JPH07316202A - Preparation of chitin sponge, chitin paper, and chitin film - Google Patents

Abstract

PURPOSE:To obtain a chitin sponge without changing the molecular weight and degree of deacetylation of chitin by dissolving the chitin in a solvent, that is easy and safe to handle, followed by coagulation and regeneration. CONSTITUTION:Chitin is dissolved in a mixed solvent composed of an alcohol, such as methyl alcohol or ethyl alcohol, and a calcium or magnesium halide to obtain a chitin solution. The solution is coagulated and regenerated in a liquid coagulant made up of water, ethylene glycol, an equeous citric acid solution, or an aqueous sodium ethylenediamene tetraacetate solution alone or a mixture thereof to obtain a coagulation. The coagulation is freeze-dried.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel method for producing chitin sponge, chitin paper, and chitin film as chitin moldings, which moldings have low immunogenicity, biocompatibility, and bioavailability inherent in chitin. Since it has properties such as degradability, it can be preferably used in a wide range of fields such as biomaterials, medical materials, agricultural materials, animal feed, and other industrial materials.

[0002]

BACKGROUND OF THE INVENTION Chitin is a natural polysaccharide in which N-acetyl-D-glucosamine is 1,4-β-bonded, and is used in crustaceans such as crabs and shrimps, beetles of insects such as beetles and grasshoppers, and fungi. It is a polysaccharide that exists in organisms in the natural world such as cell walls, and is a valuable resource with an abundance comparable to that of cellulose. Chitin has an acetamide group in the molecule and has a strong hydrogen bond between the acetamide group and the hydroxyl group, so that it has high chemical resistance and is difficult to dissolve in an organic solvent. For this reason, many solvents have been disclosed as solvents for dissolving chitin. That is, hexafluoroacetone, hexafluoroisopropanol, formic acid-dichloroacetic acid-based, dimethylcetoamide-lithium-based, trichloroacetic acid-chlorinated hydrocarbon-based polyhalogenated hydrocarbon-halogenated carboxylic acid (JP-A-63-117002). No.), N-methylpyrrolidone-lithium system (JP-A-58-134101).
No.) etc. have been proposed. With these conventional solvents,
When the degree of deacetylation is 30% or less, it is difficult to dissolve, and in order to measure the dissolution, it is necessary to repeat the operation of freezing and heating to cause the dissolution, and there is a drawback that the molecular weight is lowered.
Further, the conventional solvent is difficult to handle from the viewpoint of safety and hygiene, and there is a high risk that the operator may be adversely affected by inhalation or contact.
The Applicant has addressed this by using a degree of deacetylation of 30
%, The solvent which is easily dissolved and is safe to handle was examined, and as a chitin solution, Japanese Patent Application No. 35359/1992.
Filed No. 5.

Conventionally known chitin sponges are
"Proceedings of the First International Conferenc
e on Chitin / Chitosan) ", page 300, as" D. chitin sponges ", sodium sulfate is mixed with chitin viscose obtained by a method according to cellulose viscose, and the mixture is coagulated in water. A method for obtaining chitin sponge by regenerating sodium sulfate at the same time as regeneration is described. Also, JP-A-63-18670
No. 1 discloses that chitin is dissolved in a mixture of trichloroacetic acid and a halogenated hydrocarbon, a mixture of lithium chloride and N-methylpyrrolidone, etc., and a water-soluble polymer is added to the solution.
A method for obtaining a chitin sponge by coagulating and regenerating in water, an alcohol solution, a ketone solution, or an alkaline solution thereof, at the same time eluting a water-soluble polymer substance, and then freeze-drying the mixture is disclosed.

Regarding the conventionally known chitin paper, JP-A-60-231900 discloses that chitin and its derivatives are dissolved in formic acid, trichloroacetic acid and the like, and then the solution is extruded into a coagulating bath through a spinning nozzle to produce fibers. A method is disclosed in which after being formed into a shape, it is cut, and the short fibers are dispersed in water to make paper. Further, in Japanese Examined Patent Publication No. 4-6384, β-chitin such as squid chitin is suspended in water and vigorously stirred or freeze-thawed to give a gel, which is dispersed in water to make paper. A method of doing so is disclosed.

