US4046843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing membranes for separation of substances
Assignee: Sumitomo Chemical Co Ltd
•
Filing: 1975-08-20
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Granted: 1977-09-06
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Expires: 1995-08-20
Abstract
Abstract A semipermeable membrane is obtained by casting a cast solution comprising a mixture of a water-insoluble high polymer and a water-soluble high polymer, a mixture of a water-insoluble high polymer and a water-soluble surfactant or a mixture of a water-insoluble high polymer, a water-soluble high polymer and a water-soluble surfactant to form a shaped article, exposing the thus formed shaped article to a plasma to crosslink the surface thereof, and then washing the exposed article with water to remove uncrosslinked water-soluble high polymer or water-soluble surfactant. The membrane can be used for such substance separation methods as reverse osmosis, ultrafiltration and the like.
Inventors
- 👤 Takezo Sano
- 👤 Takatoshi Shimomura
- 👤 Masao Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:44
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/009
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
99 words
A process for preparing a membrane for separation of substances which comprises: a. dissolving a water-insoluble high polymer, and a water-soluble high polymer and/or a water-soluble surfactant in a proportion of 0.1 to 3 parts by weight of water-soluble high polymer and/or surfactant with 1 part by weight of the water-insoluble high polymer, in an organic solvent; b. casting said solution to form a shaped article; c. evaporating said organic solvent; d. exposing the thus formed shaped article to a plasma to crosslink the surface; and e. subsequently removing uncrosslinked water-soluble high polymer and/or surfactant by washing with water.
Claim 2
Dependent Claim
99 words
A process for preparing a membrane for separation of substances which comprises: a. dissolving a water-insoluble high polymer, and a water-soluble high polymer and/or a water-soluble surfactant in a proportion of 0.1 to 3 parts by weight of water-soluble high polymer and/or surfactant with 1 part by weight of the water-insoluble high polymer, in an organic solvent; b. casting said solution to form a shaped article; c. evaporating said organic solvent; d. exposing the thus formed shaped article to a plasma to crosslink the surface; and e. subsequently removing uncrosslinked water-soluble high polymer and/or surfactant by washing with water.
Claim 3
Dependent Claim
29 words
A process according to claim 1, wherein the water-insoluble high polymer is polysulfone, polyamide, polyester, polyphenylene oxide, polyacrylonitrile, polymethyl methacrylate, polyvinyl chloride, polystryene, polyacetal, cellulose acetate or cellulose nitrate.
Claim 4
Dependent Claim
15 words
A process according to claim 2, wherein the water-insoluble high polymer is polysulfone or polyacrylonitrile.
Claim 5
Dependent Claim
26 words
A process according to claim 1, wherein the water-soluble high polymer is polyethylene oxide, polyethylene glycol, polyvinylamine, polyacrylamide, polyacrylic acid, polyvinyl pyrrolidone, polyvinyl alcohol or polyethyleneimine.
Claim 6
Dependent Claim
19 words
A process according to claim 4, wherein the water-soluble high polymer is polyethylene oxide, polyethylene glycol, polyvinylamine or polyacrylamide.
Claim 7
Dependent Claim
18 words
A process according to claim 1, wherein the water-soluble surfactant is an anionic, nonionic, cationic or natural surfactant.
Claim 8
Dependent Claim
20 words
A process according to claim 6, wherein the anionic surfactant is sodium oleate, sodium laurylsulfate or sodium polyoxyethylene alkyl sulfate.
Claim 9
Dependent Claim
36 words
A process according to claim 6, wherein the nonionic surfactant is polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene sorbitan monolaurate or polyethylene glycol monostearate.
Claim 10
Dependent Claim
17 words
A process according to claim 6, wherein the cationic surfactant is laurylamine acetate or laurylmethyl ammonium chloride.
Claim 11
Dependent Claim
12 words
A process according to claim 6, wherein the natural surfactant is saponin.
Claim 12
Dependent Claim
24 words
A process according to claim 2, wherein the water-soluble surfactant is polyoxyethylene cetyl ether, polyoxethylene oleyl ether, polyoxyethylene nonylphenyl ether or polyethylene glycol monostearate.
Claim 13
Dependent Claim
24 words
The process according to claim 1 wherein said organic solvent is selected from the group consisting of dimethyl formamide, dimethyl sulfoxide, acetone, and benzene.
Claim 14
Dependent Claim
50 words
A process according to claim 1, wherein the gas used to form the plasma is at least one member selected from the group consisting of helium, argon, nitrogen, hydrogen, oxygen, carbon monoxide, carbon dioxide, hydrocarbons having 1 to 10 carbon atoms, epoxides having 2 to 10 carbon atoms, and alkylamines.
Claim 15
Dependent Claim
20 words
A process according to claim 13, wherein the gas used to form the plasma is helium, hydrogen or ethylene oxide.
Claim 16
Dependent Claim
17 words
A process according to claim 1, wherein the plasma is formed by glow discharge or corona discharge.
Claim 17
Dependent Claim
33 words
A process according to claim 15, wherein the glow discharge is effected at a gas pressure of 0.01 to 10 Torr. and under direct or alternating current voltage of 0.5 to 50 KV.
Claim 18
Dependent Claim
25 words
A process according to claim 15, wherein the corona discharge is effected at atmospheric pressure and under a direct current voltage 0.5 to 5 KV.
Claim 19
Dependent Claim
15 words
A process according to claim 1, wherein the casting is effected on a flat plate.
Claim 20
Dependent Claim
17 words
A process according to claim 1, wherein the casting is effected on a tubular or rod-shaped support.
Claim 21
Dependent Claim
20 words
A process according to claim 1, wherein the casting is effected by spinning a hollow filament from the cast solution.
Claim 22
Dependent Claim
23 words
A process according to claim 1, wherein the casting is effected by immersing a filamentary fiber in the cast solution, followed by drying.
Claim 23
Dependent Claim
16 words
A membrane for separation of substances which is obtained by the process claimed in claim 1.
Claim 24
Dependent Claim
15 words
A membrane according to claim 22 which has a thickness of 1 micron or less.
Claim 25
Dependent Claim
20 words
A membrane according to claim 23 which is used for separation or concentration of substances by reverse osmosis or ultrafiltration.
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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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |