 70/30, the repeating unit (A) represented by a following formula (I) and the repeating unit (B) represented by a following formula (II):
wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,4-butanediol, 1,5-pentanediol or 1,6-hexanediol; and
wherein R 2 is a bivalent residue obtained by removing two hydroxyl groups from 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol,
the component containing an acidic group is derived from dimethylol propionic acid, dimethylol butanoic acid, dihydroxypropionic acid, or dihydroxysuccinic acid, and
a rate of content of a component containing an acidic group in the polyurethane ionomer is from 0.3 mass % to 3.9 mass %.
7. The golf ball according to claim 6 , wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,4-butanediol, and R 2 is a bivalent residue obtained by removing two hydroxyl groups from 1,6-hexanediol
8. The golf ball according to claim 6 , wherein R 1 is a bivalent residue obtained by removing two hydroxyl groups from 1,5-pentanediol, and R 2 is a bivalent residue obtained by removing two hydroxyl groups from 1,6-hexanediol
9. The golf ball according to claim 6 , wherein the polycarbonate polyol has a weight average molecular weight of from 1,000 to 4,000.
10. The golf ball according to claim 6 , wherein the rate of content of the component containing an acidic group in the polyurethane ionomer is 1.4 mass % or more.