Adhesive-carrying porous film for battery separator and use thereof

Abstract

The invention provides an adhesive-carrying porous film for use as a battery separator, which comprises: a substrate porous film such that when a probe of a probe penetrating thermomechanical analyzer, said probe having a diameter of 1 mm, is placed on the porous film under a load of 70 g to measure a thickness thereof while heating the porous film from room temperature at a rate of 2° C./minute, a temperature at which the thickness of the porous film decreases to a half of the thickness of the porous film when the probe was initially placed thereon is 200° C. or more; and a partially crosslinked adhesive carried on the substrate porous film, the partially crosslinked adhesive being prepared by reacting a reactive polymer having a functional group capable of reacting with an isocyanate group therein with a polyfunctional isocyanate so that the reactive polymer is partially crosslinked. Such a porous film (a separator) is temporarily bonded to an electrode to provide an electrode/separator laminate. In manufacturing a battery, the use of the laminate makes it possible to manufacture a battery efficiently with no mutual slip movement between the electrode and the separator, and is addition, the porous film (the separator) itself, after manufacturing a battery, functions as a separator which does not melt or break, and has a small heat shrinkage under high temperatures

Dependencies are inferred from the claim text.