JPWO2008156109A1 - Chitin slurry and manufacturing method thereof - Google Patents

Abstract

The present invention provides a chitin slurry in which chitin can be well dispersed in a desired wide range of solvents, a production method thereof, and various additives for cosmetics, foods, medical materials, and the like using the chitin slurry. The present invention relates to a chitin slurry in which chitin is dispersed in an organic solvent, an acid and / or alkaline aqueous solution, and a method for producing the same.

Description

This patent application claims priority under the Paris Convention based on Japanese Patent Application No. 2007-161220. By quoting here, the entire contents described in the above application are described in this specification. Part of
The present invention relates to a chitin slurry in which chitin is uniformly dispersed in an organic solvent, acid and / or alkali, and a method for producing the same.

  Chitin is a natural mucopolysaccharide obtained from crustacean shells such as crabs and shrimps, insect epidermis, and bacterial cell walls such as mushrooms, and is a biological resource that exists in large quantities on the earth. It has been clarified that such chitin has various excellent properties such as moisture retention, physiological activity and biocompatibility. For this reason, many studies have been made in order to utilize the excellent characteristics of chitin in the fields of fibers, films, cosmetics, foods, medicines, medical materials and the like. For example, as an example in which chitin is applied as a medical material, vesquitin (registered trademark) commercially available from Unitika Ltd. as a wound dressing material is known. This is a wound dressing formed by impregnating a molded body made of chitin with an ointment (see Patent Document 1).

  However, chitin is known to exhibit poor solubility because it forms a hard crystal structure due to a strong hydrogen bond derived from its chemical structure. Due to this poor solubility, it is impossible to form a solution or dispersion in which chitin is dissolved or well dispersed, and the application field thereof is to physically knead chitin powder into a substrate to form a molded body. It was extremely limited, such as the purpose of use. In addition, due to the poor solubility of chitin, even if chemical modification is applied to chitin, it does not proceed smoothly, and until now it has not been possible to make use of the above-mentioned excellent characteristics of chitin.

  Accordingly, the present inventors have made extensive studies with a focus on the fact that the above-described excellent characteristics of chitin can be easily used if chitin, which is hardly soluble as described above, can be dissolved or well dispersed in a solvent. We found that chitin can be dissolved by using a specific solvent using methanol and calcium chloride dihydrate, and evaluate the characteristics of the molecular weight and amino group content of chitin present in the solution. (See Non-Patent Documents 1 and 2).

  The chitin solution obtained as described above cannot be developed for general use as it is because of the high salt concentration and the toxicity of methanol. Therefore, for example, cosmetics, foods, pharmaceuticals, In the field of medical materials, in order to use chitin directly, or to use it after chemically modifying chitin as necessary, the above chitin solution is used in a solvent required for each desired application. The development of a technology that completely dissolves or disperses finely in the water has been demanded.

JP 2003-265591 A Akihiro Shirai, Kiyohisa Takahashi, Ratana Rujiravanit, Norio Nishi and Seiichi Tokura, Title: Chitin and Chitosan: The Versatile Environmentally Friendly Modern Materials "Regeneration of Chitin Using New Solvent System", Ed. Mat B Zakaria, Wan Mohamed Wan Muda, Md Pauzi Abdullah, Pb. Universiti Kebangsaan Malaysia Press, 1995 Seiichi Tokura and Norio Nishi, Title: Chitin and Chitosan: The Versatile Environmentally Friendly Modern Materials "Specification and Characterization of Chitin and Chitosan", Ed. Mat B Zakaria, Wan Mohamed Wan Muda, Md Pauzi Abdullah, Pub. Universiti Kebangsaan Malaysia Press, 1995

  An object of the present invention is to provide a chitin slurry in which chitin can be well dispersed in a wide range of desired solvents, a method for producing the same, and various additives for cosmetics and foods using the chitin slurry.

The main and preferred embodiments of the present invention include the following.
[1] A chitin slurry comprising a solvent selected from the group consisting of chitin and an organic solvent, an acid and an alkaline aqueous solution, and having a transmittance of 10 to 90%.
[2] The chitin slurry according to [1], wherein the solvent is selected from the group consisting of monohydric or polyhydric alcohols and caustics.
[3] The chitin slurry according to [1], wherein the solvent is selected from the group consisting of an aqueous sodium hydroxide solution, glycerin, toluene, silicone oil, ethylene glycol, and butylene glycol.
[4] The chitin slurry according to any one of [1] to [3] as a cosmetic additive.
[5] The chitin slurry according to any one of [1] to [3] as a food additive.
[6] The chitin slurry according to any one of [1] to [3] as an additive for medical materials.
[7] A method for producing a chitin slurry according to any one of [1] to [6],
a) dissolving chitin in saturated alcohol of calcium halide hydrate to obtain a chitin solution;
b) a step of diluting the chitin solution with water, washing the produced chitin precipitate as necessary, and substituting calcium ions and alcohol contained in the solution with water molecules to obtain a chitin hydrate slurry;
c) a step of adding a hydrophilic solvent to the chitin hydrate slurry and substituting water molecules contained in the chitin hydrate slurry with the hydrophilic solvent to obtain a chitin gel; and d) an organic solvent, an acid in the chitin gel; And a step of adding a solvent selected from the group consisting of an aqueous alkali solution and replacing the hydrophilic solvent contained in the chitin gel with the solvent to obtain a chitin slurry.
[8] The method according to [7], wherein the hydrophilic solvent in step c) is an alcohol selected from the group consisting of methanol and ethanol.
[9] The chitin slurry according to any one of [7] to [8], wherein the solvent in step d) is selected from the group consisting of an aqueous sodium hydroxide solution and ethylene glycol.

Example 3 shows thermal characteristic profiles (suggested heat) with different degrees of ethanol substitution (the vertical axis is the suggested heat (DTA), the Arbitrary Unit, the horizontal axis is the temperature, and the EtOH percentage represents the estimated ethanol content). In Example 3, the thermal property profile of a pure hydrated chitin slurry before ethanol replacement is shown. In Example 3, the thermal characteristic profile of the chitin slurry whose ethanol substitution degree is 21% is shown. In Example 3, the thermal characteristic profile of the chitin slurry whose ethanol substitution degree is 46% is shown. In Example 3, the thermal characteristic profile of the chitin slurry of ethanol substitution degree 63% is shown. In Example 3, the thermal characteristic profile of the chitin slurry whose ethanol substitution degree is 85% is shown. In Example 3, the thermal characteristic profile of the chitin slurry of ethanol substitution degree 91% is shown. In Example 3, the thermal characteristic profile of the chitin slurry of ethanol substitution degree 95% is shown. In Example 3, the thermal characteristic profile of the chitin slurry with an ethanol substitution degree of 97% is shown. In Example 3, the thermal characteristic profile of the chitin slurry of ethanol substitution degree 100% is shown.

  As described above, in a chitin solution obtained using a specific solvent using methanol and calcium chloride dihydrate (hereinafter also referred to as calcium solvent), the solvent breaks down the hard crystal structure of chitin and the inside of the chitin molecule. As a result, it was found that a dissolved state was obtained and the dissolution was due to the effect of solvation. Therefore, in the first discovery, the present inventors first diluted the chitin solution with water to thereby obtain a chitin hydrate slurry (hereinafter referred to as hydrated chitin gel, hydrated chitin slurry) in which the calcium solvent is replaced with water molecules. (Sometimes referred to as).

  As a second discovery, in the hydrated chitin gel described above, this chitin slurry is utilized by substituting specific alcohol for the water molecules aggregated around the chitin molecule to obtain an alcohol-mixed chitin slurry. Thereafter, the alcohol in the chitin slurry can be sequentially replaced with another organic solvent having a high affinity with the alcohol, and various solvated chitins that can be developed for various desired uses. It was found that can be dispersed.

  Such solvents can be combined with a wide variety of solvents regardless of polarity or non-polarity. For example, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), nitrobenzene, as described later. This includes ethylene glycol and the like. As described above, it is understood that the environment of chitin molecules can be arbitrarily changed by combining various solvents regardless of polarity or non-polarity, and as a result, an environment suitable for chemical modification of chitin can be provided. It was.

In the present invention, chitin to be dispersed in a solvent generally includes a crustacean shell such as crab and shrimp, an insect epidermis, a skeleton such as squid, and a polysaccharide (poly N-acetyl) obtained from bacterial cell walls such as mushrooms. -D-glucosamine), which usually has powder properties. In the present invention, any commercially available chitin can be used, and it may be produced using a microorganism. Further, it may have any three-dimensional structure including α type and β type. The weight average molecular weight of chitin in the present invention is preferably in the range of 5 × 10 ^{3 to} 5 × 10 ⁶ , more preferably 5 × 10 ^{4 to} 5 × 10 ⁶ , and still more preferably 5 × 10 ^{4 to} 5 × 10 ⁵ . is there.

In the chitin slurry of the present invention, an organic solvent, an acid and / or an alkaline aqueous solution are selected as a medium in which chitin can be dispersed according to the use and purpose of use of the chitin slurry.
The use and purpose of use of the chitin slurry is, for example, used as a dispersion solvent for chitin in a form to be added to the composition in uses such as fibers, films, non-woven fabrics, cosmetics, foods, medicines, and medical materials. Alternatively, it may be used as a raw material (environmental modifier) for further chemically modifying chitin.

As the organic solvent, any of a polar solvent and a nonpolar solvent can be used. For example, alcohols, benzene, nitrobenzene, toluene, xylene, naphthalene, ethylbenzene, styrene, aniline, nitrobenzene and other aromatic compounds, diethyl This includes ether, tetrahydrofuran, methylene chloride, acetonitrile, N, N-dimethylformamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), silicone oil, and the like.
Examples of such alcohols include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutyl alcohol, 2-butanol, t-butanol, and allyl alcohol, as well as ethylene glycol, propylene glycol, This includes glycols such as dipropylene glycol and butylene glycol and polyhydric alcohols such as glycerin.

The acid is used for the purpose of catalytic reaction such as acylation, alkylation and the like, and examples thereof include perchloric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid and the like.
Alkali is used for the purpose of acylation and alkylation reaction intermediate synthesis, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, lithium hydroxide, and barium hydroxide. Can be mentioned.

  The solvent in the present invention is preferably selected from the group consisting of mono- or polyhydric alcohols and caustic alkalis. Especially, it is preferable to use ethylene glycol and sodium hydroxide from a viewpoint of expressing neutral and uniform dispersibility. Moreover, although alkalis, such as sodium hydroxide, are intermediates for acylation or alkylation of chitin, it is preferable to make the concentration as low as possible in order not to cause deacetylation.

  The chitin content in the chitin slurry can be arbitrarily set according to the purpose and application of use, but is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more, Preferably, it is set to 2% by weight or more, usually 15% by weight or less, preferably 6% by weight or less, more preferably 5% by weight or less, and further preferably 3% by weight or less.

Conventionally, it has been considered extremely difficult to disperse chitin in a solvent due to the poor solubility of chitin, but the chitin slurry according to the present invention is usually a well-distributed chitin in a solvent in a swollen state. .
Such a chitin slurry of the present invention has a characteristic that the visible light transmittance at 550 nm measured by a visible range spectrophotometer is 10 to 90%. Suitably, the visible light transmittance | permeability of the chitin slurry of this invention is 40% or more, More preferably, it is 60% or more. The visible light transmittance of the chitin slurry of the present invention is usually 90% or less, but may be 80% or less in some cases and 70% or less in other cases.

  The particle size of chitin dispersed in the slurry is preferably 1 to 100 μm, more preferably 5 to 50 μm, and still more preferably 5 to 10 μm. The particle size of chitin dispersed in the slurry can be measured, for example, with a microscope.

The chitin slurry of the present invention can be used for various applications including applications of fibers, films, nonwoven fabrics, cosmetics, foods, medicines, and medical materials. For such applications, the use as various additives or chitin Is used as a raw material (environmental modifier) for further chemical modification.
As such an additive, the chitin slurry of the present invention can be used as an additive for cosmetics, foods or medical materials, which can impart various excellent characteristics of chitin such as moisture retention, physiological activity, and biocompatibility. It is particularly advantageous to use it.

  As a further chemical modification of chitin, chitin may be directly or indirectly chemically modified to have functional groups such as carboxyl group, amino group, hydroxyl group, halogen group, aminoethyl group, phosphate group, sulfate group, aromatic derivative, etc. Introducing. Introducing a carboxyl group or a methyl group by O-alkylation reaction is also included in the scope of chemical modification of chitin in the present invention. For example, de-N-acetylation of an O-alkylchitin derivative to form O-alkylchitosan, or the amino group of O-alkylchitosan may be further chemically modified to introduce another type of functional group. Included in the scope of chemical modification.

Next, a method for producing the chitin slurry of the present invention will be described. A preferred method for producing the chitin slurry of the present invention is:
a) dissolving chitin in saturated alcohol of calcium halide hydrate to obtain a chitin solution;
b) diluting the chitin solution with water, washing the produced chitin precipitate with water if necessary, and preferably repeating the water wash, replacing calcium ions and alcohol contained in the solution with water molecules, and hydrating chitin Obtaining a product slurry;
c) a step of adding a hydrophilic solvent to the chitin hydrate slurry and substituting water molecules contained in the chitin hydrate slurry with the hydrophilic solvent to obtain a chitin gel; and d) an organic solvent, an acid in the chitin gel; And a step of adding a solvent selected from the group consisting of an aqueous alkali solution and replacing the hydrophilic solvent contained in the chitin gel with the solvent to obtain a chitin slurry.

In step a) above, chitin is dissolved in alcohol saturated with calcium halide hydrate to obtain a chitin solution. By using an alcohol saturated with calcium halide hydrate as a solvent, it becomes possible to break down the hard crystal structure of chitin, which is hardly soluble, and to allow the solvent to penetrate into the chitin molecule. It is possible to obtain a dissolved chitin solution.
In certain embodiments, chitin powder is added to the above solvent at a concentration that is preferably 0.1-5% (w / v), more preferably 0.5-2% (w / v). The solution is preferably dissolved at a temperature of 20 to 70 ° C., more preferably 40 to 70 ° C. with sufficient stirring under reflux. It is preferable to adjust the chitin concentration in the solvent according to the molecular weight of the chitin used.

In the above step b), the chitin solution obtained in step a) is diluted with water, and the chitin precipitate produced is washed with water as necessary, and the calcium ions and alcohol contained in the solution are replaced with water molecules. To obtain a chitin hydrate slurry.
In an embodiment, the chitin solution obtained in step a) is cooled to room temperature, and then the insoluble part is removed with a filter cloth (nel). Then, dilute with distilled water. The dilution concentration at that time is preferably 0.001 to 0.5% (w / v), more preferably 0.001 to 0.01% (w / v). When diluted with distilled water, chitin usually precipitates, which are collected and washed thoroughly with water to remove alcohol (methanol) and calcium ions. Finally, by centrifugation, usually 0.1% (w / v) or more, preferably 1 (w / v) or more, more preferably 2 (w / v) or more, usually 15% ( w / v) or less, preferably 6 (w / v) or less, more preferably 5 (w / v) or less, and even more preferably 4 (w / v) or less, to adjust the water content, and chitin hydrate slurry Or a hydrated chitin gel can be obtained.

In the above step c), a hydrophilic solvent is added to the chitin hydrate slurry obtained in step b), and water molecules contained in the chitin hydrate slurry are replaced with the hydrophilic solvent to be solvated. Obtain a chitin gel.
Examples of the hydrophilic solvent to be added to the chitin hydrate slurry in step c) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutyl alcohol, 2-butanol, t-butanol, and allyl alcohol. The monohydric alcohol can be exemplified, but is not limited thereto. In the present invention, when an alcohol selected from the group consisting of methanol and ethanol is used, the substitution with water molecules contained in the chitin hydrate slurry can be preferably completed.

  In some embodiments, the chitin hydrate slurry obtained in step b) is preferably alcohol in a concentration such that it is 10-100% (v / v), more preferably 90-100% (v / v). Add and agitate well, let stand for 30 minutes to 1 hour, then centrifuge to adjust to a predetermined volume of slurry. By repeating this operation several times, preferably 2 to 4 times, to complete the substitution with water molecules contained in the chitin hydrate slurry, a chitin gel in an alcohol solvent can be obtained.

  In an embodiment, instead of or in addition to the above centrifugation operation, the solvent replacement can be carried out by distillation using the difference between the boiling point of the solvent before substitution and the boiling point of the solvent after substitution. . Solvent replacement by distillation is particularly preferable because solvent replacement can be performed efficiently when a highly viscous solvent is used and when the concentration of chitin is desired to be increased. When carrying out solvent substitution by distillation, it is important that the solvent after substitution is in a region where the boiling point is clearly higher than the solvent before substitution. For example, solvent replacement by distillation can be easily utilized by replacing the solvent from chitin hydrate slurry with ethanol-chitin and using low-boiling ethanol as the solvent.

  By replacing the chitin gel in the alcohol solvent obtained by the above operation as a solvent-substituted base chitin with a solvent selected from the group consisting of another organic solvent having high affinity with alcohol, an acid and an aqueous alkali solution, the present invention The final chitin slurry can be suitably obtained.

In the above step d), a solvent selected from the group consisting of an organic solvent, an acid and an aqueous alkaline solution is added to the chitin gel obtained in step c), and the hydrophilic solvent contained in the chitin gel is replaced with the solvent. To obtain a solvated chitin slurry.
The organic solvent, acid and alkaline aqueous solution used in step d) are appropriately selected according to the use and purpose of use of the chitin slurry in which chitin is dispersed.
The use and purpose of use of the chitin slurry is, for example, used as a dispersion solvent for chitin in a form to be added to the composition in uses such as fibers, films, non-woven fabrics, cosmetics, foods, medicines, and medical materials. Alternatively, it may be used as a raw material (environmental modifier) for further chemically modifying chitin.
In particular, the chitin is well dispersed in a solvent to form the chitin slurry of the present invention, so that various kinds of chitin such as moisturizing property, physiological activity, biocompatibility, etc. can be obtained for a desired object to be mixed with chitin. Excellent properties can be imparted. Among these, it is particularly advantageous to use the chitin slurry of the present invention as an additive for cosmetics, foods or medical materials.

As the organic solvent, any of a polar solvent and a nonpolar solvent can be used. For example, alcohols, benzene, nitrobenzene, toluene, xylene, naphthalene, ethylbenzene, styrene, aniline, nitrobenzene and other aromatic compounds, diethyl This includes ether, tetrahydrofuran, methylene chloride, acetonitrile, N, N-dimethylformamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), silicone oil, and the like.
Examples of such alcohols include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutyl alcohol, 2-butanol, t-butanol, and allyl alcohol, as well as ethylene glycol, propylene glycol, This includes glycols such as dipropylene glycol and butylene glycol and polyhydric alcohols such as glycerin.

The acid is used for the purpose of catalytic reaction such as acylation, alkylation and the like, and examples thereof include perchloric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid and the like.
Alkali is used for the purpose of acylation and alkylation reaction intermediate synthesis, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, lithium hydroxide, and barium hydroxide. Can be mentioned.

  The solvent in the present invention is preferably selected from the group consisting of mono- or polyhydric alcohols and caustic alkalis. Especially, it is preferable to use ethylene glycol and sodium hydroxide from a viewpoint of expressing neutral and uniform dispersibility. Moreover, although alkalis, such as sodium hydroxide, are intermediates for acylation or alkylation of chitin, it is preferable to make the concentration as low as possible in order not to cause deacetylation.

  The chitin content in the chitin slurry can be arbitrarily set according to the purpose and application of use, but is usually 0.1% by weight or more, preferably 05% by weight or more, more preferably 1% by weight or more, and further preferably 2% by weight or more, usually 15% by weight or less, preferably 6% by weight or less, more preferably 5% by weight or less, further preferably 4% by weight or less, still more preferably 3% by weight or less, particularly preferably Set to 2 wt% or less.

  In the present invention, when carrying out solvent substitution from a chitin hydrate slurry to another solvent and to the final target solvent, the progress of substitution to the target solvent by using the solvent substitution progress measurement method shown below. (Ie, the degree of substitution) and the completion of substitution with the target solvent can be confirmed.

