Hard sealing ring and its production process

Abstract

The application relates to the technical field of high polymer composite sealing materials, and discloses a hard sealing ring and a production process method thereof. The hard sealing ring is prepared from polyether ether ketone containing a coordination functional group, filament glass fiber, glass beads, nano attapulgite, polyetherimide and metal ion precursors containing a Schiff base metal complex. The polyether ether ketone is modified by amination and is introduced with a Schiff base structure, and the metal ion precursors are copper-based binoxygen Schiff base coordination precursors. Through melt blending, blank body forming and surface strengthening heat treatment, the surface layer structure of the sealing ring is further densified, the hardness and wear resistance are improved, the material interface combination and overall uniformity are improved, the deformation and abrasion risk after long-term pressure is reduced, the size stability and service reliability under a high low temperature range, high load and friction working condition are improved, and the application is suitable for large and medium-sized motors, pump valve equipment, mechanical transmission components and industrial sealing scenes.

Description

Technical Field

[0001] This invention relates to the field of polymer composite sealing materials technology, specifically to a hard sealing ring and its manufacturing process. Background Technology

[0002] Hard seals are widely used in large and medium-sized motors, pumps and valves, hydraulic systems, compressors, transmission equipment, and other industrial components. During long-term service, they often need to withstand various operating conditions simultaneously, including friction and wear, cyclic pressure, media erosion, and relatively high temperatures within a low-temperature range. Therefore, in addition to high mechanical strength and wear resistance, seal materials also need to maintain good dimensional stability and sealing reliability under continuous load and temperature fluctuations. As equipment operating conditions continue to increase, traditional single-resin or ordinary filler-modified systems are gradually showing insufficient adaptability under complex operating conditions.

[0003] Chinese patent application CN112341721A discloses a hard EPDM rubber material for sealing rings in water supply and drainage pipes. The technical solution mainly involves adding two or three of zinc oxide, cerium oxide, and titanium dioxide to an EPDM system, along with carbon black, tackifying resin, crosslinking agent, and antioxidant to improve the sealing ring's hardness, sealing performance, support strength, and water and high-temperature resistance. Therefore, it can be seen that... Therefore, existing technologies often improve overall performance by adjusting the ratio between the rubber matrix and conventional inorganic fillers and additives, mainly relying on carbon black reinforcement, heat-resistant modification of metal oxides, and crosslinking system adjustments. While these methods can improve the rigidity and wear resistance of the material to some extent, the limited interfacial bonding between the matrix resin and the inorganic reinforcing fillers, coupled with insufficient uniform dispersion of the fillers during preparation, easily leads to problems such as localized stress concentration and interfacial debonding after molding. This, in turn, affects the stability of the sealing ring under long-term pressure and reciprocating friction conditions. Especially under high loads or high low-temperature ranges, the internal structure of the material is prone to loosening and accelerated wear.

[0004] How to improve the interfacial coordination between the polymer, reinforcing filler, and functional precursor while ensuring the processability of the matrix resin, and combine this with subsequent heat treatment to improve the surface density, hardness, and wear resistance, thereby obtaining a hard sealing ring suitable for more complex working conditions, is a technical problem that needs to be solved in this field. Summary of the Invention

[0005] To achieve the above objectives, this application provides a rigid sealing ring and its manufacturing process. This application uses polyetheretherketone (PEEK) containing coordinating functional groups as the main resin, and introduces a metal ion precursor containing a Schiff base metal complex into the material system. This results in a matrix with not only high heat resistance but also a tighter interfacial bond. Compared to ordinary PEEK systems, this material is less prone to chain segment slippage and recovery issues during compression, friction, and repeated loading, and is less likely to experience early damage at the filler-matrix interface. Therefore, it maintains high hardness while also exhibiting low compression set and good wear resistance.

[0006] The present invention provides the following technical solution: a rigid sealing ring, wherein the raw materials for preparing the rigid sealing ring, by weight, include: 60-80 parts of polyetheretherketone containing coordinating functional groups; 10-20 parts of long-filament glass fiber; 10-20 parts of glass microspheres; 0.02-0.05 parts of nano-attapulgite clay; 1-20 parts of polyetherimide; and 0.1-10 parts of a metal ion precursor containing Schiff base metal complex; The glass fibers have an average length of 2–8 mm, an average diameter of 8–20 μm, and an aspect ratio of 100–800; the glass microspheres have an average particle size of 5–80 μm; the nano-attapulgite has an average particle size of 20–100 nm; and the polyetherimide is used to improve the interfacial compatibility between polyether ether ketone containing coordinating functional groups and reinforcing fillers and metal ion precursors, and to improve the structural uniformity of the composite material.

[0007] Furthermore, the polyether ether ketone containing coordinating functional groups is a modified polyether ether ketone that has undergone amination modification and then introduced with a Schiff base structure. The raw materials for preparing the modified polyether ether ketone include, by weight: 60-90 parts of polyether ether ketone; 5-25 parts of amination modifier; 3-20 parts of aldehyde-containing aromatic compound; 0.1-3 parts of glacial acetic acid as catalyst; 100-800 parts of Schiff basification condensation reaction medium; The aldehyde-containing aromatic compound is one or more of 2-pyridinecarboxaldehyde, 2,6-pyridinedicarboxaldehyde, salicylaldehyde, and 3-methoxysalicylaldehyde; the Schiff basicization condensation reaction medium is N,N-dimethylformamide; and the modified polyetheretherketone contains at least one coordination structure of an imine bond and a nitrogen-containing aromatic ring.

[0008] Furthermore, the amination modifying agent comprises, by weight percentage: 15%–40% dopamine hydrochloride; 20%–55% polyethyleneimine; 20%–50% tris(hydroxymethyl)aminomethane buffer component; and 10%–40% deionized water.

[0009] Furthermore, the method for preparing the polyether ether ketone containing coordinating functional groups includes: 1.1) Mix polyether ether ketone with an amination modifying agent and carry out an amination modification reaction at 40℃~120℃ for 0.5h~8h to obtain an amino-containing modified polyether ether ketone intermediate; 1.2) The amino-containing modified polyether ether ketone intermediate is added to the Schiff base condensation reaction medium, and the mixture is heated to 50℃~90℃ to disperse it. Then, an aldehyde-containing aromatic compound and glacial acetic acid are added, and the condensation reaction is carried out at 60℃~140℃ for 1h~12h to introduce a Schiff base structure into the modified polyether ether ketone. 1.3) After the reaction is complete, the product is cooled to 20℃~40℃, washed 4~6 times with deionized water and 70vol% ethanol solution, filtered through a 5~20μm filter medium, and dried at 80℃~120℃ for 4h~9h to obtain polyether ether ketone containing coordination functional groups.

[0010] Furthermore, the metal ion precursor containing the Schiff base metal complex is a copper-based dinitrogen oxide Schiff base coordination precursor, and the raw materials for preparing the copper-based dinitrogen oxide Schiff base coordination precursor include, by weight: The mixture contains 20-45 parts of hydroxy aromatic aldehydes; 15-40 parts of nitrogen-containing aromatic amines; 20-40 parts of copper salts; 0.1-5 parts of glacial acetic acid as a complexing modifier; and 100-600 parts of anhydrous ethanol as an organic solvent. The hydroxyl-containing aromatic aldehyde is one or more of salicylaldehyde, 3-methoxysalicylaldehyde, and 5-chlorosalicylaldehyde; the nitrogen-containing aromatic amine is one or more of 2-aminopyridine, 2-aminomethylpyridine, and o-phenylenediamine; and the copper salt is one or more of copper acetate, copper nitrate, and copper chloride.

[0011] Furthermore, the preparation method of the copper-based dinitrogen oxide Schiff base coordination precursor includes: 2.1) A hydroxyl-containing aromatic aldehyde and a nitrogen-containing aromatic amine were added to anhydrous ethanol and subjected to a condensation reaction at 40℃~80℃ under normal pressure for 0.5h~4h. The molar ratio of the hydroxyl-containing aromatic aldehyde to the nitrogen-containing aromatic amine was controlled to be (1:0.9)~(1:1.1) to obtain a Schiff base ligand solution. 2.2) Copper salt and glacial acetic acid were added in batches to the Schiff base ligand solution, and a complexation reaction was carried out at 50℃~120℃ for 1h~6h. After the complexation was completed, the mixture was kept at the temperature for 0.5h~3h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor reaction solution. 2.3) Cool the obtained reaction solution to 20℃~40℃, add isopropanol to induce crystallization, the volume ratio of isopropanol to the reaction solution is (0.2:1)~(2:1); then let it stand for 0.5h~10h to complete crystallization, and collect the solid product by atmospheric pressure filtration; wash the obtained solid with anhydrous ethanol 1~4 times, then wash with deionized water 1~3 times, and finally dry it at 50℃~100℃ and vacuum degree of 0.06MPa~0.095MPa for 4h~24h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor in powder form.

[0012] This application also relates to a manufacturing process for the rigid sealing ring described above, comprising the following steps: S1: Weigh out the components and corresponding contents of the raw materials for preparing the hard sealing ring as described in claim 1, including polyether ether ketone containing coordination functional groups, long glass fiber, glass microspheres, nano-attapulgite, polyetherimide, and metal ion precursor containing Schiff base metal complex. S2: Add the components weighed in step S1 into the mixing equipment and melt blend them at 280℃~380℃ to obtain a polymer composite material. S3: The polymer composite material is molded into a sealing ring blank; S4: Perform surface strengthening heat treatment on the sealing ring blank to improve the surface hardness and wear resistance of the sealing ring, thereby obtaining a hard sealing ring.

[0013] Furthermore, in step S3, the process of molding the polymer composite material into a sealing ring blank is one of compression molding, injection molding, or extrusion molding; during the molding process, the mold temperature is controlled at 180℃~250℃, and the holding time is 5min~30min.

[0014] Further, in step S4, the surface strengthening heat treatment specifically involves: placing the formed sealing ring blank in a heating device, preheating it to 200°C to 250°C, and then applying localized rapid heating to the surface of the sealing ring blank at a temperature higher than the preheating temperature, so that the surface temperature rises to 260°C to 300°C, in order to promote further densification of the sealing ring surface structure and improve the surface hardness.

[0015] Furthermore, the local rapid heating is achieved by a high-frequency induction heating device with a heating rate of 50℃ / s to 200℃ / s and a heating time of 5s to 60s. After the heating treatment is completed, the sealing ring blank is cooled in stages. First, it is cooled to 150℃ to 190℃ and maintained for 15min to 30min, and then cooled to room temperature to reduce internal stress and stabilize the surface reinforcement structure of the sealing ring.

[0016] The present invention has the following beneficial effects: 1. This application simultaneously incorporates long-filament glass fiber, glass microspheres, and nano-attapulgite, creating a relatively harmonious synergy in terms of reinforcement, friction reduction, and structural homogenization. Specifically, the long-filament glass fiber enhances the material's load-bearing capacity, the glass microspheres improve local stress distribution, and the nano-attapulgite helps refine the internal structure and reduce localized loose areas. With the combined effect of these components, the rigid sealing ring is less prone to rapid surface peeling under frictional wear conditions, and is also less susceptible to premature crack propagation due to localized stress concentration.

[0017] 2. This application incorporates polyetherimide into the material system, resulting in a more thorough interfacial connection between the modified polyetheretherketone, reinforcing filler, and metal ion precursor. This treatment reduces the likelihood of significant phase separation and loose zones within the composite material, leading to a more uniform dispersion of the filler within the matrix. Under external forces, stress can be transmitted over a wider area rather than concentrating at isolated weak points. Consequently, the resulting rigid sealing ring exhibits greater overall structural stability and less performance fluctuation under long-term pressure and repeated friction conditions.

[0018] 3. This application incorporates a surface-strengthening heat treatment step after molding. First, overall preheating is performed, followed by localized rapid heating, and finally, segmented cooling. This ensures that the heat primarily affects the surface area bearing friction and contact loads. After this treatment, the sealing ring surface becomes denser, with improved surface hardness and wear resistance, while the internal areas are less affected by heat, preventing a significant weakening of the material's supporting capacity due to prolonged high-temperature treatment. The resulting hardened sealing ring is more suitable for applications requiring both surface wear resistance and overall reliability. Attached Figure Description

[0019] Figure 1 The temperature change curves of the product surface and inner blank in the heat treatment staged heating and cooling of the rigid sealing ring preparation method of Example 2 are shown.

[0020] Figure 2 Box plots comparing the Shore hardness D of Examples 1-3 and Comparative Examples 1-3 are shown.

[0021] Figure 3 The graph shows the comparison results of the change in the compression permanent deformation rate of the hard sealing ring materials in Examples 1-3 and Comparative Examples 1-3 as a function of monitoring time.

[0022] Figure 4 The graph shows a comparison of the test results of the wear amount of the hard sealing rings prepared in Examples 1-3 and Comparative Examples 1-3.

