JP2012246417A - Method for producing cellulose solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a cellulose solution, which is excellent in the solubility of a pulp, and can reduce the time and energy needed for drying.SOLUTION: The method for producing a cellulose solution includes dissolving a pulp in an ionic liquid. The water content of the pulp is made to be ≥50 mass%. The dissolution of the pulp in the ionic liquid is carried out at a heated temperature of ≥70°C. The dissolution of the pulp in the ionic liquid is preferably carried out under a pressure lower than the vapor pressure of water in a mixture of the pulp and the ionic liquid at a temperature at the dissolution.

Description

  The present invention relates to a method for producing a cellulose solution (hereinafter, also simply referred to as “manufacturing method”), and more particularly, to a method for producing a cellulose solution according to improvement of dissolution conditions of raw material pulp.

  Cellulose is the most abundant biomass resource on the earth, and is widely used for fibers and paper. Cellulose fibers are also highly elastic at room temperature and have high adhesion to rubber, and are therefore used as reinforcing materials for various rubber articles such as tire conveyor cords and belt conveyors. As a method for producing cellulose fibers, a method is known in which cellulose or pulp is dissolved in a solvent and then stretched by passing a coagulant.

  On the other hand, since cellulose has a strong hydrogen bond in the structure, it is not melted or dissolved by a general method, and various dissolution methods and dilute solution preparation methods have been proposed. Examples of the method for dissolving cellulose include a method in which cellulose is derivatized with carbon disulfide and dissolved. Also known is a method of complexing and dissolving cellulose using a copper ethylenediamine aqueous solution or a dimethylacetamide solution of lithium halide.

  However, when cellulose is derivatized using carbon disulfide, problems such as a change in the molecular structure of cellulose and a decrease in molecular weight occur. In addition, in the method of complexing using an aqueous solution of copper ethylenediamine or a dimethylacetamide solution of lithium halide, since the optimal dissolution method differs depending on the type of cellulose, it is difficult to select and manage the dissolution conditions, and the time required for dissolution is also long. . Furthermore, there are cases where some cellulose cannot be dissolved or problems such as a decrease in molecular weight occur during dissolution.

  On the other hand, for example, Patent Documents 1 and 2 propose a method of hydrating and dissolving cellulose using an ionic liquid such as an imidazolium salt. According to the cellulose dissolution method using an ionic liquid, the dissolution of cellulose is easy, and the preparation time of the cellulose solution is short. Therefore, it can be said that this technique is excellent in process.

JP-T 2009-52084 Gazette (Claims etc.) JP 2009-203467 A (Claims etc.)

  By the way, when dissolving pulp as a raw material of cellulose in an ionic liquid, conventionally, the pulp has been used in a dried state. This is because if the pulp contains a large amount of water, the water in the pulp and the ionic liquid compete with each other, so that the pulp becomes difficult to dissolve in the ionic liquid.

  Therefore, conventionally, the fibers of the pulp may be deteriorated during drying, and there is a problem that time and energy required for drying are separately required. In particular, when cellulose is used as a tire reinforcing cord, a high-concentration cellulose solution is required from the viewpoint of obtaining the strength required for the tire reinforcing cord, but dry pulp is not swellable. For this reason, there is a problem that the solubility of the ionic liquid is poor even if it is put into the ionic liquid, and as a result, the concentration of the pulp added to the ionic liquid cannot be made too high. On the other hand, when undissolved pulp remains in the cellulose solution, the undissolved pulp becomes a fracture nucleus in the obtained cellulose fiber and further in the cord, so that a high-concentration cellulose solution is obtained without generating undissolved content Therefore, it was desired to establish technology for this purpose.

  Accordingly, an object of the present invention is to provide a method for producing a cellulose solution that solves the above-described problems, has excellent pulp solubility, and can reduce the time and energy required for drying.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by setting the moisture content of the pulp to a certain amount or more and prescribing the conditions during dissolution to a predetermined level, thereby completing the present invention. It was.

  That is, in the method for producing a cellulose solution of the present invention, in the method for producing a cellulose solution by dissolving pulp in an ionic liquid, the water content of the pulp is 50% by mass or more, and the pulp is added to the ionic liquid. The dissolution is performed under heating at 70 ° C. or higher.

  In the present invention, the pulp is preferably dissolved in the ionic liquid under a pressure lower than the vapor pressure of water in the mixture of the pulp and the ionic liquid at the temperature at the time of dissolution.

  According to this invention, it became possible to implement | achieve the manufacturing method of the cellulose solution which is excellent in the solubility of a pulp and can reduce the time and energy which are required for drying by having set it as the said structure.

Hereinafter, embodiments of the present invention will be described in detail.
The present invention relates to an improvement in a method for producing a cellulose solution by dissolving pulp in an ionic liquid. In the method for producing a cellulose solution of the present invention, it is important that the moisture content of the raw material pulp is 50% by mass or more and that the pulp is dissolved in an ionic liquid under heating at 70 ° C. or higher. .

  As a result, the time and energy conventionally required for drying the pulp can be reduced, and the deterioration of the pulp accompanying the drying can be suppressed. Moreover, since a pulp with a high water content is already in a swollen state, it has good compatibility with an ionic liquid, and thus has excellent solubility. Therefore, according to the present invention, it is possible to obtain a high-concentration cellulose solution while suppressing the generation of undissolved content. On the other hand, there is usually a problem that when the water contained in the pulp is large, it becomes difficult to dissolve by competing with the ionic liquid. Even if there is much, solubility is not spoiled and a pulp can be dissolved efficiently.

  In the present invention, the moisture content of the pulp needs to be 50% by mass or more, preferably 50 to 100% by mass, and more preferably 60 to 80% by mass. When the moisture content of the pulp is less than 50% by mass, the effect of reducing time and energy cannot be sufficiently obtained, and the effect of suppressing the deterioration of the pulp and the effect of improving the solubility become insufficient.

  Moreover, in this invention, the temperature at the time of melt | dissolution to the ionic liquid of a pulp needs to be 70 degreeC or more, Preferably it is 75-110 degreeC, More preferably, it is the range of 80-105 degreeC. When the temperature at the time of dissolution is less than 70 ° C., the solubility is lowered, the number of undissolved components is increased, and a cellulose solution having a sufficiently high concentration and a small amount of undissolved components cannot be obtained.

  In the production method of the present invention, a pulp having a moisture content of 50% by mass or more may be mixed with an ionic liquid, and the pulp may be dissolved in the ionic liquid under heating at 70 ° C. or higher. Thereby, the desired effect of the present invention can be obtained, and other conditions can be appropriately set as desired, and are not particularly limited.

  In the present invention, the pulp is preferably dissolved in the ionic liquid under a pressure lower than the vapor pressure of water in the mixture of the pulp and the ionic liquid at the temperature at the time of dissolution. By dissolving under a pressure that satisfies such conditions, water contained in the mixture of pulp and ionic liquid is likely to evaporate, so that the solubility can be further improved. That is, after the pulp has become familiar with the ionic liquid in the mixture, the content of water competing with the ionic liquid can be reduced by dissolving while evaporating the water contained in the mixture, so that the pulp becomes the ionic liquid, It becomes easier to dissolve. Here, in order to obtain a pressure satisfying the above conditions, the dissolution may be performed while reducing the pressure, or the temperature at the time of dissolution may be increased, and the dissolution is preferably performed at a high temperature and a pressure close to vacuum. . When the pressure is less than the above conditions, water does not evaporate, so the effect of improving solubility cannot be obtained.

  Specifically, in the production method of the present invention, first, depending on the moisture content of the raw material pulp, the pulp is appropriately dried or water is absorbed into the pulp, and the moisture content of the pulp is 50% by mass or more. Adjust to. In addition, if desired, the fibers are loosened and sieved in order to increase the solubility to a predetermined size. Moreover, when making water absorb a pulp, after adding distilled water to a pulp and stirring, for example, what is necessary is just to mount for about 8 to 12 hours. Thereafter, an ionic liquid is added to the pulp obtained by appropriately squeezing excess water, the pulp is swollen in the ionic liquid, stirred, and further stirred under heating at 70 ° C. or higher, preferably under the predetermined pressure. However, the pulp can be dissolved in the ionic liquid by placing it for about 3 to 5 hours.

  In the present invention, any type of pulp obtained from raw materials such as wood, straw, grass and bamboo can be used as the pulp regardless of the cellulose content.

Moreover, there is no restriction | limiting in particular also about an ionic liquid, It can select suitably from well-known things and can use it. Specifically, the ionic liquid can be represented by the following formula (I) or (II).
[A] ⁺ _n [Y] ⁿ⁻ (I)
(In the formula (I), n represents 1, 2, 3 or 4, [A] ⁺ represents a quaternary ammonium cation, an oxonium cation, a sulfonium cation or a phosphonium cation, and [Y] ⁿ⁻ represents 1 Represents a tetravalent anion)
[A ¹ ] ⁺ [A ² ] ⁺ [Y] ⁿ⁻ (II−a), where n = 2
[A ¹ ] ⁺ [A ² ] ⁺ [A ³ ] ⁺ [Y] ⁿ⁻ (II−b), where n = 3
[A ¹ ] ⁺ [A ² ] ⁺ [A ³ ] ⁺ [A ⁴ ] ⁺ [Y] ⁿ⁻ (II−c), where n = 4
(In the formula, [A ¹ ] ⁺ to [A ⁴ ] ⁺ each independently represents a quaternary ammonium cation, an oxonium cation, a sulfonium cation, or a phosphonium cation, and [Y] ^n- represents 1 to 4 valences. Represents an anion of

As the cation [A] ⁺ of the ionic liquid, oxygen, phosphorus, sulfur, and particularly a nitrogen atom, for example, at least 1, preferably 1 to 10, more preferably 1 to 5, and further preferably 1 to 3. Individual, particularly preferably, compounds containing 1 to 2 nitrogen atoms can be used. These may have additional heteroatoms such as oxygen, sulfur or phosphorus atoms. Nitrogen atoms are good carriers of the positive charge of the cation of the ionic liquid, from which protons or alkyl groups can be transferred to an anion in equilibrium to form an electrically neutral molecule.

  When the nitrogen atom is the positively charged carrier of the cation of the ionic liquid, in the synthesis of the ionic liquid, the cation can first be synthesized by quaternizing the nitrogen atom of the amine or nitrogen-containing heterocyclic compound. . Quaternization of amines or nitrogen-containing heterodry compounds can be performed by alkylation of nitrogen atoms, and salts with different anions can be synthesized depending on the alkylating reagent used. If there is no possibility that the desired anion is pre-formed during quaternization, this can be synthesized in a further synthetic step. For example, a complex anion is formed by reacting a halide with a Lewis acid using ammonium halide as a starting material. As another method, halide ions can be exchanged with desired anions. This can be done by addition of a metal salt with solidification of the formed metal halide or replacement of the halide ion with a strong acid (hydrohalic acid is liberated) via an ion exchanger.

Alkyl group which may be quaternized nitrogen atom in the amines or nitrogen-containing heterocyclic compounds, for _example, C 1 _{-C 18} alkyl, preferably _C 1 _{-C 10} alkyl, particularly preferably _C 1 -C ₆ alkyl Especially preferred is methyl. An alkyl group can be unsubstituted or can contain one or more identical or different substituents.

  In the present invention, at least one 5-membered to 6-membered heterocyclic group containing at least one nitrogen atom and optionally an oxygen or sulfur atom, particularly those containing a 5-membered heterocyclic group are used. Can do. Other suitable compounds contain at least one 5- to 6-membered heterocyclic group containing 1, 2 or 3 nitrogen atoms and sulfur or oxygen atoms, more preferably 2 nitrogen atoms. Things. In the present invention, an aromatic heterocyclic compound is more preferable.

  In the present invention, the compound preferably has a molecular weight of less than 1000 g / mol, more preferably less than 500 g / mol, and even more preferably less than 300 g / mol.

As the cation in the present invention, specifically, compounds having structures represented by the following formulas (III-a) to (III-w) and oligomers having these structures can be preferably used.

In the present invention, as other cations, compounds having the following structures and oligomers having these structures may be used.

  Here, R in the above structural formula is a hydrogen atom, unsubstituted, interrupted, or organic having 1 to 20 carbon atoms substituted with 1 to 5 heteroatoms or functional groups, Represents a saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or aromatic aliphatic group.

Also, R ^{1 to} R ⁹ in the above structural formula are independently of each other a hydrogen atom, a sulfo group, unsubstituted or interrupted, or substituted with 1 to 5 heteroatoms or functional groups. Represents an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or aromatic aliphatic group having from 1 to 20 carbon atoms.

Furthermore, the carbon atom in the above structural formula, that is, R ^{1 to} R ⁹ bonded to other than the hetero atom may be a halogen atom or a functional group. Here, the heteroatom means all heteroatoms capable of exchanging —CH ₂ —, —CH═, —C≡ or ═C═ group. As the hetero atom, oxygen, nitrogen, sulfur, phosphorus and silicon are preferable. Especially, -O -, - S -, - SO -, - SO 2 -, - NR '-, - N =, - PR' -, - PR '2 - and SiR' ₂ - a and, R 'is The remainder of the carbon-containing group. In the above formula (III), when bonded to a carbon atom (not bonded to a heteroatom), R ^{1 to} R ⁹ may be bonded via a heteroatom.

Examples of the functional group include —OH (hydroxyl), ═O (particularly as a carbonyl group), —NH ₂ (amino), —NHR, —NR ₂ , ═NH (imino), —COOH (carboxyl), — CONH ₂ (carboxamide), —SO ₃ H (sulfo) and CN (cyano) can be mentioned, and preferably —OH (hydroxyl), ═O (particularly as a carbonyl group), —NH ₂ (amino), ═ NH (imino), —COOH (carboxyl), —CONH ₂ (carboxamide), —SO ₃ H (sulfo) and CN (cyano). The functional group may be bonded through a heteroatom such as —O— (ether) or —S— (thioether), and further —COO— (ester), —CONH— Secondary amide) or CONR ′-(tertiary amide) may be bonded via an atomic group. For example, di- (C ₁ -C ₄ alkyl) amino, C ₁ -C ₄ alkoxycarbonyl or C ₁ -C ₄ alkoxy can be mentioned.

  In the present invention, examples of the halogen atom include fluorine, chlorine, bromine and iodine.

Specific examples of R include methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl, 2-methyl-2-propyl, and 1-pentyl. 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2 -Pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3 -Dimethyl-1-butyl, 2-d 1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, 1-heptyl, 1-octyl, 1-nonyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-tetradecyl, 1-hexadecyl, 1-octadecyl, 2-hydroxyethyl, benzyl, 3-phenylpropyl, 2-cyanoethyl, 2- (methoxycarbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (n-butoxy Carbonyl) ethyl, trifluoromethyl, difluoromethyl, fluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoroisobutyl, undecylfluoropentyl, undecylfluoroisopentyl, 6-hydroxyhexyl and Propylsulfo Acid or hydroxyl, halogen, phenyl, _cyano, unbranched C 1 -C ₆ alkoxycarbonyl and / or SO ₃ H with one or more substituted carbons have 1 to 20 or branched chain _C 1 -C ₁₈ alkyl or, for example, R ^A O— (CHR ^B —CH ₂ —O) _m —CHR ^B —CH ₂ — or R ^A O— (CH ₂ CH ₂ CH ₂ CH ₂ O) _m —CH ₂ CH ₂ CH ₂ CH ₂ O- (wherein, ^{R a} and ^{R B} is preferably hydrogen, methyl or ethyl, m is preferably 0 to 3), in particular 3-oxabutyl, 3-oxapentyl, 3 , 6-dioxaheptyl, 3,6-dioxaoctyl, 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl, 3,6,9,12-tetraoxatridecyl and Glycol, butylene glycol and oligomers thereof having _{1 to} 100 units and hydrogen or C _{1 to} C ₈ alkyl as a terminal group, such as 3,6,9,12-tetraoxatetradecyl, and vinyl, allyl, For example, N, N-di-C ₁ -C ₆ alkylamino, such as N, N-dimethylamino and N, N-diethylamino may be used.

In the present invention, R ^{1 to} R ⁹ are preferably independently of each other hydrogen, halogen, or a functional group, but (i) C _{1 to} C ₁₈ alkyl or these are functional groups, aryl, alkyl, aryl Substituted with oxy, alkoxy, halogen, heteroatoms and / or heterocyclic groups and / or interrupted with one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups It may be what you have. Further, (ii) or C ₂ -C ₁₈ alkenyl, these functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, substituted with heteroatoms and / or heterocyclic group, and / or one or more It may be interrupted by an oxygen and / or sulfur atom and / or one or more substituted or unsubstituted imino groups, (iii) C ₆ -C ₁₂ aryl, and these are functional groups, aryl, alkyl, aryloxy _May be substituted with alkoxy, halogen, heteroatoms and / or heterocyclic groups, (iv) C ₅ -C ₁₂ cycloalkyl and these are functional groups, aryl, alkyl, aryloxy, alkoxy, halogen It may be those substituted with heteroatoms and / or heterocyclic group, (v) C ₅ C ₁₂ or cycloalkenyl, they functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, may be those substituted with heteroatoms and / or heterocyclic group, (vi) oxygen, nitrogen and / or sulfur It may be a 5- to 6-membered heterocyclic group containing atoms and optionally substituted with a functional group, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatom and / or heterocyclic group. (Vii) Both two adjacent groups are preferably substituted with a functional group, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatom and / or heterocyclic group, optionally with one or more It may be an unsaturated, saturated or aromatic ring interrupted by oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups.

As the above (i), methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert-butyl) 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl -1-propyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3 -Methyl-2-pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl , 3,3-Dime 1-butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl 1,1,3,3-tetramethylbutyl, 1-nonyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-tridecyl, 1-tetradecyl, 1-pentadecyl, 1-hexadecyl, 1-heptadecyl, 1 -Octadecyl, cyclopentylmethyl, 2-cyclopentylethyl, 3-cyclopentylpropyl, cyclohexylmethyl, 2-cyclohexylethyl, 3-cyclohexylpropyl, benzyl (phenylmethyl), diphenylmethyl (benzhydryl), triphenylmethyl, 1-phenylethyl, 2-phenylethyl, 3-phenylpropyl α, α-dimethylbenzyl, p-tolylmethyl, 1- (p-butylphenyl) ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p-methoxybenzyl, m-ethoxybenzyl, 2-cyanoethyl, 2-cyano Propyl, 2-methoxycarbonylethyl, 2-ethoxycarbonylethyl, 2-butoxycarbonylpropyl, 1,2-di- (methoxycarbonyl) -ethyl, methoxy, ethoxy, formyl, 1,3-dioxolan-2-yl, 1 , 3-Dioxolan-2-yl, 2-methyl-1,3-dioxolan-2-yl, 4-methyl-1,3-dioxolan-2-yl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxy Propyl, 4-hydroxybutyl, 6-hydroxyhexyl, 2-aminoethyl, 2-amino Propyl, 3-aminopropyl, 4-aminobutyl, 6-aminohexyl, 2-methylaminoethyl, 2-methylaminopropyl, 3-methylaminopropyl, 4-methylaminobutyl, 6-methylaminohexyl, 2-dimethyl Aminoethyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 4-dimethylaminobutyl, 6-dimethylaminohexyl, 2-hydroxy-2,2-dimethylethyl, 2-phenoxyethyl, 2-phenoxypropyl, 3- Phenoxypropyl, 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2-methoxypropyl, 3-methoxypropyl, 4-methoxybutyl, 6-methoxyhexyl, 2-ethoxyethyl, 2-ethoxypropyl, 3- Ethoxypropyl, 4-ethoxy C _m F _{2 (m−a) + (1−b)} H where sibutyl, 6-ethoxyhexyl, acetyl, m is 1-30, 0 ≦ a ≦ m, and b = 0 or 1. _{2a + b (e.g., CF 3, C 2 F 5} , CH 2 CH 2 -C (m-2) F 2 (m-2) +1, C 6 F 13, C 8 F 17, C 10 F 21, C 12 R ₂₅ ), chloromethyl, 2-chloroethyl, trichloromethyl, 1,1-dimethyl-2-chloroethyl, methoxymethyl, 2-butoxyethyl, diethoxymethyl, diethoxyethyl, 2-isopropoxyethyl, 2-butoxypropyl, 2-octyloxyethyl, 2-methoxyisopropyl, 2- (methoxycarbonyl) -ethyl, 2- (ethoxycarbonyl) -ethyl, 2- (n-butoxycarbonyl) -ethyl Butylthiomethyl, 2-dodecylthioethyl, 2-phenylthioethyl, 5-hydroxy-3-oxa-pentyl, 8-hydroxy-3,6-dioxa-octyl, 11-hydroxy-3,6,9-tolyoxa -Undecyl, 7-hydroxy-4-oxa-heptyl, 11-hydroxy-4,8-dioxa-undecyl, 15-hydroxy-4,8,12-trioxa-pentadecyl, 9-hydroxy-5-oxa-nonyl, 14 -Hydroxy-5,10-dioxa-tetradecyl, 5-methoxy-3-oxa-pentyl, 8-methoxy-3,6-dioxa-octyl, 11-methoxy-3,6,9-trioxa-undecyl, 7-methoxy -4-oxa-heptyl, 11-methoxy-4,8-dioxa-undecyl, 15-methoxy 4,8,12-trioxa-pentadecyl, 9-methoxy-5-oxa-nonyl, 14-methoxy-5,10-dioxa-tetradecyl, 5-ethoxy-3-oxa-pentyl, 8-ethoxy-3,6- Dioxa-octyl, 11-ethoxy-3,6,9-trioxa-undecyl, 7-ethoxy-4-oxa-heptyl, 11-ethoxy-4,8-dioxa-undecyl, 15-ethoxy-4,8,12- Mention may be made of trioxa-pentadecyl, 9-ethoxy-5-oxa-nonyl or 14-ethoxy-5,10-oxa-tetradecyl.

As the (ii), vinyl, 2-propenyl, 3-butenyl, cis-2-butenyl, trans-2-butenyl _{or, C m F 2 (m-} a) - a _{(1-b) H 2a-} b Can be mentioned. Here, m ≦ 30, 0 ≦ a ≦ m, and b = 0 or 1 may be used.

As (iii), preferably, phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, Diethylphenyl, isopropylphenyl, tert-butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, hexyloxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl, ethoxynaphthyl, 2,6-dimethylphenyl, 2,4 6-trimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, 4-bromophenyl, 2-nitrophenyl, 4-nitrophenyl, 2,4 -Dinitrophenyl, 2,6-dinitrophenyl, 4-dimethylaminophenyl, 4-acetylphenyl, methoxyethylphenyl, ethoxymethylphenyl, methylthiophenyl, isopropylthiophenyl or tert-butylthiophenyl or C ₆ F _{(5-a )} can be mentioned H _a. Here, 0 ≦ a ≦ 5.

As (iv) above, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, diethylcyclohexyl, butylcyclohexyl, methoxycyclohexyl, dimethoxycyclohexyl, diethoxycyclohexyl, butylthiocyclohexyl, chloro Cyclohexyl, dichlorocyclohexyl, dichlorocyclopentyl, m ≦ 30, 0 ≦ a ≦ m, b = 0 or 1, C _m F _{2 (m−a)-(1-b)} H _2a−b and Mention may be made, for example, of saturated or unsaturated bicyclic systems such as norbornyl or norbornenyl.

(V) is preferably 3-cyclopentenyl, 2-cyclohexenyl, 3-cyclohexenyl, 2,5-cyclohexanedienyl, or m ≦ 30 and 0 ≦ a ≦ m. b = 0 or _1, it can be mentioned _{C n F 2 (m-a} ) -3 (1-b) H 2a-3b.

  Examples of (vi) include furyl, thiophenyl, pyryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxyl, benzimidazolyl, benzothiazolyl, dimethylpyridyl, methylquinolyl, dimethylpyryl, methoxyfuryl, dimethoxypyridyl, or difluoropyridyl. it can.

As (vii), 1,3-propylene, 1,4-butylene, 1,5-pentylene, 2-oxa-1,3-propylene, 1-oxa-1,3-propylene, 2-oxa-1 , 3-propylene, 1-oxa-1,3-propenylene, 3-oxa-1,5-pentylene, 1-aza-1,3-propenylene, 1-C ₁ -C ₄ alkyl-1-aza-1, Mention 3-propenylene, 1,4-buta-1,3-dienylene, 1-aza-1,4-buta-1,3-dienylene or 2-aza-1,4-buta-1,3-dienylene Can do.

  When the substituents (i) to (vii) above contain an oxygen, sulfur atom, substituted or unsubstituted imino group, the number of these is not limited, but these are 5 or less, preferably 4 in the substituent. Or less, more preferably 3 or less. When the substituent contains a heteroatom, at least 1 carbon atom, preferably at least 2 carbon atoms, are present between the 2 heteroatoms.

In the present invention, more preferably, R ^{1 to} R ⁹ are independently of each other hydrogen, such as methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1, -Propyl, 2-methyl-2-propyl, 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl 2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl 2,3-dimethyl 1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, 1-heptyl, 1-octyl, 1-nonyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-tetradecyl, 1-hexadecyl, 1-octadecyl, 2-hydroxyethyl, benzyl, 3-phenylpropyl, 2-cyanoethyl, 2- (methoxycarbonyl) -Ethyl, 2- (ethoxycarbonyl) -ethyl, 2- (n-butoxycarbonyl) -ethyl, trifluoromethyl, difluoromethyl, fluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nona Fluoroisobutyl, undecylfluoropentyl, undecylfluoro Sopenchiru, 6-hydroxyhexyl, and, and substituted groups such as propyl sulfonic acid, Ya substituent these hydroxyl, halogen, phenyl, cyano, C ₁ -C ₆ alkoxycarbonyl, substituted one or more SO 3 _H , Branched C ₁ -C ₁₈ alkyl and, for example, R ^A O— (CHR ^B —CH ₂ —O) _m —CHR ^B —CH ₂ — or R ^A O— (CH ₂ CH ₂ CH ₂ CH ₂ O) _{m -CH 2 CH 2 CH 2 CH} 2 O- ( wherein, ^{R a} and ^{R B} is preferably hydrogen, methyl or ethyl, m is preferably 0-3), in particular, 3-oxabutyl 3-oxapentyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl, 3,6 , 9,12-tetraoxaspiro tridecyl and, 3,6,9,12 like tetraoxatetracosane decyl, glycols having _C 1 -C ₈ alkyl as 1 to 100 units and a hydrogen or terminal groups, butylene glycol And oligomers thereof and vinyl, allyl such as N, N-di-C ₁ -C ₆ alkylamino such as N, N-dimethylamino and N, N-diethylamino.

More preferably, R ^{1 to} R ⁹ are independently of each other hydrogen or, for example, methyl, ethyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl or 1-octyl, phenyl, 2-hydroxyethyl, 2-cyanoethyl, 2- (methoxycarbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (n-butoxycarbonyl) ethyl, N, N-dimethylamino, N, N-diethylamino, chlorine, and _{CH 3 O- (CH 2 CH 2} O) m -CH 2 CH 2 - and _{CH 3 CH 2 O- (CH 2} CH 2 O) m -CH 2 CH 2 - ( m is at 0-3 wherein C ₁ -C ₁₈ alkyl, such as

In the present invention, the pyridinium ion (III-a) more preferably used is as follows: (1) ^{one of} R ^{1 to} R ⁵ is methyl, ethyl or chlorine, and the remaining R ^{1 to} R ⁵ are hydrogen. (2) R ³ is dimethylamino and the remaining R ¹ , R ² , R ⁴ and R ⁵ are hydrogen, (3) R ^{1 to} R ⁵ are all hydrogen, 4) R ² is carboxyl or carboxamide and the remaining R ¹ , R ² , R ⁴ and R ⁵ are hydrogen, (5) R ¹ and R ² , or R ² and R ³ are 1, 4-buta-1,3-dienylene, and the remaining R ¹ , R ² , R ⁴ and R ⁵ are hydrogen, and in particular, (3) or ¹ of R ^{1 to} R ⁵ One of which is methyl or ethyl and the remaining radicals R ^{1 to} R ⁵ are hydrogen Is preferred.

  In the present invention, pyridinium ions (III-b) more preferably used include 1-methylpyridinium, 1-ethylpyridinium, 1- (1-butyl) pyridinium, 1- (1-hexyl) pyridinium, 1- ( 1-octyl) pyridinium, 1- (1-dodecyl) -pyridinium, 1- (1-tetradecyl) -pyridinium, 1- (1-hexadecyl) pyridinium, 1,2-dimethylpyridinium, 1-ethyl-2-methylpyridinium 1- (1-butyl) -2-methylpyridinium, 1- (1-hexyl) -2-methylpyridinium, 1- (1-octyl) -2-methylpyridinium, 1- (1-dodecyl) -2- Methylpyridinium, 1- (1-tetradecyl) -2-methylpyridinium, 1- (1-hexadecyl) -2 Methylpyridinium, 1-methyl-2-ethylpyridinium, 1,2-diethylpyridinium, 1- (1-butyl) -2-ethylpyridinium, 1- (1-hexyl) -2-ethylpyridinium, 1- (1- Octyl) -2-ethylpyridinium, 1- (1-dodecyl) -2-ethylpyridinium, 1- (1-tetradecyl) -2-ethylpyridinium, 1- (1-hexadecyl) -2-ethylpyridinium, 1,2 -Dimethyl-5-ethylpyridinium, 1,5-diethyl-2-methylpyridinium, 1- (1-butyl) -2-methyl-3-ethylpyridinium, 1- (1-hexyl) -2-methyl-3- Ethylpyridinium and 1- (1-octyl) -2-methyl-3-ethylpyridinium, 1- (1-dodecyl) -2-methyl-3 Ethylpyridinium, 1- (1-tetradecyl) -2-methyl-3-ethyl pyridinium, and 1- (1-hexadecyl) -2-methyl-3 can be mentioned ethyl pyridinium.

Particularly preferably used pyridazinium ions (III-b) are those in which R ^{1 to} R ⁴ are hydrogen, or one of R ^{1 to} R ⁴ is methyl or ethyl, and the remaining group R ¹ to R ⁴ can be exemplified are hydrogen.

In the present invention, as a pyrimidinium ion (III-c) more preferably used, R ¹ is hydrogen, methyl or ethyl, and R ^{2 to} R ⁴ are independently of each other hydrogen or methyl. And R ¹ is hydrogen, methyl or ethyl, R ² and R ⁴ are methyl, and R ³ is hydrogen.

The pyrazinium ion (III-d) more preferably used in the present invention is ^{one in} which R ¹ is hydrogen, methyl or ethyl, and R ^{2 to} R ⁴ are independently of each other hydrogen or methyl. R ¹ is hydrogen, methyl or ethyl, R ² and R ⁴ are methyl, R ³ is hydrogen, R ^{1 to} R ⁴ are methyl, R ^{1 to} R ⁴ May be methyl or hydrogen.

In the present invention, imidazolium ion (III-e) more preferably used is that R ¹ is hydrogen, methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-octyl, Mention may be made of allyl, 2-hydroxyethyl or 2-cyanoethyl and R ^{2 to} R ⁴ independently of one another are hydrogen, methyl or ethyl.

  Specific examples of suitable imidazolium ions (III-e) include 1-methylimidazolium, 1-ethylimidazolium, 1- (1-butyl) imidazolium, 1- (1-octyl) imidazolium, 1- (1-dodecyl) imidazolium, 1- (1-tetradecyl) imidazolium, 1- (1-hexadecyl) imidazolium, 1,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1- (1-butyl) -3-methylimidazolium, 1- (1-butyl) -3-ethylimidazolium, 1- (1-hexyl) -3-methylimidazolium, 1- (1-hexyl) -3- Ethylimidazolium, 1- (1-hexyl) -3-butylimidazolium, 1- (1-octyl) -3-methylimidazolium, 1- (1-o Til) -3-ethylimidazolium, 1- (1-octyl) -3-butylimidazolium, 1- (1-dodecyl) -3-methylimidazolium, 1- (1-dodecyl) -3-ethylimidazolium 1- (1-dodecyl) -3-butylimidazolium, 1- (1-dodecyl) -3-octylimidazolium, 1- (1-tetradecyl) -3-methylimidazolium, 1- (1-tetradecyl) -3-ethylimidazolium, 1- (1-tetradecyl) -3-butylimidazolium, 1- (1-tetradecyl) -3-octylimidazolium, 1- (1-hexadecyl) -3-methylimidazolium, 1 -(1-hexadecyl) -3-ethylimidazolium, 1- (1-hexadecyl) -3-butylimidazolium, 1- (1-hexadecyl) -3-octylimidazolium, 1,2-dimethylimidazolium, 1,2,3-trimethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1- (1-butyl) -2,3-dimethyl Imidazolium, 1- (1-hexyl) -2,3-dimethylimidazolium, 1- (1-octyl) -2,3-dimethylimidazolium, 1,4-dimethylimidazolium, 1,3,4-trimethyl Imidazolium, 1,4-dimethyl-3-ethylimidazolium, 3-butylimidazolium, 1,4-dimethyl-3-octylimidazolium, 1,4,5-trimethylimidazolium, 1,3,4,5 -Tetramethylimidazolium, 1,4,5-trimethyl-3-ethylimidazolium, 1,4,5-trimethyl-3-butylimidazoli And 1,4,5-trimethyl-3-octylimidazolium.

In the present invention, the pyrazolium ions (III-f), (III-g) or (III-g ′) which are more preferably used include R ¹ is hydrogen, methyl or ethyl, and R ^{2 to} R ⁴ Which are, independently of one another, hydrogen or methyl.

In the present invention, examples of the pyrazolium ion (III-h) more preferably used include those in which R ^{1 to} R ⁴ are each independently hydrogen or methyl.

In the present invention, examples of the 1-pyrazolium ion (III-i) more preferably used include those in which R ^{1 to} R ⁶ are each independently hydrogen or methyl.

In the present invention, as 2-pyrazolium ion (III-j) or (III-j ′) more preferably used, R ¹ is hydrogen, methyl or phenyl, and R ^{2 to} R ⁶ are independent of each other. And those that are hydrogen or methyl.

In the present invention, 3-pyrazolium ion (III-k) or (III-k ′) that can be more preferably used includes, as R ¹ and R ² , independently of one another, hydrogen, methyl, ethyl or phenyl And R ^{3 to} R ⁶ are each independently hydrogen or methyl.

In the present invention, as imidazolinium ion (III-l) that can be more preferably used, R ¹ and R ² independently of one another are hydrogen, methyl, ethyl, 1-butyl or phenyl, Mention may be made of those in which ³ and R ⁴ are independently of each other hydrogen, methyl or ethyl, and R ⁵ and R ⁶ are independently of each other hydrogen or methyl.

In the present invention, the imidazolinium ion (III-m) or (III-m ′) that can be more preferably used includes R ¹ and R ² independently of one another, hydrogen, methyl or ethyl, Mention may be made of those in which R ^{3 to} R ⁶ are independently of each other hydrogen or methyl.

In the present invention, the imidazolinium ion (III-n) or (III-n ′) that can be used more preferably includes R ^{1 to} R ³ independently of one another, hydrogen, methyl or ethyl, Mention may be made of those in which R ^{4 to} R ⁶ are independently of each other hydrogen or methyl.

In the present invention, as thiazolium ions (III-o), (III-o ′) and oxazolium ions (III-p) that can be more preferably used, R ¹ is hydrogen, methyl, ethyl or phenyl. And R ² and R ³ independently of one another are hydrogen or methyl.

In the present invention, 1,2,4-triazolium ions (III-q), (III-q ′) or (III-q ″) that can be used more preferably include R ¹ and R ² as Independently of each other, mention may be made of those which are hydrogen, methyl, ethyl or phenyl and R ³ is hydrogen, methyl or phenyl.

In the present invention, the 1,2,3-triazolium ion (III-r), (III-r ′) or (III-r ″) that can be more preferably used includes R ¹ as hydrogen, methyl Or ethyl and R ² and R ³ , independently of one another, are hydrogen or methyl, or R ² and R ³ are both 1,4-buta-1,3-dienylene. Can do.

In the present invention, pyrrolidinium ions (III-s) that can be more preferably used include: R ¹ is hydrogen, methyl, ethyl, or phenyl; and R ^{2 to} R ⁹ are each independently hydrogen or Mention may be made of methyl.

As the imidazolidinium ion (III-t) that can be more preferably used in the present invention, R ^{1 to} R ⁴ are independently of each other hydrogen, methyl, ethyl or phenyl, R ² and R ³ and Mention may be made of those in which R ^{5 to} R ⁸ are independently of each other hydrogen or methyl.

In the present invention, ammonium ions (III-u) that can be used more preferably include those in which R ^{1 to} R ³ are each independently C _{1 to} C ₁₈ alkyl, or R ¹ and R ² are And 1,5-pentylene or 3-oxa-1,5-pentylene, and R ³ is C ₁ -C ₁₈ alkyl, 2-hydroxyethyl or 2-cyanoethyl. Particularly preferred are methyl-tri- (1-butyl) ammonium, N, N-dimethylpiperidinium and N, N-dimethylmorpholinium.

  Tertiary amines that can derive quaternary ammonium ions of general formula (III-u) by quaternization with R include diethyl-n-butylamine, diethyl-tert-butylamine, diethyl-n-pentylamine. , Diethylhexylamine, diethyloctylamine, diethyl- (2-ethylhexyl) amine, di-n-propylbutylamine, di-n-propyl-n-pentylamine, di-n-propylhexylamine, di-n-propyloctyl Amine, di-n-propyl- (2-ethylhexyl) amine, diisopropylethylamine, diisopropyl-n-propylamine, diisopropylbutylamine, diisopropylpentylamine, diisopropylhexylamine, diisopropyloctylamine, diisopropyl -(2-ethylhexyl) -amine, di-n-butylethylamine, di-n-butyl-n-propylamine, di-n-butyl-n-pentylamine, di-n-butylhexylamine, di-n- Butyloctylamine, di-n-butyl- (2-ethylhexyl) -amine, Nn-butylpyrrolidine, N-sec-butylpyrrolidine, N-tert-butylpyrrolidine, Nn-pentylpyrrolidine, N, N- Dimethylcyclohexylamine, N, N-diethylcyclohexylamine, N, N-di-n-butylcyclohexylamine, Nn-propylpiperidine, N-isopropylpiperidine, Nn-butylpiperidine, N-sec-butylpiperidine, N-tert-butylpiperidine, Nn-pentylpiperidine, Nn-butyl Ruphorin, N-sec-butylmorpholine, N-tert-butylmorpholine, Nn-pentylmorpholine, N-benzyl-N-ethylaniline, N-benzyl-Nn-propylaniline, N-benzyl-N-isopropyl Aniline, N-benzyl-Nn-butylaniline, N, N-dimethyl-p-toluidine, N, N-diethyl-p-toluidine, N, N-di-n-butyl-p-toluidine, diethylbenzylamine And di-n-propylbenzylamine, di-n-butylbenzylamine, diethylphenylamine, di-n-propylphenylamine and di-n-butylphenylamine.

  In the present invention, suitable tertiary amines include diisopropylethylamine, diethyl-tert-butylamine, diisopropylbutylamine, di-n-butyl-n-pentylamine, N, N-di-n-butylcyclohexylamine, and pentyl. Isomeric tertiary amines can be mentioned, and more preferred tertiary amines can include di-n-butyl-n-pentylamine and pentyl isomeric tertiary amines. A more preferred tertiary amine having three identical substituents can include triallylamine.

Examples of the guanidinium ion (III-v) that can be preferably used in the present invention include those in which R ^{1 to} R ⁵ are methyl, and more preferable guanidinium ion (III-v) is: N, N, N ′, N ′, N ′ ′, N ′ ′-hexamethylguanidinium.

In the present invention, as the corinium ion (III-w) that can be preferably used, R ¹ and R ² are each independently methyl, ethyl, 1-butyl or 1-octyl, and R ³ is Hydrogen, methyl, ethyl, acetyl, —SO ₂ OH or PO (OH) ₂ , or R ¹ is methyl, ethyl, 1-butyl or 1-octyl, and R ² is —CH ₂ —CH _{2. A 2-} OR ⁴ group, wherein R ³ and R ⁴ are independently of each other hydrogen, methyl, ethyl, acetyl, —SO ₂ OH or PO (OH) ₂ , or R ¹ is —CH ₂ —CH ₂ OR ⁴ group, R ² is —CH ₂ —CH ₂ —OR ⁵ group, and R ^{3 to} R ⁵ are independently of each other hydrogen, methyl, ethyl, acetyl, —SO ₂ OH. or PO _{(OH) 2} Mention may be made of a certain thing.

As more preferred corinium ion (III-w), R ³ is hydrogen, methyl, ethyl, acetyl, 5-methoxy-3-oxa-pentyl, 8-methoxy-3,6-dioxa-octyl, 11-methoxy- 3,6,9-trioxa-undecyl, 7-methoxy-4-oxa-heptyl, 11-methoxy-4,8-dioxa-undecyl, 15-methoxy-4,8,12-trioxa-pentadecyl, 9-methoxy- 5-oxa-nonyl, 14-methoxy-5,10-oxa-tetradecyl, 5-ethoxy-3-oxa-pentyl, 8-ethoxy-3,6-dioxa-octyl, 11-ethoxy-3,6,9- Trioxa-undecyl, 7-ethoxy-4-oxa-heptyl, 11-ethoxy-4,8-dioxa-undecyl, 15-ethoxy Ci-4,8,12-trioxa-pentadecyl, 9-ethoxy-5-oxa-nonyl or 14-ethoxy-5,10-oxa-tetradecyl.

  Particularly preferred corinium ions (III-w) include trimethyl-2-hydroxyethylammonium, dimethyl-bis-2-hydroxyethylammonium or methyl-tris-2-hydroxyethylammonium.

In the present invention, phosphonium ions (III-x) that can be preferably used include R ^{1 to} R ³ independently of one another, C _{1 to} C ₁₈ alkyl, particularly butyl, isobutyl, 1-hexyl or 1-hexyl. Mention may be made of octyl.

