Method for producing porous separation membrane containing elastic substance, porous separation membrane (separator) produced by the method, and secondary battery comprising the separation membrane

摘要

The present invention relates to a method for producing a porous separation membrane, and more particularly to a method for producing a porous separation membrane containing an elastic substance, a separation membrane produced by the method, and a secondary battery comprising the separation membrane. According to an aspect of the present invention, an elastic material is uniformly dispersed in a polymer at a weight ratio of 40:60 to 5:95, and the tensile elongation in the direction of low tensile strength at room temperature. A porous separation membrane having a break) of 250% or more is provided. According to another aspect of the present invention, a step of extruding a mixture of a polymer and an elastic material in a weight ratio of 95: 5 to 60:40 using an extruder to form an extruded sheet; There is provided a method for producing a porous separation membrane comprising: annealing and stretching to form a membrane; and thermally fixing the stretched membrane to form a porous separation membrane. According to the present invention, it is possible to provide a porous separation membrane in which the thermal contraction rate of the membrane is reduced, the tensile elongation is greatly increased, and the stability is improved. [Selection] Figure 1