Conventionally known chitin films are:
U.S. Pat. No. 2,168,374 discloses a method in which chitin is prepared into chitin xanthate and then coagulated and regenerated in a sulfuric acid acid bath to obtain a chitin film.
JP-A-145813 discloses that chitin is dissolved in a mixed solvent of trichloroacetic acid and methylene chloride, and then spun from a T-die into a coagulation bath of organic ketones, chlorinated hydrocarbons, alcohols, amides, etc., and coagulated and regenerated. However, a method for obtaining a chitin film is disclosed.

[0006]

DISCLOSURE OF THE INVENTION The present invention has the disadvantage of the chitin-dissolving solvents disclosed in the prior art, that is, when these solvents have a deacetylation degree of about 30% or less, they are difficult to dissolve and are reactive. Because of its high molecular weight, it is likely to cause molecular chain scission and deacetylation, so that the raw material chitin and the degree of deacetylation, and the high purity chitin sponge without change in molecular weight, chitin paper,
It is a solution to the drawbacks such as difficulty in obtaining a chitin film. Furthermore, there is no need for a complicated process such as obtaining a chitin molded body after obtaining chitin viscose,
The step of fiberizing chitin can also be omitted, and a safe solvent is used, so the handling danger is solved.

[0007]

The present invention provides a chitin solution in which chitin is dissolved in a mixed solvent prepared by adding a calcium halide salt or a magnesium halide salt to an alcohol consisting of methyl alcohol or ethyl alcohol, and A chitin sponge obtained by coagulating and regenerating a coagulated product in water, ethylene glycol, an aqueous solution of citric acid, an aqueous solution of ethylenediaminetetraacetic acid or a mixture thereof to obtain a coagulated product, and then freeze-drying the coagulated product. A method for producing chitin is obtained by dissolving chitin in a mixed solvent obtained by adding a calcium halide salt or a magnesium halide salt to an alcohol consisting of methyl alcohol or ethyl alcohol, and the solution is water, ethylene glycol, an aqueous citric acid solution, Ethylenediamine tetrasodium acetate aqueous solution alone Ku is a coagulation liquid mixing these,
A method for producing chitin paper obtained by dispersing the coagulated product in water after coagulation and regeneration, and a mixed solvent obtained by adding calcium halide or magnesium halide to chitin as an alcohol consisting of methyl alcohol or ethyl alcohol. To obtain a chitin solution dissolved in
This is a method for producing a chitin film obtained by coagulating and regenerating a film in a coagulation liquid of ethylene glycol, an aqueous solution of citric acid and an aqueous solution of ethylenediaminetetraacetic acid, or a mixture thereof, and then drying.

The chitin used in the present invention may be α-chitin derived from crab shell, shrimp shell or β-chitin derived from squid shell, and chitosan obtained by deacetylating chitin is acetylated in an acetic anhydride atmosphere. It is also possible to use acetylated chitin and acetylated chitosan having a deacetylation degree of 30% or less obtained by cyclization, and the molecular weight of chitin is not particularly limited, and it can be completely dissolved in the solvent of the present invention for dissolving chitin. Selected by range.

The alcohol used as a mixed solvent for dissolving chitin is preferably methyl alcohol or ethyl alcohol, and other alcohols are not suitable. The calcium salt or magnesium salt used as a mixture is a halide, preferably calcium chloride.
Dihydrate, calcium bromide ・ Dihydrate, calcium iodide ・
Dihydrate is magnesium chloride as magnesium salt.
Hexahydrate is used. The mixed solvent used in the present invention is preferably saturated.

The chitin content of the chitin solution prepared by stirring and dissolving chitin in the above-mentioned mixed solvent at room temperature may be changed depending on the molecular weight of chitin, but the concentration is within the range of 0.1 to 10% (wt%). It can be decided as appropriate. When a chitin sponge is obtained, a third component such as a pore controlling agent or a softening effect-imparting agent in the chitin solution, a third component such as a pigment for obtaining a chitin paper or a chitin film may be added depending on its use. You may add.

The coagulation liquid used in the present invention is water, ethylene glycol, an aqueous solution of citric acid, an aqueous solution of sodium ethylenediamine tetraacetate (hereinafter referred to as sodium EDTA), or a mixture thereof.

In order to obtain a chitin sponge, the above-mentioned chitin solution is added to a coagulation bath to coagulate and regenerate the chitin, and the coagulated product is thoroughly washed with water and freeze-dried so that pores are developed. A sponge is obtained, and chitin paper is obtained by stirring and dispersing the above-obtained coagulated product in water, dehydrating and drying according to the ordinary papermaking method. In this case, chitin has self-adhesive properties. Since it is not necessary to add a binder material which is a third component such as polyvinyl alcohol used in the case of ordinary papermaking, there is no problem at all in medical applications. The chitin film is obtained by coagulating and regenerating the above-mentioned chitin solution in the form of a film in the above coagulating bath, further thoroughly washing with water, and then drying. For wet molding from a chitin solution, a general method of extruding a film form into a coagulation bath from a T-die or the like is adopted.

[0013]

The present invention will be described in detail below with reference to Examples.
The present invention is not limited to this range. The pore size, the degree of deacetylation of chitin, the molecular weight of chitin and the tensile strength were determined by the following measuring methods.

Pore size The sample was observed with a scanning electron microscope to determine the pore size.

The deacetylation degree sample chitin was finely ground (200 mesh or less), mixed with KBr powder, from the absorbance and 3450 cm ^-1 in 1655 cm ^-1 in FT-IR spectrophotometer, was estimated by the following equation.

[0016]

[Equation 1]

Molecular weight of chitin A sample was dissolved in a mixed saturated solvent of calcium chloride and methyl alcohol, the reduced viscosity was calculated with an Ubbelohde viscometer, and the molecular weight was calculated from the following formula.

[0018]

[Equation 2]

Tensile strength of chitin paper and chitin chitin film A sample of 10 mm x 20 mm was taken, the sample was attached to Tensilon and pulled at a speed of 100 mm / min. I asked.

Example 1 About 400 g of calcium chloride dihydrate was added to 400 ml of methyl alcohol and heated under reflux for about 3 hours. After cooling the solution to room temperature, the insoluble matter was removed by filtration to obtain a saturated mixed solvent of calcium chloride and methyl alcohol. Chitin from red snow crab (80mesh p
ass, deacetylation degree 13.0%, molecular weight 350,00
0) 3.0 g was added to 300 ml of the above mixed solvent, dissolved by stirring at room temperature, and insoluble matter was removed by filtration to obtain a transparent and viscous chitin solution. The obtained chitin solution is 10 cm x 10 c
After casting on a glass plate of m with a thickness of 1.5 mm, the glass plate was immersed in water for 1 hour to coagulate and regenerate.
It was peeled from the glass plate and thoroughly washed with water. The regenerated product of chitin was rapidly frozen in liquid nitrogen and then vacuum dried at room temperature to obtain a chitin sponge. The obtained chitin sponge had a thickness of 1.2 mm and a pore size of 0.25 μm on average.
The degree of deacetylation of chitin in the sponge was 12.9% and the molecular weight was 350,000, which was almost the same as the starting material.

Example 2 The chitin solution obtained in the same manner as in Example 1 was applied to a 10 cm × 10 cm glass plate at 1.0.
After casting to a thickness of mm, the glass plate was immersed in a mixed solution of a 5% sodium citrate aqueous solution and ethylene glycol (mixing ratio 1/1) for 1 hour to coagulate and regenerate. It was peeled from the glass plate and thoroughly washed with water. The regenerated product of chitin was rapidly frozen in liquid nitrogen and then vacuum dried at room temperature to obtain a chitin sponge. The obtained chitin sponge had a thickness of 0.8 mm and a pore diameter of 0.25 μm on average, and the degree of deacetylation of chitin in the sponge was 13.0%.
The molecular weight was 350,000, which was almost the same as the raw material.

Example 3 300 m of a saturated mixed solvent of calcium chloride and methanol obtained in the same manner as in Example 1.
Chitosan (molecular weight 20,000, deacetylation degree 8)
Regenerated chitin (molecular weight 2) obtained by acetylating 0%)
30 g (1,000, deacetylation degree 5%) was dissolved to obtain a transparent and viscous chitin solution. 10 cm x the chitin solution
After casting on a 10 cm glass plate with a thickness of 1.5 mm,
A chitin sponge was obtained by immersing in a 5% sodium EDTA aqueous solution for 1 hour, peeling from glass, thoroughly washing with water, slowly freezing in a freeze dryer (-35 ° C / 2 hours), and vacuum drying. The thickness of the obtained chitin sponge is 1.2 mm,
The average pore size was 0.2 μm, the degree of deacetylation of sponge chitin was 4.9%, and the molecular weight was 20,000, which was almost the same as the starting material.

