The metal cation which exists between formation of the montmorillonite which has possessed the solid-state Acid catalytic converter for carboxylic acid

摘要

PROBLEM TO BE SOLVED: To provide a solid acid catalyst for simply and economically manufacturing a carboxylic acid anhydride of high purity at a high yield, and an environmentally excellent carboxylic acid anhydride manufacturing method using it and almost producing no industrial waste.;SOLUTION: This solid acid catalyst for manufacturing the carboxylic acid anhydride is characterized in that the metal cations present between the layers of montmorillonite having a layered structure are replaced with Ti⁴⁺. In the carboxylic acid anhydride manufacturing method, a carboxylic acid having a high boiling point and an anhydride obtained by condensing a carboxylic acid, of which the boiling point is lower than that of the carboxylic acid having the high boiling point, are mixed in the presence of the solid acid catalyst for manufacturing the carboxylic acid anhydride to obtain an anhydride wherein the carboxylic acid having the high boiling point is condensed. Thereafter, this filtered-off catalyst can be again recycled to the carboxylic acid anhydride manufacturing method to be reused.;COPYRIGHT: (C)2005,JPO&NCIPI