Methylene disulfonic acid, preparation method thereof and methylene methanedisulfonate

Abstract

The invention discloses methylene disulfonic acid, a preparation method thereof and methylene methanedisulfonate. The preparation method of methylene disulfonic acid comprises the following steps: dissolving sulfur trioxide in halogenated alkane to form a complexing system, and adding methanesulfonic acid to obtain a mixed solution; and heating the mixed solution for reaction to obtain the methylene disulfonic acid. Sulfur trioxide is dissolved in halogenated alkane and then reacts with methanesulfonic acid to generate methylene disulfonic acid, and sulfur trioxide may be complexed with halogenated alkane, so that the reaction activity of sulfur trioxide is reduced, side reactions are reduced, and the reaction yield is increased; after the sulfur trioxide and the dichloroethane are complexed, the mixed solution cannot be gasified when the temperature exceeds the boiling point of the sulfur trioxide during a heating reaction, so that higher pressure is prevented from being generated, and the equipment investment is increased; the method is mild in reaction condition, low in pressure and free of high-pressure equipment; halogenated alkane can reduce sulfur trioxide sulfonation activity, side reaction is avoided, and the yield of methylene disulfonic acid is high.

Description

Technical Field

[0001] The present application belongs to the field of chemical synthesis, and specifically relates to methylene disulfonic acid and a preparation method thereof, methylene methane disulfonate, an electrolyte and a battery. Background Art

[0002] Methylene disulfonate (MMDS) is a new type of electrolyte additive for lithium-ion batteries. Adding methylene disulfonate to the production of lithium battery electrolyte can greatly improve the high-temperature cycle performance of lithium batteries and significantly extend the service life of lithium batteries. Especially in power batteries with lithium manganese oxide as the positive electrode material, the addition of methylene disulfonate can effectively prevent the manganese melted at high temperature from being adsorbed on the negative electrode surface, inhibit its impedance increase, effectively improve its cycle characteristics, and thus greatly increase its cycle life. With the increase in the market share of lithium manganese oxide batteries, the market size of MMDS will also gradually expand.

[0003] Methylene disulfonic acid is an important raw material for preparing methylene methane disulfonate. There are two main methods for its synthesis: one is to use dihaloalkane CH2X2 to react with sulfite to obtain methylene disulfonate, and then obtain solid methylene disulfonic acid after precipitation, acidification, dehydration, drying, slicing or granulation; the other is to directly react methane sulfonic acid with chlorosulfonic acid / sulfur trioxide / fuming sulfuric acid to obtain methylene disulfonic acid. Both of the above methods have the problems of complex process, harsh reaction conditions and low yield. Summary of the invention

[0004] The present application aims to solve one of the related technical problems to a certain extent. In view of this, the first object of the present application is to provide a method for preparing methylene disulfonic acid, which has high yield of methylene disulfonic acid, simple process and mild reaction conditions.

[0005] In the first aspect of the present application, a method for preparing methylene disulfonic acid is proposed, comprising: dissolving sulfur trioxide in a halogenated alkane to form a complex system, adding methane sulfonic acid to obtain a mixed solution; and heating the mixed solution to react to obtain methylene disulfonic acid.

[0006] The preparation method of methylene disulfonic acid in the present application has the following beneficial effects: the existing preparation method of methylene disulfonic acid, the reaction raw materials include sulfur trioxide, because sulfur trioxide has high reaction activity, strong oxidizing property, and is prone to side reactions, and sulfur trioxide reacts with the product methylene disulfonic acid to generate byproducts such as methane trisulfonic acid, resulting in a low yield of methylene disulfonic acid. Based on this, the present application first dissolves sulfur trioxide in halogenated alkane, and then reacts with methane sulfonic acid to generate methylene disulfonic acid, sulfur trioxide can be complexed with halogenated alkane, to a certain extent reduce the reaction activity of sulfur trioxide, on the premise of ensuring the smooth reaction of sulfur trioxide and methane sulfonic acid, minimize the occurrence of side reactions, thereby improving the yield of methylene disulfonic acid; in addition, after sulfur trioxide is complexed with halogenated alkane, the mixed solution will not be vaporized when the temperature exceeds the boiling point of sulfur trioxide during the heating reaction, thereby avoiding the generation of greater pressure and increasing equipment investment; in summary, compared with the existing preparation process of methylene disulfonic acid, the present application has mild reaction conditions, low pressure, no need for high-pressure equipment, and high yield.

