snider

Claim 1

PROCESS FOR REMOVING, FROM CRUDE EPSILON-CAPROLACTAM, IMPURITIES THEREIN OXIDIZABLE BY POTASSIUM PERMANGANATE WHICH PROCESS COMPRISES FORMING A MIXTURE CONSISTING ESSENTIALLY OF THE THREE INGREDIENTS EPSILON-CAPROLACTAM; ALKALI METAL HYDROXIDE OF THE GROUP CONSISTING OF SODIUM HYDROXIDE, POTASSIUM HYDROXIDE, AND THEIR MIXTURES; AND WATER AND CONTAINING NOT MORE THAN ABOUT TEN PARTS BY WEIGHT OF IMPURITIES PER 90 PARTS OF CAPROLACTAM, SAID MIXTURE HAVING THEREIN AT LEAST ABOUT 1% BY WEIGHT OF CAPROLACTAM AND AT LEAST ABOUT 5% ALKALI METAL HYDROXIDE; THE WEIGHT PROPORTIONS OF CAPROLACTAM:ALKALI METAL HYDROXIDE:WATER LYING ABOUT IN THE QUADRILATERAL ON AN EQUILATERAL TRIANGULAR COMPOSITION DIAGRAM BOUNDED BY THE LINES CONNECTING POINTS AT ABOUT THE POINT (1% LACTAM, 69% ALKALI METAL HYDROXIDE, 30% WATER), 1% LACTAM, 19% ALKA METAL HYDROXIDE, 80% WATER), (55% LACTAM, 5% ALKALI METAL HYDROXIDE, 40% WATER), (93% LACTAM, 5% ALKALI METAL HYDROXIDE, 2% WATER); AND ESTABLISHING IN SAID MIXTURE TEMPERATURES WITHIN THE RANGE FROM ABOUT 15*C. TO ABOUT 75*C.; SEPARATING LIQUID CAPROLACTAM PHASE FROM THE AQUEOUS ALKALI METAL HYDROXIDE PHASE; AND RECOVERING PURIFIED CAPROLACTAM BY DISTILLING THE SEPARATED CAPROLACTAM.