초록

This invention relates to novel polyimide gas separation membranes derived from alicyclic dianhydrides and aliphatic, alicyclic, or aromatic diamines, and a process for using such membranes.

대표청구항 ▼

A process of separating gases comprising: (1) contacting one side of a semi-permeable gas separation membrane with a feed gas mixture under pressure, wherein the membrane divides a separation chamber into a high pressure side into which the feed gas mixture is fed and a low pressure side; (2) mainta

A process of separating gases comprising: (1) contacting one side of a semi-permeable gas separation membrane with a feed gas mixture under pressure, wherein the membrane divides a separation chamber into a high pressure side into which the feed gas mixture is fed and a low pressure side; (2) maintaining a pressure differential across the membrane under conditions such that at least one component in the feed gas mixture selectively permeates through the membrane from the high pressure side to the low pressure side of the membrane; (3) removing from the low pressure side of the membrane permeated gas which is enriched in the selectively permeating component(s); and (4) removing from the high pressure side of the membrane non-permeated gas which is depleted in the selectively permeating component(s); wherein the membrane comprises a thin discriminating layer of a polyimide corresponding to the formula: [Figure] and R is the tetravalent residue of an alicyclic dianhydride in which: A. both anhydride moieties of the dianhydride are directly attached to the alicyclic ring structure through ortho-linkages, or B. one anhydride moiety is directly attached to the alicyclic ring structure and the alicyclic ring structure possesses at least one degree of unsaturation; and R1 is the divalent residue of an aliphatic, alicyclic, or aromatic diamine. A semi-permeable gas separation membrane comprising a thin discriminating layer of an aliphatic polyimide having repeating units corresponding to the formula: [Figure] wherein R is the tetravalent residue of an alicyclic dianhydride in which: A. both anhydride moieties of the dianhydride are directly attached to the alicyclic ring structure through ortho-linkages, or B. one anhydride moiety is directly attached to the alicyclic ring structure and the alicyclic ring structure possesses at least one degree of unsaturation; and R1 is the divalent residue of an aliphatic, alicyclic, or aromatic diamine.