US4501835A
Expired / Lapsed
US
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Polyacrylic acid/chitosan polyelectrolyte complex
Assignee: Polaroid Corp
•
Filing: 1983-11-09
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Granted: 1985-02-26
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Expires: 2003-11-09
Abstract
Abstract A novel composition of matter comprising a polyacrylic acid/chitosan complex. This complex is particularly useful as a membrane or filter.
Inventors
- 👤 Carl M. Berke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:30
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003; B; B01; B01D; B01D71/00; B01D71/06; B01D71/76; B01D71/80; C08L; C08L5/00; C08L5/08
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
25 words
As a novel composition of matter, a polyacrylic acid/chitosan complex, wherein the molecular weight (weight average) of said polyacrylic acid is less than about 10,000.
Claim 2
Dependent Claim
25 words
As a novel composition of matter, a polyacrylic acid/chitosan complex, wherein the molecular weight (weight average) of said polyacrylic acid is less than about 10,000.
Claim 3
Dependent Claim
13 words
The product of claim 1 wherein said complex is about a 1:1 complex.
Claim 4
Dependent Claim
14 words
The product of claim 1 wherein said molecular weight (weight average) is about 5000.
Claim 5
Dependent Claim
11 words
The product of claim 1 wherein said complex is a film.
Claim 6
Dependent Claim
13 words
A product of claim 4 wherein said film is carried on a support.
Claim 7
Dependent Claim
10 words
The product of claim 4 wherein said film is self-supporting.
Claim 8
Dependent Claim
11 words
The product of claim 4 wherein said film includes a surfactant.
Claim 9
Dependent Claim
11 words
The product of claim 4 wherein said film includes a plasticizer.
Claim 10
Dependent Claim
11 words
The product of claim 8 wherein said plasticizer is a polyol.
Claim 11
Dependent Claim
10 words
The product of claim 9 wherein said polyol is glycerol.
Claim 12
Dependent Claim
34 words
A membrane comprising polyacrylic acid and chitosan, said membrane having a molecular weight (weight average) cutoff of about 200, wherein said polyacrylic acid has a molecular weight (weight average) of less than about 10,000.
Claim 13
Dependent Claim
34 words
A membrane comprising polyacrylic acid and chitosan, said membrane having a molecular weight (weight average) cutoff of about 200, wherein said polyacrylic acid has a molecular weight (weight average) of less than about 10,000.
Claim 14
Dependent Claim
17 words
The product of claim 11 wherein said polyacrylic acid and said chitosan are in a 1:1 ratio.
Claim 15
Dependent Claim
14 words
The product of claim 11 wherein said molecular weight (weight average) is about 5,000.
Claim 16
Dependent Claim
10 words
The product of claim 11 wherein said membrane is self-supporting.
Claim 17
Dependent Claim
13 words
The product of claim 11 wherein said membrane is carried on a support.
Claim 18
Dependent Claim
12 words
The product of claim 15 wherein said support is a permeable support.
Claim 19
Dependent Claim
9 words
The product of claim 11 which includes a surfactant.
Claim 20
Dependent Claim
9 words
The product of claim 11 which includes a plasticizer.
Claim 21
Dependent Claim
11 words
The product of claim 18 wherein said plasticizer is a polyol.
Claim 22
Dependent Claim
10 words
The product of claim 19 wherein said polyol is glycerol.
Claim 23
Independent Claim
42 words
A method for preparing a membrane which comprises forming a polyelectrolyte complex by dissolving chitosan in an acid, adding a solution of polyacrylic acid having a molecular weight (weight average) of less than 10,000 thereto and coating a support with said complex.
Claim 24
Independent Claim
42 words
A method for preparing a membrane which comprises forming a polyelectrolyte complex by dissolving chitosan in an acid, adding a solution of polyacrylic acid having a molecular weight (weight average) of less than 10,000 thereto and coating a support with said complex.
Claim 25
Dependent Claim
17 words
The method of claim 21 which includes the step of removing the thus-formed membrane from said support.
Claim 26
Dependent Claim
18 words
The method of claim 21 wherein a surfactant is added to said complex prior to coating said support.
Claim 27
Dependent Claim
18 words
The method of claim 21 wherein a plasticizer is added to said complex prior to coating said support.
Claim 28
Dependent Claim
19 words
The method of claim 22 wherein said membrane is immersed in a plasticizer subsequent to removal from said support.
Claim 29
Independent Claim
11 words
The method of claims 24 wherein said plasticizer is a polyol.
Claim 30
Dependent Claim
10 words
The method of claim 26 wherein said polyol is glycerol.
Claim 31
Dependent Claim
17 words
The method of claim 21 wherein said polyacrylic acid and said chitosan are in a 1:1 ratio.
Claim 32
Dependent Claim
14 words
The method of claim 21 wherein said molecular weight (weight average) is about 5,000.
Claim 33
Dependent Claim
11 words
The method of claim 21 wherein said acid is acetic acid.
Claim 34
Dependent Claim
18 words
The method of claim 21 wherein the molecular weight (weight average) cutoff of said membrane is about 200.
Claim 35
Dependent Claim
41 words
The method of claim 21 which includes the steps of air drying said coating to form a skin and then contacting said complex with dilute base for a time insufficient to extract said polyacrylic acid, whereby an anisotropic membrane is formed.
Claim 36
Dependent Claim
14 words
The method of claim 32 wherein said dilute base is about 0.1N sodium hydroxide.
Claim 37
Dependent Claim
15 words
The method of claim 32 which includes the step of washing said membrane with water.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |