| 摘要 |
<p>Organic polyisocyanates characterized by allophonate linkages are prepared by reacting an organic polyisocyanate with a mono- or polyhydric compound in the presence of an organo metal catalyst. The catalyst is then deactivated using a compound such as an inorganic acid, organic acid, organic chloroformate or an organic acid chloride. The isocyanates are useful in preparing polyurethane foams.</p> |
