JP2008266401A - Molded cellulose article and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molded cellulose article obtained by using a regenerated cellulose and having good strength and flexibility derived from cellulose. <P>SOLUTION: A cellulose material is dissolved in an ionic liquid such as a quaternary ammonium salt ionic liquid and the obtained solution is brought into contact with a medium compatible with the ionic liquid and essentially free from cellulose dissolving property to obtain the molded article of a regenerated cellulose, wherein the content of the ionic liquid based on the cellulose material is adjusted to >30 mass% and ≤98 mass%. A molded article of a regenerated cellulose having excellent tensile strength and flexibility can be produced by the method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cellulose molded article and a method for producing the same, and more specifically, relates to a cellulose molded article containing a predetermined amount of ionic liquid and a method for producing the same.

Since cellulose has strong intramolecular and intermolecular hydrogen bonds, it is insoluble in water and common organic solvents. For this reason, various cellulose dissolution methods have been developed so far.
Examples of such a method include a copper ammonia solution, a method of dissolving in caustic soda and carbon disulfide used in the viscose rayon method, a method of using N-methylmorpholine-N-oxide, hydrazine and the like as a solvent.
However, these methods require the preparation of mixed solvents, and even a single solvent has problems such as the need for handling due to its toxicity and explosiveness. It was.

In recent years, knowledge that an ionic liquid has a cellulose dissolving ability has been obtained, and various techniques using an ionic liquid solution of cellulose prepared by dissolving cellulose in an ionic liquid are being developed.
For example, Patent Document 1 (Japanese Patent Publication No. 2005-506401) was prepared by dissolving cellulose materials such as fiber cellulose, wood pulp, linter, cotton balls, paper, etc., in an ionic liquid substantially free of water. A technique for regenerating cellulose by adding water to a solution is disclosed.
Patent Document 2 (Japanese Patent Application Laid-Open No. 2006-137777) discloses a method for preparing a composition by dissolving a hardly soluble polysaccharide such as cellulose or chitin in a solubilizing agent composed of a non-halogen ionic liquid. At the same time, it has been suggested that the composition can be processed into a film or fiber.

  However, according to the study by the present inventors, the cellulose regenerated from the ionic liquid has a significantly reduced molecular weight, and the original strength of cellulose itself is not sufficiently exhibited when formed into a molded body such as a film, It has been found that there is a problem of becoming fragile.

In recent years, techniques using ionic liquids as plasticizers for various polymers have also been reported.
For example, Patent Document 3 (Japanese Patent Laid-Open No. 2003-46145) discloses the use of an ionic liquid as a plasticizer for organic thermoelectric materials such as polyaniline.
Moreover, in patent document 4 (Japanese translations of PCT publication No. 2005-532440 gazette), the ionic liquid is mix | blended in the ratio of 0.1-30 mass% as a plasticizer in the partial crystalline polymer composition which does not contain an ionic group. Technology is disclosed.

  However, these technologies add an ionic liquid for the purpose of improving the conductivity of the polymer or improving the processability of the polymer, and the mechanical strength of the polymer is increased by the addition of the ionic liquid. The knowledge about how it changes is not disclosed.

JP 2005-506401 A JP 2006-137777 A JP 2003-46145 A JP 2005-532440 gazette

  This invention is made | formed in view of such a situation, and it aims at providing the cellulose molded object using the regenerated cellulose which has the favorable intensity | strength derived from cellulose itself, and a favorable flexibility. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined the ionic liquid content in the molded body in a cellulose molded body regenerated from a solution prepared by dissolving a cellulose material in an ionic liquid. By adjusting the ratio, it was found that a regenerated cellulose molded article excellent in tensile strength and flexibility was obtained, and the present invention was completed.

〔式中、Ｒ¹〜Ｒ³は、互いに同一でも異なっていてもよい、炭素数１〜５のアルキル基、炭素数３〜５のアルケニル基、またはＲ⁴−Ｏ−（ＣＨ₂）_n−で表されるアルコキシアルキル基を示し（Ｒ⁴は、メチル基またはエチル基を示す。）、ｎは１または２である。Ｙは、ハロゲン化物イオン、総炭素数１〜３のカルボン酸イオン、過塩素酸イオン、または擬ハロゲン化物イオンを示す。〕
４． 前記Ｒ¹〜Ｒ³が、互いに同一でも異なっていてもよい、メチル基、エチル基、アリル基、２−メチルアリル基、またはＲ⁴−Ｏ−（ＣＨ₂）_n−で表されるアルコキシアルキル基（Ｒ⁴およびｎは、前記と同じ意味を表す。）である３のセルロース成形体、
５． 前記イオン液体が、式（２）で示される４のセルロース成形体、

〔式中、ｎおよびＹは前記と同じ意味を表す。〕
６． 前記イオン液体が、式（３）で示される５のセルロース成形体、

７． フィルムである１〜６のいずれかのセルロース成形体、
８． セルロース材料をイオン液体に溶解して調製した溶液を、前記イオン液体に相溶し、かつ、実質的にセルロース溶解能を有しない媒体と接触させて再生したセルロース成形体を、前記媒体で洗浄し、前記セルロース材料に対する前記イオン液体の含有量を３０質量％超９８質量％以下に調節することを特徴とするセルロース成形体の製造方法、
９． セルロース材料をイオン液体に溶解して調製した溶液を、成形用板上にキャストした後、前記イオン液体に相溶し、かつ、実質的にセルロース溶解能を有しない媒体に浸漬し、前記セルロース材料に対する前記イオン液体の含有量を３０質量％超９８質量％以下に調節することを特徴とするセルロースフィルムの製造方法
を提供する。 That is, the present invention
1. A cellulose molded body regenerated by bringing a solution prepared by dissolving a cellulose material into an ionic liquid into contact with a medium that is compatible with the ionic liquid and has substantially no cellulose-dissolving ability. On the other hand, the cellulose molded body characterized in that the ionic liquid is contained more than 30 mass% and 98 mass% or less,
2. The cellulose molded body according to 1, wherein the ionic liquid is a quaternary ammonium salt having an alkoxyalkyl group,
3. The cellulosic molded body according to 2, wherein the ionic liquid is represented by the formula (1):

Wherein, R ¹ to R ³ may be the same or different, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, or _{^{R 4 -O- (CH 2) n}} , - (R ⁴ represents a methyl group or an ethyl group), and n is 1 or 2. Y represents a halide ion, a carboxylate ion having 1 to 3 carbon atoms, a perchlorate ion, or a pseudohalide ion. ]
4). An alkoxyalkyl group represented by a methyl group, an ethyl group, an allyl group, a 2-methylallyl group, or R ⁴ —O— (CH ₂ ) _n —, wherein R ^{1 to} R ³ may be the same as or different from each other. (Wherein R ⁴ and n represent the same meaning as described above) 3,
5. The cellulosic molded body according to 4, wherein the ionic liquid is represented by the formula (2):

[Wherein, n and Y represent the same meaning as described above. ]
6). The cellulose molded body of 5 represented by the formula (3), the ionic liquid,

7). Any one of the cellulose molded bodies of 1-6 which are films,
8). A cellulosic molded body regenerated by bringing a solution prepared by dissolving a cellulose material into an ionic liquid into contact with a medium that is compatible with the ionic liquid and has substantially no cellulose dissolving ability is washed with the medium. A method for producing a cellulose molded article, wherein the content of the ionic liquid with respect to the cellulose material is adjusted to more than 30% by mass and 98% by mass or less,
9. A solution prepared by dissolving a cellulose material in an ionic liquid is cast on a molding plate, and is then dissolved in a medium that is compatible with the ionic liquid and substantially has no cellulose-dissolving ability. The method for producing a cellulose film is characterized in that the content of the ionic liquid with respect to is adjusted to more than 30% by mass and 98% by mass or less.

Since the regenerated cellulose molded article of the present invention contains a predetermined amount of ionic liquid, it has good strength derived from cellulose itself and good flexibility.
For this reason, the cellulose molded object of this invention can be easily shape | molded in various shapes, and can be used suitably for various uses.
Moreover, since the cellulose molded object of this invention contains predetermined amount of ionic liquid, it can also exhibit an antistatic effect.

Hereinafter, the present invention will be described in more detail.
The cellulose molded body according to the present invention is obtained by regenerating a solution prepared by dissolving a cellulose material in an ionic liquid by bringing it into contact with a medium that is compatible with the ionic liquid and has substantially no cellulose dissolving ability. The cellulose material contains ionic liquid in an amount of more than 30% by mass and 98% by mass or less. Here, the ionic liquid refers to an organic salt that exhibits a liquid state at 100 ° C. or lower.

In this invention, there exists a possibility that the tensile strength and flexibility of a molded object may become inadequate that ionic liquid content in a cellulose molded object is 30 mass% or less. Moreover, the upper limit is arbitrary as long as the shape of a molded object can be maintained, but it is about 99 mass% normally.
In consideration of further improving the tensile strength and flexibility of the obtained molded body, the ionic liquid content in the cellulose molded body is preferably 32 to 98 mass%, more preferably 35 to 80 mass%.

The ionic liquid is arbitrary as long as it dissolves or swells cellulose. In the present invention, various conventionally known ionic liquids having such an action can be used.
Specific examples include a quaternary ammonium salt ionic liquid composed of a quaternary ammonium cation and an anion, an imidazolium salt ionic liquid composed of an imidazolium cation and an anion, and a pyridinium salt ionic liquid composed of a pyridinium cation and an anion. Is mentioned.

In this case, the anion constituting the ionic liquid is not particularly limited, and BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , AlCl ₄ ⁻ , HSO ₄ ⁻ , ClO ₄ ⁻ , CH _3. SO ₃ ⁻ , CH ₃ SO ₄ ⁻ , CH ₃ C ₆ H ₄ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ SO ₄ ⁻ , CF ₃ CO ₂ ⁻ , C ₂ F ₅ CO ₂ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , halide ion, carboxylate ion having 1 to 3 carbon atoms, perchlorate ion, pseudohalide ion, cyanamide ion (NCN ⁻ ), Conventionally known various anions that form an ionic liquid, such as dicyanamide ion (N (CN) ₂ ⁻ ), can be used, but because of its excellent ability to dissolve cellulose, halide ions, total carbon number of 1 ~ 3 carboxylate ion, perchlorate ion, pseudo-ha Gen hydride ion, Shianamidoion (NCN ^-), dicyanamide ion (N (CN) ₂ ^-) is preferred.
Examples of the halide ion include Cl ⁻ , Br ⁻ , I ^{− and the} like.
Examples of the carboxylate ion having 1 to 3 carbon atoms include C ₂ H ₅ CO ₂ ⁻ , CH ₃ CO ₂ ⁻ and HCO ₂ ⁻ .
Examples of the pseudohalide ion include CN ⁻ , SCN ⁻ , OCN ⁻ , ONC ⁻ , N ₃ ^{− and the} like which are monovalent and have characteristics similar to halides.
Among these, considering that enhance the solubility of the cellulose, in ^{_{particular, Cl -, HCO 2 -,}} Br - are preferred.

In the present invention, a quaternary ammonium salt type ionic liquid is preferable, and in particular, a quaternary ammonium salt type ionic liquid having an alkoxyalkyl group excellent in cellulose dissolving ability is preferable.
An example of such an ionic liquid is an ionic liquid represented by the following formula (1).

