US4036748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asymmetric, semipermeable membranes of polybenz-1,3-oxazine diones-(2,4)
Assignee: Bayer AG
•
Filing: 1975-04-16
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Granted: 1977-07-19
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Expires: 1995-04-16
Abstract
Abstract An asymmetric semipermeable membrane of a homo- or co-polybenz-1,3-oxazine dione-(2,4).
Inventors
- 👤 Birger Knickel
- 👤 Rudolf Binsack
- 👤 Hans Rudolph
- 👤 Hans Jurgen Rosenkranz
- 👤 Ludwig Bottenbruch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:20
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/58; B01D71/62; C; C08; C08G; C08G73/00; C08G73/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
30 words
In the method of desalination of sea water by reverse osmosis employing a membrane, the improvement wherein said membrane is an asymmetric semipermeable membrane of a homo or copoly-benz-1,3-oxazine dione-(2,4).
Claim 2
Dependent Claim
30 words
In the method of desalination of sea water by reverse osmosis employing a membrane, the improvement wherein said membrane is an asymmetric semipermeable membrane of a homo or copoly-benz-1,3-oxazine dione-(2,4).
Claim 3
Dependent Claim
104 words
The process of claim 1 wherein said membrane includes a structural moiety of the formula ##STR24## wherein Ar is a tetravalent aromatic group having 6 to 12 carbon atoms, the two bonds which bond the oxygen function and the carbonyl function are in ortho-position to each other, n is 10 to 200 and Ar I is an aromatic phenylene or naphthylene group or a group of the formula --Ar.sup.V --Y--Ar.sup.VI -- wherein Ar V and Ar VI , which may be the same or different, are aromatic groups having 6 to 12 carbon atoms and Y is a bridge member of the formula ##STR25##
Claim 4
Dependent Claim
53 words
The process of claim 2 wherein Ar is of the formula ##STR26## wherein Ar III and Ar IV are each an aromatic group with 6 to 12 carbon atoms and X is a covalent bond or a bridge member of the formula --0--, --S--, --S0 2 --, --CH 2 --, ##STR27## or --C0--.
Claim 5
Independent Claim
29 words
A method for separating or concentrating mixtures of substances by reverse osmosis employing a membrane wherein said membrane is an asymmetric semipermeable membrane of a homo- or copoly-benz-1,3-oxazine dione-(2,4).
Claim 6
Independent Claim
29 words
A method for separating or concentrating mixtures of substances by reverse osmosis employing a membrane wherein said membrane is an asymmetric semipermeable membrane of a homo- or copoly-benz-1,3-oxazine dione-(2,4).
Claim 7
Dependent Claim
104 words
The process of claim 4 wherein said membrane includes a structural moiety of the formula ##STR28## wherein Ar is a tetravalent aromatic group having 6 to 12 carbon atoms, the two bonds which bond the oxygen function and the carbonyl function are in ortho-position to each other, n is 10 to 200 and Ar I is an aromatic phenylene or naphthylene group or a group of the formula --Ar.sup.V --Y--Ar.sup.VI -- wherein Ar V and Ar VI , which may be the same or different, are aromatic groups having 6 to 12 carbon atoms and Y is a bridge member of the formula ##STR29##
Claim 8
Dependent Claim
53 words
The process of claim 4 wherein Ar is of the formula ##STR30## wherein Ar III and Ar IV are each an aromatic group with 6 to 12 carbon atoms and X is a covalent bond or a bridge member of the formula --0--, --S--, --S0 2 --, --CH 2 --, ##STR31## or --C0--.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |