| abstract |
Linear thermosettable polyester resin compositions are prepared from benzenedicarboxylic acid, an alkyl dicarboxylic acid, (e.g. 1,6-hexanedioic acid), and a short chain alkylene diol component (e.g. 2,2-dimethyl-1,3-propanediol), the resin having a number average molecular weight of about 1,500 to about 5,000 and combined acid and hydroxyl values of about 20 to about 60 mg of KOH per gram of polyester. When these polyesters are combined with an aminoplast and an acid catalyst they form coating compositions which, when applied to a substrate and cured, provide a coating having an outstanding combination of hardness, adhesion, extendability, flexibility and dry heat resistance. |