Method for anhydrous production of thiocarboxylate silane from industrial tail gas hydrogen sulfide

Abstract

The invention discloses a method for anhydrous production of thiocarboxylate silane by using industrial tail gas hydrogen sulfide, which comprises the following steps: 1) introducing the industrial tail gas hydrogen sulfide into an alcohol-alkali solution for reaction to obtain an alcohol solution of alkali sulfide; 2) adding acyl halide into the alcoholic solution of the alkali sulfide for reaction to obtain an alcoholic solution of thiocarboxylic acid alkali; 3) adding haloalkyl silane into the alcohol solution of the thiocarboxylic acid alkali for reaction to obtain a mixed solution of thiocarboxylic ester silane and salt; and desalting and dealcoholizing to obtain the target product thiocarboxylate silane. According to the method, the target product thiocarboxylate silane can be obtained with high yield under the condition that a phase transfer catalyst is not added.

Description

Technical Field

[0001] This invention relates to a method for producing thiocarboxylic acid ester silanes, and more particularly to a method for producing thiocarboxylic acid ester silanes using anhydrous hydrogen sulfide from industrial tail gas. Background Technology

[0002] Sulfur-containing silanes are widely used in rubber vulcanization and compounding, and also have extensive applications in glass fiber processing, electronic packaging, and metal bonding. With the rapid development of the global economy, industries such as automotive tires and high-end footwear materials have huge demands for sulfur-containing silanes. Currently, the most commonly used sulfur-containing silanes are bis-[3-(triethoxysilyl)propyl]-tetrasulfide and bis-[3-(triethoxysilyl)propyl]-disulfide.

[0003] However, bis-[3-(triethoxysilyl)propyl]-tetrasulfide and bis-[3-(triethoxysilyl)propyl]-disulfide, due to their excessively long sulfur chains, are prone to chain breakage during rubber compounding, leading to scorching during vulcanization and hindering processing. Therefore, second-generation sulfur-containing silanes, mercaptopropyltrialkoxysilanes, were developed to avoid sulfur chain breakage during compounding. However, due to the high vulcanization reactivity of the mercapto group, controlling compounding and vulcanization time during rubber processing was difficult. Thus, third-generation thiocarboxylic acid ester silanes with mercapto-terminated ends were further developed. These third-generation silanes, by end-capping the highly reactive mercapto group, prevent scorching caused by polysulfide chain breakage during rubber processing, while also avoiding the processing difficulties caused by excessive mercapto reactivity. They also improve the dispersibility of silica in rubber, enhancing tire wet grip and noise reduction, making them highly popular in high-end tires.

[0004] WO2005007661A1 describes an aqueous method for preparing thiocarboxylic acid ester silanes in the presence of a phase-transfer catalyst such as a quaternary ammonium salt or phosphonium salt. However, this method has a low reaction rate and requires a large amount of catalyst, which complicates the purification process. Patents CN101184767B and CN105102465B have respectively improved the phase-transfer catalyst. They first react a base sulfide with an acyl halide to generate a thiocarboxylic acid base, and then use the improved phase-transfer catalyst to react with a haloalkane in an aqueous solution to prepare the thiocarboxylic acid ester silane, aiming to improve the reaction rate and product yield. However, the prior art does not recognize the following problems with the aqueous solution system: the acyl halide hydrolyzes in water to generate acid, resulting in a large amount of acid hydrolysis of the product in the acid solution, significantly reducing the product yield; in addition, the acid solution generated by the hydrolysis of the acyl halide requires neutralization with alkali for post-treatment, and the generated salt presents difficulties in solid waste disposal. Therefore, although this method improves the reaction efficiency to some extent by improving the catalyst, the product yield is still very low, and the post-treatment is complex and the production cost is high.

[0005] Patent CN103709188B discloses a method for preparing end-capped sulfur-containing silanes by hydrosilylation. This method also requires the synthesis of sodium thiocarboxylate from alkali sulfide and acyl halide via an aqueous phase method, which will cause hydrolysis of acyl halide and acid hydrolysis of the product, resulting in a very low yield and a large amount of wastewater that needs to be treated.

[0006] Patent CN113795499B discloses a method for preparing end-capped thiocarboxylic acid esters from thioesters and mercapto-functionalized alkoxysilanes. This method uses transesterification to prepare thiocarboxylic acid esters. The disadvantage is that the transesterification reaction is an equilibrium reaction, and the target yield is not high. At the same time, mercapto-functionalized alkoxysilanes are expensive, which is not conducive to industrial production.

[0007] Patent CN100341881C discloses a method for preparing end-capped mercaptosilanes from mercaptosilanes and inorganic halides or acid anhydrides. However, this method generates a large amount of hydrogen chloride, which, if not removed in time, will also cause a large amount of acid hydrolysis of the product. At the same time, it requires the use of expensive mercaptosilanes as raw materials, making it not economically viable. Summary of the Invention

[0008] To address the above technical problems, this invention proposes a method for producing thiocarboxylic acid ester silanes using anhydrous hydrogen sulfide from industrial waste gas.

[0009] Through in-depth research, the inventors discovered that, due to limitations in upstream alkali sulfide preparation processes, industrial raw materials such as Na2S inevitably contain water of crystallization or can only exist in aqueous solution form, which cannot be removed by conventional processes. This is one of the main reasons why existing processes have not recognized that changing the solvent might improve the reaction yield. This invention, for the first time, uses industrial waste gas hydrogen sulfide as a raw material, reacting it with an alcohol-alkali mixture to generate an alcohol solution of alkali sulfides. This solution is then used to produce thiocarboxylic acid ester silanes, achieving high yields of the target product without the addition of a phase transfer catalyst. Because no water is present in the entire reaction process, this method completely solves the problems of acyl halide hydrolysis and product acidolysis, thus ensuring a high product yield and achieving a technological breakthrough. Furthermore, this method does not produce acid, avoiding subsequent alkali neutralization and concentrated brine treatment, simplifying the post-processing and significantly reducing industrial costs.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A method for producing thiocarboxylic acid ester silanes using anhydrous hydrogen sulfide from industrial waste gas includes the following steps:

[0012] 1) Hydrogen sulfide from industrial waste gas is passed into an alcohol-alkali solution for reaction to obtain an alcohol solution of alkali sulfide;

[0013] 2) The acyl halide is added to the alcoholic solution of the alkali sulfide to react and obtain an alcoholic solution of the thiocarboxylic acid base;

[0014] 3) Add the haloalkylsilane to the alcoholic solution of the thiocarboxylic acid base to react and obtain a mixed solution of thiocarboxylic acid ester silane and salt; after desalting and dealcoholizing, obtain the target product thiocarboxylic acid ester silane.

[0015] In some specific examples of the present invention, the alcohol base is an alkali metal salt of an alcohol and / or an alcohol amine, preferably an alkali metal salt of a C1-C10 alcohol and / or an alcohol amine, more preferably an alkali metal salt of a C1-C3 alcohol, and even more preferably one or more of lithium methoxide, sodium methoxide, potassium methoxide, lithium ethoxide, sodium ethoxide, potassium ethoxide, sodium propoxide, sodium isopropoxide, lithium isopropoxide, and potassium isopropoxide.

[0016] The optional alcoholamines are, for example, any primary, secondary, or tertiary amines containing a hydroxyl group, such as one or more of ethanolamine, methanolamine, propanolamine, isopropanolamine, diethanolamine, diethanolamine, dipropanolamine, triethanolamine, triethanolamine, and tripropanolamine.

[0017] In some specific examples of the present invention, in step 1), the molar ratio of hydrogen sulfide and alcohol in the industrial exhaust gas is (0.5-0.6):1, preferably (0.51-0.55):1;

[0018] Preferably, the reaction temperature in step 1) is 0-100℃, more preferably 25-70℃;

[0019] Preferably, the reaction time in step 1) is 1-10 h, more preferably 0.1-1 h.

[0020] In some specific examples of the present invention, the acyl halide is one or more of acyl fluoride, acyl chloride, acyl bromide, and acyl iodide, preferably one or more of C1-C20 acyl fluoride, acyl chloride, acyl bromide, and acyl iodide, more preferably one or more of C1-C12 acyl fluoride, acyl chloride, acyl bromide, and acyl iodide, and even more preferably one or more of acetyl chloride, octanoyl chloride, isooctanoyl chloride, nonanoyl chloride, isononanoyl chloride, octanoyl bromide, and isooctanoyl bromide.

[0021] In some specific examples of the present invention, the molar ratio of the amount of acyl halide added in step 2) to the amount of alcohol base added in step 1) is (0.5-0.6):1, preferably (0.5-0.55):1;

[0022] Preferably, the acyl halide is added to the alcohol solution of the alkali sulfide by dropwise addition over a period of 0.1-5 hours, preferably 0.1-2 hours, and the reaction continues for another 0.1-2 hours after the addition is completed.

[0023] Preferably, the reaction temperature in step 2) is from -10°C to 100°C, more preferably 10-45°C.

[0024] In some specific examples of the present invention, the haloalkylsilane is a haloalkane containing at least one -Si-O- group, wherein the halogen is selected from any one or more of Cl, Br, and I;

[0025] Preferably, the haloalkylsilane is selected from one or more of chloropropyltrimethoxysilane, chloropropyltriethoxysilane, chloropropylmethyldimethoxysilane, chloropropylmethyldiethoxysilane, chloropropylethyldimethoxysilane, and chloropropylethyldiethoxysilane.

[0026] In some specific examples of the present invention, the molar ratio of the amount of haloalkylsilane added in step 3) to the amount of alcohol base added in step 1) is (0.5-0.6):1, preferably (0.5-0.55):1;

[0027] Preferably, the reaction temperature in step 3) is 0-100℃, more preferably 40-100℃;

[0028] Preferably, the reaction time in step 3) is 1-10 hours, more preferably 1-3 hours.

[0029] In some specific examples of the present invention, the industrial exhaust hydrogen sulfide is from the industrial exhaust gas of the sulfur-containing silane Si-69, Si-75, KH-580 production unit.

[0030] Preferably, the industrial exhaust gas contains at least 50-70 vol% hydrogen sulfide.

[0031] As is known to those skilled in the art, during the production of sulfur-containing silanes Si-69, Si-75, and KH-580, the raw material sulfides / hydrsulfides and the intermediate sodium polysulfide undergo hydrolysis and ionization side reactions to produce hydrogen sulfide. Therefore, the exhaust gas from the equipment contains a large amount of hydrogen sulfide tail gas. This invention uses this type of hydrogen sulfide tail gas as raw material, which not only improves the product yield of thiocarboxylic acid ester silanes, but also solves the problem of exhaust gas treatment, realizes resource utilization and reusability, and has the characteristics of green environmental protection.

[0032] In some specific examples of the present invention, no catalyst of any kind is added to the reactions in steps 1)-3).

[0033] In some specific examples of the present invention, the desalination method in step 3) is, for example, one or a combination of filtration, centrifugation and washing, which can be easily adjusted by those skilled in the art.

[0034] In some specific examples of the present invention, the de-alcoholization method in step 3) can be any one or a combination of distillation, scraping, and short-pass processing, and can be referred to conventional removal methods in the art, without further limitation here.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1) The reaction is completely anhydrous, which completely avoids the hydrolysis of acyl halides and the resulting acid decomposition of products, thereby significantly improving product yield;

[0037] 2) The entire reaction can be carried out efficiently in the absence of a catalyst, avoiding the problems of catalyst post-treatment and high costs, resulting in significant economic benefits;

[0038] 3) The reaction is waterless and does not produce acidic byproducts, thus avoiding the problem of acidic wastewater treatment;

[0039] 4) Using hydrogen sulfide from industrial waste gas as raw material to synthesize alcohol solutions of alkali sulfides achieves green recovery and resource utilization of waste gas. Furthermore, the raw materials are widely available and have low cost, making them suitable for large-scale industrial production. Detailed Implementation

[0040] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0041] Unless otherwise specified, the raw materials used in the following embodiments of the present invention can all be purchased commercially.

[0042] Industrial exhaust gas hydrogen sulfide A: comes from Wanhua Chemical's pilot production unit of sulfur-containing silane Si-69, with a hydrogen sulfide content of 50 vol%.

[0043] Industrial exhaust gas hydrogen sulfide B: comes from Wanhua Chemical's pilot production unit of sulfur-containing silane Si-75, in which the hydrogen sulfide content is 60 vol%.

[0044] Industrial exhaust gas hydrogen sulfide C: originates from Wanhua Chemical's sulfur-containing silane KH-580 pilot production unit, with a hydrogen sulfide content of 70 vol.

[0045]

Example 1

[0046] 3-Octaylthiopropyltriethoxysilane was prepared according to the following process:

[0047] (1) In a 2000ml four-necked round-bottom flask, 500g of 21% sodium ethoxide ethanol solution was added to the reaction flask and stirred. Then, 39.35L of industrial tail gas hydrogen sulfide A was passed below the liquid surface of the sodium ethoxide solution (the molar ratio of hydrogen sulfide to sodium ethoxide was 0.51:1). The reaction was carried out at 30℃ for 1h. The sample was tested and the conversion rate of sodium ethoxide was 99.5%.

[0048] (2) 126.75g of octanoyl chloride was added dropwise to the solution obtained in step (1) (the molar ratio of octanoyl chloride to sodium ethoxide was 0.505:1). The reaction was carried out at 40℃ for 30 min, and then the reaction was continued for 30 min. The sample was tested and the conversion rate of octanoyl chloride was 99.5%.

[0049] (3) 187.6 g of 3-chloropropyltriethoxysilane was added to the solution obtained in step (2) (the molar ratio of 3-chloropropyltriethoxysilane to sodium ethoxide was 0.505:1), and the reaction was carried out at 80 °C for 3 h. The sample was taken for testing, and the conversion rate of 3-chloropropyltriethoxysilane was 98%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 275.6 g of 3-octanoylthiopropyltriethoxysilane. The purity of the product was 98.5% and the product yield was 97% as determined by GC.

[0050]

Example 2

[0051] 3-Iononanoylthiopropyltriethoxysilane was prepared according to the following process:

[0052] (1) In a 2000ml four-necked round-bottom flask, 200g of anhydrous ethanolamine was added to the reaction flask and stirred. Then, 70.95L of industrial tail gas hydrogen sulfide B was passed below the liquid surface of the ethanolamine solution (the molar ratio of hydrogen sulfide to ethanolamine was 0.52:1). The reaction was carried out at 40℃ for 0.8h. The sample was tested and the conversion rate of sodium ethanol was 97%.

[0053] (2) 295g of isononanoyl chloride was added dropwise to the solution obtained in step (1) (the molar ratio of isononanoyl chloride to ethanolamine was 0.51:1). The reaction was carried out at 10℃ for 10 min, and then the reaction was continued for 10 min. The sample was tested and the conversion rate of octanoyl chloride was 99.1%.

[0054] (3) 402 g of 3-chloropropyltriethoxysilane was added to the solution obtained in step (2) (the molar ratio of 3-chloropropyltriethoxysilane to ethanolamine was 0.51:1), and the reaction was carried out at 40 °C for 1 h. The sample was taken for testing, and the conversion rate of 3-chloropropyltriethoxysilane was 93%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 581.7 g of 3-isononanoylthiopropyltriethoxysilane. The purity of the product was 93.5% and the product yield was 92% as determined by GC.

[0055]

Example 3

[0056] 3-Isooctanoylthiopropyltrimethoxysilane was prepared according to the following process:

[0057] (1) In a 2000ml four-necked round-bottom flask, 500g of 21% sodium methoxide methanol solution was added to the reaction flask and stirred. Then, 36.45L of industrial tail gas hydrogen sulfide C was passed below the liquid surface of the sodium methoxide solution (the molar ratio of hydrogen sulfide to sodium methoxide was 0.525:1). The reaction was carried out at 50℃ for 0.4h. The sample was tested and the conversion rate of sodium methoxide was 98.6%.

[0058] (2) 162.81g of isooctanoyl chloride was added dropwise to the solution obtained in step (1) (the molar ratio of isooctanoyl chloride to sodium methoxide was 0.515:1). The reaction was carried out at 20℃ for 1 hour, and then the reaction was continued for 1 hour. The sample was tested and the conversion rate of isooctanoyl chloride was 99.8%.

[0059] (3) 198.9 g of 3-chloropropyltrimethoxysilane was added to the solution obtained in step (2) (the molar ratio of 3-chloropropyltrimethoxysilane to sodium ethoxide was 0.515:1), and the reaction was carried out at 60 °C for 1.5 h. The sample was taken for testing, and the conversion rate of 3-chloropropyltrimethoxysilane was 96%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 306.3 g of 3-isooctanoylthiopropyltrimethoxysilane. The purity of the product was 97.6% and the product yield was 95% as determined by GC testing.

