Method for preparing chlorosilanes

Abstract

The present invention relates to a method for preparing chlorosilanes, the method comprising the steps of: preparing a reactant comprising methylchlorosilane synthesis residue and methyldichlorosilane (MH); and reacting the reactant in the presence of an alumina catalyst to form a product comprising dimethyldichlorosilane (M2), methyltrichlorosilane (M1), and trimethylchlorosilane (M3), wherein the reaction is carried out at 300-500°C for 1-3 minutes.

Description

Method for producing chlorosilane

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0085573, filed June 28, 2024, and Korean Patent Application No. 10-2024-0139825, filed October 14, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method for producing chlorosilane.

[0003] Methylchlorosilane (MCS) is synthesized by reacting silicon metal powder with methylchloride (MC) gas in the presence of a copper-based catalyst. MCS is composed of a mixture of silicon monomer with a boiling point of 70°C or lower and methylchlorosilane synthesis residue (MSR) with a boiling point of 70°C or higher. It is separated through a distillation process and used as a raw material for secondary silicon products.

[0004] The main product of MCS is dimethyldichlorosilane (M2), and it also contains small amounts of methyltrichlorosilane (M1), trimethylchlorosilane (M3), methyldichlorosilane (MH), tetramethylsilane (TMS), dimethylchlorosilane (M2H), unsaturated hydrocarbons, and saturated hydrocarbons with a boiling point of 35°C or lower. In addition, MSR with a boiling point exceeding 70 ℃ is included as a by-product, and depending on the number of Cl contained in MSR, it contains pentamethylchlorodisilane (MSR-1), tetramethyldichlorodisilane (MSR-2), trimethyltrichlorodisilane (MSR-3), and dimethyltetrachlorodisilane (MSR-4) and a small amount of carbosilane.

[0005] MSR with a boiling point of 70℃ or higher is converted into silicone monomer through a cleavage reaction, and related technologies are already known. For example, U.S. Patent Publication No. US2709176 discloses a method of manufacturing silicone monomer by reacting (cleaving) an amine-based catalyst with hydrochloric acid gas. However, it includes that MSR with a lot of chlorine groups undergoes cleavage easily, but MSR with a lot of alkyl groups is difficult to cleave. In addition, the byproduct generated after the reaction contains an amine-based catalyst, so a separate process is required to remove the amine-based catalyst. In addition, since hydrochloric acid gas is used as a reaction raw material, the reactor must be a glass-lined reactor, which has the disadvantage of high equipment investment costs. The main products generated through the reaction are MH and M1, and the disadvantage is that the amount of M2, which has high utility value, is relatively small.

[0006] In addition, it is known that the amount of MH produced increases due to carbon accumulation in the reactor caused by the thermal decomposition of methane chloride in the MCS direct synthesis method, and if the amount of MH obtained through the direct synthesis method and the MSR decomposition reaction increases, the production of M2 and M3, which have high utility value, decreases. In addition, since MH is a substance containing hydrogen atoms, it is not easy to store for a long time, and there is a disadvantage that it must be packaged and sold in special-purpose tanks when sold externally. Therefore, the generated MH is generally converted into the form of methyl hydrogen fluid (MHF) through a hydrolysis reaction and stored. As a previously known technology, U.S. Patent Publication No. US5430168 discloses a method for producing MH and M2H by reacting an MSR mixture with hydrogen gas in the presence of an AlCl3 catalyst, with the aforementioned MH being generated as the main product. US Patent Publication No. US4962219 is a method for producing TMS, M3, and M2 with a lot of methyl groups by reacting MSR-4 among MSR mixtures with methane chloride in the presence of Al and Sn. It can produce TMS and M3 as products, which have a market demand but very low production volume. However, it has the disadvantage that more moles of AlCl3 are generated as a byproduct than the moles of Al introduced, requiring a separate process to remove AlCl3 in the product. In addition, since PCT Patent Publication No. WO2013-062178, US Patent Publication No. US4393229, and Korean Patent No. 10-0457847 all use AlCl3 as a catalyst, there is the disadvantage that a separate process is required to remove the AlCl3 reactant in the product after the reaction and to treat the AlCl3 reactant in the reactor.

[0007] The present invention is intended to solve the above problems, and provides a method for producing chlorosilane that does not require a separate process for treating AlCl3 and can increase the production of dimethyldichlorosilane (M2) and trimethylchlorosilane (M3).

[0008] The present invention provides a method for producing chlorosilane, comprising the steps of: preparing a reactant comprising methylchlorosilane synthesis residue (MSR) and methyldichlorosilane (MH); and reacting the reactants in the presence of an alumina catalyst to form a product comprising dimethyldichlorosilane (M2), methyltrichlorosilane (M1), and trimethylchlorosilane (M3), wherein the reaction is performed at 300°C to 500°C for 1 to 3 minutes.

[0009] The above reactant may include 5 to 90 parts by weight of the methylchlorosilane synthesis byproduct; and 5 to 30 parts by weight of the methyldichlorosilane.

[0010] The above reactant may further include dimethyldichlorosilane.

[0011] At this time, the reactant may include 5 to 90 parts by weight of the methylchlorosilane synthesis byproduct; 5 to 25 parts by weight of the methyldichlorosilane; and 5 to 70 parts by weight of dimethyldichlorosilane.

[0012] The method for producing chlorosilane according to the present invention may further include a step of introducing an inert gas or hydrogen chloride (HCl) gas before, after, or during the reaction.

[0013] The above alumina catalyst may be gamma alumina.

[0014] The pore volume of the above alumina catalyst is 0.5 to 1.0 cm 3 / g may be.

[0015] The specific surface area of ​​the above alumina catalyst is 100 to 300 m 2 / g may be.

[0016] The methyldichlorosilane included in the above reactant may have a purity of 90% or higher.

[0017] Dimethyldichlorosilane included in the above reactant may have a purity of 97% or higher.

[0018] The content of dimethyldichlorosilane in the above product may be 15 wt% or more.

[0019] According to the method of the present invention, the conversion rate of the methylchlorosilane synthesis by-product may be 50% or more, and the conversion rate of the methyldichlorosilane may be 40% or more.

[0020] The method for producing chlorosilane according to the present invention can effectively reduce methyldichlorosilane unnecessarily generated in a silicon monomer production process by including excess methyldichlorosilane generated in a methylchlorosilane decomposition process in a reactant.

[0021] In addition, when dimethyldichlorosilane is additionally included in the above reactant, the amount of trimethylchlorosilane produced in methylchlorosilane can be increased.

[0022] In addition, since the manufacturing method according to the present invention uses an alumina catalyst, by-products such as hydrochloric acid gas and AlCl3 reactants are not generated during the process, and accordingly, no additional process for by-product treatment is required, and the catalyst can be regenerated and used by injecting an inert gas or hydrogen chloride gas.

[0023] Figure 1 is a process diagram illustrating a method for manufacturing chlorosilane according to one embodiment of the present invention.

[0024] The present invention is described in detail below.

[0025]

[0026] Chlorosilane manufacturing method

[0027] A method for producing chlorosilane according to the present invention comprises the steps of: preparing a reactant including a methylchlorosilane synthesis residue (MSR) and methyldichlorosilane (MH); and reacting the reactants in the presence of an alumina catalyst to form a product including dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane).

[0028] FIG. 1 illustrates one embodiment of a process for manufacturing chlorosilane according to the present invention. Referring to FIG. 1, a method for manufacturing chlorosilane according to one embodiment of the present invention may include, for example, a step of vaporizing methylchlorosilane synthesis by-product (MSR) and methyldichlorosilane (MH) to prepare a reactant including the methylchlorosilane synthesis by-product (MSR) and methyldichlorosilane (MH); and a step of reacting the reactant in a reactor in which an alumina catalyst is disposed to form a product including dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane).

[0029]

[0030] Below, a detailed description of each step is provided.

[0031]

[0032] Steps to prepare the reactants

[0033] First, a reactant containing methylchlorosilane synthesis byproduct and methyldichlorosilane is prepared.

[0034] The step of preparing the above reactant can be performed, for example, by mixing methylchlorosilane synthesis by-product (MSR) and methyldichlorosilane (MH) to form a mixture and then vaporizing the mixture, or by vaporizing each of the methylchlorosilane synthesis by-product and methyldichlorosilane.

[0035] At this time, the vaporization can be performed by introducing methylchlorosilane synthesis byproduct (MSR) and methyldichlorosilane (MH) into the vaporizer.

[0036] For example, a reactant can be prepared by introducing the methylchlorosilane synthesis by-product and methyldichlorosilane into a vaporizer and then heating the vaporizer to about 200°C to 300°C to convert the methylchlorosilane synthesis by-product (MSR) and methyldichlorosilane (MH) into a gas phase.

[0037] The vaporizer may include a metering pump. The metering pump can control the input amount of the methylchlorosilane synthesis byproduct (MSR) and methyldichlorosilane (MH) and the residence time within the reactor.

[0038] The above vaporizer may further include a gas flowmeter capable of injecting gas for catalyst activation and regeneration. When the gas flowmeter is included, an alumina catalyst, which will be described later, can be activated or regenerated by supplying an inert gas or hydrogen chloride gas to the reactor, thereby reducing raw material costs.

[0039] Meanwhile, the above methylchlorosilane synthesis by-product (MSR) refers to a by-product generated during the methylchlorosilane synthesis process, has a boiling point of 70°C or higher, and includes pentamethylchlorodisilane (MSR-1), tetramethyldichlorodisilane (MSR-2), trimethyltrichlorodislane (MSR-3), dimethyltetrachlorodisilane (MSR-4), and carbodisilane.

[0040] The above methylchlorosilane synthesis by-product (MSR) may be included in an amount of about 5 to 90 parts by weight, preferably 30 to 90 parts by weight, and more preferably 50 to 90 parts by weight or 70 to 90 parts by weight, based on 100 parts by weight of the total reactant weight. If the content of the methylchlorosilane synthesis by-product (MSR) in the reactant is less than about 5 parts by weight, the amount of the methylchlorosilane synthesis by-product (MSR) may be small, thereby reducing the yield of the silicon monomer. If the content of the methylchlorosilane synthesis by-product (MSR) in the reactant exceeds about 90 parts by weight, the content of methyldichlorosilane (MH) or dimethyldichlorosilane (M2), which will be described later, may decrease in the reactant, thereby reducing the methylchlorosilane synthesis by-product (MSR) reaction conversion rate.

[0041] The above methylchlorosilane synthesis byproduct (MSR) can be converted into silicon monomer through a decomposition reaction. However, if MSR is reacted alone, the production of highly valuable dimethyldichlorosilane (M2) and trimethylchlorosilane (M3) may be relatively low.

[0042] To solve the above problems, the present invention uses methyldichlorosilane (MH) together with methylchlorosilane synthesis byproduct (MSR). The methyldichlorosilane (MH) can participate in the reaction and play a role in increasing the silicon monomer content of the product, and the reaction conversion rate of the methylchlorosilane synthesis byproduct (MSR) and the composition ratio of dimethyldichlorosilane (M2) and methyltrichlorosilane (M1) can be controlled depending on the input ratio of the methyldichlorosilane (MH).

[0043] The above methyldichlorosilane (MH) is an organic silane compound having a Si-H bond, and it is preferable to use methyldichlorosilane having a purity of about 90% or higher, preferably about 93% or higher, and more preferably about 95% or higher. If the purity of the methyldichlorosilane (MH) is less than about 90%, the impurity content may increase, which may reduce the effect of increasing the conversion rate of the methylchlorosilane synthesis byproduct (MSR) reaction.

[0044] The above methyldichlorosilane (MH) may be included in an amount of about 5 to 30 parts by weight, preferably about 10 to 30 parts by weight, and more preferably about 10 to 25 parts by weight, based on 100 parts by weight of the total weight of the reactants. If the methyldichlorosilane (MH) is less than about 5 parts by weight, the content of methyldichlorosilane participating in the reaction may decrease, making it difficult to expect the effect of increasing the amount of silicon monomer. If the methyldichlorosilane (MH) is more than about 30 parts by weight, the content of the methylchlorosilane synthesis byproduct (MSR) may decrease, thereby reducing the production amount of silicon monomer.

[0045] Meanwhile, if necessary, the reactant may further include dimethyldichlorosilane (M2). If dimethyldichlorosilane is additionally included in the reactant, the effect of increasing the content of trimethylchlorosilane (M3) in the product can be obtained.

[0046] The purity of the above dimethyldichlorosilane (M2) may be about 97% or higher, preferably about 98% or higher, and more preferably about 99% or higher. If the purity of the above dimethyldichlorosilane (M2) is less than about 97%, the impurity content may increase, thereby reducing the conversion rate of the methylchlorosilane synthesis byproduct (MSR) reaction.

[0047] The above dimethyldichlorosilane (M2) may be included in an amount of about 5 to 70 parts by weight, preferably about 5 to 50 parts by weight, and more preferably about 5 to 25 parts by weight, based on 100 parts by weight of the total weight of the reactants. If the dimethyldichlorosilane (M2) is less than about 5 parts by weight, it may be difficult for the dimethyldichlorosilane (M2) to effectively increase trimethylchlorosilane (M3) in the product. If the dimethyldichlorosilane (M2) exceeds about 70 parts by weight, the contents of methylchlorosilane synthesis byproduct (MSR) and methyldichlorosilane (MH) in the reactants may decrease, thereby reducing the production amount of silicon monomer.

[0048]

[0049] Steps to form a product

[0050] Next, the above reactants are reacted in the presence of an alumina catalyst to form products including dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane).

[0051] The above reaction can be carried out, for example, by introducing the reactant into a reactor equipped with an alumina catalyst to cause a cleavage reaction and a redistribution reaction of a methylchlorosilane synthesis by-product (MSR). Through the above reaction, the methylchlorosilane synthesis by-product (MSR) in the reactant is converted into a silicon monomer such as dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane).

[0052] The alumina catalyst described above promotes the decomposition and redistribution reactions of MSR and may be, for example, gamma alumina. Unlike conventional AlCl3 catalysts, gamma alumina does not generate hydrochloric acid gas or by-products upon contact with air. Therefore, when using it, no additional process is required to remove by-products.

[0053] Additionally, the pore volume of the alumina catalyst is about 0.5 to 1.0 cm 3 / g may be, preferably about 0.5 to 0.8 cm 3 / g, more preferably 0.5 to 0.7 cm 3 / g. The specific surface area of ​​the alumina catalyst is about 100 to 300 m 2 / g may be, preferably about 100 to 270 m 2 / g, more preferably about 100 to 250 m 2 / g may be.

[0054] The above pore volume is about 0.5 cm 3 / g or less, or the specific surface area is about 100 m 2If the pore volume is less than / g, the area where the alumina catalyst can react with the reactant decreases, so the reaction may not occur smoothly. The pore volume is about 1.0 cm 3 / g exceeds or the specific surface area is about 300 m 2 If / g is exceeded, the physical performance of the alumina catalyst may decrease, making it difficult to place it inside the reactor.

[0055] The above reactor may be, for example, a fixed bed reactor. The fixed bed reactor can immobilize the alumina catalyst, thereby reducing process operation and equipment costs compared to conventional stirred reactors and glass-lined reactors.

[0056] Meanwhile, in the present invention, the reaction may be performed at a temperature of about 300°C to 500°C, preferably about 300°C to 400°C, and more preferably about 330°C to 370°C. When the reaction temperature is less than about 300°C, the reaction conversion of methylchlorosilane synthesis by-product (MSR) may decrease. When the temperature exceeds about 500°C, a product with a high boiling point may be formed, thereby decreasing the reaction conversion of methylchlorosilane synthesis by-product (MSR).

[0057] In addition, the reaction can be carried out for about 1 to 3 minutes, preferably about 1 to 2 minutes, and more preferably about 1.3 to 2 minutes. If the time is less than about 1 minute, the reaction conversion of methylchlorosilane synthesis by-product (MSR) may decrease. If the time is more than about 3 minutes, the reaction conversion of methylchlorosilane synthesis by-product (MSR) may decrease as a high boiling point product is formed. In this case, the reaction time refers to the residence time in the reactor.

[0058] Additionally, through the above reaction, methylchlorosilane synthesis byproduct (MSR) is converted into silicon monomer, forming products including dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane).

[0059] The conversion rate of the methylchlorosilane synthesis by-product (MSR) of the above reactant may be about 50% or more, preferably about 50% to 90%, more preferably about 55% to 80%. In addition, the conversion rate of the methyldichlorosilane (MH) may be about 40% or more, preferably about 40% to 70%, more preferably about 40% to 60%. If the conversion rate (MSR) of the methylchlorosilane synthesis by-product is less than about 50% or the conversion rate of the methylchlorosilane (MH) is less than about 40%, the content of the silicon monomer in the product may decrease, thereby reducing the reaction efficiency.

[0060]

[0061] Since the method of the present invention has a higher conversion rate of reactants than conventional methods, the content of the produced silicon monomer increases. Specifically, the content of dimethyldichlorosilane (M2) among the silicon monomers may be about 15 wt% or more, preferably about 17 wt% or more, and more preferably about 20 wt% or more. If the content of dimethyldichlorosilane (M2) is less than about 15 wt%, the content of dimethyldichlorosilane (M2), which has high utility value, may be low, which may be disadvantageous for commercialization.

[0062] The content of methyltrichlorosilane (M1) may be about 15 wt%, preferably about 17 wt%, and more preferably about 20 wt% or more. If the content of methyltrichlorosilane (M1) is less than about 15 wt%, the content of the silicone monomer may decrease, thereby lowering the reaction efficiency.

[0063] The content of trimethylchlorosilane (M3) may be about 0.5 wt%, preferably about 1 wt%, and more preferably about 2 wt% or more. If the content of trimethylchlorosilane (M3) is less than about 0.5 wt%, trimethylchlorosilane (M3) is hardly formed, making it difficult to obtain trimethylchlorosilane (M3).

[0064]

[0065] Meanwhile, if necessary, a step of injecting an inert gas or hydrogen chloride (HCl) gas before, after, or during the reaction may be additionally performed. When the inert gas or hydrogen chloride gas is injected, the deactivated alumina catalyst can be regenerated. When the inert gas or hydrogen chloride gas is injected before or during the reaction, the composition of the silicon monomer can be increased. When the inert gas or hydrogen chloride gas is injected after the reaction, the alumina catalyst can be activated and reused.

[0066]

[0067] Once the product is formed as described above, an additional step of condensing the product can be performed. Specifically, the product can be converted to a liquid state by condensing it in a condenser at a temperature of approximately -10°C. The product converted to a liquid state can be stored in a receiver, and the liquefied product can be easily recovered from the receiver.

[0068]

[0069] Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are intended only to specifically illustrate specific embodiments of the present invention and are not intended to limit or restrict the scope of the present invention to the contents described in these examples.

[0070]

[0071] Examples 1 to 7 and Comparative Examples 1 to 6

[0072] A fixed bed reactor made of stainless steel with an inner diameter of 1 inch (2.54 cm) and a length of 30 cm was installed with an alumina catalyst (Saint gobain, SA6173, length 1.5 cm, cylinder type, specific surface area of ​​about 200 m 2 / g, pore volume approximately 0.6 cm 3 / g) was charged, the reactants having the compositions in Table 1 below were introduced into the reactor through the vaporizer, and the reaction was carried out under the conditions described in Table 1 below. In Table 1, MSR is a methylchlorosilane synthesis residue, MH is methyldichlorosilane, and M2 is dimethyldichlorosilane. The specific specifications of MSR, MH, and M2 are shown in Table 2 below. The reactant input amount was controlled using a metering pump located in front of the vaporizer, thereby controlling the residence time of the reactants in the reactor. In addition, a catalytically active gas was introduced under the conditions described in Table 1 for catalytic activity before / after the reaction. The product formed after the reaction was condensed at approximately -10°C using a condenser and stored in a receiver.