  Of the above heterocyclic cations, pyridinium ions, pyrazolinium, pyrazolium ions, imidazolinium and imidazolium ions are preferred, and ammonium and corinium ions are more preferred.

  In the present invention, particularly preferable ions include 1-methylpyridinium, 1-ethylpyridinium, 1- (1-butyl) pyridinium, 1- (1-hexyl) pyridinium, 1- (1-octyl) pyridinium, 1- ( 1-dodecyl) pyridinium, 1- (1-tetradecyl) pyridinium, 1- (1-hexadecyl) pyridinium, 1,2-dimethylpyridinium, 1-ethyl-2-methylpyridinium, 1- (1-butyl) -2- Methylpyridinium, 1- (1-hexyl) -2-methylpyridinium, 1- (1-octyl) -2-methylpyridinium, 1- (1-dodecyl) -2-methylpyridinium, 1- (1-tetradecyl)- 2-methylpyridinium, 1- (1-hexadecyl) -2-methylpyridinium, 1-methyl-2- Tilpyridinium, 1,2-diethylpyridinium, 1- (1-butyl) -2-ethylpyridinium, 1- (1-hexyl) -2-ethylpyridinium, 1- (1-octyl) -2-ethylpyridinium, 1 -(1-dodecyl) -2-ethylpyridinium, 1- (1-tetradecyl) -2-ethylpyridinium, 1- (1-hexadecyl) -2-ethylpyridinium, 1,2-dimethyl-5-ethylpyridinium, 1 , 5-diethyl-2-methylpyridinium, 1- (1-butyl) -2-methyl-3-ethylpyridinium, 1- (1-hexyl) -2-methyl-3-ethylpyridinium, 1- (1-octyl) ) -2-methyl-3-ethylpyridinium, 1- (1-dodecyl) -2-methyl-3-ethylpyridinium, 1- (1-tetradeci) ) -2-methyl-3-ethylpyridinium, 1- (1-hexadecyl) -2-methyl-3-ethylpyridinium, 1-methylimidazolium, 1-ethylimidazolium, 1- (1-butyl) imidazolium, 1- (1-octyl) imidazolium, 1- (1-dodecyl) imidazolium, 1- (1-tetradecyl) imidazolium, 1- (1-hexadecyl) imidazolium, 1,3-dimethylimidazolium, 1- Ethyl-3-methylimidazolium, 1- (1-butyl) -3-methylimidazolium, 1- (1-hexyl) -3-methylimidazolium, 1- (1-octyl) -3-methylimidazolium, 1- (1-dodecyl) -3-methylimidazolium, 1- (1-tetradecyl) -3-methylimidazolium, 1- (1-hex Sadecyl) -3-methylimidazolium, 1,2-dimethylimidazolium, 1,2,3-trimethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1- (1-butyl) -2,3 -Dimethylimidazolium, 1- (1-hexyl) -2,3-dimethylimidazolium and 1- (1-octyl) -2,3-dimethylimidazolium, 1,4-dimethylimidazolium, 1,3,4 -Trimethylimidazolium, 1,4-dimethyl-3-ethylimidazolium, 3-butylimidazolium, 1,4-dimethyl-3-octylimidazolium, 1,4,5-trimethylimidazolium, 1,3,4 , 5-tetramethylimidazolium, 1,4,5-trimethyl-3-ethylimidazolium, 1,4,5-trimethyl-3-buty Mention may be made of imidazolium, 1,4,5-trimethyl-3-octylimidazolium, trimethyl-2-hydroxyethylammonium, dimethyl-bis-2-hydroxyethylammonium, and methyl-tris-2-hydroxyethylammonium. .

で示されるカルボン酸イミド、ビス（スルホニル）イミドおよびスルホニルイミドや、一般式：

で示されるメチドを挙げることができる。 Next, as an anion of the ionic liquid, in principle, all anions can be used. Examples of the anion [Y] ⁿ⁻ of the ionic liquid include F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₃ ) ₂ N ⁻ , Halides and halogen-containing compounds represented by CF ₃ CO ₂ , CCl ₃ CO ₂ , CN ⁻ , SCN ⁻ , OCN ⁻ , and general formulas: SO ₄ ²⁻ , HSO ₄ ⁻ , SO ₃ ²⁻ , HSO ₃ ⁻ , _{^{R a OSO 3 -, R a}} SO 3 - sulfate represented by, and sulfites and sulfonates of the general _{^{formula: PO 4 3-, HPO 4 2-}} , H 2 PO 4 -, R a PO 4 2- Phosphonic acid represented by the general formulas: R ^a HPO ₃ ⁻ , R ^a R ^b PO ₂ , R ^a R ^b PO ₃ ^— , and phosphates represented by HR ^a PO ₄ ⁻ and R ^a R ^b PO ₄ ^— Salts and phosphinates, Phosphate represented by the general formulas: PO ₃ ³⁻ , HPO ₃ ²⁻ , H ₂ PO ₃ ⁻ , R ^a PO ₃ ²⁻ , R ^a HPO ₃ ⁻ , R ^{a Rb} PO ₃ ⁻ , and the general formula : R ^a R ^b PO ₂ , R ^a HPO ₂ , R ^a R ^b PO ⁻ , phosphonite and phosphite represented by R ^a HPO ⁻ , and carboxylic acid represented by the general formula: R ^a COO ⁻ And general formulas: BO ₃ ³⁻ , HBO ₃ ²⁻ , H ₂ BO ₃ ⁻ , R ^a R ^b BO ₃ ⁻ , R ^a HBO ₃ ⁻ , R ^a BO ₃ ²⁻ , B (OR ^a ) (OR ^b ) ) (OR ^c ) (OR ^d ) ⁻ , B (HSO ₄ ) ⁻ , B (R ^a SO ₄ ) ⁻ , and general formulas: R ^a BO ₂ ²⁻ , R ^a R ^b BO ⁻ Or boronic acid salt represented by the general formula: SiO ₄ ⁴⁻ , HSiO ₄ ³⁻ , H ₂ SiO ₄ ²⁻ , H ₃ SiO ₄ ⁻ , R ^a SiO ₄ ^{3 −} , R ^a R ^b SiO ₄ ²⁻ , R ^a R ^b R ^c SiO ₄ ⁻ , HR ^a SiO ₄ ²⁻ , H ₂ R ^a SiO ₄ ⁻ , HR ^a R ^b SiO ₄ ^— , silicates and silicate esters, and general formulas: R ^a SiO ₃ ³⁻ , R ^a R ^b SiO ₂ ²⁻ , R ^a R ^b R ^c SiO ⁻ , R ^a Alkyl- or arylsilane salts represented by R ^b R ^c SiO ₃ ⁻ , R ^a R ^b R ^c SiO ₂ , R ^a R ^b R ^c SiO ₃ ²⁻ , or a general formula:

Carboxylic acid imide, bis (sulfonyl) imide and sulfonylimide represented by the general formula:

Can be mentioned.

In the above structural formula, R ^a , R ^b , R ^c and R ^d are independently of each other hydrogen, (i) C ₁ -C ₃₀ alkyl, (ii) one or more non-adjacent oxygen and / or sulfur atoms, And / or C ₂ -C ₁₈ alkyl, (iii) C ₆ -C ₁₄ aryl, (iv) C ₅ -C ₁₂ cycloalkyl, (v) or oxygen interrupted by one or more substituted or unsubstituted imino groups Represents a 5-membered to 6-membered heterocyclic group containing a nitrogen and / or sulfur atom. Where two of these are both unsaturated, saturated, or aromatic, optionally interrupted by one or more oxygen and / or sulfur atoms, and / or one or more unsubstituted or substituted imino groups A ring can be formed, and (i) to (v) can each be substituted with a functional group, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatom and / or heterocyclic group.