Example 4 About 400 g of calcium bromide dihydrate was added to 400 ml of ethyl alcohol and heated under reflux for about 3 hours. The solution was cooled to room temperature and the insoluble material was removed by filtration to give a saturated mixed solvent of calcium bromide and ethyl alcohol. Chitin 1.50 from red snow crab
g (80mesh pass, deacetylation degree 13%, molecular weight 35
10,000) was dissolved in 300 ml of the above mixed solvent and the insoluble matter was removed by filtration to obtain a transparent and viscous chitin solution. 1.0 mm of the chitin solution on a glass plate of 10 cm × 10 cm
After casting to thickness of 5%, gently add 1% to 5% citric acid solution.
Let it soak for an hour. The resulting coagulated regenerated product was peeled from the glass plate, thoroughly washed with water, and then freeze-dried under the same conditions as in Example 2 to obtain a chitin sponge. The thickness of this chitin sponge is 0.6 mm, the average pore size is 0.5 μm, the degree of deacetylation of chitin in the sponge is 13.2%, the molecular weight is 350,
At 000, there was almost no change with the raw material.

Example 5 The chitin solution obtained in the same manner as in Example 4 was applied to a 10 cm × 10 cm glass plate at 1.0.
After casting to a thickness of mm, the glass plate was immersed in a 10% ethylene glycol aqueous solution for 1 hour to coagulate and regenerate. The coagulated regenerated product was peeled from the glass plate, thoroughly washed with water, and freeze-dried to obtain a chitin sponge. The obtained chitin sponge has a thickness of 0.7 mm and a pore size of 0.4 on average.
μm, the degree of deacetylation of sponge chitin is 13.0
%, And the molecular weight was 340,000, which was almost the same as the raw material.

Comparative Example 1 3 g of chitin used in Example 1
Was dissolved in 100 ml of a mixed solvent of trichloroacetic acid and methylene chloride (mixing ratio 1/1) with stirring at 5 ° C. to obtain a chitin solution. The chitin solution was cast on a glass plate in the same manner as in Example 1 and immersed in ethanol for 1 hour to coagulate and regenerate. The coagulated regenerated product was peeled from the glass plate, thoroughly washed with water, and then freeze-dried in the same manner as in Example 1 to obtain a chitin sponge. The thickness of the obtained chitin sponge is 1.5m.
m, the average pore diameter was 0.2 μm, the degree of deacetylation of sponge chitin was 23.0%, the molecular weight was 150,000, and the degree of deacetylation was high, and the decrease in molecular weight was remarkable.

Example 6 A transparent and viscous chitin solution was obtained in the same manner as in Example 1. 100 ml of the chitin solution was gently poured into 500 ml of water with stirring to coagulate and regenerate. The precipitate formed is collected by filtration, washed thoroughly with water, and then 200 ml.
Dispersed in water. The dispersion was poured into a filter equipped with filter paper and suction filtered. 1 at room temperature after removing excess water
After drying overnight, chitin paper was obtained. The resulting chitin paper had a basis weight of 58.3 g / m ² and a tensile strength of 1.75 g. The degree of deacetylation of chitin in chitin paper is 13.
The content was 3% and the molecular weight was 340,000, which was almost unchanged from the raw material.

Example 7 100 ml of the chitin solution obtained in the same manner as in Example 6 was gently poured into 500 ml of 5% sodium EDTA aqueous solution under stirring to coagulate and regenerate, and the resulting precipitate was collected by filtration. After thoroughly washing the precipitate with water, 200
Dispersed in ml water. The dispersion was poured into a filter equipped with filter paper and suction filtered. After removing excess water, it was dried overnight at room temperature to obtain a chitin paper. The obtained chitin paper had a basis weight of 60.3 g / m ² and a tensile strength of 1.55 g. The degree of deacetylation of chitin in chitin paper is 1
The molecular weight was 3.0% and the molecular weight was 340,000, which was almost the same as the raw material.

