Abstract: The present invention provides a PVDF porous film and method for producing it, which has high water permeability and high chemical resistance to washing chemicals and the like that has been difficult to realize with conventional polymer porous films, and which can be used over a prolonged period of time, and a method of producing the same and the like. Namely, the present invention provides a porous film in which the degree of crystallization of the PVDF resin is 50% or more but not more than 90%, and the product of the degree of crystallization of the PVDF resin and the specific surface area of the film is 300 (%·m2/g) or more but not more than 2000 (%·m2/g).

Abstract: A separation membrane module for separating a specific component from a mixture containing a plurality of components includes a plurality of separation stages each including a plurality of hollow fiber membranes arranged in parallel to each other. The separation stages are connected in series via connection portions allowing passage of the mixture. At lease one parameter relating to separation by the hollow fiber membrane or membranes in each separation stage is determined to provide effective separation throughout the separation stages.

Abstract: A separation membrane module for separating a specific component from a mixture containing a plurality of components includes a plurality of separation stages each including a plurality of hollow fiber membranes arranged in parallel to each other. The separation stages are connected in series via connection portions allowing passage of the mixture. At lease one parameter relating to separation by the hollow fiber membrane or membranes in each separation stage is determined to provide effective separation throughout the separation stages.

Abstract: The present invention provides a PVDF porous film, which has high water permeability and high chemical resistance to washing chemicals and the like that has been difficult to realize with conventional polymer porous films, and which can be used over a prolonged period of time; and a method of producing the same and the like. Namely, the present invention provides a porous film in which the degree of crystallization of the PVDF resin is 50% or more but not more than 90%, and the product of the degree of crystallization of the PVDF resin and the specific surface area of the film is 300 (%·m2/g) or more but not more than 2000 (%·m2/g).

Abstract: A hollow fiber filter membrane where the inner surface comprises a three-dimensional network structure having thick trunks of 10-30 .mu.m in maximum diameter and the average pore diameter of a minimum pore diameter layer of the membrane is 0.01 .mu.m or more and less than 1 .mu.m.