Composite elements for use as structural components, especially in boats and bridges, comprise two layers of metal with a polyurethane interlayer made by reacting isocyanate with polyether-polyol in presence of air

摘要

A polyisocyanate-polyaddition product (I) obtained by reacting (a) isocyanates with (b) isocyanate-reactive compounds in presence of (c) 0.1-50 vol% gas (based on the volume of I) and optionally (d) catalysts and/or (e) additives etc. is used as the middle layer (ii; thickness, 10-100 mm) in composite elements with two outer layers of metal (2-20 mm). Independent claims are also included for (A) a process for the production of composite elements in which a metal-adherent poly-addition product (I) is produced between metal layers (i) and (iii) by reaction of the above components; (B) composite elements obtained by this process; (C) boats or bridges containing these elements.