Adhesive-carrying porous film for cell separator and its application

Abstract

According to the present invention, the following adhesive-loaded porous membrane is provided: using a needle probe type thermomechanical analyzer, a probe with a diameter of 1 mm is placed on the porous membrane under a load of 70 g, and the temperature is raised from room temperature at a rate of The porous membrane was heated at 2°C / min to measure its thickness, and a porous membrane at a temperature equal to or higher than 200°C when the thickness of the porous membrane became 1 / 2 of the thickness when the probe was placed at this time was used as a base material A porous membrane, a partially crosslinked adhesive formed by reacting a polyfunctional isocyanate with a reactive polymer having a functional group capable of reacting with an isocyanate group is supported on the porous membrane of the base material, and a part of it is crosslinked to form a battery Adhesive-loaded porous membrane for separators. Such a porous film (separator) is temporarily bonded to the electrodes to form an electrode / separator laminate. By using this laminate in the manufacture of batteries, there is no mutual slippage between the electrodes and the separator, and batteries can be manufactured efficiently. Moreover, the porous membrane (separator) itself does not melt or break at high temperature after the battery is manufactured, and also plays the role of a separator with little heat shrinkage.

Description

technical field [0001] The present invention relates to the manufacturing method of the following adhesive-loaded porous film for battery separators (Separe-ta) and batteries using such an adhesive-loaded porous film. In the production of batteries, at the same time, in the batteries thus produced, the porous film carrying the adhesive will not melt or break even in a high temperature environment, and it also functions as a separator with small thermal shrinkage, so it is safe in terms of safety. is good. Background technique [0002] Conventionally, as a method of manufacturing a battery, for example, as described in JP-A No. 09-161814 or JP-A No. 11-329439, the following method is known: a positive electrode and a negative electrode are sandwiched and laminated. A separator for preventing short circuits between these electrodes, or a positive (negative) electrode, a separator, a negative (positive) electrode, and a separator are sequentially laminated and wound to form an...

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Problems solved by technology

[0006] The porous membrane obtained by this method does not cause melting or membrane rupture even in a high-temperature environment, and is good in heat resistance. However, contrary to the above-mentioned method, since it is not stretched in the manufacturing process, its strength is insufficient. And did not improve the problem of heat shrinkage

That is, there has not been known a porous membrane for separators that does not melt under high-temperature environments, does not cause membrane rupture, and has little thermal shrinkage.