Catalyst for preparing carbodiimides

Claim 1

A PROCESS FOR PREPARING ORGANIC CARBODILMIDES WHICH COMPRISES HEATING IN A RANGE OF FROM ABOUT 100*C. TO 250*C. UNDER ANHYDROUS CONDITIONS AN ORGANIC ISOCYANATE CONTAINING 1 TO 3 ISOCYANATE GROUPS AND SELECTED FROM THE GROUP CONSISTING OF CARBOCYCLIC AROMATIC ISOCYANATES CONTAINING FROM ONE TO THREE RINGS, SATURATED ALIPHATIC ISOCYANATES CONTAINING FROM TWO TO EIGHTEEN CARBONS IN THE ALIPHATIC GROUP, PYRIDINE ISOCYANATES AND QUINOLINE ISOCYANATES, SAID ISOCYANATE BEING FREE OF ZEREWITINOFF ACTIVE HYDROGEN, AND A CATALYST COMPRISING A NONIONIC ACETYLACETONE DERIVATIVE OF A METAL SELECTED FROM THE CLASS CONSISTING OF GROUP IIA, GROUP IIIB, GROUP IVB OF ATOMIC NUMBERS 40 TO 72, GROUP VB, GROUP VIB, GROUP VIIB OF ATOMIC NUMBER 25, GROUP VIII, GROUP IB OF ATOMIC NUMBER 29, GROUP IIIA OF ATOMIC NUMBERS 13 TO 81, THE LANTHANIDE SERIES OF ATOMIC NUMBERS 58 TO 71 AND THE ACTINIDE SERIES OF ATOMIC NUMBERS 89, 90 AND 92.