Preparation method of trisilyl amine

Abstract

The invention belongs to the technical field of preparation of trisilylamine, and particularly relates to a preparation method of trisilylamine, which comprises the following steps: firstly, preparing monochlorosilane from monosilane and trichlorosilane under the action of a catalyst, rectifying and purifying reactants to obtain monochlorosilane, and purifying the monochlorosilane to obtain trisilylamine; adding the obtained monochlorosilane and ammonia gas into a low-temperature reactor according to a certain proportion, and reacting for a certain time; and filtering, rectifying and purifying the reaction liquid to obtain the high-purity trisilylamine. The method for preparing the trisilyl amine is low in cost, the raw materials are simple and easy to obtain, the reaction conditions are mild, and the reaction is simple and controllable.

Description

Technical Field

[0001] This application belongs to the field of trimethylsilylamine preparation technology, specifically relating to a method for preparing trimethylsilylamine. Background Technology

[0002] Trisilylamine (SiH3)3N, abbreviated as TSA, is a liquid with a relative density of 0.895 g / cm³. 3 Silicon-based precursor materials, TSA applications include ALD, FCVD, etc. TSA uses plasma vapor deposition technology to manufacture silicon nitride thin films for use in the manufacture of DRAM and NAND.

[0003] The main methods for preparing trimethylsilylamine are: (1) reaction of monohalosilane with ammonia to prepare TSA, specifically divided into liquid phase method and gas phase method; (2) pyrolysis of perhydropolysilazane to prepare TSA. This reaction has no halogen pollution and the product purity is high, but the energy consumption is high and the yield is low, which is more suitable for laboratory manufacturing; (3) preparation of TSA through amino transfer. The preparation method has mild conditions and few side reactions, but the process is not yet mature and needs to be further improved. Therefore, the current industrial process mainly uses the reaction of chlorosilanes with ammonia to prepare TSA. The effective preparation of trimethylsilylamine is achieved by controlling the presence or absence of solvents and the ratio of monochlorosilane to ammonia. For example, patents with announcement numbers CN115636846B, CN105731464B, CN104250007B, CN108586515B, and CN103619429B disclose a method for preparing high-purity trimethylsilylamine, which uses monochlorosilanes as raw materials. However, the procurement cost of monochlorosilanes in the reaction raw materials is currently high, which increases the preparation cost of trimethylsilylamine.

[0004] Therefore, there is an urgent need to propose a method for preparing trimethylsilylamine that can effectively reduce reaction costs, so as to alleviate the current situation of high cost in the preparation of trimethylsilylamine using existing technologies. Summary of the Invention

[0005] In view of this, and to address the shortcomings of existing technologies, this invention provides a method for preparing monochlorosilane using silane and trichlorosilane in the presence of a catalyst. The reactants are purified by distillation to obtain monochlorosilane. The obtained monochlorosilane and ammonia are then added in a specific ratio to a low-temperature reactor, and the reaction is allowed to proceed for a certain period. The reaction solution is then filtered and purified by distillation to obtain high-purity trimethylsilylamine. Furthermore, since excessive ammonia during the preparation of trimethylsilylamine can cause further reaction between trimethylsilylamine and ammonia, leading to a decrease in the yield of trimethylsilylamine, this method offers lower cost, readily available and simpler raw materials, fewer byproducts, and a higher yield for the preparation of trimethylsilylamine.

[0006] The technical solution of this application is as follows:

[0007] A method for preparing trimethylsilylamine includes the following steps:

[0008] Step S1. Under the action of a catalyst, silane and trichlorosilane undergo a catalytic reaction to obtain crude monochlorosilane;

[0009] Step S2. The crude monochlorosilane obtained in step S1 is purified by distillation to obtain monochlorosilane;

[0010] Step S3. The monochlorosilane obtained from step S2 is reacted with anhydrous ammonia gas in a reaction vessel to prepare trimethylsilylamine;

[0011] Step S4. Purify the trimethylsilylamine prepared in step S3 to obtain high-purity trimethylsilylamine.

[0012] Preferably, the catalyst in step S1 is any one of aniline, diphenylamine, ethylamine, isopropylamine, hexylamine, and N,N-dimethylformamide, or any one of the basic compounds of aniline, diphenylamine, ethylamine, isopropylamine, hexylamine, and N,N-dimethylformamide.

[0013] Preferably, the catalytic reaction temperature in step S1 is 0–200°C, the time is 10–16 hours, and the amount of catalyst used is 3–5% of the mass of silane.

[0014] Preferably, the molar ratio of silane to trichlorosilane in step S1 is 14:1 to 8:1.

[0015] Preferably, the temperature for distillation purification in step S2 is -50 to 80°C.

[0016] Preferably, in step S3, before introducing monochlorosilane and anhydrous ammonia into the reactor, a solvent is added and the temperature is lowered.