[0023] Figure 5 Comparative images show the microstructure of the cross-sections of the hard sealing rings in Example 2, Comparative Example 2, and Comparative Example 3. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The polyetheretherketone used in this application embodiment was purchased from Zhongyan Co., Ltd.; the pyridine-2-formaldehyde (CAS No.: 1121-60-4) used was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd.; the pyridine-2,6-diformaldehyde (CAS No.: 5431-44-7) and dopamine hydrochloride used were purchased from Maclean; the salicylaldehyde (CAS No.: 90-02-8), glacial acetic acid and isopropanol used were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; the anhydrous ethanol and N,N-dimethylformamide used were purchased from Sinopharm Chemical Testing; the wear testing equipment used was Beijing Zhonghang Times M-200A; the scanning electron microscope used was Guoyi Quantum SEM3200; the vacuum drying oven used was Shanghai Yiheng DZF-6020; and the high-frequency induction heating equipment used was Zhengzhou Kechuang Electronics Co., Ltd. XG-40KW.

[0026] Example 1 This embodiment provides a rigid sealing ring and its manufacturing process. The raw materials for preparing the rigid sealing ring provided in this embodiment, by weight, include 60 parts of polyetheretherketone containing coordinating functional groups, 15 parts of long-filament glass fiber, 20 parts of glass microspheres, 0.035 parts of nano-attapulgite, 20 parts of polyetherimide, and 5 parts of copper-based dinitroxide Schiff base coordination precursor.

[0027] The glass fibers have an average length of 8 mm, an average diameter of 10 μm, and an aspect ratio of 800; the glass microspheres have an average particle size of 40 μm; and the nano-attapulgite has an average particle size of 20 nm.

[0028] The raw materials used in this embodiment for preparing polyether ether ketone containing coordinating functional groups include, by weight, 60 parts of polyether ether ketone, 25 parts of amylating modifier, 12 parts of 2-pyridinecarboxaldehyde, 3 parts of glacial acetic acid, and 100 parts of N,N-dimethylformamide.

[0029] The amination modifier comprises, by weight percentage: 15% dopamine hydrochloride, 25% polyethyleneimine, 50% tris(hydroxymethyl)aminomethane buffer, and 10% deionized water.

[0030] The preparation method of polyether ether ketone containing coordinating functional groups used in this embodiment includes the following steps: 1.1) First, mix 60 parts of polyether ether ketone with 25 parts of amination modification reagent and carry out the amination modification reaction at 120℃ for 0.5h to obtain an amino-containing modified polyether ether ketone intermediate. 1.2) Subsequently, the intermediate obtained in step 1.1) was added to N,N-dimethylformamide, heated to 50°C to disperse it, and then 12 parts of 2-pyridinecarboxaldehyde and 3 parts of glacial acetic acid were added. The condensation reaction was carried out at 140°C for 1 hour to introduce a Schiff base structure into the modified polyether ether ketone. 1.3) After the reaction was completed, the product was cooled to 40°C and washed 4 times with deionized water and 70 vol% ethanol solution alternately. After filtration through a filter medium with a pore size of 20 μm, it was dried at 80°C for 9 h to obtain polyether ether ketone containing coordination functional groups.

[0031] The raw materials used in this embodiment for preparing the copper-based dinitrogen oxide Schiff base coordination precursor, by weight, include: 20 parts salicylaldehyde, 40 parts 2-aminopyridine, 20 parts copper acetate, 5 parts glacial acetic acid, and 100 parts anhydrous ethanol.

[0032] The preparation method of the copper-based dinitrogen-oxygen Schiff base coordination precursor used in this embodiment includes the following steps: 2.1) Add 20 parts of salicylaldehyde and 40 parts of 2-aminopyridine to 100 parts of anhydrous ethanol and carry out a condensation reaction at 40°C under normal pressure for 4 hours. Control the molar ratio of salicylaldehyde to 2-aminopyridine to be 1:1.1 to obtain a Schiff base ligand solution. 2.2) Then, 20 parts of copper acetate and 5 parts of glacial acetic acid were added in batches to the Schiff base ligand solution obtained in step 2.1). The complexation reaction was carried out at 120°C for 1 hour, and the solution was kept warm and aged for 3 hours after the complexation was completed to obtain the copper-based dinitrogen oxide Schiff base coordination precursor reaction solution. 2.3) The obtained reaction solution was cooled to 20°C, and isopropanol was added to induce crystallization. The volume ratio of isopropanol to the reaction solution was 0.2:1. After standing for 10 h to complete crystallization, the solid product was collected by atmospheric pressure filtration. The obtained solid was washed 4 times with anhydrous ethanol, then washed once with deionized water, and finally dried at 100°C and a vacuum of 0.06 MPa for 4 h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor in powder form.

[0033] The manufacturing process of the rigid sealing ring provided in this embodiment includes the following steps: S1: Weigh out 60 parts of polyether ether ketone containing coordination functional groups, 15 parts of long glass fiber, 20 parts of glass microspheres, 0.035 parts of nano-attapulgite, 20 parts of polyetherimide and 5 parts of copper-based dinitroxide Schiff base coordination precursor by weight. S2: Add the above components into a mixing equipment and melt-blend at 300°C to obtain a polymer composite material; S3: Subsequently, the polymer composite material is molded, the mold temperature is controlled at 250℃, and the holding time is 5min, to obtain the sealing ring blank; S4: Place the obtained sealing ring blank in a high-frequency induction heating device, preheat the whole to 210℃, and then locally and rapidly heat the surface of the sealing ring blank to raise the surface temperature to 260℃. The heating rate is 50℃ / s, and the heating time is 30s. After the heat treatment is completed, the sealing ring blank is cooled in stages. First, it is cooled to 150℃ and maintained for 30min, and then cooled to room temperature to obtain a hard sealing ring.

[0034] Example 2 This embodiment provides a rigid sealing ring and its manufacturing process. The raw materials for preparing the rigid sealing ring provided in this embodiment, by weight, include 72 parts of polyetheretherketone with coordinating functional groups, 20 parts of long-filament glass fiber, 10 parts of glass microspheres, 0.05 parts of nano-attapulgite, 10 parts of polyetherimide, and 0.1 parts of copper-based dinitroxide Schiff base coordination precursor.

[0035] The glass fibers have an average length of 2 mm, an average diameter of 20 μm, and an aspect ratio of 100; the glass microspheres have an average particle size of 80 μm; and the nano-attapulgite has an average particle size of 60 nm.

[0036] The raw materials used in this embodiment for preparing polyether ether ketone containing coordinating functional groups, by weight, include 75 parts of polyether ether ketone, 15 parts of amylating modifier, 20 parts of 2,6-pyridinedicarboxaldehyde, 1.5 parts of glacial acetic acid, and 450 parts of N,N-dimethylformamide.

[0037] The amination modifier comprises, by weight percentage: 30% dopamine hydrochloride, 35% polyethyleneimine, 20% tris(hydroxymethyl)aminomethane buffer, and 15% deionized water.

