WO2013085053A1 - Method for producing aqueous cellulose solution and method for producing cellulose derivative - Google Patents

Method for producing aqueous cellulose solution and method for producing cellulose derivative Download PDF

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WO2013085053A1
WO2013085053A1 PCT/JP2012/081857 JP2012081857W WO2013085053A1 WO 2013085053 A1 WO2013085053 A1 WO 2013085053A1 JP 2012081857 W JP2012081857 W JP 2012081857W WO 2013085053 A1 WO2013085053 A1 WO 2013085053A1
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cellulose
aqueous
quaternary ammonium
solution
producing
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PCT/JP2012/081857
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French (fr)
Japanese (ja)
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貴志 酒井
正 依馬
小原　則行
拓三 小見山
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株式会社ダイセル
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Priority to CN201280049066.9A priority Critical patent/CN103842384B/en
Publication of WO2013085053A1 publication Critical patent/WO2013085053A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
    • C08L71/02—Polyalkylene oxides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B1/00—Preparatory treatment of cellulose for making derivatives thereof, e.g. pre-treatment, pre-soaking, activation
    • C08B1/003—Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/02—Alkyl or cycloalkyl ethers
    • C08B11/04—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals
    • C08B11/08—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals with hydroxylated hydrocarbon radicals; Esters, ethers, or acetals thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/02—Alkyl or cycloalkyl ethers
    • C08B11/04—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals
    • C08B11/14—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals with nitrogen-containing groups
    • C08B11/155—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals with nitrogen-containing groups with cyano groups, e.g. cyanoalkyl ethers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B3/00—Preparation of cellulose esters of organic acids
    • C08B3/06—Cellulose acetate, e.g. mono-acetate, di-acetate or tri-acetate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B3/00—Preparation of cellulose esters of organic acids
    • C08B3/22—Post-esterification treatments, including purification
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
    • C08H8/00—Macromolecular compounds derived from lignocellulosic materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/02—Cellulose; Modified cellulose
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D101/00—Coating compositions based on cellulose, modified cellulose, or cellulose derivatives
    • C09D101/02—Cellulose; Modified cellulose
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
    • D01F2/02—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from solutions of cellulose in acids, bases or salts
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D1/00—Treatment of filament-forming or like material
    • D01D1/02—Preparation of spinning solutions
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
    • D21H11/14—Secondary fibres

Definitions

  • the present invention relates to a method for producing a cellulose aqueous solution and a method for producing a cellulose derivative using the cellulose aqueous solution obtained by the production method.
  • Cellulose derivatives represented by acetylcellulose, nitrocellulose, cyanoethylcellulose, etc. are widely used in a wide range of industrial sectors such as packaging, textiles, plastics, photography, surface coating, military demand, airplanes, recording, chemicals, pharmaceuticals, tobacco, and electricity. It is an extremely important material for industrial use.
  • Cellulose derivatives are generally produced by introducing (derivatizing) various functional groups into hydroxy groups of cellulose.
  • cellulose has three hydroxy groups per unit of glucopyranose, and since these hydrogen groups have extremely strong hydrogen bonding forces between molecules or between molecules, cellulose is insoluble in water and most organic solvents. It is hardly soluble. Therefore, prior to the production of the cellulose derivative, in order to enable cellulose to be dissolved in various solvents, treatments for hydrogen bond cleavage and prevention of re-formation are performed by the following dissolution methods.
  • a method of forming a cellulose complex is commonly used.
  • copper is ⁇ coordinated to the hydroxyl groups at the C (2) and C (3) positions of cellulose (see (a) below).
  • Ca (SCN) 2 it is considered that the calcium ion is coordinated to the C (5) position and the C (6) position to form a five-membered ring structure (see (b) below).
  • SO 2 / diethylamine method a SO 2 -amine complex is formed at a ratio of 1: 1 to all the hydroxy groups of cellulose (see (c) below).
  • a cellulose derivative having a substitution degree of 0.1 to 0.5 is soluble in an alkaline aqueous solution, and a cellulose derivative having a substitution degree of around 1 is soluble in water.
  • a method of solvating cellulose is known.
  • a concentrated inorganic acid / water system sulfuric acid, phosphoric acid, polyphosphoric acid aqueous solution, etc.
  • a concentrated inorganic salt / water system such as ZnCl 2 aqueous solution
  • a sodium hydroxide aqueous solution system etc.
  • water is first hydrated to the solvent component to form a hydrated structure.
  • the hydrated structure interacts (solvates) with the cellulose to dissolve the cellulose. Therefore, in order to maintain the hydration structure or promote solvation, there are many low temperature dissolution type dissolution systems in which dissolution proceeds at lower temperatures.
  • DMAC N, N-dimethylacetamide
  • LiCl LiCl
  • DMSO dimethylsulfoside DMSO dimethylsulfoside
  • TBAF tetrabutylammonium fluoride Trihydrate
  • a method using an ionic liquid is not suitable for industrial use because the ionic liquid is expensive and it is difficult to separate products.
  • Non-Patent Document 1 Non-Patent Document 2 and Non-Patent Document 3
  • cellulose forms an addition compound (amine cellulose) with various amines, thereby swelling or dissolving cellulose, and tetramethyl as the amine.
  • Ammonium hydroxide, tetraethylammonium hydroxide, and the like are mentioned, and the larger the alkyl group of the amine, the lower the minimum concentration at which cellulose is dispersed and dissolved.
  • Non-Patent Document 4 includes tetrabutylphosphonium. It describes that cellulose is made into a solution using hydroxide (TBPH) or tetrabutylammoniumhydroxide (TBAH). However, it can be said that TBPH has major problems with respect to problems such as raw material costs and wastewater treatment. Also, the table in this document 2 shows an experiment in which the concentration of water in TBAH and the amount of cellulose were changed. Looking at the result of 60% (equivalent to 40% TBAH), it can be seen that cellulose does not dissolve even at 0.5 wt%.
  • TBPH hydroxide
  • TBAH tetrabutylammoniumhydroxide
  • Non-Patent Document 5 describes a method of reacting cellulose with sodium hydroxide and an unsaturated nitrile.
  • sodium hydroxide is used in this method, there is a problem that hydrolysis of cyano groups introduced into cellulose occurs as a side reaction.
  • the present invention provides a means capable of dissolving cellulose under a mild condition using a relatively safe substance (in other words, producing a cellulose solution). Objective.
  • cellulose can be easily dissolved by bringing cellulose into contact with an aqueous quaternary ammonium hydroxide solution such as tetrabutylammonium hydroxide (TBAH).
  • TBAH tetrabutylammonium hydroxide
  • the present inventors have investigated the cause, and by selecting a product in which the concentration of metal ions (for example, alkali metal inorganic salt such as KBr) mixed in the aqueous quaternary ammonium hydroxide solution is a predetermined value or less, It has been found that a practical dissolution system capable of reliably dissolving cellulose can be used.
  • metal ions for example, alkali metal inorganic salt such as KBr
  • cellulose was dissolved when a cyclic polyether (sometimes called “crown ether”) was added to an aqueous quaternary ammonium hydroxide solution even in the presence of the metal ions.
  • the cyclic polyether functions not only as a metal ion scavenger but also as an accelerator for improving the water solubility of cellulose in cooperation with quaternary ammonium hydroxide, and remarkably accelerates the dissolution rate. Increase the transparency of the resulting solution.
  • DMSO or PEG which is a chain polyether, and is unique to cyclic polyethers.
  • the cellulose aqueous solution (dissolving system) obtained as described above is extremely useful for the production of cellulose derivatives, the recovery of cellulose, and the like. That is, acrylonitrile, epoxide, acetic anhydride, acrylic acid ester is added to the cellulose aqueous solution. , By adding alkyl halides and mixing at room temperature, the corresponding derivatives of cyanoethyl cellulose, hydroxyalkyl cellulose, acetyl cellulose, etc. can be produced quantitatively, or cellulose such as methanol can be added to the cellulose aqueous solution. The inventors have found that cellulose can be easily precipitated and collected by adding a poor solvent, and the present invention has been completed.
  • a method for producing an aqueous cellulose solution comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution.
  • a method for producing an aqueous cellulose solution comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution,
  • cellulose raw material a purified cellulose or a substance containing cellulose
  • the total concentration of the alkali metal halide and / or alkaline earth metal halide dissolved in the aqueous quaternary ammonium hydroxide solution in the state of contact with the cellulose raw material is 1% by weight or less.
  • a method for producing an aqueous cellulose solution comprising a step of contacting a cellulose raw material with an aqueous quaternary ammonium hydroxide solution, wherein the contact between the cellulose raw material and the aqueous quaternary ammonium hydroxide solution is carried out in the presence of a cyclic polyether.
  • the manufacturing method of the cellulose aqueous solution characterized by performing. *
  • the cyclic polyether is at least selected from the group consisting of 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6 and diaza-18-crown-6
  • a cellulose comprising a step of mixing an aqueous cellulose solution obtained by the production method according to any one of [1] to [7] and a hydroxy group-reactive compound used as a raw material for a cellulose derivative.
  • a method for producing a derivative is
  • the hydroxy group-reactive compound is selected from the group consisting of ⁇ , ⁇ -unsaturated nitriles, epoxides, organic carboxylic acid anhydrides, ⁇ , ⁇ -unsaturated carboxylic acid esters, and alkyl halides.
  • a method for producing a cellulose film comprising a step of removing a solvent by drying from an aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
  • [14] A cellulose film obtained by the production method according to [13].
  • [15] A method for producing a cellulose fiber, comprising spinning an aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
  • a pretreatment for dissolving cellulose is unnecessary, and an aqueous cellulose solution can be easily produced simply by bringing a cellulose raw material and an aqueous quaternary ammonium hydroxide solution into contact with each other at room temperature.
  • a cellulose raw material not only a purified product of cellulose, but also a cellulose product such as filter paper and a plant waste material such as sawdust can be used.
  • the cellulose aqueous solution obtained by the present invention is a versatile raw material that can be used for producing various derivatives and recovering cellulose. That is, if various compounds for derivatization are added to this aqueous cellulose solution, each derivative can be quantitatively produced simply by mixing under mild conditions, and a poor solvent such as methanol is added to the aqueous cellulose solution. If added, the cellulose derivative can be isolated by reprecipitation.
  • the present invention can be carried out under mild conditions without requiring special equipment or technology, it is possible to safely produce purified cellulose, cellulose derivatives, processed products thereof, etc. on an industrial large scale, safely. It is expected that it will be possible to manufacture at a cost.
  • Example 8 Visually and optically observed images of the coating liquid prepared from cellulose and 40 wt% TBAH aqueous solution in (2).
  • Example 8 Visually and optically observed images of the coating liquid prepared from cellulose and a 55 wt% TBAH aqueous solution in (3). The photograph which shows precipitation of the quaternary ammonium salt of the cellulose from a supernatant liquid and a residue in [Example 9].
  • Comparative Example of Mixed Solution in [Example 11-1] (KBr addition effect). Comparative photograph of the mixed solution in [Example 11-2] (addition effect of 18C6). Comparative photograph of the mixed solution in [Example 11-3] (difference in dissolution with and without metal ions and crown ether). Comparative photograph of the mixed solution in (1) of [Example 11-4] (when 40% TBAH aqueous solution or ion-exchanged water is used instead). Comparative photograph of the mixed solution in (2) of [Example 11-4] (when KOH or NaOH is used instead of 40% TBAH aqueous solution). The comparative photograph of the mixed solution in (3a) of [Example 11-4] (when DMSO is mixed instead of 18C6). The comparative photograph of the mixed solution in (3b) of [Example 11-4] (when PEG is mixed instead of 18C6).
  • the method for producing an aqueous cellulose solution according to the present invention includes a step of contacting a cellulose raw material (purified cellulose or a substance containing cellulose) with an aqueous quaternary ammonium hydroxide solution.
  • the substance dissolved in the aqueous solution obtained by the above process is presumed to be a cellulose / quaternary ammonium complex produced by the reaction of quaternary ammonium hydroxide with any hydroxy group of cellulose.
  • an aqueous solution in which such a complex is estimated to be dissolved will be referred to as a “cellulose aqueous solution”.
  • the “cellulose raw material” in the present invention may be a purified cellulose, that is, a general product such as cellulose powder or cellulose having the same degree of purity, or other substances containing cellulose, It may be a processed product such as a paper product obtained from a plant raw material (pulp), or may be a crop, plant waste, or other plant substance.
  • the wood usually contains a relatively large amount of hemicellulose, lignin and the like in addition to cellulose, but the present invention can be applied.
  • the cellulose raw material may be refined and pulverized to an appropriate size as necessary. For example, it can be used in the form of sawdust, wood chips or the like produced as a by-product during lumbering.
  • the concentration of the aqueous quaternary ammonium hydroxide used in the method for producing an aqueous cellulose solution of the present invention must be not less than a predetermined value at which the cellulose dissolution reaction proceeds, preferably not less than 35% by weight. It is desirable to do.
  • the “predetermined value” relating to the concentration of the quaternary ammonium hydroxide aqueous solution is estimated to be between 32 and 35% by weight under the conditions of Examples described later. If the concentration in the aqueous quaternary ammonium hydroxide solution is lower than a predetermined value, the cellulose does not dissolve and the aqueous cellulose solution may not be obtained.
  • the upper limit of the concentration of the aqueous quaternary ammonium hydroxide solution can be set while taking other conditions into consideration, if necessary. If the concentration of the aqueous quaternary ammonium solution satisfies the above-mentioned concentration conditions (for example, a product having a concentration of 40% by weight is readily available), there is no need to increase it.
  • the amount of quaternary ammonium hydroxide in the aqueous quaternary ammonium hydroxide solution relative to the amount of glucopyranose units constituting the cellulose in the cellulose raw material when the cellulose raw material is brought into contact with the aqueous quaternary ammonium hydroxide solution
  • the ratio needs to be a predetermined value or more so that the cellulose is sufficiently dissolved in water. If the amount of quaternary ammonium hydroxide is insufficient, the cellulose may not be sufficiently dissolved.
  • the lower limit of the above ratio may vary depending on the concentration of the aqueous quaternary ammonium hydroxide used. For example, when the concentration of the quaternary ammonium hydroxide aqueous solution is 55% by weight, the lower limit value can be 1.5 as described above. However, when the concentration of the quaternary ammonium hydroxide aqueous solution is 40% by weight, when the ratio is 1.5, the solubility of cellulose is poor, and it is appropriate to raise the lower limit to about 2.
  • the quaternary ammonium hydroxide used in the present invention preferably has a substituted or unsubstituted alkyl group and / or a substituted or unsubstituted aryl group as four substituents. That is, the four substituents of the quaternary ammonium hydroxide can be each independently a substituted alkyl group, an unsubstituted alkyl group, a substituted aryl group, or an unsubstituted aryl group.
  • the four substituents of the quaternary ammonium hydroxide can be selected from the substituents of known quaternary ammonium hydroxides.
  • the total number of carbon atoms is 4 to 60, preferably Is preferably a combination of substituents such as 4-24.
  • TBAH tetrabutylammonium hydroxide
  • TMAH tetramethylammonium hydroxide
  • BTMAH benzyltrimethylammonium
  • the method for producing an aqueous cellulose solution of the present invention comprises an alkali metal halide and / or an alkaline earth metal halide dissolved in an aqueous quaternary ammonium hydroxide solution in contact with a cellulose raw material (
  • the total concentration of “may be referred to as“ inorganic salt impurities. ”) Must be a predetermined value or less that does not inhibit the dissolution reaction of cellulose, and the concentration is preferably 1% by weight or less. .
  • the “predetermined value” is estimated to exist between 1 and 2% by weight under the conditions of the examples described later.
  • the concentration of the inorganic salt impurities dissolved in the quaternary ammonium hydroxide aqueous solution is higher than a predetermined value, the cellulose dissolution reaction may be inhibited, and the cellulose aqueous solution may not be obtained. It is ideal that the inorganic salt impurity is not substantially contained at all, that is, it is considered that the concentration should be as low as possible. Therefore, the lower limit value of the concentration of the inorganic salt impurity may not be provided (may be 0). However, if necessary, it may be set in consideration of other conditions.
  • the concentration of the inorganic salt impurity dissolved in the aqueous quaternary ammonium hydroxide solution is not limited to the above range, and may exceed the above range. It is possible to dissolve cellulose.
  • the concentration may be adjusted according to the change.
  • inorganic salt impurities include, but are not limited to, KBr, LiBr, and NaBr. When a plurality of types of inorganic salt impurities coexist, the above concentration conditions are considered based on the total concentration of each inorganic salt impurity.
  • Quaternary ammonium hydroxide that satisfies the above conditions for inorganic salt impurities can be obtained as a specific product.
  • an inorganic salt impurity (KBr, etc.) is not substantially mixed in an aqueous solution of quaternary ammonium hydroxide (TBAH, etc.) manufactured by Aldrich, and is suitable as a product that satisfies the above requirements.
  • TBAH quaternary ammonium hydroxide
  • a predetermined purification step membrane purification, recrystallization, extraction, etc.
  • the inorganic salt impurities dissolved in the aqueous quaternary ammonium hydroxide solution are assumed to be mainly contained in the aqueous quaternary ammonium hydroxide solution (for example, those mixed in the manufacturing process of the product). It can also be assumed that it is contained (for example, what was originally contained in the cellulose raw material, or that was mixed in the pretreatment performed if necessary).
  • the manufacturing method of the cellulose aqueous solution by this invention is obtained while improving the dissolution rate of a cellulose, when a cellulose raw material and quaternary ammonium hydroxide are made to contact in presence of cyclic polyether (crown ether). Since transparency of a solution can be improved, it is more preferable. Even if the cyclic polyether is brought into contact with the cellulose raw material alone without using quaternary ammonium hydroxide, the cellulose can hardly be dissolved.
  • the cyclic polyether examples include 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6, and diaza-18-crown-6.
  • the cyclic polyether is considered to function not only as a metal ion scavenger but also as an accelerator for improving water solubility (dissolution rate and transparency) of cellulose in cooperation with quaternary ammonium hydroxide. ing. While considering the effect, an appropriate cyclic polyether may be used according to conditions such as the kind of alkali metal ions and / or alkaline earth metal ions present in the aqueous quaternary ammonium hydroxide solution. When potassium ions are present in the aqueous quaternary ammonium hydroxide, 15-crown-5 and 18-crown-6 are preferred.
  • the use of the cyclic polyether in the present invention is not limited to the case where the total concentration of the inorganic salt impurities is 1% by weight or less, but rather the total concentration of the inorganic salt impurities is more than 1% by weight. In some cases, it is suitable as a means for enabling dissolution of cellulose.
  • the amount of the cyclic polyether used is not particularly limited.
  • the concentration of quaternary ammonium hydroxide, the amount of cellulose, the total concentration of alkali metal halide and / or alkaline earth metal halide, cyclic polyether is usually 0.01 to 5M, although it can be adjusted as appropriate in consideration of the type of compound and the degree of desired effect (dissolution rate, transparency). Preferably it is 0.5-2M.
  • the step of bringing the cellulose raw material into contact with the aqueous quaternary ammonium hydroxide can be performed by mixing them in a reaction vessel while stirring.
  • a quaternary ammonium hydroxide for example, a quaternary ammonium hydroxide aqueous solution and a cyclic polyether may be mixed in advance, and this solution and cellulose may be mixed.
