Low-temperature heat-conducting oil based on ionic liquid and method for preparing same

Abstract

The application discloses a kind of low temperature heat conducting oil based on ionic liquid and preparation method, including: ionic liquid eutectic component 90-98 parts by weight, cleaning dispersant 2-10 parts;Ionic liquid eutectic component is the eutectic of binary or multi-ion liquid mixture.Formed.The application has higher safety, product toxicity is small, can obtain raw material is wide, low in price;Prepared heat conducting oil thermal stability is good, freezing temperature can be as low as-100 DEG C, low temperature viscosity is small, vapor pressure is extremely low, thermal efficiency is high, and cold quantity transmission efficiency is excellent, and low temperature performance is excellent.In addition to the above performance advantages, it also has the advantages of more than 10 years of service life, not easy to coke, and can reduce pollutant emissions, energy saving and environmental protection, widely used, can also be used as ultra-low temperature electrolyte and other low temperature working fluid, etc..

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat conducting oil, in particular to a low-temperature heat conducting oil based on ionic liquid and a preparation method thereof. BACKGROUND

[0002] Heat conducting oil is also known as heat conducting oil, heat conducting oil, etc. It is a kind of heat transfer medium. Due to its characteristics of uniform heating, accurate temperature control, high temperature and low temperature under low steam pressure, good heat transfer effect, energy saving, convenient transportation and operation, etc., it has been widely used in energy industry, petrochemical industry, life system, fine chemical industry and other fields in recent years.

[0003] The ultra-low temperature heat conducting oil (<-40 DEG C) is needed in the fields of chemical fiber manufacturing, pharmaceuticals, fine chemicals, etc. The minimum temperature of conventional low-temperature heat conducting oil is usually about-30 DEG C, so it is difficult to meet the market demand. Due to the limitation of the properties of raw materials and other factors, it is difficult to further break through the low temperature of ordinary heat conducting oil. The minimum temperature in highland area can reach-60 DEG C every year. The extreme low temperature environment puts forward very high requirements for military equipment. The heat conducting oil commonly used for lubrication and heat dissipation will be frozen into solid, and the evaporation speed is fast, which can not meet the high mobility required by weapon equipment. Therefore, it is urgent to develop an ultra-low temperature heat conducting oil with excellent comprehensive performance. SUMMARY

[0004] The present application provides a low-temperature heat conducting oil based on ionic liquid with a freezing temperature as low as-100 DEG C, low cost and long service life, and a preparation method thereof.

[0005] The technical scheme adopted by the present application is:

[0006] A low-temperature heat conducting oil based on ionic liquid, including 90-98 parts of ionic liquid eutectic component and 2-10 parts of cleaning dispersant by weight.

[0007] Further, the ionic liquid mixture is composed of one or both of the proton type and the aprotic type ionic liquid.

[0008] Further, the ionic liquid eutectic component contains at least one of the following cations: heterocyclic pyridinium ion, piperidinium ion, pyrrolidinium ion, imidazolium ion, triazole ion, benzimidazolium ion, benzotriazolium ion, phosphine-based cation, quaternary phosphonium cation, amine-based cation, quaternary ammonium cation, triethanolamine cation, tetraethanolammonium cation, guanidino cation.

[0009] Further, the ionic liquid eutectic component contains at least one of the following anions: methanesulfonate ion, trifluoromethylsulfonate ion, bis(trifluoromethylsulfonyl)imide anion, bis(fluorosulfonyl)imide anion, bis(perfluoroethanesulfonyl)imide anion, thiocyanate ion, dicyanamide ion, tricyanion, acetate ion, saturated fatty acid ion, trifluoroacetate ion, fluorosulfonate ion, hydrogen sulfate ion, sulfate ion, p-alkylbenzenesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, perfluorobutylsulfonate ion, perfluorooctylsulfonate ion, cyclic perfluoroalkylsulfonylimide anion, and halide ion.

[0010] Further, the cleaning dispersant is one of gamma-butyrolactone, petroleum sulfonate, synthetic sulfonate, sulfur-phosphorus polyisobutylene salt, alkyl salicylate, naphthenate, alkenyl butanediol imine, one of sulfided alkyl phenate, a mixture of two or more in any ratio.

[0011] Further, the ionic liquid eutectic component is a mixture of trioctylamine methanesulfonate and trimethylbutylammonium bis(trifluoromethylsulfonyl)imide salt; wherein the trioctylamine methanesulfonate is prepared by mixing trioctylamine and methanesulfonic acid in an equimolar ratio.

[0012] A preparation method of an ionic liquid-based low-temperature heat conducting oil, comprising the following steps:

[0013] Step 1: adding a cleaning dispersant to the molten ionic liquid eutectic component, and mechanically stirring for 1-7 hours to fully mix and uniform;

[0014] Step 2: placing at normal pressure and room temperature for 2-8 hours to obtain the required ionic liquid-based low-temperature heat conducting oil.

[0015] The present application has the following advantages:

[0016] (1) The hydrogen bond donor and the hydrogen bond acceptor in the ionic liquid eutectic component form a hydrogen bond, which can significantly reduce the freezing point of the eutectic component; the low eutectic component has strong hydrogen bonding, and the freezing point of the formed eutectic component is low to meet the actual demand;

[0017] (2) The present application has high safety, low product toxicity, wide available raw materials, and low price;

[0018] (3) The heat conducting oil has good thermal stability, low viscosity at low temperature, extremely low vapor pressure, high thermal efficiency, high cold transfer efficiency, excellent low temperature performance, long service life, is not easy to coking, can reduce pollutant emissions, is safe and environmentally friendly, and has wide application. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1A schematic diagram of the principle of the ionic liquid eutectic component in the application.

[0020] Figure 2 A differential scanning calorimetry curve of the main components of the heat conducting oil obtained by the embodiment of the application. DETAILED DESCRIPTION

[0021] The application will be further described below in combination with specific drawings and embodiments.

[0022] An ionic liquid-based low-temperature heat conducting oil, comprising 90-98 parts by weight of an ionic liquid eutectic component and 2-10 parts by weight of a cleaning dispersant; wherein the ionic liquid eutectic component is a eutectic formed by a binary or multi-component ionic liquid mixture.

[0023] The ionic liquid mixture is composed of one or both of a protic ionic liquid and an aprotic ionic liquid. The ionic liquid eutectic component contains at least one of the following cations: heterocyclic pyridinium ion, piperidinium ion, pyrrolidinium ion, imidazolium ion, triazolium ion, benzimidazolium ion, benzotriazolium ion, phosphine-based cation, quaternary phosphonium cation, amine-based cation, quaternary ammonium cation, triethanolamine cation, tetraethanolammonium cation, guanidinium cation. The ionic liquid eutectic component contains at least one of the following anions: methyl sulfonate ion (CH3SO3 - ), trifluoromethyl sulfonate ion (CF3SO3 - ), bis(trifluoromethylsulfonyl)imide anion, bis(fluorosulfonyl)imide anion, bis(perfluoroethanesulfonyl)imide anion, thiocyanate ion (SCN - ), dicyanamide ion (DCA - ), tricyanide ion (TCM - ), acetate ion, saturated fatty acid ion, trifluoroacetate ion, fluorosulfonate ion, bisulfate ion, sulfate ion, p-alkylbenzenesulfonate ion, tetrafluoroborate ion, hexafluorophosphate ion, perfluorobutylsulfonate ion, perfluorooctylsulfonate ion, cyclic perfluoroalkylsulfonylimide anion, and one or more halide ions. The ionic liquid eutectic component is an electrically neutral molten salt composed of at least one of the above cations and at least one of the above anions.

[0024] The cleaning dispersant is one of γ-butyrolactone, petroleum sulfonate, synthetic sulfonate, sulfur-phosphorus polyisobutylene salt, alkyl salicylate, naphthenate, alkenyl butanediol imine, sulfurized alkyl phenate, or a mixture of two or more thereof in any ratio.

[0025] A preparation method of an ionic liquid-based low-temperature heat conducting oil, comprising the following steps:

[0026] Step 1: Add a cleaning dispersant to the molten ionic liquid eutectic component and mechanically stir for 1-7 hours to mix thoroughly.

