| abstract |
(57) [Problem] To provide a porous film exhibiting a sufficient heat-resistant temperature range and having high mechanical strength in which conductive fine particles are hardly penetrated. SOLUTION: On both sides of a mixed layer comprising 40 parts by weight of polypropylene (PP) having a melt index (MI) of 0.8 and 60 parts by weight of high density polyethylene (PE) having an MI of 0.7, A layer of a mixture consisting of 85 parts by weight of PP of 0.5 and 15 parts of high-density PE having an MI of 0.6 is laminated, and the laminated film is stretched to form a porous film. In this porous film, A plasma treatment was performed using oxygen as an introduced gas at an output of 0.2 w / cm 2 and a treatment time of 10 sec. Apply by spray method at 100 ℃ A heat treatment is performed for 10 minutes to form a silicon oxide film. |