| 摘要 |
PURPOSE:To obtain a porous sheet material having excellent mechanical properties, etc., without using complicated gelling and drying steps of conventional process and completing the above steps within 10min, by applying a porous layer composed of a specific polyurethane resin on a substrate. CONSTITUTION:The objective sheet material can be produced by coating a substrate with a porous layer composed of a polyurethane resin having a molecular weight of 20,000-500,000 and fine particles derived from an active hydrogen- containing polyfunctional compound having a molecular weight of <=50 per one functional group and an organic polyisocyanate. The above material can be produced by using the fine particle in a form dispersed in an organic solvent as a W/O-type polyurethane emulsion and water emulsified in an organic solvent. The fine particle is produced in an organic solvent solution of a polyurethane resin having a molecular weight of 20,000-250,000.
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