US4045337A
Expired / Lapsed
US
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Asymmetric, semipermeable membranes of cyclic polyureas
Assignee: Bayer AG
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Filing: 1975-06-24
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Granted: 1977-08-30
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Expires: 1995-06-24
Abstract
Abstract Asymmetric, semipermeable membranes of polyhydantoins or polyparabanates.
Inventors
- 👤 Birger Knickel
- 👤 Hans Rudolph
- 👤 Jurgen Hocker
- 👤 Jurgen Lewalter
- 👤 Hans Jurgen Rosenkranz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:28
CPC Classifications
C; C08; C08L; C08L79/00; C08L79/04; B; B01; B01D; B01D71/00; B01D71/06; B01D71/58; B01D71/62
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
218 words
An asymmetric semipermeable membrane of a cyclic polyurea selected from the group consisting of a polyhydantoin of the formula and a polyparabanate of the formula ##STR16## wherein R 1 and R 2 , when taken separately, are each selected from the group consisting of hydrogen, C 1 to C 6 alkyl and C 3 to C 6 cycloalkyl; R 1 and R 2 , when taken together with the carbon atom to which they are attached, are cycloalkyl having 5 to 10 carbon atoms; R 3 and R 4 are each selected from the group consisting of C 1 to C 12 alkylene, C 3 to C 6 cycloalkylene, arylene and any two of the aforesaid members defining R 3 and R 4 connected together by a member selected from the group consisting of --O--, --CH 2 , ##STR17## --S--, --SO 2 -- and --CO--; R 5 is selected from the group consisting of a bond and the members of the group defining each of R 3 and R 4 ; X and Y are each selected from the group consisting of a bond, ##STR18## wherein R 6 is selected from the group consisting of aryl, C 1 to C 12 hydroxyalkyl and C 1 to C 12 alkoxyalkyl and n is an integer from 2 to 200.
Claim 2
Dependent Claim
218 words
An asymmetric semipermeable membrane of a cyclic polyurea selected from the group consisting of a polyhydantoin of the formula and a polyparabanate of the formula ##STR16## wherein R 1 and R 2 , when taken separately, are each selected from the group consisting of hydrogen, C 1 to C 6 alkyl and C 3 to C 6 cycloalkyl; R 1 and R 2 , when taken together with the carbon atom to which they are attached, are cycloalkyl having 5 to 10 carbon atoms; R 3 and R 4 are each selected from the group consisting of C 1 to C 12 alkylene, C 3 to C 6 cycloalkylene, arylene and any two of the aforesaid members defining R 3 and R 4 connected together by a member selected from the group consisting of --O--, --CH 2 , ##STR17## --S--, --SO 2 -- and --CO--; R 5 is selected from the group consisting of a bond and the members of the group defining each of R 3 and R 4 ; X and Y are each selected from the group consisting of a bond, ##STR18## wherein R 6 is selected from the group consisting of aryl, C 1 to C 12 hydroxyalkyl and C 1 to C 12 alkoxyalkyl and n is an integer from 2 to 200.
Claim 3
Dependent Claim
17 words
A membrane as claimed in claim 1 wherein n is an integer of from 2 to 150.
Claim 4
Dependent Claim
15 words
A membrane as claimed in claim 1, in which the cyclic polyurea is said polyhydantoin.
Claim 5
Dependent Claim
15 words
A membrane as claimed in claim 1, in which the cyclic polyurea is said polyparabanate.
Claim 6
Dependent Claim
20 words
A process for the desalination of water, which comprises passing the water through a membrane as claimed in claim 1.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 5, wherein the desalination takes place at pressures of up to 300 atmospheres.
Claim 8
Dependent Claim
23 words
A process for the separation or concentration of substance mixtures which comprises passing the mixtures through a membrane as claimed in claim 1.
Claim 9
Dependent Claim
19 words
A process as claimed in claim 7, wherein the mixtures have a pH value of from 0 to 4.
Claim 10
Dependent Claim
17 words
A process as claimed in claim 7, wherein the concentration or separation takes place at elevated temperatures.
References Cited (Backward Citations)
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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) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |