A method for synthesizing photoinitiator 2,4-diethylthioxanthone by one-pot

Abstract

The application discloses a one-pot synthesis method of a photoinitiator 2,4-diethylthioxanthone, and relates to the technical field of fine chemical industry. The one-pot synthesis method of the photoinitiator 2,4-diethylthioxanthone is realized by a 2,4-diethylthioxanthone production device. The 2,4-diethylthioxanthone production device comprises a reaction kettle, a cooling chamber is arranged in the reaction kettle, and a driving trigger mechanism is arranged in the reaction kettle. The application can more quickly complete the feeding process of 1,3-diethylbenzene, meanwhile, the heat generated when a large amount of 1,3-diethylbenzene is added is avoided to influence the normal progress of the reaction process, the industrialized preparation efficiency of the 2,4-diethylthioxanthone is improved, and the application is more suitable for the industrialized preparation of the 2,4-diethylthioxanthone.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, and in particular to a one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthrone. Background Technology

[0002] Thioxanthone compounds are commonly used as photoinitiators or activators for radiation-cured or radiation-crosslinked unsaturated compounds, and have a wide range of applications in the fields of UV-curable inks, coatings and adhesives. Among them, 2,4-diethylthioxanthone is the most common, with the molecular formula C17H16OS. It is a pale yellow crystalline powder and is mainly used in UV-curable coatings and inks.

[0003] In actual production, 2,4-diethylthioxanthrone is mainly produced using thiosalicylic acid or dithiosalicylic acid in combination with 1,3-diethylbenzene as raw material. Concentrated sulfuric acid is used as solvent and catalyst, and a condensation reaction is carried out in the presence of a co-catalyst. After the reaction is complete, the product is extracted by adding an organic solvent, washed and concentrated, and finally recrystallized to obtain the target product 2,4-diethylthioxanthrone.

[0004] However, after practical application by those skilled in the art, the above preparation method still has some drawbacks. The most obvious one is that when adding 1,3-diethylbenzene, technicians often need to use a dropwise addition method. Since 1,3-diethylbenzene is the main raw material and the amount used is large, it takes a long time to complete the addition of 1,3-diethylbenzene, which has a significant impact on the industrial preparation efficiency of 2,4-diethylthioxanthrone.

[0005] In response to the above situation, those skilled in the art have considered using a large-scale, multiple-droplet feeding method for 1,3-diethylbenzene. However, during the feeding process, the mixed reaction solution will experience a significant temperature rise, which will prevent the reaction from proceeding normally and increase the difficulty of the reaction.

[0006] Therefore, it is necessary to invent a one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthrone to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide a one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthrone, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthonone, wherein the one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthonone is implemented using a 2,4-diethylthioxanthonone production device, the 2,4-diethylthioxanthonone production device including a reaction vessel, the reaction vessel having a cooling chamber inside, a drive triggering mechanism being provided inside the reaction vessel, and a 1,3-diethylbenzene storage mechanism and a trigger-type flow divider being arranged sequentially from top to bottom outside the drive triggering mechanism, and a mixing and cooling mechanism being provided at the bottom of the trigger-type flow divider;

[0009] The drive triggering mechanism includes a drive shaft, a drive motor, an ice-salt water output port, an ice-salt water return hose, a lifting plate, a guide shaft, a pressure plate, and an ice-salt water diversion pipe.

[0010] The drive shaft passes through the reactor and is rotatably connected to the reactor via bearings. The drive motor is fixedly installed on the left side of the bottom of the reactor and is connected to the drive shaft. The brine outlet is located at the top front of the drive shaft. Two brine return hoses are provided, which are respectively fixedly installed through the bottom front and bottom back of the drive shaft. The lifting plate is sleeved on the outside of the drive shaft and is connected to the drive shaft via reciprocating threads. Two guide shafts are provided, which are respectively fixedly installed on both sides of the top of the lifting plate. The pressure plate is slidably sleeved on the outside of the drive shaft and fixedly installed at the top of the two guide shafts. The first output end of the brine distributor is fixedly installed through the side wall of the reactor and connected to the cooling chamber. The second output end of the brine distributor is connected to the bottom end of the drive shaft via a rotary joint.

[0011] Preferably, the 1,3-diethylbenzene storage mechanism includes a storage box, an annular channel, an annular connecting plate, and a discharge pipe.

[0012] Preferably, the storage box is fixedly installed at the top of the inner cavity of the reactor and is rotatably sleeved on the outside of the drive shaft via a bearing. The pressure plate is slidably installed inside the storage box in the vertical direction. The annular channel is opened at the bottom of the inner cavity of the storage box. The annular connecting plate is rotatably nested at the bottom of the storage box via a bearing. There are two discharge pipes. The two discharge pipes are fixedly installed through both sides of the bottom of the annular connecting plate and are connected to the inner cavity of the storage box via the annular channel.

