| 摘要 |
The present invention relates to a process for the preparation of polyisocyanates which have a biuret structure of reacting excess quantities of aliphatic diisocyanates with biuretizing agents at elevated temperature, characterized in that the biuretizing agent contains (a) alpha , alpha , alpha -trisubstituted acetic acids which do not contain isocyanate-reactive groups apart from the carboxyl group, and optionally (b) water, wherein the molar ratio of biuretizing components (a) to (b) is within the range of from 1:0 to 1:2.5. |
