Golf ball cover resin composition and golf ball

1. A golf ball comprising a cover formed by injection molding a golf ball cover resin composition which comprises a resin component and (C) a zinc compound,

wherein the resin component consist of

(A) an ionomer resin consisting of a metal ion-neutralized product of a ternary copolymer composed of an olefin, an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms, and an α,β-unsaturated carboxylic acid ester and

(B) a binary copolymer composed of an olefin and an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a ternary copolymer composed of an olefin, an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms, and an α,β-unsaturated carboxylic acid ester,

wherein a content ratio ((A)/(B)) of (A) component to (B) component ranges from 50/50 to 80/20 in a mass ratio and a content of (C) component ranges from 0.1 part to 20 parts with respect to 100 parts by mass of a sum of (A) component and (B) component, and

the golf ball cover resin composition has a melt flow rate (190° C., 2.16 kg) of 5 g/10 min or more and a bending stiffness ranging from 10 MPa to 86 MPa, and

wherein (A) the ionomer resin has a melt flow rate (190° C., 2.16 kg) ranging from 0.1 g/10 min to 20 g/10 min.

2. The golf ball according to claim 1 , wherein the cover has a thickness ranging from 0.5 mm to 1.5 mm.

3. The golf ball according to claim 1 , wherein (C) the zinc compound is zinc oxide, zinc hydroxide, or zinc carbonate.

4. The golf ball according to claim 1 , wherein the golf ball cover resin composition has a slab hardness ranging from 35 to 55 in Shore D hardness.

5. The golf ball according to claim 1 , wherein A1, A2, B1, and B2 defined below satisfy following expressions:

P 1= A 1/( A 1+ B 1)

P 2= A 2/( A 2+ B 2)

0.3≦ P 1≦1.0

0.3≦ P 2≦1.0

1 . 1 ≦ P 2/ P 1≦2.5

wherein

A1 is defined as an area under a peak around 1600 cm −1 and B1 is defined as an area under a peak around 1700 cm −1 in a spectrum obtained by analyzing the golf ball cover resin composition before injection molding by FT-IR, and

A2 is defined as an area under a peak around 1600 cm −1 and B2 is defined as an area under a peak around 1700 cm −1 in a spectrum obtained by analyzing the golf ball cover resin composition after injection molding by FT-IR.

6. The golf ball according to claim 1 , wherein a degree of neutralization of the carboxyl groups contained in (A) the ionomer resin ranges from 20 mole % to 90 mole %.

7. The golf ball according to claim 1 , wherein (A) the ionomer resin has a bending stiffness ranging from 10 MPa to 100 MPa and a slab hardness ranging from 20 to 70 in Shore D hardness.

8. The golf ball according to claim 1 , wherein (B) the binary copolymer and/or the ternary copolymer has a melt flow rate (190° C., 2.16 kg) ranging from 55 g/10 min to 1,700 g/10 min.

9. The golf ball according to claim 1 , comprising a core covered with the cover, wherein the core has a center hardness ranging from 30 to 50 in Shore D hardness.

10. The golf ball according to claim 1 , comprising a core covered with the cover, wherein the core has a surface hardness ranging from 20 to 70 in Shore D hardness.

11. The golf ball according to claim 1 , comprising a core covered with the cover, wherein the core has a hardness difference between a surface hardness and a center hardness ranging from 4 to 40 in Shore D hardness.

12. The golf ball according to claim 1 , wherein

(A) component is a metal ion-neutralized product of a ternary copolymer composed of ethylene, (meth)acrylic acid, and (meth)acrylic acid ester, and

(B) component is a binary copolymer composed of ethylene and methacrylic acid and/or a ternary copolymer composed of ethylene, (meth)acrylic acid, and (meth)acrylic acid ester.

13. The golf ball according to claim 12 , wherein the (C) zinc compound is the only component employed to neutralize non-neutralized carboxyl groups of the (A) ionomer resin and (B) binary copolymer components.

14. The golf ball according to claim 5 , wherein the (C) zinc compound is the only component employed to neutralize non-neutralized carboxyl groups of the (A) ionomer resin and (B) binary copolymer components.

15. The golf ball according to claim 4 , further comprising a core covered with the cover, wherein the core has a surface hardness ranging from 65 to 70 in Shore D hardness, and wherein the cover has a thickness ranging from 0.5 mm to 1.3 mm.

16. The golf ball according to claim 1 , further comprising a core covered with the cover, wherein the core has a surface hardness ranging from 65 to 70 in Shore D hardness,

wherein the cover has a thickness ranging from 0.5 mm to 1.3 mm,

wherein the (A) ionomer resin component is a metal ion-neutralized product of a ternary copolymer composed of ethylene, (meth)acrylic acid, and (meth)acrylic acid ester, and the (B) binary copolymer component is a binary copolymer composed of ethylene and methacrylic acid and/or a ternary copolymer composed of ethylene, (meth)acrylic acid, and (meth)acrylic acid ester,

wherein the (C) zinc compound is the only component employed to neutralize non-neutralized carboxyl groups of the (A) ionomer resin and (B) binary copolymer components, and

wherein the golf ball cover resin composition has a slab hardness ranging from 35 to 55 in Shore D hardness.

17. The golf ball according to claim 1 , further comprising a core covered with the cover, wherein the core has a surface hardness ranging from 65 to 70 in Shore D hardness,

wherein the cover has a thickness ranging from 0.5 mm to 1.0 mm,

wherein the golf ball cover resin composition has a slab hardness ranging from 35 to 55 in Shore D hardness,

and

wherein (B) the binary copolymer and/or the ternary copolymer has a melt flow rate (190° C., 2.16 kg) ranging from 55 g/10 min to 1,700 g/10 min.