Method for preparing electronic-grade alkoxy silane from mixed alcohol

Abstract

The invention relates to a method for preparing electronic grade alkoxy silane from mixed alcohol, which is characterized by comprising the following steps: a, sequentially adding silicon powder slurry and a catalyst into a reaction kettle, b, introducing the mixed alcohol into the reaction kettle at a certain temperature, and carrying out a synthetic reaction, c, feeding the material after the synthetic reaction into a first rectifying tower through a condenser by virtue of a discharge pipeline, d, taking out the material of the second rectifying tower from the top of the tower as a first alkoxy silane product, e, returning the material of the third rectifying tower to the third rectifying tower from the top of the tower, and f, taking out the material of the fourth rectifying tower as a second alkoxy silane product from the top of the tower. The method for preparing the electronic-grade alkoxy silane from the mixed alcohol has the advantages that alkoxy silane can be prepared from the mixed alcohol, resource reutilization of materials is achieved, the overall production cost can be reduced, multiple electronic-grade alkoxy silane products can be continuously prepared at the same time, and the method is suitable for industrial production. And the prepared product has the advantages of few by-products and high purity of the rectified and recovered product.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical synthesis technology, specifically, it is a method for preparing electronic-grade alkoxysilanes from mixed alcohols. Background Technology

[0002] Mixed alcohols are organic waste liquids generated during the production processes of the pharmaceutical, chemical, and food industries, which are then recovered, dehydrated, and purified. Conventional methods for disposing of mixed alcohols include multi-tower distillation to separate and purify the recovered products for resale at a low price or as incineration fuel. For example, patent (CN105152860A) describes a method for refining mixed alcohols using a distillation-pervaporation coupled process. This method uses a pervaporation membrane to distill the mixed alcohol to obtain C1-C3 mixed alcohol products, and then separates them to obtain C4-C8 mixed alcohol products. While this achieves clean production and resource recovery, the recovered materials are difficult to utilize further and cannot increase profits; they can only be used as fuel. Patent (CN200580049206.2) uses C1-C8 mixed alcohols as fuel for internal combustion engines, furnaces, and boilers.

[0003] Silicate esters are important organosilicon products. Polysilicate esters, prepared by the hydrolysis of their monomers, are widely used in precision casting, semiconductors, coatings, and other industries. Applying silicate esters to substrate surfaces creates wear-resistant and hardening materials. Hydrolysis and condensation form a silica film, which protects ceramic and glass surfaces, prevents the diffusion of impurities, and improves electrical and mechanical properties. Furthermore, alkyl orthosilicates are widely used in silicone resin synthesis, silicone aerogel preparation, electronic component adhesives, precision castings, and the preparation of heat-resistant and corrosion-resistant paints. The traditional silicon tetrachloride method for producing alkoxysilanes involves reacting silicon tetrachloride with an alcohol, but this method generates a large amount of hydrochloric acid. Patent (CN109748931B) describes a method and system for preparing high-purity tetraethyl orthosilicate. This method utilizes a distillation reaction column to react silicon tetrachloride with ethanol to obtain tetraethyl orthosilicate, followed by decolorization, resin adsorption, and distillation to remove light and heavy components, ultimately yielding high-purity tetraethyl orthosilicate. While the preparation method and production system for high-purity tetraethyl orthosilicate can achieve continuous production, the equipment investment cost is high, and the chloride ion liquid in the product is difficult to completely remove, affecting subsequent application stages. In contrast, the synthesis of alkoxysilanes using silicon powder releases hydrogen gas during the reaction process, with no other harmful byproducts. The generated hydrogen gas can be recovered to produce high-purity hydrogen or incinerated in an incinerator to generate steam. This method is more suitable for modern industrial production.

[0004] Patent (CN101096374B) discloses a method for the direct synthesis of alkoxysilanes from silanols. This method is characterized by using a mixture of polyalkoxysilane and copper salt to promote the reaction of a single type of alcohol with silica powder to prepare alkoxyhydrosilane products. The disadvantages of this technology are: a large amount of catalyst is used during esterification synthesis, and a large amount of new polyalkoxysilane solvent needs to be added in subsequent batches. The high-temperature cracking of polyalkoxysilane and other side reactions generate a large amount of polymers, leading to increased energy consumption and subsequent reactor residue disposal costs. Furthermore, the recovered product is singular, while the variety of byproducts is numerous.

[0005] Patent (CN108640943A) describes a method for producing tetraethyl orthosilicate using silicon powder. This method also uses copper-based compounds as catalysts, but the catalyst preparation process is extremely complex and requires stirring at a high speed of 1000 rpm / min for more than 10 hours, making industrial production difficult. Furthermore, it involves high reaction pressure, long reaction time, and low production efficiency. Patent (CN107216348A) describes a direct method for preparing tetramethoxysilanes. It uses copper oxide or cuprous oxide as a catalyst, mixed with silicon powder and fed into a reactor. At a high temperature of 220°C, gas-phase methanol and silicon powder undergo a gas-solid phase catalytic reaction to synthesize tetramethoxysilanes. This method has high reaction temperature, excessive energy consumption, and produces many byproducts, resulting in low product conversion rates, making industrial production difficult. Patent (CN1027508C) describes a direct method for synthesizing alkoxysilanes, using a copper-based catalyst and adding metal elements such as Mn, Co, and Sb as auxiliary agents. The main reaction product is trialkoxysilane.

[0006] In addition to the above-mentioned problems in the production process of silicates, the existing technologies for the production of alkoxysilanes also have the following problems: the initial reaction activity of methyl orthosilicate production is too high, which poses a certain risk; the reaction in the middle and later stages of ethyl orthosilicate production is poor, which affects production efficiency.

[0007] In summary, solving the technical problems of numerous byproducts, low conversion rate, and high cost of silicate esters, and how to use recycled mixed alcohols as starting materials to directly prepare electronic-grade alkoxysilane products for application in the more advanced semiconductor industry, is one of the key challenges that urgently needs to be overcome in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing electronic-grade alkoxysilanes from mixed alcohols with fewer byproducts and higher product purity.

[0009] To achieve the above objectives, the technical solution of the present invention is:

[0010] A method for preparing electronic-grade alkoxysilanes from mixed alcohols, characterized by comprising the following steps:

[0011] a. Add silicon powder slurry and catalyst sequentially to the reaction vessel to obtain crude mixed alkoxysilane.

[0012] b. A synthesis reaction is carried out by introducing a mixed alcohol into the reactor at a certain temperature;

[0013] c. After the synthesis reaction, the material is discharged through a condenser into the first distillation column. After passing through the condenser, a portion of the material is removed as crude mixed alkoxysilanes and returned to the reactor via a mixed alcohol. The other portion of the crude mixed alkoxysilanes is pumped through the condenser into the second distillation column.

[0014] d. After the material in the second distillation column passes through the top condenser, part of it is taken out from the top of the column as the first product of alkoxysilane, and the other part is pumped from the bottom of the column into the third distillation column;

[0015] e. After passing through the top condenser of the third distillation column, part of the material is returned to the third distillation column from the top of the column, part is taken out to supply the synthesis reaction with mixed alcohol, and the other part is fed into the fourth distillation column from the bottom of the column after being added to the middle of the column for alcohol reaction.

[0016] f. After the material in the fourth distillation column passes through the top condenser, a portion is taken out from the top of the column as the second product of alkoxysilane, and the other portion is returned to the fourth distillation column. The residue at the bottom of the column is collected separately from the bottom of the column.

[0017] The method for preparing electronic-grade alkoxysilanes from mixed alcohols of the present invention can be further implemented using the following technical measures.

[0018] In the aforementioned method, the silicon powder slurry is prepared by blending silicon powder and crude mixed alkoxysilanes, wherein the silicon powder is commercially available 200-800 mesh elemental silicon powder.

[0019] In the aforementioned method, the catalyst is a commercially available catalyst such as sodium ethoxide, potassium ethoxide, Cu-Si alloy, copper oxide, cuprous oxide, cuprous chloride, cuprous chloride, mixed copper salt, YKCH708, or Si / Pt organic polymerization catalyst.

[0020] In the aforementioned method, the mixed alcohol is a mixed alcohol waste liquid generated by the pharmaceutical or chemical industries. The mixed alcohol waste liquid contains methanol, ethanol, n-propanol, isopropanol, butanol, ethylene glycol, glycerol, pentanol, or a combination thereof. The water content in the mixed alcohol is less than 5000 ppm, preferably less than 1000 ppm.

[0021] In the aforementioned method, the material at the bottom of the first distillation column is deionized by an adsorption column and then enters the second distillation column to separate and recover electronic-grade methyl silicate. The top temperature of the first distillation column is controlled at 75-90°C, and the metal ion content of the material after passing through the adsorption column is 40-90 ppm. The electronic-grade product, methyl silicate, has a metal ion content of <1 ppb and an alcohol content of <1 ppb.

[0022] In the aforementioned method, the alkoxysilane mixed at the bottom of the second distillation column enters the third distillation column for reactive distillation; the temperature of the second distillation column is controlled at 121-122°C.

[0023] In the aforementioned method, the temperature at the top of the third distillation column is controlled at 75-90°C; the mixed alcohol produced by the reaction is condensed at the top of the column and then used for the synthesis reaction; ethyl silicate is produced at the bottom of the third distillation column; ethanol is added to the middle of the third distillation column for transesterification.

[0024] In the aforementioned method, the ethanol content is selected to be 95-99.9%, preferably 99-99.9%, and the water content is 2000 ppm, preferably 500 ppm, and most preferably 50 ppm.

[0025] In the aforementioned method, the ethyl silicate content is 99.5-99.9%.

[0026] In the aforementioned method, the ethyl silicate at the bottom of the third distillation column enters the fourth distillation column for distillation to obtain electronic grade ethyl silicate.

[0027] In the aforementioned method, the temperature at the top of the fourth column of the distillation column is controlled at 167.8-168.5℃.

[0028] In the aforementioned method, the electronic grade tetraethyl orthosilicate metal ion content is <1 ppb, and the alcohol content is <1 ppb.

[0029] In the aforementioned method, the alcohol in step e is R1OH / (R2OH)m, where R1 is an alkyl group having 1 to 6 carbon atoms, R2 is a methylene group having 1 to 3 carbon atoms, and m = 1-3.

[0030] In the aforementioned method, the amount of alcohol used is 2-6 times the theoretical amount, preferably 2.5-4 times. The reaction temperature is 100-300℃.

[0031] In the aforementioned method, the pressure of the reactor is 0.1-0.5 MPa.

[0032] After adopting the above technical solution, the method for preparing electronic-grade alkoxysilanes from mixed alcohols of the present invention has the following advantages:

[0033] 1. Mixed alcohols can be used to prepare alkoxysilanes, enabling the resource reuse of materials and reducing overall production costs;

[0034] 2. Capable of simultaneously and continuously preparing multiple electronic-grade alkoxysilane products;

[0035] 3. The prepared product has fewer by-products, and the product recovered by distillation has high purity. Attached Figure Description

[0036] Figure 1 This is a process flow diagram for preparing electronic-grade alkoxysilanes from mixed alcohols according to an embodiment of the present invention.

[0037] In the diagram: 1. Condenser, 2. Mixed alcohol, 3. Catalyst, 4. Silica powder / solvent. Detailed Implementation

[0038] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0039] Please see now Figure 1 , Figure 1 This is a process flow diagram for preparing electronic-grade alkoxysilanes from mixed alcohols according to an embodiment of the present invention. In the embodiments, the silicon powder used is 550-600 mesh with a content of 99.5%.

[0040] Example 1

[0041] Example 1 uses a recycled methanol / ethanol mixture and includes the following steps:

[0042] Step 1: Weigh a certain amount of silicon powder and solvent 4 and mix them evenly in a reaction vessel (the solvent is crude alkoxysilane obtained from the reaction of methyl ethyl ethanol). Add catalyst 3: cuprous oxide, copper oxide, and sodium methoxide. After heating to 125℃, add methyl ethyl ethanol dropwise to carry out the synthesis reaction. The reaction formula is as follows:

[0043]

[0044] Where: m≤4, n≤4, m+n=4; x≥1.

[0045] Step 2: The reaction product enters the first distillation column through the discharge pipe. The top temperature of the column is controlled at 80-85℃ to remove the mixed ethanol / ethanol in the system. The mixed ethanol is condensed and returned to the reactor for the synthesis reaction. The bottom mixed ester enters the second distillation column after passing through the adsorption column.

[0046] Step 3: Control the temperature at the top of column 2 to 121-122℃, and separate electronic grade methyl orthosilicate by distillation. After cooling, it is recovered in a clean room.

[0047] Step 4: The remaining material enters the reactive distillation column three, and ethanol solution is added into the column to carry out the reaction. The temperature at the top of the column is controlled at 80-85℃ to produce mixed alcohol. The mixed alcohol is returned to the reactor after passing through condenser 1 for the synthesis reaction. The ethyl silicate collected at the bottom of the reactor enters the distillation column four.

[0048] Step 5: Control the temperature at the top of column four to 168-168.5℃, and separate electronic grade tetraethyl orthosilicate by distillation. After cooling, it is recovered in a clean room. The enriched material at the bottom of distillation column four is collected separately and can be used to prepare other products.

[0049] Example 2

[0050] Example 2 uses a recycled methanol / n-propanol mixture.

[0051] Step 1: Weigh a certain amount of silicon powder and solvent and mix them evenly in the reaction vessel (the solvent is crude alkoxysilane obtained by the reaction of methanol / n-propanol). Add the catalyst: Cu-Si alloy. After heating to 135℃, add methanol and n-propanol mixed alcohol dropwise to carry out the reaction.

[0052] Step 2: The reaction products enter the first distillation column through the discharge pipe. The top temperature of the column is controlled at 98-100℃ to remove the methanol and n-propanol mixture in the system. The mixed alcohol is condensed and returned to the reactor for the synthesis reaction. The bottom mixed ester enters the second distillation column after passing through the adsorption column.

[0053] Step 3: Control the temperature at the top of column 2 to 121-122℃, and separate electronic grade methyl orthosilicate by distillation. After cooling, it is recovered in a clean room.

[0054] Step 4: The remaining material enters the reaction distillation column three, and n-propanol solution is added into the column to carry out the reaction. The temperature at the top of the column is controlled at 98-100℃ to produce mixed alcohol. The mixed alcohol is condensed and returned to the reactor for the synthesis reaction. The propyl silicate collected at the bottom of the reactor enters the distillation column four.

[0055] Step 5: Control the temperature at the top of column four to 224.5-225.5℃, and separate electronic grade propyl orthosilicate by distillation. After cooling, it is recovered in a clean room. The enriched material at the bottom of distillation column four is collected separately and can be used to prepare other products.

[0056] Example 3

[0057] Example 3 uses a recycled n-propanol / n-butanol mixture.

[0058] Step 1: Weigh a certain amount of silicon powder and solvent and mix them evenly in the reaction vessel (the solvent is crude alkoxysilane obtained by the reaction of n-propanol / n-butanol). Add catalyst: YKCH708. After heating to 230℃, add n-propanol and n-butanol mixed alcohol dropwise to carry out the reaction.

[0059] Step 2: The reaction product enters the first distillation column through the discharge pipe. The top temperature of the column is controlled at 118-120℃ to remove the mixed alcohols of n-propanol and n-butanol in the system. The mixed alcohols are condensed and returned to the reactor for the synthesis reaction. The mixed esters at the bottom enter the second distillation column after passing through the adsorption column.

[0060] Step 3: Control the temperature at the top of column 2 to 224.5-225.5℃, and separate electronic grade propyl orthosilicate by distillation. After cooling, it is recovered in a clean room.

[0061] Step 4: The remaining material enters the third reactive distillation column, where n-butanol solution is added to the column for reaction. The temperature at the top of the column is controlled at 118-120℃ to produce a mixed alcohol. The mixed alcohol is condensed and returned to the reactor for the synthesis reaction. The propyl silicate collected at the bottom of the reactor enters the fourth distillation column.

[0062] Step 5: Control the temperature at the top of column four to 275-275.5℃, and separate electronic grade tetrabutyl orthosilicate by distillation. After cooling, it is recovered in a clean room. The enriched material at the bottom of distillation column four is collected separately and can be used to prepare other products.

[0063] The test results of the method for preparing electronic-grade alkoxysilanes from mixed alcohols of the present invention are shown in Table 1.

[0064] Comparative Example 1

[0065] Comparative Example 1 uses industrial-grade methanol to prepare methyl silicate.

[0066] Step 1: Weigh a certain amount of silicon powder and solvent and mix them evenly in the reaction vessel (the solvent is a mixture of methanol and methyl silicate). Add the catalyst: sodium methoxide. After heating to 100°C, add industrial-grade methanol dropwise to carry out the reaction.

[0067] Step 2: The reaction product enters the first distillation column through the discharge pipe. The top temperature of the column is controlled at 68-70℃ to remove the methanol solution in the system. The methanol is condensed and returned to the reactor for the synthesis reaction. The bottom methyl ester enters the second distillation column after passing through the adsorption column.

[0068] Step 3: Control the temperature at the top of column 2 to 121-122℃, and separate electronic grade methyl orthosilicate by distillation. After cooling, it is recovered in a clean room. The enriched material at the bottom of distillation column 2 is collected separately and can be used to prepare other products.

[0069] Comparative Example 2

[0070] Comparative Example 2 uses industrial-grade ethanol to prepare alkoxyhydrosilanes.

[0071] Step 1: Weigh a certain amount of silicon powder and solvent and mix them evenly in a reaction vessel (the solvent is polyalkoxysilane). Add the catalyst: mixed copper salt. After heating to 115°C, add industrial grade ethanol dropwise to carry out the reaction.

[0072] Step 2: The reaction products enter the first distillation column through the discharge pipe. The top temperature of the column is controlled at 78-80℃ to remove the ethanol solution in the system. The ethanol is condensed and returned to the reactor for the synthesis reaction. The bottom mixed ester enters the second distillation column after passing through the adsorption column.

[0073] Step 3: Control the temperature at the top of column 2 to 113.5-114℃, and perform intermittent distillation to separate triethoxysilane, which is then recovered after cooling; the enriched material at the bottom of distillation column 2 is collected separately and disposed of by an external contractor; this production process will generate tetraethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, etc., resulting in a large number of byproducts.

[0074] Table 1 Comparison of test results of the examples and the comparative examples

[0075]

[0076] This invention possesses substantial features and significant technological advancements. The method for preparing electronic-grade alkoxysilanes from mixed alcohols presents an improvement over existing technologies. The main improvements include: resource utilization of mixed alcohol waste liquid to synthesize higher-value alkoxysilanes, avoiding resource waste; the use of mixed alcohols instead of single alcohols in esterification reactions to simultaneously prepare multiple alkoxysilanes; the replacement of high-boiling-point solvents such as high-boiling-point polyalkoxysilanes with crude mixed alkoxysilanes as solvents to avoid introducing other organic impurities; and the direct preparation of electronic-grade alkoxysilane products through stepwise distillation for separation and purification. The mixed alcohols produced in subsequent processes are still used for alkoxysilane synthesis, forming a virtuous cycle. The purpose of this invention's method for preparing electronic-grade alkoxysilanes from mixed alcohols is to utilize recovered mixed alcohols as raw materials, achieving resource utilization of mixed alcohols and improving economic efficiency; and to realize the goal of directly preparing multiple alkoxysilanes from mixed alcohols to meet the requirements of industrial production.

[0077] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of this invention and are defined by the claims.

