Polyether ether ketone hybrid resin for 3d printing and method of making the same

Abstract

The application relates to a polyether ether ketone mixed resin for 3D printing and a preparation method thereof, which comprises the following steps: mixing hydroquinone and difluorobenzophenone, adding an inorganic salt catalyst and a diphenyl sulfone solvent, and performing a polymerization reaction; before the polymerization reaction is completed, mixing carbon fibers with the reactants to obtain a mixture; performing a first impurity removal treatment on the mixture to remove part of the diphenyl sulfone; performing a crushing treatment and a second impurity removal treatment on the reactants subjected to the first impurity removal treatment to obtain a polyether ether ketone mixed resin mixed with the carbon fibers. The method can simply and conveniently prepare the polyether ether ketone mixed resin which is small in particle size and uniform in mixing of the polyether ether ketone and the carbon fibers.

Description

Technical Field

[0001] This application relates to the field of polymer materials, specifically to polyetheretherketone mixed resins for 3D printing and their preparation methods. Background Technology

[0002] Polyetheretherketone (PEEK) is a high-performance engineering plastic widely used in aerospace, automotive manufacturing, electronics, medical, and food processing due to its high-temperature resistance, good self-lubrication, chemical resistance, radiation resistance, and superior mechanical properties. Selective laser sintering (SLS) is a 3D printing technology where a laser selectively melts a uniformly spread layer of powder to create the interface of the part, which is then sintered with the interface of the previous layer. This process is repeated layer by layer to create a complete part. While PEEK powder can be used in SLS, parts printed from pure PEEK powder using this technology only achieve a maximum strength of 80% of PEEK's inherent properties. To enhance its performance, it needs to be blended with other materials. However, PEEK resin mixed with carbon fiber and other materials still faces challenges such as difficulty in uniform dispersion, complex production processes, and a wide particle size distribution.

[0003] Therefore, polyetheretherketone (PEEK) mixed resins used for 3D printing and their preparation methods still need improvement. Summary of the Invention

[0004] This application provides a polyetheretherketone (PEEK) mixed resin for 3D printing and a method for preparing the same.

[0005] In a first aspect, this application proposes a method for preparing a polyetheretherketone (PEEK) mixed resin for 3D printing. The method includes mixing hydroquinone and difluorobenzophenone and adding an inorganic salt catalyst and diphenyl sulfone solvent to carry out a polymerization reaction; before the polymerization reaction is completed, mixing carbon fibers with the reactants to obtain a mixture; subjecting the mixture to a first impurity removal treatment to remove at least a portion of the diphenyl sulfone; and subjecting the reactants after the first impurity removal treatment to a pulverization treatment and a second impurity removal treatment to obtain a PEEK mixed resin containing the carbon fibers. This method can easily produce a PEEK mixed resin with small particle size and uniform mixing of PEEK and carbon fibers.

[0006] Specifically, this application involves adding carbon fibers to the system before the polyetheretherketone (PEEK) polymerization reaction is fully completed. After the carbon fibers and reactants are thoroughly mixed, at least part of the diphenyl sulfone is removed. This allows for thorough mixing during the product stage of the carbon fiber and PEEK reaction, and as the reaction continues, the carbon fibers are at least partially encapsulated within the polymer particles. After uniform mixing, partial removal of diphenyl sulfone, followed by pulverization and a second impurity removal process, reduces the strength and toughness of the particles during pulverization. This prevents the refined PEEK from absorbing and offsetting the energy of the pulverization impact through deformation, effectively reducing the particle size and obtaining a small-particle-size product with the desired particle size.

[0007] According to an embodiment of this application, the mixture is obtained by adding carbon fibers to a reaction vessel and mixing them with the reactants. The first impurity removal process includes adjusting the pressure inside the reaction vessel to a negative pressure to remove some of the diphenyl sulfone, and introducing an inert gas into the reaction vessel to discharge the reactants before performing the pulverization process. By adding carbon fibers before the complete polymerization of polyetheretherketone (PEEK) and then removing diphenyl sulfone, a uniform mixture of carbon fibers and PEEK can be achieved, resulting in a mixed resin with stable performance, good appearance, small particle size, high sphericity, and high purity.

[0008] According to an embodiment of this application, the pulverization process includes: subjecting the reactants that have undergone the first impurity removal treatment to a first pulverization process to obtain mixed coarse powder particles with a median particle size of 4-30 mesh; and subjecting the mixed coarse powder particles to a second pulverization process to obtain mixed fine powder particles, wherein the second pulverization process includes an air jet mill. This further improves the processing efficiency.

[0009] According to an embodiment of this application, the reaction vessel is equipped with a stirrer, and the mixing of carbon fibers and reactants is carried out under stirring conditions. This further ensures that the materials are mixed uniformly.

[0010] According to an embodiment of this application, the mixing of carbon fiber and reactants to obtain a mixture includes: before the polymerization reaction is completed, introducing an inert gas into the reactor to discharge the reactants onto a sheeting steel belt; subjecting the reactants discharged onto the sheeting steel belt to a first pulverization treatment to obtain coarse powder particles with a median particle size of 4-30 mesh; mixing the carbon fiber and the coarse powder particles and extruding and granulating them using a twin-screw extruder, and performing the first impurity removal treatment during the extrusion granulation process, the first impurity removal treatment including controlling the ambient pressure to negative pressure under vacuum to allow at least some diphenyl sulfone to volatilize. This improves the treatment effect; by adding carbon fiber before the complete polymerization of polyetheretherketone (PEEK) and then removing diphenyl sulfone and inorganic salts, a uniform mixture of carbon fiber and PEEK can be achieved, resulting in a mixed resin with stable performance, good appearance, small particle size, high sphericity, and high purity.

[0011] According to an embodiment of this application, the removal of a portion of the diphenyl sulfone comprises reducing the content of diphenyl sulfone in the system to 20%-70% of the diphenyl sulfone content in the reactants. This allows the particles to undergo appropriate deformation and absorption during subsequent processing, offsetting the energy from impacts and achieving breakage, while also appropriately reducing the content of diphenyl sulfone in the system.

[0012] According to an embodiment of this application, the second impurity removal process includes sequential washing with acetone and then pure water. This effectively removes residual solvent and impurities such as inorganic salts.

[0013] According to embodiments of this application, the length of the carbon fiber is 0.06-0.08 mm; the amount of carbon fiber added is 5-50% of the total mass of the mixture; the carbon fiber includes at least one of chopped carbon fiber, carbon fiber powder, or continuous carbon fiber. This effectively enhances the strength of the polyetheretherketone (PEEK) mixed resin while giving the PEEK mixed resin powder good flowability.

[0014] According to embodiments of this application, the polyetheretherketone (PEEK) mixed resin containing the carbon fibers satisfies at least one of the following conditions: a median particle size of 200-1000 mesh; and the content of diphenyl sulfone in the PEEK mixed resin is less than 0.1 wt%, and the content of the inorganic salt is less than 0.05 wt%. Thus, the PEEK mixed resin has a small particle size and high purity.

[0015] Secondly, this application proposes a polyetheretherketone (PEEK) mixed resin, which is prepared using the method described above. Therefore, this PEEK mixed resin has advantages such as stable performance, good appearance, small particle size, high sphericity, and high purity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0017] Figure 1 A schematic flowchart illustrating a method for preparing polyetheretherketone mixed resin according to some embodiments of this application; Figure 2 Here is a scanning electron microscope image of the polyetheretherketone mixed resin from Example 1; Figure 3 A scanning electron microscope image of the polyetheretherketone mixed resin of Comparative Example 1; Figure 4 This is a scanning electron microscope image of the polyether ether ketone mixed resin from Example 2. Detailed Implementation

[0018] The embodiments of this application are hereby disclosed in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0019] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, it is also expected that ranges of 60 to 110 and 80 to 120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise stated, the numerical range "a to b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 and 5" have been listed in this article; "0 to 5" is just a shortened representation of these numerical combinations. In addition, when a parameter is stated as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0020] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0021] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0022] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0023] This application is based on the inventor's research and discoveries on the following issues: Due to their excellent insulation properties, polyetheretherketone (PEEK) particles easily accumulate static electricity during friction or processing, which is difficult to dissipate or dissipate. Furthermore, their highly symmetrical molecular structure and high crystallinity result in low surface energy. This exacerbates the tendency for PEEK particles to agglomerate rather than disperse evenly with other materials when mixed and modified with other materials such as carbon fiber. Even with high-speed dispersers, uniform dispersion is difficult, leading to uneven resin performance and rough surfaces during use. Moreover, PEEK possesses high strength and toughness. The internal structure of refined coarse powder particles is porous, allowing them to absorb energy through deformation under shear and impact. Therefore, even after pulverization, the reduction in particle size is relatively small, resulting in generally large particle sizes for PEEK particles or powders. The median particle size (D50) of fine powder particles typically does not exceed 1000 mesh, and the sphericity of fine powder particles is relatively low. Furthermore, polyetheretherketone (PEEK) is prone to containing trace amounts of diphenyl sulfone and soluble inorganic salts. During the production process, a small amount of dust is usually mixed in, causing secondary pollution of the finished product. During the production process, there is a strong mutual collision between the material and the crushing equipment, which may mix in a small amount of metal particles, affecting product quality. At the same time, the production efficiency is relatively low and the energy consumption is high.

