METHOD FOR PRODUCING A POLYURETHANE FOAM AND POLYURETHANE FOAM OBTAINABLE THEREBY.

摘要

The invention relates to a method for producing a polyurethane foam having bimodal cell size distribution, comprising the steps of: providing a mixture in a mixing head, wherein the mixture comprises: A) a component reactive in the presence of isocyanates; B) a surfactant component; C) a propellant component selected from the group comprising linear, branched, or cyclic C1- to C6-Alkane, linear, branched, or cyclical C1- to C6 fluoralkane, N2, O2, Argon and/or CO2, wherein the propellant component C) is present in the supercritical or near-critical state; and D) a polyisocyanate component; and discharging the mixture comprising the components A, B, C, D from the mixing head, wherein the pressure present in the mixture is lowered to atmospheric pressure when discharging the mixture.