| 摘要 |
<p>The present invention relates to the production of polyurethane foam used in the production of heat-insulation articles. This invention essentially comprises producing polyurethane foam from a reaction mixture that contains a hydroxyl-containing component, target additives, a filler and an isocyanate component which are mixed together. According to this invention, the hydroxyl-containing component (simple or complex polyesters) is first mixed with the target additives (a foam stabiliser, a catalyst, a foaming agent, etc.) and with the filler. The invention further involves acting on the mixture thus obtained with the isocyanate component which consists of di- and polyisocyanates having an NCO-group content of between 29 and 33 wt.%. The filler consists of a liquid sodium glass having a module of up to 4.0 and a density of between 1.3 and 1.5 g/cm3. Between 50 and 150 parts by weight of the liquid sodium glass, in terms of sodium silicate (polysilicon acid)σ are added to 100 parts by weight of the sum of the hydroxyl-containing and isocyanate components. It is thus possible to obtain a polyurethane foam having a density of between 75 and 120 kg/m3, a compressive strength of between 0.4 and 0.5, a heat resistance of between 180 and 250 °C and a fire-resistance relative to the burning time of between 2 and 4 seconds.</p> |
