Abstract:
The present invention relates to an epoxy-resin composition as matrix component for sheet molding compounds (SMC) and/or bulk molding compounds (BMC), comprising a resin component comprising at least one epoxy resin and a hardener component comprising at least one imidazole compound and at least one latent hardener. In said epoxy-resin composition, the amount of the imidazole compounds used is in the range from 0.007 to 0.025 mol per mole of epoxy groups of the entire composition, and the total amount of primary amine groups optionally comprised does not exceed a proportion of 0.09 mol per mole of epoxy groups of the entire composition. The invention also relates to a fiber-matrix-semifinished-product composition (SMC composition or BMC composition) with, as matrix component, the epoxy-resin composition mentioned, and with, suspended therein, short reinforcement fibers with an average length of from 0.3 to 5.0 cm. The fiber-matrix-semifinished-product composition can be produced via mixing of the constituents, whereupon the composition thickens. The resultant thickened product (semisolid fiber-matrix semifinished product) features comparatively short maturing time and comparatively long available operating time. The invention also relates to the corresponding semisolid fiber-matrix composite, in particular to the semisolid SMC and to the corresponding cured fiber-matrix semifinished product, in particular the cured SMC. Finally, the invention also relates to a screening process for identifying epoxy-resin-based compositions which are suitable for use as thermoset matrix for producing SMC.
Abstract:
Described herein is a two-component polyurethane adhesive that exhibits a glass transition temperature (Tg) of ≥70° C. and an open time in the range of ≥45 to ≤90 minutes at a temperature of ≥70° C. and a relative humidity of 50%. Also described is a method of producing the two-component polyurethane adhesive having a long open time with good humidity tolerance which is suitable for bonding large and bulky components or surfaces, including but not limited to, rotor blades of wind turbines.
Abstract:
The present invention relates to the use of substantially linear polypropyleneimine as a hardener for epoxy resins, and also to a corresponding curable composition, to the curing thereof, and to the cured epoxy resin obtainable therefrom.
Abstract:
The present invention relates to a curable composition which comprises epoxy resin, epoxy-group-bearing reactive diluent and the hardener 2,2′,6,6′-tetramethyl-4,4′-methylenebis(cyclohexylamine), curing thereof, and the cured epoxy resin obtainable therefrom, and the use of 2,2′,6,6′-tetramethyl-4,4′-methylenebis(cyclohexylamine) as a hardener for epoxy resins in curable compositions with epoxy-group-bearing reactive diluent.