[0007] In some embodiments, the halogenated alkane includes at least one of dichloroethane and tetrachloroethane. Thus, the yield of methylene disulfonic acid is high, the process is simple and the reaction conditions are mild.

[0008] In some embodiments, the molar ratio of the methanesulfonic acid to the sulfur trioxide is 1:(1-1.5). Thus, the yield of methylene disulfonic acid is high, the process is simple and the reaction conditions are mild.

[0009] In some embodiments, the mass ratio of the sulfur trioxide to the halogenated alkane is 1:(1-10), and can be 1:(3-5). Thus, the yield of methylene disulfonic acid is high, the process is simple, and the reaction conditions are mild.

[0010] In some embodiments, the heating reaction time is 10 hours to 24 hours. Thus, the yield of methylene disulfonic acid is high, the process is simple and the reaction conditions are mild.

[0011] In some embodiments, the temperature of the heating reaction is 80° C.-145° C. Thus, the yield of methylene disulfonic acid is high, the process is simple and the reaction conditions are mild.

[0012] In the second aspect of the present application, a methylene disulfonic acid is provided. The methylene disulfonic acid is prepared by the method described in the first aspect of the present application.

[0013] The methylene disulfonic acid proposed in the present application has the following beneficial effects: the methylene disulfonic acid proposed in the present application is prepared by the method described in the first aspect of the present application, the above preparation method has mild reaction conditions, low pressure, and does not require high-pressure equipment; halogenated alkanes can reduce the sulfonation activity of sulfur trioxide, and on the premise of ensuring the smooth progress of the main reaction, the occurrence of side reactions is minimized, thereby improving the yield of methylene disulfonic acid.

[0014] In the third aspect of the present application, a methylene disulfonate is provided, wherein the methylene disulfonate is prepared by using the methylene disulfonic acid prepared by the method described in the first aspect of the present application or the methylene disulfonic acid described in the second aspect of the present application. The methylene disulfonic acid is used to prepare the methylene disulfonate, so that high-purity methylene disulfonate can be prepared.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 This is an ion chromatogram of the reaction product obtained according to the method of Example 1 of the present application. DETAILED DESCRIPTION

[0018] The embodiments of the present application are described in detail below, which are intended to be used to explain the present application but should not be construed as limiting the present application.

[0019] Methylene disulfonic acid is an important raw material for preparing methylene methane disulfonate. There are two main methods for its synthesis: one is to use dihaloalkane CH2X2 to react with sulfite to obtain methylene disulfonate, and then obtain solid methylene disulfonic acid after precipitation, acidification, dehydration, drying, slicing or granulation; the other is to directly react methane sulfonic acid with chlorosulfonic acid / sulfur trioxide / fuming sulfuric acid to obtain methylene disulfonic acid. Both of the above methods have the problems of complex process, harsh reaction conditions and low yield.

[0020] Based on this, in the first aspect of the present application, a method for preparing methylene disulfonic acid is proposed, the method comprising:

[0021] S1: dissolving sulfur trioxide in halogenated alkane to form a complex system, adding methanesulfonic acid to obtain a mixed solution;

[0022] In this step, sulfur trioxide is dissolved in halogenated alkane, and methane sulfonic acid is added to form a homogeneous mixed liquid, which is not only convenient for feeding, but also can create a homogeneous environment for subsequent reactions, with mild reaction conditions, high yield, low cost, and can achieve industrial production. In this process, sulfur trioxide can form a complex with halogenated alkane, thereby reducing the reaction activity of sulfur trioxide, reducing side reactions and improving the reaction yield without affecting the smooth reaction of sulfur trioxide and methane sulfonic acid; in addition, after sulfur trioxide and halogenated alkane are complexed, the mixed liquid will not be vaporized when the temperature exceeds the boiling point of sulfur trioxide during heating reaction, thereby avoiding the generation of large pressure and increasing equipment investment.

