Copolyester resin for solventborne coating and coating composition comprising the same

A copolyester resin for solventborne coating composition, said copolyester resin prepared by polycondensing components consisting essentially of:

• (a) an acid component comprising
• 60–90 mol % of aromatic dicarboxylic acid selected from the group consisting of isophthalic acid, C1–C2 alkylester of isophthalic acid, phthalic acid, C1–C2 alkylester of phthalic acid, phthalic anhydride, and mixtures thereof, and
• 10–40 mol % of cycloaliphatic dicarboxylic acid selected from the group consisting of 1,2-cyclohexane dicarboxylic anhydride, 1,2-cyclohexane dicarboxylic acid, C1–C2 alkylester of 1,2-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, C1–C2 alkylester of 1,4-cyclohexane dicarboxylic acid, and mixtures thereof;
• (b) an alcohol component comprising polyvalent alcohol present in an amount of 40% or less, and 60–100 mol % of 2,2-dialkyl-1,3-propanediol wherein
• said polyvalent alcohol is selected from the group consisting of cyclohexanedimethanol, propylene glycol, 2,2,4-trimethylpentanediol, tricyclodecanedimethanol, ethylene glycol, 2-methylpropanediol, butanediol, 1,6-hexanediol, and mixtures thereof, and
• said 2,2-dialkyl-1,3-propanediol is the mixture of 2-butyl-2-ethyl-1,3-propanediol and neopentyl glycol, and the 2-butyl-2-ethyl-1,3-propanediol is present in an amount of 10–55 mol % of the total alcohol component;
• and
• (c) a polyfunctional component having a functionality of three or higher, present in an amount of 5 mol % or less, based on the total moles of acid and alcohol components, wherein said polyfunctional component comprises polyacid, polyol, or mixtures thereof.