Patent ID: 8602222

Claim:
A composite semipermeable membrane, comprising: a porous substrate film; and a separating functional polyamide layer formed on the substrate film, wherein the polyamide that forms the separating functional polyamide layer contains a cyclic aliphatic group and/or an aromatic group in its molecular chain, the cyclic aliphatic group and/or the aromatic group has at least two substituents represented by either Formula (1) or (2), wherein one or more of the at least two substituents is represented by Formula (1): wherein n represents 0 or 1, X represents O or S, R 1 and R 2 each represents a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, wherein at least one of R 1 and R 2 is a hydrogen atom, R 3 and R 4 each represents a hydrogen atom or a C 1 to C 12 alkyl or aromatic group optionally having a substituent other than a carboxyl group, R 1 and R 3 are optionally covalently bonded between atoms to form a ring structure, A represents a hydroxyl group or a nitrogen of an amide bond of a polyamide molecule, and A in at least one of the at least two substituents is a nitrogen of an amide bond of a polyamide molecule.