  In the present invention, as (i), for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2,4,4- Trimethylpentyl, decyl, dodecyl, tetradecyl, heptadecyl, octadecyl, 1,1-dimethylpropyl, 1,1-dimethylbutyl, 1,1,3,3-tetramethylbutyl, benzyl, 1-phenylethyl, α, α- Dimethylbenzyl, benzhydryl, p-tolylmethyl, 1- (p-butylphenyl) ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p-methoxybenzyl, m-ethoxybenzyl, 2-cyanoethyl, 2-cyanopropyl, 2-methoxycarbonylethyl, 2-ethoxycarbonyl Ethyl, 2-butoxycarbonylpropyl, 1,2-di- (methoxycarbonyl) ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, diethoxymethyl, diethoxyethyl, 1,3-dioxolane-2 -Yl, 1,3-dioxan-2-yl, 2-methyl-1,3-dioxolan-2-yl, 4-methyl-1,3-dioxolan-2-yl, 2-isopropoxyethyl, 2-butoxy Propyl, 2-octyloxyethyl, chloromethyl, trichloromethyl, trifluoromethyl, 1,1-dimethylbutyl-2-chloroethyl, 2-methoxyisopropyl, 2-ethoxyethyl, butylthiomethyl, 2-dodecylthioethyl, 2 -Phenylthioethyl, 2,2,2-trifluoroethyl, 2-hydroxyethyl, 2- Droxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl, 2-aminoethyl, 2-aminopropyl, 4-aminobutyl, 6-aminohexyl, 2-methylaminoethyl, 2-methylaminopropyl 3-methylaminopropyl, 4-methylaminobutyl, 6-methylaminohexyl, 2-dimethylaminoethyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 4-dimethylaminobutyl, 6-dimethylaminohexyl, 2 -Hydroxy-2,2-dimethylethyl, 2-phenoxyethyl, 2-phenoxypropyl, 3-phenoxypropyl, 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2-methoxypropyl, 3-methoxypropyl, 4-methoxybutyl 6-methoxyhexyl, 2-ethoxyethyl, 2-ethoxypropyl, 3-ethoxypropyl, 4-ethoxybutyl or 6-ethoxyhexyl, and their functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatoms and And / or those substituted with a heterocyclic group.

  In the present invention, as (ii), for example, 5-hydroxy-3-oxapentyl, 8-hydroxy-3,6-dioxaoctyl, 11-hydroxy-3,6,9-trioxaundecyl, 7- Hydroxy-4-oxaheptyl, 11-hydroxy-4,8-dioxaundecyl, 15-hydroxy-4,8,12-trioxapentadecyl, 9-hydroxy-5-oxanonyl, 14-hydroxy-5,10 -Oxatetradecyl, 5-methoxy-3-oxapentyl, 8-methoxy-3,6-dioxaoctyl, 11-methoxy-3,6,9-trioxaundecyl, 7-methoxy-4-oxaheptyl, 11-methoxy-4,8-dioxaundecyl, 15-methoxy-4,8,12-trioxapentadecyl, 9-methoxy-5- Xanonyl, 14-methoxy-5,10-oxatetradecyl, 5-ethoxy-3-oxapentyl, 8-ethoxy-3,6-dioxaoctyl, 11-ethoxy-3,6,9-trioxaundecyl, 7-ethoxy-4-oxaheptyl, 11-ethoxy-4,8-dioxaundecyl, 15-ethoxy-4,8,12-trioxapentadecyl, 9-ethoxy-5-oxanonyl or 14-ethoxy-5 , 10-oxatetradecyl, and their functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatoms and / or substituted with heterocyclic groups.

Among these, when two substituents form a ring, they together are, for example, 1,3-propylene, 1,4-butylene, 2-oxa-1,3-propylene, 1- Oxa-1,3-propylene, 2-oxa-1,3-propenylene, 1-aza-1,3-propenylene, 1-C ₁ -C ₄ alkyl-1-aza-1,3-propenylene, 1,4 It is preferably -buta-1,3-dienylene, 1-aza-1,4-buta-1,3-dienylene or 2-aza-1,4-buta-1,3-dienylene.

  In the present invention, the number of non-adjacent oxygen and / or sulfur atoms and / or imino groups is not particularly limited, but is limited by the size of the substituent or ring unit. In general, there are 5 or less, preferably 4 or less, or particularly preferably 3 or less in a particular substituent. Also, it is generally preferred that at least 1, preferably at least 2 carbon atoms are present between 2 heteroatoms.

  Substituted and unsubstituted imino groups can include, for example, imino, methylimino, isopropylimino, n-butylimino, or tert-butylimino.

Here, the “functional group” means, for example, carboxyl, carboxamide, hydroxyl, di- (C ₁ -C ₄ alkyl) amino, C ₁ -C ₄ alkoxycarbonyl, cyano or C ₁ -C ₄ alkoxy below. To do. In this _case, C 1 -C ₄ alkyl are methyl, ethyl, propyl, isopropyl, n- butyl, sec- butyl or tert- butyl.

  In the present invention, (iii) includes, for example, phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl, ethyl Phenyl, diethylphenyl, isopropylphenyl, tert-butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, hexyloxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl, ethoxynaphthyl, 2,6-dimethylphenyl, 2, 4,6-trimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, 4-bromophenyl, 2- or 4-nitrophenyl, 2,4 -Or 2,6-dinitrophenyl, 4-dimethylaminophenyl, 4-acetylphenyl, methoxyethylphenyl or ethoxymethylphenyl and their functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatoms and / or The thing substituted by the heterocyclic group can be mentioned.

  In the present invention, as (iv), for example, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, diethylcyclohexyl, butylcyclohexyl, methoxycyclohexyl, dimethoxycyclohexyl, diethoxycyclohexyl, Saturated or unsaturated bicyclic systems such as butylthiocyclohexyl, chlorocyclohexyl, dichlorocyclohexyl, dichlorocyclopentyl, and norbornyl or norbornenyl, and their functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatoms and / or Or the thing substituted by the heterocyclic group can be mentioned.

  In the present invention, (v) is, for example, furyl, thiophenyl, pyryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxyl, benzimidazolyl, benzothiazolyl, dimethylpyridyl, methylquinolyl, dimethylpyryl, methoxyfuryl, dimethoxypyridyl, difluoro List pyridyl, methylthiophenyl, isopropylthiophenyl or tert-butylthiophenyl and those substituted with these functional groups, aryl, alkyl, aryloxy, alkoxy, halogen, heteroatoms and / or heterocyclic groups Can do.

The above ionic liquids may be used alone or in combination of two or more. In the present invention, an imidazolium cation is particularly preferable. More preferably, the 1- and 3-positions or the 1-, 2- and 3-positions of the imidazolium ring are substituted with a (C ₁ -C ₆ ) alkyl group. As the imidazolium cation, 1-ethyl-3-methylimidazolium, 1,3-dimethylimidazolium or 1-butyl-3-methylimidazolium cation is particularly suitable.

In the present invention, neither the cation of the ionic liquid nor the corresponding anion is particularly limited. Anions include halides, perchloric acid, pseudohalides, sulfuric acid, especially hydrogen sulfate, sulfurous acid, sulfonic acid, phosphoric acid, alkyl phosphates, particularly mono- and / or dialkyl phosphate anions (preferred alkyl groups are methyl And an carboxylic acid anion, particularly a C _{1 to} C ₆ carboxylate anion (preferably an acetic acid or propionate anion). Halide ions are present as chloride, bromide and / or iodide ions, pseudohalide ions are present as cyanide, thiocyanate and / or cyanate ions, and C ₁ -C ₆ carboxylic acids It is particularly preferred that the ions are present as formic acid, acetic acid, propionic acid, butyric acid, hexanoic acid, maleic acid, fumaric acid, oxalic acid, lactic acid, pyruvic acid, methanesulfonic acid, tosylate and / or alkanesulfate ions.

The following suitable anions may also be mentioned: R ^a —COO ⁻ , R ^a —SO ₃ ^— , R ^a R ^b PO ₄ ^— (wherein R ^a and R ^b have the above-mentioned meanings). In particular, there are anions of (CH ₃ O) ₂ PO ₂ and (C ₂ H ₅ O) ₂ PO ₂ and benzoate anions, preferably (C ₂ H ₅ O) ₂ PO ₂ and benzoic acid anions. included.

  In the present invention, a cation and an anion can be appropriately combined. Particularly preferable ionic liquids include 1-ethyl-3-methylimidazolium acetate, 1,3-dimethylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium chloride, 1 -Ethyl-3-methylimidazolium diethyl phosphate, 1-methyl-3-methylimidazolium dimethyl phosphate, 1-methyl-3-methylimidazolium formate, 1-ethyl-3-methylimidazolium octanoate, Examples include 1,3-diethylimidazolium acetate and 1-ethyl-3-methylimidazolium propionate. Of these, 1-ethyl-3-methylimidazolium acetate, 1,3-dimethylimidazolium acetate, 1-butyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1- Methyl-3-methylimidazolium dimethyl phosphate, 1,3-diethylimidazolium acetate and 1-ethyl-3-methylimidazolium propionate.

  In the present invention, the cation and anion can be appropriately selected according to the purpose. Particularly preferred anions and cations are shown below.

