Polyaryletherketone resin as well as preparation method and application thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to polyaryletherketone resin as well as a preparation method and application thereof. According to the invention, the molecular chain of the PAEK resin is terminated by the alkali metal salt of 4-hydroxybenzophenone, so that the effect of reducing the fluorine content of the PAEK resin on the premise of not changing the existing synthesis method is realized, and the problem that the fluorine element exists in the end group of the molecular chain of the PAEK resin is solved; in addition, a plurality of problems caused by adopting 4-fluorobenzophenone or 4-hydroxybenzophenone for end capping are avoided. Specifically, alkali metal salt of 4-hydroxybenzophenone can directly react with a fluorine end group, and is directly suitable for the existing synthesis method, so that the cost is saved; 4-hydroxybenzophenone has low reaction activity and is extremely sensitive to water molecules in the system, and the alkali metal salt of 4-hydroxybenzophenone can prevent water molecules from being introduced into the system in the end capping process, so that the reaction activity is improved, and the water molecules can be prevented from causing breakage and generation of defects of formed molecular chains.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a polyaryletherketone resin, its preparation method, and its applications. Background Technology

[0002] Polyaryletherketone (PAEK) materials, especially polyetheretherketone (PEEK), have become core materials for medical implants and high-end food contact devices due to their unique comprehensive properties. PEEK's molecular structure is characterized by repeating aromatic etherketone units, giving it extreme environmental tolerance: long-term operating temperatures can reach 260 degrees Celsius, and short-term heat resistance exceeds 315 degrees Celsius, while also possessing excellent mechanical strength (tensile strength greater than 90 MPa) and creep stability. Regarding biocompatibility, PEEK has passed all tests according to the ISO 10993 standard, confirming its lack of cytotoxicity and sensitization, and exhibiting excellent bioinertness in the human body.

[0003] Despite the superior performance of PEEK materials, their synthesis process suffers from inherent chemical defects that have long been overlooked. Currently, the mainstream industrial process for preparing PEEK relies on nucleophilic substitution polycondensation: using 4,4'-difluorobenzophenone (DFBP) and hydroquinone as monomers, the polymerization proceeds gradually in a diphenyl sulfone solvent under alkali metal carbonate catalysis at high temperatures of 300–320 degrees Celsius. This reaction mechanism results in polymer chains being predominantly end-capped with fluorine atoms, forming stable CF bonds. However, the generation of low-degree-of-polymerization segments is unavoidable during polymerization, and the presence of low-molecular-weight oligomers (molecular weight less than 10 kDa) significantly increases the proportion of fluorine end groups. Theoretical calculations show that when the degree of polymerization n is 5, the proportion of fluorine end groups exceeds 25 wt‰; even when n is increased to 100, the residual fluorine still exceeds 0.1 wt‰.

[0004] Currently, fluorine-free PAEK resins generally use 4-fluorobenzophenone as the capping agent. However, when using 4-fluorobenzophenone for capping, the amount of bisphenol monomer in the reaction system needs to be controlled to be greater than that of difluoro monomer to ensure that the molecular chain ends are hydroxyl groups in the later stages of the reaction. Before capping, a large number of reactive hydroxyl groups are more prone to chain structure defects and oxidation discoloration compared to fluorinated end groups composed of difluoro monomers, thus affecting product quality. After capping, if 4-fluorobenzophenone fails to react completely with the hydroxyl groups in the system, hydroxyl end groups will remain, directly affecting the stability and color of the product during processing. If 4-fluorobenzophenone is in excess, during solvent recovery, there will be indistinguishable 4-fluorobenzophenone residues in the solvent, directly affecting the molecular chain growth during polymerization using that solvent. Moreover, if 4-fluorobenzophenone remains in the subsequent purification process, it will directly become a harmful substance that endangers human health. Summary of the Invention

[0005] In view of this, the present invention provides a polyaryletherketone resin, its preparation method and application. The polyaryletherketone resin provided by the present invention has a low fluorine content and can avoid the above-mentioned problems of using 4-fluorobenzophenone for end-capping.

[0006] This invention provides a polyaryletherketone resin, wherein the end groups of the polyaryletherketone resin are ketone-benzene structure end groups; the structure of the ketone-benzene structure end groups is shown in Formula A: Formula A.

[0007] Preferably, the structure of the polyaryletherketone resin is as shown in Formula I: Formula I.

[0008] The present invention also provides a method for preparing the polyaryletherketone resin described above, comprising the following steps: The polyaryletherketone resin is obtained by polymerizing a mixture of hydroquinone, diphenyl sulfone, 4,4-difluorobenzophenone, alkali metal carbonate, and alkali metal salt of 4-hydroxybenzophenone.

[0009] Preferably, the molar ratio of hydroquinone to 4,4-difluorobenzophenone is 1:1 to 1:1.1; and the molar ratio of hydroquinone to the alkali metal salt of 4-hydroxybenzophenone is 100:1 to 100:20.

[0010] Preferably, the alkali metal salt of 4-hydroxybenzophenone includes one or both of the potassium salt and sodium salt of 4-hydroxybenzophenone.

[0011] Preferably, the method for preparing the alkali metal salt of 4-hydroxybenzophenone includes the following steps: mixing an alkali metal carbonate, diphenyl sulfone, and 4-hydroxybenzophenone to carry out a salt-forming reaction to obtain the alkali metal salt of 4-hydroxybenzophenone.

[0012] Preferably, the temperature of the salt formation reaction is 250-270 degrees Celsius, and the holding time is 1-2 hours.

[0013] Preferably, the polymerization reaction is further preceded by heating; the heating is a programmed heating; the programmed heating includes sequentially performing a first stage, a second stage, and a third stage; the temperature of the first stage is 200~210 degrees Celsius, and the holding time is 1~1.5 hours; the temperature of the second stage is 280~290 degrees Celsius, and the holding time is 1~1.5 hours; the temperature of the third stage is 310~320 degrees Celsius, and the holding time is 1~1.5 hours.

[0014] Preferably, the polymerization reaction is carried out at a temperature of 310-320 degrees Celsius and a holding time of 30-90 minutes; the polymerization reaction is carried out under stirring conditions.

[0015] The present invention also provides the application of the polyaryletherketone resin described in the above-described scheme or the polyaryletherketone resin prepared by the above-described scheme in the fields of medical implantation or food.

[0016] This invention provides a polyaryletherketone (PAEK) resin. By end-capping the molecular chain of PAEK resin with an alkali metal salt of 4-hydroxybenzophenone, this invention achieves a reduction in the fluorine content of PAEK resin without altering existing synthesis methods. This not only solves the problem of fluorine presence at the end groups of the PAEK resin molecular chain but also avoids many problems associated with end-capping with 4-fluorobenzophenone or 4-hydroxybenzophenone. Specifically: (1) The alkali metal salt of 4-hydroxybenzophenone can react directly with the fluorine end group, which is directly applicable to the existing synthesis method without the need to redesign the synthesis method. This saves huge trial and error costs for mass production.

[0017] (2) 4-hydroxybenzophenone has low reactivity and is extremely sensitive to water molecules in the system. Using alkali metal salts of 4-hydroxybenzophenone can avoid the introduction of water molecules into the system during the end-capping process, improve the reactivity, and further avoid water molecules causing the already formed molecular chains to break and produce defects.

[0018] (3) The alkali metal salt of 4-hydroxybenzophenone is easier to remove during solvent recovery, and the alkali metal salt of 4-hydroxybenzophenone is easily oxidized and turns yellow, which directly becomes a qualitative indicator of whether it has been cleaned, making it more suitable for existing solvent recovery and reuse processes.

[0019] This invention also provides a method for preparing the polyaryletherketone resin described above. The preparation method provided by this invention is simple in steps, has good safety, and is low in cost.

[0020] This invention also provides applications of the polyaryletherketone (PAEK) resin described in the above-described scheme or the PAEK resin prepared by the above-described method in the fields of medical implantation or food. This invention uses an alkali metal salt of 4-hydroxybenzophenone as a capping agent in the synthesis process of PAEK resin, achieving the effect of changing the end-group structure of PAEK resin without altering existing synthesis techniques, thus reducing the fluorine content of PAEK resin and making it more suitable for use in the fields of medical implantation or food. Attached Figure Description

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

[0022] Figure 1 The infrared spectrum of the PAEK resin prepared in Example 1; Figure 2 The infrared spectrum of the PAEK resin prepared in Comparative Example 1 is shown. Detailed Implementation

[0023] This invention provides a polyaryletherketone resin, wherein the end groups of the polyaryletherketone resin are ketone-benzene structure end groups; the structure of the ketone-benzene structure end groups is shown in Formula A: Formula A.

[0024] In this invention, the structure of the polyaryletherketone resin is preferably as shown in Formula I: Formula I.

[0025] The present invention also provides a method for preparing the polyaryletherketone resin described above, comprising the following steps: Hydroquinone, diphenyl sulfone (denoted as first diphenyl sulfone), 4,4-difluorobenzophenone, alkali metal carbonate (denoted as first alkali metal carbonate), and alkali metal salt of 4-hydroxybenzophenone are mixed (denoted as first mixture, to obtain first reaction solution) and subjected to polymerization reaction to obtain the polyaryletherketone resin.

[0026] In this invention, the first diphenyl sulfone is preferably molten diphenyl sulfone; the solid content of the first reaction solution is preferably 20:100~40:100, more preferably 25:100~35:100.

[0027] In this invention, the molar ratio of hydroquinone and 4,4-difluorobenzophenone is preferably 1:1 to 1:1.1, more preferably 1:1.05.

[0028] In this invention, the first alkali metal carbonate preferably includes one or both of sodium carbonate and potassium carbonate.

[0029] In this invention, the mass ratio of hydroquinone to the first alkali metal carbonate is preferably 1:1 to 1:1.5, more preferably 1:1.1 to 1:1.3.

[0030] In this invention, the alkali metal salt of 4-hydroxybenzophenone preferably includes one or both of the potassium salt and sodium salt of 4-hydroxybenzophenone; the structural formula of the alkali metal salt of 4-hydroxybenzophenone is shown in Formula II: Formula II; In Equation II, M is K or Na.

[0031] In this invention, the method for preparing the alkali metal salt of 4-hydroxybenzophenone preferably includes the following steps: mixing an alkali metal carbonate (referred to as the second alkali metal carbonate), diphenyl sulfone (referred to as the second diphenyl sulfone) and 4-hydroxybenzophenone (referred to as the second mixture) to carry out a salt-forming reaction to obtain the alkali metal salt of 4-hydroxybenzophenone.

[0032] In this invention, the second alkali metal carbonate preferably includes one or both of potassium carbonate and sodium carbonate.

[0033] In this invention, the mass ratio of the second alkali metal carbonate to 4-hydroxybenzophenone is preferably 1:1.1 to 1:2, more preferably 1:1.2 to 1:1.5.

[0034] In this invention, the second diphenyl sulfone is preferably molten diphenyl sulfone.

[0035] In this invention, the second mixing preferably includes the following steps: premixing a second alkali metal carbonate and a second diphenyl sulfone to obtain a premix, and stirring the premix with 4-hydroxybenzophenone.

[0036] In this invention, the second mixing is preferably carried out in a protective atmosphere; the protective atmosphere is preferably argon; the premixing temperature is preferably 160-180 degrees Celsius, more preferably 170 degrees Celsius.

[0037] In this invention, the preferred temperature for the salt-forming reaction is 250-270 degrees Celsius, more preferably 260 degrees Celsius, and the preferred holding time is 1-2 hours, more preferably 1.5 hours. This invention obtains a mixture of alkali metal salts of 4-hydroxybenzophenone (containing diphenyl sulfone and unreacted second alkali metal carbonate) through the salt-forming reaction, which is used for subsequent reactions.

[0038] In this invention, the molar ratio of hydroquinone and the alkali metal salt of 4-hydroxybenzophenone is preferably 100:1 to 100:20, more preferably 100:5 to 100:15.

[0039] In this invention, the first mixing preferably includes the following steps: mixing a first diphenyl sulfone, 4,4-difluorobenzophenone and a first alkali metal carbonate under vacuum conditions, heating the mixture after introducing a protective gas while keeping the flow rate of the protective gas constant, and then mixing the mixture with hydroquinone.

[0040] In this invention, the first mixing is preferably carried out under stirring conditions; the stirring conditions are preferably mechanical stirring; the vacuum degree of the vacuum conditions is preferably less than -0.1 MPa; the protective gas is preferably argon; the argon gas introduction rate is preferably 50-100 ml per minute; the target heating temperature is preferably 170-180 degrees Celsius, more preferably 175 degrees Celsius.

[0041] In this invention, the polymerization reaction preferably includes a heating process; the heating process is preferably a programmed heating process; the programmed heating process preferably includes a first stage, a second stage, and a third stage sequentially; the temperature of the first stage is preferably 200-210 degrees Celsius, more preferably 205 degrees Celsius, and the holding time is preferably 1-1.5 hours; the temperature of the second stage is preferably 280-290 degrees Celsius, more preferably 285 degrees Celsius, and the holding time is preferably 1-1.5 hours; the temperature of the third stage is preferably 310-320 degrees Celsius, more preferably 315 degrees Celsius, and the holding time is preferably 1-1.5 hours.

[0042] In this invention, the temperature of the polymerization reaction is preferably 310-320 degrees Celsius, more preferably 315 degrees Celsius, and the holding time is preferably 30-90 minutes, more preferably 40-70 minutes; the polymerization reaction is preferably carried out under stirring conditions.

[0043] In this invention, the polymerization reaction preferably further includes collecting, pulverizing, boiling in ethanol and boiling in water in sequence; the pulverization is preferably condensation pulverization.

[0044] The present invention also provides the application of the polyaryletherketone resin described in the above-described scheme or the polyaryletherketone resin prepared by the above-described scheme in the fields of medical implantation or food.

[0045] This invention uses the alkali metal salt of 4-hydroxybenzophenone as a capping agent in the synthesis process of PAEK resin, which achieves the effect of changing the end group structure of PAEK resin without changing the existing synthesis technology, reducing the fluorine content of PAEK resin, and making it more suitable for use in the medical implantation or food fields.

[0046] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. 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.

[0047] Example 1 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, potassium carbonate and diphenyl sulfone were mixed and heated to 180 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:1.1. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 270 degrees Celsius for 1 hour to obtain a mixture of potassium salts of 4-hydroxybenzophenone.

[0048] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and potassium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1 and the solid content of 20:100. Then, argon gas is introduced into the vacuum environment at a rate of 50 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 170 degrees Celsius to mix the raw materials and obtain a premix.

[0049] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to a molar ratio of 1:1 between hydroquinone and 4,4-difluorobenzophenone. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain a reaction solution.

[0050] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 200 degrees Celsius and held for 1.5 hours; then, it is raised to 280 degrees Celsius and held for 1 hour; then, it is raised to 320 degrees Celsius and held for 1 hour. After that, a mixture of potassium salt of 4-hydroxybenzophenone prepared in step (I) is added according to a molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:1, and the mixture is stirred continuously for 30 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0051] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0052] Example 2 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, potassium carbonate and diphenyl sulfone were mixed and heated to 160 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:1.13. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 250 degrees Celsius for 1 hour to obtain a mixture of potassium salts of 4-hydroxybenzophenone.

[0053] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and sodium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1 and the solid content of 20:100. Then, argon gas is introduced into the vacuum environment at a rate of 100 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 180 degrees Celsius to mix the raw materials and obtain a premix.

[0054] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to the molar ratio of hydroquinone to 4,4-difluorobenzophenone of 1:1.1. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain the reaction solution.

[0055] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 210 degrees Celsius and held for 1 hour; then, the temperature is raised to 280 degrees Celsius and held for 1 hour; then, the temperature is raised to 310 degrees Celsius and held for 1.5 hours. After that, a mixture of potassium salt of 4-hydroxybenzophenone prepared in step (I) is added according to a molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:10, and the mixture is stirred continuously for 90 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0056] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0057] Example 3 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, potassium carbonate and diphenyl sulfone were mixed and heated to 170 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:1.5. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 260 degrees Celsius for 1.5 hours to obtain a mixture of potassium salts of 4-hydroxybenzophenone.

[0058] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and potassium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1.5 and the solid content of 40:100. Then, argon gas is introduced into the vacuum environment at a rate of 80 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 175 degrees Celsius to mix the raw materials and obtain a premix.

[0059] (2) Under the conditions of mechanical stirring and argon, hydroquinone is weighed according to the molar ratio of hydroquinone to 4,4-difluorobenzophenone of 1:1.05. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain the reaction solution.

[0060] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 205 degrees Celsius and held for 1.2 hours; then, it is raised to 285 degrees Celsius and held for 1.5 hours; then, it is raised to 315 degrees Celsius and held for 1 hour. After that, a mixture of potassium salt of 4-hydroxybenzophenone prepared in step (I) is added according to the molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:20, and the mixture is stirred continuously for 50 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0061] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0062] Example 4 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, potassium carbonate and diphenyl sulfone were mixed and heated to 165 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:1.15. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 270 degrees Celsius for 1.5 hours to obtain a mixture of potassium salts of 4-hydroxybenzophenone.

[0063] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and potassium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1.5 and the solid content of 30:100. Then, argon gas is introduced into the vacuum environment at a rate of 90 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 172 degrees Celsius to mix the raw materials and obtain a premix.

[0064] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to the molar ratio of hydroquinone to 4,4-difluorobenzophenone of 1:1.1. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain the reaction solution.

[0065] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 200 degrees Celsius and held for 1.5 hours; then, it is raised to 280 degrees Celsius and held for 1 hour; then, it is raised to 315 degrees Celsius and held for 1 hour. After that, a mixture of potassium salt of 4-hydroxybenzophenone prepared in step (I) is added according to the molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:20, and the mixture is stirred continuously for 70 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0066] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0067] Example 5 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, sodium carbonate and diphenyl sulfone were mixed and heated to 175 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:2. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 265 degrees Celsius for 2 hours to obtain a mixture of sodium salts of 4-hydroxybenzophenone.

[0068] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and sodium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1.5 and the solid content of 30:100. Then, argon gas is introduced into the vacuum environment at a rate of 60 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 178 degrees Celsius to mix the raw materials and obtain a premix.

[0069] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to a molar ratio of 1:1 between hydroquinone and 4,4-difluorobenzophenone. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain a reaction solution.

[0070] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 205 degrees Celsius and held for 1.5 hours; then, it is raised to 280 degrees Celsius and held for 1.5 hours; then, it is raised to 314 degrees Celsius and held for 1.5 hours. After that, a mixture of sodium salt of 4-hydroxybenzophenone prepared in step (I) is added according to a molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:10, and the mixture is stirred continuously for 60 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0071] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0072] Example 6 (a) Synthesis of alkali metal salts of 4-hydroxybenzophenone: Under argon protection, sodium carbonate and diphenyl sulfone were mixed and heated to 160 degrees Celsius according to the mass ratio of alkali metal carbonate and 4-hydroxybenzophenone of 1:2. Then, 4-hydroxybenzophenone was added, and the mixture was stirred and heated to 270 degrees Celsius for 2 hours to obtain a mixture of sodium salts of 4-hydroxybenzophenone.

[0073] (II) Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and potassium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1.2 and the solid content of 30:100. Then, argon gas is introduced into the vacuum environment at a rate of 50 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 180 degrees Celsius to mix the raw materials and obtain a premix.

[0074] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to the molar ratio of hydroquinone to 4,4-difluorobenzophenone of 1:1.1. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain the reaction solution.

[0075] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 200 degrees Celsius and held for 1 hour; then, the temperature is raised to 280 degrees Celsius and held for 1 hour; then, the temperature is raised to 320 degrees Celsius and held for 1.5 hours. After that, a mixture of sodium salt of 4-hydroxybenzophenone prepared in step (I) is added according to a molar ratio of hydroquinone and alkali metal salt of 4-hydroxybenzophenone of 100:8, and the mixture is stirred continuously for 45 minutes to carry out the reaction. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0076] The polyaryletherketone resin prepared in this embodiment was subjected to fluorine element detection. The detection method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the detection result was "not detected".

[0077] Comparative Example 1 Synthesis of polyaryletherketone resins: (1) In a vacuum environment with a vacuum degree of less than -0.1 MPa, diphenyl sulfone, 4,4-difluorobenzophenone and potassium carbonate are mixed according to the mass ratio of hydroquinone and alkali metal carbonate of 1:1 and the solid content of 20:100. Then, argon gas is introduced into the vacuum environment at a rate of 50 ml per minute. While keeping the argon gas flow rate constant, the temperature is raised to 170 degrees Celsius to mix the raw materials and obtain a premix.

[0078] (2) Under mechanical stirring and in the presence of argon, hydroquinone is weighed according to a molar ratio of 1:1 between hydroquinone and 4,4-difluorobenzophenone. The weighed hydroquinone is added to the premix prepared in step (1) and mixed evenly to obtain a reaction solution.

