Production method of isobutyl acrylate

Abstract

The invention discloses a production method of isobutyl acrylate, and relates to the technical field of organic chemical synthesis, in the presence of a polymerization inhibitor, acrylic acid and isobutanol are used as reaction raw materials, under the action of a catalyst, direct esterification is performed to synthesize isobutyl acrylate, oxygen is introduced into a reactor in the reaction process, and water generated in the reaction is taken out of the reactor; and after the reaction is finished, filtering the esterification reaction liquid to remove the catalyst, sequentially carrying out alkali washing, water washing and standing, and separating a water phase to obtain the product isobutyl acrylate, the catalyst is (3, 6-diamino-9-acridinyl) boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O. The invention further discloses a preparation method of the catalyst. The production method is low in preparation cost, simple and feasible in process, low in corrosion to reaction equipment and high in product yield.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical synthesis, in particular to a method for producing isobutyl acrylate. Background Art

[0002] Isobutyl acrylate is an important organic synthesis intermediate, widely used in the preparation of polymers and resins, such as polyacrylate, polyisobutyl acrylate, etc. These polymers and resins are often used in coatings, adhesives, inks, plastic additives and other industries. In addition, isobutyl acrylate can also be used as an additive for fragrances, a solvent, and a raw material for synthesizing other organic compounds. With the further expansion of its application range, the market demand for isobutyl acrylate is increasing, and the requirements for its purity and reaction conversion rate are also getting higher and higher.

[0003] At present, in the related art, isobutyl acrylate is usually obtained by esterification reaction of acrylic acid and isobutyl alcohol under strong acid catalysis. Since the method uses a strong acid as a catalyst, the reaction equipment is severely corroded and the acidic wastewater generated is difficult to treat. In addition, other preparation methods of isobutyl acrylate disclosed in the prior art also have more or less technical defects such as product purity and reaction conversion rate need to be further improved, the preparation process is complicated, the preparation cost is expensive, the energy consumption is large, and it is easy to cause environmental problems.

[0004] In order to solve the above technical problems, the Chinese invention patent with the authorization announcement number CN115536527B discloses a method for preparing isobutyl (meth)acrylate, which includes using chloroplatinic acid as the main catalyst and phenothiazine as the co-catalyst, preparing chloroplatinic acid and phenothiazine into a platinum complex catalyst in a low-grade alcohol solvent; using (meth)acrylic acid and isobutylene as raw materials, using a hindered phenol antioxidant as an inhibitor, and using a platinum complex catalyst in a closed reactor under the protection of an inert gas to make (meth)acrylic acid and isobutylene undergo an anti-Markovnikov rule addition reaction to synthesize isobutyl (meth)acrylate, and then reducing the pressure on the reaction liquid to recover isobutylene, and distilling to obtain isobutyl (meth)acrylate. The method for preparing isobutyl (meth)acrylate provided by the application can obtain the product of anti-Markovnikov rule addition, and the reaction system does not produce acidic wastewater, and has almost no corrosion to equipment, pipelines, and instruments, solving the problem of difficult treatment of acidic wastewater. However, it uses an expensive platinum catalyst, which makes the preparation cost high; and its yield needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for producing isobutyl acrylate with low preparation cost, simple process, low corrosion to reaction equipment and high product yield.

[0006] To achieve the above object, the technical scheme adopted by the present invention is: a method for producing isobutyl acrylate, in the presence of a polymerization inhibitor, acrylic acid and isobutyl alcohol are used as reaction raw materials, isobutyl acrylate is directly synthesized by esterification under the action of a catalyst, oxygen is introduced into the reactor during the reaction, and water generated by the reaction is taken out of the reactor; after the reaction, the esterification reaction liquid is filtered to remove the catalyst, and the reaction liquid is washed with alkali and water in sequence, and the water phase is allowed to stand and separated to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl) boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0007] Preferably, the method for preparing the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, reacting at 190-210° C. for 15-22 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 80-90° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 50-60° C. for 3-5 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir and react at 70-80° C. for 4-6 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0008] Preferably, the aluminum source in step S1 is at least one of aluminum chloride and aluminum nitrate; the silicon source is at least one of sodium silicate and silicon tetrachloride; the titanium source is at least one of titanium tetrachloride and titanium nitrate; and the rare earth source is at least one of lanthanum nitrate, cerium nitrate and yttrium nitrate.

[0009] Preferably, the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent and sodium acetate is 1:(0.1-0.2):(0.08-0.12):(0.03-0.05):0.03:(10-20):3.

[0010] Preferably, the alcohol solvent is at least one of ethanol, ethylene glycol and n-butanol.

[0011] Preferably, the calcination temperature is 600-850°C and the calcination time is 4-6 hours.

[0012] Preferably, the mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide in step S2 is (3-5):(15-25):1:(0.5-0.8):0.3.

[0013] Preferably, the polymerization inhibitor is one or more of diethylhydroxylamine, p-hydroxyanisole, hydroquinone, phenothiazine, and 2,6-di-tert-butyl-p-cresol.

[0014] Preferably, the amount of the polymerization inhibitor is 0.1-1% of the mass of the acrylic acid.

[0015] Preferably, the molar ratio of acrylic acid to isobutyl alcohol is 1:1.

[0016] Preferably, the amount of the catalyst used is 4-8% of the mass of acrylic acid.

[0017] Preferably, the reaction temperature of the direct esterification is 60-120° C. and the reaction time is 6-22 h.

[0018] Due to the application of the above technical solution, the present invention has the following beneficial effects: the present invention reasonably selects the type and dosage ratio of the catalyst, so that the production method of isobutyl acrylate does not need to use strong acid, has low corrosion to the reaction equipment, avoids a complicated post-treatment process, and has a high product yield; the solid catalyst is used, and subsequent operations such as distillation are not required, which can effectively reduce energy consumption and save costs, and is conducive to achieving the organic unity of economic benefits, social benefits and ecological benefits. DETAILED DESCRIPTION

[0019] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0020] Embodiment 1 A method for producing isobutyl acrylate comprises the following steps: in the presence of a polymerization inhibitor, using acrylic acid and isobutyl alcohol as reaction raw materials, directly esterifying and synthesizing isobutyl acrylate under the action of a catalyst, introducing oxygen into a reactor during the reaction to take water generated by the reaction out of the reactor; after the reaction, filtering the esterification reaction liquid to remove the catalyst, sequentially washing with alkali and water, standing and separating the water phase to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0021] The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, reacting at 190° C. for 15 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 80° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 50° C. for 3 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir the reaction at 70° C. for 4 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0022] In step S1, the aluminum source is aluminum chloride; the silicon source is sodium silicate; the titanium source is titanium tetrachloride; the rare earth source is lanthanum nitrate; the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent, and sodium acetate is 1:0.1:0.08:0.03:0.03:10:3; the alcohol solvent is ethanol; the calcination temperature is 600°C and the time is 4 hours.

[0023] The mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide in step S2 is 3:15:1:0.5:0.3.

[0024] The polymerization inhibitor is diethylhydroxylamine; the dosage of the polymerization inhibitor is 0.1% of the mass of the acrylic acid; the molar ratio of the acrylic acid to isobutyl alcohol is 1:1; the dosage of the catalyst is 4% of the mass of the acrylic acid; the reaction temperature of the direct esterification is 60°C; and the reaction time is 6 hours.

[0025] Embodiment 2 A method for producing isobutyl acrylate comprises the following steps: in the presence of a polymerization inhibitor, using acrylic acid and isobutyl alcohol as reaction raw materials, directly esterifying and synthesizing isobutyl acrylate under the action of a catalyst, introducing oxygen into a reactor during the reaction to take water generated by the reaction out of the reactor; after the reaction, filtering the esterification reaction liquid to remove the catalyst, sequentially washing with alkali and water, standing and separating the water phase to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0026] The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, reacting at 195° C. for 17 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 83° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 50-60° C. for 3.5 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir the reaction at 73° C. for 4.5 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0027] In step S1, the aluminum source is aluminum nitrate; the silicon source is silicon tetrachloride; the titanium source is titanium nitrate; the rare earth source is cerium nitrate; the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent, and sodium acetate is 1:0.13:0.09:0.035:0.03:13:3; the alcohol solvent is ethylene glycol; the calcination temperature is 650°C and the time is 4.5h.

[0028] The mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide in step S2 is 3.5:17:1:0.65:0.3.

[0029] The inhibitor is p-hydroxyanisole; the dosage of the inhibitor is 0.3% of the mass of the acrylic acid; the molar ratio of the acrylic acid to isobutyl alcohol is 1:1; the dosage of the catalyst is 5% of the mass of the acrylic acid; the reaction temperature of the direct esterification is 80° C.; and the reaction time is 12 hours.

[0030] Embodiment 3 A method for producing isobutyl acrylate comprises the following steps: in the presence of a polymerization inhibitor, using acrylic acid and isobutyl alcohol as reaction raw materials, directly esterifying and synthesizing isobutyl acrylate under the action of a catalyst, introducing oxygen into a reactor during the reaction to take water generated by the reaction out of the reactor; after the reaction, filtering the esterification reaction liquid to remove the catalyst, sequentially washing with alkali and water, standing and separating the water phase to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0031] The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, and reacting at 200° C. for 19 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 85° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 55° C. for 4 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir the reaction at 75° C. for 5 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0032] In step S1, the aluminum source is aluminum chloride; the silicon source is silicon tetrachloride; the titanium source is titanium tetrachloride; the rare earth source is yttrium nitrate; the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent, and sodium acetate is 1:0.15:0.1:0.04:0.03:15:3; the alcohol solvent is ethylene glycol; the calcination temperature is 750°C and the time is 5 hours.

[0033] The mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide in step S2 is 4:20:1:0.65:0.3.

[0034] The polymerization inhibitor is hydroquinone; the dosage of the polymerization inhibitor is 0.6% of the mass of the acrylic acid; the molar ratio of the acrylic acid to isobutyl alcohol is 1:1; the dosage of the catalyst is 6% of the mass of the acrylic acid; the reaction temperature of the direct esterification is 90° C.; and the reaction time is 15 hours.

[0035] Embodiment 4 A method for producing isobutyl acrylate comprises the following steps: in the presence of a polymerization inhibitor, using acrylic acid and isobutyl alcohol as reaction raw materials, directly esterifying and synthesizing isobutyl acrylate under the action of a catalyst, introducing oxygen into a reactor during the reaction to take water generated by the reaction out of the reactor; after the reaction, filtering the esterification reaction liquid to remove the catalyst, sequentially washing with alkali and water, standing and separating the water phase to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0036] The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, and reacting at 205° C. for 20 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 88° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 58° C. for 4.5 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir the reaction at 78° C. for 5.5 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0037] In step S1, the aluminum source is aluminum chloride and aluminum nitrate mixed in a mass ratio of 1:3; the silicon source is sodium silicate and silicon tetrachloride mixed in a mass ratio of 2:1; the titanium source is titanium tetrachloride and titanium nitrate mixed in a mass ratio of 1:1; the rare earth source is lanthanum nitrate, cerium nitrate, and yttrium nitrate mixed in a mass ratio of 1:2:1; the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent, and sodium acetate is 1:0.18:0.11:0.045:0.03:18:3; the alcohol solvent is ethanol, ethylene glycol, and n-butanol mixed in a mass ratio of 1:2:1; the roasting temperature is 830°C and the time is 5.5h.

[0038] In step S2, the mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide is 4.5:23:1:0.75:0.3; the inhibitor is a mixture of diethylhydroxylamine, p-hydroxyanisole, hydroquinone, phenothiazine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 1:1:2:1:3; the amount of the inhibitor is 0.9% of the mass of the acrylic acid; the molar ratio of the acrylic acid to isobutyl alcohol is 1:1; the amount of the catalyst is 7% of the mass of the acrylic acid; the reaction temperature of the direct esterification is 110° C.; and the reaction time is 20 hours.

[0039] Embodiment 5 A method for producing isobutyl acrylate comprises the following steps: in the presence of a polymerization inhibitor, using acrylic acid and isobutyl alcohol as reaction raw materials, directly esterifying and synthesizing isobutyl acrylate under the action of a catalyst, introducing oxygen into a reactor during the reaction to take water generated by the reaction out of the reactor; after the reaction, filtering the esterification reaction liquid to remove the catalyst, sequentially washing with alkali and water, standing and separating the water phase to obtain the product isobutyl acrylate; the catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

[0040] The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, and reacting at 210° C. for 22 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 90° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 60° C. for 5 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir the reaction at 80° C. for 6 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

[0041] In step S1, the aluminum source is aluminum nitrate; the silicon source is silicon tetrachloride; the titanium source is titanium nitrate; the rare earth source is lanthanum nitrate; the mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent, and sodium acetate is 1:0.2:0.12:0.05:0.03:20:3; the alcohol solvent is n-butanol; the calcination temperature is 850°C and the time is 6 hours.

[0042] In step S2, the mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide is 5:25:1:0.8:0.3; the inhibitor is phenothiazine; the amount of the inhibitor is 1% of the mass of the acrylic acid; the molar ratio of acrylic acid to isobutyl alcohol is 1:1; the amount of the catalyst is 8% of the mass of acrylic acid; the reaction temperature of the direct esterification is 120° C.; and the reaction time is 22 hours.

[0043] Comparative Example 1 A method for producing isobutyl acrylate is substantially the same as that of Example 1, except that no niobium source and (3,6-diamino-9-acridinyl)boric acid are added.

[0044] Comparative Example 2 A method for producing isobutyl acrylate is substantially the same as that of Example 1, except that no titanium source and 1-aminopropyl-3-methylimidazolium bromide are added.

[0045] In order to further illustrate the beneficial technical effects of the production methods of isobutyl acrylate involved in each embodiment of the present invention, the purity and yield of isobutyl acrylate produced by the production methods of isobutyl acrylate involved in Examples 1-5 and Comparative Examples 1-2 were tested, counted and calculated. The results are shown in Table 1.

[0046] Table 1 Test items Yield purity unit ％ % Example 1 97.5 99.62 Example 2 97.8 99.73 Example 3 98.3 99.82 Example 4 98.5 99.90 Example 5 98.6 99.95 Comparative Example 1 96.1 97.57 Comparative Example 2 95.7 97.13 It can be seen from the data in Table 1 that the production methods of isobutyl acrylate involved in the embodiments of the present invention have higher yield and purity than the comparative example method, and the combined use of niobium source, (3,6-diamino-9-acridinyl)boric acid, titanium source and 1-aminopropyl-3-methylimidazolium bromide is beneficial to improving the above properties.

[0047] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing isobutyl acrylate, characterized in that: In the presence of a polymerization inhibitor, acrylic acid and isobutyl alcohol are used as reaction raw materials, and isobutyl acrylate is directly esterified under the action of a catalyst to synthesize isobutyl acrylate. During the reaction, oxygen is introduced into the reactor to take out the water generated by the reaction. After the reaction, the esterification reaction liquid is filtered to remove the catalyst, and the reaction liquid is washed with alkali and water in sequence, and then allowed to stand and the water phase is separated to obtain the product isobutyl acrylate. The catalyst is (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide co-modified Al-Si-Ti-rare earth element-Nb-O.

2. The method for producing isobutyl acrylate according to claim 1, characterized in that: The preparation method of the catalyst comprises the following steps: Step S1, dispersing an aluminum source, a silicon source, a titanium source, a rare earth source and a niobium source in an alcohol solvent, stirring evenly, slowly adding sodium acetate to obtain a mixture, transferring the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, reacting at 190-210° C. for 15-22 hours; cooling to room temperature, repeatedly washing with anhydrous ethanol, drying in a vacuum drying oven at 80-90° C. to constant weight, and then calcining to obtain Al-Si-Ti-rare earth element-Nb-O; Step S2, dispersing the Al-Si-Ti-rare earth element-Nb-O prepared in step S1 in dimethyl sulfoxide, then adding silane coupling agent KH560 thereto, stirring at 50-60° C. for 3-5 hours, then adding (3,6-diamino-9-acridinyl)boric acid and 1-aminopropyl-3-methylimidazolium bromide, continuing to stir and react at 70-80° C. for 4-6 hours, and then successively subjecting the mixture to rotary evaporation, washing, and drying to obtain a catalyst.

3. The method for producing isobutyl acrylate according to claim 2, characterized in that: In step S1, the aluminum source is at least one of aluminum chloride and aluminum nitrate; the silicon source is at least one of sodium silicate and silicon tetrachloride; the titanium source is at least one of titanium tetrachloride and titanium nitrate; and the rare earth source is at least one of lanthanum nitrate, cerium nitrate and yttrium nitrate.

4. The method for producing isobutyl acrylate according to claim 2, characterized in that: The mass ratio of the aluminum source, silicon source, titanium source, rare earth source, niobium source, alcohol solvent and sodium acetate is 1:(0.1-0.2):(0.08-0.12):(0.03-0.05):0.03:(10-20):

3.

5. The method for producing isobutyl acrylate according to claim 2, characterized in that: The alcohol solvent is at least one of ethanol, ethylene glycol and n-butanol.

6. The method for producing isobutyl acrylate according to claim 2, characterized in that: The calcination temperature is 600-850° C. and the calcination time is 4-6 hours.

7. The method for producing isobutyl acrylate according to claim 2, characterized in that: The mass ratio of Al-Si-Ti-rare earth element-Nb-O, dimethyl sulfoxide, silane coupling agent KH560, (3,6-diamino-9-acridinyl)boric acid, and 1-aminopropyl-3-methylimidazolium bromide in step S2 is (3-5):(15-25):1:(0.5-0.8):0.

3.

8. The method for producing isobutyl acrylate according to claim 1, characterized in that: The polymerization inhibitor is one or more of diethylhydroxylamine, p-hydroxyanisole, hydroquinone, phenothiazine, and 2,6-di-tert-butyl-p-cresol; and the dosage of the polymerization inhibitor is 0.1-1% of the mass of the acrylic acid.

9. The method for producing isobutyl acrylate according to claim 1, characterized in that: The molar ratio of acrylic acid to isobutyl alcohol is 1:1; the amount of the catalyst used is 4-8% of the mass of acrylic acid.

10. The method for producing isobutyl acrylate according to claim 1, characterized in that: The reaction temperature of the direct esterification is 60-120° C. and the reaction time is 6-22 hours.