| abstract |
The invention relates to a xerogel comprisingn from 30 to 90% by weight of a monomer component (a1) composed of at least one polyfunctional isocyanate and from 10 to 70% by weight of a monomer component (a2) composed of at least one polyfunctional aromatic amine, at least one of which is selected from 4,4′-diaminodiphenylmethane, 2,4′-diaminodiphenylmethane, 2,2′-dIamino-diphenylmethane and oligomeric diaminodiphenylmethane, nn where the sum of the % by weight of monomer components (a1) and (a2) adds up to 100% by weight and where the monomer components are present in polymeric form in the xerogel and the volume-weighted mean pore diameter of the xerogel is at most 5 μm. n The invention further relates to a process for preparing xerogels, to the xerogels thus obtainable and to the use of the xerogels as an insulating material and in vacuum insulation panels. |