US4985147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid separation membrane for pervaporation
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1988-12-14
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Granted: 1991-01-15
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Expires: 2008-12-14
Abstract
Abstract A liquid separation membrane for pervaporation composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations; and a method for pervaporation, which comprises separating a water-organic liquid mixture or an organic liquid-organic liquid mixture by pervaporation using a separation membrane, said membrane being composed of a polymeric substance having in the main chain a glycosidic skeleton containing cationic groups and/or anionic groups at least some of which form a salt with counter anions and/or counter cations and being dried so as to have a water content of not more than 25% by weight.
Inventors
- 👤 Akira Mochizuki
- 👤 Yoshio Sato
- 👤 Hisashi Ogawara
- 👤 Syuzo Yamashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:41
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D61/00; B01D61/36; B01D61/362; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/20; B01D71/22; B01D71/76; B01D71/80; B01D2323/00; B01D2323/30; Y; Y10; Y10S; Y10S159/00; Y10S159/27
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
29 words
A membrane for pervaporation composed of a salt of chitosan containing at least 2 mole % of nonpolymeric polybasic acid ion based on the amino groups of the chitosan.
Claim 2
Dependent Claim
29 words
A membrane for pervaporation composed of a salt of chitosan containing at least 2 mole % of nonpolymeric polybasic acid ion based on the amino groups of the chitosan.
Claim 3
Dependent Claim
15 words
The membrane for pervaporation of claim 1 in which the polybasic acid is sulfuric acid.
Claim 4
Dependent Claim
15 words
The membrane for pervaporation of claim 1 in which the polybasic acid is phosphoric acid.
Claim 5
Dependent Claim
94 words
A membrane for pervaporation composed of a salt of chitosan containing at least 2 mole % of nonpolymeric polybasic acid ion based on the amino group of the chitosan, said membrane being produced by a process comprising the steps of: (I) dissolving chitosan in a dilute aqueous solution of a monobasic acid, (II) producing a membrane composed of a chitosan salt containing a monobasic acid ion, (III) neutralizing the membrane with an aqueous alkaline solution, and (IV) contacting the chitosan membrane thus produced with an acid solution containing at least a nonpolymeric polybasic acid.
Claim 6
Dependent Claim
94 words
A membrane for pervaporation composed of a salt of chitosan containing at least 2 mole % of nonpolymeric polybasic acid ion based on the amino group of the chitosan, said membrane being produced by a process comprising the steps of: (I) dissolving chitosan in a dilute aqueous solution of a monobasic acid, (II) producing a membrane composed of a chitosan salt containing a monobasic acid ion, (III) neutralizing the membrane with an aqueous alkaline solution, and (IV) contacting the chitosan membrane thus produced with an acid solution containing at least a nonpolymeric polybasic acid.
Claim 7
Dependent Claim
15 words
The membrane for pervaporation of claim 4 in which the polybasic acid is sulfuric acid.
Claim 8
Dependent Claim
15 words
The membrane for pervaporation of claim 4 in which the polybasic acid is phosphoric acid.
References Cited (Backward Citations)
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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) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |