Continuous aftertreatment system and process for polyaryletherketone polymerization products

Abstract

The application discloses a continuous post-treatment system and process for polyaryletherketone polymerization reaction products, and relates to the technical field of polyaryletherketone. The continuous post-treatment system for polyaryletherketone polymerization reaction products comprises a sedimentation reactor, at least one separation and reslurry unit, a water washing tower, an extraction tower and a matching rectification recovery device. The process of the application adopts a sedimentation agent to make the polyaryletherketone melt shear sedimentation, in-situ crystallization into porous loose aggregates, and then the solvent is recovered through countercurrent separation, countercurrent water washing and double-path rectification. The application does not need mechanical crushing, avoids damage to molecular chains, has low impurity content and narrow molecular weight distribution, realizes efficient recovery and circulation of the solvent and the sedimentation agent, has small solvent loss, realizes continuous operation in the whole process, has low energy consumption and labor cost, and is suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of polyaryletherketone (PAEK) technology, and more specifically to a continuous post-processing system and process for PAEK polymerization products. Background Technology

[0002] Polyaryletherketone (PAEK) is a class of semi-crystalline aromatic thermoplastic special engineering plastics with excellent comprehensive properties. With its ultra-high heat resistance, outstanding mechanical strength, excellent chemical corrosion resistance, fatigue resistance, and good biocompatibility and electrical insulation properties, it is now widely used in high-end fields such as aerospace structural components, high-end electronic and electrical systems, medical device implants, high-voltage systems for new energy vehicles, and semiconductor wafer carriers. It is one of the core categories for measuring the development level of a country's high-performance polymer materials industry. Polyetheretherketone (PEEK), as the most industrialized and widely used mainstream variety in the PEEK family, is also the core direction for current domestic PEEK production capacity layout and technological breakthroughs.

[0003] Currently, the industrial production of PEEK mainly employs a nucleophilic substitution polycondensation route: using 4,4'-difluorobenzophenone and hydroquinone as monomers, and diphenyl sulfone as a high-boiling solvent, a high-temperature polycondensation reaction is carried out in the presence of alkali metal carbonates. After polymerization, the reaction mixture is a high-viscosity melt containing PEEK, a large amount of diphenyl sulfone (typically more than 65% of the total mass of the reaction system), and byproduct inorganic salts (sodium fluoride or potassium fluoride). To obtain pure PEEK product, post-processing is necessary to efficiently separate and remove diphenyl sulfone and inorganic salts.

[0004] Current post-processing generally involves the following steps: cooling the polymerization product and mechanically crushing it into coarse particles; then repeatedly extracting or washing with an organic solvent (such as acetone) to remove diphenyl sulfone; followed by washing with water to remove inorganic salts; and finally drying to obtain coarse PEEK powder. This process has the following shortcomings: (1) Damage to molecular chains during crushing: The polymer products after cooling are hard and need to be mechanically crushed before extraction. The crushing process not only introduces metal shavings, but also causes the PEEK molecular chains to break due to mechanical impact, which widens the molecular weight distribution (PDI is usually >2) and reduces the mechanical properties of the material.

[0005] (2) Low recovery rate and high energy consumption of diphenyl sulfone: Existing extraction processes usually require 8-10 batches of washing, with a diphenyl sulfone recovery rate of only 70-80%, and the recovered diphenyl sulfone is not pure enough (often containing impurities such as methyl diphenyl sulfone and chlorodiphenyl sulfone), which affects the controllability of the polymerization reaction.

[0006] (3) High solvent consumption and long operation cycle: PEEK extraction requires a large amount of organic solvent, and the extraction and washing processes are mostly intermittent operations, resulting in low equipment utilization and high labor costs.

[0007] (4) Large fluctuations in product impurity residue: Due to uneven particle size and unstable extraction efficiency, the product has difficulty in consistently meeting the requirements of high-end applications in terms of diphenyl sulfone residue and ash content.

[0008] Therefore, developing a continuous post-processing technology that avoids mechanical crushing, achieves high-yield solvent recovery, and enables the recycling of precipitating agents is of great significance for the upgrading of the polyaryletherketone industry. Summary of the Invention

[0009] The technical problem to be solved by this invention is to address the problems in existing polyaryletherketone (PAE) post-processing processes, such as molecular chain damage caused by mechanical crushing, low diphenyl sulfone recovery rate and insufficient purity, high organic solvent consumption, and significant fluctuations in product impurity residues. The invention provides a continuous post-processing system and process for PAE polymerization products to achieve the following: avoidance of mechanical crushing operations; direct extraction and washing of the obtained PAE powder; diphenyl sulfone recovery rate > 90% and recovery purity ≥ 99.9%; precipitant recovery rate ≥ 95% and purity ≥ 99.8%; final PAE product ash content ≤ 0.1 wt.%, diphenyl sulfone residue < 300 ppm, and molecular weight distribution index (PDI) < 2.

[0010] The technical solution of this invention is as follows: On one hand, the present invention provides a continuous post-processing system for polyaryletherketone polymerization products, including a precipitation reactor connected to a polyaryletherketone melt delivery pipeline and equipped with a shear stirrer or shear mixer; the precipitation reactor is sequentially connected to at least one stage of separation and re-slurrying unit, the separation and re-slurrying unit including a pre-separator and a pulping tank connected thereto; the pulping tank in the last stage of separation and re-slurrying unit is connected to a final separator; when a single stage of separation and re-slurrying unit is provided, the overflow outlet of the pre-separator is connected to a solvent recovery unit via a pipeline, the pulping tank is connected to a fresh precipitant delivery pipeline, and the overflow outlet of the final separator is connected to the precipitation reactor via a pipeline; when two or more stages of separation and re-slurrying units are provided, the overflow outlet of the pre-separator in the first stage of separation and re-slurrying unit is connected to a solvent recovery unit via a pipeline, the pulping tank in the last stage of separation and re-slurrying unit is connected to a fresh precipitant delivery pipeline, and the pre-separator in the last ..., the pulping tank in the last stage of separation and re-slurrying unit is connected to a solvent recovery unit, the pulping tank in the last stage of separation and re-slurrying unit is connected to a solvent recovery unit, the pulping tank in the last stage of separation and re-slurrying unit is connected to a The overflow outlet of the separator is connected to the precipitation reactor via a pipeline. The overflow outlet of the final separator is connected to the pulping tank in the penultimate separation and re-pulping unit via a pipeline. The overflow outlets of the pre-separators in the remaining separation and re-pulping units are connected to the pulping tanks in the previous separation and re-pulping unit via pipelines. The concentrated slurry outlet at the bottom of the final separator is connected to a washing tower via a pipeline. The washing tower is connected to an inlet pipeline, a polymer wet material conveying pipeline, and a washing wastewater conveying pipeline. The pipeline is connected to a drying tower, and the washing wastewater delivery pipeline is connected to an extraction tower; the extraction tower is connected to an extractant delivery pipeline, and the extraction tower is connected to a precipitant-extractant removal distillation tower via a pipeline; the precipitant-extractant removal distillation tower is connected to an extractant recovery pipeline and a precipitant refining and recovery tower, the precipitant refining and recovery tower is connected to a precipitant recovery pipeline, a waste liquid discharge pipeline, and a tail gas discharge pipeline, the precipitant recovery pipeline is connected to a precipitant circulation pipeline, and the precipitant circulation pipeline is connected to a fresh precipitant delivery pipeline.

[0011] Preferably, the pre-separator and the final separator are settling tanks or cyclone separators.

[0012] Preferably, the polyaryletherketone inlet of the precipitation reactor is equipped with an atomizing nozzle, a rotating atomizing disc, or a porous distribution plate.

[0013] Preferably, the solvent recovery unit includes a solvent deprecipitant distillation tower and a solvent refining and recovery tower connected in sequence. The solvent deprecipitant distillation tower is connected to the precipitant refining and recovery tower via a pipeline, and the solvent refining and recovery tower is connected to a solvent circulation pipeline and a waste liquid discharge pipeline.

[0014] Preferably, the extraction tower is connected to a brine stripping tower via pipelines, and the brine stripping tower is connected to a hot nitrogen delivery pipeline, a tail gas emission pipeline, and a brine emission pipeline.

[0015] On the other hand, the present invention provides a continuous post-processing technology for polyarylether ketone polymerization products, which is carried out using the above-mentioned continuous post-processing system for polyarylether ketone polymerization products, and includes the following steps: S1 Shear Precipitation: The polymer melt (temperature 295-320℃) after the polymerization of polyaryletherketone is completed is transported to a precipitation reactor and stirred and dispersed with a liquid precipitant at 120-180℃ pre-placed in the precipitation reactor. During this process, the diphenyl sulfone solvent in the polymer melt diffuses and migrates to the precipitant phase, and the polyaryletherketone undergoes solvent-induced crystallization, dispersing in the precipitant to form a slurry. The precipitant can be an aromatic solvent, an aprotic polar solvent, or a halogenated aromatic solvent. S2 Separation: The slurry at the bottom of the precipitation reactor is transported to the separation and re-slurrying unit. When a primary separation and re-slurrying unit is installed, fresh precipitant and circulating precipitant from the precipitant circulation pipeline are transported to the pulping tank, where they are stirred and mixed with the concentrated slurry formed after solid-liquid separation in the pre-separator for re-slurrying. This allows the residual diphenyl sulfone solvent in the polymer particle pores to be fully dissolved and replaced by the precipitant. The overflow from the pre-separator is transported to the solvent recovery unit for diphenyl sulfone solvent recovery. The slurry in the pulping tank then enters the final separator for solid-liquid separation. The overflow from the final separator is returned to the precipitation reactor to participate in the precipitation of the polymer melt. Analysis; When two or more separation and re-pulping units are set up, the fresh precipitant and the circulating precipitant returned from the precipitant circulation pipeline are transported to the pulping tank in the last separation and re-pulping unit. The overflow liquid of the pre-separator in the last separation and re-pulping unit is returned to the precipitation reactor. The overflow liquid of the pre-separator in the first separation and re-pulping unit is transported to the solvent recovery unit for the recovery of diphenyl sulfone solvent. The overflow liquid of the last separator is transported to the pulping tank in the penultimate separation and re-pulping unit. The overflow liquid of the pre-separator in the remaining separation and re-pulping units is transported to the pulping tank in the previous separation and re-pulping unit. S3 Countercurrent Washing: The concentrated slurry at the bottom of the final separator is introduced from the top of the washing tower and forms a countercurrent contact with the deionized water introduced from the bottom of the washing tower and flowing upward, thus performing countercurrent washing on the concentrated slurry; the water-containing polyaryletherketone wet material is continuously discharged from the tower bottom and transported to the dryer through the polymer wet material conveying pipeline, and the polyaryletherketone product is obtained after drying. S4 Dual-Path Solvent Distillation and Recovery: Overflow from the pre-separator is treated by the solvent recovery unit, and the recovered diphenyl sulfone solvent is returned to the polyarylether ketone polymerization section for recycling; the washing wastewater from the top of the water washing tower is sent to the extraction tower for continuous countercurrent liquid-liquid extraction, and the extract phase (extractant + precipitant) is sent to the precipitant-extractant removal distillation tower. Under nitrogen protection, the extractant collected from the top of the tower is recycled back to the extraction tower, and the bottom material enters the precipitant refining and recovery tower. High-purity precipitant (purity ≥99.8%) is collected from the top of the tower and returned to the pulping tank through the precipitant circulation pipeline.

[0016] Preferably, in step S1, the polymer melt is injected into the precipitation reactor in the form of a thin stream or spray; the volume ratio of polymer melt to precipitation agent is 1:(3-7), and the precipitation residence time is 1-60 min.

[0017] Preferably, in step S1, the aromatic solvent is at least one of trimethylbenzene, xylene, mesitylene, ethylbenzene, and diethylbenzene; the aprotic polar solvent is at least one of N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and sulfolane; and the haloaromatic solvent is at least one of 1-chloronaphthalene, 1,2,4-trichlorobenzene, and o-dichlorobenzene.

[0018] Preferably, in step S2, the mixing temperature of the slurry and fresh precipitant or overflow liquid in the pulping tank is 40-200℃, and the mixing time is 5-30 min.

[0019] Preferably, in step S3, the residence time of the concentrated slurry in the water washing tower is 90-180 min, and the temperature of the deionized water is 40-100℃.

[0020] Preferably, in step S4, the raffinate (a brine solution containing trace amounts of extractant) at the top of the extraction tower is sent to a brine stripping tower for stripping with hot nitrogen at 80-120°C. The nitrogen and extractant vapor at the top of the brine stripping tower are condensed, the extractant is recycled back into the extraction tower, and the nitrogen is reheated and recycled. A purified brine solution is obtained in the bottom of the tower.

[0021] Preferably, in step S4, the extractant is a haloalkane extractant.

[0022] Preferably, in step S4, the extractant is chloroform (i.e., trichloromethane).

[0023] The specific process flow of the continuous post-processing technology for the polyarylether ketone polymerization product of the present invention is as follows: S1 shear precipitation The polymer melt (temperature 295-320℃) after the polyaryletherketone polymerization reaction is completed is directly fed into the precipitation reactor. The polymer melt contains polyaryletherketone, molten diphenyl sulfone solvent and suspended sodium fluoride or potassium fluoride particles.

[0024] A liquid precipitant with a pre-set temperature of 120-180℃ is placed in the precipitation reactor. Under the condition of full stirring and dispersion by a shear stirrer or shear mixer, the polymer melt containing polyaryletherketone is injected into the precipitation reactor in the form of a fine stream or spray.

[0025] In this process, the polymer melt containing polyaryletherketone is injected in the form of a fine stream or spray. The average diameter of the droplets in the fine stream or spray is controlled to be 0.1-5 mm, so as to increase the contact surface area between the polymer melt and the precipitant and achieve instantaneous uniform solvent replacement and solute precipitation.

[0026] Due to its good miscibility with the precipitant, the diphenyl sulfone solvent in the polymer melt can rapidly diffuse and migrate to the precipitant phase; the polyaryletherketone macromolecular chains undergo solvent-induced crystallization upon losing the solvent. The precipitated polyaryletherketone particles exhibit the following morphological characteristics: under scanning electron microscopy, the particles show a porous cluster structure formed by interconnected microspheres with a particle size of 10-30 μm, forming a three-dimensional interconnected pore network between the microspheres, with an overall porosity of 20-50%; several porous clusters further aggregate to form loose aggregates with a macroscopic particle size of 100 μm-2 mm (e.g., ...). Figure 2 and Figure 3 As shown in the figure, its appearance can be fibrous, powdery, or irregularly granular.

[0027] The porous aggregates are partially retained after drying, giving the final polyaryletherketone (PAEK) product the following unique physical properties: the specific surface area of ​​the PAEK, determined by nitrogen adsorption BET method, is 5-50 m². 2 / g, bulk density is 0.1-0.3g / cm³ 3 The oil absorption rate (dioctyl phthalate) is 0.5-1.5 g / g, and the internal porosity of the particles is 10-35% (mercury porosimetry).

[0028] Based on the above physical properties, the polyaryletherketone powder has the following special applications: (1) The matrix resin of high-filled composite materials: its porous structure can accommodate a higher proportion of fillers, and the "anchoring effect" between the fillers and the matrix can improve the interlaminar shear strength of the composite material. (2) Semiconductor and medical applications: Ultra-low ash content (≤0.1wt.%) and metal ion residue (<50ppm) enable it to meet the stringent purity requirements of wafer carriers, CMP rings and medical implants; (3) Porous support materials: Their high specific surface area makes them suitable as catalyst supports or heavy metal ion adsorbents; (4) Precursors for foaming materials or separation membranes: Their easy swelling and easy solubility are beneficial for preparing uniform and porous functional materials.

[0029] The porous aggregates disperse in the precipitant to form a flowing slurry, which is then fed into the next process.

[0030] The core objective of step S1 is to achieve the controlled precipitation of polyarylether ketone from solution to solid state and to give it a specific loose and porous morphology, which is a prerequisite for subsequent efficient separation and purification.

[0031] The criteria for determining whether step S1 meets the standards are: (1) The precipitated polyaryletherketone solids form a pumpable, uniform slurry in the precipitant without clumping or sticking to the wall; (2) The porosity of the obtained polyaryletherketone powder is controlled at 20-50%, and the macroscopic particle size distribution is 100μm-2mm; (3) After the precipitation process is completed, the diphenyl sulfone content dissolved in the precipitant reaches or approaches the saturation concentration at that temperature, that is, the single solvent replacement efficiency is not less than 90% (determined by sampling and analyzing the diphenyl sulfone concentration of the precipitant phase).

[0032] The precipitation temperature, shear rate, and residence time of polymer melt in the precipitation reactor can be adjusted according to the molecular weight and powder morphology of the target product. For example, the precipitation temperature, shear rate, and residence time can be adjusted according to the intrinsic viscosity (IV) or melt mass flow rate (MFR) of the target product, with the following empirical correlations: (1) For high molecular weight polyarylether ketones (IV>0.8dL / g or MFR<20g / 10min), a higher precipitation temperature (160-180℃) and a lower shear rate (linear velocity<3m / s) should be selected to prevent excessive deentanglement of molecular chains, which would result in overly fine particles. The residence time should be 15-30min. (2) For low molecular weight polyaryletherketone (IV<0.6dL / g or MFR>50g / 10min), a lower precipitation temperature (130-150℃) and a higher shear rate (linear velocity 5-10m / s) should be selected to promote its rapid curing and the formation of clusters with good structural strength. The residence time can be shortened to 5-15min. (3) For medium molecular weight polyetheretherketone (IV=0.6-0.8 dL / g or MFR=20-50 g / 10 min), the precipitation temperature, shear rate, and residence time should be the middle values ​​of the two above. Recommended values ​​are: precipitation temperature 145-165℃, shear rate (linear velocity) 3-6 m / s, and residence time 10-20 min. Within this range, the parameters can be adjusted by linear interpolation or small-scale experiments: the closer the molecular weight is to the high molecular weight range, the closer the parameters are to the high temperature, low shear, and long residence time side; the closer the molecular weight is to the low molecular weight range, the closer the parameters are to the low temperature, high shear, and short residence time side. This intermediate range can balance the porosity of the powder (controlled in the medium-high range of 25-40%) and particle strength, ensuring the efficiency of subsequent washing and replacement while avoiding separation difficulties caused by excessively fine powder.

[0033] Generally, the target porosity is positively correlated with precipitation temperature, negatively correlated with shear rate, and positively correlated with residence time within a certain range; those skilled in the art can optimize the parameters within the above range based on the molecular weight of the target product and the required powder morphology.

[0034] S2 separation The process is illustrated using a two-stage separation and re-pulping unit as an example: The slurry obtained in step S1 is passed sequentially through the pre-separator (referred to as the first-stage separator) of the first-stage separation and re-slurrying unit → pulping tank (referred to as the first-stage pulping tank) → pre-separator (referred to as the second-stage separator) of the second-stage separation and re-slurrying unit → pulping tank (referred to as the second-stage pulping tank) → final separator (referred to as the third-stage separator) for continuous solid-liquid separation.

[0035] Fresh precipitant and circulating precipitant from the precipitant circulation pipeline are added to the secondary pulping tank, where they are thoroughly mixed with the concentrated slurry discharged from the secondary separator. The residence time is controlled at 5-30 minutes to ensure that the diphenyl sulfone remaining in the polymer particle pores is fully dissolved and replaced by the precipitant. Fresh precipitant is only added from the secondary pulping tank, and the overflow from the secondary separator is returned counter-currently to the precipitation reactor for dilution and mixing, achieving counter-current series operation and maximizing the utilization of the precipitant.

[0036] The overflow from the primary separator (mainly containing diphenyl sulfone and precipitant, which is a pure organic system) is sent to the solvent recovery unit; the underflow slurry from the tertiary separator (a concentrated slurry containing precipitant, salt and polyarylether ketone solids, with a diphenyl sulfone residue of ≤0.5 wt.%) is sent to the next process.

[0037] Step S2 is the core step for achieving multi-stage countercurrent solvent replacement. The slurry obtained in step S1 undergoes at least one stage of "separation-concentration-re-slurrying" treatment. Each stage includes a solid-liquid separation step and a re-slurrying step in which the concentrated solid phase is mixed with the next stage (or fresh) precipitant.

[0038] Countercurrent series connection: The overflow liquid of the primary separator (rich in diphenyl sulfone) enters the solvent recovery unit; the secondary pulping tank introduces fresh and recovered precipitant; the overflow liquid of the tertiary separator is used as the repulping liquid of the primary pulping tank.

[0039] The criteria for determining whether step S2 meets the standards are: (1) The residual amount of diphenyl sulfone carried by polyaryletherketone solids in the underflow slurry of the final separator is ≤0.03% (based on solid weight). (2) The concentration of diphenyl sulfone in the overflow liquid of the first-stage pre-separator is not less than 90% of its saturated concentration in the precipitant at the operating temperature, indicating that the solvent replacement efficiency is high.

[0040] S3 Countercurrent Continuous Water Washing The underflow concentrated slurry from the final separator is introduced from the top of the washing tower. The tower contains multiple mixing chambers separated by baffles, each equipped with agitator blades. Under gravity, solid particles move downwards through the connections between the mixing chambers, forming multi-stage countercurrent contact with 80-100℃ deionized water introduced from the bottom of the tower and flowing upwards, thus continuously washing the slurry countercurrently.

[0041] The wet polyaryletherketone (PAEK) slurry containing water is continuously discharged from the bottom of the tower and sent to the dryer via the polymer wet slurry conveying pipeline. After drying, the PAEK product is obtained. Washing wastewater containing precipitant and salt is continuously discharged from the top of the tower and sent to the next process. The total washing water consumption is ≤15 tons / ton of PAEK, and the residence time of the slurry in the washing tower is 90-180 minutes.

[0042] The obtained polyaryletherketone product has the following characteristics: (1) Narrow molecular weight distribution: PDI of the final product < 2. In traditional processes (mechanical grinding + extraction), PDI is usually > 2. This indicates that the process of the present invention avoids the shearing damage to the molecular chains caused by mechanical grinding, thus maintaining the excellent intrinsic mechanical properties of the polymer.

[0043] (2) Consistency of ultra-low impurity levels: Not only is the ash content ≤0.1wt.% and the diphenyl sulfone residue <300ppm, but the stability brought by the continuous process is unmatched by the batch process.

[0044] (3) Complete retention of intrinsic properties: direct comparison of the mechanical properties of polyaryletherketones obtained by the process of the present invention and conventional processes (comparison at the same MFR). For example, the tensile yield stress of Example 1 (MFR 38) is 95 MPa, while conventional processes usually require higher polymerization temperatures (which can lead to branching) or more vigorous crushing to achieve a similar MFR.

[0045] S4 Dual-Path Solvent Distillation Recovery The entire distillation process is operated under nitrogen protection and is divided into two independent processing routes, A and B, to process pure organic systems and aqueous and saline systems, respectively.

[0046] Process A: Pure organic system of diphenyl sulfone and precipitant The overflow from the primary separator in step S2 is separated by vacuum distillation in a solvent deprecipitant distillation column. The solvent deprecipitant distillation column operates under reduced pressure and nitrogen protection. The precipitant collected at the top of the column is sent to a precipitant refining and recovery column for further purification. The diphenyl sulfone-rich stream from the bottom of the column enters the solvent refining and recovery column, which operates under reduced pressure and nitrogen protection. Diphenyl sulfone with a purity ≥99.9% is obtained at the top of the column and returned to the polymerization section for recycling via the solvent circulation pipeline. The bottom residue is treated as waste liquid. The diphenyl sulfone recovery rate is >90%, and the precipitant recovery rate is ≥95%.

[0047] Process B: Aqueous and saline system of precipitant + water + salt The washing wastewater from the top of the water washing tower in step S3 is fed into the extraction tower. Continuous countercurrent liquid-liquid extraction is performed using a haloalkane extractant (preferably chloroform).

[0048] The extractant phase (extractant + precipitant) is fed into a precipitant-extractant removal distillation column, operated under nitrogen protection. The extractant collected at the top of the column is recycled back to the extraction column. The bottom material enters a precipitant refining and recovery column, where a high-purity precipitant (purity ≥ 99.8%) is collected at the top and returned to the secondary pulping tank in step S2 via the precipitant circulation pipeline. The precipitant recovery rate is ≥ 95%, and the extractant loss is < 10%.

[0049] The raffinate (a brine solution containing trace amounts of extractant) is fed into a brine stripping column and stripped with hot nitrogen at 80-120°C. The nitrogen gas and trace extractant vapor at the top of the column are condensed to recover the extractant, and the nitrogen gas is reheated and recycled. A purified brine solution is obtained at the bottom of the column.

[0050] Compared with the prior art, the present invention has the following advantages: 1. This invention uses a precipitating agent to directly contact the polymer melt for solvent replacement, and polyaryletherketone is precipitated in situ as loose porous micro-aggregates. Inorganic salts are fully exposed on the particle surface and internal channels. The ash content of the polyaryletherketone product can be stably controlled below 0.1 wt.% through countercurrent displacement and countercurrent water washing.

[0051] 2. The solvent recovery unit of the present invention adopts a dual-tower vacuum distillation operation of a solvent deprecipitant distillation tower and a solvent refining and recovery tower. The solvent recovery rate is >90% and the purity is ≥99.9%. It can be directly reused in the polymerization section without affecting the product performance.

[0052] 3. This invention achieves a precipitant recovery rate of ≥95% and a purity of ≥99.8% through vacuum distillation in a solvent deprecipitant distillation tower and dehydration treatment in a precipitant refining and recovery tower, significantly reducing the consumption of fresh precipitant and waste liquid discharge.

[0053] 4. The continuous operation of this invention avoids intermittent batch differences, and the final polyaryletherketone product has an ash content of ≤0.1wt.% and a solvent residue of <300ppm, meeting the requirements of aerospace and electronic applications.

[0054] 5. The continuous post-processing system for polyaryletherketone polymerization products of the present invention does not require frequent heating and cooling, has high equipment utilization, and lower overall energy consumption than traditional intermittent post-processing, while also reducing labor costs. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the continuous post-processing system for polyaryletherketone polymerization products of the present invention.

[0056] Figure 2 This is one of the SEM images of the loose aggregates of polyaryletherketone precipitated in step S1 of the present invention.

[0057] Figure 3 This is the second SEM image of the loose aggregates of polyaryletherketone precipitated in step S1 of the present invention.

[0058] In the diagram, 1. Precipitation reactor; 2. Shear stirrer; 3. Primary sedimentation tank; 4. Primary pulping tank; 5. Secondary sedimentation tank; 6. Secondary pulping tank; 7. Tertiary sedimentation tank; 8. Washing tower; 9. Extraction tower; 10. Precipitator-extractant distillation tower; 11. Brine stripping tower; 12. Precipitator refining and recovery tower; 13. Solvent-deprecipitant distillation tower; 14. Solvent refining and recovery tower; 15. Polymer wet material conveying pipeline; 16. Precipitator circulation pipeline; 17. Solvent circulation pipeline. Detailed Implementation

[0059] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0060] The following examples illustrate the continuous post-processing technology for poly(arylether ether ketone) polymerization products of the present invention, using poly(arylether ether ketone) as an example. This process is implemented through the following continuous post-processing system for poly(arylether ether ketone) polymerization products: like Figure 1 As shown, the continuous post-processing system for polyetheretherketone (PEEK) polymerization products includes a precipitation reactor 1. The precipitation reactor 1 is connected to a PEEK melt delivery pipeline and is equipped with a shear stirrer 2 or a shear mixer. An atomizing nozzle, a rotating atomizing disc, or a porous distribution plate is installed at the PEEK inlet within the precipitation reactor 1. The precipitation reactor 1 is sequentially connected to at least one stage of separation and re-slurrying unit. Each separation and re-slurrying unit includes a pre-separator and a pulping tank connected to it. The pulping tank in the final stage of the separation and re-slurrying unit is connected to a final separator.

[0061] When a primary separation and re-pulping unit is set up, the overflow outlet of the pre-separator is connected to the solvent recovery unit through a pipeline, the pulping tank is connected to a fresh precipitant delivery pipeline, and the overflow outlet of the final separator is connected to the precipitation reactor 1 through a pipeline.

[0062] When two or more separation and repulping units are set up, the overflow outlet of the pre-separator in the first-stage separation and repulping unit is connected to the solvent recovery unit through a pipeline. The pulping tank in the last-stage separation and repulping unit is connected to a fresh precipitant delivery pipeline. The overflow outlet of the pre-separator in the last-stage separation and repulping unit is connected to the precipitation reactor 1 through a pipeline. The overflow outlet of the last separator is connected to the pulping tank in the penultimate separation and repulping unit through a pipeline. The overflow outlet of the pre-separator in the remaining separation and repulping units is connected to the pulping tank in the previous stage separation and repulping unit through a pipeline.

[0063] like Figure 1 As shown, the solvent recovery unit includes a solvent deprecipitant distillation column 13 and a solvent refining and recovery column 14 connected in sequence. The solvent deprecipitant distillation column 13 is connected to the precipitant refining and recovery column 12 via pipelines. The solvent refining and recovery column 14 is connected to a solvent circulation pipeline 17 and a waste liquid discharge pipeline 2.

[0064] The concentrated slurry outlet at the bottom of the final separator is connected to the water washing tower 8 via a pipeline. The water washing tower 8 is connected to an inlet pipeline, a polymer wet material conveying pipeline 15, and a washing wastewater conveying pipeline. The polymer wet material conveying pipeline 15 is connected to a drying tower, and the washing wastewater conveying pipeline is connected to an extraction tower 9.

[0065] Extraction tower 9 is connected to an extractant delivery pipeline. Extraction tower 9 is also connected via pipelines to a precipitant-to-extractant distillation tower 10 and a brine stripping tower 11. The precipitant-to-extractant distillation tower 10 is connected to an extractant recovery pipeline and a precipitant refining and recovery tower 12. The precipitant refining and recovery tower 12 is connected to a precipitant recovery pipeline, a waste liquid discharge pipeline, and a tail gas discharge pipeline. The precipitant recovery pipeline is connected to a precipitant circulation pipeline 16, which is connected to a fresh precipitant delivery pipeline. The brine stripping tower 11 is connected to a hot nitrogen delivery pipeline, a tail gas discharge pipeline, and a brine discharge pipeline.

[0066] Among them, the pre-separator and the final separator can be a settling tank or a cyclone separator.

[0067] Example 1 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using NMP as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: 250 kg of NMP preheated to 140°C is pre-placed in precipitation reactor 1. Shear stirrer 2 is turned on, and the speed is adjusted to 1000 rpm, with an impeller linear velocity of approximately 3.5 m / s. The polyetheretherketone melt is synthesized via nucleophilic substitution polycondensation, specifically composed of approximately 7.8 kg of polyetheretherketone, approximately 30 kg of diphenyl sulfone solvent, approximately 2.2 kg of sodium fluoride salt, and other trace impurities are negligible. In this embodiment, approximately 40 kg of this melt is used as the processing target. 40 kg of the polyetheretherketone-containing polymer melt at approximately 310°C is injected in a thin stream into the stirred NMP. The stream is formed through a distribution plate with multiple small holes, and the average droplet diameter is 0.4 mm. After injection, stirring continues for 10 minutes, and the polyetheretherketone precipitates as a loose, porous, fine powder, forming a flowing slurry. The slurry is then fed to the next process.

[0068] S2: The slurry sequentially passes through primary settling tank 3 → primary pulping tank 4 → secondary settling tank 5 → secondary pulping tank 6 → tertiary settling tank 7. Fresh NMP and circulating NMP returned from the precipitant circulation line 16 are added to secondary pulping tank 6, totaling 200 kg; overflow from tertiary settling tank 7 is returned to primary pulping tank 4. Each pulping tank is stirred and mixed at 140℃ for 10 min. Polyetheretherketone (PEEK) precipitates as a loose, porous, fine powder. Samples are taken, and after nitrogen purging to remove surface NMP, the porosity is measured to be 35% using mercury intrusion porosimetry, and the particle size is measured to be 50-500 μm using scanning electron microscopy. This powder forms a flowing slurry.

[0069] The overflow from the primary settling tank 3 is sent to step S4 for solvent recovery. The underflow concentrate from the tertiary settling tank 7 is sent to the next process, and a sample is taken to test the residual diphenyl sulfone content, which is 0.008 wt.%.

[0070] S3: The concentrated slurry from the three-stage settling tank 7 is introduced from the top of the washing tower 8. The tower contains six mixing chambers separated by baffles, each equipped with frame-type stirring blades at a rotation speed of 20 rpm. Deionized water at 85°C is introduced from the bottom of the tower at a flow rate of approximately 60 L / h, with a total water consumption of approximately 96 kg. The slurry resides in the washing tower 8 for approximately 180 min. The wet material from the bottom of the tower is sent to a dryer via polymer wet material conveying pipeline 15 and vacuum-dried at 150°C for 12 h, yielding approximately 7.78 kg of polyetheretherketone (PEEK) product, with diphenyl sulfone residue <100 ppm and salt residue <1000 ppm. The washing wastewater from the top of the tower is sent to the next process.

[0071] S4: The overflow from the primary settling tank 3 in step S2 (containing approximately 28 kg of diphenyl sulfone and NMP) is sent to the solvent deprecipitant distillation column 13. Under reduced pressure (10 kPa absolute pressure, nitrogen protection), NMP (98% purity) is collected from the top of the column and sent to the precipitant refining and recovery column 12 for further refining. The diphenyl sulfone-rich stream from the bottom of the column enters the solvent refining and recovery column 14. Under reduced pressure (3 kPa absolute pressure, bottom temperature approximately 250°C, nitrogen protection), approximately 27.6 kg of diphenyl sulfone (99.92% purity) is obtained from the top of the column and returned to the polymerization section for recycling via the solvent circulation pipeline 17. Based on the total amount of diphenyl sulfone in the feed solution, the diphenyl sulfone recovery rate is 92.1%.

[0072] The washing wastewater (containing NMP, fluoride salts, and water) from the top of the water washing tower 8 in step S3 is sent to the extraction tower 9. Chloroform is used as the extractant, with a chloroform-to-water mass ratio of approximately 1:3, and the operation is at room temperature. The extracted phase is sent to the precipitant removal distillation tower 10 (nitrogen protection, atmospheric pressure), and the chloroform (98.5% purity) collected from the top is recycled back to the extraction tower 9. The bottom material enters the precipitant refining and recovery tower 12 (vacuum distillation, 8 kPa absolute pressure), and NMP (99.82% purity) is collected from the top and returned to the secondary pulping tank 6 in step S2 via the precipitant circulation pipeline 16. The total NMP recovery rate is 95.8%.

[0073] The remaining aqueous phase was fed into brine stripping column 11, where residual chloroform was stripped off with hot nitrogen at 110°C. The nitrogen and chloroform vapor at the top of the column were condensed to recover chloroform, and the nitrogen was reheated and recycled. The residual chloroform was reduced to below 5 ppm, with a chloroform loss of 8.5%.

[0074] All indicators of the product test results meet the typical application requirements of aerospace-grade or electronic-grade polyetheretherketone (PEEK) materials. The test results are shown in Table 1. Specifically, the ash content of PEEK was tested according to GB / T 9345.1-2008 "Determination of Ash Content in Plastics - Part 1: General Method"; the melt flow rate was tested according to GB / T 3682.1-2018 "Determination of Melt Flow Rate (MFR) and Melt Volume Flow Rate (MVR) in Thermoplastic Plastics - Part 1: Standard Method"; the tensile yield stress was tested according to GB / T 1040.1-2025 "Determination of Tensile Properties of Plastics - Part 1: General"; the flexural strength was tested according to GB / T 9341-2008 "Determination of Flexural Properties of Plastics"; and the glass transition temperature (T0) was also tested. g The test was conducted according to GB / T 19466.2-2025 "Differential Scanning Calorimetry (DSC) for Plastics - Part 2: Determination of Glass Transition Temperature and Step Height"; the melting peak temperature (T...) mThe test was conducted in accordance with GB / T 19466.3-2025 "Differential Scanning Calorimetry (DSC) for Plastics - Part 3: Determination of Melting and Crystallization Temperatures and Enthalpy"; the molecular weight distribution index (PDI) was tested using the GPC method.

[0075] Table 1 Test Results of Polyetheretherketone Products

[0076] Summary of material recovery: NMP total recovery rate 95.8%, purity 98% (top of solvent deprecipitant distillation column 13) / 99.82% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 92.1%, purity 99.92%; chloroform recovery purity 98.5%, loss 8.5%.

[0077] Example 2 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using NMP as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Preheat 150 kg of NMP to 120°C to the precipitation reactor 1. Inject 40 kg of polymer melt containing polyether ether ketone at approximately 310°C into the precipitation reactor 1, and stir for 5 minutes. Other operations are the same as step S1 in Example 1.

[0078] S2: Fresh NMP and circulating NMP returned from the precipitant circulation pipeline 16 are added to the secondary pulping tank 6, totaling 50 kg; the pulping tanks at each stage are stirred and mixed at 120°C for 5 min. Other operations are the same as step S2 in Example 1. The diphenyl sulfone residue in the underflow concentrate of the tertiary sedimentation separation tank 7 is 0.01 wt.%.

[0079] S3: The total water consumption of water washing tower 8 is approximately 100 kg, and the residual diphenyl sulfone is <130 ppm. Other operations are the same as step S3 in Example 1.

[0080] S4: Same as step S4 in Example 1.

[0081] The product test results are shown in Table 2: Table 2 Test Results of Polyetheretherketone Products

[0082] Summary of material recovery: NMP total recovery rate 95.5%, purity 98% (top of solvent deprecipitant distillation column 13) / 99.83% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 92.8%, purity 99.9%; chloroform recovery purity 98.6%, loss 8.4%.

[0083] Example 3 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using NMP as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Preheat 250 kg of NMP to 180°C in precipitation reactor 1. Inject 40 kg of polymer melt containing polyether ether ketone at approximately 310°C into precipitation reactor 1, and stir for 20 min. Other operations are the same as step S1 in Example 1.

[0084] S2: Fresh NMP and circulating NMP returned from the precipitant circulation line 16 are added to the secondary pulping tank 6, totaling 320 kg; the pulping tanks at each stage are stirred and mixed at 140°C for 15 min. A sample of the underflow concentrate from the tertiary settling tank 7 is taken for testing, and the residual amount of diphenyl sulfone is 0.006 wt.%. Other operations are the same as step S2 in Example 1.

[0085] S3: The temperature of the deionized water introduced into the water washing tower 8 is 95°C. The residence time of the slurry in the water washing tower 8 is about 180 minutes. The total water consumption is about 110 kg. The residual diphenyl sulfone is <100 ppm. Other operations are the same as step S3 in Example 1.

[0086] S4: Same as step S4 in Example 1.

[0087] The product testing results are shown in Table 3: Table 3 Test Results of Polyetheretherketone Products

[0088] Summary of material recovery: NMP total recovery rate 95.2%, purity 98.1% (top of solvent deprecipitant distillation column 13) / 99.84% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 94%, purity 99.93%; chloroform recovery purity 98.5%, loss 8.7%.

[0089] Example 4 This embodiment adopts a single-stage separation and re-pulping unit scheme, omitting the secondary pulping tank 6 and the tertiary settling and separation tank 7. The product quality difference between the two-stage separation and re-pulping unit scheme and the single-stage separation and re-pulping unit scheme is compared and verified, specifically including the following steps: S1: Same as step S1 in Example 1.

[0090] S2: The slurry passes sequentially through primary settling tank 3 → primary pulping tank 4 → secondary settling tank 5. Fresh NMP and circulating NMP returned from the precipitant circulation pipeline 16 are added to primary pulping tank 4, totaling 200 kg; the overflow from secondary settling tank 5 is returned to sedimentation reactor 1. Each pulping tank is stirred and mixed at 140°C for 15 min. A sample is taken from the underflow concentrated slurry of secondary settling tank 5, and the residual diphenyl sulfone content is found to be 0.03 wt.%. Other operations are the same as step S2 in Example 1.

[0091] S3: The total water consumption of water washing tower 8 is approximately 110 kg, and the residual diphenyl sulfone is <300 ppm. Other operations are the same as step S3 in Example 1.

[0092] S4: Same as step S4 in Example 1.

[0093] The product testing results are shown in Table 4: Table 4 Test Results of Polyetheretherketone Products

[0094] Summary of material recovery: NMP total recovery rate 95.4%, purity 98.1% (top of solvent deprecipitant distillation column 13) / 99.8% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 92%, purity 99.9%; chloroform recovery purity 98.6%, loss 8.3%.

[0095] Comparing Examples 1 and 4, it can be seen that the polyether ether ketone product obtained by adopting the single-stage separation and re-slurrying unit has a higher ash content than the two-stage separation and re-slurrying unit scheme, but it is still significantly better than the traditional post-processing process (>0.1wt.%). Moreover, the separation and re-slurrying unit is reduced by one stage, which is suitable for product specifications with moderately relaxed requirements for ash content.

[0096] Example 5 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using NMP as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Same as step S1 in Example 1.

[0097] S2: Same as step S2 in Example 1.

[0098] S3: The temperature of the deionized water introduced into the water washing tower 8 is 80°C. The residence time of the slurry in the water washing tower 8 is about 90 minutes. The total water consumption is about 90 kg. The residual diphenyl sulfone is <200 ppm. Other operations are the same as step S3 in Example 1.

[0099] S4: Same as step S4 in Example 1.

[0100] The product test results are shown in Table 5: Table 5 Test Results of Polyetheretherketone Products

[0101] Summary of material recovery: NMP total recovery rate 96%, purity 98.2% (top of solvent deprecipitant distillation column 13) / 99.87% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 93.2%, purity 99.91%; chloroform recovery purity 98.7%, loss 7.6%.

[0102] Example 6 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using NMP as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Same as step S1 in Example 1.

[0103] S2: Same as step S2 in Example 1.

[0104] S3: The temperature of the deionized water introduced into the water washing tower 8 is 95°C. The residence time of the slurry in the water washing tower 8 is about 180 minutes. The total water consumption is about 100 kg. The residual diphenyl sulfone is <90 ppm. Other operations are the same as step S3 in Example 1.

[0105] S4: Same as step S4 in Example 1.

[0106] The product test results are shown in Table 6: Table 6 Test Results of Polyetheretherketone Products

[0107] Summary of material recovery: NMP total recovery rate 96.5%, purity 98.1% (top of solvent deprecipitant distillation column 13) / 99.81% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 93.8%, purity 99.93%; chloroform recovery purity 98.3%, loss 8.2%.

[0108] Comparing Example 1 and Example 6, it can be seen that under the conditions of higher temperature and longer residence time of the deionized water introduced into the water washing tower 8, the ash content of the product is further reduced to 0.04%, which verifies the deep desalination effect of high washing temperature and long residence time, and provides a process solution for electronic grade polyether ether ketone products.

[0109] Example 7 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using DMF as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Preheat 250 kg of DMF to 140°C into precipitation reactor 1, and inject 40 kg of polymer melt containing polyether ether ketone at approximately 310°C into precipitation reactor 1. Stir and hold for 15 min. Other operations are the same as step S1 in Example 1.

[0110] S2: The slurry is sequentially passed through a primary hydrocyclone separator → primary pulping tank 4 → secondary hydrocyclone separator → secondary pulping tank 6 → tertiary hydrocyclone separator. Fresh DMF and circulating DMF returned from the precipitant circulation line 16 are added to the secondary pulping tank 6, totaling 80 kg; each pulping tank is stirred and mixed at 140°C for 15 min. Other operations are the same as step S2 in Example 1. A sample of the underflow concentrate from the tertiary hydrocyclone separator was taken and tested; the residual amount of diphenyl sulfone was 0.008 wt.%.

[0111] S3: The temperature of the deionized water introduced into the water washing tower 8 is 95°C. The residence time of the slurry in the water washing tower 8 is about 120 minutes, and the diphenyl sulfone residue is <100ppm. Other operations are the same as step S3 in Example 1.

[0112] S4: Solvent purification and recovery tower 14 is operated under reduced pressure (absolute pressure 2 kPa). Other operations are the same as step S4 in Example 1.

[0113] The product test results are shown in Table 7: Table 7 Test Results of Polyetheretherketone Products

[0114] Summary of material recovery: DMF total recovery rate 95.5%, purity 98.3% (top of solvent deprecipitant distillation column 13) / 99.83% (precipitant refining and recovery column 12); diphenyl sulfone recovery rate 93.8%, purity 99.93%; chloroform recovery purity 98.8%, loss 7.2%.

[0115] Example 8 This embodiment demonstrates a continuous post-processing technology for polyetheretherketone (PEEK) polymerization products using sulfolane as a precipitant and chloroform as an extractant, employing a two-stage separation and re-slurrying unit. The specific steps include: S1: Preheat 250 kg of sulfolane to 180 °C in precipitation reactor 1, and inject 40 kg of polymer melt containing polyether ether ketone at approximately 310 °C into precipitation reactor 1. Stir and hold for 10 min. Other operations are the same as step S1 in Example 1.

[0116] S2: Fresh sulfolane and circulating sulfolane from the precipitant circulation pipeline 16 are added to the secondary pulping tank 6, totaling 150 kg. Other operations are the same as step S2 in Example 1. The residual amount of diphenyl sulfone in the underflow concentrate of the tertiary settling separation tank 7 is 0.012 wt.%.

[0117] S3: The temperature of the deionized water introduced into the water washing tower 8 is 95°C. The residence time of the slurry in the water washing tower 8 is about 120 minutes, and the diphenyl sulfone residue is <150ppm. Other operations are the same as step S3 in Example 1.

[0118] S4: Solvent deprecipitant distillation column 13 is operated under reduced pressure (absolute pressure 3 kPa, nitrogen protection); solvent purification and recovery column 14 is operated under reduced pressure (absolute pressure 1 kPa, column bottom temperature approximately 260°C, nitrogen protection). Other operations are the same as step S4 in Example 1.

[0119] The product testing results are shown in Table 8: Table 8 Test Results of Polyetheretherketone Products

[0120] Summary of material recovery: Sulfolane total recovery rate 95%, purity 98.7% (top of solvent deprecipitant distillation column 13) / 99.84% (precipitant refining and recovery column 12); Diphenyl sulfone recovery rate 91.5%, purity 99.9%; Chloroform recovery purity 98.5%, loss 7.6%.

[0121] The results of this embodiment show that even when using sulfolane with a boiling point as high as 285°C as a precipitant, the purity of diphenyl sulfone can still reach 99.9% and the recovery rate is >90% through high-vacuum distillation, which verifies the adaptability of the process of the present invention to high-boiling-point precipitants.

[0122] Example 9 Under the premise that steps S1 and S4 are completely consistent with those in Example 1, the residence time in the pulping tank and the temperature of the deionized water introduced into the washing tower 8 were adjusted respectively, for a total of 6 sets of tests. The test results of each set of tests are shown in Table 9: Table 9. Detection results of 6 groups of tests

[0123] As shown in Table 9, when the residence time in the pulping tank is ≥10 min and the deionized water temperature is ≥90℃, the ash content of the product can be stably controlled at <0.1%. A residence time of 15 min in the pulping tank, combined with 95℃ deionized water in the washing tower 8, yields a high-quality polyetheretherketone (PEEK) product with 0.05% ash and PDI=1.6. The diphenyl sulfone recovery rate slightly increases with the extension of the pulping tank residence time, indicating that more thorough interstage solvent replacement is beneficial for subsequent distillation recovery. This embodiment establishes a clear multivariate operating window between "pulping tank residence time - deionized water temperature - ash content - PDI - diphenyl sulfone recovery rate," providing a reliable basis for parameter selection and adjustment in industrial production.

[0124] Comparative Example 1 This comparative example uses a traditional steel belt cooling + mechanical crushing + acetone extraction + intermittent water washing post-treatment process. The treated material is 40 kg of polymer melt, identical to that in Example 1. Product indicators and material consumption are compared based on polymer melts of the same source and quality. Specific operations are as follows: 40 kg of a polymer melt containing polyetheretherketone (PEEK) at approximately 310°C was rapidly cooled on a steel belt condenser, causing the material temperature to drop quickly to below 80°C and solidify into dense lumps. These lumps were coarsely crushed and then fed into a mill for fine grinding to obtain powder. The powder was intermittently extracted 8 times with acetone in an extraction vessel (each extraction using 10 times the powder mass, approximately 64 kg / extraction, each extraction at 50°C for 1.5 hours, totaling 512 kg of acetone). It was then intermittently washed 8 times with deionized water in a washing vessel (each washing using 8 times the powder mass, approximately 16 kg / extraction, each washing at 90°C for 1.5 hours, totaling 128 kg of deionized water). Finally, it was vacuum dried at 150°C for 12 hours.

[0125] The process comparison between Example 1 and Comparative Example 1 is shown in Table 10: Table 10 Comparison of processes between Example 1 and Comparative Example 1

[0126] As can be seen from the comparison in Table 10, the continuous precipitation purification method of the present invention has significant improvements over the traditional process in terms of product purity, molecular weight distribution, solvent consumption, operational continuity and solvent recovery.

Claims

1. A continuous post-processing system for polyaryletherketone polymerization products, characterized in that, The system includes a precipitation reactor (1), which is connected to a polyaryletherketone melt delivery pipeline and is equipped with a shear stirrer (2) or a shear mixer. The precipitation reactor (1) is sequentially connected to at least one stage of separation and re-slurrying unit, which includes a pre-separator and a pulping tank connected thereto. The pulping tank in the final stage of separation and re-slurrying unit is connected to a final separator. When a first-stage separation and re-slurrying unit is installed, the overflow outlet of the pre-separator is connected to a solvent recovery unit via a pipeline. The pulping tank is connected to a fresh precipitant delivery pipeline, and the overflow outlet of the final separator is connected to the precipitation reactor (1) via a pipeline; when two or more separation and repulping units are set up, the overflow outlet of the pre-separator in the first-stage separation and repulping unit is connected to the solvent recovery unit via a pipeline, the pulping tank in the last-stage separation and repulping unit is connected to a fresh precipitant delivery pipeline, and the overflow outlet of the pre-separator in the last-stage separation and repulping unit is connected to the precipitation reactor (1) via a pipeline, and the overflow outlet of the final separator is connected to the solvent recovery unit. The overflow outlet is connected to the pulping tank in the penultimate separation and re-pulping unit via a pipeline. The overflow outlet of the pre-separator in the remaining separation and re-pulping units is connected to the pulping tank in the previous separation and re-pulping unit via a pipeline. The concentrated slurry outlet at the bottom of the final separator is connected to the washing tower (8) via a pipeline. The washing tower (8) is connected to an inlet pipeline, a polymer wet material conveying pipeline (15), and a washing wastewater conveying pipeline. The polymer wet material conveying pipeline (15) is connected to a drying tower, and the washing wastewater conveying pipeline is connected to an extraction tower. Tower (9); Extraction tower (9) is connected to an extractant delivery pipeline, and extraction tower (9) is connected to a precipitant de-extractant distillation tower (10) via a pipeline; precipitant de-extractant distillation tower (10) is connected to an extractant recovery pipeline and a precipitant refining and recovery tower (12), precipitant refining and recovery tower (12) is connected to a precipitant recovery pipeline, a waste liquid discharge pipeline and a tail gas discharge pipeline, the precipitant recovery pipeline is connected to a precipitant circulation pipeline (16), and the precipitant circulation pipeline (16) is connected to a fresh precipitant delivery pipeline.

2. The continuous post-processing system for polyaryletherketone polymerization products as described in claim 1, characterized in that, The pre-separator and the final separator are either sedimentation tanks or cyclone separators.

3. The continuous post-processing system for polyaryletherketone polymerization products as described in claim 1, characterized in that, The precipitation reactor (1) is equipped with an atomizing nozzle, a rotating atomizing disc, or a porous distribution plate at the polyaryletherketone inlet.

4. The continuous post-processing system for polyarylether ketone polymerization products as described in claim 1, characterized in that, The solvent recovery unit includes a solvent deprecipitant distillation column (13) and a solvent refining and recovery column (14) connected in sequence. The solvent deprecipitant distillation column (13) is connected to the precipitant refining and recovery column (12) through a pipeline. The solvent refining and recovery column (14) is connected to a solvent circulation pipeline (17) and a waste liquid discharge pipeline.

5. The continuous post-processing system for polyarylether ketone polymerization products as described in claim 1, characterized in that, The extraction tower (9) is connected to a brine stripping tower (11) via pipelines. The brine stripping tower (11) is connected to a hot nitrogen delivery pipeline, a tail gas discharge pipeline, and a brine discharge pipeline.

6. A continuous post-processing technology for polyaryletherketone polymerization products, characterized in that, The process is carried out using the continuous post-processing system for polyarylether ketone polymerization products as described in any one of claims 1-5, and includes the following steps: S1 Shear Precipitation: The polymer melt after the polymerization of polyaryletherketone is completed is transported to the precipitation reactor (1) and stirred and dispersed with a liquid precipitant at 120-180℃ pre-placed in the precipitation reactor (1); during this process, the diphenyl sulfone solvent in the polymer melt diffuses and migrates to the precipitant phase, and the polyaryletherketone undergoes solvent-induced crystallization and is dispersed in the precipitant to form a slurry; the precipitant is an aromatic solvent, an aprotic polar solvent, or a halogenated aromatic solvent; S2 Separation: The slurry at the bottom of the precipitation reactor (1) is transported to the separation and re-slurrying unit. When a primary separation and re-slurrying unit is set up, the fresh precipitant and the circulating precipitant returned from the precipitant circulation pipeline (16) are transported to the pulping tank and stirred and mixed with the concentrated slurry formed after solid-liquid separation by the pre-separator for re-slurrying. This allows the residual diphenyl sulfone solvent in the pores of the polymer particles to be fully dissolved and replaced by the precipitant. The overflow liquid from the pre-separator is transported to the solvent recovery unit for diphenyl sulfone solvent recovery. The slurry in the pulping tank then enters the final separator for solid-liquid separation. The overflow liquid from the final separator is returned to the precipitation reactor (1) to participate in the polymer melt. When two or more separation and re-pulping units are set up, the fresh precipitant and the circulating precipitant returned by the precipitant circulation pipeline (16) are transported to the pulping tank in the last separation and re-pulping unit. The overflow liquid of the pre-separator in the last separation and re-pulping unit is returned to the precipitation reactor (1). The overflow liquid of the pre-separator in the first separation and re-pulping unit is transported to the solvent recovery unit for the recovery of diphenyl sulfone solvent. The overflow liquid of the last separator is transported to the pulping tank in the penultimate separation and re-pulping unit. The overflow liquid of the pre-separator in the remaining separation and re-pulping units is transported to the pulping tank in the previous separation and re-pulping unit. S3 Countercurrent Washing: The concentrated slurry at the bottom of the final separator is introduced from the top of the washing tower (8) and forms a countercurrent contact with the deionized water introduced from the bottom of the washing tower (8) and flowing upward, thus washing the concentrated slurry in a countercurrent manner; the water-containing polyaryletherketone wet material is continuously discharged from the tower bottom and transported to the dryer through the polymer wet material conveying pipeline (15), and the polyaryletherketone product is obtained after drying; S4 Dual-path Solvent Distillation and Recovery: The overflow liquid from the pre-separator is treated by the solvent recovery unit for solvent recovery. The recovered diphenyl sulfone solvent is returned to the polyarylether ketone polymerization section for recycling. The washing wastewater from the top of the water washing tower (8) is sent to the extraction tower (9) for continuous countercurrent liquid-liquid extraction. The extracted phase is sent to the precipitant de-extractant distillation tower (10). Under nitrogen protection, the extractant collected from the top of the tower is recycled back to the extraction tower (9). The bottom material enters the precipitant refining and recovery tower (12). The precipitant collected from the top of the tower is returned to the pulping tank through the precipitant circulation pipeline (16).

7. The continuous post-processing technology for polyarylether ketone polymerization products as described in claim 6, characterized in that, In step S1, the polymer melt is injected into the precipitation reactor (1) in the form of a fine stream or spray; the volume ratio of polymer melt to precipitant is 1:(3-7), and the precipitation residence time is 1-60 min.

8. The continuous post-processing technology for polyarylether ketone polymerization products as described in claim 6, characterized in that, In step S2, the mixing temperature of the slurry and fresh precipitant or overflow liquid in the pulping tank is 40-200℃, and the mixing time is 5-30 min.

9. The continuous post-processing technology for the polyarylether ketone polymerization product as described in claim 6, characterized in that, In step S3, the residence time of the concentrated slurry in the water washing tower (8) is 90-180 min, and the temperature of the deionized water is 40-100℃.

10. The continuous post-processing technology for polyarylether ketone polymerization products as described in claim 6, characterized in that, In step S4, the raffinate at the top of the extraction tower (9) is transported to the brine stripping tower (11) and stripped with hot nitrogen at 80-120°C. The nitrogen and extractant vapor at the top of the brine stripping tower (11) are condensed, the extractant is recycled back to the extraction tower (9), and the nitrogen is recycled after reheating. The bottom of the tower is then purified brine solution.

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