Ionic liquid dissolving agent mixture as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of chemical production, and discloses an ionic liquid dissolving agent mixture as well as a preparation method and application thereof. The ionic liquid dissolving agent mixture is prepared from the following raw materials: modified long-carbon-chain imidazole tetrafluoroborate, modified long-carbon-chain imidazole long-carbon-chain anion salt, betaine salt, imidazole acetate, imidazole haloid, imidazole bis (fluorosulfonyl) imide salt, imidazole hexafluorophosphate, imidazole long-carbon-chain anion salt and quaternary ammonium long-carbon-chain anion salt. And pyridine halogen salts. When the ionic liquid dissolving agent mixture is used for dissolving PE powder and PP powder, a dichloromethane extracting agent can be replaced with water, cyclic utilization of the ionic liquid can be achieved, an original high-investment tail gas treatment device is eliminated, cost reduction and efficiency improvement are achieved for the industry, and meanwhile the performance of PE and PP diaphragms can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and particularly relates to an ionic liquid solvent mixture, a preparation method and an application thereof. Background Art

[0002] The existing wet process for lithium battery separators (as shown in Figure 1 ), or the wet process for ultra-high molecular weight polyethylene fibers (as shown in Figure 2 ), both use white oil (a liquid hydrocarbon mixture) as a solvent and a pore former, and mix and dissolve white oil and polyethylene powder (PE powder) for extrusion. After extrusion, the PE separator or PE fiber needs to be extracted and washed with solvents such as dichloromethane to remove the white oil, and a large number of rectification and tail gas treatment devices are required to achieve efficient separation and recovery of dichloromethane and white oil. However, the solubility of PE powder in white oil is not high. Moreover, the production processes of the above two PE materials both require the use of toxic and harmful dichloromethane extractants and high-energy-consuming and high-investment tail gas treatment devices. Summary of the Invention

[0003] The purpose of the present invention is to provide an ionic liquid solvent mixture, a preparation method and an application thereof, so as to solve the problems that the production processes of existing PE or PE materials both require the use of toxic and harmful dichloromethane extractants and high-energy-consuming and high-investment tail gas treatment devices.

[0004] In order to achieve the above invention purpose, the present invention provides the following technical solutions:

[0005] The present invention provides an ionic liquid solvent mixture, comprising the following raw materials in parts by mass:

[0006] 10-20 parts of modified long-chain carbon imidazole tetrafluoroborate, 10-15 parts of modified long-chain carbon imidazole long-chain anion salt, 10-15 parts of betaine salt, 5-10 parts of imidazole acetate, 10-20 parts of imidazole halide salt, 5-10 parts of imidazole bis(fluorosulfonyl)imide salt, 5-10 parts of imidazole hexafluorophosphate, 5-10 parts of imidazole long-chain anion salt, 10-20 parts of quaternary ammonium long-chain anion salt, 10-15 parts of pyridine halide salt.

[0007] Preferably, in the ionic liquid solvent mixture, the modified long-chain carbon imidazole tetrafluoroborate is composed of a modified long-chain carbon imidazole-based cation and a tetrafluoroborate-based anion;

[0008] The modified long-chain carbon imidazole long-chain anion salt is composed of a modified long-chain carbon imidazole-based cation and a long-chain-based anion;

[0009] In the modified long-chain carbon imidazole tetrafluoroborate or the modified long-chain carbon imidazole long-chain anion salt, the modified long-chain carbon imidazole-based cation is prepared by a substitution reaction of N-methylimidazole and long-chain carbon glycidyl ether.

[0010] Preferably, in the ionic liquid solvent mixture, the long-chain carbon glycidyl ether independently includes one or more of octyl glycidyl ether, decyl glycidyl ether, fatty alcohol polyoxyethylene ether, 4-nonylphenyl glycidyl ether, ethylene glycol diglycidyl ether, coconut oil glucoside, lauryl glucoside, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, castor oil triglycidyl ether, sorbitol glycidyl ether, pentaerythritol tetraglycidyl ether, dipropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, benzyl glycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, and neopentyl glycol diglycidyl ether.

[0011] Preferably, in the ionic liquid solvent mixture, the betaine salt includes citric acid betaine salt and / or salicylic acid betaine salt.

[0012] Preferably, in the ionic liquid solvent mixture, the imidazole acetate is composed of an imidazole-based cation and an acetate-based anion;

[0013] The imidazole halide salt is composed of an imidazole-based cation and a halide-based anion;

[0014] The imidazole bis(fluorosulfonyl)imide salt is composed of an imidazole-based cation and a bis(fluorosulfonyl)imide-based anion;

[0015] The imidazole hexafluorophosphate is composed of an imidazole-based cation and a hexafluorophosphate-based anion;

[0016] The imidazole long-chain anion salt is composed of an imidazole-based cation and a long-chain-based anion.

