Membrane filter material having excellent organic solvent resistance, method for formation of membrane filter and process for preparation of bismaleimide polymer to be used for membrane filter.

摘要

A bismaleimide polymer, useful as a membrane filter material, is formed by polymerising a bismaleimide compound with a perhydrodiaza-type heterocyclic compound and has a main structural skeleton represented by the following formula: <CHEM> wherein R1, R2, R3 and R4 represent a lower carbon chain which is linear or contains a methyl group or ethyl group on the side chain, R5 represents a divalent group containing an aromatic ring, Y is >R< or >N-R-N< in which R is a lower carbon chain, and m is 0 or 1. This membrane filter material has excellent organic solvent resistance and when formed into a hollow fiber or plain film has a high separating and filtering capacity and an excellent organic resistance.