Preparation of flame-protected polyurethane, used e.g. as outer casing of boilers, comprises reacting polyisocyanate with compound having isocyanate reactive hydrogen in presence of e.g. foamed melamine formaldehyde condensation products

Preparation of flame-protected polyurethane (I) (preferably polyurethane-foam materials) comprises reaction of polyisocyanate with compounds with at least two hydrogen atoms reactive with isocyanate group, where the reaction is carried out in the presence of (a) foamed melamine formaldehyde condensation products and/or (b) hydroxyl groups containing reaction products of (a) with alkylene oxide. Independent claims are also included for: (1) a hydroxyl group containing compounds (II), producible by reaction of (a) with alkylene oxide; (2) a method for the preparation of (II) comprising reaction of (a) with alkylene oxide; and (3) a flame protected polyurethane, produced by the preparation method. Gegenstand der Erfindung ist ein Verfahren zur Herstellung von flammgeschützten Polyurethanen, insbesondere Polyurethan-Schaumstoffen, durch Umsetzung von DOLLAR A a) Polyisocyanaten mit DOLLAR A b) Verbindungen mit mindestens zwei mit Isocyanatgruppen reaktiven Wasserstoffatomen, dadurch gekennzeichnet, dass die Umsetzung in Anwesenheit von DOLLAR A c1) geschäumten Melamin-Formaldehyd-Kondensationsprodukten und/oder DOLLAR A c2) Hydroxylgruppen enthaltenden Umsetzungsprodukten von geschäumten Melamin-Formaldehyd-Kondensationsprodukten mit Alkylenoxiden DOLLAR A durchgeführt wird.