| 摘要 |
<p>The invention is a membrane closure apparatus comprising a selectively permeable gas separation membrane (8) having a feed side which is in communication with an organic gas in a fuel or storage tank (6). The apparatus is particularly useful as a means for closing the filler tube (2) or vent line of a fuel tank or storage tank. The gas separation membranes which may be used with the apparatus are not limiting; however, a preferred membrane may be formed from amorphous polymers of perfluoro-2,2-dimethyl-1,3-dioxole, especially copolymers with a complementary amount of at least one of tetrafluoroethylene, perfluoromethyl vinyl ether, vinylidene fluoride and chlorotrifluoroethylene. More preferably, the polymer is a dipolymer containing 65-99 mole % of perfluoro-2,2-dimethyl-1,3-dioxole and having a glass transition temperature of at least 140 °C.</p> |
