Preparing rigid polyurethane foams

Abstract

The invention relates to a process for preparing rigid polyurethane foams, which comprises reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms reactive with isocyanate groups in the presence of c) blowing agents, wherein said compounds having at least two hydrogen atoms reactive with isocyanate groups b) comprise at least one polyether alcohol b1) having a functionality of 2-8 and a hydroxyl number of 200-800 mgKOH/g, obtained by addition of an alkylene oxide b1b) onto a compound having at least two hydrogen atoms b1a), hereinafter also known as starter substances, reactive with alkylene oxides by using an amine b1c) as catalyst.

Dependencies are inferred from the claim text.