[Solvent substitution progress measurement method]
1. The hydrated chitin slurry obtained according to the method of the present invention was measured at room temperature in an air atmosphere using a differential heat measurement device (manufactured by Shimadzu Corporation, “Shimadzu differential heat / thermogravimetric measurement device” DTG-60). To 400 ° C. (temperature increase rate 5 ° C./min), and heat loss analysis (TGA) and differential thermal analysis (DTA) are performed (hereinafter also referred to as DTA-TG).
2. For the solvent for substitution, the thermal characteristics are measured in the same manner as described above.
3. Solvent replacement is performed according to the method of the present invention.
4). The chitin slurry or gel obtained by the solvent replacement is measured for thermal properties in the same manner as described above.
5). The degree of substitution is confirmed from the endothermic peak of the solution obtained by differential thermal analysis (DTA).
6). By repeating the above solvent substitution and thermal measurement until the final target solvent, it is confirmed that the substitution to the final target solvent is completed.

Further, by using the following method, it can be confirmed that the chitin slurry according to the present invention is in a state of being solvated by being substituted to the final target solvent.
1. For the chitin hydrate slurry or chitin gel obtained according to the method of the present invention, the thermal characteristics are measured in the same manner as described above to obtain a differential thermal profile. Similarly, a differential thermal profile of the water or solvent used in the chitin hydrate slurry or chitin gel is obtained. Further, a differential heat profile of the final target solvent is obtained.
2. Solvent replacement is performed according to the method of the present invention.
3. The final target chitin slurry obtained by the solvent replacement is allowed to stand at room temperature for 24 hours or more, and it is visually confirmed that no separation occurs.
4). The thermal characteristics of the final chitin slurry are measured to obtain a differential thermal profile.
5). By comparing each of the differential thermal profiles described above, it is confirmed that the final target solvent is substituted.
6). The final chitin slurry is allowed to stand at room temperature for 30 days or more, and visually confirmed that there is no separation or precipitation, and it is confirmed that the chitin slurry is in a stable state.

  In the chitin slurry of the present invention, a sweetener, a coloring agent, a preservative, a thickening stabilizer, an antioxidant, a bleaching agent, a seasoning, a bittering agent, an acidulant, a fortifying agent, a fragrance, and a spice as needed. Additives such as manufacturing agents, enzymes, gum bases, brighteners, emulsifiers, thickeners, film formers, sequestering agents, alkaline agents, oily raw materials, moisturizers, drugs, plant extracts, etc. it can. The addition amount of the additive in this case can be appropriately selected according to the purpose.

The chitin slurry of the present invention can be applied to the application fields of chitin and chitosan. That is, it can be applied to the following application fields.
(1) Cosmetics field: Health care, skin care, hair care, oral care, anti-aging cream, cleansing, etc. (humectant, thickener, inflammation suppression, ultraviolet light, hair damage suppression, skin damage suppression, skin regeneration), Repellents, etc.
(2) Food field: Improvement of intestinal metabolism (proliferation of lactic acid bacteria, promotion of production of β-galactosase necessary for lactose digestion), immunity enhancement, improvement of bread bulge, promotion of hyaluronic acid production, prevention and improvement of osteoarthritis, etc. Health food, functional food, etc.
(3) Medical field: Wound healing agent (material), non-woven fabric, artificial skin, surgical suture, cream, pharmaceuticals (medicine, non-woven fabric shape cancer cell proliferation suppression, immune enhancement effect (cancer cell growth suppression and opportunistic infection) (Protective effect against fungus-Lysera monocytogenes), growth of lactic acid bacteria, promotion of production of β-galactose required for digestion of lactose, promotion of hyaluronic acid production, prevention and improvement of osteoarthritis, improvement of inflammation, healing (stomatitis, gingivitis, alveolar pyorrhea Etc.), analgesic suppressants, hemostatic agents, bactericides), biomaterials (bones, teeth, etc.),
(4) Plant field: soil improvement material, plant control material, etc.
(5) Biotechnology field: Cell growth substrate, etc.
(6) Molding material field: Fillers for plastic products (thickeners, biodegradable materials), natural material molded products, films, etc.
(7) Thickener and the like.

  Hereinafter, the effectiveness of the present invention will be described with reference to examples, but the present invention is not limited thereto. In addition, the evaluation method of the physical property in the following examples is as follows.

1. Transmittance of chitin slurry The transmittance of the chitin slurry was measured by measuring the visible light transmittance at 550 nm under the following conditions.
Cell: Glass cell of 0.1 cm or 1.0 cm Measuring method: The gel to be produced is injected into the glass cell, or the gel is applied to a predetermined glass plate, and is light transmissive in visible light of 550 to 600 nm. Was measured.

[Preparation Example 1: Preparation of calcium solvent]
About 84 g of calcium chloride dihydrate was added to 100 mL of commercially available primary methanol and stirred at 40-50 ° C. for about 4 hours, and then allowed to stand at room temperature for about 15 hours. Next, the insoluble part was removed by filtration using a filter cloth, and the obtained solution was used as a calcium solvent.

[Preparation Example 2: Preparation of solvent-substituted base chitin]
2 g of chitin powder (product number: chitin TC-L, weight average molecular weight 1 × 10 ⁵ , manufactured by Kyowa Technos Co., Ltd.) was dissolved in 100 mL of a calcium solvent at 40 to 50 ° C. with sufficient stirring under reflux. After cooling to room temperature, the insoluble part was removed with a filter cloth (nel), and then diluted with 1 L of distilled water. Since chitin precipitated, it was collected and washed thoroughly with water to remove methanol and calcium ions. Then, it was washed with water by a centrifugal method using a centrifugal dehydrator (H-1.22, manufactured by Kokusan Co., Ltd.) to completely remove calcium salts. The water content was adjusted to obtain 100 mL of a hydrated chitin gel (chitin hydrate slurry). For complete removal of the calcium salt, a conductivity meter was used to confirm that the conductivity of the filtrate was the same as deionized water.

  Next, 50 mL of ethanol was added to 100 mL of this chitin hydrate slurry and sufficiently stirred. After standing for 30 to 60 minutes, centrifugation was performed using a centrifuge (CN-820, manufactured by ASONE Corporation), The volume was adjusted to 100 mL slurry. This operation was repeated 3 to 5 times to complete the substitution with water molecules to obtain a chitin gel in which chitin was uniformly dispersed.

[Example 1: Preparation of chitin slurry as EG solvation slurry]
50 mL of ethylene glycol was added to 100 mL of the chitin gel (solvated base chitin) obtained in Preparation Example 2 at room temperature and sufficiently stirred. After leaving still for 0.5 to 1 hour, centrifugation was performed using a centrifuge (CN-820, manufactured by ASONE Co., Ltd.) to obtain a 100 mL sample. This operation was repeated 20 times to complete the solvent replacement. The obtained chitin slurry as a solvation slurry was measured for transmittance using a power meter (407A, manufactured by Spectra-Physics) after applying this slurry to a 0.1 cm thick glass plate. Had.
Transmittance: 71% using ethylene glycol as a control
The chitin slurry was sterilized by autoclaving (120 ° C.) for 30 minutes for use as an additive for cosmetics, foods or medical materials.

[Example 2: Preparation of chitin slurry using alkali as solvent]
Various concentrations of aqueous sodium hydroxide solution were added to the 100 mL chitin gel (solvated base chitin) obtained in Preparation Example 2 within a range of 4 to 35% (w / w). This was frozen at −20 ° C. overnight and then thawed at room temperature, and the transmittance at 550 nm was measured.
The results are shown in Table 1.

As shown in Table 1, the chitin slurry-containing sodium hydroxide aqueous solution became almost transparent as early as possible at a 6% (w / w) NaOH concentration, suggesting that mercerization was advanced.
On the other hand, an attempt was made to directly disperse chitin powder in an aqueous sodium hydroxide solution, but even with an 18% (w / w) NaOH concentration, the transmittance was about 2%, and a transparent liquid was not obtained ( Comparative Example 1). That is, the chitin slurry according to the present invention suggests that hydration is sufficiently advanced.

[Example 3: Preparation of chitin slurry using ethanol as solvent]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 5.6% by weight) was obtained. 80 g of this chitin hydrate slurry was centrifuged at 2600 rpm with a centrifuge (desk centrifuge H103N, manufactured by Kokusan Co., Ltd.) to separate water (water at the top and chitin at the bottom). Thereafter, the supernatant water was discarded. Next, ethanol having the same weight as the discarded water was added to the lower chitin and mixed. The ratio (weight ratio) of ethanol and water in the obtained slurry was 0.21: 0.79. And it centrifuged on the same conditions as the above. The separated supernatant was discarded, and ethanol having the same weight as the discarded liquid was added and mixed.
Assuming that the composition ratio of water and ethanol in the separated supernatant is the same as the composition ratio in the chitin slurry before centrifugation, the composition ratio of water and ethanol in the chitin slurry after addition and mixing of ethanol is calculated. The calculation was 0.54: 0.46.

Here, the above calculation method will be described with reference to the following example.
a. When 50 g of water is separated from 100 g of pure chitin slurry (for simplification, the composition ratio of chitin is 0), and 50 g of ethanol is added and mixed, 50 wt% ethanol and 50 wt% water are mixed. Become chitin.
b. Further, if 50 g of the solution is separated by centrifugation, the composition ratio of the separated solution is the same as that of the solution before centrifugation (50 wt% ethanol / 50 wt% water mixed chitin), which is 25 g water and 25 g ethanol. Assuming that When 50 g of ethanol is further added, since water is 25 g and ethanol is 75 g, it is calculated as chitin of ethanol 75 wt% (water 25 wt%).
c. Repeat the above calculation.

While repeating the above operation, the thermal characteristics were measured according to the above-described method (DTA-TGA) to obtain a corresponding differential thermal profile. Thermal characteristic profiles of chitin slurry before ethanol substitution (ethanol substitution degree 0%) and various ethanol substitution degrees are shown in FIGS. The degree of ethanol substitution was determined by concentrating the chitin hydrate slurry with a centrifuge, adding ethanol, stirring well, allowing to stand for 1 minute, and subtracting the supernatant liquid after repeated concentration with a centrifuge and addition of ethanol. It is the calculated value of ethanol fraction. In FIG. 1, it can be seen from the right that the differential thermal peak moved from water to ethanol chitin depending on the degree of ethanol substitution. Since the amount of heat on the vertical axis varies depending on the measured amount, it is important here that the peak temperature (horizontal axis) has moved.
From these results, it was found that the temperature peak of the chitin slurry was moved from the water side to the ethanol side, and it was finally confirmed that the water portion as a peak was almost eliminated. Therefore, the progress of substitution was confirmed by measurement of thermal properties.
Thus, it was confirmed that the differential heat peak moves from the solvent before substitution (in this case, water) to the solvent after substitution (in this case, ethanol) as the solvent substitution progresses. The transmittance of solvated chitin (chitin slurry) obtained by this example was 81%.

[Example 4: Preparation of high-concentration chitin slurry using glycerin as a solvent, using a distillation method]
In the same manner as in Example 3, a chitin slurry using ethanol as a solvent (chitin concentration 3.5% by weight) was obtained. 18.20 g of this ethanolic chitin and 28.94 g of glycerin (reagent special grade glycerol manufactured by Sigma-Aldrich Japan) were mixed. Subsequently, the above mixed solution was heated and distilled at 110 ° C. for 1 hour and 20 minutes so that the concentration of glycerin-chitin was 6.6% by weight using a hot plate, and the weight of the mixed solution was adjusted to 30 g. When the thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), it was confirmed that the solvent was substituted from ethanol to glycerin. The transmittance of solvated chitin (chitin slurry) obtained by this example was 90%.

[Example 5: Solvent replacement by distillation using a vacuum rotary evaporator]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 4% by weight) was obtained. By mixing 500 g of this chitin hydrate slurry and 1350 g of ethanol and centrifuging, 1677 g of ethanol-chitin was produced. 713 g of glycerin was mixed with the obtained ethanol sum chitin. The mixture was divided into two parts, and each mixture was distilled at 80 ° C. in vacuum using a vacuum rotary evaporator (manufactured by EYELA) to obtain 670 g of glycerin sum chitin (chitin concentration 2 to 4 wt%). When the thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), it was confirmed that the solvent was replaced with glycerin. The transmittance of solvated chitin (chitin slurry) obtained by this example was 90%.
As a result of the above examples, it was found that solvent substitution by distillation using a vacuum rotary evaporator is effective for producing a large amount of glycerin-chitin.

[Example 6: Preparation of high concentration chitin slurry using butylene glycol as solvent, using distillation method]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 2% by weight) was obtained. 20.0833 g of this chitin hydrate slurry and 4.64 g of butylene glycol were mixed. The mixture was heated on a hot plate at 65 ° C. and distilled to 4.79 g grams to obtain high-concentration butylene glycol chitin having a chitin concentration of 8%. When the thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), it was confirmed that the solvent was substituted with butylene glycol. The transmittance of solvated chitin (chitin slurry) obtained by this example was 51%.

[Example 7: Preparation of chitin slurry using toluene as solvent]
In the same manner as in Example 3, an ethanol-containing chitin slurry using ethanol as a solvent (chitin concentration 5% by weight) was obtained, and ethanol and toluene were replaced in the same manner as in Example 3 as follows. The obtained ethanol-gated chitin (58 g) was centrifuged at 2600 rpm with a centrifuge (desk centrifuge H103N, manufactured by Kokusan Co., Ltd.) to separate water (ethanol at the top and chitin at the bottom). Thereafter, ethanol in the supernatant was discarded. Next, toluene having the same weight as the discarded ethanol was added to the lower chitin and mixed. And it centrifuged on the same conditions as the above. The separated supernatant was discarded, and toluene having the same weight as the discarded liquid was added and mixed.
While repeating the above operation, the thermal characteristics were measured according to the above-mentioned method (DTA-TGA) to obtain the corresponding differential thermal profile, and finally it was confirmed that the ethanol portion as a peak was almost eliminated. The transmittance of solvated chitin (chitin slurry) obtained by this example was 81%.

[Example 8: Preparation of chitin slurry using silicone oil as solvent]
In the same manner as in Example 3, an ethanol sum chitin slurry (chitin concentration 6.5% by weight) using ethanol as a solvent was obtained. After mixing 4 g of this ethanolic chitin and 4 ml of silicone oil and performing centrifugation, the supernatant was discarded. 4 ml of silicone oil was added to the obtained separated product, and after centrifugation, the supernatant was discarded. After repeating this operation four times, 4 ml of silicone oil was added to the obtained separated product, and ethanol was distilled on a hot plate (65 ° C.). When the thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), it was confirmed that the solvent was replaced with silicone oil. The permeability of solvated chitin (chitin slurry) obtained by this example was 39%.

