摘要 |
The present invention relates to stable equilibrium mixtures of carbodiimides, uretone imines and organic isocyanates and to stable solutions of carbodiimides and uretone imines in polyisocyanates which are free from carbodiimide groups. Either the carbodiimide, or the uretone imine, or both, may contain isocyanate groups. The present invention also relates to a process for the preparation of such products by "heterogeneous catalysis" and the use thereof for the production of polyurethane resins. According to one embodiment of the process according to the instant invention, individual isocyanates in a mixture of various isocyanates may be carbodiimidized selectively. |