A catalyst for preparing ethylene sulfite, a method for preparing ethylene sulfite

Abstract

The present application relates to a kind of catalyst for preparing ethylene sulfite, the preparation method of ethylene sulfite, the catalyst includes organic aluminum compound and amine, the molar ratio of the organic aluminum compound and the amine is 1-5:1.The preparation method of ethylene sulfite includes the reaction of contacting ethylene oxide with sulfur dioxide in the presence of the catalyst.The quaternary ammonium salt in the catalyst of the present application and trialkylaluminum are excited by phase transfer and coordination, etc.Effect, monomer ring-opening of ethylene oxide, promote SO2 and ethylene oxide to react to generate ethylene sulfite, and then high-purity ethylene sulfite is prepared with high yield.

Description

Technical Field

[0001] The present invention relates to the technical field of ester compounds, and in particular to a catalyst for preparing vinyl sulfite and a method for preparing vinyl sulfite. Background Art

[0002] Ethylene sulfite is an important organic chemical product and an intermediate for synthesizing other chemical products. It can be used as an additive for organic electrolytes of lithium-ion secondary batteries.

[0003] At present, there are many methods for preparing vinyl sulfite. For example, it can be prepared by the reaction of ethylene glycol and sulfur oxychloride. However, the sulfur oxychloride in this method is very toxic, and the reaction byproducts are relatively large, making post-processing purification difficult. Especially when vinyl sulfite is used as a lithium ion battery electrolyte or electrolyte additive, it has very high requirements for impurities. The vinyl sulfite prepared by this reaction contains more byproduct chloroethanol, which greatly affects the storage stability of the electrolyte in the electrolyte, thereby affecting the stability of the lithium ion secondary battery. Moreover, reducing the content of chloroethanol in the vinyl sulfite is a complicated and time-consuming process.

[0004] Currently known methods for preparing vinyl sulfite use ethylene oxide and sulfur dioxide as raw materials, using alkali metal halides, alkaline earth metal halides, or halides of iron, cobalt, nickel, or aluminum as catalysts, and reacting under high temperature and high pressure to produce vinyl sulfite. However, these methods suffer from low catalyst safety, demanding reaction conditions, low yields, and the generation of a large number of byproducts. Developing a new catalyst for preparing vinyl sulfite that can produce high-purity vinyl sulfite in high yield by simply controlling the reaction conditions is a pressing technical challenge. Summary of the Invention

[0005] The present invention provides a catalyst for preparing vinyl sulfite and a method for preparing vinyl sulfite, so as to synthesize vinyl sulfite under simple reaction conditions based on the catalyst of the present invention.

[0006] In a first aspect, the present invention relates to a catalyst for preparing vinyl sulfite, comprising an organoaluminum compound and an amine, wherein the molar ratio of the organoaluminum compound to the amine is 1 to 5:1.

[0007] Optionally, the organoaluminum compound is selected from trialkylaluminum, and the amine is selected from quaternary ammonium salts; wherein the trialkylaluminum is represented by AlR1R2R3, and R1, R2 and R3 are each independently selected from a chain alkyl group with 1 to 8 carbon atoms or a cycloalkyl group with 3 to 8 carbon atoms.

[0008] Optionally, the trialkylaluminum is selected from the group consisting of one or more of a combination of trimethylaluminum, triethylaluminum, tripropylaluminum, and triisobutylaluminum.

[0009] Optionally, the quaternary ammonium salt is selected from the group consisting of one or more of a combination of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and hexadecyltrimethylammonium bromide.

[0010] In a second aspect, the present application relates to a method for preparing ethylene sulfite, the method comprising: contacting ethylene oxide with sulfur dioxide in the presence of the catalyst.

[0011] Optionally, the catalyst is used in an amount of 0.5-1% by weight of the amount of ethylene oxide fed.

[0012] Optionally, the contacting of ethylene oxide with sulfur dioxide comprises: adding ethylene oxide to a reaction system, heating to 80-130°C, introducing sulfur dioxide to make the pressure of the reaction system 0.5-2 MPa, and reacting for 0.5-4 hours.

[0013] Optionally, the method further comprises, before the adding of ethylene oxide to the reaction system, the step of: adding the catalyst to the reaction system and introducing an inert gas to purge.

[0014] Optionally, the method further comprises, before the adding of the catalyst to the reaction system, the step of: adding dehydrated ethylene sulfite to the reaction system.

[0015] Optionally, the dehydrated ethylene sulfite is prepared by the method of: adding ethylene sulfite in an amount of 1-3 times the weight of ethylene oxide fed, heating to 85-100°C, and performing vacuum distillation for 0.5-1 hour.

[0016] Optionally, the method further comprises, after the reacting for 0.5-4 hours, the step of: cooling and emptying the reaction system to obtain crude ethylene sulfite product; and performing vacuum distillation of the crude ethylene sulfite product at 85-100°C and a vacuum degree of 0.095-0.1 MPa for 0.5-1 hour to obtain ethylene sulfite product.

[0017] Advantages:

[0018] The quaternary ammonium salt and trialkylaluminum in the catalyst of the present application excite the ring opening of ethylene oxide monomers through phase transfer and coordination, etc., promote the reaction of SO2 with ethylene oxide to generate ethylene sulfite, and further prepare high-purity ethylene sulfite with high yield. DETAILED DESCRIPTION

[0019] The application will be further described in detail by examples. The features and advantages of the application will become more apparent through these descriptions.

[0020] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0021] Furthermore, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict.

[0022] In a first aspect, the application relates to a catalyst for preparing ethylene sulfite, the catalyst comprising an organic aluminum compound and an amine, the molar ratio of the organic aluminum compound to the amine being 1-5:1.

[0023] It should be noted that the catalyst of the application is a composition catalyst, and the organic aluminum compound can be a trialkylaluminum, a dialkylaluminum, a monoalkylaluminum, an alkylaluminum dihydride, or the like. The dialkylaluminum, the monoalkylaluminum, and the alkylaluminum dihydride can be a dialkylaluminum chloride, a monoalkylaluminum dihydride chloride, a trialkylaluminum trihydride chloride, or the like.

[0024] According to one specific embodiment of the catalyst of the first aspect of the application, the organic aluminum compound is selected from trialkylaluminums, and the amine is selected from quaternary ammonium salts; wherein the trialkylaluminum is represented as AlR1R2R3, and R1, R2, and R3 are each independently selected from a linear alkyl group having a carbon number of 1-8 or a cyclic alkyl group having a carbon number of 3-8.

[0025] It should be noted that the linear alkyl group having a carbon number of 1-8 can be a straight-chain alkyl group or a branched-chain alkyl group. In the trialkylaluminum AlR1R2R3, R1, R2, and R3 can be selected from the same or different groups, such as the same or different linear alkyl groups or branched-chain alkyl groups having a carbon number of 1-8, such as R1, R2, and R3 can be methyl, ethyl, and butyl, respectively, or ethyl, propyl, and isobutyl, respectively.

[0026] According to one specific embodiment of the catalyst of the first aspect of the application, the trialkylaluminum is selected from a combination of one or more of trimethylaluminum, triethylaluminum, tripropylaluminum, and triisobutylaluminum.

[0027] According to another specific embodiment of the catalyst of the first aspect of the application, the quaternary ammonium salt is selected from a combination of one or more of benzyltriethylammonium chloride (TEBA), tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate (TBAB), trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and hexadecyltrimethylammonium bromide.

[0028] It should be noted that, in the catalyst for preparing ethylene sulfite of the present application, firstly, the catalyst is compounded by the above-mentioned trialkylaluminum and quaternary ammonium salt, and the phase transfer catalysis of the quaternary ammonium salt can coordinate with the organic aluminum during the catalytic reaction to promote the raw materials to react to generate ethylene sulfite, so that the ethylene sulfite can be well synthesized under mild and easy-to-control conditions; secondly, the catalyst compounded by the above-mentioned trialkylaluminum and quaternary ammonium salt in a molar ratio of 1-5:1 can obtain high purity and yield when catalytically synthesizing ethylene sulfite.

[0029] In a second aspect, the present application relates to a preparation method of ethylene sulfite, which comprises: contacting ethylene oxide with sulfur dioxide in the presence of the catalyst of the first aspect of the present application.

