Moisture-permeable waterproof fabric and process for producing same

Abstract

A moisture-permeable waterproof fabric which has a well-balanced combination of moisture permeability and waterproofing properties and has excellent strength, in particular, tensile strength, is provided without increasing environmental burden. A synthetic-polymer solution comprising a synthetic polymer consisting mainly of a polyurethane, fine inorganic particles, and a polar organic solvent is applied to one surface of a fibrous fabric and then brought into contact with a gaseous phase in which waterdrops having an average particle diameter of 1-30 μm have been evenly dispersed, thereby making the synthetic polymer semisolid. The fabric is then immersed in water to completely solidify the polymer and thereby obtain a moisture-permeable waterproof fabric comprising the fibrous fabric and, united to one surface thereof, a microporous film of a single-layer structure comprising the synthetic polymer consisting mainly of a polyurethane (the number of micropores having a pore diameter of 0.1-5 μm is (5-200)×104/mm2 in a vertical cross-section, and the film has a tensile strength of 3-80 MPa, a moisture permeability as measured by the calcium chloride method of 6,000 g/m2·24 hr or higher or a moisture permeability as measured by the potassium acetate method of 6,000 g/m2·24 hr or higher, and a water pressure resistance of 60 kPa or higher).

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