Flame-resistant, low-temperature curing cyanate-based prepreg resins for honeycomb sandwich components with excellent surfaces

A textile web material impregnated with a mixture comprising at least the following components:

• a prepolymer prepolymerized from a first starting material of one or more bifunctional or polyfunctional organic cyanates and a second starting material of one or more bifunctional or polyfunctional aromatic alcohols, wherein said one or more bifunctional or polyfunctional organic cyanates and said one or more bifunctional or polyfunctional aromatic alcohols are present in weight ratios ensuring a molar ratio of the OCN groups to the OH groups between 95:5 and 70:30 in the first and second starting materials;
• and
• one or more fillers;
• wherein said one or more bifunctional or polyfunctional organic cyanates are selected from cyanates of the structural formulas I, II, and III, as well as from mixtures of and/or prepolymers of said cyanates of said structural formulas I, II, and III
• wherein R1 to R4 are, independent from one another, hydrogen, C1-C10 alkyl, C3-C8 cycloalkyl, C1-C10 alkoxy, phenyl or phenoxy;
• wherein R5 to R8 are the same as R1 to R4 above and Z is a chemical bond, SO2, CH2, CH(CH3), isopropylene, C1-C10 alkylene, O, NR9, N═N, CH═CH, COO, CH═N, CH═N—N═CH, alkylene oxyalkylene with C1-C8 alkylene, S, Si(CH3)2,
• wherein R9 is hydrogen or C1-C10 alkyl and n is an integer of 0 to 20;
• wherein said one or more bifunctional or polyfunctional aromatic alcohols are selected from the group consisting of the compounds having a structure according to said structural formulas I, II, and III, with the proviso that the cyanate groups in said structural formulas I, II, and III are replaced with OH groups.