[0030] It should be noted that, in the preparation method of ethylene sulfite of the present application, the phase transfer catalysis of the quaternary ammonium salt in the catalyst can not only coordinate with the organic aluminum to stimulate the ring opening of the ethylene oxide monomer, but also promote the reaction of SO2 and ethylene oxide to generate ethylene sulfite, thereby preparing high-purity ethylene sulfite with high yield.

[0031] According to a specific embodiment of the preparation method of the second aspect of the present application, the amount of the catalyst is 0.5-1% by weight of the amount of ethylene oxide.

[0032] It should be noted that, in the preparation method of ethylene sulfite of the present application, the catalyst is used in a small amount to prepare high-purity ethylene sulfite with high yield.

[0033] According to a specific embodiment of the preparation method of the second aspect of the present application, the contacting of ethylene oxide with sulfur dioxide comprises:

[0034] The ethylene oxide is added to the reaction system, the temperature is raised to 80-130°C, the sulfur dioxide is introduced to make the pressure of the reaction system 0.5-2Mpa, and the reaction is carried out for 0.5-4 hours.

[0035] It should be noted that, in the contacting reaction process of the preparation method of the present application, as a preferred embodiment, the ethylene oxide is slowly added to the system, and then heated and raised in temperature. When the temperature of the reaction system is raised to 80-130°C, the sulfur dioxide is introduced to make the pressure of the reaction system 0.5-2Mpa. As the reaction proceeds, the pressure in the system begins to drop, and then the sulfur dioxide is supplemented to make the pressure in the system 0.5-2Mpa. When the pressure no longer changes, the aging can be carried out for 0.2-0.6 hours, such as about 0.5 hours, and the cumulative reaction time can be 0.5-4 hours.

[0036] It should be noted that in the preparation of ethylene sulfite, the above catalyst is selected and the amount of catalyst is controlled according to the above amount range, and then high purity ethylene sulfite can be prepared in high yield under the above mild conditions.

[0037] According to another specific embodiment of the preparation method of the second aspect of the present application, the preparation method further comprises the following step before the step of adding the ethylene oxide into the reaction system:

[0038] The catalyst is added into the reaction system, and inert gas is introduced for purging.

[0039] It should be noted that before the ethylene oxide and sulfur dioxide are added into the reaction system, the catalyst, i.e. the trialkylaluminum and the quaternary ammonium salt, is first added into the reaction system, and nitrogen or other inert gas can be introduced for purging to remove air or other gases in the reaction system, so that the occurrence of side reactions can be reduced to prepare the target product ethylene sulfite with higher purity.

[0040] According to one specific embodiment of the preparation method of the second aspect of the present application, the preparation method further comprises the following step before the step of adding the catalyst into the reaction system:

[0041] The dehydrated ethylene sulfite is added into the reaction system.

[0042] It should be noted that in the preparation method of the present application, before the catalyst, ethylene oxide and sulfur dioxide are added into the reaction system, ethylene sulfite as a diluent is also added into the reaction system, so that the contact area of ethylene oxide and sulfur dioxide and the catalyst is increased, and the reaction can be carried out more fully to improve the yield of the reaction. The phase transfer catalysis of the quaternary ammonium salt in the catalyst of the present application can not only coordinate with the organic aluminum to transfer the organic aluminum to the diluent to initiate the ring-opening reaction of the ethylene oxide monomer, but also can make the inorganic phase SO2 react with the ethylene oxide in the organic phase solvent. By using the catalyst with higher safety, the reaction can be carried out under mild conditions with a small amount of catalyst, and the purity and yield of ethylene sulfite can be improved.

[0043] According to one specific embodiment of the preparation method of the second aspect of the present application, the dehydrated ethylene sulfite is prepared by the following method:

[0044] The ethylene sulfite is heated to 85-100°C for 0.5-1 hours under reduced pressure distillation with the ethylene oxide being 1-3 times the weight of the ethylene sulfite.

[0045] It should be noted that the above amount of ethylene sulfite is subjected to vacuum distillation to remove water and the like contained therein according to the above procedure, and then used as a diluent to perform the preparation process of ethylene sulfite, which can further improve the purity and yield of the final prepared ethylene sulfite product.

[0046] According to a specific embodiment of the preparation method according to the second aspect of the present application, the preparation method further comprises the following step after the reaction is performed for 0.5-4 hours:

[0047] The reaction system is cooled and evacuated to obtain a crude ethylene sulfite product; the crude ethylene sulfite product is subjected to vacuum distillation at 85-100°C and a vacuum degree of 0.095-0.1 MPa for 0.5-1 hour to obtain an ethylene sulfite product.

[0048] It should be noted that the vacuum degree of 0.095-0.1 MPa can refer to a pressure of -0.095 MPa to -0.1 MPa; the crude product prepared is subjected to the above vacuum distillation process, which can further improve the purity of the target product ethylene sulfite.

[0049] The present application is further described in detail through the following examples, but the present application is not limited thereto.

[0050] In the following examples and comparative examples, the materials, reagents and the like used are commercially available, for example, commercially available analytical grade chemical reagents, unless otherwise specified, among which the organoaluminum is mostly hexane solution, except that the concentration of triisobutylaluminum hexane solution is 25 mass%, and the others are 15 mass%.

[0051] Example 1

[0052] Take 150 g of ethylene sulfite in a round-bottom flask and heat to 85°C, and perform dehydration treatment by vacuum distillation for 1 hour, then pour it into a 500 mL autoclave, take 0.87 g of triethylaluminum hexane solution and 0.37 g of tetrabutylammonium bromide (catalyst composition molar ratio 1:1) and add them to the reaction kettle, N2 purging 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in the ethylene sulfite, then slowly add 50 g of ethylene oxide, then heat to warm up, when the reaction temperature rises to 130°C, sulfur dioxide is introduced to 2 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 2 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50°C by introducing cooling water in the autoclave, evacuate and release the product in the kettle, to obtain 275.7 g of crude ethylene sulfite product. The obtained crude product is subjected to vacuum distillation (vacuum degree 0.1 MPa) at 85°C for 1 hour to obtain 272.71 g of ethylene sulfite.

[0053] Example 2

[0054] 150g of vinyl sulfite was heated to 100°C in a round-bottom flask and dehydrated by vacuum distillation for 30 minutes. The mixture was then poured into a 500mL autoclave. 2.13g of triethylaluminum hexane solution and 0.18g of tetrabutylammonium bromide (catalyst composition molar ratio 5:1) were added to the autoclave. N2 was purged three times, and the stirring blade was activated until the vinyl sulfite was completely dissolved or evenly dispersed. 50g of ethylene oxide was slowly added. The reaction temperature was then increased. When the reaction temperature reached 130°C, sulfur dioxide was introduced to 2MPa. As the reaction proceeded, the pressure began to drop, and sulfur dioxide was added to 2MPa. When the pressure stabilized, the reaction was allowed to mature for 0.5h, for a total reaction time of 2h. Cooling water was introduced into the autoclave, cooled to 50°C, and the contents were emptied and the product was discharged to obtain 275.3g of crude vinyl sulfite. The obtained crude product was distilled under reduced pressure (vacuum degree 0.1 MPa) at 85° C. for 1 hour to obtain 273.16 g of vinyl sulfite.

[0055] Example 3

[0056] Take 150g of vinyl sulfite in a round-bottom flask and heat it to 85°C. Dehydrate it by vacuum distillation for 1 hour, then pour it into a 500mL autoclave. Take 1g of triethylaluminum hexane solution and 0.1g of benzyltriethylammonium chloride (catalyst composition molar ratio 3:1) and add them to the reactor. N2 is purged 3 times. Start the stirring blade and stir until it is completely dissolved or evenly dispersed in the vinyl sulfite. Slowly add 50g of ethylene oxide. Then, heat and raise the temperature. When the reaction temperature rises to 120°C, introduce sulfur dioxide to 1.5MPa. As the reaction proceeds, the pressure begins to drop, and then add sulfur dioxide to 1.5MPa. When the pressure no longer changes, mature for 0.5 hour, and the cumulative reaction time is 3 hours. Cooling water is introduced into the autoclave, cooled to 50°C, emptied and discharged, and 275.1g of crude vinyl sulfite product is obtained. The obtained crude product was distilled under reduced pressure (vacuum degree 0.1 MPa) at 85° C. for 1 hour to obtain 273.1 g of vinyl sulfite.

[0057] Example 4

[0058] Take 100 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 1.13 g of tripropyl aluminum hexane solution and 0.08 g of tetrabutyl ammonium bromide (molar ratio of catalyst composition 4:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 100 °C, sulfur dioxide is introduced to 1 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 2.5 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, get 224.3 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85 °C for 1 hour (vacuum degree 0.1 MPa), get 223.66 g of ethylene sulfite.

[0059] Example 5

[0060] Take 75 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 1.08 g of triisobutyl aluminum hexane solution and 0.08 g of tetrabutyl ammonium chloride (molar ratio of catalyst composition 5:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 80 °C, sulfur dioxide is introduced to 0.8 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 0.8 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 4 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, get 199.7 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85 °C for 1 hour (vacuum degree 0.1 MPa), get 199.36 g of ethylene sulfite.

[0061] Example 6

[0062] Take 150 g of ethylene sulfite in a round bottom flask to 100°C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 1.33 g of trimethyl aluminum hexane solution and 0.3 g of tetrabutylammonium hydrogen sulfate (catalyst composition molar ratio 3:1) into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 130°C, sulfur dioxide is introduced to 2 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 2 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 2 hours. Cool to 50°C by circulating water in the autoclave, empty and release the product in the kettle, get 275.8 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85°C (vacuum degree 0.1 MPa) for 1 hour, get 273.85 g of ethylene sulfite.

[0063] Example 7

[0064] Take 150 g of ethylene sulfite in a round bottom flask to 85°C, dehydrated by distillation under reduced pressure for 1 hour, then pour it into a 500 mL autoclave, take 2.2 g of triethyl aluminum hexane solution and 0.17 g of tetradecyl trimethyl ammonium chloride (catalyst composition molar ratio 5:1) into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120°C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50°C by circulating water in the autoclave, empty and release the product in the kettle, get 275.7 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85°C (vacuum degree 0.1 MPa) for 1 hour, get 273.59 g of ethylene sulfite.

[0065] Example 8

[0066] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, vacuum distillation for 1 hour for dehydration treatment, then pour it into a 500 mL autoclave, take 2 g of triethyl aluminum hexane solution and 0.2 g of trioctylmethyl ammonium chloride (catalyst composition molar ratio 5:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, 274.1 g of ethylene sulfite crude product is obtained. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, 271.68 g of ethylene sulfite is obtained.

[0067] Example 9

[0068] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, vacuum distillation for 1 hour for dehydration treatment, then pour it into a 500 mL autoclave, take 2 g of triethyl aluminum hexane solution and 0.2 g of trioctylmethyl ammonium chloride (catalyst composition molar ratio 5:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, 274.1 g of ethylene sulfite crude product is obtained. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, 271.68 g of ethylene sulfite is obtained.

[0069] Example 10

[0070] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, vacuum distillation for 1 hour for dehydration treatment, then pour it into a 500 mL autoclave, take 1.56 g of triisobutyl aluminum hexane solution and 0.11 g of tetradecyl trimethyl ammonium chloride (catalyst composition molar ratio 5:1) into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the kettle, 275.5 g of ethylene sulfite crude product is obtained. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, 273.89 g of ethylene sulfite is obtained.

[0071] Example 11

[0072] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, vacuum distillation for 1 hour for dehydration treatment, then pour it into a 500 mL autoclave, take 1.56 g of triisobutyl aluminum hexane solution and 0.11 g of tetradecyl trimethyl ammonium chloride (catalyst composition molar ratio 5:1) into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the kettle, 275.5 g of ethylene sulfite crude product is obtained. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, 273.89 g of ethylene sulfite is obtained.

[0073] Example 12

[0074] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, dehydrated by vacuum distillation for 1 hour, then pour it into a 500 mL autoclave, take 2.3 g of tripropyl aluminum hexane solution and 0.16 g of cetyl trimethyl ammonium bromide (catalyst composition molar ratio 5:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, aging for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by introducing cooling water into the autoclave, empty and release the product in the reactor, get 274.9 g of ethylene sulfite crude product. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, get 272.3 g of ethylene sulfite.

