| abstract |
PURPOSE:To improve the air permeability and waterproofness by reacting a specific polyol with a polyisocyanate in the presence of a cell stabilizer and a blowing agent. CONSTITUTION:At least one polyol selected from the group consisting of a polydiene polyol, a dimer acid polyol, a castor oil polyol, and a polyether polyol contg. 90mol% or higher addition-polymerized 3C or higher alkylene oxide is reacted with a polyisocyanate (e.g. polymethylene polyphenylene polyisocyanate) in the presence of a cell stabilizer comprising an organosilicone compd. of the formula wherein R is alkyl (e.g. methyl, ethyl, or butyl) or aryl (e.g. phenyl); and x is an integer), a blowing agent (e.g. methylene dichloride), a catalyst (e.g. triethylenediamine), and if necessary a filler having a b.p. at normal pressure of 200 deg.C or higher and an m.p., or a softening point, of 150 deg.C or lower (e.g. paraffin); thus a polyurethane foam sealing material having a permeability in 10mm thickness of 20cc/cm<2>/sec or lower is prepd. |