JP3058009B2 - Chitosan derivatives, compositions for near-infrared absorbers comprising them and near-infrared absorbers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel chitosan derivative, a metal ion adsorbent, a composition for a near-infrared absorbing agent comprising the same, and a near-infrared absorbing agent obtained by heating the composition for a near-infrared absorbing agent. . More specifically, the present invention relates to a novel derivative in which a thiourea group is introduced into a hydrolysis product of chitin, and a near-infrared absorbing agent obtained by heating a composition of the compound and a copper compound.

[0002]

BACKGROUND OF THE INVENTION For a review of chitin / chitosan, see "The Last Biomass Chitin, Chitosan (1988)" and "Chitin,
Application of Chitosan (1990) "is published by Gihodo Shuppan. According to it, the definition of chitin and chitosan is written as follows. Chitin is N-acetyl-D-
It is a polysaccharide in which many glucosamine residues are β- (1,4) -linked, and the deacetylated product is called chitosan. However, this is a typical case, and chitin usually has a partial loss of acetyl groups. On the other hand, chitosan is typically a β- (1,4) -polymer of D-glucosamine. Like chitin, those containing some acetyl groups are usually called “chitosan”.

[0003] Chitin exists in the kingdoms of fungi, plants and animals. Currently, chitin is used as an industrial raw material by separating proteins, inorganic salts and the like from cuticles of various crabs and shrimp. This chitin has properties that are not found in conventional synthetic polymers, such as excellent biodegradability, and is relatively abundant as a resource. Chitin and chitosan are natural basic polysaccharides that are widely found in nature, but have long been neglected as unused resources. However, in recent years, research and application to effective use of chitin and chitosan have become active, and flocculants, ion exchangers, enzyme fixing agents, cosmetics, pharmaceuticals, medical materials, foods,
Many uses such as a soil conditioner have been considered. Various chemical modifications are possible using chitin / chitosan as a starting material, and can be formed into functional films, sheets, fibers, gel particles, microcapsules and the like by combining with an appropriate solvent. If these macromolecules are hydrolyzed, they can be obtained from medium- and high-molecular compounds of various lengths to low-molecular oligosaccharides depending on their degree.

[0004] Unshared electron pairs on the nitrogen atom of chitin and chitosan form complexes with heavy metal cations. This complex-forming ability varies with the type of metal and the chemical modification of chitin and chitosan. In particular, chitosan is an excellent heavy metal collector because it selectively and efficiently adsorbs and binds transition metal ions. There have been many studies on chitin / chitosan derivatives as metal ion adsorbents, but the purpose is to recover metal ions and to use them as carriers for chromatography. Therefore, these chitin / chitosan derivatives themselves are merely used for adsorption and desorption of metals, and it has not been considered to utilize the chitin / chitosan derivatives themselves in the state of adsorbing a metal.

[0005]

Accordingly, the present invention provides a derivative obtained by introducing a thiourea compound into chitosan, and can not only be used as a metal ion adsorbent but also absorbs a wide range of near-infrared rays. It was an object to provide something with character.

[0006]

Means for Solving the Problems The present invention has been proposed in order to achieve the above-mentioned object, and has a feature in that a chitosan derivative having a thiourea group having a specific structure has been found. That is, the present invention provides a chitosan containing X structural units represented by the formula (1), Y structural units represented by the formula (2), and Z structural units represented by the formula (3). In the derivative, a = X / (X + Y + Z) × 100 = 0 to 30 (mol%) b = Y / (X + Y + Z) × 100 = 0 to 70 (mol%) c = Z / (X + Y + Z) × 100 = 30 to 100 (However, the sum of the mole percentages is a + b + c = 100
%. X and Y represent an integer of 0 or more, and Z represents an integer of 1 or more. However, X + Y + Z ≧ 2. ), Which relates to a novel chitosan derivative.

[0007]

Embedded image (Wherein, R1 is a substituted or unsubstituted carbon number 6)
~ 30 aryl groups, substituted or unsubstituted C6-C3
0 benzoyl group, substituted or unsubstituted 7 to 30 carbon atoms
An aralkyl group, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkoxycarbonyl group having 2 to 20 carbon atoms. )

[0008] The novel chitosan derivative in the present invention is
It is a chitosan derivative that can be easily produced using natural chitin or chitosan obtained by deacetylating chitin without using any special equipment or process. That is, it is a chitosan derivative obtained by thiourea-forming this compound using an isothiocyanate compound, and is characterized by the above-mentioned three structural units (1), (2) and (3).

In a preferred embodiment of the present invention, the chitosan derivative contains at least the structural unit of the formula (3) and the number of oligomers is preferably 4 to 50, most preferably 6 to 5.
It has 30 structural units. The polymer chitosan derivative has up to 10,000 structural units, preferably 8000
, And most preferably up to 5,000.

The degree of deacetylation and the degree of polymerization of chitosan used in the present invention are not particularly limited, and any chitosan analogs may be used. The degree of deacetylation is usually 100 to 30%, preferably 80%. Before and after, the viscosity in an aqueous solution having a chitosan concentration of 1% and an acetic acid concentration of 1% is preferably about 0.01 to 2 Pa · s.

Formulas (1), (2) and (3) in the product
The content of the formula (1) in the content of each structural unit is the degree of acetyl group remaining in the raw material chitosan, and is determined by the degree of deacetylation of the starting material chitin. And the content of formula (3) can be adjusted relatively arbitrarily by appropriately selecting the reaction conditions for the thioureation.

