Cleaning liquid for cleaning resin

Abstract

To provide a cleaning liquid capable of effectively cleaning a resin adhering to a spinneret, a filter or the like after use and allowing a worker to work safely, especially in the spinning of resins such as polyamide, wholly aromatic polyamide, wholly aromatic copolyamide, polyamide-imide, aromatic polyamide-imide, polyimide, cellulose, cellulose acetate, and polyacrylonitrile.SOLUTION: A cleaning liquid contains an ionic liquid and a base, and the content ratio of the ionic liquid to an entirety of the cleaning liquid is 1.00 to 99.99 mass% and the content ratio of the base to the cleaning liquid is 0.01 to 50.00 mass%.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a cleaning solution for washing resins, and more particularly to a cleaning solution for washing resins, which contains an ionic liquid and a base. [Background technology]

[0002] Synthetic fibers are formed into fibers by extruding a polymer solution through the nozzle of a spinneret. By extruding the polymer solution for a long period of time, resin, inorganic particles, etc. adhere to the nozzle of the spinneret, and dirt accumulates. A dirty spinneret leads to a decrease in spinning stability and fiber quality, so it is necessary to periodically replace the spinneret and spin pack, and to clean the spin pack and spinneret.

[0003] As such a cleaning method, JP-A-62-205122 (Patent Document 1) reports a method for cleaning a spinneret using an alkaline aqueous solution containing hypochlorite as a cleaning solution, but the cleaning ability is insufficient. In addition, the alkaline aqueous solution containing hypochlorite is a harmful substance and may pose a danger to workers.

[0004] In addition, Japanese Patent Laid-Open Publication No. 3-213503 (Patent Document 2) reports a method for cleaning a spinneret using an oxidizing molten salt with a temperature of 260°C to 462°C as a cleaning solution, but this method has the problem of requiring a long cleaning time because it reacts with the resin.In addition, the cleaning solution is high temperature and uses harmful substances such as potassium hydroxide and potassium permanganate, which also poses a danger to workers.

[0005] In addition, Japanese Patent Laid-Open Publication No. 62-206013 (Patent Document 3) reports a method for cleaning a spinneret using an organic solvent, dimethyl sulfoxide, and an alkali metal organic compound, an alkali metal hydride compound, etc., as a cleaning solution, but the cleaning ability was insufficient. In addition, the use of an alkali metal organic compound, an alkali metal hydride compound, etc., is a harmful substance, which also poses a danger to workers.

[0006] Furthermore, JP 2011-89217 A (Patent Document 4) and JP 2022-159304 A (Patent Document 5) report a method for cleaning a spinneret using an organic solvent such as DMAc or acetone as a cleaning solution, but the cleaning ability is also insufficient, and the cleaning ability is particularly low for some polymers such as cellulose and fully aromatic polyamide. In addition, since DMAc and acetone are highly toxic, there has been a demand for the development of a cleaning solution for resins that is highly cleanable and safer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 62-205122 [Patent Document 2] Japanese Patent Application Publication No. 3-213503 [Patent Document 3] Japanese Patent Publication No. 62-206013 [Patent Document 4] JP 2011-89217 A [Patent Document 5] JP 2022-159304 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to solve the problems in the conventional techniques and to provide a cleaning liquid which can effectively clean resin adhering to spinnerets, filters, etc. after use in the spinning of resins such as polyamide, wholly aromatic polyamide, wholly aromatic copolyamide, polyamideimide, aromatic polyamideimide, polyimide, cellulose, cellulose acetate, polyacrylonitrile, etc., and which allows workers to work safely. [Means for solving the problem]

[0009] The present inventors have conducted intensive research to solve the above problems and have found that by using a cleaning solution containing an ionic liquid and a base, it is possible to provide a cleaning solution that effectively cleans resins and that enables cleaning to be performed safely, thereby completing the present invention.

[0010] That is, according to the present invention, 1. A cleaning solution for washing a resin, comprising an ionic liquid and a base, the content of the ionic liquid in the entire cleaning solution being 1.00 to 99.99% by mass, and the content of the base in the cleaning solution being 0.01 to 50.00% by mass. And, 2. The resin cleaning solution according to the above item 1, wherein the anion of the ionic liquid is at least one anion selected from the group consisting of halides, hydroxides, alkoxides, carboxylates, carbonates, phosphates, phosphonates, sulfonates, sulfates, and nitrates. is provided. Effect of the Invention

[0011] According to the present invention, a spinneret cleaning liquid can be provided that can effectively clean resins such as polyamide, wholly aromatic polyamide, wholly aromatic copolyamide, polyamideimide, aromatic polyamideimide, polyimide, cellulose, cellulose acetate, and polyacrylonitrile, and that allows workers to work safely. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] <Items to be cleaned> The object to be cleaned in the present invention is a member having a resin attached thereto, etc., including, but not limited to, a spinneret, a spin pack, a die, a filter, a packing, a tank, a pipe, a mixer, a roller, a substrate, a sheet, etc. The cleaning solution of the present invention is particularly effective for cleaning spin packs and spinnerets.

[0014] <Spinning pack> The spin pack in the present invention is a member composed of a spinneret, a filter, a distribution plate, a perforated plate, or a holder, a plate, a packing, and the like.

[0015] <Spinneret> The spinneret in the present invention is a member for forming a fiber-like shape by extruding a polymer solution. The material of the spinneret is not particularly limited, but examples thereof include iron, steel, stainless steel, tantalum, aluminum alloy, copper alloy, titanium alloy, and nickel alloy. The surface may be treated by chrome plating or the like. The shape of the spinneret is not particularly limited, but examples include a circle, an ellipse, a doughnut shape, a dish-shaped circle, a rectangle, and a triangle.

[0016] The hole arrangement of the spinneret is not particularly limited, but examples include a parallel arrangement, a staggered arrangement, an island arrangement, etc. The cross-sectional shape of the spinneret is not particularly limited, but examples include a circle, an ellipse, a flat, a multilobal, a multilobal flat, a hollow, a triangle, a polygon, a Y-shape, an X-shape, a C-shape, a dogbone shape, etc. The cleaning method of the present invention can also be used for spinnerets for producing composite fibers, such as an island-in-the-sea type. The number of holes in the spinneret is not particularly limited, but can be in the range of 1 to 30,000, for example.

[0017] The diameter of the spinning hole is not particularly limited, but may be in the range of 0.01 mm to 10.00 mm. If it is less than 0.01 mm, the washability is reduced, which is not preferable. If it exceeds 10.00 mm, it can be sufficiently washed with a conventional washing solution.

[0018] <Resin> The resin used in the present invention contains additives such as a polymer, a solvent for the polymer, a dissolving aid, a pigment, a dye, a lubricant, a dispersant, etc. The polymer contained in the resin is not particularly limited, but examples thereof include polyamide, wholly aromatic polyamide, wholly aromatic copolyamide, polyamideimide, aromatic polyamideimide, polyimide, cellulose, cellulose acetate, polyacrylonitrile, etc. A blend polymer of these may also be used.

[0019] The cleaning solution of the present invention can be suitably used for cleaning resins containing wholly aromatic polyamides, wholly aromatic copolyamides, polyacrylonitrile, cellulose, and cellulose acetate, more suitably used for resins containing wholly aromatic polyamides, wholly aromatic copolyamides, and cellulose, and particularly suitably used for wholly aromatic polyamides and wholly aromatic copolyamides.

[0020] <Fully aromatic polyamide> A wholly aromatic polyamide is a polymer in which one or more types of divalent or higher aromatic groups are directly linked by amide bonds. The aromatic groups have benzene rings bonded at the para or meta positions, and these divalent or higher aromatic groups may contain lower alkyl groups such as methyl and ethyl groups, halogen groups such as methoxy and chlorine groups, and cyano groups.

[0021] Further, wholly aromatic polyamides are classified into para-type and meta-type, with para-type wholly aromatic polyamides being wholly aromatic polyamides mainly composed of para-type wholly aromatic polyamides consisting of a para-type aromatic dicarboxylic acid chloride component and a para-type aromatic diamine component, with the main component being 50 mol% or more of the total repeating units. Meta-type wholly aromatic polyamides being wholly aromatic polyamides mainly composed of meta-type wholly aromatic polyamides consisting of a meta-type aromatic dicarboxylic acid chloride component and a meta-type aromatic diamine component, with the main component being 50 mol% or more of the total repeating units.

[0022] [Raw material for fully aromatic polyamide] (Aromatic carboxylic acid chloride component) Examples of the aromatic carboxylic acid chloride component used in the wholly aromatic polyamide include isophthalic acid chloride, terephthalic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 2,5-furandicarboxylic acid chloride, 3,4-furandicarboxylic acid chloride, pyridine-2,6-dicarboxylic acid chloride, 1,3,5-benzenedicarboxylic acid dichloride, 2,2'-bis(5-chloroformyl 2-furyl)propane, 2-pyrone-4,6-dicarboxylic acid dichloride, etc. Also, derivatives having a substituent such as halogen, an alkoxy group having 1 to 3 carbon atoms, a sulfonic acid group, or a sodium sulfonate group on the aromatic ring of these, such as 3-chloroisophthalic acid chloride, 3-methoxyisophthalic acid chloride, etc. may be used.

[0023] (Aromatic diamine component) Examples of the aromatic amine components used in the fully aromatic polyamide include metaphenylenediamine, paraphenylenediamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 1,8-diaminonaphthalene, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzanilide, 2,5-bis(aminomethyl)furan, 1,3,5-benzenetriamine, 2,2'-bis(trifluoromethyl)benzidine, 3,5-diaminobenzoic acid, methyldivanillylamine, and 5-amino-2-(4-aminophenyl)benzimidazole. In addition, derivatives having a substituent such as halogen, an alkoxy group having 1 to 3 carbon atoms, a sulfonic acid group, or a sodium sulfonate group on the aromatic ring, such as 2,4-toluylenediamine, 2,6-toluylenediamine, 2,4-diaminochlorobenzene, and 2,6-diaminochlorobenzene, may also be used.

[0024] <Cleaning solution> The resin washing solution of the present invention is a solution for washing the resin, and contains an ionic liquid and a base. The ionic liquid may contain salts, protic solvents, aprotic organic solvents, eutectic mixtures, etc., in addition to the ionic liquid and the base, as long as the object of the present invention is not impaired.

[0025] <Ionic liquids> The ionic liquid in the present invention is a compound in which an anion derived from an acid and a cation derived from a base are ionic-bonded, and is a salt having a melting point of 100° C. or lower.

[0026] The type of ionic liquid is not particularly limited, but examples include aprotic ionic liquids, protic ionic liquids, chelate ionic liquids, metal complex ionic liquids, inorganic ionic liquids, zwitterionic liquids, and the like.

[0027] Examples of cations of the ionic liquid include pyrrolium, imidazolium, pyrazolium, pyridinium, pyrimidinium, pyridazinium, pyrazinium, oxazolimu, thiazolium, triazolium, ammonium, cholinium, pyrrolidinium, piperidinium, morpholinium, phosphonium, sulfonium, sulfoquinium, protonated amine, protonated amidine, and protonated guanidine.

[0028] The anion of the ionic liquid is not particularly limited, but may be a halide such as F, Cl, Br, or I, a hydroxide, or an alkoxide (RO - ), acetate, ethanol, and other alkyl carboxylates (RCOO - ), amino acid anions such as glycinate, alanine, and valinate, alkyl carbonates such as carbonate, methyl carbonate, and ethyl carbonate (ROCOO - ), P.F. 6 - phosphates such as dimethyl phosphate, diethyl phosphate, dibutyl phosphate, etc. (RO) 2 PO 2 -), alkyl phosphonates such as methyl methyl phosphonate, sulfonates such as methanesulfonate, trifluoromethanesulfonate, dodecylbenzenesulfonate, and tosylates (RSO 3 - ), hydrogen sulfate, methyl sulfate, and other sulfates (ROSO 3 - ), trifluoromethanesulfonate, bis(fluorosulfonyl)imide, bis(trifluoromethylsulfonyl)imide and other imide anions, dicyanamide, tricyanomethanide, tetrafluoroborate, trifluoro(trifluoromethyl)borate, nitrate, thiocyanate, tetrachloroferrate, hexafluoroanitimonate and the like.

[0029] From the viewpoint of cleaning properties, the anion of the ionic liquid is preferably at least one anion selected from the group consisting of halides such as F, Cl, Br, and I, hydroxides, alkoxides, carboxylates, carbonates, phosphates, phosphonates, sulfonates, sulfates, and nitrates.

[0030] It is essential that the content of the ionic liquid in the entire cleaning liquid is 1.00 to 99.99 mass %, preferably 5.00 to 99.99 mass %, more preferably 10.0 to 99.99 mass %, and even more preferably 50.0 to 95.00 mass %. If the content of the ionic liquid in the entire cleaning solution is less than 1.00% by mass, the cleaning ability of the cleaning solution will be poor. On the other hand, if the content of the ionic liquid in the entire cleaning solution is more than 99.99% by mass, the cleaning ability of the cleaning solution will also be poor.

[0031] <base> The base in the present invention is not particularly limited, and examples thereof include oxides of alkali metals and alkaline earth metals, hydroxides (hydroxides) of alkali metals and alkaline earth metals, organometallic compounds (alkoxides) of alkali metals and alkaline earth metals, amines, pyridines, pyrimidines, heterocyclic amines, and phosphorus compounds. Examples of the base include potassium hydroxide, sodium hydroxide, calcium oxide, calcium hydroxide, potassium tert-butoxide, and sodium tert-butoxide, 1,4-diazabicyclo[2.2.2]octane, pyrimidine, guanidine, 1,1,3,3-tetramethylguanidine (TMG), 2-tert-butyl-1,1,3,3-tetramethylguanidine, diazabicyclononene (DBN), diazabicycloundecene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,4,5,6-tetrahydropyrimidine (THP), 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (DMP), phasphazene base, proazaphosphotlane base, etc.

[0032] More preferred are potassium hydroxide, sodium hydroxide, calcium oxide, calcium hydroxide, guanidine, 1,1,3,3-tetramethylguanidine (TMG), 2-tert-butyl-1,1,3,3-tetramethylguanidine, diazabicyclononene (DBN), diazabicycloundecene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,4,5,6-tetrahydropyrimidine (THP), and 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine (DMP).

