Device and method for preparing 2-vinyloxyethoxy ethyl methacrylate

Abstract

The device comprises a reaction kettle 1, a kettle top condenser 2, a nitrogen compressor, a molecular distillation tower bottom feeding pump, a molecular distillation tower, a tower top condenser, a receiving tank A, a receiving tank B and a receiving tank C. The top output end of the reaction kettle is connected with the input end of the kettle top condenser through a pipeline; a bottom discharge hole of the reaction kettle 1 is connected with a material inlet of the molecular distillation tower through a tower bottom feeding pump; a top output port of the molecular distillation tower is connected with an input end of a tower top condenser; an output end of the tower top condenser is connected with an input end of a receiving tank B; according to the method, the methanol and the methyl methacrylate after ester exchange are separated in the ascending pipe at the top of the reaction kettle by adopting the hot nitrogen, and the content of the methyl methacrylate after separation is less than 10%, so that the problem that the methanol and the methyl methacrylate are difficult to separate due to azeotropy is solved, the carrying-out amount of the methyl methacrylate is reduced, and the conversion rate of the reaction is improved.

Description

Technical Field

[0001] The invention relates to 2-vinyloxyethoxyethyl methacrylate, in particular to a device and a method for preparing 2-vinyloxyethoxyethyl methacrylate. Background Art

[0002] 2-vinyloxyethoxyethyl methacrylate (VEEM) and 2-vinyloxyethoxyethyl acrylate (VEEA) are both bifunctional monomers, that is, they have free radical polymerizable acryloyl functional groups and cationic curable vinyl ether functional groups. As a vinyl ether monomer, VEEM and VEEA have excellent UV curing properties, strong dilution ability, good water resistance, good stability, no irritating odor and low toxicity, and are widely used in coatings, inks and adhesives.

[0003] At present, the main method for industrial production of VEEM and VEEA is mainly based on transesterification, that is, methyl methacrylate (ethyl acrylate) and diethylene glycol monovinyl ether react in the presence of a catalyst to produce VEEM and methanol (VEEA and ethanol). Since the reaction is a reversible reaction, the conversion rate of VEEM and VEEA is largely determined by the molar ratio of the reactants and the removal rate of methanol (ethanol). However, in the production process, increasing the molar ratio of the reactants will make it difficult to recycle the raw materials and cause a large amount of waste; the product methanol and the reactant methyl methacrylate (ethanol and ethyl acrylate) azeotropy makes it difficult to remove methanol (ethanol) from the reaction system. Although there are documents that adding an azeotroping agent can increase the proportion of methanol (ethanol) removed, it still cannot obtain a high conversion rate, and methyl methacrylate (ethyl acrylate) is easy to polymerize during the removal process; the 2-vinyloxyethoxy ethyl methacrylate (2-vinyloxyethoxy ethyl acrylate) and diethylene glycol monovinyl ether generated by the reaction are difficult to separate by ordinary distillation to obtain a high-purity product, and 2-vinyloxyethoxy ethyl methacrylate (2-vinyloxyethoxy ethyl acrylate) is easy to polymerize when heated and is not suitable for traditional distillation. As a result, the reaction time is long, the reaction conversion rate is low, the product purity is low, the material is easy to polymerize, and the raw materials and energy are wasted. Summary of the invention

[0004] The object of the present invention is to provide a device and method for preparing 2-vinyloxyethoxyethyl methacrylate to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A device for preparing 2-vinyloxyethoxyethyl methacrylate comprises a reactor 1, a reactor top condenser 2, a nitrogen compressor, a molecular distillation tower bottom feed pump, a molecular distillation tower, a tower top condenser, a receiving tank A, a receiving tank B and a receiving tank C; the top output end of the reactor is connected to the input end of the reactor top condenser through a pipeline, wherein the reactor top condenser is provided with a nitrogen output end and a liquid output end, the nitrogen output end of the reactor top condenser is connected to the inlet of the nitrogen compressor, and the liquid output end at the bottom of the reactor top condenser is connected to the receiving tank C; the bottom discharge port of the reactor is connected to the material inlet of the molecular distillation tower through the tower bottom feed pump; the top output port of the molecular distillation tower is connected to the input end of the tower top condenser, and the output end of the tower top condenser is connected to the input end of the receiving tank B; the bottom outlet of the molecular distillation tower is connected to the input port of the receiving tank A.

[0007] As a further solution of the present invention: the output port of the nitrogen compressor is connected to the nitrogen inlet of the reactor through a nitrogen heater.

[0008] A method for preparing 2-vinyloxyethoxyethyl methacrylate, the specific steps are as follows:

[0009] (1) adding methyl methacrylate, diethylene glycol vinyl ether, a catalyst and a polymerization inhibitor into a reaction kettle and mixing them, and performing an ester exchange reaction at 75-130° C., wherein methyl methacrylate and diethylene glycol vinyl ether undergo an ester exchange reaction to generate products such as 2-vinyloxyethoxyethyl methacrylate (VEEM) and methanol;

[0010] (2) introducing hot nitrogen to carry out the methanol produced by the reaction and the excess methyl methacrylate from the reactor riser and condense them through the reactor top condenser. The reactor top condenser can condense the methanol and methyl methacrylate into liquid and then discharge them, and the nitrogen is recycled;

[0011] (3) Excess diethylene glycol monovinyl ether and 2-vinyloxyethoxy ethyl methacrylate are transported to a molecular distillation tower by a tower bottom feed pump for distillation and separation to obtain high-purity 2-vinyloxyethoxy ethyl methacrylate; the purity of the 2-vinyloxyethoxy ethyl methacrylate obtained after molecular distillation is greater than 99%.

[0012] As a further solution of the present invention: the molar ratio of methyl methacrylate to diethylene glycol vinyl ether in step (1) is 0.8 to 3.5: 1. Preferably, the molar ratio of methyl methacrylate to diethylene glycol vinyl ether is 1 to 2.5: 1.

[0013] As a further solution of the present invention: the temperature of the hot nitrogen in step (1) is 60-100° C. Preferably, the temperature of the hot nitrogen is 80-100° C.

[0014] As a further solution of the present invention: the nitrogen pressure in step (1) is 0.5-1.5 MPa, preferably, the nitrogen pressure is 0.5-1.0 MPa.

[0015] As a further embodiment of the present invention: the catalyst in step (1) is one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium acrylate, tetrabutyl titanate and dibutyltin oxide.

[0016] As a further embodiment of the present invention: the inhibitor in step (1) is one or more of p-hydroxyanisole, hydroquinone, phenothiazine, dibutyl copper dithiocarbamate, 4-hydroxy-2,2,6,6-tetramethylpyridine-1-oxyl free radical and tetramethylpyridine nitrogen oxide free radical phosphite triester.

[0017] As a further embodiment of the present invention: in step (1), the mass ratio of the catalyst, the polymerization inhibitor and methyl methacrylate is (0.001-0.02):(0.0001-0.001):1. Preferably, the mass ratio of the catalyst, the polymerization inhibitor and methyl methacrylate is (0.007-0.02):(0.0007-0.001):1.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The present invention uses hot nitrogen to separate methanol and methyl methacrylate after ester exchange in the riser at the top of the reactor. After separation, the content of methyl methacrylate is less than 10%, which solves the problem that methanol and methyl methacrylate are difficult to separate in an azeotropic manner, reduces the amount of methyl methacrylate carried out, and improves the conversion rate of the reaction.

[0020] (2) The present invention uses hot nitrogen to effectively inhibit the polymerization of methyl methacrylate, thereby solving the polymerization problem of the raw material methyl methacrylate in the kettle top condenser.

[0021] (3) The present invention separates diethylene glycol monovinyl ether and 2-vinyloxyethoxyethyl methacrylate by molecular distillation, thereby reducing the temperature of the distillation tower and solving the polymerization problem of 2-vinyloxyethoxyethyl methacrylate during the separation process. The purity of the obtained 2-vinyloxyethoxyethyl methacrylate is greater than 99%.

[0022] (4) The present invention selects suitable inhibitors and catalysts, and suitable ratios of inhibitors, catalysts and reaction raw materials to prepare the product VEEM, which effectively inhibits the polymerization of reactants and products, reduces the occurrence of side reactions, and improves the selectivity and yield of VEEM. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1The figure is a schematic diagram of the structure of a device for preparing 2-vinyloxyethoxyethyl methacrylate. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] See also Figure 1 In an embodiment of the present invention, a device for preparing 2-vinyloxyethoxyethyl methacrylate comprises a reactor 1, a top condenser 2, a nitrogen compressor 3, a nitrogen heater 4, a molecular distillation tower bottom feed pump 5, a molecular distillation tower 6, a top condenser 7, a receiving tank 8, a receiving tank 9 and a receiving tank 10; the top output end of the reactor 1 is connected to the input end of the top condenser 2 through a pipeline, wherein the top condenser 2 is provided with a nitrogen output end and a liquid output end, the nitrogen output end of the top condenser 2 is connected to the inlet of the nitrogen compressor 3, and the liquid output end at the bottom of the top condenser 2 is connected to the receiving tank 10; the methanol and methyl methacrylate generated by the reaction form an azeotrope, which is taken out to the top condenser for cooling by hot nitrogen.

