| abstract |
An improved process for the preparation of a diaryl ester containing only small amounts of the corresponding monoesters comprises reacting a mixture of an aryl diacid, a monohydroxy aromatic compound and a catalyst, cooling, adding a controlled amount of water, and cooling further. Typically, diaryl esters, such as diphenyl isophthalate (DPI), containing only about 1-5% of the monoester, such as monophenyl isophthalate are obtained upon addition to the reaction mixture of approximately 5-15% by weight of water at 60°-80°C, followed by cooling to about 15°-35°C. |