Method for preparing organosilane by silicon powder ball milling catalysis

Abstract

The present invention belongs to the field of chemical engineering, particularly to the field of synthesis of organosilanes. Specifically, it relates to a method for preparing organosilanes by ball-milling catalysis using silicon powder as a raw material, which comprises the following steps: Step 1, preparing metal-clad grinding balls as catalysts; Step 2, ball-milling reaction: fully mixing and reacting the metal-clad grinding balls obtained in Step 1, silicon powder and reaction raw materials for preparing organosilanes in a ball-milling device for 2 to 8 hours, and then through post-treatment, obtaining organosilanes; the molar ratio of silicon powder to reaction raw materials required for preparing organosilanes is 1:1.5 to 4. The present invention utilizes laser cladding technology to prepare a metal catalyst clad on the surface of grinding balls, and adopts mechanochemical ball-milling method to synthesize organosilanes, which is beneficial to promoting green and efficient production in the field of organosilane chemical engineering and reducing the discharge of three wastes.

Description

Technical Field

[0001] The present invention belongs to the field of chemical engineering, especially the field of synthesis of organosilanes, and particularly relates to a method for preparing organosilanes by ball-milling catalysis using silicon powder as a raw material. Background Art

[0002] Organosilanes are an important class of chemical materials and have extensive applications in fields such as aerospace, electronics and electrical engineering, construction, environment, energy, and biomedicine.

[0003] Silane products prepared from silicon powder as a raw material include chlorosilanes, phenylchlorosilanes, alkoxysilanes, etc. In the prior art, methods for producing organosilanes such as chlorosilanes, alkylchlorosilanes, phenylchlorosilanes, and alkoxysilanes using silicon powder mostly employ equipment such as fixed beds and fluidized beds, use copper as the main catalyst, and are carried out under high-temperature conditions.

[0004] Taking the production of phenylchlorosilane as an example, the current industrial production process uses chlorobenzene and silicon powder as raw materials, uses copper as the main catalyst, the reaction temperature is 450 - 600°C, the reaction pressure is 0.2 - 0.5 MPa, and the main products formed are phenyltrichlorosilane and diphenyldichlorosilane.

[0005] In the method for preparing phenylchlorosilane disclosed in Patent CN202110337859.1, metal hydrogen fluoride is used to activate silicon powder and a copper catalyst to obtain a silicon-copper contact body; then the pretreated silicon-copper contact body is added to a reactor, chlorobenzene is introduced, and phenylchlorosilane monomers are prepared by reaction. The reaction temperature is 450 - 600°C, and the pressure is 0.1 - 1 MPa.

[0006] In the method for preparing phenylchlorosilane disclosed in Patent 201811551861.3, silicon powder, a copper catalyst, and a sodium-containing compound are added to a reactor, and then a silicon-copper modifier is introduced for pretreatment to obtain a silicon-copper contact body. Finally, the treated silicon-copper contact body is mixed with a quaternary copper catalyst and added to the reactor, chlorobenzene is introduced, and the reaction temperature is controlled at 400 - 700°C to prepare phenylchlorosilane by reaction.

[0007] In the method for directly synthesizing trialkoxysilane disclosed in Patent CN200780028974.9, a reaction mixture composed of a solvent, silicon powder, and a nanoscale copper catalyst is added to a reactor and stirred and heated. The reaction temperature is about 200 - 280°C, the pressure is 0.1 - 0.5 MPa, the reaction time is 8 - 16 hours, and then an alcohol and a nitrile additive are added to the reaction mixture to prepare trialkoxysilane by reaction.

[0008] The deficiencies of the above methods are as follows: Most of the above methods use fluidized beds and fixed beds as reaction equipment, and their reaction conditions are relatively harsh, and the reaction temperature usually needs to be above 200°C. The new process synthesized by the mechanochemical method can promote green and efficient production in the organosilicon chemical industry.