[0017] Preferably, the temperature is reduced to -60 to 40°C.

[0018] Preferably, the reaction time in step S3 is 8 to 16 hours, and the reaction pressure is 0.2 MPa.

[0019] Preferably, the solvent is one or more of toluene, xylene, trimethylbenzene, dichloromethane, n-hexane, and n-heptane, and the mass ratio of the solvent to the monochlorosilane is (9-10):1.

[0020] Preferably, in step S3, the molar ratio of monochlorosilane to anhydrous ammonia is 2:1 to 5:1. Preferably, the purification process in step S4 involves: first filtering to remove solid ammonium chloride, followed by two-stage distillation, wherein the temperature of the first-stage distillation is 15–20°C, and the temperature of the second-stage distillation is 40–70°C. The beneficial effects of this application are as follows:

[0021] (1) This application yields high-purity products with low by-product content. It utilizes organic catalysts such as aniline and ethylamine to achieve efficient conversion between silane and trichlorosilane at 0–200°C. Compared to traditional metal catalysts, organic catalysts offer advantages in environmental friendliness and mild reaction conditions, avoiding the high cost of precious metals and reducing side reaction pathways. In step S4 of this application, ammonium chloride solid is removed by filtration, and high-purity trimethylsilylamine is obtained by combining low-temperature and high-temperature distillation.

[0022] (2) When preparing the reaction raw material monochlorosilane in this application, the reaction temperature is easy to control and the operation is stable. There is no need for strict temperature control conditions. Secondly, in step S3 of this application, solvents such as toluene and n-hexane are added in advance and the temperature is lowered to -60 to 40°C. The high specific heat capacity of the solvent is used to buffer the exothermic reaction, and the temperature fluctuation of the system is small, avoiding local overheating and side reactions.

[0023] (3) The process of this application is reasonable, easy to operate and low in cost. The raw materials used in this application are silane, trichlorosilane and conventional solvents, which are widely available and low in cost. Furthermore, steps S1 to S4 can be carried out in a continuous operation mode to avoid intermediate transfer loss, which is suitable for large-scale production.

[0024] (4) This application uses a self-made method with monochlorosilane to prepare trimethylsilylamine, which can effectively reduce the high cost and storage difficulties associated with purchasing monochlorosilane. This process can effectively reduce costs by approximately 30%, providing a solid foundation for the industrial production of trimethylsilylamine. Attached Figure Description

[0025] Appendix Figure 1 A diagram of the apparatus for preparing monochlorosilanes according to this application;

[0026] Appendix Figure 2 This is a diagram of the apparatus used to prepare trimethylsilylamine according to this application.

[0027] Attached image labels:

[0028] 1. Gas cylinder; 2. First reaction vessel; 3. Distillation and purification vessel; 4. First collection vessel; 5. Second reaction vessel; 6. Filter; 7. First distillation column; 8. Second distillation column; 9. Second collection vessel. Detailed Implementation

[0029] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0030] Device example 1

[0031] This example provides an apparatus for preparing monochlorosilane, as shown in the attached diagram. Figure 1 As shown, the system includes, in sequence, a gas cylinder 1, a first reaction vessel 2, a distillation and purification vessel 3, and a first collection vessel 4 connected together. The distillation and purification device is also connected to the first reaction vessel 2 and is used to recover gases such as trichlorosilane.

[0032] The principle of the device is as follows: At the beginning of the reaction, ethylamine and trichlorosilane are added to the first reaction vessel 2 to react. Under the action of the catalyst, the monochlorosilane generated then enters the distillation purification device for distillation purification. The monochlorosilane then enters the first collection tank 4, while the trichlorosilane and other gases are returned to the first reaction vessel 2 for recycling.

[0033] Device example 2

[0034] This example provides an apparatus for preparing trimethylsilylamine, as shown in the attached diagram. Figure 2 As shown, it includes a second reaction vessel 5, a filter 6, a first distillation column 7, a second distillation column 8, and a second collection tank 9 arranged sequentially along the material flow direction.

[0035] The principle of the apparatus: At the start of the reaction, solvent is added to the second reaction vessel 5 in advance, and the temperature of the second reaction vessel 5 is adjusted. Then, anhydrous ammonia and monochlorosilane are introduced to react. The trimethylsilylamine generated by the reaction enters the filter 6 to remove ammonium chloride solid, and then enters the first distillation column 7 and the second distillation column 8 to obtain high-purity trimethylsilylamine, and finally enters the second collection tank 9.

[0036] Example 1

[0037] This embodiment provides a method for preparing trimethylsilylamine. First, 6g of ethylamine and 200g of trichlorosilane are added to a first reaction vessel 2. The temperature of the first reaction vessel 2 is controlled at 180°C, and stirring is started. The reaction is carried out for 14 hours. Then, 475g of silane is added to the first reaction vessel 2. After the reaction is complete, the first reaction vessel 2 is cooled to room temperature, and the collected gas is transferred to a distillation purification device for distillation at 80°C. The product, monochlorosilane (MCS), is collected by distillation and enters a first collection tank 4. The yield of monochlorosilane is 65%.

[0038] Toluene was added to the second reactor 5, controlling the mass ratio of solvent to monochlorosilane to be 9:1. The temperature of the second reactor 5 was pre-set to -40℃. Stirring was started, and anhydrous ammonia and purified monochlorosilane were introduced into the second reactor 5, with the monochlorosilane and anhydrous ammonia added at a molar ratio of 2:1. The reaction time was 15 hours, and the reaction pressure was 0.2 MPa. After the reaction was completed, the reaction solution was filtered to remove solid ammonium chloride. The resulting filtrate was then distilled. First, it was heated to 15℃ to remove excess unreacted anhydrous ammonia and monochlorosilane. Then, the temperature was further increased to 70℃ to collect trimethylsilylamine. After two distillations, high-purity trimethylsilylamine was obtained. The yield of the trimethylsilylamine product was 68%, and the purity was greater than 99.6%.

[0039] Example 2

[0040] This embodiment provides a method for preparing trimethylsilylamine. First, 12g of isopropylamine and 200g of trichlorosilane are added to a first reaction vessel 2. The temperature of the first reaction vessel 2 is controlled at 160°C, and stirring is started. The reaction is carried out for 10 hours. Then, 475g of silane is added to the first reaction vessel 2. After the reaction is complete, the first reaction vessel 2 is cooled to room temperature, and the collected gas is transferred to a distillation purification device for distillation at 60°C. The product, monochlorosilane (MCS), is collected by distillation and enters a first collection tank 4. The yield of monochlorosilane is 50%.

[0041] Xylene solvent was added to the second reactor 5, with the mass ratio of solvent to monochlorosilane controlled at 10:1. The temperature of the second reactor 5 was pre-set to -40℃. Stirring was started, and anhydrous ammonia gas and purified monochlorosilane were introduced into the second reactor 5, with the molar ratio of monochlorosilane to anhydrous ammonia gas being 4:1. The reaction time was 16 hours, and the reaction pressure was 0.2 MPa.

[0042] After the reaction is complete, the reaction solution is passed through filter 6 to remove solid ammonium chloride. The resulting filtrate is then distilled. First, it is heated to 15°C to remove excess unreacted anhydrous ammonia and monochlorosilane. Then, the temperature is further increased to 70°C to collect trimethylsilylamine. After two distillations, high-purity trimethylsilylamine is obtained. The yield of trimethylsilylamine is 80%, and the purity is greater than 99.6%.

[0043] Example 3

[0044] This embodiment provides a method for preparing trimethylsilylamine. First, 10g of N,N-dimethylformamide and 200g of trichlorosilane are added to a first reaction vessel 2. The temperature of the first reaction vessel 2 is controlled at 180°C, and stirring is started. The reaction is carried out for 16 hours. Then, 475g of silane is added to the first reaction vessel 2. After the reaction is complete, the first reaction vessel 2 is cooled to room temperature, and the collected gas is transferred to a distillation purification device for distillation at 20°C. The product, monochlorosilane (MCS), is collected by distillation and enters a first collection tank 4. The yield of monochlorosilane is 65%.

[0045] In the second reaction vessel 5, thallium solvent was added, controlling the mass ratio of solvent to monochlorosilane to be 9:1. The temperature of the second reaction vessel 5 was pre-set to -30℃, and stirring was started. Anhydrous ammonia gas and purified monochlorosilane were introduced into the second reaction vessel 5, with the monochlorosilane and anhydrous ammonia gas added at a molar ratio of 3:1. The reaction time was 8 hours, and the reaction pressure was 0.2 MPa. After the reaction was completed, the reaction solution was passed through filter 6 to remove solid ammonium chloride. The resulting filtered liquid was then distilled. First, it was heated to 15℃ to remove excess unreacted anhydrous ammonia gas and monochlorosilane. Then, the temperature was further increased to 70℃ to collect trimethylsilylamine. After two distillations, high-purity trimethylsilylamine product was obtained. The yield of trimethylsilylamine product was approximately 70%.

[0046] Example 4

[0047] This embodiment provides a method for preparing trimethylsilylamine. First, 8g of aniline and 200g of trichlorosilane are added to a first reaction vessel 2. The temperature of the first reaction vessel 2 is controlled at 200℃, and stirring is started. The reaction is carried out for 12 hours. Then, 308g of silane is added to the first reaction vessel 2. After the reaction is complete, the first reaction vessel 2 is cooled to room temperature, and the collected gas is transferred to a distillation purification device for distillation at -30℃. The product, monochlorosilane (MCS), is collected by distillation and enters a first collection tank 4. The yield of monochlorosilane is 56%.

