JP2826899B2 - Chitosan derivative, process for producing the same, detergent builder and humectant comprising the same - Google Patents

Description

The present invention relates to novel chitosan derivatives, and more particularly to specific chitosan derivatives.
The present invention relates to a chitosan derivative having an N, N-dicarboxymethylglucosamine derivative as a constituent unit and having a high ion-trapping ability and a moisturizing effect, a method for producing the same, a detergent builder and a moisturizer comprising the same.

[Problems to be solved by conventional technology and invention]

Generally, detergents are produced by blending a surfactant with a detergent builder and other additives. As a detergent builder, condensed phosphate compounds such as sodium tripolyphosphate (STPP) have been widely used in terms of performance and price, but due to eutrophication of rivers and the like caused by an increase in the amount of phosphorus compounds on the surface and in water. Due to the occurrence of environmental problems, their replacement has been rapidly advanced in recent years.

As an alternative to this STPP, zeolites that have no problem in terms of eutrophication and safety have come to be used in recent years, but zeolites are insoluble in water and do not have the dispersing ability that STPP has . Therefore, the detergent containing this has a disadvantage that the cleaning power is inferior to the detergent containing STPP having chelating ability and dispersing ability, and that it cannot be incorporated into a liquid detergent.

In addition, studies have been made on water-soluble low molecular weight compounds having chelating ability for metal ions, and polyvalent carboxylic acids such as citric acid and succinic acid, and nitrogen-containing carboxylic acids such as nitrilotriacetic acid have been provided. However, although these low molecular compounds also have a useful chelating ability, they do not have a dispersing ability in water, so that a detergent containing this compound has inferior detergency.

Furthermore, in recent years, anionic polymer compounds have been used as detergent builders, which have both a chelating ability and a dispersing ability derived from the protective colloid effect of the polymer. Obtainable.
However, synthetic anionic polymer compounds are poor in biodegradability and have a problem in terms of environmental pollution, and although anionic polymer compounds derived from natural polymers such as carboxymethyl cellulose have some degree of biodegradability, However, there is a problem in that the degree of carboxymethylation during the reaction is limited, and the ability of each carboxyl group to chelate calcium ions is weak, so that it does not have a sufficient ability to sequester calcium ions.

Therefore, development of a detergent builder which has excellent chelating ability and dispersing ability, has good biodegradability and has no problem of environmental pollution has been desired.

Also, hyaluronic acid has attracted attention as a humectant for cosmetics and as a raw material for pharmaceuticals. Hyaluronic acid binds to a large amount of water to retain moisture in the skin and has the effect of softening the skin.It is also widely used as a raw material for cosmetics, ophthalmology and surgical drugs because it has a relationship with the lubricating effect of contact. Have been.

Conventionally, as a method for producing hyaluronic acid, there are known a method of isolating and purifying from a tissue in a living body such as chicken squirrel and a fermentation method using a microorganism (Japanese Patent Application Laid-Open No. 58-56692). The former method is too costly, and the latter method has disadvantages such as requiring special equipment and technology.

Therefore, the development of an inexpensive humectant having performance equal to or higher than that of hyaluronic acid has been desired.

On the other hand, chitin, which is a raw material of chitosan, is N-acetyl-
D-glucosamine is a polysaccharide consisting of 1,4-linked,
It is present in supporting tissues such as crustaceans, insects, and fungi, and has the second highest production in nature after cellulose. However, chitin has an acetamido group in the molecule,
Since chitin in a textured form is a compound that is extremely stable, its crystal structure is not as strong as that of cellulose, but is a polysaccharide with extremely poor processability and reactivity. Therefore, despite the fact that research began at about the same time as cellulose,
Little utility has been found, and most of the natural chitin is discarded. Therefore, if chitin can be recycled, it is extremely advantageous from the viewpoint of effective use of unused natural polymers.

In addition, chitosan obtained from chitin has only been used as a flocculant or the like as a cationic polymer compound derived from a natural polymer.

In addition, carboxymethylation of chitin and chitosan
In general, this is performed to ensure solubility in water in the neutral region.For example, U.S. Pat.No. 4,699,195 discloses that N, O-dicarboxymethyl is obtained by reacting monochloroacetic acid with chitosan under strong alkali in isopropyl alcohol. Pure & Appl. Chem., 54 , (11), 2141
(1982) discloses a method in which chitosan and glyoxylic acid are reacted to form an imine structure, and then reduced with a reducing agent such as NaBH ₃ CN to obtain N-carboxymethylated chitosan. Appl.22780A / 81 (1
7 , (2), 87 (1987), but none of the chitosan derivatives has sufficient chelating ability. In addition, chitosan is O-
Carboxymethylated compounds having improved chelating ability with heavy metals have also been developed [Polym. J., 15 , (8), 597 (1)
983)], but this was still not satisfactory.

In addition, N, N-dicarboxymethylated chitosan has not been obtained.

[Means for solving the problem]

Under these circumstances, the present inventors have conducted intensive studies and as a result, when a monohalogenoacetic acid or a salt thereof is reacted with chitosan or a derivative thereof in a certain pH range, a novel N, N
-It has been found that a dicarboxymethylated chitosan derivative can be produced, and that the obtained chitosan derivative has high ion-sequestering ability and moisturizing action, has good biodegradability, and has no problem of environmental pollution. Completed the invention.

That is, the present invention provides the following general formula (I) [Wherein, M ¹ represents a hydrogen atom, an alkali metal atom, an ammonium group, an alkylammonium group or a quaternary ammonium group which may be substituted with a hydroxy group], an N, N-dicarboxymethylglycosamine derivative represented by And a method for producing the same, and a detergent builder and a humectant comprising the same.

The chitosan derivative of the present invention is represented by the above general formula (I)
An N, N-dicarboxymethylglucosamine derivative is contained as a structural unit in the molecule.

(I) In the formula, examples of the alkali metal atom represented by M ¹ include a lithium atom, a sodium atom, and a potassium atom. Examples of the alkyl ammonium group which may be substituted with a hydroxy group include a diethanol ammonium group. , A triethanolammonium group and a triisopropanolammonium group.

The chitosan derivative of the present invention may contain a structural unit represented by the following general formula (IV) in addition to the structural unit represented by the general formula (I).

Wherein R ² and R ³ are the same or different and are a hydrogen atom, a group --CH
₂ COOM ¹ , group EO _p PO _q H, (Wherein, M ¹ represents a hydrogen atom, an alkali metal atom, an ammonium group, an alkylammonium group or a quaternary ammonium group which may be substituted with a hydroxy group, EO represents ethylene oxide, PO represents propylene oxide, p
Represents a number of 0 to 5, and q represents a number of 0 to 5. Where p
And q are not simultaneously 0), and R ⁴ and R ⁵ are the same or different and are a hydrogen atom, a group —COCH ³ , a group EO _p P
O _q H, group --CH ₂ COOM ¹ , (Wherein, M ¹ , EO, PO, p and q have the same meanings as described above). The chitosan derivative of the present invention contains 50 structural units represented by the above general formula (I) in its molecule. Preferably, it is contained in an amount of up to 100% by weight.

The chitosan derivative having the structural unit (I) of the present invention can be prepared by, for example, adding a monohalogenoacetic acid or a salt thereof (II) to a chitosan derivative having the structural unit (II) according to the following reaction formula.
It can be produced by reacting I) and, if necessary, performing salt exchange.

Wherein M ¹ has the same meaning as described above, M ² represents a hydrogen atom, an alkali metal atom, a trialkylammonium group or a quaternary ammonium group which may be substituted with a hydroxy group, and R ¹ represents hydrogen An atom or group —CH ₂ COOM ² (M ² has the same meaning as described above), and X represents a halogen atom. In the formula (III), examples of the halogen atom represented by X include a chlorine atom and a bromine Atoms, iodine atoms and the like.

Examples of the chitosan derivative having the structural unit of the above formula (II) include chitosan, deacetylated chitin, and N-monocarboxymethylated chitosan.

The reaction of the chitosan derivative having the structural unit (II) with the monohalogenoacetic acid or the salt thereof (III) is carried out in a solvent at pH 6 to 11.
It is performed in. If the pH is less than 6, that is to say the acid side,
The amino group in chitosan or a derivative thereof becomes an ammonium group, and the reactivity with monohalogenoacetic acid (salt) decreases. On the other hand, when the pH exceeds 11 and becomes alkaline, the reaction between monohalogenoacetic acid (salt) and the hydroxyl group in chitosan or its derivative becomes dominant, and the reaction to the amino group is inhibited. In this reaction, an acid such as hydrochloric acid is purified with the progress of the reaction.Therefore, it is preferable to use a base for the purpose of maintaining the pH of the reaction system in the above-mentioned range. , Potassium hydroxide, triethanolamine and the like.

The reaction solvent used is preferably an aqueous solvent, particularly preferably water. The reaction is preferably carried out with stirring, and is almost completed in 2 to 14 hours at a reaction temperature from room temperature to reflux temperature, preferably from 60 to 100 ° C.

After completion of the reaction, the resulting reaction solution is centrifuged as necessary to remove insoluble unreacted chitosan derivative, and then poured into a hydrophilic organic solvent to obtain the desired N, N-diamine. A chitosan derivative having the carboxymethylglucosamine derivative (I) as a structural unit can be obtained as a precipitate. Examples of the hydrophilic organic solvent used here include ketones such as acetone and methyl ethyl ketone; and alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol.

Furthermore, the thus obtained chitosan derivative having the N, N-gicarboxymethylglucosamine derivative (I) as a constitutional unit can be used as it is, but if necessary, may be used after performing salt exchange. . In the formula (I), those in which M ¹ is an alkylammonium group which may be substituted by a hydroxy group such as an ammonium group or a diethanolammonium group are preferably produced by the above salt exchange.

The chitosan derivative of the present invention has good biodegradability, high ion-trapping ability, and a high stability constant, so that it can strongly block calcium ions and the like present in water, and can be used as a polymer electrolyte. Therefore, it is easy to form a protective colloid, and is excellent in dispersibility of solid particles and the like in water.
Therefore, it can be suitably used as a detergent builder.

In addition, the chitosan derivative of the present invention has a high moisturizing action equivalent to that of hyaluronic acid, and is also useful as a humectant to be incorporated in cosmetics, pharmaceuticals, and the like.

〔The invention's effect〕

The chitosan derivative of the present invention is a novel chitosan derivative having an N, N-dicarboxymethyl group. It has good biodegradability and does not cause environmental pollution, is also useful as a detergent builder because it has a high ion-sequestering ability, and has a high moisturizing effect, so that it can be used in cosmetics and pharmaceuticals. It is also useful as a humectant.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples.
The present invention is not limited by these examples.

Example 1 4.0 g (24.8 mmol) of chitosan, 50 ml of water, monochloroacetic acid
11.7 g (100 mmol) of Na was weighed into a 300 ml flask and stirred at 80 ° C. The reaction proceeded with the chitosan powder dispersed in an aqueous solution of sodium monochloroacetate. The system becomes acidic as the reaction progresses.
The pH of the system was maintained at 7 by slowly adding a 5N aqueous sodium hydroxide solution. When the reaction was carried out at 80 ° C. for 6 hours, the insoluble chitosan almost disappeared at pH 7, and the reaction was stopped because the pH of the system did not shift to the acidic side without adding sodium hydroxide. The reaction solution was diluted to 300 ml with water and centrifuged to remove a small amount of insoluble chitosan gel. After the supernatant was filtered through a glass filter, the mother liquor was concentrated and adjusted to pH 11 with NaOH, and then poured into a large amount of methanol for reprecipitation. The precipitate is taken out and dried under reduced pressure, N, N-dicarboxymethyl chitosan sodium salt 5.5 g
Was obtained as a light brown powder.

The obtained sodium salt of N, N-dicarboxymethylchitosan did not dissolve in water in the pH range of 0.7 to 2.0, but completely dissolved in water in other pH ranges.