The thiourea reaction of chitosan has a concentration of 0.2
An isothiocyanate compound, which is a compound to be introduced into the amino group of the D-glucosamine structural unit of chitosan, is added to a 10% to 10% aqueous methanol solution of an acid salt such as an acetate, hydrochloride or nitrate of chitosan, and the mixture is stirred. . Heating may be performed if necessary. The reaction is preferably performed in a homogeneous solution state, and the reaction temperature affects the viscosity of the reaction solution and the thioureation reaction rate.If the viscosity of the chitosan solution is high, the reaction at a high temperature increases the uniformity of the reaction solution. Is preferred.

The product thus obtained is a light yellow to brownish yellow mass or powder, and its solubility in organic solvents, acids and alkalis depends on the degree of thioureaization, that is, the formula (1) , Formula (2), and Formula (3).

The compound of the structural unit of the formula (3) of the present invention is
It can be synthesized by a reaction between an amino group of chitosan and an isothiocyanate compound.

Embedded image

That is, in the reaction, an isothiocyanate compound is added in such a manner that a desired degree of thiourea conversion is obtained with respect to 1 mol of amino group of a glucosamine structural unit constituting chitosan. As the acid used in the present invention, as long as it can dissolve or sufficiently swell the chitosan,
Any of organic acids such as formic acid, acetic acid, pyruvic acid and lactoic acid, and inorganic acids such as hydrochloric acid and nitric acid may be used, but among these, acetic acid is preferred. And, as the solvent to be used, chitosan or an isothiocyanate compound may be dissolved and mixed as long as it is a non-proton-donating polar solvent such as dimethylformamide, dimethylacetamide, and dimethylsulfoxide, or an alcohol such as methanol or ethanol, or These are mixed solvents. The reaction temperature is 0 to 150 ° C, preferably 20 to 80 ° C.

The following are examples of the isothiocyanate compound used in the present invention. Phenylisothiocyanate, 4-chlorophenylisothiocyanate, 3
-Chlorophenyl isothiocyanate, 2-chlorophenyl isothiocyanate, 3,4-dichlorophenyl isothiocyanate, 2,5-dichlorophenyl isothiocyanate, 4-bromophenyl isothiocyanate,
4-fluorophenyl isothiocyanate, 1-naphthyl isothiocyanate, 4-tolyl isothiocyanate, 3-tolyl isothiocyanate, 2-tolyl isothiocyanate, 2,6-dimethylphenyl isothiocyanate, 4-ethylphenyl Isothiocyanate, 4-
Butylphenyl isothiocyanate, 3-trifluorophenyl isothiocyanate, 4-nitrophenyl isothiocyanate, 3-nitrophenyl isothiocyanate, 2-nitrophenyl isothiocyanate, 4-methoxyphenyl isothiocyanate, 3-butoxy Phenylisothiocyanate, 2-ethoxyphenylisothiocyanate, 4-butoxycarbonylphenylisothiocyanate, 3-ethoxycarbonylphenylisothiocyanate, 2-methoxycarbonylphenylisothiocyanate, benzoylisothiocyanate, 4-methoxybenzoylisothiate Osocyanate, 4-phenylbenzoyl isothiocyanate, 2,4,6-trimethylbenzoyl isothiocyanate, benzyl isothiocyanate, α-methyl Benzyl isothiocyanate, β-phenylethyl isothiocyanate, methyl isothiocyanate, ethyl isothiocyanate, butyl isothiocyanate, isobutyl isothiocyanate, heptyl isothiocyanate, dodecyl isothiocyanate, octadecyl isothiocyanate, cyclohexyl Isothiocyanate, allyl isothiocyanate, 3-butenyl isothiocyanate, 4-pentenyl isothiocyanate, ethoxycarbonyl isothiocyanate and the like. Preferably, phenyl isothiocyanate and benzoyl isothiocyanate are used, and a chitosan derivative having structural units of formulas (4) and (5) is obtained.

[0017]

Embedded image

The novel chitosan derivative of the present invention is preferably produced as follows. For example, from 15 ° C to 2
At 5 ° C., chitosan with 80% degree of deacetylation (0.
A 5% solution having a viscosity of 20 cps) is dispersed in water, and an acid is added thereto in an amount of 0.1 to 5 moles, preferably 1.2 moles, based on the amino groups in the chitosan. Is prepared. This is diluted by adding 3 to 10 times the volume of methanol to the aqueous solution. The above-mentioned isothiocyanate compound as a thiourea-forming agent is added to the amino group of chitosan so as to have a desired ratio of the degree of thiourea.
When the mixture is stirred at a temperature of 5 minutes to 24 hours, the amino group of chitosan is converted into thiourea almost quantitatively. After that, the reaction gel is added to a large amount of acetone to cause gelation.The supernatant is removed, fresh acetone is added, the mixture is stirred, filtered or centrifuged, washed with acetone, dried, and dried. Get. If unreacted amino groups are present depending on the reaction conditions, neutralization may be carried out by adding a methanol solution of an alkali such as sodium hydroxide.

[0019] In this way the infrared absorption spectrum of the chitosan derivatives have different absorption wave numbers depending on the kind of substituents 1440cm ^_-1 ~1550cm _-1 to NH deformation vibration of thiourea (R1, R1 is In the case of an aromatic substituent, one strong broad absorption (1530 cm ⁻¹ ) or two sharp strong absorptions (eg, 1490 cm ⁻¹ , 1550
cm ^-1 ) or 1560 for an aliphatic substituent.
cm- ¹ ), the presence of the N-thiocarbamoyl-D-glucosamine structural unit of formula (3) was confirmed. Further, in addition to the absorption of thiourea, absorption of CC stretching vibration of the aromatic ring is observed at around 700 cm ⁻¹ , so that the N-phenylthiocarbamoyl-D-glucosamine structural unit of the formula (4) or N-benzoylthiocarbamoyl-D- of the formula (5)
The presence of the glucosamine structural unit was confirmed. There was no absorption (2273-2000 cm ^-1 ) of the raw material isothiocyanate compound, and it was confirmed that the reaction product was purified.

