| 摘要 |
The present invention relates to a process for preparing rigid polyurethane foams or rigid polyisocyanurate foams by using certain polyetherester polyols B) based on aromatic dicarboxylic acids, optionally further polyester polyols C), which differ from those of component B), and polyether polyols D), wherein the mass ratio of total components B) and optionally C) to component D) is less than 1.6. The present invention also relates to the rigid foams thus obtainable and to their use for producing sandwich elements having rigid or flexible outer layers. The present invention further relates to the underlying polyol components.
|