Example 2 Deacetylated chitin (deacetylation degree: 0.8) 4.0 g (23.6 m
mol), water 50ml, sodium monochloroacetate 11.7g (100m
mol) was weighed into a 300 ml flask and stirred at 80 ° C. The reaction proceeded with the deacetylated chitin powder dispersed in an aqueous solution of sodium monochloroacetate. Since the system became acidic with the progress of the reaction, a 5N aqueous sodium hydroxide solution was gradually added from the dropping funnel to maintain the pH of the system at 7. When the reaction was carried out at 80 ° C. for 6 hours, the insoluble deacetylated chitin almost disappeared at pH 7, and the reaction was stopped because the pH of the system did not shift to the acidic side without adding sodium hydroxide. . The reaction solution was diluted with water to 300 ml, and a small amount of the remaining insoluble deacetylated chitin gel was removed by centrifugation.The supernatant was filtered through a glass filter, the mother liquor was concentrated, and the pH was adjusted to 11 with sodium hydroxide. Then, the mixture was poured into a large amount of methanol and reprecipitated. The precipitate was taken out and dried under reduced pressure to obtain 5.5 g of partially N, N-dicarboxymethylated chitin sodium salt as a light brown powder.

The structure is confirmed by IR and NMR, and the molecular weight is measured by G
Measured by PC. The results are shown below.

◎ IR COONa: 1410, 1600 cm ^-1 -OH: 3200-3500 cm ^-1 ◎ Average molecular weight: 9.3 × 10 ⁴ ◎ ¹³ C-NMR a: 182 ppm b: 181 ppm c: 100-105 ppm d: 65-80 ppm e ₁ , e _{2: 58~64ppm} (the e ₁ and e ₂ can not be identified and separated.) f: 54ppm g: 25ppm Test Example 1 Determination of carboxyl group The content of carboxyl group was determined by colloid titration. Table 1 shows the results.

Test Example 2 Measurement of calcium ion chelating ability Calcium ion chelating ability was measured at pH 10 using a calcium ion electrode. Table 2 shows the results.

From the results shown in Table 2, it can be seen that the chitosan derivative obtained according to the present invention has excellent calcium ion trapping ability.

Test Example 3 Measurement of the rate of increase in moisture absorption and the rate of residual moisture The rate of increase in moisture absorption and the rate of residual moisture were measured by the following methods. Table 3 shows the results.

(Moisture absorption increase rate)

A desiccator having a relative humidity of 81% with a saturated aqueous solution of ammonium sulfate and a desiccator having a relative humidity of 43% with a saturated aqueous solution of potassium carbonate were prepared in a constant temperature room at 20 ° C. The rate of increase in moisture absorption was determined from the weight of the sample after standing according to the following equation.

Rate of increase in moisture absorption (%) = [(Wn−WO) / WO] × 100 WO: weight before standing Wn: weight after standing [water remaining rate] 0.5 g of each sample was precisely weighed in a beaker having a diameter of 3 cm, and then the sample was weighed. About 10% by weight of water was added to the sample, and the mixture was placed in a desiccator adjusted to 43% relative humidity with a saturated aqueous solution of potassium carbonate.
Left at 40 ° C. for 40 hours. After standing, each sample was precisely weighed, and the residual moisture ratio of the following formula was determined as an index of moisture retention.

Water remaining rate (%) = (Hn / HO) × 100 = [(Wn−S) / (WO-S)] × 10
0 HO: Water content added Hn: Water content after standing WO: Weight of water-containing sample before standing Wn: Sample weight after standing S: Dry sample weight From the results shown in Table 3, it can be seen that the chitosan derivative obtained according to the present invention has the same level of water retention as hyaluronic acid.

Claims (4)

(57) [Claims] 1. The following general formula (I) [Wherein, M ¹ represents a hydrogen atom, an alkali metal atom, an ammonium group, an alkylammonium group or a quaternary ammonium group which may be substituted with a hydroxy group], an N, N-dicarboxymethylglycosamine derivative represented by A chitosan derivative having as a constituent unit. 2. The following general formula (II) [Wherein, R ¹ represents a hydrogen atom or a group —CH ₂ COOM ² (M ² represents a hydrogen atom, an alkali metal atom, a trialkylammonium group or a quaternary ammonium group which may be substituted with a hydroxy group)] A chitosan derivative having a structural unit represented by the following general formula (III): X-CH ₂ COOM ² (III) wherein X represents a halogen atom and M ² has the same meaning as described above. The method for producing a chitosan derivative according to claim 1, wherein the represented monohalogenoacetic acid or a salt thereof is reacted at pH 6 to 11. 3. A detergent builder comprising the chitosan derivative according to claim 1. 4. A humectant comprising the chitosan derivative according to claim 1.