β-1,3-glucan solution and method for producing the same

Abstract

The objective is to provide a β-1,3-glucan solution with excellent quality, such as solidification properties and wet moldability, and a new method for producing such a β-1,3-glucan solution. Furthermore, the objective is to provide β-1,3-glucan ether derivatives using the above-mentioned β-1,3-glucan solution and methods for producing the same. [Solution] When β-1,3-glucan is dissolved in a mixed solution of tetraalkylammonium hydroxide and water as a solvent, the resulting β-1,3-glucan solution exhibits excellent quality, including coagulation properties and wet moldability. A method for producing a β-1,3-glucan ether derivative is also provided, which includes the step of adding an ether modifying agent to the β-1,3-glucan solution and stirring the mixed solution.

Description

Technical Field

[0001] The present invention relates to a β-1,3-glucan solution, a method for producing the same, and a method for producing a molded article using the solution. The present invention also relates to an ether derivative using the β-1,3-glucan solution and a method for synthesizing the same.

Background Art

[0002] Resource and environmental problems such as the depletion of fossil resources and global warming are one of the major problems in the 21st century. In order to solve these problems, the establishment of alternative resource technologies that are environmentally friendly, abundantly present on the earth, and sustainable is required. Biomass of polysaccharides such as cellulose, paramylon, and chitin is the most abundant organic resource on the earth and is also a renewable resource.

[0003] However, these polysaccharides have a strong crystal structure, are insoluble in most organic solvents, and have extremely poor moldability, so their uses are significantly limited. Generally, even if they belong to polysaccharides, if there are slight differences in molecular structure and higher-order structure, the solubility is very different. For example, solvents that can dissolve cellulose cannot dissolve chitin or starch, and the development of solvents that can dissolve polysaccharides is very difficult. Therefore, a simple method for dissolving polysaccharides is required.

[0004] Paramylon, which is a polysaccharide and a kind of β-1,3-glucan, is a polysaccharide produced only by Euglena (Japanese name: green algae) as an intracellular storage substance, has physiological activity, and has a helical structure, so it is expected to have mechanical properties different from those of polysaccharides such as cellulose and chitin of polysaccharides. For example, when fibers are produced using paramylon as a raw material, it is expected to become a natural fiber like silk due to the properties derived from the helical structure.

[0005] Conventional methods for dissolving paramylon include various methods such as the sodium hydroxide aqueous solution method (Patent Document 1), the formic acid method (Patent Document 2), the LiCl / DMAc method (Patent Document 3), and the viscose method (Patent Document 4). The paramylon solution obtained by the sodium hydroxide aqueous solution method has a slow solidification rate, low wet gel strength, and poor wet moldability, making it difficult to perform film forming and spinning. The formic acid method and the LiCl / DMAc method have extremely long dissolution times, yet the solubility of paramylon is low, making them extremely difficult to use in large-scale industrial production. The viscose method was discovered in the 19th century as a method for dissolving cellulose, but it has challenges such as environmental impact and high cost, and furthermore, the dissolution process is complex, making it extremely difficult to use in large-scale industrial production.

[0006] Furthermore, the applicant has discovered a mixture of tetraalkylammonium acetate and an aprotic polar solvent as a solvent for dissolving cellulose (Patent Document 5). This solvent can also dissolve paramylon, but the resulting paramylon solution has poor coagulation and wet moldability. In addition, the applicant has discovered a solvent that can be used to dissolve cellulose and chitin in a mixture of an aqueous solution of tetraalkylammonium hydroxyside and an aprotic polar solvent (Patent Document 6). This solvent can dissolve paramylon, but the resulting paramylon solution has poor coagulation and wet moldability.

[0007] Furthermore, there is a method of adding paramylon powder to a cellulose solution and spinning the paramylon (Patent Document 7), but the paramylon is not completely dissolved, and the amount of paramylon added is less than that of cellulose, so the paramylon does not exhibit its inherent properties. In addition, there is a disclosure of imparting thermoplasticity to paramylon by esterification modification and then forming fibers by melt spinning (Patent Document 8), but the molecular structure of the disclosed esterified paramylon is different from that of ordinary paramylon, so it is unclear whether it retains the properties unique to paramylon.

[0008] In addition to the above, the solvents used in Patent Documents 2 to 6 contain organic solvents and chemical substances that are harmful to the natural environment and living organisms, and therefore may have adverse effects on the natural environment and living organisms.

[0009] Patent document 9 discloses paramylon-containing regenerated cellulose fibers derived from Euglena, but the problem of reduced paramylon dispersibility remained.

[0010] Furthermore, the synthesis and application of paramylon ester derivatives have been reported as paramylon derivatives. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2014-95159 [Patent Document 2] Japanese Patent Publication No. 2004-331837 [Patent Document 3] Patent No. 6029155 [Patent Document 4] Japanese Patent Publication No. 2023-86237 [Patent Document 5] Japanese Patent Publication No. 2012-211302 [Patent Document 6] Japanese Patent Publication No. 2022-169188 [Patent Document 7] Japanese Patent Publication No. 2021-31785 [Patent Document 8] Japanese Patent Publication No. 2017-218566 [Patent Document 9] Japanese Patent Publication No. 2021-31785 [Overview of the project] [Problems that the invention aims to solve]

[0012] As mentioned above, conventional paramylon dissolution methods have had various problems, including the safety and dissolution efficiency of the solvents used, as well as the solidification and moldability of the dissolved paramylon solution, making them extremely difficult to use in industrial production. Furthermore, because the solidification and wet moldability of the paramylon solution were not good, there was a need to develop a simple method for dissolving paramylon, as well as a method for producing a paramylon solution that has excellent quality, such as solidification and wet moldability, and is highly safe.

[0013] Furthermore, there is no disclosure regarding the synthesis or application of paramylon ether derivatives, which are paramylon derivatives, and the potential use of paramylon solutions remains unknown.

[0014] Therefore, the present invention aims to provide a β-1,3-glucan solution with excellent quality, such as solidification properties and wet moldability, and a new means for producing such a β-1,3-glucan solution. Furthermore, the present invention aims to provide a β-1,3-glucan ether derivative using the above-mentioned β-1,3-glucan solution and a new means for producing the same. [Means for solving the problem]

[0015] The inventors conducted diligent research to solve the above problems and found that when β-1,3-glucan is dissolved in a mixed solution of tetraalkylammonium hydroxide and water as a solvent, the resulting β-1,3-glucan solution exhibits excellent quality in terms of solidification and wet moldability. Furthermore, they discovered a simple method for producing a β-1,3-glucan solution, thus completing the present invention.