[Example 9: Preparation of chitin slurry using silicone oil as solvent]
In the same manner as in Example 3, an ethanol sum chitin slurry (chitin concentration 6.5% by weight) using ethanol as a solvent was obtained. After mixing 4 g of this ethanolic chitin and 4 ml of modified silicone oil (SH556 Fluid, phenyl-modified by Toray Dow Corning Co., Ltd.) and performing centrifugation, the supernatant was discarded. 4 ml of modified silicone oil was added to the obtained separated product, and after centrifugation, the supernatant was discarded. After repeating this operation 4 times, 4 ml of modified silicone oil was added to the obtained separated product, and ethanol was distilled on a hot plate (65 ° C.). When the thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), it was confirmed that the solvent was replaced with the modified silicone oil. The permeability of solvated chitin (chitin slurry) obtained by this example was 82%.

[Comparative Example 1]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 5.9% by weight) was obtained. 20 ml of this chitin hydrate slurry and the same amount of toluene were added to a 50 ml test tube. The test tube was placed in water heated and boiled using a hot plate and stirred for 1 hour while keeping warm. However, since the chitin hydrate slurry and toluene did not mix and became a small aggregate in toluene, a chitin slurry using toluene as a solvent could not be obtained.
From this result, it was found that when the chitin hydrate slurry was directly replaced with toluene without replacing the chitin hydrate slurry with ethanol to obtain ethanol-hydrated chitin, the solvation state was not obtained. It was found that a chitin slurry using as a solvent could not be obtained. That is, it was found that it is effective for solvent replacement to obtain ethanol-chitin by substituting ethanol from a chitin hydrate slurry in advance.

[Comparative Example 2]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 5.9% by weight) was obtained. 20 ml of this chitin hydrate slurry and the same amount of toluene were added to a 50 ml test tube. The test tube was placed in water heated and boiled using a hot plate and stirred for 1 hour while keeping warm. Ethanol was added to the mixture of chitin hydrate slurry and toluene and stirred for 10 minutes. Although there was no large agglomeration in the solvent and it was dispersed, precipitation was generated when the stirring was stopped, so that a chitin slurry using toluene as a solvent was not finally obtained.
From this result, it was found that even if ethanol was simply mixed with toluene without replacing the chitin hydrate slurry with ethanol to obtain ethanol-based chitin, the solvent could not be replaced with toluene. That is, it was found that it is effective for solvent replacement to obtain ethanol-chitin by substituting ethanol from a chitin hydrate slurry in advance.

[Comparative Example 3]
In the same manner as in Preparation Example 1 and Preparation Example 2, a chitin hydrate slurry (chitin concentration 8.9% by weight) was obtained. 50 g of this chitin hydrate slurry and the same amount of glycerin were mixed. Next, in the same manner as in Example 4, the mixed solution was heated at 110 ° C. for 3 hours and 10 minutes using a hot plate to perform distillation. When thermal characteristics were measured in the same manner as in Example 3 (DTA-TGA), an endothermic shoulder presumed to be water was observed in addition to the DTA curve of glycerin sum chitin.
From this result, in the case of glycerin, it was judged that the hydrated chitin slurry can be directly replaced with glycerin-chitin, but the hydrated state remains. This is considered to be because the substitution to glycerin is not performed efficiently due to the strong hydration. Therefore, in the case of glycerin, the substitution itself is possible without using ethanol-chitin, but it is inefficient and low-quality glycerin-chitin that does not eliminate the hydration state. That is, it was found that it is effective for solvent replacement to obtain ethanol-chitin by substituting ethanol from a chitin hydrate slurry in advance.

Claims (9)

  A chitin slurry comprising a solvent selected from the group consisting of chitin and an organic solvent, an acid and an alkaline aqueous solution, and having a transmittance of 10 to 90%.   The chitin slurry according to claim 1, wherein the solvent is selected from the group consisting of monohydric or polyhydric alcohols and caustics.   The chitin slurry according to claim 1, wherein the solvent is selected from the group consisting of an aqueous sodium hydroxide solution, glycerin, toluene, silicone oil, ethylene glycol, and butylene glycol.   The chitin slurry according to any one of claims 1 to 3 as a cosmetic additive.   The chitin slurry according to any one of claims 1 to 3 as a food additive.   The chitin slurry in any one of Claims 1-3 as an additive for medical materials. A method for producing the chitin slurry according to claim 1,
a) dissolving chitin in saturated alcohol of calcium halide hydrate to obtain a chitin solution;
b) a step of diluting the chitin solution with water, washing the produced chitin precipitate as necessary, and substituting calcium ions and alcohol contained in the solution with water molecules to obtain a chitin hydrate slurry;
c) a step of adding a hydrophilic solvent to the chitin hydrate slurry and substituting water molecules contained in the chitin hydrate slurry with the hydrophilic solvent to obtain a chitin gel; and d) an organic solvent, an acid in the chitin gel; And a step of adding a solvent selected from the group consisting of an aqueous alkali solution and replacing the hydrophilic solvent contained in the chitin gel with the solvent to obtain a chitin slurry.   8. The method according to claim 7, wherein the hydrophilic solvent in step c) is an alcohol selected from the group consisting of methanol and ethanol.   The chitin slurry according to any one of claims 7 to 8, wherein the solvent in step d) is selected from the group consisting of an aqueous sodium hydroxide solution and ethylene glycol.

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