Aliphatic polyester coating compositions containing tetramethyl cyclobutanediol

A curable, aliphatic polyester, consisting of:

• i. diacid residues, consisting essentially of about 50 to 100 mole percent of the residues of 1,4-cyclohexanedicarboxylic acid, hexahydrophthalic anhydride, or a mixture thereof and about 50 to 0 mole percent of the residues of adipic acid, based on the total moles of diacid residues;
• ii. diol residues, consisting essentially of about 75 to 100 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol;
• and
• iii. about 3 to about 30 mole percent of the residues of trimethylolpropane, based on the total moles of diol and polyol residues;
• wherein said curable, aliphatic polyester has a number average molecular weight of about 300 to about 10,000 daltons, a glass transition temperature of about −35° C. to about 35° C., a hydroxyl number of about 20 to about 450 mg KOH/g of polyester, and an acid number of 0 to about 80 mg KOH/g of polyester.

A thermosetting coating composition, comprising:

• (A). about 50 to about 90 weight percent, based on the total weight of (A) and (B) of at least one curable, aliphatic polyester, consisting of
• i. diacid residues, comprising at least 90 mole percent, based on the total moles of diacid residues, of the residues of at least one aliphatic diacid, said aliphatic dicacid comprising about 50 to 100 mole percent of a cycloaliphatic dicarboxylic acid
• ii. diol residues, comprising about 50 to 100 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol;
• and
• iii. about 3 to about 30 mole percent of the residues of at least one polyol chosen from trimethylolpropane, pentaerythritol, trimethylolethane, erythritol, threitol, dipentaerythritol, sorbitol, and glycerine, based on the total moles of diol and polyol residues;
• wherein said curable, aliphatic polyester has a number average molecular weight of about 300 to about 10,000 daltons, a glass transition temperature of about −35° C. to about 35° C., a hydroxyl number of about 20 to about 450 mg KOH/g of polyester, and an acid number of 0 to about 80 mg KOH/g of polyester;
• (B). about 10 to about 50 weight percent, based on the total weight of (A) and (B) of a crosslinker comprising at least one compound reactive with a carboxylic acid or a hydroxyl group;
• and
• (C). about 10 to about 60 weight percent, based on the total weight of (A), (B), and (C) of at least one nonaqueous solvent.