Patent ID: 6458861
Filing Date: 2002-10-01
Classification: C08G,C08J

Abstract:
A process for the preparation of microcellular flexible polyurethane foam having a density of less than 0.75 g/cm3, comprising:A) providing a reactive mixture comprising 1) an isocyanate-functional component; 2) an isocyanate-reactive component comprising 2a) at least one hydroxyl-functional polyol having a theoretical functionality between 2 and 4; 2b) optionally a chain extender having a molecular weight below 300 Da; 2c) optionally a crosslinker having a molecular weight below 300 Da; 3) a urethane promoting catalyst and optionally, if water is also present, a catalyst for the isocyanate-water blowing reaction; 4) a surfactant effective to form stable cells having an average diameter below 200 &mgr;m; and B) an amount of blowing agent suitable to form a microcellular polyurethane foam with a density between 0.1 g/cm3 and 0.75 g/cm3, wherein said blowing agent comprises carbon dioxide which has been dissolved into said isocyanate-functional component A, said isocyanate-reactive component B, or both component A and component B, and optionally a minor amount of water, said minor amount of water being less than 50% by weight of the amount of water required to produce an all-water-blown microcellular elastomer of the same density from the same formulation not containing dissolved CO2.