Protective-layer-covered gas separation membrane, method for producing protective-layer-covered gas separation membrane, gas separation membrane module, and gas separation apparatus

A protective-layer-covered gas separation membrane comprising:

• a gas separation membrane including a resin layer containing a compound having a siloxane bond;
• a protective layer located on the resin layer;
• and
• a porous layer on the protective layer,
• wherein the protective layer includes a region PLi present in the porous layer and a region PLe present on the porous layer, and
• a degree of infiltration of the protective layer into the porous layer is 10% to 90%, the degree of infiltration being expressed by the following formula:
• degree of infiltration of protective layer into porous layer=100%×(thickness of PLi)/(thickness of PLi+thickness of PLe),
• wherein the porous layer has a carbon dioxide permeability coefficient of 2,000 barrers or more, and
• wherein the gas separation membrane satisfies one of conditions 1, 3, and 4:
• condition 1:
• the resin layer satisfies inequalities 1 and 2:
• inequality 1:
• 0.9≥A/B≥0.55
• inequality 2:
• B≥1.7
• wherein A represents an O/Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms contained in the resin layer at a depth of 10 nm from a surface of the resin layer, and B represents an O/Si ratio that is a ratio of the number of oxygen atoms to the number of silicon atoms in the surface of the resin layer;
• condition 3:
• a minimum percentage Si0 of Si2+ and Si3+ peaks relative to all Si peaks in ESCA depth profiling of the resin layer is 1% to 40%;
• and
• condition 4:
• a positron lifetime τ3 of a third component formed by implantation of a positron with an energy of 1 keV into the surface of the resin layer is 3.40 to 4.20 ns.