Metal ion impurity removal device in polymer production

Abstract

The utility model belongs to the technical field of chemical product preparation, and particularly relates to a metal ion impurity removal device in polymer production. The utility model provides a metal ion impurity removal device in polymer production. The metal ion impurity removal device comprises a precipitation kettle, a filter, a washing kettle and a centrifugal machine. According to the technical scheme provided by the invention, metal ions are precipitated and then separated out, and are further filtered, washed and centrifuged to obtain a purified product after impurity removal, and the purified product does not react with polyphenyl ether in the impurity removal process, so that the structural stability of the polyphenyl ether is ensured; through determination, the copper content in the polyphenyl ether after impurity removal is less than 2.0 mg / kg, and the technical defect of poor copper removal stability of a method for removing copper ions in the polyphenyl ether by using a chelating agent in the prior art is overcome.

Description

Technical Field

[0001] This application belongs to the field of chemical product preparation technology, and in particular relates to a metal ion removal device in polymer production. Background Technology

[0002] Polyphenylene oxide (PPE) resin is one of the five major engineering plastics, possessing advantages such as low dielectric constant, low loss factor, high glass transition temperature, flame retardancy, and dimensional stability. It is widely used in industries such as electronics, automotive, home appliances, and industrial machinery. PPE production processes include solvent-free melt polymerization, homogeneous solution polycondensation, precipitation polycondensation, and all-aqueous medium polymerization. Industrially produced PPE typically uses 2,6-dimethylphenol as a raw material, which polymerizes with oxygen in an oxygen-containing gas under the action of a copper-amine complex catalyst. The residual copper ions in PPE products are unavoidable. Copper content is one of the main performance indicators of the product. According to the national standard "Plastics - Polyphenylene Oxide (PPE) Resin" (GB / T41874-2022), the copper content of qualified products should not exceed 10.0 mg / kg, and the copper content of superior-grade products should not exceed 3.0 mg / kg.

[0003] In the existing technology, the method for removing copper from polyphenylene ether products mostly involves adding chelating agents such as ethylenediaminetetraacetic acid and its salts to the polymer solution. However, the chelates formed by this method have poor stability, and copper ions in the chelates can easily re-enter the polyphenylene ether product, making it difficult to obtain polyphenylene ether products that meet the standards.

[0004] Therefore, the development of a metal ion removal device for polymer production, which addresses the technical deficiency of poor copper removal stability in existing methods using chelating agents to remove copper ions from polyphenylene ether, has become a problem urgently needing to be solved by those skilled in the art. Utility Model Content

[0005] Therefore, it is necessary to address the technical shortcomings of existing methods for removing copper ions from polyphenylene ether using chelating agents, which suffer from poor copper removal stability, and to provide a metal ion removal device for polymer production.

[0006] This application provides a metal ion removal device for polymer production, comprising: a precipitation tank, a filter, a washing tank, and a centrifuge; the liquid phase outlet of the precipitation tank is connected to the filter, the liquid phase outlet of the filter is connected to the washing tank, and the liquid phase outlet of the washing tank is connected to the centrifuge.

[0007] In one embodiment, the impurity removal device further includes a sedimentation tank disposed between the sedimentation vessel and the filter.

[0008] In one embodiment, the impurity removal device further includes a first pump, which is disposed between the liquid phase outlet end of the filter and the water washing tank.

[0009] In one embodiment, the impurity removal device further includes a second pump, which is disposed between the liquid phase discharge end of the washing vessel and the centrifuge.

[0010] In one embodiment, the sedimentation vessel is provided with a stirring section;

[0011] And / or,

[0012] The washing kettle is equipped with a stirring section.

[0013] In one embodiment, the impurity removal device further includes a third pump, which is disposed between the sedimentation tank and the sedimentation vessel.

[0014] In one embodiment, the impurity removal device further includes a post-processing unit, which is connected to the liquid phase discharge end of the centrifuge;

[0015] The post-processing unit includes any one or more of the following: a concentration section, a washing section, and a drying section.

[0016] In one embodiment, the washing tank is provided with a washing liquid inlet.

[0017] In one embodiment, the filter has a particle size of 20 to 400 mesh.

[0018] In one embodiment, the filter has a particle size of 50-200 mesh.

[0019] In one embodiment, the centrifuge is a liquid-liquid two-phase centrifuge or a solid-liquid-liquid three-phase centrifuge.

[0020] In summary, this application provides a metal ion removal device for polymer production, comprising: a precipitation vessel, a filter, a washing vessel, and a centrifuge. In the technical solution provided by this application, metal ions are precipitated, and then further filtered, washed, and centrifuged to obtain a pure product after impurity removal. During the impurity removal process, no reaction occurs with polyphenylene ether, ensuring the stability of the polyphenylene ether structure. Measurements show that the copper content in the polyphenylene ether after impurity removal is less than 2.0 mg / kg, overcoming the technical defect of poor copper removal stability in existing methods using chelating agents to remove copper ions from polyphenylene ether. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 A schematic diagram of the structure of a metal ion removal device in polymer production, provided in the embodiments of this application;

[0023] Figure 2 A schematic diagram of the process of removing metal ions using the impurity removal device provided in this application in the technical solution provided in the embodiments of this application;

[0024] The components include a sedimentation tank R1, a stirring unit M, a sedimentation tank V1, a filter F1, a first pump B1, a water washing tank V2, a second pump B2, and a centrifuge M1. Detailed Implementation

[0025] This application provides a metal ion removal device for polymer production, which addresses the technical defect of poor copper removal stability in existing methods for removing copper ions from polyphenylene ether using chelating agents.

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0027] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0032] Please see Figure 1 This application provides a metal ion removal device for polymer production, comprising: a precipitation tank, a filter, a washing tank, and a centrifuge; the liquid phase outlet of the precipitation tank is connected to the filter, the liquid phase outlet of the filter is connected to the washing tank, and the liquid phase outlet of the washing tank is connected to the centrifuge. This metal ion removal device for polymer production solves the technical defect of poor copper removal stability in existing methods using chelating agents to remove copper ions from polyphenylene ether.

[0033] To more clearly illustrate the metal ion removal device for polymer production provided in this application, the process of removing copper ions from a polyphenylene ether product containing copper ions using this metal ion removal device is described herein. However, it should be emphasized that this does not constitute a limitation on the scope of protection of this application; the metal ion removal device provided in this application can also be used to remove metal ions mixed in other organic substances.

[0034] In the technical solution provided in this application embodiment, polyphenylene ether containing copper ions precipitates in a precipitation tank. Here, copper ions can be precipitated by adding a precipitant, such as a precipitant containing hydroxide or carbonate ions. After thorough stirring with the polyphenylene ether containing copper ions, precipitation occurs, with the copper ions precipitating out as copper hydroxide or copper carbonate. The specific principle is as follows:

[0035] Cu 2+ +2OH - →Cu(OH)2↓

[0036] 2Cu 2+ +CO3 2- +2OH - →Cu2(OH)2CO3↓

[0037] The remaining liquid polyphenylene ether product, after passing through a filter to remove incompletely settled precipitates, is further washed away in a water washing kettle to remove precipitated impurities. Then, the liquid polyphenylene ether is centrifuged to remove any remaining solids, resulting in a purified polyphenylene ether product.

[0038] To further optimize the technical solution, the impurity removal device provided in this application embodiment also includes a precipitation tank, which is disposed between the precipitation vessel and the filter. After copper ions undergo a precipitation reaction in the precipitation vessel, the device is allowed to stand in the precipitation tank to ensure complete precipitation of copper-containing precipitates, thereby further optimizing the impurity removal effect.

[0039] Between the filter and the washing tank, liquid polyphenylene ether flowing from the liquid phase outlet can flow from the filter to the washing tank under gravity. In actual impurity removal operations, to effectively improve the impurity removal efficiency, the impurity removal device provided in this application further includes a first pump, which is positioned between the liquid phase outlet of the filter and the washing tank. Through the action of the first pump, the liquid polyphenylene ether to be removed can be uniformly and continuously drawn smoothly from the filter into the washing tank, improving the working efficiency of the impurity removal device.

[0040] Similarly, the impurity removal device provided in this application embodiment further includes a second pump, which is disposed between the liquid phase outlet of the washing kettle and the centrifuge. Through the action of the second pump, the liquid-phase polyphenylene ether to be removed can be uniformly and continuously pumped into the centrifuge, thereby improving the working efficiency of the impurity removal device.

[0041] To further optimize the technical solution, in order to ensure that the precipitant in the precipitation tank can fully contact the copper-containing polyphenylene ether, so that the copper ions can be fully precipitated and the copper ion removal effect can be optimized, the technical solution provided in this application embodiment is provided with a stirring part in the precipitation tank; by stirring with the stirring part, the precipitant can be fully contacted with the copper ions and precipitation can occur, thereby better achieving the removal effect of copper ions.

[0042] Similarly, in the impurity removal device provided in this application embodiment, a stirring section is provided in the washing tank. The stirring section in the washing tank can fully mix the unfiltered copper-containing precipitate in the polyphenylene ether to be removed with the washing liquid, optimize the washing effect of the washing tank, and ensure a good impurity removal effect for copper ions.

[0043] The impurity removal device provided in this application embodiment further includes a third pump, which is disposed between the sedimentation tank and the sedimentation vessel. The third pump can accelerate the flow rate of the impurity removal mixing system between the sedimentation vessel and the sedimentation tank, thereby improving the impurity removal efficiency of the device.

[0044] To achieve integrated impurity removal processing of polyphenylene ether, an embodiment of this application provides an impurity removal device that further includes a post-processing unit connected to the liquid phase discharge end of a centrifuge. The post-processing unit includes any one or more of a concentration section, a washing section, and a drying section. After concentration, washing, and drying, the polyphenylene ether product is obtained from the impurity-removed polyphenylene ether.

[0045] To further optimize the technical solution, while ensuring a good washing effect in the washing tank, the working efficiency of the washing tank is effectively improved, and the washing continuity of the washing tank is achieved. In the technical solution provided in the embodiments of this application, the washing tank is provided with a washing liquid inlet. Clean washing liquid is continuously added to the washing tank through the washing liquid inlet, which effectively ensures the washing effect of the washing tank and also enables continuous washing of the washing tank.

[0046] In the technical solution provided in this application embodiment, in order to ensure the filtration effect of the filtration section, the particle size of the filter is 20 to 400 mesh.

[0047] Further optimize the technical solution to improve the filtration effect of the filtration section, with a filter particle size of 50-200 mesh.

[0048] In the technical solutions provided in this application embodiment, to ensure the centrifugation effect of the centrifuge, the centrifuge is a liquid-liquid two-phase centrifuge or a solid-liquid-liquid three-phase centrifuge.

[0049] Please refer to this again. Figure 1 The impurity removal process of the metal ion removal device provided in this application is briefly described.

[0050] The copper-containing polyphenylene ether stream 1, to be purified, enters the precipitation tank R1, and the precipitant stream 2 also enters the precipitation tank R1. Under the action of the stirring unit M, streams 1 and 2 come into full contact in the precipitation tank R1, and the copper ions in stream 1 precipitate. After precipitation, the mixed system stream 3 enters the precipitation tank V1 for further precipitation. After precipitation in the precipitation tank V1, the liquid phase stream 5 enters the filter F1 for filtration. The solid precipitate stream 4 in the precipitation tank V1 is discharged from the precipitation tank V1 and undergoes other treatments.

[0051] In filter F1, the filtered liquid stream 7 passes through the first pump B1, while the solid stream 6 is discharged from filter F1 for further processing. The liquid stream 8 passing through the first pump B1 enters the washing tank (the composition of streams 7 and 8 remains unchanged here, serving only to distinguish streams flowing through different structures). The washing liquid stream 9 enters the washing tank, and under the stirring action of the stirring unit M, streams 8 and 9 come into full contact, washing away any unfiltered solid impurities in stream 8.

[0052] The liquid phase stream 10 after washing in the water washing tank passes through the second pump B2, and the liquid phase stream 11 passing through the second pump B2 (the composition of streams 10 and 11 has not changed, and is only used to distinguish streams flowing through different structures) enters the centrifuge M1 for centrifugation. The liquid phase stream 13 after centrifugation is the polyphenylene ether after impurity removal, and the solid phase stream 12 after centrifugation undergoes other treatments.

[0053] Please see here. Figure 2 The method for removing metal ions using the metal ion removal device provided in this application in polymer production includes:

[0054] Step 1, Precipitation: Mix the liquid to be purified with the precipitant, collect the liquid product after precipitation to obtain the first product;

[0055] Step 2, Filtration: The first product is filtered and the liquid phase product is collected to obtain the second product;

[0056] Step 3, water washing: Wash the second product with water and collect the liquid phase product to obtain the third product;

[0057] Step 4: Centrifugation: Centrifuge the third product to obtain the purified product.

[0058] To ensure the precipitation effect of the precipitant on the liquid to be purified, in the purification method provided in this application embodiment, the precipitant in step one includes: alkaline solution and / or carbonate aqueous solution.

[0059] To further optimize the precipitation effect, in the technical solution provided in the embodiments of this application, in step one, the alkaline solution is a strong alkaline aqueous solution, and the concentration of hydroxide ions in the alkaline solution is 0.25-2.5 mol / L.

[0060] A more optimized technical solution is that, in step one, the concentration of hydroxide ions in the alkaline solution is 1-2 mol / L.

[0061] To further optimize the precipitation effect, in the technical solution provided in the embodiments of this application, in step one, the carbonate aqueous solution is sodium carbonate and / or sodium bicarbonate.

[0062] To further optimize the precipitation effect, in step one, the concentration of bicarbonate ions in the carbonate aqueous solution is 0.25-2.5 mol / L; and / or, the concentration of carbonate ions in the carbonate aqueous solution is 0.125-1.25 mol / L.

[0063] To further optimize the precipitation effect, in step one, the concentration of bicarbonate ions in the carbonate aqueous solution is 1-2 mol / L; and / or, the concentration of carbonate ions in the carbonate aqueous solution is 0.5-1.0 mol / L.

[0064] To further optimize the precipitation effect, in the technical solution provided in the embodiments of this application, in step one, the amount of precipitant added is 1.5wt% to 5.0wt% of the polymer solution to be purified.

[0065] To further optimize the precipitation effect, the amount of precipitant added is 2.0-4.0 wt% of the polymer solution to be purified.

[0066] To achieve integrated impurity removal processing of the product to be impurized, an embodiment of this application provides an impurity removal method that further includes: post-treatment, wherein the impurity-removed product is sequentially concentrated, washed and dried to obtain a post-treated impurity-removed product.

[0067] The following is a specific example of removing metal ions from polyphenylene ether, based on a metal ion removal device and corresponding removal method provided in this application for polymer production.

[0068] In Examples 1-4, using Figure 1 The process apparatus shown has a volume of R1 of 0.8 m³. 3 Sedimentation tank V1 is a vortex sedimentation tank with a volume of 1m³. 3 Filter F1 is a basket filter with a 200-mesh screen; V2 has a volume of 1.3m³. 3 The centrifuge is a solid-liquid-liquid three-phase centrifuge. The precipitant is a 1.5 mol / L NaOH aqueous solution; please refer to Table 1 for the feed flow rate and copper ion content of stream 1, stream 2, stream 9 (water feed flow rate), and the copper content of the purified polyphenylene ether product.

[0069] Table 1

[0070] Example 1 2 3 4 Logistics flow rate 1 kg / h 388.27 388.27 388.27 388.27 Logistics 1 Copper quality fraction (wt%) 0.008 0.013 0.015 0.017 Logistics 2 Flow rate kg / h 7.99 12.98 14.98 16.97 Logistics 9 flow rate kg / h 16.46 11.79 9.93 8.06 Copper content of polyphenylene ether products (mg / kg) 0.7 0.9 0.9 1.2

[0071] As can be seen from Table 1, the technical solution provided in this application has a good effect on removing copper from copper-containing polyphenylene ether, and the removal process will not affect the polyphenylene ether. The polyphenylene ether obtained after removal has a stable structure and meets and exceeds the national standard for the copper metal content of superior grade polyphenylene ether products being less than 3 ppm.

[0072] The metal ion removal device provided by this application can effectively remove metal ion impurities from polyphenylene ether, especially copper ions that are often mixed in polyphenylene ether.

[0073] In summary, this application provides a metal ion removal device for polymer production, comprising: a precipitation vessel, a filter, a washing vessel, and a centrifuge. In the technical solution provided by this application, metal ions are precipitated, and then further filtered, washed, and centrifuged to obtain a pure product after impurity removal. During the impurity removal process, no reaction occurs with polyphenylene ether, ensuring the stability of the polyphenylene ether structure. Measurements show that the copper content in the polyphenylene ether after impurity removal is less than 2.0 mg / kg, overcoming the technical defect of poor copper removal stability in existing methods using chelating agents to remove copper ions from polyphenylene ether.

[0074] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.

[0075] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A metal ion removal device for polymer production, characterized in that, The impurity removal device includes: a sedimentation tank, a filter, a washing tank, and a centrifuge; the liquid phase outlet of the sedimentation tank is connected to the filter, the liquid phase outlet of the filter is connected to the washing tank, and the liquid phase outlet of the washing tank is connected to the centrifuge.

2. The impurity removal device according to claim 1, characterized in that, The impurity removal device further includes a sedimentation tank, which is disposed between the sedimentation vessel and the filter.

3. The impurity removal device according to claim 1 or 2, characterized in that, The impurity removal device further includes a first pump, which is disposed between the liquid phase outlet end of the filter and the water washing tank.

4. The impurity removal device according to claim 1 or 2, characterized in that, The impurity removal device further includes a second pump, which is located between the liquid phase discharge end of the washing kettle and the centrifuge.

5. The impurity removal device according to claim 1 or 2, characterized in that, The sedimentation vessel is equipped with a stirring section; And / or, The washing kettle is equipped with a stirring section.

6. The impurity removal device according to claim 2, characterized in that, The impurity removal device further includes a third pump, which is disposed between the sedimentation tank and the sedimentation vessel.

7. The impurity removal device according to claim 1 or 2, characterized in that, The impurity removal device further includes a post-processing unit, which is connected to the liquid phase discharge end of the centrifuge; The post-processing unit includes any one or more of the following: a concentration section, a washing section, and a drying section.

8. The impurity removal device according to claim 1 or 2, characterized in that, The washing kettle is equipped with a washing liquid inlet.

9. The impurity removal device according to claim 1 or 2, characterized in that, The filter has a particle size of 20 to 400 mesh.

10. The impurity removal device according to claim 1 or 2, characterized in that, The centrifuge is a liquid-liquid two-phase centrifuge or a solid-liquid-liquid three-phase centrifuge.

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