A kind of preparation method of allyl glycidyl ether

Abstract

The present invention provides a preparation method of allyl glycidyl ether, belonging to the technical field of organic synthesis, the preparation method comprising: allyl alcohol, boron trifluoride catalyst and epichlorohydrin are mixed to form a material, introduced into a tubular reaction device, the tubular reaction device is filled with a tin-containing molecular sieve catalyst, the material is contacted with the tin-containing molecular sieve catalyst in the tubular reaction device for catalysis to perform a ring-opening reaction, and an intermediate product is obtained after the reaction is completed; the intermediate product is mixed with a base for a ring-closing reaction, and after the reaction is completed, post-processing is performed to obtain allyl glycidyl ether. The preparation method provided by the present invention uses boron trifluoride and tin-containing molecular sieve combined catalysts to act synergistically, utilizes a tubular reaction device, and adopts a catalytic method in which the catalyst is immobilized in the tubular reaction device, significantly improves the reaction selectivity, conversion rate and product yield of allyl glycidyl ether, and simplifies the post-processing process of the reaction.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing allyl glycidyl ether. Background Art

[0002] Allyl glycidyl ether contains unsaturated double bonds and epoxy groups. It is an important polymerization monomer and organic synthesis intermediate. It is widely used in many fields such as coatings, adhesives, and composite materials.

[0003] The preparation process of allyl glycidyl ether is mainly a two-step ring-opening and ring-closing process, which is also an industrial production method. The two-step ring-opening and ring-closing process is generally carried out under the action of an acidic catalyst, with allyl alcohol and epichlorohydrin undergoing a ring-opening reaction to obtain an allyloxychlorohydrin intermediate, and then the intermediate is removed of hydrogen chloride under the action of sodium hydroxide and then closed to obtain allyl glycidyl ether.

[0004] CN103333137A discloses a method for synthesizing allyl glycidyl ether. In the ring-opening reaction process, a ternary composite catalyst composed of boron trifluoride etherate, tin dichloride and tin tetrachloride is used to catalyze an intermediate, and then a ring-closing reaction is completed under the action of sodium hydroxide to prepare the product allyl glycidyl ether. Using tin chloride salt as a catalyst, the catalyst selectivity and stability are insufficient, and the catalyst is difficult to recycle and reuse, which is not conducive to process cost and convenience, and increases the difficulty of post-processing.

[0005] CN104592166A discloses a molecular sieve immobilized catalytic synthesis method of allyl glycidyl ether, using allyl alcohol and epichlorohydrin as raw materials, using molecular sieve immobilized concentrated sulfuric acid and trifluoromethanesulfonic acid as catalysts in the ring-opening reaction, preparing an intermediate, and then performing a closed-loop reaction with sodium hydroxide under the action of a phase transfer catalyst. The method uses an immobilized catalyst, which is a catalyst component mixed with a immobilized carrier for adsorption and loading, and the loading stability is insufficient. The catalyst component is easily lost in long-term continuous production and use, causing the catalyst to be deactivated, and a trace amount is mixed into the subsequent process.

[0006] At the same time, in order to improve the reaction efficiency of the ring-opening reaction, the existing process has improved the process mode of the ring-opening reaction. CN117258739A discloses a tubular reaction system and method for continuous synthesis of benzyl glycidyl ether, in which tubular reactors are set in both the ring-opening reaction and the closed-loop reaction to improve the mixing degree of materials and the reaction efficiency. This method mixes the reaction raw materials and the catalyst together into the reactor, which significantly increases the amount of catalyst used, increases waste discharge, and increases the difficulty of post-processing.

[0007] Based on the problems of low catalyst selectivity, large dosage, high cost and limited reaction efficiency in the prior art, the present invention provides a method for preparing allyl glycidyl ether. Summary of the invention

[0008] The purpose of the present invention is to provide a method for preparing allyl glycidyl ether, improve the reaction selectivity of the preparation of allyl glycidyl ether, reduce the amount of catalyst used, and simplify the post-processing process of the preparation process.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for preparing allyl glycidyl ether, the preparation method comprising:

[0011] (1) Allyl alcohol, boron trifluoride catalyst and epichlorohydrin are mixed to form a material, which is introduced into a tubular reaction device, in which a tin-containing molecular sieve catalyst is loaded, and the material is contacted with the tin-containing molecular sieve catalyst in the tubular reaction device to perform a ring-opening reaction, and an intermediate product is obtained after the reaction is completed;

[0012] (2) The intermediate product, saturated sodium chloride solution and base are mixed to carry out a ring-closing reaction, and after the reaction is completed, post-treatment is performed to obtain allyl glycidyl ether.

[0013] The preparation method provided by the present invention reduces the back-mixing of reaction materials by means of a tubular reaction device in the ring-opening reaction through the structure and reaction mode of the tubular reaction device, effectively avoids the side reaction of further polymerization of the intermediate product as alcohol and epichlorohydrin, and because the target reaction is a strongly exothermic reaction, it is helpful to achieve effective temperature control of the reaction; on the other hand, a combined catalyst of boron trifluoride and a tin-containing molecular sieve is used, and the synergistic effect of boron trifluoride and the tin-containing molecular sieve is used to effectively improve the reaction selectivity and conversion rate. In the tin-containing molecular sieve, tin forms a bond with the molecular sieve framework and enters the molecular sieve framework to form a stable structure, thereby improving the catalytic stability and catalytic activity of the catalyst. The catalyst has a high tin content, which can increase the active components in contact with the unit material and improve the catalytic efficiency. In addition, the tin-containing catalyst is formed into a solid and can be loaded in the reaction device, so that the catalyst can continue to catalyze and can be recovered, thereby simplifying the post-processing process and difficulty of subsequent separation of the catalyst.

[0014] Preferably, the tin content in the tin-containing molecular sieve catalyst in step (1) is 4-10wt%, for example, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% or 10wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0015] Preferably, the preparation method of the tin-containing molecular sieve catalyst in step (1) comprises: subjecting a zeolite molecular sieve to dealumination treatment with an acid to obtain a dealuminated molecular sieve, mixing the dealuminated molecular sieve with a tin salt solution for reaction, separating the solid from the liquid after the reaction to obtain a molecular sieve solid, and calcining and activating the molecular sieve solid to obtain the tin-containing molecular sieve catalyst.

[0016] In the preparation method of the tin-containing molecular sieve catalyst of the present invention, the zeolite molecular sieve is firstly treated with acid, and the aluminum atoms in the molecular sieve are removed under the action of the acid, so that a large number of silanol groups exist inside the molecular sieve, and adjacent silanol groups form silanol vacancies due to the action of hydrogen bonds, and then the tin ions in the solution exchange ions with the high-silicon molecular sieve matrix, so that tin occupies these silanol vacancies, and under calcination activation, the tin ions form bonds with the silanols in the molecular sieve framework and enter the molecular sieve framework, thereby forming a stable tin-containing molecular sieve.

[0017] Preferably, the acid used in the dealumination treatment includes any one of hydrochloric acid, nitric acid or sulfuric acid, or a combination of at least two of them. Typical but non-limiting combinations include a combination of hydrochloric acid and nitric acid, a combination of nitric acid and sulfuric acid, a combination of hydrochloric acid and sulfuric acid, or a combination of hydrochloric acid, nitric acid and sulfuric acid.

[0018] Preferably, the temperature of the dealumination treatment is 80-140°C, for example, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or 140°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Further preferably, when the acid is nitric acid, the temperature of the dealumination treatment is 80°C; when the acid is hydrochloric acid, the temperature of the dealumination treatment is 110°C; when the acid is sulfuric acid, the temperature of the dealumination treatment is 140°C.

[0020] Preferably, the dealumination process comprises sequentially performing a first acid treatment and a second acid treatment.

[0021] Preferably, the acid used in the first acid treatment comprises hydrochloric acid.

[0022] Preferably, the acid used in the second acid treatment comprises nitric acid.

[0023] Preferably, the dealumination treatment is followed by washing with deionized water.

[0024] Preferably, the tin salt comprises tin tetrachloride.

[0025] Preferably, the tin concentration in the tin salt solution is 0.001-0.3 mol / L, for example, it can be 0.001 mol / L, 0.005 mol / L, 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L or 0.3 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable, preferably 0.05-0.2 mol / L.

[0026] Preferably, the pH of the tin salt solution is >1, <4, for example, it can be 1.1, 1.5, 2, 2.5, 3, 3.5 or 3.9, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the volume mass ratio of the tin salt solution to the dealuminated molecular sieve is 5-30 mL / g, for example, 5 mL / g, 10 mL / g, 15 mL / g, 20 mL / g, 25 mL / g or 30 mL / g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 10 mL / g.

[0028] Preferably, the reaction temperature is 70-130°C, for example, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or 130°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the reaction time is 0.5-6 h, for example, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h or 6 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 3 h.

[0030] Preferably, the solid-liquid separation is followed by drying.

[0031] Preferably, the drying temperature is 70-100°C, for example, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the drying time is 0.5-4 h, for example, 0.5 h, 1 h, 2 h, 3 h or 4 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the calcination activation temperature is 200-500°C, for example, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C or 500°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the calcination activation time is 1-6 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the calcination and activation are followed by tableting, crushing and screening.

[0036] Preferably, the pore size of the sieve is 300-800 μm, for example, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm or 800 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the mesh size of the tin-containing molecular sieve catalyst is 20-50 meshes, for example, 20 meshes, 30 meshes, 40 meshes or 50 meshes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0038] Preferably, the particle size of the tin-containing molecular sieve catalyst is 0.5-0.8 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the amount of allyl alcohol used in step (1) is 1-5eq, for example, 1eq, 2eq, 3eq, 4eq or 5eq, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 2-3eq, and the amount is calculated based on epichlorohydrin.

[0040] Preferably, the boron trifluoride catalyst in step (1) comprises boron trifluoride etherate.

[0041] Preferably, the amount of boron trifluoride in the boron trifluoride catalyst in step (1) is 0.0005-0.005eq, for example, it can be 0.0005eq, 0.001eq, 0.002eq, 0.003eq, 0.004eq or 0.005eq, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. The amount is calculated based on epichlorohydrin.

[0042] Preferably, in step (1), the temperature of the material is controlled to be 50-70°C, for example, 50°C, 55°C, 60°C, 65°C or 70°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the mixing process in step (1) comprises: mixing allyl alcohol and a boron trifluoride catalyst to form a first raw material, taking the epichlorohydrin as a second raw material, and then mixing the first raw material and the second raw material to form a material.

[0044] Preferably, the first raw material and the second raw material are mixed using a mixer.

[0045] Preferably, the mixer comprises a static mixer and / or a dynamic mixer, preferably a static propeller mixer.

[0046] In the present invention, the feed rates of the first raw material and the second raw material are controlled by a metering valve to ensure that the first raw material and the second raw material are mixed in a fixed ratio so that the first raw material and the second raw material are used up in the same time. The feed rate of the first raw material is 0.28-0.93 kg / h, and the feed rate of the second raw material is 0.31-0.49 kg / h.

[0047] Preferably, the filling height of the tin-containing molecular sieve catalyst in step (1) is 85-95% of the length of the tubular reaction device, for example, it can be 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94% or 95%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] Preferably, during the ring-opening reaction in step (1), a water bath is used for temperature control, and the temperature of the water bath is 40-70°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C or 70°C, but is not limited to the listed values, and other values ​​within the numerical range not listed are also applicable.

[0049] Preferably, the tubular reaction device in step (1) comprises a shell-and-tube reactor.

[0050] In the present invention, the tube diameter ratio of the tubes in the tube reactor is 1:(1.5-2.5), and the reaction temperature is controlled by circulating water between the tubes, and the temperature of the circulating water is 40-70°C.

[0051] Preferably, the reaction residence time of the ring-opening reaction in step (1) is 25-40 min, for example, 25 min, 28 min, 30 min, 32 min, 35 min, 38 min or 40 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] Preferably, the base in step (2) comprises any one of sodium hydroxide, potassium hydroxide or calcium hydroxide, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of sodium hydroxide and potassium hydroxide, a combination of potassium hydroxide and calcium hydroxide, a combination of sodium hydroxide and calcium hydroxide, or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide, preferably sodium hydroxide.

[0053] Preferably, the amount of the base in step (2) is 1-1.5 eq, for example, 1 eq, 1.1 eq, 1.2 eq, 1.3 eq, 1.4 eq or 1.5 eq, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable. Preferably, it is 1.05-1.2 eq, and the amount is calculated based on epichlorohydrin.

[0054] Preferably, the temperature of the ring-closure reaction in step (2) is 20-70°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C or 70°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0055] Preferably, the post-treatment in step (2) comprises: standing for stratification to separate an aqueous phase and an organic phase, subjecting the organic phase to distillation and purification to obtain the allyl glycidyl ether, subjecting the aqueous phase to solid-liquid separation to obtain sodium chloride solid and a saturated sodium chloride solution, and the saturated sodium chloride solution is reused as the aqueous phase in the ring-closure reaction in step (2).

[0056] Preferably, the solid-liquid separation method comprises filtration and / or centrifugation.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The preparation method provided by the present invention uses a boron trifluoride and tin-containing molecular sieve combined catalyst to act synergistically, utilizes a tubular reaction device, and adopts a catalytic method of immobilizing the catalyst in the tubular reaction device, thereby significantly improving the reaction selectivity, conversion rate and product yield of allyl glycidyl ether, the selectivity can reach more than 89.3%, the conversion rate can reach more than 94.7%, the yield is more than 87.5%, and the post-processing process of the reaction is simplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 The process flow chart of the preparation method of allyl glycidyl ether provided in Example 1 is shown. DETAILED DESCRIPTION

[0060] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0061] In order to clearly illustrate the technical solution of the present invention, in a specific implementation manner, the Beta zeolite molecular sieve used is NKF-6-40H type produced by Nankai Catalyst Factory, and ICP-AES elemental analysis uses a Plasma-Spec-Ⅱ inductively coupled plasma atomic emission spectrometer.

[0062] In order to clearly illustrate the technical solution of the present invention, in a specific embodiment, allyl alcohol and epichlorohydrin undergo a ring-opening reaction, and the reaction process of the ring-opening reaction is as follows:

[0063]

[0064] Preparation Example 1

[0065] This preparation example provides a tin-containing molecular sieve catalyst, and the preparation method of the tin-containing molecular sieve catalyst is as follows:

[0066] (a) Take 50 g of Beta zeolite molecular sieve with a Si / Al ratio of 38, add it to 200 g of 38% concentrated hydrochloric acid, heat it under reflux at 110°C for 2 h, filter out the solid, then add the solid to 250 g of 68% concentrated nitric acid, heat it under reflux at 70°C for 3 h, filter out the solid, and wash it with water until it is neutral;

[0067] (b) 11.3 g (0.05 mol) of tin tetrachloride dihydrate was added with water to prepare 500 mL of solution, wherein the tin concentration in the solution was 0.1 mol / L, and hydrochloric acid was added to adjust the pH of the solution to 3.5, and then the acid-treated molecular sieve solid was added to the tin tetrachloride solution, and ultrasonic vibration was used for 30 min, and then the temperature was raised to 100° C. and refluxed for 1 h, and the solid was filtered out and dried at 80° C. for 1 h, and the solid was transferred to a muffle furnace and calcined at 270° C. for 3 h, and the powdered molecular sieve was tableted and crushed, and a 20-50 mesh solid (particle size 0.3-0.8 mm) was sieved out to obtain the tin-containing molecular sieve catalyst.

[0068] In this preparation example, the obtained tin-containing molecular sieve catalyst sample was subjected to ICP-AES elemental analysis, and the Sn content in the sample was measured to be 4.25 wt %.

[0069] Comparative Preparation Example 1

[0070] This comparative preparation example provides a tin-supported molecular sieve catalyst, and the preparation method of the tin-supported molecular sieve catalyst is as follows:

[0071] Take 50g of Beta zeolite molecular sieve with a Si / Al ratio of 38, take 11.3g (0.05mol) of tin tetrachloride dihydrate and add water to prepare 500mL of solution, the tin concentration in the solution is 0.1mol / L, add hydrochloric acid to adjust the pH of the solution to 3.5, then add Beta zeolite molecular sieve to the tin tetrachloride solution, use ultrasonic vibration for 30min, filter out the solid and dry it at 80℃ for 1h, transfer the solid to a muffle furnace and calcine at 270℃ for 3h, press the powdered molecular sieve into tablets and crush it, sieve out 20-50 mesh solids (particle size 0.3-0.8mm), and obtain the tin-loaded molecular sieve catalyst.

[0072] Example 1

[0073] This embodiment provides a Figure 1 The preparation method of allyl glycidyl ether shown in the figure comprises:

[0074] (1) 1.74 kg (30 mol) of allyl alcohol and 3.6 g of boron trifluoride ether (the content of boron trifluoride is 47 wt %, the molar weight is 0.012 mol) are mixed to form a first raw material, and 1.11 kg (12 mol) of epichlorohydrin is used as a second raw material, wherein the amount of allyl alcohol used is 2.5 eq of epichlorohydrin, and the amount of boron trifluoride used is 0.001 eq of epichlorohydrin. The tin-containing molecular sieve prepared in Preparation Example 1 is loaded into a tubular reactor, wherein the tubular reactor includes 20 tubulars with an inner diameter of 4 mm, each tubular being 2.0 m long. The reactor is cooled by circulating water at 45° C. The catalyst is loaded in a dense stacking manner, the stacking coefficient is 0.4, and the density of the catalyst is 2 g / cm 3 The filling height is 85% of the tube length, and the total amount of catalyst is 170g, which contains SnO 2 0.7 g, containing 0.005 mol of Sn;

[0075] (2) The first raw material and the second raw material are fed by adjusting the metering valve. The feeding rate of the first raw material is 0.58 kg / h, and the feeding rate of the second raw material is 0.37 kg / h. After the first raw material and the second raw material are mixed in the mixer, the temperature is raised to 50°C by the heat exchanger, and then enter the tubular reactor. The total volume of the raw materials is about 3 L, the reactor volume is 0.25 L, the flow rate is 0.22 cm / s, and the liquid space velocity is 4 h -1 The average residence time is 30 minutes. The raw materials are added at a uniform speed within 3 hours. The materials flowing out of the tubular reactor enter the storage tank for cooling and collection. The material components are analyzed by HPLC-MS. The results are listed in Table 1, and the reaction conversion rate and selectivity are calculated.

[0076] (3) The material in the storage tank is distilled to recover allyl alcohol, and the remaining material is put into the reactor. The reactor contains 1L of saturated brine. 0.58kg (14.4mol) of sodium hydroxide is added to the reactor, where the amount of sodium hydroxide is 1.2eq. After heating to 40°C and stirring for 15min, the reactor is allowed to stand for stratification, and the upper organic phase is separated. The lower aqueous phase is centrifuged to separate sodium chloride. The organic phase is purified by distillation to obtain 1.20kg of allyl glycidyl ether with a yield of 87.5%. The aqueous phase has 1.2kg, containing 5.8% of allyl glycidyl ether (a loss of 5.3% yield).

[0077] Example 2

[0078] This embodiment provides a method for preparing allyl glycidyl ether, the preparation method comprising:

[0079] (1) 1.74 kg (30 mol) of allyl alcohol and 3.6 g of boron trifluoride ether (boron trifluoride content is 47 wt %, molar weight is 0.012 mol) are mixed to form a first raw material, and 1.11 kg (12 mol) of epichlorohydrin is used as a second raw material, wherein the amount of allyl alcohol used is 2.5 eq of epichlorohydrin, and the amount of boron trifluoride used is 0.001 eq of epichlorohydrin. The tin-containing molecular sieve catalyst prepared in Preparation Example 1 is loaded into a tubular reactor, wherein the tubular reactor includes 20 tubulars with an inner diameter of 4 mm, each tubular being 2.0 m long, and the reactor is cooled by circulating water at 45° C. The tin-containing molecular sieve catalyst is loaded in a dense stack, and the stacking coefficient is 0.4. The density of the tin-containing molecular sieve catalyst is 2 g / cm 3 The filling height of the tin-containing molecular sieve catalyst is 85% of the tube length, and the total amount of the tin-containing molecular sieve catalyst is 170g, which contains SnO 2 0.7 g, containing 0.005 mol of Sn;

[0080] (2) The first raw material and the second raw material are fed by adjusting the metering valve. The feeding rate of the first raw material is 0.58 kg / h, and the feeding rate of the second raw material is 0.37 kg / h. After the first raw material and the second raw material are mixed in the mixer, the temperature is raised to 50°C by the heat exchanger, and then enter the tubular reactor. The total volume of the raw materials is about 3 L, the reactor volume is 0.25 L, the flow rate is 0.22 cm / s, and the liquid space velocity is 4 h -1 The average residence time is 30 minutes. The raw materials are added at a uniform speed within 3 hours. The materials flowing out of the tubular reactor enter the storage tank for cooling and collection. The material components are analyzed by HPLC-MS. The results are listed in Table 1, and the reaction conversion rate and selectivity are calculated.

