Process of manufacturing diaryl esters of dicarboxylic acids

Claim 1

In a process for preparing esters which comprises reacting a monohydroxy aromatic compound with at least one dicarboxylic acid in a reactor having a distillation means, said acid being represented by the formula: ##STR5## wherein X is oxygen or sulfur, Z is alkylene, --Ar-- or --Ar--Y--Ar-- wherein Ar is aromatic, Y is alkylene of 1 to 10 carbon atoms, haloalkylene, --O--, --SO--, --SO 2 --, --SO 3 --, --CO--, ##STR6## or GN═, and G is alkyl, haloalkyl, aryl, haloaryl, alkylaryl, haloalkylaryl, arylalkyl, haloarylalkyl, cycloalkyl and halocycloalkyl, n is 0 or 1, and R 1 and R 2 are independently selected from the group consisting of hydrogen and lower alkyl, said reaction being conducted at a temperature between about 220° to about 300° C., continuously removing a by-product of said reaction comprising water and/or lower alkyl alcohol(s) in admixture with said monohydroxy aromatic compound from said reactor through said distillation means, and supplying to said reactor a make-up amount of said monohydroxy aromatic compound, the improvement which comprises using as said make-up material a monohydroxy aromatic compound containing no more than about 100 ppm of water.