[0009] Mechanochemistry is a new discipline that studies chemical reactions, physicochemical properties, or internal microstructural changes that occur in materials under the induction and action of mechanical forces. For most chemical syntheses, the reaction takes place in solution; while mechanochemistry relying on mechanical forces basically does not require solvents, it has low energy consumption, fast reaction speed, and can basically synthesize a series of functional molecules quantitatively. Mechanochemistry provides a new idea for the preparation process of organosilanes. It has been reported that silicon powder, copper powder and alcohol are mixed and ball-milled in a planetary ball mill to synthesize alkoxysilanes at room temperature (ACS Sustainable Chemistry & Engineering, 2022, 10(49): 16159-16168).

[0010] For metal surfaces, the main modification methods include: thermal spraying technology, thermal spray welding technology, electroplating technology, brush plating technology, laser cladding technology, etc. Among them, laser cladding technology refers to a cladding preparation method in which a high-energy laser beam is used to irradiate the coating material coated on the surface of the substrate material, so that it melts together with the surface of the substrate material and then solidifies rapidly, achieving metallurgical bonding between the coating material and the substrate material. For example, Patent CN114262889 discloses a method for preparing a Ni-Cu-Mo-Si-W alloy cladding layer by laser cladding on the surface of a copper alloy, and this method improves the surface strength of the copper alloy. Patent CN115341207 discloses a method for preparing a wear-resistant coating on a titanium alloy by laser cladding, and this method prepares a laser cladding coating with good wear resistance on the surface of the substrate. However, at present, there are few reports on cladding metal catalysts on the surface of grinding balls by laser cladding. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a method for preparing organosilanes by the silicon powder ball milling catalysis method, which uses silicon powder as the main raw material and a metal cladding layer grinding ball as the catalyst, and uses the ball milling method to prepare organosilanes.

[0012] To solve the above technical problems, the present invention provides a method for preparing organosilanes by the silicon powder ball milling catalysis method, including the following steps:

[0013] Step 1: Prepare a metal cladding layer grinding ball as a catalyst;

[0014] Step 2: Ball milling reaction:

[0015] The metal cladding layer grinding balls, silicon powder and reaction raw materials for preparing organosilane obtained in Step 1 are fully mixed and reacted in a ball milling device (ball mill) for 2 to 8 hours (preferably 6 to 8 hours), and then after-treatment is carried out to obtain organosilane;

[0016] The molar ratio of silicon powder to the reaction raw materials required for preparing organosilane is 1:1.5 to 4 (preferably 1:2 to 4).

[0017] As an improvement to the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention:

[0018] The said Step 1 includes the following steps:

[0019] S1. Alloy powder material preparation:

[0020] Powdery main metal is mixed with W (tungsten) and B (boron) to form an alloy powder, and the alloy powder is dried to obtain the dried alloy powder for later use;

[0021] The main metal is two of Fe (iron), Co (cobalt), Ni (nickel), and Cu (copper), and the content of each is 35wt% to 60wt%;

[0022] W accounts for 1wt% to 5wt% of the weight of the alloy powder (preferably 2 to 3wt%), and B accounts for 1wt% to 5wt% of the weight of the alloy powder (preferably 2 to 3wt%);

[0023] Note: The role of compounding and adding boron element is to increase the wettability of the cladding layer, improve the hardness and wear resistance of the cladding layer, etc.; the residual moisture in the alloy powder is a factor affecting the number of pores in the alloy cladding layer, so it is necessary to remove the possible residual moisture by drying;

[0024] S2. Grinding ball pretreatment:

[0025] The surface dirt and oxide layer of the grinding balls are removed, washed with ethanol, and then placed in a drying oven for drying treatment to remove ethanol, obtaining the treated grinding balls for later use;

[0026] S3. Grinding ball cladding:

[0027] The dried alloy powder obtained in Step S1 is wetted with a binder (prepared by mixing 502 glue and acetone in a volume ratio of 1:20 ± 2), and then bonded to the surface of the treated grinding balls obtained in Step S2. After drying with hot air (generally drying with hot air at 60 to 80°C for 30 to 60 minutes), it is preheated to 150 to 180°C, and then placed (fixed) on a cladding workbench to carry out laser cladding on the surface of the grinding balls to obtain metal cladding layer grinding balls;

[0028] The particle size of the grinding balls is 20mm to 40mm;

[0029] When the particle size of the grinding balls is 20 mm, 11 - 12 g (preferably 11.2 g) of dried alloy powder is used for each grinding ball.

[0030] When the particle size of the grinding balls is 30 mm, 27 - 29 g (preferably 28 g) of dried alloy powder is used for each grinding ball.

[0031] When the particle size of the grinding balls is 40 mm, 54 - 58 g (preferably 56 g) of dried alloy powder is used for each grinding ball.

[0032] Note: The purpose of the above hot air drying is to evaporate the binder as much as possible. The presence of the binder will affect the number of pores on the surface of the cladding layer, thus affecting the performance of the cladding layer.

[0033] The binder can be obtained by mixing 502 glue and acetone in a volume ratio of 1:20 ± 2; the ratio of dried alloy powder to binder is about 1:0.8 - 1.1.

[0034] When the particle size of the grinding balls is too small (beyond the lower limit set in the present invention), the impact energy generated by the collision between the grinding balls cannot meet the energy required for the reaction, resulting in a decrease in the conversion rate of silicon powder.

[0035] As a further improvement to the method for preparing organosilane by the ball - milling catalysis method of silicon powder of the present invention, step two is as follows:

[0036] Load the metal - clad grinding balls obtained in step one, silicon powder, and reaction raw materials for preparing organosilane into the ball - milling tank; carry out ball - milling at a reaction pressure of 0.1 - 1 MPa, a rotation speed of 600 - 1000 rpm, and at room temperature for 2 - 8 hours (preferably 6 - 8 hours).

[0037] The post - treatment is as follows: After the reaction ends, take out the reaction mixture in the ball - milling tank, filter it to obtain a filtrate and a filter cake (mainly unreacted silicon powder and grinding balls clad with alloy), wash the filter cake with ethyl acetate (usually wash 2 - 3 times) to obtain a washing solution, and after combining the washing solution and the filtrate, carry out rectification to obtain organosilane.

[0038] Note: Generally, in a 1 - L volume ball - milling tank, put grinding balls containing 280 ± 20 g of dried alloy powder, and the mass of silicon powder is 50 ± 10 g.

[0039] The number of grinding balls is 5 - 25, which is adjusted according to the selected particle size, specifically 5 (40 mm), 10 (30 mm), 25 (20 mm).

[0040] The grinding balls are both the grinding medium in the ball - milling process and the carrier of the catalyst.

[0041] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention, in step S3:

[0042] The process parameters of laser cladding are: laser power 2 - 4 kW, pulse frequency 10 - 50 Hz, and spot diameter 2 - 4 mm.

[0043] The average thickness of laser cladding is about 0.8 - 1.2 mm.

[0044] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention, the reaction raw materials for preparing organosilane are any one of the following: chlorobenzene, methanol, ethanol, propanol, isopropanol, hydrogen chloride, chloromethane, chloroethane;

[0045] The organosilane (silane monomer) is any one of the following: monochlorosilane, dichlorosilane, trichlorosilane, silicon tetrachloride, phenyltrichlorosilane, diphenyldichlorosilane, triphenylchlorosilane, trimethoxysilane, tetramethoxysilane, triethoxysilane, tetraethoxysilane, tripropoxysilane, tetrapropoxysilane, triisopropoxysilane, methyldichlorosilane, methyltrichlorosilane, dimethyldichlorosilane, tetramethylsilane, triethylchlorosilane, ethyltrichlorosilane, diethyldichlorosilane, tetraethylsilane.

[0046] Specifically:

[0047] When the reaction raw material is chlorobenzene, the obtained organosilane is mainly diphenyldichlorosilane, and the by - products are phenyltrichlorosilane and triphenylchlorosilane;

[0048] When the reaction raw material is methanol, the obtained organosilane is mainly trimethoxysilane, and the by - product is tetramethoxysilane;

[0049] When the reaction raw material is ethanol, the obtained organosilane is mainly triethoxysilane, and the by - product is tetraethoxysilane;

[0050] When the reaction raw material is propanol, the obtained organosilane is mainly tripropoxysilane, and the by - product is tetrapropoxysilane;

[0051] When the reaction raw material is isopropanol, the obtained organosilane is mainly triisopropoxysilane, and the by - product is tetraisopropoxysilane;

[0052] When the reaction raw material is hydrogen chloride, the obtained organosilane is mainly trichlorosilane, and the by - products are monochlorosilane, trichlorosilane, and silicon tetrachloride;

[0053] When the reaction raw material is chloromethane, the obtained organosilane is mainly dimethyldichlorosilane, and the by - products are methyldichlorosilane, methyltrichlorosilane, and tetramethylsilane;

[0054] When the reaction raw material is chloroethane, the obtained organosilane is mainly diethyldichlorosilane, and the by-products are triethylchlorosilane, ethyltrichlorosilane, and tetraethylsilane.

[0055] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention, in step S1:

[0056] The particle sizes of the powdery main metal, W, and B are all 20 - 50 μm, and the shape is spherical.

[0057] The powdery main metal, W, and B are mixed in a dry powder mixer, and the mixing time is 2 - 4 hours.

[0058] The drying (drying) temperature is 60 - 80 °C, and the drying time is 1 - 2 hours.

[0059] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention, the diameter of the grinding balls is 20 - 40 mm, and the material is 303 stainless steel, 304 stainless steel, tungsten carbide, or zirconia.

[0060] The number of grinding balls is 5 - 25, and the quantity is adjusted according to the selected particle size. Generally, for a ball milling tank with a volume of 1 L, it is 5 (40 mm), 10 (30 mm), 25 (20 mm).

[0061] The grinding balls are both the grinding medium in the ball milling process and the carrier of the catalyst.

[0062] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention, the mass fraction of silicon in the silicon powder is ≥99%, and the particle size of the silicon powder is 50 - 80 μm.

[0063] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention: the ball milling equipment is a vibration ball mill or a planetary ball mill.

[0064] As a further improvement of the method for preparing organosilane by the silicon powder ball milling catalysis method of the present invention: the preferred formula of the alloy powder is: Ni 45 wt%, Cu 50 wt%, W 2 wt%, B 3 wt%.

[0065] In the present invention, the grinding balls are polished with 200 - 600 - mesh sandpaper to remove surface dirt and oxide layers. The polishing requirement is to completely remove the oxide film on the surface of the grinding balls without thick scratches, the direction of the grinding marks is consistent, and the surface is bright.

[0066] For the method for preparing organosilane provided by the present invention, the prepared alloy powder is loaded on the surface of the grinding balls by laser cladding to obtain metal - clad layer grinding balls with catalytic performance. The grinding balls, silicon powder, and the raw materials required for preparing the target silane are fully mixed in a ball mill for reaction to obtain organosilane.

[0067] The present invention prepares grinding balls with metal catalysts clad on the surface and develops a process for preparing silicon powder downstream products by ball milling, which has the following advantages:

[0068] 1. Mechanical ball milling reduces the use of a large amount of organic solvents in the preparation process, and the production process is more green and economical;

[0069] 2. The reaction conditions of the mechanical ball milling method are milder than those of the fluidized bed and fixed bed. The catalyst coated on the ball mill is easy to use, simple to separate, not easy to deactivate, and can be recycled many times.

[0070] In summary, the present invention utilizes laser cladding technology to prepare a metal catalyst clad on the surface of a grinding ball and adopts a mechanochemical ball milling method to synthesize organosilane, which is beneficial to promoting green and efficient production in the field of organosilicon chemical industry and reducing the emission of three wastes, and is of great significance. DETAILED DESCRIPTION

[0071] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0072] The particle sizes of the main metals (Fe, Co, Ni, Cu), W and B in the alloy powder are all 20 to 50 μm and the shapes are spherical.

