JPH0131761B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention provides novel cationized chitin that is soluble in water,
More specifically, the active hydrogen in the chitin molecule has the general formula () (In the formula, R represents a methyl group or an ethyl group, and X represents a halogen atom.) A method for producing cationized chitin substituted with a quaternary nitrogen-containing group represented by the following and whose intermolecular hydrogen bonds are broken: Regarding.

[Conventional technology]

Chitin is a polysaccharide consisting of 1,4 bonds of N-acetyl-D-glucosamine, and is present in supporting tissues of crustaceans, insects, fungi, etc., and is produced in the second largest amount in nature after cellulose. Structurally, the structure of chitin is similar to that of crystalline cellulose, with the only difference being that the hydroxyl group at the _C2 position of glucose, which forms cellulose, has been replaced with acetamide. However, since chitin has an acetamide group in its molecule, its crystal structure is not as strong as that of cellulose, and it is a polysaccharide with significantly poor processability and reactivity compared to cellulose.

As described above, structured chitin is a stable carbohydrate, and although research began around the same time as cellulose etc., little utility value has been found, and only chitosan has been used as a flocculant. It's just that it's being done. Most of the natural chitin is treated as marine waste and is a source of environmental pollution. Therefore, if chitin can be converted into a resource, it will be extremely advantageous from both the standpoints of effectively utilizing unused natural polymers and preventing environmental pollution.

Tissue-like chitin has an extremely stable structure and is difficult to recover as a resource due to its poor solubility and reactivity, but it is also known to have excellent biocompatibility, biocompatibility, and antithrombotic properties. It is being Therefore, in order to take advantage of these advantages, it is necessary to improve the processability of chitin, that is, to first solubilize chitin.

Natural polymers or their derivatives have favorable properties such as high safety and good feeling in use, and are widely used as compounding agents in cosmetics, perfumery products, and the like. Chitin and its derivatives are also expected to be used as additives in cosmetics and cosmetics, and various uses have been investigated. However, as mentioned earlier, chitin is stabilized by strong intermolecular hydrogen bonds, so it is not a good solvent and has little utility value as it is.

Therefore, research has been carried out to obtain soluble derivatives of chitin, and for example, carboxymethylated chitin and deacetylated chitin (chitosan) have been reported (Japanese Patent Application Laid-open No. 90505/1983).

[Problem that the invention seeks to solve]

However, the use of the above chitin derivatives in cosmetics etc. has the following drawbacks. In other words, since the surface of the human body is generally weakly acidic, negatively charged carboxymethylated chitin has poor adsorption to the skin and hair, and chitosan has amino groups and is expected to have adsorption to the skin and hair. However, this substance dissolves only in acidic solutions and cannot be used as a neutral aqueous solution. Therefore, there has been a wide demand for chitin derivatives that provide a good feeling when used in cosmetics and cosmetics and have high adsorption properties to hair and skin, but so far no such derivatives have been found. It has not been.

[Means for solving problems]

The present inventors have solved the above problems, and in particular, provided a chitin derivative that is soluble in neutral water, provides a good feeling when used in cosmetics, etc., and has high adsorption to hair and skin. As a result of intensive research, we found that cationized chitin, in which the active hydrogen in the chitin molecule was substituted with a quaternary nitrogen-containing group represented by the general formula (), and the intermolecular hydrogen bonds were broken, achieved the above purpose. The present invention has been completed based on the discovery that the present invention can be achieved.

Therefore, the present invention provides a new method for producing a novel chitin derivative that is soluble in water and has excellent properties when incorporated into cosmetics and the like.

The cationized chitin of the present invention has chitin with the general formula () or (), A glycidyltrialkylammonium salt or a 3-chloro-2-hydroxypropyltrialkylammonium salt represented by the formula (in the formula, R and X are the same as above) is reacted, and the resulting product is then dissolved in an acid solution. Manufactured by

() of the cationizing agent used in the method of the present invention
Examples of compounds of the formula include glycidyltrimethylammonium chloride, glycidyltriethylammonium chloride, glycidyldimethylethylammonium chloride, and corresponding bromides and iodides; examples of compounds of the formula () include, for example, 3-chloro-2 -Hydroxypropyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltriethylammonium chloride, and corresponding bromides, iodides, and the like.

The amount of these cationizing agents used must be at least 30 parts by weight per 100 parts by weight of chitin; if it is less than 30 parts, the water solubility of the product will be insufficient, and if this amount is too large, it will be economically disadvantageous. Not only this, but also the purification of the product becomes complicated, which is not preferable.

The reaction between chitin and the compounds represented by the above general formulas () and () is carried out in water, alcohol, or a water-alcohol mixed solvent in the presence of an alkali. Here, as the alcohol, for example, methanol, ethanol, isopropanol, n-propanol, etc. are used, and as the alkali, for example, sodium hydroxide, potassium hydroxide, etc. are suitable. When using a cationizing agent (), the amount of alkali to be used is 0.1 to 20 parts by weight, preferably 2 to 10 parts by weight, per 100 parts by weight of ().
Parts by weight are desirable, and when a cationizing agent () is used, it is preferably 20 to 50 parts by weight, preferably 22 to 30 parts by weight, per 100 parts by weight of ().

The reaction is completed by stirring for 1 to 10 hours at a temperature of 15-80°C, preferably 40-60°C. This reaction does not dissolve cationized chitin.

After the reaction is completed, the reaction mixture is neutralized by adding an acid such as hydrochloric acid, sulfuric acid, acetic acid, or oxalic acid. The amount of acid required for this neutralization is 0.5 to 4.0 times the mole of the alkali catalyst, preferably 0.5 to 1.5 moles. Neutralization is 20
Complete in 0.5-2 hours at a temperature of ~50°C.

Next, the reactant is obtained from the neutralized reaction mixture by filtration and thoroughly washed with alcohol. At this time, unreacted cationizing agent is dissolved in alcohol and removed.

The cationized chitin thus obtained is still in a textured state, and as it is, it will not dissolve in neutral water due to strong intermolecular hydrogen bonds within the texture.

This intermolecular hydrogen bond is broken by dissolving the cationized chitin in an acid solution, such as a 1N or higher hydrochloric acid or sulfuric acid aqueous solution. Once cationized chitin is dissolved, it remains dissolved even if it is neutralized. Therefore, an acid solution in which cationized chitin is dissolved is neutralized with an alkali such as sodium hydroxide or potassium hydroxide, and the neutralized solution is poured into a hydrophilic organic solvent to collect the precipitated cationized chitin. Then, water-soluble cationized chitin can be obtained. Examples of the hydrophilic organic solvent used here include ketones such as acetone and methyl ethyl ketone; methanol, ethanol, n-propanol, isopropanol, n-butanol,
Examples include alcohols such as isobutanol.

The cationized chitin of the present invention thus obtained is a white to pale yellow polymer compound that is soluble in water and insoluble in absolute ethanol.

〔Effect of the invention〕

The cationized chitin of the present invention has high adsorption to hair and skin, and when used in cosmetics and cosmetics, it has a remarkable effect on improving the feeling of use and finish. It is useful as a base for cosmetics and cosmetics.

〔Example〕

The present invention will be specifically explained below using Examples.

Example 1 20.3 g of chitin (powdered chitin manufactured by Wako Pure Chemical Industries, Ltd.) was mixed with 200 g of water-isopropanol mixed solvent (25/75).
0.7 g of sodium hydroxide is added thereto, and the mixture is stirred at room temperature for 10 minutes. Next, 15.2 g of glycidyltrimethylammonium chloride was added, and the
Warm to ℃ and react for 8 hours. 36% after reaction completion
Neutralize by adding 1.8 g of hydrochloric acid. The reacted chitin is taken, washed with ethanol to remove unreacted glycidyltrimethylammonium chloride, and then dried. The obtained cationized chitin is added to 200 ml of 1N hydrochloric acid to break the hydrogen bonds between chitin molecules and completely dissolved, and then the hydrochloric acid is neutralized with sodium hydroxide. This solution is poured into isopropanol (1) to precipitate cationized chitin and separate it. After repeating such reprecipitation purification three times, the product was dried under reduced pressure to obtain 18.2 g of water-soluble cationized chitin in which chitin molecules do not have hydrogen bonds with each other. This was completely dissolved in neutral water. The degree of cationization *○ of this product measured using a colloid titration method was 0.48 per chitin residue. The results of elemental analysis of the obtained cationized chitin are shown below, and the values are the values of the degree of cationization measured using colloid titration method.
0.48, and it was confirmed that the target substance was obtained.

Elemental analysis results (%) C H N O Cl Actual value: 46.7 7.2 7.4 32.7 5.4 Theoretical value: 47.3 7.2 7.5 32.1 5.9 *○ Degree of cationization: Refers to the number of cation groups per chitin residue. The chitin residue contains 3 as shown in the formula below.
Since there are active hydrogens, if all of these are substituted with cationic groups, the degree of cationization will be 3.

Example 2 60% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution in 200g of water
Add 18.8 g, add 4 g of sodium hydroxide, and stir for 30 minutes. Next, add chitin 20.3 to this liquid.
Add 0.7g of sodium hydroxide, suspend, and add 0.7g of sodium hydroxide.
g was added, heated to 50°C, and reacted for 8 hours.
The subsequent operations were carried out according to Example 1 to obtain 17.8 g of neutral water-soluble cationized chitin. The degree of cationization measured by colloid titration was 0.41 per chitin residue. The results of elemental analysis of the obtained cationized chitin are shown below, and the values are the values of the degree of cationization measured using colloid titration method.
This agrees well with the theoretically calculated value using 0.41, indicating that the target substance has been isolated.

Elemental analysis results (%) C H N O Cl Actual value: 46.8 7.3 7.3 33.1 5.1 Theoretical value: 47.3 7.2 7.5 32.6 5.1

Claims (1)

[Claims] 1 Chitin has the general formula () or (), (In the formula, R represents a methyl group or an ethyl group, and X represents a halogen atom.) A glycidyltrialkylammonium salt or a 3-chloro-2-hydroxypropyltrialkylammonium salt represented by A method for producing cationized chitin, which comprises dissolving it in an acid solution.