[0033] It is essential that the content of the above base in the entire cleaning solution is 0.01 to 50.00 mass %, preferably 0.01 to 20.00 mass %, and more preferably 0.10 to 20.00 mass %. If the content of the base in the entire cleaning solution is less than 0.01% by mass, the cleaning ability of the cleaning solution will be poor, whereas if the content of the base in the entire cleaning solution is more than 50.00% by mass, the cleaning ability of the cleaning solution will be poor.

[0034] <Salt> The salt in the present invention is a compound in which an anion derived from an acid and a cation derived from a base are ionic bonded to each other, and includes inorganic salts and organic salts. Inorganic salts are salts in which a cation and anion derived from an inorganic compound are ionic bonded, and examples of such salts include combinations of cations such as alkali metal ions, alkaline earth metal ions, rare earth metal ions, and ammonium ions, and anions such as halide ions, sulfate ions, hydrogen sulfate ions, silicate ions, nitrate ions, and phosphate ions. Specific examples of such salts include lithium chloride, calcium chloride, potassium nitrate, and potassium sulfate.

[0035] On the other hand, organic salts are those in which either the acid or base is derived from an organic compound, such as lithium acetate, ammonium acetate, potassium propionate, tetramethylammonium chloride, tetrabutylammonium fluoride, tetrabutylammonium bromide, and choline chloride.

[0036] The content ratio of the inorganic salt and organic salt in the entire cleaning solution is preferably 10.00 mass % or less. If the content ratio of the inorganic salt and organic salt in the entire cleaning solution exceeds 10.00 mass %, the salt is likely to precipitate, and cleaning residues due to the salt are likely to remain, which is not preferable.

[0037] <Aprotic organic solvent> In the present invention, the cleaning liquid may be an aprotic organic solvent by adjusting the viscosity.

[0038] The aprotic organic solvent in the present invention is a solvent that does not have a proton-donating group such as a hydroxyl group, which is made of an organic compound, and examples of such an organic solvent include ethyl carbonate, propyl carbonate, ethyl fluorocarbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, 1,2-butylene carbonate, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, dipropyl sulfone, sulfolane, dimethyl sulfide, diethyl sulfide, diisopropyl sulfide, dimethyl sulfoxide, diethyl sulfoxide, diethyl ether, propyl ether, isopropyl ether, and dibutyl ether. ter, diisobutyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, dioxane, dihydrolevoglucosenone, α-angelica lactone, γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptanolactone, γ-octanolactone, γ-nonalactone, γ-decanolactone, δ-valerolactone, δ-hexanolactone, δ-octanolactone, δ-decanolactone, δ-tetradecanolactone, ε-caprolactone, ε-decanolactone, Dimethyl isosorbide, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, tert-butyl acetate, lauryl acetate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, isopropyl acetoacetate, butyl acetoacetate, isobutyl acetoacetate, tert-butyl acetoacetate, lauryl acetoacetate, methyl levulinate, ethyl levulinate, propyl levulinate, isopropyl levulinate, Butyl levulinate, isobutyl levulinate, tert-butyl levulinate, dimethyl succinate, diethyl succinate, acetonitrile, succinonitrile, cumene, limonene, methylcyclohexane, N-methylformamide, N-methylacetamide, N,N-dimethylformamide (DMF), N,N-diethylformamide, N,N-dipropylformamide, N,N-diisopropylformamide, N,N-dibutylformamide, N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N,N-dipropylacetamide, N,N-Diisopropylacetamide, N,N-Dibutylacetamide, N,N-Dimethylacetoacetamide, N,N-Diethylacetoacetamide, 3-Methoxy-N,N-Dimethylpropanamide, 3-Butoxy-N,N-Dimethylpropanamide, N,N-Dimethyloctanamide, N,N-Dimethyldecanamide, N,N-Diethylhexanamide, N,N-Diethylbenzamide, N,N-Diethyl-3-methylbenzamide, Malonamide, Pyrrolidine, N-Acetyl-2-pyrrolidine, 2-Pyrrolidinamide N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), 1-(2-hydroxyethyl)-2-pyrrolidone, 1-propylpyrrolidin-2-one, N-isopropyl-2-pyrrolidone, 1-butylpyrrolidin-2-one, N-isobutyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, 1-cyclohexyl-2-pyrrolidone, 1-n-octyl-2-pyrrolidone, N-vinylpyrrolidone, 3-bromo-N-methylpyrrolidone, 3- Hydroxy-n-methylpyrrolidone, 5-hydroxy-N-methylpyrrolidone, 5-methyl-2-pyrrolidone, 1,5-dimethyl-2-pyrrolidone, 5-methyl-N-ethylpyrrolidone, 5-methyl-N-hydroxyethylpyrrolidone, 5-methyl-N-propylpyrrolidone, 5-methyl-N-isopropylpyrrolidone, 5-methyl-N-butylpyrrolidone, 5-methyl-N-isobutylpyrrolidone, 5-methyl-N-cyclohexylpyrrolidone, 5-methyl-N-phenylpyrrolidone, 5-ethyl-2-pyrrolidone 5-propyl-2-pyrrolidone, piperidine, 2,2,6,6-tetramethylpiperidine, 2-piperidone, 4-piperidone, N-methyl-2-piperidone, N-methyl-4-piperidone, N-ethyl-4-piperidone, 1,3-dimethyl-2-piperidone, 1,5-dimethyl-2-piperidone, 1,3-dimethyl-4-piperidone, ε-caprolactam, N-methyl-ε-caprolactam, N-vinyl-ε-caprolactam, 1-methylimidazole, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylpropylene urea, tetramethyl urea, morpholine, 4-methylmorpholine, 4-ethylmorpholine, 4-propylmorpholine, 4-formylmorpholine, 4-acetylmorpholine, 1,4-diacetylpiperazine, N,N-dimethylglycine, N,N-diacetylglycine, pyridine, 2-hydroxypyridine, 2-methylpyridine, 4-methylpyridine, 3,4-dimethylpyridine, 2,6-lutidine, 4-dimethylaminopyridine, 1-methyl-2-pyridone, quinoline, 1-methyl-2-quinoline, hexamethylphosphoric triamide, and the like.

[0039] The content of the aprotic organic solvent in the entire cleaning solution is preferably 0.00 to 98.09% by mass, and more preferably 0.00 to 90.00% by mass. If the solvent content exceeds 98.09% by mass, the cleaning properties are reduced, which is not preferable.

[0040] <Protic Solvents> In the present invention, a protic solvent can be used as the cleaning liquid by adjusting the viscosity. The protic solvent in the present invention is a solvent that has a hydroxyl group and can act as a proton donor, and examples of such solvents include water, alcohols, amino acids, carboxylic acids, sulfonic acids, and sugars.

[0041] Examples of the solvent include, but are not limited to, water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butyl alcohol, 1-pentanol, 1-hexanol, 2-ethylhexanol, cyclohexanol, 1-octanol, 2-methoxyethanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, glycerin, diacetone alcohol, and glycerol 1,2-carbonate. , formic acid, acetic acid, propionic acid, 3-hydroxypropionic acid, butanoic acid, isobutyric acid, 3-hydroxybutanoic acid, caproic acid, lactic acid, succinic acid, levulinic acid, glycolic acid, oxalic acid, methyl lactate, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, 2-ethylhexyl lactate, sugars such as diformylxylose, amino acids such as glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine, tryptophan, phenylalanine, asparagine, cytosine, glutamine, serine, threonine, serine, maleimide, N-hydroxysuccinimide, etc.

[0042] More preferred examples include water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butyl alcohol, 1-pentanol, 1-hexanol, 2-ethylhexanol, cyclohexanol, 1-octanol, 2-methoxyethanol, ethylene glycol, glycerin, formic acid, acetic acid, propionic acid, 3-hydroxypropionic acid, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine, tryptophan, phenylalanine, asparagine, cytosine, glutamine, serine, threonine, amino acids such as serine, maleimide, and N-hydroxysuccinimide.

[0043] The content ratio of the protic solvent in the entire cleaning solution is preferably 0.00 to 50.00 mass%, more preferably 0.00 to 30.00 mass%, and even more preferably 0.00 to 10.00 mass%. If the solvent ratio exceeds 50.00 mass%, the cleaning ability decreases, which is not preferable. These aprotic organic solvents and protic solvents may be used alone or in combination of two or more.

[0044] In addition, protic solvents and aprotic organic solvents derived from animals and plants can also be used in the present invention. The protic solvents and aprotic organic solvents derived from animals and plants in the present invention refer to organic compounds synthesized from plant-derived raw materials (sugar / starch biomass, lignocellulosic biomass including cellulose, hemicellulose, lignin, etc.) and natural products produced by animals, plants, and microorganisms. There is no difference in physical properties such as molecular weight and thermal properties (melting point, boiling point) between organic solvents derived from animals and plants and organic solvents derived from fossils. Therefore, the biomass degree is generally used to distinguish between them.

[0045] Biomass degree is the radioactive carbon ( 14 This is a measurement of the amount of carbon derived from biomass, using a carbon dioxide (C, half-life 5730 years) measurement. 14 N 14 C, which is converted to carbon dioxide in the atmosphere. 14 Carbon dioxide is fixed in plants as carbohydrates during photosynthesis, so 14 On the other hand, fossil-derived petroleum contains the same amount of C. 14 Since carbon is substantially absent, carbon derived from plants can be distinguished from carbon derived from fossils. Generally, methods for measuring the biomass degree are known, such as ASTM D6866. Therefore, the organic solvent derived from animals and plants of the present invention can also be distinguished by measuring the biomass degree after extracting the organic solvent in the polymer solution.

[0046] In addition, specific examples of the solvents of animal or plant origin in the present invention include, but are not limited to, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, glycerin, benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, formic acid, acetic acid, 3-hydroxypropionic acid, butanoic acid, 3-hydroxybutanoic acid, lactic acid, succinic acid, levulinic acid, glycolic acid, acrylic acid, oxalic acid, dimethyl sulfone, dimethyl sulfoxide, diethyl ether, propyl ether, and isopropyl ether. , dibutyl ether, diisobutyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, dihydrolevoglucosenone, diformylxylose, gamma-butyrolactone, gamma-valerolactone, delta-valerolactone, delta-decanolactone, epsilon-caprolactone, dimethylisosorbide, acetone, cyclopentanone, ethyl acetate, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, 2-ethylhexyl lactate, methyl levulinate, ethyl levulinate, propyl levulinate, propyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, vinyl ethylene carbonate, 1,2-butylene carbonate, glycerol 1,2-carbonate, acetonitrile, succinonitrile, N,N-Dimethylacetamide (DMAc), 2-pyrrolidone, N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), 1-(2-hydroxyethyl)-2-pyrrolidone, 1-propylpyrrolidin-2-one, 1-isopropylpyrrolidin-2-one, 1-butylpyrrolidin-2-one, 1-isobutylpyrrolidin-2-one, 1-pentylpyrrolidin-2-one, 1-isopentylpyrrolidin-2-one, 1-n-octyl-2-pyrrolidone, and other N-alkyl-2-pyrrolidones, N-vinyl-2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, 5-methyl-2-pyrrolidone, 1,5-dimethyl Examples include 2-pyrrolidone, 5-methyl-N-ethylpyrrolidone, 5-methyl-N-hydroxyethylpyrrolidone, 5-methyl-N-propylpyrrolidone, 5-methyl-N-isopropylpyrrolidone, 5-methyl-N-butylpyrrolidone, 5-methyl-N-isobutylpyrrolidone, 5-methyl-N-cyclohexylpyrrolidone, 5-methyl-N-phenylpyrrolidone, N-methylcaprolactam, 2,6-lutidine, glycine, alanine, valine, leucine, isoleucine, methionine, tyrosine, tryptophan, phenylalanine, asparagine, cytosine, glutamine, serine, threonine, and amino acids such as serine.

[0047] <eutectic mixture> The cleaning liquid in the present invention may contain a eutectic mixture or may be in the form of a eutectic mixture. The eutectic mixture in the present invention is a mixture in which one or more hydrogen bond donors and one or more hydrogen bond acceptors are mixed together to lower the eutectic melting point, resulting in a mixture with a lower melting point than the individual substances.

[0048] For example, 4-aminobenzoic acid and choline chloride, malic acid and alanine, malic acid and glycine, malic acid and proline, oxalic acid and histidine, oxalic acid and proline, urea and acetamide, ε-caprolactam and acetamide, urea and ε-caprolactam, urea and choline chloride, urea and choline bromide, urea and betaine hydrochloride, glycerin and choline chloride, thiourea and choline chloride, TMG and thiourea, DBN and thiourea, DBU and thiourea, DBU and methylthiourea, DBU and dimethylthiourea. Combinations that have been reported include: dithiourea, DBU and trimethylthiourea, DBU and lithium nitrate, DBU and lithium bis(trifluoromethanesulfonyl)imide, DBU, dimethylurea and ethylene glycol, glycerin, DBU and choline chloride, glycerin, DBN and choline chloride, DBU, imidazole ionic liquid and ethylene glycol, DBU, indole ionic liquid and ethylene glycol, and DBU, 1,2,4-triazole ionic liquid and ethylene glycol.

[0049] The content ratio of the eutectic mixture in the entire cleaning liquid is preferably 0.00 to 98.09 mass%, and more preferably 0.00 to 90.00 mass%. If the solvent ratio exceeds 98.09 mass%, the cleaning performance is reduced, which is not preferable.