[0073] The mass fraction of silicon in the silicon powder is ≥99%, and the particle size of the silicon powder is 50 to 80 μm.

[0074] The products obtained by the present invention have all verified their correctness.

[0075] Embodiment 1: A method for preparing organosilane by silicon powder ball milling catalysis method, comprising the following steps in sequence:

[0076] S1. Alloy powder material configuration:

[0077] The alloy powder is composed of 45wt% Ni, 50wt% Cu, 2wt% W and 3wt% B by mass;

[0078] Weigh the alloy powder, and then mix it in a dry powder mixer for 3 hours, and dry it at 60° C. for about 1 hour to obtain a dried alloy powder for standby use.

[0079] Note: The purpose of the above drying is that the residual moisture in the powder is a factor that affects the number of pores in the alloy coating, so it is necessary to remove the possible residual moisture through drying; during the above drying process, the change in the weight of the alloy powder is slight.

[0080] S2. Pretreatment of grinding balls: Take 25 zirconia grinding balls with a diameter of 20 mm, and polish the surface of the zirconia grinding balls with 600-mesh sandpaper. The polishing requirement is to completely remove the surface dirt and oxide layer, that is, remove the oxide film on the surface of the grinding balls until there are no thick scratches, the directions of the grinding marks are consistent and the surface is bright. After cleaning with ethanol (about 50 mL), put them into a drying oven at 60 °C for drying treatment for about 1 hour to obtain the polished grinding balls for later use.

[0081] S3. Cladding of grinding balls:

[0082] Mix 280 g of the dried alloy powder obtained in step S1 with an equal mass of binder (prepared by mixing 502 glue and acetone in a volume ratio of 1:20) to form a paste, and then evenly coat the surface of the polished grinding balls obtained in step S2, and dry with hot air (dry with hot air at 80 °C for 30 minutes to evaporate the binder).

[0083] Preheat the grinding balls to 180 °C and then fix them on the laser cladding workbench. Set the process parameters of laser cladding: laser power 4 kW, pulse frequency 10 Hz, spot diameter 4 mm, and clad a Ni-Cu-W-B cladding layer on the surface of the grinding balls, with an average thickness of about 1 mm.

[0084] S4. Ball milling reaction:

[0085] Put all the clad grinding balls obtained in step S3 into a ball mill (1 L), and put silicon powder and chlorobenzene into the ball mill according to a molar ratio of 1:2 (about 50 g of silicon powder is contained in the ball mill), and carry out mechanical ball milling for 6 hours. The pressure in the ball mill is 0.1 MPa, and the ball milling speed is 1000 rpm.

[0086] After the reaction is completed, take out the reaction mixture in the ball mill, filter to obtain the filtrate, and wash the solid obtained after filtration (mainly unreacted silicon powder and grinding balls clad with alloy) with ethyl acetate 2 - 3 times (the volume of ethyl acetate used each time is at least 30 mL) to obtain the washing liquid. After mixing the washing liquid and the filtrate, carry out rectification, and collect the fraction at 295 - 305 °C as diphenyldichlorosilane, collect the fraction at 191 - 201 °C as phenyltrichlorosilane, and collect the fraction at 364 - 374 °C as triphenylchlorosilane.

[0087] The obtained results are as follows: the conversion rate of silicon powder is 95.3%, the yield of diphenyldichlorosilane is 77.2%, the yield of phenyltrichlorosilane is 11.3%, and the yield of triphenylchlorosilane is 6.8%.

[0088] Si, in × 100%, where n Si，in is the addition amount of silicon powder, and n Si，out is the remaining amount of silicon powder after the reaction, both expressed in terms of the amount of substance.

[0089] Taking diphenyldichlorosilane as an example, the yield Y of diphenyldichlorosilane 二苯基二氯硅烷 is calculated by the formula: where n 二苯基二氯硅烷，out is the diphenyldichlorosilane obtained after the reaction, expressed in terms of amount of substance.

[0090] Examples 2-5

[0091] Relative to Example 1, the type of main metal in the alloy powder was changed (the content remained unchanged), and other operations were the same as in Example 1, obtaining Examples 2-5. The process parameters and reaction results are shown in Table 1.

[0092] Table 1

[0093]

[0094] Examples 6-10

[0095] Relative to Example 1, the component ratio in the alloy powder was changed, and other operations were the same as in Example 1, obtaining Examples 6-10. The specific process parameters are as follows:

[0096] The alloy powder ratio of Example 6 is Ni 40wt%, Cu 55wt%, W 2wt%, B 3wt%;

[0097] Example 7, the alloy powder ratio is Ni 35wt%, Cu 60wt%, W 2wt%, B 3wt%;

[0098] Example 8, the alloy powder ratio is Ni 50wt%, Cu 45wt%, W 2wt%, B 3wt%;

[0099] Example 9, the alloy powder ratio is Ni 55wt%, Cu 40wt%, W 2wt%, B 3wt%;

[0100] Example 10, the alloy powder ratio is Ni 60wt%, Cu 35wt%, W 2wt%, B 3wt%.

[0101] The reaction results are shown in Table 2.

[0102] Table 2

[0103]

[0104]

[0105] Examples 11-12

[0106] Change the particle size and corresponding quantity of the grinding balls, that is, change the "zirconia grinding balls" in Example 1 from "25 pieces with a diameter of 20 mm" to those described in Table 3 below. Other operations are the same as in Example 1, and Examples 11 - 12 are obtained. See Table 3 for process parameters and reaction results.

[0107] Table 3

[0108]

[0109] As can be seen from Table 3: When the particle size of the grinding balls increases, the movement space in the ball mill is restricted, resulting in a decrease in the collision frequency between the grinding balls, which will in turn affect the reaction efficiency.

[0110] Examples 13 - 15

[0111] Change the material of the grinding balls. Other operations are the same as in Example 1, and Examples 13 - 15 are obtained. See Table 4 for process parameters and reaction results.

[0112] Table 4

[0113]

[0114] Examples 16 - 17

[0115] Change the energy power of laser cladding. Other operations are the same as in Example 1, and Examples 16 - 18 are obtained. See Table 5 for process parameters and reaction results.

[0116] Table 5

[0117]

[0118] Note: The energy of the laser acting on the cladding layer material is uneven. The energy is relatively concentrated near the center of the laser beam, and the energy of the cladding layer edge far from the center of the laser beam is lower. Decreasing the laser power will result in a decrease in the average cladding thickness.

[0119] Examples 18 - 20

[0120] Change the ball milling reaction time in step S4. Other operations are the same as in Example 1, and Examples 18 - 20 are obtained. See Table 6 for process parameters and reaction results.

[0121] Table 6

[0122]

[0123] Examples 21 - 24

[0124] Change the ball milling speed in step S4. Other operations are the same as in Example 1, and Examples 21 - 24 are obtained. See Table 7 for process parameters and reaction results.

[0125] Table 7

[0126]

[0127] Examples 25 - 27

[0128] By changing the molar ratio of silicon powder to chlorobenzene in step S4 while keeping the amount of silicon powder unchanged and performing other operations equivalent to those in Example 1, Examples 25 - 27 are obtained. See Table 8 for process parameters and reaction results.

[0129] Table 8

[0130]

[0131] Examples 28 - 34

[0132] By changing the reaction raw materials with the same molar amount as that of chlorobenzene in Example 1, and keeping the amount of silicon powder unchanged, and performing other operations equivalent to those in Example 1, Examples 28 - 34 are obtained. See Table 9 for process parameters and reaction results.

[0133] Table 9

[0134] Example Raw material Conversion rate of silicon powder (%) Yield of main product (%) Main product 28 Hydrogen chloride 80.4 66.4 Trichlorosilane 29 Methyl chloride 92.8 81.6 Dimethyldichlorosilane 30 Chloroethane 90.8 80.4 Diethyldichlorosilane 31 Methanol 87.1 77.9 Trimethoxysilane 32 Ethanol 88.6 81.3 Triethoxysilane 33 Propanol 81.3 70.6 Tripropoxysilane 34 Isopropanol 77.6 64.3 Triisopropoxysilane

[0135] Comparative Example 1: Without laser cladding alloy powder on the grinding balls, directly add the metal powder described in Example 1 to the ball mill before the reaction (i.e., directly add 280 g of the dried alloy powder), and perform other operations equivalent to those in Example 1 to obtain Comparative Example 1.

[0136] The obtained results are as follows: the conversion rate of silane is 47.2%, the yield of diphenyldichlorosilane is 33.3%, the yield of phenyltrichlorosilane is 10.3%, and the yield of triphenylchlorosilane is 3.4%.

[0137] Comparative Example 2 - 1: Change the ratio of the alloy powder materials, specifically: Fe 80 wt%, Cr 9 wt%, Mo 1 wt%, V 10 wt%. Perform other operations equivalent to those in Example 1 to obtain Comparative Example 2 - 1.

[0138] The obtained results are as follows: the conversion rate of silicon powder is 46.5%, the yield of diphenyldichlorosilane is 27.1%, the yield of phenyltrichlorosilane is 16.2%, and the yield of triphenylchlorosilane is 3.2%.

[0139] Comparative Example 2 - 2: Change the ratio of the alloy powder materials, specifically: Ni 45 wt%, Cu 50 wt%, W 5 wt%. Perform other operations equivalent to those in Example 1.

[0140] The obtained results are as follows: the conversion rate of silicon powder is 70.8%, the yield of diphenyldichlorosilane is 63.1%, the yield of phenyltrichlorosilane is 3.5%, and the yield of triphenylchlorosilane is 4.2%.

[0141] Comparative Example 2-3: The proportion of the alloy powder materials was changed, specifically: Ni 45wt%, Cu 45wt%, W 4wt%, B 6wt%. Other operations were the same as those in Example 1.

[0142] The results obtained were as follows: the silicon powder conversion rate was 81.5%, the diphenyldichlorosilane yield was 69.2%, the phenyltrichlorosilane yield was 8.5%, and the triphenylchlorosilane yield was 3.8%.

[0143] Comparative Example 3: The laser energy power of laser cladding is changed to 1 kW, and other operations are the same as those in Example 1, to obtain Comparative Example 3.

[0144] The results obtained were as follows: the silicon powder conversion rate was 52.7%, the diphenyldichlorosilane yield was 38.5%, the phenyltrichlorosilane yield was 10.8%, and the triphenylchlorosilane yield was 3.4%.

[0145] Comparative Example 4: The ball mill speed of the ball mill in step S4 was changed to 200 rpm, and the other operations were the same as those in Example 1, to obtain Comparative Example 4.

[0146] The results obtained were as follows: the silicon powder conversion rate was 46.7%, the diphenyldichlorosilane yield was 25.3%, the phenyltrichlorosilane yield was 17.3%, and the triphenylchlorosilane yield was 4.1%.

