A continuous process and system for the preparation of isobomyl methacrylate
By using a combination of microwave reactor and fluidized bed in the production of isobornyl methacrylate, the problems of uneven heating in the reaction vessel and long production cycle were solved, achieving high-purity and high-efficiency continuous preparation and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FOSHAN SANSHUI JINGZE CHEM CO LTD
- Filing Date
- 2023-07-25
- Publication Date
- 2026-06-09
Smart Images
Figure CN117142951B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of isobornyl methacrylate preparation, and particularly to a continuous preparation method and system for isobornyl methacrylate. Background Technology
[0002] Isobornyl methacrylate is a raw material widely used in coatings, adhesives, and other fields. Currently, it is mainly prepared from camphene and methacrylic acid. During the production process, the synthesis of isobornyl methacrylate requires control within a specific temperature range; otherwise, the yield will be low and the amount of byproducts will increase. Existing reaction vessels generally use sleeves or jackets for heating. The heat from the sleeves or jackets needs to be gradually transferred from the outside to the center of the reaction vessel. However, due to the generally large volume of the reaction vessels, the external temperature is actually higher than the internal temperature. Furthermore, the large volume of the reaction vessels results in slow stirring speeds, leading to uneven mixing of the solution and ultimately low purity of the isobornyl methacrylate produced. In addition, the large volume of the reaction vessels in the factory results in long production cycles, and each batch must produce a sufficient quantity of isobornyl methacrylate to avoid increasing production costs and reducing production flexibility.
[0003] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a continuous preparation method and system for isoborneol methacrylate, which aims to improve the purity of isoborneol methacrylate products and increase production efficiency.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] The first aspect of this invention provides a continuous preparation method for isobornyl methacrylate, comprising the following steps:
[0007] Camphene and methacrylic acid in a mass ratio of 1:(0.8-0.85) were mixed evenly, and a polymerization inhibitor was added to obtain a raw material mixture.
[0008] The raw material mixture is fed into a microwave reactor for reaction to obtain a product mixture; the microwave reactor includes a fluidized bed and multiple microwave generators, and catalyst particles are disposed in the fluidized bed; the residence time of the raw material mixture in the fluidized bed is 20-30 minutes.
[0009] The product mixture is fractionated to obtain a raw material recovery liquid, isobornyl methacrylate finished product, and a by-product mixture; the raw material recovery liquid is composed of camphene and methacrylic acid;
[0010] The acidity of the raw material recovery liquid is measured, the content of methacrylic acid is calculated based on the acidity, and the mass ratio of camphene to methacrylic acid is further calculated. Camphene or methacrylic acid is added to make the mass ratio of camphene to methacrylic acid in the raw material recovery liquid the same as that in the raw material mixture, and the raw material recovery liquid is recycled.
[0011] In the continuous preparation method of isobornyl methacrylate, the power of the microwave reactor is 200-400W.
[0012] The continuous preparation method of isobornyl methacrylate, wherein the reaction temperature in the microwave reactor is 40-45°C.
[0013] In the continuous preparation method of isobornyl methacrylate, the amount of the polymerization inhibitor added is 0.02% to 0.03% of the total weight of methacrylic acid and camphene.
[0014] The continuous preparation method of isoborneol methacrylate, wherein the polymerization inhibitor is composed of phenothiazine and hydroquinone.
[0015] In the continuous preparation method of isoborneol methacrylate, the mass ratio of phenothiazine to hydroquinone in the polymerization inhibitor is 1:(1.5-2).
[0016] The continuous preparation method of isobornyl methacrylate includes adding a polymerization inhibitor to the uncooled raw material recovery liquid immediately after fractionation.
[0017] A second aspect of the present invention provides a continuous preparation system for isobornyl methacrylate, for implementing the continuous preparation method of isobornyl methacrylate described above. The continuous preparation system includes a mixing device, a microwave reactor, a first heating device, a first fractionating column, a second heating device, and a second fractionating column connected in sequence. A recovery tank is connected to the top of the first fractionating column, and the recovery tank is connected to the mixing device. A first storage tank and a second storage tank are also connected upstream of the mixing device.
[0018] The continuous preparation system for isobornyl methacrylate includes a microwave reactor comprising a fluidized bed and multiple microwave generators. The fluidized bed comprises multiple sets of connecting pipes arranged in parallel. Each connecting pipe is composed of multiple reaction tubes connected in series, and catalyst particles are disposed inside each reaction tube. Each reaction tube is vertically arranged, with its inlet end located at the bottom and its outlet end located at the top.
[0019] The continuous preparation system for isobornyl methacrylate includes a reaction tube with a mesh at the bottom and top, and the catalyst disposed between the two meshes.
[0020] Beneficial effects:
[0021] The first aspect of this invention provides a continuous preparation method for isobornyl methacrylate. The continuous preparation method uses a microwave reactor to carry out the esterification reaction of methacrylic acid and camphene, which is highly efficient and produces few by-products. The continuous preparation method can also further reuse the raw materials obtained by fractionation, which greatly improves the utilization rate of the raw materials.
[0022] The second aspect of the present invention provides a continuous preparation system for isoborneol methacrylate, which can efficiently prepare isoborneol methacrylate, and the production volume can be flexibly controlled without affecting the purity of the product. Attached Figure Description
[0023] Figure 1 This is a schematic diagram illustrating the continuous preparation of isobornyl methacrylate provided by the present invention.
[0024] Figure 2 This is a schematic diagram of a fluidized bed.
[0025] Figure 3 This is a schematic diagram of the structure of a microwave reactor.
[0026] Explanation of main component symbols: 1-mixing device, 2-microwave reactor, 3-first heating device, 4-first fractionation tower, 5-second heating device, 6-second fractionation tower, 7-first storage tank, 8-second storage tank, 9-recovery tank, 21-fluidized bed, 22-microwave generator, 211-reaction tube, 212-screen. Detailed Implementation
[0027] This invention provides a continuous preparation method and system for isobornyl methacrylate. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.
[0028] In the description of this invention, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientational structure and operation. Therefore, they should not be construed as limitations on the invention. Furthermore, "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more.
[0029] The first aspect of this invention provides a continuous preparation method for isobornyl methacrylate, comprising the following steps:
[0030] Camphene and methacrylic acid are mixed uniformly at a mass ratio of 1:(0.8-0.85), and a polymerization inhibitor is added to obtain a raw material mixture. The raw material mixture is then transported to a microwave reactor, which includes a fluidized bed and multiple microwave generators. Catalyst particles are placed in the fluidized bed. The residence time of the raw material mixture in the fluidized bed is 20-30 minutes. The raw material mixture reacts in the microwave reactor to obtain a product mixture. The product mixture is then fractionated to obtain a raw material recovery liquid, isobornyl methacrylate product, and a by-product mixture. The raw material recovery liquid consists of camphene and methacrylic acid.
[0031] The acidity of the raw material recovery liquid is measured, the content of methacrylic acid is calculated based on the acidity, and the mass ratio of camphene to methacrylic acid is further calculated. Camphene or methacrylic acid is added to make the mass ratio of camphene to methacrylic acid in the raw material recovery liquid the same as that in the raw material mixture, and the raw material recovery liquid is recycled.
[0032] The microwave reactor emits microwaves to heat the raw material mixture. Compared to traditional heat conduction, microwaves have a faster transmission speed and more accurate temperature control, resulting in a more uniform temperature of the raw material mixture within the fluidized bed and thus a higher purity product mixture. Because the microwave reactor has a smaller diameter, it allows for more flexible control of the production rate.
[0033] Specifically, the percentage content of camphene is equal to the percentage content of 1-methacrylic acid. The catalyst can be an ion exchange resin.
[0034] Preferably, the power of the microwave reactor is 200-400W.
[0035] Preferably, the reaction temperature in the microwave reactor is 40–45°C. Within this temperature range, the concentration of isobornyl methacrylate in the product mixture is the highest.
[0036] Preferably, the amount of the polymerization inhibitor added is 0.02% to 0.03% of the total weight of methacrylic acid and camphene. The polymerization inhibitor is used to prevent the polymerization reaction from occurring, thereby reducing the formation of by-products.
[0037] Preferably, the polymerization inhibitor is composed of phenothiazine and hydroquinone. The mass ratio of phenothiazine to hydroquinone in the polymerization inhibitor is 1:(1.5–2). The combined use of phenothiazine and hydroquinone can further enhance the polymerization inhibition effect.
[0038] Preferably, after fractionation, a polymerization inhibitor is immediately added to the uncooled raw material recovery liquid to prevent the recovered raw materials methacrylic acid and camphene from undergoing polymerization reaction at high temperatures.
[0039] Please see Figure 1 The second aspect of this invention provides a continuous preparation system for isobornyl methacrylate, used to implement the continuous preparation method of isobornyl methacrylate described above. The continuous preparation system includes a mixing device 1, a microwave reactor 2, a first heating device 3, a first fractionating column 4, a second heating device 5, and a second fractionating column 6 connected in sequence. A recovery tank 9 is connected to the top of the first fractionating column 4, and the recovery tank 9 is connected to the mixing device 1. A first storage tank 7 and a second storage tank 8 are also connected upstream of the mixing device 1. Specifically, the first storage tank 7 and the second storage tank 8 are used to store methacrylic acid and camphene, respectively. The first fractionating column 4 is used to separate the insufficiently reacted raw materials from the product mixture, and the recovered raw material liquid is stored in the recovery tank 9. The mixture at the bottom of the first fractionating column 4 is further fed to the second heating device 5 for further heating. The second fractionating column 6 is used to separate isobornyl methacrylate from the by-products. The isobornyl methacrylate is discharged from the top of the second fractionating column 6, while the by-product mixture is discharged from the bottom of the second fractionating column 6.
[0040] Please see Figure 2 The continuous preparation system for isobornyl methacrylate includes a microwave reactor 2 comprising a fluidized bed 21 and multiple microwave generators 22. The fluidized bed 21 comprises multiple sets of connecting pipes arranged in parallel. Each connecting pipe consists of multiple reaction tubes 211 connected in series, and each reaction tube 211 contains a catalyst. The reaction tubes 211 are vertically arranged, with their inlet at the bottom and their outlet at the top. The raw material mixture is transported from the bottom to the top of the reaction tube 211 and then discharged. During this process, the upward-flowing raw material mixture carries the catalyst upwards within the reaction tube 211, causing it to tumble and ensuring more thorough contact between the catalyst and the raw material. The fluidized bed 21, comprising multiple sets of connecting pipes, can compensate for insufficient production and allow for the reduction of some connecting pipes as needed. For ease of control of the connecting pipes, valves are installed at both the inlet and outlet ends of each connecting pipe. Specifically, a transfer pump is provided between the mixing device 1 and the microwave reactor 2. The optimal time range for the raw material mixture to pass through the microwave reactor 2 is 20 to 30 minutes. If the time is too long, it may result in excessive microwave radiation time, excessively high temperature, and increased by-products. If the time is too short, the heating temperature will not reach the optimal range.
[0041] Specifically, each reaction tube 211 is equipped with multiple microwave generators 22, and the operating power of the upstream microwave generator 22 is greater than that of the downstream microwave generator 22, so that the microwave radiation received by the raw material mixture is more stable as it gets closer to the optimal reaction temperature.
[0042] Please see Figure 3 The continuous preparation system for isobornyl methacrylate includes a reaction tube 211 with a partition 212 at the bottom and top, and the catalyst is disposed between the two partitions 212.
[0043] Example 1
[0044] A continuous preparation method for isobornyl methacrylate includes the following steps:
[0045] S001. Camphene and methacrylic acid are mixed evenly in a mass ratio of 1:0.8, and a polymerization inhibitor is added to obtain a raw material mixture; the amount of polymerization inhibitor added is 0.03% of the total weight of methacrylic acid and camphene; the polymerization inhibitor is composed of phenothiazine and hydroquinone, and the mass ratio of phenothiazine to hydroquinone is 1:1.7.
[0046] S002. The raw material mixture is conveyed to a microwave reactor, which includes a fluidized bed and multiple microwave generators. Catalyst particles are disposed within the fluidized bed. The residence time of the raw material mixture in the fluidized bed is 25 minutes. The raw material mixture reacts in the microwave reactor to obtain a product mixture. The fluidized bed includes multiple sets of connecting pipes, each set of connecting pipes connecting multiple reaction tubes in series. The multiple reaction tubes are divided into three groups: the microwave generator corresponding to the upstream reaction tubes has an operating power of 400W, the microwave generator corresponding to the midstream reaction tubes has an operating power of 300W, and the microwave generator corresponding to the downstream reaction tubes has an operating power of 200W. During operation, the temperature inside the reaction tubes rises to 40–45°C.
[0047] S003. The product mixture is fractionally distilled to obtain a raw material recovery liquid, isobornyl methacrylate finished product, and a by-product mixture; the raw material recovery liquid is composed of camphene and methacrylic acid;
[0048] S004. Determine the acidity of the raw material recovery liquid, calculate the content of methacrylic acid based on the acidity, and further calculate the mass ratio of camphene to methacrylic acid. Add camphene or methacrylic acid to make the mass ratio of camphene to methacrylic acid in the raw material recovery liquid the same as that in the raw material mixture. Add the raw material recovery liquid into the mixing device to recycle the raw material recovery liquid.
[0049] Example 2
[0050] A continuous preparation method for isobornyl methacrylate, which differs from Example 1 in that:
[0051] In S001, the mass ratio of camphene to methacrylic acid is 1:0.85, and the mass ratio of phenothiazine to hydroquinone is 1:2.
