US3773181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing membranes in a reverse osmosis module
Assignee: Graftech Technology LLC
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Filing: 1971-07-08
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Granted: 1973-11-20
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Expires: 1991-07-08
Abstract
Abstract A method of sealing reverse osmosis membranes to a porous support comprises applying a sealant composition, comprising diepoxide resin and amidopolyamine, to the membrane and support in an atmosphere having a relative humidity over 85 percent, said sealant contacting both the membrane and the support.
Inventors
- 👤 A Calderwood
- 👤 R Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:47
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/06; B01D63/061; B01D61/00; B01D61/02; B01D61/08; B01D2313/00; B01D2313/04; B01D2313/041
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
31 words
The method of claim 1 wherein the porous support is a module having a flat end face and at least one bore therethrough containing therein a tubular semipermeable cellulose ester membrane.
Claim 2
Dependent Claim
37 words
about 8 to 42 weight percent of a liquid diglycidyl ether of an aliphatic polyglycol having a viscosity between about 30 and 500 cp at 25*C and an epoxy equivalent weight between about 250 and 400 and
Claim 3
Dependent Claim
20 words
about 22 to 55 weight percent of an amidopolyamine selected from the group consisting of amidopolyamines having the structural formula:
Claim 4
Dependent Claim
58 words
The method of claim 2 wherein the membrane is cast in place within the module bores and leached in water to form an osmotic skin, wherein as a first step the water is drained from the porous module, and wherein the sealant contacts the module bore ends and the membrane ends to seal the membrane and support together.
Claim 5
Dependent Claim
66 words
The method of claim 2, wherein the diglycidyl ether of bisphenol ''''A'''' is a liquid, has a viscosity between about 7,000 and 15,000 cp at 25*C and an epoxy equivalent weight beTween about 170 and 250, the diglycidyl ether of an aliphatic polyglycol is a liquid, has a visocity between about 30 and 500 cp at 25*C and an epoxy equivalent weight between about 250 and
Claim 6
Dependent Claim
35 words
The method of claim 2 wherein the sealant composition applied to the module end faces also contains about 1/2 to 20 weight percent filler having an average particle size between about 0.001 and 150 microns.
Claim 7
Dependent Claim
65 words
The method of claim 2 wherein the filler particles making up the module have an average particle size between about 40 and 500 microns and the resin bonding said particles together comprises from about 1 to 18 percent of the coated filler particle weight, said resin being selected from the group consisting of phenolics, polyglycidylethers, polyesters, silicones, polystyrenes, polyimides, polyamide-imides, allyl resins and furane resins.
Claim 8
Dependent Claim
57 words
The method of claim 2 wherein the filler is sand, the resin coating the filler is a phenolic resin, the membrane is a modified cellulose acetate membrane, the diglycidyl ether of an aliphatic polyglycol is a diglycidyl ether of a polypropylene glycol and the amidopolyamine is seleceted from the group consisting of amidopolyamines having the structural formula:
Claim 9
Dependent Claim
36 words
The method of claim 2 wherein, before step 1, the membrane ends are primed with a resin-solvent composition that will partially dissolve the membrane ends to form a rough slightly tacky surface on the membrane ends.
Claim 10
Dependent Claim
9 words
A cellulose acetate reverse osmosis membrane sealant composition comprising:
Claim 11
Dependent Claim
22 words
The sealant composition of claim 9 also containing filler particles having an average particle size range from about 0.001 to 150 microns.
Claim 12
Dependent Claim
86 words
A reverse osmosis apparatus to provide purified water from a feed liquid comprising: a. a porous reverse osmosis membrane support made of bonded resin coated filler particles, b. a cellulose ester semipermeable reverse osmosis membrane in contact with the support, c. a sealant composition contacting the membrane and support and sealing them together, said sealant having the composition of claim 9, d. means to supply feed liquid to the apparatus, e. means to exhaust feed liquid from the apparatus, and f. means to collect purified water.
Claim 13
Dependent Claim
38 words
The reverse osmosis apparatus of claim 11 wherein the porous support is a module made of resin bonded filler particles, having a flat end face and at least one bore therethrough containing therein a semi-permeable cellulose ester membrane.
Claim 14
Dependent Claim
76 words
The reverse osmosis apparatus of claim 12 wherein the filler making up the module is sand having an average particle size between about 40 and 500 microns, the resin bonding said particles together comprises from about 1 to 18 percent of the coated filler particle weight, the resin being selected from the group consisting of phenolics, polyglycidylethers, polyesters, silicones, polystyrenes, polyimides, polyamide-imides, allyl resins and furane resins and the membrane Is a modified cellulose acetate membrane.
Claim 15
Dependent Claim
1 words
21.
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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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |