Preparation method of triisopropyl silyl acrylate

Abstract

The invention belongs to the technical field of silane compound preparation, and particularly relates to a preparation method of triisopropylsilyl acrylate, which comprises the following steps: mixing acrylic acid and a solvent under the protection of inert gas, dropwise adding an acid-binding agent and triisopropylchlorosilane in stages, washing with water, purifying, recovering the solvent, performing high-vacuum rectification and the like, thereby obtaining the triisopropylsilyl acrylate. And finally, the high-purity triisopropyl silicon-based acrylate is obtained. Through precise temperature control, raw material ratio optimization and by-product cyclic utilization, side reactions such as acrylic acid auto-polymerization and silane hydrolysis are effectively inhibited, high-selectivity synthesis of triisopropyl silicon-based acrylate is realized, use of an expensive catalyst and generation of a by-product inorganic salt are avoided, the production cost is remarkably reduced, and the method is suitable for industrial production. The green and industrial production requirements are met.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of silane compounds, and particularly relates to a method for preparing triisopropylsilyl acrylate. Background Art

[0002] As a novel composite functional material monomer, triisopropylsilyl acrylate is mainly used for preparing high-performance coatings and surface treatment materials, and is widely used in fields such as marine ships, building antifouling, and surface coatings of transportation vehicles. In addition, after the triisopropylsilyl acrylate product is crosslinked and formed, it has good strength and excellent toughness, and can be used in the military industry to manufacture bulletproof products such as helmets. In addition, triisopropylsilyl acrylate is also an important pharmaceutical intermediate and has broad application prospects.

[0003] The prior art has disclosed various processes for preparing triisopropylsilyl acrylate, such as a method of synthesizing using acrylic acid and triisopropylsilanol as raw materials. However, this method has significant defects. The catalyst tetrabutylammonium fluoride used has a high cost, and the reaction is difficult to proceed completely.

[0004] In addition, Chinese Patent with Publication No. CN104725414B discloses a method for preparing trialkylsilyl acrylate or trialkylsilyl methacrylate, which is carried out in two steps: First, trialkylhydroxyoxysilane is reacted with an oxygen-containing inorganic acid or sulfonic acid to generate a silyl inorganic acid ester or a silyl sulfonic acid ester; Second, the silyl inorganic acid ester or the silyl sulfonic acid ester is reacted with acrylate or methacrylate in the presence of a polymerization inhibitor to obtain trialkylsilyl acrylate or trialkylsilyl methacrylate. However, this preparation method produces by-product inorganic salts, which not only results in a low reaction conversion rate but also does not meet the requirements of clean production.

[0005] Based on this, the present application is specifically proposed. Summary of the Invention

[0006] In view of this, the present invention aims to solve problems such as many by-products, low reaction conversion rate, and difficult reaction in the existing preparation methods of triisopropylsilyl acrylate. The present invention discloses a method for preparing triisopropylsilyl acrylate. By optimizing the process flow, optimizing the raw material ratio, and controlling the temperature in stages, combined with an efficient by-product recovery mechanism, the generation of by-products is effectively reduced, the reaction conversion rate is increased, and the complete progress of the reaction is ensured. The simple and efficient reaction path and environmentally friendly production process of the present invention not only reduce the production cost but also improve the product purity, providing strong support for the large-scale production and application of triisopropylsilyl acrylate, bringing significant economic and environmental benefits.

[0007] To achieve the above object, the technical solution of the present invention is realized as follows:

[0008] A preparation method of triisopropylsilyl acrylate, comprising the following steps:

[0009] S1. Under the protection of an inert gas, acrylic acid and a solvent are put into a reaction kettle and mixed;

[0010] S2. Control the temperature of the reaction kettle at 20°C to 35°C, dropwise add an acid-binding agent. After the addition is completed, the material is kept warm and reacted in the reaction kettle for 0.5 to 2 hours;

[0011] S3. Control the temperature of the reaction kettle at 25°C to 35°C, dropwise add triisopropylchlorosilane. After the addition is completed, the material is kept warm and reacted in the reaction kettle for 0.5 to 2 hours;

[0012] S4. After the reaction in step S3 is completed, add water to the reaction kettle and stir. After standing and separating layers, add an alkali solution to the aqueous layer, transfer the alkali-treated aqueous layer to a recovery kettle to recover triethylamine, and concentrate the organic layer in a concentration kettle;

[0013] S5. First distill the concentrated liquid obtained in step S4 at normal pressure, and then distill under negative pressure to remove the residual solvent to obtain the crude triisopropylsilyl acrylate;

[0014] S6. Transfer the crude triisopropylsilyl acrylate obtained in step S5 to a distillation column, add an inhibitor, and remove the residual unreacted substances and by-products by continuous distillation under high vacuum to obtain triisopropylsilyl acrylate.

[0015] Further, the inert gas is selected from at least one of nitrogen, argon, carbon dioxide, and helium.

[0016] Further, in step S1, the solvent is selected from at least one of dichloromethane, ethyl acetate, tetrahydrofuran, and toluene, and the mass ratio of the solvent to acrylic acid in step S1 is (5:1) to (10:1).

[0017] Further, the acid-binding agent is selected from triethylamine, and the mass ratio of the acid-binding agent to acrylic acid is (1:1) to (2:1).

[0018] Further, the mass ratio of triisopropylchlorosilane added in step S3 to acrylic acid is (1:1) to (5:1), the dropping time of the acid-binding agent in step S2 is 1 to 3 hours, and the dropping time of triisopropylchlorosilane in step S3 is 2 to 4 hours.

[0019] Further, in step S4, the amount of water added is 1 to 2 times the volume of the organic layer, the stirring time is 1 to 2 hours, and the standing time is 1 to 3 hours.

[0020] Further, in step S4, triethylamine is recovered by distilling the aqueous layer.

[0021] Further, in step S6, the conditions for vacuum distillation are as follows: vacuum degree is -0.095 to -0.10 MPa, the top temperature is 80 to 150 °C, and the reflux ratio is (2:1) to (10:1).

[0022] Further, the inhibitor described in step S6 is selected from one or more of hydroquinone, p-methoxyphenol, and BHT.

[0023] Further, the addition amount of the inhibitor described in step S6 is calculated based on 0.01% to 0.03% of the mass of triisopropylchlorosilane.

[0024] Compared with the prior art, the preparation method of the triisopropylsilyl acrylate of the present invention has the following advantages:

[0025] 1. By precisely controlling the reaction temperature in stages, side reactions such as self-polymerization of acrylic acid and hydrolysis of triisopropylchlorosilane are effectively inhibited, the reaction selectivity and yield are improved, and the reaction rate is ensured.

[0026] 2. By optimizing the raw material ratio and dropping time, it is ensured that the reactants are fully contacted and mixed evenly. Combining water washing purification and triethylamine recovery technology not only reduces raw material waste but also lowers the waste liquid treatment cost, realizing efficient recycling of resources.

[0027] 3. The entire process adopts a stepped temperature control and inhibitor addition strategy, with strong operation stability and high repeatability. It not only avoids equipment loss caused by high temperature but also ensures the feasibility of continuous production, providing a reliable solution for large-scale industrial preparation of high-purity products. Specific Embodiments

[0028] The technical solutions in the embodiments of the present application will be clearly described below in conjunction with the specific embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0029] In the description of the present application, it should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. Technologies, methods, and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technologies, methods, and equipment should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0030] It should be noted that in this application, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element. In addition, it should be noted that the scope of the methods and devices in the embodiments of this application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0031] A method for preparing triisopropylsilyl acrylate, characterized by comprising the following steps:

[0032] S1. Under the protection of an inert gas, acrylic acid and a solvent are put into a reaction kettle and mixed;

[0033] S2. Control the temperature of the reaction kettle at 20°C to 35°C, dropwise add an acid-binding agent. After the addition is complete, the material is kept warm and reacted in the reaction kettle for 0.5 to 2 hours;

[0034] S3. Control the temperature of the reaction kettle at 25°C to 35°C, dropwise add triisopropylchlorosilane. After the addition is complete, the material is kept warm and reacted in the reaction kettle for 0.5 to 2 hours;

[0035] S4. After the reaction in step S3 is completed, water is added to the reaction kettle and stirred. After standing and separating layers, an alkali solution is added to the aqueous layer, and the alkali-treated aqueous layer is transferred to a recovery kettle to recover triethylamine, and the organic layer is concentrated in a concentration kettle;

[0036] S5. The concentrated solution obtained in step S4 is first distilled at atmospheric pressure, and then distilled under reduced pressure to remove the residual solvent to obtain a crude product of triisopropylsilyl acrylate;

[0037] S6. The crude product of triisopropylsilyl acrylate obtained in step S5 is transferred to a distillation column, an inhibitor is added, and the residual unreacted substances and by-products are removed by continuous high-vacuum distillation to obtain triisopropylsilyl acrylate.

[0038] Preferably, in step S1, the inert gas is selected from at least one of nitrogen, argon, carbon dioxide, and helium.

[0039] More preferably, in step S1, the inert gas is selected from at least one of nitrogen and argon.