[0024] In addition, existing technologies include a scheme using a cryogenic pulverizer for pulverization. This scheme consumes a large amount of liquid nitrogen, increases product costs, has a complex process, requires highly skilled personnel to operate, and avoids frostbite. Furthermore, due to uneven mixing of materials and liquid nitrogen, the material cools at different rates, resulting in uneven particle size distribution of materials produced by the same production process and large differences in particle size between batches.

[0025] In view of this, this application proposes a method for preparing polyetheretherketone (PEEK) mixed resin for 3D printing. This method involves adding carbon fibers before the complete polymerization of PEEK, removing some diphenyl sulfone, followed by subsequent pulverization and further impurity removal. This achieves a uniform mixture of carbon fibers and PEEK, resulting in a mixed resin with stable performance, good appearance, small particle size, high sphericity, and high purity. Furthermore, this method is easy to produce and has high production efficiency.

[0026] In some embodiments of this application, reference is made to Figure 1 The method includes: S100: Hydroquinone and difluorobenzophenone are mixed and an inorganic salt catalyst and diphenyl sulfone solvent are added to carry out a polymerization reaction.

[0027] In this step, hydroquinone and difluorobenzophenone are mixed and an inorganic salt catalyst and diphenyl sulfone solvent are added to carry out a polymerization reaction. The polymerization reaction is carried out at a high temperature (250-350℃). The diphenyl sulfone solvent provides the reaction site. In the presence of inorganic salts (sodium carbonate or potassium carbonate), the hydroxyl groups of hydroquinone are deprotonated to form a more nucleophilic phenolate anion. The phenolate anion attacks the carbon atom attached to a fluorine atom in the difluorobenzophenone molecule, undergoing an aromatic nucleophilic substitution reaction, forming an ether bond and losing a fluorine ion. The newly formed molecule has a phenolate at one end and the remaining fluorine atom at the other end, and continues to react with another monomer molecule, thus repeatedly forming polyetheretherketone.

[0028] S200: After the polymerization reaction is completed and before the material is cooled, carbon fiber is mixed with the reactants to obtain a mixture.

[0029] In this step, after the polymerization reaction is complete and before cooling, the carbon fibers are mixed with the reactants to obtain a mixture.

[0030] In some embodiments of this application, carbon fibers can be added directly to the reactor after the polymerization reaction is completed but before cooling, for example, when the viscosity of the material reaches a predetermined level, allowing the carbon fibers to mix with the reactants to obtain a mixture. The specific timing of adding the carbon fibers can be selected by those skilled in the art according to requirements, as long as the material is still in a molten state. Therefore, carbon fiber mixing can be performed in advance while the material is still in a molten state. At this time, the reactants have not been purified, so the surface electrostatic interaction is weak, making it easier to obtain a homogeneous system. Furthermore, the molten state of the system allows for more complete encapsulation of the carbon fibers, thus enabling more uniform modification of polyetheretherketone (PEEK) using carbon fibers and improving the performance of the resulting resin material.

[0031] During the addition of carbon fiber, stirring components such as a stirring paddle can be used within the reactor for agitation. More specifically, the rotation speed of the stirring paddle can be increased to ensure that the polyether ether ketone (PEEK) formed in the reaction is evenly dispersed within the reactor, thereby achieving a uniform mixture of carbon fiber and PEEK.