[0048] Hexane was added as solvent to the second reaction vessel 5, controlling the mass ratio of solvent to monochlorosilane to be 10. The temperature of the second reaction vessel 5 was pre-set to -60℃. Stirring was started, and anhydrous ammonia and purified monochlorosilane were introduced into the second reaction vessel 5, with the monochlorosilane and anhydrous ammonia added at a molar ratio of 3:1. The reaction time was 10 hours, and the reaction pressure was 0.2 MPa. After the reaction was completed, the reaction solution was filtered to remove solid ammonium chloride. The resulting filtrate was then distilled. First, it was heated to 10℃ to remove excess unreacted anhydrous ammonia and monochlorosilane. Then, the temperature was further raised to 80℃ to collect trimethylsilylamine. Distillation was carried out at -50 to 80℃, and high-purity trimethylsilylamine was obtained through two distillations. The yield of the trimethylsilylamine product was 71%, and the purity was greater than 99.6%.

[0049] Example 5

[0050] This embodiment provides a method for preparing trimethylsilylamine. First, 11g of diphenylamine and 200g of trichlorosilane are added to a first reaction vessel 2. The temperature of the first reaction vessel 2 is controlled at 0°C, and stirring is started. The reaction is carried out for 12 hours. Then, 664g of silane is added to the first reaction vessel 2. After the reaction is complete, the first reaction vessel 2 is cooled to room temperature, and the collected gas is transferred to a distillation purification device for distillation at -50°C. The product, monochlorosilane (MCS), is collected by distillation and enters a first collection tank 4. The yield of monochlorosilane is 55%.

[0051] Dichloromethane was added to the second reaction vessel 5, with the mass ratio of solvent to monochlorosilane controlled at 10. The temperature of the second reaction vessel 5 was pre-set to 40°C. Stirring was started, and anhydrous ammonia and purified monochlorosilane were introduced into the second reaction vessel 5, with the molar ratio of monochlorosilane to anhydrous ammonia being 5:1. The reaction time was 12 hours, and the reaction pressure was 0.2 MPa. After the reaction was completed, the reaction solution was filtered to remove solid ammonium chloride. The resulting filtrate was then distilled. First, it was heated to 20°C to remove excess unreacted anhydrous ammonia and monochlorosilane. Then, the temperature was further increased to 40°C to collect trimethylsilylamine. After two distillations, high-purity trimethylsilylamine was obtained. The yield of the trimethylsilylamine product was 72%, and the purity was greater than 99.6%.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing trimethylsilylamine, characterized in that, Includes the following steps: Step S1. Under the action of a catalyst, silane and trichlorosilane undergo a catalytic reaction to obtain crude monochlorosilane; Step S2. The crude monochlorosilane obtained in step S1 is purified by distillation to obtain monochlorosilane; Step S3. The monochlorosilane obtained from step S2 is reacted with anhydrous ammonia gas in a reaction vessel to prepare trimethylsilylamine; Step S4. Purify the trimethylsilylamine prepared in step S3 to obtain high-purity trimethylsilylamine.

2. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The catalyst in step S1 is any one of aniline, diphenylamine, ethylamine, isopropylamine, hexylamine, and N,N-dimethylformamide, or any one of the basic compounds of aniline, diphenylamine, ethylamine, isopropylamine, hexylamine, and N,N-dimethylformamide.

3. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The catalytic reaction temperature in step S1 is 0–200°C, the time is 10–16 hours, and the amount of catalyst used is 3–5% of the mass of silane.

4. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The molar ratio of silane to trichlorosilane in step S1 is 14:1 to 8:

1.

5. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The distillation purification temperature in step S2 is -50 to 80°C.

6. The method for preparing trimethylsilylamine according to claim 1, characterized in that, Before introducing monochlorosilane and anhydrous ammonia into the reactor in step S3, a solvent is added and the temperature is lowered to -60 to 40°C.

7. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The reaction time in step S3 is 8 to 16 hours, and the reaction pressure is 0.2 MPa.

8. The method for preparing trimethylsilylamine according to claim 6, characterized in that, The solvent is one or more of toluene, xylene, trimethylbenzene, dichloromethane, n-hexane, and n-heptane, and the mass ratio of the solvent to the monochlorosilane is (9-10):

1.

9. The method for preparing trimethylsilylamine according to claim 1, characterized in that, In step S3, the molar ratio of monochlorosilane to anhydrous ammonia is 2:1 to 5:

1.

10. The method for preparing trimethylsilylamine according to claim 1, characterized in that, The purification process in step S4 is as follows: first, filter to remove ammonium chloride solid, and then perform two-stage distillation, wherein the temperature of the first-stage distillation is 10-20℃ and the temperature of the second-stage distillation is 40-80℃.

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