JP7223006B2 - Method for producing cellulose monolith and cellulose monolith obtained by said method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel method for producing a cellulose monolith and a cellulose monolith obtained by the method.

In recent years, the development and application of recyclable materials have been required in various fields from the viewpoint of resource problems, waste disposal, and environmental conservation. Cellulose is one of the materials attracting attention as its resource. Cellulose is a macromolecular material produced by living organisms with the highest production volume on earth, and is a renewable macromolecular resource. Cellulose is a hydrophilic, chemically and physically stable compound that can be modified to add various functional groups to its surface. As one method of utilizing cellulose, many attempts have been made to increase the specific surface area while maintaining the properties of cellulose. As one of them, cellulose is made into a monolith, and its high specific surface area matrix is utilized to apply it to adsorbents, enzyme immobilization, catalyst carriers, etc. Furthermore, by chemically modifying its surface, not only adsorption but also chromatography packing material , sensors, and ion-exchange resins. The monolith in the present invention is a mass of porous body having a continuous skeleton and voids, and has a high porosity (e.g., void ratio of 20% by volume or more) and a specific surface area (e.g., 10 m ² /g or more). refers to materials with Therefore, a monolith is a material that also has properties such as high air permeability, high liquid permeability, high strength, and light weight. A cellulose monolith refers to a monolith whose skeleton is mainly (for example, 90% by mass or more of the skeleton) made of a cellulose material.

So far, as a method for producing a cellulose monolith containing porous spherical cellulose, for example,
(1) A method of dropping a cellulose acetate solution described in Non-Patent Documents 1 and 2, Patent Documents 1 to 4, etc. into an aqueous medium, followed by deacetylation;
(2) A method of dropping a cellulose acetate solution previously added with water and acid and/or alkali into an aqueous medium, as described in Non-Patent Document 3, Patent Documents 5 to 7, etc.
(3) A method of forming a W/O emulsion from a cellulose acetate solution and deacetylating it, as described in Patent Document 8, etc.
(4) A method of making from a solution using a calcium thiocyanate salt described in Patent Documents 9 to 10, etc.
(5) a method of obtaining porous microparticle cellulose particles by spray-drying a microparticle cellulose slurry, as described in Patent Documents 11 to 12;
(6) a method of emulsifying a cellulose acetate solution and then deacetylating it, as described in Patent Document 13;
(7) A method of dispersing an aqueous solution of cellulose acetate in an organic solvent in the presence of a surfactant, adding water, and then deacetylating the method and the packing material for chromatography obtained by the method, described in Patent Document 14 and the like;
(8) A method of foaming a calcium carbonate-containing aqueous viscose dispersion at the same time as it is solidified, as described in Patent Document 15, etc.
(9) A method of dispersing and solidifying an ionic liquid of cellulose in an organic solvent or an aqueous medium, as described in Non-Patent Document 4, Patent Documents 16-17, etc.
(10) A method of suspending and granulating an alkali cellulose solution, described in Non-Patent Document 5, Patent Documents 18 to 19, etc.
(11) A method of converting an alkali/urea solution of cellulose into a hydrogel cellulose porous membrane in a poor solvent, which is described in Patent Document 20 and the like, is known.

Further, Patent Document 21 discloses a porous cellulose medium obtained by low-temperature mixing of a cellulose acetate solution, a deacetylating agent and a catalyst, but gelation of the medium itself is caused by deacetylation. Yes, it requires a catalyst. Further, in order to obtain particles by this method, there is a problem that a dispersion medium such as a surfactant or liquid paraffin is required, and the process becomes complicated.

Japanese Patent Publication No. 55-39565 Japanese Patent Publication No. 55-40618 JP-A-63-95237 Japanese Patent Application Laid-Open No. 62-277401 JP-A-57-38801 WO2016/159334 WO2016/012368 JP-A-63-83144 Japanese Patent Publication No. 63-62252 JP 2003-326145 A JP-A-2-84401 JP-A-9-132601 JP-A-6-145202 WO2015/029790 JP-A-2001-323095 Japanese Patent Application Laid-Open No. 2011-214003 JP 2012-87202 A Japanese Unexamined Patent Application Publication No. 2011-209221 JP 2016-153449 A JP 2012-206063 A WO2017/195884

L. F. Chen et. al. , Biotechnol. Bioeng. 18 (1976), 1507, K. Ono et. al. , Kobunshi Ronbunshu 42 (1985), 219 Yong-Xao Bai et. al. , Carbohydrate Polymers 64 (2006) 402 K. Du, J.; Chromatogr. A, 40 (2017) 1494 Na Zhang et. al, J. Appl. Polym. Sci. 131 (2014), 40987

These known methods for producing cellulose monoliths are to deacetylate cellulose acetate to gel and form a monolith, or to form a monolith from dissolved cellulose, or to form a monolith followed by deacetylation. A simpler method of making a cellulose monolith is desired.

The present invention has been made in view of the above circumstances, and provides an epoch-making method for producing a cellulose monolith of any shape from cellulose acylate in one step. That is, the method for producing a cellulose monolith of the present invention provides the following inventions.
(1) A cellulose acylate solution is brought into contact with a medium containing water and a deacylating agent to deacylate while exchanging the solvent with water, or a cellulose formate solution is mixed with water and a deformylating agent. A method for producing a cellulose monolith, which comprises contacting a medium containing the cellulose monolith and deformylating the cellulose monolith while exchanging the solvent with water.
(2) A cellulose acylate solution is added dropwise to a stirring medium containing water and a deacylating agent, and deacylated while exchanging the solvent with water to obtain cellulose monolith particles, or a cellulose formate solution is 4. A method for producing a cellulose monolith, which is characterized in that it is added dropwise to a medium containing water and a deformylating agent under stirring, and deformylated while exchanging the solvent with water to obtain cellulose monolith particles.
(3) The shaped cellulose acylate solution is brought into contact with a medium containing water and a deacylating agent, and deacylated while exchanging the solvent with water to obtain a cellulose monolith shaped body, or a shaped cellulose. 1. A method for producing a cellulose monolith, comprising contacting a formate solution with a medium containing water and a deformylating agent, and subjecting the solution to deformylation while exchanging the solvent with water to obtain a cellulose monolith shaped article.
(4) contacting a cellulose acylate molded product formed by cooling a cellulose acylate solution to a temperature below its melting point with a medium containing water, or cooling a cellulose formate solution to a temperature below its melting point; A method for producing a cellulose monolith, comprising contacting a molded cellulose formate molded article with a medium containing water.
(5) A method for producing a cellulose monolith, which comprises heat-treating a cellulose monolith in the presence of urea and phosphoric acid (salt).

In addition, the cellulose monolith of the present invention provides the following inventions.
(i) A cellulose monolith in which one or more other cellulose monolith layers are laminated on a cellulose monolith layer.
(ii) a white cellulose monolith containing colored particles;
(iii) a cellulose monolith having carbamoyl groups; The cellulose monolith (iii) may further have a phosphate group.
(iv) a cellulose monolith having a retained water absorption in saline of at least 8 g/g;

Furthermore, the present invention provides a fluid heterogeneous composition obtained by mixing a cellulose acylate solution or a cellulose formate solution and an aqueous sodium hydroxide solution.

Furthermore, the present invention provides a molded article obtained by cooling a cellulose acylate solution and/or a cellulose formate solution to a temperature below the melting point thereof.

According to the present invention, using a cellulose acylate solution as a starting material, 1) a monolith in which the skeleton forming the monolith is mainly (for example, 90% by mass or more) made of a cellulose material, 2) in an arbitrary shape, 3) one It has the characteristics of 4) being able to be made at room temperature without requiring energy such as heating, 5) being safe, and 6) being simple. As the monolith, a monolith consisting of a 100% pure cellulose skeleton is preferred.

1 is a scanning electron microscope (SEM) photograph of the particle surface of a cellulose monolith particle of one embodiment of the present invention obtained in Example 1. FIG. 1 is an SEM photograph of the inside of a cellulose monolith particle of one embodiment of the present invention obtained in Example 1. FIG. 4 is an SEM photograph of the surface of cellulose monolith particles obtained in Comparative Example 1. FIG. 4 is an SEM photograph of the inside of the cellulose monolith particles obtained in Comparative Example 1. FIG. 1 is an FT-IR chart of cellulose monolith particles of one embodiment of the present invention obtained in Example 1 and cellulose monolith particles obtained in Comparative Example 1. FIG. 4 is an SEM photograph of the inside of the sheet-like cellulose monolith molded body obtained in Example 16. FIG. 10 is a stereoscopic micrograph of the appearance of cellulose monolith particles (14) obtained in Example 25. FIG. 10 is a stereomicrograph of a cross section of the cellulose monolith particles (14) obtained in Example 25 after absorbing water. FIG. 10 is a stereomicrograph of a cross section of another cellulose monolithic particle (14) obtained in Example 25 and a cross section after dyeing with an aqueous Congo red solution. FIG. 10 is a stereomicrograph of a cross section of another cellulose monolithic particle (14) obtained in Example 25 and a cross section after dyeing with an aqueous Congo red solution. 10 is a stereomicrograph of a cross section of cellulose monolith particles containing activated carbon and titanium oxide obtained in Example 26. FIG. 10 is a stereomicroscopic photograph of a cellulose monolith molded body containing activated carbon inside obtained in Example 28 and its cross section. 10 is a stereoscopic micrograph of a section of a cellulose monolith molded body containing activated carbon inside obtained in Example 28, dyed with a dye. 11 is a photograph of a butterfly-shaped cellulose monolith molded body obtained in Example 36. FIG. 10 is an optical micrograph of activated carbon-encapsulating cellulose monolith particles obtained in Example 45. FIG. 10 is an optical micrograph of a cross section of activated carbon-encapsulating cellulose monolith particles obtained in Example 45. FIG.

As a method of making a polymer monolith, a method utilizing phase separation of a polymer solution is known. As such a phase separation method, a non-solvent induced phase separation method (NIPS method, Non-solvent Induced Phase Separation) that induces phase separation by incorporating a non-solvent (water) (solvent exchange), phase separation is induced by cooling A thermally induced phase separation method (TIPS method), a polymerization (reaction) induced phase separation method (PIPS) in which phase separation proceeds with a polymerization reaction, and the like are known. In the present invention, the monolith is made by solvent exchange, the so-called NIPS method, which involves deacylation using water containing a deacylating agent (a medium containing water and a deacylating agent), or It is characterized by involving deformylation using water containing a deformylating agent (a medium containing water and a deformylating agent).

The cellulose acylate used as a starting material in the present invention may be any one that forms a monolith by solvent exchange with water. Examples of such compounds include cellulose monoacetate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate and cellulose acetate butyrate. Among them, cellulose acetate, which is industrially easily available, can be preferably used.

Cellulose formate used as a raw material in the present invention includes cellulose monoformate, cellulose diformate, and the like.

Typical physical properties of cellulose acetate or cellulose formate include degree of polymerization and degree of substitution. In the present invention, the degree of polymerization is preferably 50 or more in mass average from the viewpoint of increasing the mechanical strength of the resulting cellulose monolith and preventing elution into the solvent during use. On the other hand, any available upper limit can be used. The degree of substitution affects the solubility of cellulose acetate or cellulose formate. The degree of substitution in acetylcellulose or cellulose formate is a numerical value indicating how many of the three hydroxyl groups per glucose repeating unit of cellulose are esterified (acetylated or formylated). In general, those having a degree of substitution with acetyl groups of around 2.8 to 2.9 are widely used as triacetates, and those having a degree of substitution of around 2.4 to 2.5 are industrially used as diacetates. In the present invention, any cellulose acetate or cellulose formate may be used as long as it forms a monolith by solvent substitution with water.

The solvent for forming the cellulose acylate solution or cellulose formate solution in the present invention is required to have a high dissolving power for the cellulose acylate or cellulose formate and to form a monolith by solvent exchange with water. . Adding water in advance to the cellulose acylate solution or cellulose formate solution is not preferable from the viewpoint of the possibility of inducing phase separation and the storage stability of the cellulose acylate solution or cellulose formate solution. Therefore, in the present invention, no new water should be added during the preparation of the cellulose acylate solution or the cellulose formate solution. These solvents can be used without purification as long as they are not exchanged to form a monolith. Such solvents include, for example, aprotic polar solvents such as dimethylsulfoxide (DMSO), acetone, sulfolane, dimethylimidazolidinone, tetramethylurea, dimethylformamide (DMF), N-methylpyrrolidone, dimethylacetamide (DMAc). Organic solvent; polar organic solvents such as tetrahydrofuran, dimethyl ether (DME), ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, acetamide, formamide, and mixed solvents thereof. In the present invention, a solvent having a melting point of 0° C. or higher, which does not require a large amount of energy when forming a molded article, is preferred. Among the above solvents, DMSO having a melting point of 19° C. is preferred.
The cellulose acylate solution preferably contains the cellulose formate.

The concentration of cellulose acylate in the cellulose acylate solution in the invention is in the range of 50% by mass to 0.1% by mass, preferably in the range of 15% by mass to 1% by mass. Further, the concentration of cellulose formate in the cellulose formate solution in the present invention is in the range of 50% by mass to 0.1% by mass, preferably in the range of 15% by mass to 1% by mass. If the concentration exceeds 50% by mass, the water absorption of the resulting monolith will decrease, and if the concentration is lower than 0.1% by mass, the strength of the resulting monolith will decrease, which is not preferable. The cellulose acylate solution or cellulose formate solution of the present invention is preferably degassed in advance before solvent exchange with water. By degassing in advance, a monolith having homogeneous pores can be obtained.

In the production method (1) of the cellulose monolith of the present invention, it is important to deacylate the cellulose acylate solution while exchanging the solvent with water. contains a deacylating agent. As such a deacylating agent, for example, a water-soluble acidic compound or basic compound can be used. Examples of such compounds include hydrochloric acid, sulfuric acid, nitric acid, ammonia, hydrazine and their alkyl-substituted products, guanidines, amidines and their substituted products, diamines, hydroxylamines such as hydroxylamine and ethanolamine, ethylamine, Alkylamines such as propylamine, metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and sodium hydrogen carbonate, quaternary ammonium hydroxide, metal alcoholates, hydroxamic acid Inorganic bases such as salts can be mentioned. Among them, sodium hydroxide is preferable as the deacylating agent from the viewpoint of the balance between the solvent exchange rate with water and the deacylation rate. Aqueous solutions are preferred, with aqueous sodium hydroxide solutions being preferred.

The concentration of the deacylating agent in the aqueous solution of the deacylating agent is preferably in the range of 0.001% by mass to 1% by mass. When the concentration of the deacylating agent is lower than this, the deacylation rate is slow, and the balance with the solvent exchange rate with water is not maintained, which is not preferred. On the other hand, if the concentration is too high above this range, the deacylation rate is too fast to obtain a monolith with suitable pores, which is not preferred. A more preferred deacylating agent concentration range is from 0.005% to 0.5% by weight.

The method of deacylating the cellulose acylate solution while exchanging the solvent with water by contacting the cellulose acylate solution with a "medium containing water and a deacylating agent" is not particularly limited. Even if it is in the form of mist or steam, it may be in any form as long as it deacylates the cellulose acylate solution while exchanging the solvent with water.

Similarly, in the production method (1) of the cellulose monolith of the present invention, it is important to deformylate the cellulose formate solution while exchanging the solvent with water. "Medium" includes a deformylating agent. As such deformylating agents, for example, water-soluble acidic compounds and basic compounds can be used. Examples of such compounds include compounds similar to those exemplified as the above deacylating agents.

The concentration of the deformylating agent in the aqueous solution of the deformylating agent is preferably in the range of 0.001% by mass to 1% by mass. When the concentration of the deformylating agent is lower than this, the deformylation rate is slow, and the balance with the solvent exchange rate with water cannot be achieved, which is not preferable. On the other hand, if the concentration is higher than this range, the deformylation rate is too fast to obtain a monolith having suitable pores, which is not preferred. A more preferred concentration range of the deformylating agent is in the range of 0.005% to 0.5% by weight.

The method of deformylating a cellulose formate solution while exchanging the solvent with water by contacting the cellulose formate solution with a "medium containing water and a deformylating agent" is not particularly limited. Even if it is in the form of mist or steam, any form may be used as long as the cellulose formate solution is deformylated while exchanging the solvent with water.

The ratio of the cellulose acylate solution or cellulose formate solution to water is not particularly limited as long as the solvent in the solution can be solvent-exchanged with water. It is preferred to use more water than the solvent used. If the amount of water is less than the amount of the solvent, solvent exchange with water may be insufficient. Therefore, in the present invention, the amounts of water and solvent are preferably at least the amount at which water is excessive in volume ratio, and there is no particular limitation as long as the amount is at least this amount. Preferably the amount of water used is at least 5 times the volume of the solvent, more preferably at least 10 times the volume.

In the present invention, the temperature for deacylation or deformylation while exchanging the solvent with water can be selected from a temperature range where water exists as a liquid, but the range of 10 ° C. to 50 ° C. is preferable and economical. Room temperature (for example, 25±5° C.) is more preferable from the point of view. The reaction time for deacylation or deformylation while exchanging the solvent with water depends on the size and temperature of the monolith to be obtained, and the required degree of deacylation or deformylation. It ranges from minutes to 240 hours, preferably from 2 minutes to 100 hours, more preferably from 5 minutes to 50 hours, even more preferably from 10 minutes to 24 hours.

The cellulose monolith obtained in the present invention can be washed with water or ethanol, added with a preservative such as alcohol, and stored in a wet state. Considering the wastewater of the water used in the present invention, the water may be neutralized after cellulose monolith formation. After that, it is further washed with water or ethanol as necessary. A method of replacing water with a low boiling point solvent such as ethanol or hexane after washing with water and drying under reduced pressure can also be employed. The drying method is not limited to reduced pressure, and known drying methods such as freeze drying, hot air drying and microwave drying can be employed. In the case of drying, an appropriate amount of sugars such as glycerin, sucrose, trehalose and starch syrup, sugar alcohols, various amides, polar solvents such as DMSO, and urea can be added. These additions can impart flexibility and the like to the obtained cellulose monolith. The cellulose monolith obtained in the present invention can be dried by a simple method such as microwave drying if it does not contain metal.

In the present invention, the size of cellulose monolith, pore diameter, specific surface area, water absorption, compression energy when wet are, for example, polymerization degree of cellulose acylate or cellulose formate, degree of substitution of cellulose acylate or cellulose formate, cellulose Various conditions such as concentration of acylate solution or cellulose formate solution, solvent used for cellulose acylate solution or cellulose formate solution, pH of water used for solvent exchange with cellulose acylate solution or cellulose formate solution, etc. It can be controlled by changing.

In the production method (2) of the cellulose monolith of the present invention, cellulose monolith particles are obtained, the size of which is controlled by the viscosity and size of the cellulose acylate solution or cellulose formate solution to be dropped, stirring efficiency, and the like. can. The viscosity of the cellulose acylate solution or cellulose formate solution decreases as the concentration of cellulose acylate or cellulose formate in the cellulose acylate solution or cellulose formate solution decreases. Therefore, at the same stirring rotation speed, the lower the concentration of cellulose acylate or cellulose formate, the better the stirring efficiency and the smaller the particle size. Further, when obtaining particles in the present invention, an ordinary stirring blade or stirrer can be used for stirring, but methods such as ultrasonic vibration can also be used as long as the cellulose acylate solution or cellulose formate solution to be dropped can be stirred. be able to.

In the present invention, particles can be obtained without using a surfactant. Surfactants such as known anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants may be used if necessary. Examples of anionic surfactants include sodium lauryl sulfate, N-acyl amino acids, alkyl ether carboxylic acids and the like. Examples of cationic surfactants include compounds such as aliphatic amine salts and aliphatic quaternary ammonium salts. Examples of nonionic surfactants include polyoxyethylene sorbitan monolaurate, sorbitan sesquiolate, and block copolymers having polyoxypropylene chains and polyoxyethylene chains.

The size of the cellulose monolith particles obtained in the present invention varies depending on the purpose of use. A product larger than this and a product produced from a molded cellulose acylate solution or cellulose formate solution are referred to as molded products in the present invention. As for the shape of the molded body, it is possible to make a monolith of any shape by using various casting molds such as sheet-like, film-like, cubic, rectangular parallelepiped, columnar, and bar-like.

