JPS6160701A - Production of cationic chitosan derivative - Google Patents

Abstract

PURPOSE:To produce a water-soluble chitosan derivative excellent in cationic activity and suitable as, e.g., a cosmetic base or a coagulant, by reacting chitosan with a specified cationizing agent. CONSTITUTION:Chitosan, e.g., a compound obtained by deacetylating chitin at about 50-130 deg.C in an aqueous alkali solution of a concentration of about 30-50% and having a degree of deacetylation of about 50-99%, is reacted with a cationizing agent having a nitrogen atom in the form of a quaternary ammonium salt (e.g., 2,3-epoxypropyltrialkylammonium halide in which the alkyl group is of about 1-3C) at about 20-120 deg.C for about 2-20hr in an organic solvent in an amount of about 1-20pts.wt. per pt.wt. chitosan. The water solubility of the resulting reaction product can be further improved by reaction with a hydroxyalkylating agent (e.g., ethylene oxide).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel cationic chitosan derivative using chitosan as a starting material, which can be obtained inexpensively and in large quantities by deacetylating chitin, which is an unused natural resource. .

Chitosan is obtained by deacetylating chitin contained in the shells of shrimp, crabs, etc. in a concentrated alkaline aqueous solution. Chitosan becomes a water-soluble chitosan salt by neutralizing the free 7-mino group with an acid such as hydrochloric acid, acetic acid, or lactic acid, and this chitosan salt is used as a flocculant for some industrial wastewater and urban sewage. However, since chitosan salt becomes insoluble and precipitates in neutral or alkaline conditions, its uses are actually quite limited.

As a method for obtaining chitosan with excellent water solubility, a method has been proposed in which chitosan is reacted with ethylene oxide or glycidol (Japanese Patent Laid-Open No. 59-8701), but most of the M-ethylene oxide or glycidol is a constituent of chitosan. Since it is introduced into the amino group of certain glucosamines, it has the drawback of decreasing cationic activity.

An object of the present invention is to provide a method for easily producing a chitosan derivative that is soluble in water and has excellent cationic activity.

The first aspect of the present invention is a method for producing a cationic chitosan derivative, which is characterized by reacting chitosan with a cationizing agent having quaternary ammonium salt type nitrogen in the molecule.

Another aspect of the present invention is a method for producing a cationic chitosan derivative, which comprises further reacting a hydroxyalkylating agent with a reaction product of chitosan and a cationizing agent.

Chitosan is a β-acetylated N-acetylated glucosamine represented by the general formula (1).
In the present invention, which is an acetylated product of chitin bonded with 1,4, a deacetylation rate of 50 to 99% is suitable. Such chitosan, for example, has chitin of 30 to 5
It can be obtained by acetylation in a 0% alkaline aqueous solution at a temperature of 50 to 130°C. It is preferable that chitosan is reacted with a cationizing agent in the form of a fine powder.

The cationizing agent used in the present invention is a compound having a quaternary ammonium salt type nitrogen in its molecule, and has an active group for glucosamine. Among such cationizing agents, 3-chloro-2-hydroxypropyltrialkylammonium halide and 2°3-epoxypropyltrialkylammonium halide are preferred, with chloride being particularly preferred, and 3-chloro-2- Specific examples of hydroxypropyltrialkylammonium halides include 3-chloro-2-hydroxypropyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltriethylammonium chloride, and 3-chloro-2-hydroxypropyltriprobylammonium chloride. Ru. Also, 2
, 3-epoxypropyltrialkylammonium halides include 2,3-epoxypropyltrimethylammonium chloride, 2,3-epoxypropyltriethylammonium chloride, and 2,3-epoxypropyltripropylammonium chloride.

Among these, in the case of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 2.3-epoxypropyltrimethylammonium ammonium chlorideroxybrobyltrimethylammonium chloride, 2. , 3-epoxypropyltrimethylammonium chloride before the reaction.

