Silicone-modified polyester coating

1. A method of making a silicone-modified polyester liquid coating composition, comprising:

making a siliconized polyester by a method comprising

providing at least 30% by weight of at least one hydroxy-functional silicone compound;

providing at least one hydroxy-functional compound;

reacting the hydroxy-functional silicone compound and the hydroxy-functional compound to produce a siliconized hydroxy-functional polymer having predominantly silyl ether functionality; and

esterifying the siliconized hydroxy-functional polymer with at least one carboxylic acid-functional compound or derivative thereof to form the siliconized polyester having an acid number of 5 to 6; and

blending the siliconized polyester with one or more other components in the presence of a crosslinker, wherein the blending process is carried out in a liquid carrier.

2. The method of claim 1 , wherein the hydroxy-functional silicone has number average molecular weight (Mn) of 500 to 1200.

3. The method of claim 1 , wherein the siliconized hydroxy-functional polymer has Mw of about 3000 to about 4500.

4. The method of claim 1 , wherein the siliconized hydroxy-functional polymer has an OH number of at least about 85.

5. The method of claim 1 , wherein the hydroxy-functional compound is a polyol.

6. The method of claim 1 , wherein the hydroxy-functional compound is a polyol comprising at least one of 1,6-hexanediol, pentaerythritol, trimethylolpropane, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, trimethylol ethane, 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropionate (HPHP), and combinations thereof.

7. The method of claim 1 , wherein the hydroxy-functional compound is a polyol comprising at least one of 1,6-hexanediol, trimethylolpropane, neopentyl glycol, ethylene glycol, 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropionate (HPHP), and combinations thereof.

8. The method of claim 1 , wherein the carboxylic-acid functional compound is a polyacid or derivative thereof.

9. The method of claim 1 , wherein the carboxylic-acid functional compound is a polyacid comprising at least one of phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, benzophenone dicarboxylic acid, diphenic acid, 4,4-di carboxydiphenyl ether, 2,5-pyridine dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, trimellitic acid, trimellitic anhydride, and combinations thereof.

10. The method of claim 1 , wherein the hydroxy-functional silicone compound and the hydroxy-functional compound are present in a 1:2 ratio by weight.

11. The method of claim 1 , wherein the siliconized hydroxy-functional polymer and the carboxylic acid-functional compound are present in a 1:1 ratio by weight.

12. The method of claim 1 , wherein the siliconized polyester has a Gardner viscosity of N at 25° C.

13. The method of claim 1 , further comprising a catalyst for the step of reacting the hydroxy-functional silicone compound and the hydroxy-functional compound.

14. The method of claim 13 , wherein the catalyst comprises at least one of stannous oxalate, stannous chloride, butylstannoic acid, dibutyl tin oxide, tetrabutyltitanate, or tetra butylzirconate, and mixtures thereof.

15. The method of claim 13 , wherein the catalyst is a tetrabutyl titanate catalyst.

16. A method, comprising:

providing a planar metal substrate having the coating composition made by the method of claim 1 applied on at least a portion of the metal substrate; and

curing the coating composition on the substrate to form a coated article.