[0038] The preparation method of polyether ether ketone containing coordinating functional groups used in this embodiment includes the following steps: 1.1) First, mix 75 parts of polyether ether ketone with 15 parts of amination modification agent and carry out the amination modification reaction at 80°C for 4 hours to obtain an amino-containing modified polyether ether ketone intermediate. 1.2) The intermediate was then added to N,N-dimethylformamide and heated to 70°C to disperse it. Then 2,6-pyridinedicarboxaldehyde and glacial acetic acid were added, and a condensation reaction was carried out at 100°C for 6 hours to introduce a Schiff base structure into the modified polyether ether ketone. 1.3) After the reaction is complete, the product is cooled to 30°C and washed 5 times alternately with deionized water and 70 vol% ethanol solution. After filtration through a filter medium with a pore size of 10 μm, it is dried at 100°C for 6 h to obtain polyether ether ketone containing coordination functional groups.

[0039] The raw materials used in this embodiment for preparing the copper-based dinitrogen oxide Schiff base coordination precursor, by weight, include 32 parts of 3-methoxysalicylaldehyde, 25 parts of 2-aminomethylpyridine, 30 parts of copper nitrate, 2 parts of glacial acetic acid, and 300 parts of anhydrous ethanol.

[0040] The preparation method of the copper-based dinitrogen-oxygen Schiff base coordination precursor used in this embodiment includes the following steps: 2.1) First, 32 parts of 3-methoxysalicylaldehyde and 25 parts of 2-aminomethylpyridine were added to 300 parts of anhydrous ethanol and condensed at 60°C under normal pressure for 2 hours. The molar ratio of 3-methoxysalicylaldehyde to 2-aminomethylpyridine was controlled to be 1:1.0 to obtain a Schiff base ligand solution. 2.2) Then, 30 parts of copper nitrate and 2 parts of glacial acetic acid were added in batches to the Schiff base ligand solution obtained in step 2.1), and the complexation reaction was carried out at 80°C for 3 hours. After the complexation was completed, the solution was kept warm and aged for 1.5 hours to obtain the copper-based dinitrogen oxide Schiff base coordination precursor reaction solution. 2.3) The obtained reaction solution was cooled to 30℃, and isopropanol was added to induce crystallization. The volume ratio of isopropanol to the reaction solution was 1.0:1. After standing for 4 hours to complete crystallization, the solid product was collected by filtration under normal pressure. The obtained solid was washed twice with anhydrous ethanol, then twice with deionized water, and finally dried at 75℃ and a vacuum of 0.08 MPa for 12 hours to obtain a copper-based dinitrogen oxide Schiff base coordination precursor in powder form.

[0041] The manufacturing process of the rigid sealing ring provided in this embodiment includes the following steps: S1: Weigh out 72 parts of polyether ether ketone containing coordination functional groups, 20 parts of long glass fiber, 10 parts of glass microspheres, 0.05 parts of nano-attapulgite, 10 parts of polyetherimide and 0.1 parts of copper-based dinitroxide Schiff base coordination precursor by weight. S2: Add the above components into a mixing equipment and melt-blend at 380°C to obtain a polymer composite material; S3: The polymer composite material is then molded, with the mold temperature controlled at 180°C and the holding time at 18 minutes, to obtain the sealing ring blank.

[0042] S4: The obtained sealing ring blank is placed in a high-frequency induction heating device, preheated to 200℃, and then the surface of the sealing ring blank is locally and rapidly heated to 300℃ at a heating rate of 125℃ / s for 60s. After the heat treatment, the sealing ring blank is cooled in stages: first cooled to 170℃ and maintained for 22min, and then cooled to room temperature to obtain a hard sealing ring.

[0043] Figure 1 The diagram shows the temperature change curves of the product surface and inner blank in the heat treatment staged heating and cooling process of the hard sealing ring preparation method of Example 2. From... Figure 1 As can be seen, the heat treatment in this application is divided into three continuous stages: overall preheating, localized rapid heating, and segmented cooling. The billet is heated from approximately 25°C to 200°C in about 20 minutes and held for about 5 minutes. At this point, the surface and internal temperatures are basically the same, indicating that the billet is already in a relatively uniform thermal state before the strengthening treatment. This preheating method can reduce the sudden temperature difference between the inside and outside caused by the subsequent instantaneous temperature rise of the surface layer, and also allows the subsequent surface strengthening to be based on a more stable temperature foundation.

[0044] During the localized rapid heating phase, the surface temperature rises rapidly from 200°C in approximately 25 minutes, while the internal temperature only rises from 200°C to approximately 225°C, a temperature difference of about 125°C. Considering the heating rate of 125°C per second and the holding time of 60 seconds, this phase does not involve raising the entire sealing ring to a high temperature. Instead, the heat is concentrated on the surface area, allowing the surface to achieve more thorough thermal compaction and structural adjustment in a shorter time, while the interior maintains a lower temperature. This approach improves surface hardness and wear resistance while avoiding brittleness and dimensional instability caused by prolonged high temperatures throughout the surface.

[0045] During the segmented cooling phase, the surface and internal temperatures both drop to 170°C after the rapid heating ends, and remain near this temperature for about 22 minutes before slowly decreasing to room temperature. Figure 1 During the approximately 28-50 minute cooling cycle, instead of rapid heating followed by direct natural cooling, a temperature stabilization phase was created through temperature control. Since the surface layer had already reached a high temperature in the previous stage (approximately 225°C internally), directly cooling to room temperature would exacerbate residual stress due to the difference in shrinkage between the internal and external layers. This application addresses this by incorporating a temperature stabilization phase within the segmented cooling process. This phase lowers both the surface and internal temperatures to 170°C and maintains this temperature before continuing cooling, which is more effective in releasing stress and preserving the strengthened surface layer.

[0046] Looking at the three stages as a whole, the heat treatment method according to this embodiment of the application first raises the overall temperature to 200°C for about 20 minutes, then heats the surface to 300°C with localized rapid heating for about 1 minute, while controlling the internal temperature at about 225°C, and finally holds at 170°C for 22 minutes before cooling to room temperature. Therefore, the manufacturing process of the hard sealing ring provided by this application does not involve placing the entire sealing ring blank under high-temperature conditions for an extended period. Instead, it first establishes a relatively stable temperature base through overall preheating, then applies a short-term rapid heating to the surface layer, and finally completes the heat treatment with segmented cooling. In this way, the heat mainly acts on the surface area that actually bears the friction and contact load, while the internal area is relatively less affected. Therefore, it is beneficial for improving surface hardness and wear resistance, and also helps reduce problems caused by excessive dimensional changes after heat treatment and insufficient structural stability during subsequent use.

[0047] Example 3 This embodiment provides a rigid sealing ring and its manufacturing process. The raw materials for preparing the rigid sealing ring provided in this embodiment, by weight, include 80 parts of polyetheretherketone containing coordinating functional groups, 10 parts of long-filament glass fiber, 15 parts of glass microspheres, 0.02 parts of nano-attapulgite clay, 1 part of polyetherimide, and 10 parts of copper-based dinitroxide Schiff base coordination precursor.

[0048] The glass fibers have an average length of 5 mm, an average diameter of 8 μm, and an aspect ratio of 625; the glass microspheres have an average particle size of 5 μm; and the nano-attapulgite has an average particle size of 100 nm.

[0049] The raw materials used in this embodiment for preparing polyether ether ketone containing coordinating functional groups include, by weight, 90 parts of polyether ether ketone, 5 parts of amylating modifier, 3 parts of salicylaldehyde, 0.1 parts of glacial acetic acid, and 800 parts of N,N-dimethylformamide.

[0050] The amination modifier comprises, by weight percentage: 40% dopamine hydrochloride, 20% polyethyleneimine, 20% tris(hydroxymethyl)aminomethane buffer, and 20% deionized water.

[0051] The preparation method of polyether ether ketone containing coordinating functional groups used in this embodiment includes the following steps: 1.1) First, mix 90 parts of polyether ether ketone with 5 parts of amination modification agent and carry out the amination modification reaction at 40°C for 8 hours to obtain an amino-containing modified polyether ether ketone intermediate. 1.2) Subsequently, the intermediate obtained in step 1.1) was added to N,N-dimethylformamide, heated to 90°C to disperse it, and then 3 parts of salicylaldehyde and 0.1 parts of glacial acetic acid were added. The condensation reaction was carried out at 60°C for 12 hours to introduce a Schiff base structure into the modified polyether ether ketone. 1.3) After the reaction was completed, the product was cooled to 20°C and washed 6 times with deionized water and 70 vol% ethanol solution alternately. After filtration through a filter medium with a pore size of 5 μm, it was dried at 120°C for 4 h to obtain polyether ether ketone containing coordination functional groups.

[0052] The raw materials used in this embodiment for preparing the copper-based dinitrogen oxide Schiff base coordination precursor, by weight, include: 45 parts of 5-chlorosalicylaldehyde, 15 parts of o-phenylenediamine, 40 parts of copper chloride, 0.1 parts of glacial acetic acid, and 600 parts of anhydrous ethanol.

[0053] The preparation method of the copper-based dinitrogen-oxygen Schiff base coordination precursor used in this embodiment includes the following steps: 2.1) First, 45 parts of 5-chlorosalicylaldehyde and 15 parts of o-phenylenediamine were added to anhydrous ethanol and condensed at 80°C under normal pressure for 0.5 h. The molar ratio of 5-chlorosalicylaldehyde to o-phenylenediamine was controlled to be 1:0.9 to obtain a Schiff base ligand solution. 2.2) Then, 40 parts of copper chloride and 0.1 parts of glacial acetic acid were added in batches to the Schiff base ligand solution obtained in step 2.1). The complexation reaction was carried out at 50°C for 6 hours, and the solution was kept warm and aged for 0.5 hours after the complexation was completed to obtain the copper-based dinitrogen oxide Schiff base coordination precursor reaction solution. 2.3) The obtained reaction solution was cooled to 40℃, and isopropanol was added to induce crystallization. The volume ratio of isopropanol to the reaction solution was 2.0:1. After standing for 0.5 h to complete crystallization, the solid product was collected by atmospheric pressure filtration. The obtained solid was washed once with anhydrous ethanol, then washed three times with deionized water, and finally dried at 50℃ and a vacuum of 0.095 MPa for 24 h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor in powder form.

[0054] The manufacturing process of the rigid sealing ring provided in this embodiment includes the following steps: S1: Weigh out 80 parts of polyether ether ketone containing coordination functional groups, 10 parts of long glass fiber, 15 parts of glass microspheres, 0.02 parts of nano-attapulgite, 1 part of polyetherimide, and 10 parts of copper-based dinitroxide Schiff base coordination precursor by weight.

[0055] S2: Add the above components to the mixing equipment and melt-blend at 280°C to obtain a polymer composite material. S3: The polymer composite material is then molded, with the mold temperature controlled at 215°C and the holding time at 30 minutes, to obtain the sealing ring blank.

[0056] S4: Place the obtained sealing ring blank in a high-frequency induction heating device, preheat the whole to 250℃, and then perform localized rapid heating on the surface of the sealing ring blank to raise the surface temperature to 280℃. The heating rate is 200℃ / s, and the heating time is 5s. After the heat treatment is completed, the sealing ring blank is cooled in stages. First, it is cooled to 190℃ and maintained for 15 minutes, and then cooled to room temperature to obtain a hard sealing ring.

[0057] Comparative Example 1 The only difference between this comparative example and Example 2 is that no metal ion precursor containing Schiff base metal complex is added; the rest of the raw material composition, preparation steps, and process conditions are the same as in Example 2.

[0058] Specifically, by weight, 72 parts of polyetheretherketone containing coordinating functional groups, 20 parts of long-filament glass fiber, 10 parts of glass microspheres, 0.05 parts of nano-attapulgite clay, and 10 parts of polyetherimide were weighed as prepared in Example 2, without adding copper-based dinitrogen oxide Schiff base coordination precursors. The above components were melt-blended at 420°C, and then molded into a sealing ring preform at a mold temperature of 180°C and a holding time of 18 minutes. Surface strengthening heat treatment was then performed as in Example 2 to obtain a hard sealing ring.

[0059] Comparative Example 2 The only difference between this comparative example and Example 2 is that the polyether ether ketone containing coordination functional groups is replaced with ordinary polyether ether ketone that has not undergone amination modification and Schiff basification treatment. The other raw material composition, preparation steps and process conditions are the same as in Example 2.

[0060] Specifically, by weight, 72 parts of commercially available polyetheretherketone, 20 parts of long-filament glass fiber, 10 parts of glass microspheres, 0.05 parts of nano-attapulgite clay, 10 parts of polyetherimide, and 0.1 parts of the copper-based dinitrogen oxide Schiff base coordination precursor prepared in Example 2 were weighed. The above components were melt-blended at 420°C, and then molded into a sealing ring blank at a mold temperature of 180°C and a holding time of 18 minutes. Surface strengthening heat treatment was then performed as in Example 2 to obtain a hard sealing ring.

[0061] Comparative Example 3 The only difference between this comparative example and Example 2 is that the surface strengthening heat treatment step is not performed; the other raw material composition, preparation steps, and process conditions are the same as in Example 2.

[0062] Specifically, by weight, 72 parts of polyetheretherketone containing coordinating functional groups prepared in Example 2, 20 parts of long-filament glass fiber, 10 parts of glass microspheres, 0.05 parts of nano-attapulgite, 10 parts of polyetherimide, and 0.1 parts of the copper-based dinitrogen oxide Schiff base coordination precursor prepared in Example 2 were weighed. The above components were melt-blended at 420°C, and then molded into a sealing ring preform at a mold temperature of 180°C and a holding time of 18 minutes. After molding, the preform was directly cooled to room temperature naturally without overall preheating, local rapid heating, or segmented cooling treatment, resulting in a hard sealing ring.

[0063] Five comparative tests were conducted to demonstrate the performance of the hard sealing rings prepared in the examples and comparative examples.

[0064] (I) Shore hardness D test The hard sealing rings prepared in Examples 1-3 and Comparative Examples 1-3 were tested for Shore hardness D. Figure 2As shown, the upright and inverted "T" shaped line segments above and below each column represent the extended range of values ​​for that group of samples after removing outliers. The small dots distributed around the top and bottom of the column represent the original data points obtained from each independent test. The black horizontal line in the middle of the column represents the median of the data group, and the cross in the middle represents the average value. Therefore, this graph can reflect both the concentration level of each group of samples and the degree of dispersion and repeatability. In terms of numerical values, the median of Example 2 is approximately 76.2, and the average value is also stable around 76, which is the highest among the six groups of samples, indicating that its hardness improvement is the most significant. The median of Example 1 is approximately 74.1, and that of Example 3 is approximately 72.0, both significantly higher than that of Comparative Example 1 (approximately 69.2), Comparative Example 2 (approximately 67.3), and Comparative Example 3 (approximately 63.0). Compared with Comparative Example 1, Example 2 shows an increase of approximately 7 Shore hardness; compared with Comparative Example 2, an increase of approximately 9; and compared with Comparative Example 3, an increase of approximately 13, which is already quite significant. Based on the substitutions in each comparative example, after removing the metal ion precursor containing Schiff base metal complex in Comparative Example 1, the hardness decreased from approximately 76 in Example 2 to approximately 69, indicating that the precursor has a direct effect on improving the material's hardness. After replacing the polyetheretherketone containing coordinating functional groups with ordinary polyetheretherketone in Comparative Example 2, the hardness further decreased to approximately 67, indicating that the synergistic effect formed between the modified polyetheretherketone and other components in the system is necessary to improve the surface mechanical properties of the finally prepared hard sealing ring. After canceling the surface strengthening heat treatment while retaining the formula, Comparative Example 3 had the lowest hardness, only about 63, indicating that in the preparation method provided in this application, the subsequent heat treatment step in step S4 for the sealing ring blank obtained in step S3 is the key step to truly release the performance of the polymer composite material obtained by mixing the material system used in step S1 in step S2. Furthermore, considering the column height and the distribution of the original data points, the data from Examples 1 to 3 are more concentrated overall. In particular, the column in Example 2 is more compact with shorter upper and lower whiskers, indicating that the hard sealing ring prepared in Example 2 not only has higher hardness but also exhibits less fluctuation in its Shore hardness D. This suggests that the hard sealing ring prepared in Example 2 also has better consistency in the sealing ring blank after molding in step S3. Therefore, this application demonstrates that the performance improvement is not achieved through a single component or a single step, but rather through the combination of polyetheretherketone containing coordinating functional groups, a metal ion precursor containing Schiff base metal complexes, and surface strengthening heat treatment, resulting in a more stable and significant improvement in the surface hardness of the hard sealing ring.

[0065] (II) Finished product compression set test The compression set of the hard sealing rings prepared in Examples 1-3 and Comparative Examples 1-3 was tested. During the molding process in step S3, the hard sealing ring materials of Examples 1-3 and Comparative Examples 1-3 were processed into cylindrical sealing ring blanks with a diameter of 29±0.5 mm and a thickness of 12.5±0.5 mm. A specified compression amount was set to 25% of the original thickness of the sample. The compression was continuously carried out in a constant temperature environment of 100±1℃ until the thickness of each sample was compressed to 9.4±0.3 mm. Referring to GB / T 7759.1-2015 "Determination of Compression Set of Vulcanized or Thermoplastic Rubber - Part 1: Under Normal and High Temperature Conditions", the samples were removed after 24 h, 48 h, 72 h, 96 h, and 120 h, respectively. After unloading the samples, the thickness recovery was measured, and the compression set was calculated.

[0066] like Figure 3As shown, Examples 1 to 3 of this application consistently showed lower values ​​than Comparative Examples 1 to 3 throughout the entire testing period, with Example 2 exhibiting the most stable performance. For example, at 48 hours, the compression set of Example 2 was approximately 9.1%, significantly lower than 10.9% for Example 1 and 11.8% for Example 3, and also significantly lower than 13.8% for Comparative Example 1, 15.2% for Comparative Example 2, and 18.4% for Comparative Example 3. At 120 hours, the relatively low percentage remained similar to that at 48 hours, with Example 2 at approximately 10.0%, Example 1 at approximately 12.4%, and Example 3 at approximately 13.4%, while Comparative Examples 1, 2, and 3 increased to 16.2%, 18.1%, and 22.0%, respectively. This indicates that the hard sealing ring prepared using the raw materials and methods provided in this application does not only exhibit low deformation in the initial stage but also maintains good recovery capability during continuous compression. Compared to Example 2, the technical solution of Comparative Example 1 showed a significant increase in compression set after removing the metal ion precursor containing Schiff base metal complexes. This indicates that the addition of the metal ion precursor containing Schiff base metal complexes to the raw materials can form more coordination sites in the matrix that can participate in stress regulation, making the material less prone to irreversible chain slippage and local loosening during continuous compression. Therefore, the thickness recovery after unloading is higher, and the compression set is correspondingly lower. Compared to Example 2, Comparative Example 2 showed a further increase in deformation rate after replacing the polyetheretherketone containing coordination functional groups with ordinary polyetheretherketone. This indicates that the polyetheretherketone containing coordination functional groups provides active sites that can bind with the metal ion precursor during the melt blending process in step S2, making it easier to form a tighter interfacial bond between the precursor, reinforcing filler, and matrix. When it is replaced by ordinary polyetheretherketone, this binding basis is weakened, and interfacial loosening and stress concentration are more likely to occur during compression, resulting in greater residual deformation after compression. Compared to Example 2, Comparative Example 3 changed the preparation method by omitting the surface strengthening heat treatment in step S4. Comparative Example 3 showed the highest values ​​in all monitoring periods, indicating that the surface strengthening heat treatment in step S4 of the preparation method provided in this application does not simply increase the surface hardness, but rather further compacts the surface structure of the sealing ring during subsequent heating and segmented cooling, while releasing some of the internal stress left over from the molding process. Without this step, the material is more likely to continuously undergo local yielding and deformation accumulation under long-term pressure, thus ultimately exhibiting a higher compressive permanent deformation rate.

