| 摘要 |
To prepare foam plastics, in particular polyurethane foam plastics, which are free from chlorofluorocarbons (CFCs), the blowing agent used is pure nitrogen obtained by simultaneous, binary reaction of the ions NH4<+> and NO2<-> of two NH4<+> and NO2<H N=0><-> ion-forming solutions of ammonium salts and alkali metal nitrites, such as ammonium chloride or ammonium sulphate solution and sodium nitrite or potassium nitrite solution. |
