JP2584772B2 - Method for producing trialkoxysilane - Google Patents

Description

The present invention relates to a method for producing trialkoxysilane,
In particular, the present invention relates to a method for producing trialkoxysilane in a high yield by reacting metal silicon and an alcohol in the presence of a copper catalyst.

[Prior art] Trialkoxysilanes in which three alkoxy groups and one hydrogen atom are bonded to one silicon atom, such as trimethoxysilane and triethoxysilane, are extremely unstable and highly reactive in themselves. Addition, copolymerization, co-condensation, etc. of many organic compounds to produce useful substances, for example, silane coupling agents, coating agents, used as a raw material when manufacturing heat-resistant paints, etc. I have.

Examples of a method for producing such trialkoxysilane include a method of reacting trichlorosilane with an alcohol: HSiCl ₃ + 3ROH → HSi (OR) ₃ + 3HCl (where R represents an alkyl group), or According to the reaction conditions, the following five types of reactions are considered to occur in a complicated manner. The method of directly reacting silicon metal and alcohol in a gas phase or a liquid phase in the presence of a copper catalyst: (1) Si + 4ROH → Si (OR) ₄ + 2H ₂ (2) Si + 3ROH → HSi (OR) ₃ + H ₂ (3) Si + 2ROH → H ₂ Si (OR) ₂ (4) Si + 2ROH → SiO ₂ + 2RH (5) ROH + H ₂ → RH + H ₂ O (6 ) Other products RSi (OR) ₃ , (RO) ₃ Si—O—Si (OR) ₃ (where R represents an alkyl group) is known.

However, in the former method, the by-produced hydrogen halide reacts with the alcohol to produce an alkyl halide and water, and the produced water hydrolyzes the raw material trichlorosilane to form a high condensate. However, there is a problem in the production that the yield of the trialkoxysilane as a target product is low and that hydrogen by-products corrode the reactor.

In the latter method, an excess of alcohol is usually used relative to silicon metal in order to increase the reaction rate as the reaction rate of silicon metal. However, if the reaction is a gas phase reaction, the above general formula (1) The reaction of formula (4) and (5) occurs because the reaction temperature is high, and the water generated at this time reacts with metal silicon or copper which is a catalyst. A film of silicic acid or silicon oxide (silica) is formed on the surface, and copper becomes copper oxide, which becomes inactive, and eventually stops the reaction halfway, resulting in a low reaction rate of silicon metal. Thus, there is a problem that the yield of the trialkoxysilane, which is the target, is low.

By the way, in the latter method performed by a liquid phase reaction, at the beginning of the reaction, the reaction represented by the general formula (2) takes precedence, and the selectivity of the trialkoxysilane as the target substance is improved, but the reaction proceeds. As a result, the selectivity of trialkoxysilane gradually decreases, and there was a problem that a satisfactory yield of the target trialkoxysilane could not be achieved. Although the cause is not clear, the cause of the decrease in the selectivity of trialkoxysilane as the reaction proceeds as described above is that the metal silicon used as an industrial raw material has a concentration of about 1% by weight or less as an impurity. The various alkali metals and one or alkaline earth metals contained in the above react with the alcohol to form a metal alcoholate, and as the reaction proceeds, the formed metal alcoholate gradually accumulates, and the accumulation of the metal alcoholate increases. As the acidity in the reaction system gradually shifts to the neutral or alkaline side as a result, it is considered that the trialkoxysilane once formed due to this is decomposed into tetraalkoxysilane, and the reaction rate is Activate the metallic silicon and copper catalyst as much as possible and react at a relatively low temperature. (4)
It is considered important to suppress the reactions of (5) and (5) as much as possible.

For this reason, in the latter method performed in this liquid phase reaction,
One solution to solve the above mentioned problem is:
For example, we believe that it is necessary to improve the purity of metal silicon itself used as a raw material, or to convert it to a substance that does not react with alcohols, so that the acidity in this reaction system can always be maintained at a constant acidity. However, refining silicon metal requires a great deal of time and money, and it is not possible to increase the purity of silicon metal used on an industrial scale when producing trialkoxysilane to such an extent that the reaction is not adversely affected. It is almost impossible.

In the method of directly reacting silicon metal and alcohol in a gas phase or a liquid phase in the presence of a copper catalyst, hydrogen fluoride or ammonium acid fluoride is added to the reaction system in order to improve the yield of trialkoxysilane. It has also been proposed to introduce it (JP-A-48-39442). In this method, the selectivity of trialkoxysilane in the reaction product is improved, and the yield of trialkoxysilane is improved. However, the trialkoxysilane in the reaction product is unstable and the separation and purification can be performed efficiently. It is difficult to obtain trialkoxysilane with high yield.

[Problems to be Solved by the Invention] Accordingly, the present inventors have conducted intensive studies in view of the above viewpoints, and as a result, the metal silicon and the copper catalyst used for the reaction were previously converted into an organic halogen in a liquid or gaseous phase. The present inventors have found that by performing a pretreatment for bringing the compound into contact with a halide, it is possible to prevent a decrease in the selectivity of trialkoxysilane and the conversion of metal silicon, thereby achieving the present invention.

Therefore, it is an object of the present invention to provide both excellent reaction rate of metal silicon and selectivity of trialkoxysilane, and furthermore, the reaction product is excellent in stability and trialkoxysilane can be produced with high yield. An object of the present invention is to provide a method for producing trialkoxysilane.

[Means for Solving the Problems] That is, the present invention precedes the above reaction in producing trialkoxysilane by reacting silicon metal and an alcohol in a liquid phase or a gas phase in the presence of a copper catalyst. The method is a method for producing trialkoxysilane in which a metal silicon or copper catalyst and an organic halide are brought into contact in a liquid phase or a gas phase to perform a pretreatment.

In the method of the present invention, the metal silicon used as a raw material has a purity of 80% by weight or more and an average particle diameter of 20%.
Any powder having a particle size of 0 μm or less may be used.For example, an inexpensive general commercial product having a purity of 80 to 99% by weight and an average particle size of 50 to 100 μm, which is produced by means such as a vibration mill or a ball mill, may be used as it is. it can. Such metal silicon typically contains Fe, Ca, Mg, Zn, Al, Ti, Cr, Ni, Mn, Ba,
Metals such as Cu and Zr are contained in a large amount of about 1% by weight, and small amounts of about several ppm.

Alkyl alcohol is usually used as a raw material alcohol, and preferably has a carbon number such as methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, and amyl alcohol. 1-6 lower alkyl alcohols are used. These alcohols have a purity of 98% by weight or more, preferably 9% by weight.
The content is preferably not less than 9.9% by weight and the water content is not more than 0.2% by weight, preferably not more than 0.1% by weight. The amount of the alcohol used is usually 3 to 1 mol per 1 mol of silicon metal.
Although it is 10 mol, it is preferable to use it in excess with respect to the metal silicon in order to improve the reaction rate of the metal silicon, and it is preferably 4 to 8 mol.

The copper catalyst used in the method of the present invention may be a conventionally known one, for example, metal copper powder, cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, copper iodide. Copper compounds such as cuprous, cupric iodide, cuprous fluoride, copper formate, copper acetylacetonate, cuprous acetate, cupric acetate, cuprous oxide, cupric oxide and the like. Can be. One of these metallic copper powders and copper compounds may be used alone, or two or more thereof may be used in combination. These copper catalysts are usually used in an amount of 0.005 to 0.5 mol, preferably 0.01 to 0.1 mol, per 1 mol of silicon metal. If the amount is less than 0.005 mol, there is a problem that the reaction rate of silicon metal is reduced. However, even if the amount exceeds 0.5 mol, the conversion of metal silicon and the selectivity of trialkoxysilane are not improved, which is uneconomical. The copper catalyst may be mixed with the above-mentioned metal silicon in advance, pulverized and heat-treated at 200 to 600 ° C., preferably 200 to 400 ° C. in a nitrogen stream to activate the copper catalyst.

Further, as the organic halide used in the present invention, for example, methyl chloride, methyl bromide, methyl fluoride, methyl iodide, ethyl chloride, ethyl bromide, ethyl fluoride, ethyl iodide, n-propyl chloride, Alkyl halides such as n-propyl bromide, alkenyl halides such as dichloromethane and dichloroethane, aryl halides such as chlorobenzene and dichlorobenzene, and other organic acid halides such as chloroform, carbon tetrachloride and acetic chloride. And the like.

And about the usage of this organic halide,
The amount is usually 0.0001 to 1 mol, preferably 0.001 to 0.5 mol, per 1 mol of the above metal silicon. If the amount is less than 0.0001 mol, the metal silicon and the copper catalyst are not sufficiently activated, and the alkali which is an impurity of the silicon metal is used. In addition, alcoholates of alkaline earth metals can be formed, and the reaction system becomes alkaline and the selectivity of trialkoxysilane decreases. On the other hand, if it exceeds 1 mol, the acidity becomes too strong, and The problem arises that the selectivity of silane is reduced and at the same time it is economically disadvantageous. This organic halide can be used alone, but it is preferable to use the organic halide diluted with an inert gas such as a nitrogen gas or a hydrogen gas in order to adjust the amount of use or to facilitate handling. .

