Manufacturing dialkyl phthalate, useful as plasticizer, comprises reacting phthalic anhydride with alcohol compound in presence of sulfuric acid and solvent forming azeotrope with water and subjecting reaction mixture to thermal treatment

摘要

Manufacturing dialkyl phthalate (I) having a Hazen color of less than 25 measured according to ISO 2211/1973, comprises reacting phthalic anhydride with an alcohol compound (I) in the presence of sulfuric acid and a solvent forming an azeotrope with water, where the sulfuric acid solution in an amount of 45-96 wt.% is used, and subjecting the crude reaction mixture neutralized and stripped of solvent to a thermal treatment prior to conventional treatment of washing with water of the ester. Manufacturing dialkyl phthalate (I) having a Hazen color of less than 25 measured according to ISO 2211/1973, comprises reacting phthalic anhydride with an alcohol compound of formula (ROH) (II) in the presence of sulfuric acid and a solvent forming an azeotrope with water, where the sulfuric acid solution in an amount of 45-96 wt.% is used, and subjecting the crude reaction mixture neutralized and stripped of solvent to a thermal treatment prior to conventional treatment of washing with water of the ester. R : linear or branched 8-13 (preferably 9-13)C alkyl. An independent claim is included for the dialkyl phthalate having a Hazen color of less than 20, measured according to ISO 2211/1973, produced by the above process.