The ^anion, R a COO ^- (wherein ^{R a} is preferably an alkyl, especially _C 1 -C ₈ alkyl, more preferably _C 1 -C ₃ alkyl or phenyl); phosphate (preferably dialkyl - Phosphate, especially di- (C ₁ -C ₃ alkyl) phosphate, dimethyl-phosphate, diethyl-phosphate and di-n-propyl phosphate are particularly preferred; phosphonates (especially O-alkylalkyl-phosphonates, O-methyl) Methyl-phosphonate, O-methyl-ethyl-phosphonate, O-ethyl-methyl-phosphonate and O-ethylethyl-phosphonate are particularly preferred).

  Examples of the cation include compounds of the above formula (III-e), particularly 1-ethyl-3-methylimidazolium (EMIM), 1-butyl-3-methylimidazolium (BMIM), 1-ethyl-2,3-dimethyl. Imidazolium (EMMIM) and 1-butyl-2,3-dimethylimidazolium (BMMIM); compounds of the above formula (III-a), preferably N-alkyl-pyridinium, more preferably N-methylpyridinium, N-ethyl Pyridinium, N-methyl-2-methylpyridinium, N-methyl-3-methylpyridinium, N-ethyl-2-methylpyridinium and N-ethyl-3-methylpyridinium; compounds of formula (III-f) above, preferably Mention may be made of 1,2,4-trimethylpyrazolium.

In the present invention, R ^a COO ⁻ as an anion, ^a combination of the compound of the above formula (III-e) as a cation, a phosphate as an anion, and a combination of the compound of the above formula (III-e) as a cation are particularly preferable. It is.

  In the production method of the present invention, a high-concentration cellulose solution of about 5 to 12% by mass can be obtained as the content of dry cellulose in the cellulose solution while suppressing the generation of undissolved substances.

  The cellulose solution obtained by the present invention can be used for spinning cellulose fibers. Since the cellulose solution according to the present invention has little undissolved pulp and a high concentration, the cellulose fiber obtained by using the cellulose solution has higher strength than the conventional cellulose fiber, and the reinforcing cord for tire or It is suitable for applications such as reinforcing materials such as belt conveyors.

Hereinafter, the present invention will be described in more detail with reference to examples.
<Example 1>
100 g of pulp manufactured by Oji Paper Co., Ltd. (water content of about 70%) was dried at 110 ° C. for 10 hours in an oven adjusted to about 100 Pa. The dried pulp was loosened with a kitchen mixer manufactured by Zojirushi Co., Ltd. for 10 minutes. The loosened pulp was sieved using a vibrator type sieve. Pulp collected between 2 mm and 1 mm sieve was collected for the experiment.

  2.5 g of dried and finely crushed pulp was taken into a 500 cc jar. In this bottle, 12.5 g of distilled water (500% of dry pulp weight) was added. The contents of the bottle were mixed well by stirring for 5 minutes with a spatula. The bottle was tightly stoppered and kept at room temperature for 12 hours to absorb water well.

  The contents of this bottle were taken out and placed between two glass plates for 1 hour, and water was squeezed under a constant pressure. A portion of the squeezed pulp is dried at 110 ° C. in an oven adjusted to about 100 Pa, and used to measure the moisture content, and the remaining wet pulp is placed in a tightly capped bottle. Oita. The moisture content of the squeezed pulp was measured as 79% by mass.

  1.25 g of wet pulp was taken in a 50 cc sample bottle. In this bottle, 4.75 g of C2mimAc (1-ethyl-3-methylimidazolium acetate) as an ionic liquid was added. The contents of the bottle were mixed well by stirring for 5 minutes with a spatula. This bottle was placed in an oven set at about 80 ° C. and about 100 Pa.

  The contents of this bottle were well agitated manually for 2 minutes using a spatula for 30 minutes, 1 hour, 2 hours and 3 hours, respectively. The bottle was removed from the oven after 4 hours. The dissolution state of the sample was evaluated using a polarizing microscope manufactured by Leica. The density | concentration of this cellulose solution was 5.2 mass% as content of the dry cellulose in a solution.

<Example 2>
A part of pulp manufactured by Oji Paper Co., Ltd. was dried at 110 ° C. in an oven adjusted to about 100 Pa, and used for the measurement of moisture content. The moisture content of the squeezed pulp was measured as 64% by mass.

  0.75 g of pulp manufactured by Oji Paper Co., Ltd. was placed in a 50 cc sample bottle. In this bottle, 4.75 g of C2mimAc as an ionic liquid was added. The contents of this bottle were mixed well by stirring for 10 minutes with a spatula. This bottle was placed in an oven set at about 80 ° C. and about 100 Pa.

  The contents of this bottle were well agitated manually for 2 minutes using a spatula for 30 minutes, 1 hour, 2 hours and 3 hours, respectively. The bottle was removed from the oven after 4 hours. The dissolution state of the sample was evaluated using a polarizing microscope manufactured by Leica. The density | concentration of this cellulose solution was 5.4 mass% as content of the dry cellulose in a solution.

<Example 3>
A part of pulp manufactured by Oji Paper Co., Ltd. was dried at 110 ° C. in an oven adjusted to about 100 Pa, and used for the measurement of moisture content. The moisture content of the squeezed pulp was measured as 64% by mass.

  1.5 g of pulp from Oji Paper Co., Ltd. was placed in a 50 cc sample bottle. In this bottle, 4.5 g of C2mimAc as an ionic liquid was added. The contents of this bottle were mixed well by stirring for 10 minutes with a spatula. This bottle was placed in an oven set at about 80 ° C. and about 100 Pa.

  The contents of this bottle were well agitated manually for 2 minutes using a spatula for 30 minutes, 1 hour, 2 hours and 3 hours, respectively. The bottle was removed from the oven after 4 hours. The dissolution state of the sample was evaluated using a polarizing microscope manufactured by Leica. The density | concentration of this cellulose solution was 10.7 mass% as content of the dry cellulose in a solution.

<Comparative example>
100 g of pulp from Oji Paper Co., Ltd. was dried at 110 ° C. for 10 hours in an oven adjusted to about 100 Pa. The dried pulp was loosened with a kitchen mixer manufactured by Zojirushi Co., Ltd. for 10 minutes. The loosened pulp was sieved using a vibrator type sieve. Pulp collected between 2 mm and 1 mm sieve was collected for the experiment.

  0.25 g of loose pulp was taken into a 50 cc sample bottle. Into this bottle was added 4.75 g of C2mimAc as ionic liquid. The contents of the bottle were mixed well by stirring for 5 minutes with a spatula. The bottle was placed in an oven set at 80 ° C.

  The contents of this bottle were well agitated manually for 2 minutes using a spatula for 30 minutes, 1 hour, 2 hours and 3 hours, respectively. The bottle was removed from the oven after 4 hours. The dissolution state of the sample was evaluated using a polarizing microscope manufactured by Leica. The density | concentration of this cellulose solution was 5 mass% as content of the dry cellulose in a solution.

<Evaluation results>
(1) Regarding the dissolved state in the cellulose solution, improvements were confirmed in the examples according to the present invention. Images of undissolved pulp in the cellulose solution were obtained with a microscope using polarized light. The total area in pixels was calculated by image analysis. As a result, it was found that the area of non-dissolved pulp was higher in the pulp solution dried without swelling in the comparative example than in the wet pulp solution swollen in advance.

(2) Regarding the same area of undissolved pulp in the solution, the improvement of the degree of the dissolved solution was confirmed in the examples according to the present invention. Images of undissolved pulp in the cellulose solution were obtained with a microscope using polarized light. The total area in pixels was calculated by image analysis. The area of undissolved pulp for 10 wt% untreated HDP pulp was found to be the same as the only 5 wt% solution of the unswelled and dried pulp of the comparative example.

(3) The total energy consumption in the preparation and dissolution steps decreased globally. If untreated pulp (water content 64% by weight) is used, there is no need for drying (in a vacuum oven at 110 ° C. for 10 hours) and loosening / sieving. In contrast, dissolution requires vacuum oven treatment, but only 4 hours compared to 10 hours for drying.

(4) Drying at 110 ° C. for 10 hours, loosening in a kitchen mixer, and sieving in a vibrator damages the pulp fibers and hinders the dissolving ability of the pulp.

Claims (2)

In a method for producing a cellulose solution by dissolving pulp in an ionic liquid,
A method for producing a cellulose solution, wherein the moisture content of the pulp is 50% by mass or more, and the pulp is dissolved in the ionic liquid under heating at 70 ° C. or more.   The method for producing a cellulose solution according to claim 1, wherein the dissolution of the pulp in the ionic liquid is performed under a pressure lower than the vapor pressure of water in the mixture of the pulp and the ionic liquid at the temperature at the time of dissolution.