Esterification of terephthalic acid with an alkylene glycol in the presence of a pyridine dicarboxylic acid compound

摘要

The esterification of an aromatic dicarboxylic acid with an alkylene glycol containing 2 to 10 carbon atoms is described under conditions of direct esterification wherein the resultant polyester has low ether content. The dicarboxylic acid is esterified with the alkylene glycol in the presence of a compound of the formula <IMAGE> wherein M is H, an alkali metal selected from the group consisting of lithium, sodium and potassium or an alkaline earth metal selected from the group calcium and magnesium.