Fiber composite component and a process for the production thereof

A sheet-form fibre composite component prepared by the vacuum-assisted resin transfer moulding process, for use in the production of rotor blades of wind turbines, comprising a fibre layer impregnated with polyurethane, wherein the polyurethane is obtainable from a reaction mixture comprising

• A) one or more polyisocyanates;
• B) one or more polyether polyols comprising an addition product of propylene oxide on a di-functional or poly-functional starter molecule, the polyether polyol(s) comprising at least 80% secondary OH groups;
• C) one or more polyepoxides;
• and
• D) optionally additives,
• wherein the reaction mixture has a viscosity at 35° C. of from 50 to 250 mPa and a ratio of the number of NCO groups to the number of OH groups of component B) of from 1.3:1 to 10:1 and a ratio of the number of NCO groups to the number of epoxide groups of component C) of from 1.1:1 to 10:1, and
• wherein the one or more polyisocyanates consists of mixtures of diphenylmethane diisocyanate and polyphenylenepolymethylene polyisocyanate with a monomer content of from 70 to 95 wt. % in the polyisocyanate component of A) based on the total weight of the polyisocyanate components.