Patent ID: 7453008

Claim:
A method of synthesizing glycol diester, comprising reacting a linear aliphatic carboxylic acid and a glycol monoester in the presence of a Lewis acid type catalyst, wherein after introducing the glycol monoester, the linear aliphatic carboxylic acid and the Lewis acid type catalyst into a reactor, (1) the reaction occurs to produce reaction products and water in the reactor; (2) an excess of the linear aliphatic carboxylic acid forms an azeotrope with water during the reaction to be sent to a condenser through a distillation column; (3) the linear aliphatic carboxylic acid and water passed through the condenser are divided into an organic layer and an aqueous layer in an oil water separator; and, (4) the organic layer is returned to the distillation column through a material cycling line and water in the aqueous layer is removed through a water removal line, wherein the aliphatic carboxylic acid is butyric acid, the glycol monoester is 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate and the Lewis acid type catalyst is tetraisopropyl titanate.