Anisotropic composite materials based on polyisocyanates

Process for producing a composite polyisocyanurate material, comprising the steps of

• a) providing a reactive resin mixture comprising all compounds that react with each other during the process, the reactive resin mixture comprising:
• at least one reactive polyisocyanate composition A consisting of at least 50% by weight of one or more aliphatic isocyanates, and at least one crosslinking catalyst B,
• wherein the at least one crosslinking catalyst B comprises a trimerization catalyst;
• b) providing a fibrous filler C, the fibres of which have an aspect ratio of at least 1000,
• c) wetting the fibrous filler C with the reactive resin mixture from process step a), wherein the molar ratio of free isocyanate groups to the sum of hydroxyl, amino and thiol groups in the reactive resin mixture is at least 5.0:1.0,
• d) curing the resin-impregnated fibrous filler, to give a profile by means of one or more chemical reactions, the curing comprising at least 50% of the free isocyanate groups in the polyisocyanate composition A being crosslinked on the resin-impregnated fibrous filler to form isocyanurate structures and optionally at least one structure selected from the group consisting of uretdione, allophanate, biuret, iminooxadiazinedione, oxadiazinetrione, and combinations thereof, the curing continued until at most 10% of the free isocyanate groups from the reactive resin mixture remain.