US4929722A
Expired / Lapsed
US
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Acid decrystallization of aminopolysaccharides and derivatives thereof
Assignee: Union Carbide Chemicals and Plastics Technology LLC
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Filing: 1987-06-02
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Granted: 1990-05-29
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Expires: 2007-06-02
Abstract
Abstract Heterogeneous acid decrystallization of aminopolysaccharides, especially chitosen, using diluent, organic acid and water, provides novel salts and covalent derivatives useful in diverse applications including biomedicine, personal care and fluid separation.
Inventors
- 👤 Emmett M. Partain, III
- 👤 II George L. Brode
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:11
CPC Classifications
A; A61; A61Q; A61Q19/00; A61K; A61K47/00; A61K47/30; A61K47/36; A61K8/00; A61K8/18; A61K8/72; A61K8/73; A61K8/736; A61K9/00; A61K9/0012; A61K9/0014; A61K9/70; A61K9/7015; A61L; A61L26/00; A61L26/0009; A61L26/0023; A61L26/0061; A61L26/0076; A61Q17/00; A61Q17/04; B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003; C08L; C08L5/00; C08L5/08; A61Q5/00
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
196 words
A heterogeneous method for preparing chitin or chitosan derivative from highly crystalline, partially deacetylated chitin or chitosan which comprises the steps of: (a) forming a mixture of a pulverulent, partially deacetylated chitin or chitosan and (1) a diluent medium in which the chitin or chitosan is swellable but essentially insoluble; the medium comprised of: (i) an inert, water soluble polar organic diluent in which the chitin or chitosan is insoluble and the chitin or chitosan derivative is insoluble; (ii) at least one organic acid which is at least partially soluble in water, is sufficiently acidic to form the ammonium salt of the chitin or chitosan and yet not sufficiently acidic to cause hydrolysis of the chitin or chitosan or the chitin or chitosan derivative, and which is present in an amount sufficient to protonate the reactive sites of the decacetylated chitin or chitosan; (2) water in an amount in excess of the amount of organic acid and up to about 65 weight percent of the medium; (b) agitating the mixture at a temperature and for a period of time to effect at least partial decrystallization; and (c) recovering the chitin or chitosan derivative from the mixture.
Claim 2
Dependent Claim
196 words
A heterogeneous method for preparing chitin or chitosan derivative from highly crystalline, partially deacetylated chitin or chitosan which comprises the steps of: (a) forming a mixture of a pulverulent, partially deacetylated chitin or chitosan and (1) a diluent medium in which the chitin or chitosan is swellable but essentially insoluble; the medium comprised of: (i) an inert, water soluble polar organic diluent in which the chitin or chitosan is insoluble and the chitin or chitosan derivative is insoluble; (ii) at least one organic acid which is at least partially soluble in water, is sufficiently acidic to form the ammonium salt of the chitin or chitosan and yet not sufficiently acidic to cause hydrolysis of the chitin or chitosan or the chitin or chitosan derivative, and which is present in an amount sufficient to protonate the reactive sites of the decacetylated chitin or chitosan; (2) water in an amount in excess of the amount of organic acid and up to about 65 weight percent of the medium; (b) agitating the mixture at a temperature and for a period of time to effect at least partial decrystallization; and (c) recovering the chitin or chitosan derivative from the mixture.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the chitin or chitosan is chitosan.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the chitin or chitosan is in powdered or flake form.
Claim 5
Dependent Claim
33 words
The method of claim 1 wherein the chitin or chitosan has been deacetylated to about 60 to about 90 percent and has a molecular weight of from about 10,000 to about 5 million.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the diluent is an alcohol.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein the diluent is methanol, ethanol, n-propanol, isopropanol, t-butanol or mixtures thereof.
Claim 8
Dependent Claim
46 words
The method of claim 1 wherein the acid is represented by the formula: R-(COOH).sub.n wherein n has a value of 1 or 2 and R represents a mono-or divalent organic radical composed of carbon, hydrogen and up to one or more oxygen, nitrogen and sulfur atoms.
Claim 9
Dependent Claim
40 words
The method of claim 7 wherein the acid is formic, acetic, N-acetylglycine, acetylsalicylic, furamic, glycolic, iminodiacetic, itaconic, DL-lactic, maleic, DL-malic, nicotinic, 2-pyrrolidone-5-carboxylic, salicylic, succinamic, succinic acid, ascorbic, aspartic, glutamic, glutaric, malonic, pyruvic, sulfonyldiacetic, thiodiacetic or thioglycolic acid or mixtures thereof.
Claim 10
Dependent Claim
21 words
The method of claim 8 wherein the acid is acetic, 2-pyrrolidone-5-carboxylic, succinic, aspartic, glutamic, nicotinic or itaconic acid or mixtures thereof.
Claim 11
Dependent Claim
23 words
The method of claim 1 wherein said chitosan derivative is recovered from said mixture by dewatering with a water-soluble, organic diluent and dried.
Claim 12
Dependent Claim
28 words
The method of claim 1 wherein after swelling and decrystallization a base is added to said mixture to neutralize the acid and form causticized, amorphous chitin or chitosan.
Claim 13
Dependent Claim
12 words
The causticized chitin or chitosan produced by the process of claim 11.
Claim 14
Dependent Claim
22 words
The method of claim 11 wherein the causticized chitosan is further reacted with at least one electrophile to provide covalently-modified chitosan derivatives.
Claim 15
Dependent Claim
36 words
The method of claim 13 wherein the electrophile is ethylene oxide, propylene oxide, ethyl chloride, methyl chloride, chloroacetic acid or its salt, a glycidyl trialkyl ammonium salt, 3-chloro-2-hydroxy propyl trialkylammonium salt, N-dodecyl-N,N-dimethylammonium 3-chloro-2-hydroxypropane or mixtures thereof.
Claim 16
Dependent Claim
17 words
The method of claim 13, wherein the causticized chitosan is further reacted with at least two electrophiles.
Claim 17
Dependent Claim
12 words
A chitin or chitosan derivative produced by the process of claim 1.
Claim 18
Dependent Claim
15 words
A film comprising suitable film additives and the chitin or chitosan derivative of claim 16.
Claim 19
Dependent Claim
20 words
A personal care formulation comprising suitable carrier and an effective amount of the chitin or chitosan derivative of claim 16.
Claim 20
Dependent Claim
19 words
A sunscreen formulation comprising sunscreen agent and an effective amount of the chitin or chitosan derivative of claim 16.
Claim 21
Dependent Claim
15 words
The film of claim 17 in the form of a membrane useful in fluid separation.
Claim 22
Dependent Claim
16 words
Chitosonium salt of an acid selected from the group consisting of: 2-pyrrolidone-5-carboxylic, itaconic and nicotinic acids.
Claim 23
Dependent Claim
16 words
Chitosonium salt of an acid selected from the group consisting of: 2-pyrrolidone-5-carboxylic, itaconic and nicotinic acids.
Claim 24
Dependent Claim
15 words
A personal care composition containing an effective amount of a chitosonium salt of claim 21.
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| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
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