Abstract: Disclosed is a gas separation composite membrane comprising a polyamidoamine dendrimer (A) having a specific group, a vinyl alcohol-based polymer (B) containing 0.5 to 5 mol % of carboxyl groups, and a crosslinking agent (C) having an azetidinium group, wherein the mass ratio (A)/(C) of the polyamidoamine dendrimer (A) to the crosslinking agent (C) having an azetidinium group is 20/80 to 65/35, and the mass ratio (B)/(C) of the vinyl alcohol-based polymer (B) to the crosslinking agent (C) having an azetidinium group is 20/80 to 80/20. Thus, a gas separation composite membrane capable of separating a specific type of gas from a mixed gas containing water vapor is provided.

Abstract: Disclosed is a gas separation composite membrane comprising a polyamidoamine dendrimer (A) having a specific group, a vinyl alcohol-based polymer (B) containing 0.5 to 5 mol % of carboxyl groups, and a crosslinking agent (C) having an azetidinium group, wherein the mass ratio (A)/(C) of the polyamidoamine dendrimer (A) to the crosslinking agent (C) having an azetidinium group is 20/80 to 65/35, and the mass ratio (B)/(C) of the vinyl alcohol-based polymer (B) to the crosslinking agent (C) having an azetidinium group is 20/80 to 80/20. Thus, a gas separation composite membrane capable of separating a specific type of gas from a mixed gas containing water vapor is provided.

Abstract: This invention relates to hydrous gel membranes for gas separation which comprise support membranes formed by solvent-soluble polymeric materials containing in their repeating unit a bulky structural part and hydrophilic functional groups represented by the following general formula (1) ##STR1## (R.sub.1, R.sub.2, R.sub.3, and R.sub.4 designate hydrogen, alkyl group, and halogen and R.sub.5 and R.sub.6 designate any one of --H, --SO.sub.3 H, --COOH, and --OH) and water or an aqueous solution of substances with affinity for CO.sub.2 substantially uniformly retained in the support membranes. The membranes show not only high CO.sub.2 permeation and CO.sub.2 selectivity but also long-term stable membrane performance and ease of fabricability into membranes and are capable of recovering a large volume of CO.sub.2 generated at stationary sites efficiently at low cost.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) and (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having units (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(HN--X--NH--Z.sub.1).sub.l -- (II)--(HN--X--NH--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--(O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: A separation membrane comprising a soluble aromatic polysulfone having the formula --(X--Y)--, wherein X and Y comprise the constituent unit shown below, and the inherent viscosity (.eta..sub.inh) based on the value of a solution of 0.5 g of the polysulfone dissolved in 100 ml of N-methyl-2-pyrrolidone measured at 30.degree. C. is 0.4 or more: ##STR1## wherein R.sub.1 -R.sub.4 are each either H, CH.sub.3 or C.sub.2 H.sub.5, and R.sub.5 -R.sub.6 are each either H, Cl, or NO.sub.2.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) an (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having units (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(HN--X--NH--Z.sub.1).sub.l -- (II)--HN--X--NH--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) and (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having unit (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(NN--X--NH--Z.sub.1).sub.l -- (II)--(NN--X--Nh--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.