Crosslinked composite semipermeable membrane

Claim 1

A composite semipermeable membrane comprising a porous support and a crosslinked thin film formed on said porous support, said crosslinked thin film being prepared by the process consisting essentially of forming a film consisting essentially of compound (A) and compound (B) on a porous support, contacting said film with a solution of compound (C) and then drying said film to form a crosslinked film, said compound (A), being at least one compound selected from the group consisting of polyalkylenimines and polyalkylenimine derivatives which have been prepared by the process consisting essentially of reacting part of the amino groups of polyalkylenimines with compounds having functional groups reactive with said amino groups of said polyalkylenimines and which have been rendered soluble in water or solvent mixtures comprising mainly water, said compound (B) being at least one compound selected from the group consisting of: compound (B 1 ) of the general formula ##STR6## wherein R 1 to R 8 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, compound (B 2 ) of the general formula ##STR7## wherein R 1 to R 10 each represent a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, and n denotes an integer of 1 to 3, compound (B 3 ) of the general formula ##STR8## wherein R 1 to R 10 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n denotes an integer of 1 to 3, compound (B 4 ) of the general formula ##STR9## wherein R 1 to R 10 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n denotes an integer of 1 to 3, and compound (B 5 ) (excluding compound (A)) of the general formula ##STR10## wherein R 1 to R 4 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; m and n each represent an integer of 2 or 3; x denotes an integer of 1 to 4; R 5 and R 6 each represent an alkylene group having 1 to 4 carbon atoms; and R 5 and R 6 may each represent hydrogen atoms or an alkyl group having 1 to 4 carbon atoms without being bonded to each other, and said compound (C) being a compound having in one molecule two or more functional groups capable of reacting with amino groups.