US4761234A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interfacially synthesized reverse osmosis membrane
Assignee: Toray Industries Inc
•
Filing: 1986-07-30
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Granted: 1988-08-02
•
Expires: 2006-07-30
Abstract
Abstract A semipermeable composite membrane comprising a microporous substrate and an ultra-thin membrane with which the substrate is coated, characterized in that the ultra-thin membrane is composed of a cross-linked aromatic polyamide and the cross-linked aromatic polyamide contains a tri- or higher functional aryl residue having at least two --NH groups. The semipermeable composite membrane has a high solute rejection, high and stable water flux and durability, and thereby may be applicable to various fields.
Inventors
- 👤 Tadahiro Uemura
- 👤 Yoshio Himeshima
- 👤 Masaru Kurihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:25
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D71/00; B01D71/06; B01D71/56
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
133 words
A reverse osmosis membrane comprising a microporous substrate and an ultra-thin membrane with which the substrate is coated, characterized in that said ultra-thin membrane is composed of a cross-linked aromatic polyamide having a degree of cross-linking sufficiently high to provide a salt rejection of about at least 99% and water flux of at least 0.7-1.3 m 3/m 2.day under conditions of applied pressure of at least 15-56 Kg/cm 2 in the cases of brackish to sea water desalination, which is prepared by interfacial polycondensation of monomeric aromatic amine and monomeric aromatic acid halide and contains a tri- or higher functional aryl residue having at least two --NH-- groups, and that the aryl residue does not have any carbonyl group as a substituent directly adjacent to a carbonyl group of a cross-linking amide bond.
Claim 2
Dependent Claim
133 words
A reverse osmosis membrane comprising a microporous substrate and an ultra-thin membrane with which the substrate is coated, characterized in that said ultra-thin membrane is composed of a cross-linked aromatic polyamide having a degree of cross-linking sufficiently high to provide a salt rejection of about at least 99% and water flux of at least 0.7-1.3 m 3/m 2.day under conditions of applied pressure of at least 15-56 Kg/cm 2 in the cases of brackish to sea water desalination, which is prepared by interfacial polycondensation of monomeric aromatic amine and monomeric aromatic acid halide and contains a tri- or higher functional aryl residue having at least two --NH-- groups, and that the aryl residue does not have any carbonyl group as a substituent directly adjacent to a carbonyl group of a cross-linking amide bond.
Claim 3
Dependent Claim
38 words
A reverse osmosis membrane according to claim 1, wherein the tri- or higher functional aryl residue having at least two --NH-- groups is at least one selected from aryl residues represented by the formulae I and II. ##STR12##
Claim 4
Dependent Claim
35 words
A reverse osmosis membrane according to claim 2, wherein one or both of the aryl residues represented by the formulae I and II contain not less than 5% by weight of the cross-linked aromatic polyamide.
Claim 5
Dependent Claim
27 words
A reverse osmosis membrane according to claim 1, wherein the cross-linked aromatic polyamide additionally contains at least one of the aryl residues represented by the formulae; ##STR13##
Claim 6
Dependent Claim
25 words
A reverse osmosis membrane according to claim 1, wherein the thickness of the ultra-thin membrane is in a range of from 10 to 100 nm.
Claim 7
Dependent Claim
14 words
A reverse osmosis membrane according to claim 1, wherein the microporous substrate comprises polysulfone.
Claim 8
Dependent Claim
23 words
A reverse osmosis membrane according to claim 1, wherein the microporous substrate is reinforced with a fabric selected from polyester and aromatic polyamide.
Claim 9
Dependent Claim
49 words
A reverse osmosis membrane according to claim 1, wherein the interfacial polycondensation is effected with an aqueous solution containing aromatic amines having an average functionality higher than 2.05 and a solution containing aromatic acid halides having an average functionality higher than 2.00 in an organic solvent immiscible with water.
Claim 10
Dependent Claim
21 words
A reverse osmosis membrane according to claim 8, wherein the average functionality of the aromatic amine is from 2.05 to 3.00.
Claim 11
Dependent Claim
22 words
A reverse osmosis membrane according to claim 8, wherein the average functionality of the aromatic acid halide is from 2.00 to 3.00.
Claim 12
Dependent Claim
36 words
A reverse osmosis membrane according to claim 8, wherein the average functionality of the aromatic amine is from 2.05 to 3.00 and the average functionality of the aromatic acid halide is of from 2.00 to 3.00.
Claim 13
Dependent Claim
25 words
A reverse osmosis membrane according to claim 8, wherein the aromatic amine contains at least one of the compounds represented by the following formulae; ##STR14##
Claim 14
Dependent Claim
24 words
A reverse osmosis membrane according to claim 12, wherein the aromatic amine additionally contains at least one compound represented by the following formulae; ##STR15##
Claim 15
Dependent Claim
24 words
A reverse osmosis membrane according to claim 8, wherein the aromatic amine contains 1,3,5-triaminobenzene present in an amount of at least 5% by weight.
Claim 16
Dependent Claim
27 words
A reverse osmosis membrane according to claim 8, wherein the aromatic acid halide in the organic solvent contains at least one compound represented by the formulae; ##STR16##
Claim 17
Dependent Claim
18 words
A reverse osmosis membrane according to claim 8, wherein the organic solvent is selected from n-hexane and trifluorotrichloroethane.
Claim 18
Dependent Claim
23 words
A reverse osmosis membrane according to claim 8, wherein the solution of the organic solvent contains from 10 to 500 ppm of dimethylformamide.
Claim 19
Dependent Claim
21 words
A reverse osmosis membrane according to claim 8, which is further modified by being brought into contact with a chlorine-containing solution.
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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) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |