Activation methods for liquid fatty amines, preparation processes of liquid fatty amines and silanes.

Abstract

This invention provides an activation method for a liquid fatty amine, a preparation process for the liquid fatty amine and silane, wherein the liquid fatty amine has a tertiary amine group; the activation method involves activating the liquid fatty amine with silicon tetrachloride; this method can significantly improve the catalytic effect of the liquid fatty amine, and the activated liquid fatty amine exhibits higher catalytic activity in the process of disproportionation of trichlorosilane to prepare silane, which can effectively reduce the reaction activation energy, increase the reaction rate, and improve the single-pass reaction efficiency and conversion rate.

Description

Technical Field

[0001] This invention relates to the field of silane preparation technology, and more particularly to a method for activating a liquid fatty amine, the liquid fatty amine, and a process for preparing silane using the activated liquid fatty amine. Background Technology

[0002] Silane (SiH4) is an important silicon source material, widely used in industries such as semiconductor microelectronics ICs, photovoltaic solar cells (PV), and liquid crystal displays (LCDs).

[0003] There are three main processes for preparing silanes: 1) Sodium aluminum fluoride method: This method uses sodium aluminum hydride and silicon tetrafluoride as raw materials to synthesize silane gas. After subsequent adsorption, distillation, separation, and purification, high-purity electronic-grade silane gas with a purity of 6N or higher is obtained; 2) Silicon-magnesium alloy method: Also known as the Komatsu method, this method uses industrial silicon powder, metallic magnesium, and ammonium chloride as raw materials. Silane is obtained through a two-step reaction, but the cost is high, and there are currently no large-scale production lines; 3) Chlorosilane disproportionation method: This method mainly uses trichlorosilane as raw material. Through multiple disproportionation reactions, silane and silicon tetrachloride are finally produced. Silicon tetrachloride can be returned to the hydrogenation process to form a closed loop, resulting in fewer emissions, which is beneficial to the environment, high material utilization, and no by-products. The chlorosilane disproportionation method has become the mainstream process for preparing silanes.

[0004] In existing partial chlorosilane disproportionation processes, aliphatic amine liquids are used as catalysts for the chlorosilane disproportionation reaction. Aliphatic amine liquids possess catalytic properties such as basicity, solubility, coordination ability, and reversibility, making them suitable for various organic synthesis reactions, metal catalysis reactions, and surface catalysis reactions. Furthermore, the relatively long carbon chain structure of aliphatic amine compounds inherently holds potential for catalytic activity. However, existing aliphatic amine liquid catalysts exhibit low activity and inefficient performance when directly applied to the chlorosilane disproportionation reaction, failing to meet the demands of industrial-scale production. Summary of the Invention

[0005] The purpose of this invention is to provide a method for activating liquid fatty amines, liquid fatty amines, and a process for preparing silanes using activated liquid fatty amines, in order to solve the problems of low catalytic activity and low catalytic efficiency of liquid catalysts in the existing silane preparation process, which are difficult to meet the needs of industrial production.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: an activation method for a liquid fatty amine, wherein the liquid fatty amine has a tertiary amine group; characterized in that: the activation method is to activate the liquid fatty amine with silicon tetrachloride.

[0007] As a further improvement to the present invention, "activating the liquid fatty amine with silicon tetrachloride" specifically includes the following steps:

[0008] The liquid fatty amine is mixed with liquid silicon tetrachloride and then activated at a preset pressure and a preset temperature to obtain a pre-activated liquid fatty amine. The preset pressure and the preset temperature are set to make the activation reaction a homogeneous liquid-phase reaction.

[0009] The residual silicon tetrachloride in the preliminarily activated liquid fatty amine is removed to obtain the activated liquid fatty amine.

[0010] As a further improvement to the present invention, the reaction formula in the activation process is: R3N + SiCl4 → [R3NSiCl3] + Cl - .

[0011] As a further improvement of the present invention, the mass percentage of silicon tetrachloride in the mixture obtained by mixing the liquid fatty amine and the liquid silicon tetrachloride is 50% to 90%.

[0012] As a further improvement of the present invention, the preset pressure is: atmospheric pressure to 5 barg; and / or the preset temperature is 60℃ to 180℃.

[0013] As a further improvement of the present invention, the activation reaction time is not less than 30 minutes.

[0014] As a further improved technical solution of the present invention, "removing the residual silicon tetrachloride from the preliminarily activated liquid fatty amine to obtain the activated liquid fatty amine" is as follows: the activated liquid fatty amine is subjected to distillation treatment, and the pressure during distillation treatment is atmospheric pressure and the temperature is not lower than 140°C.

[0015] As a further improvement of the present invention, the liquid fatty amine has 12 or more carbon atoms.

[0016] To achieve the above-mentioned objectives, the present invention also provides a liquid fatty amine, wherein the liquid fatty amine is activated by the above-mentioned activation method for liquid fatty amine.

[0017] To achieve the above-mentioned objective, the present invention also provides a liquid fatty amine, wherein the liquid fatty amine has the following composition: [R3NSiCl3] + Cl - .

[0018] As a further improvement of the present invention, the liquid fatty amine also has 12 or more carbon atoms.

[0019] To achieve the above-mentioned objective, the present invention also provides a process for preparing silane, comprising the following steps: disproportionating trichlorosilane under the action of a liquid catalyst to prepare silane, wherein the liquid catalyst is the aforementioned liquid aliphatic amine.

[0020] The beneficial effects of this invention are as follows: In the activation method of liquid fatty amines in this invention, the liquid fatty amine is activated by silicon tetrachloride. The tertiary amine groups in the liquid fatty amine react with silicon tetrachloride to form a silicon tetrachloride-coordinated complex, which can significantly improve the catalytic effect of the liquid fatty amine. The activated liquid fatty amine exhibits higher catalytic activity in the process of trichlorosilane disproportionation to prepare silane, which can effectively reduce the reaction activation energy, increase the reaction rate, and improve the single-pass reaction efficiency and conversion rate. This improved method solves the problem of low catalytic activity of liquid fatty amines in their original state and promotes the optimization of the disproportionation reaction process. Attached Figure Description

[0021] Figure 1 This is a flowchart of a method for activating liquid fatty amines according to a specific embodiment of the present invention;

[0022] Figure 2 This is an experimental image taken at room temperature for 1 hour after mixing different mass percentages of liquid silicon tetrachloride with liquid fatty amine in a specific embodiment of the present invention.

[0023] Figure 3 for Figure 2 Images of experiments in which different mass percentages of silicon tetrachloride liquid and liquid fatty amine were mixed and placed at 70°C for 2 hours;

[0024] Figure 4 Thermogravimetric analysis results for unactivated trioctylamine liquid;

[0025] Figure 5 The thermogravimetric analysis (TGA) results of trioctylamine liquid activated with silicon tetrachloride at 160°C are shown. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. Please refer to the accompanying drawings for further details. Figures 1-5 The figures shown represent preferred embodiments of the present invention. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent modifications or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0027] This invention provides a method for activating a liquid fatty amine, which, after activation, can be used as a liquid catalyst for the trichlorosilane disproportionation reaction to prepare silanes. The activated liquid fatty amine will be specifically described below as a liquid catalyst for the trichlorosilane disproportionation reaction to prepare silanes. However, this is not a limitation; in other embodiments, the activated liquid fatty amine can also be used for catalytic applications in other organic synthesis reactions, metal-catalyzed reactions, and surface catalytic reactions.

[0028] The liquid fatty amine has a tertiary amine group. Preferably, the liquid fatty amine also has 12 or more carbon atoms, and long-chain liquid fatty amines have better catalytic effects in the field of catalysis.

[0029] In some optional embodiments, the liquid fatty amine may be trioctylamine, trihedramine, or trihexylamine. Of course, it is not limited to these.

[0030] The activation method involves activating the liquid aliphatic amine with silicon tetrachloride. Specifically, the reaction formula during the activation process is: R3N + SiCl4 → [R3NSiCl3] + Cl - That is, during the activation of the liquid fatty amine using silicon tetrachloride, the tertiary amine groups in the liquid fatty amine react with silicon tetrachloride to form a silicon tetrachloride-coordinated complex. This complex introduces new active centers, which can more effectively promote the disproportionation reaction of trichlorosilane molecules and improve catalytic efficiency. Simultaneously, the generated complex contains positively charged active sites, which can better attract partially negatively charged trichlorosilane molecules. By enhancing the charge effect between the catalyst and reactants, the interaction force between the catalyst and reactants is strengthened, thereby promoting the disproportionation reaction. Furthermore, the formation of the complex alters the lipid... The spatial configuration of aliphatic amine molecules is improved by reducing the steric hindrance caused by their long carbon chains, allowing them to effectively contact more reactant molecules in the reaction system and enhancing catalytic activity. Furthermore, the complex formed by the reaction of silicon tetrachloride and tertiary amine groups exhibits higher thermal and chemical stability, maintaining catalytic activity at higher temperatures, thus adapting to the high-temperature conditions of the trichlorosilane disproportionation reaction. Therefore, the liquid aliphatic amine catalyst activated with silicon tetrachloride significantly improves catalytic performance. This activated liquid aliphatic amine demonstrates higher catalytic activity in the trichlorosilane disproportionation process to prepare silane, effectively reducing the activation energy, increasing the reaction rate, and improving single-pass reaction efficiency and conversion. This improved method solves the problem of low catalytic activity of liquid aliphatic amines in their original state, promoting the optimization of the disproportionation reaction process.

[0031] Specifically, in combination Figure 1As shown, the "activation of the liquid fatty amine using silicon tetrachloride" specifically includes the following steps:

[0032] The liquid fatty amine is mixed with liquid silicon tetrachloride and then activated at a preset pressure and a preset temperature to obtain a pre-activated liquid fatty amine. The preset pressure and the preset temperature are set to make the activation reaction a homogeneous liquid-phase reaction.

[0033] The residual silicon tetrachloride in the preliminarily activated liquid fatty amine is removed to obtain the activated liquid fatty amine.

[0034] On the one hand, by setting preset pressure and temperature, the activation reaction becomes a homogeneous liquid-phase reaction, which is more conducive to the activation process and improves the activation effect of the liquid fatty amine. Consequently, it can enhance the catalytic activity of the activated liquid fatty amine, thereby improving the disproportionation efficiency and yield when the activated liquid fatty amine participates in the trichlorosilane disproportionation reaction. On the other hand, after the activation reaction is completed, the residual silicon tetrachloride in the pre-activated liquid fatty amine is removed to prevent the residual silicon tetrachloride from affecting the chlorine-silicon ratio in the trichlorosilane disproportionation reaction process and affecting the disproportionation reaction equilibrium. This allows the trichlorosilane disproportionation reaction to proceed as far as possible towards the disproportionation to dichlorosilane and silicon tetrachloride stages, thereby improving the disproportionation efficiency and yield.

[0035] In one specific embodiment, the preset pressure is: atmospheric pressure to 5 barg, preferably 1 barg. The preset temperature is 60℃ to 180℃, preferably 160℃. It is understood that the combination of the preset pressure and the preset temperature is sufficient to keep both the liquid fatty amine and the silicon tetrachloride in a liquid state, thus ensuring that the activation reaction is a homogeneous liquid-phase reaction.

[0036] In one specific embodiment, the mass percentage of silicon tetrachloride in the mixture obtained after mixing the liquid fatty amine and liquid silicon tetrachloride is 50% to 90%. If the silicon tetrachloride content is too low, it will affect the bonding between silicon tetrachloride and tertiary amine groups, resulting in incomplete activation of the liquid fatty amine; if the silicon tetrachloride content is too high, it will increase the difficulty of separating the residual silicon tetrachloride in the subsequent process.

[0037] Specifically, the activation reaction time is not less than 30 minutes to improve the activation effect on liquid fatty amines.

[0038] In some optional embodiments, "removing residual silicon tetrachloride from the pre-activated liquid fatty amine to obtain activated liquid fatty amine" means: distilling the pre-activated liquid fatty amine at atmospheric pressure and a temperature not lower than 140°C. That is, the pre-activated liquid fatty amine is passed into a distillation column and distilled at atmospheric pressure not lower than 140°C to remove silicon tetrachloride from the pre-activated liquid fatty amine, obtaining activated liquid fatty amine, which can then be used as a liquid catalyst for the trichlorosilane disproportionation reaction.

[0039] Combination Figure 2 The image shown is an experimental image of different mass percentages of liquid silicon tetrachloride mixed with liquid fatty amine, after 1 hour at room temperature. In this experiment, the liquid fatty amine used was trioctylamine. Figure 3 As shown, Figure 2 The images show experimental results of mixing different mass percentages of silicon tetrachloride liquid with liquid fatty amine and then placing the mixture at 70°C for 2 hours. It can be seen that when the mass percentage of silicon tetrachloride in the silicon tetrachloride liquid is less than 75%, the mixture of silicon tetrachloride liquid and liquid fatty amine will become cloudy and form a complex after 1 hour at room temperature; however, upon increasing the temperature, this complex exhibits good solubility in the silicon tetrachloride solution.

[0040] Combination Figures 4-5 As shown, where Figure 4 Thermogravimetric results are for unactivated trioctylamine liquid. Figure 5 The thermogravimetric analysis (TGA) results are shown for trioctylamine liquid activated with silicon tetrachloride at 160°C. It can be seen that the complex did not lose weight after activation at 160°C, indicating that the process of separating the residual silicon tetrachloride from the initially activated liquid fatty amine does not affect the activated liquid fatty amine, that is, it does not affect the generated complex.

[0041] Furthermore, the present invention also provides a liquid fatty amine, wherein the liquid fatty amine is activated by the above-described activation method for liquid fatty amines.

[0042] The activated liquid fatty amine possesses: [R3NSiCl3] + Cl -This complex introduces new active centers that can more effectively promote the disproportionation reaction of trichlorosilane molecules, improving catalytic efficiency. Simultaneously, the generated complex contains positively charged active sites, which can better attract partially negatively charged trichlorosilane molecules, enhancing the charge effect between the catalyst and reactants and strengthening their interaction, thereby promoting the disproportionation reaction. Furthermore, the formation of the complex alters the spatial configuration of the aliphatic amine molecules, reducing the steric hindrance effect caused by their long carbon chains, allowing them to effectively contact more reactant molecules in the reaction system and improving catalytic activity. Moreover, the complex formed by the reaction of silicon tetrachloride and tertiary amine groups exhibits higher thermal and chemical stability, maintaining its catalytic activity at higher temperatures, thus adapting to the high-temperature conditions of the trichlorosilane disproportionation reaction. Therefore, the liquid aliphatic amine catalyst activated by silicon tetrachloride can significantly improve catalytic performance. This activated liquid aliphatic amine exhibits higher catalytic activity in the process of trichlorosilane disproportionation to prepare silane, effectively reducing the activation energy, increasing the reaction rate, and improving single-pass reaction efficiency and conversion rate. This improved method solves the problem of low catalytic activity of liquid fatty amines in their original state, and promotes the optimization of the disproportionation reaction process.

[0043] In a preferred embodiment, the activated liquid fatty amine also has 12 or more carbon atoms, thereby exhibiting better catalytic effects.

[0044] Furthermore, the present invention also provides a process for preparing silanes, comprising the following steps: disproportionating trichlorosilane in the presence of a liquid catalyst to prepare silanes, wherein the liquid catalyst is the aforementioned activated liquid aliphatic amine. This activated liquid aliphatic amine exhibits higher catalytic activity, effectively reducing the activation energy, increasing the reaction rate, and improving the single-pass reaction efficiency and conversion rate.

[0045] In the process of preparing silane, the existing equipment such as distillation columns can be used, and the process parameters can be adjusted according to specific needs.

[0046] The following examples, along with corresponding comparative examples, will be used to illustrate the catalytic effect of the activated liquid fatty amines in this invention.

[0047] Example 1 and Comparative Example 1: In Comparative Example 1, unactivated trihedrine was used as a liquid catalyst to catalyze the disproportionation of trichlorosilane to dichlorosilane and silicon tetrachloride. The liquid catalyst accounted for 12% of the mass of the reactant trichlorosilane. Under normal pressure and a reaction temperature of 35°C for 20 min, the conversion rate of trichlorosilane was 7.6%. In Example 1, activated trihedrine was used as the liquid catalyst, and under the same reaction conditions, the conversion rate of trichlorosilane was 18.2%.

