Abstract: The invention relates to novel polysilicic acid/polyisocyanate basic materials, binding materials and foams with improved mechanical properties as well as a higher resistance against heat and chemicals. It is characteristic of the new base materials that they are built up (composed) of______________________________________ 100 parts by mass of a polyisocyanate, 50-400 parts by mass of a polysilicic acid component, 0.5-70 parts by mass of phosphoric acid triesters and/or salts of phosphoric acid mono- and/or diesters formed with amines and/or alkaline metals, and optionally 0-5 parts by mass of a catalysts containing a tertiary amino group, 0-50 parts by mass of a reactive diluent, 0-10 parts by mass of tenside(s) ______________________________________as well as 0-400% by mass of fillers and optionally other auxiliaries, calculated for the total mass (=100%) of the components listed above.