[0075] Comparative Example 1

[0076] Take 150 g of ethylene sulfite in a round bottom flask to 85 °C, dehydrated by vacuum distillation for 1 hour, then pour it into a 500 mL autoclave, take 2.3 g of tripropyl aluminum hexane solution and 0.16 g of cetyl trimethyl ammonium bromide (catalyst composition molar ratio 5:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 120 °C, sulfur dioxide is introduced to 1.5 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 1.5 MPa, when the pressure no longer changes, aging for 0.5 hours, the cumulative reaction time is 3 hours. Cool to 50 °C by introducing cooling water into the autoclave, empty and release the product in the reactor, get 274.9 g of ethylene sulfite crude product. The obtained crude product is distilled at 85 °C under vacuum (vacuum degree 0.1 MPa) for 1 hour, get 272.3 g of ethylene sulfite.

[0077] Comparative Example 2

[0078] Take 150 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 1.67 g of triethylaluminum hexane solution into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 130 °C, sulfur dioxide is introduced to 2 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 2 MPa, when the pressure no longer changes, aging for 0.5 hours, the cumulative reaction time is 4 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the kettle, get 273.5 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85 °C (vacuum degree 0.1 MPa) for 1 hour, get 243.94 g of ethylene sulfite.

[0079] Comparative Example 3

[0080] Take 150 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 1.67 g of triethylaluminum hexane solution into the reaction kettle, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 130 °C, sulfur dioxide is introduced to 2 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 2 MPa, when the pressure no longer changes, aging for 0.5 hours, the cumulative reaction time is 4 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the kettle, get 273.5 g of ethylene sulfite crude product. The obtained crude product is distilled under vacuum at 85 °C (vacuum degree 0.1 MPa) for 1 hour, get 243.94 g of ethylene sulfite.

[0081] Comparative Example 4

[0082] Take 150 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 2.27 g of triethylaluminum hexane solution and 0.16 g of tetrabutylammonium bromide (catalyst composition molar ratio 6:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 130 °C, sulfur dioxide is introduced to 2 MPa, as the reaction proceeds, the pressure begins to drop, then supplement sulfur dioxide to 2 MPa, when the pressure no longer changes, mature for 0.5 hours, the cumulative reaction time is 4 hours. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, 273.3 g of crude ethylene sulfite product is obtained. The obtained crude product is distilled under vacuum at 85 °C (vacuum degree 0.1 MPa) for 1 hour, 272.19 g of ethylene sulfite is obtained.

[0083] Comparative Example 5 (conventional ethoxylation catalyst cannot catalyze the synthesis of ethylene sulfite)

[0084] Take 150 g of ethylene sulfite in a round bottom flask to 100 °C, dehydrated by distillation under reduced pressure for 30 min, then pour it into a 500 mL autoclave, take 2.27 g of triethylaluminum hexane solution and 0.16 g of tetrabutylammonium bromide (catalyst composition molar ratio 6:1) into the reactor, N2purge 3 times, start the stirring paddle, stir until completely dissolved or uniformly dispersed in ethylene sulfite, slowly add 50 g of ethylene oxide, then heat up, when the reaction temperature rises to 130 °C, sulfur dioxide is introduced to 2 MPa, 2 hours pressure almost no change. Cool to 50 °C by circulating cooling water in the autoclave, empty and release the product in the reactor, 273.3 g of crude ethylene sulfite product is obtained. The obtained crude product is distilled under vacuum at 85 °C (vacuum degree 0.1 MPa) for 1 hour, 272.19 g of ethylene sulfite is obtained.

[0085] Comparative Example 6 (catalytic system cannot make ethylene oxide monomer polymerize)

[0086] Take 150 g of ethylene sulfite in a round-bottom flask to 100 ℃, and dehydrate for 30 min under reduced pressure, then pour it into a 500 mL autoclave, take 2.13 g of triethylaluminum hexane solution and 0.18 g of tetrabutylammonium bromide (catalyst composition molar ratio 5:1) into the reactor, N2 purging 3 times, starting the stirring paddle, stirring until completely dissolved or uniformly dispersed in ethylene sulfite, slowly adding 100 g of ethylene oxide, then heating, when the reaction temperature rises to 130 ℃, reacting for 6 hours. Cool to 50 ℃ by circulating cooling water in the autoclave, empty and release the product in the reactor, get 206.2 g of crude product. The obtained crude product is distilled at 85 ℃ under vacuum (vacuum degree 0.1 MPa) for 1 hour, get 151.6 g of mixture, and the ethylene oxide monomer almost does not occur polymerization.