From the above results, it can be confirmed that the method of the present invention can selectively make only an amino group into a thiourea without protecting the hydroxyl group of chitosan and making use of the difference in reactivity between the amino group and the hydroxyl group. Was.

According to the result of X-ray diffraction, the chitosan derivative of the present invention had lower crystallinity than the chitosan as the starting material.

In the present invention, the reaction between the chitosan and the isothiocyanate compound is carried out not only by the method of immediately reacting both components as described above, but also by arranging the form of the desired product in advance with both or one of the raw materials. Later, in the latter case, after adding other components, the reaction can be carried out under reaction conditions to obtain the desired product.

By appropriately selecting the reaction conditions for the thioureation, the contents of the formulas (2) and (3) can be adjusted arbitrarily arbitrarily. (For example, a dialdehyde compound such as glutaraldehyde, a diisocyanate compound such as hexamethylene diisocyanate, etc.) can crosslink amino groups to be insolubilized. Further, the hydroxyl groups may be cross-linked and insolubilized by a diisocyanate compound such as hexamethylene diisocyanate, a diepoxy compound such as ethylene glycol diglycidyl ether, or the like.

The chitosan derivative of the present invention may be a molded product such as a film or a fibrous material, a metal ion adsorbent, a separating agent, an adhesive, a fixing agent, a processing agent, a coating material, a soil improving agent, a fertilizer coating agent, a water absorbing agent. It can be used as a conductive material.

The use of the chitosan derivative as a metal ion adsorbent is effective for recovering and removing heavy metal ions from wastewater. The chitosan derivative may be a mere powder, a molded product such as a film, a particle, a fibrous material, or a gel material. Heavy metal ions in the wastewater can be removed by placing the wastewater in the wastewater and allowing the heavy metals to be sufficiently adsorbed and then recovered.

When used in the form of powder or particles,
A column method in which this is packed into a column and a solution containing heavy metal ions is passed through, or a batch method in which powder or particulate matter is added to the solution containing heavy metal ions and the two are sufficiently contacted by stirring is used. Can also. Furthermore, a powdery or particulate chitosan derivative can be added to a pulp slurry liquid and dried to use as an adsorption filter paper.

The heavy metal compound used in the present invention may be any water-soluble salt such as sulfate, hydrochloride and acetate. When the heavy metal compound is brought into contact with the chitosan derivative, the pH of the aqueous solution containing heavy metal ions is adjusted to 2 or less. It is preferable to adjust to ~ 6. Performing such pH adjustment is advantageous in that the ability to adsorb heavy metal ions is improved.

The chitosan derivative of the present invention adsorbs the metal ions of the platinum group elements such as copper, silver and gold, and the platinum group elements such as platinum and palladium, but the nickel ions, cobalt ions, chromium ions and iron ions. Metal ions do not adsorb much. On the other hand, water-soluble heavy metal oxide ions such as vanadyl can also be adsorbed. In particular, it has excellent adsorption ability for copper ions and noble metal ions.

A solution in which a water-insoluble organic acid metal compound is dissolved in a solvent such as alcohols such as methanol and ethanol, ketones such as acetone and methyl ethyl ketone, and esters such as ethyl acetate and butyl acetate is used in the present invention. Can also be brought into contact with and adsorbed to a chitosan derivative.

In order to use the chitosan derivative of the present invention as a separating agent for separating a mixture of compounds,
It is common to use a chromatography method such as gas chromatography, liquid chromatography, thin-layer chromatography or the like packed with the chitosan derivative of the present invention.In addition, a membrane containing the chitosan derivative of the present invention is formed, and the membrane is separated therefrom. Can also be performed.

In order to apply the chitosan derivative of the present invention to a liquid chromatography method as a separating agent, a method of packing the powder as a powder in a column is simple. The chitosan derivative is preferably ground or beaded, and more preferably the particles are porous. Further, it is also preferable to support a chitosan derivative on a carrier in order to improve the pressure resistance of the separating agent, prevent swelling and shrinkage due to solvent substitution, and improve the number of theoretical plates.

The method of supporting the chitosan derivative on a carrier is intoxicated by a chemical method or a physical method. As a physical method, a chitosan derivative is dissolved in a soluble solvent, mixed well with a carrier, and the solvent is distilled off by air current under reduced pressure or heating, or the chitosan derivative is dissolved in a soluble solvent, and the carrier and There is also a method in which, after mixing well, a soluble solvent is diffused by separating the chitosan derivative into an insoluble solvent.

The carrier to be used includes a porous organic carrier or a porous inorganic carrier, and preferably a porous inorganic carrier. Suitable examples of the porous organic carrier include a polymer substance composed of polystyrene, polyacrylamide, polyacrylate, and the like. Suitable as a porous inorganic carrier are silica, alumina, glass, kaolin, titanium oxide, silicate, etc., which improve the affinity of these surfaces with chitosan derivatives and improve the surface characteristics of the carrier itself. May be used after performing the necessary processing to perform the processing.

The use of the chitosan derivative of the present invention is, of course, not limited to this. One of the notable functions of the chitosan derivative of the present invention is that the chitosan derivative containing the formula (6) or (7) is mixed with a copper compound and heated. To obtain near infrared absorption. This will be specifically described below.

The copper compound used in the present invention has the following general formula (8)

Embedded image (Wherein, R 8 represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, aralkyl group, and heterocyclic residue, X represents COO, SO ₄ , SO ₃ , PO ₄ , and n represents 1 Selected from organic acid copper compounds or copper bisacetylacetonate, or inorganic copper compounds such as copper hydroxide, cupric chloride, copper sulfate and copper perchlorate. At least one copper compound can be preferably used. Specific examples of the compound represented by the general formula (8) include the following, but are not limited thereto.

Copper stearate, copper palmitate, copper oleate, copper behenate, copper laurate, copper caprate, copper caprylate, copper caproate, copper valerate, copper isobutyrate, 4
-Copper cyclohexyl butyrate, copper butyrate, copper propionate, copper acetate, copper formate, copper benzoate, copper toluate, copper t-butyl benzoate, copper chlorobenzoate, copper dichlorobenzoate,
Copper trichlorobenzoate, copper bromobenzoate, copper iodobenzoate, copper phenylbenzoate, copper benzoylbenzoate,
Copper nitrobenzoate, copper aminobenzoate, copper oxalate, copper malonate, copper succinate, copper glutarate, copper adipate,
Copper pimerate, copper suberate, copper azelate, copper sebacate, copper citrate, copper phthalate, copper monoalkylester phthalate, copper monoacryloylester phthalate,
Copper naphthenate, copper naphthalenecarboxylate, copper diphenylamine-2-carboxylate, copper tartrate, copper gluconate, copper octylate, copper benzenesulfonate, copper p-toluenesulfonate, copper 2,5-dimethylbenzenesulfonate, 2
-Methoxycarbonyl-5-methylsulfonate copper, copper dodecylbenzenesulfonate, copper naphthalenesulfonate,
Copper aminonaphthalene sulfonate, copper dodecyl sulfate, α-
Copper naphthyl phosphate, copper stearyl phosphate, copper lauryl phosphate, copper di-2-ethylhexyl phosphate, copper isodecyl phosphate.

The copper compound and the novel chitosan derivative alone do not absorb in the near-infrared region (780 nm to 2500 nm), or at least slightly absorb a specific wavelength. Even if the treatment is performed, the absorption in the near infrared region does not substantially change. Also,
The composition in which both the copper compound and the novel chitosan derivative are mixed and coexist does not substantially change the near-infrared absorption by itself. However, when this composition is heat-treated, it immediately has a substantially uniform and strong absorption throughout the near infrared region. Therefore, a composition obtained by mixing and coexisting a novel chitosan derivative and a copper compound is an excellent composition for a near-infrared absorber, and the reaction product obtained by heat-treating this composition is extremely excellent. It becomes a near infrared absorber.

Further, a novel chitosan derivative is mixed with an aqueous solution of the above copper compound to adsorb copper ions to the chitosan derivative, or the chitosan derivative is dissolved or swollen in a solvent such as dimethyl sulfoxide to form the copper compound. Is dissolved in water or an organic solvent and mixed, and a copper-adsorbed chitosan derivative is obtained by, for example, causing copper to be adsorbed on the chitosan derivative.

The degree of near-infrared absorption can be arbitrarily adjusted by adjusting the types and ratios of the novel chitosan derivative and the copper compound, the heating temperature, the heating time and the like. The use ratio of the novel chitosan derivative and the copper compound is usually 5: 1 in molar ratio.
To 1: 1, preferably about 2: 1 to 1: 1, and a heating temperature of 100 to 250 ° C, preferably 120 to 180 ° C.
A heating time of about several milliseconds is sufficient, but is preferably 1 to 5 minutes.

Various uses can be considered using this property. For example, the part given thermal energy has little absorption in the visible part, so this part becomes a latent image of the heating pattern. An image can be obtained. If a laser beam having a wavelength in the near infrared region is used as a heat source, a non-contact visible image recording system can be obtained.

Further, by utilizing the property of having a strong absorbing property over almost the entire near infrared region, a near infrared absorbing molded article or a heat ray shielding material can be obtained.

The near-infrared-absorbing molded article is obtained by heating and melting a novel chitosan derivative and a copper compound or a composition obtained by mixing them together with a resin and then heating them, or heating them to a predetermined temperature or higher in advance. By subjecting the near-infrared absorbing agent to heat molding together with a resin, it is possible to obtain an arbitrary shape such as a particle shape, a film shape, a sheet shape, a board shape, or a desired three-dimensional shape. Furthermore, a near-infrared absorbing agent or a composition for a near-infrared absorbing agent may be sprayed, applied or impregnated on a desired substrate, and dried and heated to impart near-infrared absorbing properties to the substrate. Since near-infrared rays act as heat rays, by using a highly transparent resin for the above resin or substrate,
These can be used at the same time as a heat ray shielding material for blocking the near infrared region.

Further, the high molecular weight chitosan derivative containing the structural unit containing the formula (6) or (7) can be formed into a desired shape such as a fibrous, particulate, film, or sponge shape by a wet method. it can. Therefore, a dope obtained by dissolving a chitosan derivative in a solvent is processed into a fibrous form by a wet method, and heat treatment is performed after adsorbing copper, whereby a near infrared absorbing fiber can be obtained. Further, after immersing fibers such as acrylonitrile, polyester, and nylon in the solution of the chitosan derivative of the present invention to coat the surface, immersing the fibers in an aqueous solution containing copper ions to adsorb copper, and performing heat treatment, the near-infrared ray. An absorbent fiber is obtained. Clothing made using this fiber absorbs near-infrared rays (heat rays) from sunlight, stores and keeps heat, and can be used as clothing in cold regions. In addition, it can be formed into particles or a film by a wet method, and by performing heat treatment after adsorbing copper, near-infrared absorbing particles or near-infrared absorbing films can be obtained.