[0016] Furthermore, we discovered that the β-1,3-glucan solution produced as described above is suitable for the production of β-1,3-glucan ether derivatives, thus completing the present invention.

[0017] In other words, a preferred embodiment of the present invention provides the following β-1,3-glucan solution. [1] A β-1,3-glucan solution, (A) β-1,3-glucan, (B) tetraalkylammonium hydroxide represented by the following formula (1), and (C) water, comprising a β-1,3-glucan solution in which the concentration of (A) in the β-1,3-glucan solution is 1.0 to 35% by mass, the concentration of (B) is 1.0 to 40% by mass, and the concentration of (C) is 25 to 98% by mass. [Chemical formula] In the formula, R1, R2, R3 and R4 each independently represent an alkyl group having 1 to 4 carbon atoms.

[0018] Also provided is a method for producing the β-1,3-glucan solution described below. [2] A method for producing a β-1,3-glucan solution, comprising the step of adding (A) β-1,3-glucan to a solution containing (B) tetraalkylammonium hydroxide and (C) water and stirring the mixed solution.

[0019] Furthermore, provided is a method for producing a β-1,3-glucan ether derivative described below. [3] A method for producing a β-1,3-glucan ether derivative, comprising the step of adding an ether-modifying agent to the β-1,3-glucan solution described in [1] and stirring the mixed solution.

[0020] Furthermore, provided is a β-1,3-glucan ether derivative described below. [4] A β-1,3-glucan ether derivative synthesized by the production method described in [3]. [Advantages of the Invention]

[0021] When β-1,3-glucan is dissolved in a mixed solution of tetraalkylammonium hydroxide and water as a solvent, it is possible to provide a β-1,3-glucan solution with excellent quality, such as coagulation properties and wet moldability, as well as a simple method for producing such a β-1,3-glucan solution.

[0022] Furthermore, it is possible to provide a method for synthesizing ether derivatives using the above-mentioned β-1,3-glucan solution, and the ether derivatives thereof. [Brief explanation of the drawing]

[0023] [Figure 1] These are photographs of the appearance of the paramylon solutions prepared in Examples 1-3 and 6-9 of Test Example 1. [Figure 2] This is a photograph of the appearance of paramylon fibers obtained from the paramylon solution of Example 1 in Test Example 1. [Figure 3] These are photographs of the appearance of the beads obtained from the paramylon solution in Example 3 of Test Example 1, before and after drying. [Figure 4] This is a photograph of the appearance of the paramylon film obtained from the paramylon solution prepared in Example 8 of Test Example 1. [Figure 5] This is a photograph of the appearance of the paramylon film obtained from the paramylon solution prepared in Example 9 of Test Example 1. [Figure 6] These are photographs of the appearance of the paramylon solution and the spun yarn sample obtained therefrom in Comparative Example 1 of Test Example 1. [Figure 7] These are photographs of the appearance of the paramylon solutions prepared in Comparative Examples 1, 2, 4, 5, and 6 of Test Example 1. [Figure 8] These are the IR spectra of ethylparamylon and unmodified paramylon synthesized in Examples 14 and 15. [Modes for carrying out the invention]

[0024] [β-1,3-glucan solution] A β-1,3-glucan solution according to one embodiment of the present invention comprises (A) β-1,3-glucan, (B) tetraalkylammonium hydroxide, and (C) water.

[0025] Another embodiment of the present invention provides a β-1,3-glucan solution comprising (A) β-1,3-glucan, (B) tetraalkylammonium hydroxide, and (C) water, wherein (A) the β-1,3-glucan solution is a paramylon solution.

[0026] ((A)β-1,3-glucan) β-1,3-glucan is a type of polysaccharide in which glucose molecules are linked together by β-1,3-glycosidic bonds.

[0027] In this invention, β-1,3-glucan includes paramylon.

[0028] Paramylon is a type of linear β-1,3-glucan and a polysaccharide that is an intracellular storage substance produced by the Euglena genus.

[0029] The purity of the paramylon used in the present invention can be, for example, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, etc., but is not limited to these. Other examples include 100% by mass or less, 99% by mass or less, 98% by mass or less, 97% by mass or less, 96% by mass or less, etc. Among these, from the viewpoint of significantly achieving the effects of the present invention, 80% by mass or more is preferred, 85% by mass or more is more preferred, 90% by mass or more is even more preferred, and 95% by mass or more is even more preferred. Also, 100% by mass or less is preferred, 99% by mass or less is more preferred, 98% by mass or less is even more preferred, and 97% by mass or less is even more preferred.

[0030] The method for measuring the purity of paramylon is not particularly limited and can be any known method, but examples include the phenol-sulfuric acid method.

[0031] Examples of β-1,3-glucan raw materials in the present invention include commercially available β-1,3-glucan and paramylon. Among these, β-1,3-glucan and paramylon with a linear β-1,3-glucan content of 50% by mass or more are preferred from the viewpoint of significantly exhibiting the effects of the present invention.

[0032] The β-1,3-glucan in the present invention is not limited, but is preferably in solid or powder form.

[0033] The β-1,3-glucan content in the β-1,3-glucan solution of the present invention can be, for example, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, etc. Also, it can be 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 17.5% by mass or less, etc. Furthermore, it can be 2-35% by mass, 2-30% by mass, 2-25% by mass, 3-35% by mass, 3-30% by mass, 3-25% by mass, 5-35% by mass, 5-30% by mass, 5-25% by mass, etc., but is not limited to these. Among these, from the viewpoint of significantly exhibiting the effects of the present invention, 2% by mass or more is preferred, 3% by mass or more is more preferred, and 5% by mass or more is even more preferred. Also, 35% by mass or less is preferred, 30% by mass or less is more preferred, and 25% by mass or less is even more preferred. Furthermore, a β-1,3-glucan content of 2 to 35% by mass is preferred, 3 to 30% by mass is more preferred, and 5 to 25% by mass is even more preferred. A β-1,3-glucan content of less than 2% by mass is undesirable because it results in poor moldability and low productivity. Also, a β-1,3-glucan content exceeding 35% by mass is undesirable because it reduces the dissolution rate of β-1,3-glucan, and even if β-1,3-glucan dissolves, the viscosity of the β-1,3-glucan solution increases, reducing moldability, which is also undesirable.

[0034] ((B) Tetraalkylammonium hydroxide) In this invention, tetraalkylammonium hydroxide is represented by the following formula (1). [ka] In the formula, R1, R2, R3, and R4 each independently represent an alkyl group having 1 to 4 carbon atoms.

[0035] The tetraalkylammonium hydroxide used in the present invention includes, but is not limited to, tetramethylammonium hydroxide, tetraethylammonium hydroxide, propylammonium hydroxide, and tetrabutylammonium hydroxide. It may also be one of these or a mixture of two or more. In particular, from the viewpoint of significantly achieving the effects of the present invention, at least one selected from the group consisting of tetraethylammonium hydroxide, propylammonium hydroxide, and tetrabutylammonium hydroxide is preferred.

[0036] The tetraalkylammonium hydroxide used in this invention is not limited to solid or solution forms. From the viewpoint of stability, aqueous solutions or alcoholic solutions are preferred, and from the viewpoint of solubility, aqueous solutions are more preferred.

[0037] The content of tetraalkylammonium hydroxide in the β-1,3-glucan solution of the present invention is not particularly limited, but examples include 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, etc. Also, examples include 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 17.5% by mass or less, etc. Furthermore, examples include 2-40% by mass, 3-40% by mass, 4-40% by mass, 5-40% by mass, 2-35% by mass, 3-35% by mass, 4-35% by mass, 5-35% by mass, 2-30% by mass, 3-30% by mass, 4-30% by mass, 5-30% by mass, 2-25% by mass, 3-25% by mass, 4-25% by mass, 5-25% by mass, etc. In particular, from the viewpoint of significantly demonstrating the effects of the present invention, a content of 2% by mass or more is preferred, more preferably 3% by mass or more, even more preferably 4% by mass or more, and even more preferably 5% by mass or more. Furthermore, 40% by mass or less is preferred, more preferably 35% by mass or less, and even more preferably 30% by mass or less. Furthermore, 2 to 40% by mass is preferred, more preferably 3 to 35% by mass, even more preferably 4 to 30% by mass, and even more preferably 5 to 25% by mass. If the content of tetraalkylammonium hydroxide is less than 2% by mass, it may be difficult to dissolve β-1,3-glucan, or the solubility of β-1,3-glucan may decrease, which is undesirable because it reduces the moldability and productivity of the resulting β-1,3-glucan solution. Furthermore, if the content of tetraalkylammonium hydroxide exceeds 40% by mass, not only β-1,3-glucan but also tetraalkylammonium hydroxide may become unstable and decompose, which is undesirable. Furthermore, if the content of tetraalkylammonium hydroxide exceeds 40% by mass, the viscosity increases, which may reduce the solubility of paramylon.

[0038] The molar ratio of component (B) to component (A) in the present invention is not particularly limited, but examples include 0.2 or more, 0.3 or more, 0.35 or more, 0.4 or more, etc. Also, examples include 2.0 or less, 1.5 or less, 1.0 or less, 0.9 or less, etc. Furthermore, examples include 0.2 to 2.0, 0.2 to 1.5, 0.2 to 1.0, 0.2 to 0.9, 0.3 to 2.0, 0.3 to 1.5, 0.3 to 1.0, 0.3 to 0.9, 0.35 to 2.0, 0.35 to 1.5, 0.35 to 1.0, 0.35 to 0.9, 0.4 to 2.0, 0.4 to 1.5, 0.4 to 1.0, 0.4 to 0.9, etc. In particular, from the viewpoint of significantly exhibiting the effects of the present invention, a ratio of 0.2 or higher is preferred, 0.3 or higher is more preferred, 0.35 or higher is even more preferred, and 0.4 or higher is even more preferred. Furthermore, a ratio of 2.0 or lower is preferred, 1.5 or lower is more preferred, 1.0 or lower is even more preferred, and 0.9 or lower is even more preferred. Moreover, a ratio of 0.2 to 2.0 is preferred, 0.3 to 1.5 is more preferred, 0.35 to 1.0 is even more preferred, and 0.4 to 0.9 is even more preferred. A molar ratio of component (B) to component (A) of less than 0.2 is undesirable because it results in incomplete dissolution of β-1,3-glucan. Furthermore, a molar ratio exceeding 2.0 is undesirable because it makes the obtained β-1,3-glucan solution unstable, potentially leading to decomposition of β-1,3-glucan during storage, or because the viscosity of the obtained β-1,3-glucan solution becomes very high, resulting in poor moldability and potentially making it impossible to form the desired molded product.

[0039] ((C)Water) The water used in this invention is not particularly limited, but examples include groundwater, tap water, deionized water, pure water, ultrapure water, and RO water. Among these, groundwater, tap water, and deionized water are preferred from the viewpoint of significantly demonstrating the effects of this invention and from the viewpoint of production costs.

[0040] The water content in the β-1,3-glucan solution of the present invention is not particularly limited, but examples include 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, etc. Also, examples include 99% by mass or less, 98% by mass or less, 96.5% by mass or less, 95% by mass or less, 90% by mass or less, 88% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, etc. Furthermore, percentages such as 25-98% by mass, 25-96.5% by mass, 25-95% by mass, 25-90% by mass, 25-88% by mass, 30-98% by mass, 30-96.5% by mass, 30-95% by mass, 30-90% by mass, 30-88% by mass, 35-98% by mass, 35-96.5% by mass, 35-95% by mass, 35-90% by mass, 35-88% by mass, 40-98% by mass, 40-96.5% by mass, 40-95% by mass, 40-90% by mass, and 40-88% by mass are also mentioned. Among these, from the viewpoint of significantly exhibiting the effects of the present invention, 25% by mass or more is preferred, 30% by mass or more is more preferred, 35% by mass or more is even more preferred, 40% by mass or more is even more preferred, and 45% by mass or more is particularly preferred. Furthermore, 98% by mass or less is preferred, 96.5% by mass or less is more preferred, 95% by mass or less is even more preferred, 90% by mass or less is even more preferred, and 88% by mass or less is particularly preferred. Moreover, 25 to 98% by mass is preferred, 40 to 90% by mass is more preferred, 48 to 88% by mass is even more preferred, 50 to 85% by mass is even more preferred, and 55 to 83% by mass is particularly preferred.