[0087] Test Example 1

[0088] The purity of the ethylene sulfite prepared in the above examples and comparative examples was determined, wherein the purity of the ethylene sulfite was tested according to the provisions of GB / T30431-2020.

[0089] The purity results obtained by chromatographic analysis are shown in Table 1 below:

[0090] Table 1

[0091]

[0092] As can be seen from the data in Table 1, the above examples in the presence of the catalyst of the present application, ethylene oxide and sulfur dioxide are prepared by catalytic reaction to obtain ethylene sulfite with higher purity.

[0093] Test Example 2

[0094] The yield of the product of the above examples and comparative examples was calculated, wherein the yield (Y R ) of the product was calculated according to the following formula:

[0095]

[0096] In the formula, m1 is the total mass of ethylene sulfite obtained after vacuum distillation refining, g;

[0097] s is the purity of ethylene sulfite obtained after vacuum distillation refining, %;

[0098] m is the amount of ethylene sulfite added as diluent, g;

[0099] m2 is the actual amount of ethylene oxide added, g;

[0100] m3 is the theoretical amount of sulfur dioxide added (equal to the number of moles of ethylene oxide added), g.

[0101] The data of the yield calculated according to the above formula is shown in Table 2 below:

[0102] Table 2

[0103]

[0104]

[0105] From the data in Table 2, it can be seen that the above examples have higher yield in the catalytic reaction of ethylene oxide and sulfur dioxide to prepare vinyl sulfite in the presence of the catalyst of the present application.

[0106] The above description of the present application is based on preferred embodiments, which are only exemplary and serve only to illustrate the present application. On this basis, various substitutions and improvements can be made to the present application, which all fall within the protection scope of the present application.

Claims

1. A method for preparing vinyl sulfite, wherein: The preparation method comprises: in the presence of a catalyst, allowing ethylene oxide to contact and react with sulfur dioxide; The catalyst comprises an organic aluminum compound and an amine, wherein the molar ratio of the organic aluminum compound to the amine is 1-5:

1.

2. The preparation method according to claim 1, wherein The organoaluminum compound is selected from trialkylaluminum, and the amine is selected from quaternary ammonium salts; The trialkylaluminum is represented by AlR1R2R3, and R1, R2 and R3 are each independently selected from a chain alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms.

3. The preparation method according to claim 2, wherein The trialkylaluminum is selected from a combination of one or more of trimethylaluminum, triethylaluminum, tripropylaluminum and triisobutylaluminum.

4. The preparation method according to claim 2, wherein The quaternary ammonium salt is selected from one or more combinations of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride and hexadecyltrimethylammonium bromide.

5. The preparation method according to claim 1, wherein The amount of the catalyst used is 0.5-1% by weight of the ethylene oxide feed amount.

6. The preparation method according to claim 1, wherein The contact reaction of ethylene oxide and sulfur dioxide comprises: Ethylene oxide is added to the reaction system, the temperature is raised to 80-130° C., sulfur dioxide is introduced to make the pressure of the reaction system 0.5-2 MPa, and the reaction is carried out for 0.5-4 hours.

7. The preparation method according to claim 6, wherein The preparation method further comprises the following steps before adding ethylene oxide to the reaction system: The catalyst is added into the reaction system, and an inert gas is introduced for purging.

8. The preparation method according to claim 7, wherein The preparation method further comprises the following steps before adding the catalyst to the reaction system: The dehydrated vinyl sulfite is added into the reaction system.

9. The preparation method according to claim 8, wherein The dehydrated vinyl sulfite is prepared by the following method: Ethylene sulfite in an amount of 1 to 3 times the weight of the ethylene oxide feed is heated to 85 to 100°C and subjected to reduced pressure distillation for 0.5 to 1 hour.

10. The preparation method according to claim 6, wherein The preparation method further comprises the following steps after the reaction is carried out for 0.5 to 4 hours: The reaction system is cooled and evacuated to obtain a crude vinyl sulfite product; the crude vinyl sulfite product is subjected to reduced pressure distillation at 85-100° C. and a vacuum degree of 0.095-0.1 MPa for 0.5-1 hour to obtain a vinyl sulfite product.

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