[0027] It should be noted that the input end, nitrogen output end and liquid output end of the kettle top condenser 2 are respectively three ports of a T-shaped pipe, and the outside of the T-shaped pipe is arranged in a low-temperature environment. The low-temperature environment can be a water bath at 0 degrees Celsius, an air-cooled system or a water-cooled radiator, etc., which are technologies known to those skilled in the art and will not be elaborated here, so that methanol and methyl methacrylate can condense into liquid, while nitrogen remains in a gaseous state. Finally, nitrogen is output from the nitrogen output end located above, and liquid methanol and methyl methacrylate are output from the liquid output end facing downward.

[0028] The output port of the nitrogen compressor 3 is connected to the nitrogen inlet of the reactor 1 through the nitrogen heater 4 .

[0029] The bottom discharge port of the reactor 1 is connected to the material inlet of the molecular distillation tower 6 through a bottom feed pump 5;

[0030] The top output port of the molecular distillation tower 6 is connected to the input end of the top condenser 7, and the output end of the top condenser 7 is connected to the input end of the receiving tank 9; the bottom outlet of the molecular distillation tower 6 is connected to the input port of the receiving tank 8.

[0031] Hot nitrogen is introduced into the reactor, and the hot nitrogen carries methanol and methyl methacrylate out from the rising pipe at the top of the reactor. The content of methyl methacrylate in the components after cooling by the top condenser is less than 10%, which effectively solves the problem of high content of methyl methacrylate in the azeotropic composition. The presence of hot nitrogen can inhibit the polymerization of methyl methacrylate, solving the problem of methyl methacrylate polymerization. The final conversion rate of 2-vinyloxyethoxyethyl methacrylate can reach up to 85%. The temperature of the distillation tower can be reduced by the separation method of molecular distillation, which effectively solves the problem of polymerization of 2-vinyloxyethoxyethyl methacrylate during the distillation process; after distillation in the molecular distillation tower, the content of 2-vinyloxyethoxyethyl methacrylate is greater than 99%.

[0032] In this example, the method for preparing 2-vinyloxyethoxyethyl methacrylate, the specific steps are as follows:

[0033] 100 kg of methyl methacrylate, 132 kg of diethylene glycol vinyl ether, 5 kg of potassium hydroxide and 0.4 kg of hydroquinone are added to the reactor 1 through the raw material pipeline for ester exchange reaction at a reaction temperature of 110-130° C.; hot nitrogen is introduced into the reactor 1 at a temperature of 80-100° C. and a pressure of 0.05-0.1 MPa, and the azeotropic product of methanol and raw material methyl methacrylate generated by the reaction is taken out through the reactor top riser to the reactor top condenser 2 for condensation; nitrogen After cooling, the material is pressurized to 0.05-0.15 MPa from the top of the kettle top condenser 2 to the nitrogen compressor 3, and then enters the nitrogen heater 4 to be heated to 80-100° C. and enters the reactor 1; the methyl methacrylate content in the material condensed by the kettle top condenser 2 is 9%; the conversion rate of 2-vinyloxyethoxyethyl methacrylate in the reactor 1 is 85.8%, and after distillation in the molecular distillation tower 6, the purity of 2-vinyloxyethoxyethyl methacrylate in the receiving tank 8 is 99.3%.

[0034] Diethylene glycol monovinyl ether and 2-vinyloxyethoxy ethyl methacrylate are transported to a molecular distillation tower by a tower bottom feed pump for distillation and separation to obtain high-purity 2-vinyloxyethoxy ethyl methacrylate; the purity of the 2-vinyloxyethoxy ethyl methacrylate obtained after distillation is greater than 99%.

[0035] The above (1) to (2) are continuous processes. Under this operating condition, after 6 hours of reaction, sampling and analysis showed that the reaction conversion rate was 85.8%, the selectivity was 99.8%, and the reaction was complete. The product was recovered from the reaction solution, and the product yield was 98.6%.

[0036] Example 2

[0037] The difference between this embodiment and embodiment 1 is that 150 kg of methyl methacrylate is added, the reaction time is 6 hours, the reaction conversion rate is 93.3%, the selectivity is 99.15%, and the product yield is 99.10%. The methyl methacrylate content in the material condensed from the kettle top condenser is 15%.

[0038] Example 3

[0039] The difference between this embodiment and embodiment 1 is that 90 kg of methyl methacrylate is added, the reaction time is 6 hours, the reaction conversion rate is 82.7%, the selectivity is 99.2%, and the product yield is 98.8%. The methyl methacrylate content of the material condensed from the kettle top condenser is 6%.

[0040] Example 4

[0041] The difference between this embodiment and embodiment 1 is that 10 kg of potassium hydroxide is added, the reaction time is 4.5 hours, the reaction conversion rate is 89.6%, the selectivity is 98.9%, the product yield is 98.7%, and the methyl methacrylate content in the material condensed from the kettle top condenser is 8.3%.

[0042] Example 5

[0043] The difference between this embodiment and embodiment 1 is that 2.5 kg of potassium hydroxide is added, the reaction time is 9 hours, the reaction conversion rate is 55.5%, the selectivity is 98.8%, the product yield is 80.0%, and the methyl methacrylate in the material condensed from the kettle top is 35.8%.

[0044] Example 6

[0045] The difference between this embodiment and Example 1 is that the nitrogen pressure is 0.2 MPa, the reaction time is 5 hours, the reaction conversion rate is 63.6%, the selectivity is 99.1%, the product yield is 88.9%, and the methyl methacrylate content of the material condensed from the top of the kettle is 18.3%.

[0046] Example 7

[0047] The difference between this example and Example 1 is that the nitrogen pressure is 0.03 MPa, the reaction time is 9.6 hours, the reaction conversion rate is 90.8%, the selectivity is 99.2%, and the product yield is 99.5%. The methyl methacrylate in the material condensed from the top of the kettle is 5.1%.

[0048] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preparing 2-vinyloxyethoxyethyl methacrylate, comprising a reactor 1, a reactor top condenser 2, a nitrogen compressor, a molecular distillation tower bottom feed pump, a molecular distillation tower, a tower top condenser, a receiving tank A, a receiving tank B and a receiving tank C, characterized in that: The top output end of the reactor is connected to the input end of the top condenser through a pipeline, wherein the top condenser is provided with a nitrogen output end and a liquid output end, the nitrogen output end of the top condenser is connected to the inlet of the nitrogen compressor, and the liquid output end at the bottom of the top condenser is connected to the receiving tank C; the bottom discharge port of the reactor 1 is connected to the material inlet of the molecular distillation tower through a bottom feed pump; the top output port of the molecular distillation tower is connected to the input end of the top condenser, and the output end of the top condenser is connected to the input end of the receiving tank B; the bottom outlet of the molecular distillation tower is connected to the input port of the receiving tank A.

2. The device for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 1, characterized in that: The output port of the nitrogen compressor is connected to the nitrogen inlet of the reactor 1 through a nitrogen heater.

3. A method for preparing 2-vinyloxyethoxyethyl methacrylate, characterized in that: The specific steps are as follows: (1) adding methyl methacrylate, diethylene glycol vinyl ether, a catalyst and a polymerization inhibitor into a reaction kettle and mixing them, and performing an ester exchange reaction at 75-130° C., wherein methyl methacrylate and diethylene glycol vinyl ether undergo an ester exchange reaction to generate products 2-vinyloxyethoxyethyl methacrylate and methanol; (2) introducing hot nitrogen to remove the methanol produced by the reaction and the excess methyl methacrylate from the reactor riser and then condense and separate them through the reactor top condenser; (3) Excess diethylene glycol monovinyl ether and 2-vinyloxyethoxyethyl methacrylate are transported to a molecular distillation tower by a tower bottom feed pump for distillation and separation to obtain high-purity 2-vinyloxyethoxyethyl methacrylate.

4. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 3, characterized in that: In the step (1), the molar ratio of methyl methacrylate to diethylene glycol vinyl ether is 0.8 to 3.5:

1.

5. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 4, characterized in that: The temperature of the hot nitrogen in step (1) is 60-100°C.

6. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 5, characterized in that: The nitrogen pressure in step (1) is 0.5-1.5 MPa.

7. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 6, characterized in that: The catalyst in step (1) is one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium acrylate, tetrabutyl titanate and dibutyltin oxide.

8. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 7, characterized in that: The inhibitor in step (1) is one or more of p-hydroxyanisole, hydroquinone, phenothiazine, dibutyl copper dithiocarbamate, 4-hydroxy-2,2,6,6-tetramethylpyridine-1-oxyl free radical and tetramethylpyridine nitrogen oxide free radical phosphite triester.

9. The method for preparing 2-vinyloxyethoxyethyl methacrylate according to claim 8, characterized in that: The mass ratio of the catalyst, the polymerization inhibitor and the methyl methacrylate in the step (1) is (0.001-0.02):(0.0001-0.001):1.

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