| 摘要 |
PURPOSE:To obtain a composite membrane excellent in gas separability and gas permeability, by providing a silicone high-molecular layer excellent in film forming property between a layer comprising a high-molecular material excellent in gas separability and a support. CONSTITUTION:This composite membrane is obtained by forming a membrane 4 comprising a silicone high-molecular material having excellent film forming property and high gas permeability and a membrane 1 comprising a high-molecular material B of which the glass transition temp. Tg is an atmospheric temp. or less and which is relatively good in gas separability but inferior to gas permeability to the surface of a porous support 2. As the high-molecular material B, polyolefin, polybuten, polypentene, polymethylpentene or polyhexane are represented. Because this membrane has the layer 4 comprising the material good in gas permeability as a first layer, this layer 4 prevents the penetration of the high-molecular B-layer 1 into the support 3 and, therefore, the high- molecular B-layer 1 can be constituted extremely thin and gas permeability can be enhanced while gas separability is kept high. |
