Process for preparing in situ reticulated polyurethane foam

摘要

An improved process for in situ production of a reticulated, open-cell polyurethane foam which comprises reacting a polyester/polyether polyol mixture with an aromatic polyisocyanate having a ratio of isocyanate moieties to aromatic moieties of about 2:1 in the presence of a catalyst and a blowing agent, the improvement comprises: said polyol mixture being (a) 80 to 95 parts by weight of polyester polyol and (b) 20 to 5 parts by weight of polyoxypropylene polyether polyol or a mixed poly(oxyethylene/oxypropylene polyether polyol, each having at least one polymer of ethylenically unsaturated monomers dispersed therein and a stabilizing surfactant for polyether polyurethane foam, and said process produces a polyurethane foam which has excellent strength properties and an exceeding low resistance to air flow.