Low density rigid reinforced polyurethanes and a process for their production

摘要

Fiber-reinforced polyurethanes having densities no greater than 0.9 g/cc which are suitable for use as automotive components are produced from a polyurethane-forming reaction mixture in which carbon dioxide is dissolved in one or both of the reaction components. The amount of dissolved carbon dioxide is from 0.2 to 2.0 g/l. The isocyanate-reactive component is a polyol having a functionality of from 3 to 8 and a hydroxyl number of at least 600. Any fibrous material may be used but glass fiber, particularly glass fibers having lengths from 12.5 to 100 mm are particularly preferred.