〔式中、Ｒ¹〜Ｒ³は、互いに同一でも異なっていてもよい、炭素数１〜５のアルキル基、炭素数３〜５のアルケニル基、またはＲ⁴−Ｏ−（ＣＨ₂）_n−で表されるアルコキシアルキル基を示し（Ｒ⁴は、メチル基またはエチル基を示す。）、ｎは１または２である。Ｙは、ハロゲン化物イオン、総炭素数１〜３のカルボン酸イオン、過塩素酸イオン、または擬ハロゲン化物イオンを示す。〕

Wherein, R ¹ to R ³ may be the same or different, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, or _{^{R 4 -O- (CH 2) n}} , - (R ⁴ represents a methyl group or an ethyl group), and n is 1 or 2. Y represents a halide ion, a carboxylate ion having 1 to 3 carbon atoms, a perchlorate ion, or a pseudohalide ion. ]

In the formula (1), the alkyl group having 1 to 5 carbon atoms includes methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, s-butyl group, 2-methylpropyl group, 1 , 1-dimethylethyl group, n-pentyl group, s-pentyl group, t-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 2,2-dimethylpropyl group and the like. Examples of the alkenyl group having 3 to 5 carbon atoms include 1-propenyl group, 2-propenyl group (allyl group), isopropenyl group, 1-butenyl group, 2-butenyl group (crotyl group), 3-butenyl group, and isocrotyl group. , 2-methylallyl group (methallyl group) and the like. Examples of the alkoxyalkyl group represented by R ⁴ —O— (CH ₂ ) _n — include a methoxy or ethoxymethyl group and a methoxy or ethoxyethyl group.

Among these, R ¹ to R ³ in Formula (1) may be the same or different, a methyl group, an ethyl group, an allyl group, methallyl group, or _{^{R 4 -O- (CH 2) n}} , - with What is represented is an alkoxyalkyl group (particularly a methoxyethyl group or a methoxymethyl group).
More specifically, an ionic liquid represented by the following formula (2) can be preferably used.

〔式中、ｎおよびＹは上記と同じ意味を表す。〕

[Wherein, n and Y represent the same meaning as described above. ]

Also in this case, as Y, Cl ⁻ , HCO ₂ ⁻ and Br ⁻ are preferable from the viewpoint of enhancing the solubility of cellulose.
In particular, an ionic liquid represented by the following formula (3) in which n = 2 and Y = Cl ⁻ is preferable.

  Moreover, the ionic liquid shown by following formula (4) can also be used suitably.

（式中、Ｒ¹、Ｒ⁴、Ｙおよびｎは、上記と同じ意味を表す。）

(In the formula, R ¹ , R ⁴ , Y and n represent the same meaning as described above.)

  Among the ionic liquids represented by the formula (4), N-methyl-N-2-methoxyethyl pyrrolidinium cation, N-ethyl-N-2-methoxyethyl pyrrolidinium cation is superior because of its excellent ability to dissolve cellulose. An ionic liquid having a nium cation, an N-methyl-N-2-methoxymethylpyrrolidinium cation, an N-ethyl-N-2-methoxymethylpyrrolidinium cation, or the like is preferable.

Examples of the imidazolium type ionic liquid that can be used in the present invention include 1-methyl-3- (n-pentyl) imidazolium cation, 1-N-butyl-3-methylimidazolium cation, 1-methyl-3-n- Propyl imidazolium cation, 1-ethyl-3-methylimidazolium cation, 1- (2-methoxyethyl) -3-methylimidazolium cation, 1- (2-methoxymethyl) -3-methylimidazolium cation, etc. An ionic liquid is preferred.
As the pyridinium type ionic liquid, an ionic liquid having an N-normalbutylpyridinium cation, an N-2-methoxyethylpyridinium cation, an N-2-methoxymethylpyridinium cation, or the like is preferable.

  The melting point of the ionic liquid is not particularly limited, but is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, and even more preferably 70 ° C. or lower, in consideration of the heat treatment temperature during cellulose dissolution.

The cellulose may be appropriately selected from known cellulose materials and used, for example, plant-derived cellulose, animal-derived cellulose, bacterial-derived cellulose, regenerated cellulose, and the like.
Examples of plant-derived cellulose include cotton lint, cotton linter, conifer cellulose, hardwood cellulose, bast cellulose, leaf cellulose, hemp cellulose, kenaf cellulose, banana fiber cellulose, bamboo fiber cellulose and the like.
Examples of the animal-derived cellulose include caudate-derived cellulose, and in particular, squirt cellulose.
Examples of the bacterial cellulose include cellulose derived from bacteria such as Acetobacter, Agrobacterium, and Rhizobium.
Regenerated cellulose is dissolved by the xanthate method, copper ammonia method, N ₂ O ₄ / DMF method, (CH ₂ O) _x / DMSO method, NMMO method, LiCl / DMAc method, steam explosion alkaline aqueous solution method, ionic liquid method, etc. The cellulose regenerated after having been used.
In addition, as long as it melt | dissolves in an ionic liquid, even if what derivatized cellulose is applicable. For example, a derivative obtained by etherifying or esterifying a hydroxyl group of cellulose, a cyanoethylated derivative, or the like can also be used.

Among the above-mentioned various celluloses, banana fiber cellulose is excellent in solubility in ionic liquids, and since the viscosity of the solution is relatively low, it is excellent in film forming properties when used as a film and the like, and moldability when regenerated. Therefore, it can be suitably used in the present invention.
In addition, if the amount of lignin contained in the cellulose is too large, the strength of the regenerated cellulose may decrease. Therefore, the amount of lignin in the cellulose is preferably 20% by mass or less, and preferably 10% by mass or less. Is preferred.

There is no restriction | limiting in particular as a form of a cellulose, The cellulose of various forms, such as thread form, cloth form, paper form, film form, cotton form, powder form, granular form, rod form, is employable.
The crystal structure of cellulose is not particularly limited, and cellulose having a structure composed of any one of I-type, II-type, III-type, IV-type, and amorphous structure or a combination thereof can be employed. Further, the crystallinity of cellulose is not particularly limited.
Although the molecular weight (degree of polymerization) of cellulose is arbitrary, if the ionic liquid of Formula (1) is used, cellulose having a relatively large molecular weight of about 2 million to 40,000, particularly about 2 million to 200,000 is easily obtained. Can be dissolved.

The regenerated cellulose molded article of the present invention may be a blend polymer with other polymers.
Other polymers may be those that dissolve or swell in the ionic liquid, or may not.
Other polymers that dissolve or swell in the ionic liquid include polysaccharides such as chitin, chitosan, starch, agarose, and carrageenan; and proteins such as silk, wool, collagen, keratin, sericin, fibroin, and casein.
Other polymers that do not dissolve or swell in the ionic liquid include acrylic resin, polycarbonate resin, ABS resin, polylactic acid, polycaprolactone, polyamide (nylon), polystyrene, and the like.
In addition, although content of these other polymers is arbitrary, about 5-95 mass% is suitable with respect to the whole cellulose material.

In the present invention, the specific method for dissolving cellulose in the ionic liquid is not particularly limited, and the ionic liquid may be added to the cellulose, or the cellulose may be added to the ionic liquid. When the ionic liquid is solid at room temperature, it may be mixed with cellulose as it is, or may be mixed with cellulose after being once heated and melted.
The heating temperature may be a temperature at which the ionic liquid is in a liquid state, but in order to promote dissolution of cellulose, it is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, further preferably 80 ° C. or higher, and still more preferably. Is 100 ° C. or higher.

Any heating means may be used, but general heating means such as heating with an oven, heating with a water or oil bath, heating with a microwave, etc. may be used.
In heating, it is preferable to perform stirring in order to promote dissolution of cellulose. Stirring means is also optional, and among the known stirring methods represented by mechanical stirring with a stirrer or stirring blade, stirring by shaking the container, stirring by ultrasonic irradiation, etc., appropriate means depending on the scale etc. Adopt it.
In addition, since dissolution time changes according to process temperature, it cannot unconditionally be specified.

