| 摘要 |
The invention provides a process for producing rigid polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms reactive with isocyanates in the presence of c) blowing agents, characterized in that component b) comprises castor oil bi), and in that the reaction is performed in the presence of a compound d) selected from the group comprising alkylene carbonates, carboxamides and pyrrolidones. |
