Patent US4952220A successfully refreshed from Google Patents.
US4952220A
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Membranes formed from unsaturated polyimides
Assignee: Air Products and Chemicals Inc
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Filing: 1989-10-11
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Granted: 1990-08-28
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Expires: 2009-10-11
Abstract
Abstract The present invention is a class of polyimide membranes containing copolymerizable, surface modifiable units containing both aromatic diamines and alkenylated diamines having an allyl or allylaryl group preferably positoned ortho to an amine functionality. The polyimide membranes can be surface modified by treatment with an activating force such as high energy electromagnetic irradiation or with a free radical source to impart high selectivity to the membrane without causing a large decrease in composite permeance.
Inventors
- 👤 Michael Langsam
- 👤 William F. Burgoyne, Jr.
- 👤 Jeremiah P. Casey
- 👤 Michael E. Ford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:14
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; B01D71/76; B01D71/82; C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1042; B01D2323/00; B01D2323/30
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
52 words
A semi-permeable membrane formed of a polyimide containing copolymerizable, surface modifiable units of the formula: ##STR20## where N--A--N is an aromatic diamine; Q is an alkenylated phenylene or diphenylene containing an allyl or allylaryl group; and m and n are integers such that the ratio of m:n is from 0.1 to 99.
Claim 2
Dependent Claim
52 words
A semi-permeable membrane formed of a polyimide containing copolymerizable, surface modifiable units of the formula: ##STR20## where N--A--N is an aromatic diamine; Q is an alkenylated phenylene or diphenylene containing an allyl or allylaryl group; and m and n are integers such that the ratio of m:n is from 0.1 to 99.
Claim 3
Dependent Claim
29 words
A membrane in accordance with claim 1 which has been contacted with a source of high energy electromagnetic irradiation to effect surface modification among the co-polymerizable, surface modifiable units.
Claim 4
Dependent Claim
36 words
A membrane in accordance with claim 2 wherein said source of high energy electromagnetic irradiation is selected from the group consisting of longwave UV irradiation, shortwave UV irradiation and X-ray irradiation with and without photo sensitizers.
Claim 5
Dependent Claim
16 words
A membrane in accordance with claim 1 which has been contacted with a free radical source.
Claim 6
Dependent Claim
37 words
A membrane in accordance with claim 4 which has been contacted with a free radical source selected from the group consisting of volatile peresters, peroxides and azo compounds followed by thermal activation with or without metal accelerators.
Claim 7
Dependent Claim
29 words
A membrane in accordance with claim 1 wherein Q is an alkenylated phenylene having the general structural formula: ##STR21## wherein each R is independently an allyl or allylaryl group.
Claim 8
Dependent Claim
72 words
A membrane in accordance with claim 6 wherein R is an allyl group having the general structural formula: ##STR22## wherein R 1 , R 2 , R 3 , R 4 , and R 5 , are hydrogen C 1 -C 3 aliphatic, phenyl, halogen or alkoxy radicals or R 2 and R 4 or R 5 are bridged via an alkylene radical --(CH 2 ) y -- wherein Y=2 to 5.
Claim 9
Dependent Claim
86 words
A membrane in accordance with claim 6 wherein R is an allylaryl group having the general structural formula: ##STR23## wherein R 6 is --CH 2 --, Ar is phenylene or substituted phenylene, d=0 or 1 and R 1 , R 2 , R 3 , R 4 and R 5 are hydrogen, C 1 -C 3 aliphatic, phenyl, halogen or alkoxy radicals or R 2 and R 4 or R 5 are bridged via an alkylene radical --(CH 2 ) y -- wherein y=2 to 5.
Claim 10
Dependent Claim
55 words
A membrane in accordance with claim 1 wherein Q is an alkenylated diphenylene having the general structural formula: ##STR24## wherein each R is independently an allyl or allylaryl group; X is methylene, alkylene or C 1 -C 6 branched alkylene group, oxygen, sulfur, sulfonyl, carbonyl, or fluoroalkylene and each c is independently 0 or 1.
Claim 11
Dependent Claim
14 words
A membrane in accordance with claim 9 wherein each R is an allyl group.
Claim 12
Dependent Claim
13 words
A membrane in accordance with claim 9 wherein R is an allylaryl group.
Claim 13
Dependent Claim
23 words
A membrane in accordance with claim 1 wherein Q has the structural formula: ##STR25## wherein R 1 is H or CH 3 .
Claim 14
Dependent Claim
14 words
A membrane in accordance with claim 1 wherein Q has the structural formula: ##STR26##
Claim 15
Dependent Claim
44 words
A membrane in accordance with claim 1 wherein said polyimide also contains third polymerizable units of the formula: ##STR27## wherein N--A--N is an aromatic diamine; and Z is ##STR28## wherein A 3 is C(CH 3 ) 2 , O, S or SO 2 .
Claim 16
Dependent Claim
24 words
A membrane in accordance with claim 14 wherein said third polymerizable units make up to 95% of the total polymerizable units of the polyimide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |