Preparation method of solid acid catalyst, solid acid catalyst and application

Abstract

The invention discloses a preparation method of a solid acid catalyst, the solid acid catalyst and application, and relates to the technical field of catalysts. The solid acid catalyst is prepared by mixing a benzene diacid compound, a zirconium salt compound, concentrated hydrochloric acid and water and carrying out hydrothermal reaction, the preparation method is simple and easy to implement, the Bronsted acid site on the prepared catalyst shows very high catalytic activity and selectivity, the required reaction conditions are mild, and the catalyst is convenient to separate from a reaction system and can be repeatedly utilized. Besides, when the solid acid catalyst is applied to preparation of the single-ended hydrogen-containing silicone oil (such as 1, 1, 1, 3, 3-pentamethyldisiloxane), the single-ended hydrogen-containing silicone oil with higher yield can be obtained, and meanwhile, the preparation process of the single-ended hydrogen-containing silicone oil can be simplified.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and more specifically, to a method for preparing a solid acid catalyst, the solid acid catalyst itself, and its applications. Background Technology

[0002] Hydrogen-containing silicone oil, as a very important chemical raw material, is a precursor for the production of high-performance organosilicon materials, playing an irreplaceable role, especially in hydrosilylation reactions. Through hydrosilylation reactions with substances containing unsaturated bonds, it generates silicone oils, silicone rubbers, and silicone resins with various properties.

[0003] Single-ended hydrogen-containing silicone oil is a type of hydrogen-containing silicone oil with a special structure, and its preparation method has always been a focus of attention for many researchers. Patent CN104860976 A uses alkali metal silanodes and dimethyl halosilanes as raw materials to produce 1,1,1,3,3-pentamethyldisiloxane. The production process is difficult to control effectively, requiring the addition of large amounts of solvents such as tetrahydrofuran during the reaction, which is detrimental to environmental protection. Patent CN101875662B uses high-hydrogen-content silicone oil to react with Grignard reagents, followed by hydrolysis to generate 1,1,1,3,3-pentamethyldisiloxane. Grignard reagents are very sensitive to water, so large amounts of solvents such as ethers or tetrahydrofuran are required during the reaction, making the production process complex. Patent CN118638143A describes the production of 1,1,1,3,3-pentamethyldisiloxane by reacting dimethylchlorosilane monomer with alkoxysilane, using anhydrous ferric chloride or anhydrous aluminum chloride as catalyst. The process is difficult to control, requires a large amount of catalyst, and is sensitive to water.

[0004] Therefore, there is an urgent need to develop novel catalysts with high catalytic activity and selectivity to simplify the production process of single-ended hydrogen-containing silicone oil.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a solid acid catalyst, the solid acid catalyst itself, and its application. The aim is to provide a novel catalyst with high catalytic activity and high selectivity for single-ended hydrogen-containing silicone oil, thereby simplifying the preparation process of single-ended hydrogen-containing silicone oil and improving product yield.

[0007] This invention is implemented as follows: In a first aspect, the present invention provides a method for preparing a solid acid catalyst, comprising: mixing a phthalic acid compound, a zirconium salt compound, concentrated hydrochloric acid and water, and carrying out a hydrothermal reaction at 160°C-180°C; The mass ratio of phthalic acid compounds, zirconium salt compounds, concentrated hydrochloric acid and water is (1-1.5):(1-1.4):(0.3-0.4):(16-18).

[0008] In an optional embodiment, the phthalic acid compound is 2-sulfonic acid-based terephthalic acid; And / or, the zirconium salt compound is zirconium tetrachloride or zirconium sulfate; And / or, the mass fraction of concentrated hydrochloric acid is 36%-38%; And / or, the hydrothermal reaction time is 18h-24h.

[0009] In an optional embodiment, the method further includes: performing solid-liquid separation after the hydrothermal reaction, and washing and drying the resulting solid material.

[0010] In an optional embodiment, washing includes washing with water and anhydrous ethanol in sequence, wherein the amount of water used for 1g of solid material is 50mL-80mL and the amount of anhydrous ethanol used for 1g of solid material is 15mL-20mL. And / or, vacuum drying is used, with the drying temperature controlled at 100℃-120℃, the pressure at -0.09MPa~-0.10MPa, and the drying time at 18h-24h.

[0011] Secondly, the present invention provides a solid acid catalyst, which is prepared by any of the preparation methods described in the foregoing embodiments.

[0012] Thirdly, the present invention provides the application of the solid acid catalyst of the aforementioned embodiments in the preparation of single-ended hydrogen-containing silicone oil.

[0013] In an optional embodiment, the single-ended hydrogen-containing silicone oil is 1,1,1,3,3-pentamethyldisiloxane, with the following structural formula: .

[0014] In an optional embodiment, the preparation process of the single-ended hydrogen-containing silicone oil includes: mixing and reacting hexamethyldisiloxane, tetramethyldihydrodisiloxane and a solid acid catalyst.

[0015] In an optional embodiment, the mass ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane is (0.8-1.5):1; And / or, the amount of solid acid catalyst used is 0.3%-0.5% of the total mass of hexamethyldisiloxane and tetramethyldihydrodisiloxane.

[0016] In an optional embodiment, the mixing reaction is carried out at a temperature of 50°C-70°C for 3-5 hours. And / or, after the mixed reaction is completed, the reaction product is purified and distilled, and the fraction is collected to obtain single-end hydrogen-containing silicone oil.

[0017] This invention offers the following advantages: It utilizes a hydrothermal reaction of phthalic acid compounds, zirconium salts, concentrated hydrochloric acid, and water to prepare a solid acid catalyst. The preparation method is simple and easy to implement. The prepared catalyst exhibits high catalytic activity and selectivity at the bronsted acid sites. The required reaction conditions are mild, and the catalyst is easily separated from the reaction system and can be reused. Furthermore, applying this solid acid catalyst to the preparation of single-ended hydrogen-containing silicone oils (such as 1,1,1,3,3-pentamethyldisiloxane) can yield high yields of single-ended hydrogen-containing silicone oils while simplifying the preparation process. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a gas chromatogram of the 1,1,1,3,3-pentamethyldisiloxane product from Example 1. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0021] In existing technologies, catalysts used to prepare single-ended hydrogen-containing silicone oil often suffer from complex preparation methods, environmental unfriendliness, and difficulty in controlling the production process. Therefore, this invention improves the catalyst preparation method by developing a MOF (Metal-Oxide-Factory) material solid acid catalyst. This catalyst is simple to prepare, environmentally friendly, easily separated, and recyclable. Furthermore, applying this solid acid catalyst to the production of single-ended hydrogen-containing silicone oil yields a high-yield product.

[0022] This invention provides a method for preparing a solid acid catalyst, comprising the following steps: S1, hydrothermal reaction A solid acid catalyst for MOF materials was prepared by hydrothermal reaction of phthalic acid compounds, zirconium salts, concentrated hydrochloric acid, and deionized water. In the preparation of MOF materials, the addition of hydrochloric acid mainly plays a coordination regulation role. By adjusting the acid-base environment of the reaction system, it affects the degree of deprotonation of organic ligands and the coordination behavior of metal ions, thereby achieving precise control over the growth rate, defect structure, and pore properties of MOF crystals.

[0023] In some embodiments, the phthalic acid compound may be 2-sulfonic acid terephthalic acid, but is not limited thereto, wherein a sulfonic acid group is introduced onto the organic ligand to give it a Bronsted acid site. The zirconium salt compound may be zirconium tetrachloride or zirconium sulfate, but is not limited thereto. The concentrated hydrochloric acid is commercially available concentrated hydrochloric acid with a mass fraction of 36%-38%.

[0024] The mass ratio of phthalic acid compounds, zirconium salt compounds, concentrated hydrochloric acid, and deionized water is (1-1.5):(1-1.4):(0.3-0.4):(16-18), such as 1.0:1.0:0.30:16.0, 1.1:1.1:0.33:16.5, 1.2:1.2:0.35:17.0, 1.3:1.3:0.36:17.5, 1.4:1.35:0.38:17.8, 1.5:1.4:0.40:18.0, etc.

[0025] In some embodiments, the hydrothermal reaction temperature is 160℃-180℃, such as 160℃, 165℃, 170℃, 175℃, 180℃, etc.; the hydrothermal reaction time is 18h-24h, such as 18h, 19h, 20h, 21h, 22h, 23h, 24h, etc.

[0026] S2, Post-processing After the hydrothermal reaction, solid-liquid separation is carried out by means of filtration, the obtained solid material is washed to remove surface impurities, and then dried to obtain the solid acid catalyst product.

[0027] In some embodiments, washing includes washing with water and anhydrous ethanol sequentially, i.e., washing with water first, followed by washing with anhydrous ethanol. The amount of water used per 1g of solid material is 50mL-80mL, such as 50mL, 60mL, 70mL, 80mL, etc.; the amount of anhydrous ethanol used per 1g of solid material is 15mL-20mL, such as 15mL, 16mL, 17mL, 18mL, 19mL, 20mL, etc. Washing the hydrothermal reaction product until the filtrate is neutral can prevent free acidic substances from affecting the yield of the subsequent single-ended hydrogen-containing silicone oil.

[0028] In some embodiments, vacuum drying is employed, with the drying temperature controlled at 100℃-120℃, such as 100℃, 105℃, 110℃, 115℃, 120℃, etc.; the pressure at -0.09MPa to -0.10MPa, such as -0.090MPa, -0.095MPa, -0.100MPa, etc.; and the drying time at 18h-24h, such as 18h, 20h, 22h, 24h, etc. The vacuum drying method described in this application allows the catalyst to have a larger specific surface area than that obtained by forced-air drying, meaning more catalytically active sites on the catalyst surface.

[0029] This invention also provides a solid acid catalyst, prepared by the method provided in this invention, which is a metal-organic framework material. This solid acid catalyst has a large specific surface area, exhibits high catalytic activity and selectivity, and its preparation method is simple and recyclable. This solid acid catalyst is used for the production of single-ended hydrogen-containing silicone oil; the production process is simple and can obtain a high yield of single-ended hydrogen-containing silicone oil.

[0030] This invention also provides the application of the above-mentioned solid acid catalyst in the preparation of single-ended hydrogen-containing silicone oil. The preparation process of the above-mentioned solid acid catalyst is simple and easy to implement, and the yield of single-ended hydrogen-containing silicone oil is relatively high.

[0031] In some embodiments, the single-ended hydrogen-containing silicone oil may be 1,1,1,3,3-pentamethyldisiloxane, with the following structural formula: .

[0032] The solid acid catalyst provided in the embodiments of the present invention can be used to prepare 1,1,1,3,3-pentamethyldisiloxane with higher yield.

[0033] Furthermore, the preparation process of single-ended hydrogen-containing silicone oil includes: mixing and reacting hexamethyldisiloxane, tetramethyldihydrodisiloxane, and a solid acid catalyst, with the following reaction equation: .

[0034] The embodiments of the present invention use hexamethyldisiloxane, tetramethyldihydrodisiloxane and solid acid catalyst as raw materials. Taking advantage of the large number of bronsted acid sites on the solid acid catalyst, which has high catalytic activity and selectivity, 1,1,1,3,3-pentamethyldisiloxane can be synthesized with high selectivity.

[0035] In some embodiments, the mass ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane is (0.8-1.5):1, such as 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, etc. The amount of solid acid catalyst is 0.3%-0.5% of the total mass of hexamethyldisiloxane and tetramethyldihydrodisiloxane, such as 0.3%, 0.4%, 0.5%, etc. By adjusting the ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane and the amount of solid acid catalyst, the yield of single-ended hydrogen-containing silicone oil can be further improved.

[0036] In some embodiments, the mixing reaction temperature is 50℃-70℃, such as 50℃, 55℃, 60℃, 65℃, 70℃, etc.; the time is 3h-5h, such as 3h, 4h, 5h, etc. After the mixing reaction is completed, the reaction product is purified and distilled, and the fraction is collected to obtain single-end hydrogen-containing silicone oil. Specifically, after the reaction is completed, the solid acid catalyst is removed by filtration, and then atmospheric distillation is performed to collect the fraction at 85-87℃, which is 1,1,1,3,3-pentamethyldisiloxane.

[0037] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0038] Example 1 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalysts 10g of 2-sulfonic acid terephthalic acid, 10g of zirconium tetrachloride, and 3g of concentrated hydrochloric acid (commercially available, approximately 36%~38%) were dissolved in 180g of deionized water. The mixture was then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 170℃ for 24h. The reaction solution was removed and filtered. The resulting reaction product was added sequentially to deionized water and anhydrous ethanol (the ratio of reaction product, deionized water, and anhydrous ethanol was 1g:60mL:20mL), and filtered after stirring for 30min each time. The reaction product was then dried in a vacuum drying oven at 120℃ and -0.09MPa for 18h to obtain a solid acid catalyst.

[0039] (2) Preparation of single-ended hydrogen-containing silicone oil 120g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 60℃ for 4 hours. The amount of solid acid catalyst used was 0.4% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction collected at 85℃-87℃ was obtained by atmospheric distillation to produce 1,1,1,3,3-pentamethyldisiloxane (e.g., ...). Figure 1 (As shown).

[0040] Example 2 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalysts 10g of 2-sulfonic acid terephthalic acid, 12g of zirconium tetrachloride, and 3.5g of concentrated hydrochloric acid were dissolved in 170g of deionized water. The mixture was then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 180℃ for 20h. The reaction solution was then filtered. The resulting reaction product was added sequentially to deionized water and anhydrous ethanol (ratio 1g:80mL:20mL), and stirred for 30min each time before filtration. The reaction product was then dried in a vacuum drying oven at 100℃ and -0.10MPa for 24h to obtain a solid acid catalyst.

[0041] (2) Preparation of single-ended hydrogen-containing silicone oil 80g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 50℃ for 5 hours. The amount of solid acid catalyst used was 0.4% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction at 85℃-87℃ was collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0042] Example 3 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalysts 15g of 2-sulfonic acid terephthalic acid, 13.6g of zirconium sulfate, and 4g of concentrated hydrochloric acid were dissolved in 180g of deionized water. The mixture was then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 160℃ for 24h. The reaction solution was then filtered. The resulting reaction product was added sequentially to deionized water and anhydrous ethanol (ratio 1g:60mL:15mL), and filtered after stirring for 30min each time. The reaction product was then dried in a vacuum drying oven at 110℃ and -0.10MPa for 24h to obtain a solid acid catalyst.

[0043] (2) Preparation of single-ended hydrogen-containing silicone oil 90g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 70℃ for 3 hours. The amount of solid acid catalyst used was 0.3% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction at 85℃-87℃ was collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0044] Example 4 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalysts 12g of 2-sulfonic acid terephthalic acid, 14g of zirconium tetrachloride, and 4g of concentrated hydrochloric acid were dissolved in 170g of deionized water. The mixture was then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 180℃ for 18h. The reaction solution was removed and filtered. The resulting reaction product was added sequentially to deionized water and anhydrous ethanol (ratio 1g:50mL:20mL), and filtered after stirring for 30min each time. The reaction product was then dried in a vacuum drying oven at 120℃ and -0.10MPa for 24h to obtain a solid acid catalyst.

[0045] (2) Preparation of single-ended hydrogen-containing silicone oil 120g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 60℃ for 4 hours. The amount of solid acid catalyst used was 0.5% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction at 85℃-87℃ was collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0046] Example 5 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalyst: Same as in Example 1.

[0047] (2) Preparation of single-ended hydrogen-containing silicone oil 130g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 70℃ for 4 hours. The amount of solid acid catalyst used was 0.5% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction at 85℃-87℃ was collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0048] Example 6 This embodiment provides a solid acid catalyst and uses it to catalyze the preparation of single-ended hydrogen-containing silicone oil, as detailed below: (1) Preparation of solid acid catalysts 15g of 2-sulfonic acid terephthalic acid, 10g of zirconium tetrachloride, and 4g of concentrated hydrochloric acid were dissolved in 160g of deionized water. The mixture was then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 160℃ for 24h. The reaction solution was then filtered, and the resulting reaction product was added sequentially to deionized water and anhydrous ethanol (ratio 1g:70mL:20mL), with stirring for 30min each time followed by filtration. The reaction product was then dried in a vacuum drying oven at 120℃ and -0.095MPa for 18h to obtain a solid acid catalyst.

[0049] (2) The preparation of single-ended hydrogen-containing silicone oil includes the following steps: the same as in Example 1.

[0050] Comparative Example 1 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the mass ratio of 2-sulfonic acid-based terephthalic acid to zirconium tetrachloride in the preparation of the solid acid catalyst is not within the stated range, specifically including: The preparation of the solid acid catalyst includes the following steps: 10g of 2-sulfonic acid-based terephthalic acid, 5g of zirconium tetrachloride, and 3g of concentrated hydrochloric acid are dissolved in 180g of deionized water. The mixture is then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 170℃ for 24h. The reaction solution is then filtered, and the resulting reaction product is added sequentially to deionized water and anhydrous ethanol (ratio 1g:60mL:20mL), with stirring for 30min each time followed by filtration. The reaction product is then dried in a vacuum drying oven at 120℃ and -0.09MPa for 18h to obtain the solid acid catalyst.

[0051] Comparative Example 2 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the hydrothermal reaction temperature in the preparation of the solid acid catalyst is not within the stated range, specifically including: The preparation of the solid acid catalyst includes the following steps: 10g of 2-sulfonic acid terephthalic acid, 10g of zirconium tetrachloride, and 3g of concentrated hydrochloric acid are dissolved in 180g of deionized water. The mixture is then transferred to a Teflon reactor and subjected to a hydrothermal reaction at 130℃ for 24h. The reaction solution is then filtered, and the resulting reaction product is added sequentially to deionized water and anhydrous ethanol (ratio 1g:60mL:20mL), with stirring for 30min each time followed by filtration. The reaction product is then dried in a vacuum drying oven at 120℃ and -0.09MPa for 18h to obtain the solid acid catalyst.

[0052] Comparative Example 3 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the mass ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane in the preparation of the single-ended hydrogen-containing silicone oil is not within the stated range (too small), specifically including: The preparation of single-ended hydrogen-containing silicone oil includes the following steps: 60g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane are reacted at 60℃ for 4 hours. The amount of solid acid catalyst used is 0.4% of the total mass of the raw materials. After the reaction is complete, the catalyst is removed by filtration to obtain crude single-ended hydrogen-containing silicone oil. The fraction at 85℃-87℃ is collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0053] Comparative Example 4 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the mass ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane in the preparation of the single-ended hydrogen-containing silicone oil is not within the stated range (too large), specifically including: The preparation of single-ended hydrogen-containing silicone oil includes the following steps: 180g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane are reacted at 60℃ for 4 hours. The amount of solid acid catalyst used is 0.4% of the total mass of the raw materials. After the reaction is complete, the catalyst is removed by filtration to obtain crude single-ended hydrogen-containing silicone oil. The fraction at 85℃-87℃ is collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0054] Comparative Example 5 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the reaction temperature in the preparation of the single-ended hydrogen-containing silicone oil is not within the stated range, specifically including: The preparation of single-ended hydrogen-containing silicone oil includes the following steps: 120g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane are reacted at 30℃ for 4 hours. The amount of solid acid catalyst used is 0.4% of the total mass of the raw materials. After the reaction is complete, the catalyst is removed by filtration to obtain crude single-ended hydrogen-containing silicone oil. The fraction at 85℃-87℃ is collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0055] Comparative Example 6 This comparative example provides a solid acid catalyst and a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the amount of catalyst used in the preparation of the single-ended hydrogen-containing silicone oil is not within the stated range, specifically including: The preparation of single-ended hydrogen-containing silicone oil includes the following steps: 120g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane are reacted at 60℃ for 4 hours. The amount of solid acid catalyst used is 0.2% of the total mass of the raw materials. After the reaction is complete, the catalyst is removed by filtration to obtain crude single-ended hydrogen-containing silicone oil. The fraction at 85℃-87℃ is collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0056] Comparative Example 7 This comparative example provides a single-ended hydrogen-containing silicone oil, which differs from Example 1 in that the solid acid catalyst in the preparation of the single-ended hydrogen-containing silicone oil is replaced with acidic clay, specifically including: 120g of hexamethyldisiloxane and 100g of tetramethyldihydrodisiloxane were reacted at 60℃ for 4 hours. The amount of acidic clay catalyst was 0.4% of the total mass of the raw materials. After the reaction was completed, the catalyst was removed by filtration to obtain crude single-end hydrogen-containing silicone oil. The fraction at 85℃-87℃ was collected by atmospheric distillation to obtain 1,1,1,3,3-pentamethyldisiloxane.

[0057] Experimental Example 1 In this experiment, an Agilent 7820A gas chromatograph was used to test the purity X of 1,1,1,3,3-pentamethyldisiloxane in the distillate fractions of Examples 1-6 and Comparative Examples 1-7. The yield Y of 1,1,1,3,3-pentamethyldisiloxane was calculated using the formula: Yield Y = (Fraction mass × Purity X / Total feed mass) × 100%. Relevant data are shown in Table 1.

[0058] Table 1 Gas Chromatography Test Data Results

[0059] As can be seen from Table 1, in Examples 1-6 provided by the present invention, when the preparation methods of the solid acid catalyst and the single-ended hydrogen-containing silicone oil are within the range provided by the present invention, the purity and yield of the obtained 1,1,1,3,3-pentamethyldisiloxane are relatively high.

[0060] Comparative Examples 1 and 2 show that increasing the mass ratio of 2-sulfonic acid to zirconium tetrachloride and decreasing the hydrothermal reaction temperature during the preparation of solid acid catalysts resulted in decreased purity and yield of the obtained 1,1,1,3,3-pentamethyldisiloxane.

[0061] Comparative Examples 3-6 show the preparation of 1,1,1,3,3-pentamethyldisiloxane by reducing or increasing the mass ratio of hexamethyldisiloxane to tetramethyldihydrodisiloxane, decreasing the reaction temperature, and reducing the amount of catalyst, respectively. The results show that the purity and yield of the obtained 1,1,1,3,3-pentamethyldisiloxane are reduced.

[0062] In Comparative Example 7, the solid acid catalyst used in the preparation of single-ended hydrogen-containing silicone oil in Example 1 was replaced with acidic clay. The results showed that the yield of the prepared 1,1,1,3,3-pentamethyldisiloxane decreased.

[0063] In summary, this invention provides a solid acid catalyst, its preparation method, and its application. The provided solid acid catalyst possesses a large number of bronsted acid sites, exhibiting high catalytic activity and selectivity, and its preparation process is environmentally friendly. Applying the above-mentioned solid acid catalyst to the production of single-ended hydrogen-containing silicone oil can achieve high purity and yield of the oil. Furthermore, the byproducts generated during the distillation process can be reused as raw materials for the production of single-ended hydrogen-containing silicone oil, demonstrating recycling value.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a solid acid catalyst, characterized by, The application relates to a preparation method of a solid acid catalyst. The benzene-dicarboxylic acid compound, the zirconium salt compound, concentrated hydrochloric acid and water are mixed, and a hydrothermal reaction is carried out at 160 DEG C-180 DEG C; The mass ratio of the benzene-dicarboxylic acid compound, the zirconium salt compound, concentrated hydrochloric acid and water is (1-1.5):(1-1.4):(0.3-0.4):(16-18).

2. The production method according to claim 1, characterized by, The benzene-dicarboxylic acid compound is 2-sulfonic acid p-phthalic acid; The zirconium salt compound is zirconium tetrachloride or zirconium sulfate; The mass fraction of the concentrated hydrochloric acid is 36%-38%; The hydrothermal reaction time is 18h-24h.

3. The production method according to claim 1, characterized by, The application further relates to a preparation method of a solid acid catalyst. After the hydrothermal reaction, solid-liquid separation is carried out, and the obtained solid material is washed and dried.

4. The production method according to claim 3, characterized by, The washing comprises: sequentially using water and anhydrous ethanol for washing, 1g of the solid material corresponds to the water use amount of 50mL-80mL, and 1g of the solid material corresponds to the anhydrous ethanol use amount of 15mL-20mL; The drying is carried out in a vacuum drying mode, the drying temperature is controlled to be 100 DEG C-120 DEG C, the pressure is controlled to be -0.09MPa~-0.10MPa, and the drying time is controlled to be 18h-24h.

5. A solid acid catalyst characterized by, The application further relates to a solid acid catalyst prepared by the preparation method.

6. The application of the solid acid catalyst in the preparation of a single-end hydrogen-containing silicone oil.

7. Use according to claim 6, characterized in that, The single-end hydrogen-containing silicone oil is 1,1,1,3,3-pentamethyldisiloxane, and the structural formula is: 。 8. Use according to claim 7, characterized in that, The preparation process of the single-end hydrogen-containing silicone oil comprises the following steps: mixing and reacting hexamethyldisiloxane, tetramethyldihydrodisiloxane and the solid acid catalyst.

9. Use according to claim 8, characterized in that, The mass ratio of the hexamethyldisiloxane and the tetramethyldihydrodisiloxane is (0.8-1.5):1; The solid acid catalyst is used in an amount of 0.3%-0.5% of the total mass of the hexamethyldisiloxane and the tetramethyldihydrodisiloxane.

10. Use according to claim 8, characterized in that, The mixing and reacting temperature is 50 DEG C-70 DEG C, and the mixing and reacting time is 3h-5h; After the mixing and reacting, the reaction product is subjected to impurity removal and rectification, and the distillate is collected to prepare the single-end hydrogen-containing silicone oil.

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