Patent ID: 8455090

Claim:
A prepreg, consisting essentially of A) at least one fibrous support, and B) a matrix material comprising at least one highly reactive powdery polyurethane composition comprising at least one uretdione group, said composition consisting essentially of: a) at least one curing agent comprising at least one uretdione group obtained by polyaddition of at least one aliphatic, (cyclo)aliphatic, or cycloaliphatic polyisocyanate comprising at least one uretdione group and at least one compound comprising at least one hydroxyl, wherein the curing agent exists in solid form across an entire range below 40° C. and in liquid form across an entire range above 125° C., and has a free NCO content of less than 5 wt. % and a uretdione content of 3-25 wt. %; b) at least one hydroxyl group-comprising polymer, which exists in solid form across an entire range below 40° C. and in liquid form above 125° C., across an entire range and has an OH number between 20 and 200 mg KOH/gram; c) 0.1 to 5 wt. % of at least one catalyst selected from the group consisting of a quaternary ammonium salt and a quaternary phosphonium salt with at least one counter-ion selected from the group consisting of a halogen, a hydroxide, an alcoholate, an organic acid anion, and an inorganic acid anion; d) 0.1 to 5 wt. % of at least one cocatalyst selected from the group consisting of d1) an epoxide, and d2) at least one acetylacetonate cocatalyst selected from the group consisting of a quaternary ammonium acetylacetonate cocatalyst, a quaternary phosphonium acetylacetonate cocatalyst, and a combination thereof; and e) optionally, at least one selected from the group consisting of an auxiliary substance and a polyurethane additive, wherein the at least one curing agent a) and the at least one hydroxy-comprising polymer b) are present in a ratio such that for every hydroxyl group of the polymer b) 0.3 to 1 uretdione groups of the curing agent a) is consumed.