[0081] (3) The material in the storage tank was distilled to recover allyl alcohol, and the remaining material was fed into a reactor. The reactor contained 1 L of saturated brine, which was the aqueous phase separated in step (3) of Example 1. 0.50 kg (12.6 mol) of sodium hydroxide was added to the reactor, and the reaction was heated to 40° C. and stirred for 15 min. The reactor was allowed to stand for stratification, and the upper organic phase was separated. The lower aqueous phase was centrifuged to separate sodium chloride. The organic phase was purified by distillation to obtain 1.27 kg of allyl glycidyl ether with a yield of 92.8%.

[0082] That is, compared with Example 1, Example 2 is the same as Example 1 in that the saturated brine in the reactor in step (3) is the aqueous phase saturated brine separated in Example 1, and the rest is the same as Example 1.

[0083] Embodiment 3-7

[0084] Examples 3-7 respectively provide a method for preparing allyl glycidyl ether. Compared with Example 2, the temperatures at which the first raw material and the second raw material are heated by the heat exchanger in step (2) are respectively changed, and the circulating water temperature of the shell-and-tube reactor is changed. The rest is the same as Example 2.

[0085] The parameter changes of Examples 3-7 are shown in the following table.

[0086]

[0087] Embodiment 8-15

[0088] Examples 8-15 respectively provide a method for preparing allyl glycidyl ether. Compared with Example 2, the amount of allyl alcohol in step (1) is changed, and the feeding rate of the first raw material in step (2) is changed. The rest is the same as Example 2.

[0089] The parameter changes of Examples 8-15 are shown in the following table.

[0090]

[0091] Examples 16-18

[0092] Examples 16-18 respectively provide a method for preparing allyl glycidyl ether. Compared with Example 2, the feed rates of the first raw material and the second raw material in step (2) are respectively changed to change the average residence time of the reaction. The rest is the same as Example 2.

[0093] The parameter changes of Examples 16-18 are shown in the following table.

[0094]

[0095] Examples 19-20

[0096] Examples 19-20 respectively provide a method for preparing allyl glycidyl ether. Compared with Example 2, the masses of boron trifluoride ether are set to 18.0 g (Example 19) and 1.8 g (Example 20), respectively, and the rest are the same as Example 2, that is, in Example 19, the molar amount of boron trifluoride is 0.06 mol, and the equivalent is 0.005 eq. In Example 20, the molar amount of boron trifluoride is 0.006 mol, and the equivalent is 0.0005 eq.

[0097] Examples 21-23

[0098] Examples 21-23 respectively provide a method for preparing allyl glycidyl ether. Compared with Example 2, the loading amounts of the tin-containing molecular sieve catalyst are changed respectively, and the rest are the same as Example 2.

[0099] The parameter changes of Examples 21-23 are shown in the following table.

[0100]

[0101] Comparative Example 1

[0102] This comparative example provides a method for preparing allyl glycidyl ether, the preparation method comprising:

[0103] (1) 1.11 kg (12 mol) of epichlorohydrin and 170 g of the tin-containing molecular sieve catalyst prepared in Preparation Example 1 were added to a reaction kettle, stirring and heating were started to raise the temperature of the reaction kettle to 50° C. 1.74 kg (30 mol) of allyl alcohol and 3.6 g of boron trifluoride ether (the content of boron trifluoride was 47 wt %, the molar amount was 0.012 mol) were mixed and uniformly added dropwise to the kettle within 30 min. During this period, heat exchange was started to maintain the temperature in the reaction kettle at 50-60° C. After the addition was completed, the reaction was continued to be kept warm for 1.5 h, and the reaction liquid components were analyzed by HPLC-MS. The results are listed in Table 1, and the reaction conversion rate and selectivity were calculated;

[0104] (2) After filtering the reaction liquid in the reactor to recover the molecular sieve catalyst, the excess allyl alcohol was recovered by vacuum distillation. The remaining reaction liquid was added to the reactor, 1 L of saturated brine was added, and 0.58 kg (14.4 mol) of sodium hydroxide was added. After stirring at room temperature for 15 min, the organic phase was separated and purified by vacuum distillation to obtain 1.12 kg of the product allyl glycidyl ether with a yield of 82.2%.

[0105] Comparative Example 2

[0106] This comparative example provides a method for preparing allyl glycidyl ether. Compared with Example 2, the tin-containing molecular sieve catalyst is not loaded into the tubular reactor, and the rest is the same as Example 2.

[0107] Comparative Example 3

[0108] This comparative example provides a method for preparing allyl glycidyl ether. Compared with Example 2, 3.1 g (0.012 mol) of anhydrous tin chloride is added to the first raw material, wherein the molar amount of tin is the same as that of the tin-containing molecular sieve catalyst in Example 2, and the shell-and-tube reactor is not loaded with the tin-containing molecular sieve catalyst, and the rest is the same as Example 2.

[0109] Comparative Example 4

[0110] This comparative example provides a method for preparing allyl glycidyl ether. Compared with Example 2, the tin-containing molecular sieve catalyst is replaced with the tin-loaded molecular sieve catalyst provided in Comparative Preparation Example 1 according to an equal mass of tin. The loading method of the tin-loaded molecular sieve catalyst is the same as that in Example 2, and the rest is the same as that in Example 2.

[0111] The material components of the material obtained after the ring-opening reaction of allyl alcohol and epichlorohydrin in the examples and comparative examples were analyzed by HPLC-MS, and the results are listed in Table 1.

[0112] Table 1

[0113]

[0114]

[0115] “ / ” in the table means no data.

[0116] In the table, the main product refers to 1-allyloxy-3-chloro-2-propanol, and the structure is as follows:

[0117]

[0118] By-products refer to the sum of isomers, dimers and higher polymers of the main product.

[0119] The reaction process of one of the side reactions is as follows:

[0120]

[0121] The conversion rate and selectivity of epichlorohydrin in the examples and comparative examples were calculated, and the yield of the product allyl glycidyl ether was calculated. The results are listed in Table 2.

[0122] Table 2

[0123]

[0124]

[0125] “ / ” in the table means no data.

[0126] As can be seen from Table 2, the preparation method provided by the present invention has a high reaction conversion rate and selectivity. The conversion rate can especially reach more than 97.5%, the selectivity can especially reach more than 95.2%, and the yield of the product allyl glycidyl ether can reach more than 92.8%, which greatly improves the reaction efficiency.

[0127] Compared to Example 2, in Examples 3-7, the increase in reaction temperature has limited effect on the improvement of epichlorohydrin conversion, but the reaction selectivity can be significantly reduced, and the excessively high reaction temperature leads to a reduction in the selectivity of the ring-opening addition step of allyl alcohol to epichlorohydrin, and the isomer of the intermediate increases, and on the other hand, it also promotes the competition of the intermediate and allyl alcohol to react with epichlorohydrin, so that the dimer by-product is increased. In Examples 8-15, the conversion rate and selectivity of the reaction are related to the allyl alcohol dosage, and when the allyl alcohol equivalent rises, the conversion rate and selectivity of the reaction are increased, and excessive allyl alcohol plays the dilution effect of the solvent, so that the intermediate and epichlorohydrin concentrations in the material are reduced, and the generation of dimers is reduced, but excessive allyl alcohol can increase the subsequent material recovery energy consumption, and when the allyl alcohol relative epichlorohydrin equivalent is less than 2.5, the reaction conversion rate and selectivity are significantly reduced. In Examples 16-18, the residence time of the material in the device significantly affects the conversion rate and selectivity of the reaction. If the average residence time of the material in the reactor is too low, the reaction will be insufficient and the conversion rate will be low. If the average residence time of the material in the reactor is too high, the reaction side reactions will increase and the reaction selectivity will decrease. In Examples 19-20, when the amount of boron trifluoride is less than 0.001eq, the reaction conversion rate decreases, and excessive boron trifluoride will cause waste. In Examples 21-23, the molecular sieve catalyst loading affects the reaction conversion rate. When the molecular sieve loading height is less than 85%, the reaction efficiency decreases significantly.

[0128] Compared to Example 2, in Comparative Example 1, a kettle reactor is used to significantly reduce the reaction selectivity, and it can be seen that a tubular reactor reduces the degree of back mixing of materials, making it difficult for the intermediate generated by the reaction to react with the epichlorohydrin of the non-residual reaction, and greatly reducing the generation of dimerization by-products. In Comparative Examples 2 and 3, tin-containing molecular sieve catalysts are not used or the catalyst is replaced with anhydrous tin chloride, and the reaction efficiency is significantly reduced. After removing the molecular sieve catalyst, boron trifluoride occurs with relatively low activity and selective catalytic reaction, and the product contains more isomer by-products. When tin chloride is used, the catalyst is evenly dispersed in the raw material liquid, and the local concentration of the molecular sieve catalyst catalytic site is higher, and the material conversion efficiency in the reactor is higher, while the heterogeneous molecular sieve catalyst is affected by steric hindrance, etc., hindering the attack of allyl alcohol on epichlorohydrin No. 2 C position, reducing the generation of isomer impurities; in Comparative Example 4, molecular sieve loaded tin chloride is loaded, and the material is passed through the reaction to dissolve tin chloride, thereby causing the catalyst to be deactivated, and the reaction cannot be continued.

[0129] In summary, the preparation method provided by the present invention uses the synergistic effect of a combination catalyst of boron trifluoride and a tin-containing molecular sieve, utilizes a tubular reaction device, and adopts a catalytic method of immobilizing the catalyst in the tubular reaction device, which significantly improves the reaction selectivity, conversion rate and product yield of allyl glycidyl ether, the selectivity can reach more than 89.3%, the conversion rate can reach more than 94.7%, the yield is more than 87.5%, and the post-processing process of the reaction is simplified.

Claims

1. A method for preparing allyl glycidyl ether, characterized in that: The preparation method comprises: (1) Allyl alcohol, boron trifluoride catalyst and epichlorohydrin are mixed to form a material, which is introduced into a tubular reaction device, in which a tin-containing molecular sieve catalyst is loaded, and the material is contacted with the tin-containing molecular sieve catalyst in the tubular reaction device to perform a ring-opening reaction, and an intermediate product is obtained after the reaction is completed; The tin content of the tin-containing molecular sieve catalyst is 4-10wt%, and the preparation method of the tin-containing molecular sieve catalyst comprises: subjecting a zeolite molecular sieve to dealumination with an acid to obtain a dealuminated molecular sieve, then mixing the dealuminated molecular sieve with a tin salt solution for reaction, separating the solid from the liquid after the reaction to obtain a molecular sieve solid, and calcining and activating the molecular sieve solid to obtain the tin-containing molecular sieve catalyst; (2) The intermediate product is mixed with a base to carry out a ring-closing reaction, and after the reaction is completed, post-treatment is performed to obtain allyl glycidyl ether.

2. The preparation method according to claim 1, characterized in that: The temperature of the dealumination treatment is 80-140°C; The acid used in the dealumination treatment includes any one of hydrochloric acid, nitric acid or sulfuric acid or a combination of at least two thereof; The process of dealumination treatment comprises sequentially performing a first acid treatment and a second acid treatment; The calcination activation temperature is 200-500°C.

3. The preparation method according to claim 1, characterized in that: The boron trifluoride catalyst in step (1) includes boron trifluoride etherate; The amount of boron trifluoride in the boron trifluoride catalyst in step (1) is 0.0005-0.005 eq, calculated based on epichlorohydrin.

4. The preparation method according to claim 1, characterized in that: The filling height of the tin-containing molecular sieve catalyst in step (1) is 85-95% of the length of the tubular reaction device.

5. The preparation method according to claim 1, characterized in that: In step (1), the temperature of the material is controlled to be 50-70°C.

6. The preparation method according to claim 1, characterized in that: During the ring-opening reaction in step (1), a water bath is used for temperature control, and the temperature of the water bath is 40-70°C.

7. The preparation method according to claim 1, characterized in that: During the ring-opening reaction in step (1), the reaction residence time is 25-40 min.

8. The preparation method according to claim 1, characterized in that: The amount of the base used in step (2) is 1-1.5 eq, calculated based on epichlorohydrin; The temperature of the ring-closure reaction in step (2) is 20-70°C.

9. The preparation method according to claim 1, characterized in that: The aqueous phase used in the ring-closing reaction in step (2) comprises a saturated sodium chloride solution; The post-treatment in step (2) includes: standing for stratification, separating to obtain an aqueous phase and an organic phase, subjecting the organic phase to rectification and purification to obtain the allyl glycidyl ether, subjecting the aqueous phase to solid-liquid separation to obtain sodium chloride solid and a saturated sodium chloride solution, and recycling the saturated sodium chloride solution to the aqueous phase of the ring-closing reaction in step (2).

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