[0040] Preferably, in step S1, the solvent is selected from at least one of dichloromethane, ethyl acetate, tetrahydrofuran, and toluene, and the mass ratio of the solvent to acrylic acid is (5:1) to (10:1).

[0041] More preferably, in step S1, the solvent is selected from dichloromethane.

[0042] Further, in step S2, the acid-binding agent is selected from triethylamine, and may also be selected from at least one of pyridine and N,N-diisopropylethylamine. The mass ratio of the acid-binding agent to acrylic acid is (1:1) to (2:1), and the dropping time of the acid-binding agent is 1 to 3 hours.

[0043] Preferably, in step S2, the acid-binding agent is selected from triethylamine.

[0044] Further, in step S3, the mass ratio of triisopropylchlorosilane to acrylic acid is (1:1) to (5:1), and the dropping time of triisopropylchlorosilane is 2 to 4 hours.

[0045] In the present invention, in step S2, the temperature of the reaction kettle is strictly controlled at 20°C to 35°C. This temperature range can not only ensure the full reaction of the acid-binding agent and acrylic acid, but also avoid side reactions that may be caused by high temperatures. In step S3, the temperature is slightly increased to 25°C to 35°C to further promote the combination of triisopropylchlorosilane and the reaction intermediate, enabling the reaction to proceed under optimal conditions, greatly improving the reaction rate and yield. By precisely controlling the mass ratios of the solvent to acrylic acid (5:1 to 10:1), the acid-binding agent to acrylic acid (1:1 to 2:1), and triisopropylchlorosilane to acrylic acid (1:1 to 5:1) in step S1, step S2, and step S3, acrylic acid and triisopropylchlorosilane can fully react. By controlling the dropping times of the acid-binding agent and triisopropylchlorosilane (the dropping time of the acid-binding agent in step S2 is 1 to 3 hours, and the dropping time of triisopropylchlorosilane in step S3 is 2 to 4 hours), it is ensured that the reactants are uniformly and slowly mixed, avoiding side reactions caused by too high local concentration, and at the same time ensuring the full progress of the reaction.

[0046] This application reduces the occurrence of side reactions by precisely controlling the reaction temperature, raw material ratio, and dropping time, ensures the efficient progress of the reaction, and realizes the highly selective synthesis of triisopropylsilyl acrylate.

[0047] In step S2 of the present invention, since acrylic acid has a certain activity, too high a temperature may trigger its own polymerization reaction or other side reactions, while too low a temperature will slow down the reaction rate, prolong the reaction time, and reduce production efficiency. Therefore, the temperature is controlled within an appropriate range (20°C to 35°C). This temperature range helps the acid-binding agent to mix fully with acrylic acid and react, while avoiding overly violent reactions and side reactions caused by too high a temperature. After the acid-binding agent is completely added dropwise, keep the temperature for 1 to 2 hours to fully neutralize HCl and maintain a certain pH environment in the system, eliminating the corrosion risk of the acidic environment to the equipment. By controlling the temperature, it is ensured that the acid-binding agent and acrylic acid are fully mixed to form a stable reaction system, laying a stable pH foundation for the subsequent silylation reaction.

[0048] In step S3, the temperature is raised to 25°C to 35°C to provide moderate activation energy and accelerate the esterification reaction between triisopropylchlorosilane and acrylic acid. At the same time, since triisopropylchlorosilane will cause the hydrolysis side reaction of isopropylchlorosilane to intensify in the presence of higher temperature and moisture, controlling the temperature within this range can reduce the occurrence of hydrolysis side reactions and improve the purity and yield of the product.

[0049] In this application, by gradually raising the temperature in stages for step S2 and step S3, the reaction temperature is precisely controlled. In step S2, the low temperature of 20°C to 35°C effectively reduces the self-polymerization rate of acrylic acid. In step S3, by controlling the appropriate temperature, the local overheating hydrolysis of chlorosilane is effectively avoided, thus significantly reducing the impurity content.

[0050] From the above description, it can be seen that by precisely controlling the temperature at each reaction stage, the reaction can proceed along the expected path, reducing the occurrence of side reactions, shortening the reaction time, improving the reaction efficiency, enhancing the overall production efficiency, and reducing the production cost.

[0051] Further, in step S4, the amount of water added is 1 to 2 times the volume of the organic layer, the stirring time is 1 to 2 hours, and the standing time is 1 to 3 hours.

[0052] Furthermore, in step S4, triethylamine is recovered by distilling the aqueous layer, and the recovered triethylamine is recycled for use in the next batch of reactions.

[0053] In step S4 of the present invention, further, a certain amount of water is added to hydrolyze the residual triisopropylchlorosilane reagent and the by-product triethylamine hydrochloride to purify the organic phase and realize the recycling of raw materials. The volume of water added to the organic phase in step S4 is 1 to 2 times the volume of the organic layer, and the water washing temperature is maintained below 35°C to avoid volatilization loss of organic solvents (such as dichloromethane) caused by high temperature. The stirring time is 1 to 2 hours, and the standing time is 1 to 3 hours to ensure complete stratification. At this time, the solution is divided into an aqueous layer and an organic layer. The aqueous layer contains the by-product (triethylamine hydrochloride) and a small amount of unreacted acrylic acid, and the organic layer contains the target product (triisopropylsilyl acrylate), solvent and trace impurities. Then, a 10% NaOH solution is added to the aqueous layer to adjust the pH to 11 to 12, so that triethylamine hydrochloride is converted into free triethylamine, which is convenient for subsequent distillation recovery. The alkali-treated aqueous layer (containing free triethylamine) is transferred to a recovery kettle, and triethylamine-water azeotrope is distilled out by atmospheric distillation. The azeotrope is condensed and stratified, with triethylamine in the upper layer and water in the lower layer. By setting the distillation conditions (the number of trays is 10 to 15 layers, and the reflux ratio is 3:1 to 5:1), triethylamine is recovered, and the obtained triethylamine is directly used in the next batch of reactions.

[0054] Therefore, the water washing process in step S4 of the present application can effectively remove the water-soluble impurities in the reaction system, reduce the residue of impurities in the product, and thus improve the purity of triisopropylsilyl acrylate. By recycling triethylamine, the amount of acid-binding agent used can be reduced; at the same time, recycling triethylamine realizes the recycling of resources, improves the resource utilization rate of the entire production process, thereby reducing the production cost and improving the economic benefits of the production process.

[0055] Further, the polymerization inhibitor in step S6 refers to one or more of hydroquinone, p-methoxyphenol, and BHT, and the addition amount of the polymerization inhibitor is calculated based on 0.01% to 0.03% of the mass of triisopropylchlorosilane. In the present invention, the target product triisopropylsilyl acrylate (containing acrylate structure) is prone to free radical polymerization reaction under high temperature and vacuum conditions, resulting in a decrease in product purity and yield, and even blocking of equipment. Adding a polymerization inhibitor can effectively capture free radicals and inhibit the occurrence of polymerization side reactions, ensuring the stability of the rectification process and the quality of the target product.

[0056] Further, the conditions for vacuum rectification in step S6 are: vacuum degree -0.095 to -0.10 MPa, top temperature 80 to 150°C, reflux ratio (2:1) to (10:1).

[0057] The following is an example of the preparation method of the above triisopropylsilyl acrylate through specific examples:

[0058] Example 1:

[0059] S1. Under nitrogen protection, dichloromethane and acrylic acid are charged into a 2000L reactor, and the mass ratio of dichloromethane to acrylic acid is 5:1;

[0060] S2. Control the temperature of the reactor at 25°C, and add triethylamine dropwise. The mass ratio of triethylamine to acrylic acid is 1:1, and it takes about 1 hour to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm in the reactor for 1.5 hours;

[0061] S3. Control the temperature of the reactor at 30°C, and add triisopropylchlorosilane dropwise. The mass ratio of triisopropylchlorosilane to acrylic acid is 1:1, and it takes about 2 hours to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm in the reactor for 2 hours;

[0062] S4. After the reaction in step S3 is completed, add water to the reactor. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0063] After standing and separating, add a 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to the recovery kettle, and concentrate the organic layer in the concentration kettle;

[0064] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, and the filling amount does not exceed 70% of the kettle volume. Distill at normal pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5L / h, switch to the negative pressure stage. Turn on the vacuum pump, gradually reduce the system pressure to -0.08 - -0.095MPa, continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60°C, and stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0065] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the distillation column, add 0.01% hydroquinone, and set the conditions for empty distillation as follows: vacuum degree -0.095 - -0.10MPa, top temperature 120°C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 91.2% and a purity of 98.6%.

[0066] Example 2:

[0067] S1. Under nitrogen protection, dichloromethane and acrylic acid are charged into a 2000L reactor, and the mass ratio of dichloromethane to acrylic acid is 7.5:1;

[0068] S2. Control the temperature of the reactor at 20°C, and add triethylamine dropwise. The mass ratio of triethylamine to acrylic acid is 1.4:1, and it takes about 2 hours to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm in the reactor for 0.5 hours;

[0069] S3. Control the temperature of the reaction kettle at 25°C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and it takes about 3 hours to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm and reacted in the reaction kettle for 1 hour;

[0070] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0071] After standing and separating layers, add a 10% NaOH solution to the aqueous layer to adjust the pH to 11 - 12. Transfer the alkali-treated aqueous layer to the recovery kettle, and concentrate the organic layer in the concentration kettle;

[0072] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle. The filling amount does not exceed 70% of the kettle volume. Distill at normal pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Turn on the vacuum pump and gradually reduce the system pressure to -0.08 to -0.095 MPa. Continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60°C, and stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0073] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the distillation column, add 0.01% hydroquinone. Set the conditions for empty distillation as: vacuum degree -0.095 to -0.10 MPa, top temperature 120°C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 92.1% and a purity of 99.2%.

[0074] Example 3:

[0075] S1. Under argon protection, put dichloromethane and acrylic acid into a 2000 L reaction kettle. The mass ratio of dichloromethane to acrylic acid is 10:1;

[0076] S2. Control the temperature of the reaction kettle at 25°C, and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 2:1, and it takes about 3 hours to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm and reacted in the reaction kettle for 1.5 hours;

[0077] S3. Control the temperature of the reaction kettle at 30°C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 5:1, and it takes about 4 hours to finish the dropwise addition. After the dropwise addition is completed, the material is kept warm and reacted in the reaction kettle for 2 hours;

[0078] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0079] After static stratification, add 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to the recovery kettle, and concentrate the organic layer in the concentration kettle.

[0080] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, with the filling amount not exceeding 70% of the kettle volume. Distill at atmospheric pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Start the vacuum pump, gradually reduce the system pressure to -0.08 - -0.095 MPa, continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60 °C, and stop concentration to obtain the crude product of triisopropylsilyl acrylate.

[0081] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the distillation column, add 0.01% hydroquinone, and set the conditions for empty distillation as: vacuum degree -0.095 - -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 92.7% and a purity of 99.6%.

[0082] Example 4:

[0083] S1. Under argon protection, put dichloromethane and acrylic acid into a 2000 L reaction kettle, and the mass ratio of dichloromethane to acrylic acid is 7.5:1.

[0084] S2. Control the temperature of the reaction kettle at 20 °C, and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 1.4:1, and the dropping is completed in about 2 hours. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 1.5 hours.

[0085] S3. Control the temperature of the reaction kettle at 25 °C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and the dropping is completed in about 3 hours. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 2 hours.

[0086] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0087] After static stratification, add 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to the recovery kettle, and concentrate the organic layer in the concentration kettle.

[0088] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, with the filling amount not exceeding 70% of the kettle volume. Distill at normal pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Start the vacuum pump and gradually reduce the system pressure to -0.08 to -0.095 MPa. Continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60 °C, then stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0089] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the rectifying column, add 0.02% of p-hydroxyanisole, and set the conditions for empty rectification as: vacuum degree -0.095 to -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products by high-vacuum continuous rectification to obtain triisopropylsilyl acrylate with a yield of 92.3% and a purity of 99.1%.

[0090] Example 5:

[0091] S1. Under nitrogen protection, put dichloromethane and acrylic acid into a 2000 L reaction kettle, and the mass ratio of dichloromethane to acrylic acid is 7.5:1;

[0092] S2. Control the temperature of the reaction kettle at 35 °C and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 1.4:1, and it takes about 2 hours to finish dropping. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 1.5 hours;

[0093] S3. Control the temperature of the reaction kettle at 35 °C and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and it takes about 3 hours to finish dropping. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 2 hours;

[0094] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0095] After standing and separating layers, add a 10% NaOH solution to the water layer and adjust the pH to 11 - 12. Transfer the alkali-treated water layer to the recovery kettle, and concentrate the organic layer in the concentration kettle;

[0096] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, with the filling amount not exceeding 70% of the kettle volume. Distill at normal pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Start the vacuum pump and gradually reduce the system pressure to -0.08 to -0.095 MPa. Continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60 °C, then stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0097] S6. Transfer the crude triisopropylsilyl acrylate obtained in step S5 to a distillation column, add 0.03% BHT, and set the conditions for empty distillation as follows: vacuum degree -0.095 to -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the residual unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 93.1% and a purity of 99.3%.

[0098] Comparative Example 1:

[0099] S1. Under nitrogen protection, charge dichloromethane and acrylic acid into a 2000 L reactor, and the mass ratio of dichloromethane to acrylic acid is 3:1.

[0100] S2. Control the temperature of the reactor at 25 °C, and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 0.5:1, and the addition is completed in about 1 hour. After the addition is completed, the material is kept warm and reacted in the reactor for 1.5 hours.

[0101] S3. Control the temperature of the reactor at 30 °C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 0.5:1, and the addition is completed in about 2 hours. After the addition is completed, the material is kept warm and reacted in the reactor for 2 hours.

[0102] S4. After the reaction in step S3 is completed, add water to the reactor. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let stand for 2 hours.

[0103] After standing and separating, add a 10% NaOH solution to the aqueous layer to adjust the pH to 11 - 12. Transfer the alkali-treated aqueous layer to a recovery kettle, and concentrate the organic layer in a concentration kettle.

[0104] S5. Pump the concentrated liquid obtained in step S4 into a concentration kettle, and the filling amount does not exceed 70% of the kettle volume. Distill at atmospheric pressure. The evaporated dichloromethane is liquefied by a condenser and flows into a recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Turn on the vacuum pump, gradually reduce the system pressure to -0.08 to -0.095 MPa, continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60 °C, and stop concentration to obtain the crude triisopropylsilyl acrylate.

[0105] S6. Transfer the crude triisopropylsilyl acrylate obtained in step S5 to a distillation column, add 0.01% hydroquinone, and set the conditions for empty distillation as follows: vacuum degree -0.095 to -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the residual unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 85.3% and a purity of 96.2%.

[0106] Comparative Example 2:

[0107] S1. Under nitrogen protection, dichloromethane and acrylic acid were charged into a 2000L reaction kettle, and the mass ratio of dichloromethane to acrylic acid was 12:1;

[0108] S2. The temperature of the reaction kettle was controlled at 25°C, and triethylamine was added dropwise. The mass ratio of triethylamine to acrylic acid was 3:1, and it took about 4 hours to finish the dropwise addition. After the dropwise addition was completed, the material was kept warm and reacted in the reaction kettle for 1.5 hours;

[0109] S3. The temperature of the reaction kettle was controlled at 30°C, and triisopropylchlorosilane was added dropwise. The mass ratio of triisopropylchlorosilane to acrylic acid was 6:1, and it took about 5 hours to finish the dropwise addition. After the dropwise addition was completed, the material was kept warm and reacted in the reaction kettle for 2 hours;

[0110] S4. After the reaction in step S3 was completed, water was added to the reaction kettle. The amount of water added was 1.5 times the volume of the organic layer. It was stirred for 1 hour and left to stand for 2 hours.

[0111] After standing and separating, a 10% NaOH solution was added to the aqueous layer to adjust the pH to 11 - 12. The alkali-treated aqueous layer was transferred to a recovery kettle, and the organic layer was concentrated in a concentration kettle;

[0112] S5. The concentrated liquid obtained in step S4 was pumped into a concentration kettle, and the filling amount did not exceed 70% of the kettle volume. It was distilled under normal pressure. The evaporated dichloromethane was liquefied by a condenser and flowed into a recovery storage tank. When the condensate flow rate < 5L / h, it was switched to the negative pressure stage. The vacuum pump was started, and the system pressure was gradually reduced to -0.08 - -0.095MPa. Stirring was continued and the negative pressure was maintained to remove dichloromethane until the kettle temperature reached 60°C, and the concentration was stopped to obtain crude triisopropylsilyl acrylate;

[0113] S6. The crude triisopropylsilyl acrylate obtained in step S5 was transferred to a distillation column, and 0.01% hydroquinone was added. The conditions for empty distillation were set as: vacuum degree -0.095 - -0.10MPa, top temperature 120°C, reflux ratio 5:1. Residual unreacted substances and by-products were removed by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 86.1% and a purity of 96.4%.

[0114] Comparative Example 3:

[0115] S1. Under nitrogen protection, dichloromethane and acrylic acid were charged into a 2000L reaction kettle, and the mass ratio of dichloromethane to acrylic acid was 7.5:1;

[0116] S2. The temperature of the reaction kettle was controlled at 15°C, and triethylamine was added dropwise. The mass ratio of triethylamine to acrylic acid was 1.4:1, and it took about 2 hours to finish the dropwise addition. After the dropwise addition was completed, the material was kept warm and reacted in the reaction kettle for 1.5 hours;

[0117] S3. Control the temperature of the reaction kettle at 25 °C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and the dropping is completed in about 3 hours. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 2 hours;

[0118] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0119] After standing and separating layers, add a 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to the recovery kettle, and concentrate the organic layer in the concentration kettle;

[0120] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, and the filling amount does not exceed 70% of the kettle volume. Distill at normal pressure. The evaporated dichloromethane is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Turn on the vacuum pump, gradually reduce the system pressure to -0.08 - -0.095 MPa, continuously stir and maintain the negative pressure to remove dichloromethane until the kettle temperature reaches 60 °C, and stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0121] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the distillation column, add 0.02% of p-hydroxyanisole, and set the conditions for empty distillation as follows: vacuum degree -0.095 - -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products through high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 85.5% and a purity of 97.1%.

[0122] Comparative Example 4:

[0123] S1. Under nitrogen protection, put dichloromethane and acrylic acid into a 2000 L reaction kettle. The mass ratio of dichloromethane to acrylic acid is 7.5:1;

[0124] S2. Control the temperature of the reaction kettle at 20 °C, and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 1.4:1, and the dropping is completed in about 2 hours. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 1.5 hours;

[0125] S3. Control the temperature of the reaction kettle at 20 °C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and the dropping is completed in about 3 hours. After the dropping is completed, the material is kept warm and reacted in the reaction kettle for 2 hours;

[0126] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0127] After static separation, add a 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to a recovery kettle, and concentrate the organic layer in a concentration kettle.

[0128] S5. Pump the concentrated liquid obtained in step S4 into a concentration kettle, with the filling amount not exceeding 70% of the kettle volume. Distill at atmospheric pressure. The evaporated dichloromethane is liquefied by a condenser and flows into a recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Start the vacuum pump, gradually reduce the system pressure to -0.08 - -0.095 MPa, continuously stir and maintain the negative pressure to remove dichloromethane. When the kettle temperature reaches 60 °C, stop concentration to obtain crude triisopropylsilyl acrylate.

[0129] S6. Transfer the crude triisopropylsilyl acrylate obtained in step S5 to a distillation column, add 0.03% BHT, and set the conditions for empty distillation as: vacuum degree -0.095 - -0.10 MPa, top tower temperature 120 °C, reflux ratio 5:1. Remove the remaining unreacted substances and by-products through high-vacuum continuous distillation to obtain triisopropylsilyl acrylate with a yield of 85.7% and a purity of 97.5%.

[0130] Comparative Example 5:

[0131] S1. Under nitrogen protection, put dichloromethane and acrylic acid into a 2000 L reaction kettle, and the mass ratio of dichloromethane to acrylic acid is 7.5:1.

[0132] S2. Control the reaction kettle temperature at 15 °C, and dropwise add triethylamine. The mass ratio of triethylamine to acrylic acid is 1.4:1, and the dropping is completed in about 0.5 hours. After the dropping is completed, the material is kept warm in the reaction kettle for 1.5 hours.

[0133] S3. Control the reaction kettle temperature at 35 °C, and dropwise add triisopropylchlorosilane. The mass ratio of triisopropylchlorosilane to acrylic acid is 2.5:1, and the dropping is completed in about 3 hours. After the dropping is completed, the material is kept warm in the reaction kettle for 2 hours.

[0134] S4. After the reaction in step S3 is completed, add water to the reaction kettle. The amount of water added is 1.5 times the volume of the organic layer. Stir for 1 hour and let it stand for 2 hours.

[0135] After static separation, add a 10% NaOH solution to the aqueous layer, adjust the pH to 11 - 12, transfer the alkali-treated aqueous layer to a recovery kettle, and concentrate the organic layer in a concentration kettle.

[0136] S5. Pump the concentrated liquid obtained in step S4 into the concentration kettle, with the filling amount not exceeding 70% of the kettle volume. Distill at normal pressure. The evaporated methylene chloride is liquefied by the condenser and flows into the recovery storage tank. When the condensate flow rate < 5 L / h, switch to the negative pressure stage. Turn on the vacuum pump, gradually reduce the system pressure to -0.08 to -0.095 MPa, continuously stir and maintain the negative pressure to remove methylene chloride. When the kettle temperature reaches 60 °C, stop concentration to obtain the crude product of triisopropylsilyl acrylate;

[0137] S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to the distillation column, add 0.03% of BHT, and set the conditions for empty distillation as: vacuum degree -0.095 to -0.10 MPa, top temperature 120 °C, reflux ratio 5:1. Remove the residual unreacted substances and by-products by high-vacuum continuous distillation to obtain triisopropylsilyl acrylate, with a yield of 84.1% and a purity of 96.3%.

[0138] Table 1 Process parameters of Examples 1 - 5 and Comparative Examples 1 - 5

[0139]

[0140]

[0141] Compared with Comparative Examples 1 - 5, Examples 1 - 5 are different in that in steps S1, S2, and S3, the mass ratios of the solvent to acrylic acid (5:1 - 10:1), the acid-binding agent to acrylic acid (1:1 - 2:1), and triisopropylchlorosilane to acrylic acid (1:1 - 5:1) are precisely controlled; in step S2, the reaction temperature is precisely controlled at 20 °C - 35 °C, and the dropping rate is 1 - 3 h; in step S3, the reaction temperature is precisely controlled at 25 °C - 35 °C, and the dropping rate is 2 - 4 h; while one or more parameters in Comparative Examples 1 - 5 are not within the above ranges. For example, when comparing Example 1 with Comparative Example 1, the reaction temperature and dropping time in Example 1 and Comparative Example 1 are controlled to be the same, and only the parameter of the raw material ratio in Comparative Example 1 is not within the above range. The yield of the target product in Example 1 is 91.2%, and the purity of the target product is 98.6%, while the yield of the target product in Comparative Example 1 is 85.3%, and the purity of the target product is 96.2%. Another example is when comparing Example 5 with Comparative Example 5, the raw material ratios in Example 5 and Comparative Example 5 are controlled to be the same, and the reaction temperature and dropping time in step S2 of Comparative Example 5 are changed and not within the above range. The yield of the target product in Example 5 is 93.1%, and the purity of the target product is 99.3%, while the yield of the target product in Comparative Example 5 is 84.1%, and the purity of the target product is 96.3%.

[0142] As can be seen from Table 1, the yields of the target products generated in Examples 1 to 5 are between 91.2% and 93.1%, and the purities of the target products are between 98.6% and 99.3%. Compared with Comparative Examples 1 to 4, by precisely controlling the reaction temperature, raw material ratio, and dropping time, and optimizing the process flow, the present invention ensures the efficient progress of the reaction and realizes the highly selective synthesis of triisopropylsilyl acrylate.

[0143] The embodiments of the present application have been described above. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection scope of the present application.

Claims

1. A method for preparing triisopropylsilyl acrylate, characterized in that It includes the following steps: S1. Under the protection of inert gas, acrylic acid and a solvent are put into a reaction kettle for mixing; S2. Control the temperature of the reaction kettle at 20°C to 35°C, dropwise add an acid-binding agent. After the addition is completed, the materials are kept warm in the reaction kettle for 0.5 to 2 hours; S3. Control the temperature of the reaction kettle at 25°C to 35°C, dropwise add triisopropylchlorosilane. After the addition is completed, the materials are kept warm in the reaction kettle for 0.5 to 2 hours; S4. After the reaction in step S3 ends, add water to the reaction kettle and stir. After standing for liquid separation, add an alkali solution to the aqueous layer, transfer the alkali-treated aqueous layer to a recovery kettle to recover triethylamine, and concentrate the organic layer in a concentration kettle; S5. First, distill the concentrated liquid obtained in step S4 at atmospheric pressure, and then distill under negative pressure to remove the residual solvent to obtain a crude product of triisopropylsilyl acrylate; S6. Transfer the crude product of triisopropylsilyl acrylate obtained in step S5 to a distillation column, add an inhibitor, and remove the residual unreacted substances and by-products by continuous high-vacuum distillation to obtain triisopropylsilyl acrylate.

2. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, The inert gas is selected from at least one of nitrogen, argon, carbon dioxide, and helium.

3. The preparation method of triisopropylsilyl acrylate according to claim 1, wherein In step S1, the solvent is selected from at least one of dichloromethane, ethyl acetate, tetrahydrofuran, and toluene, and the mass ratio of the solvent to acrylic acid in step S1 is (5:1) to (10:1).

4. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, The acid-binding agent is selected from triethylamine, and the mass ratio of the acid-binding agent to acrylic acid is (1:1) to (2:1).

5. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, In step S3, the mass ratio of triisopropylchlorosilane added to acrylic acid is (1:1) to (5:1). In step S2, the dropping time of the acid-binding agent is 1 to 3 hours. In step S3, the dropping time of triisopropylchlorosilane is 2 to 4 hours.

6. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, In step S4, the amount of water added is 1 to 2 times the volume of the organic layer, the stirring time is 1 to 2 hours, and the standing time is 1 to 3 hours.

7. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, In step S4, triethylamine is recovered by distilling the aqueous layer.

8. The method for preparing triisopropylsilyl acrylate according to claim 1, wherein, In step S6, the conditions for vacuum distillation are: vacuum degree -0.095 to -0.10 MPa, top temperature 80 to 150°C, reflux ratio (2:1) to (10:1).

9. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, In step S6, the inhibitor is selected from one or more of hydroquinone, p-methoxyphenol, and BHT.

10. The preparation method of triisopropylsilyl acrylate according to claim 1, characterized in that, In step S6, the addition amount of the inhibitor is calculated based on 0.01% to 0.03% of the mass of triisopropylchlorosilane.

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