  • the reaction time may be sufficient for cellulose to dissolve depending on the cellulose raw material to be used and the form of the aqueous quaternary ammonium hydroxide, but it is generally about 1 to 6 hours. If a cyclic polyether is used, this time can be reduced to 10 minutes.
  • the reaction temperature can usually be room temperature, but if necessary, it may be heated or cooled so that the reaction proceeds at an appropriate rate.
  • a method for producing a cellulose / quaternary ammonium complex according to the present invention comprises mixing a cellulose aqueous solution obtained by the production method as described above and a poor solvent for cellulose. Including a step of precipitating a quaternary ammonium complex.
  • the quaternary ammonium hydroxide used for dissolving cellulose can be reused after removing a poor solvent such as methanol from which cellulose has been reprecipitated.
  • the method for producing a cellulose / quaternary ammonium complex of the present invention can be used as a method for obtaining a cellulose / quaternary ammonium complex as an intermediate product in the course of the production method for obtaining a desired final product. it can.
  • the use of the cellulose / quaternary ammonium complex recovered by the method of the present invention is not particularly limited.
  • the efficiency of enzymatic saccharification of cellulosic biomass used for bioethanol production can be improved.
  • cellulose has a crystal structure
  • crystalline cellulose has a complex structure surrounded by hemicellulose and lignin, and solid-liquid reaction is used until the final stage of saccharification.
  • the manufacturing method of the cellulose film by this invention includes the process of removing a solvent by drying from the cellulose aqueous solution obtained by the above manufacturing methods.
  • the solvent used in the cellulose aqueous solution of the present invention is water, it can be easily removed by natural drying or general drying means. Therefore, for example, by removing the solvent after spreading the aqueous cellulose solution on a flat surface, a film that is dissolved in the aqueous cellulose solution, that is, formed from a cellulose / quaternary ammonium complex, is re-dissolvable in water ( In the present invention, this is referred to as “cellulose film”).
  • cellulose aqueous solution various cellulose products can be manufactured, such as manufacturing a cellulose fiber using a solution (wet) spinning method, for example.
  • the cellulose fiber production method using the cellulose aqueous solution of the present invention can be applied to a conventional cellulose fiber production method.
  • the cellulose aqueous solution can be applied from a spinning nozzle to an appropriate coagulating liquid (for example, methanol or the like).
  • Cellulose fibers composed of a cellulose / quaternary ammonium complex can be produced by extrusion into a solvent), recovery, washing and the like.
  • the manufacturing method of the cellulose derivative by this invention includes the process of mixing the cellulose aqueous solution obtained by the above manufacturing methods, and the hydroxy group reactive compound used as the raw material of a cellulose derivative.
  • hydroxy group-reactive compound a compound having a functional group capable of reacting with the hydroxy group of the cellulose in a cellulose solution, desirably under mild conditions (for example, only by stirring at room temperature) is used. be able to.
  • a compound is selected according to the target cellulose derivative, and a compound used in a conventional method for producing a cellulose derivative can also be used in the present invention.
  • hydroxyl group-reactive compound examples include ⁇ , ⁇ -unsaturated nitriles, epoxides, organic carboxylic acid anhydrides such as acetic anhydride, ⁇ , ⁇ -unsaturated carboxylic acid esters, and alkyl halides. Any compound can be added to an aqueous cellulose solution and stirred at room temperature for a sufficient time to react with the cellulose / quaternary ammonium complex to produce a predetermined derivative.
  • ⁇ , ⁇ -unsaturated nitrile, epoxide, and organic carboxylic acid anhydride are, in order, cyanoethyl cellulose, hydroxyalkyl (ethyl, propyl, hexyl, etc.) cellulose, acyl (acetyl, etc.), respectively. ) It can be used as a raw material for producing cellulose.
  • alkyl cellulose ester compounds such as methyl cellulose
  • alkyl halide such as methyl chloride
  • the mode of the reaction between the cellulose / quaternary ammonium complex and the hydroxy group-reactive compound in the cellulose aqueous solution is not particularly limited.
  • epoxy hexane see [Example 6] described later
  • quaternary ammonium hydroxide is added to some hydroxy groups in the cellulose.
  • cyanoethyl cellulose is recovered after a treatment in which the quaternary ammonium hydroxide is further removed by addition of an acid to return it to a hydroxy group.
  • the step of mixing the aqueous cellulose solution and the hydroxy group-reactive compound in this method for producing a cellulose derivative can be performed as a continuous step from the aforementioned method for producing an aqueous cellulose solution. That is, when a cellulose aqueous solution in which a cellulose / quaternary ammonium complex is produced according to the present invention is produced, a hydroxy group-reactive compound can be added to the cellulose aqueous solution to perform the step.
  • the process of the method for producing a cellulose derivative may be performed again.
  • the cellulose derivatization reaction is preferably allowed to proceed under mild conditions as described above (for example, only by stirring at room temperature). However, if necessary, heating, cooling, and other purposes of the present invention are lost. You may make it advance by adding operation of the grade which is not made to reject.
  • the produced cellulose derivative can be recovered by using a known method, for example, filtering after adding a poor solvent and precipitating.
  • the cellulose derivative obtained by the production method of the present invention can be used in the same application as the cellulose derivative obtained by a conventional method.
  • packaging eg packaging film: acetylcellulose
  • woven fabric eg fiber: acetylcellulose
  • plastic eg molded product: acetylcellulose, ethylcellulose
  • photograph eg film: acetylcellulose
  • surface coat eg lacquer: nitro
  • a processed product formed from the cellulose derivative using an aqueous solution of the cellulose derivative obtained by the production method as described above.
  • the solvent of the cellulose derivative aqueous solution can be easily removed by natural drying or general drying means, a film made of the cellulose derivative is produced by removing the solvent after the cellulose derivative aqueous solution is developed. can do.
  • carboxyethyl cellulose can be produced by reacting cyanoethyl cellulose with sodium hydroxide.
  • Example 1-2 The cellulose-ammonium complex was isolated according to the procedure shown in FIG. Although cellulose itself is insoluble in DMSO, the solid after the reaction of cellulose and TBAH was dissolved in DMSO after washing with ethyl acetate, ethanol and acetone. It was presumed to be an ammonium salt of cellulose (not an attached substance).
  • the IR spectrum of the collected solid is shown in FIG. It shows that the collected solid is a substance different from cellulose.
  • the 1 H-NMR spectrum is shown in FIG. 3 (bottom). This indicates that the recovered solid has a tetrabutylammonium moiety, and it is considered that any hydroxy group of cellulose is ammoniumated.
  • Example 2 Cellulose and filter paper were each dissolved in tetrabutylammonium hydroxide (Aldrich, 40% in water), and the resulting solution was transferred to a petri dish and allowed to dry naturally. A film was formed from each.
  • tetrabutylammonium hydroxide Aldrich, 40% in water
  • the TBAH product 2 contains about 2.1% by weight of K + and about 2.4% by weight of Br ⁇
  • the TBAH product 3 contains about 2.0% by weight of K + and about 1% of Br ⁇ . 9% by weight (refer to columns K-KA and BR-KA, respectively), but TBAH product 1 (Aldrich) contains virtually no K + and Br ⁇ it is conceivable that. It has been confirmed that cellulose can always be dissolved when TBAH product 1 is used, whereas cellulose cannot be dissolved when TBAH products 2 and 3 are used (depending on the lot).
  • Example 3-2 The TBAH product 1 (manufactured by Aldrich) with KBr added at the following levels was added to a 20 ml test tube containing 500 mg of a small cut filter paper (qualitative filter paper No. 2). The solubility of cellulose after standing at 10 ° C. for 12 hours was visually confirmed, and the state where the filter paper was dissolved was evaluated as “ ⁇ ”, and the state where the filter paper was not dissolved was evaluated as “X” (see FIG. 5). The results are shown in the table below. Entry where KBr concentration in TBAH exceeds 5% by weight In No. 4, cellulose could not be dissolved.
  • Example 3-3 Salt was added to 10 ml of an aqueous quaternary ammonium hydroxide solution at each level, and 500 mg of small cut filter paper (qualitative filter paper No. 2) was added to a 20 ml test tube and allowed to stand at 10 ° C. for 12 hours. The results are shown in the table below. The evaluation criteria for solubility are the same as in Example 3-2. Tetrabutylammonium hydroxide (TBAH), tetramethylammonium hydroxide (TMAH), and benzyltrimethylammonium hydroxide (BTMAH) are all manufactured by Aldrich, and all of the products are initial (when no KBr is added). The KBr concentration is approximately 0% by weight.
  • TBAH Tetrabutylammonium hydroxide
  • TMAH tetramethylammonium hydroxide
  • BTMAH benzyltrimethylammonium hydroxide
  • the inorganic salt When the inorganic salt was 1% by weight or less, cellulose was dissolved in any aqueous solution of quaternary ammonium salt (concentration 40% by weight). On the other hand, when the inorganic salt was 2% by weight or more, it did not dissolve in any aqueous solution of quaternary ammonium salt, and did not dissolve even when the concentration of quaternary ammonium salt was increased.
  • Example 4 A small cut filter paper (qualitative filter paper No. 2) was placed in a 20 ml test tube, 10 ml of each of the following levels of diluted tetrabutylammonium hydroxide (TBAH) was added, and the mixture was allowed to stand at 10 ° C. for 24 hours. The results are shown in the table below. The evaluation criteria for solubility are the same as in Example 3-2. In the case of TBAH, it was confirmed that cellulose was dissolved at a concentration of 35% by weight or more. However, at 32% by weight, cellulose could not be dissolved regardless of the amount of cellulose.
  • TBAH diluted tetrabutylammonium hydroxide
  • the manufacturing method of the conventional cyanoethyl cellulose uses NaOH, and as a side reaction, there is a problem that hydrolysis occurs in the cyano group introduced into cellulose.
  • the above-described method according to the present invention is advantageous in that hydrolysis is unlikely to occur because an aqueous solution of a quaternary ammonium hydroxide (TBAH or the like) that is a weak base is used.
  • TBAH quaternary ammonium hydroxide
  • FIG. 7 shows the 1 H-NMR spectrum of the collected solid. Proton peaks of CH 2 CN, glucopyranose, and tetrabutylammonium were confirmed. From these results, it was estimated that the recovered solid was an ammonium salt of cyanoethyl cellulose.
  • Example 5-1 A stirring bar and the solid recovered in Example 5-1 were placed in a 10 ml two-necked reactor, and N 2 was substituted. Water was added and stirring was started to completely dissolve the cellulose. 10% hydrochloric acid was added and stirred at room temperature for 1 hour. Reprecipitation was performed with methanol, and suction filtration was performed to collect a solid. The recovered amount was 2.32 g. The recovered solid was soluble in both DMSO and water.
  • Example 5-3 160 mg of the solid (cyanoethyl cellulose) recovered in Example 5-1 was dissolved in 3 ml of water, transferred to a petri dish and naturally dried for 36 hours to form a film. This film was translucent.
  • the IR spectrum of the collected solid is shown in FIG. Absorption of a cyano group was confirmed at 2252.7 cm ⁇ 1 .
  • the 1 HNMR spectrum is shown in FIG. Although the protons of CH 2 CN and glucopyranose were confirmed, the proton peak of the tetrabutylammonium moiety disappeared. From these results, it was estimated that the recovered solid was cyanoethyl cellulose.
  • FIG. 11 shows the IR spectrum of the obtained white solid.
  • the NMR spectrum is shown in FIG. 1 H-NMR (300 MHz, DMSO) ⁇ 0.80-1.00 (m), 1.20-1.48 (m) 3.00-5.80 (m); IR (KBr) 3174, 2869, 2364, 2129, 2044, 1643, 1431, 1049, 675cm -1 ; From these spectral data, it was judged that cellulose was modified.
  • the appearance and IR spectrum of the obtained white solid are shown in FIG. 1735.8 Absorption of a carbonyl group was confirmed at cm- 1 .
  • the 1 H-NMR spectrum is shown in FIG. 1 H-NMR (300 MHz, DMSO) ⁇ 1.80-2.10 (m), 4.10 (q) 3.00-5.80 (m); IR (KBr) 3228,2896,1735,1654, 1375, 1244, 1033, 896, 613cm -1 ; Signals of glucopyranose and acetyl group were confirmed. From these results, it was judged that acetylcellulose was produced.
  • the said IR spectrum corresponded with the IR spectrum with a commercial item (Kishida Chemical Co., Ltd. acetylcellulose, acetic acid degree 55%).
  • Acetylcellulose (299 mg), N, N-dimethylaminopyridine (DMAP) (150 mg, mmol), propionic anhydride (4.5 ml, mmol) were added to replace N 2 , DMSO (4 ml), pyridine (4.5 ml) ) And stirred at 100 ° C. for 1 h.
  • the product was precipitated by adding 15 ml of methanol, filtered and dried with a vacuum pump to obtain 321 mg of the desired product as a white solid.
  • Example 8 A coating solution was prepared by mixing 560 mg of cellulose (Merck, Inc., 102330) and 3 g of an aqueous acrylic resin (Washin Paint aqueous polish varnish, solid content 30%). This coating solution was applied onto a flat plate, and the state of cellulose before dissolution was observed visually and with an optical microscope. The coated sample was white, and when observed with an optical microscope, cellulose fine particles were observed as they were (see FIG. 17).
  • Example 9 Extraction of cellulose from sawdust Wood was cut with an electric saw to prepare sawdust. A 10 ml two-necked reactor was charged with 200 mg of a stir bar and its sawdust and replaced with N 2 . 5 ml of tetrabutylammonium hydroxide aqueous solution (Aldrich, 40% in water, MW 259.47, d0.99, 7.71 mmol) was added, and the mixture was stirred at room temperature for 3 days. When the supernatant (2.89 g) was transferred to a vial and 9 ml of methanol was added, cellulose / quaternary ammonium salt was precipitated. Further, when 9 ml of methanol was added to the residue, cellulose / quaternary ammonium salt was precipitated from here.
  • tetrabutylammonium hydroxide aqueous solution Aldrich, 40% in water, MW 259.47, d0.99, 7.71 mmol
  • Example 10-1 515 mg (3.2 mmol) of cellulose was added to 5 ml of tetrabutylammonium hydroxide (TBAH) (manufactured by Aldrich, 40 wt% aqueous solution, 2.39 equivalents with respect to cellulose) while stirring little by little.
  • Sample A after standing for 1 week and Sample B after standing for 1 day were observed with a 40 ⁇ bright field and a polarizing microscope (POM).
  • Neither sample A nor B was considered to be an isotropic solution because no fibrous substance was observed and birefringence based on the anisotropy (crystallinity) of the sample was not observed in the POM image.
  • Example 10-2 Cellulose (515mg, 3.2 mmol) and 5 ml of TBAH (Aldrich, 40% aqueous solution, 2.39 equivalents) were added, and after 5 h, 15 ml of methanol was added for reprecipitation. The white solid was collected by filtration and dried with a vacuum pump for 5 h to obtain 601 mg of a crisp solid.
  • FIG. 22 shows a wide-angle X-ray analysis profile (measurement conditions: sample shape, pulverized in a mortar for 2 minutes; room temperature; sampling every 0.01 °; scan speed, 2 ° / min) of this solid (reprecipitation sample).
  • Cellulose type I is a crystal system unique to natural cellulose.
  • the amorphous halo is bimodal, and the peak position corresponds to the cellulose II crystal.
  • Cellulose II is a crystal system peculiar to a sample precipitated (regenerated) through a molecularly dispersed dissolved state, and cellophane, rayon, and the like are applicable. Together with the results of observation with a polarizing microscope, it is considered that cellulose is dissolved in this solvent as it appears.

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Abstract

[Problem] To provide a means which is capable of dissolving a cellulose under mild conditions using a relatively safe substance. [Solution] A method for producing an aqueous cellulose solution, which comprises a step wherein a purified cellulose or a substance containing a cellulose is brought into contact with an aqueous quaternary ammonium hydroxide solution, and which is characterized in that the total concentration of alkali metal halides and/or alkaline earth metal halides dissolved in the aqueous quaternary ammonium hydroxide solution is 1% by weight or less in a state where the aqueous quaternary ammonium hydroxide solution is in contact with the cellulose starting material. Alternatively, a method for producing an aqueous cellulose solution, which comprises a step wherein a cellulose starting material is brought into contact with an aqueous quaternary ammonium hydroxide solution, and which is characterized in that the cellulose starting material is brought into contact with the aqueous quaternary ammonium hydroxide solution in the presence of a cyclic polyether.

Description

セルロース水溶液の製造方法およびセルロース誘導体の製造方法Method for producing cellulose aqueous solution and method for producing cellulose derivative
　本発明は、セルロース水溶液の製造方法および当該製造方法により得られたセルロース水溶液を用いるセルロース誘導体の製造方法に関する。 The present invention relates to a method for producing a cellulose aqueous solution and a method for producing a cellulose derivative using the cellulose aqueous solution obtained by the production method.
　アセチルセルロース、ニトロセルロース、シアノエチルセルロースなどに代表されるセルロース誘導体は、包装、織物、プラスチック、写真、表面コート、軍需、飛行機、記録、化学薬品、医薬、タバコ、電気などの幅広い産業部門において様々な用途を有する、産業上極めて重要な素材である。 Cellulose derivatives represented by acetylcellulose, nitrocellulose, cyanoethylcellulose, etc. are widely used in a wide range of industrial sectors such as packaging, textiles, plastics, photography, surface coating, military demand, airplanes, recording, chemicals, pharmaceuticals, tobacco, and electricity. It is an extremely important material for industrial use.
　セルロース誘導体は一般的に、セルロースが有するヒドロキシ基に様々な官能基を導入する（誘導体化する）ことで製造される。しかしながら、セルロースはグルコピラノース１単位あたり３つのヒドロキシ基を有し、これらのヒドロキシ基同士が分子内または分子間で起こす水素結合の力は極めて強いため、セルロースは水および大部分の有機溶媒に不溶ないし難溶である。そのため、セルロース誘導体の製造に先立って、セルロースが各種の溶媒に溶解できるようにするために、以下に挙げるような溶解法により水素結合の開裂と再形成防止のための処理が行われている。 Cellulose derivatives are generally produced by introducing (derivatizing) various functional groups into hydroxy groups of cellulose. However, cellulose has three hydroxy groups per unit of glucopyranose, and since these hydrogen groups have extremely strong hydrogen bonding forces between molecules or between molecules, cellulose is insoluble in water and most organic solvents. It is hardly soluble. Therefore, prior to the production of the cellulose derivative, in order to enable cellulose to be dissolved in various solvents, treatments for hydrogen bond cleavage and prevention of re-formation are performed by the following dissolution methods.
　第一の溶解法として、セルロースの錯体を形成させる方法が慣用されている。たとえば、[Cu(NH3)4](OH)2を用いる銅アンモニア法では、セルロースのＣ（２）位およびＣ（３）位のヒドロキシ基に銅がδ配位する（下記(a)参照）。Ca(SCN)2を用いるチオシアン酸カルシウム法では、カルシウムイオンがＣ（５）位およびＣ（６）位に配位し、五員環構造をとると考えられる（下記(b)参照）。SO2/ジエチルアミン法は、セルロースのヒドロキシ基全てにSO2－アミン錯体が１：１の割合で錯体を形成する（下記(c)参照）。 As a first dissolution method, a method of forming a cellulose complex is commonly used. For example, in the copper ammonia method using [Cu (NH 3 ) 4 ] (OH) 2 , copper is δ coordinated to the hydroxyl groups at the C (2) and C (3) positions of cellulose (see (a) below). ). In the calcium thiocyanate method using Ca (SCN) 2 , it is considered that the calcium ion is coordinated to the C (5) position and the C (6) position to form a five-membered ring structure (see (b) below). In the SO 2 / diethylamine method, a SO 2 -amine complex is formed at a ratio of 1: 1 to all the hydroxy groups of cellulose (see (c) below).
Figure JPOXMLDOC01-appb-C000001
 　第二の溶解法として、セルロースのヒドロキシ基を溶剤成分と共有結合させることで誘導体化する方法が知られている。なお、置換度０．１～０．５のセルロース誘導体はアルカリ水溶液に可溶であり、置換度１前後のセルロース誘導体は水に可溶である。二硫化炭素(CS2)/水酸化ナトリウム水溶液を用いて誘導体化するビスコース法（下記式参照）のほか、アルデヒド（パラホルムアルデヒド、ホルムアルデヒド、クロラールCCl3CHOなど）、ニトロシル化合物（N2O4、NOCl）、硫黄含有化合物（SO3、SO2Cl2）などを溶剤として用いる方法がある。
Figure JPOXMLDOC01-appb-C000001
 As a second dissolution method, a method of derivatization by covalently bonding a hydroxy group of cellulose with a solvent component is known. A cellulose derivative having a substitution degree of 0.1 to 0.5 is soluble in an alkaline aqueous solution, and a cellulose derivative having a substitution degree of around 1 is soluble in water. In addition to the viscose method (see the following formula) for derivatization using carbon disulfide (CS 2 ) / sodium hydroxide aqueous solution, aldehydes (paraformaldehyde, formaldehyde, chloral CCl 3 CHO, etc.), nitrosyl compounds (N 2 O 4 , N 2 O 2 Cl 2 ), sulfur-containing compounds (SO 3 , SO 2 Cl 2 ) and the like as a solvent.
Figure JPOXMLDOC01-appb-C000002
 　第三の溶解法として、セルロースを溶媒和する方法が知られている。この方法には、濃厚無機酸／水系（硫酸、リン酸、ポリリン酸水溶液など）、濃厚無機塩／水系（ＺｎＣｌ2水溶液など）、水酸化ナトリウム水溶液系などの溶解系が用いられ、全て含水系である。これらの溶解系では、まず水が溶剤成分に水和し水和構造を形成する。次に、この水和構造体がセルロースと相互作用（溶媒和）してセルロースを溶解させる。よって、水和構造の維持または溶媒和の促進のため、低温ほど溶解が進む低温溶解型の溶解系が多い。
Figure JPOXMLDOC01-appb-C000002
 As a third dissolution method, a method of solvating cellulose is known. In this method, a concentrated inorganic acid / water system (sulfuric acid, phosphoric acid, polyphosphoric acid aqueous solution, etc.), a concentrated inorganic salt / water system (such as ZnCl 2 aqueous solution), a sodium hydroxide aqueous solution system, etc. are used. It is. In these dissolution systems, water is first hydrated to the solvent component to form a hydrated structure. Next, the hydrated structure interacts (solvates) with the cellulose to dissolve the cellulose. Therefore, in order to maintain the hydration structure or promote solvation, there are many low temperature dissolution type dissolution systems in which dissolution proceeds at lower temperatures.
　その他、近年では、ＤＭＡＣ（N,N-dimethylacetamide）／ＬｉＣｌ法、ＤＭＳＯdimethylsulfoside）／ＴＢＡＦ（tetrabutylammonium 
fluoride 
trihydrate）法、イオン液体を用いる方法なども知られている。しかしながら、たとえばイオン液体を用いる方法には、イオン液体は高価であり、生成物の分離が難しいなど、工業的な利用には向かない面がある。 In addition, in recent years, DMAC (N, N-dimethylacetamide) / LiCl method, DMSO dimethylsulfoside) / TBAF (tetrabutylammonium)
fluoride
Trihydrate) method and a method using an ionic liquid are also known. However, for example, a method using an ionic liquid is not suitable for industrial use because the ionic liquid is expensive and it is difficult to separate products.
　また、非特許文献１、非特許文献２および非特許文献３には、セルロースが各種アミン類とも付加化合物（アミンセルロース）を形成し、それによりセルロースを膨潤ないし溶解すること、当該アミンとしてテトラメチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシドなどが挙げられること、当該アミンのアルキル基の大きなものほどセルロースが分散溶解する最低濃度が低いことなどが記載されている。 Further, in Non-Patent Document 1, Non-Patent Document 2 and Non-Patent Document 3, cellulose forms an addition compound (amine cellulose) with various amines, thereby swelling or dissolving cellulose, and tetramethyl as the amine. Ammonium hydroxide, tetraethylammonium hydroxide, and the like are mentioned, and the larger the alkyl group of the amine, the lower the minimum concentration at which cellulose is dispersed and dissolved.
　非特許文献４には、tetrabutylphosphonium 
hydroxide(TBPH)またはtetrabutylammoniumhydroxide(TBAH)を用いてセルロースを溶液化することが記載されている。しかしながら、TBPHは原材料コストおよび排水処理等の問題に関して大きな課題があるといえる。また、この文献のTable 
2には、TBAH中の水の濃度とセルロースの量を変えた実験が示されているが、Run1のwater content 
60%(TBAH40%相当）の結果をみると、セルロースが0.5wt%であっても溶解しないことがわかる。 Non-Patent Document 4 includes tetrabutylphosphonium.
It describes that cellulose is made into a solution using hydroxide (TBPH) or tetrabutylammoniumhydroxide (TBAH). However, it can be said that TBPH has major problems with respect to problems such as raw material costs and wastewater treatment. Also, the table in this document
2 shows an experiment in which the concentration of water in TBAH and the amount of cellulose were changed.
Looking at the result of 60% (equivalent to 40% TBAH), it can be seen that cellulose does not dissolve even at 0.5 wt%.
　上記のように様々な方法が提案されているにもかかわらず、今日まで、四級アンモニウム塩を用いてセルロースを溶解する方法は実用化されていなかった。
　一方、代表的なセルロース誘導体の製造方法としては、次のようなものが知られている。 Although various methods have been proposed as described above, a method for dissolving cellulose using a quaternary ammonium salt has not been put to practical use until now.
On the other hand, as a typical method for producing a cellulose derivative, the following is known.
　シアノエチルセルロースの製造方法として、非特許文献５には、セルロースと水酸化ナトリウムおよび不飽和ニトリルとを反応させる方法が記載されている。しかしながらこの方法では水酸化ナトリウムを用いるので、副反応として、セルロースに導入したシアノ基における加水分解が起きるという問題がある。 As a method for producing cyanoethyl cellulose, Non-Patent Document 5 describes a method of reacting cellulose with sodium hydroxide and an unsaturated nitrile. However, since sodium hydroxide is used in this method, there is a problem that hydrolysis of cyano groups introduced into cellulose occurs as a side reaction.
　ヒドロキシアルキルセルロースの製造方法としては、特許文献１に記載されているようにセルロースと水酸化ナトリウムとを反応させた後、エポキシド（グリシジル化合物）を反応させるという方法がある。しかしながらこの方法には、置換度や選択性が低い、水洗・乾燥後の副生成物（ナトリウム塩）が残留する、強塩基（水酸化ナトリウム）とエポキシドの直接反応による副生成物が生じる可能性があるなどの問題がある。 As a method for producing hydroxyalkyl cellulose, as described in Patent Document 1, there is a method in which cellulose and sodium hydroxide are reacted and then epoxide (glycidyl compound) is reacted. However, this method may produce by-products due to the direct reaction between a strong base (sodium hydroxide) and an epoxide, in which the degree of substitution and selectivity are low, and by-products (sodium salts) remain after washing and drying. There are problems such as.
特開２００１－１２２９１２号公報JP 2001-122912 A
　上述したような従来のセルロースの溶解方法、あるいはその溶解方法により得られたセルロース溶液からセルロースを回収する方法には、重金属やその塩、毒性や爆発性を有する物質、高価な物質の使用や、爆砕や極低温への冷却など過酷な操作が必要であった。 In the conventional cellulose dissolution method as described above, or a method for recovering cellulose from the cellulose solution obtained by the dissolution method, heavy metals and salts thereof, toxic and explosive substances, use of expensive substances, Severe operations such as blasting and cooling to cryogenic temperatures were required.
　また、セルロースを溶解するとともにシアノエチルセルロース、ヒドロキシアルキルセルロース、アセチルセルロースなどに誘導体化する従来の方法にも各種の問題点があった。 Also, the conventional method of dissolving cellulose and derivatizing it into cyanoethyl cellulose, hydroxyalkyl cellulose, acetyl cellulose, etc. has various problems.
　本発明はこのような課題を解決するため、比較的安全性の高い物質を用いて温和な条件下でセルロースを溶解する（換言すればセルロース溶液を製造する）ことのできる手段を提供することを目的とする。 In order to solve such problems, the present invention provides a means capable of dissolving cellulose under a mild condition using a relatively safe substance (in other words, producing a cellulose solution). Objective.
　本発明者らは、テトラブチルアンモニウムヒドロキシド（ＴＢＡＨ）等の水酸化四級アンモニウム水溶液にセルロースを接触させることにより、セルロースを容易に溶解させることができるとの知見を得たが、この際、同じ種類の水酸化四級アンモニウム水溶液であっても、製品（ないしロット）によって、セルロースの溶解に常に成功するものと失敗しやすいものとがあることに気付いた。本発明者らはその原因を追究し、水酸化四級アンモニウム水溶液に混在している金属イオン（たとえばＫＢｒ等のアルカリ金属の無機塩）の濃度が所定の値以下の製品を選択することにより、セルロースを確実に溶解できる、実用的な溶解系を利用することができるようになることを見いだした。 The present inventors have obtained knowledge that cellulose can be easily dissolved by bringing cellulose into contact with an aqueous quaternary ammonium hydroxide solution such as tetrabutylammonium hydroxide (TBAH). I have noticed that even with the same kind of aqueous quaternary ammonium hydroxide, some products (or lots) always succeed in dissolving cellulose and others tend to fail. The present inventors have investigated the cause, and by selecting a product in which the concentration of metal ions (for example, alkali metal inorganic salt such as KBr) mixed in the aqueous quaternary ammonium hydroxide solution is a predetermined value or less, It has been found that a practical dissolution system capable of reliably dissolving cellulose can be used.
　さらに、前記金属イオンの存在下でも、水酸化四級アンモニウム水溶液に環状ポリエーテル（「クラウンエーテル」と呼ばれることもある。）を添加するとセルロースが溶解することを見いだした。この際、環状ポリエーテルは、単に金属イオンの捕捉剤としてではなく、水酸化四級アンモニウムと協同してセルロースの水溶性を向上する促進剤としても機能しており、溶解速度を著しく促進するとともに得られる溶液の透明性を増す。このような効果は、DMSOや鎖状ポリエーテルであるPEGには見られず、環状ポリエーテルに特有のものである。 Furthermore, it was found that cellulose was dissolved when a cyclic polyether (sometimes called “crown ether”) was added to an aqueous quaternary ammonium hydroxide solution even in the presence of the metal ions. In this case, the cyclic polyether functions not only as a metal ion scavenger but also as an accelerator for improving the water solubility of cellulose in cooperation with quaternary ammonium hydroxide, and remarkably accelerates the dissolution rate. Increase the transparency of the resulting solution. Such an effect is not seen in DMSO or PEG, which is a chain polyether, and is unique to cyclic polyethers.
　また、上記のようにして得られるセルロース水溶液（溶解系）は、セルロース誘導体の製造やセルロースの回収等のために極めて有用であること、すなわち、セルロース水溶液にアクリロニトリル、エポキシド、無水酢酸、アクリル酸エステル、ハロゲン化アルキル等を添加し、室温下で混合するだけで、それぞれに対応するシアノエチルセルロース、ヒドロキシアルキルセルロース、アセチルセルロース等の誘導体が定量的に生成することや、セルロース水溶液にメタノール等のセルロースの貧溶媒を添加することにより容易にセルロースを析出させて回収することができることなどを見いだし、本発明を完成させるに至った。 In addition, the cellulose aqueous solution (dissolving system) obtained as described above is extremely useful for the production of cellulose derivatives, the recovery of cellulose, and the like. That is, acrylonitrile, epoxide, acetic anhydride, acrylic acid ester is added to the cellulose aqueous solution. , By adding alkyl halides and mixing at room temperature, the corresponding derivatives of cyanoethyl cellulose, hydroxyalkyl cellulose, acetyl cellulose, etc. can be produced quantitatively, or cellulose such as methanol can be added to the cellulose aqueous solution. The inventors have found that cellulose can be easily precipitated and collected by adding a poor solvent, and the present invention has been completed.
　すなわち、本発明は下記の発明を包含する。
　［１］　セルロース精製物またはセルロースを含有する物質（以下「セルロース原料」と総称する。）と水酸化四級アンモニウム水溶液とを接触させる工程を含むことを特徴とする、セルロース水溶液の製造方法。
［２］　セルロース精製物またはセルロースを含有する物質（以下「セルロース原料」と総称する。）と水酸化四級アンモニウム水溶液とを接触させる工程を含むセルロース水溶液の製造方法であって、
　前記セルロース原料と接触した状態において、前記水酸化四級アンモニウム水溶液中に溶解しているアルカリ金属のハロゲン化物および／またはアルカリ土類金属のハロゲン化物の合計の濃度が１重量％以下であることを特徴とする［１］に記載のセルロース水溶液の製造方法。　 That is, the present invention includes the following inventions.
[1] A method for producing an aqueous cellulose solution, comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution.
[2] A method for producing an aqueous cellulose solution comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution,
The total concentration of the alkali metal halide and / or alkaline earth metal halide dissolved in the aqueous quaternary ammonium hydroxide solution in the state of contact with the cellulose raw material is 1% by weight or less. The method for producing an aqueous cellulose solution as described in [1]. 　
　［３］　前記水酸化四級アンモニウム水溶液の濃度が３５重量％以上である、［１］に記載のセルロース水溶液の製造方法。
　［４］　前記水酸化四級アンモニウムが、置換もしくは非置換のアルキル基および／または置換もしくは非置換のアリール基を４つの置換基として有するものであり、当該４つの置換基の炭素原子数の合計が４～６０である、［２］に記載のセルロース水溶液の製造方法。 [3] The method for producing a cellulose aqueous solution according to [1], wherein the concentration of the aqueous quaternary ammonium hydroxide solution is 35% by weight or more.
[4] The quaternary ammonium hydroxide has a substituted or unsubstituted alkyl group and / or a substituted or unsubstituted aryl group as four substituents, and the total number of carbon atoms of the four substituents The method for producing an aqueous cellulose solution according to [2], wherein is from 4 to 60.
　［５］　セルロース原料と水酸化四級アンモニウム水溶液とを接触させる工程を含むセルロース水溶液の製造方法であって、前記セルロース原料と前記水酸化四級アンモニウム水溶液との接触を環状ポリエーテルの存在下に行うことを特徴とするセルロース水溶液の製造方法。　 [5] A method for producing an aqueous cellulose solution comprising a step of contacting a cellulose raw material with an aqueous quaternary ammonium hydroxide solution, wherein the contact between the cellulose raw material and the aqueous quaternary ammonium hydroxide solution is carried out in the presence of a cyclic polyether. The manufacturing method of the cellulose aqueous solution characterized by performing. *
　［６］　前記環状ポリエーテルが、12-クラウン-4、15-クラウン-5、18-クラウン-6、ジベンゾ-18-クラウン-6およびジアザ-18-クラウン-6からなる群から選ばれた少なくとも１種である、［４］に記載のセルロース水溶液の製造方法。 [6] The cyclic polyether is at least selected from the group consisting of 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6 and diaza-18-crown-6 The manufacturing method of the cellulose aqueous solution as described in [4] which is 1 type.
　　［７］　前記水酸化四級アンモニウム水溶液中の環状ポリエーテルの濃度が０．０１～５Ｍである［５］に記載のセルロース水溶液の製造方法。
　［８］［１］～［７］のいずれかに記載の製造方法により得られる、セルロース水溶液。 [7] The method for producing an aqueous cellulose solution according to [5], wherein the concentration of the cyclic polyether in the aqueous quaternary ammonium hydroxide solution is 0.01 to 5M.
[8] An aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
　［９］　［１］～［７］のいずれかに記載の製造方法により得られるセルロース水溶液中に生成している、セルロースと水酸化四級アンモニウムとから形成された複合体。
　［１０］　［１］～［７］のいずれかに記載の製造方法により得られるセルロース水溶液と、セルロース誘導体の原料となるヒドロキシ基反応性化合物とを混合する工程を含むことを特徴とする、セルロース誘導体の製造方法。 [9] A composite formed from cellulose and quaternary ammonium hydroxide, produced in an aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
[10] A cellulose comprising a step of mixing an aqueous cellulose solution obtained by the production method according to any one of [1] to [7] and a hydroxy group-reactive compound used as a raw material for a cellulose derivative. A method for producing a derivative.
　［１１］　前記ヒドロキシ基反応性化合物が、α，β－不飽和ニトリル、エポキシド、有機カルボン酸無水物、α，β－不飽和カルボン酸エステルおよびハロゲン化アルキルからなる群より選択されるものである、［１０］に記載のセルロース誘導体の製造方法。 [11] The hydroxy group-reactive compound is selected from the group consisting of α, β-unsaturated nitriles, epoxides, organic carboxylic acid anhydrides, α, β-unsaturated carboxylic acid esters, and alkyl halides. [10] The method for producing a cellulose derivative according to [10].
　［１２］　［１］～［７］のいずれかに記載の製造方法により得られるセルロース水溶液と、セルロースの貧溶媒とを混合し、セルロース・四級アンモニウム複合体を析出させる工程を含むことを特徴とする、セルロース・四級アンモニウム複合体の製造方法。 [12] A step of mixing a cellulose aqueous solution obtained by the production method according to any one of [1] to [7] and a poor solvent for cellulose to precipitate a cellulose / quaternary ammonium complex. And a method for producing a cellulose-quaternary ammonium complex.
　［１３］　［１］～［７］のいずれかに記載の製造方法により得られるセルロース水溶液から、乾燥により溶媒を除去する工程を含むことを特徴とする、セルロースフィルムの製造方法。 [13] A method for producing a cellulose film, comprising a step of removing a solvent by drying from an aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
　［１４］　［１３］に記載の製造方法により得られるセルロースフィルム。
　［１５］　［１］～［７］のいずれかに記載の製造方法により得られるセルロース水溶液を紡糸することを特徴とする、セルロース繊維の製造方法。 [14] A cellulose film obtained by the production method according to [13].
[15] A method for producing a cellulose fiber, comprising spinning an aqueous cellulose solution obtained by the production method according to any one of [1] to [7].
　［１６］　［１５］に記載の製造方法により得られるセルロース繊維。 [16] Cellulose fibers obtained by the production method described in [15].
　本発明では、セルロースを溶解させるための前処理は不要であり、セルロース原料と水酸化四級アンモニウム水溶液とを常温下で接触させるだけでセルロース水溶液を容易に製造することができる。セルロース原料としては、セルロースの精製物のみならず、濾紙のようなセルロース製品やおがくずのような植物廃材を用いることができる。 In the present invention, a pretreatment for dissolving cellulose is unnecessary, and an aqueous cellulose solution can be easily produced simply by bringing a cellulose raw material and an aqueous quaternary ammonium hydroxide solution into contact with each other at room temperature. As a cellulose raw material, not only a purified product of cellulose, but also a cellulose product such as filter paper and a plant waste material such as sawdust can be used.
　また、本発明により得られるセルロース水溶液は、さらに各種の誘導体を製造したり、セルロースを回収したりするために利用できる、汎用性のある原料となる。すなわち、このセルロース水溶液に誘導体化のための各種の化合物を添加すれば、温和な条件下で混合するだけで各誘導体を定量的に製造することができるし、セルロース水溶液にメタノール等の貧溶媒を添加すれば、再沈殿によりセルロース誘導体を単離することができる。 Further, the cellulose aqueous solution obtained by the present invention is a versatile raw material that can be used for producing various derivatives and recovering cellulose. That is, if various compounds for derivatization are added to this aqueous cellulose solution, each derivative can be quantitatively produced simply by mixing under mild conditions, and a poor solvent such as methanol is added to the aqueous cellulose solution. If added, the cellulose derivative can be isolated by reprecipitation.
　このような本発明は、特殊な装置や技術を要することなく、温和な条件下で実施できるため、セルロース精製物やセルロース誘導体、これらの加工品などを工業的な大規模で、安全に、低コストで製造することができるようになると期待される。 Since the present invention can be carried out under mild conditions without requiring special equipment or technology, it is possible to safely produce purified cellulose, cellulose derivatives, processed products thereof, etc. on an industrial large scale, safely. It is expected that it will be possible to manufacture at a cost.
［実施例１－１］におけるセルロースの溶解を示す、操作前（左）および操作後（右）の写真。The photograph before operation (left) and after operation (right) showing dissolution of cellulose in [Example 1-1]. ［実施例１－２］の操作手順等を示す図。The figure which shows the operation procedure etc. of [Example 1-2]. ［実施例１－２］で回収した固体のＩＲスペクトル（上）および1Ｈ　ＮＭＲスペクトル（下）。IR spectrum (upper) and 1 H NMR spectrum (lower) of the solid recovered in [Example 1-2]. ［実施例２］におけるセルロースのフィルム化（上）および濾紙のフィルム化（下）を示す写真。The photograph which shows film formation (upper) of cellulose in [Example 2] and film formation (lower) of filter paper. ［実施例３－２］におけるセルロースの溶解性を示す写真。左：溶解性の評価が○のentry 3、右：溶解性の評価が×のentry 4。3 is a photograph showing the solubility of cellulose in [Example 3-2]. Left: entry 3 with a solubility rating of ○, right: entry 4 with a solubility rating of ×. ［実施例５－１］で回収した固体のＩＲスペクトル。IR spectrum of the solid recovered in [Example 5-1]. ［実施例５－１］で回収した固体の1Ｈ　ＮＭＲスペクトル。 1 H NMR spectrum of the solid recovered in [Example 5-1]. ［実施例５－２］で用いた固体（左）およびこれから得られたフィルム（右）。Solid (left) used in [Example 5-2] and a film obtained therefrom (right). ［実施例５－３］で回収した固体のＩＲスペクトル。IR spectrum of the solid recovered in [Example 5-3]. ［実施例５－３］で回収した固体の1Ｈ　ＮＭＲスペクトル。 1 H NMR spectrum of the solid recovered in [Example 5-3]. ［実施例６］で回収した固体のＩＲスペクトル。IR spectrum of the solid collect | recovered in [Example 6]. ［実施例６］で回収した固体の1Ｈ　ＮＭＲスペクトル。 1 H NMR spectrum of the solid recovered in [Example 6]. ［実施例７－１］で回収した固体のＩＲスペクトル。IR spectrum of the solid recovered in [Example 7-1]. ［実施例７－１］で回収した固体の1Ｈ　ＮＭＲスペクトル。 1 H NMR spectrum of the solid recovered in [Example 7-1]. ［実施例７－２］で回収した固体のＩＲスペクトル。IR spectrum of the solid collected in [Example 7-2]. ［実施例７－３］で回収した固体の1Ｈ　ＮＭＲスペクトル。 1 H NMR spectrum of the solid recovered in [Example 7-3]. ［実施例８］（１）における、セルロースと水性アクリル樹脂とから調製した塗工液の、目視および光学顕微鏡による観察画像。[Example 8] Visually and optically observed images of the coating liquid prepared from cellulose and an aqueous acrylic resin in (1). ［実施例８］（２）における、セルロースと４０重量％ＴＢＡＨ水溶液とから調製した塗工液の、目視および光学顕微鏡による観察画像。[Example 8] Visually and optically observed images of the coating liquid prepared from cellulose and 40 wt% TBAH aqueous solution in (2). ［実施例８］（３）における、セルロースと５５重量％ＴＢＡＨ水溶液とから調製した塗工液の、目視および光学顕微鏡による観察画像。[Example 8] Visually and optically observed images of the coating liquid prepared from cellulose and a 55 wt% TBAH aqueous solution in (3). ［実施例９］における、上澄みおよび残渣からのセルロースの・四級アンモニウム塩の析出を示す写真。The photograph which shows precipitation of the quaternary ammonium salt of the cellulose from a supernatant liquid and a residue in [Example 9]. ［実施例１０－１］の試料Ａ（上）、試料Ｂ（下）それぞれについての、４０倍の明視野像（右）および偏光顕微鏡（ＰＯＭ）像（左）。40-times bright field image (right) and polarization microscope (POM) image (left) for each of Sample A (top) and Sample B (bottom) of [Example 10-1]. ［実施例１０－２］における、再沈殿試料の広角Ｘ－線解析プロファイル。Wide-angle X-ray analysis profile of the reprecipitation sample in [Example 10-2]. ［実施例１１－１］（KBrの添加効果）における混合溶液の比較写真。Comparative Example of Mixed Solution in [Example 11-1] (KBr addition effect). ［実施例１１－２］（18C6の添加効果）における混合溶液の比較写真。Comparative photograph of the mixed solution in [Example 11-2] (addition effect of 18C6). ［実施例１１－３］（金属イオンとcrown etherの有無による溶解の違い）における混合溶液の比較写真。Comparative photograph of the mixed solution in [Example 11-3] (difference in dissolution with and without metal ions and crown ether). ［実施例１１－４］の（１）（40% TBAH水溶液またはその代わりにイオン交換水を用いた場合）における混合溶液の比較写真。Comparative photograph of the mixed solution in (1) of [Example 11-4] (when 40% TBAH aqueous solution or ion-exchanged water is used instead). ［実施例１１－４］の（２）（40% TBAH水溶液の代わりにKOHまたはNaOHを用いた場合）における混合溶液の比較写真。Comparative photograph of the mixed solution in (2) of [Example 11-4] (when KOH or NaOH is used instead of 40% TBAH aqueous solution). ［実施例１１－４］の（３ａ）（18C6の代わりにDMSOを混合した場合）における混合溶液の比較写真。The comparative photograph of the mixed solution in (3a) of [Example 11-4] (when DMSO is mixed instead of 18C6). ［実施例１１－４］の（３ｂ）（18C6の代わりにPEGを混合した場合）における混合溶液の比較写真。The comparative photograph of the mixed solution in (3b) of [Example 11-4] (when PEG is mixed instead of 18C6).
　－セルロース水溶液－
　本発明によるセルロース水溶液の製造方法は、セルロース原料（セルロース精製物またはセルロースを含有する物質）と水酸化四級アンモニウム水溶液とを接触させる工程を含む。上記工程により得られる水溶液中に溶解している物質は、セルロースのいずれかのヒドロキシ基に水酸化四級アンモニウムが反応して生成したセルロース・四級アンモニウム複合体であると推定されるが、本発明ではそのような複合体が溶解していると推定される水溶液を「セルロース水溶液」と称することにする。 -Cellulose aqueous solution-
The method for producing an aqueous cellulose solution according to the present invention includes a step of contacting a cellulose raw material (purified cellulose or a substance containing cellulose) with an aqueous quaternary ammonium hydroxide solution. The substance dissolved in the aqueous solution obtained by the above process is presumed to be a cellulose / quaternary ammonium complex produced by the reaction of quaternary ammonium hydroxide with any hydroxy group of cellulose. In the invention, an aqueous solution in which such a complex is estimated to be dissolved will be referred to as a “cellulose aqueous solution”.
　・セルロース原料
　本発明における「セルロース原料」は、セルロース精製物、すなわちセルロース粉末などとして一般的な製品やそれと同程度の純度を有するセルロースであってもよいし、その他のセルロースを含有する物質、すなわち植物原料（パルプ）から得られる紙製品等の加工品などであってもよいし、作物、植物廃棄物、その他の植物性の物質などであってもよい。なお、木質は通常、セルロース以外にも比較的多量のヘミセルロース、リグニン等を含有するが、本発明を適用することが可能である。セルロース原料は、必要に応じて適切なサイズに微細化、粉末化しておいてもよく、たとえば、製材の際に副製するおがくず、木質チップ等の形態でも利用できる。 Cellulose raw material The “cellulose raw material” in the present invention may be a purified cellulose, that is, a general product such as cellulose powder or cellulose having the same degree of purity, or other substances containing cellulose, It may be a processed product such as a paper product obtained from a plant raw material (pulp), or may be a crop, plant waste, or other plant substance. The wood usually contains a relatively large amount of hemicellulose, lignin and the like in addition to cellulose, but the present invention can be applied. The cellulose raw material may be refined and pulverized to an appropriate size as necessary. For example, it can be used in the form of sawdust, wood chips or the like produced as a by-product during lumbering.
　・水酸化四級アンモニウム
　本発明のセルロース水溶液の製造方法に用いる水酸化四級アンモニウム水溶液の濃度は、セルロースの溶解反応が進行する所定の値以上とする必要があり、好ましくは３５重量％以上で行うことが望ましい。上記水酸化四級アンモニウム水溶液の濃度に係る「所定の値」は、後記実施例の条件下では、３２～３５重量％の間に存在すると推測される。水酸化四級アンモニウム水溶液中の濃度が所定の値より低いと、セルロースが溶解せず、セルロース水溶液が得られないおそれがある。当該水酸化四級アンモニウム水溶液の濃度の上限値は、必要であれば他の条件を考慮しながら設定することもできるが、通常は特に設定されるべきものではなく、製品として入手できる水酸化四級アンモニウム水溶液の濃度が上記の濃度の条件を満たしていれば（たとえば当該濃度が４０重量％の製品は容易に入手可能である）、それより高める必要はない。 -Quaternary ammonium hydroxide The concentration of the aqueous quaternary ammonium hydroxide used in the method for producing an aqueous cellulose solution of the present invention must be not less than a predetermined value at which the cellulose dissolution reaction proceeds, preferably not less than 35% by weight. It is desirable to do. The “predetermined value” relating to the concentration of the quaternary ammonium hydroxide aqueous solution is estimated to be between 32 and 35% by weight under the conditions of Examples described later. If the concentration in the aqueous quaternary ammonium hydroxide solution is lower than a predetermined value, the cellulose does not dissolve and the aqueous cellulose solution may not be obtained. The upper limit of the concentration of the aqueous quaternary ammonium hydroxide solution can be set while taking other conditions into consideration, if necessary. If the concentration of the aqueous quaternary ammonium solution satisfies the above-mentioned concentration conditions (for example, a product having a concentration of 40% by weight is readily available), there is no need to increase it.
　なお、用いる水酸化四級アンモニウムの種類を変化させても、上記のような水酸化四級アンモニウム水溶液の望ましい濃度には同じ傾向が見られるが、必要であれば、用いる水酸化四級アンモニウムに応じて濃度を調整してもよい。 Even if the type of quaternary ammonium hydroxide to be used is changed, the same tendency is seen in the desired concentration of the quaternary ammonium hydroxide aqueous solution as described above. The density may be adjusted accordingly.
　また、セルロース原料と水酸化四級アンモニウム水溶液とを接触させる際の、セルロース原料中のセルロースを構成するグルコピラノース単位の物質量に対する、水酸化四級アンモニウム水溶液中の水酸化四級アンモニウムの物質量の割合は、セルロースが十分に水に溶解するよう所定の値以上とする必要がある。水酸化四級アンモニウムの量が不足すると、セルロースが十分に溶解しないおそれがある。 In addition, the amount of quaternary ammonium hydroxide in the aqueous quaternary ammonium hydroxide solution relative to the amount of glucopyranose units constituting the cellulose in the cellulose raw material when the cellulose raw material is brought into contact with the aqueous quaternary ammonium hydroxide solution The ratio needs to be a predetermined value or more so that the cellulose is sufficiently dissolved in water. If the amount of quaternary ammonium hydroxide is insufficient, the cellulose may not be sufficiently dissolved.
　なお、上記割合の下限値は用いる水酸化四級アンモニウム水溶液の濃度によって変動する可能性がある。たとえば、水酸化四級アンモニウム水溶液の濃度が５５重量％である場合は、上記のように下限値を１．５とすることができる。ところが、水酸化四級アンモニウム水溶液の濃度が４０重量％である場合は、上記割合が１．５ではセルロースの溶解性が悪く、下限値を２程度に引き上げることが適切である。セルロース原料の量および水酸化四級アンモニウム水溶液の濃度を勘案しながら、水酸化四級アンモニウムの量が不足してセルロースの溶解性に悪影響を与えることのないよう、水酸化四級アンモニウム水溶液の添加量を調整することが適切である。 The lower limit of the above ratio may vary depending on the concentration of the aqueous quaternary ammonium hydroxide used. For example, when the concentration of the quaternary ammonium hydroxide aqueous solution is 55% by weight, the lower limit value can be 1.5 as described above. However, when the concentration of the quaternary ammonium hydroxide aqueous solution is 40% by weight, when the ratio is 1.5, the solubility of cellulose is poor, and it is appropriate to raise the lower limit to about 2. Add quaternary ammonium hydroxide aqueous solution so as not to adversely affect cellulose solubility due to insufficient amount of quaternary ammonium hydroxide, taking into account the amount of cellulose raw material and the concentration of quaternary ammonium hydroxide aqueous solution It is appropriate to adjust the amount.
　一方、上記割合の上限値は特に設定する必要はなく、通常は水酸化四級アンモニウムが過剰であってもセルロースの溶解性に悪影響はないと考えられるが、コストやその他の条件を勘案して水酸化四級アンモニウムの濃度は適度な範囲に留めておくことが適切である。 On the other hand, it is not necessary to set the upper limit of the above-mentioned ratio, and it is considered that there is no adverse effect on the solubility of cellulose even if quaternary ammonium hydroxide is excessive, but considering the cost and other conditions It is appropriate to keep the concentration of the quaternary ammonium hydroxide within an appropriate range.
　本発明で用いる水酸化四級アンモニウムは、好ましくは、置換もしくは非置換のアルキル基および／または置換もしくは非置換のアリール基を４つの置換基として有するものである。つまり、上記水酸化四級アンモニウムの４つの置換基は、それぞれ独立に、置換アルキル基、非置換アルキル基、置換アリール基または非置換アリール基であり得る。 The quaternary ammonium hydroxide used in the present invention preferably has a substituted or unsubstituted alkyl group and / or a substituted or unsubstituted aryl group as four substituents. That is, the four substituents of the quaternary ammonium hydroxide can be each independently a substituted alkyl group, an unsubstituted alkyl group, a substituted aryl group, or an unsubstituted aryl group.
　また、上記水酸化四級アンモニウムの４つの置換基は、公知の水酸化四級アンモニウムが有する置換基の中から選択することが可能であるが、たとえば炭素原子数の合計が４～６０、好ましくは４～２４となるような置換基の組み合わせとすることが好ましい。 The four substituents of the quaternary ammonium hydroxide can be selected from the substituents of known quaternary ammonium hydroxides. For example, the total number of carbon atoms is 4 to 60, preferably Is preferably a combination of substituents such as 4-24.
　このような炭素原子数に係る条件を満たす水酸化四級アンモニウムの具体例としては、テトラブチルアンモニウムヒドロキシド（ＴＢＡＨ、炭素原子数１６）、テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ、炭素原子数４）、ベンジルトリメチルアンモニウムヒドロキシド（ＢＴＭＡＨ、炭素原子数１０）、テトラヘキシルアンモニウムヒドロキシド（ＴＨＡＨ、炭素原子数２４）など実施例で用いられているものの他、テトラエチルアンモニウムヒドロキシド（炭素原子数８）、トリエチルベンジルアンモニウムヒドロキシド（炭素原子数１３）、トリメチルペンチルアンモニウムヒドロキシド（炭素原子数８）、トリブチルエチルアンモニウムヒドロキシド（炭素原子数１４）が挙げられる。 Specific examples of the quaternary ammonium hydroxide satisfying such conditions relating to the number of carbon atoms include tetrabutylammonium hydroxide (TBAH, carbon atom number 16), tetramethylammonium hydroxide (TMAH, carbon atom number 4), In addition to those used in the examples such as benzyltrimethylammonium hydroxide (BTMAH, carbon number 10), tetrahexylammonium hydroxide (THAH, carbon number 24), tetraethylammonium hydroxide (carbon number 8), triethyl Examples include benzylammonium hydroxide (carbon atom number 13), trimethylpentylammonium hydroxide (carbon atom number 8), and tributylethylammonium hydroxide (carbon atom number 14).
　・無機塩不純物
　本発明のセルロース水溶液の製造方法は、セルロース原料と接触した状態における、水酸化四級アンモニウム水溶液中に溶解しているアルカリ金属のハロゲン化物および／またはアルカリ土類金属のハロゲン化物（本発明において「無機塩不純物」と称する場合もある。）の合計の濃度が、セルロースの溶解反応を阻害しない所定の値以下で行う必要があり、当該濃度が１重量％以下で行うことが好ましい。なお、後記実施例の条件下では、上記「所定の値」は１～２重量％の間に存在すると推測される。水酸化四級アンモニウム水溶液中に溶解している無機塩不純物の濃度が所定の値より高いと、セルロースの溶解反応が阻害され、セルロース水溶液が得られないおそれがある。無機塩不純物は実質的に全く含まれないことが理想的である、つまり濃度は極力低い方がよいと考えられるため、無機塩不純物の濃度の下限値は設けなくてもよい（０としてもよい）が、必要であれば他の条件を考慮しながら設定してもよい。ただし、後述するように、環状ポリエーテルを用いる場合は、水酸化四級アンモニウム水溶液中に溶解している無機塩不純物の濃度は上記範囲に限定されるものではなく、上記範囲を超えていてもセルロースを溶解することが可能である。 Inorganic salt impurities The method for producing an aqueous cellulose solution of the present invention comprises an alkali metal halide and / or an alkaline earth metal halide dissolved in an aqueous quaternary ammonium hydroxide solution in contact with a cellulose raw material ( In the present invention, the total concentration of “may be referred to as“ inorganic salt impurities. ”) Must be a predetermined value or less that does not inhibit the dissolution reaction of cellulose, and the concentration is preferably 1% by weight or less. . Note that the “predetermined value” is estimated to exist between 1 and 2% by weight under the conditions of the examples described later. If the concentration of the inorganic salt impurities dissolved in the quaternary ammonium hydroxide aqueous solution is higher than a predetermined value, the cellulose dissolution reaction may be inhibited, and the cellulose aqueous solution may not be obtained. It is ideal that the inorganic salt impurity is not substantially contained at all, that is, it is considered that the concentration should be as low as possible. Therefore, the lower limit value of the concentration of the inorganic salt impurity may not be provided (may be 0). However, if necessary, it may be set in consideration of other conditions. However, as will be described later, when a cyclic polyether is used, the concentration of the inorganic salt impurity dissolved in the aqueous quaternary ammonium hydroxide solution is not limited to the above range, and may exceed the above range. It is possible to dissolve cellulose.
　なお、後記実施例に示されているように、用いる水酸化四級アンモニウムの種類および濃度（ただし前述のようなセルロースを溶解させることができる濃度の下限値以上の範囲）を変化させても、また無機塩不純物の種類を変化させても、上記のような無機塩不純物の望ましい濃度には同じ傾向が見られるが、必要であれば、上記の変化に応じて濃度を調整してもよい。 As shown in Examples below, even if the type and concentration of quaternary ammonium hydroxide to be used (however, the range above the lower limit of the concentration at which cellulose can be dissolved) can be changed, Even if the type of inorganic salt impurity is changed, the same tendency is observed in the desired concentration of the inorganic salt impurity as described above. However, if necessary, the concentration may be adjusted according to the change.
　無機塩不純物としては、たとえばＫＢｒ、ＬｉＢｒ、ＮａＢｒが挙げられるが、これらに限定されるものではない。複数種の無機塩不純物が混在する場合は、各無機塩不純物の濃度の合計により、上記の濃度の条件を考えるようにする。 Examples of inorganic salt impurities include, but are not limited to, KBr, LiBr, and NaBr. When a plurality of types of inorganic salt impurities coexist, the above concentration conditions are considered based on the total concentration of each inorganic salt impurity.
　なお、たとえば４０％ＴＢＡＨ水溶液に対して５重量％添加する場合、ＮａＣｌおよびＫＣｌは水に溶解するがＴＢＡＨ水溶液とは分離し（２層になる）、ＬｉＣｌ、ＫＩ、ＣａＣｌ2、ＭｇＣｌ2は沈殿が生じるため、これらの化合物は水酸化四級アンモニウム水溶液中に溶解する無機塩不純物とはなりにくい。 For example, when 5% by weight is added to 40% TBAH aqueous solution, NaCl and KCl are dissolved in water but separated from the TBAH aqueous solution (two layers), and LiCl, KI, CaCl 2 and MgCl 2 are precipitated. Therefore, these compounds are unlikely to become inorganic salt impurities dissolved in the aqueous quaternary ammonium hydroxide solution.
　無機塩不純物について上記の条件を満たす水酸化四級アンモニウムは、特定の製品として入手することができる。たとえば、アルドリッチ社製の水酸化四級アンモニウム（ＴＢＡＨ等）水溶液には無機塩不純物（ＫＢｒ等）が実質的に混在しておらず、上記の要件を満たす製品として好適である。また、上記の条件を満たさない水酸化四級アンモニウム水溶液（製品）について、所定の精製工程（膜精製、再結晶、抽出等）を施して無機塩不純物を除去し、上記の条件を満たすようにしたのちに用いることも可能である。 Quaternary ammonium hydroxide that satisfies the above conditions for inorganic salt impurities can be obtained as a specific product. For example, an inorganic salt impurity (KBr, etc.) is not substantially mixed in an aqueous solution of quaternary ammonium hydroxide (TBAH, etc.) manufactured by Aldrich, and is suitable as a product that satisfies the above requirements. In addition, for a quaternary ammonium hydroxide aqueous solution (product) that does not satisfy the above conditions, a predetermined purification step (membrane purification, recrystallization, extraction, etc.) is performed to remove inorganic salt impurities so that the above conditions are satisfied. It can also be used later.
　水酸化四級アンモニウム水溶液中に溶解している無機塩不純物は、主として水酸化四級アンモニウム水溶液に含まれているもの（たとえば製品の製造工程で混入したもの）が想定されるが、セルロース原料に含まれているもの（たとえばセルロース原料に元から含まれていたものや、必要により行われる前処理で混入したもの）であることも想定されうる。 The inorganic salt impurities dissolved in the aqueous quaternary ammonium hydroxide solution are assumed to be mainly contained in the aqueous quaternary ammonium hydroxide solution (for example, those mixed in the manufacturing process of the product). It can also be assumed that it is contained (for example, what was originally contained in the cellulose raw material, or that was mixed in the pretreatment performed if necessary).
　・環状ポリエーテル
　本発明によるセルロース水溶液の製造方法は、環状ポリエーテル（クラウンエーテル）の存在下に、セルロース原料と水酸化四級アンモニウムとを接触させると、セルロースの溶解速度を向上させるとともに得られる溶液の透明性を向上させることができるため、より好ましい。水酸化四級アンモニウムを用いずに、環状ポリエーテルを単独でセルロース原料と接触させても、セルロースはほとんど溶解することができない。 -Cyclic polyether The manufacturing method of the cellulose aqueous solution by this invention is obtained while improving the dissolution rate of a cellulose, when a cellulose raw material and quaternary ammonium hydroxide are made to contact in presence of cyclic polyether (crown ether). Since transparency of a solution can be improved, it is more preferable. Even if the cyclic polyether is brought into contact with the cellulose raw material alone without using quaternary ammonium hydroxide, the cellulose can hardly be dissolved.
　環状ポリエーテルとしては、たとえば、12-クラウン-4、15-クラウン-5、18-クラウン-6、ジベンゾ-18-クラウン-6、ジアザ-18-クラウン-6などが挙げられる。本発明において、環状ポリエーテルは、金属イオンの捕捉剤としてだけではなく、水酸化四級アンモニウムと協同してセルロースの水溶性（溶解速度および透明性）を向上する促進剤としても機能すると考えられている。その効果を考慮しながら、水酸化四級アンモニウム水溶液中に存在しているアルカリ金蔵イオンおよび／またはアルカリ土類金属イオンの種類などの条件に応じて適切な環状ポリエーテルを用いればよいが、たとえば水酸化四級アンモニウム水溶液中にカリウムイオンが存在する場合は、15-クラウン-5および18-クラウン-6が好ましい。 Examples of the cyclic polyether include 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6, and diaza-18-crown-6. In the present invention, the cyclic polyether is considered to function not only as a metal ion scavenger but also as an accelerator for improving water solubility (dissolution rate and transparency) of cellulose in cooperation with quaternary ammonium hydroxide. ing. While considering the effect, an appropriate cyclic polyether may be used according to conditions such as the kind of alkali metal ions and / or alkaline earth metal ions present in the aqueous quaternary ammonium hydroxide solution. When potassium ions are present in the aqueous quaternary ammonium hydroxide, 15-crown-5 and 18-crown-6 are preferred.
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　前記無機塩不純物の合計の濃度が１重量％より多い場合（すなわち水酸化四級アンモニウム単独では溶解しにくい場合）であっても、環状ポリエーテルを併用することにより、セルロースを溶解することが可能となる。すなわち、本発明における環状ポリエーテルの使用は、前記無機塩不純物の合計の濃度が１重量％以下の場合に限定されるものではなく、むしろ前記無機塩不純物の合計の濃度が１重量％より多い場合においてセルロースの溶解を可能にするための手段として好適である。環状ポリエーテルの使用量は特に限定されるものではなく、水酸化四級アンモニウムの濃度、セルロースの量、アルカリ金属のハロゲン化物および／またはアルカリ土類金属のハロゲン化物の合計の濃度、環状ポリエーテルの種類、そして希望する効果の程度（溶解速度、透明度）などを考慮しながら適宜調整することができるが、水酸化四級アンモニウム水溶液中の環状ポリエーテルの濃度は、通常０．０１～５Ｍ、好ましくは０．５～２Ｍである。 Even when the total concentration of the inorganic salt impurities is more than 1% by weight (that is, when it is difficult to dissolve with quaternary ammonium hydroxide alone), it is possible to dissolve cellulose by using cyclic polyether together. It becomes. That is, the use of the cyclic polyether in the present invention is not limited to the case where the total concentration of the inorganic salt impurities is 1% by weight or less, but rather the total concentration of the inorganic salt impurities is more than 1% by weight. In some cases, it is suitable as a means for enabling dissolution of cellulose. The amount of the cyclic polyether used is not particularly limited. The concentration of quaternary ammonium hydroxide, the amount of cellulose, the total concentration of alkali metal halide and / or alkaline earth metal halide, cyclic polyether The concentration of the cyclic polyether in the aqueous quaternary ammonium hydroxide solution is usually 0.01 to 5M, although it can be adjusted as appropriate in consideration of the type of compound and the degree of desired effect (dissolution rate, transparency). Preferably it is 0.5-2M.
　・接触工程
　セルロース原料と水酸化四級アンモニウム水溶液とを接触させる（すなわちセルロースと水酸化四級アンモニウムとを反応させる）工程は、これらを反応容器内で撹拌しながら混合することにより行うことができる。環状ポリエーテルを用いる場合は、たとえば、あらかじめ水酸化四級アンモニウム水溶液と環状ポリエーテルとを混合しておき、この溶液とセルロースとを混合するようにすればよい。 -Contacting step The step of bringing the cellulose raw material into contact with the aqueous quaternary ammonium hydroxide (that is, reacting cellulose with quaternary ammonium hydroxide) can be performed by mixing them in a reaction vessel while stirring. . In the case of using a cyclic polyether, for example, a quaternary ammonium hydroxide aqueous solution and a cyclic polyether may be mixed in advance, and this solution and cellulose may be mixed.
　反応時間は、用いるセルロース原料および水酸化四級アンモニウム水溶液の態様に応じて、セルロースが溶解するのに十分な時間をかければよいが、一般的には１時間～６時間程度である。環状ポリエーテルを用いる場合は、この時間を１０分に短縮することも可能である。反応温度は、通常は室温とすることができるが、必要であれば適切な速度で反応が進行するよう加熱または冷却をしてもよい。 The reaction time may be sufficient for cellulose to dissolve depending on the cellulose raw material to be used and the form of the aqueous quaternary ammonium hydroxide, but it is generally about 1 to 6 hours. If a cyclic polyether is used, this time can be reduced to 10 minutes. The reaction temperature can usually be room temperature, but if necessary, it may be heated or cooled so that the reaction proceeds at an appropriate rate.
　－セルロース水溶液の用途－
　・セルロース・四級アンモニウム複合体の製造方法
　本発明によるセルロース・四級アンモニウム複合体の製造方法は、前述のような製造方法により得られるセルロース水溶液と、セルロースの貧溶媒とを混合し、セルロース・四級アンモニウム複合体を析出させる工程を含むことを特徴とする。 -Use of aqueous cellulose solution-
Method for producing cellulose / quaternary ammonium complex A method for producing a cellulose / quaternary ammonium complex according to the present invention comprises mixing a cellulose aqueous solution obtained by the production method as described above and a poor solvent for cellulose. Including a step of precipitating a quaternary ammonium complex.
　なお、セルロースを溶解するために使用した水酸化四級アンモニウムは、セルロースを再沈殿させたメタノール等の貧溶媒を除去した後、再び利用することが可能になる。また、本発明のセルロース・四級アンモニウム複合体の製造方法は、所望の最終産物を得る製造方法の途中において、中間生成物としてセルロース・四級アンモニウム複合体を得るための方法として利用することができる。 The quaternary ammonium hydroxide used for dissolving cellulose can be reused after removing a poor solvent such as methanol from which cellulose has been reprecipitated. Further, the method for producing a cellulose / quaternary ammonium complex of the present invention can be used as a method for obtaining a cellulose / quaternary ammonium complex as an intermediate product in the course of the production method for obtaining a desired final product. it can.
　本発明の方法により回収されたセルロース・四級アンモニウム複合体の用途は特に限定されるものではない。たとえば、本発明を利用することにより、バイオエタノールの生産に利用されるセルロース系バイオマスの酵素糖化の効率を向上できる可能性がある。従来のセルロース系バイオマスの酵素糖化には、セルロースが結晶構造を有していること、結晶セルロースをヘミセルロースやリグニンが取り囲んだ複雑な構造を形成していること、糖化の最終段階まで固液反応である（セロオリゴ糖の溶解度が低い）こと、グルコース以外にヘミセルロース由来の種々の糖（キシロース、マンノース、アラビノースなど）が生成することなど、デンプン系資材の酵素糖化に比べて多くの問題点があった。そのため、複雑な構造のバイオマスに酵素を働かせるために、脱リグニンあるいはヘミセルロースの部分分解を中心とした前処理や、結晶セルロースを分解するために大量の酵素（セルラーゼ）を用いた処理が必要であるなどの課題があった。これに対し、本発明を利用すれば、セルロース系バイオマスから容易にセルロースを溶出させ、セルロース・四級アンモニウム複合体の形態で回収することができ、当該複合体を酵素糖化に用いれば、少量の酵素で速い速度で糖を生産することが可能となる。 The use of the cellulose / quaternary ammonium complex recovered by the method of the present invention is not particularly limited. For example, by using the present invention, there is a possibility that the efficiency of enzymatic saccharification of cellulosic biomass used for bioethanol production can be improved. In conventional enzymatic saccharification of cellulosic biomass, cellulose has a crystal structure, crystalline cellulose has a complex structure surrounded by hemicellulose and lignin, and solid-liquid reaction is used until the final stage of saccharification. There are many problems compared to enzymatic saccharification of starch-based materials, such as certain (low solubility of cellooligosaccharides) and the generation of various sugars derived from hemicellulose (such as xylose, mannose, arabinose) in addition to glucose . Therefore, pretreatment centering on partial degradation of delignification or hemicellulose, and treatment using a large amount of enzyme (cellulase) to decompose crystalline cellulose are required to make the enzyme work on biomass having a complex structure. There were issues such as. In contrast, if the present invention is used, cellulose can be easily eluted from cellulosic biomass and recovered in the form of a cellulose / quaternary ammonium complex. If the complex is used for enzymatic saccharification, a small amount of cellulose can be recovered. It becomes possible to produce sugar at a high rate with an enzyme.
　・セルロースフィルムの製造方法
　本発明によるセルロースフィルムの製造方法は、前述のような製造方法により得られるセルロース水溶液から、乾燥により溶媒を除去する工程を含む。 -Manufacturing method of a cellulose film The manufacturing method of the cellulose film by this invention includes the process of removing a solvent by drying from the cellulose aqueous solution obtained by the above manufacturing methods.
　本発明のセルロース水溶液に用いられている溶媒は水なので、自然乾燥または一般的な乾燥手段を用いて容易に除去することができる。したがって、たとえばセルロース水溶液を平面上に展開した後に溶媒を除去することにより、セルロース水溶液中に溶解していた物質、すなわちセルロース・四級アンモニウム複合体から形成された、水に再溶解可能なフィルム（本発明ではこれを「セルロースフィルム」と称する。）を製造することができる。 Since the solvent used in the cellulose aqueous solution of the present invention is water, it can be easily removed by natural drying or general drying means. Therefore, for example, by removing the solvent after spreading the aqueous cellulose solution on a flat surface, a film that is dissolved in the aqueous cellulose solution, that is, formed from a cellulose / quaternary ammonium complex, is re-dissolvable in water ( In the present invention, this is referred to as “cellulose film”).
　・セルロース繊維の製造方法
　また、セルロース水溶液からは、たとえば溶液（湿式）紡糸法を用いてセルロース繊維を製造したりするなど、各種のセルロース製品の製造が可能となる。本発明のセルロース水溶液を用いたセルロース繊維の製造方法は、従来のセルロース繊維の製造方法を応用することが可能であるが、たとえば、セルロース水溶液を紡糸ノズルから適切な凝固液（たとえばメタノール等の貧溶媒）中に押し出し、回収、洗浄等することにより、セルロース・四級アンモニウム複合体からなるセルロース繊維を製造することができる。 -Manufacturing method of cellulose fiber Moreover, from cellulose aqueous solution, various cellulose products can be manufactured, such as manufacturing a cellulose fiber using a solution (wet) spinning method, for example. The cellulose fiber production method using the cellulose aqueous solution of the present invention can be applied to a conventional cellulose fiber production method. For example, the cellulose aqueous solution can be applied from a spinning nozzle to an appropriate coagulating liquid (for example, methanol or the like). Cellulose fibers composed of a cellulose / quaternary ammonium complex can be produced by extrusion into a solvent), recovery, washing and the like.
　・セルロース誘導体の製造方法
　本発明によるセルロース誘導体の製造方法は、前述のような製造方法により得られるセルロース水溶液と、セルロース誘導体の原料となるヒドロキシ基反応性化合物とを混合する工程を含む。 -Manufacturing method of a cellulose derivative The manufacturing method of the cellulose derivative by this invention includes the process of mixing the cellulose aqueous solution obtained by the above manufacturing methods, and the hydroxy group reactive compound used as the raw material of a cellulose derivative.
　「ヒドロキシ基反応性化合物」としては、セルロース溶液中で、望ましくは穏和な条件下で（たとえば室温における撹拌のみにより）、当該セルロースが有するヒドロキシ基と反応することのできる官能基を有する化合物を用いることができる。このような化合物は、目的とするセルロース誘導体に応じたものが選択され、従来のセルロース誘導体の製造方法に用いられている化合物を本発明で用いることもできる。 As the “hydroxy group-reactive compound”, a compound having a functional group capable of reacting with the hydroxy group of the cellulose in a cellulose solution, desirably under mild conditions (for example, only by stirring at room temperature) is used. be able to. Such a compound is selected according to the target cellulose derivative, and a compound used in a conventional method for producing a cellulose derivative can also be used in the present invention.
　ヒドロキシ基反応性化合物の具体例としては、α，β－不飽和ニトリル、エポキシド、無水酢酸などの有機カルボン酸無水物、α，β－不飽和カルボン酸エステル、ハロゲン化アルキルなどが挙げられる。いずれの化合物も、セルロース水溶液に添加し、常温で十分な時間撹拌することにより、セルロース・四級アンモニウム複合体と反応し、所定の誘導体を生成することができる。 Specific examples of the hydroxyl group-reactive compound include α, β-unsaturated nitriles, epoxides, organic carboxylic acid anhydrides such as acetic anhydride, α, β-unsaturated carboxylic acid esters, and alkyl halides. Any compound can be added to an aqueous cellulose solution and stirred at room temperature for a sufficient time to react with the cellulose / quaternary ammonium complex to produce a predetermined derivative.
　上記具体例のうち、α，β－不飽和ニトリル、エポキシド、有機カルボン酸無水物（無水酢酸等）は、それぞれ順に、シアノエチルセルロース、ヒドロキシアルキル（エチル、プロピル、ヘキシル等）セルロース、アシル（アセチル等）セルロースを製造する際の原料として用いることができる。 Among the above specific examples, α, β-unsaturated nitrile, epoxide, and organic carboxylic acid anhydride (such as acetic anhydride) are, in order, cyanoethyl cellulose, hydroxyalkyl (ethyl, propyl, hexyl, etc.) cellulose, acyl (acetyl, etc.), respectively. ) It can be used as a raw material for producing cellulose.
　また、セルロース水溶液に二酸化炭素を添加した後、さらにハロゲン化アルキルを添加して反応させることにより、セルロースカーボネートを製造できる可能性がある。
　さらに、ハロゲン化アルキル（塩化メチル等）をヒドロキシ基反応性化合物として用いることにより、アルキルセルロース（メチルセルロース等のエステル化合物）を製造できる可能性もある。 In addition, after adding carbon dioxide to the cellulose aqueous solution, it may be possible to produce cellulose carbonate by further adding an alkyl halide to react.
Furthermore, alkyl cellulose (ester compounds such as methyl cellulose) may be produced by using an alkyl halide (such as methyl chloride) as a hydroxy group-reactive compound.
　さらに、アクリル酸エステルをヒドロキシ基反応性化合物として用いることにより、一旦生成するカルボアルコキシアルキル誘導体から、加水分解よりさらにカルボキシアルキルセルロース誘導体を製造できる可能性もある。 Furthermore, by using an acrylate ester as a hydroxy group-reactive compound, there is a possibility that a carboxyalkyl cellulose derivative can be further produced from hydrolysis from a carboalkoxyalkyl derivative once formed.
　セルロース水溶液中のセルロース・四級アンモニウム複合体とヒドロキシ基反応性化合物との反応の態様は特に限定されるものではない。たとえばエポキシヘキサンを用いる場合（後記［実施例６］参照）、前記複合体において水酸化四級アンモニウムが結合しているヒドロキシ基に、ヒドロキシ基反応性化合物が代わりに結合するものと推測される（得られるヒドロキシヘキシルセルロースからは水酸化四級アンモニウムが脱離している）。あるいは、アクリロニトリルを用いる場合（後記［実施例５－２］参照）、セルロース・四級アンモニウム複合体とアクリロニトリルとを反応させた段階では、セルロース中の一部のヒドロキシ基に水酸化四級アンモニウムが結合したままであり、さらに酸を添加してその水酸化四級アンモニウムを脱離させヒドロキシ基に戻す処理を行った後、シアノエチルセルロースを回収するという態様もある。 The mode of the reaction between the cellulose / quaternary ammonium complex and the hydroxy group-reactive compound in the cellulose aqueous solution is not particularly limited. For example, when epoxy hexane is used (see [Example 6] described later), it is presumed that a hydroxy group-reactive compound is bound instead to the hydroxy group to which quaternary ammonium hydroxide is bound in the composite ( Quaternary ammonium hydroxide is eliminated from the resulting hydroxyhexylcellulose). Alternatively, when acrylonitrile is used (see [Example 5-2] described later), at the stage of reacting the cellulose / quaternary ammonium complex with acrylonitrile, quaternary ammonium hydroxide is added to some hydroxy groups in the cellulose. There is also an embodiment in which cyanoethyl cellulose is recovered after a treatment in which the quaternary ammonium hydroxide is further removed by addition of an acid to return it to a hydroxy group.
　このセルロース誘導体の製造方法における、セルロース水溶液とヒドロキシ基反応性化合物とを混合する工程は、前述したセルロース水溶液の製造方法から連続した工程として行うことができる。すなわち、本発明によりセルロース・四級アンモニウム複合体が生成しているセルロース水溶液が製造されたら、このセルロース水溶液にヒドロキシ基反応性化合物を添加し、当該工程を行うことができる。もちろん、連続的な工程とせず、セルロース・四級アンモニウム複合体を単離したのち、あらためてセルロース誘導体の製造方法の当該工程を行うようにしてもよい。 The step of mixing the aqueous cellulose solution and the hydroxy group-reactive compound in this method for producing a cellulose derivative can be performed as a continuous step from the aforementioned method for producing an aqueous cellulose solution. That is, when a cellulose aqueous solution in which a cellulose / quaternary ammonium complex is produced according to the present invention is produced, a hydroxy group-reactive compound can be added to the cellulose aqueous solution to perform the step. Of course, after the cellulose / quaternary ammonium complex is isolated without being a continuous process, the process of the method for producing a cellulose derivative may be performed again.
　また、セルロースの誘導体化の反応は、上述のように穏和な条件下で（たとえば室温における撹拌のみにより）進行させることが望ましいが、必要であれば加熱、冷却、その他の本発明の趣旨を没却させない程度の操作を加えて進行させるようにしてもよい。 The cellulose derivatization reaction is preferably allowed to proceed under mild conditions as described above (for example, only by stirring at room temperature). However, if necessary, heating, cooling, and other purposes of the present invention are lost. You may make it advance by adding operation of the grade which is not made to reject.
　生成したセルロース誘導体は、たとえば貧溶媒を添加して析出させた後に濾過するなど、公知の手法を用いて回収することができる。
　本発明の製造方法により得られるセルロース誘導体は、従来の方法により得られるセルロース誘導体と同様の用途において利用することができる。 The produced cellulose derivative can be recovered by using a known method, for example, filtering after adding a poor solvent and precipitating.
The cellulose derivative obtained by the production method of the present invention can be used in the same application as the cellulose derivative obtained by a conventional method.
　たとえば、包装（たとえば包装用フィルム：アセチルセルロース）、織物（たとえば繊維：アセチルセルロース）、プラスチック（たとえば成形品：アセチルセルロース、エチルセルロース）、写真（たとえばフィルム：アセチルセルロース）、表面コート（たとえばラッカー：ニトロセルロース、アセチルセルロース、エチルセルロース；塗料：カルボキシメチルセルロース、ヒドロキシエチルセルロース、メチルセルロース、エチルセルロース）、軍需（たとえば火薬：ニトロセルロース）、飛行機（たとえばロケット推進剤：ニトロセルロース）、記録（たとえばテープ：アセチルセルロース）、化学薬品（たとえば耐水性セロファン：ニトロセルロース）、医薬（たとえば下剤：カルボキシメチルセルロース；造粒剤：メチルセルロース、ヒドロキシプロピルセルロース）、タバコ（たとえばフィルター：アセチルセルロース）、電気（たとえば絶縁材料：ベンジルセルロース、シアノエチルセルロース）などがセルロース誘導体の用途として挙げられる。 For example, packaging (eg packaging film: acetylcellulose), woven fabric (eg fiber: acetylcellulose), plastic (eg molded product: acetylcellulose, ethylcellulose), photograph (eg film: acetylcellulose), surface coat (eg lacquer: nitro) Cellulose, acetylcellulose, ethylcellulose; paint: carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose), military demand (eg, gunpowder: nitrocellulose), airplane (eg, rocket propellant: nitrocellulose), recording (eg, tape: acetylcellulose), chemical Chemicals (for example, water-resistant cellophane: nitrocellulose), pharmaceuticals (for example, laxative: carboxymethyl cellulose; granulating agent: methyl cell) Over scan, hydroxypropyl cellulose), tobacco (e.g. Filter: acetyl cellulose), electrical (e.g., insulating material: benzyl cellulose, cyanoethyl cellulose) may be mentioned as applications of the cellulose derivative.
　また、上記のような製造方法により得られるセルロース誘導体の水溶液を用いて、当該セルロース誘導体で形成される加工品を製造することも可能である。たとえば、セルロース誘導体水溶液の溶媒は自然乾燥または一般的な乾燥手段を用いて容易に除去することができるので、セルロース誘導体水溶液を展開した後に溶媒を除去することにより、当該セルロース誘導体からなるフィルムを作製することができる。 In addition, it is also possible to produce a processed product formed from the cellulose derivative using an aqueous solution of the cellulose derivative obtained by the production method as described above. For example, since the solvent of the cellulose derivative aqueous solution can be easily removed by natural drying or general drying means, a film made of the cellulose derivative is produced by removing the solvent after the cellulose derivative aqueous solution is developed. can do.
　さらに、一旦製造されたセルロース誘導体を原料として、さらに別のセルロース誘導体を製造することも可能である。たとえば、シアノエチルセルロースに水酸化ナトリウムを反応させることによりカルボキシエチルセルロースを製造することができる。 Furthermore, it is possible to produce another cellulose derivative using the cellulose derivative once produced as a raw material. For example, carboxyethyl cellulose can be produced by reacting cyanoethyl cellulose with sodium hydroxide.
　［実施例１－１］ [Example 1-1]
Figure JPOXMLDOC01-appb-C000004
 　１０ml二ツ口反応器に撹拌子およびセルロース１０３mg（ＭＷ１６２．１４、０．６４mmol）を入れてＮ2置換した。テトラブチルアンモニウムヒドロキシド水溶液１ml（アルドリッチ社、４０％ｉｎ 
ｗａｔｅｒ、ＭＷ２５９．４７、ｄ０．９９、１．５３mmol）を加え、室温で撹拌した。約２時間でセルロースが完全に溶解した。
Figure JPOXMLDOC01-appb-C000004
 A 10 ml two-necked reactor was charged with a stirring bar and 103 mg of cellulose (MW 162.14, 0.64 mmol), and N 2 was substituted. 1 ml of tetrabutylammonium hydroxide aqueous solution (Aldrich, 40% in)
water, MW259.47, d0.99, 1.53 mmol) was added and stirred at room temperature. The cellulose was completely dissolved in about 2 hours.
　［実施例１－２］
　図２に示す手順に従って、セルロース・アンモニウム複合体を単離した。セルロース自体はＤＭＳＯに不溶であるが、セルロースとＴＢＡＨとの反応後の固体は、酢酸エチル、エタノールおよびアセトンでの洗浄後もＤＭＳＯに溶解したので、当該固体は（単にセルロースの表面にアンモニウム塩が付着した物質ではなく）セルロースのアンモニウム塩であると推定された。 [Example 1-2]
The cellulose-ammonium complex was isolated according to the procedure shown in FIG. Although cellulose itself is insoluble in DMSO, the solid after the reaction of cellulose and TBAH was dissolved in DMSO after washing with ethyl acetate, ethanol and acetone. It was presumed to be an ammonium salt of cellulose (not an attached substance).
　回収した固体のＩＲスペクトルを図３（上）に示す。回収した固体がセルロースとは異なる物質であることを示している。1Ｈ－ＮＭＲスペクトルを図３（下）に示す。回収した固体にテトラブチルアンモニウム部があることを示しており、セルロースのいずれかのヒドロキシ基がアンモニウム化されているものと思われる。 The IR spectrum of the collected solid is shown in FIG. It shows that the collected solid is a substance different from cellulose. The 1 H-NMR spectrum is shown in FIG. 3 (bottom). This indicates that the recovered solid has a tetrabutylammonium moiety, and it is considered that any hydroxy group of cellulose is ammoniumated.
　［実施例２］
　セルロース、濾紙をそれぞれテトラブチルアンモニウムヒドロキシド（アルドリッチ社、４０％ｉｎ　ｗａｔｅｒ）に溶解させ、得られた溶解液をシャーレに移して自然乾燥させたところ、それぞれからフィルムが形成された。 [Example 2]
Cellulose and filter paper were each dissolved in tetrabutylammonium hydroxide (Aldrich, 40% in water), and the resulting solution was transferred to a petri dish and allowed to dry naturally. A film was formed from each.
　［実施例３－１］
　濾紙Ｎｏ．２に３種類のＴＢＡＨ製品を１０μｌ滴下し、５０℃で３ｈ乾燥した後、蛍光Ｘ線測定を行なった。濃度が既知のＫＢｒ水溶液を用いて蛍光Ｘ線測定を行い、検量線を作成し（Ｋ－ＫＡ：ｙ＝１０１０４ｘ－１６４４．４、Ｂｒ－ＫＡ：ｙ＝９５０．２４ｘ－８４６．３３、ｙはＫＢｒの濃度［ppm］、ｘはピーク強度）、各ＴＢＡＨ製品に含まれるＫおよびＢｒの濃度を求めた。結果は下記表に示すとおりである。ＴＢＡＨ製品２にはＫ+が約２．１重量％、Ｂｒ-が約２．４重量％含まれており、ＴＢＡＨ製品３にはＫ+が約２．０重量％、Ｂｒ-が約１．９重量％含まれているものと考えられるが（それぞれK-KAおよびBR-KAの列参照）、ＴＢＡＨ製品１（アルドリッチ社製）にはＫ+およびＢｒ-は実質上ほとんど含まれていないものと考えられる。なお、ＴＢＡＨ製品１を用いると常にセルロースを溶解することができる一方、ＴＢＡＨ製品２および３を用いると（ロットによって）セルロースを溶解することができない場合があることが確認されている。 [Example 3-1]
Filter paper No. After dropping 10 μl of 3 types of TBAH products into 2 and drying at 50 ° C. for 3 h, fluorescent X-ray measurement was performed. X-ray fluorescence measurement was performed using an aqueous KBr solution having a known concentration, and a calibration curve was prepared (K-KA: y = 10104x-1644.4, Br-KA: y = 950.24x-846.33, y is The concentration of KBr [ppm], x is the peak intensity), and the concentrations of K and Br contained in each TBAH product were determined. The results are as shown in the following table. The TBAH product 2 contains about 2.1% by weight of K + and about 2.4% by weight of Br − , and the TBAH product 3 contains about 2.0% by weight of K + and about 1% of Br − . 9% by weight (refer to columns K-KA and BR-KA, respectively), but TBAH product 1 (Aldrich) contains virtually no K + and Br − it is conceivable that. It has been confirmed that cellulose can always be dissolved when TBAH product 1 is used, whereas cellulose cannot be dissolved when TBAH products 2 and 3 are used (depending on the lot).
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　［実施例３－２］
　小さくカットした濾紙（定性濾紙No.２）を500mg入れた20ml試験管に、ＫＢｒを下記各水準で加えた前記ＴＢＡＨ製品１（アルドリッチ社製）を加えた。10℃で12h静置した後のセルロースの溶解性を目視で確認し、濾紙が溶解した状態を○、濾紙が溶解していない状態を×と評価した（図５参照）。結果を下記表に示す。ＴＢＡＨ中のＫＢｒ濃度が５重量％を超えたentry 
4では、セルロースを溶解することができなかった。 [Example 3-2]
The TBAH product 1 (manufactured by Aldrich) with KBr added at the following levels was added to a 20 ml test tube containing 500 mg of a small cut filter paper (qualitative filter paper No. 2). The solubility of cellulose after standing at 10 ° C. for 12 hours was visually confirmed, and the state where the filter paper was dissolved was evaluated as “◯”, and the state where the filter paper was not dissolved was evaluated as “X” (see FIG. 5). The results are shown in the table below. Entry where KBr concentration in TBAH exceeds 5% by weight
In No. 4, cellulose could not be dissolved.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　［実施例３－３］
　水酸化四級アンモニウム塩水溶液10mlに塩を各水準で加え、20ml試験管に小さくカットした濾紙（定性濾紙No.２）を500mg加え、10℃で12h静置した。結果を下記表に示す。溶解性の評価基準は実施例３－２と同じである。なお、テトラブチルアンモニウムヒドロキシド（ＴＢＡＨ）、テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）、ベンジルトリメチルアンモニウムヒドロキシド（ＢＴＭＡＨ）はいずれもアルドリッチ社製のものであり、いずれの製品も初期の（ＫＢｒ無添加時の）ＫＢｒ濃度はほぼ０重量％である。無機塩が１重量％以下の場合、どの四級アンモニウム塩の水溶液（濃度４０重量％）にもセルロースは溶解した。一方、無機塩が２重量％以上の場合、どの四級アンモニウム塩の水溶液にも溶解せず、四級アンモニウム塩の濃度を上げても溶解しなかった。 [Example 3-3]
Salt was added to 10 ml of an aqueous quaternary ammonium hydroxide solution at each level, and 500 mg of small cut filter paper (qualitative filter paper No. 2) was added to a 20 ml test tube and allowed to stand at 10 ° C. for 12 hours. The results are shown in the table below. The evaluation criteria for solubility are the same as in Example 3-2. Tetrabutylammonium hydroxide (TBAH), tetramethylammonium hydroxide (TMAH), and benzyltrimethylammonium hydroxide (BTMAH) are all manufactured by Aldrich, and all of the products are initial (when no KBr is added). The KBr concentration is approximately 0% by weight. When the inorganic salt was 1% by weight or less, cellulose was dissolved in any aqueous solution of quaternary ammonium salt (concentration 40% by weight). On the other hand, when the inorganic salt was 2% by weight or more, it did not dissolve in any aqueous solution of quaternary ammonium salt, and did not dissolve even when the concentration of quaternary ammonium salt was increased.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　［実施例４］
　20ml試験管に小さくカットした濾紙（定性濾紙No.２）を入れ、下記各水準の希釈テトラブチルアンモニウムヒドロキシド（TBAH）を10ml加え、10℃で24時間静置した。結果を下記表に示す。溶解性の評価基準は実施例３－２と同じである。ＴＢＡＨの場合、濃度が３５重量％以上でセルロースが溶解することが確認されたが、３２重量％ではセルロースの量に関わりなくセルロースを溶解することができなかった。 [Example 4]
A small cut filter paper (qualitative filter paper No. 2) was placed in a 20 ml test tube, 10 ml of each of the following levels of diluted tetrabutylammonium hydroxide (TBAH) was added, and the mixture was allowed to stand at 10 ° C. for 24 hours. The results are shown in the table below. The evaluation criteria for solubility are the same as in Example 3-2. In the case of TBAH, it was confirmed that cellulose was dissolved at a concentration of 35% by weight or more. However, at 32% by weight, cellulose could not be dissolved regardless of the amount of cellulose.
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
　［実施例５－１］
　シアノエチルセルロースアンモニウム塩の合成 [Example 5-1]
Synthesis of cyanoethyl cellulose ammonium salt
Figure JPOXMLDOC01-appb-C000009
 　１０ml二ツ口反応器に撹拌子およびセルロース３．０１ｇ（ＭＷ１６２．１４、１８．６mmol）を入れてＮ2置換した。テトラブチルアンモニウムヒドロキシド水溶液２４．０ml（アルドリッチ社、４０％ｉｎ　ｗａｔｅｒ、ＭＷ２５９．４７、ｄ０．９９、３６．０mmol）を加え、室温で２４時間撹拌し、セルロースを完全に溶解させた。次いで、アクリロニトリル７．３０ml（ＭＷ５３．０６、ｄ０．８１、１１．１mmol）を加え、室温で２４時間撹拌した。メタノールを加えて再沈殿を行い、吸引濾過した。残渣を回収し、真空乾燥した。回収した固体は、ＤＭＳＯ、水どちらにも可溶だった。
Figure JPOXMLDOC01-appb-C000009
 A 10 ml two-necked reactor was charged with a stirring bar and 3.01 g of cellulose (MW 162.14, 18.6 mmol), and N 2 was substituted. Tetrabutylammonium hydroxide aqueous solution 24.0 ml (Aldrich, 40% in water, MW 259.47, d0.99, 36.0 mmol) was added and stirred at room temperature for 24 hours to completely dissolve the cellulose. Then, 7.30 ml of acrylonitrile (MW 53.06, d0.81, 11.1 mmol) was added and stirred at room temperature for 24 hours. Methanol was added for reprecipitation and suction filtration was performed. The residue was collected and dried in vacuo. The recovered solid was soluble in both DMSO and water.
　なお、従来のシアノエチルセルロースの製造方法（非特許文献４： 
Zhou, J.; Li, Q.; Song, Y.; Zhangand, L.; Lin, X. Polym. Chem., 2010, 
1,1662-1668.）ではＮａＯＨを用いるので、副反応として、セルロースに導入したシアノ基における加水分解が起きるという問題がある。これに対して本発明による上記の方法では、弱塩基である水酸化四級アンモニウム（ＴＢＡＨ等）の水溶液を用いるので、加水分解が起きにくい点で有利である。 In addition, the manufacturing method of the conventional cyanoethyl cellulose (nonpatent literature 4:
Zhou, J .; Li, Q .; Song, Y .; Zhangand, L .; Lin, X. Polym. Chem., 2010,
1,1662-1668.) Uses NaOH, and as a side reaction, there is a problem that hydrolysis occurs in the cyano group introduced into cellulose. In contrast, the above-described method according to the present invention is advantageous in that hydrolysis is unlikely to occur because an aqueous solution of a quaternary ammonium hydroxide (TBAH or the like) that is a weak base is used.
　回収した固体のＩＲスペクトルを図６に示す。2252.7cm-1にシアノ基の吸収が確認できた。また、回収した固体の1Ｈ－ＮＭＲスペクトルを図７に示す。CH2CNのプロトン、グルコピラノースのプロトンおよびテトラブチルアンモニウム部分のプロトンのピークが確認できた。これらの結果から、回収した固体はシアノエチルセルロースのアンモニウム塩であると推定された。 The IR spectrum of the collected solid is shown in FIG. Absorption of a cyano group was confirmed at 2252.7 cm −1 . FIG. 7 shows the 1 H-NMR spectrum of the collected solid. Proton peaks of CH 2 CN, glucopyranose, and tetrabutylammonium were confirmed. From these results, it was estimated that the recovered solid was an ammonium salt of cyanoethyl cellulose.
　［実施例５－２］
　シアノエチルセルロースの合成 [Example 5-2]
Synthesis of cyanoethyl cellulose
Figure JPOXMLDOC01-appb-C000010
 　１０ml二ツ口反応器に撹拌子および実施例５－１で回収した固体を入れてＮ2置換した。水を加えて撹拌を開始し、セルロースを完全に溶解させた。10％塩酸を加えて室温で１時間撹拌した。メタノールで再沈殿を行い、吸引濾過し、固体を回収した。回収量は２．３２ｇであった。回収した固体は、ＤＭＳＯ、水どちらにも可溶だった。
Figure JPOXMLDOC01-appb-C000010
 A stirring bar and the solid recovered in Example 5-1 were placed in a 10 ml two-necked reactor, and N 2 was substituted. Water was added and stirring was started to completely dissolve the cellulose. 10% hydrochloric acid was added and stirred at room temperature for 1 hour. Reprecipitation was performed with methanol, and suction filtration was performed to collect a solid. The recovered amount was 2.32 g. The recovered solid was soluble in both DMSO and water.
　［実施例５－３］
　実施例５－１で回収した固体（シアノエチルセルロース）１６０mgを水３mlに溶解させ、シャーレに移して３６時間自然乾燥させたところフィルム化した。このフィルムは半透明だった。 [Example 5-3]
160 mg of the solid (cyanoethyl cellulose) recovered in Example 5-1 was dissolved in 3 ml of water, transferred to a petri dish and naturally dried for 36 hours to form a film. This film was translucent.
　回収した固体のＩＲスペクトルを図９に示す。2252.7cm-1にシアノ基の吸収が確認できた。また、1ＨＮＭＲスペクトルを図１０に示す。CH2CNのプロトンおよびグルコピラノースのプロトンは確認できたが、テトラブチルアンモニウム部分のプロトンのピークは消えていた。これらの結果から、回収した固体はシアノエチルセルロースであると推定された。 The IR spectrum of the collected solid is shown in FIG. Absorption of a cyano group was confirmed at 2252.7 cm −1 . The 1 HNMR spectrum is shown in FIG. Although the protons of CH 2 CN and glucopyranose were confirmed, the proton peak of the tetrabutylammonium moiety disappeared. From these results, it was estimated that the recovered solid was cyanoethyl cellulose.
　［実施例６］
　ヒドロキシヘキシルセルロースの合成 [Example 6]
Synthesis of hydroxyhexyl cellulose
Figure JPOXMLDOC01-appb-C000011
 　１０ml二ツ口反応器に撹拌子およびセルロース５０３mg（ＭＷ１６２．１４、３．１０mmol）を入れてＮ2置換した。テトラブチルアンモニウムヒドロキシド水溶液４．００ml（アルドリッチ社、４０％ｉｎ　Ｗａｔｅｒ、ＭＷ２５９．４７、ｄ０．９９、６．１０mmol）を加え、室温で６時間撹拌し、セルロースを完全に溶解させた。次いで、エポキシヘキサン１．１０ml（ＭＷ１００．１６、ｄ０．８４、９．２１mmol）を加え、室温で２４時間撹拌した。メタノールを加えて再沈殿を行い、吸引濾過した。残渣を回収し、真空乾燥した。回収量は１３３mgだった。回収した固体はＤＭＳＯに可溶だった。
Figure JPOXMLDOC01-appb-C000011
 A 10 ml two-necked reactor was charged with a stirring bar and 503 mg of cellulose (MW 162.14, 3.10 mmol), followed by N 2 substitution. 4.00 ml of tetrabutylammonium hydroxide aqueous solution (Aldrich, 40% in Water, MW 259.47, d0.99, 6.10 mmol) was added and stirred at room temperature for 6 hours to completely dissolve the cellulose. Then, 1.10 ml of epoxy hexane (MW 100.16, d0.84, 9.21 mmol) was added and stirred at room temperature for 24 hours. Methanol was added for reprecipitation and suction filtration was performed. The residue was collected and dried in vacuo. The recovered amount was 133 mg. The recovered solid was soluble in DMSO.
　得られた白色固体のＩＲスペクトルを図１１に示す。また、1Ｈ 
ＮＭＲスペクトルを図１２に示す。1H-NMR (300 MHz, DMSO) δ 0.80-1.00 (m), 1.20-1.48 
(m)3.00-5.80(m); IR (KBr) 3174, 2869, 2364, 2129, 2044, 1643, 1431, 1049, 
675cm-1 
;これらのスペクトルデータから、セルロースは修飾されていると判断した。 FIG. 11 shows the IR spectrum of the obtained white solid. 1 H
The NMR spectrum is shown in FIG. 1 H-NMR (300 MHz, DMSO) δ 0.80-1.00 (m), 1.20-1.48
(m) 3.00-5.80 (m); IR (KBr) 3174, 2869, 2364, 2129, 2044, 1643, 1431, 1049,
675cm -1
; From these spectral data, it was judged that cellulose was modified.
　［実施例７－１］
　アセチルセルロースの合成 [Example 7-1]
Synthesis of acetylcellulose
Figure JPOXMLDOC01-appb-C000012
 　１０ml二ツ口反応器に撹拌子およびセルロース５０９mg（ＭＷ１６２．１４、３．１３mmol）を入れてＮ2置換した。テトラブチルアンモニウムヒドロキシド水溶液４．００ml（アルドリッチ社、40%in 
water、ＭＷ２５９．４７、ｄ０．９９、６．１０mmol）を加え、室温で１９時間撹拌し、セルロースを完全に溶解させた。次いで、無水酢酸１．１０ml（ＭＷ１０２．０９、ｄ１．０８、９．２１mmol）を加え、固体化したがそのまま室温で２４時間撹拌した。メタノールを加えて再沈殿を行い、吸引濾過した。残渣を回収し、真空乾燥した。回収量は４５８mgだった。回収した固体はＤＭＳＯに可溶だった。
Figure JPOXMLDOC01-appb-C000012
 A stirrer and 509 mg of cellulose (MW 162.14, 3.13 mmol) were placed in a 10 ml two-necked reactor, and N 2 was substituted. 4.00 ml of tetrabutylammonium hydroxide aqueous solution (Aldrich, 40% in
water, MW 259.47, d0.99, 6.10 mmol) was added, and the mixture was stirred at room temperature for 19 hours to completely dissolve the cellulose. Next, 1.10 ml of acetic anhydride (MW 102.09, d1.08, 9.21 mmol) was added to solidify, but the mixture was stirred at room temperature for 24 hours. Methanol was added for reprecipitation and suction filtration was performed. The residue was collected and dried in vacuo. The recovered amount was 458 mg. The recovered solid was soluble in DMSO.
　得られた白色固体の外観およびＩＲスペクトルを図１３に示す。1735.8 
cm-1にカルボニル基の吸収が確認できた。また、1Ｈ－ＮＭＲスペクトルを図１４に示す。1H-NMR 
(300 MHz, DMSO) δ 1.80-2.10 (m), 4.10 (q) 3.00-5.80(m); IR (KBr) 
3228,2896,1735,1654, 1375, 1244, 1033, 896, 613cm-1 
;グルコピラノースおよびアセチル基のシグナルが確認できた。これらの結果からアセチルセルロースが生成していると判断した。なお、当該ＩＲスペクトルは、市販品（キシダ化学社製アセチルセルロース、酢酸度５５％）とのＩＲスペクトルと一致した。 The appearance and IR spectrum of the obtained white solid are shown in FIG. 1735.8
Absorption of a carbonyl group was confirmed at cm- 1 . The 1 H-NMR spectrum is shown in FIG. 1 H-NMR
(300 MHz, DMSO) δ 1.80-2.10 (m), 4.10 (q) 3.00-5.80 (m); IR (KBr)
3228,2896,1735,1654, 1375, 1244, 1033, 896, 613cm -1
; Signals of glucopyranose and acetyl group were confirmed. From these results, it was judged that acetylcellulose was produced. In addition, the said IR spectrum corresponded with the IR spectrum with a commercial item (Kishida Chemical Co., Ltd. acetylcellulose, acetic acid degree 55%).
　［実施例７－２］
　アセチルセルロースの置換度の決定のためのプロピオニル化 [Example 7-2]
Propionylation for the determination of the degree of substitution of acetylcellulose.
Figure JPOXMLDOC01-appb-C000013
 　アセチルセルロース（２９９mg）、Ｎ，Ｎ－ジメチルアミノピリジン（ＤＭＡＰ）(１５０mg，mmol)、無水プロピオン酸（４．５ml，mmol)を入れてＮ2置換し、ＤＭＳＯ（４ml）、pyridine（４．５ml）を加えて１００℃で１ｈ撹拌した。メタノール１５mlを加えて生成物を沈殿させ、ろ過、真空ポンプで乾燥し、目的物３２１mgを白色固体として得た。
Figure JPOXMLDOC01-appb-C000013
 Acetylcellulose (299 mg), N, N-dimethylaminopyridine (DMAP) (150 mg, mmol), propionic anhydride (4.5 ml, mmol) were added to replace N 2 , DMSO (4 ml), pyridine (4.5 ml) ) And stirred at 100 ° C. for 1 h. The product was precipitated by adding 15 ml of methanol, filtered and dried with a vacuum pump to obtain 321 mg of the desired product as a white solid.
　得られた白色固体の外観およびＩＲスペクトルを図１５に、1Ｈ 
ＮＭＲスペクトル（６００ＭＨｚ）を図１６に示す。このＩＲスペクトルから、ヒドロキシ基がほぼプロピオニル化されたことを確認し、1Ｈ 
ＮＭＲスペクトル中のピーク面積の積分比から置換度は１９％と算出された。なお、この手法についてはKelin, H.; Ben, W.; Yan, 
C.;Huiquan, L.; Jinshu, W.;Weijiang , L.; Chaoshi , M.; Dankui, L. J. Agric. 
Food Chem,2011, 59 (10), 
5376-538.を参考にした。 15 the appearance and IR spectra of the obtained white solid, 1 H
The NMR spectrum (600 MHz) is shown in FIG. From this IR spectrum, it was confirmed that the hydroxy group was almost propionylated, and 1 H
The degree of substitution was calculated to be 19% from the integration ratio of the peak areas in the NMR spectrum. For this method, Kelin, H .; Ben, W .; Yan,
C.; Huiquan, L .; Jinshu, W.; Weijiang, L .; Chaoshi, M .; Dankui, L. J. Agric.
Food Chem, 2011, 59 (10),
Reference was made to 5376-538.
　［実施例８］
　（１）セルロース（メルク社、102330）５６０mgと水性アクリル樹脂（和信ペイント水性艶出しニス、固形分３０％）３ｇとを混合して塗工液を調製した。この塗工液を平板上に塗工し、溶解前のセルロースの状態を目視および光学顕微鏡で観察した。塗工サンプルは白く、光学顕微鏡で観察するとセルロースの微粒子がそのまま観察された（図１７参照）。 [Example 8]
(1) A coating solution was prepared by mixing 560 mg of cellulose (Merck, Inc., 102330) and 3 g of an aqueous acrylic resin (Washin Paint aqueous polish varnish, solid content 30%). This coating solution was applied onto a flat plate, and the state of cellulose before dissolution was observed visually and with an optical microscope. The coated sample was white, and when observed with an optical microscope, cellulose fine particles were observed as they were (see FIG. 17).
　（２）次に、上記セルロースと濃度４０重量％のＴＢＡＨ水溶液（アルドリッチ社、178780-1L）とを、セルロース中のグルコピラノース単位／ＴＢＡＨの比（mol/mol）が１／２となる量で混合した塗工液を調製し、同様に観察したところ、塗工サンプルは透明で、光学顕微鏡観察でもほぼセルロースは溶解していたが、上記の比を１／１．５に変更した塗工サンプルは白く、セルロースの溶け残りも多く見られた（図１８参照）。 (2) Next, the above cellulose and a 40% by weight aqueous TBAH solution (Aldrich, 178780-1L) are added in such an amount that the ratio of glucopyranose unit / TBAH in cellulose (mol / mol) is halved. When a mixed coating solution was prepared and observed in the same manner, the coating sample was transparent, and the cellulose was dissolved by optical microscope observation, but the above-mentioned ratio was changed to 1 / 1.5. Was white and a lot of undissolved cellulose was observed (see FIG. 18).
　（３）一方、上記セルロースと濃度５５重量％のＴＢＡＨ水溶液（アルドリッチ社、86863-100MLL）とを用いて塗工液を調製した場合、上記の比が１／２のとき、１／１．５のときいずれも、セルロースはほぼ溶解していた（図１９参照）。 (3) On the other hand, when the coating liquid was prepared using the above cellulose and a 55% by weight aqueous TBAH solution (Aldrich, 86863-100MLL), when the above ratio was 1/2, In both cases, cellulose was almost dissolved (see FIG. 19).
　［実施例９］
　おが屑からのセルロース抽出
　電動のこぎりで木材を切断しておがくずを用意した。１０ml二ツ口反応器に撹拌子およびそのおがくず２００mgを入れてＮ2置換した。テトラブチルアンモニウムヒドロキシド水溶液５ml（アルドリッチ社、40%in 
water、ＭＷ２５９．４７、ｄ０．９９、７．７１mmol）を加え、室温で３日間撹拌した。上澄み（２．８９ｇ）をバイアルに移し、メタノール９mlを加えたところ、セルロース・四級アンモニウム塩が析出した。また、残渣にもメタノール９mlを加えたところ、こちらからもセルロース・四級アンモニウム塩が析出した。 [Example 9]
Extraction of cellulose from sawdust Wood was cut with an electric saw to prepare sawdust. A 10 ml two-necked reactor was charged with 200 mg of a stir bar and its sawdust and replaced with N 2 . 5 ml of tetrabutylammonium hydroxide aqueous solution (Aldrich, 40% in
water, MW 259.47, d0.99, 7.71 mmol) was added, and the mixture was stirred at room temperature for 3 days. When the supernatant (2.89 g) was transferred to a vial and 9 ml of methanol was added, cellulose / quaternary ammonium salt was precipitated. Further, when 9 ml of methanol was added to the residue, cellulose / quaternary ammonium salt was precipitated from here.
　［実施例１０－１］
　セルロース５１５mg（３．２mmol）を、テトラブチルアンモニウムヒドロキシド（ＴＢＡＨ）５ml（アルドリッチ社製、４０重量％水溶液、セルロースに対して２．３９当量）に少量ずつ撹拌しながら加えた。この溶液を１週間放置した後の試料Ａおよび１日放置した後の試料Ｂについて、４０倍の明視野と偏光顕微鏡（ＰＯＭ）で観察した。試料ＡおよびＢいずれも、繊維状の物質は観られず、またＰＯＭ像でサンプルの異方性（結晶性）に基づく複屈折が観られなかったため、等方性溶液と考えられる。 [Example 10-1]
515 mg (3.2 mmol) of cellulose was added to 5 ml of tetrabutylammonium hydroxide (TBAH) (manufactured by Aldrich, 40 wt% aqueous solution, 2.39 equivalents with respect to cellulose) while stirring little by little. Sample A after standing for 1 week and Sample B after standing for 1 day were observed with a 40 × bright field and a polarizing microscope (POM). Neither sample A nor B was considered to be an isotropic solution because no fibrous substance was observed and birefringence based on the anisotropy (crystallinity) of the sample was not observed in the POM image.
　［実施例１０－２］
　セルロース（515mg, 
3.2 
mmol）およびＴＢＡＨ５ml（アルドリッチ社、40%水溶液、2.39当量）を加え、５ｈ後に、メタノール１５mlを加えて再沈殿させた。濾過して白色固形物を回収し、真空ポンプで５ｈ乾燥して、６０１mgのパリパリ状の固形物を得た。この固形物（再沈殿試料）の広角Ｘ－線解析プロファイル（測定条件：試料形状，乳鉢で2分間粉砕；室温；0.01°毎にサンプリング；スキャンスピード，2°/min）を図２２に示す。明確なセルロースI型結晶の回折は観られないため非晶のサンプルが得られている。従って、溶解時に結晶の溶け残りは無いと考えられる。セルロースI型は天然のセルロースに特有な結晶系である。非晶ハローはbimodalになっており、ピーク位置はセルロースII結晶に相当する。セルロースIIは分子分散した溶解状態を経て析出（再生）させた試料に特有な結晶系で、セロハンやレーヨンなどが該当する。偏光顕微鏡観察の結果とあわせて、セルロースは見た目の通り本溶媒に溶解していると考えられる。 [Example 10-2]
Cellulose (515mg,
3.2
mmol) and 5 ml of TBAH (Aldrich, 40% aqueous solution, 2.39 equivalents) were added, and after 5 h, 15 ml of methanol was added for reprecipitation. The white solid was collected by filtration and dried with a vacuum pump for 5 h to obtain 601 mg of a crisp solid. FIG. 22 shows a wide-angle X-ray analysis profile (measurement conditions: sample shape, pulverized in a mortar for 2 minutes; room temperature; sampling every 0.01 °; scan speed, 2 ° / min) of this solid (reprecipitation sample). Since no clear diffraction of cellulose type I crystal is observed, an amorphous sample is obtained. Therefore, it is considered that there is no undissolved crystal at the time of dissolution. Cellulose type I is a crystal system unique to natural cellulose. The amorphous halo is bimodal, and the peak position corresponds to the cellulose II crystal. Cellulose II is a crystal system peculiar to a sample precipitated (regenerated) through a molecularly dispersed dissolved state, and cellophane, rayon, and the like are applicable. Together with the results of observation with a polarizing microscope, it is considered that cellulose is dissolved in this solvent as it appears.
　［実施例１１－１］KBrの添加効果 [Example 11-1] Effect of adding KBr
Figure JPOXMLDOC01-appb-T000014
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量のKBr、40% 
TBAH水溶液（2.0mL、アルドリッチ社製で、Ｋ+およびＢｒ-は実質上ほとんど含まれていないものと考えられる（以下同様））を入れて室温で24時間撹拌し、混合溶液の状態を比較した（図２３）。 
KBrの濃度の増加に伴って溶液が懸濁した。
Figure JPOXMLDOC01-appb-T000014
 Stir bar, cellulose (0.200
g), KBr in the amount shown in the table above, 40%
TBAH aqueous solution (2.0 mL, manufactured by Aldrich, which is considered to be substantially free of K + and Br − (hereinafter the same)) was added and stirred at room temperature for 24 hours, and the states of the mixed solutions were compared. (FIG. 23).
The solution suspended with increasing KBr concentration.
　［実施例１１－２］18C6の添加効果 [Example 11-2] Effect of adding 18C6
Figure JPOXMLDOC01-appb-T000015
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量の18C6、20 mMKBr含有40% TBAH水溶液（2.0 
mL）を入れ、室温で24時間撹拌後、混合溶液の状態を比較した（図２４）。KBrを含む溶液のうち、18C6を添加したものは添加していないものに比べてより溶けている。KBrを含まないものと比較しても、18C6を添加したものの方が溶けている。18C6の濃度が高いほど溶液の透明性が高く、より短時間で溶解した(18C6を3.0M添加した時は、約10分で溶解した)。これらの結果から、（ａ）18C6がK+を捕捉しセルロースが溶解した、（ｂ）18C6がTBAHと相互作用してセルロースの溶解を促進した、（ｃ）18C6そのものがセルロースを溶解した、という3つの可能性が考えられる。そこで、これらの可能性を検証するために以下の実験を行った。
Figure JPOXMLDOC01-appb-T000015
 Stir bar, cellulose (0.200
g), 18C6, 20 mM KBr containing 40% TBAH aqueous solution (2.0
mL) was added and stirred at room temperature for 24 hours, and the states of the mixed solutions were compared (FIG. 24). Of the solution containing KBr, the one with 18C6 added is more soluble than the one without. Compared with the material not containing KBr, the material with 18C6 added is more soluble. The higher the concentration of 18C6 was, the higher the transparency of the solution was, and the solution was dissolved in a shorter time (when 3.0M of 18C6 was added, the solution was dissolved in about 10 minutes). From these results, (a) 18C6 captured K + and cellulose was dissolved, (b) 18C6 interacted with TBAH to promote cellulose dissolution, and (c) 18C6 itself dissolved cellulose. There are three possibilities. Therefore, the following experiment was conducted to verify these possibilities.
　［実施例１１－３］金属イオンとクラウンエーテルの有無による溶解の違い
　（１）金属イオンが無い場合 [Example 11-3] Difference in dissolution with and without metal ion and crown ether (1) When there is no metal ion
Figure JPOXMLDOC01-appb-T000016
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量のクラウンエーテル（無、18C6、15C5、12C4）、40% TBAH（2.0 mL）を入れ、室温で6 
時間撹拌後、混合溶液の状態を比較した（図２５：Metal無）。
Figure JPOXMLDOC01-appb-T000016
 Stir bar, cellulose (0.200
g), crown ether (no, 18C6, 15C5, 12C4) and 40% TBAH (2.0 mL) as shown in the table above.
After stirring for a period of time, the states of the mixed solutions were compared (FIG. 25: no metal).
　（２）Li+イオンの場合 (2) Li + ion
Figure JPOXMLDOC01-appb-T000017
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、LiCl（8.48 mg, 0.20 mmol）、上表に示す量のクラウンエーテル（無、18C6、15C5、12C4）、40% 
TBAH水溶液（2.0mL）を入れ、室温で6時間撹拌後、混合溶液の状態を比較した（図２５：LiCl）。
Figure JPOXMLDOC01-appb-T000017
 Stir bar, cellulose (0.200
g), LiCl (8.48 mg, 0.20 mmol), the amount of crown ether shown in the above table (none, 18C6, 15C5, 12C4), 40%
A TBAH aqueous solution (2.0 mL) was added, and after stirring at room temperature for 6 hours, the states of the mixed solutions were compared (FIG. 25: LiCl).
　（３）Na+イオンの場合 (3) In the case of Na + ions
Figure JPOXMLDOC01-appb-T000018
 　5mLサンプル管に撹拌子、セルロース（0.200g）、NaCl（11.7 
mg, 0.20 mmol）、下表に示す量のクラウンエーテル（無、18C6、15C5、12C4）、40% 
TBAH水溶液（2.0mL）を入れ、室温で6時間撹拌後、混合溶液の状態を比較した（図２５：NaCl）。
Figure JPOXMLDOC01-appb-T000018
 Stirring bar, cellulose (0.200 g), NaCl (11.7
mg, 0.20 mmol), crown ether in the amount shown in the table below (none, 18C6, 15C5, 12C4), 40%
A TBAH aqueous solution (2.0 mL) was added, and after stirring at room temperature for 6 hours, the states of the mixed solutions were compared (FIG. 25: NaCl).
　（４）K+イオンの場合 (4) In case of K + ion
Figure JPOXMLDOC01-appb-T000019
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、KBr（23.8 mg, 0.20 mmol）、下表に示す量のクラウンエーテル（無、18C6、15C5、12C4）、40% TBAH水溶液（2.0 
mL）を入れ、室温で6時間撹拌後、混合溶液の状態を比較した（図２５：KBr）。
Figure JPOXMLDOC01-appb-T000019
 Stir bar, cellulose (0.200
g), KBr (23.8 mg, 0.20 mmol), the amount of crown ether shown in the table below (none, 18C6, 15C5, 12C4), 40% TBAH aqueous solution (2.0
mL) was added and stirred at room temperature for 6 hours, and the states of the mixed solutions were compared (FIG. 25: KBr).
　上記（１）～（４）より、アルカリ金属イオン、とくにK+イオンを添加するとセルロースの溶解が妨げられ懸濁液が得られることが分かる。これは、とくにK+イオンがセルロースに配位し架橋するためと考えられる（下図参照）。また、18C6を混合すると金属イオンの種類に関わらず透明な水溶液が得られた。15C5の場合にも同様の効果を確認できた。一方、12C4を混合した場合は、金属イオンの種類に関わらず懸濁したままであった。セルロースの溶解にはクラウンエーテルの環のサイズが重要である。 From the above (1) to (4), it can be seen that the addition of alkali metal ions, particularly K + ions, hinders the dissolution of cellulose and provides a suspension. This is thought to be because, in particular, K + ions coordinate to cellulose and crosslink (see the figure below). When 18C6 was mixed, a transparent aqueous solution was obtained regardless of the type of metal ions. The same effect was confirmed in the case of 15C5. On the other hand, when 12C4 was mixed, it remained suspended regardless of the type of metal ion. The size of the ring of the crown ether is important for the dissolution of cellulose.
Figure JPOXMLDOC01-appb-C000020
Figure JPOXMLDOC01-appb-C000020
　［実施例１１－４］18-crown-6の効果の検証
　（１）40%TBAH水溶液またはその代わりにイオン交換水を用いた場合 [Example 11-4] Verification of effect of 18-crown-6 (1) When 40% TBAH aqueous solution or ion-exchanged water is used instead
Figure JPOXMLDOC01-appb-T000021
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量の18C6、40% TBAH水溶液（2.0 mL）もしくはイオン交換水（2.0mL）を入れ、室温で24 
時間撹拌後、混合溶液の状態を比較した（図２６）。TBAHが溶解していないイオン交換水を用いた場合、18C6のみを用いてもセルロースは溶解せず、混合液は白濁したままであった
　（２）40%TBAH水溶液の代わりにKOHまたはNaOHを用いた場合
Figure JPOXMLDOC01-appb-T000021
 Stir bar, cellulose (0.200
g) Add 18C6, 40% TBAH aqueous solution (2.0 mL) or ion-exchanged water (2.0 mL) in the amount shown in the above table, and add 24% at room temperature.
After stirring for a period of time, the states of the mixed solutions were compared (FIG. 26). When ion-exchanged water in which TBAH was not dissolved was used, cellulose was not dissolved even if only 18C6 was used, and the mixture remained cloudy. (2) Use KOH or NaOH instead of 40% TBAH aqueous solution. If
Figure JPOXMLDOC01-appb-T000022
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、下表に示す量の18C6、3.66 M KOH水溶液もしくは3.95 M 
NaOH水溶液（2.0mL）を入れ、室温で24時間撹拌後、混合溶液の状態を比較した（図２７）。TBAHの代わりにKOHやNaOHを用いて18C6を添加した場合も、混合液は白濁したままであった。
Figure JPOXMLDOC01-appb-T000022
 Stir bar, cellulose (0.200
g) 18C6, 3.66 M KOH aqueous solution or 3.95 M in the amount shown in the table below
Aqueous NaOH solution (2.0 mL) was added, and after stirring for 24 hours at room temperature, the states of the mixed solutions were compared (FIG. 27). Even when 18C6 was added using KOH or NaOH instead of TBAH, the mixture remained cloudy.
　上記（１）および（２）の結果から、セルロースの溶解にはTBAHのような水酸化四級アンモニウム水溶液が必須であり、クラウンエーテル単独ではセルロースを溶解する力がないことが判明した。クラウンエーテルは、アルカリ金属イオンを捕捉する効果とTBAHによるセルロース溶解を補助する効果がある。例えば、TBAHのOH-によるセルロースのヒドロキシ基のプロトンの引き抜きとクラウンエーテルによるセルロースのヒドロキシ基との水素結合による協同効果によって、セルロース分子間の水素結合を効率よく切断するために、セルロースの水溶性が向上したと推測される。 From the results of (1) and (2) above, it was found that an aqueous solution of quaternary ammonium hydroxide such as TBAH is essential for dissolving cellulose, and crown ether alone has no ability to dissolve cellulose. Crown ether has the effect of capturing alkali metal ions and assisting cellulose dissolution by TBAH. For example, OH of TBAH - by cooperative effect due to hydrogen bonding with the by hydroxy groups of the cellulose by pulling the crown ether of the proton of the hydroxy groups of the cellulose, in order to cut efficiently hydrogen bonds between cellulose molecules, water-soluble cellulose Is estimated to have improved.
　（３）18C6の代わりにDMSOまたはPEGを混合した場合
　（３ａ）DMSOの場合 (3) When DMSO or PEG is mixed instead of 18C6 (3a) When DMSO
Figure JPOXMLDOC01-appb-T000023
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量のDMSO、40% 
TBAH水溶液（2.0mL）を入れ、室温で24時間撹拌後、混合溶液の状態を比較した（図２８）。DMSOの濃度を上げても混合溶液は透明にならず、セルロースは懸濁した状態のままであった。
Figure JPOXMLDOC01-appb-T000023
 Stir bar, cellulose (0.200
g) DMSO in the amount shown in the table above, 40%
TBAH aqueous solution (2.0 mL) was added, and after stirring for 24 hours at room temperature, the state of the mixed solution was compared (FIG. 28). Even when the concentration of DMSO was increased, the mixed solution did not become transparent, and the cellulose remained suspended.
　（３ｂ）PEGの場合 (3b) For PEG
Figure JPOXMLDOC01-appb-T000024
 　5mLサンプル管に撹拌子、セルロース（0.200 
g）、上表に示す量のPEG、40% 
TBAH水溶液（2.0mL）を入れ、室温で24時間撹拌後、混合溶液の状態を比較した（図２９）。図中のPEG濃度は、モノマー単位（CH2CH2O）に換算した濃度である。PEGの濃度を上げても混合溶液は透明にならず、セルロースは懸濁した状態のままであった。
Figure JPOXMLDOC01-appb-T000024
 Stir bar, cellulose (0.200
g), the amount of PEG shown in the table above, 40%
A TBAH aqueous solution (2.0 mL) was added, and after stirring at room temperature for 24 hours, the states of the mixed solutions were compared (FIG. 29). The PEG concentration in the figure is a concentration converted to a monomer unit (CH 2 CH 2 O). Even when the concentration of PEG was increased, the mixed solution did not become transparent, and the cellulose remained suspended.
　上記（３ａ）および（３ｂ）の結果に示されるように、DMSOや鎖状ポリエーテルであるPEGにはクラウンエーテルで見られた効果は観測できなかった。このことから、クラウンエーテル（特に18C6および15C5）に特有のセルロース溶解促進効果があることが判明した。 As shown in the results of (3a) and (3b) above, DMSO and PEG, which is a chain polyether, could not observe the effect seen with crown ether. From this, it was found that crown ethers (particularly 18C6 and 15C5) have a cellulose dissolution promotion effect specific to crown ethers.

Claims (16)

  1. 　セルロース精製物またはセルロースを含有する物質（以下「セルロース原料」と総称する。）と水酸化四級アンモニウム水溶液とを接触させる工程を含むことを特徴とする、セルロース水溶液の製造方法。 A method for producing an aqueous cellulose solution, comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution.
  2. 　セルロース精製物またはセルロースを含有する物質（以下「セルロース原料」と総称する。）と水酸化四級アンモニウム水溶液とを接触させる工程を含むセルロース水溶液の製造方法であって、
    　前記セルロース原料と接触した状態において、前記水酸化四級アンモニウム水溶液中に溶解しているアルカリ金属のハロゲン化物および／またはアルカリ土類金属のハロゲン化物の合計の濃度が１重量％以下であることを特徴とする請求項１に記載のセルロース水溶液の製造方法。     A method for producing an aqueous cellulose solution comprising a step of contacting a purified cellulose or a substance containing cellulose (hereinafter collectively referred to as “cellulose raw material”) with an aqueous quaternary ammonium hydroxide solution,
    The total concentration of the alkali metal halide and / or alkaline earth metal halide dissolved in the aqueous quaternary ammonium hydroxide solution in the state of contact with the cellulose raw material is 1% by weight or less. The method for producing an aqueous cellulose solution according to claim 1.
  3. 　前記水酸化四級アンモニウム水溶液の濃度が３５重量％以上である、請求項１に記載のセルロース水溶液の製造方法。 The method for producing an aqueous cellulose solution according to claim 1, wherein the concentration of the aqueous quaternary ammonium hydroxide solution is 35% by weight or more.
  4. 　前記水酸化四級アンモニウムが、置換もしくは非置換のアルキル基および／または置換もしくは非置換のアリール基を４つの置換基として有するものであり、当該４つの置換基の炭素原子数の合計が４～６０である、請求項２に記載のセルロース水溶液の製造方法。 The quaternary ammonium hydroxide has a substituted or unsubstituted alkyl group and / or a substituted or unsubstituted aryl group as four substituents, and the total number of carbon atoms of the four substituents is 4 to The method for producing an aqueous cellulose solution according to claim 2, wherein
  5. 　セルロース原料と水酸化四級アンモニウム水溶液とを接触させる工程を含むセルロース水溶液の製造方法であって、
    　前記セルロース原料と前記水酸化四級アンモニウム水溶液との接触を環状ポリエーテルの存在下に行うことを特徴とする請求項１に記載のセルロース水溶液の製造方法。     A method for producing an aqueous cellulose solution comprising a step of contacting a cellulose raw material with an aqueous quaternary ammonium hydroxide solution,
    The method for producing a cellulose aqueous solution according to claim 1, wherein the cellulose raw material and the quaternary ammonium hydroxide aqueous solution are contacted in the presence of a cyclic polyether.
  6. 　前記環状ポリエーテルが、12-クラウン-4、15-クラウン-5、18-クラウン-6、ジベンゾ-18-クラウン-6およびジアザ-18-クラウン-6からなる群から選ばれた少なくとも１種である、請求項４に記載のセルロース水溶液の製造方法。 The cyclic polyether is at least one selected from the group consisting of 12-crown-4, 15-crown-5, 18-crown-6, dibenzo-18-crown-6 and diaza-18-crown-6. The method for producing an aqueous cellulose solution according to claim 4.
  7. 　前記水酸化四級アンモニウム水溶液中の環状ポリエーテルの濃度が０．０１～５Ｍである請求項５に記載のセルロース水溶液の製造方法。 The method for producing an aqueous cellulose solution according to claim 5, wherein the concentration of the cyclic polyether in the aqueous quaternary ammonium hydroxide solution is 0.01 to 5M.
  8. 　請求項１～７のいずれかに記載の製造方法により得られる、セルロース水溶液。 An aqueous cellulose solution obtained by the production method according to any one of claims 1 to 7.
  9. 　請求項１～７のいずれかに記載の製造方法により得られるセルロース水溶液中に生成している、セルロースと水酸化四級アンモニウムとから形成された複合体。 A composite formed from cellulose and quaternary ammonium hydroxide, produced in an aqueous cellulose solution obtained by the production method according to any one of claims 1 to 7.
  10. 　請求項１～７のいずれかに記載の製造方法により得られるセルロース水溶液と、セルロース誘導体の原料となるヒドロキシ基反応性化合物とを混合する工程を含むことを特徴とする、セルロース誘導体の製造方法。 A method for producing a cellulose derivative, comprising a step of mixing an aqueous cellulose solution obtained by the production method according to any one of claims 1 to 7 and a hydroxy group-reactive compound that is a raw material for the cellulose derivative.
  11. 　前記ヒドロキシ基反応性化合物が、α，β－不飽和ニトリル、エポキシド、有機カルボン酸無水物、α，β－不飽和カルボン酸エステルおよびハロゲン化アルキルからなる群より選択されるものである、請求項１０に記載のセルロース誘導体の製造方法。 The hydroxy group-reactive compound is selected from the group consisting of α, β-unsaturated nitriles, epoxides, organic carboxylic acid anhydrides, α, β-unsaturated carboxylic acid esters, and alkyl halides. 10. A method for producing a cellulose derivative according to 10.
  12. 　請求項１～７のいずれかに記載の製造方法により得られるセルロース水溶液と、セルロースの貧溶媒とを混合し、セルロース・四級アンモニウム複合体を析出させる工程を含むことを特徴とする、セルロース・四級アンモニウム複合体の製造方法。 A step of mixing a cellulose aqueous solution obtained by the production method according to any one of claims 1 to 7 with a poor solvent for cellulose to precipitate a cellulose-quaternary ammonium complex, A method for producing a quaternary ammonium complex.
  13. 　請求項１～７のいずれかに記載の製造方法により得られるセルロース水溶液から、乾燥により溶媒を除去する工程を含むことを特徴とする、セルロースフィルムの製造方法。 A method for producing a cellulose film comprising a step of removing a solvent by drying from an aqueous cellulose solution obtained by the production method according to any one of claims 1 to 7.
  14. 　請求項１３に記載の製造方法により得られるセルロースフィルム。 A cellulose film obtained by the production method according to claim 13.
  15. 　請求項１～７のいずれかに記載の製造方法により得られるセルロース水溶液を紡糸することを特徴とする、セルロース繊維の製造方法。 A method for producing a cellulose fiber, comprising spinning an aqueous cellulose solution obtained by the production method according to any one of claims 1 to 7.
  16. 　請求項１５に記載の製造方法により得られるセルロース繊維。 Cellulose fiber obtained by the production method according to claim 15.
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