[0032] In the above process, the inert gas may include nitrogen, which provides the driving force for the discharge of the high-temperature molten reactants and isolates oxygen to prevent oxidation of polyetheretherketone (PEEK). Discharging the reactants onto the sheeting steel belt allows for rapid cooling and solidification into brittle, glassy flakes. These brittle flakes facilitate subsequent pulverization, resulting in coarse powder particles with smaller particle sizes. The high-temperature molten reactants contain a large amount of diphenyl sulfone and inorganic salts, which also helps reduce the strength and toughness of the material, facilitating the pulverization process to obtain coarse powder particles with smaller particle sizes. This application can obtain coarse powder particles with a median particle size of 4-30 mesh, while the median particle size of coarse powder particles obtained by prior art is around 3 mm. These coarse powder particles include PEEK, diphenyl sulfone, and inorganic salts. The specific pulverization method for the first pulverization process is not particularly limited and can be mechanical pulverization.

[0033] In other embodiments of this application, the mixing of carbon fibers can also be carried out outside the reaction vessel, such as a reactor. Specifically, after the polymerization reaction is completed, the material is in a molten state. Before cooling, the discharge valve is opened, and inert gas is introduced into the reactor to allow the reactants to be discharged onto the agglomerating steel belt. Subsequently, the reactants discharged onto the agglomerating steel belt undergo a first crushing process to obtain coarse powder particles with a median particle size of 4-30 mesh. Subsequently, the carbon fibers and coarse powder particles are extruded and granulated using a twin-screw extruder, and the twin-screw extruder is used for simultaneous mixing and granulation to obtain a mixture.

[0034] Carbon fiber and coarse powder particles can be extruded and granulated using a twin-screw extruder to achieve mixing of carbon fiber and polyetheretherketone (PEEK). During extrusion, the carbon fiber and coarse powder particles can be mixed and fed into the main feed port of the twin-screw extruder, or the coarse powder particles can be fed into the main feed port while the carbon fiber is fed into the side feed port. During the extrusion granulation process, the feed section temperature can be 280-300℃, and the melt section temperature can be 290-320℃ to ensure uniform mixing of carbon fiber and PEEK.

[0035] Because this application mixes the carbon fibers before the polymerization reaction is completely completed, it can select carbon fibers of various morphologies and sizes without excessive control over the parameters of the carbon fibers, thus obtaining a relatively uniformly mixed system. Specifically, in some embodiments of this application, the length of the added carbon fibers can be 0.06-0.08 mm, for example, 0.06 mm, 0.065 mm, 0.07 mm, 0.075 mm, and 0.08 mm. Selecting carbon fibers with lengths within the above range can effectively enhance the strength of the polyetheretherketone (PEEK) mixed resin and also give the PEEK mixed resin powder good flowability.

[0036] In some embodiments of this application, the amount of carbon fiber added is 5-50% of the total mass of the mixture, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%. Keeping the amount of carbon fiber added within the above range can effectively enhance the strength of the polyether ether ketone (PEEK) mixed resin, while also giving the PEEK mixed resin powder good flowability.

[0037] In some embodiments of this application, the added carbon fiber may include at least one of chopped carbon fiber, carbon fiber powder, or continuous carbon fiber. Adding carbon fiber before the polyetheretherketone polymerization is complete increases the range of carbon fiber types that can be selected. When two or more types of carbon fiber are added, the specific proportions of the various carbon fibers are not particularly limited, and those skilled in the art can design the product according to the actual product performance.

[0038] S300: Perform a first impurity removal treatment on the mixture to remove some of the diphenyl sulfone.

[0039] In this step, the mixture undergoes a first impurity removal treatment to remove some of the diphenyl sulfone.

[0040] In some embodiments of this application, when carbon fiber is directly added to the reactor and mixed with the reactants to obtain a mixture, the mixture undergoes a first impurity removal treatment. Specifically, this can involve increasing the vacuum level of the reactor to create a negative pressure inside, lowering the boiling point of diphenyl sulfone, promoting the large-scale evaporation of diphenyl sulfone, and then cooling the mixture with a condenser to reduce the diphenyl sulfone content in the mixture to 20-70% of its original value. The negative pressure can be -0.09 to -0.095 MPa to ensure the large-scale evaporation of diphenyl sulfone. During the evaporation process, diphenyl sulfone can also simultaneously carry away some inorganic salts and other impurities from the reaction system.