[0050] <Deep eutectic solvent> The deep eutectic solvent in the present invention is a mixture in which one or more types of hydrogen bond donors and hydrogen bond acceptors are mixed in a certain ratio, causing a eutectic melting point depression and becoming liquid at room temperature. Examples of the compound include, but are not limited to, malic acid and alanine (molar ratio 1:1), malic acid and glycine (molar ratio 1:1), malic acid and proline (molar ratio 1:2), oxalic acid and histidine (molar ratio 9:1), oxalic acid and proline (molar ratio 1:1), urea and acetamide (molar ratio 1:2), ε-caprolactam and acetamide (molar ratio 1:1), urea and ε-caprolactam (molar ratio 1:3), urea and choline chloride (molar ratio 2:1), urea and choline bromide (molar ratio 2:1), urea and betaine hydrochloride (molar ratio 4:1), glycerin and choline chloride (molar ratio 2:1), thiourea and choline chloride (molar ratio 2:1), TMG and thiourea (molar ratio 2:1), DBN and thiourea (molar ratio 2:1), DBU and thiourea. The following combinations have been reported: DBU and methylthiourea (2:1 molar ratio), DBU and dimethylthiourea (2:1 molar ratio), DBU and trimethylthiourea (2:1 molar ratio), DBU and lithium nitrate (3:1 molar ratio), DBU and lithium bis(trifluoromethanesulfonyl)imide (4:1 molar ratio), glycerin, DBU, and choline chloride (1:2:6 molar ratio), glycerin, DBN, and choline chloride (1:2:6 molar ratio), DBU, an ionic liquid of imidazole, and ethylene glycol (7:3 molar ratio), DBU, an ionic liquid of indole, and ethylene glycol (7:3 molar ratio), and DBU, an ionic liquid of 1,2,4-triazole, and ethylene glycol (7:3 molar ratio).

[0051] The content ratio of the deep eutectic solvent in the entire cleaning liquid is preferably 0.00 to 98.09 mass%, more preferably 0.00 to 90.00 mass%. If the solvent ratio exceeds 98.09 mass%, the cleaning ability decreases, which is not preferable.

[0052] <Cleaning method> In the present invention, the resin is washed using the above-mentioned washing solution, and the washing method includes immersion, stirring, circulation, shaking, ultrasonic washing, jet washing, bubbling washing, water washing, compressed air, drying, etc., and the above-mentioned steps may be carried out multiple times or repeatedly. In addition, heating and pressurization may be performed during washing.

[0053] The cleaning temperature is not particularly limited as long as it is within the range of the melting point, boiling point, or decomposition point of the ionic liquid used, but is preferably 0 to 200° C., and more preferably 25 to 150° C. If the cleaning temperature is lower than 0° C., the cleaning ability of the polymer residue is reduced, which is not preferable. On the other hand, if the cleaning temperature exceeds 200° C., the operational risk increases and the handling becomes poor.

[0054] In the present invention, cleaning is preferably carried out in the following steps. (1) Immersing a nozzle or the like in the cleaning solution of the present invention (2) Ultrasonic cleaning of nozzles, etc. using the cleaning solution of the present invention (3) Rinse off any cleaning fluid adhering to the nozzles, etc. (4) Drying of nozzles, etc. EXAMPLES

[0055] The present invention will be described in detail below with reference to examples and comparative examples, but the scope of the present invention is not limited to the following examples and comparative examples. In addition, each physical property in the examples was measured by the following methods.

[0056] [Washability] The spinning holes were observed using a stereomicroscope, and the degree of fouling was evaluated according to the following classification.

[0057] Category 2: No clogging or dirt on the spinneret Category 1: Spinner holes are dirty Category 0: Spinnerhole is blocked In the above evaluation, Class 2 was given 2 points, Class 1 was given 1 point, and Class 0 was given 0 points. The score of each spinning hole in the spinneret was multiplied by the number of spinning holes that gave that score to obtain a total score, and the cleanability was calculated using the following formula. Cleanability = [(2 points x number of holes in category 2) + (1 point x number of holes in category 1) + (0 point x number of holes in category 0)] / (total number of holes x 2) If the cleaning performance value is 0.95 or more, it can be said that sufficient cleaning is achieved.

[0058] <Comparative Example 1> A polymer solution containing 93.7% by mass of N-methyl-2-pyrrolidone (NMP) as the solvent and 6.3% by mass of copolyparaphenylene-3,4'-oxydiphenylene-terephthalamide as the spinning dope was used. The spinneret, which had been used for 7 consecutive days of spinning (material: SUS316L, hole shape: circular, hole diameter: 0.2 mm, number of holes: 10), was cleaned using the following procedure.

[0059] The spinneret was washed by immersing it in 100% by mass NMP solvent for 8 hours at 90 ° C. The spinneret was then washed with water at 50 ° C., the water was removed with compressed air, and the spinneret was dried in a dryer at 120 ° C. The spinneret was observed using a stereo microscope to evaluate the cleanability, and the holes in the spinneret were clogged or many parts had dirt attached, indicating that the cleanability was insufficient.

[0060] <Comparative Example 2> The same procedure as in Comparative Example 1 was carried out, except that the cleaning method was changed from immersion to ultrasonic treatment (frequency 40 kHz, 65°C, 8 hr). As a result of observing the spinneret using a stereomicroscope, one of the holes in the spinneret was cleaned, but the others were clogged or had dirt attached thereto, and cleaning performance was insufficient.

