| abstract |
An object of the present invention is to capture a fine polymer with high efficiency, high flow rate, no clogging, long filtration life, high strength crystalline polymer microporous membrane, and accuracy of the crystalline polymer microporous membrane A method for producing a crystalline polymer microporous membrane that can be produced well, and a filter for filtration using the crystalline polymer microporous membrane. A crystalline polymer is spread in a mold and pressed to form a plurality of preforms, and first and second crystalline polymer films are produced from the plurality of preforms, and the first Heating at least one surface of the first and second crystalline polymer films to form a temperature gradient in the thickness direction of the films, and stretching the first and second crystalline polymer films, respectively; A method for producing a crystalline polymer microporous membrane comprising laminating the first and second crystalline polymer films to form a laminate, and heating and thermally fixing the laminate. [Selection figure] None |