[0048] Example 2 and Comparative Example 2: In Comparative Example 2, unactivated trihexylamine was used as a liquid catalyst to catalyze the disproportionation of trichlorosilane to dichlorosilane and silicon tetrachloride. The liquid catalyst accounted for 12% of the mass of the trichlorosilane reactant. The reaction was carried out at atmospheric pressure and a reaction temperature of 35°C for 20 minutes, resulting in a trichlorosilane conversion rate of 6.3%. In Example 2, activated trihexylamine was used as the liquid catalyst, and under the same reaction conditions, the trichlorosilane conversion rate was 16.1%.

[0049] As can be seen from the comparison between Example 1 and Comparative Example 1, and the comparison between Example 2 and Comparative Example 2, the liquid aliphatic amine catalyst activated by silicon tetrachloride in this invention can significantly improve the catalytic effect. The activated liquid aliphatic amine exhibits higher catalytic activity in the process of trichlorosilane disproportionation to prepare silane, which can effectively reduce the reaction activation energy, increase the reaction rate, and improve the single-pass reaction efficiency and conversion rate.

[0050] Compared with the prior art, the activation method of liquid fatty amine in this invention activates the liquid fatty amine with silicon tetrachloride. The tertiary amine group in the liquid fatty amine reacts with silicon tetrachloride to form a silicon tetrachloride-coordinated complex, which can significantly improve the catalytic effect of the liquid fatty amine. The activated liquid fatty amine exhibits higher catalytic activity in the disproportionation of trichlorosilane to prepare silane, which can effectively reduce the reaction activation energy, increase the reaction rate, and improve the single-pass reaction efficiency and conversion rate. This improved method solves the problem of low catalytic activity of liquid fatty amine in its original state and promotes the optimization of the disproportionation reaction process.

[0051] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0052] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for activating a liquid fatty amine, wherein the liquid fatty amine has a tertiary amine group; characterized in that: The activation method involves activating the liquid fatty amine with silicon tetrachloride.

2. The activation method for liquid fatty amines as described in claim 1, characterized in that: The activation of the liquid fatty amine using silicon tetrachloride specifically includes the following steps: The liquid fatty amine is mixed with liquid silicon tetrachloride and then activated at a preset pressure and a preset temperature to obtain a pre-activated liquid fatty amine. The preset pressure and the preset temperature are set to make the activation reaction a homogeneous liquid-phase reaction. The residual silicon tetrachloride in the preliminarily activated liquid fatty amine is removed to obtain the activated liquid fatty amine.

3. The activation method for liquid fatty amines as described in claim 1 or 2, characterized in that: The reaction formula in the activation process is: R3N + SiCl4 → [R3NSiCl3] + Cl - .

4. The activation method for liquid fatty amines as described in claim 2, characterized in that: The mass percentage of silicon tetrachloride in the mixture obtained by mixing the liquid fatty amine and the liquid silicon tetrachloride is 50% to 90%.

5. The activation method for liquid fatty amines as described in claim 2, characterized in that: The preset pressure is: atmospheric pressure to 5 barg; and / or the preset temperature is 60℃ to 180℃.

6. The activation method for liquid fatty amines as described in claim 2, characterized in that: The activation reaction time shall not be less than 30 minutes.

7. The activation method for liquid fatty amines as described in claim 2, characterized in that: "Removing residual silicon tetrachloride from the preliminarily activated liquid fatty amine to obtain activated liquid fatty amine" means: distilling the preliminarily activated liquid fatty amine at atmospheric pressure and a temperature of not less than 140℃.

8. The activation method for liquid fatty amines as described in claim 1, characterized in that: The liquid fatty amine has 12 or more carbon atoms.

9. A liquid fatty amine, characterized in that: The liquid fatty amine is activated using the activation method described in any one of claims 1 to 8.

10. A liquid fatty amine, characterized in that: The liquid fatty amine possesses: [R3NSiCl3] + Cl - .

11. The liquid fatty amine as described in claim 10, characterized in that: The liquid fatty amine also has 12 or more carbon atoms.

12. A process for preparing silane, characterized in that: The method includes the following steps: disproportionating trichlorosilane in the presence of a liquid catalyst to prepare silane, wherein the liquid catalyst is a liquid aliphatic amine as described in any one of claims 9 to 11.

Images