[0013] Preferably, the trigger-type diversion mechanism includes a rotary lifting seat, a first diversion chamber, an annular sealing plate, a second diversion chamber, a sealing sleeve, a first spring, a fixed sleeve, a sliding rod, and a limiting sleeve.

[0014] Preferably, the rotary lifting seat is slidably sleeved on the outside of the drive shaft, the first diversion cavity is opened at the top of the rotary lifting seat, the annular sealing plate is rotatably nested on the top of the inner side of the first diversion cavity via a bearing, the two discharge pipes slide through the top two sides of the annular sealing plate respectively, and both extend to the bottom of the inner cavity of the first diversion cavity, the second diversion cavity is opened inside the rotary lifting seat, the sealing sleeve is fixedly installed at the bottom of the rotary lifting seat and slidably sleeved on the outside of the drive shaft, the first spring is sleeved on the outside of the sealing sleeve, the fixed sleeve is fixedly sleeved on the outside of the drive shaft, the first spring is located between the rotary lifting seat and the fixed sleeve, the sliding rod is fixedly installed on the inner side of the rotary lifting seat, and the limiting sleeve is slidably sleeved on the outside of the sliding rod and fixedly nested on the drive shaft.

[0015] Preferably, the mixing and cooling mechanism includes two sets of mixing components, an annular pad, and a cooling enhancement tube. The two sets of mixing components are respectively disposed on both sides of the bottom of the rotating lifting seat. Each mixing component includes a mixing tube, a dispersion hole, a sealing rod, a T-shaped channel, two connecting sleeves, and a second spring.

[0016] Preferably, the mixing tube is fixedly installed through the bottom of the rotary lifting seat and communicates with the first diversion chamber. Multiple dispersion holes are provided, evenly distributed on the outer bottom of the mixing tube. The sealing rod is slidably installed on the inner bottom of the mixing tube. The T-shaped channel is located inside the sealing rod. Two connecting sleeves are provided, fixedly fitted onto the outer bottom of the mixing tube and the outer bottom of the sealing rod, respectively. The second spring is fitted onto the outer side of the sealing rod and fixedly connected to both connecting sleeves. The annular pad is rotatably nested in the bottom of the reactor cavity via a bearing. Two cooling enhancement tubes are provided, fixedly installed through the front and rear sides of the bottom of the rotary lifting seat, respectively, and both communicate with the second diversion chamber. The cooling enhancement tubes are connected to the drive shaft via adjacent ice-salt water return hoses.

[0017] Preferably, the method specifically includes the following steps:

[0018] S1. Add concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid into the reactor. Add 1,3-diethylbenzene into the storage tank. Inject ice-salt water through the ice-salt water distribution pipe. The ice-salt water enters the cooling chamber through the first output end of the ice-salt water distribution pipe and enters the drive shaft through the second output end of the ice-salt water distribution pipe. Since the ice-salt water output hole is blocked by the sealing sleeve, the ice-salt water stays inside the drive shaft.

[0019] S2. Start the drive motor. After the drive motor starts, it drives the drive shaft to rotate. When the drive shaft rotates, it drives the rotating lifting seat to rotate synchronously through the sliding rod and the limit sleeve. When the rotating lifting seat rotates, it mixes concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid through the mixing tube.

[0020] S3. During the rotation of the drive shaft, the lifting plate is driven to descend continuously. When the lifting plate descends, it drives the pressure plate to descend synchronously through the guide shaft. When the pressure plate descends inside the storage box, it pressurizes the inner cavity of the storage box. The 1,3-diethylbenzene inside the storage box enters the discharge pipe through the annular channel. The bottom opening of the discharge pipe is blocked by the inner wall of the first diversion chamber. At this time, the 1,3-diethylbenzene inside the discharge pipe cannot be discharged.

[0021] S4. When the lifting plate descends to the first threshold, the bottom of the lifting plate is in contact with the top of the rotating lifting seat. As the lifting plate continues to descend, the rotating lifting seat descends along the drive shaft and compresses the first spring. When the rotating lifting seat descends, it drives the mixing tube to descend synchronously. After the mixing tube descends, the connecting sleeve plate below is pushed by the annular pad, which in turn drives the sealing rod to rise and seal the bottom opening of the mixing tube.

[0022] S5. Simultaneously, as the rotating lifting seat descends, the inner wall of the first diversion chamber gradually releases the seal on the bottom opening of the feed pipe. At this time, the 1,3-diethylbenzene inside the storage tank quickly enters the first diversion chamber through the feed pipe under pressure, then enters the mixing pipe and is ejected through multiple dispersion holes, and then is evenly mixed into the mixed solution of concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid.

[0023] S6. When the lifting plate descends to the second threshold, the ice-salt water output hole enters the inner side of the second diversion chamber. At this time, the ice-salt water inside the drive shaft is input into the second diversion chamber and then into the two cooling enhancement tubes respectively. As the rotating lifting seat continues to rotate, the two cooling enhancement tubes that are continuously cooled by the ice-salt water continue to rotate in the mixed solution, thereby cooling the mixed solution. The excess ice-salt water inside the cooling enhancement tubes is returned to the drive shaft through the ice-salt water return hose and then output by the drive shaft.