[0061] <Comparative Example 3> The same procedure as in Comparative Example 1 was repeated, except that the cleaning liquid was changed to a 20% by mass aqueous solution of NaOH. When the spinneret was observed using a stereomicroscope, the holes in the spinneret were found to be clogged, and cleaning properties were insufficient.

[0062] <Comparative Example 4> The same procedure as in Comparative Example 2 was repeated, except that the cleaning liquid was changed to a 20% by mass aqueous solution of NaOH. When the spinneret was observed using a stereomicroscope, the holes in the spinneret were clogged or dirty, and cleaning properties were insufficient.

[0063] <Comparative Example 5> The same procedure as in Comparative Example 1 was carried out, except that the cleaning solution was changed to a cleaning solution containing 100 mass% of the ionic liquid [DBUH][OAc] by mixing diazabicycloundecene (DBU) which is a base and acetic acid (AcOH) which is an acid. When the spinneret was observed using a stereomicroscope, dirt was found to be attached to the holes of the spinneret, and cleaning properties were insufficient.

[0064] <Example 1> The same procedure as in Comparative Example 1 was carried out, except that the cleaning solution was changed to a mixture of diazabicycloundecene (DBU) as a base and acetic acid (AcOH) as an acid, containing 92% by mass of the ionic liquid [DBUH][OAc] and 8% by mass of the base DBU. Observation of the spinneret using a stereomicroscope revealed that the holes in the spinneret were cleanly cleaned, and the cleaning ability was sufficient.

[0065] <Example 2> The same procedure as in Example 1 was repeated, except that the cleaning liquid was changed to one containing 92 mass% of the ionic liquid [DBUH][OAc], 7 mass% of NaOH, and 1 mass% of water. When the spinneret was observed using a stereomicroscope, the holes in the spinneret were cleaned and the cleaning ability was sufficient.

[0066] <Example 3> The same procedure as in Example 1 was repeated, except that the cleaning method was changed from immersion to ultrasonic treatment (frequency 40 kHz, 65°C, 8 hr). When the spinneret was observed using a microscope, the holes in the spinneret were cleaned and the cleaning ability was sufficient.

[0067] <Example 4> In Example 1, the cleaning solution was ionic liquid 1-butyl-3-methylimidazolium chloride ([C 4 C 1 The same procedure as in Example 1 was carried out, except that the cleaning solution was changed to one containing 90 mass% of [IM][Cl]; manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 mass% of DBU. When the spinneret was observed using a microscope, the holes of the spinneret were thoroughly cleaned, and the cleaning ability was sufficient.

[0068] <Example 5> In Example 1, the cleaning solution was ionic liquid 1-butyl-3-methylimidazolium acetate ([C 4 C 1 The same procedure as in Example 1 was carried out, except that the cleaning solution was changed to one containing 90 mass% of [IM][OAc]; manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 mass% of DBU. When the spinneret was observed using a microscope, the holes of the spinneret were thoroughly cleaned, and the cleaning ability was sufficient.

[0069] <Example 6> The same procedure as in Example 1 was repeated, except that the cleaning solution was changed to one containing 52 mass% of the ionic liquid [DBUH][OAc], 8 mass% of DBU, and 40 mass% of DMSO. When the spinneret was observed using a stereomicroscope, the holes in the spinneret were cleaned and the cleaning ability was sufficient.

[0070] <Example 7> The same procedure as in Example 1 was repeated, except that the cleaning solution was changed to one containing 52 mass% of the ionic liquid [DBUH][OAc], 8 mass% of DBU, and 40 mass% of NMP. Observation of the spinneret using a stereomicroscope revealed that the holes in the spinneret were cleaned and the cleaning properties were sufficient. The results of the above-mentioned Examples and Comparative Examples are shown in Table 1.

[0071] [Table 1] [Industrial Applicability]

[0072] According to the present invention, in particular in the spinning of resins such as polyamide, wholly aromatic polyamide, wholly aromatic copolyamide, polyamideimide, aromatic polyamideimide, polyimide, cellulose, cellulose acetate, polyacrylonitrile, etc., it is possible to provide a cleaning liquid that can effectively clean resin adhering to spinnerets, filters, etc. after use and that allows workers to work safely, and therefore the present invention has high industrial applicability and extremely great industrial value.

Claims

1. A cleaning solution for resin washing, comprising an ionic liquid and a base, the cleaning solution having a content ratio of the ionic liquid in the entire cleaning solution of 1.00 to 99.99% by mass and a content ratio of the base in the cleaning solution of 0.01 to 50.00% by mass.

2. 2. The resin cleaning solution according to claim 1, wherein the anion of the ionic liquid is at least one anion selected from the group consisting of halides, hydroxides, alkoxides, carboxylates, carbonates, phosphates, phosphonates, sulfonates, sulfates, and nitrates.

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