[0073] Input ratio (weight ratio) Reaction temperature (℃) Retention time (min) Catalyst active gas MSRMHM2 Example 1 1-350 1.6450 ℃ N25hr Example 2 31-350 1.6450 ℃ N25hr Example 39 1-350 1.6450 ℃ N25hr Example 4 310.5 350 1.6450 ℃ N25hr Example 5 310.5 350 1.6480 ℃ HCl 3hr Example 6 314 70 1.6450 ℃ N25hr Example 7 313 50 2.7450 ℃ N25hr Comparative Example 11--350 1.6450 ℃ N25hr Comparative Example 231-350 0.32 450 ℃ N25hr Comparative Example 331-3500.81450℃ N25hr Comparative Example 431-3503.2450℃ N25hr Comparative Example 531-2001.6450℃ N25hr Comparative Example 631-5501.6450℃ N25hr

[0074]

[0075] Manufacturer Product Name MSRKCC-SC-MSRMHKCC-SC-MHM2KCC-SM2

[0076]

[0077] Experimental example

[0078] The components of the reactants and products were analyzed using a column (DB-210) in a gas chromatograph thermal conductivity detector (GC-TCD, Agilent 7890A), and the analysis results are shown in Table 3 below.

[0079] In Table 3 below, MSR is Methylchlorosilane Synthesis Residue, MH is Methyldichlorosilane, LB (Low boiler) represents the sum of tetramethylsilane (TMS), trichlorosilane (TCS), and dimethylchlorosilane (M2H), M3 is trimethylchlorosilane, M1 is methyltrichlorosilane, and M2 is dimethyldichlorosilane. HB (High boiler) represents the sum of pentamethylchlorodisilane (MSR-1), tetramethyldichlorodisilane (MSR-2), trimethyltrichlorodislane (MSR-3), dimethyltetrachlorodisilane (MSR-4), ethylmethyldichlorosilane (EM), and carbosilane. The methylchlorosilane synthesis by-product (MSR) reaction conversion refers to the conversion before and after the reaction of MSR-1 to 4, excluding the conversion of ethylmethyldichlorosilane (EM) and carbosilane. The chemical structures of each compound are shown in Table 4.

[0080] Reaction Conversion (%) Composition (%) MSRMHLBMHM3M1M2HB Example 1 Before reaction 74540.051.70.00.10.547.7 After reaction 2.524.01.425.420.726.0 Example 2 Before reaction 73570.026.10.10.01.872.0 After reaction 0.911.22.127.429.928.5 Example 3 Before reaction 64460.09.10.20.01.689.1 After reaction 0.44.93.318.431.841.3 Example 4 Before reaction 72570.023.20.10.012.764.0 After reaction 0.910.12.826.134.525.7 Example 5Before reaction 72580.023.20.10.012.764.0After reaction 0.99.72.826.735.124.7Example 6Before reaction 67570.026.10.10.01.872.0After reaction 1.011.21.724.427.434.4Example 7Before reaction 64590.026.10.10.01.872.0After reaction 0.810.31.723.127.037.2Comparative example 1Before reaction 54-0.00.00.00.01.099.0After reaction 0.32.82.214.024.156.6Comparative example 2Before reaction 35320.026.10.10.01.872.0After reaction 1.017.21.513.514.552.8Comparative example 3Before reaction 62490.026.10.10.01.872.0After reaction 0.713.21.723.626.235.5Comparative example 4Before reaction 39650.026.10.10.01.872.0After reaction 0.99.31.616.920.950.4Comparative example 5Before reaction -400.026.10.10.01.872.0After reaction 0.115.60.13.27.074.1Comparative example 6Before reaction 13690.026.10.10.01.872.0After reaction 0.98.21.012.314.762.9

[0081]

[0082] TMSM2HMHM3 M1M2MSR-1MSR-2 MSR-3MSR-4carbodisilane

[0083]

[0084] As shown in Table 3 above, it can be confirmed that the product manufactured by the method of Example 1 using a reactant with added MH contains more silicone monomers (M1 to M3) than the product manufactured by the method of Comparative Example 1 using a reactant that does not contain MH. This indicates that MH participated in the reaction and increased the content of silicone monomers.

