HIGHLY-SELECTIVE POLYIMIDE MEMBRANES WITH INCREASED PERMEANCE, SAID MEMBRANES CONSISTING OF BLOCK COPOLYIMIDES Russian patent published in 2018 - IPC C08G73/10 C08L79/08 B01D67/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a block copolyimide, to options of the for producing thereof, to an integral asymmetric membrane or an integral asymmetric flat membrane, to modules based on such a membrane, as well as to a gas-separation method and a gas-separation device. Block copolyimide comprises blocks (A) and (B) having structures (Ia) and (Ib) below, wherein each of block lengths n and m is 5 to 1000, and radicals R₁, R₂, R₃, R₄ are values indicated in the claims. Block copolyimide is soluble in an aprotic dipolar solvent. According to the first embodiment, the method for producing a block copolyimide comprises reacting the oligoimide obtained from at least one dianhydride and at least one diamine with at least one dianhydride and at least one diisocyanate. According to the second embodiment, the method for producing a block copolyimide comprises reacting the oligoimide – block (A) obtained from at least one dianhydride and at least one diisocyanate, with at least one dianhydride and at least one diamine. Resulting polyimide/polyamic acid is further imidated to produce block (B) soluble in an aprotic dipolar solvent. Or the polyimide/polyamic acid is imidated chemically, preferably by using pyridine and acetic anhydride. Integral asymmetric membrane or integral asymmetric flat membrane is produced from said block copolyimide. Such a membrane is used to produce modules. Membranes and modules are used to separate gases. .

EFFECT: invention provides highly-selective integrally asymmetric gas-separation membranes with improved permeance, characterized by low layer thickness values.

16 cl, 17 tbl, 42 ex