发明授权
US4278805A Process for the preparation of an aryl mono-, di-, and/or polyurethane 失效
芳基单 - ,二 - 和/或聚氨酯的制备方法

Process for the preparation of an aryl mono-, di-, and/or polyurethane
摘要:
A process for the preparation of an aryl-mono and/or polyurethane comprising the steps ofA. reacting a primary aromatic mono, di-, and/or polyamine with an O-alkyl carbamate in the presence of alcohol and catalysts, andB. separating the ammonia and other by-products from the aliphatic and/or cycloaliphatic di- and/or polyurethane.The reaction is preferably carried out in the presence of urea. The aryl mono-, di-, and/or polyurethanes produced are valuable end and intermediate products. They can be transferred into the corresponding isocyanates which can then be used for the preparation of polyurethanes.
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