Hybrid component part comprising a local stiffening composed of a two-stage-crosslinked polyurethane-based fibre composite material

Process for producing a hybrid component part comprising the steps of:

• a) providing a reactive composition at least comprising:
• at least one hardener which is a uretdione having an NCO functionality of at least two,
• at least one binder which is a polyol compound having an OH functionality of 3 to 6 and which comprises at least one polar functional group selected from an ester, carbonate, amide, urethane, urea, thioester or thiocarbonate functionality;
• b) providing fibres;
• c) coating the fibres with the reactive composition;
• d) exposing at least the reactive composition to heat to perform a first crosslinking reaction in the course of which hardener and binder are converted into a thermoplastic polymer, thus embedding the fibres into the thermoplastic polymer;
• e) providing a metallic main body or a semifinished precursor thereof;
• f) placing the thermoplastic polymer comprising the fibres embedded therein onto a localized area of the main body/semifinished precursor thereof;
• g) pressing the thermoplastic polymer onto the main body/semifinished precursor thereof so that the fibres adhere to the main body/semifinished precursor thereof via the thermoplastic polymer;
• h) forming the semifinished precursor comprising the thermoplastic polymer adherent thereto to afford the metallic main body provided that only a semifinished precursor of the main body was provided in step e);
• i) exposing at least the thermoplastic polymer to heat to perform a second crosslinking reaction in the course of which the thermoplastic polymer is converted to a thermoset polymer;
• k) obtaining the hybrid component part comprising at least the metallic main body provided with at least one local stiffening composed of a fibre composite material, wherein the fibre composite material comprises a matrix formed from the thermoset polymer and the fibres embedded therein,
• wherein the thermoplastic polymer comprising the fibres embedded therein is provided in layerwise fashion, in that the layers are compressed to afford a stack in the absence of the main body/the semifinished precursor thereof and in that the sequence of steps f) and q) is effected by placing and pressing the stack onto the main body/the semifinished precursor thereof.