A solution obtained by dissolving cellulose in an ionic liquid may be used in the subsequent step as it is, but if undissolved or insoluble components remain in the solution, use them after filtering them. Also good.
The obtained solution may be used immediately, but may be used after being stored for a predetermined time as long as the moldability and the strength and flexibility of the molded product can be maintained. In particular, if it is stored at a low temperature such as room temperature after dissolution, it can be stored for a long time.

In the present invention, after preparing a cellulose-containing ionic liquid solution as described above, this solution is compatible with the ionic liquid and brought into contact with a medium that does not substantially have cellulose dissolving ability.
The contact method can be appropriate depending on the shape of the molded body, for example, in the case of forming a molded body such as a lump, bead, or pellet, the above solution is compatible with the ionic liquid, and In addition to a medium having substantially no cellulose-dissolving ability, regenerated cellulose is precipitated, or a medium that is compatible with the ionic liquid and has substantially no cellulose-dissolving ability is added to the above solution for regeneration. A method such as precipitation of cellulose can be used.
In this case, a porous (sponge-like) regenerated cellulose can be obtained by contacting with the above medium in a state where a liquid or solid incompatible with this solution is dispersed in an ionic liquid solution of cellulose.

  In the case of a film-like or fibrous shaped body, the above solution is compatible with an ionic liquid through a T die or the like, and extruded into a medium that does not substantially have cellulose dissolving ability, Examples include a method in which the solution is cast on a forming plate such as a glass plate and then immersed in a medium that is compatible with the ionic liquid and does not substantially have cellulose dissolving ability.

Further, in the present invention, the obtained regenerated cellulose molded product is compatible with an ionic liquid and kept in contact with a medium that does not substantially have cellulose dissolving ability for a predetermined time, or the regenerated cellulose molded product is washed with the same medium. For example, the ionic liquid content in the regenerated cellulose molded body is adjusted to the above range.
Since the ionic liquid can be almost completely removed from the molded body by bringing the cellulose molded body into contact with the medium for a long time, the contact time is appropriately adjusted according to the shape of the molded body, and the molded body. The content of the ionic liquid can be easily adjusted to above 30% by mass and 98% by mass or less.
The contact or cleaning time cannot be unconditionally defined because it depends on the shape of the molded body, but is usually about 30 minutes to 48 hours.
The medium used for cellulose regeneration and the medium used for removing the ionic liquid from the regenerated cellulose may be the same medium or different media.

In the present invention, specific examples of a medium that is compatible with an ionic liquid and has substantially no cellulose dissolving ability include water, alcohols such as methanol and ethanol, ethers such as tetrahydrofuran and dioxane, acetone, and methyl ethyl ketone. Such as ketones, acetonitrile, chloroform and the like. These may be used alone or in combination of two or more.
Among these, water and alcohols are preferable in view of efficiently regenerating cellulose, and water is more preferable in consideration of the environment.
Moreover, when aiming at efficient and economical collection | recovery of an ionic liquid, it is preferable to use the organic solvent of a low boiling point among the said media. Specific examples of the low boiling point solvent include methanol and ethanol.
The “medium having substantially no cellulose-dissolving ability” does not mean a medium in which cellulose is not dissolved at all. In addition to the ionic liquid solution of cellulose, the amount of cellulose added is increased to a critical amount or more. Means a medium on which can be deposited.

The cellulose molding which adjusted ionic liquid content by the said method dries and removes the used medium. In this case, the drying method may be air drying (room temperature), or may be dried by heating in a thermostatic chamber or the like.
The form of the regenerated cellulose molded body is not particularly limited, and may be various shapes such as powder, granule, lump, cotton, short fiber, long fiber, rod, sponge, film, etc. be able to.

  EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example.

Synthesis Example 1 Synthesis of N, N-diethyl-N-methyl-N-2-methoxyethylammonium chloride

71 parts by mass of diethylamine (manufactured by Kanto Chemical Co., Ltd.) and 88 parts by mass of 2-methoxyethyl chloride (manufactured by Kanto Chemical Co., Ltd.) were mixed and reacted at 120 ° C. for 24 hours in an autoclave. At this time, the maximum ultimate internal pressure was 4.5 kgf / cm ² (0.44 MPa). After 24 hours, the precipitated crystals were washed with tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) and separated by filtration. The filtrate was distilled at atmospheric pressure to obtain 81 parts by mass of a fraction having a boiling point of around 135 ° C. It was confirmed by nuclear magnetic resonance spectrum (NMR) that this compound was 2-methoxyethyldiethylamine.
Subsequently, 9.0 parts by mass of 2-methoxyethyldiethylamine was dissolved in 80 parts by mass of tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) in an autoclave, and 15% methyl chloride gas (in nitrogen, Nippon Special Corporation) was stirred. Chemical Industry Co., Ltd.) was introduced. Methyl chloride gas was added until the internal pressure reached 4 kgf / cm ² (0.39 MPa), and then the temperature was gradually raised to 60 ° C. over 3 hours. At this time, the maximum internal pressure was 5.4 kgf / cm ² (0.53 MPa). Thereafter, the mixture was allowed to cool while stirring, and the precipitated crystals were separated by filtration. The crystals were dried under reduced pressure to obtain 12 parts by mass of the target product, N, N-diethyl-N-methyl-N-2-methoxyethylammonium chloride.

[Example 1]
In a 50 ml sample bottle, N, N-diethyl-N-methyl-N-2-methoxyethylammonium chloride (DEMECl, melting point 59-60 ° C.) (moisture content 7600 ppm) obtained in Synthesis Example 1 is put, and the temperature is increased to 100 ° C. Heated to melt.
Into this, cotton (American pima cotton sliver) previously dried at 105 ° C. for 2 hours was added in an amount of 2% by mass, and stirred with a stir bar occasionally to dissolve the cotton.
The prepared solution was cast on a glass plate so as to have a wet film thickness of 1 mm, and immersed in a vat filled with methanol for 5 hours.
After immersion, the glass plate was removed from the vat and air dried at room temperature to obtain a regenerated cellulose film.

[Example 2]
In the same manner as in Example 1 except that banana fiber (banana yarn obtained by refining and defibrating banana stems according to the method described in JP-A-2004-052716) was used instead of cotton. A regenerated cellulose film was obtained.

[Example 3]
A regenerated cellulose film was obtained in the same manner as in Example 1 except that filter paper (Whatman qualitative filter paper No. 1, manufactured by Whatman) was used instead of cotton.

[Example 4]
A regenerated cellulose film was obtained in the same manner as in Example 1 except that hemp (linen) was used instead of cotton.

[Example 5]
A regenerated cellulose film was obtained in the same manner as in Example 1 except that the immersion time in methanol was 6 hours.

[Example 6]
A regenerated cellulose film was obtained in the same manner as in Example 1 except that the immersion time in methanol was 7 hours.

[Example 7]
A regenerated cellulose film was obtained in the same manner as in Example 2 except that the immersion time in methanol was 6 hours.

[Comparative Example 1]
A regenerated cellulose film was obtained in the same manner as in Example 1 except that the immersion time in methanol was 25 hours.

[Comparative Example 2]
A regenerated cellulose film was obtained in the same manner as in Example 2 except that the immersion time in methanol was 25 hours.

[Comparative Example 3]
A regenerated cellulose film was obtained in the same manner as in Example 3 except that the immersion time in methanol was 25 hours.

[Comparative Example 4]
A regenerated cellulose film was obtained in the same manner as in Example 4 except that the immersion time in methanol was 25 hours.

Table 1 shows the crystallinity, cellulose content, lignin content, solubility in ionic liquid, and film-formability at 2% by mass for the cellulose materials used in the above Examples and Comparative Examples. In addition, the content rate of a cellulose and lignin is a literature value.
Table 2 shows the results of measuring and evaluating the ionic liquid content, film strength, and flexibility of the regenerated cellulose films obtained in the above Examples and Comparative Examples.

Each evaluation item in Table 1 was measured and evaluated by the following method.
[Crystallinity]
It was measured by an X-ray diffraction method (XD-D1, manufactured by Shimadzu Corporation).
[Solubility in ionic liquid]
Evaluation was made according to the following criteria.
A: Dissolved within 5 hours.
○: Dissolved within 10 hours.
Δ: It takes 10 hours or more.
[Film-formability at 2% by mass]
Evaluation was made according to the following criteria.
A: A film having a uniform thickness was easily obtained.
A: A film having a slight unevenness in thickness was obtained.
(Triangle | delta): Only the thing with nonuniform thickness was obtained.

Each evaluation item in Table 2 was measured and evaluated by the following method.
[Ionic liquid content]
The content of the ionic liquid was calculated according to mass measurement and the following formula.
Content ratio of ionic liquid = {(mass of film) − (mass of film from which ionic liquid is completely removed)} / (mass of film) × 100
[Film strength]
The obtained film was lightly pulled by hand and evaluated according to the following criteria.
○: It does not break even if it is pulled lightly. △: It breaks only by lightly pulling.
Evaluation was made according to the following criteria.
○: No damage after bending 10 times.
Δ: Damaged when bent several times.
X: Damaged when bent once.

  As shown in Table 2, since the regenerated cellulose films obtained in Examples 1 to 7 contain a predetermined amount of ionic liquid, the films containing no ionic liquid (Comparative Examples 1 to 4) It can be seen that the film strength and flexibility are superior.

Claims (9)

A cellulose molded body which is prepared by dissolving a cellulose material in an ionic liquid, reconstituted in contact with a medium that is compatible with the ionic liquid and has substantially no cellulose dissolving ability,
The cellulose molded body, wherein the molded body contains the ionic liquid in an amount of more than 30% by mass and 98% by mass or less.   The cellulose molded body according to claim 1, wherein the ionic liquid is a quaternary ammonium salt having an alkoxyalkyl group. The cellulose molded body according to claim 2, wherein the ionic liquid is represented by the formula (1).

Wherein, R ¹ to R ³ may be the same or different, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, or _{^{R 4 -O- (CH 2) n}} , - (R ⁴ represents a methyl group or an ethyl group), and n is 1 or 2. Y represents a halide ion, a carboxylate ion having 1 to 3 carbon atoms, a perchlorate ion, or a pseudohalide ion. ] An alkoxyalkyl group represented by a methyl group, an ethyl group, an allyl group, a 2-methylallyl group, or R ⁴ —O— (CH ₂ ) _n —, wherein R ^{1 to} R ³ may be the same as or different from each other. The cellulose molded body according to claim 3, wherein R ⁴ and n represent the same meaning as described above. The cellulose molded body according to claim 4, wherein the ionic liquid is represented by the formula (2).

[Wherein, n and Y represent the same meaning as described above. ] The cellulose molded body according to claim 5, wherein the ionic liquid is represented by the formula (3).

  It is a film, The cellulose molded object of any one of Claims 1-6.   A cellulosic molded body regenerated by bringing a solution prepared by dissolving a cellulose material into an ionic liquid into contact with a medium that is compatible with the ionic liquid and has substantially no cellulose dissolving ability is washed with the medium. The method for producing a cellulose molded article, wherein the content of the ionic liquid with respect to the cellulose material is adjusted to be more than 30% by mass and 98% by mass or less.   A solution prepared by dissolving a cellulose material in an ionic liquid is cast on a molding plate, and is then dissolved in a medium that is compatible with the ionic liquid and substantially has no cellulose-dissolving ability. A method for producing a cellulose film, comprising adjusting the content of the ionic liquid to more than 30% by mass and 98% by mass or less.