[0085] In Example 2 and Comparative Examples 2 to 4, Comparative Examples 2 to 3 had low MSR reaction conversions due to low retention times, and Comparative Example 4 had a high MSR reaction conversion rate that may decrease as high-boiling-point products are formed due to high retention times. In addition, Comparative Example 5 had a low MSR reaction conversion rate due to low reaction temperatures, and Comparative Example 6 had a low MSR reaction conversion rate that may decrease as high-boiling-point products are formed. Examples 2 and Examples 6 to 7 can have high MSR reaction conversion rates due to appropriate reaction temperatures and retention times. Through this, it can be confirmed that the MSR reaction conversion rate is high when the reaction temperature is 300 to 500°C and the retention time is 1 to 3 minutes.

[0086] Additionally, in Examples 1 to 3, as the MH content of the raw material decreased, the composition of M3 increased and the composition of M1 decreased. This shows that the content of silicone monomer and the content of M3 can be controlled according to the MH content.

[0087] In Examples 2 and 4, the content of M3 increased as M2 was additionally added to the raw material. In addition, in Examples 4 and 5, it was confirmed that the use of hydrogen chloride gas in the catalyst regeneration method was effective in increasing the composition of the silicone monomer.

Claims

1. A step of preparing a reactant including a methylchlorosilane synthesis residue and methyldichlorosilane (MH); and In the presence of an alumina catalyst, a step of reacting the above reactants to form a product including dimethyldichlorosilane (M2, Dimethyldichlorosilane), methyltrichlorosilane (M1, Methyltrichlorosilane), and trimethylchlorosilane (M3, Trimethylchlorosilane), A method for producing chlorosilane, wherein the above reaction is performed at 300°C to 500°C for 1 to 3 minutes.

2. In paragraph 1, A method for producing chlorosilane, wherein the reactants include 5 to 90 parts by weight of the methylchlorosilane synthesis byproduct; and 5 to 30 parts by weight of the methyldichlorosilane.

3. In paragraph 1, A method for producing chlorosilane, wherein the above reactant further comprises dimethyldichlorosilane.

4. In paragraph 3, A method for producing chlorosilane, wherein the reactants include 5 to 90 parts by weight of the methylchlorosilane synthesis byproduct; 5 to 25 parts by weight of the methyldichlorosilane; and 5 to 70 parts by weight of dimethyldichlorosilane.

5. In paragraph 1, A method for producing chlorosilane, further comprising a step of introducing an inert gas or hydrogen chloride (HCl) gas before, after, or during the reaction.

6. In paragraph 1, A method for producing chlorosilane, wherein the above alumina catalyst is gamma alumina.

7. In paragraph 1, The pore volume of the above alumina catalyst is 0.5 to 1.0 cm 3 / g, a method for producing chlorosilane.

8. In paragraph 1, The specific surface area of ​​the above alumina catalyst is 100 to 300 m 2 / g, a method for producing chlorosilane.

9. In paragraph 1, A method for producing chlorosilane, wherein methyldichlorosilane included in the above reactants has a purity of 90% or more.

10. In paragraph 3, A method for producing chlorosilane, wherein the dimethyldichlorosilane included in the above reactants has a purity of 97% or more.

11. In paragraph 1, A method for producing chlorosilane, wherein the content of dimethyldichlorosilane in the above product is 15% by weight or more.

12. In paragraph 1, A method for producing chlorosilane, wherein the conversion rate of the above methylchlorosilane synthesis by-product is 50% or more and the conversion rate of the above methylchlorosilane is 40% or more.

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