Patent ID: 8721774

Claim:
A gas separation composite membrane comprising a polyamidoamine dendrimer (A) having a group represented by formula (1): wherein A 1 represents a divalent organic residue having 1 to 3 carbon atoms and n represents an integer of 0 or 1, or a group represented by formula (2): wherein A 2 represents a divalent organic residue having 1 to 3 carbon atoms and n represents an integer of 0 or 1, 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.