Patent US4606943A successfully refreshed from Google Patents.
US4606943A
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Method for preparation of semipermeable composite membrane
Assignee: Culligan International Co
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Filing: 1984-11-26
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Granted: 1986-08-19
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Expires: 2004-11-26
Abstract
Abstract An excellent reverse osmosis membrane having a high flux with superior chlorine resistance and low salt passage can be obtained by interfacially condensing a water soluble aromatic polyamide prepolymer with an essentially monomeric, aromatic, amine reactive polyfunctional acyl halide. The polyamide prepolymer may be prepared through the condensation reaction of an aromatic diamine and an aromatic anhydride acyl halide. Preferably the amide prepolymer, prepared from metaphenylene diamine and trimelletic anhydride acid chloride, is reacted with trimesoylchloride to form the thin film membrane of the subject invention.
Inventors
- 👤 Stanley F. Rak
- 👤 Kenneth Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:51
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D69/1251; B01D71/00; B01D71/06; B01D71/56
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
The method for the preparation of a semipermeable composite membrane which comprises: reacting solutions of (1) a molar excess of an aromatic di-primary amine with (2) a mixture of a major amount of trimellitic anhydride acid halide and a minor amount of trimesoylchloride to form a water soluble prepolymer; placing an aqueous solution of said prepolymer on a porous support to form a prepolymer film; reacting said prepolymer film with (3) a nonpolar solvent solution containing trimesoylchloride; and drying the membrane formed thereby.
Claim 2
Independent Claim
83 words
The method for the preparation of a semipermeable composite membrane which comprises: reacting solutions of (1) a molar excess of an aromatic di-primary amine with (2) a mixture of a major amount of trimellitic anhydride acid halide and a minor amount of trimesoylchloride to form a water soluble prepolymer; placing an aqueous solution of said prepolymer on a porous support to form a prepolymer film; reacting said prepolymer film with (3) a nonpolar solvent solution containing trimesoylchloride; and drying the membrane formed thereby.
Claim 3
Dependent Claim
22 words
The method of claim 1 in which the aromatic di-primary amine is in solution in a mixture of dichloromethane and dimethyl formamide.
Claim 4
Dependent Claim
17 words
The method of claim 2 in which the ratio of dichloromethane to dimethylformamide is 10 to 1.
Claim 5
Dependent Claim
14 words
The method of claim 1 in which ingredient (2) is in solution in dichloromethane.
Claim 6
Dependent Claim
22 words
The method of claim 1 in which solution (3) contains heptane as the nonpolar solvent and trimesoyl chloride at 0.5 percent concentration.
Claim 7
Dependent Claim
21 words
The method of claim 1 in which said membrane is dried and cured by heating at 130° C. for 5 minutes.
Claim 8
Dependent Claim
25 words
The method of claim 1 in which ingredient (2) contains 9 molar parts of trimellitic anhydride acid chloride per one molar part of trimesoyl chloride.
Claim 9
Dependent Claim
11 words
The method of claim 1 in which said halide is chloride.
Claim 10
Dependent Claim
16 words
The method of claim 8 in which said solution containing trimesoylchloride also contains a diacyl chloride.
Claim 11
Dependent Claim
13 words
The method of claim 9 in which said diacyl chloride is isophthaloyl chloride.
Claim 12
Independent Claim
81 words
The method for the preparation of a semipermeable, composite membrane which comprises: reacting solutions of (1) a molar excess of metaphenylene diamine with (2) a mixture of about 9 molar parts of trimellitic anhydride acid chloride with about one molar part of trimesoylchloride to form a prepolymer; placing an aqueous solution of said prepolymer on a porous support to form a prepolymer film; reacting said prepolymer film with (3) a nonpolar solvent solution containing trimesoylchloride; and drying the membrane formed thereby.
Claim 13
Independent Claim
81 words
The method for the preparation of a semipermeable, composite membrane which comprises: reacting solutions of (1) a molar excess of metaphenylene diamine with (2) a mixture of about 9 molar parts of trimellitic anhydride acid chloride with about one molar part of trimesoylchloride to form a prepolymer; placing an aqueous solution of said prepolymer on a porous support to form a prepolymer film; reacting said prepolymer film with (3) a nonpolar solvent solution containing trimesoylchloride; and drying the membrane formed thereby.
Claim 14
Dependent Claim
21 words
The method of claim 11 in which solution (3) contains heptane as the nonpolar solvent and trimesoyl chloride at 0.5% concentration.
Claim 15
Dependent Claim
16 words
The method of claim 11 in which said solution containing trimesoylchloride also contains a diacyl chloride.
Claim 16
Dependent Claim
13 words
The method of claim 13 in which said diacyl chloride is isophthaloyl chloride.
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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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |