JPH0788212B2 - Method for producing trichlorosilane - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing trichlorosilane from silicon tetrachloride and hydrogen.

2. Description of the Related Art With the recent development of the electronics industry, the demand for polycrystalline silicon, single crystal silicon, monosilane gas, etc. is increasing rapidly, and it is expected that the demand will continue to increase in the future. Here, trichlorosilane is used in the largest amount as a raw material of the above silicon substance. For example, high-purity polycrystalline silicon is manufactured by thermal decomposition of trichlorosilane, and currently most of the high-purity polycrystalline silicon in the world is manufactured by this method. Further, recently, a method for producing monosilane by a disproportionation reaction of trichlorosilane has been put into practical use, and the demand for trichlorosilane will be extremely important in the future. However, in these methods, trichlorosilane is consumed and a large amount of silicon tetrachloride is produced as a by-product. For example, in the production of high-purity polycrystalline silicon by thermal decomposition of trichlorosilane, about 60% of trichlorosilane is by-produced as silicon tetrachloride, and in the production of monosilane by disproportionation of trichlorosilane, substantially monosilane is produced. 3 times the molar amount of silicon tetrachloride will be produced as a by-product. Therefore, there is known a method of reducing the production cost of trichlorosilane by using this by-produced silicon tetrachloride as a raw material for, for example, aerosil, but the practically best method of utilizing silicon tetrachloride is It is to convert it into trichlorosilane again and reuse it as a raw material for the above method. The production of monosilane by the disproportionation of trichlorosilane, for example by converting silicon tetrachloride to trichlorosilane, has resulted in a process that is practically used with the production of monosilane from metallic silicon and hydrogen. is there.

Therefore, the technology for converting silicon tetrachloride to trichlorosilane is extremely useful, and it is extremely important to carry out this inexpensively, easily and efficiently in terms of process economics.

Conventionally, the following methods are known as methods for converting silicon tetrachloride into trichlorosilane.

(1) A method for producing trichlorosilane by reacting silicon tetrachloride with hydrogen at a temperature of about 1000 ° C. or higher.

(2) A method for producing trichlorosilane by reacting silicon tetrachloride, hydrogen and metallic silicon at around 500 ° C.

(3) Silicon tetrachloride, hydrogen, metallic silicon and hydrogen chloride
A method for producing trichlorosilane by reacting at around 500 ° C.

Regarding the method (1), for example, in JP-A-57-3711, a method in which hydrogen and silicon tetrachloride are sprayed onto a heating element having the above temperature at 1100-1600 ° C., the content of trichlorosilane is 60%.
Is obtained in a yield of. In JP-A-57-156318, hydrogen and silicon tetrachloride are reacted at a temperature of 900 ° C. at a molar ratio of H ₂ / SiCl ₄ = 2 to obtain trichlorosilane in a yield of 25%. Further, in JP-A-59-45920, trichlorosilane is obtained by reacting silicon tetrachloride with hydrogen in plasma. Further, in JP-A-60-81010, 1
By reacting silicon tetrachloride with hydrogen in the temperature range of 200-1400 ° C, trichlorosilane is obtained in a yield of about 30%.

It can be said that the method (2) is energetically advantageous because the reaction proceeds at a relatively low temperature as compared with the method (1). The method (3), which uses hydrogen chloride gas in order to more effectively proceed the reaction by the method (2), naturally has the same characteristics. Regarding the methods of (2) and (3), it is effective to use a catalyst, and a copper compound or metallic copper is used as a catalyst. For example, JP-A-56-7361
In No. 7, trichlorosilane was obtained by conducting a fluidized bed reaction at 350-600 ° C using copper powder as a catalyst. Also, JP-A-58-11
In No. 042, trichlorosilane is obtained by performing a reaction using a catalyst supporting copper or supporting copper and nickel.

Among these methods, for example, in the method (1), trichlorosilane was obtained with a considerably high conversion rate of silicon tetrachloride, but especially in order to obtain trichlorosilane with a yield of 30% or more, the temperature of 1000 ° C or more was used. The energy required to carry out the reaction at high temperature is enormous. In addition, since it is a high-temperature reaction, it suffers from severe corrosion of the reactor and the like due to silicon chloride, and also has the drawback that chlorosilanes of undesired high molecular weight are inevitably produced as a by-product, which is far from practical use. It is a thing.

On the other hand, the methods (2) and (3) are useful methods for producing trichlorosilane from a thermodynamic point of view, and as described above, the methods for producing monosilane by disproportionation of trichlorosilane are sub-methods. The production of trichlorosilane by converting raw silicon tetrachloride can be said to be a very useful method, in particular, since the method (2) substantially produces monosilane from silicon and hydrogen. In addition,
In the method of (3), although the yield of trichlorosilane is high, hydrogen chloride does not participate in the conversion of silicon tetrachloride into trichlorosilane, and practically it is necessary to synthesize trichlorosilane from metallic silicon. Not too much. Therefore, from the viewpoint of reuse of silicon tetrachloride, it is somewhat less useful than the method of (2), but on the other hand, it also has the advantage that the yield of trichlorosilane is high, and the amount of hydrogen chloride used. It is desirable that the feature be exhibited by using a small amount.

Furthermore, a process in which these methods (2) and (3) are combined is also known (JP-A-60-36318).

Of the above methods, the method (2) is the best from the viewpoint of effective reuse of silicon tetrachloride, and the method (3) is also the best from the viewpoint of trichlorosilane formation. It's hard.

That is, the method (2) or (3) is highly economical, and the method (2) in particular is currently being put to practical use as a favorite method.

However, in the method (2), the reaction temperature is usually 500 to 600 ° C., and there is no case where trichlorosilane is substantially produced at the reaction temperature of 300 ° C. or lower. Therefore, as a matter of course, as in the present invention, an example of producing trichlorosilane by a heterogeneous reaction of a gas-liquid-solid phase with silicon tetrachloride in a liquid state below the critical temperature of silicon tetrachloride has been heretofore known at all. Absent.

Further, in the method (2), a gas-solid phase fluidized bed apparatus is conventionally used when a large amount of trichlorosilane is continuously produced. However, in that case, since a fluidized bed is used, loss of effective components due to volatilization of silicon metal and catalyst components whose particle size is reduced by reaction, volatilization of catalyst components due to high temperature reaction, corrosion of equipment, and high molecular weight chlorosilane. There are many drawbacks to be solved further for industrialization, such as a decrease in the selectivity of trichlorosilane due to the formation of silanes, a large amount of energy being used at high temperatures, and so on.

As a result of intensive studies conducted by the present inventors, surprisingly, silicon tetrachloride is reacted in a liquid state at a temperature below the critical temperature of silicon tetrachloride, and the treatment is performed at a high yield and per unit volume of silicon tetrachloride. The inventors have found a method of producing trichlorosilane in an increased amount with extremely high economic advantages, and have completed the present invention.

OBJECT OF THE INVENTION That is, the object of the present invention is to convert by-produced silicon tetrachloride into trichlorosilane in the production of polycrystalline silicon by thermal decomposition of trichlorosilane or the production of monosilane by disproportionation reaction of trichlorosilane. However, it is to provide an extremely economical method for effectively using silicon tetrachloride.

According to the present invention, in a method for producing trichlorosilane by reacting silicon tetrachloride and metallic silicon with hydrogen or hydrogen and hydrogen chloride, the reaction system is prepared by bringing the silicon tetrachloride into a liquid state below its critical temperature. Trichlorosilane characterized in that it is a gas-liquid-solid phase heterogeneous reaction and the gas-liquid-solid phase heterogeneous reaction is carried out in the presence of copper metal, a metal halide and aluminum halide. A method of manufacturing the same is provided.

DISCLOSURE OF THE INVENTION The present invention will be described in detail below.