The reaction between chitosan and the cationizing agent is carried out in an organic solvent.
2 to 120°C, preferably 40 to 80"C.
This is carried out by stirring while maintaining the slurry state for 20 hours. Preferably, the reaction is carried out in the presence of water6
The water concentration during the reaction is 5 to 50%, preferably 10 to 30%. Examples of organic solvents include alcohols such as methanol, ethanol, and isopropyl alcohol, acetone,
Ketones such as methyl ethyl ketone are used.

The amount used is 1 to 20 times the weight of chitosan.

The reaction mixture is separated into solid matter and solution by solid-liquid separation means such as filtration or centrifugation.

Powdered cationic chitosan is recovered as a solid. If necessary, the solid material is washed with a 50-100% ketone or alcohol aqueous solution and dried at a temperature of 50-120"C under reduced pressure or normal pressure. The resulting quaternary cationic chitosan It is preferable to adjust parameters such as the amount of the cationizing agent added so that the nitrogen content of the ammonium salt type is 0.5 to 10%, preferably 1 to 6%.

In addition, water solubility can be increased by allowing a hydroxyalkylating agent to further act on the reaction product of chitosan and a cationizing agent.

As the hydroxyalkylating agent, ethylene oxide, propylene oxide, glycidol, etc. are used. The hydroxyalkylation reaction can be carried out after separating and recovering chitosan and cationic chitosan, or after purification if necessary, or it can be carried out by immediately adding a hydroxylating agent to the reaction mixture.

Hydroxyalkylation conditions are the same as in the case of cationization of chitosan, but it is preferably carried out in the presence of a basic catalyst. As the basic catalyst, trimethylamine,
Alkylamines such as triethylamine, hydroxides of alkali metals or alkaline earth metals, and the like are used.

The amount of catalyst used is O,S~2 for cationic chitosan.
0%, preferably 2 to 10%.

Hydroxyalkylation is when the hydroxyalkyl group content is 5
It is appropriate to set the amount to 80%, preferably 10 to 50%.

The cationic chitosan obtained by the present invention is water-soluble and has high cationic activity, and does not impair film-forming properties, so it can be used as a cosmetic base material.

It can be used for purposes such as flocculants and antistatic agents.

Example 1 Powdered chitosan with a deacetylation rate of 87 mol% (moisture 7.8
%) was dispersed in 140 g of isopropyl alcohol. 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution (purity 50%) 55.
19. Equimolar amount of 30.4% caustic soda aqueous solution to 8g.
After adding and mixing 52 g at room temperature, it was added to the above dispersion. The reaction was carried out at 60±1°C for 5 hours. Then, after filtration and repeated washing with 80 wt% isopropyl alcohol, the filtration residue was dried at 100±5°C for 2 hours to obtain 3 g of powdered cationic chitosan. (in terms of dry matter) was obtained.

This cationic chitosan was dissolved in cold water, and analysis by colloid titration showed that the nitrogen content of the 4g ammonium salt form was 4.8%.

Example 2 Powdered chitosan with a deacetylation rate of 87 mol% (moisture 7.8
%) 20g to 80% isopropyl alcohol aqueous solution 1
40 g of the mixture, 20 g of 2,3-epoxypropyltrimethylammonium chloride (purity 75%) was added, and the mixture was reacted at 60±1° C. for 5 hours.

After filtration and repeated washing with 80 wt % isopropyl alcohol, the filtration residue was dried at 100±5° C. for 2 hours to obtain 30 g (in terms of dry matter) of powdery cationic chitosan. This cationic chitosan was dissolved in cold water, and as a result of analysis by colloid titration, the nitrogen content in the quaternary ammonium salt form was 3.5%.

Example 3 Powdered chitosan with a deacetylation rate of 87 mol% (moisture 7.8
%) 20g to 80% isopropyl alcohol aqueous solution 14
8.0g of 2,3-epoxypropyltrimethylammonium chloride aqueous solution (purity 75%) was added and reacted at 60±1°C for 5 hours.Then, the mixture was cooled to room temperature and 15% caustic soda aqueous solution8. After adding 0 g of ethylene oxide, one portion of ethylene oxide was added, and the reaction was carried out at 60±1° C. for 5 hours.

