摘要 |
PROBLEM TO BE SOLVED: To provide a gasket used in a sealed type secondary battery (storage battery) such as a lithium ion secondary battery, excellent in wet heat resistance and electrolyte-proofness, hardly generating stress relaxation even when compressed under a fixed strain, and capable of maintaining air tightness over a long period. SOLUTION: This gasket is used in the secondary battery constituted of a positive electrode, a negative electrode, a sealing body, a gasket, a separator and an electrolyte, and includes a resin composition for the gasket containing a thermoplastic elastomer and a thermoplastic resin. An absolute value of a compression stress after 100 hours is 10 MPa or more in a compression stress relaxation test under a fixed condition (23°C, 10% strain, 3 mm of test piece thickness and 60 mm<SP>2</SP>of compression face side surface area) of an injection molding, in the gasket for the secondary battery. COPYRIGHT: (C)2011,JPO&INPIT |