Coating compositions for golf balls and coated golf balls

1. A coating composition for a golf ball comprising:

(A) 20 to 40 percent by weight of a polymeric polyol comprising:

(i) 80 to 95 percent by weight of a polyurethane polyol,

(ii) 5 to 20 percent by weight of a polytetramethylene ether glycol;

(B) 30 to 50 percent by weight of a polyisocyanate,

(C) 0.01 to 1 percent by weight of a polyether-modified polysiloxane; and

(D) 0.2 to 2.0 percent by weight of a boron-containing compound;

the percentage by weight of (i) and (ii) being based on total weight of (i) and (ii), and the percentage by weight of (A), (B), (C) and (D) being based on total weight of the coating composition.

2. The coating composition of claim 1 in which the polyurethane polyol is a polyester-urethane)polyol.

3. The coating composition of claim 1 in which the polyisocyanate is a (cyclo)aliphatic polyisocyanate.

4. The coating composition of claim 3 in which the (cyclo)aliphatic polyisocyanate is an isocyanurate.

5. The coating composition of claim 4 in which the isocyanurate is a mixture of the isocyanurates of hexamethylene diisocyanate and isophorone diisocyanate.

6. The coating composition of claim 1 in which the boron-containing compound is selected from boric acid and boric acid esters.

7. The coating composition of claim 6 in which the boric add ester is a polysiloxane borate.

8. The coating composition of claim 7 in which the polysiloxane borate is the reaction product of:

(A) R 1 n R 2 m SiO (4-n-m)/2 wherein each R 1 , which may be identical or different, represents H, OH, a monovalent hydrocarbon group or a monovalent siloxane group; each R 2 , which may be identical or different, represents a group comprising one or more active hydrogens; m and n each represent a positive number fulfilling the requirements of 0<m<4, 0<n<4 and 2≦(m+n)<4; and

(B) a boron-containing compound selected from boric acid and boric acid esters and mixtures thereof.