[0067] (III) Wear test To compare the wear resistance differences of the hard sealing ring materials in Examples 1-3 and Comparative Examples 1-3 under friction conditions, wear tests were conducted using uniform sample specifications, uniform friction pair materials, and uniform operating parameters. The tests were conducted according to GB / T 3960-2016 "Plastics - Test Method for Sliding Friction and Wear," using an M-200 ring-block friction and wear testing machine. The friction rings were made of quenched 45 steel. Each group of samples was machined from the corresponding hard sealing ring blank into rectangular specimens of uniform size (30mm × 7mm × 6mm), and friction tests were conducted under conditions of 200N load, 200rpm rotation speed, and 0.42m / s linear velocity. The change in sample mass was measured before and after the test, and the wear amount of each group of samples was calculated accordingly to compare and analyze the wear resistance performance of hard sealing ring materials under different formulations and heat treatment conditions. The bar chart of the statistical analysis of the test results is shown below. Figure 4 As shown, Figure 4 Above each column are error lines representing the dispersion of the sample wear test results.

[0068] Example 2 showed the lowest wear amount, at only 14.9 mg, while Examples 1 and 3 showed 18.6 mg and 21.8 mg, respectively. All three were significantly lower than Comparative Example 1 (28.7 mg), Comparative Example 2 (33.5 mg), and Comparative Example 3 (41.2 mg). Taking Example 2 as an example, it showed a reduction of 13.8 mg compared to Comparative Example 1, 18.6 mg compared to Comparative Example 2, and 26.3 mg compared to Comparative Example 3, demonstrating a significant difference. Comparative Example 1, after removing the metal ion precursor containing Schiff base metal complexes, showed a significant increase in wear amount, indicating that the precursor, after entering the system, did not merely exist as a regular filler but provided more bonding nodes between the matrix and the reinforcing components, making it less prone to particle shedding and localized peeling during friction. In Comparative Example 2, replacing the polyetheretherketone (PEEK) containing coordinating functional groups with ordinary PEEK further increased the wear rate, indicating that the active sites provided by the modified matrix facilitate a tighter interfacial bond between the precursor and the matrix, thereby reducing interfacial loosening and crack propagation during friction. Comparative Example 3 showed the highest wear rate after eliminating the surface strengthening heat treatment, indicating that the subsequent heat treatment is not an incidental step but a crucial process for further compacting the surface structure and reducing loose areas and microcracks. In summary, this application, through the combination of modified PEEK, a copper-based precursor, and surface strengthening heat treatment, makes the hard sealing ring less prone to surface material loss under friction, thus exhibiting lower wear and better wear resistance.

[0069] (iv) Microscopic morphology observation of the cross-section of the hard sealing ring The radial cross-section along the thickness direction of the hard sealing rings prepared in Examples 2, 2, and 3 is the cross-sectional area extending inward from the outer surface subjected to friction and contact load to the core. This sampling method can simultaneously cover the surface reinforcement zone and the internal matrix zone, facilitating comparison of the density of the surface-treated tissue and the connection between the internal region and the internal structure. Specifically, samples including the outer surface layer were cut from the hard sealing rings corresponding to Examples 2, 2, and 3. A relatively realistic fracture cross-section was obtained using liquid nitrogen cryogenic fracture. The samples were then dried under vacuum, and gold or gold-palladium conductive sputtering was performed on the cross-sectional surface before observation using a scanning electron microscope. The observation conditions were set to secondary electron imaging mode, accelerating voltage of 5.0 kV, and working distance controlled between 10 mm and 11 mm. The overall interface morphology between the surface and the interior was first observed at approximately 250x magnification, and then the local particle bonding state, porosity, cracks, and surface compaction were observed at approximately 1000x magnification. The results are as follows: Figure 5 As shown.

[0070] like Figure 5 As shown in (a), in the radial cross-section of Example 2, the area near the outer surface layer is relatively continuous, and the transition from the surface layer to the internal matrix is ​​also relatively gentle, with no obvious through cracks observed overall. The local particle distribution is relatively uniform, and they maintain a relatively tight bond with the surrounding matrix. The cross-section as a whole exhibits a morphological characteristic of a relatively dense surface layer and a relatively uniform interior. This result indicates that Example 2 forms a better compacted structure in the outer region, with high surface integrity, while the internal matrix also has a relatively stable bond, thus its cross-sectional morphology is significantly more regular.

[0071] Figure 5 As shown in (b), although Comparative Example 2 maintained its basic formed structure, its cross-section showed more obvious cracks, and in some areas, the particles were not tightly bonded and the structure was discontinuous. The connection between the surface and the interior was also not as uniform as in Example 2. This morphology indicates that the material of Comparative Example 2 has obvious weak points at the interface, which are more likely to propagate along these areas during fracture, thus exhibiting the characteristics of increased cracks and loose structure. Figure 5 (a) Compared to the previous version, its cross-sectional integrity and density both decreased.

[0072] Figure 5 As shown in (c), the upper surface region of Comparative Example 3 exhibits more pronounced looseness and open cracks, with some peeling fracture surfaces visible locally. The surface continuity is significantly insufficient, and the underlying structure is also relatively coarse. This result indicates that without surface-strengthening heat treatment, the outer region cannot further form a denser compacted structure. The expected surface stabilization effect after heat treatment is not established, thus the cross-section is more prone to surface cracking, local collapse, and poor bonding. Its surface morphology is significantly inferior to that of Example 2.

[0073] comprehensive Figure 5 (a)- Figure 5 The comparative analysis in (c) shows that the cross-sectional morphology of Example 2 is more continuous and dense, with a more natural connection between the surface and the interior, indicating better external strengthening effect and overall structural stability. Comparative Example 2, on the other hand, mainly exhibits increased cracks and insufficient interfacial bonding, while Comparative Example 3 mainly shows a loose surface and obvious open cracks. This demonstrates that the technical solution of this application not only improves the internal bonding state of the material but also enhances the compaction degree and structural integrity of the surface area, resulting in a harder sealing ring with better density and stability in its cross-sectional structure. This is consistent with its superior hardness, wear resistance, and structural retention ability under pressure.