[0041] (Other ingredients) The β-1,3-glucan solution of the present invention may contain other components as appropriate, in addition to the components (A) to (C) above. For example, it may contain sulfur-based solvents such as dimethyl sulfoxide (DMSO), nitrogen-based solvents such as dimethylacetamide (DMAc), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NPM), alcohols such as isopropyl alcohol (IPA), ethanol, and methanol, ketone-based solvents such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK), and ethers such as tetrahydrofuran (THF) and 1,4-dioxane, but is not limited to these.

[0042] Furthermore, if necessary, components other than those listed above may also be included in the β-1,3-glucan solution of the present invention. These are not particularly limited, as long as they do not affect the dissolution of paramylon or the storage stability of the paramylon solution, but examples include natural polymers such as cellulose, chitin, chitosan, chondroitin, and hyaluronic acid, as well as glycerin, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and polyvinyl alcohol. Additives such as pigments, fragrances, and antibacterial agents may also be included. In addition, inorganic nanoparticles, such as ceramic or metal-based materials, may also be included.

[0043] The amount of other components added to the β-1,3-glucan solution in this invention is not particularly limited as long as it does not affect the solubility of paramylon, but examples include 1 to 35% by mass, 5 to 25% by mass, etc.

[0044] The visible light transmittance of the β-1,3-glucan solution in the present invention is not particularly limited, but examples include 55% or more, 60% or more, 70% or more, 75% or more, 82.5% or more, 85% or more, etc. Also, examples include 95% or less, 94% or less, 93% or less, etc. Furthermore, examples include 55%~95%, 60%~95%, 70%~95%, 75%~95%, 82.5%~95%, 85%~95%, 55%~94%, 60%~94%, 70%~94%, 75%~94%, 82.5%~94%, 85%~94%, 55%~93%, 60%~93%, 70%~93%, 75%~93%, 82.5%~93%, 85%~93%, etc. In particular, from the viewpoint of significantly demonstrating the effects of the present invention, a visible light transmittance of 55% or more is preferred, 60% or more is more preferred, and 75% or more is even more preferred. Furthermore, 95% or less is preferred, 94% or less is more preferred, and 93% is even more preferred. Moreover, 55% to 95% is preferred, 60% to 94% is more preferred, and 75% to 93% is even more preferred. A visible light transmittance of less than 55% is undesirable because it may result in the presence of undissolved paramylon fine particles, which may reduce wet moldability and the physical properties of the final molded product. However, if other components such as inorganic particles are added to the β-1,3-glucan solution, the visible light transmittance may decrease due to the influence of the other components.

[0045] The visible light transmittance values ​​mentioned above were measured using a UV-Vis spectrophotometer. Examples of UV-Vis spectrophotometers include, but are not limited to, the UV-3600 manufactured by Shimadzu Corporation. In the following examples, the UV-3600 was used.

[0046] The β-1,3-glucan solution of the present invention can be used as a starting material.

[0047] The paramylon solution of the present invention can be used as a starting material for molded articles such as β-1,3-glucan fibers, films, or beads, but is not limited to these.

[0048] [Method for producing β-1,3-glucan fibers, films, and beads] One embodiment of the present invention is a method for producing β-1,3-glucan fibers, films, and beads using a β-1,3-glucan solution to produce molded articles of β-1,3-glucan fibers, films, or beads.

[0049] The β-1,3-glucan solution in this invention is the same as that described in the section [β-1,3-glucan solution] above.

[0050] The molded articles of the β-1,3-glucan fibers, films, or beads described above are not limited, but can be formed, for example, by wet spinning, wet film formation, or wet granulation using a β-1,3-glucan solution.

[0051] (Wet spinning method) The wet spinning method, similar to the rayon fiber forming method, involves extruding a paramylon solution from a nozzle into a coagulation solution to form fibers.

[0052] (Wet film formation method) The wet film deposition method, similar to the cellophane manufacturing method, involves pouring a polymer solution onto a smooth substrate or belt and then immersing them in a solidifying solution to form a film.

[0053] (Wet granulation method) Wet granulation methods include, but are not limited to, a method in which a paramylon solution is stirred in a coagulation liquid (dispersion medium) to disperse paramylon fine particles through a phase separation phenomenon between the paramylon solution and the dispersion medium, and then coagulates these particles; a method in which a paramylon solution is sprayed into a coagulation liquid from a nozzle with high-pressure gas to form fine particles; and a method in which a paramylon solution is drawn up with a dropper, dropped into a coagulation liquid, coagulated in the coagulation liquid, washed with distilled water or the like, and then dried to form fine particles.

[0054] The coagulation solution used when producing molded articles of β-1,3-glucan fibers, films, or beads from the β-1,3-glucan solution of the present invention as a starting material may be an acidic solution, but is not limited thereto. In particular, from the viewpoint of significantly demonstrating the effects of the present invention, it is preferably an acidic solution, more preferably an inorganic acid solution and / or an organic acid solution, even more preferably at least one selected from the group consisting of hydrochloric acid solution, sulfuric acid solution, nitric acid solution, phosphoric acid solution, acetic acid, and formic acid, and even more preferably at least one selected from the group consisting of aqueous hydrochloric acid solution, sulfuric acid solution, aqueous nitric acid solution, aqueous phosphoric acid solution, acetic acid, and formic acid.

[0055] The concentration of the acidic component in the above-mentioned coagulation solution is not particularly limited, but the higher the concentration, the higher the coagulation rate. In particular, from the viewpoint of significantly demonstrating the effects of the present invention, it is preferably 0.1 to 5 mol / L, more preferably 0.2 to 4 mol / L, even more preferably 0.25 to 3 mol / L, and even more preferably 0.3 to 2 mol / L.

[0056] Other conditions in the manufacturing method of the present invention shall be in accordance with the section on [β-1,3-glucan solution].

[0057] [Method for producing β-1,3-glucan solution] One embodiment of the present invention is a method for producing a β-1,3-glucan solution, which includes the step of stirring a mixed solution to which (A) β-1,3-glucan has been added to a solution containing (B) tetraalkylammonium hydroxide and (C) water.

[0058] In this invention, (A) β-1,3-glucan, (B) tetraalkylammonium hydroxide, and (C) water are the same as those described in the section on [β-1,3-glucan solution] above.

[0059] In the method for producing a β-1,3-glucan solution of the present invention, the stirring of the mixed solution, in which β-1,3-glucan is added to a solution containing tetraalkylammonium hydroxide and water, may be done manually, or by using a mechanical stirrer, magnetic stirrer, homogenizer, kneader, or the like.

