JPH0649725B2 - Method for producing cationic chitosan derivative - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a novel cationic chitosan derivative using chitosan as a starting material, which is inexpensive and can be obtained in a large amount by deacetylating an unused natural resource, chitin.

2. Description of the Related Art Chitosan can be obtained by deacetylating chitin contained in shells of shrimp and crab in a concentrated alkaline aqueous solution. Chitosan becomes a water-soluble chitosan salt by neutralizing a free amino group with an acid such as hydrochloric acid, acetic acid or lactic acid, and this chitosan salt is used as a coagulant for a part of industrial wastewater and municipal wastewater. However, since the chitosan salt becomes insoluble and precipitates on the neutral or alkaline side, its use is actually limited.

As a method for obtaining chitosan having excellent water solubility, a method of reacting chitosan with ethylene oxide or glycidol has been proposed (JP-A-59-8701), but most of ethylene oxide or glycidol is a constituent component of chitosan. Since it is introduced into the amino group of glucosamine, there is a drawback that the cationic activity is reduced.

OBJECT OF THE INVENTION It is an object of the present invention to provide a method capable of easily producing a chitosan derivative which is soluble in water and has an excellent cationic activity.

Structure of the Invention 1 of the present invention is characterized by reacting chitosan with a cationizing agent which is a C3-C2,3-epoxypropyltrialkylammonium halide of the alkyl group represented by the general formula (I). And a method for producing a cationic chitosan derivative.

(R: alkyl group having 1 to 3 carbon atoms X: halogen) In another aspect of the present invention, after reacting chitosan with the above cationizing agent, the obtained reaction product is reacted with a hydroxyalkylating agent. The method for producing a cationic chitosan derivative is characterized in that

Chitosan has the general formula (II) The N-acetylated-D-glucosamine represented by
It is a deacetylated product of chitin linked by 1,4. In the present invention, those having an acetylation rate of 50 to 99% are suitable. Such chitosan can be obtained, for example, by deacetylating chitin in a 30 to 50% aqueous alkaline solution at a temperature of 50 to 130 ° C. Chitosan is preferably in finely divided form and is reacted with a cationizing agent.

The 2,3-epoxypropyltrialkylammonium halide having an alkyl group having 1 to 3 carbon atoms used as a cationizing agent in the present invention has a quaternary ammonium salt type nitrogen and an active group for glucosamine in the molecule. It is a compound.

Among such cationizing agents, chloride is particularly preferable, and specific examples thereof include 2,3-epoxypropyltrimethylammonium chloride, 2,3-epoxypropyltriethylammonium chloride and 2,3-epoxypropyltripropylammonium chloride. To be Among these, 2,3-epoxypropyltrimethylammonium ammonium chloride is preferable. 3-chloro-2-hydroxypropyltrimethylammonium chloride was previously added in an equimolar amount of 5 to 5.
By mixing with an alkaline aqueous solution of 50, 2,3-epoxypropyltrimethylammonium chloride can be obtained, which can be used in the reaction.

The reaction between chitosan and the cationizing agent is performed in an organic solvent at 20
It is carried out by stirring at a temperature of ~ 120 ° C, preferably 40 ~ 80 ° C for 2 to 20 hours while maintaining the slurry state. Desirably, the reaction is carried out in the presence of water. The water concentration during the reaction is 5 to 50%, preferably 10 to 30%. As the organic solvent, alcohols such as methanol, ethanol and isopropyl alcohol, and ketones such as acetone and methyl ethyl ketone are used. Their use amount is 1 to 20 times the weight of chitosan.

The reaction mixture is separated into a solid matter and a solution by solid-liquid separation means such as filtration or centrifugation, and powdery cationic chitosan is collected as a solid matter. If necessary, the solid matter is washed with a 50 to 100% aqueous ketone or alcohol solution and dried under reduced pressure or normal pressure at a temperature of 50 to 120 ° C. The resulting quaternary ammonium salt form of cationic chitosan has a nitrogen content of 0.5-10%, preferably 1.
It is preferable to adjust parameters such as the addition amount of the cationizing agent so as to be ˜6%.

Further, the reaction product of chitosan and the cationizing agent may be further reacted with a hydroxyalkylating agent to increase the water solubility.

Ethylene oxide, propylene oxide, glycidol and the like are used as the hydroxyalkylating agent. The hydroxyalkylation reaction can be performed after separating and recovering chitosan and cationic chitosan, or after purifying if necessary, or by immediately adding a hydroxylating agent to the reaction mixture.

The hydroxyalkylation conditions are the same as those for the cationization of chitosan described above, but it is preferable to carry out the reaction in the presence of a basic catalyst. As the basic catalyst, an alkylamine such as trimethylamine or triethylamine, a hydroxide of an alkali metal or an alkaline earth metal, and the like are used. The amount of catalyst used is 0.5 to 2 with respect to cationic chitosan.
It is 0 wt%, preferably 2 to 10 wt%.

Hydroxyalkylation has a hydroxyalkyl group content of 5
It is suitable to be -80%, preferably 10-50%.

EFFECTS OF THE INVENTION According to the present invention, a water-soluble cationic chitosan having a high cationic activity can be easily obtained, and the film-forming property inherent in chitosan is not impaired. Therefore, it can be used for cosmetic base materials, coagulants, antistatic agents, and the like.

Example 1 Powdered chitosan having a deacetylation rate of 87 mol% (water content: 7.8%) 2
0 g was dispersed in 140 g of isopropyl alcohol. 3-
Chlor-2-hydroxypropyltrimethylammonium chloride aqueous solution (pure content 50%) 55.8 g of equimolar amount of 3
19.52 g of a 0.4% caustic soda aqueous solution was added at room temperature and mixed to give 2,3-epoxypropyltrimethylammonium chloride in advance, which was then added to the above dispersion. 60
The reaction was carried out at ± 1 ° C for 5 hours. It is then filtered to 80 wt%
After repeating washing with isopropyl alcohol,
The filtration residue was dried at 100 ± 5 ° C. for 2 hours to obtain 38.3 g (as dry matter) of cationic chitosan as powder. This cationic chitosan was dissolved in cold water and analyzed by colloid titration to find that the quaternary ammonium salt type had a nitrogen content of 4.8%.

Example 2 Powdered chitosan having a deacetylation rate of 87 mol% (water content: 7.8%) 2
0 g was dispersed in 140 g of 80% isopropyl alcohol water-soluble, 20 g of 2,3-epoxypropyltrimethylammonium chloride (pure content 75%) was added, and the mixture was reacted at 60 ± 1 ° C. for 5 hours. Then, after filtering and repeating washing with 80 wt% isopropyl alcohol, the filtration residue is 100 ± 5.
It was dried at 0 ° C. for 2 hours to obtain 30 g of powdered cationic chitosan (as dry matter). This cationic chitosan was dissolved in cold water and analyzed by colloid titration to find that the quaternary ammonium salt type had a nitrogen content of 3.5%.

Example 3 Chitosan powder having a deacetylation rate of 87 mol% (water content: 7.8%) 2
0 g was dispersed in 140 g of 80% isopropyl alcohol aqueous solution, 20 g of 2,3-epoxypropyltrimethylammonium chloride aqueous solution (75% of pure content) was added, and the mixture was reacted at 60 ± 1 ° C. for 5 hours. Next, the mixture was cooled to room temperature, 8.0 g of 15% caustic soda water-soluble was added, 15 g of ethylene oxide was added, and the reaction was carried out at 60 ± 1 ° C. for 5 hours. After the reaction, acetic acid 2.3
80 g to neutralize free caustic soda by adding g
The washing with the isopropyl alcohol aqueous solution was repeated. The filter residue was dried at 100 ± 5 ℃ for 2 hours and powdered hydroxyalkylated cationic chitosan 40.5g (dry matter conversion)
Got This cationic chitosan was dissolved in cold water and was analyzed by colloid titration to find that the quaternary ammonium salt type had a nitrogen content of 2.5%. Also, the Morgan method showed that the hydroxyethyl group content was 25.9%. It was

Example 4 Powdered chitosan having a deacetylation rate of 87 mol% (water content: 7.8%) 2
Disperse 0 g in 140 g of 90% isopropyl alcohol aqueous solution, add 20 g of 3-chloro-2-hydroquinpropyltrimethylammonium chloride aqueous solution (pure content 50%) with equimolar amount of 30.3% caustic soda aqueous solution 7.0 at room temperature and mix, After making 2,3-epoxypropyltrimethylammonium chloride, it was added to the above dispersion. 60
The reaction was carried out at ± 1 ° C for 5 hours. Next, after cooling to room temperature, 8 g of 15% caustic soda aqueous solution was added. Glycidol (30 g) 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, and after filtration, washing with an 80% isopropyl alcohol aqueous solution was repeated. The filtration residue was dried at 100 ± 5 ° C. for 2 hours to obtain 39.9 g (as dry matter) of hydroxyalkylated cationic chitosan. This cationic chitosan was dissolved in cold water, and as a result of analysis by colloidal titration, the nitrogen content of the quaternary ammonium salt type was 1.5%, and the glyceryl group content was 37.6% from the increased yield.

Example 5 20 g of chitosan (water content 7.8%) with a deacetylation rate of 87 mol%
Was dispersed in 140 g of an 80% aqueous isopropyl alcohol solution, 20 g of 2,3-epoxypropyltrimethylammonium chloride water-soluble (pure content 75%) was added, and the mixture was reacted at 60 ± 1 ° C. for 5 hours. Then, the mixture was cooled to room temperature, and 13 g of 15% caustic soda aqueous solution was added. Add 60 g of propylene oxide 60
The reaction was performed at ± 1 ° C for 8 hours. After the reaction, 3 g of acetic acid was added to neutralize free caustic soda, and the filtration residue was dried at 100 ± 5 ° C. for 2 hours to obtain 35.3 g of powdered hydroxyalkylated cationic chitosan (as dry matter). This cationic chitosan was dissolved in cold water and the colloid titration analysis showed that the quaternary ammonium salt type nitrogen content was 2.6%, and the Morgan analysis showed that the hydroxypropyl group content was 17.8%. there were.

Claims (5)

[Claims] 1. Chitosan and general formula (I) (R: alkyl group having 1 to 3 carbon atoms X: halogen) characterized by reacting with a cationizing agent which is 2,3-epoxypropyltrialkylammonium halide having 1 to 3 carbon atoms in the alkyl group. And a method for producing a cationic chitosan derivative. 2. Chitosan and the general formula (I) (R: alkyl group having 1 to 3 carbon atoms X: halogen), after reacting with a cationizing agent which is a 2,3-epoxypropyltrialkylammonium halide having an alkyl group having 1 to 3 carbon atoms, A method for producing a cationic chitosan derivative, which comprises reacting the obtained reaction product with a hydroxyalkylating agent. 3. The production method according to claim 2, wherein the hydroxyalkylating agent is ethylene oxide. 4. The method according to claim 2, wherein the hydroxyalkylating agent is propylene oxide. 5. The production method according to claim 2, wherein the hydroxyalkylating agent is glycidol.