Abstract: A separator roll including a separator wound around a core, the separator including: a porous substrate; and a porous layer obtained by solidifying a coating layer formed by coating one or both sides of the porous substrate with a coating liquid including a resin and/or an inorganic particle, the separator having a shrinkage rate in MD direction, determined by a method, of ?1.0%, the method including: removing, from the separator roll, the separator by five revolutions of the separator roll starting from an outer end of the separator roll, and cutting out, from an end of the remaining separator roll, a piece of the separator of 200 mm-length in MD direction, to prepare a sample; leaving the sample in a tensionless state at 25° C. for 24 hours; measuring a length of the sample in MD direction before and after the leaving; and calculating the shrinkage rate in MD direction.

Abstract: A method of manufacturing a composite film, the method including: a coating step including coating a coating liquid containing a resin on one surface or both surfaces of a porous substrate to form a coating layer; a solidification step including solidifying the resin by bringing the coating layer into contact with a solidifying liquid to obtain a composite film including the porous substrate and a porous layer that is formed on one surface or both surfaces of the porous substrate and that includes the resin; a water washing step including washing the composite film with water; and a drying step including drying by removing water from the composite film while transporting the composite film at a transport speed of 30 m/min or more using a drying apparatus including a drying device including a contact type heating device and a hot air blowing device, wherein the composite film is brought into contact with a contact type heating device as well as exposed to hot air blown from a hot air blowing device, to remove

Abstract: A method of manufacturing a composite film, the method including: a coating step including coating a coating liquid containing a resin on one surface or both surfaces of a porous substrate to form a coating layer, the porous substrate having a tensile strength at 2% elongation in a machine direction of 0.3 N/cm or more; a solidification step including solidifying the resin by bringing the coating layer into contact with a solidifying liquid to obtain a composite film including the porous substrate and a porous layer that is formed on one surface or both surfaces of the porous substrate and that includes the resin; and a water wishing step including washing the composite film with water by transporting the composite film at a transport speed of 30 m/min or more in a water washing tank; the water washing tank including two or more drive rolls for supporting and transporting the composite film, and a path length between any two adjacent drive rolls being from 0.5 m to 5 m.

Abstract: The embodiment according to the present disclosure provides a method of manufacturing a composite film. This method includes: subjecting a porous substrate containing a thermoplastic resin to a heat treatment at a temperature T which satisfies the Formula: Tg+60° C.?temperature T?Tm (wherein Tg represents a glass transition temperature (° C.) of the thermoplastic resin; and Tm represents a melting point (° C.) of the thermoplastic resin); coating a coating liquid containing at least a resin and a solvent on one surface or both surfaces of the porous substrate, which has been subjected to the heat treatment, to form a coating layer, with a tensile stress in a machine direction in the porous substrate adjusted to be within a range in which an elongation of the porous substrate is 2% or less; and solidifying the coating layer to obtain a composite film including the porous substrate and a porous layer containing at least the resin formed on one surface or both surfaces of the porous substrate.