In the production method (3) of the cellulose monolith of the present invention, in order to obtain a cellulose monolith molded article from the cellulose acylate solution, the pre-molded cellulose acylate solution is deacylated while exchanging the solvent with water. Deacylation may be performed after water and solvent exchange. In order to mold the cellulose acylate solution, a method of putting the cellulose acylate solution into various shaped containers or cast molds and exchanging the solvent with water can be usually employed. For example, it can be obtained by coating a glass plate with a cellulose acylate solution and immersing it in water containing a deacylating agent or water. A more preferable method is to put the cellulose acylate solution into various shaped containers or casting molds, cool to a temperature below the melting point of the solution, take out the solidified molding solution (molded product), and add a deacetylating agent. In this method, a solidified cellulose acylate solution (molded article) is immersed in an aqueous solution or water, and deacylation is performed while exchanging the solvent with water, or deacylation is performed after exchanging the solvent with water. By this method, a monolithic molded body of arbitrary shape can be easily obtained without destroying the shape. As a method for manufacturing a cellulose acylate molded article by cooling a cellulose acylate solution to a temperature below the melting point of the solution, a freezer at about -10°C is used for a short period of time to produce a "molded cellulose acylate. solution (cellulose acylate molded product)” can be produced.

Similarly, in the production method (3) of the cellulose monolith of the present invention, in order to obtain a cellulose monolith molded article from the cellulose formate solution, the preformed cellulose formate solution is deformylated while exchanging the solvent with water. Deformylation may be performed after water and solvent exchange. In order to mold the cellulose formate solution, a method of putting the cellulose formate solution into various shaped containers or cast molds and exchanging the solvent with water can be usually adopted. For example, it can be obtained by applying a cellulose formate solution on a glass plate and immersing it in water containing a deformylating agent or in water. A more preferred method is to put the cellulose formate solution in various shaped containers or casting molds, cool to a temperature below the melting point of the solution, remove the solidified molding solution (molded article), and add a deformylating agent. In this method, a solidified cellulose formate solution (molded product) is immersed in an aqueous solution or water, and deformylation is performed while exchanging the solvent with water, or deformylation is performed after exchanging the solvent with water. By this method, a monolithic molded body of arbitrary shape can be easily obtained without destroying the shape. As a method for manufacturing a molded cellulose formate product by cooling a cellulose formate solution to a temperature below the melting point of the solution, a freezer at about -10°C can be used in a short time to produce a molded cellulose formate. solution (cellulose formate molded article)" can be produced.

In the present invention, various functional substances may be added to the starting cellulose acylate solution or cellulose formate solution in order to impart further functions to the obtained cellulose monolith. Examples of such functional substances include water-soluble polymers such as PEG200, PEG600, polyacrylic acid (salt), gelatin, carboxymethylcellulose, polyvinyl alcohol and polyvinylpyrrolidone.

In addition, as the functional substance, activated carbon; clay minerals such as kaolinite, smectite, montmorillonite, sericite, illite, glauconite, chlorite, talc and zeolite; cellulose materials such as cellulose monolith, oxidized cellulose and pulp; Examples include silicon compounds such as silicon, metal oxides such as titanium oxide, and nanoparticles such as titanium oxide nanoparticles. By adding these, deodorizing properties and the like can be imparted to the obtained cellulose monolith. For example, activated carbon-containing cellulose monolith particles can have a specific surface area of 100 m ² /g or more, preferably 300 m ² /g or more, more preferably 500 m ² /g or more, still more preferably 1000 m ² /g or more. Although the upper limit of the specific surface area is not particularly limited, it is about 10000 m ² /g.

Other functional substances include carbon materials such as carbon nanotubes and carbon black, photocatalysts, fragrances, activated carbon, antibacterial agents, adsorbents, deodorants, defoamers, leveling agents, light stabilizers, ultraviolet absorbers, surface Colorants such as modifiers, pigments and dyes, polymer components for improving film properties and adhesion, water repellents, oil repellents, cross-linking agents with chemical bonds, matting agents, silane coupling agents, fillers agents, lubricants, plasticizers, release agents, antioxidants, flame retardants, surfactants, pH adjusters, antistatic agents, weather stabilizers, heat stabilizers, anti-slip agents, anti-blocking agents, foaming agents, crystals Chemical aids, anti-fogging agents, (transparent) nucleating agents, anti-aging agents, hydrochloric acid absorbers, impact modifiers, cross-linking agents, co-cross-linking agents, cross-linking aids, adhesives, softeners, processing aids, etc. can be done.

One or more of the above functional substances can be optionally added. The amount of the functional substance added is, for example, 0 to 80 parts by mass, preferably 0 to 70 parts by mass, with respect to 100 parts by mass of cellulose acylate in the cellulose acylate solution. For 100 parts by mass of mate, it can be, for example, 0 to 80 parts by mass, preferably 0 to 70 parts by mass.
According to the method for producing a cellulose monolith of the present invention, a cellulose monolith in which a functional substance is dispersed can be simply and easily produced. For example, a cellulose monolith in which activated carbon is included and dispersed can remove the odors of ammonia, methyl mercaptan, etc., is excellent in adsorbing ink and the like, and is excellent in purifying contaminated water. Although depending on the amount used, the odor removal, contaminated water purification, etc. can be achieved preferably within 1 minute, more preferably within 30 seconds. Activated carbon, even if it is finely powdered, becomes excellent in handleability while retaining functions such as deodorization by encapsulating and dispersing it in the cellulose monolith of the present invention.

The present invention also provides a cellulose monolith (i) in which one or more other cellulose monolith layers are laminated on a cellulose monolith layer. Preferably, when a particulate functional substance such as activated carbon is added, it is possible to provide a cellulose monolith in which one or more other cellulose monolith layers are laminated on a cellulose monolith layer formed by adding the functional substance. .

The present invention also provides a white cellulose monolith (ii) containing colored particles. In the cellulose monolith layer formed by adding the above functional substance, the functional substance having a large specific gravity such as activated carbon sinks to the bottom of the layer to form a layer. Therefore, by laminating at least one other cellulose monolith layer on the side on which the functional substance is unevenly distributed, a functional substance having a dark color such as activated carbon can be accommodated inside the laminated cellulose monolith. be able to. Therefore, it is possible to easily prepare a sheet-like white cellulose monolith that is almost white, preferably white, while having colored particles such as a functional substance such as activated carbon having a dark color. Furthermore, by adding a coloring agent or the like, coloring or dyeing can be performed to freely color the material.

Moreover, according to the method for producing a cellulose monolith of the present invention, a cellulose monolith layer can be formed around the functional substance, and microencapsulation is also possible. In this case also, a white particulate white cellulose monolith can be made that is mostly white, preferably white, while having a functional material such as activated carbon with a dark color. Furthermore, by adding a coloring agent or the like, the particles can be colored or dyed for free coloring.

In the present invention, a solid compound that reacts with water to generate carbon dioxide gas is previously added to a cellulose acylate solution or a cellulose formate solution, and deacylation or deformylation is performed while exchanging the solvent with water. It is also possible to form a monolith with a larger specific surface area by foaming during the molding.

In the present invention, the obtained cellulose monolith may be surface-modified by reacting it with a compound that reacts with hydroxyl groups of cellulose. Examples of such compounds include, but are not limited to, compounds having a carboxyl group such as citric acid and polyacrylic acid, compounds having an acyl group such as acid anhydrides and acyl halide groups, compounds having an epoxy group, and isocyanate groups. a compound having a vinyl group, a compound having an oxazoline group, a compound having an oxirane group, and a compound having one or more of these functional groups.

Compounds having a carboxyl group include aliphatic carboxylic acids, aromatic carboxylic acids, alicyclic carboxylic acids, and the like. Specifically, for example, in addition to citric acid and polyacrylic acid, it has substituents such as acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, (meth)acrylic acid, cinnamic acid, and trifluoroacetic acid. good aliphatic carboxylic acids; benzoic acid, 1-naphthylcarboxylic acid, 2-naphthylcarboxylic acid, m-methylbenzoic acid, p-methylbenzoic acid, m-methoxybenzoic acid, p-methoxybenzoic acid, 3,5- Dimethoxybenzoic acid, 3,4,5-trimethoxybenzoic acid, 2,4,6-trimethylbenzoic acid, m-cyanobenzoic acid, p-cyanobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, m- fluorobenzoic acid, p-fluorobenzoic acid, 2,5-dichlorobenzoic acid, p-acetylbenzoic acid, p-phenylbenzoic acid, p-formylbenzoic acid, pt-butylbenzoic acid, p-butoxybenzoic acid, m-acetoxybenzoic acid, p-acetoxybenzoic acid, m-methoxycarbonylbenzoic acid, p-methoxycarbonylbenzoic acid, m-benzyloxybenzoic acid, p-benzyloxybenzoic acid, p-cyclohexylbenzoic acid, p-methanesulfonyl aminobenzoic acid, p-nitrobenzoic acid, m-nitrobenzoic acid, m-acetaminobenzoic acid, p-acetaminobenzoic acid, m-benzoylaminobenzoic acid, p-benzoylaminobenzoic acid, m-benzoyloxybenzoic acid, p -benzoyloxybenzoic acid, m-benzylbenzoic acid, p-benzylbenzoic acid, m-(N-phenylcarbamoyloxy)benzoic acid, p-(N-phenylcarbamoyloxy)benzoic acid, p-(ethoxycarbonylamino)benzoic acid Aromatic carboxylic acids optionally having substituents such as acid, p-methylthiobenzoic acid, p-phenylthiobenzoic acid, p-hydroxybenzoic acid, p-(4-pyridyl)benzoic acid; An alicyclic carboxylic acid which may have a substituent and the like can be mentioned. These carboxylic acids may have a substituent.

Examples of the substituents include halogen atoms, cyano groups, hydroxyl groups, nitro groups, silyl groups, silyloxy groups, alkyl groups having 1 to 12 carbon atoms (methyl, ethyl, propyl, isopropyl, butyl, t-butyl groups, etc.). ), alkoxy groups having 1 to 12 carbon atoms (methoxy, ethoxy, propoxy groups, etc.), aryl groups having 6 to 20 carbon atoms (phenyl, naphthyl groups, etc.), aryloxy groups having 6 to 20 carbon atoms (phenyloxy, naphthyl oxy group, etc.), an acyl group having 1 to 20 carbon atoms (acetyl, propionyl, benzoyl group, etc.), a substituted or unsubstituted carbamoyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbamoyloxy group having 1 to 20 carbon atoms, sulfamoyl group having 1 to 20 carbon atoms, sulfamoyloxy group having 1 to 20 carbon atoms, phosphino group, phosphinyl group, phosphono group, phosphinyloxy group, phosphonooxy group, phosphinylamino group, phosphonoamino group, number of carbon atoms Ureido groups of 1 to 20, carboxyl groups, substituted oxycarbonyl groups of 1 to 20 carbon atoms (alkoxycarbonyl groups, aryloxycarbonyl groups, aralkyloxycarbonyl groups, etc.) and the like can be mentioned.

Examples of acid anhydrides include carboxylic acid anhydrides corresponding to the above carboxylic acids. Examples of compounds having an acyl group such as an acyl halide group include carboxylic acid chlorides and carboxylic acid bromides corresponding to the above carboxylic acids.

Compounds having an isocyanate group include aromatic isocyanates, aliphatic isocyanates, alicyclic isocyanates, and the like. Specifically, for example, phenyl isocyanate, 1-naphthyl isocyanate, 2-naphthyl isocyanate, 2-methylphenyl isocyanate, 3-methylphenyl isocyanate, 4-methylphenyl isocyanate, 3,5-dimethylphenyl isocyanate, 2-chlorophenyl isocyanate , 3-chlorophenyl isocyanate, 4-chlorophenyl isocyanate, 2-methoxyphenyl isocyanate, 3-methoxyphenyl isocyanate, 4-methoxyphenyl isocyanate, 2-nitrophenyl isocyanate, 3-nitrophenyl isocyanate, 4-nitrophenyl isocyanate, etc. isocyanate; aliphatic isocyanate such as methyl isocyanate, ethyl isocyanate, butyl isocyanate, and the like; These isocyanates may have a substituent. Examples of substituents include the same substituents as the substituents that the carboxylic acid may have.

Examples of the vinyl group-containing compound include (meth)acrylic acid, ester compounds of (meth)acrylic acid, vinyl alcohol, vinylpyrrolidone, vinyl chloride, vinyl acetate, and vinylcyclohexane.

Examples of compounds having an epoxy group include halohydrins such as epichlorohydrin, epibromohydrin and dichlorohydrin; bifunctional bisepoxides (bisoxirane); polyfunctional polyepoxides (polyoxirane) and the like. can.

In addition, compounds having an epoxy group that can be used in the present invention include resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenato bisphenol A diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl terephthalate, diglycidyl orthophthalate, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, Examples include pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether and the like.

Examples of compounds having an oxazoline group include Epocross K1010E, K1020E, K1030E, CX-K2010E, CX-K2020E and CX-K2030E manufactured by Nippon Shokubai Co., Ltd.

In the present invention, when a compound having good reaction efficiency under alkaline conditions such as an oxirane compound is used as the surface modifier, the reaction solution in which the cellulose monolith is formed by deacylation is pH-adjusted as necessary. It is also possible to directly add an oxirane compound while reacting, and then wash with water to obtain a surface-modified cellulose monolith. The amount of the oxirane compound added is usually in the range of 0.01 to 10 times the volume of the resulting cellulose monolith. If the volume is less than 0.01 times the volume of the cellulose monolith, the desired increase in strength may not be achieved. By using it in this range, the strength of the cellulose monolith can be improved. For example, when the cellulose monolith is used for the purpose of adsorption purification, etc., the adsorption amount of the purification target can be increased, which is preferable.

For separation of antibody proteins, proteins such as protein A, protein G, protein L and functional variants thereof may be used to modify the surface of cellulose monoliths. For example, the method described in Patent Document 21 can be applied to the surface modification with the protein or the like. Also included are compounds such as histidine, histamine, cytosine, adenine, compounds containing primary amino groups, secondary amino groups and polymyxins for the removal of exogenous pyrogens or pyrogens such as bacterial by-products and bacterial debris. Nitrogen compounds may be surface-modified.

The cellulose monolith obtained in the present invention has the degree of deacylation in the reaction, the concentration of cellulose acylate, the type and amount of the deacylating agent, or the degree of deformylation in the reaction, the concentration of cellulose formate, the concentration of the deformylating agent. By controlling the type, amount, etc., it is possible to obtain a water-absorbing cellulose monolith. The control technique described above has made it possible to easily produce water-absorbing cellulose monoliths having different water absorption amounts in the present invention. Moreover, the water-absorbing agent obtained by the above-described method for producing a molded body can be made into any shape such as granules, sheets, strips, rods, and the like. Therefore, depending on its shape, it can be used for any part that requires water absorption, such as paper diapers and sanitary napkins. Furthermore, since the water-absorbing cellulose monolith obtained in the present invention has continuous pores inside, sheet-like, strip-like, and rod-like ones have the ability to absorb water in the vertical direction. Therefore, it can be used for applications such as paper chromatography. Further, the water-absorbing cellulose monolith of the present invention can be made into a water-absorbing cellulose monolith having deodorizing properties by placing a material having a deodorizing function such as activated carbon or zeolite inside.

In the present invention, the composition obtained by deacylating a cellulose acylate solution while exchanging the solvent with water or deformylating a cellulose formate solution while exchanging the solvent with water is a cellulose acylate solution or Cellulose acylate or cellulose formate forms a monolith by solvent exchange between the cellulose formate solution and water to form a fluid, heterogeneous composition (including gel). Therefore, another aspect of the present invention also provides a fluid heterogeneous composition in which a cellulose acylate solution or cellulose formate solution and an aqueous sodium hydroxide solution are mixed.

The present invention also provides a method (5) for producing a cellulose monolith, which comprises heat-treating a cellulose monolith in the presence of urea and phosphoric acid (salt). In the production method (5) above, the amount of urea used is preferably 10 to 1,000 parts by mass, more preferably 20 to 500 parts by mass, per 100 parts by mass of the cellulose monolith. The amount of phosphoric acid (salt) used is preferably 10 to 100 parts by mass, more preferably 15 to 80 parts by mass, per 100 parts by mass of the cellulose monolith.

The present invention also provides a cellulose monolith (iii) having carbamoyl groups. Cellulose monolith (iii) may further have a phosphate group. This cellulose monolith (iii) is obtained by the production method (5) above. A cellulose monolith (monolithic cellulose carbamate phosphate) having a carbamoyl group and a phosphate group has nonions and anions, and is excellent in water retention and absorption of water, physiological saline, and the like. Moreover, since it is crosslinked with phosphoric acid (salt), it has excellent strength. The retained water absorption amount will be described in detail later.

The present invention also provides a cellulose monolith (iv) having a retained water absorption in saline of at least 8 g/g. This cellulose monolith (iv) is preferably the above cellulose monolith (iii). The above cellulose monoliths (iii) and (iv) are excellent in water swelling. Hereinafter, the cellulose monoliths (iii) and (iv) may be referred to as water-swellable cellulose monoliths. The retention water absorption for the physiological saline is preferably 10 g/g or more, more preferably 12 g/g or more.

In the present specification, "water absorption" and "retained water absorption" are clearly distinguished. "Amount of water absorption" is the weight (g/g) of the monolith before immersion in water, which is obtained by immersing the monolith in water and removing excess water from the surface of the monolith under no load (g). It is a value obtained as a water absorption amount (unit: g/g). On the other hand, the "retained water absorption amount" is obtained as the water absorption amount (unit: g/g) after immersing the cellulose monolith in a medium to allow it to swell freely, then draining the water in a centrifuge (250 G) for 3 minutes. is the value Water and physiological saline are preferable as the medium.

<Application>
The cellulose monolith of the present invention can be used for sanitary materials such as paper diapers and sanitary napkins, cosmetics, freshness-keeping agents, soil conditioners, adsorbents, deodorants, water purification agents, metal ion removal agents, gel filtration chromatography carriers, It can be applied to various fields such as release drug carriers, desalination of seawater, ion-exchange chromatography carriers, affinity chromatography carriers, and the like.

The present invention will be described in detail below using examples and comparative examples. However, the present invention is not limited to the examples. Unless otherwise specified, the cellulose acetate used in Examples and Comparative Examples was acetylcellulose having a molecular weight of 50,000 and an acetyl content of 39.2 to 40.2% by mass, purchased from Sigma-Aldrich.

<Water absorption (g/g)>
The obtained monolith was immersed in water, and the mass (g) of the monolith after absorbing water after removing excess water on the surface of the monolith under no load was divided by the mass (g/g) of the monolith before immersion in water. The water absorption amount (g/g) was obtained.

<Compression energy of monolith>
A water-absorbed cellulose monolith was used as a sample, and compression ratio (%) and compression stiffness were measured using a compression tester KES-G5 (manufactured by Kato Tech Co., Ltd.).

<Specific surface area>
It was measured using BELSORP-MR6 manufactured by Microtrac BEL.

<IR>
It was measured by Diamond ATR using iS50R FT-IR manufactured by Thermo.

<SEM image>
The image was taken using FE-SEM SU8020 manufactured by Hitachi High Technology.

<Micrograph>
Photographed using a Leica Z6 APO.

<Stereomicrograph>
Carton's DSZ-44FT (product number MS4572) was used, and the images were taken with iPhone 7 (registered trademark, manufactured by Apple Inc.).

<Amount of retained water absorption of water-swellable cellulose monolith>
The retained water absorption of the water-swellable cellulose monolith was measured according to the EDANA method (ERT441.2-02). Specifically, 0.2 g of a water-swellable cellulose monolith was placed in a non-woven fabric bag, then immersed in a large excess of 0.9% by weight sodium chloride aqueous solution for 30 minutes to allow free swelling, and then centrifuged. It was obtained as the amount of water absorption (unit: g/g) after draining at (250 G) for 3 minutes. Deionized water was used in place of the 0.9% by weight aqueous sodium chloride solution in the same manner, and the water absorption to deionized water was also measured. The amount of water-swellable cellulose monolith in the case of deionized water was 0.05 g.

[Example 1]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, deacetylated while exchanging the solvent with water, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (1) according to one embodiment of the present invention. Regarding the obtained cellulose monolithic particles (1), FIG. 1 shows a particle surface, and FIG. 2 shows a scanning electron microscope (SEM) photograph of the inside of the particle. The cellulose monolith particles (1) had a water absorption of 5.2 g/g, a compressibility (%) of 45%, a compression stiffness of 0.87, and a specific surface area of 31.96 m ² /g.

FIG. 5 shows an FT-IR chart of the cellulose monolith particles (1). As seen in FIG. 5, the cellulose monolith particles (1) lost the absorption at 1735 cm ⁻¹ derived from the ester group of the raw material acetylcellulose, and instead increased the absorption at around 3400 cm ⁻¹ and 2900 cm ⁻¹ derived from the hydroxyl group. and the deacetylation was completed.

[Comparative Example 1]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was added dropwise to 30 mL of deionized water with stirring, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain comparative cellulose monolith particles (1). Regarding the obtained comparative cellulose monolithic particles (1), FIG. 3 shows a particle surface, and FIG. 4 shows a scanning electron microscope (SEM) photograph of the inside of the particle. The comparative cellulose monolithic particles (1) had a water absorption of 1.7 g/g, a compressibility (%) of 2%, a compression stiffness of 0.85, and a specific surface area of 19.43 m ² /g.

FIG. 5 shows an FT-IR chart of Comparative Cellulose Monolith Particles (1) obtained in Comparative Example 1. As shown in FIG. As seen in FIG. 5, the comparative cellulose monolithic particles (1) still had 1735 cm ⁻¹ derived from the ester group of the raw material acetylcellulose and had a low water absorption. In addition, as shown in FIGS. 3 and 4, the comparative cellulose monolith particle (1) has a monolith surface and an internal structure that are larger than those of the cellulose monolith particle (1) (FIGS. 1 and 2), which is one embodiment of the present invention. was different.

[Example 2]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. . After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (2) of one embodiment of the present invention. The cellulose monolith particles (2) had a water absorption of 8.3 g/g and a specific surface area of 26.37 m ² /g.

[Example 3]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 6 hours while deacetylating while exchanging the solvent with water. . After 6 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (3) of one embodiment of the present invention. The cellulose monolith particles (3) had a water absorption of 5.5 g/g and a specific surface area of 25.01 m ² /g.

[Example 4]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 4 hours while deacetylating while exchanging the solvent with water. . After 4 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (4) of one embodiment of the present invention. The cellulose monolith particles (4) had a water absorption of 8.1 g/g, a compressibility (%) of 52% and a compression stiffness of 0.76.

[Example 5] Sheet-shaped monolith After coating a glass plate with a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass), the glass plate was immersed in 50 mL of a 0.1 mol/L sodium hydroxide aqueous solution to exchange the solvent with water. Deacetylated and left for 18 hours. After 18 hours, the obtained cellulose monolith sheet was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith sheet was replaced with ethanol and dried under reduced pressure to obtain a cellulose monolith sheet (1) of one embodiment of the present invention having a length of 40 mm and a width of 15 mm. The water absorption of the cellulose monolith sheet (1) cut into strips along the long axis was 10.5 g/g. A monolith sheet (length 40 mm×width 4 mm) cut into strips was hung with the long axis direction up and down, and when the lower end was immersed in a petri dish filled with water, the water was sucked up to the upper end.

[Example 6]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 90 hours while deacetylating while exchanging the solvent with water. . After 90 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (5) of one embodiment of the present invention. The cellulose monolith particles (5) had a water absorption of 8.3 g/g and a specific surface area of 25.41 m ² /g.

[Example 7]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 90 hours while deacetylating while exchanging the solvent with water. . After 90 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol, and the particles were dried by heating in a 600 W microwave oven for 1 minute to obtain cellulose monolith particles (6) according to one embodiment of the present invention. The water absorption of the cellulose monolith particles (6) was 8.5 g/g.

[Example 8]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. . After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (7) of one embodiment of the present invention. The cellulose monolith particles (7) had a water absorption of 15.5 g/g, a specific surface area of 23.61 m ² /g, a compressibility (%) of 81%, and a compression stiffness of 0.34.

[Example 9]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 2 hours while deacetylating while exchanging the solvent with water. . After 2 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (8) of one embodiment of the present invention. The cellulose monolith particles (8) had a water absorption of 15.5 g/g, a specific surface area of 25.51 m ² /g, a compressibility (%) of 80%, and a compression stiffness of 0.30.

[Comparative Example 2]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was added dropwise to 30 mL of deionized water with stirring, and stirring was continued for 2 hours. After 2 hours, the obtained cellulose monolith particles were washed with water. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain comparative cellulose monolith particles (2). The comparative cellulose monolith particles (2) had a water absorption of 2.5 g/g and a specific surface area of 22.05 m ² /g.

[Comparative Example 3]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was added dropwise to 30 mL of deionized water with stirring, and stirring was continued for 2 hours. After 2 hours, the obtained cellulose monolith particles were washed with water, filtered, immersed in a 0.1 mol/L sodium hydroxide aqueous solution, and stirred for 2 hours. After washing with water until the filtrate became neutral, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain comparative cellulose monolith particles (3). The comparative cellulose monolith particles (3) had a water absorption of 14.1 g/g, a compressibility (%) of 79%, a compression stiffness of 0.35, and a specific surface area of 15.08 m ² /g.

[Example 10]
To a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass), sodium carbonate powder and anhydrous sodium sulfate powder were added at a mass ratio of 12% by mass and 50% by mass, respectively, with respect to cellulose acetate, and these particles were uniformly dispersed. A dispersed solution was prepared. This solution was added dropwise to 30 mL of a 0.1 mol/L sodium hydroxide aqueous solution with stirring, and the mixture was stirred for 4 hours. After 4 hours the particles were suction filtered. After washing with water until the filtrate became neutral, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (9) of one embodiment of the present invention. The cellulose monolith particles (9) had a water absorption of 7.6 g/g and a specific surface area of 27.03 m ² /g.

[Comparative Example 4]
To a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass), sodium carbonate powder and anhydrous sodium sulfate powder were added at a mass ratio of 12% by mass and 50% by mass, respectively, with respect to cellulose acetate, and these particles were uniformly dispersed. A dispersed solution was created. This solution was added dropwise to 30 mL of deionized water with stirring, and the mixture was stirred for 4 hours. After 4 hours, the particles were suction-filtered, then the solvent was replaced with ethanol, and dried under reduced pressure to obtain comparative cellulose monolithic particles (4). The comparative cellulose monolith particles (4) had a water absorption of 2.1 g/g and a specific surface area of 20.22 m ² /g.

[Comparative Example 5]
To a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass), sodium carbonate powder and anhydrous sodium sulfate powder were added at a mass ratio of 12% by mass and 50% by mass, respectively, with respect to cellulose acetate, and these particles were uniformly dispersed. A dispersed solution was prepared. This solution was added dropwise to 30 mL of deionized water with stirring, and the mixture was stirred for 4 hours. After 4 hours the particles were suction filtered. The obtained particles were added to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution and stirred for 64 hours. After 64 hours the particles were suction filtered. After washing with water until the filtrate became neutral, the water inside the particles was replaced with ethanol and dried under reduced pressure to obtain comparative cellulose monolithic particles (5). The comparative cellulose monolith particles (5) had a water absorption of 7.8 g/g and a specific surface area of 12.22 m ² /g.

[Example 11]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was added dropwise to 30 mL of a 0.1 mol/L potassium hydroxide aqueous solution with stirring, and stirring was continued for 1 hour while deacetylating while exchanging the solvent with water. . After 1 hour, the obtained cellulose monolith particles were neutralized with a 0.1 mol/L hydrochloric acid aqueous solution and washed with water. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (10) according to one embodiment of the present invention. The water absorption of the cellulose monolith particles (10) was 5.7 g/g.

[Example 12]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium carbonate aqueous solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (11) according to one embodiment of the present invention. The water absorption of the cellulose monolith particles (11) was 4.8 g/g.

[Example 13]
0.825 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was placed in a polyethylene container with a capacity of 6 mL (container size: base 18 mm×18 mm, height 30 mm). This product was placed in a freezer for one hour together with the container to freeze and solidify. After one hour, the container was taken out from the freezer, and the sheet-like DMSO solution molded body of cellulose acetate that had been solidified and molded was taken out from the container, immersed in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The deacetylation reaction was carried out for 190 hours. After 190 hours, the resulting sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a cellulose monolith molded body (2) of one embodiment of the present invention. The cellulose monolith molded body (2) had a water absorption of 10.5 g/g and a specific surface area of 17.43 m ² /g.

[Example 14]
0.799 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was placed inside a U-shaped polypropylene straw. This product was placed in a freezer together with a straw for one hour to freeze and solidify. After one hour, the straw was taken out from the freezer, and the rod-shaped cellulose acetate DMSO solution molded body solidified and molded was taken out from the inside of the straw, immersed in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution, and solvent-exchanged with water. The deacetylation reaction was carried out for 190 hours. After 190 hours, the rod-shaped cellulose monolith molded body obtained was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a rod-shaped cellulose monolith molded body (3) according to one embodiment of the present invention. The cellulose monolith molded body (3) had a water absorption of 12.5 g/g and a specific surface area of 23.66 m ² /g.

[Example 15]
19.85 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) was poured into a silicon cuboid container having a width of 55 mm, a length of 105 mm and a height of 22 mm. The container was placed in a freezer for 4 hours while being kept horizontal with a lid, and solidified by freezing. After 4 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 400 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The reaction was carried out for 20 hours while deacetylating. After 20 hours, the obtained sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (4) according to one embodiment of the present invention. The cellulose monolith molded body (4) had a water absorption of 9.2 g/g and a specific surface area of 14.4 m ² /g.
A portion of the cellulose monolith molded body (4) was cut and immersed in a 10% by mass glycerin aqueous solution. Thereafter, excess glycerin aqueous solution was wiped off with paper and dried in a hot air dryer at 90° C. to obtain a cellulose monolith molded body (5) of one embodiment of the present invention. The cellulose monolith molded body (5) was a flexible sheet even after drying.

[Example 16]
0.9 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm and a height of 13 mm. The container was placed in a freezer for 4 hours while being kept horizontal with a lid, and solidified by freezing. After 4 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 40 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. While deacetylating, the reaction was carried out for 38 hours. After 38 hours, the obtained sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (6) according to one embodiment of the present invention. The cellulose monolith molded body (6) had a water absorption of 9.2 g/g and a specific surface area of 23.03 m ² /g. An SEM image of the inside of the cellulose monolith molded body (6) is shown in FIG.
A 1% by mass Congo red aqueous solution was applied to the obtained cellulose monolith molded body (6). As a result, a red-dyed cellulose monolith molded body (6') was obtained.

[Example 17]
14.66 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was poured into a silicon cuboid container having a width of 55 mm, a length of 105 mm and a height of 22 mm. The container was placed in a freezer for 16 hours while being kept horizontal with a lid, and solidified by freezing. After 16 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 300 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The reaction was carried out for 22 hours while deacetylating. After 22 hours, the obtained sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried in a hot air dryer at 90°C for 30 minutes to obtain a sheet-like cellulose monolith molded body (7) according to one embodiment of the present invention. The water absorption of the cellulose monolith molded body (7) was 11.7 g/g.
The cellulose monolith molded body (7) was immersed in a 10% by weight glycerin aqueous solution, the excess glycerin aqueous solution was wiped off with paper, and then dried in a hot air dryer at 90°C for 30 minutes. was

[Example 18]
1.7 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 4.0% by mass) was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm and a height of 13 mm. The container was placed in a freezer for 2 hours while being kept horizontal with a lid, and solidified by freezing. After 2 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 30 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The reaction was carried out for 15 hours while deacetylating. After 15 hours, the resulting sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (8) of one embodiment of the present invention. The cellulose monolith molded body (8) had a water absorption of 20.1 g/g and a specific surface area of 27.99 m ² /g.

[Example 19]
0.72 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 14.5% by mass) was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm and a height of 13 mm. The container was placed in a freezer for 2 hours while being kept horizontal with a lid, and solidified by freezing. After 2 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 30 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The reaction was carried out for 15 hours while deacetylating. After 15 hours, the resulting sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (9) according to one embodiment of the present invention. The cellulose monolith molded body (9) had a water absorption of 5.7 g/g and a specific surface area of 16.71 m ² /g.

[Example 20]
2.25 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was placed in a polyethylene container with a capacity of 6 mL (container size: base 18 mm x 18 mm, height 30 mm). This product was placed in a freezer for 4 hours together with the container to freeze and solidify. After 4 hours, the container was taken out of the freezer, and the cube-shaped cellulose acetate DMSO solution molded body solidified and molded was taken out from the container, immersed in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The deacetylation reaction was carried out for 62 hours. After 62 hours, the obtained diced cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol, and dried under reduced pressure to obtain a dice-shaped cellulose monolith molded body (10) of one embodiment of the present invention. The cellulose monolith molded body (10) had a water absorption of 12.0 g/g and a specific surface area of 14.98 m ² /g.

[Example 21]
2.15 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was placed in a polyethylene container with a capacity of 6 mL (the size of the container was 18 mm×18 mm at the base and 30 mm in height). This product was placed in a freezer for 4 hours together with the container to freeze and solidify. After 4 hours, the container was taken out from the freezer, and the cube-shaped cellulose acetate DMSO solution molded body solidified and molded was taken out from the container, immersed in 30 mL of deionized water, and the solvent was exchanged with water, and the reaction was carried out for 62 hours. . After 62 hours, the resulting dice-shaped cellulose monolith molded body was washed with water. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a dice-shaped cellulose monolith molded body (11) of one embodiment of the present invention. The cellulose monolith molded body (11) had a water absorption of 7.0 g/g and a specific surface area of 8.85 m ² /g.

[Example 22]
2.01 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was placed in a polyethylene container with a capacity of 6 mL (container size: base 18 mm×18 mm, height 30 mm). This product was placed in a freezer for 4 hours together with the container to freeze and solidify. After 4 hours, the container was taken out from the freezer, and the cube-shaped cellulose acetate DMSO solution molded body solidified and molded was taken out from the container, immersed in 30 mL of deionized water, and the solvent was exchanged with water, and the reaction was carried out for 62 hours. . After 62 hours, the resulting dice-shaped cellulose monolith molded body was washed with water and immersed in a 0.1 mol/L sodium hydroxide aqueous solution. After being immersed in an aqueous sodium hydroxide solution for 20 hours, it was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a diced cellulose monolith molded body (12) of one embodiment of the present invention. The cellulose monolith molded body (12) had a water absorption of 10.0 g/g and a specific surface area of 15.62 m ² /g.

[Example 23]
A DMSO solution of cellulose triacetate (cellulose triacetate concentration: 10.8% by mass) was added dropwise to 30 ml of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and the solution was stirred for 2 hours while deacetylating while exchanging the solvent with water. continued. After 2 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (12) according to one embodiment of the present invention. The cellulose monolith particles (12) had a water absorption of 6.7 g/g and a specific surface area of 39.51 m ² /g.

[Example 24]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) in an amount half the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain activated carbon. A cellulose acetate solution was prepared. The obtained activated carbon-containing cellulose acetate solution was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. After 18 hours, the obtained cellulose monolith particles containing activated carbon were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (13) of one embodiment of the present invention. The cellulose monolith particles (13) had a water absorption of 3.6 g/g, a compressibility (%) of 45%, a compression stiffness of 0.93, and a specific surface area of 592.2 m ² /g. Observation of the cross section of the obtained cellulose monolith particles (13) revealed that activated carbon (black particles) was contained inside. The specific surface area of activated carbon alone (“Taiko 350SZ” manufactured by Futamura Chemical Co., Ltd.) was 1378.8 m ² /g.

32 mg of cellulose monolith particles (13) were added to 40 ml of an aqueous solution of toluidine blue (initial concentration: 12.5 mg/L) in a 50 ml polypropylene container (vial (PV-7, manufactured by Marem)) and stirred at 30° C. at 100 rpm. kept under gentle agitation. Samples were collected at various adsorption times, filtered using a 0.2 μm filter (manufactured by Advantech, DISMIC-13HP), and the residual toluidine blue concentration of the sample was measured using a spectral transmittance meter (manufactured by Shimadzu Corporation UV-1650PC). was measured at 630 nm. In the measurement, the sample was diluted with water as necessary so that the transmittance at 630 nm was in the range of 15 to 99.9%.

The toluidine blue equilibrium concentration in solution at different adsorption times was determined from the transmittance, and the amount of toluidine blue adsorbed by the cellulose monolith particles (13) was calculated by the formula: The adsorption test was performed under light shielding.
Q = (Co-Ct) V/m
Here, Q is the equilibrium adsorption amount (mg/g), Co and Ct are the initial and equilibrium concentrations of toluidine blue in solution at different time points. V is the volume of the toluidine blue aqueous solution and m is the weight of the cellulose monolith particles (13).

The adsorption capacity of the cellulose monolith particles (13) increased sharply in the first 10 hours, reached 75% of the equilibrium adsorption capacity, and reached equilibrium in 96 hours. When the initial concentration was 12.5 mg/L, the cellulose monolith particles (13) finally showed an adsorption capacity of 14.8 mg/g and the solution became clear as a result of complete adsorption of toluidine blue.

5 L of nitrogen-diluted 122 ppm ammonia gas (purchased from Iwatani Fine Chemicals) was sealed in an aluminum gas bag (AL: AA-5, manufactured by GL Sciences). A 5 cm end of an aluminum gas bag was cut into the gas bag, 2.00 g of cellulose monolith particles (13) were inserted into the gas bag, and then the cut was fixed with a sealing clip (CL-15-10, manufactured by AS ONE). bottom. While keeping the bag at 25 ° C., various gas concentrations were adsorbed using ammonia gas detection tubes (3La and 3L manufactured by Gastech Co., Ltd., 3La was used at 70 ppm or more, and 3L was used at less than 70 ppm). measured in hours. A blank was prepared by performing the same operation without adding the adsorbent. The blank was 96 ppm after 48 hours, while the ammonia gas concentration in the gas bag decreased to 2.6 ppm when cellulose monolith particles (13) were used.

5 L of 80 ppm methyl mercaptan gas (purchased from Iwatani Fine Chemicals) diluted with nitrogen gas was sealed in an aluminum gas bag (AL: AA-5, manufactured by GL Sciences). A 5 cm cut was made at the end of an aluminum gas bag into which an AC-containing monolithic bead (CAMB) could be inserted, 0.800 g of cellulose monolith particles (13) were inserted into the gas bag, and this cut was then attached to a clip with seal. (CL-15-10 manufactured by AS ONE) was used for fixation. While the bag was kept at 25° C., the gas concentration was measured at various adsorption times using a methyl mercaptan gas detector tube (manufactured by Gastech, 71). A blank was prepared by performing the same operation without adding the adsorbent. Cellulose monolith particles (13) completely adsorbed methyl mercaptan in about 10 hours, and the methyl mercaptan concentration in the gas bag became zero.
From these results, it was found that the activated carbon-containing cellulose monolith particles (13) not only have an excellent adsorption amount of toluidine blue, but also can adsorb and remove gases such as ammonia and methylcaptan.

[Example 25]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) in an amount equal to the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain cellulose acetate containing activated carbon. made a solution. The obtained activated carbon-containing cellulose acetate solution was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. After 18 hours, the obtained cellulose monolith particles containing activated carbon were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles containing activated carbon.
Next, this monolithic particle containing activated carbon was immersed in a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass), and the monolithic particle containing activated carbon coated with the obtained cellulose acetate solution was washed with 30 mL of 0.1 mol/L water. It was added dropwise to an aqueous sodium oxide solution with stirring, and stirring was continued for 18 hours while deacetylating while exchanging the solvent with water. The obtained monolith particles coated with cellulose monolith and containing activated carbon were washed with water until the filtrate became neutral. After washing with water, the water in the monolithic particles containing activated carbon coated with cellulose monoliths was replaced with ethanol and dried under reduced pressure to obtain white cellulose monolithic particles (14) according to one embodiment of the present invention. The water absorption of the cellulose monolith particles (14) was 4.4 g/g.

Figures 7 and 8 show the appearance of the cellulose monolith particles (14) and cross-sectional micrographs after water absorption. 9 and 10 show a cross section of another cellulose monolith particle (14) and a cross section stained with Congo red aqueous solution. It can be seen that the particles are formed with continuous pores in two layers. Therefore, it is also possible to form a multi-layered monolith by this method, and it is also possible to produce white cellulose monolith particles containing a coloring material by using a known microencapsulation device.

[Example 26]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) and titanium oxide (AEOXIDE P25 manufactured by Nippon Aerosil Co., Ltd.) were added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 8.5% by mass) in the same amount as the cellulose acetate in the solution. The mass was added and uniformly stirred to make a cellulose acetate solution containing activated carbon and titanium oxide. The cellulose acetate solution was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 4 hours while deacetylating while exchanging the solvent with water. After 4 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (15) of one embodiment of the present invention containing activated carbon and titanium oxide. The cellulose monolith particles (15) of the present invention had a water absorption of 2.8 g/g and a specific surface area of 467.94 m ² /g. FIG. 11 shows a cross-sectional micrograph of the cellulose monolith particles (15) of one embodiment of the present invention.

[Example 27]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) in an amount half the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain activated carbon. A cellulose acetate solution was prepared. This cellulose acetate solution was developed in a petri dish on filter paper pre-moistened with 0.1 mol/L sodium hydroxide aqueous solution, and the developed solution was immersed in additional 0.1 mol/L sodium hydroxide aqueous solution, followed by adding water. Deacetylation was carried out for 18 hours with solvent exchange. After 18 hours, the obtained activated carbon-containing cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a cellulose monolith molded body (13) of one embodiment of the present invention containing activated carbon. The cellulose monolith molded body (13) had a water absorption of 2.8 g/g, a compressibility of 45%, and a compression stiffness of 0.68.

[Example 28]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) in an amount equal to the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain cellulose acetate containing activated carbon. made a solution. 1.0 g of this cellulose acetate solution was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm and a height of 13 mm. The activated carbon particles were sedimented at the bottom of the container by allowing the container to stand for 2 hours while being kept horizontal with the lid closed. In this state, the container was placed in a freezer for 2 hours to freeze and solidify. After 2 hours, the container was taken out of the freezer, and a sheet-like DMSO solution molded body of cellulose acetate containing activated carbon that had been solidified from the inside of the container was taken out and immersed in 30 mL of a 0.1 mol/L sodium hydroxide aqueous solution. The deacetylation was carried out for 18 hours while exchanging the solvent. After 18 hours, the obtained sheet-like cellulose monolith molded body containing activated carbon was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body with activated carbon particles adhered to the bottom (black on the activated carbon side and white on the opposite side). rice field.

Next, a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) was applied to the surface on the activated carbon side, immersed in a 0.1 mol/L sodium hydroxide aqueous solution in this state, and deacetylated while exchanging the solvent with water. The reaction was carried out for 18 hours. The obtained activated carbon-containing cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a cellulose monolith molded body (14) of one embodiment of the present invention containing activated carbon. The water absorption of the cellulose monolith molded body (14) was 6.8 g/g. FIG. 12 shows the appearance of the cellulose monolith molded body (14) of one embodiment of the present invention, and the stereomicrograph of the cross section. Activated carbon was covered with a white monolith.

A 1% by mass Congo red aqueous solution was applied to the obtained cellulose monolith molded body (14). As a result, a red-dyed cellulose monolith molded body (14') was obtained. FIG. 13 shows a stereomicroscopic photograph of the cross section of the cellulose monolith molded body (14'), in which the activated carbon was covered with a red monolith.

[Example 29]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) in an amount equal to the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain cellulose acetate containing activated carbon. made a solution. The obtained cellulose acetate solution containing activated carbon was added dropwise to 30 mL of a 0.1 mol/L aqueous sodium hydroxide solution with stirring, and the solution was deacetylated while exchanging the solvent with water. The cellulose monolith particles containing activated carbon were washed with water until the filtrate became neutral. After washing with water, water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (16) according to one embodiment of the present invention. The cellulose monolith particles (16) had a water absorption of 2.3 g/g and a specific surface area of 545.69 m ² /g. 46 mg of these particles were added to 10 g of a 0.0025% by mass toluidine blue aqueous solution and stirred for 16 hours, and the toluidine blue aqueous solution became transparent.

[Example 30]
1% by mass of a nonionic surfactant (trade name: Pluronic P103) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass) to obtain a uniform solution. This solution was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and deacetylated while exchanging the solvent with water, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (17) according to one embodiment of the present invention. The water absorption of the cellulose monolith particles (17) was 6.3 g/g.

[Example 31]
A uniform solution was obtained by adding 1% by mass of a nonionic surfactant (trade name: Pluronic P108) to a DMSO solution of cellulose acetate (cellulose acetate concentration: 10.2% by mass). 1.26 g of this solution was poured into a polyethylene rectangular parallelepiped container having a width of 18 mm, a length of 30 mm, and a height of 18 mm. Frozen sheet (1)).
1.17 g of the same solution was poured into a polyethylene rectangular parallelepiped container having a width of 18 mm, a length of 30 mm, and a height of 18 mm. Frozen sheet (2)).

1.57 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 4.0% by mass) was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm, and a height of 18 mm. The sheet was placed in a freezer for a period of time to freeze and solidify (this sheet is referred to as frozen sheet (3)).

After 1 hour, the frozen sheets (1) to (3) were taken out from the freezer and superimposed in the order of (1), (3), and (2) at room temperature, and the three sheets were superimposed and covered with a polyethylene film. , and placed in the freezer again for 1 hour to freeze and solidify. After 1 hour, the frozen sheet in which the three sheets were superimposed was taken out from the freezer to obtain a molded cellulose acylate molded article. The resulting cellulose acylate molded product was immersed in 200 mL of a 0.1 mol/L sodium hydroxide aqueous solution, deacetylated while exchanging the solvent with water, and reacted for 18 hours. After 18 hours, the obtained sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (15) according to one embodiment of the present invention.
The water absorption amount of the cellulose monolith molded body (15) was 11.2 g/g, and the cellulose monolith molded body (15) absorbed water and swelled preferentially in the vertical direction.

[Example 32]
1.7 g of a DMSO solution of cellulose acetate (cellulose acetate concentration: 4.0% by mass) was poured into a polyethylene cuboid container having a width of 18 mm, a length of 30 mm and a height of 13 mm. The container was placed in a freezer for 20 hours while being kept horizontal with a lid, and solidified by freezing. After 20 hours, the container was removed from the freezer, and the sheet-like cellulose acetate DMSO solution formed by solidification was removed from the inside of the container, immersed in 30 mL of a 0.1 mol/L sodium hydroxide aqueous solution, and the solvent was exchanged with water. The reaction was carried out for 5 hours while deacetylating. After 5 hours, the resulting sheet-like cellulose monolith molded body was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like cellulose monolith molded body (16) according to one embodiment of the present invention. The water absorption of the cellulose monolith molded body (16) was 19.8 g/g.

[Example 33]
A DMSO solution of cellulose acetate (cellulose acetate concentration: 5.4% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and stirring was continued for 12 hours while deacetylating while exchanging the solvent with water. . After 12 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (18) according to one embodiment of the present invention. The cellulose monolith particles (18) have a water absorption of 14.0 g/g, a specific surface area of 35.50 m ² /g, a retained water absorption of 6.4 g/g in a 0.9% by weight sodium chloride aqueous solution, and a water absorption of 6.4 g/g in deionized water. The retained water absorption was 6.2 g/g.

[Example 34]
An aqueous solution consisting of 150 parts of urea, 20 parts of sodium dihydrogen phosphate dihydrate and 700 parts of deionized water was added to 100 parts of cellulose monolith particles (18), followed by heat treatment at 145° C. for 20 minutes. The heat-treated product is washed with a mixed solvent of methanol/pure water (volume mixing ratio of methanol and pure water is 3:1), and the washed product is washed with methanol again, filtered by suction, and dried under reduced pressure to obtain the water-swelling property of the present invention. A cellulose monolith (1) was obtained. The water-swellable cellulose monolith (1) of one embodiment of the present invention has a specific surface area of 54.02 m ² /g, a retained water absorption in a 0.9 wt% sodium chloride aqueous solution of 12.4 g/g, and a water absorption capacity of 12.4 g/g in deionized water. The retained water absorption was 48.1 g/g. It was confirmed from the FT-IR chart that the water-swellable cellulose monolith (1) has a cellulose carbamate phosphate structure. It was also confirmed from the SEM image that it had a monolithic structure.

[Example 35]
A DMSO solution (cellulose triacetate concentration: 5.4% by mass) of cellulose triacetate (reagent purchased from Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and water and solvent were added. Stirring was continued for 16 hours while exchanging and deacetylating. After 16 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (19) according to one embodiment of the present invention. The cellulose monolith particles (18) have a water absorption of 12.0 g/g, a specific surface area of 29.97 m ² /g, and a retained water absorption of 5.2 g/g in a 0.9 wt% sodium chloride aqueous solution. The retained water absorption was 4.8 g/g.

[Example 36]
Activated carbon ("Taiko 350SZ" manufactured by Futamura Chemical Co., Ltd.) was added to a DMSO solution of cellulose acetate (cellulose acetate concentration: 7.8% by mass) in an amount equal to the mass of cellulose acetate in the solution, and the mixture was uniformly stirred to obtain cellulose acetate containing activated carbon. made a solution. The resulting DMSO solution of cellulose acetate containing activated carbon was poured into a silicone mold (butterfly) purchased from Can Do. The surface was covered with a polyethylene film and placed in a freezer for 20 hours while keeping the mold container horizontal to freeze and solidify. After 20 hours, the container was removed from the freezer, and the butterfly-shaped cellulose acetate DMSO solution molded body solidified and molded from the inside of the container was taken out, immersed in 150 mL of 0.1 mol / L sodium hydroxide aqueous solution, and the solvent was exchanged with water. While deacetylating, the reaction was carried out for 16 hours. After 16 hours, the resulting butterfly-shaped cellulose monolith was washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith molded body was replaced with ethanol and dried under reduced pressure to obtain a sheet-like activated carbon-containing cellulose monolith molded body (17) according to one embodiment of the present invention. The cellulose monolith molded body (17) had a water absorption of 8.0 g/g and a weight of 0.9 g. FIG. 14 shows an image of the butterfly-shaped cellulose monolith molded body (17).

The cellulose monolith molded body (17) was placed in a polyethylene bag together with a Philippine banana weighing 190 g, and the bag was sealed. For comparison, 187 g of Philippine banana was placed in a polyethylene bag and the bag was sealed. A Philippine banana containing cellulose monolith molded body (17) and a Philippine banana not containing cellulose monolith molded body (17) were placed in a refrigerator at the same time and refrigerated for one week. Bananas with bodies (17) bagged together had no blackening, whereas bananas without cellulose monolith bodies (17) were blackened. The activated carbon-containing cellulose monolith molded body (17) adsorbed gas and moisture, and thus had a freshness-keeping effect.

[Example 37]
An aqueous solution consisting of 152 parts of urea, 50 parts of sodium dihydrogen phosphate dihydrate and 600 parts of deionized water was added to 100 parts of cellulose monolith particles (19), followed by heat treatment at 145° C. for 20 minutes. The heat-treated product is washed with a mixed solvent of methanol/pure water (volume mixing ratio of methanol and pure water is 3:1), and the washed product is washed with methanol again, filtered by suction, and dried under reduced pressure to obtain the water-swelling property of the present invention. A cellulose monolith (2) was obtained. The water-swellable cellulose monolith (2) of one embodiment of the present invention has a specific surface area of 29.84 m ² /g, a retained water absorption in a 0.9 wt% sodium chloride aqueous solution of 11.1 g/g, and a water absorption capacity of 11.1 g/g in deionized water. The retained water absorption was 36.5 g/g. It was confirmed from the FT-IR chart that the water-swellable cellulose monolith (2) has a cellulose carbamate phosphate structure having a carbamoyl group and a phosphoric acid group. It was also confirmed from the SEM image that it had a monolithic structure.

[Example 38] Synthesis example of cellulose formate (1)
4.86 g of ground pulp, 156.9 g of formic acid (88%), 279.3 g of phosphoric acid and 30 g of water were charged in a flask and stirred at room temperature for 3 days. 450 g of the stirred mixture was added dropwise to 1350 g of acetone and stirred for 10 minutes. After filtration under reduced pressure, the filtrate was washed with acetone three times and dried under reduced pressure to obtain cellulose formate (1). In the FT-IR chart of cellulose formate (1), absorption was confirmed at 1715 cm ^-1 derived from formyl groups.

[Example 39] Synthesis example of cellulose formate (2)
4.86 g of pulverized pulp, 156.9 g of formic acid (88%), 279.3 g of phosphoric acid, and 30 g of water are charged in a flask, and a homogenizer (manufactured by Hsiang Tai, body model number: HG-200, generator model number: K-12S) is used. The mixture was stirred at 16,000 rpm for 15 minutes at 60° C. or below, and further stirred at 20,000 rpm for 15 minutes. 450 g of the stirred mixture was added dropwise to 1350 g of acetone and stirred for 10 minutes. After filtration under reduced pressure, the filtrate was washed with acetone three times and dried under reduced pressure to obtain cellulose formate (2).

[Example 40]
A DMSO solution in which cellulose formate (1) was dissolved (cellulose formate concentration: 7.8% by mass) was added dropwise to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring, and after stirring for 0.2 hours, 18 It was allowed to stand for a period of time and deacetylated while exchanging the solvent with water. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (20) according to one embodiment of the present invention. The resulting cellulose monolith particles (20) had a water absorption of 3.8 g/g, a compressibility (%) of 49% and a compression stiffness of 0.76.

[Example 41]
A DMSO solution in which cellulose formate (1) and cellulose acetate were dissolved (cellulose formate concentration: 5.8% by mass, cellulose acetate concentration: 2.0% by mass) was stirred in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution. The mixture was added dropwise to the bottom, stirred for 0.2 hours, allowed to stand for 18 hours, and deacetylated while exchanging the solvent with water. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (21) according to one embodiment of the present invention. The resulting cellulose monolith particles (21) had a water absorption of 13.9 g/g, a compressibility of 70% and a compression stiffness of 0.45.

[Example 42]
Cellulose formate (1) and cellulose acetate dissolved in DMSO solution (cellulose formate concentration: 3.9% by mass, cellulose acetate concentration: 3.9% by mass) was stirred in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution. The mixture was added dropwise to the bottom, and the mixture was deacetylated while exchanging the solvent with water, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (22) according to one embodiment of the present invention. The obtained cellulose monolith particles (22) had a water absorption of 9.7 g/g, a compressibility (%) of 48% and a compression stiffness of 0.69.

[Example 43]
A DMSO solution in which cellulose formate (1) and cellulose acetate were dissolved (concentration of cellulose formate: 2.7% by mass, cellulose acetate concentration: 2.7% by mass) was stirred in 30 mL of 0.1 mol/L sodium hydroxide aqueous solution. The mixture was added dropwise to the bottom, and the mixture was deacetylated while exchanging the solvent with water, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (23) according to one embodiment of the present invention. The water absorption of the obtained cellulose monolith particles (23) was 18.5 g/g.

[Example 44]
Cellulose formate (2) and cellulose acetate dissolved in DMSO solution (cellulose formate concentration: 2.7% by mass, cellulose acetate concentration: 2.7% by mass) was added to 30 mL of 0.1 mol/L sodium hydroxide aqueous solution with stirring. and deacetylated while exchanging the solvent with water, and stirring was continued for 18 hours. After 18 hours, the obtained cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, water inside the cellulose monolith particles was replaced with ethanol and dried under reduced pressure to obtain cellulose monolith particles (24) according to one embodiment of the present invention. The water absorption of the obtained cellulose monolith particles (24) was 6.8 g/g.

[Example 45]
Using an encapsulator Encapusulator B-390 (manufactured by Buchi), activated carbon-encapsulating cellulose monolith particles were produced. An activated carbon dispersion prepared by dispersing 10.4 g of activated carbon SA1000 (manufactured by Futamura Chemical Co., Ltd.) in 100 mL of cyclohexane was continuously passed through a concentric nozzle (core nozzle for inclusions (inner diameter: 450 µm), while at the same time a DMSO solution of cellulose acetate (cellulose An acetate concentration of 5.4% by mass) was passed through a shell nozzle (inner diameter: 900 μm) for a membrane material as a shell liquid. Droplets of a DMSO solution of cellulose acetate encapsulating an activated carbon dispersion were continuously added dropwise to a stirred 0.1 mol/L aqueous sodium hydroxide solution for 10 minutes, and then the particles formed in the aqueous sodium hydroxide solution were added to the solution for 18 minutes. left for time. After 18 hours, the obtained activated carbon-encapsulated cellulose monolith particles were washed with water until the filtrate became neutral. After washing with water, the activated carbon-encapsulated cellulose monolith particles were washed with ethanol and dried under reduced pressure to obtain activated carbon-encapsulated cellulose monolith particles of one embodiment of the present invention having a diameter of about 800 µm. The obtained particles were covered with a white cellulose monolith as shown in FIG. 15, and contained activated carbon particles inside as shown in a cross-sectional view of FIG.

[Example 46]
An aqueous solution consisting of 200 parts of citric acid and 380 parts of deionized water was added to 100 parts of the cellulose monolith particles (2), followed by heat treatment at 120° C. for 60 minutes. The heat-treated product was washed with pure water, and the washed product was again washed with methanol, filtered by suction, and dried under reduced pressure to obtain a carboxyl group-containing cellulose monolith (1) according to one embodiment of the present invention. It was confirmed from the FT-IR chart that the carboxyl group-containing cellulose monolith (1) has carboxyl groups. Further, titration revealed that the carboxyl group-containing cellulose monolith (1) had 0.45 millimoles of carboxyl groups per gram.

The cellulose monolith production method of the present invention and the cellulose monolith obtained by the production method can be used as sanitary materials such as disposable diapers and sanitary napkins, cosmetics, freshness-keeping agents, soil modifiers, adsorbents, deodorants, water purifiers, metals, etc. It can be applied to various fields such as ion removal, gel filtration chromatography carrier, sustained release drug carrier, seawater desalination, ion exchange chromatography carrier and affinity chromatography carrier.

Claims (5)

A cellulose acylate solution comprising a cellulose acylate, a solvent, and optionally a functional substance and/or a compound capable of reacting with water to generate carbon dioxide gas is brought into contact with a medium containing water and a deacylating agent. and deacylating while exchanging the solvent with water, wherein the amount of the solvent and the water is equal to or greater than the amount of the excess water in volume ratio, or
A cellulose formate solution comprising cellulose formate, a solvent, a functional substance as an optional component, and/or a compound that reacts with water to generate carbon dioxide gas is brought into contact with a medium containing water and a deformylating agent. and deformylating while exchanging the solvent with water, wherein the amount of the solvent and the water is greater than or equal to the excess amount of the water in volume ratio, the method comprising:
The cellulose acylate solution is added dropwise to a stirring medium containing the water and the deacylating agent, and deacylated while exchanging the solvent with water to obtain cellulose monolith particles, or the cellulose formate solution. is added dropwise to a medium containing the water and the deformylating agent under stirring, and deformylation is performed while exchanging the solvent with water to obtain cellulose monolith particles; or the cellulose acylate solution is poured into a container or cast. The cellulose acylate solution molded body that has been frozen and solidified is removed from the container or the casting mold, and the cellulose acylate solution molded body is poured into the medium containing the water and the deacylating agent. It is brought into contact and deacylated while exchanging the solvent with water to obtain a cellulose monolith molded body. The cellulose formate solution molded body that has been frozen and solidified is brought into contact with a medium containing the water and the deformylating agent, and deformylated while exchanging the solvent with water to form a cellulose monolith. get a body
The molded cellulose acylate solution molded article is obtained by cooling the cellulose acylate solution to a temperature below its melting point, or the molded cellulose formate solution molded article is obtained from the cellulose formate solution. obtained by cooling to a temperature below its melting point ,
The solvent in the cellulose acylate solution and the solvent in the cellulose formate solution are dimethylsulfoxide (DMSO), acetone, sulfolane, dimethylimidazolidinone, tetramethylurea, dimethylformamide (DMF), N-methylpyrrolidone, A method for producing a cellulose monolith characterized by using at least one solvent selected from the group consisting of dimethylacetamide (DMAc), tetrahydrofuran, dimethyl ether (DME), ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, acetamide, and formamide. . 2. The method for producing a cellulose monolith according to claim 1, wherein the medium containing the water and the deacylating agent or the water and the deformylating agent is an aqueous sodium hydroxide solution. 3. The method for producing a cellulose monolith according to claim 1 or 2, wherein said deacylation or said deformylation is carried out at room temperature. 4. The method for producing a cellulose monolith according to any one of claims 1 to 3, wherein the cellulose acylate solution contains cellulose formate. The method for producing a cellulose monolith according to any one of claims 1 to 4, wherein the cellulose monolith particles or the cellulose monolith molded body is heat-treated in the presence of urea and phosphoric acid (salt).

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