Insulated pipe containing polyurethane foam which is foamed by an environmentally friendly foaming agent and has a low degree of brittleness

Abstract

Described herein is a process for producing a pipe insulated with polyurethane foam, where (a) isocyanates are mixed with (b) polyols, (c) blowing agent including at least one aliphatic, halogenated hydrocarbon compound (c1), made up of from 2 to 5 carbon atoms, at least one hydrogen atom and at least one fluorine and/or chlorine atom, where the compound (c1) includes at least one carbon-carbon double bond, (d) catalyst including N,N-dialkylbenzylamine, optionally (e) chain extenders and/or crosslinkers and optionally (f) auxiliaries and additives to give a reaction mixture, the reaction mixture is applied to a pipe for media and is allowed to cure to give the polyurethane foam. Also described herein is an insulated pipe obtained by such a process and a method of using such an insulated pipe as insulated composite wall pipe for district heating or district cooling networks laid in the ground.

Dependencies are inferred from the claim text.