[0060] The stirring time described above can be adjusted as appropriate depending on the composition of the solution and the concentration of paramylon, and is not particularly limited, but examples include 10 minutes or more, 20 minutes or more, 30 minutes or more, etc. Also, examples include 7 hours or less, 5 hours or less, 4 hours or less, 2 hours or less, 1 hour or less, etc. Among these, 20 minutes or more is preferred from the viewpoint of significantly achieving the effects of the present invention. Also, 5 hours or less is preferred. Furthermore, 20 minutes to 5 hours is preferred. In addition, the solution may be stirred until it becomes a uniform, transparent solution, regardless of the stirring time.

[0061] The temperature during stirring described above is not particularly limited, but examples include 5°C or higher, 10°C or higher, 15°C or higher, 20°C or higher, etc. Also, examples include 60°C or lower, 50°C or lower, 45°C or lower, 40°C or lower, 35°C or lower, 30°C or lower, etc. Furthermore, examples include 5-60°C, 5-50°C, 5-45°C, 5-40°C, 5-35°C, 5-30°C, 10-60°C, 10-50°C, 10-45°C, 10-40°C, 10-35°C, 10-30°C, 15-60°C, 15-50°C, 15-45°C, 15-40°C, 15-35°C, 15-30°C, 20-60°C, 20-50°C, 20-45°C, 20-40°C, 20-35°C, 20-30°C, etc. In particular, from the viewpoint of significantly exhibiting the effects of the present invention, a temperature of 10 to 50°C is preferred, 15 to 45°C is more preferred, 20 to 40°C is even more preferred, and 15 to 30°C is even more preferred.

[0062] Other conditions in the manufacturing method of the present invention shall be in accordance with the section on [β-1,3-glucan solution].

[0063] [Method for producing β-1,3-glucan ether derivatives] The present invention relates to a method for producing β-1,3-glucan ether derivatives.

[0064] In this specification, β-1,3-glucan ether derivatives are obtained by converting the hydroxyl groups contained in β-1,3-glucan to ether. By substituting the hydrogen atoms of the hydroxyl groups of β-1,3-glucan with methyl groups or the like to inhibit the formation of hydrogen bonds, solubility in water-soluble solvents or general-purpose organic solvents can be obtained. Paramylon is a type of β-1,3-glucan, and paramylon ether derivatives possess the inherent physiological activity of paramylon as well as properties such as solubility, viscosity, and adhesiveness similar to polysaccharide ethers, making them promising for applications in the pharmaceutical, cosmetic, food, and inorganic paint fields. Furthermore, by introducing ether functional groups, the glass transition temperature and crystal temperature of paramylon can be lowered, providing melt-processable moldability similar to general-purpose plastics, and thus offering potential applications as bioplastics.

[0065] Examples of β-1,3-glucan ether derivatives used in this manufacturing method include, but are not limited to, alkyl paramylons such as methylparamylon, ethylparamylon, ethylmethylparamylon, benzylparamylon, and butylparamylon; carboxymethylparamylon and carboxyethylparamylon having a carboxyl group at the terminal; or hydroxyalkylparamylons such as hydroxyethylparamylon and hydroxypropylparamylon having a hydroxyl group at the terminal. In particular, from the viewpoint of reducing the impact on living organisms and the natural environment, at least one or more from the group consisting of methylparamylon, ethylparamylon, ethylmethylparamylon, carboxymethylparamylon, hydroxyethylparamylon, and hydroxypropylparamylon is preferred.

[0066] Furthermore, in other embodiments, the β-1,3-glucan ether derivative is preferably an ether functional group with a large sterically bulky structure, from the viewpoint of imparting melt processability and thermoplasticity to the paramylon ether derivative. Examples include alkyl groups with 3 to 18 carbon atoms, such as benzylparamylon, butylparamylon, and laurylparamylon. Moreover, it is preferable to introduce both a small and a large functional group simultaneously, as this disrupts the symmetry of the paramylon molecular chain and further improves thermoplasticity. Examples of small functional groups include ethyl groups and propyl groups.

[0067] In this specification, the number of etherified hydroxyl groups in a β-1,3-glucan ether derivative represents the degree of substitution (DS), which is the average number of hydroxyl groups substituted with ether groups per glucose ring unit of paramylon. The degree of substitution can be measured by methods such as NMR. In the present invention, the degree of substitution can be appropriately adjusted by controlling the reaction conditions depending on the type of ether group and its application. For example, it can be adjusted in the range of 0.5 to 2.8, but is not limited to this range. In particular, from the viewpoint of significantly exhibiting the effects of the present invention, the degree of substitution is preferably 0.5 to 2.8, more preferably 0.6 to 2.5, and even more preferably 0.8 to 2.0. If the degree of substitution is too low or too high, solvent solubility and melt processability cannot be exhibited, which is undesirable. When solubility is desired, the optimal degree of substitution can be appropriately adjusted depending on the type of functional group and the type of solvent in which it is dissolved, but is preferably 0.5 to 2.8, and more preferably 0.8 to 2.5. On the other hand, in order to impart melt processability or thermoplasticity, the degree of substitution is preferably 1 to 2.8, and more preferably 1.5 to 2.5. In this specification, the degree of substitution is the value measured by NMR.

[0068] This manufacturing method includes, but is not limited to, a method in which an ether modifying agent is added to the β-1,3-glucan solution obtained above, the mixture is stirred at a predetermined temperature and time, the reactants are recovered by precipitation in a poor solvent, and the reactants are washed to prepare the ether derivative.

[0069] The β-1,3-glucan solution used as a raw material in this manufacturing method shall conform to the provisions of the [β-1,3-glucan solution] section.

[0070] The ether modifying agent in this manufacturing method is not particularly limited and can be appropriately selected depending on the intended use of the resulting paramylon ether derivative. Examples include alkyl halides and aryl halides. Among these, alkyl halides or aryl halides are preferred from the viewpoint of significantly exhibiting the effects of the present invention. Examples of alkyl halides include methyl bromide, ethyl bromide, propyl bromide, butyl bromide, benzyl bromide, lauryl bromide, methyl chloride, ethyl chloride, propyl chloride, butyl chloride, benzyl chloride, and lauryl chloride. Among these, alkyl bromides are preferred from the viewpoint of reactivity, and ethyl bromide is more preferred.

[0071] Poor solvents used in this manufacturing method include, for example, single solvents such as water, acetone, and isopropanol, or mixed solutions thereof, but vary depending on the degree of substitution with the ether group. It is not limited to these, as long as it is a poor solvent capable of precipitating paramylon ether derivatives.

[0072] In this manufacturing method, a mixed solution containing β-1,3-glucan solution and an ether modifying agent should be stirred within the following temperature range. Stirring may be done manually, or using equipment such as a mechanical stirrer, magnetic stirrer, homogenizer, or kneader.

[0073] The stirring time described above can be appropriately adjusted depending on the temperature, the composition of the solution, and the concentration of the β-1,3-glucan solution or paramylon solution, and is not particularly limited, but can be adjusted in the range of 20 minutes to 10 hours, for example. Since the etherification reaction can be carried out with high efficiency by using the β-1,3-glucan solution described above, it is preferably 30 minutes to 8 hours, more preferably 1 to 6 hours, and even more preferably 1 to 4 hours.

[0074] The stirring temperature described above can be appropriately selected within the range of 10 to 150°C, but is not limited thereto. In particular, from the viewpoint of significantly exhibiting the effects of the present invention, 15 to 120°C is preferred, and 20 to 100°C is more preferred.

[0075] Other conditions in this manufacturing method shall be in accordance with the section on [β-1,3-glucan solution].

[0076] [β-1,3-glucan ether derivatives] This invention relates to β-1,3-glucan ether derivatives. One embodiment of the present invention is paramylon ether. Paramylon ether obtained in a homogeneous reaction system has superior quality in terms of solvent solubility, melt plasticity, mechanical properties, heat resistance, etc., compared to paramylon ether obtained in a heterogeneous surface reaction system, because the ether group can be uniformly introduced into the paramylon molecular chain. It also exhibits excellent reproducibility.

[0077] The present invention is synthesized by a manufacturing method in accordance with the description in the above-mentioned [Method for Producing β-1,3-Glucan Ether Derivatives].

[0078] The present invention includes the following embodiments. [1] A β-1,3-glucan solution, (A) β-1,3-glucan, (B) Tetraalkylammonium hydroxide represented by the following formula (1), and (C) Water; Includes, A β-1,3-glucan solution in which the concentration of (A) is 1.0 to 35% by mass, the concentration of (B) is 1.0 to 40% by mass, and the concentration of (C) is 25 to 98% by mass. [ka] In the formula, R1, R2, R3, and R4 each independently represent an alkyl group having 1 to 4 carbon atoms. [2] The β-1,3-glucan solution of [1] comprising (B) tetraalkylammonium hydroxide, selected from the group consisting of tetraethylammonium hydroxide, propylammonium hydroxide, and tetrabutylammonium hydroxide. [3] A β-1,3-glucan solution of [1] or [2], wherein the (A)β-1,3-glucan is paramylon. [4] A molded body of β-1,3-glucan fibers, film, or beads, comprising using the β-1,3-glucan solution of [1] to produce a molded body of β-1,3-glucan fibers, film, or beads. [5] A method for producing a β-1,3-glucan solution, comprising the steps of adding (A) β-1,3-glucan to a solution containing (B) tetraalkylammonium hydroxide and (C) water, and stirring the mixed solution. [6] A method for producing a β-1,3-glucan ether derivative, comprising the steps of adding an ether modifying agent to the β-1,3-glucan solutions of [1] to [3] and stirring the mixed solution. [7] A method for producing [6], wherein the ether modifying agent is an alkyl halide or an aryl halide. [8] A β-1,3-glucan ether derivative synthesized by the manufacturing method of [6]. [Examples]

[0079] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0080] [Test Example 1: Test to confirm the dissolution time of paramylon and the moldability of paramylon solution] The following raw materials and solvents were used. (1) Paramylon derived from the Euglena genus (purity 90-100% by mass) (2) 40% tetrabutylammonium hydroxide aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd.) (3) 40% tetrapropylammonium hydroxide aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd.) (4) 35% tetraethylammonium hydroxide aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0081] (Measurement of paramylon purity) The purity of the paramylon derived from the Euglena genus used in Test Example 1 was measured by the phenol-sulfuric acid method. The measurement method is as follows. (1) Dissolve a predetermined amount of paramylon in a 1 mol / L aqueous sodium hydroxide solution, (2) Dilute the above solution with a 5% by mass aqueous phenol solution and stir with a vortex mixer. (3) After stirring, a 90% by mass aqueous sulfuric acid solution was added to the solution and allowed to stand for 30 minutes until the reaction stabilized. Then, the absorbance at 490 nm was measured using a spectrophotometer, and the amount of paramylon contained in the solution was calculated from the obtained absorbance.

[0082] (Method for forming paramylon films using a wet molding method) A paramylon solution was applied to a glass plate, and the coated glass plate was placed in a solidification solution (1 mol / L hydrochloric acid aqueous solution) to solidify. After solidification into a film-like gel, the solidified body (film-like gel) was washed with distilled water, then placed on a PET film and left to dry overnight at room temperature (23°C, the same applies below), and the film thickness was measured. The film thickness was measured using a micrometer. The following examples and comparative examples were measured in the same manner.

[0083] (Method for forming paramylon yarn using a wet molding method) 6-8 ml of paramylon solution was drawn up into a 10 ml syringe, a plastic needle (PN-23G-B, manufactured by Musashi Engineering Co., Ltd.) was attached to the syringe, and the solution was pushed into a 1 mol / L hydrochloric acid aqueous solution at room temperature while being pulled to allow it to solidify. After solidification, the solidified material (fibrous gel) was washed with distilled water. The solidified material was left on a glass plate and dried overnight at room temperature, and the fiber diameter was measured. The diameter was observed and measured using a microscope. The following examples and comparative examples were observed and measured in the same manner.

[0084] (Tensile test of paramylon film) The tensile test of the paramylon film was performed under the following conditions.

[0085] Tensile testing of the paramylon film was performed using a dumbbell-shaped die to punch out five specimens from the paramylon film. The thickness of each specimen was measured, and then measured again using a tensile testing machine. The values ​​for each specimen were then averaged. The tensile testing of the paramylon film was performed using a MinebeaMitsumi tensile and compression testing machine. The measurement temperature was 23°C, and the tensile speed was 0.5 mm / min.

[0086] (Tensile test of paramylon yarn) The tensile test of the paramylon yarn was performed under the following conditions.

[0087] The tensile strength of the paramylon yarn was measured in accordance with JIS L1095, "9.5 Tensile Strength and Elongation of Single Yarns," "9.5.1 JIS Method." The tensile test was performed using a MinebeaMitsumi tensile and compression testing machine. The measurement temperature was 23°C and the tensile speed was 0.5 mm / min.

[0088] (Example 1) The paramylon solution was prepared using the following method. (1) Add 1 g of 40% tetrabutylammonium hydroxide (TBOH) aqueous solution and 4 g of distilled water to a 10 ml vial. While stirring at room temperature with a magnetic stirrer at medium speed, add 0.55 g of paramylon and continue stirring. (2) After stirring for a certain period of time, a uniform, transparent paramylon solution was obtained.

[0089] The solution was observed at regular time intervals, and the point at which it became a uniform, transparent solution was defined as the point at which paramylon had completely dissolved. The dissolution time from the start of stirring to the point of complete dissolution was then measured.

[0090] Tables 1-1 and 1-2 show the composition, dissolution time, and wet moldability evaluation of the solution in Example 1. Figure 1 shows a photograph of the solution at the point when the paramylon was completely dissolved.

[0091] Six ml of the paramylon solution obtained above was drawn up into a 10 ml syringe, fitted with a plastic needle (PN-23G-B, manufactured by Musashi Engineering Co., Ltd.), and dispensed into a 1 mol / L hydrochloric acid aqueous solution at room temperature to form a fibrous transparent gel. Subsequently, the fibrous transparent gel was washed with distilled water to remove residual tetrapropylammonium hydroxide and hydrochloric acid, and the gel was air-dried overnight at room temperature to obtain a paramylon yarn with a diameter of 39 μm. Tensile tests conducted according to the conditions of the "Tensile Test of Paramylon Yarn" described above showed a strength of 186 MPa and an elastic modulus of 4910 MPa. The elongation (tensile strain) was 49%.

[0092] The elongation (tensile strain) was calculated using the following formula (2).

[0093]

number

[0094] The paramylon solution obtained in Example 1 was left standing for 10 days, but no change in viscosity or moldability was observed. From this result, it is presumed that no degradation of the paramylon polymer chain occurred during the standing period, and the molecular weight was maintained to a high degree.

[0095] (Examples 2-5, 11) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, TBOH aqueous solution, and distilled water listed in Table 1-1 to achieve the compositions shown in Table 1-2, and then evaluated. The composition, dissolution time, and wet moldability of each solution are shown in Tables 1-1 and 1-2.

[0096] The paramylon solution prepared in Example 2 was drawn up with a dropper and added dropwise to a 1 mol / L hydrochloric acid aqueous solution. After addition, the solidified wet beads were washed with distilled water and air-dried at room temperature overnight to obtain dried beads. Figure 3 shows the appearance of the wet beads before drying and the dried beads after drying.

[0097] (Examples 6-10, 12-13) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, tetraethylammonium (TEOH) or tetrapropylammonium (TPOH) aqueous solution, and distilled water listed in Table 2-1 to achieve the compositions shown in Table 2-2, and then evaluated. The composition, dissolution time, and wet moldability of each solution are shown in Tables 2-1 and 2-2.

[0098] The paramylon solutions obtained in Examples 8 and 9 were applied to separate glass plates, and the glass plates were placed in a 1 mol / L sulfuric acid aqueous solution to solidify. After washing with distilled water, the plates were dried at room temperature overnight to obtain paramylon films with a thickness of 42 μm. The paramylon films obtained using Examples 8 and 9 are shown in Figures 4 and 5.

[0099] Tensile tests were conducted according to the conditions for the "Tensile Test of Paramylon Yarn" described above. The strength of the film obtained in Example 8 was 97 MPa, and its modulus was 2690 MPa. The elongation (tensile strain) calculated using formula (2) above was 52%. The strength of the film obtained in Example 9 was 91 MPa, and its modulus was 2100 MPa. The elongation (tensile strain) calculated using formula (2) above was 39%.

[0100] The paramylon solutions obtained in Examples 2-13 were left to stand for 10 days in the same manner as in Example 1, but no changes in viscosity or moldability were observed. From these results, it is presumed that no degradation of the paramylon polymer chains occurred during the standing period, and that the molecular weight was maintained to a high degree.

[0101] (Comparative Examples 1-3) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, TBOH aqueous solution, and distilled water listed in Table 1-1 to achieve the compositions shown in Table 1-2, and then evaluated. The composition, dissolution time, and wet moldability of each solution are shown in Tables 1-1 and 1-2.

[0102] Spinning was attempted using the paramylon solution of Comparative Example 1 in the same manner as in Example 1, but spinning was not possible. The appearance of the solution and spinning test sample of Comparative Example 1 is shown in Figure 6. Furthermore, when the solution of Comparative Example 1 was left overnight, the viscosity of the solution decreased significantly and the color changed to black. This decrease in viscosity and discoloration is thought to be due to the decomposition of paramylon. In addition, attempts were made to form beads in Comparative Examples 1 to 3, similar to Example 2, but the solidification rate was slow in all of Comparative Examples 1 to 3, and the formation of fibers or beads was not possible.

[0103] (Comparative Example 4) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, TPOH aqueous solution, and distilled water listed in Table 2-1 to achieve the composition shown in Table 2-2, and then evaluated. The composition of the solutions, dissolution time, and wet moldability are shown in Tables 2-1 and 2-2.

[0104] (Comparative Example 5) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, TEOH aqueous solution, and distilled water listed in Table 2-1 to achieve the composition shown in Table 2-2, and then evaluated. The composition of the solutions, dissolution time, and wet moldability are shown in Tables 2-1 and 2-2.

[0105] (Comparative Examples 6-9) Paramylon solutions were prepared using the same procedure as in Example 1, with the amounts of paramylon, sodium hydroxide (NaOH), and distilled water listed in Table 3-1 to achieve the compositions shown in Table 3-2, and then evaluated. The composition, dissolution time, and wet moldability of each solution are shown in Tables 3-1 and 3-2.

[0106] The wet moldability was evaluated as follows.

[0107] (Evaluation criteria for wet moldability) ○: It can dissolve paramylon and has good moldability. Furthermore, it allows for easy acquisition of desired molded products (threads, films, or beads). △: Paramylon can be dissolved, but the solidification rate is slow. Moldability is low, but it is possible to obtain the desired molded product (thread, membrane, or beads). ×: Although it can dissolve paramylon, its high viscosity either causes it to lose fluidity or it will not solidify at all in the solidification solution, and the paramylon will diffuse into the solidification solution, making it impossible to mold.

[0108] [Table 1-1]

[0109] [Table 1-2]

[0110] [Table 2-1]

[0111] [Table 2-2]

[0112] [Table 3-1]

[0113] [Table 3-2]

[0114] (Method for measuring visible light transmittance) Each prepared paramylon solution was placed in a quartz cell with a path length of 10 mm and measured using a UV-Vis spectrophotometer. Visible light transmittance at a wavelength of 589 nm (D-line) was evaluated. The measurement conditions were as follows:

[0115] Measuring device: UV-3600 (manufactured by Shimadzu Corporation) Measurement wavelength range: 400nm~800nm

[0116] Table 4 shows the visible light transmittance of the paramylon solutions obtained in Examples 1-14 and Comparative Examples 1-9.

[0117] [Table 4]

[0118] As shown in Tables 1-1, 1-2, 2-1, and 2-2, in Examples 1 to 13, paramylon could be easily dissolved even when the molar ratio of tetraalkylammonium hydroxide to paramylon was 0.7 or less. Furthermore, the solutions obtained in each example did not decrease in viscosity even after being left for a long time, maintaining high molecular weight and moldability, and the resulting paramylon solutions exhibited excellent wet moldability.

[0119] On the other hand, in Comparative Examples 6-9, when the molar ratio of sodium hydroxide to paramylon was 0.74 or less, the paramylon stopped dissolving. When the molar ratio was 1.16 or more, the paramylon could be dissolved, but the solidification of the resulting paramylon was extremely slow, making wet molding impossible.

[0120] Furthermore, since the paramylon polymers in each solution of Examples 1 to 13 were stable, it is expected that they will improve the physical properties of the final molded product.

[0121] (Example 14) A paramylon solution was prepared using the same composition and dissolution method as in Example 3. Specifically, 3 g of 40% TBOH aqueous solution and 7 g of distilled water were added to a 20 ml vial. While stirring at a medium speed with a magnetic stirrer at room temperature, 1.5 g of paramylon was added and stirred until a homogeneous clear solution was obtained. 2.1 ml of ethyl bromide was added to the obtained paramylon solution and stirred at room temperature for 2 hours. The solution was then precipitated in a mixed solvent of 15 ml of acetone and 35 ml of isopropanol, and washed with the same mixed solvent. After drying in a forced-air dryer at 105°C for 5 hours, the solution was analyzed by FT-IR.

[0122] The measured IR spectra are shown in Figure 8. Compared with the IR spectrum of the unmodified dried paramylon beads obtained in Example 3, the IR spectrum of Example 14 at 2900 cm⁻¹ was found to be different. -1 ~3000cm -1An absorption band of the ethyl group was detected between these points. Furthermore, both were detected at 3100 cm⁻¹. -1 ~3700cm -1 An absorption band originating from the OH group exists between the peaks, but compared to the unmodified paramylon of Example 3 (corresponding to "paramylon" in Figure 8), the peak in Example 14 is smaller and shifted to a higher frequency range, confirming that ethylparamylon was synthesized. Furthermore, the degree of substitution of Example 14 was 1.2 as measured by 1H-NMR.

[0123] The ethylparamylon obtained in Example 14 was soluble in common solvents such as DMSO, water, or methanol (single solvent or mixture). This confirmed that the paramylon solution obtained in the above example is suitable as a raw material for the synthesis of paramylon ether.

[0124] (Example 15) 11.1 g of paramylon solution was prepared using the same composition and dissolution method as in Example 6. 2.3 ml of ethyl bromide was added to the paramylon solution, and the mixture was stirred at room temperature for 3 hours. After precipitation, washing, and drying using the same method as in Example 14, the solution was analyzed by FT-IR.

[0125] The measured IR spectra are shown in Figure 8. Similar to Example 14, it was confirmed that ethylparamylon was synthesized in Example 15. Furthermore, 1H-NMR measurements showed that the degree of substitution in Example 15 was 1.6.

[0126] The ethylparamylon obtained in Example 15 could also be dissolved in common solvents such as DMSO, water, or methanol, similar to Example 14. [Industrial applicability]

[0127] By using the β-1,3-glucan solution of the present invention as a starting material, it is possible to mold β-1,3-glucan fibers, membranes, or beads by a wet molding method. Furthermore, because the β-1,3-glucan solution of the present invention has excellent coagulation and moldability, it can be widely applied in the technical fields of manufacturing β-1,3-glucan molded products. Moreover, the β-1,3-glucan solution of the present invention can be reused after use by recovering and concentrating tetraalkylammonium hydroxyside. In addition, because the β-1,3-glucan solution of the present invention can dissolve high concentrations of β-1,3-glucan, it has high industrial production efficiency.

[0128] Furthermore, paramylon ether is water-soluble or soluble in common organic solvents. Because paramylon ether possesses the properties of cellulose ether in addition to the inherent physiological activity of paramylon, it is expected to have applications in the pharmaceutical, cosmetic, and food industries.

Claims

1. A β-1,3-glucan solution, (A) β-1,3-glucan, (B) Tetraalkylammonium hydroxide represented by the following formula (1), and (C) water; Includes, A β-1,3-glucan solution in which the concentration of (A) is 1.0 to 35% by mass, the concentration of (B) is 1.0 to 40% by mass, and the concentration of (C) is 25 to 98% by mass. 【Chemistry 1】 In the formula, R １ , R ２ , R ３ and R ４ Each of these independently represents an alkyl group having 1 to 4 carbon atoms.

2. The β-1,3-glucan solution according to claim 1, wherein the (B) tetraalkylammonium hydroxide comprises at least one selected from the group consisting of tetraethylammonium hydroxide, propylammonium hydroxide, and tetrabutylammonium hydroxide.

3. The β-1,3-glucan solution according to claim 1, wherein the (A)β-1,3-glucan is paramylon.

4. A molded body of β-1,3-glucan fibers, film, or beads, manufactured using the β-1,3-glucan solution described in claim 1.

5. A method for producing a β-1,3-glucan solution, comprising the steps of adding (A) β-1,3-glucan to a solution containing (B) tetraalkylammonium hydroxide and (C) water, and stirring the mixed solution.

6. A method for producing a β-1,3-glucan ether derivative, comprising the steps of adding an ether modifying agent to a β-1,3-glucan solution according to any one of claims 1 to 3, and stirring the mixed solution.

7. The manufacturing method according to claim 6, wherein the ether modifying agent is an alkyl halide or an aryl halide.

8. A β-1,3-glucan ether derivative synthesized by the manufacturing method described in claim 6.

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