PROCESS FOR PREPARING HEXAHYDROPHTHALIC ACID ANHYDRIDE

摘要

PURPOSE: A method for preparing hexahydrophthalic acid anhydride is provided to prevent impurity generation and to prepare hexahydrophthalic acid anhydride without melting point reduction. CONSTITUTION: A hexahydrophthalic acid is prepared by hydrogenation of tetrahydrophthalic acid under the presence of hydrogenation catalyst. The hydrogenation catalyst is obtained by pretreatment of a catalyst containing palladium using acid and alkali solution. The hydrogenation is performed without separate reaction solution. The tetrahydrophthalic acid is unpurified crude-tetrahydrophthalic acid or purified pure-tetrahydrophthalic acid which is a reactant of anhydrous maleic acid and 1,3-butadiene.