[0027] Step 2: Place the mixture under normal pressure and temperature for 2 to 8 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0028] Ionic liquids are molten salts that are liquid at room temperature or below 100°C, or at their operating temperature. The cations are typically organic. The positively charged sites of the cations are predominantly N, P, and S atoms. Based on whether their cation precursor is a Brønsted base, they can be classified into protic ionic liquids and aprotic ionic liquids. Protic ionic liquids are prepared by reacting Brønsted bases with Brønsted acids, and their central atoms at the positively charged sites carry protons. Aprotic ionic liquids can be considered as their counterparts in protic ionic liquids, where the protons at the central atoms at the positively charged sites are replaced by corresponding alkyl groups.

[0029] Figure 1 This is a schematic diagram illustrating the principle of eutectic composition of ionic liquids. As shown in the figure, the eutectic temperature (T...) e The freezing point of a eutectic component is an important physical parameter. Because hydrogen bond donors and acceptors in a eutectic component form hydrogen bonds, the stronger the hydrogen bonding, the lower the freezing point of the eutectic component is generally. Compared to the individual melting points of the hydrogen bond donors and acceptors in the pure components, the freezing point of the eutectic component can typically be 20–120 °C lower.

[0030] Example 1

[0031] Low-temperature heat transfer oil based on ionic liquids was prepared according to the following method:

[0032] Step 1: The eutectic component of the ionic liquid comprises 45 parts by weight of pyridinium trifluoroacetate and 45 parts by weight of benzimidazolium bis(trifluoromethanesulfonyl)imide. The cleaning and dispersing agent consists of a total of 10 parts of petroleum sulfonate and synthetic sulfonate. The cleaning and dispersing agent is added to the molten ionic liquid eutectic component, and the mixture is mechanically stirred for 2 hours to ensure thorough mixing.

[0033] Step 2: Place the mixture under normal pressure and temperature for 2 to 8 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0034] Tests showed that the low-temperature heat transfer oil obtained in this embodiment has a freezing point of -76°C, which is significantly lower than the freezing point of existing commercial heat transfer oil products; for example, the freezing point of mineral oil is around -30°C.

[0035] The performance indicators of the heat transfer oil obtained in this embodiment are shown in Table 1:

[0036] Table 1. Performance Indicators of Example 1

[0037]

[0038] Example 2

[0039] Low-temperature heat transfer oil based on ionic liquids was prepared according to the following method:

[0040] Step 1: The ionic liquid eutectic component comprises, by weight, 47 parts of 1-hexyl-3-methylimidazolium hydrogen sulfate and 47 parts of piperidine acetate. The cleaning and dispersing agent is 6 parts of synthetic sulfonate. The cleaning and dispersing agent is added to the molten ionic liquid eutectic component, and the mixture is mechanically stirred for 3 hours to achieve uniform mixing.

[0041] Step 2: Place the mixture at normal pressure and temperature for 5 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0042] Tests showed that the low-temperature heat transfer oil obtained in this embodiment has a freezing point of -59°C, which is significantly lower than the freezing point of existing commercial heat transfer oil products.

[0043] Example 3

[0044] Low-temperature heat transfer oil based on ionic liquids was prepared according to the following method:

[0045] Step 1: The ionic liquid eutectic component comprises 48 parts by weight of tetraethylammonium tetrafluoroborate and 48 parts by weight of 1-butyl-3-methylimidazolium hexafluorophosphate. The cleaning and dispersing agent is 4 parts of sulfur-phosphated polyisobutylene salt. Add the cleaning and dispersing agent to the molten ionic liquid eutectic component and mechanically stir for 4 hours to mix evenly.

[0046] Step 2: Place the mixture at normal pressure and temperature for 4 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0047] Tests showed that the low-temperature heat transfer oil obtained in this embodiment has a freezing point of -61°C, which is significantly lower than the freezing point of existing commercial heat transfer oil products.

[0048] Example 4

[0049] Low-temperature heat transfer oil based on ionic liquids was prepared according to the following method:

[0050] Step 1: The ionic liquid eutectic component comprises, by weight, 49 parts imidazole perfluorobutyl sulfonate and 49 parts imidazole cyclic perfluoroalkyl sulfonyl imide salt. The cleaning and dispersing agent is 2 parts alkyl salicylate. The cleaning and dispersing agent is added to the molten ionic liquid eutectic component, and the mixture is mechanically stirred for 5 hours until homogeneous.

[0051] Step 2: Place the mixture at normal pressure and temperature for 3 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0052] Tests showed that the low-temperature heat transfer oil obtained in this embodiment has a freezing point of -70°C, which is significantly lower than the freezing point of existing commercial heat transfer oil products.

[0053] Example 5

[0054] Low-temperature heat transfer oil based on ionic liquids was prepared according to the following method:

[0055] Step 1: The eutectic component of the ionic liquid comprises, by weight, 80 parts of trioctylamine methanesulfonate (prepared by equimolar mixing of trioctylamine and methanesulfonic acid) and 16 parts of trimethylbutylammonium bis(trifluoromethanesulfonyl)imine salt. The cleaning and dispersing agent is 4 parts of alkyl salicylate. The cleaning and dispersing agent is added to the molten ionic liquid eutectic component, and the mixture is mechanically stirred for 3 hours to achieve uniform mixing.

[0056] Step 2: Place the mixture at normal pressure and temperature for 2 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

[0057] Figure 2 The figure shows the differential scanning calorimetry (DSC) curves of the main components of the heat transfer oil obtained in this embodiment. It can be seen from the figure that its freezing point can reach -86.2℃.

[0058] Trioctylamine methanesulfonate and trimethylbutylammonium bis(trifluoromethanesulfonyl)imine salt are eutectic. Since the cation of trioctylamine methanesulfonate is a hydrogen bond donor and the anion of trimethylbutylammonium bis(trifluoromethanesulfonyl)imine salt is a hydrogen bond acceptor, hydrogen bonding occurs between them, resulting in a very low freezing point and further reduction in overall viscosity of the eutectic component. Furthermore, the N atom in the bis(trifluoromethanesulfonyl)imine anion undergoes charge delocalization, transferring negative charge to the S and O atoms and the trifluoromethyl group, reducing the interaction with the cation and leading to a decrease in the overall viscosity of the heat transfer oil. Moreover, the freezing temperature of the eutectic system obtained by mixing ternary or multi-component ionic liquids can be further reduced, allowing the freezing point to be below -100°C.

[0059] The ionic liquid cations and anions suitable for this invention are shown in Tables 2 and 3, respectively:

[0060] Table 2. Cations

[0061]

[0062]

[0063] Table 3. Anions

[0064]

[0065]

[0066] This invention offers high safety, low product toxicity, readily available and inexpensive raw materials, and produces a heat transfer oil with excellent thermal stability, low low-temperature viscosity, extremely low vapor pressure, high thermal efficiency, excellent cold energy transfer efficiency, and superior low-temperature performance. In addition to these advantages, it also boasts a service life of over 10 years, is less prone to coking, reduces pollutant emissions, is energy-saving and environmentally friendly, has a wide range of applications, and can be used as an ultra-low temperature electrolyte, among others.

Claims

1. A low-temperature heat transfer oil based on ionic liquids, characterized in that, By weight, it comprises: 96 parts of ionic liquid eutectic component and 4 parts of cleaning dispersant; the ionic liquid eutectic component consists of 80 parts of trioctylamine methanesulfonate and 16 parts of trimethylbutylammonium bis(trifluoromethanesulfonyl)imine salt; wherein the trioctylamine methanesulfonate is prepared by mixing trioctylamine and methanesulfonic acid in an equimolar ratio. The cleaning dispersant is 4 parts of alkyl salicylate.

2. The method for preparing a low-temperature heat transfer oil based on ionic liquids as described in claim 1, characterized in that, Includes the following steps: Step 1: Add a cleaning dispersant to the molten ionic liquid eutectic component and mechanically stir for 1-7 hours to mix thoroughly. Step 2: Place the mixture under normal pressure and temperature for 2 to 8 hours to obtain the desired low-temperature heat transfer oil based on ionic liquid.

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