[0079] (3) The reaction solution obtained in step (2) is subjected to a programmed temperature increase, which is carried out as follows: first, the temperature of the reaction solution is raised to 200 degrees Celsius and held at that temperature for 1.5 hours; then, the temperature is raised to 280 degrees Celsius and held at that temperature for 1 hour; then, the temperature is raised to 320 degrees Celsius and held at that temperature for 1 hour. After that, the reaction is carried out by continuous stirring for 30 minutes. After the reaction, the collected product is subjected to condensation and pulverization, ethanol boiling treatment and water boiling treatment to obtain polyaryletherketone resin.

[0080] The polyaryletherketone resin prepared in this comparative example was tested for fluorine content. The test method was in accordance with EN 14582:2016, the detection limit was 20 mg / kg, and the result was 1441 mg / kg.

[0081] Test Example 1 Infrared spectral analysis was performed on the polyaryletherketone resins prepared in Example 1 and Comparative Example 1, and the results are as follows: Figures 1-2 As shown. According to Figures 1-2As can be seen from the comparison of the infrared spectra of Example 1 and Comparative Example 1, it can be clearly observed that the spectrum of Example 1 is in the range of 690~720cm. -1 There are two sharp small peaks, which are characteristic peaks of the benzene ring end group; however, these two peaks are not present in Comparative Example 1, because the end group of the polyaryletherketone resin in Comparative Example 1 is (benzene)-fluorine, while the end group of the polyaryletherketone resin in Example 1 is (ketone)-benzene. The above results are consistent with the fluorine element detection data of the product.

[0082] The fluorine content detection data and infrared spectra from Example 1 and Comparative Example 1 demonstrate that the alkali metal salt of 4-hydroxybenzophenone successfully reacts with the fluorine at the molecular chain end of the polyaryletherketone resin, transforming the original (benzene)-fluorine end group into a (ketone)-benzene end group. This proves that the present invention can effectively reduce the fluorine content in polyaryletherketone resin.

[0083] The embodiments of the present invention have been described above; however, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A polyaryletherketone resin, characterized in that, The polyaryletherketone resin has ketone-benzene end groups; the structure of the ketone-benzene end groups is shown in Formula A: Formula A.

2. The polyaryletherketone resin according to claim 1, characterized in that, The structure of the polyaryletherketone resin is shown in Formula I: Formula I.

3. The method for preparing the polyaryletherketone resin according to any one of claims 1 to 2, characterized in that, Includes the following steps: The polyaryletherketone resin is obtained by polymerizing a mixture of hydroquinone, diphenyl sulfone, 4,4-difluorobenzophenone, alkali metal carbonate, and alkali metal salt of 4-hydroxybenzophenone.

4. The preparation method according to claim 3, characterized in that, The molar ratio of hydroquinone and 4,4-difluorobenzophenone is 1:1 to 1:1.1; The molar ratio of hydroquinone and the alkali metal salt of 4-hydroxybenzophenone is 100:1 to 100:

20.

5. The preparation method according to claim 3, characterized in that, The alkali metal salts of 4-hydroxybenzophenone include one or both of the potassium salt and sodium salt of 4-hydroxybenzophenone.

6. The preparation method according to claim 3, characterized in that, The preparation method of the alkali metal salt of 4-hydroxybenzophenone includes the following steps: An alkali metal carbonate, diphenyl sulfone, and 4-hydroxybenzophenone are mixed and subjected to a salt-forming reaction to obtain the alkali metal salt of the 4-hydroxybenzophenone.

7. The preparation method according to claim 6, characterized in that, The salt formation reaction is carried out at a temperature of 250-270 degrees Celsius for 1-2 hours.

8. The preparation method according to claim 3, characterized in that, The polymerization reaction is preceded by a temperature increase, which is a programmed temperature increase. The temperature rise process includes sequentially performing a first stage, a second stage, and a third stage; The temperature in the first stage is 200~210 degrees Celsius, and the holding time is 1~1.5 hours; The temperature in the second stage is 280~290 degrees Celsius, and the holding time is 1~1.5 hours; The temperature of the third stage is 310~320 degrees Celsius, and the holding time is 1~1.5 hours.

9. The preparation method according to claim 3 or 8, characterized in that, The polymerization reaction is carried out at a temperature of 310-320 degrees Celsius for 30-90 minutes. The polymerization reaction is carried out under stirring conditions.

10. The use of the polyaryletherketone resin according to any one of claims 1 to 2 or the polyaryletherketone resin obtained by the preparation method according to any one of claims 3 to 9 in the field of medical implantation or food.

Images