| 摘要 |
PROBLEM TO BE SOLVED: To provide water vapor permeable sheets which pass only water vapor and do not pass moisture and have high mechanical strength and, in addition, excellent stress relaxation properties. SOLUTION: The water vapor permeable sheets are composed of a film molded product prepared by coating an aqueous dispersion of a urethane acrylic polymer comprising 10-90 wt.% urethane component and 90-10 wt.% acrylic component and having neutralized carboxyl groups in the molecule, the film molded product (with a thickness of 50μm) having a tensile modulus by tensile testing of >=0.5 kg/mm2, a stress retained one minute after 50% elongation of <=50% and, simultaneously, a water vapor permeability of >=500 g/m2.24 hr as the film-forming material, drying it and the like.
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