SEAL MEMBER

摘要

An annular seal member comprising an elastic annular base, and a screen film formed on the surface of the base. The screen film is made of a resin material which is less permeable to gas than is butyl rubber. Another annular seal member comprising a circumferentially stretchable portion provided only in part of the circumference. As a result, the assembling operation efficiency improves, and gas leakage can be entirely prevented. Further, the construction is simple and a housing in which the seal member is mounted can be reduced in size. Further, permeation of CO2 gas can be fully suppressed.