| 摘要 |
<p>Disclosed is a copolyester resin having number average molecular weight over 5,000 for solventborne metal coating binder, which has superior gloss retention and color stability after long term outdoor exposure, and a coating composition comprising the same. The copolyester has excellent weatherability and color stability. The copolyester resin is prepared through the polycondensation of 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, an alcohol component comprising 60-100 mol % of 2,2-dialkyl-1,3-propandiol and 0-40 mol % of a polyvalent alcohol and 0-5 mol % of a polyvalent alcohol or acid.</p> |