[0060]

Example 4

[0061] 3-Acetylthiopropylmethyldiethoxysilane was prepared according to the following process:

[0062] (1) In a 2000ml four-necked round-bottom flask, 500g of 21% sodium ethoxide ethanol solution was added to the reaction flask and stirred. Then, 44.27L of industrial tail gas hydrogen sulfide A was passed below the liquid surface of the sodium ethoxide solution (the molar ratio of hydrogen sulfide to sodium ethoxide was 0.515:1). The reaction was carried out at 60℃ for 0.6h. The sample was tested and the conversion rate of sodium ethoxide was 98.1%.

[0063] (2) 33.412 g of acetyl chloride was added dropwise to the solution obtained in step (1) (the molar ratio of acetyl chloride to sodium ethoxide was 0.52:1). The reaction was carried out at 30°C for 1.5 h, and then the reaction was continued for 1.5 h. The acetyl chloride conversion rate was 99%.

[0064] (3) 187.6 g of 3-chloropropylmethyldiethoxysilane was added to the solution obtained in step (2) (the molar ratio of 3-chloropropylmethyldiethoxysilane to sodium ethoxide was 0.52:1), and the reaction was carried out at 70 °C for 2 h. The sample was taken for testing, and the conversion rate of 3-chloropropylmethyldiethoxysilane was 97%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 210.4 g of 3-acetylthiopropylmethyldiethoxysilane. The purity of the product was 97.1% and the product yield was 94% as determined by GC testing.

[0065]

Example 5

[0066] 3-Isooctanoylthiopropylethyldimethoxysilane was prepared according to the following process:

[0067] (1) In a 2000ml four-necked round-bottom flask, 500g of 21% potassium methoxide methanol solution was added to the reaction flask and stirred. Then, 38.56L of industrial tail gas hydrogen sulfide A was passed below the liquid surface of the potassium methoxide solution (the molar ratio of hydrogen sulfide to potassium methoxide was 0.515:1). The reaction was carried out at 70℃ for 0.7h. The sample was tested and the conversion rate of potassium methoxide was 98.5%.

[0068] (2) 60.88 g of isooctanoyl chloride was added dropwise to the solution obtained in step (1) (the molar ratio of isooctanoyl chloride to potassium methoxide was 0.525:1). The reaction was carried out at 45°C for 2 hours, and then the reaction was continued for 2 hours. The sample was tested and the conversion rate of isooctanoyl chloride was 99.6%.

[0069] (3) 152.1 g of 3-chloropropylethyldimethoxysilane was added to the solution obtained in step (2) (the molar ratio of 3-chloropropylethyldimethoxysilane to potassium methoxide was 0.525:1), and the reaction was carried out at 100 °C for 2.5 h. The sample was taken for testing, and the conversion rate of 3-chloropropylethyldiethoxysilane was 98.9%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 241.88 g of 3-octanoylthiopropylethyldiethoxysilane. The purity of the product was 98.2% and the product yield was 96% as determined by GC testing.

[0070] Comparative Example 1

[0071] 3-Octaylthiopropyltriethoxysilane was prepared according to the following process:

[0072] (1) In a 2000ml four-necked round-bottom flask, 290g of industrial sodium sulfide (60wt% sodium sulfide, 37wt% water of crystallization, 1wt% sodium hydrosulfide, and 2wt% other impurities) was added to the reaction flask. 920g of tap water was added to the reaction flask and stirred to dissolve. Then, 370g of octanoyl chloride was added dropwise to the reaction flask (the amount was based on a molar ratio of octanoyl chloride to sodium sulfide of 1.02:1). The reaction was carried out at a reaction temperature of 40℃ for 30min, and then the reaction was continued for 30min. The sample was taken for testing, and the conversion rate of octanoyl chloride was 85%.

[0073] (2) 10g of tetrabutylammonium bromide catalyst was added to the solution obtained in step (1) (the molar ratio of tetrabutylammonium bromide to industrial sodium sulfide was 0.014:1), and 547.6g of 3-chloropropyltriethoxysilane was added to the solution obtained in step (1) (the molar ratio of 3-chloropropyltriethoxysilane to industrial sodium sulfide was 1.02:1). The reaction was carried out at 80℃ for 3h. Samples were taken for testing, and the conversion rate of 3-chloropropyltriethoxysilane was 81%. After the reaction was completed, the mixture was filtered and distilled to remove alcohol, yielding 660.1g of 3-octanoylthiopropyltriethoxysilane. The purity of the product was 80.5% and the product yield was 79.6% as determined by GC.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A process for the anhydrous production of a thiocarboxylic acid ester silane using industrial off-gas hydrogen sulfide, characterized in that, The method comprises the following steps: 1) reacting industrial tail gas hydrogen sulfide with an alcoholic alkali solution to obtain an alcoholic alkali sulfide solution; 2) adding an acyl halide to the alcoholic alkali sulfide solution to obtain an alcoholic alkali thio carboxylic acid solution; 3) adding a haloalkyl silane to the alcoholic alkali thio carboxylic acid solution to obtain a mixed solution of a thio carboxylic acid ester silane and a salt; and obtaining the target product thio carboxylic acid ester silane after desalination and dealcoholization.

2. The method for producing thioester silane without water using industrial off-gas hydrogen sulfide according to claim 1, characterized by, The alcoholic alkali is an alkali metal salt of an alcohol and / or an alcohol amine, preferably an alkali metal salt of a C1-C10 alcohol and / or an alcohol amine, more preferably an alkali metal salt of a C1-C3 alcohol, and further preferably one or more of methanolic lithium, methanolic sodium, methanolic potassium, ethanolic lithium, ethanolic sodium, ethanolic potassium, propanolic sodium, isopropanolic sodium, isopropanolic lithium, and isopropanolic potassium.

3. The method for producing a thioester silane using industrial off-gas hydrogen sulfide anhydrous production according to claim 1 or 2, characterized by, In step 1), the molar ratio of the industrial tail gas hydrogen sulfide to the alcoholic alkali is (0.5-0.6):1, preferably (0.51-0.55):

1. Preferably, the reaction temperature in step 1) is 0-100°C, more preferably 25-70°C. Preferably, the reaction time in step 1) is 1-10h, more preferably 0.1-1h.

4. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 3, characterized in that, The acyl halide is one or more of an acyl fluoride, an acyl chloride, an acyl bromide, and an acyl iodide, preferably one or more of a C1-C20 acyl fluoride, a C1-C20 acyl chloride, a C1-C20 acyl bromide, and a C1-C20 acyl iodide, more preferably one or more of a C1-C12 acyl fluoride, a C1-C12 acyl chloride, a C1-C12 acyl bromide, and a C1-C12 acyl iodide, and further preferably one or more of acetyl chloride, octanoyl chloride, isooctanoyl chloride, nonanoyl chloride, isononanoyl chloride, octanoyl bromide, and isooctanoyl bromide.

5. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 4, characterized in that, In step 2), the molar ratio of the amount of the acyl halide added to the amount of the alcoholic alkali added in step 1) is (0.5-0.6):1, preferably (0.5-0.55):

1. Preferably, the acyl halide is added to the alcoholic alkali sulfide solution in the form of dropwise addition, the dropwise addition time is 0.1-5h, preferably 0.1-2h, and after the dropwise addition is completed, the reaction is continued for 0.1-2h. Preferably, the reaction temperature in step 2) is -10°C to 100°C, preferably 10-45°C.

6. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 5, characterized in that, The haloalkyl silane is a haloalkane containing at least one -Si-O- group, wherein the halogen is selected from any one or more of Cl, Br, and I. Preferably, the haloalkyl silane is selected from one or more of chloropropyl trimethoxysilane, chloropropyl triethoxysilane, chloropropyl methyl dimethoxysilane, chloropropyl methyl diethoxysilane, chloropropyl ethyl dimethoxysilane, and chloropropyl ethyl diethoxysilane.

7. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 6, characterized in that, In step 3), the molar ratio of the amount of the haloalkyl silane added to the amount of the alcoholic alkali added in step 1) is (0.5-0.6):1, preferably (0.5-0.55):

1. Preferably, the reaction temperature in step 3) is 0-100°C, more preferably 40-100°C. Preferably, the reaction time in step 3) is 1-10h, more preferably 1-3h.

8. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 7, characterized in that, The industrial tail gas hydrogen sulfide is industrial tail gas from a production device of a sulfur-containing silane Si-69, Si-75, and KH-580. Preferably, the industrial tail gas contains at least 50-70vol% of hydrogen sulfide.

9. The process for the anhydrous production of thioester silanes using industrial off-gas hydrogen sulfide according to any one of claims 1 to 8, characterized in that, The reactions in steps 1) - 3) are all carried out without the addition of any form of catalyst.