[0044]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

<Synthesis Example of the Present Invention> [Example 1] (Reaction 1 of chitosan and phenylisothiocyanate) Chitosan dispersed in 6 ml of deionized water (a purified product of Kimitsu Chemical Co., Ltd., degree of deacetylation: approx. 80%, viscosity 5-2
0 mPa · s) To 0.5 g, 4 ml of a 10% aqueous acetic acid solution was added to neutralize free D-glucosamine constituent units,
After complete dissolution, the mixture was diluted with 40 ml of methanol. Next, 10 ml of a methanol solution of phenylisothiocyanate in an equivalent amount to the free D-glucosamine structural unit was used.
And stirred at 60 ° C. for 2 hours.
After adding 00 ml, the mixture was stirred at room temperature overnight. After removing the supernatant, 400 ml of acetone was added, and the mixture was stirred at room temperature for one day. After filtration, washing with acetone, washing with ether,
Dried over phosphorus pentoxide in a desiccator. (Yield 0.77
g) The infrared absorption spectrum of the product is shown in FIG. 1, and for comparison, the infrared absorption spectrum of the raw material chitosan is shown in FIG. The infrared absorption spectrum of the product was 1548 cm
^-1, strong absorption due to thiourea group 1499Cm ^-1 is, 748 cm ^-1, absorption of the aromatic ring is observed at 696 cm ^-1. These are absorptions not found in the infrared absorption spectrum of chitosan. Elemental analysis of the product was N; 9.30.
%, C; 52.04%, H; 5.40%, and N- of formula (1)
Calculated values when the acetyl-D-glucosamine unit is 20% and the N-phenylthiocarbamoyl-D-glucosamine unit of the formula (3) is 80% (N: 9.22%, C: 51.66%,
H; 5.24%). From the above results, the structure of the product was confirmed.

[Example 2] (Reaction 2 of chitosan and phenylisothiocyanate) Chitosan (Chitosan 10B, manufactured by Katoyoshi Bio Inc.) dispersed in 40 ml of deionized water, deacetylation degree 100%,
To 3.2 g of a viscosity of 50 to 200 mPa · s), 60 ml of a 10% acetic acid aqueous solution was added to neutralize free D-glucosamine structural units, and the mixture was completely dissolved.
ml was added for dilution. Next, 30 ml of a methanol solution of phenylisothiocyanate in an approximately equivalent amount was added to the free D-glucosamine structural unit, and the mixture was stirred at 60 ° C. for 2 hours. Then, 2 l of methanol was added and the mixture was stirred at room temperature overnight. After removing the supernatant, 2 l of acetone was added and the mixture was stirred at room temperature for one day. After filtration, washing with acetone and washing with ether, the resultant was dried with phosphorus pentoxide in a desiccator. (Yield 5.0
g) The infrared absorption spectrum of the product is shown in FIG. 3, and for comparison, the infrared absorption spectrum of the raw material chitosan is shown in FIG. The product had an infrared absorption spectrum of 1544 cm
^-1, strong absorption due to thiourea group 1497Cm ^-1 is, 748 cm ^-1, absorption of the aromatic ring is observed at 690 cm ^-1. These are absorptions not found in the infrared absorption spectrum of chitosan. Elemental analysis of the product was N; 9.90.
%, C: 52.38%, H: 5.25%, and N- of formula (3)
Phenylthiocarbamoyl-D-glucosamine unit 10
Calculated value assuming 0% (N; 9.80%, C; 52.70%,
H; 5.07%). From the above results, the structure of the product was confirmed.

Example 3 (Reaction 3 of Chitosan and Phenylisothiocyanate 3) Chitosan (a purified product of Kimitsu Chemical Co., Ltd., deacetylation degree: about 80%, viscosity: 5 to 20 mPa · s) was added to 1.0 g. Free D
-15 ml of 10% acetic acid aqueous solution was added to neutralize the glucosamine structural unit, and after complete dissolution, methanol 6
0 ml was added for dilution. Next, 10 ml of a methanol solution of about 7/8 equivalent of phenylisothiocyanate was added to the free D-glucosamine structural unit, and the mixture was stirred at 60 ° C. for 2 hours. Then, 300 ml of methanol was added and the mixture was stirred at room temperature overnight. . After removing the supernatant, 400 ml of acetone was added, and the mixture was stirred at room temperature for one day. After filtration, washing with acetone and washing with ether, the resultant was dried with phosphorus pentoxide in a desiccator. (Yield 1.55 g) The infrared absorption spectrum of the product is shown in FIG. The infrared absorption spectrum of the above product shows 1560 cm ⁻¹ , 1545 cm
^The strong absorption attributable to the thiourea group is 749 c
Absorption of an aromatic ring is observed at m ⁻¹ and 696 cm ⁻¹ . These are absorptions not found in the infrared absorption spectrum of chitosan. The absorption at 1702 cm ^{−1 is} the absorption of acetate of the unreacted amino group. Elemental analysis of the product was N; 8.90.
%, C: 50.63%, H: 5.70%, and N- of formula (1)
Calculated value when the acetyl-D-glucosamine unit is 20%, the D-glucosamine unit of the formula (2) is 10%, and the N-phenylthiocarbamoyl-D-glucosamine unit of the formula (3) is 70% (N; 9.12%) , C: 50.89%, H: 5.35%)
And almost match. From the above results, the structure of the product was confirmed.

