Use of highly branched polyols for the preparation of polyurethane foams, two-component foam systems containing these polyols, and their use

摘要

Described are the use of highly branched and/or dendritic polyols with a number average molecular weight (Mn) of 500 to 100,000 g/mole and preferably of 1,000 to 10,000 g/mole and an average hydroxy functionality per molecule of 10 to 1000 and preferably of 25 to 100, as polyol for the preparation of polyurethane foams with a higher ratio of compressive strength to density, a two-component foam system for the preparation of polyurethane foams with a higher ratio of compressive strength to density, with a polyisocyanates component (A) and a component (B) (polyol component) containing compounds having reactive hydrogen atoms, which are present in separate containers and, for use, can be caused to react by being mixed, which is characterized in that the polyol component (B) contains 1 to 50% by weight and preferably 2 to 30% by weight, based on the weight of the compounds of the polyol component (B) having reactive hydrogen atoms, at least one highly branched and/or dendritic polyol (B1) with a number average molecular weight (Mn) of 500 to 100,000 g/mole and preferably of 1000 to 10,000 g/mole and an average hydroxy functionality per molecule of 10 to 1000 and preferably of 25 to 100, as well as the use of this two-component foam system as installation foam, especially for the installation of door and window frames or of staircases and/or as fire protection foam for sealing openings and/or wall bushings and/or ceilings of buildings.