| 摘要 |
<p>Highly elastic polyether-urethane foams are produced in form of blocks of any length, using polyether as OH component, isocyanate, activator, water and/or halohydrocarbons as blowing agent. Polyether used has mol. wt. >3500, high proportion of primary OH groups of >50% of reactive OH groups and/or tert. N atoms in mol. Crude 4,4'-diphenylmetahne diisocyanate, pref. mixed with toluylene diisocyanate, is used as isocyanate component. Foam structure has adjacent regions with regular and mixed-cell structure. Physical properties of foam are improved, esp. its deformation characteristics and recoil elasticity.</p> |