Example 4 (Reaction 4 of chitosan and phenylisothiocyanate) Chitosan (Chitosan 10B, manufactured by Katoyoshi Bio Inc.) dispersed in 6 ml of deionized water, degree of deacetylation 100%, viscosity 50 to 200 mPa · s) 1.0 g of a 10% aqueous acetic acid solution to neutralize free D-glucosamine structural units
After adding 4 ml and completely dissolving, methanol 60 ml
For dilution. Next, about 2/3 equivalent amount of phenylisothiocyanate methanol solution (10 ml) was added to the free D-glucosamine structural unit, and the mixture was stirred at 60 ° C. for 2 hours. Then, methanol (300 ml) was added and the mixture was stirred at room temperature overnight. . After removing the supernatant, 400 ml of acetone was added, and the mixture was stirred at room temperature for one day. After filtration, washing with acetone and washing with ether, the resultant was dried with phosphorus pentoxide in a desiccator.
(Yield 1.50 g) The infrared absorption spectrum of the product is shown in FIG. The infrared absorption spectrum of the above product shows 1560 cm ⁻¹ , 1544 cm
^The strong absorption attributable to the thiourea group at ^-1 was 756 c
Absorption of an aromatic ring is observed at m ⁻¹ and 697 cm ⁻¹ . These are absorptions not found in the infrared absorption spectrum of chitosan. The absorption at 1702 cm ^{−1 is} the absorption of acetate of the unreacted amino group. Elemental analysis of the product was N; 9.24.
%, C: 50.30%, H: 5.65%, and D- of formula (2)
This is almost the same as the calculated value (N: 9.45%, C: 50.13%, H: 5.46%) when the glucosamine unit is 33% and the N-phenylthiocarbamoyl-D-glucosamine unit in the formula (3) is 67%. From the above results, the structure of the product was confirmed.

Example 5 (Reaction between chitosan and p-methylphenylisothiocyanate) The same procedure as in Example 1 was carried out except that phenylisothiocyanate was replaced with p-methylphenylisothiocyanate. (Yield 0.76 g) The infrared absorption spectrum of the product is shown in FIG. As in Example 1, absorption of a thiourea group was confirmed at 1561 cm ^-1 and 1514 cm ^-1 . The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 6] (Reaction of chitosan with p-chlorophenylisothiocyanate) The procedure of Example 1 was repeated except that phenylisothiocyanate was replaced with p-chlorophenylisothiocyanate. (Yield 0.76 g) The infrared absorption spectrum of the product is shown in FIG. In the same manner as in Example 1 1544cm ^-1, and absorption of the thiourea group in 1492cm ^-1, confirming the absorption of the aromatic ring in the 750 cm ^-1. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 7] (Reaction of chitosan with p-nitrophenylisothiocyanate) The procedure of Example 1 was repeated except that phenylisothiocyanate was replaced with p-nitrophenylisothiocyanate. (Yield 0.77 g) The infrared absorption spectrum of the product is shown in FIG. In the same manner as in Example 1 1546 cm ^-1, absorption of thiourea groups 1509cm ^-1, 1338cm ^-1, and absorption of the nitro group to 853 cm ^-1 74
Absorption of the aromatic ring was confirmed at 8 cm ^-1 . The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

Example 8 (Reaction between chitosan and α-naphthyl isothiocyanate) The same procedure as in Example 1 was carried out except that phenyl isothiocyanate was replaced with α-naphthyl isothiocyanate. (Yield 0.79 g) The infrared absorption spectrum of the product is shown in FIG. 1544cm
It confirmed the absorption of the aromatic ring to absorb and 776 cm ^-1 thiourea groups to ^-1. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 9] (Reaction 1 of chitosan and benzoyl isothiocyanate) The procedure of Example 1 was repeated except that phenyl isothiocyanate was replaced with benzoyl isothiocyanate.
(Yield 0.77 g) The infrared absorption spectrum of the product is shown in FIG. 1538cm
⁻¹ , absorption of thiourea group and 792 cm ⁻¹ , 715 cm ⁻¹
The absorption of the aromatic ring was confirmed. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 10] (Reaction 2 between chitosan and benzoyl isothiocyanate) The same procedure as in Example 2 was carried out except that phenyl isothiocyanate was replaced with benzoyl isothiocyanate.
(Yield 5.1 g) The infrared absorption spectrum of the product is shown in FIG. 1545cm
⁻¹ , 1525 cm ⁻¹ absorption of thiourea group and 792 c
The absorption of the aromatic ring was confirmed at m ^-1 and 715 cm ^-1 . The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 11] (Reaction between chitosan and benzyl isothiocyanate) The same procedure as in Example 1 was carried out except that phenyl isothiocyanate was replaced with benzyl isothiocyanate.
(Yield 0.71 g) The infrared absorption spectrum of the product is shown in FIG. Example 1
Similarly, 1562 cm and ^{- 1} to absorb and 740 cm thiourea group
Absorption of an aromatic ring was confirmed at ^-1 and 700 cm ^-1 . The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 12] (Reaction of chitosan and allyl isothiocyanate) The same procedure as in Example 1 was carried out except that phenyl isothiocyanate was replaced with allyl isothiocyanate. (Yield 0.65 g) The infrared absorption spectrum of the product is shown in FIG. 1564cm
^{At -1} , absorption of a thiourea group was confirmed. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 13] (Reaction between chitosan and ethoxycarbonyl isothiocyanate) The procedure of Example 1 was repeated except that phenylisothiocyanate was replaced with ethoxycarbonylisothiocyanate. (Yield 0.75 g) The infrared absorption spectrum of the product is shown in FIG. 1546cm
⁻¹ , absorption of thiourea group, 1720 cm ⁻¹ , 1243 cm ⁻¹
The absorption of the ester group was confirmed. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

[Example 14] (Reaction between chitosan and n-butyl isothiocyanate) A reaction was carried out in the same manner as in Example 1 except that phenyl isothiocyanate was replaced with n-butyl isothiocyanate.
(Yield 0.65 g) The infrared absorption spectrum of the product is shown in FIG. 1563cm
^{At -1} , absorption of a thiourea group was confirmed. The elemental analysis value of the product almost coincided with the calculated value at the time of quantitative reaction.

<Example of Adsorption of Chitosan Derivative of the Present Invention and Metal Ion> [Example 15] A gel obtained by swelling 0.1 g of the chitosan derivative synthesized in Examples 1 and 9 with 20 ml of dimethyl sulfoxide was used. 20ml of various heavy metal ion aqueous solutions
(1 mmol / l) and adsorbed for 24 hours. Filtration was performed, and the resultant was sufficiently washed with water to obtain various metal ion-adsorbed chitosan derivatives. Table 1 shows the color and the adsorption capacity of the gel.

[0060]

[Table 1]

The adsorption ability was comprehensively judged from the adsorption rate after mixing the chitosan derivative and the metal ion, the degree of coloring of the gel, and the color of the supernatant. A: The adsorption speed is very fast. The gel is colored and the supernatant is colorless. ：: The adsorption rate is slow, but the gel is colored. Δ: The adsorption rate is slow, and the gel is slightly colored. X: No change.

<Method for Forming Copper-Adsorbed Chitosan Derivative of the Present Invention> [Example 16] Chitosan dispersed in 60 ml of deionized water (a purified product of Kimitsu Chemical Co., Ltd., degree of deacetylation 80%)
To 3.2 g, 40 ml of a 10% aqueous acetic acid solution was added to neutralize the free D-glucosamine constituent unit, and after complete dissolution, the mixture was diluted with 200 ml of methanol. next,
30 ml of a methanol solution of phenylisothiocyanate almost equivalent to the amount of the free D-glucosamine structural unit was added, and 6
After stirring at 0 ° C. for 2 hours, the temperature is returned to room temperature, and the caliber is reduced to 0.
The reaction solution was set in a syringe with a 7 mm injection needle, and dropped into acetone to obtain particles of a chitosan derivative. After sufficiently washing with acetone, water was added to perform replacement, and an aqueous solution of copper chloride was added. After sufficient copper was adsorbed, it was taken out, washed sufficiently with water, and freeze-dried to obtain green particles of 10 to 100 μm of the copper-adsorbed chitosan derivative.

Example 17 After dissolving chitosan in the same manner as in Example 16, 30 ml of a methanol solution of phenylisothiocyanate was added in an amount approximately equal to the amount of the free D-glucosamine structural unit, followed by stirring at 60 ° C. for 2 hours. After returning to room temperature, the reaction solution was set in a syringe with a 0.7 mm diameter injection needle, and extruded into a 1: 1 mixed solvent of an aqueous sodium hydroxide solution and methanol to obtain fibers of a chitosan derivative. After washing sufficiently with methanol, water was added for replacement, and an aqueous solution of copper acetate was added. After the copper was sufficiently adsorbed, it was taken out, washed sufficiently with water, and air-dried to obtain a green fiber of about 100 μm of the copper-adsorbed chitosan derivative.

Example 18 After chitosan was dissolved in the same manner as in Example 16, approximately 30 ml of a methanol solution of phenylisothiocyanate was added to the free D-glucosamine structural unit, and the mixture was stirred at 60 ° C. for 2 hours. After performing, the temperature was returned to room temperature, the reaction solution was cast on a glass plate, and acetone was added in a Petri dish to obtain a film of a chitosan derivative.
After sufficiently washing with acetone, water was added to perform replacement, and an aqueous solution of copper sulfate was added. After the copper was sufficiently adsorbed, it was taken out, sufficiently washed with water, and naturally dried to obtain a light green film of the copper-adsorbed chitosan derivative.

<Example of Near Infrared Absorber of the Present Invention> [Example 19] The powder of the chitosan derivative synthesized in Example 1 and the powder of copper stearate were mixed with copper for the thiourea residue of the chitosan derivative. Uniformly mixed in a 2: 1 molar ratio,
The mixture was heated and melted on a filter plate at 180 ° C. for 1 minute. The obtained powder was recorded with a self-recording spectrophotometer (Shimadzu Corporation)
The reflection spectrum was measured in the range of 240 nm to 2500 nm using UV-3100 (manufactured by Hitachi, Ltd.) and a multipurpose large sample room (MPC-3100) with a built-in integrating sphere. For comparison, only the chitosan derivative powder and the copper stearate powder were similarly heated and melted on a filter paper at 180 ° C. for 1 minute on a filter paper, and the reflection spectrum was measured. FIG.
As shown in the figure, the heated melt of the chitosan derivative and copper stearate (C) absorbed in the entire near infrared region, but the chitosan derivative alone (A) and the copper stearate alone (B) absorbed in the near infrared region. There was no.

Example 20 0.1 g of the chitosan derivative powder synthesized in Example 1 was added to dimethyl sulfoxide 20
After swelling and dissolving in 20 ml, 20 ml of acetone solution of copper monobutyl phthalate was added. The precipitated gel was filtered, washed sufficiently with acetone, and dried in a desiccator over phosphorus pentoxide to obtain a copper-adsorbed chitosan derivative. As shown in FIG.
The reflection spectrum of the powder (E) after heating at 120 ° C. for 5 minutes was measured in the same manner as in Example 17. The powder also had near-infrared absorptivity. Did not have near infrared absorption.

Example 21 The thin green film of the copper-adsorbed chitosan derivative obtained in Example 18 was heated at 150 ° C. for 2 minutes to obtain a dark green film.

FIG. 19 shows transmission spectra of the above three types of films (chitosan derivative before copper adsorption, unheated chitosan derivative after copper adsorption, and heated chitosan derivative after copper adsorption).
The unheated chitosan derivative film alone (F) and the unheated copper-adsorbed chitosan derivative film (G) did not absorb near-infrared light, but the heated copper-adsorbed chitosan derivative film (H) absorbed over the entire near-infrared region. did.

[Comparative Examples 1 to 3] The following compounds and copper compounds were mixed and heated, but none of them had near-infrared absorptivity. Chitin (Chitin EX manufactured by Katoyoshi Co., Ltd.) Chitosan (Chitosan 10B manufactured by Katoyoshi Co., Ltd., deacetylation degree 100%) Chitosan (Kimitsu Chemical Co., Ltd. purified product, deacetylation degree 8)
0%)

[0070]

Industrial Applicability The novel chitosan derivative having a thiourea group introduced therein can be used not only as a metal ion adsorbent, but also a chitosan derivative having a specific thiourea structure can be mixed with a copper compound and heated. By doing so, it becomes a near infrared absorber.

Further, the chitosan derivative of the present invention can be formed into a molded product such as a particle, fiber or film by a wet method, can adsorb copper as it is in water, and can be subjected to near-infrared absorption molding by heat treatment. The body can be manufactured.

[Brief description of the drawings]

FIG. 1 is an FT-IR spectrum of a compound synthesized in Example 1.

Fig. 2 Raw material chitosan (degree of deacetylation: about 80%)
FT-IR spectrum of

FIG. 3 is an FT-IR spectrum of the compound synthesized in Example 2.

FIG. 4 Raw material chitosan (degree of deacetylation: 100%)
FT-IR spectrum of

FIG. 5 is an FT-IR spectrum of the compound synthesized in Example 3.

FIG. 6 is an FT-IR spectrum of the compound synthesized in Example 4.

FIG. 7 is an FT-IR spectrum of the compound synthesized in Example 5.

FIG. 8 is an FT-IR spectrum of the compound synthesized in Example 6.

FIG. 9 is an FT-IR spectrum of the compound synthesized in Example 7.

FIG. 10 is an FT-IR spectrum of the compound synthesized in Example 8.

FIG. 11 is an FT-IR spectrum of the compound synthesized in Example 9.

FIG. 12 is an FT-IR spectrum of the compound synthesized in Example 10.

FIG. 13 is an FT-IR spectrum of the compound synthesized in Example 11.

FIG. 14 is an FT-IR spectrum of the compound synthesized in Example 12.

FIG. 15 is an FT-IR spectrum of the compound synthesized in Example 13.

FIG. 16 is an FT-IR spectrum of the compound synthesized in Example 14.

FIG. 17 shows absorption spectra of the chitosan derivative, copper stearate and the mixture of Example 16 after heating.

FIG. 18 shows absorption spectra of the precipitate obtained in Example 17 before and after heating. D: Before heating, E: After heating.

FIG. 19 shows absorption spectra of a film obtained in Example 18 and a copper adsorption film before and after heating.

[Explanation of symbols]

 A chitosan derivative B copper stearate C chitosan derivative: copper stearate = 2: 1 F chitosan derivative before heating G copper-adsorbed chitosan derivative before heating H copper-adsorbed chitosan derivative after heating

Claims (6)

(57) [Claims] 1. A chitosan derivative containing X structural units represented by the formula (1), Y structural units represented by the formula (2), and Z structural units represented by the formula (3). In the formula, a = X / (X + Y + Z) × 100 = 0 to 30 (mol%) b = Y / (X + Y + Z) × 100 = 0 to 70 (mol%) c = Z / (X + Y + Z) × 100 = 30 to 100 ( (Mol%) (The total of the molar percentages is a + b + c = 100%, provided that X and Y are integers of 0 or more, Z represents an integer of 1 or more, and X + Y + Z ≧ 2). Chitosan derivative. Embedded image (Wherein, R1 is a substituted or unsubstituted carbon number 6)
~ 30 aryl groups, substituted or unsubstituted C6-C3
0 benzoyl group, substituted or unsubstituted 7 to 30 carbon atoms
An aralkyl group, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted 2 to 20 carbon atoms
Represents an alkoxycarbonyl group. ) 2. The chitosan derivative according to claim 1, represented by formula (4), wherein R1 in formula (3) is a phenyl group. Embedded image 3. R3 of the formula (3) is a benzoyl group.
The chitosan derivative according to claim 1, represented by formula (5). Embedded image 4. R1 is the formula (6) or the formula (7),
The chitosan derivative according to claim 1, wherein a composition for a near-infrared absorber in which copper ions are adsorbed to a thiourea residue at a molar ratio of 5: 1 to 1: 1 or a copper compound in a molar ratio of 5: A composition for a near-infrared absorber mixed in a ratio of 1 to 1: 1. Embedded image (However, R2 to R6 independently of one another have 1 to 1 carbon atoms.
4 represents a lower alkyl group, a lower alkoxy group having 1 to 4 carbon atoms, a nitro group, a cyano group, a halogen atom or a hydrogen atom. ) 5. A composition for a near-infrared absorbing agent in which a copper ion is adsorbed to a chitosan derivative according to claim 2 with respect to a thiourea residue at a molar ratio of 5: 1 to 1: 1 or a copper compound in a molar ratio. A composition for a near-infrared absorber mixed in a ratio of 5: 1 to 1: 1. 6. A near-infrared absorbing agent obtained by heating the composition for a near-infrared absorbing agent according to claim 4 or 5.