Claims

1. A method for preparing electronic-grade alkoxysilanes from mixed alcohols, characterized in that... Includes the following steps: a. Add the silicon powder slurry and catalyst to the reactor in sequence; b. A synthesis reaction is carried out by introducing a mixed alcohol into the reactor at a certain temperature; c. After the synthesis reaction, the material is discharged through the discharge pipe and enters the first distillation column through the condenser. After the material in the first distillation column passes through the condenser, part of it is taken out as crude mixed alkoxysilane and returned to the reactor through mixed alcohol. The other part of the crude mixed alkoxysilane is pumped through the condenser into the second distillation column. d. After the material in the second distillation column passes through the top condenser, part of it is taken out from the top of the column as the first product of alkoxysilane, and the other part is pumped from the bottom of the column into the third distillation column; e. After passing through the top condenser of the third distillation column, part of the material is returned to the third distillation column from the top of the column, part is taken out to supply the synthesis reaction with mixed alcohol, and the other part is fed into the fourth distillation column from the bottom of the column after being added to the middle of the column for alcohol reaction. f. After the material in the fourth distillation column passes through the top condenser, a portion is taken out from the top of the column as the second product of alkoxysilane, and the other portion is returned to the fourth distillation column. The residue at the bottom of the column is collected separately from the bottom of the column.

2. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The silicon powder slurry is made by blending silicon powder and crude mixed alkoxysilanes, and the silicon powder is commercially available 200-800 mesh elemental silicon powder.

3. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The catalyst is a commercially available catalyst such as sodium ethoxide, potassium ethoxide, Cu-Si alloy, copper oxide, cuprous oxide, cuprous chloride, cuprous chloride, mixed copper salt, YKCH708, or Si / Pt organic polymerization catalyst.

4. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The mixed alcohol is a mixed alcohol waste liquid generated by the pharmaceutical and chemical industries. The mixed alcohol waste liquid contains methanol, ethanol, n-propanol, isopropanol, butanol, ethylene glycol, glycerol, pentanol, or a combination thereof. The water content in the mixed alcohol is less than 5000 ppm, preferably less than 1000 ppm.

5. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The material at the bottom of the first distillation column is fed into the second distillation column after metal ions are removed by the adsorption column to separate and recover electronic grade methyl silicate. The top temperature of the first distillation column is controlled at 75-90℃. After passing through the adsorption column, the metal ion content of the material is 40-90ppm. The electronic grade methyl silicate has a metal ion content of <1ppb and an alcohol content of <1ppb.

6. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The mixed alkoxysilane at the bottom of the second distillation column enters the third distillation column for reactive distillation; the temperature of the second distillation column is controlled at 121-122℃.

7. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The temperature at the top of the third distillation column is controlled at 75-90℃; the mixed alcohol produced by the reaction is condensed at the top of the column and then used for the synthesis reaction; ethyl silicate is produced at the bottom of the third distillation column; ethanol is added to the middle of the third distillation column for transesterification.

8. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 7, characterized in that, The ethanol content is selected to be 95-99.9%, preferably 99-99.9%, and the water content is 2000ppm, preferably 500ppm, and most preferably 50ppm.

9. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 7, characterized in that, The ethyl silicate content is 99.5-99.9%.

10. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 7, characterized in that, The ethyl silicate at the bottom of the third distillation column enters the fourth distillation column for distillation to obtain electronic grade ethyl silicate.

11. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The temperature at the top of the four columns of the distillation column is controlled at 167.8-168.5℃.

12. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The electronic-grade tetraethyl orthosilicate has a metal ion content of <1 ppb and an alcohol content of <1 ppb.

13. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The alcohol mentioned in step e is R1OH / (R2OH)m, where R1 is an alkyl group with 1 to 6 carbon atoms, R2 is a methylene group with 1 to 3 carbon atoms, and m = 1-3.

14. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 13, characterized in that, The amount of alcohol used is 2-6 times the theoretical amount, preferably 2.5-4 times. The reaction temperature is 100-300℃.

15. The method for preparing electronic-grade alkoxysilanes from mixed alcohols as described in claim 1, characterized in that, The pressure in the reactor is 0.1-0.5 MPa.

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