| abstract |
The invention relates to a process for producing polyurethane prepregs which are stable during storage, and to mouldings (composite components) produced therefrom. The prepregs or components are produced by mixing (meth)acrylate monomers, (meth)acrylate polymers, hydroxy-functionalized (meth)acrylate monomers and/or hydroxy-functionalized (meth)acrylate polymers with uretdione materials and moreover with aromatic amines which accelerate a free-radical polymerization reaction. This mixture or solution is applied by known processes to fibre material, e.g. carbon fibres, glass fibres or polymer fibres, and is polymerized at room temperature or higher temperatures with the aid of initiators, e.g. dibenzoyl peroxide. Instead of amine acceleration and subsequent hardening with initiators, it is also possible to use other known room-temperature curing systems, e.g. permaleate systems. n Polymerization, e.g. at room temperature or at up to 80° C., gives thermoplastics or, respectively, thermoplastic prepregs which can subsequently be subjected to forming processes. By using elevated temperature, the hydroxy-functionalized acrylate constituents can then be crosslinked with the uretdiones already present in the system. It is thus possible to produce dimensionally stable thermosets and, respectively, crosslinked composite components. |