| 摘要 |
<p>Process for producing polymer foams derived from reactive polycondensation resins and having a maximum pore diameter of 1 mum, which comprises: 1) preparing a gelable mixture of the reactive polycondensation resin in a solvent or dispersion medium, 2) preparing an aqueous dispersion comprising polymer particles, 3) mixing the mixture from step 1) with the dispersion from step 2) to give a water-containing gel, and 4) drying the water-containing gel to give the polymer foam, with drying in step 4) being carried out at a pressure and a temperature which are below the critical pressure and below the critical temperature of the liquid phase of the gel and the gel not being brought into contact with an organic liquid to replace the water present in the gel by this liquid after step 3) and before step 4).</p> |
