POROUS POLYPROPYLENE FILM ROLL

• Main Authors: MATSUI RYOSUKE, OKURA MASATOSHI, FUJIMOTO SOICHI
• Format: Patent
• Language: English
• Published: 28.10.2010
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; ELECTRICITY; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

PROBLEM TO BE SOLVED: To provide a porous polypropylene film roll suitable as a separator for use in electric energy storage devices, that has reduced characteristic variations between the electric energy storage devices when the film roll is used as a separator for an electric energy storage device thereby being capable of attaining uniform quality because of excellent gas permeability and porosity, as well as reduced variations in the gas permeability and porosity. SOLUTION: The porous polypropylene film roll is a roll of a porous polyethylene film wound around a core. When gas permeation resistance of the porous polypropylene film roll is measured at 61 points in the longitudinal direction with 50 mm intervals in its longitudinal optional sites, assuming a maximum air resistance as Gmax (sec), a minimum gas permeation resistance as Gmin (sec), and an overall gas permeation resistance as Gave (sec), the value of Gmax-Gmin is 0 to 20 sec, and the Gave is 50 to 500 sec. COPYRIGHT: (C)2011,JPO&INPIT