Abstract: The present invention relates to heat-curable reaction resin mixtures comprising at least one organic polyisocyanate, at least one organic compounds having epoxy rings, and mixtures of certain tertiary amines as reaction accelerators. These reaction resin mixtures are suitable as casting resins for mold making and for the production of various kinds of composites. The curing of the resins takes place in economically reasonable time periods, without excessive evolution of heat, while avoiding shrinkage and the formation of cracks and bubbles.

Abstract: The present invention directed to an at least substantially pore-free polyurethane prepared by reacting at least one polyisocyanate and a component containing a partial carboxylic acid ester which is the reaction product of a carboxylic acid and an at least trihydric alcohol in quantities such that at least one of the hydroxyl groups of said alcohol is not esterified.

Abstract: This invention relates to a process for the preparation of foundry cores and molds by mixing a filler and a casting resin mixture and then curing the resultant mixture. The casting resin mixture is made from (a) 25 to 99.9% of at least one organic polyisocyanate, (b) 0.1 to 50% of at least one organic compound containing at least two epoxide groups, and (c) up to 50% of a polyhydroxyl compound, the quantities being based on the total quantity of resin.

Abstract: It is now possible to provide reaction resin mixtures based on organic polyisocyanates and organic polyepoxides that can be hot-cured to high-quality plastics having isocyanurate and oxazolidinone groups that are largely storage-stable at room temperature, without their curing having to be stopped at any time, so that the systems exist in an intermediate "B-stage" (i.e., in a state that is solid at ambient or moderately elevated temperature but still fusible), so that at any later time, for example after pulverizing or dissolving in a suitable solvent, they can be converted by shaping and further thermal action to their ultimate, crosslinked and no longer fusible final state.

Abstract: Hardenable mixtures ofA. 40 to 90% by weight of at least one aromatic polyfunctional cyanic acid ester,B. 10 to 60% by weight of at least one polymerizable olefinically unsaturated monomer and, optionally,C. 0.01 to 10% by weight, based on the sum of A) and B) of at least one hardening catalyst such as amines, Mannich bases and organic metal compounds. They are suitable for use as casting resins and as pourable sealing compounds for covering materials, for producing shaped articles, coatings, bonds, electrical insulations, as binders for fibre-reinforced plastics.