[0023] In some specific embodiments of the present application, the halogenated alkane includes at least one of dichloroethane and tetrachloroethane. Using at least one of the above halogenated alkanes as a solvent, on the one hand, has good solubility for sulfur trioxide, does not participate in the reaction, has good stability, and can provide a homogeneous and mild reaction environment. On the other hand, the above halogenated alkane has a good complexing effect with sulfur trioxide, which reduces the reaction activity of sulfur trioxide, improves the reaction selectivity, and thus improves the yield. After sulfur trioxide is complexed with the halogenated alkane, when the temperature is raised for the reaction, sulfur trioxide will not volatilize, smoke, and generate pressure, which is convenient for equipment selection.

[0024] In some specific embodiments of the present application, the molar ratio of the methane sulfonic acid to the sulfur trioxide is 1:(1-1.5). For example, the molar ratio of methane sulfonic acid to sulfur trioxide can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, etc. By controlling the molar ratio of methane sulfonic acid to sulfur trioxide within the above range, the two can react fully, and the incomplete complexation with the solvent caused by excessive sulfur trioxide can be reduced, and the side reaction can be participated in the subsequent reaction process to ensure the purity and yield of the obtained methylene disulfonic acid; it can also reduce the incomplete reaction with methane sulfonic acid caused by too little sulfur trioxide, and further improve the yield of methylene disulfonic acid. In some other specific embodiments of the present application, the mass ratio of the sulfur trioxide to the halogenated alkane is 1:(3-5).

[0025] In some specific embodiments of the present application, the mass ratio of the sulfur trioxide to the halogenated alkane is 1:(1-10). For example, the mass ratio of sulfur trioxide to halogenated alkane can be 1:1, 1:3, 1:5, 1:7, 1:9, 1:10, etc. By controlling the mass ratio of sulfur trioxide to halogenated alkane within the above range, sulfur trioxide and halogenated alkane can be complexed, and the reaction of sulfur trioxide and methane sulfonic acid will not be affected. The probability of sulfur trioxide participating in side reactions can be reduced, thereby improving the yield and purity of methylene disulfonic acid.

[0026] S2: heating the mixed solution to react and obtaining methylene disulfonic acid.

[0027] In this step, sulfur trioxide and methanesulfonic acid are reacted by heating to obtain methylene disulfonic acid. The reaction process is as follows:

[0028]

[0029] In some specific embodiments of the present application, the temperature of the heating reaction is 80°C-145°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 145°C, etc. Controlling the temperature of the heating reaction within the above range can promote the full reaction of sulfur trioxide and methane sulfonic acid, and prevent the temperature from being too high to cause the volatilization and decomposition of the components in the mixed solution, thereby reducing the occurrence of side reactions and further improving the yield and purity of methylene disulfonic acid.

[0030] In some specific embodiments of the present application, the heating reaction time is 10h-24h. For example, the heating reaction time can be 10h, 12h, 15h, 18h, 20h, 24h, etc. Specifically, controlling the heating reaction time within the above range can promote the full reaction of sulfur trioxide and methane sulfonic acid, reduce the incomplete reaction caused by too short reaction time, improve the yield of methylene disulfonic acid, reduce the occurrence of side reactions caused by too long reaction time, and improve the purity of methylene disulfonic acid.

[0031] In summary, the preparation method of methylene disulfonic acid proposed in the present application is to first dissolve sulfur trioxide in halogenated alkane, and then react with methane sulfonic acid to generate methylene disulfonic acid. Sulfur trioxide may be complexed with halogenated alkane, thereby reducing the reaction activity of sulfur trioxide, reducing side reactions, and improving the reaction yield; in addition, after sulfur trioxide is complexed with dichloroethane, when the mixed solution is heated for reaction, the temperature exceeds the boiling point of sulfur trioxide and will not be vaporized, thereby avoiding the generation of large pressure and increasing equipment investment; compared with the existing preparation process of methylene disulfonic acid, the present application has mild reaction conditions, low pressure, and no need for high-pressure equipment; halogenated alkane can reduce the sulfonation activity of sulfur trioxide, avoid the occurrence of side reactions, and the yield of methylene disulfonic acid is high.

[0032] In the second aspect of the present application, a methylene disulfonic acid is provided. The methylene disulfonic acid is prepared by the method described in the first aspect of the present application.

[0033] Therefore, the methylene disulfonic acid proposed in the present application is prepared by the method described in the first aspect of the present application, and the obtained methylene disulfonic acid has high purity, low impurity content and high yield.

[0034] In the third aspect of the present application, a methylene disulfonate is provided, wherein the methylene disulfonate is prepared by using the methylene disulfonic acid prepared by the method described in the first aspect of the present application or the methylene disulfonic acid described in the second aspect of the present application. The methylene disulfonic acid is used to prepare the methylene disulfonate, so that high-purity methylene disulfonate can be prepared.

[0035] The embodiments of the present application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, unless otherwise explicitly stated, all reagents used in the following embodiments are commercially available or can be synthesized according to this article or known methods, and the reaction conditions not listed are also easily available to those skilled in the art.

[0036] Example 1

[0037] At room temperature, 144.12 g (1.46 mol) of ethylene dichloride was added to a dry reactor, and 48.04 g (0.6 mol) of sulfur trioxide was slowly added dropwise. After stirring for 1 hour, 48.06 g (0.5 mol) of methanesulfonic acid was added. The temperature was raised to 83°C and refluxed for 18 hours. At this time, the pressure gauge showed no pressure (0). The reaction was completed, and ion chromatography was performed. The test results were as follows: Figure 1 As shown, the yield of methylene disulfonic acid is 85.21%.

[0038] Embodiments 2 to 19

[0039] The differences between Examples 2 to 19 and Example 1 are shown in Table 1.

[0040] Comparative Example 1

[0041] 48.06 g of methanesulfonic acid and 48.04 g of sulfur trioxide were added to a dry reactor at room temperature, and the mixture was stirred and heated to 100° C. for reaction for 14 h, at which time the pressure was 0.37 MPa. After the reaction was completed, ion chromatography analysis showed a yield of 38.62%.

[0042] The differences between Comparative Examples 2-5 and Comparative Example 1 are shown in Table 1.

[0043] Comparative Example 6

[0044] At 30°C, add 9.61g (0.100mol) of methanesulfonic acid to a 200mL four-necked pressure bottle, replace it with nitrogen three times, remove the air in the reaction system, and replace it with a nitrogen atmosphere. Stir at 100rpm, slowly drop 8.0g (0.100mol) of sulfur trioxide liquid, release heat during the dropwise addition, and control the system temperature to 30°C by cooling. After the dropwise addition is completed, seal the four-necked pressure bottle, heat up to 60°C, and react for 24h. After the reaction is completed, cool to 30°C to obtain a white solid containing methylene disulfonic acid, and use an ion chromatograph (Wantong 930) to detect and determine that the methanesulfonic acid raw material has reacted.

[0045] Comparative Example 7

[0046] 144.12 g of ethyl acetate was added to a dry reactor at room temperature, and 48.04 g (0.6 mol) of sulfur trioxide was slowly added dropwise. After stirring for 1 h, 48.06 g (0.5 mol) of methanesulfonic acid was added, and the temperature was raised to 83°C and refluxed for 18 h. After the reaction was completed, ion chromatography detection showed a yield of 0.

[0047] Comparative Examples 8-12

[0048] Comparative Examples 8-12 differ from Comparative Example 7 in that acetonitrile, methyl sulfoxide, 1,4-dioxane, dimethyl carbonate, and ethyl methyl carbonate are used as solvents instead of ethyl acetate. No product is obtained according to the preparation and post-treatment methods of Comparative Example 7.

