| 摘要 |
<p>Method for the preparation of polymeric isocyanates by decomposing polymeric ureas of the formula: R?1(NHCONR2R3)¿x wherein x is at least 2, R1 is an organic radical of valency x and R?2 and R3¿ are monovalent organic radicals, into polymeric isocyanates of the formula: R1(NCO)x and secondary amines of the formula: R2NHR3 characterised in that at least one of the radicals R?2 and R3¿ is bound to the nitrogen atom of the amine by a tertiary carbon atom.</p> |