[0017] Preferably, in the ionic liquid solvent mixture, in the imidazole acetate, the imidazole halide salt, the imidazole bis(fluorosulfonyl)imide salt, the imidazole hexafluorophosphate, or the imidazole long-chain anion salt, the imidazole-based cation independently includes one or more of 1-butyl-3-methylimidazolium cation, 1-ethyl-3-methylimidazolium cation, and 1-butyl-2,3-dimethylimidazolium cation.

[0018] Preferably, in the ionic liquid solvent mixture, the quaternary ammonium long-chain anion salt is composed of a quaternary ammonium-based cation and a long-chain-based anion;

[0019] The quaternary ammonium cations include one or more of N,N-dimethylbenzylammonium cations, triethanolamine cations, diethanolamine cations, dimethylammonium cations, and ammonium ions;

[0020] In the modified long-chain imidazole long-chain anion salt, the imidazole long-chain anion salt, or the quaternary ammonium long-chain anion salt, the long-chain alkyl anions independently include one or more of dodecylsulfonate, dodecylbenzenesulfonate, dodecanoate, tetradecanoate, hexadecanoate, octadecanoate, octadecenoate, hexadecenoate, and docosahexaenoate.

[0021] Preferably, in the ionic liquid solvent mixture, the pyridine halide salt is composed of a pyridinium cation and a halogen anion;

[0022] The pyridinium cations include one or more of N-methylpyridinium cations, N-ethylpyridinium cations, and N-butylpyridinium cations;

[0023] In the imidazole halide salt or the pyridine halide salt, the halogen anions independently include one or more of bromide ions, chloride ions, iodide ions, and fluoride ions.

[0024] The present invention also provides a method for preparing an ionic liquid solvent mixture, comprising the following steps:

[0025] According to the mass parts, mix modified long-chain imidazole tetrafluoroborate, modified long-chain imidazole long-chain anion salt, betaine salt, imidazole acetate, imidazole halide salt, imidazole bis(fluorosulfonyl)imide salt, imidazole hexafluorophosphate, imidazole long-chain anion salt, quaternary ammonium long-chain anion salt, and pyridine halide salt to obtain an ionic liquid solvent mixture.

[0026] The present invention also provides an application of the ionic liquid solvent mixture in dissolving polyethylene, polypropylene, or polyurethane.

[0027] Through the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Under the condition of 200 °C, the ionic liquid solvent mixture prepared in this application can dissolve polyethylene with a molecular weight of 10 million and a mass fraction of more than 15%. In contrast, white oil can only dissolve 5-7%. The solubility is doubled. Using the ionic liquid solvent mixture of this application to dissolve polyethylene under the same process treatment can improve the production capacity and reduce the extraction treatment volume. At the same time, the ionic liquid solvent mixture provided in this application can also effectively dissolve polypropylene or polyurethane, and can further prepare a polypropylene diaphragm (the process is as Figure 6 shown), and has broad application prospects.

[0029] (2) After dissolving PE powder with the ionic liquid solvent mixture of the present application, casting or spinning can be carried out. The cast film or PE fibers are extracted with ethanol, water or dichloromethane to remove the ionic liquid, and a separator or polyethylene fibers are prepared. The process is as Figure 3 (or Figure 5 ) Figure 4 shown. Extraction and washing are carried out with ethanol, water or dichloromethane. The extracted ionic liquid is concentrated and purified to separate the extractant and the ionic liquid, thereby realizing the recycling of the ionic liquid. Moreover, the original high-investment tail gas treatment device is eliminated, solving the problem that the wet process for preparing lithium battery separators or the wet process for preparing ultra-high molecular weight polyethylene fibers requires high-energy-consuming and high-investment equipment after being dissolved with white oil. The extractant can also be replaced with water to reduce costs and increase efficiency for the industry. At the same time, before the existing device is depreciated, the existing distillation device can be used to carry out extraction and separation with dichloromethane or ethanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art.

[0031] Figure 1 It is a schematic diagram of the wet process for preparing a lithium battery separator by dissolving polyethylene with white oil;

[0032] Figure 2 It is a schematic diagram of the wet process for preparing polyethylene fibers by dissolving polyethylene with white oil;

[0033] Figure 3 It is a schematic diagram of the wet process for preparing a lithium battery separator by dissolving polyethylene with an ionic liquid solvent mixture;

[0034] Figure 4 It is a schematic diagram of the wet process for preparing polyethylene fibers by dissolving polyethylene with an ionic liquid solvent mixture;

[0035] Figure 5 It is a schematic diagram of the wet process for preparing a lithium battery separator by dissolving polyethylene with an ionic liquid solvent mixture;

[0036] Figure 6 It is a schematic diagram of the wet process for preparing a separator by dissolving polypropylene with an ionic liquid solvent mixture;

[0037] Figure 7 It is an apparent diagram of the mixed system after cooling after dissolving 20 wt% of polyethylene with a weight average molecular weight of 1 million;

[0038] Figure 8 It is an apparent diagram of the mixed system after cooling after dissolving polyethylene in Application Example 1;

[0039] Figure 9 Apparent diagram after cooling of the mixed system after dissolving polyethylene in Application Example 2;

[0040] Figure 10 Apparent diagram after cooling of the mixed system after dissolving polyethylene in Application Example 3;

[0041] Figure 11 Apparent diagram after cooling of the mixed system after dissolving polyethylene in Application Example 4;

[0042] Figure 12 Apparent diagram after cooling of the mixed system after dissolving polypropylene in Application Example 5;

[0043] Figure 13 Apparent diagram after cooling of the mixed system after dissolving polypropylene in Application Example 6;

[0044] Figure 14 Apparent diagram after cooling of the mixed system after dissolving polyethylene in Comparative Application Example 1. Detailed implementation mode

[0045] The present invention provides an ionic liquid solvent mixture, comprising raw materials in the following parts by mass:

[0046] 10 - 20 parts of modified long-chain carbon imidazole tetrafluoroborate, 10 - 15 parts of modified long-chain carbon imidazole long-chain anion salt, 10 - 15 parts of betaine salt, 5 - 10 parts of imidazole acetate, 10 - 20 parts of imidazole halide salt, 5 - 10 parts of imidazole bis(fluorosulfonyl)imide salt, 5 - 10 parts of imidazole hexafluorophosphate, 5 - 10 parts of imidazole long-chain anion salt, 10 - 20 parts of quaternary ammonium long-chain anion salt, 10 - 15 parts of pyridine halide salt.

[0047] In the present invention, the modified long-chain carbon imidazole tetrafluoroborate preferably consists of a modified long-chain carbon imidazole-based cation and a tetrafluoroborate-based anion.

[0048] In the present invention, the modified long-chain carbon imidazole long-chain anion salt preferably consists of a modified long-chain carbon imidazole-based cation and a long-chain-based anion.

[0049] In the present invention, in the modified long-chain carbon imidazole tetrafluoroborate or the modified long-chain carbon imidazole long-chain anion salt, the modified long-chain carbon imidazole-based cation is preferably prepared by a substitution reaction of N-methylimidazole and long-chain glycidyl ether.

[0050] In the present invention, the substitution reaction preferably includes the following steps: mixing N-methylimidazole and long-chain glycidyl ether for a substitution reaction.

[0051] In the present invention, the long-chain glycidyl ether preferably independently includes one or more of octyl glycidyl ether, decyl glycidyl ether, fatty alcohol polyoxyethylene ether, 4-nonylphenyl glycidyl ether, ethylene glycol diglycidyl ether, coconut glucoside, lauryl glucoside, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, castor oil triglycidyl ether, sorbitol glycidyl ether, pentaerythritol tetraglycidyl ether, dipropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, benzyl glycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether; further preferably includes one or more of octyl glycidyl ether, decyl glycidyl ether, 4-nonylphenyl glycidyl ether, ethylene glycol diglycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, castor oil triglycidyl ether, sorbitol glycidyl ether, pentaerythritol tetraglycidyl ether, dipropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether; more preferably includes one or more of octyl glycidyl ether, decyl glycidyl ether, 4-nonylphenyl glycidyl ether.

[0052] In the present invention, the molar ratio of the N-methylimidazole to the long-chain glycidyl ether is preferably 1:1.01 to 1:1.05, further preferably 1:1.02 to 1:1.04, and more preferably 1:1.03.

[0053] In the present invention, the temperature of the substitution reaction is preferably 50 to 80 °C, further preferably 55 to 65 °C, and more preferably 60 °C; the time of the substitution reaction is preferably 2 to 4 h, further preferably 2.5 to 3.5 h, and more preferably 3 h.

[0054] In the present invention, the betaine salt preferably includes citric acid betaine salt and / or salicylic acid betaine salt, and further preferably citric acid betaine salt.

[0055] In the present invention, the imidazole acetate is preferably composed of an imidazolium cation and an acetate anion.

[0056] In the present invention, the imidazole halide salt is preferably composed of an imidazolium cation and a halide anion.

[0057] In the present invention, the imidazole bis(fluorosulfonyl)imide salt is preferably composed of an imidazolium cation and a bis(fluorosulfonyl)imide anion.

[0058] In the present invention, the imidazole hexafluorophosphate preferably consists of an imidazolium cation and a hexafluorophosphate anion.

[0059] In the present invention, the imidazole long-chain anion salt preferably consists of an imidazolium cation and a long-chain anion.

[0060] In the present invention, among the imidazole acetate, the imidazole halide, the imidazole bis(fluorosulfonyl)imide salt, the imidazole hexafluorophosphate or the imidazole long-chain anion salt, the imidazolium cation preferably independently includes one or more of 1-butyl-3-methylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, more preferably includes 1-butyl-3-methylimidazolium cation, 1-ethyl-3-methylimidazolium cation or 1-butyl-2,3-dimethylimidazolium cation, and even more preferably is 1-ethyl-3-methylimidazolium cation.

[0061] In the present invention, the quaternary ammonium long-chain anion salt preferably consists of a quaternary ammonium cation and a long-chain anion.

[0062] In the present invention, the quaternary ammonium cation preferably includes one or more of N,N-dimethylbenzylammonium cation, triethanolammonium cation, diethanolammonium cation, dimethylammonium cation, ammonium ion, more preferably includes one or more of N,N-dimethylbenzylammonium cation, dimethylammonium cation, ammonium ion, and even more preferably includes N,N-dimethylbenzylammonium cation and / or dimethylammonium cation.

[0063] In the present invention, among the modified long-chain imidazole long-chain anion salt, the imidazole long-chain anion salt or the quaternary ammonium long-chain anion salt, the long-chain anion preferably independently includes one or more of dodecylsulfonate, dodecylbenzenesulfonate, dodecanoate, tetradecanoate, hexadecanoate, octadecanoate, octadecenoate, hexadecenoate, docosahexaenoate, more preferably includes one or more of dodecylsulfonate, dodecylbenzenesulfonate, octadecenoate, hexadecenoate, docosahexaenoate, and even more preferably includes dodecylsulfonate and / or dodecylbenzenesulfonate.

[0064] In the present invention, the pyridine halide preferably consists of a pyridinium cation and a halide anion.

[0065] In the present invention, in the pyridine halide, the pyridinium cation preferably includes one or more of N-methylpyridinium cation, N-ethylpyridinium cation, N-butylpyridinium cation, more preferably includes N-methylpyridinium cation, N-ethylpyridinium cation or N-butylpyridinium cation, and even more preferably is N-methylpyridinium cation.

[0066] In the present invention, in the imidazole halide salt or the pyridine halide salt, the halogen-based anion preferably independently includes one or more of bromide ion, chloride ion, iodide ion, and fluoride ion, more preferably includes bromide ion, chloride ion, iodide ion, or fluoride ion, and still more preferably is bromide ion.

[0067] In the present invention, the mass fraction of the modified long-chain carbon imidazole tetrafluoroborate is preferably 12 to 18 parts, more preferably 14 to 16 parts, and still more preferably 15 parts.

[0068] In the present invention, the mass fraction of the modified long-chain carbon imidazole long-chain carbon anion salt is preferably 11 to 15 parts, more preferably 12 to 14 parts, and still more preferably 13 parts.

[0069] In the present invention, the mass fraction of the betaine salt is preferably 11 to 15 parts, more preferably 12 to 14 parts, and still more preferably 13 parts.

[0070] In the present invention, the mass fraction of the imidazole acetate is preferably 6 to 10 parts, more preferably 7 to 9 parts, and still more preferably 8 parts.

[0071] In the present invention, the mass fraction of the imidazole halide salt is preferably 12 to 18 parts, more preferably 14 to 16 parts, and still more preferably 15 parts.

[0072] In the present invention, the mass fraction of the imidazole bis(fluorosulfonyl)imide salt is preferably 6 to 10 parts, more preferably 7 to 9 parts, and still more preferably 8 parts.

[0073] In the present invention, the mass fraction of the imidazole hexafluorophosphate is preferably 6 to 10 parts, more preferably 7 to 9 parts, and still more preferably 8 parts.

[0074] In the present invention, the mass fraction of the imidazole long-chain carbon anion salt is preferably 6 to 10 parts, more preferably 7 to 9 parts, and still more preferably 8 parts.

[0075] In the present invention, the mass fraction of the quaternary ammonium long-chain carbon anion salt is preferably 12 to 18 parts, more preferably 14 to 16 parts, and still more preferably 15 parts.

[0076] In the present invention, the mass fraction of the pyridine halide salt is preferably 11 to 15 parts, more preferably 12 to 14 parts, and still more preferably 13 parts.

[0077] The present invention also provides a preparation method of an ionic liquid solvent mixture, comprising the following steps:

[0078] According to the parts by mass, a modified long-chain carbon imidazole tetrafluoroborate, a modified long-chain carbon imidazole long-chain carbon anion salt, a betaine salt, an imidazole acetate, an imidazole halide, an imidazole bis(fluorosulfonyl)imide salt, an imidazole hexafluorophosphate, an imidazole long-chain carbon anion salt, a quaternary ammonium long-chain carbon anion salt, and a pyridine halide are mixed to obtain an ionic liquid solvent mixture.

[0079] In the present invention, the mixing method preferably includes the following steps:

[0080] The modified long-chain carbon imidazole tetrafluoroborate, the modified long-chain carbon imidazole long-chain carbon anion salt, the betaine salt, the imidazole acetate, and the imidazole halide are subjected to a first mixing; an imidazole bis(fluorosulfonyl)imide salt, an imidazole hexafluorophosphate, an imidazole long-chain carbon anion salt, and a quaternary ammonium long-chain carbon anion salt are added to the material obtained from the first mixing for a second mixing; and a pyridine halide is added to the material obtained from the second mixing for a third mixing.

[0081] In the present invention, the temperature of the first mixing is preferably 50 to 80 °C, more preferably 55 to 65 °C, and even more preferably 60 °C; the time of the first mixing is preferably 20 to 60 min, more preferably 25 to 40 min, and even more preferably 30 min.

[0082] In the present invention, the temperature of the second mixing is preferably 50 to 80 °C, more preferably 55 to 70 °C, and even more preferably 60 °C; the time of the second mixing is preferably 20 to 60 min, more preferably 25 to 35 min, and even more preferably 30 min.

[0083] In the present invention, the temperature of the third mixing is preferably 50 to 80 °C, more preferably 55 to 65 °C, and even more preferably 60 °C; the time of the third mixing is preferably 20 to 60 h, more preferably 25 to 35 h, and even more preferably 30 h.

[0084] The present invention also provides an application of the ionic liquid solvent mixture in dissolving polyethylene, polypropylene, or polyurethane.

[0085] In the present invention, the mass ratio of the ionic liquid solvent mixture to the polyethylene, the ionic liquid solvent mixture to the polypropylene, or the ionic liquid solvent mixture to the polyurethane is independently preferably 9 to 8:1 to 2, more preferably 8.8 to 8.2:1.2 to 1.8, and even more preferably 8.5:1.5.

[0086] In the present invention, when the ionic liquid solvent mixture dissolves polyethylene, the conditions include: the temperature is preferably 160 - 210 °C, more preferably 180 - 210 °C, and even more preferably 180 °C; the time is preferably 5 - 10 min, more preferably 5 - 8 min, and even more preferably 5 min.

[0087] In the present invention, the weight-average molecular weight of the polyethylene, polypropylene or polyurethane is preferably 600,000 - 10,000,000, more preferably 1,500,000 - 6,000,000, and even more preferably 6,000,000.

[0088] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0089] Example 1

[0090] This example provides an ionic liquid solvent mixture, which contains the following raw materials in parts by mass:

[0091] 10 parts of modified long-chain carbon imidazole tetrafluoroborate, 10 parts of modified long-chain carbon imidazole dodecyl sulfonate, 10 parts of citric acid betaine salt, 5 parts of 1-butyl-3-methylimidazole acetate, 15 parts of 1-butyl-3-methylimidazole bromide, 5 parts of 1-butyl-3-methylimidazole bis(fluorosulfonyl)imide salt, 5 parts of 1-butyl-3-methylimidazole hexafluorophosphate, 5 parts of 1-butyl-3-methylimidazole dodecyl sulfonate, 10 parts of triethanolamine dodecyl sulfonate, 10 parts of N-methylpyridine bromide;

[0092] Among them, the cation in the modified long-chain carbon imidazole tetrafluoroborate is prepared by feeding N-methylimidazole and 4-nonylphenyl glycidyl ether in a molar ratio of 1:1.02, heating to 60 °C, and reacting for 3 h.

[0093] The cation in the modified long-chain carbon imidazole dodecyl sulfonate is prepared by feeding N-methylimidazole and 4-nonylphenyl glycidyl ether in a molar ratio of 1:1.02, heating to 60 °C, and reacting for 3 h.

[0094] This example also provides a preparation method of the ionic liquid solvent mixture, which includes the following steps:

[0095] By mass parts, first add modified long-chain carbon imidazole tetrafluoroborate, modified long-chain carbon imidazole dodecyl sulfonate, citric acid betaine salt, 1-butyl-3-methylimidazole acetate, 1-butyl-3-methylimidazole bromide, heat up to 60 °C and react for 30 min, then add 1-butyl-3-methylimidazole bis(fluorosulfonyl)imide salt, 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-3-methylimidazole dodecyl sulfonate, triethanolamine dodecyl sulfonate, react at 60 °C for 30 min, and finally add N-methylpyridine bromide, use mechanical stirring, and react at 60 °C for 24 h to obtain an ionic liquid solvent mixture.

[0096] Example 2

[0097] This example provides an ionic liquid solvent mixture (the preparation method refers to Example 1), which contains the following raw materials in mass parts:

[0098] 15 parts of modified long-chain carbon imidazole tetrafluoroborate, 10 parts of modified long-chain carbon imidazole hexadecanoate, 10 parts of salicylic acid betaine salt, 5 parts of 1-ethyl-3-methylimidazole acetate, 10 parts of 1-ethyl-3-methylimidazole chloride, 5 parts of 1-ethyl-3-methylimidazole bis(fluorosulfonyl)imide salt, 5 parts of 1-ethyl-3-methylimidazole hexafluorophosphate, 5 parts of 1-ethyl-3-methylimidazole dodecyl sulfonate, 10 parts of diethanolamine dodecyl sulfonate, 15 parts of N-methylpyridine chloride;

[0099] Among them, the cation in the modified long-chain carbon imidazole tetrafluoroborate is prepared by feeding N-methylimidazole and octyl glycidyl ether in a molar ratio of 1:1.05, heating up to 60 °C, and reacting for 3 h;

[0100] The cation in the modified long-chain carbon imidazole hexadecanoate is prepared by feeding N-methylimidazole and octyl glycidyl ether in a molar ratio of 1:1.05, heating up to 60 °C, and reacting for 3 h;

[0101] Example 3

[0102] This example provides an ionic liquid solvent mixture (the preparation method refers to Example 1), which contains the following raw materials in mass parts:

[0103] 12 parts of modified long-chain carbon imidazole tetrafluoroborate, 12 parts of modified long-chain carbon imidazole dodecylbenzenesulfonate, 10 parts of salicylic acid betaine salt, 8 parts of 1-butyl-2,3-dimethylimidazole acetate, 10 parts of 1-butyl-2,3-dimethylimidazole iodide, 8 parts of 1-butyl-2,3-dimethylimidazole bis(fluorosulfonyl)imide salt, 5 parts of 1-butyl-2,3-dimethylimidazole hexafluorophosphate, 5 parts of 1-butyl-2,3-dimethylimidazole dodecylbenzenesulfonate, 10 parts of triethanolamine dodecylbenzenesulfonate, 10 parts of N-ethylpyridine iodide;

[0104] Among them, the cation in the modified long carbon chain imidazole tetrafluoroborate is prepared by feeding N-methylimidazole and dodecyl glycidyl ether in a molar ratio of 1:1.03, heating to 60 °C, and reacting for 3 h;

[0105] Among them, the cation in the modified long carbon chain imidazole dodecylbenzenesulfonate is prepared by feeding N-methylimidazole and dodecyl glycidyl ether in a molar ratio of 1:1.03, heating to 60 °C, and reacting for 3 h;

[0106] Example 4

[0107] This example provides an ionic liquid solvent mixture (the preparation method refers to Example 1), which contains the following raw materials in parts by mass:

[0108] 15 parts of modified long carbon chain imidazole tetrafluoroborate, 15 parts of modified long carbon chain imidazole hexadecenoate, 10 parts of citric acid betaine salt, 5 parts of 1-ethyl-3-methylimidazole acetate, 10 parts of 1-ethyl-3-methylimidazole bromide, 5 parts of 1-ethyl-3-methylimidazole bis(fluorosulfonyl)imide salt, 5 parts of 1-ethyl-3-methylimidazole hexafluorophosphate, 5 parts of 1-ethyl-3-methylimidazole dodecylbenzenesulfonate, 10 parts of diethanolamine dodecylbenzenesulfonate, 10 parts of N-butylpyridinium bromide;

[0109] Among them, the cation in the modified long carbon chain imidazole tetrafluoroborate is prepared by feeding N-methylimidazole and diethylene glycol diglycidyl ether in a molar ratio of 1:1.01, heating to 60 °C, and reacting for 3 h;

[0110] Among them, the cation in the modified long carbon chain imidazole hexadecenoate is prepared by feeding N-methylimidazole and diethylene glycol diglycidyl ether in a molar ratio of 1:1.01, heating to 60 °C, and reacting for 3 h;

[0111] Application Example 1

[0112] Add 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 600,000 weight average molecular weight PE powder into a round bottom flask, place it in an oil bath for heating, use a mechanical stirrer for stirring, raise the temperature to 180 °C and react for 5 min, and the PE powder is completely dissolved, as Figure 8 shown.

[0113] Application Example 2

[0114] Add 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 2,000,000 weight average molecular weight PE powder into a round bottom flask, place it in an oil bath for heating, use a mechanical stirrer for stirring, raise the temperature to 180 °C and react for 5 min, and the PE powder is completely dissolved, as Figure 9as shown

[0115] Application Example 3

[0116] 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 6 million weight-average molecular weight PE powder were added to a round-bottom flask, placed in an oil bath and heated, stirred using a mechanical stirrer, the temperature was raised to 210 °C and reacted for 5 min, and the PE powder was completely dissolved, as Figure 10 as shown

[0117] Application Example 4

[0118] 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 10 million weight-average molecular weight PE powder were added to a round-bottom flask, placed in an oil bath and heated, stirred using a mechanical stirrer, the temperature was raised to 210 °C and reacted for 5 min, and the PE powder was completely dissolved, as Figure 11 as shown

[0119] Application Example 5

[0120] 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 1.5 million weight-average molecular weight polypropylene (PP) powder were added to a round-bottom flask, placed in an oil bath and heated, stirred using a mechanical stirrer, the temperature was raised to 160 °C and reacted for 5 min, and the PP powder was completely dissolved, as Figure 12 as shown

[0121] Application Example 6

[0122] 85 parts by mass of the ionic liquid solvent mixture of Example 1 and 15 parts by mass of 600,000 weight-average molecular weight polypropylene (PP) powder were added to a round-bottom flask, placed in an oil bath and heated, stirred using a mechanical stirrer, the temperature was raised to 180 °C and reacted for 5 min, and the PP powder was completely dissolved, as Figure 13 as shown

[0123] Comparative Application Example 1

[0124] 85 parts by mass of white oil (Zhejiang Zhengxin Petroleum Technology Co., Ltd., No. 50 white oil) and 15 parts by mass of 600,000 weight-average molecular weight PE powder were added to a round-bottom flask, placed in an oil bath and heated, stirred using a mechanical stirrer, the temperature was raised to 220 °C and reacted for 5 min, and the PE powder was completely dissolved, as Figure 14 as shown

[0125] Comparative Application Example 2

[0126] 85 parts by mass of white oil (No. 50 white oil, Zhejiang Zhengxin Petroleum Technology Co., Ltd.) and 15 parts by mass of PP powder with a weight-average molecular weight of 600,000 were added to a round-bottom flask, placed in an oil bath for heating, and stirred using a mechanical stirrer. The temperature was raised to 220 °C and reacted for 5 min, and the PP powder was completely dissolved.

[0127] Film-making process: 85 parts by mass of ionic liquid solvent mixture / white oil and 15 parts by mass of PE powder / PP powder were used. The temperature was raised to 180 °C in an extruder to extrude and form a separator. Refer to GB / T 1040.3-2006 "Testing of Tensile Properties of Plastics" to test the tensile strength of the obtained film materials. The results are shown in Table 1.

[0128] Table 1. Comparison table of the dissolution of PE and PP by ionic liquid solvent mixture and white oil and the film-making effect

[0129]

[0130]

[0131] As can be seen from Table 1, the tensile strength of the PE powder and PP powder dissolved by the ionic liquid solvent mixture is greater than that of the PE powder and PP powder dissolved by white oil, indicating that the ionic liquid solvent mixture can replace white oil as the solvent for dissolving PE powder and PP powder.

[0132] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An ionic liquid solvent mixture, characterized in that Contains the following raw materials in parts by weight: 10-20 parts of modified long carbon chain imidazole tetrafluoroborate, 10-15 parts of modified long carbon chain imidazole long carbon chain anion salt, 10-15 parts of betaine salt, 5-10 parts of imidazole acetate, 10-20 parts of imidazole halogen salt, 5-10 parts of imidazole bisfluorosulfonyl imide salt, 5-10 parts of imidazole hexafluorophosphate, 5-10 parts of imidazole long carbon chain anion salt, 10-20 parts of quaternary ammonium long carbon chain anion salt, and 10-15 parts of pyridine halogen salt.

2. An ionic liquid solvent mixture according to claim 1, characterized in that: The modified long carbon chain imidazole tetrafluoroborate is composed of a modified long carbon chain imidazole cation and a tetrafluoroborate anion; The modified long carbon chain imidazole long carbon chain anion salt is composed of a modified long carbon chain imidazole-based cation and a long carbon chain-based anion; In the modified long-chain imidazole tetrafluoroborate or the modified long-chain imidazole long-chain anion salt, the modified long-chain imidazole cation is prepared by a substitution reaction between N-methylimidazole and a long-chain glycidyl ether.

3. An ionic liquid solvent mixture according to claim 2, characterized in that: The long carbon chain glycidyl ether independently includes one or more of octyl glycidyl ether, decyl glycidyl ether, fatty alcohol polyoxyethylene ether, 4-nonylbenzene glycidyl ether, ethylene glycol diglycidyl ether, coconut oil glucoside, lauryl glucoside, carbon undecyl glycidyl ether, carbon dodecyl glycidyl ether, carbon tridecyl glycidyl ether, carbon tetradecyl glycidyl ether, castor oil triglycidyl ether, sorbitol glycidyl ether, pentaerythritol tetraglycidyl ether, dipropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, benzyl glycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, and neopentyl glycol diglycidyl ether.

4. An ionic liquid solvent mixture according to claim 1, characterized in that: The betaine salts include betaine citric acid salt and / or betaine salicylic acid salt.

5. The ionic liquid solvent mixture according to claim 1, characterized in that: The imidazole acetate is composed of an imidazole cation and an acetate anion; The imidazolium halogen salt is composed of an imidazolium cation and a halogen anion; The imidazolium bis(fluorosulfonyl)imide salt is composed of an imidazolium cation and a bis(fluorosulfonyl)imide anion; The imidazolium hexafluorophosphate is composed of an imidazolium cation and a hexafluorophosphate anion; The imidazolium long carbon chain anion salt is composed of an imidazolium-based cation and a long carbon chain-based anion.

6. An ionic liquid solvent mixture according to claim 5, characterized in that: In the imidazolium acetate, the imidazolium halogen salt, the imidazolium bis(fluorosulfonyl)imide salt, the imidazolium hexafluorophosphate or the imidazolium long carbon chain anion salt, the imidazolium-based cation independently includes one or more of a 1-butyl-3-methylimidazolium cation, a 1-ethyl-3-methylimidazolium cation and a 1-butyl-2,3-dimethylimidazolium cation.

7. An ionic liquid solvent mixture according to claim 2, 5 or 6, characterized in that: The quaternary ammonium long carbon chain anion salt is composed of a quaternary ammonium cation and a long carbon chain anion; The quaternary ammonium cation includes one or more of N,N-dimethylbenzylammonium cation, triethanolamine cation, diethanolamine cation, dimethylammonium cation, and ammonium ion; In the modified long-chain imidazole long-chain anion salt, the imidazole long-chain anion salt or the quaternary ammonium long-chain anion salt, the long-chain base anion independently includes one or more of dodecyl sulfonate, dodecylbenzene sulfonate, dodecanoate, tetradecanoate, hexadecanoate, octadecanoate, octadecenoate, hexadecenoate, and docosahexaenoate.

8. An ionic liquid solvent mixture according to claim 5, characterized in that: The pyridinium halogen salt is composed of a pyridyl cation and a halogen anion; The pyridyl cation includes one or more of N-methylpyridinium cation, N-ethylpyridinium cation, and N-butylpyridinium cation; In the imidazolium halogen salt or the pyridinium halogen salt, the halogen-based anions independently include one or more of bromide ions, chloride ions, iodide ions, and fluoride ions.

9. The method for preparing an ionic liquid solvent mixture according to any one of claims 1 to 8, characterized in that: The following steps are involved: According to the mass fractions, modified long carbon chain imidazole tetrafluoroborate, modified long carbon chain imidazole long carbon chain anion salt, betaine salt, imidazole acetate, imidazole halogen salt, imidazole bisfluorosulfonyl imide salt, imidazole hexafluorophosphate, imidazole long carbon chain anion salt, quaternary ammonium long carbon chain anion salt, and pyridinium halogen salt are mixed to obtain an ionic liquid solvent mixture.

10. Use of an ionic liquid solvent mixture according to any one of claims 1 to 8 or an ionic liquid solvent mixture prepared by the preparation method according to claim 9 in dissolving polyethylene, polypropylene or polyurethane.

Images