| 摘要 |
PURPOSE:To prevent rupture to obtain a sealed alkaline battery having high safety by using an insulating nylon gasket having specified tensile breaking elongation and thickness in a safety valve part. CONSTITUTION:A negative cap 5 and an insulating gasket 8 made of nylon are placed on the upper part of a metal container 1. A thin part is partially formed in the gasket 8 as a safety valve 8a. When internal pressure within a battery is increased by gas evolution, the safety valve 8a is elongated, then broken, and gas is exhausted outside. If nylon whose tensile breaking elongation (mm/mm) is larger than 70% is used, the safety valve does not operate. The tensile breaking elongation of nylon is selected to 50-70%. The thickness of a safety valve part is selected to 0.1-0.3mm. If the thickness is less than 0.1mm, fraction defective of gasket is increased, and if it is more than 0.3, the safety valve is not properly operated. |
