Patent ID: 7497951

Claim:
A composite semipermeable membrane which comprises a separating functional layer comprising polyamide formed on a porous substrate film, wherein an acyl group selected from formulae (1) to (3) is bound via a covalent bond to a polyamide molecule in the separating functional layer comprising polyamide: wherein n represents 0 or 1; X represents O, S or NR 6 ; R 1 , R 2 and R 6 each represents a hydrogen atom or an alkyl group having from 1 to 3 carbon atoms, and at least one of R 1 and R 2 is a hydrogen atom; R 3 and R 4 each represents a hydrogen atom, or an alkyl group having from 1 to 12 carbon atoms or aromatic group which may have a substituent(s) other than a carboxyl group; R 5 represents an alkyl group having from 1 to 12 carbon atoms or aromatic group which may have a substituent(s) other than a carboxyl group; and any atoms of R 1 , R 3 , R 5 and R 6 may form a ring structure via a covalent bond, wherein n, R 1 and R 2 have the same meanings as defined above; Y represents a halogen atom; R 7 and R 8 each represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 12 carbon or aromatic group which may have a substituent(s) other than a carboxyl group; and atoms of R 1 and R 7 may form a ring structure via a covalent bond, and wherein R 9 represents a 5-membered ring aromatic group having 1 to 12 carbon atoms, has at least two atoms selected from a nitrogen atom, an oxygen atom and a sulfur atom within the ring and may have a substituent(s) other than a carboxyl group.