After the reaction, 2.3 g of acetic acid was added to neutralize free caustic soda, filtered, and washed with 80% aqueous isopropyl alcohol solution again. The filter residue was dried at 100±5° C. for 2 hours to obtain 40.5 g (in terms of dry matter) of powdered hydroxyalkylated cationic chitosan. This cationic chitosan was dissolved in cold water and analyzed by colloid titration.
The nitrogen content of the 4th All ammonium salt type was 2.5%, and the hydroxyethyl group content was 25.9% as a result of analysis by the 1 Morgan method.

Example 4 Powdered chitosan with a deacetylation rate of 87 mol% (moisture 7.8
%) 20g to 90% isopropyl alcohol aqueous solution 1
It was dispersed in 40g. 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution (purity 5
An equimolar amount of 7.0 g of a 30.3% caustic soda aqueous solution was added to 20 g of 0%) at room temperature, mixed, and then added to the above dispersion. The reaction was carried out at 60±1° C. for 5 hours. After cooling to room temperature, 8 g of 15% caustic soda aqueous solution was added. After 30 g of glycidol was added and the reaction was carried out at 60±1° C. for 5 hours, 2.3 g of acetic acid was added to neutralize free caustic soda, and after filtration, washing with an 80% aqueous isopropyl alcohol solution was repeated. 10 filtration residue
It was dried at 0±5° C. for 2 hours to obtain 39.9 g (in terms of dry matter) of hydroxyalkylated cationic chitosan. This cationic chitosan was dissolved in cold water, and as a result of colloid titration analysis, the nitrogen content of the 41st & ammonium salt type was 1.
Based on the increase in yield at 5%, the glyceryl group content was 37.6%.

Example 5 Chitosan with a deacetylation rate of 87 mol% (moisture 7.8%)
2, dispersed in 140 g of 80% isopropyl alcohol aqueous solution, added 20 g of 2,3-epoxypropyltrimethylammonium chloride aqueous solution M (purity 75%),
The reaction was carried out at 60±1°C for 5 hours.

Next, cool to room temperature and add 13g of 15% caustic soda aqueous solution.
added. Add 15g of propylene oxide and heat at 60±1°C.
After 0 hours of reaction, 3 g of acetic acid was added to neutralize the free caustic soda, and the filtration residue was dried at 100 ± 5°C for 2 hours to give 35.3 g of hydroxyalkylated cationic chitosan powder (in terms of dry matter). ) was obtained. This cationic chitosan was dissolved in cold water, and as a result of analysis by colloid titration method, the nitrogen content in the quaternary ammonium salt form was 2.6%, and as a result of analysis by Morgan method, the hydroxypropyl content was 17%. It was 8%.

Claims (1)

[Claims] 1. A method for producing a cationic chitosan derivative, which comprises reacting chitosan with a cationizing agent having a quaternary ammonium salt type nitrogen in its molecule. 2. The cationizing agent is 3 in which the alkyl group has 1 to 3 carbon atoms.
-Chloro-2-hydroxypropyltrialkylammonium halide, the manufacturing method according to claim 1. 3. The cationizing agent is 2 in which the alkyl group has 1 to 3 carbon atoms.
, 3-epoxypropyltrialkylammonium halide. 4. A method for producing a cationic chitosan derivative, which comprises further reacting a hydroxyalkylating agent with a reaction product of chitosan and a cationizing agent having nitrogen in the molecule of a quaternary ammonium salt. 5. The cationizing agent is 3 in which the alkyl group has 1 to 3 carbon atoms.
-Chloro-2-hydroxypropyltrialkylammonium halide, the manufacturing method according to claim 4. 6. The cationizing agent is 2 in which the alkyl group has 1 to 3 carbon atoms.
, 3-epoxypropyltrialkylammonium halide. 7. The manufacturing method according to any one of claims 4, 5, and 6, wherein the hydroxyalkylating agent is ethylene oxide. 8. The manufacturing method according to any one of claims 4, 5, and 6, wherein the hydroxyalkylating agent is propylene oxide. 9. The manufacturing method according to any one of claims 4, 5, and 6, wherein the hydroxyalkylating agent is glycidol.