Device for preparing polyphenyl ether resin

Abstract

The utility model belongs to the technical field of chemical engineering and material science, and particularly relates to a device for preparing polyphenyl ether resin. The device for preparing the polyphenyl ether resin comprises a precipitation kettle, a stirring unit and an inner sleeve, the stirring unit extends into the inner sleeve, the device further comprises one or more partition plates, the inner sleeve is connected with the inner wall of the precipitation kettle through the partition plates, a discharge port is formed in the upper portion of the precipitation kettle, and the inner sleeve is connected with the inner wall of the precipitation kettle through the partition plates. The discharging port is formed between the top of the inner sleeve and the top of the partition plate. The device provided by the utility model is simple in structure, and can be realized only by simply transforming a conventional precipitation device. The polyphenyl ether resin obtained by the device disclosed by the utility model has the advantages of low powder content, compact particles and spherical close packing.

Description

Technical Field

[0001] This utility model belongs to the field of chemical and materials science and technology, and specifically relates to an apparatus for preparing polyphenylene ether resin. Background Technology

[0002] Polyphenylene oxide (PPE) is one of the five major general-purpose engineering plastics, widely used in electronics, automobiles, home appliances, office equipment, and industrial machinery. In recent years, with the rapid development of photovoltaic power generation, new energy vehicles, and lightweight vehicles, PPE has played a crucial role as an ideal alternative material for battery casings and lightweight automotive parts, leading to a growing market demand for it.

[0003] There are two methods for producing polyphenylene ether (PPE): solution extraction and precipitation. Solution-processed PPE has advantages such as lower impurities and copper content. However, the solution-process product requires precipitation in a poor solvent, resulting in a loose, brittle, and low-density PPE product that poses significant challenges for transportation and packaging. Furthermore, it generates substantial amounts of dust during use, leading to product loss, electrical safety risks, and health hazards for operators. Therefore, it is necessary to develop a method that allows PPE solution products to precipitate into denser, less dust-prone particles with a specific particle size during the precipitation process.

[0004] Patent CN1 12111057A describes a method for manufacturing polyphenylene ether (PPE): by controlling the ratio of good to bad solvents, PPE agglomerates into particles of a certain size during precipitation. These particles are then continuously tumbled under stirring, extracting the solvent from the particles while simultaneously making them more compact. However, since a single precipitation vessel cannot achieve satisfactory precipitation results, this method adds a second precipitation vessel to increase the retention time of the PPE particles in the solvent, undoubtedly increasing equipment costs.

[0005] There are also patents related to reducing dust during polyphenylene ether (PPE) granulation. Patent CN107446125A discloses a PPE manufacturing method where a poorly mixed PPE solvent and water are introduced into the precipitation vessel through different pipes during the precipitation process. This design eliminates the need for pre-mixing the PPE solvent and water, simplifying the process. However, thorough mixing in the precipitation vessel requires a certain amount of time, which can affect the precipitation effect. Furthermore, the design includes an internal sleeve within the vessel to isolate the precipitated particles from the stirring blades, preventing further breakage of the PPE particles after formation. However, this design increases the complexity of the internal apparatus, and the particles prepared without sufficient stirring have lower hardness, making them brittle during transportation and packaging. Moreover, even after drying, the prepared product still contains a significant proportion of PPE powder with a diameter less than 100 μm.

[0006] Patent CN1 17258726A further improves the shape of the sleeve device based on the above technology and optimizes the agitator to a propulsion type to control the movement direction of the material. In this technology, the precipitated polyphenylene ether material will be precipitated within the sleeve device and enter the space between the sleeve and the vessel wall for aging under the action of the propulsion agitator. However, because the material in the space between the sleeve and the vessel wall will recirculate from the top of the sleeve into the inner side of the sleeve, the precipitated polyphenylene ether solid will be broken up again by the action of the agitator, resulting in smaller polyphenylene ether particles in the final product, and a higher dust content in the material. Utility Model Content

[0007] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide an apparatus for preparing polyphenylene ether resin, which solves a number of problems existing in the polyphenylene ether manufacturing technology, including brittle particles, low bulk density, difficulties in transportation and packaging, and product loss and safety risks caused by severe dust. Although the improvement measures have increased the equipment and complexity, they have still failed to effectively solve these key problems.

[0008] To achieve the above and other related objectives, this utility model provides an apparatus for preparing polyphenylene ether resin, comprising a precipitation vessel, a stirring unit, and an inner sleeve, wherein the stirring unit extends into the inner sleeve, and the apparatus further comprises one or more partitions, wherein the inner sleeve is connected to the inner wall of the precipitation vessel through the partitions, and the upper part of the precipitation vessel is provided with a discharge port, which is located between the top of the inner sleeve and the top of the partitions.

[0009] In some embodiments of this utility model, the top of the precipitation vessel is further provided with a polyphenylene ether solution inlet, which is connected to the inner sleeve.

[0010] In some embodiments of this utility model, the apparatus for preparing polyphenylene ether resin further includes a jacket layer for the flow of heating oil. The jacket layer is disposed on the outer wall of the precipitation vessel. The bottom of the jacket layer is provided with a heating oil inlet, and the top of the jacket layer is provided with a heating oil outlet.

[0011] In some embodiments of this utility model, the inner sleeve is a cylinder with a uniform diameter, the height of the inner sleeve is 52-57cm, and the radius of the inner sleeve is 12-17cm.

[0012] In some embodiments of this utility model, the distance between the top of the inner sleeve and the discharge port is 3-7cm, and the distance between the bottom of the inner sleeve and the bottom of the precipitation vessel is 8-12cm.

[0013] In some embodiments of this utility model, the length of each partition is 42-47cm and the width is 8-12cm.

[0014] In some embodiments of this utility model, the bottom of the precipitation vessel is provided with a poor solvent inlet, which is connected to the inner sleeve.

[0015] In some embodiments of this utility model, the stirring unit includes a connected stirring shaft and a stirring paddle, the blade length of the stirring paddle is 10-14cm, and the distance between the stirring paddle and the bottom of the precipitation vessel is 32-37cm.

[0016] In some embodiments of this utility model, the stirring paddle is located below the discharge port, and the distance between the stirring paddle and the discharge port is 32-37cm.

[0017] In some embodiments of this invention, the apparatus for preparing polyphenylene ether resin further includes a driving component for driving the stirring unit to rotate.

[0018] As described above, the apparatus for preparing polyphenylene ether resin according to this invention has the following beneficial effects:

[0019] This invention improves upon existing technology by modifying the apparatus for preparing polyphenylene ether resin. A sleeve structure isolates solid particles from the stirring paddle, extending the precipitation time and enabling single-reactor solid precipitation. The apparatus is simple in structure, requiring only minor modifications to conventional equipment. The resulting polyphenylene ether resin exhibits advantages such as low powder content, dense particle size, and spherical packing. The proportion of particles smaller than 300μm can be controlled to within 3wt%, and the dried particles exhibit greater hardness and are less prone to breakage. Attached Figure Description

[0020] Figure 1 The diagram shown is a schematic diagram of the apparatus for preparing polyphenylene ether resin disclosed in Embodiment 1 of this utility model.

[0021] Component designation explanation

[0022] 1 precipitation kettle

[0023] 11 Polyphenylene ether solution inlet

[0024] 12 Undesirable solvent inlet

[0025] 13. Discharge port

[0026] 14 Discharge port

[0027] 2. Stirring Unit

[0028] 21 Stirring Shaft

[0029] 22. Stirring paddle

[0030] 3. Inner sleeve

[0031] 31 partition

[0032] 4. Jacket layer

[0033] 41 Heating oil inlet

[0034] 42 Heating oil outlet

[0035] 5. Driver Components Detailed Implementation

[0036] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0037] Please see Figure 1 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0038] This invention provides an apparatus for preparing polyphenylene ether resin, such as... Figure 1 The apparatus includes a precipitation vessel 1, a stirring unit 2, and an inner sleeve 3. The stirring unit 2 extends into the inner sleeve 3. It also includes one or more baffles 31. The inner sleeve 3 is connected to the inner wall of the precipitation vessel 1 via the baffles 31. The upper part of the precipitation vessel 1 has a discharge port 13, located between the top of the inner sleeve 3 and the top of the baffles 31. The inner and outer sides of the inner sleeve 3 form a simple communicating vessel, and the movement of materials within the precipitation vessel 1 is driven by the pressure difference caused by the height difference of the liquid levels. A balance between production efficiency and product quality can be struck simply by controlling the amount of polyphenylene ether solution added and the corresponding proportion of undesirable solvent flow rate. Simultaneously, because the space between the outer wall of the inner sleeve 3 and the inner wall of the precipitation vessel 1 is divided into a narrow channel by the baffles 31, the polyphenylene ether slurry enters the apparatus and moves along the flow direction at this point, significantly reducing backmixing of the slurry and helping to make the particle size distribution of the polyphenylene ether product more concentrated.

[0039] In this embodiment, the top of the precipitation vessel 1 is also provided with a polyphenylene ether solution inlet 11, which is connected to the inner sleeve 3. The capacity of the precipitation vessel 1 is 100-140 mL, which can be selected as 100-120 mL or 120-140 mL.

[0040] In this embodiment, the apparatus for preparing polyphenylene ether resin further includes a jacket layer 4 for the flow of heating oil. The jacket layer 4 is disposed on the outer wall of the precipitation vessel 1. The bottom of the jacket layer 4 is provided with a heating oil inlet 41, and the top of the jacket layer 4 is provided with a heating oil outlet 42. The jacket layer 4 is a continuous design, and heating oil flows inside it.

[0041] In this embodiment, the inner sleeve 3 is a cylinder with a uniform diameter, and the height of the inner sleeve 3 is 52-57cm, which can be 52-53cm or 53-57cm; the radius of the inner sleeve 3 is 12-17cm, which can be 12-15cm or 15-17cm.

[0042] In this embodiment, the distance between the top of the inner sleeve 3 and the discharge port 13 is 3-7cm, which can be 3-5cm or 5-7cm; the distance between the bottom of the inner sleeve 3 and the bottom of the precipitation vessel 1 is 8-12cm, which can be 8-10cm or 10-12cm.

[0043] In this embodiment, the length of each partition 31 is 42-47cm, optionally 42-45cm or 45-47cm, and the width is 8-12cm, optionally 8-10cm or 10-12cm. One side of each partition 31 is connected to the inner sleeve 3, and the other side is connected to the inner wall of the precipitation vessel 1. The number of partitions 31 is at least 3, preferably 4. After the inner sleeve 31 is fixed in the precipitation vessel 1 by the partitions 31, the space between the inner sleeve 3 and the inner wall of the vessel, which is a circular cross-section, is divided into a long channel by the partitions 31. This allows the solution and undesirable solvent in the device to mix and precipitate near the stirring paddle. The slurry then enters the channel through the bottom of the vessel. Due to the presence of the partitions 31, the material in the channel cannot move parallel to the horizontal plane and can only slowly reach the outlet from bottom to top. During the near-static process, the collision and adhesion between solid particles are reduced. After the solvent in the solid particles is dissolved, larger, compact solid particles are obtained.

[0044] In this embodiment, the bottom of the precipitation vessel 1 is provided with a defective solvent inlet 12, which is connected to the inner sleeve 3. The defective solvent is transported from the defective solvent inlet 12 at the bottom of the precipitation vessel 1 to the vicinity of the stirring paddle 22 through a pipeline.

[0045] In this embodiment, the stirring unit 2 includes a connected stirring shaft 21 and a stirring paddle 22. The blade length of the stirring paddle 22 is 10-14 cm, optionally 10-12 cm or 12-14 cm. The distance between the stirring paddle 22 and the bottom of the precipitation vessel 1 is 32-37 cm, optionally 32-35 cm or 35-37 cm. The blades of the stirring paddle 22 are one or more layers, and the stirring blades can be paddle blades, spiral blades, or ribbon blades, etc., and are not limited to the above-mentioned stirring blade forms. The rotation radius of the stirring blade is 0.3 to 0.9 times the inner radius of the precipitation vessel 1, optionally 0.3-0.6 times or 0.6-0.9 times, and the stirring speed is 50 to 1000 rpm, optionally 50-200 rpm, 200-500 rpm, 500-800 rpm, or 800-1000 rpm, etc.

[0046] In this embodiment, the stirring paddle is located below the discharge port 13, and the distance between the stirring paddle and the discharge port 13 is 32-37cm, which can be selected as 32-35cm or 35-37cm.

[0047] In this embodiment, the apparatus for preparing polyphenylene ether resin further includes a drive assembly 5, which drives the stirring unit 2 to rotate. The drive assembly 5 drives the stirring shaft 21, causing the stirring paddle 22 to rotate and adjusting its speed.

[0048] The process of using this invention is as follows: A polyphenylene ether (PPE) solution is added to the inner sleeve 3 through the PPE solution inlet 11, while a defective solvent is injected into the vicinity of the stirring paddle 22 inside the inner sleeve 3 through the defective solvent inlet 12. After the PPE solution and defective solvent are mixed and stirred by the stirring paddle 22, the PPE solid precipitates and settles below the stirring paddle 22, and then flows into the channel formed by the inner sleeve 3, the inner wall of the precipitation vessel 1, and the baffle 31. During this process, the stirring paddle 22 never comes into contact with the precipitated PPE solid to prevent excessive breakage and resulting in excessively low PPE particle size. The slurry obtained after the good and defective solvents at the bottom of the precipitation vessel 1 have been fully mixed and precipitated enters the outer side of the inner sleeve 3. Due to the presence of the longitudinal baffle 31, the residual kinetic energy of the material is rapidly consumed after stirring the slurry, and it no longer maintains a parallel motion to the rotation plane of the stirring paddle 22. Instead, it maintains a relatively stable and slow speed as it moves upward from the channel between the inner sleeve 3 and the inner wall of the precipitation vessel 1 to the outlet 13. During this period, the good solvent contained in the polyphenylene ether particles in the polyphenylene ether slurry further precipitates out. The longer this stage lasts, the more thorough the solvent extraction in the polyphenylene ether particles, resulting in more compact particles and a higher density after drying. The remaining slurry in the device is discharged from the bottom discharge port 14.

[0049] Example 1

[0050] Setup of the apparatus for preparing polyphenylene ether resin: such as Figure 1 As shown, the precipitation vessel has a capacity of 120L and an inner radius of 25cm. The outer wall of the vessel is jacketed, with heating oil inside the jacket. The agitator blade has a radius of 12cm and is paddle-type. The blade is 35cm from the bottom of the vessel and 25cm above the discharge port. The inner sleeve is 55cm long and 15cm in radius, with its lower end 10cm from the bottom and its upper end 5cm above the discharge port. The inner sleeve is connected to the inner wall of the vessel by four baffles, each 45cm long and 10cm wide, with the upper end of each baffle lower than the discharge port. The polyphenylene ether reaction solution is added from the top of the vessel into the inner sleeve, while the undesirable solvent is transported from the bottom of the vessel to the vicinity of the agitator through pipelines.

[0051] Preparation of polyphenylene ether: 250 kg of toluene, 5.9 kg of 50 wt% cuprous bromide aqueous solution, and 10.35 kg of triethylamine were added to a 1000 L precipitation reactor. Simultaneously, 250 kg of 2,6-dimethylphenol was added to the reactor. The mixture was stirred at 50 °C, and oxygen was introduced into the reactor at a rate of 765 L / min for 35 min to prepare a polyphenylene ether product with a target molecular weight of 20,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system. The mixture was washed at high speed at 60 °C for 30 minutes, then allowed to stand for 30 minutes. The lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0052] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. A 6% (by mass) methanol solution with a water content was pumped from the bottom of the reactor until the liquid level was above the agitator blades. The stirring speed was maintained at 400 rpm, and the PPE solution was pumped into a 120 L precipitation reactor. The feed point was inside the sleeve, and the flow rate of the PPE toluene solution was controlled at 9.5 L / min, with an average residence time of 12.6 min. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the solution flow rate. The temperature inside the reactor was maintained at 55°C for stirring and precipitation. The liquid levels on both sides of the sleeve gradually rose and reached the outlet of the precipitation reactor. The unit continued to operate, while the PPE slurry was transferred from the outlet of the precipitation reactor to a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules. The solution added to the precipitation vessel before precipitation can be a poor solvent or a mixed solution of recovered good and poor solvents. After precipitation, the toluene / methanol solution remaining in the precipitation vessel can be left untreated and retained for the next batch of reaction.

[0053] The average molecular weight (Mn) of the polyphenylene ether solid was calculated to be 21786 Da according to the method in GB / T1632-1993; the particle size distribution of the polyphenylene ether particles was tested using a laser particle size analyzer according to GB / T 19077-2016 standard; and the average breaking force of the solid particles was tested using a particle hardness tester.

[0054] Examples 2-7

[0055] Based on Example 1, the reaction conditions for other examples are as follows:

[0056]

[0057]

[0058] Example 2

[0059] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 42 min, to prepare a polyphenylene ether product with a target molecular weight of 25,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0060] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 30 wt%. Recovered toluene / methanol solution was added to the precipitation vessel, and the stirring speed was maintained at 400 rpm. The PPE solution was pumped into the 120 L effective volume precipitation vessel, with the feed point inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel, with a flow rate of 11.4 L / min (the undesirable solvent), which was 1.2 times the solution flow rate. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the precipitation vessel outlet into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0061] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0062] Example 3

[0063] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 55 min, to prepare a polyphenylene ether product with a target molecular weight of 30,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0064] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 25 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the flow rate of the solution. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0065] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0066] Example 4

[0067] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 28 min, to prepare a polyphenylene ether product with a target molecular weight of 18000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0068] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 40 wt%. The PPE solution was pumped into a 120 L precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the flow rate of the solution. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0069] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0070] Example 5

[0071] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 22 min, to prepare a polyphenylene ether product with a target molecular weight of 15000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0072] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 45 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the solution flow rate. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0073] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0074] Example 6

[0075] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 35 min, to prepare a polyphenylene ether product with a target molecular weight of 20,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0076] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L precipitation vessel while maintaining a stirring speed of 100 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the flow rate of the solution. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0077] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0078] Example 7

[0079] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 35 min, to prepare a polyphenylene ether product with a target molecular weight of 20,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0080] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L precipitation vessel while maintaining a stirring speed of 800 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE-toluene mixture was controlled at 9.5 L / min, and the average residence time of the material was 12.6 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 11.4 L / min, which was 1.2 times the flow rate of the solution. The temperature inside the vessel was maintained at 55 °C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0081] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0082] Example 8

[0083] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 35 min, to prepare a polyphenylene ether product with a target molecular weight of 20,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0084] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 11.9 L / min, and the average residence time of the material was 10.1 min. Simultaneously, a 15% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 17.8 L / min, which was 1.5 times the solution flow rate. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0085] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0086] Example 9

[0087] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 35 min, to prepare a polyphenylene ether product with a target molecular weight of 20,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0088] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 7.6 L / min, and the average residence time of the material was 15.8 min. Simultaneously, a 10% water-to-methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 7.6 L / min, which was 1.0 times the flow rate of the solution. The temperature inside the vessel was maintained at 55°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0089] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0090] Example 10

[0091] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 85 min, to prepare a polyphenylene ether product with a target molecular weight of 50,000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, the mixture was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0092] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 24.0 L / min, and the average residence time of the material was 5 min. Simultaneously, a 20% water content methanol solution was pumped in from the bottom of the vessel. The flow rate of the undesirable solvent was 48.0 L / min, twice the flow rate of the solution. The temperature inside the vessel was maintained at 65°C for stirring and precipitation. The PPE slurry was discharged from the outlet of the precipitation vessel into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain the PPE granular product.

[0093] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0094] Example 11

[0095] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 19 min, to prepare a polyphenylene ether product with a target molecular weight of 12000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0096] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The stirring speed was maintained at 400 rpm, and the PPE solution was pumped into a 120 L effective volume precipitation vessel. The feed point was located inside the inner sleeve, and the flow rate of the PPE toluene solution was controlled at 4.8 L / min, with an average residence time of 25 min. Simultaneously, methanol with a water content of 0% was pumped in from the bottom of the vessel at a flow rate of 2.4 L / min (0.5 times the solution flow rate). The temperature inside the vessel was maintained at 40 °C for stirring and precipitation. The PPE slurry was discharged from the precipitation vessel outlet into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0097] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0098] Example 12

[0099] The reaction was carried out using the same raw material ratio as in Example 1, with the reaction time controlled at 15 min, to prepare a polyphenylene ether product with a target molecular weight of 8000. After polymerization, the oxygen was turned off, and 13.8 kg of 10 wt% EDTA disodium salt solution was added to the system. After stirring thoroughly for 45 minutes, 250 kg of deionized water was added to the system, and the mixture was washed at high speed at 60°C for 30 minutes. Then, it was allowed to stand for 30 minutes, and the lower layer of water was separated to form a polyphenylene ether toluene solution product.

[0100] Toluene was added to adjust the concentration of the polyphenylene ether (PPE) solution to 35 wt%. The PPE solution was pumped into a 120 L effective volume precipitation vessel while maintaining a stirring speed of 400 rpm. The feed point was located inside the inner sleeve. The flow rate of the PPE toluene solution was controlled at 2.0 L / min, and the average residence time of the material was 60 min. Simultaneously, a 6% water content methanol solution was pumped in from the bottom of the vessel at a flow rate of 1.0 L / min (0.5 times the solution flow rate). The temperature inside the vessel was maintained at 25°C for stirring and precipitation. The PPE slurry was discharged from the precipitation vessel outlet into a storage tank. After the PPE solution was completely added, the remaining slurry in the unit was discharged from the bottom outlet and combined with the slurry in a temporary storage tank. The slurry in the storage tank was washed, filtered, and dried to obtain PPE granules.

[0101] The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0102] Comparative Example 1

[0103] A polyphenylene ether solution was prepared according to the method of Example 1. During the precipitation stage, the polyphenylene ether solution and the unsuitable solvent were pumped together from the top of the device into the inner sleeve. Other conditions during the precipitation stage remained unchanged. The solution was stirred and precipitated, and the slurry overflowed from the outlet into a storage tank. After collection, the solution was washed, filtered, and dried to obtain polyphenylene ether granules. The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0104] Comparative Example 2

[0105] A polyphenylene ether solution was prepared according to the method of Example 1. During the precipitation stage, the precipitation vessel was modified: the vessel sleeve was removed, and the polyphenylene ether solution and the unsuitable solvent were pumped in together from above. Other conditions during the precipitation stage remained unchanged. The solution was stirred until it precipitated, and the slurry overflowed from the outlet into a storage tank. After collection, the solution was washed, filtered, and dried to obtain polyphenylene ether granules. The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0106] Comparative Example 3

[0107] Polyphenylene ether solution was prepared according to the method of Example 1. During the precipitation stage, the precipitation vessel was modified: the length of the inner sleeve was reduced to 35 cm, and after assembly, the upper opening of the inner sleeve was lower than the discharge port plane. The polyphenylene ether solution was pumped into the inner region of the sleeve from above, while the undesirable solvent was pumped into the outer region of the sleeve from above. Other conditions during the precipitation stage remained unchanged. The mixture was stirred until precipitation occurred, and the slurry overflowed from the discharge port into a storage tank. After collection, the slurry was washed, filtered, and dried to obtain polyphenylene ether granules. The average molecular weight Mn of the polymer, the particle size distribution of the polyphenylene ether particles, and the average breaking force of the solid particles were calculated using the same method as in Example 1.

[0108]

[0109]

[0110] Particles with a diameter of less than 300μm are fine powders, which are not only difficult to process, but also easy to be scattered, polluting the production environment and endangering workers' health.

[0111]

[0112] Average force test of crushed particles: 20 particles were randomly selected within the particle size range for strength testing, and the average value was taken. The particle strength tester cannot measure the strength of particles smaller than 100μm.

[0113] The examples in the above data demonstrate that the device is suitable for completing the precipitation and granulation of polyphenylene ether under different conditions, and the polyphenylene ether particles prepared by the method of the present invention have the advantages of uniform particle size, low dust content, and dense particles that are not easily broken.

[0114] In the comparative data above, Comparative Example 1 shows that the location of the addition of the undesirable solvent affects the precipitation result. In particular, when the undesirable solvent comes into contact with the solution too early and precipitates polyphenylene ether solids before passing through the agitator, it will not only lead to excessive breakage and increase the specific gravity of fine powder, but also cause the slurry to precipitate as blocky solids near the agitator and adhere to the agitator blades. Furthermore, the subsequent slurry does not have a sufficient precipitation gradient, resulting in incomplete toluene precipitation. The final polyphenylene ether particles prepared have uneven morphology and are easily broken.

[0115] Comparative Example 2 further removed the internal sleeve device based on Comparative Example 1. After the precipitated polyphenylene ether slurry was stirred by the agitator for a long time, the dust content increased significantly. At the same time, the morphology of the polyphenylene ether particles was irregular, which led to a decrease in the average crushing force of the particles. This means that the material is easy to be further crushed during transportation.

[0116] Comparative Example 3 confines the internal sleeve device only to the vicinity of the agitator. While this reduces the direct contact between the agitator and the solid powder to some extent, and decreases the powder's proportion in the polyphenylene ether solid, the lack of a precipitation process at a lower kinetic energy state between the internal sleeve and the reactor wall results in poorer particle morphology and a lower average crushing force. Furthermore, because the overflow outlet is higher than the top of the sleeve, some slurry overflows back into the sleeve and contacts the agitator, further crushing the precipitated solid particles. This leads to a wider particle size distribution in the produced polyphenylene ether particles and a higher powder proportion in the product.

[0117] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An apparatus for preparing polyphenylene ether resin, characterized in that, The device includes a precipitation vessel (1), a stirring unit (2), and an inner sleeve (3). The stirring unit (2) extends into the inner sleeve (3). The device also includes one or more partitions (31). The inner sleeve (3) is connected to the inner wall of the precipitation vessel (1) through the partitions (31). The upper part of the precipitation vessel (1) is provided with a discharge port (13), which is located between the top of the inner sleeve (3) and the top of the partitions (31).

2. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The top of the precipitation vessel (1) is also provided with a polyphenylene ether solution inlet (11), which is connected to the inner sleeve (3).

3. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The apparatus for preparing polyphenylene ether resin further includes a jacket layer (4) for the flow of heating oil. The jacket layer (4) is disposed on the outer wall of the precipitation vessel (1). The bottom of the jacket layer (4) is provided with a heating oil inlet (41), and the top of the jacket layer (4) is provided with a heating oil outlet (42).

4. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The inner sleeve (3) is a cylinder with a uniform diameter, the height of the inner sleeve (3) is 52-57cm, and the radius of the inner sleeve (3) is 12-17cm.

5. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The distance between the top of the inner sleeve (3) and the outlet (13) is 3-7cm, and the distance between the bottom of the inner sleeve (3) and the bottom of the precipitation vessel (1) is 8-12cm.

6. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, Each of the partitions (31) has a length of 42-47cm and a width of 8-12cm.

7. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The bottom of the precipitation vessel (1) is provided with a poor solvent inlet (12), which is connected to the inner sleeve (3).

8. The apparatus for preparing polyphenylene ether resin as described in claim 1, characterized in that, The stirring unit (2) includes a connected stirring shaft (21) and a stirring paddle (22). The blade length of the stirring paddle is 10-14cm, and the distance between the stirring paddle and the bottom of the precipitation vessel (1) is 32-37cm.

9. The apparatus for preparing polyphenylene ether resin as described in claim 8, characterized in that, The stirring paddle is located below the discharge port (13), and the distance between the stirring paddle and the discharge port (13) is 32-37cm.

10. The apparatus for preparing polyphenylene ether resin according to claim 1, characterized in that, The apparatus for preparing polyphenylene ether resin further includes a drive assembly (5) for driving the stirring unit (2) to rotate.

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