[0049] Table 1

[0050]

[0051]

[0052] The yield of methylene disulfonic acid obtained in Example 1-19 and Comparative Example 1-12 was measured by ion chromatography, and the pressure in the reactor was recorded. The test results are shown in Table 2.

[0053] Table 2

[0054]

[0055]

[0056] Results and Conclusions:

[0057] Referring to Table 2, in Examples 1-19 of the present application, halogenated alkanes are used as solvents to react sulfur trioxide and methanesulfonic acid, the reaction conditions are mild, the yield of methylene disulfonic acid is high, and the system pressure is low. This is because sulfur trioxide and halogenated alkanes form a complex, thereby reducing the reaction activity of sulfur trioxide, reducing side reactions, and improving the reaction yield; in addition, after sulfur trioxide and halogenated alkanes form a complex, when the mixed solution is heated for reaction, the temperature exceeds the boiling point of sulfur trioxide and will not be vaporized, thereby avoiding the generation of a large pressure and increasing equipment investment.

[0058] In Example 15, compared with other examples, the amount of halogenated alkane added is small and insufficient to complex sulfur trioxide. Therefore, during the reaction, part of the sulfur trioxide volatilizes, resulting in loss of raw materials and increase in system pressure, and thus the reaction yield is reduced. In Example 18, since the temperature of the heating reaction is too high, exceeding the boiling point of the complex formed by sulfur trioxide and halogenated alkane, part of the sulfur trioxide and halogenated alkane will also volatilize, the system pressure is high, and the yield is reduced.

[0059] Comparative Examples 1-6 do not use halogenated alkanes as solvents, the yield of methylene disulfonic acid is low, and the system pressure increases. This is because, during the heating reaction, the raw materials are easily volatilized, resulting in the loss of reaction raw materials and the increase of system pressure. Under heating conditions, sulfur trioxide will promote the carbonization of methane sulfonic acid, further causing the loss of raw materials. In addition, sulfur trioxide lacks the restraint of halogenated alkanes, has high activity, and is easy to participate in side reactions. All of the above result in a decrease in the yield of methylene disulfonic acid and an increase in system pressure.

[0060] Comparative Examples 7-12 use several organic substances other than halogenated alkanes as solvents. These solvents are incompatible with halogenated alkanes. When sulfur trioxide is added to these solvents, heat is released violently and smoke is generated, and the target product cannot be obtained.

[0061] In summary, the method for preparing methylene disulfonic acid in the embodiment of the present application has a high yield of methylene disulfonic acid, a simple process and mild reaction conditions.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0063] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for preparing methylene disulfonic acid, characterized in that: include: Dissolving sulfur trioxide in halogenated alkane to form a complex system, adding methanesulfonic acid to obtain a mixed solution; The mixed solution is heated to react to obtain methylene disulfonic acid.

2. The method according to claim 1, characterized in that The halogenated alkane includes at least one of ethylene dichloride and tetrachloroethane.

3. The method according to claim 1 or 2, characterized in that: The molar ratio of the methane sulfonic acid to the sulfur trioxide is 1:(1-1.5).

4. The method according to claim 1 or 2, characterized in that: The mass ratio of the sulfur trioxide to the halogenated alkane is 1:(1-10).

5. The method according to claim 1 or 2, characterized in that: The mass ratio of the sulfur trioxide to the halogenated alkane is 1:(3-5).

6. The method according to claim 1 or 2, characterized in that: The heating reaction time is 10h-24h.

7. The method according to claim 1 or 2, characterized in that: The temperature of the heating reaction is 80°C-145°C.

8. A methylene disulfonic acid, characterized in that The methylene disulfonic acid is prepared by the method according to any one of claims 1 to 7.

9. A methylene methanedisulfonate, characterized in that The methylene disulfonate is prepared by using methylene disulfonic acid prepared by the method of any one of claims 1 to 7 or the methylene disulfonic acid according to claim 8.

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