| 摘要 |
PURPOSE:To make it possible to obtain an explosion-preventive mechanism of an easy manufacture and a stable operation by making the melting point of a polyethylene or polypropylene film in the differential scanning calorie measuring method 120 deg.C to 170 deg.C. CONSTITUTION:A valve body consists of a complex membrane made by sticking a polyethylene or polypropylene film which has a sealing property to a metal, and a thin metal plate, and the melting point of the high density polyethylene or polypropylene film in the differential scanning calorie measuring method (DSC method) is made 120 deg.C to 170 deg.C. A gas release hole 2 is formed at a part of a sealing plate 1 being a positive electrode terminal concurrently, and the valve body of the complex membrane 3, which is made by sticking a thermal-fusing type resin film 3a of a polypropylene to which an adhesive property to a metal is given by graft-polymerizing anhydrous maleic acid to polypropylene, and a thin metal plate 3b, is thermal-fused around the outer periphery of the gas release hole 2, to form an explosion-preventive mechanism which blocks the gas release hole 2 constantly in the airtight condition. Consequently, the formation of the explosion-preventive mechanism is easy, a cell explosion in a high pressure is prevented, and the safety is improved. |
