Separation of aromatic acids

Claim 1

A PROCESS FOR THE SEPARATION OF A MIXTURE OF AROMATIC ACIDS COMPRISING PER PART OF TEREPHATHALIC ACID IN SAID MIXTURE, 1 TO 3.5 PARTS ISOPHTHALIC ACID, AND .1 TO .5 PART BENZOIC ACID, WHICH COMPRISES REMOVING THE BENZOIC ACID FROM SAID MIXTURE BY EXTRACTING SAID MIXTURE WITH ABOUT 3 PARTS ACETIC ACID PER PART OF SAID ACID MIXTURE, TO FORM AN EXTRACT COMPRISING BENZOIC ACID DISSOLVED IN SAID ACETIC ACID, AND AN EXTRAHEND COMPRISING ISOPHTHALIC ACID AND TEREPHTHALIC ACID, THEN EXTRACTING THE EXTRAHEND WITH ABOUT 35 TO 350 PARTS OF A SOLVENT PER PART OF SAID ISOPHTHALIC ACID SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC ALCOHOLS HAVING FROM 1 TO 5 CARBON ATOMS AND KETONES HAVING FROM 3 TO 5 CARBON ATOMS, PER PART OF ISOPHTHALIC ACID TO FORM AN EXTRAHEND COMPRISING RELATIVELY PURE TEREPHTHALIC ACID AND AN EXTRACT COMPRISING ISOPHTHALIC ACID DISSOLVED IN SAID SOLVENT, BOTH EXTRACTIONS BEING CARRIED OUT AT A TEMPERATURE OF FROM 20 TO 25*C., THEN CONCENTRATING THE EXTRACTS, AND FILTERING SAID CONCENTRATED EXTRACTS TO REMOVE THE ISOPHTHALIC ACID, AND BENZOIC ACID FROM THEIR RESPECTIVE SOLVENTS.