Example 8 Saturated mixed solvent 3 of calcium chloride and methyl alcohol obtained in the same manner as in Example 6
30 g of regenerated chitin (molecular weight 21,000, deacetylation degree 5%) obtained by acetylating chitosan (molecular weight 20,000, deacetylation degree 80%) was dissolved in 00 ml to give a transparent and viscous chitin solution. Obtained. 5% of the chitin solution
Pour gently into the sodium EDTA aqueous solution with stirring,
The resulting precipitate was collected by filtration. The precipitate was thoroughly washed with water, filtered with a filter paper, and dried at 50 ° C. for 5 hours to obtain a chitin paper. The obtained chitin paper had a basis weight of 110.5 g / m ² , a tensile strength of 3.55 g, a chitin deacetylation degree of 4.9%, and a molecular weight of 20,000, which was unchanged from the raw material.

Example 9 In the same manner as in Example 4, a saturated mixed solvent of calcium bromide and ethyl alcohol was obtained.
3.0 g of chitin derived from red snow crab (80 mesh pass, deacetylation degree 13%, molecular weight 350,000) was dissolved in 300 ml of the above mixed solvent, and insoluble matter was removed by filtration to obtain a transparent and viscous chitin solution. It was 50 ml of the solution is 300 m
It was gently poured into 1% of 5% citric acid solution under stirring to coagulate and regenerate, and the generated precipitate was collected by filtration. The precipitate was thoroughly washed with water, filtered on filter paper, and dried overnight at room temperature to obtain chitin paper.
The obtained chitin paper had a basis weight of 58.3 g / m ² and a tensile strength of 1.45 g. The degree of deacetylation of chitin in the chitin paper was 13.2% and the molecular weight was 350,000, and both were almost the same as the raw materials.

Example 10 50 ml of the chitin solution obtained in the same manner as in Example 8 was poured into 300 ml of 10% ethylene glycol aqueous solution with stirring to coagulate and regenerate, and the resulting precipitate was collected by filtration and washed thoroughly with water at room temperature. And dried overnight to obtain chitin paper. The weight of the obtained chitin paper is 63.8 g / m ^2.
The tensile strength was 2.65 g. The degree of deacetylation of chitin in chitin paper is 13.0% and the molecular weight is 34.
At 10,000, there was almost no change from the raw material.

<< Comparative Example 2 >> 3 g of chitin used in Example 6
Was dissolved in 100 ml of a mixed solvent of trichloroacetic acid and methylene chloride (mixing ratio 1/1) at 5 ° C. to obtain a chitin solution. The chitin solution was gently poured into 300 ml of ethyl alcohol under stirring to coagulate and regenerate, and the resulting precipitate was collected by filtration, washed thoroughly with water, and dried overnight at room temperature to obtain a chitin paper. The obtained chitin paper has a basis weight of 58.6 g / m ² , a tensile strength of 0.8 g, and a chitin deacetylation degree of 23.
0%, molecular weight 150,000, low tensile strength,
The degree of deacetylation was high and the decrease in molecular weight was remarkable.

Example 11 A transparent and viscous chitin solution was obtained in the same manner as in Example 1. 1 of the obtained chitin solution
After cast on a 0 cm × 10 cm glass plate with a thickness of 15 mm, the glass plate was immersed in water for 1 hour to coagulate and regenerate. It was peeled from the glass plate, thoroughly washed with water, and then air-dried at room temperature overnight to obtain a chitin film. The thickness of the obtained chitin film was 25 μm, the tensile strength was 1.75 kg, and the degree of deacetylation of chitin in the film was 1.
2.9%, the molecular weight was 350,000, which was almost the same as the raw material.

<< Example 12 >> A chitin solution obtained in the same manner as in Example 11 was applied to a glass plate of 10 cm × 10 cm.
After casting to a thickness of 5 mm, the glass plate was immersed in a 5% sodium citrate aqueous solution and ethylene glycol (mixing ratio 1/1) for 1 hour to coagulate and regenerate. It was peeled from the glass plate, thoroughly washed with water, and then dried with hot air at 50 ° C. for 5 hours to obtain a chitin film. The obtained chitin film has a thickness of 30 μm and a tensile strength of 2.0 k.
g, the degree of deacetylation of film chitin is 13.0%,
The molecular weight was 350,000, which was almost the same as the raw material.

