Verfahren zur Herstellung von mikroporoesen Flaechengebilden

摘要

1,229,970. Microporous polyurethane laminates. FARBENFABRIKEN BAYER A.G. 9 Oct., 1968 [25 Oct., 1967], No. 47833/68. Heading B5N. [Also in Division C3] Laminates may be produced having as one layer a microporous foil prepared by dissolving an isocyanate prepolymer and a disecondary amine in a solvent liquid which does not dissolve the polyaddition product which is formed but only causes it to swell, applying the resulting polyurethane-urea dispersion to a support and drying to form the foil. A monomeric polyisocyanate may be included in the reaction mixture. The solvent liquid may be a single compound or a mixture of organic compounds one of which may be a solvent for the polyaddition product and another of which is a " non- solvent " for the polyaddition product so that the said solvent liquid has the required properties. The prepolymers are prepared in a conventional manner, suitably from polyethers and diisocyanates. Suitable disecondary diamines are N,N1-dimethylethylene diamine, N,N1-dimethylhexamethylene diamine-(1,6), N,N1-dialkylcyclohexylenediamines, N,N1-dialkylphenylenediamines and 4,41-bis-(N-methylamine)- diphenylmethane. The microporous foils may be stripped from the support and glued by discontinuous layers of adhesive to woven or knitted fabrics, fleeces, felts or split leather.