[0024] S7. When the lifting plate descends to the third threshold, the lifting plate moves to the lowest end of the reciprocating thread on the outside of the drive shaft. As the drive shaft continues to rotate, the lifting plate gradually moves up and resets. When the lifting plate rises to the fourth threshold, all the 1,3-diethylbenzene in the storage tank has been added. At the same time, the reset rotating lifting seat also drives the sealing sleeve to seal the ice-salt water output hole again. At this time, the input of ice-salt water to the ice-salt water distribution pipe is stopped, and the mixed solution is allowed to heat up naturally.

[0025] S8. During the natural heating process of the mixed solution, the drive shaft continues to drive the mixing tube and the cooling enhancement tube to stir the mixed solution through the rotating lifting seat. After the natural heating is completed, the mixed solution is heated by the electric heating element inside the reactor until the dithiosalicylic acid reaction is complete.

[0026] S9. Ice-salt water is introduced again through the ice-salt water diversion pipe. Then, a mixture of 1,3-diethylbenzene and water is added into the storage tank. Driven by the drive shaft, the mixture of 1,3-diethylbenzene and water is once again evenly added to the mixed solution and continuously mixed under the action of the mixing pipe and the cooling enhancement pipe. During the mixing process, the cooling enhancement pipe works with the cooling chamber to cool the mixture.

[0027] S10. After mixing, the mixed solution inside the reactor is output. After the mixed solution is output, it is allowed to stand and separate into phases. The organic phase is concentrated after being washed with alkali and water, and then cooled and allowed to stand. The concentrated solution is then filtered. The filter cake is washed with a small amount of ice-cold ethanol and then vacuum dried to obtain the finished product.

[0028] The technical effects and advantages of this invention are as follows:

[0029] This invention incorporates a drive triggering mechanism, a 1,3-diethylbenzene storage mechanism, a trigger-type diversion mechanism, and a mixing and cooling mechanism. The drive triggering mechanism simultaneously drives the rotation and elevation of the trigger-type diversion mechanism while pressurizing the 1,3-diethylbenzene storage mechanism. The rotation of the trigger-type diversion mechanism drives the mixing and cooling mechanism to continuously mix the solution. During elevation, the 1,3-diethylbenzene storage mechanism and the drive triggering mechanism work together to input 1,3-diethylbenzene and ice-salt water into the mixing and cooling mechanism. Finally, 1,3-diethylbenzene is rapidly and uniformly added to the mixed solution through the mixing and cooling mechanism. In this process, the ice-salt water continuously cools the mixed solution from within the mixing and cooling mechanism during the addition of 1,3-diethylbenzene and the mixing of the solution. This cools the solution and counteracts the heat generated during the reaction of 1,3-diethylbenzene. Compared to similar devices or methods in the prior art, this invention can complete the addition process of 1,3-diethylbenzene more quickly, while avoiding the heat generated when adding large amounts of 1,3-diethylbenzene from affecting the normal progress of the reaction. This improves the industrial preparation efficiency of 2,4-diethylthioxanthrone and is more suitable for the industrial preparation of 2,4-diethylthioxanthrone. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall front cross-sectional structure of the present invention.

[0031] Figure 2 This is a front cross-sectional view of a portion of the drive triggering mechanism and the mixing and cooling mechanism of the present invention.

[0032] Figure 3 This is a front cross-sectional view of a portion of the drive triggering mechanism and the 1,3-diethylbenzene storage mechanism of the present invention.

[0033] Figure 4 This is a partial front cross-sectional view of the drive triggering mechanism and the trigger-type diversion mechanism of the present invention.

[0034] Figure 5 This is a bottom view of the trigger-type flow splitting mechanism and the mixing and cooling mechanism of the present invention.

[0035] In the diagram: 1. Reactor; 2. Cooling chamber; 3. Drive triggering mechanism; 31. Drive shaft; 32. Drive motor; 33. Ice-salt water output port; 34. Ice-salt water return hose; 35. Lifting plate; 36. Guide shaft; 37. Pressure boosting plate; 38. Ice-salt water diversion pipe; 4. 1,3-Diethylbenzene storage mechanism; 41. Storage box; 42. Annular channel; 43. Annular connecting plate; 44. Feed pipe; 5. Trigger-type diversion mechanism; 51. Rotary lifting seat; 52. First diversion chamber; 53. Annular sealing plate; 54. Second diversion chamber; 55. Sealing sleeve; 56. First spring; 57. Fixed sleeve; 58. Sliding rod; 59. Limiting sleeve; 6. Mixing and cooling mechanism; 61. Mixing pipe; 62. Dispersion hole; 63. Sealing rod; 64. T-shaped channel; 65. Connecting sleeve; 66. Second spring; 67. Annular pad; 68. Cooling enhancement pipe. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] This invention provides, for example Figure 1 -5 shows a one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthonone. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthonone is realized by a 2,4-diethylthioxanthonone production device. The 2,4-diethylthioxanthonone production device includes a reactor 1, a cooling chamber 2 inside the reactor 1, a drive triggering mechanism 3 inside the reactor 1, and a 1,3-diethylbenzene storage mechanism 4 and a trigger-type flow divider 5 arranged sequentially from top to bottom outside the drive triggering mechanism 3. A mixing and cooling mechanism 6 is arranged at the bottom of the trigger-type flow divider 5.

[0039] like Figure 2 - Figure 5 As shown, the drive triggering mechanism 3 includes a drive shaft 31, a drive motor 32, an ice-salt water output port 33, an ice-salt water return hose 34, a lifting plate 35, a guide shaft 36, a pressure plate 37, and an ice-salt water distribution pipe 38. The drive shaft 31 passes through the reactor 1 and is rotatably connected to the reactor 1 via a bearing. The drive motor 32 is fixedly located on the bottom left side of the reactor 1 and is drive-connected to the drive shaft 31. The ice-salt water output port 33 is located on the top front of the drive shaft 31. Two ice-salt water return hoses 34 are provided, each fixedly passing through the drive shaft 35. The driving shaft 31 has a front bottom and a back bottom. The lifting plate 35 is sleeved on the outside of the driving shaft 31 and is connected to the driving shaft 31 through a reciprocating thread. There are two guide shafts 36, which are respectively fixed on the top two sides of the lifting plate 35. The pressure plate 37 is slidably sleeved on the outside of the driving shaft 31 and fixed on the top of the two guide shafts 36. The first output end of the ice-salt water diversion pipe 38 is fixedly installed through the side wall of the reactor 1 and connected to the cooling chamber 2. The second output end of the ice-salt water diversion pipe 38 is connected to the bottom end of the driving shaft 31 through a rotary joint.

[0040] It should also be noted that the drive shaft 31 has two chambers inside, an upper chamber connected to the ice-salt water output port 33 and a lower chamber connected to the ice-salt water return hose 34. The two chambers are not interconnected.

[0041] like Figure 3 As shown, the 1,3-diethylbenzene storage mechanism 4 includes a storage box 41, an annular channel 42, an annular connecting plate 43, and a discharge pipe 44. The storage box 41 is fixedly installed at the top of the inner cavity of the reactor 1 and is rotatably sleeved on the outside of the drive shaft 31 via a bearing. The pressure plate 37 is slidably installed inside the storage box 41 in the vertical direction. The annular channel 42 is opened at the bottom of the inner cavity of the storage box 41. The annular connecting plate 43 is rotatably nested at the bottom of the storage box 41 via a bearing. There are two discharge pipes 44, which are fixedly installed through both sides of the bottom of the annular connecting plate 43 and are connected to the inner cavity of the storage box 41 via the annular channel 42.

[0042] By setting up the aforementioned drive trigger mechanism 3 and 1,3-diethylbenzene storage mechanism 4, when the drive motor 32 drives the drive shaft 31 to rotate, the drive shaft 31 can drive the lifting plate 35 to continuously descend. When the lifting plate 35 descends, it drives the pressure plate 37 to continuously descend inside the storage box 41 through the guide shaft 36, thereby increasing the pressure inside the storage box 41. Subsequently, when the feed pipe 44 is no longer blocked, the 1,3-diethylbenzene inside the storage box 41 is quickly output through the feed pipe 44 under the pressure inside the storage box 41, thereby accelerating the output efficiency of 1,3-diethylbenzene.

[0043] like Figure 4 and Figure 5 As shown, the trigger-type diversion mechanism 5 includes a rotary lifting seat 51, a first diversion cavity 52, an annular sealing plate 53, a second diversion cavity 54, a sealing sleeve 55, a first spring 56, a fixed sleeve 57, a sliding rod 58, and a limiting sleeve 59. The rotary lifting seat 51 is slidably sleeved on the outside of the drive shaft 31. The first diversion cavity 52 is located at the top of the rotary lifting seat 51. The annular sealing plate 53 is rotatably nested within the top of the first diversion cavity 52 via a bearing. The two discharge pipes 44 slidably penetrate the top two sides of the annular sealing plate 53 and extend to the first diversion cavity. The second diversion cavity 54 is opened inside the rotary lifting seat 51 at the bottom of the cavity 52. ​​The sealing sleeve 55 is fixedly installed at the bottom of the rotary lifting seat 51 and slidably sleeved on the outside of the drive shaft 31. The first spring 56 is sleeved on the outside of the sealing sleeve 55. The fixed sleeve 57 is fixedly sleeved on the outside of the drive shaft 31. The first spring 56 is located between the rotary lifting seat 51 and the fixed sleeve 57. The sliding rod 58 is fixedly installed inside the rotary lifting seat 51. The limiting sleeve 59 is slidably sleeved on the outside of the sliding rod 58 and fixedly nested on the drive shaft 31.

[0044] By setting the above structure, the drive shaft 31 can drive the rotary lifting seat 51 to rotate synchronously through the sliding rod 58 and the limiting sleeve 59. When the rotary lifting seat 51 rotates, it can drive the mixing and cooling mechanism 6 to rotate synchronously, thereby mixing the mixed solution. At the same time, when the rotary lifting seat 51 is pressed down, the rotary lifting seat 51 compresses the first spring 56, and at the same time, the inner wall of the first diversion cavity 52 releases the blockage of the bottom opening of the feed pipe 44. At this time, the 1,3-diethylbenzene inside the storage box 41 can enter the first diversion cavity 52 through the feed pipe 44, and then be input into the mixing and cooling mechanism 6 from the first diversion cavity 52.

[0045] like Figure 2 and Figure 5As shown, the mixing and cooling mechanism 6 includes two sets of mixing components, an annular pad 67, and a cooling enhancement tube 68. The two sets of mixing components are respectively disposed on both sides of the bottom of the rotary lifting seat 51. Each mixing component includes a mixing tube 61, a dispersion hole 62, a sealing rod 63, a T-shaped channel 64, two connecting sleeves 65, and a second spring 66. The mixing tube 61 is fixedly disposed through the bottom of the rotary lifting seat 51 and communicates with the first diversion chamber 52. Multiple dispersion holes 62 are provided, and the multiple dispersion holes 62 are evenly opened on the bottom outer side of the mixing tube 61. The sealing rod 63 is slidably disposed on the bottom inner side of the mixing tube 61. The T-shaped channel 64 is opened on the sealing rod 61. Inside the reactor 1, there are two connecting sleeves 65. The two connecting sleeves 65 are fixedly sleeved on the bottom outer side of the mixing tube 61 and the bottom outer side of the sealing rod 63, respectively. The second spring 66 is sleeved on the outside of the sealing rod 63 and fixedly connected to the two connecting sleeves 65. The annular pad 67 is rotatably nested in the bottom of the reactor 1 through a bearing. There are two cooling enhancement tubes 68. The two cooling enhancement tubes 68 are fixedly inserted through the bottom front side and the bottom rear side of the rotating lifting seat 51, respectively, and are both connected to the second diversion chamber 54. The cooling enhancement tubes 68 are connected to the drive shaft 31 through the adjacent ice-salt water return hose 34.

[0046] By setting the above structure, when the rotating lifting seat 51 rotates, it can drive the two mixing tubes 61 and the two cooling enhancement tubes 68 to rotate synchronously, thereby mixing the reaction solution. At the same time, when the rotating lifting seat 51 descends, it can drive the mixing tubes 61 to descend synchronously. At this time, due to the obstruction of the annular pad 67, the connecting sleeve 65 located below pushes the sealing rod 63, thereby causing the sealing rod 63 to move upward and block the bottom opening of the mixing tube 61. This ensures that the 1,3-diethylbenzene entering the mixing tube 61 can only be output through multiple dispersion holes 62, and cannot be directly output through the bottom opening of the mixing tube 61, thus ensuring the uniformity of the 1,3-diethylbenzene output.

[0047] When the mixed solution inside the reactor 1 is output, since the mixing tube 61 has been reset, the second spring 66 drives the sealing rod 63 to reset synchronously. At this time, the mixed solution remaining inside the mixing tube 61 can be discharged synchronously through the T-shaped channel 64, thereby preventing the mixed solution from remaining.

[0048] Example 2

[0049] The method specifically includes the following steps:

[0050] S1. Add concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid into the reactor 1, add 1,3-diethylbenzene into the storage tank 41, inject ice-salt water through the ice-salt water diversion pipe 38, the ice-salt water enters the cooling chamber 2 through the first output end of the ice-salt water diversion pipe 38, and enters the drive shaft 31 through the second output end of the ice-salt water diversion pipe 38. Since the ice-salt water output hole 33 is blocked by the sealing sleeve 55, the ice-salt water stays inside the drive shaft 31.

[0051] S2. Start the drive motor 32. After the drive motor 32 starts, it drives the drive shaft 31 to rotate. When the drive shaft 31 rotates, it drives the rotating lifting seat 51 to rotate synchronously through the sliding rod 58 and the limiting sleeve 59. When the rotating lifting seat 51 rotates, it mixes concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid through the mixing tube 61.

[0052] S3. During the rotation of the drive shaft 31, the lifting plate 35 is driven to descend continuously. When the lifting plate 35 descends, it drives the pressure plate 37 to descend synchronously through the guide shaft 36. When the pressure plate 37 descends inside the storage box 41, it pressurizes the inner cavity of the storage box 41. The 1,3-diethylbenzene inside the storage box 41 enters the discharge pipe 44 through the annular channel 42. The bottom opening of the discharge pipe 44 is blocked by the inner wall of the first diversion chamber 52. At this time, the 1,3-diethylbenzene inside the discharge pipe 44 cannot be discharged.

[0053] S4. When the lifting plate 35 descends to the first threshold, the bottom of the lifting plate 35 is in contact with the top of the rotating lifting seat 51. As the lifting plate 35 continues to descend, the rotating lifting seat 51 descends along the drive shaft 31 and compresses the first spring 56. When the rotating lifting seat 51 descends, it drives the mixing tube 61 to descend synchronously. After the mixing tube 61 descends, the connecting sleeve 65 located below is pushed by the annular pad 67, which in turn drives the sealing rod 63 to rise and seal the bottom opening of the mixing tube 61.

[0054] S5. Simultaneously, as the rotating lifting seat 51 descends, the inner wall of the first diversion chamber 52 gradually releases the seal on the bottom opening of the feed pipe 44. At this time, the 1,3-diethylbenzene inside the storage box 41 quickly enters the first diversion chamber 52 through the feed pipe 44 under pressure, then enters the mixing pipe 61 and is ejected through multiple dispersion holes 62, and then is evenly mixed into the mixed solution of concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid.

[0055] S6. When the lifting plate 35 descends to the second threshold, the ice-salt water output hole 33 enters the inner side of the second diversion chamber 54. At this time, the ice-salt water inside the drive shaft 31 is input into the second diversion chamber 54, and then input into the two cooling enhancement tubes 68 respectively. As the rotating lifting seat 51 continues to rotate, the two cooling enhancement tubes 68, which are continuously cooled by ice-salt water, continue to rotate in the mixed solution, thereby cooling the mixed solution. The excess ice-salt water inside the cooling enhancement tubes 68 is returned to the drive shaft 31 through the ice-salt water return hose 34, and then output by the drive shaft 31.

[0056] S7. When the lifting plate 35 descends to the third threshold, the lifting plate 35 moves to the lowest end of the reciprocating thread on the outside of the drive shaft 31. As the drive shaft 31 continues to rotate, the lifting plate 35 gradually moves up and resets. When the lifting plate 35 rises to the fourth threshold, all the 1,3-diethylbenzene in the storage box 41 has been added. At the same time, the reset rotating lifting seat 51 also drives the sealing sleeve 55 to seal the ice-salt water output hole 33 again. At this time, the input of ice-salt water to the ice-salt water diversion pipe 38 is stopped, and the mixed solution is allowed to heat up naturally.

[0057] S8. During the natural heating process of the mixed solution, the drive shaft 31 continues to drive the mixing tube 61 and the cooling enhancement tube 68 to stir the mixed solution through the rotating lifting seat 51. After the natural heating is completed, the electric heating element inside the reaction vessel 1 is used to heat the mixed solution until the dithiosalicylic acid reaction is complete.

[0058] S9. Ice-salt water is introduced again through the ice-salt water diversion pipe 38. Then, a mixture of 1,3-diethylbenzene and water is added into the storage tank 41. Driven by the drive shaft 31, the mixture of 1,3-diethylbenzene and water is once again uniformly added to the mixed solution and continuously mixed under the action of the mixing pipe 61 and the cooling enhancement pipe 68. During the mixing process, the cooling enhancement pipe 68 works with the cooling chamber 2 to cool the mixed solution.

[0059] S10. After mixing, the mixed solution inside reactor 1 is output. After the mixed solution is output, it is allowed to stand and separate into phases. The organic phase is concentrated after being washed with alkali and water, and then cooled and allowed to stand. The concentrated solution is then filtered. The filter cake is washed with a small amount of ice-cold ethanol and then vacuum dried to obtain the finished product.

[0060] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A one-pot method for synthesizing the photoinitiator 2,4-diethylthioxanthrone, characterized in that: The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthonone is achieved through a 2,4-diethylthioxanthonone production equipment, which includes a reactor (1), a cooling chamber (2) inside the reactor (1), a drive triggering mechanism (3) inside the reactor (1), and a 1,3-diethylbenzene storage mechanism (4) and a trigger-type flow divider mechanism (5) arranged sequentially from top to bottom on the outside of the drive triggering mechanism (3). A mixing and cooling mechanism (6) is arranged at the bottom of the trigger-type flow divider mechanism (5). The drive triggering mechanism (3) includes a drive shaft (31), a drive motor (32), an ice-salt water output hole (33), an ice-salt water return hose (34), a lifting plate (35), a guide shaft (36), a pressure plate (37), and an ice-salt water diversion pipe (38). The drive shaft (31) passes through the reactor (1) and is rotatably connected to the reactor (1) via a bearing. The drive motor (32) is fixedly installed on the bottom left side of the reactor (1) and is connected to the drive shaft (31) for transmission. The ice-salt water output port (33) is opened on the top front of the drive shaft (31). Two ice-salt water return hoses (34) are provided. The two ice-salt water return hoses (34) are fixedly installed through the bottom front and bottom back of the drive shaft (31) respectively. The lifting plate (35) is sleeved on the outside of the drive shaft (31) and is connected to the drive shaft (31) via a bearing. The reciprocating thread is connected to the drive shaft (31) for transmission. There are two guide shafts (36). The two guide shafts (36) are respectively fixed on the top two sides of the lifting plate (35). The pressure plate (37) is slidably sleeved on the outside of the drive shaft (31) and fixed on the top of the two guide shafts (36). The first output end of the ice-salt water diversion pipe (38) is fixedly installed through the side wall of the reactor (1) and connected to the cooling chamber (2). The second output end of the ice-salt water diversion pipe (38) is connected to the bottom end of the drive shaft (31) through a rotary joint. The 1,3-diethylbenzene storage mechanism (4) includes a storage box (41), an annular channel (42), an annular connecting plate (43), and a discharge pipe (44). The storage box (41) is fixedly installed at the top of the inner cavity of the reactor (1) and is rotatably sleeved on the outside of the drive shaft (31) via a bearing. The pressure plate (37) is slidably installed in the storage box (41) in the vertical direction. The annular channel (42) is opened at the bottom of the inner cavity of the storage box (41). The annular connecting plate (43) is rotatably nested at the bottom of the storage box (41) via a bearing. There are two feeding pipes (44). The two feeding pipes (44) are fixedly installed through the bottom sides of the annular connecting plate (43) and are connected to the inner cavity of the storage box (41) via the annular channel (42).

2. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthrone according to claim 1, characterized in that: The trigger-type diversion mechanism (5) includes a rotary lifting seat (51), a first diversion chamber (52), an annular sealing plate (53), a second diversion chamber (54), a sealing sleeve (55), a first spring (56), a fixed sleeve (57), a sliding rod (58), and a limiting sleeve (59).

3. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthone according to claim 2, characterized in that: The rotary lifting seat (51) is slidably sleeved on the outside of the drive shaft (31). The first diversion cavity (52) is opened on the top of the rotary lifting seat (51). The annular sealing plate (53) is rotatably nested on the top of the inner side of the first diversion cavity (52) through a bearing. The two discharge pipes (44) slide through the top two sides of the annular sealing plate (53) respectively, and both extend to the bottom of the inner cavity of the first diversion cavity (52). The second diversion cavity (54) is opened inside the rotary lifting seat (51). The sealing sleeve (55) is fixedly installed on the rotary lifting seat (51). The bottom of the rotating lifting seat (51) is slidably sleeved on the outside of the drive shaft (31), the first spring (56) is sleeved on the outside of the sealing sleeve (55), the fixed sleeve (57) is fixedly sleeved on the outside of the drive shaft (31), the first spring (56) is located between the rotating lifting seat (51) and the fixed sleeve (57), the sliding rod (58) is fixedly sleeved on the inside of the rotating lifting seat (51), and the limiting sleeve (59) is slidably sleeved on the outside of the sliding rod (58) and fixedly nested on the drive shaft (31).

4. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthone according to claim 3, characterized in that: The mixing and cooling mechanism (6) includes two sets of mixing components, an annular pad (67) and a cooling enhancement tube (68). The two sets of mixing components are respectively arranged on both sides of the bottom of the rotating lifting seat (51). Each mixing component includes a mixing tube (61), a dispersion hole (62), a sealing rod (63), a T-shaped channel (64), two connecting sleeves (65) and a second spring (66).

5. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthrone according to claim 4, characterized in that: The mixing tube (61) is fixedly installed through the bottom of the rotating lifting seat (51) and communicates with the first diversion chamber (52). Multiple dispersion holes (62) are provided, evenly distributed on the outer bottom of the mixing tube (61). The sealing rod (63) is slidably installed on the inner bottom of the mixing tube (61). The T-shaped channel (64) is located inside the sealing rod (63). Two connecting sleeves (65) are provided, respectively fixedly sleeved on the outer bottom of the mixing tube (61) and the outer bottom of the sealing rod (63). The second spring (66) is sleeved on the outside of the closed rod (63) and fixedly connected to the two connecting sleeves (65) respectively. The annular pad (67) is nested in the bottom of the inner cavity of the reactor (1) through the bearing. There are two cooling enhancement tubes (68). The two cooling enhancement tubes (68) are fixedly installed through the front side of the bottom of the rotating lifting seat (51) and the rear side of the bottom of the rotating lifting seat (51) respectively, and both are connected to the second diversion chamber (54). The cooling enhancement tubes (68) are connected to the drive shaft (31) through the adjacent ice-salt water return hose (34).

6. The one-pot synthesis method for the photoinitiator 2,4-diethylthioxanthone according to claim 5, characterized in that, The method specifically includes the following steps: S1. Add concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid into the reactor (1), add 1,3-diethylbenzene into the storage tank (41), inject ice-salt water through the ice-salt water distribution pipe (38), the ice-salt water enters the cooling chamber (2) through the first output end of the ice-salt water distribution pipe (38), and enters the drive shaft (31) through the second output end of the ice-salt water distribution pipe (38). Since the ice-salt water output hole (33) is blocked by the sealing sleeve (55), the ice-salt water stays inside the drive shaft (31). S2. Start the drive motor (32). After the drive motor (32) starts, it drives the drive shaft (31) to rotate. When the drive shaft (31) rotates, it drives the rotating lifting seat (51) to rotate synchronously through the sliding rod (58) and the limiting sleeve (59). When the rotating lifting seat (51) rotates, it mixes concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid through the mixing tube (61). S3. During the rotation of the drive shaft (31), the lifting plate (35) is driven to descend continuously. When the lifting plate (35) descends, the pressure plate (37) is driven to descend synchronously through the guide shaft (36). When the pressure plate (37) descends inside the storage box (41), it pressurizes the inner cavity of the storage box (41). The 1,3-diethylbenzene inside the storage box (41) enters the discharge pipe (44) through the annular channel (42). The bottom opening of the discharge pipe (44) is blocked by the inner wall of the first diversion chamber (52). At this time, the 1,3-diethylbenzene inside the discharge pipe (44) cannot be discharged. S4. When the lifting plate (35) descends to the first threshold, the bottom of the lifting plate (35) is in contact with the top of the rotating lifting seat (51). As the lifting plate (35) continues to descend, the rotating lifting seat (51) descends along the drive shaft (31) and compresses the first spring (56). When the rotating lifting seat (51) descends, it drives the mixing tube (61) to descend synchronously. After the mixing tube (61) descends, the connecting sleeve (65) located below is pushed by the annular pad (67), which in turn drives the sealing rod (63) to rise and seal the bottom opening of the mixing tube (61). S5. Simultaneously, as the rotating lifting seat (51) descends, the inner wall of the first diversion chamber (52) gradually releases the seal on the bottom opening of the feed pipe (44). At this time, the 1,3-diethylbenzene inside the storage box (41) quickly enters the first diversion chamber (52) under pressure through the feed pipe (44), then enters the mixing pipe (61) and is ejected through multiple dispersion holes (62), and then is evenly mixed into the mixed solution of concentrated sulfuric acid, dithiosalicylic acid and polyphosphoric acid. S6. When the lifting plate (35) descends to the second threshold, the ice-salt water output hole (33) enters the inner side of the second diversion chamber (54). At this time, the ice-salt water inside the drive shaft (31) is input into the second diversion chamber (54) and then input into the two cooling enhancement tubes (68). As the rotating lifting seat (51) continues to rotate, the two cooling enhancement tubes (68) that are continuously cooled by the ice-salt water continue to rotate in the mixed solution, thereby cooling the mixed solution. The excess ice-salt water inside the cooling enhancement tube (68) is returned to the drive shaft (31) through the ice-salt water return hose (34) and then output by the drive shaft (31). S7. When the lifting plate (35) descends to the third threshold, the lifting plate (35) moves to the lowest end of the reciprocating thread on the outside of the drive shaft (31). As the drive shaft (31) continues to rotate, the lifting plate (35) gradually moves up and resets. When the lifting plate (35) rises to the fourth threshold, all the 1,3-diethylbenzene in the storage box (41) has been added. At the same time, the reset rotating lifting seat (51) also drives the sealing sleeve (55) to seal the ice-salt water output hole (33) again. At this time, the ice-salt water diversion pipe (38) stops inputting ice-salt water and waits for the mixed solution to heat up naturally. S8. During the natural heating process of the mixed solution, the drive shaft (31) continues to drive the mixing tube (61) and the cooling enhancement tube (68) to stir the mixed solution through the rotating lifting seat (51). After the natural heating is completed, the electric heating element inside the reaction vessel (1) is used to heat the mixed solution until the dithiosalicylic acid reaction is complete. S9. Ice-salt water is input again through the ice-salt water diversion pipe (38), and then a mixture of 1,3-diethylbenzene and water is added into the storage tank (41). Under the drive of the drive shaft (31), the mixture of 1,3-diethylbenzene and water is once again uniformly added to the mixed solution, and is continuously mixed under the action of the mixing pipe (61) and the cooling enhancement pipe (68). During the mixing process, the cooling enhancement pipe (68) is used in conjunction with the cooling chamber (2) to cool the mixture. S10. After mixing, the mixed solution inside the reactor (1) is output. After the mixed solution is output, it is allowed to stand and separate into phases. The organic phase is concentrated after being washed with alkali and water and then cooled and allowed to stand. The concentrated solution is then filtered. The filter cake is washed with a small amount of ice ethanol and then vacuum dried to obtain the finished product.

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