The solvent used when the method of the present invention is carried out in the liquid phase may be any solvent as long as it is stable in the reaction system and can be raised to a predetermined reaction temperature, and various hydrocarbon compounds are used. For example, octane, decane,
Paraffinic hydrocarbons such as dodecane, tetradecane, hexadecane, octadecane, eicosane, etc .; alkylbenzene hydrocarbons such as ethylbenzene, trimethylbenzene, cymene, diethylbenzene, butylbenzene, butyltoluene, octylbenzene, dodecylbenzene, didodecylbenzene and hydrides thereof And diphenyl-based hydrocarbons such as diphenyl, diphenylether, monoethyldiphenyl, diethyldiphenyl and triethyldiphenyl or hydrides thereof, alkylnaphthalene-based hydrocarbons and hydrides thereof, triphenyl-based hydrocarbons and hydrides thereof and the like. , May be used alone, or two or more may be used in combination. Preferred among these solvents are those that do not foam during the reaction and have a boiling point of 100 to 4 at normal pressure.
00 ° C, preferably 150-300 ° C. The relationship between the solvent used in the pretreatment of the metal silicon and the copper catalyst and the solvent used in the reaction of the metal silicon and the alcohol may be different from each other. Is preferably performed continuously, and it is therefore preferable that the same solvent be used.

When the method of the present invention is carried out in a liquid phase, the reaction is carried out, for example, by the following method. That is, an alcohol inlet tube, a halide inlet tube, a product distilling tube, and a thermometer are set in a reaction vessel equipped with a stirrer, metal silicon, a copper catalyst, and a reaction solvent are charged in the reaction vessel, and nitrogen gas or the like is used as necessary. The boiling point of the reaction solvent (usually within the range of 100 to 400 ° C.), preferably 150 ° C., while blowing the inert gas or hydrogen gas, or mixing with the inert gas or hydrogen gas to stir the organic halide. To 300 ° C. while heating, bringing the metal silicon and copper catalysts into contact with the organic halide for a predetermined period of time, and, if necessary, aging under an atmosphere of an inert gas or hydrogen gas while aging the metal silicon or copper catalyst. A pretreatment for activating the catalyst is performed.

After the pretreatment is completed in this way, alcohol is poured into the reaction vessel at a constant speed from the alcohol introduction tube to cause a reaction, and the reaction product distilled out from the product distillation tube is subjected to the product distillation tube. Cool with a cooler connected to the outlet of
The desired trialkoxysilane and unreacted alcohol are condensed and collected. At this time, a small amount of organic halide is dissolved in the reaction system by dissolving the organic halide in the alcohol to be introduced, or diluting or diluting with an inert gas or hydrogen gas using the halide introducing tube. The halide is introduced, and the acidity of the distillate in the reaction system and the target substance such as trialkoxysilane is adjusted to pH 1 to 6, preferably pH 2.
It is preferable to adjust the value to に な る 4, which further improves the selectivity of trialkoxysilane.

Further, when the method of the present invention is carried out in the gas phase, the reaction may be the same as a conventionally known method using a vertical reactor or a horizontal reactor. While the reactor filled with is usually heated to 150 to 600 ° C., preferably 200 to 400 ° C., an organic halide equivalent to that in the case of the liquid phase reaction is diluted or diluted with an inert gas or hydrogen gas. The reaction can be carried out by heating and aging while preferably introducing an inert gas or hydrogen gas for a predetermined time thereafter.

Furthermore, after the metal silicon is consumed through a series of steps from the pretreatment of the metal silicon and the copper catalyst to the reaction between the metal silicon and the alcohol, a new metal silicon is added (if necessary, the copper catalyst is added). However, the addition of a new copper catalyst is usually unnecessary.) By repeating the same pretreatment and reaction as above, the target trialkoxysilane can be repeatedly produced in the same reaction vessel. .

[Operation] In the method of the present invention, the metal silicon and copper catalyst and the halide are brought into contact with each other under heating to carry out a pretreatment,
Probably the following reaction: CuCl + Si → SiCl ₄ + Cu 2Cu + RCl → CuCl + RCu 3 (Si + 2RCl) → R ₂ SiCl ₂ + RSiCl ₃ + R ₃ SiCl etc. occurs in the system, and the metal silicon and copper catalysts are activated and react with alcohols It is believed that this improves the reactivity and suppresses undesired side reactions, thereby improving the conversion of silicon metal and the selectivity of trialkoxysilane.

In addition, the organic halide or the organic halide and a metal silicon and a copper catalyst neutralize an alcoholate formed by a reaction of an alkali metal and / or an alkaline earth metal accompanied by an impurity with the metal silicon and an alcohol with an alcohol. However, it is considered that the inside of the reaction system is always maintained in an acidic state, thereby preventing the once generated trialkoxysilane from being decomposed into tetraalkoxysilane, and maintaining the selectivity of trialkoxysilane at a high level. Although the rationale is not clear, the stability of the obtained reaction product is also improved.

[Examples] Hereinafter, the method of the present invention will be specifically described based on examples and comparative examples.

Example 1 An alcohol introduction tube, a halide introduction tube, a product distillation tube, and a thermometer were set in a 500 ml reaction vessel equipped with a stirrer.
98% pure by weight in the reaction vessel ｛Impurity: 0.83wt% Fe, C
a: 0.35 wt%, Mg: 150 ppm, Zn: 320 ppm, Al: 0.60 wt%, Ti:
860 ppm, Cr: 40 ppm, Ni: 43 ppm, Mn: 240 ppm, Ba: 50 ppm, C
u: 32 ppm, Zr: 180 ppm (measured by ICP emission spectroscopy), 150 g of metallic silicon with an average particle size of about 50 μm, and a boiling point of 280
300 ml of an alkylbenzene-based hydrocarbon (manufactured by Mitsubishi Yuka Co., Ltd .: AB-HL) at 7.5 ° C. and 7.5 g of cuprous chloride were charged, and a condenser was set at the outlet of the distillation pipe.

Next, the temperature was raised to 200 ° C. with stirring over a period of 60 minutes while flowing nitrogen gas at a flow rate of 30 ml / min. In the reaction vessel, followed by nitrogen gas 20 ml / min. And methyl chloride (as gas) 1
0 ml / min. Was introduced at a temperature of 200 to 260 ° C. for 10 hours. Further, introduction of methyl chloride was stopped, and aging was performed at a temperature of 200 to 230 ° C. for 4 hours while introducing 20 ml / min. Of nitrogen gas.

After the pretreatment of silicon metal and cuprous chloride in this way, methyl alcohol having a purity of 99.9% by weight or more is introduced into the reaction vessel at a rate of 25 g / hr. While introducing 2 ml / min. Of methyl chloride (as gas) and 10 ml / min. Of nitrogen gas from the halide inlet tube, the reaction was carried out for 40 hours while maintaining the inside of the reaction vessel at 160-170 ° C, and the product was distilled off. The reaction product discharged from the outlet of the tube was cooled by a cooler connected to the outlet to obtain 980 g of a reaction product.

The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethalkoxysilane, 46.4% by weight, tetramethoxysilane 9.5% by weight, unreacted methyl alcohol 39.1% by weight, dimethoxysilane 0.2% by weight,
It has a composition of 0.6% by weight of methyldimethoxysilane, 1.1% by weight of methyltrimethoxysilane, a total of 1.1% by weight of three kinds of dimers and 3.0% by weight of a solvent, and a reaction rate of silicon metal of 81.0% by weight. The selectivity for trimethoxysilane was 88.2 mol%.

Further, after the obtained reaction product was sealed and allowed to stand at 20 ° C. for 15 days, gas chromatography analysis was performed again, but no change in the composition of the reaction product was observed, and the stability of the reaction product was good. Turned out to be.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that the pretreatment for introducing methyl chloride was not performed, and 970 g of a reaction product was obtained.

The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane, 25.1% by weight,
It has a composition of 24.2% by weight of tetramethoxysilane, 46.1% by weight of unreacted methyl alcohol, and 4.6% by weight of others. The conversion of silicon metal is 66.3% by weight, and the selectivity of trimethoxysilane is 56.7% by mole. Met.

Example 2 150 g of the metal silicon used in Example 1 and 7.5 g of cuprous chloride were filled in a 30 mm φ Pyrex glass tube, and heated with a band heater for 2 hours while flowing nitrogen gas at 20 ml / min. The temperature was raised to 250 ° C, followed by nitrogen gas 20ml /
min. and methyl chloride (as gas) at 10 ml / min.
Introduce for 4 hours at a temperature of 0 ° C, further stop introduction of methyl chloride and heating, and introduce nitrogen gas at 20 ml / min.
The mixture was aged for 3 hours until the temperature reached 0 ° C.

The thus obtained metal silicon and cuprous chloride were put into a reaction vessel, and methyl alcohol was introduced under exactly the same conditions as in Example 1 to obtain 990 g of a reaction product.

The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane, 44.5% by weight,
It has a composition of 10.3% by weight of tetramethoxysilane, 37.6% by weight of unreacted methyl alcohol, and 2.2% by weight. The conversion of silicon metal is 80.4% by weight, and the selectivity of trimethoxysilane is 84.3% by mole. Met.

Example 3 The same stainless steel reaction vessel with a stirrer having a capacity of 8 as used in Example 1 was charged with 2 kg of metal silicon, 100 g of cuprous chloride and alkylbenzene hydrocarbon 4 as in Example 1, and stirred. At 200 to 260 ° C., nitrogen gas 20 ml / min. And methyl chloride (as gas) 10 ml / min. Are introduced for 6 hours, and at 200 to 230 ° C., nitrogen gas 30 ml / min. And methyl chloride (as gas) 10 ml / min. min. was introduced for 6 hours, then heating and introduction of methyl chloride were stopped, and nitrogen gas 30 ml / min. was introduced for 2 hours until the temperature reached 160 ° C., followed by aging.

After pretreatment of silicon metal and cuprous chloride in this way, as in Example 1, methyl alcohol was introduced into the reaction vessel as a liquid at a rate of 145 g / hr. Is introduced at a reaction temperature of 160 to 17 while introducing 3 ml / min. Of methyl chloride (as gas) and 20 ml / min. Of nitrogen gas.
The reaction was performed at 0 ° C. for 40 hours to obtain 5,750 g of a reaction product as a first reaction.

The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane, 71.0% by weight,
It has a composition of 18.5% by weight of tetramethoxysilane, 5.1% by weight of unreacted methyl alcohol and 4.5% by weight of others,
The conversion of silicon metal was 56.7% by weight, and the selectivity for trimethoxysilane was 82.7% by mole.

Next, while introducing methyl alcohol as a liquid into the reaction vessel at a rate of 94 g / hr.
The reaction was conducted for a time, and 2,680 g of a reaction product was obtained as a second reaction.

The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane, 51.2% by weight,
It has a composition of 33.5% by weight of tetramethoxysilane, 9.8% by weight of unreacted methyl alcohol and 6.5% by weight of others,
As a sum of the first and second reactions, the conversion of silicon metal was 80.7% by weight, and the selectivity for trimethoxysilane was 65.5 mol%.

After completion of the reaction in this way, 1.5 kg of metal silicon is again charged into the reaction vessel, and the same pretreatment as described above is performed without adding the copper catalyst, and then, as in the above,
Methyl alcohol is introduced into the reaction vessel as a liquid at a rate of 140 g / hr., And methyl chloride (as gas) is 3 ml / min.
And nitrogen gas 20 ml / min.
Perform the reaction at 180 ° C for 30 hours.
The reaction product of was obtained. The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane 68.0% by weight, tetramethoxysilane 21.0% by weight,
It has a composition of unreacted methyl alcohol of 7.8% by weight and other 3.2% by weight. The reaction rate of silicon metal is 53.2% by weight based on newly added metal silicon, and the selectivity of trimethoxysilane is 80.1 mol%.

Further, while introducing methyl alcohol as a liquid into the reaction vessel at a rate of 90 g / hr.
The reaction was performed for 5 hours, and as a fourth reaction, 2,140 g of a reaction product was obtained. The obtained reaction product was analyzed by gas chromatography to find that the target product, trimethoxysilane 5
It has a composition of 0.0% by weight, 31.0% by weight of tetramethoxysilane, 11.6% by weight of unreacted methyl alcohol, and 7.4% by weight of others, and the reaction rate of metal silicon as the sum of the third and fourth reactions is It was 78.4% by weight, based on the newly added metal silicon, and the selectivity for trimethoxysilane was 67.3% by mole.

Comparative Example 2 The same procedure as in Example 3 was performed except that the pretreatment was not performed by introducing methyl chloride, and that the reaction temperature was set to 200 ° C.
In the first reaction, 5,680 g of a reaction product was obtained, and in the second reaction, 2,590 g of a reaction product was obtained.

As a result of analysis by gas chromatography, the composition of the first reaction product was 29.0% by weight of trimethoxysilane, 33.4% by weight of tetramethoxysilane, 32.5% by weight of unreacted methyl alcohol, and other components were 5.1% by weight. The composition of the reaction product was 21.2% by weight of trimethoxysilane, 31.4% by weight of tetramethoxysilane, 39.4% by weight of unreacted methyl alcohol, and 8.0% by weight of the other target substances, and the total of the first and second reactions described above. The reaction rate of silicon metal was 50.2% by weight, and the selectivity of trimethoxysilane was 46.4 mol%.

Example 4 Ethyl alcohol was used in place of methyl alcohol, ethyl chloride was used in place of methyl chloride, the supply rate of ethyl alcohol was 25 g / min., And the reaction temperature was
940 g of a reaction product was obtained in the same manner as in Example 1 except that the temperature was changed to 200 to 220 ° C. As a result of analysis by gas chromatography, the obtained reaction product had the following composition: 43.2% by weight of triethoxysilane, 15.4% by weight of tetraethoxysilane, 35.3% by weight of unreacted ethyl alcohol, and 6.1% by weight of other products. The conversion of silicon metal was 60.2% by weight, and the selectivity of triethoxysilane was 78.4% by mole.

Comparative Example 3 A reaction was carried out in the same manner as in Example 4 except that the pretreatment with ethyl chloride was not performed, and 930 g of a reaction product was obtained. As a result of analysis by gas chromatography, the obtained reaction product had the following composition: 17.1% by weight of triethoxysilane, 21.0% by weight of tetraethoxysilane, 54.8% by weight of unreacted ethyl alcohol, and 7.1% by weight of other components.
The conversion of silicon metal was 35.0% by weight, and the selectivity of triethoxysilane was 50.3% by mole.

Comparative Example 4 A pretreatment of silicon metal and cuprous chloride and a reaction between silicon metal and methyl alcohol were performed in exactly the same manner as in Example 1 except that hydrogen chloride was used instead of methyl chloride in the pretreatment step. In 40 hours, 955 g of a reaction product was obtained. As a result of analysis by gas chromatography, the obtained reaction product was analyzed to be 45.5% by weight of trimethoxysilane, 10.6% by weight of tetramethoxysilane,
It had a composition of 8.5% by weight and another 5.4% by weight. The conversion of silicon metal was 78.9% by weight, and the selectivity for trimethoxysilane was 84.2% by mole.

Further, after the obtained reaction product was sealed and allowed to stand at 20 ° C. for 15 days, it was subjected to gas chromatography analysis again. As a result, trimethoxysilane (20.4% by weight), tetramethoxysilane (41.7% by weight), and methyl alcohol (29.8%) were obtained. % By weight, 0.02% by weight of dimethoxysilane, 0.08% by weight of methyldimethoxysilane, 1.4% by weight of methyltrimethoxysilane, a total of 3.6% by weight of three kinds of dimers and 3.0% by weight of solvent
Met. As a result, as compared with Example 1 using methyl chloride, the ratio of the target product, trimethoxysilane, was significantly reduced, and it was found that the stability of the reaction product was poor.

[Effects of the Invention] According to the method of the present invention, both the reaction rate of metal silicon and the selectivity of trialkoxysilane are improved, and the reaction product is excellent in stability to produce trialkoxysilane in good yield. Can be.

Claims (6)

(57) [Claims] In producing a trialkoxysilane by reacting a metal silicon and an alcohol in a liquid phase or a gas phase in the presence of a copper catalyst, prior to the reaction, the metal silicon and the copper catalyst and the organic halide are reacted with each other. A pretreatment by contacting the compound in a liquid phase or a gaseous phase. 2. The process for producing trialkoxysilane according to claim 1, wherein the pretreatment in the liquid phase is carried out at a temperature of 100 to 400 ° C. 3. The process for producing trialkoxysilane according to claim 1, wherein the pretreatment in the gas phase is carried out at a temperature of 150 to 600 ° C. 4. The organic halide is an alkyl halide,
The method for producing a trialkoxysilane according to any one of claims 1 to 3, wherein the method is an alkenyl halide or an aryl halide. 5. The method for producing trialkoxysilane according to claim 1, wherein the alcohol is a lower alkyl alcohol. 6. The reaction between silicon metal and alcohols is carried out by 100 to 3 times.
The method for producing a trialkoxysilane according to any one of claims 1 to 5, which is performed at 00 ° C.