Use of layer structures in wind power plants

1. A process for the production of rotor blades for wind power plants comprising providing a layer structure, wherein the layer structure comprises

a) a release agent layer

b) a fiber layer treated with a polyurethane,

c) a fiber layer provided with the polyurethane

wherein at least one of the treatment of the fiber layer b) and the providing of the fiber layer c) comprises injection of a polyurethane reaction mixture through a vacuum-assisted resin transfer moulding process into a mould comprising the fiber layer b) and the fiber layer c), and wherein the polyurethane reaction mixture has a viscosity of 5000 mPas at 25° C., 30 minutes after a mixing of the polyurethane reaction mixture.

2. Process for the production of rotor blades according to claim 1 for wind power plants, comprising providing rotor blades comprising a casing comprising the layer structure.

3. Process according to claim 2 , wherein the reaction mixture comprises an isocyanate diphenylmethane diisocyanate and/or polyphenylenepolymethylene polyisocyanate having an NCO content of more than 25 wt. %.

4. Process according to claim 2 , wherein the reaction mixture contains a compound having at least two hydrogen atoms reactive towards isocyanate a polyether polyol in which at least 60% of the OH groups are secondary OH groups and which has an OH number of from 200 to 1830 mg KOH/g.

5. Process according to claim 2 , wherein the reaction mixture is applied to the fiber layers at a temperature of from 20 to 80° C.

6. Process according to claim 2 , wherein the reaction mixture is cured at a temperature of from 40 to 160° C.

7. Process according to claim 2 , wherein the reaction mixture has a viscosity of ≤5000 mPas 30 minutes after a mixing of the reaction mixture.

8. The process according to claim 2 , wherein the reaction mixture comprises an isocyanate diphenylmethane diisocyanate and/or polyphenylenepolymethylene polyisocyanate having an NCO content of more than 25 wt. %, wherein the reaction mixture contains as the compound having at least two hydrogen atoms reactive towards isocyanate a polyether polyol in which at least 60% of the OH groups are secondary OH groups and which has an OH number of from 200 to 1830 mg KOH/g, and wherein the reaction mixture has a viscosity of ≤5000 mPas 30 minutes after a mixing of the reaction mixture.

9. The process according to claim 8 , wherein the reaction mixture has a viscosity of ≤2000 mPas 30 minutes after the mixing of the reaction mixture.