Patent ID: 7825276

Claim:
A process for the preparation of organic isocyanates containing carbodiimide and/or uretonimine groups, comprising A) partially carbodiimidizing (1) one or more organic isocyanates having a Hazen color number of ≦100 APHA, in the presence of (2) one or more catalysts of the phospholine type, and (3) at least one secondary amine which contains at least one aliphatic or cycloaliphatic or araliphatic hydrocarbon radical which is optionally substituted and which optionally contains heteroatoms, wherein (3)said secondary amine is present in concentrations of ≦1,000 ppm, based on the weight of the isocyanate employed, and said secondary amine corresponds to a general structure selected from the group consisting of: structure (II): wherein: R 4 represents a hydrogen atom; and R 5 to R 12 each independently represents a hydroxyl group, an amino group, or aliphatic, cycloaliphatic, aromatic or araliphatic hydrocarbon radical which can optionally contain heteroatoms and which can optionally carry additional functional groups, and in which two or more of the radicals R 5 to R 12 can be bonded to one another to form cyclic, bicyclic or polycyclic structures; with the proviso that (i) at least one of the radicals R 5 to R 12 is selected from the group consisting of aliphatic, cycloaliphatic or araliphatic hydrocarbon radicals which are optionally substituted and which optionally contain heteroatoms: and structure (III): wherein: R 13 represents a hydrogen atom; R 14 to R 17 each independently represents an aliphatic hydrocarbon radical which can optionally contain heteroatoms and which can optionally carry additional functional groups, and in which two or more of the radicals R 14 to R 17 can be bonded to one another to form cyclic, bicyclic or polycyclic structures; and R 18 to R 23 : each independently represents a hydrogen atom, a hydroxyl group, an amino group, or an aliphatic, cycloaliphatic, aromatic or araliphatic hydrocarbon radical which can optionally contain heteroatoms and which can optionally carry additional functional groups, and in which two or more of the radicals R 18 to R 23 can be bonded to one another to form cyclic, bicyclic or polycyclic structures; and subsequently, (B) terminating the carbodiimidization.