[0147] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A method for preparing organosilane by ball milling silicon powder for catalysis, characterized in that It includes the following steps: Step 1 includes the following steps: S1： Mix the powdery main metal with W and B to form an alloy powder, and dry the alloy powder to obtain the dried alloy powder. The main metal is two of Fe, Co, Ni, and Cu, and the content of each is 35 wt% - 60 wt%. W accounts for 2 - 3 wt% of the weight of the alloy powder, and B accounts for 2 - 3 wt% of the weight of the alloy powder. S2： Remove the surface dirt and oxide layer of the grinding balls, wash them with ethanol, and then put them into a drying oven for drying treatment to remove ethanol, obtaining the treated grinding balls. S3： Moisten the dried alloy powder obtained in step S1 with a binder, then bond it to the surface of the treated grinding balls obtained in step S2, dry it with hot air, preheat it to 150 - 180 °C, and then place it on a cladding workbench for laser cladding on the surface of the grinding balls. The laser power is 2 - 4 kW, the pulse frequency is 10 - 50 Hz, and the spot diameter is 2 - 4 mm; obtaining the grinding balls with a metal cladding layer. The particle size of the grinding balls is 20 mm - 40 mm. Step 2: Mix and react the grinding balls with a metal cladding layer, silicon powder, and reaction raw materials obtained in step 1 in a ball milling device at a rotation speed of 600 - 1000 rpm for 4 - 8 hours, and then through post-treatment, obtain organosilane. The reaction raw material is any one of the following: chlorobenzene, methanol, ethanol, n-propanol, isopropanol, hydrogen chloride, chloromethane, chloroethane. The molar ratio of silicon powder to the reaction raw material is 1:1.5 - 4.

2. The method for preparing organosilane by the silicon powder ball milling catalysis method according to claim 1, wherein: When the particle size of the grinding balls is 20 mm, each grinding ball is equipped with 11 - 12 g of the dried alloy powder. When the particle size of the grinding balls is 30 mm, each grinding ball is equipped with 27 - 29 g of the dried alloy powder. When the particle size of the grinding balls is 40 mm, each grinding ball is equipped with 54 - 58 g of the dried alloy powder.

3. The method for preparing organosilane by the silicon powder ball milling catalysis method according to claim 1 or 2, wherein: Said step 2 is: Load the grinding balls with a metal cladding layer obtained in step 1, silicon powder, and the reaction raw materials into a ball milling tank; under a reaction pressure of 0.1 - 1 MPa, at a rotation speed of 600 - 1000 rpm, ball mill at room temperature for 4 - 8 hours. The post-treatment is: after the reaction ends, take out the reaction mixture in the ball milling tank, filter it to obtain a filtrate and a filter cake respectively, wash the filter cake with ethyl acetate to obtain a washing solution, and after combining the washing solution and the filtrate, rectify it to obtain organosilane.

4. The method for preparing organosilane by the silicon powder ball milling catalysis method according to claim 3, wherein: The organosilane is any one of the following: monochlorosilane, dichlorosilane, trichlorosilane, silicon tetrachloride, phenyltrichlorosilane, diphenyldichlorosilane, triphenylchlorosilane, trimethoxysilane, tetramethoxysilane, triethoxysilane, tetraethoxysilane, tri-n-propoxysilane, tetra-n-propoxysilane, triisopropoxysilane, methyldichlorosilane, methyltrichlorosilane, dimethyldichlorosilane, tetramethylsilane, triethylchlorosilane, ethyltrichlorosilane, diethyldichlorosilane, tetraethylsilane.

5. The method for preparing organosilane by silicon powder ball milling catalysis according to claim 4, characterized in that: In step S1: The particle sizes of the powdery main metal, W, and B are all 20 - 50 mm, and the shape is spherical. The powdery main metal, W, and B are mixed in a dry powder mixer, and the mixing time is 2 - 4 hours. The drying temperature is 60 - 80 °C, and the drying time is 1 - 2 hours.

6. The method for preparing organosilane by silicon powder ball milling catalysis according to claim 5, characterized in that: The diameter of the grinding balls is 20 - 40 mm, and the material is 303 stainless steel, 304 stainless steel, tungsten carbide or zirconia.

7. The method for preparing organosilane by silicon powder ball milling catalysis according to claim 6, characterized in that: The mass fraction of silicon in the silicon powder is ≥99%, and the particle size of the silicon powder is 50 - 80 mm.

8. The method for preparing organosilane by silicon powder ball milling catalysis according to claim 7, characterized in that: The ball milling equipment is a vibration ball mill or a planetary ball mill.

9. The method for preparing organosilane by silicon powder ball milling catalysis according to claim 8, characterized in that: The formula of the alloy powder is: Ni 45 wt%, Cu 50 wt%, W 2 wt%, B 3 wt%.

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