| 摘要 |
The invention relates to a method for producing polyurethane rigid foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms that are reactive with isocyanate groups in the presence of c) expanding agents, characterized in that the compounds having at least two hydrogen atoms that are reactive with isocyanate groups contain b) at least one aromatic polyester alcohol bi), at least one polyester alcohol bii) having a functionality of 4 to 8 and a hydroxyl number ranging between 300 and 600 mgKOH/gh. |