[0074] The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. The above description is only a preferred embodiment of this invention and is not intended to limit this invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A rigid sealing ring, characterized in that, The raw materials for preparing the rigid sealing ring, by weight, include: 60-80 parts of polyetheretherketone containing coordinating functional groups; 10-20 parts of long-filament glass fiber; 10-20 parts of glass microspheres; 0.02-0.05 parts of nano-attapulgite clay; 1-20 parts of polyetherimide; and 0.1-10 parts of a metal ion precursor containing Schiff base metal complex. The glass fibers have an average length of 2–8 mm, an average diameter of 8–20 μm, and an aspect ratio of 100–800; the glass microspheres have an average particle size of 5–80 μm; and the nano-attapulgite has an average particle size of 20–100 nm.

2. The hard sealing ring according to claim 1, characterized in that, The polyether ether ketone containing coordinating functional groups is a modified polyether ether ketone that has undergone amination modification and then introduced with a Schiff base structure. The raw materials for preparing the modified polyether ether ketone include, by weight: 60-90 parts of polyether ether ketone; 5-25 parts of amination modifier; 3-20 parts of aldehyde-containing aromatic compound; 0.1-3 parts of glacial acetic acid as catalyst; 100-800 parts of Schiff basification condensation reaction medium; The aldehyde-containing aromatic compound is one or more of 2-pyridinecarboxaldehyde, 2,6-pyridinedicarboxaldehyde, salicylaldehyde, and 3-methoxysalicylaldehyde; the Schiff basicization condensation reaction medium is N,N-dimethylformamide; and the modified polyetheretherketone contains at least one coordination structure of an imine bond and a nitrogen-containing aromatic ring.

3. The hard sealing ring according to claim 2, characterized in that, The amination-modifying reagent comprises, by weight percentage: 15%–40% dopamine hydrochloride; 20%–55% polyethyleneimine; 20%–50% tris(hydroxymethyl)aminomethane buffer; and 10%–40% deionized water.

4. The hard sealing ring according to claim 2, characterized in that, The method for preparing the polyether ether ketone containing coordinating functional groups includes: 1.1) Mix polyether ether ketone with an amination modifying agent and carry out an amination modification reaction at 40℃~120℃ for 0.5h~8h to obtain an amino-containing modified polyether ether ketone intermediate; 1.2) The amino-containing modified polyether ether ketone intermediate is added to the Schiff base condensation reaction medium, and the mixture is heated to 50℃~90℃ to disperse it. Then, an aldehyde-containing aromatic compound and glacial acetic acid are added, and the condensation reaction is carried out at 60℃~140℃ for 1h~12h to introduce a Schiff base structure into the modified polyether ether ketone. 1.3) After the reaction is complete, the product is cooled to 20℃~40℃, washed 4~6 times with deionized water and 70vol% ethanol solution, filtered through a 5~20μm filter medium, and dried at 80℃~120℃ for 4h~9h to obtain polyether ether ketone containing coordination functional groups.

5. The hard sealing ring according to claim 1, characterized in that, The metal ion precursor containing the Schiff base metal complex is a copper-based dinitrogen oxide Schiff base coordination precursor, and the raw materials for preparing the copper-based dinitrogen oxide Schiff base coordination precursor include, by weight: The mixture contains 20-45 parts of hydroxy aromatic aldehydes; 15-40 parts of nitrogen-containing aromatic amines; 20-40 parts of copper salts; 0.1-5 parts of glacial acetic acid as a complexing modifier; and 100-600 parts of anhydrous ethanol as an organic solvent. The hydroxyl-containing aromatic aldehyde is one or more of salicylaldehyde, 3-methoxysalicylaldehyde, and 5-chlorosalicylaldehyde; the nitrogen-containing aromatic amine is one or more of 2-aminopyridine, 2-aminomethylpyridine, and o-phenylenediamine; and the copper salt is one or more of copper acetate, copper nitrate, and copper chloride.

6. The hard sealing ring according to claim 5, characterized in that, The method for preparing the copper-based dinitrogen oxide Schiff base coordination precursor includes: 2.1) A hydroxyl-containing aromatic aldehyde and a nitrogen-containing aromatic amine were added to anhydrous ethanol and subjected to a condensation reaction at 40℃~80℃ under normal pressure for 0.5h~4h. The molar ratio of the hydroxyl-containing aromatic aldehyde to the nitrogen-containing aromatic amine was controlled to be (1:0.9)~(1:1.1) to obtain a Schiff base ligand solution. 2.2) Copper salt and glacial acetic acid were added in batches to the Schiff base ligand solution, and a complexation reaction was carried out at 50℃~120℃ for 1h~6h. After the complexation was completed, the mixture was kept at the temperature for 0.5h~3h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor reaction solution. 2.3) Cool the obtained reaction solution to 20℃~40℃, add isopropanol to induce crystallization, the volume ratio of isopropanol to the reaction solution is (0.2:1)~(2:1); then let it stand for 0.5h~10h to complete crystallization, and collect the solid product by atmospheric pressure filtration; wash the obtained solid with anhydrous ethanol 1~4 times, then wash with deionized water 1~3 times, and finally dry it at 50℃~100℃ and vacuum degree of 0.06MPa~0.095MPa for 4h~24h to obtain a copper-based dinitrogen oxide Schiff base coordination precursor in powder form.

7. A manufacturing process for a hard sealing ring as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Weigh out the components and corresponding contents of the raw materials for preparing the hard sealing ring as described in claim 1, including polyether ether ketone containing coordination functional groups, long glass fiber, glass microspheres, nano-attapulgite, polyetherimide, and metal ion precursor containing Schiff base metal complex. S2: Add the components weighed in step S1 into the mixing equipment and melt-blend them at 280℃~380℃ to obtain a polymer composite material. S3: The polymer composite material is molded into a sealing ring blank; S4: Perform surface strengthening heat treatment on the sealing ring blank to improve the surface hardness and wear resistance of the sealing ring, thereby obtaining a hard sealing ring.

8. The production process method according to claim 7, characterized in that, In step S3, the process of molding the polymer composite material into a sealing ring blank is one of compression molding, injection molding or extrusion molding; during the molding process, the mold temperature is controlled at 180℃~250℃ and the holding time is 5min~30min.

9. The production process method according to claim 7, characterized in that, In step S4, the surface strengthening heat treatment specifically involves placing the formed sealing ring blank in a heating device, preheating it to 200°C to 250°C, and then applying localized rapid heating to the surface of the sealing ring blank at a temperature higher than the preheating temperature, so that the surface temperature rises to 260°C to 300°C.

10. The production process method according to claim 9, characterized in that, The local rapid heating is achieved by a high-frequency induction heating device with a heating rate of 50℃ / s to 200℃ / s and a heating time of 5s to 60s. After the heating treatment is completed, the sealing ring blank is cooled in stages. First, it is cooled to 150℃ to 190℃ and maintained for 15min to 30min, and then cooled to room temperature.

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