Patent US4879044A successfully refreshed from Google Patents.
US4879044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Highly aromatic anisotropic polyurea/urethane membranes and their use for the separation of aromatics from non aromatics
Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1989-02-03
•
Granted: 1989-11-07
•
Expires: 2009-02-03
Abstract
Abstract An anisotropic elastomeric membrane preferably made from polyurea/urethane has been prepared. These anisotropic membranes are made from the corresponding polymeric material by preparing the polymeric material in a good solvent containing less than 5 vol % non-solvent, producing a film of the polymer solution on a support with a maximum pore size less than 20 microns, subjecting the film to conditions such that the solvent vapor pressure-time factor is 1000 mm Hg-min. or less, preferably 200 mm Hg-min or less, most preferably approaching 0 mm Hg-min and quenching the membrane film in a non-solvent yielding a three-layered anisotropic membrane. The preferred anisotropic membranes made from the polyurea/urethane copolymer, useful for the separation of aromatics from mixtures thereof with non-aromatics and saturates, in, for example, a naphtha feed stream, are characterized by possessing a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole percent, a functional group density of at least about 10 per 1000 grams of polymer and a C=O/NH ratio of less than about 8.0.
Inventors
- 👤 Joseph L. Feimer
- 👤 Bernd A. Koenitzer
- 👤 Robert C. Schucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:11
CPC Classifications
C; C10; C10G; C10G31/00; C10G31/11; B; B01; B01D; B01D63/00; B01D63/02; B01D67/00; B01D67/0002; B01D67/0009; B01D69/00; B01D69/12; B01D69/1216; B01D71/00; B01D71/06; B01D71/76; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; B01D2325/00; B01D2325/02; B01D2325/022; B01D71/54
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
33 words
An anisotropic membrane: comprising layers of aromatic polyurea/urethane, including a thin dense layer, a thin non-continuous skin and an open porous structure between the aforesaid thin dense layer and the thin non-continuous skin.
Claim 2
Dependent Claim
33 words
An anisotropic membrane: comprising layers of aromatic polyurea/urethane, including a thin dense layer, a thin non-continuous skin and an open porous structure between the aforesaid thin dense layer and the thin non-continuous skin.
Claim 3
Dependent Claim
60 words
The anisotropic aromatic polyurea/urethane membrane of claim 1 further characterized in that it possesses a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole %, a functional group density Σ(C═O+NH) per 1000 grams of polymer greater than about 10 and a C═O+NH ratio of less than about 8.
Claim 4
Dependent Claim
48 words
The anisotropic aromatic polyurea/urethane membrane of claim 2 wherein the urea index at least about 40% but less than 100% aromatic carbon content is at least about 20 mole %, the functiona group density is greater than about 12 and the C═O+NH ratio is less than about 5.
Claim 5
Independent Claim
30 words
A method comprising separating aromatics from a mixture of aromatics with non-aromatics-saturates by contacting the mixture with one side of an anisotropic aromatic polyurea/urethane membrane characterized by possessing three layers.
Claim 6
Independent Claim
30 words
A method comprising separating aromatics from a mixture of aromatics with non-aromatics-saturates by contacting the mixture with one side of an anisotropic aromatic polyurea/urethane membrane characterized by possessing three layers.
Claim 7
Dependent Claim
60 words
The method of claim 4 wherein the anisotropic aromatic polyurea/urethane membrane is characterized by possessing a urea index of at least about 20% but less than 100%, an aromatic carbon content of at least about 15 mole %, a functional group density Σ(C═O+NH) per 1000 grams polymer greater than about 10 and a C═O/NH ratio of less than about 8.
Claim 8
Dependent Claim
51 words
The method of claim 5 wherein the anisotropic aromatic polyurea/urethane membrane has a urea index of at least about 40% but less than 100%, an aromatic carbon content of at least about 20, a functional group density of greater than about 12 and a C═O/NH ratio of less than about 5.
Claim 9
Dependent Claim
87 words
The method of claim 4, 5 or 6 wherein the anisotropic polyurea/urethane membrane is made by preparing a polyurea/urethane copolymer in a good solvent which contains less than about 5 volume percent non-solvent to produce a casting solution, depositing a film of said casting solution on a support substrate having a maximum pore size of less than 20 microns, subjecting the film to conditions such that the solvent vapor pressure-time factor is about 1000 mm Hg-min or less, and quenching said film on a nonsolvent quenching medium.
Claim 10
Dependent Claim
47 words
The method of claim 7 wherein the high boiling solvent is dimethylformamide and contains about 0 volume percent non-solvent, the support substrate is non-porous glass, metal or release paper, the solvent vapor pressure-time factor is about 200 mm Hg-min. or less and the quenching medium is water.
Claim 11
Dependent Claim
24 words
The method of claim 6 wherein the separation of aromatics from non-aromatics and saturates using the anisotropic polyurea/urethane membrane is conducted under pervaporation conditions.
Claim 12
Dependent Claim
24 words
The method of claim 7 wherein the separation of aromatics from non-aromatics and saturates using the anisotropic polyurea/urethane membrane is conducted under pervaporation conditions.
Claim 13
Dependent Claim
24 words
The method of claim 4 wherein the separation of aromatics from non-aromatics and saturates using the anisotropic polyurea/urethane membrane is conducted under pervaporation conditions.
References Cited (Backward Citations)
DE151952C
Cited
DE150620C
Cited
DE151874C
Cited
US2970106A
Cited
US3456037A
Cited
US3370102A
Cited
US3567810A
Cited
US3709774A
Cited
GB1391559A
Cited
US3776970A
Cited
US4129559A
Cited
US3876738A
Cited
US4086209A
Cited
US4036748A
Cited
US4230583A
Cited
US4115465A
Cited
US4137113A
Cited
US4277340A
Cited
US4107151A
Cited
US4340479B1
Cited
US4340479A
Cited
EP0017905A1
Cited
CA1206294A
Cited
US4528004A
Cited
GB2115344A
Cited
US4532316A
Cited
US4814083A
Cited
DE3513980A1
Cited
US4704130A
Cited
JPS64430A
Cited
JPH01101212A
Cited
JPH01101211A
Cited
JPH0887115A
Cited
JPH0892418A
Cited
JPH0959222A
Cited
JPH0959220A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-06 | 1993-05-08 | 1993-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-06 | 1997-05-08 | 1997-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-06 | 2001-05-08 | 2001-11-07 | $7700.00 | Window Closed / Lapsed |