| 摘要 |
<p>A process for the partial or thorough conversion of isocyano groups, contained in organic compounds, into carbodiimido and/or urethonimino groups by heating compounds containing free isocyano functional groups, in particular polyisocyanates, at temperatures in the range of from 140 DEG to 300 DEG C in the presence of solid, inorganic, acid catalysts, having surfaces of at least 2 m<2>/g, selected from amongst silica, alumina and the mixtures or derivatives wherein said two oxides are united and/or mixed with each other and/or with alkaline or alkaline-earth oxides.</p> |