Example 13 Obtained by acetylating 300 ml of a saturated mixed solvent of calcium chloride and methyl alcohol obtained in the same manner as in Example 11 with chitosan (molecular weight 20,000, deacetylation degree 80%). 30 g of regenerated chitin (molecular weight 21,000, deacetylation degree 5%) was dissolved to obtain a transparent and viscous chitin solution. The chitin solution was cast on a glass plate of 10 cm × 10 cm to a thickness of 15 mm, immersed in a 5% sodium EDTA aqueous solution for 1 hour, peeled from the glass plate, thoroughly washed with water, and dried overnight at room temperature to give a chitin film. Got The thickness of the obtained chitin film was 40 μm, the tensile strength was 3.55 kg, the degree of deacetylation of chitin in the film was 4.9%, and the molecular weight was 2
At 10,000, there was almost no change from the raw material.

Example 14 A transparent and viscous chitin solution was obtained in the same manner as in Example 4. This chitin solution is 10 cm
After being cast on a glass plate of 10 cm in thickness of 10 mm, it was coagulated and regenerated by gently immersing it in a 5% citric acid solution for 1 hour. It was peeled from the glass plate, thoroughly washed with water, and dried in the same manner as in Example 12 to obtain a chitin film. The thickness of this chitin film is 15 μm, and the tensile strength is 1.35.
kg, the degree of deacetylation of chitin in the film is 13.2
%, The molecular weight was 350,000, and there was almost no change with the raw material.

Example 15 The chitin solution obtained in the same manner as in Example 14 was applied to a glass plate of 10 cm × 10 cm.
After casting with a thickness of 5 mm, the glass plate was immersed in a 10% ethylene glycol aqueous solution for 1 hour to coagulate and regenerate. It was peeled from the glass plate, washed thoroughly with water, and then dried overnight at room temperature to obtain a chitin film. The obtained chitin film has a thickness of 35 μm and a tensile strength of 2.0.
4 kg, the degree of deacetylation of the film chitin is 13.0
%, The molecular weight was 340,000, and both were almost unchanged from the raw materials.

Comparative Example 3 Chitin 3 g used in Example 1
Was dissolved in 100 ml of a mixed solvent of trichloroacetic acid and methylene chloride (mixing ratio 1/1) at 5 ° C. to obtain a chitin solution. The chitin solution was cast on a glass plate by the same operation as in Example 11 and immersed in ethyl alcohol for 1 hour to coagulate and regenerate. After peeling from the glass plate and thoroughly washing with water, the same procedure as in Example 11 was performed to obtain a chitin film. The thickness of the obtained chitin film is 25 μm, the tensile strength is 0.8 kg, the deacetylation degree of chitin of the film is 23.0%, the molecular weight is 150,000, the tensile strength is low and the deacetylation degree is high. The decrease in molecular weight was remarkable.

[0038]

EFFECT OF THE INVENTION The method for producing the chitin sponge, the chitin paper and the chitin film of the present invention uses chemicals which are safer to handle and easier to handle than conventional solvents which dissolve chitin during the production. Further, since there is no decrease in the molecular weight of chitin and increase in the degree of deacetylation during dissolution, it is possible to obtain a high purity chitin sponge, chitin paper, or chitin film that has never been obtained. The chitin sponge, chitin paper, and chitin film obtained by the present invention do not use harmful solvents such as formic acid, trichloroacetic acid, and dimethylacetamide when dissolving chitin, and use ethyl alcohol or methyl alcohol and salts such as calcium chloride. Since it uses only chisel, there are almost no chemicals remaining in the molded article that pose a safety problem, there is no danger even if it is used as a medical material in the human body, and the low immunogenicity and biocompatibility of chitin. , Retains excellent properties such as biodegradability.

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Claims (3)

[Claims] 1. A chitin solution is obtained by dissolving chitin in a mixed solvent of an alcohol consisting of methyl alcohol or ethyl alcohol and a calcium halide salt or a magnesium halide salt, and the chitin solution is prepared by adding water, ethylene glycol,
A method for producing a chitin sponge, which comprises subjecting a coagulated product to coagulation regeneration in an aqueous solution of citric acid, an aqueous solution of sodium ethylenediamine tetraacetate or a mixture thereof to obtain a coagulated product, and then freeze-drying the coagulated product. 2. A method for producing chitin paper, which comprises dispersing the coagulated product according to claim 1 in water to produce paper. 3. The chitin solution according to claim 1,
A method for producing a chitin film, which comprises coagulating and regenerating a film in the coagulating liquid described in 1 and then drying.