The conversion of silicon tetrachloride into trichlorosilane according to the present invention is basically represented by the following formula 3SiCl ₄ + 2H ₂ + Si → 4HSiCl ₃ Cl (I). This reaction is an equilibrium reaction, and the higher the temperature, the higher the pressure, and the higher the H ₂ / SiCl ₄ molar ratio, the more the reaction proceeds to the right. In addition, as will be described later, the seaside temperature of silicon tetrachloride is 233.6 ℃ (actually 230 ℃).
Below) no example of producing trichlorosilane by a low temperature gas phase-liquid phase-solid phase reaction in which silicon tetrachloride is in a liquid state at the following temperature has not been known so far, but in the present invention, the above reaction is carried out using metallic copper. , Metal halides and aluminum halides are added in the presence of specific additives to dissolve trichlorosilane in a liquid state or in an inert solvent in the reaction state and react in a liquid state to give trichlorosilane. It has been made possible to produce the above in good yield. Further, as a matter of course, it is possible to adopt a means which obviously results in increasing the yield of trichlorosilane by adding hydrogen chloride gas into the reaction system of the present invention.

The purity of metallic silicon used in the present invention is not particularly limited, and may be a low-purity metallurgical silicon or a high-purity silicon. From the economical point of view, it is preferable to use the former. The form of these metallic silicons is not limited, but it is recommended to use them in the form of powder having a large surface area from the viewpoint of reaction rate. Of course, it can be used in other forms such as granular form.

In the present invention, the above reaction is carried out in the presence of copper metal, a metal halide and aluminum halide, but the metal copper used in the present invention is not particularly limited, and commercially available electrolytic copper is usually used. Other reduced copper can also be used. Purity need not be so much of a concern. The form of metallic copper does not matter, but it is recommended to use it in the form of powder having a large surface area from the viewpoint of reaction rate. Of course, it can be used in other forms such as granular form.

The metal halide used in the present invention is an elemental symbol of Cu, Ti, V, Cr, Mn, Mn, Fe, Co, Ni, Zn, Zr, W, Mo, Ru, Rh, Pd,
Ag, Sn, Sb, Hg, Pt and Pb halides, and their specific molecular formulas are CuCl, CuCl ₂ , TiCl ₃ , TiCl ₄ , VCl ₃ , VCl ₅ , VOC
_{l 3, CrCl 2, CrCl 3} , MnCl 2, FeCl 2, FeCl 3, CoCl 2, NiCl 2, ZnC
l ₂ , ZrCl ₄ , ZrOCl ₂ , MoCl ₃ , MoCl ₅ , RuCl ₂ , RuCl ₃ , RhCl ₃ , PdCl
₂ , AgCl, SnCl ₂ , SnCl ₄ , SbC ₃ , SbCl ₅ , WCl ₅ , WCl ₆ , Hg ₂ Cl ₂ , HgC
Metal chlorides such as l ₂ , PtCl ₄ , PbCl ₂ and PbCl ₄ ; CuBr, CuBr ₂ , T
iBr ₄ , VBr ₃ , CrBr ₃ , MnBr ₂ , FeBr ₂ , FeBr ₃ , CoBr ₂ , NiBr ₂ , ZnBr
₂ , ZrBr ₄ , MoBr ₃ , PdBr ₂ , AgBr, SnBr ₂ , SnBr ₄ , SbBr ₃ , WBr ₅ , Hg
Metal bromides such as ₂ Br ₂ , HgBr ₂ , and PbBr ₂ ; and CuI, TiI ₄ , C
rI ₂ ,, MnI ₂ ,, FeI ₂ ,, CoI ₂ ,, NiI ₂ ,, ZnI ₂ ,, ZrI ₄ ,, PdI ₂ ,, AgI, SnI ₂ ,, Sn
Examples thereof include metal iodides such as I ₄ , SbI ₃ , SbI ₅ , WI ₄ , Hg ₂ I ₂ , PtI ₂ , PtI ₄ , and PbI ₂ . Further, a halide in which two or more kinds of halogen atoms are mixed is also effective, and one kind or a mixture of two or more kinds thereof is used.

The aluminum halide used in the present invention is aluminum chloride, aluminum bromide and aluminum iodide, and one or a mixture of two or more of them is used.

Next, the method for converting silicon tetrachloride to trichlorosilane in the present invention will be described.

The conversion reaction is basically carried out according to the above formula (I), but in the present invention, the reaction is carried out in a so-called gas-liquid-solid phase heterogeneous system of gas phase-liquid phase-solid phase. Normally, silicon tetrachloride is made into a liquid state, and pressure is applied to carry out a heating reaction.
As a matter of course, the reaction pressure should be higher than the vapor pressure of silicon tetrachloride at the set reaction temperature. Hydrogen used in the reaction is a medium (gas) that is inert to the reaction in advance.
For example, it may be diluted with argon, helium and / or nitrogen, etc., but it is preferable to use hydrogen alone from the viewpoint of reaction equilibrium, reaction rate and economical efficiency. It does not matter if it contains impurities that are normally expected. Under the reaction conditions, the solvent is inert to the raw materials, products, and additives such as metallic copper, metal halides and aluminum halides, for example, aliphatic hydrocarbons represented by n-hexane and n-heptane. It is also possible to use alicyclic hydrocarbons typified by cyclohexane and cyclooctane, and aromatic hydrocarbons typified by benzene and toluene.

Next, the significance of reacting silicon tetrachloride in a liquid state, which is the most remarkable point in the present invention, will be described.

The reaction of silicon tetrachloride while keeping it in a liquid state is performed by reacting liquid silicon tetrachloride with solid metal silicon, and hydrogen taken into the liquid silicon tetrachloride by dissolution or the like or by gas-liquid contact. Are meant to react, so the reaction field is almost essentially a liquid-solid phase. The trichlorosilane formed there is first formed in the liquid phase and dissolved in the liquid, but further transfers to the gas phase.
At this time, it goes without saying that silicon tetrachloride also shifts to the gas phase. Since the vapor pressures of trichlorosilane and silicon tetrachloride at the same temperature are higher in trichlorosilane, the concentration ratio of SiHCl ₃ / SiCl _{4 in the} gas phase is higher than that of SiHCl ₃ / SiCl _{4 in the} liquid phase. It becomes higher. Thus, if the reaction is carried out continuously, SiHCl ₃ / SiC in the liquid phase is always obtained.
Since the l ₄ concentration ratio tends to decrease, the reaction rate of the reaction is increased from the viewpoint of reaction equilibrium, and the reaction proceeds in a more advantageous direction for the production of trichlorosilane. Therefore, as compared with the case where the product gas composition is discharged as it is, as in the case of a normal fluidized bed reaction, the effect that the composition of the product always acts in favor of the product in terms of reaction equilibrium can be expected. Of.

Furthermore, the amount of trichlorosilane produced can be further increased by using anhydrous hydrogen chloride gas in the reaction.

As described above, in the present invention, the reaction temperature is not higher than the critical temperature of silicon tetrachloride, preferably not higher than 230 ° C.
Do above ℃. At temperatures below 100 ° C, substantial formation of trichlorosilane is not expected. It should be noted that trichlorosilane in an amount equal to or less than the reaction equilibrium amount may be mixed in the silicon tetrachloride charged as a raw material when carrying out this reaction. This means that when trichlorosilane produced by the reaction is separated by distillation, etc. It means that it is possible to use the one in which trichlorosilane remains, but it is preferable to use silicon tetrachloride that does not contain trichlorosilane or has the trichlorosilane content as low as possible in view of reaction equilibrium. This is desirable because it substantially produces the largest amount of trichlorosilane.

Next, the amounts used of the raw materials, additives such as metallic copper and metal halides in the present invention will be described. In the present invention,
The amount of metallic silicon used is not particularly limited, but when it is carried out in a batch system, it is preferably carried out in an amount of 1% by weight or more based on silicon tetrachloride. There is a risk that you will not be able to do it.
The amount of additives such as copper metal, metal halide and aluminum halide is not particularly limited, but metal copper is 0.5% or more in metal atom ratio to metal silicon, and metal halide and aluminum halide are not used. It is preferable to perform it at 0.1% or more in terms of reaction rate.

Next, a specific mode for actually carrying out the present invention will be described. As described above, since the reaction in the present invention requires 100 ° C. or higher, it is carried out under pressure (preferably hydrogen pressurization), and it can be carried out by either a flow reaction method or a batch reaction method. is there.

The method for carrying out the present invention is not particularly limited, but the following methods are mentioned as a method that is easy to carry out. Of course, the present invention is not limited to these methods.

(1) A method in which a predetermined amount of silicon tetrachloride, metal silicon, metal copper, metal halide, and aluminum halide are put in an autoclave, and then hydrogen is pressurized to a predetermined pressure, and then a heating and stirring reaction is performed.

(2) A predetermined amount of silicon tetrachloride, copper, a metal halide, and an aluminum halide are continuously introduced into a pressure reactor previously kept at a predetermined temperature and a predetermined pressure with hydrogen, and the produced gas and / or A method in which the product solution is continuously withdrawn and the reaction is carried out.

(3) Metallic silicon, copper, metal halide and aluminum halide are put in a reactor in advance and maintained at a predetermined temperature, and silicon tetrachloride and hydrogen are continuously introduced by hydrogen pressure and a produced gas and / or a produced gas. A method in which the reaction is carried out while continuously extracting the liquid, and metallic silicon, metallic copper, a metallic halide, and an aluminum halide are intermittently introduced as necessary.

Particularly, the method (2) or (3) is preferable as a method for producing trichlorosilane in a large amount. By conducting a continuous reaction in addition, metallic silicon is consumed by the reaction,
Copper, metal halides, and aluminum halides are practically not consumed. Therefore, if the reaction is carried out at a low temperature, these volatilizations can be prevented, so even if the ratio of copper, metal halide, and aluminum halide to the metal silicon is high in the reactor, it is not necessary to add them further. Therefore, it can be implemented as a method that can be economically established. In the methods (1) to (3) above, the reaction product is obtained by removing the solvent and the like from the product obtained by previously reacting the aluminum halide with the metal halide in an inert solvent or the like. It is also possible to use the isolated one.

Effect of the Invention The present invention is an extremely effective method for economically converting silicon tetrachloride into trichlorosilane. By operating below the critical temperature of silicon tetrachloride, which was previously impossible, silicon tetrachloride can be introduced into the reactor in the liquid state and the reaction can be carried out in the liquid state. Therefore, the reaction container can be easily downsized, which is economical. In addition, as a matter of course, since it is possible to carry out the reaction at a low temperature, it is possible to suppress the corrosion of the reaction device, etc. In addition, it is possible to produce trichlorosilane with low energy, and the economical effect is extremely high. Very large and extremely useful industrially. In other words, what used to require a large amount of energy due to the high temperature reaction, but this has enabled a significant reduction in energy, and since the liquid phase (silicon tetrachloride) reaction has become possible at low temperatures, the reaction vessel has a small size. It is possible to reduce the amount of equipment, such as the reduction of corrosion, the suppression of reactor corrosion, and the use of low-temperature heat media such as steam.

EXAMPLES Hereinafter, the present invention will be described more specifically by way of examples.

Example 1 Pressure resistance 300 Kg / cm ² G, temperature resistance 500 ° C SUS316 200 ml autoclave, metallic silicon (200 mesh, purity 99.9%) 9.00 g
(320mg-atm), aluminum chloride 5.00g (37.5mmol)
Commercially available metallic copper powder B 7.00 g (110 mg-atm), commercially available cuprous chloride 3.70 g (37.5 mmol) and silicon tetrachloride 130 g (765 mmo
l) and then pressurize hydrogen at room temperature to a pressure of 110 kg / cm ² G (H ₂ / SiCl _{4 to} 0.75 mol ratio), stir at 300 rpm and heat to 230 C (heating time 20 minutes) 230 The reaction was carried out at 0 ° C for 5 hours.
After the reaction was completed, the autoclave was cooled to 5 ° C., and the reaction solution after depressurization was analyzed by gas chromatography. The composition of the reaction solution was 28.2 mol% of trichlorosilane and 71.8% of silicon tetrachloride.
It was mol%, which corresponds to a conversion of silicon tetrachloride of 22.5%, and trichlorosilane could be obtained in a very high yield.

Example 2 The reaction liquid was analyzed by a gas chromatographic method under the same reaction conditions as in Example 1 except that the reaction time was 2.5 and 1 hour. The results are shown in Table 1.

From the above, it was found that a very high conversion rate of silicon tetrachloride can be obtained even if the reaction is carried out in a short time.

Comparative Example 1 (Blank Test) Under the same reaction conditions as in Example 1, A) aluminum chloride was not added, B) copper chloride was not added, and C) aluminum chloride and copper chloride were not added, and other conditions were carried out at all. A heating reaction was carried out for 5 hours under the same reaction conditions as in Example 1. The results are all extremely low chlorination rates of silicon tetrachloride as compared with the results of Example 1, and it was found that the combination of metallic copper, copper chloride and aluminum chloride in the present invention is extremely effective in this reaction. The results of Comparative Example 1 are summarized in Table 2.

Example 3 The same amount of metallic copper, metallic silicon, aluminum chloride and silicon tetrachloride as in Example 1 and various metallic chlorides in the same molar amount as cuprous chloride of Example 1 were put into an autoclave and the hydrogen charging pressure was 55 kg /. cm ² G (charged H ₂ / SiCl ₄ molar ratio ~ 0.38) was charged with hydrogen, heated at 230 ° C with stirring and reacted at that temperature for 2.5 hours, then cooled to 5 ° C and reduced in pressure, It was analyzed by gas chromatography. As shown in Table 3, various metal chlorides gave good results. At this time, the maximum reaction pressure was 100 kg / cm ² G. All chlorides were anhydrous.

Comparative Example 2 6.46 g (110 mg-atm) of metallic Ni powder was used instead of copper metal, and the reaction was carried out exactly the same as No. 3 of Example 3 except that the reaction was carried out under the same charging amount, hydrogen charging pressure and reaction conditions. Then, cooling, depressurization and analysis of the reaction solution were performed. The composition of the reaction solution is TCS / STC =
The molar ratio is 1.0 / 99.0, and the conversion rate of silicon tetrachloride is only 0.7.
%Met. Therefore, the presence of copper metal was found to be essential in this method.

Example 4 The same composition as in No. 3 of Example 3, the same hydrogen charging pressure, and the same reaction temperature as the nominal reaction temperature were used, and the reaction time was immediately after the temperature was raised, and the reaction was performed for 5 hours and 1 hour after the temperature was raised. Examples 1-3
After the same operation as above, the reaction solution was analyzed. The results are from Example 3.
It is shown in Table 4 together with No3.

Example 5 9.0 g of each metal silicon having a purity of 99.9%, 200 mesh or a purity of 98%, 150 mesh was placed in the same autoclave as in Example 1.
Copper metal powder B 7.0g (110mg-atm), nickel chloride 4.86g
(37.5 mmol), aluminum chloride 5.00 g (37.5 mmol) and silicon tetrachloride 130 g (765 mmol) were charged, and each was pressurized to 110 Kg / cm ² G with hydrogen at room temperature and then heated and stirred at 200 ° C for 5 hours. (Maximum reaction pressure 170 Kg / cm ² G), the reaction liquid was analyzed after cooling and reducing the pressure in the same manner as in Examples 1 to 4.
As shown in Table 5, no difference was found depending on the purity of metallic silicon, and it was found that inexpensive 98% silicon could be used.

Example 6 In the same autoclave as in Examples 1-5, aluminum chloride 37.5 mmol or aluminum bromide 37.5 mmol was charged with metallic silicon (purity 99.9%, 200 mesh) and metallic copper powder B7.00 g (11
(0 mg-atm) Nickel chloride (4.86 g, 37.5 mmol) and silicon tetrachloride (176.7 g, 1.04 mol) were added to the mixture, hydrogen was introduced at a predetermined pressure at room temperature, and the mixture was reacted at a predetermined temperature for a predetermined time. After cooling and depressurizing in the same manner as above, the reaction solution was analyzed.
As a result, as shown in Table 6, it was found that the activity was sufficiently observed even when the aluminum halide was replaced with aluminum chloride or aluminum bromide. Furthermore, in this method, trichlorosilane was obtained in a very high yield even at low temperature and in a short time, and the STY (space time yield) was about 1.6 mol.
It was found to reach /1.hr, which is 500-55
It was found to be extremely excellent, being equivalent to or exceeding the pressure fluidized bed reaction at 0 ° C.

Example 7 When cuprous chloride and aluminum chloride were mixed in equimolar amounts in toluene and stirred, most of them were uniformly dissolved and reacted. From this, toluene was distilled off under reduced pressure, and the remaining solid was sufficiently dried, 8.70 g (equivalent to 37.5 mmol of each of AlCl ₃ and CuCl), metallic copper powder B7.00 g (110 mg-atm), metallic silicon (purity 99.9%) 9.00 g ( 320 mg-atm) and silicon tetrachloride 1
After adding 30 g (765 mmol) and pressurizing to 55 Kg / cm ² G with hydrogen, cooling, depressurization and analysis of the reaction solution were performed in the same manner as in Examples 1-6. The composition of the reaction solution was 8.6 mol% of trichlorosilane and 91.4 mol% of silicon tetrachloride, and the result was the same as that of No. 1 of Example 3.

Example 8 N of Example 3 in the same autoclave as in Examples 1-7.
Put the same amount of metallic silicon, metallic copper, aluminum chloride and silicon tetrachloride as o.1 and add nickel chloride 4.86g (3
7.5 mmol) was added and the reaction was carried out for 1 hour at the same hydrogen pressure and reaction temperature as in Examples 3 and 4, and then cooling, depressurization and analysis of the reaction solution were performed in the same manner as in Examples 1-7. The reaction solution composition was 15.3 mol% of trichlorosilane and 84.7 mol% of silicon tetrachloride, which was a higher value than No. 3 of Example 4, and a synergistic effect of cuprous chloride and nickel chloride was recognized.

Example 9 The same amount of metal copper, metal silicon, aluminum chloride, and silicon tetrachloride as in Example 1 and the same amount of various metal bromides and iodides as the copper chloride of Example 1 were placed in the same autoclave as in Example 1. Filling hydrogen charge pressure 55 kg / cm ² G (charge H ₂ / SiCl ₄
After injecting hydrogen at a molar ratio of ~ 0.38), stirring at 230C and heating while reacting at that temperature for 2.5 hours (maximum reaction pressure 1
00 Kg / cm ² G), cooling and reducing the pressure in the same manner as in Example 1 and analyzing the reaction solution. The results are shown in Table 7. The bromide and iodide used in the reaction are all anhydrous.

As described above, it was found that various bromide iodides exhibit extremely high activity.

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Claims (3)

[Claims] 1. A method for producing trichlorosilane by reacting silicon tetrachloride and metallic silicon with hydrogen or hydrogen and hydrogen chloride, wherein the reaction system is vaporized by bringing the silicon tetrachloride into a liquid state below its critical temperature. -The liquid-solid phase heterogeneous reaction, and the gas-liquid-solid phase heterogeneous reaction,
A method for producing trichlorosilane, which is carried out in the presence of metallic copper, a metal halide and aluminum halide. 2. The metal halide is Cu, Ti, V, Cr, Mn, Fe, Co,
Chlorides of Ni, Zn, Zr, Mo, Ru, Rh, Pd, Ag, Sn, Sb, W, Hg, Pt, Pb,
The method of claim 1 which is a metal halide selected from the group consisting of bromide and iodide. 3. A method according to claim 1 wherein the aluminum halide is an aluminum halide selected from the group consisting of aluminum fluoride, aluminum chloride, aluminum bromide and aluminum iodide.