[0052] In S002, the residence time of the raw material mixture in the fluidized bed is 30 minutes.
[0053] Example 3
[0054] A continuous preparation method for isobornyl methacrylate, which differs from Example 1 in that:
[0055] In S001, the mass ratio of camphene to methacrylic acid is 1:0.8; the amount of polymerization inhibitor added is 0.03% of the total weight of methacrylic acid and camphene; and the mass ratio of phenothiazine to hydroquinone is 1:1.5.
[0056] In S002, the residence time of the raw material mixture in the fluidized bed is 25 minutes.
[0057] Comparative Example 1
[0058] A continuous preparation method for isobornyl methacrylate, which differs from Example 1 in that:
[0059] In S001, the mass ratio of phenothiazine to hydroquinone is 1:1.
[0060] Comparative Example 2
[0061] A continuous preparation method for isobornyl methacrylate, which differs from Example 1 in that:
[0062] In S001, the mass ratio of phenothiazine to hydroquinone is 1:2.5.
[0063] Comparative Example 3
[0064] A continuous preparation method for isobornyl methacrylate, which differs from Example 1 in that:
[0065] In S001, the amount of polymerization inhibitor added is 0.01% of the total weight of methacrylic acid and camphene.
[0066] The yield of the methacrylate product in the product mixture was determined, and the results are as follows:
[0067]
[0068] The results above show that the yields of isobornyl methacrylate in Examples 1-3 all reached over 84%, which is at least 5% higher than the existing reactor production process (where the yield of isobornyl methacrylate is 70%–79%). The increased yield of isobornyl methacrylate indicates both the formation of fewer byproducts and a higher conversion rate of the raw materials.
[0069] In Comparative Example 1, the mass ratio of phenothiazine to hydroquinone was lower than that in Examples 1-3. The results showed that the yield of isobornyl methacrylate was significantly reduced, indicating that a smaller mass ratio of phenothiazine to hydroquinone would affect the polymerization inhibition effect.
[0070] In Comparative Example 2, the mass ratio of phenothiazine to hydroquinone was greater than that in Examples 1-3. The results showed that the yield of isobornyl methacrylate was significantly reduced, indicating that a higher mass ratio of phenothiazine to hydroquinone can also affect the polymerization inhibition effect.
[0071] In Comparative Example 3, the amount of polymerization inhibitor added was less than that in Examples 1-3, and the yield of isobornyl methacrylate was also lower than that in Examples 1-3. When the amount of polymerization inhibitor added increased to 0.03%, the yield of isobornyl methacrylate did not increase significantly.
[0072] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.
Claims
1. A continuous preparation method for isobornyl methacrylate, characterized in that, Includes the following steps: Camphene and methacrylic acid in a mass ratio of 1:0.8 are mixed evenly, and a polymerization inhibitor is added. The amount of the polymerization inhibitor added is 0.02% to 0.03% of the total weight of methacrylic acid and camphene. The polymerization inhibitor is composed of phenothiazine and hydroquinone in a mass ratio of 1:1.7 to obtain a raw material mixture. The raw material mixture is fed into a microwave reactor for reaction to obtain a product mixture. The microwave reactor includes a fluidized bed and multiple microwave generators. The fluidized bed includes multiple sets of connecting pipes arranged in parallel. Each connecting pipe is composed of multiple reaction tubes connected in series, and catalyst particles are placed inside each reaction tube. The reaction tubes are vertically arranged, with their inlet end at the bottom and their outlet end at the top. Partitions are provided at the bottom and top of each reaction tube, and the catalyst is placed between two partitions. The residence time of the raw material mixture in the fluidized bed is 20–30 minutes. The product mixture is fractionated, and immediately after fractionation, a polymerization inhibitor is added to the uncooled raw material recovery liquid to obtain the raw material recovery liquid, isobornyl methacrylate product, and a mixture of by-products; the raw material recovery liquid is composed of camphene and methacrylic acid. The acidity of the raw material recovery liquid is measured, the content of methacrylic acid is calculated based on the acidity, and the mass ratio of camphene to methacrylic acid is further calculated. Camphene or methacrylic acid is added to make the mass ratio of camphene to methacrylic acid in the raw material recovery liquid the same as that in the raw material mixture, and the raw material recovery liquid is recycled.
2. The continuous preparation method of isobornyl methacrylate according to claim 1, characterized in that, The power of the microwave reactor is 200-400W.
3. The continuous preparation method of isobornyl methacrylate according to claim 1, characterized in that, The reaction temperature in the microwave reactor is 40–45°C.