[0041] In this embodiment, after the mixture undergoes a first impurity removal treatment, the vacuum is closed, the discharge valve is opened, and an inert gas is introduced into the reactor, allowing the reactants that have undergone the first impurity removal treatment to be discharged onto the agglomerating steel belt. The inert gas may include nitrogen, which provides the driving force for discharging the high-temperature molten reactants and simultaneously isolates oxygen to prevent oxidation of polyetheretherketone. Discharging the reactants onto the agglomerating steel belt allows the high-temperature molten reactants to cool rapidly and solidify into brittle, glassy flakes. These brittle flakes facilitate subsequent pulverization, resulting in mixed coarse powder particles with smaller particle sizes.

[0042] In some other embodiments of this application, when the reactants are discharged and crushed before the polymerization reaction ends, and then extruded and granulated with carbon fibers to obtain a mixture, the mixture is subjected to a first impurity removal treatment. Specifically, during the extrusion granulation process, a vacuum volatilization device is used to volatilize diphenyl sulfone, thereby reducing the content of diphenyl sulfone in the mixture.

[0043] According to an embodiment of this application, in the first purification process, the amount of diphenyl sulfone removed can be such that after the first purification process, the content of diphenyl sulfone in the system is reduced to 20-70% of the original content.

[0044] S400: The reactants that have undergone the first impurity removal treatment are subjected to pulverization and a second impurity removal treatment.

[0045] In this step, the reactants after the first impurity removal treatment are subjected to pulverization and a second impurity removal treatment to obtain a polyetheretherketone mixed resin containing carbon fibers. This is beneficial for obtaining resin particles with high purity and small particle size: before the second impurity removal treatment, a certain amount of impurities such as diphenyl sulfone and inorganic salts remain in the system. Therefore, during pulverization, the strength and toughness of the material are low, and the pores in the particles are filled with impurities such as diphenyl sulfone and inorganic salts, making them easier to be crushed by mechanical force, resulting in smaller particle size. After pulverization, the particle size is effectively reduced, and the second impurity removal treatment can further increase the contact area between the particles and the cleaning solution, thereby improving the effect of the second impurity removal treatment.

[0046] In some embodiments of this application, the reaction mixture after the first impurity removal treatment is pulverized, which may include: firstly pulverizing the reaction mixture after the first impurity removal treatment to obtain mixed coarse powder particles with a median particle size of 4-30 mesh. Subsequently, the mixed coarse powder particles are subjected to a second pulverization treatment to obtain mixed fine powder particles. The first pulverization treatment can be mechanical pulverization, and the mixed coarse powder particles include carbon fibers, polyetheretherketone (PEEK), diphenyl sulfone, and inorganic salts, resulting in mixed coarse powder particles with a smaller particle size (4-30 mesh). The second pulverization treatment may include a fluidized bed air jet mill, with a grinding air pressure of 0.8-0.9 MPa. This allows for relatively easy pulverization of the mixed coarse powder particles into mixed fine powder particles, which can then be screened by a grading device to obtain the product with the desired particle size. The air jet mill uses filtered clean gas, preventing material from colliding with the equipment and resulting in lower internal impurities. In contrast, in the prior art, the material comes into contact with and collides with the pulverizing equipment, introducing some metallic impurities. Therefore, this method can improve the purity and quality of the final PEEK mixed resin.

[0047] In some embodiments of this application, after pulverizing the reactants that have undergone the first impurity removal treatment, the process further includes a second impurity removal treatment. The second impurity removal treatment involves sequentially washing the mixed fine powder particles with acetone and then with pure water, i.e., a refining process. Specifically, acetone is first used to wash away diphenyl sulfone from the mixed fine powder particles, followed by pure water to wash away inorganic salts and residual acetone. Finally, the mixture is dried to obtain a polyether ether ketone mixed resin with higher purity. During the second impurity removal treatment, because the material is a fine powder, the contact area with acetone and pure water is large, making it easier to remove residual diphenyl sulfone and inorganic salts from the product, resulting in a product with higher purity, while reducing the consumption of acetone and pure water. In some specific embodiments of this application, the mixed fine powder particles are washed five times each with acetone and pure water to remove diphenyl sulfone and inorganic salts, whereas in the prior art, fifteen washings are required each time. Therefore, this application significantly reduces the consumption of acetone and pure water.

[0048] In some embodiments of this application, an integrated acetone washing, water washing and drying machine can be used to perform a second impurity removal treatment on the mixed fine powder particles to ensure product quality, reduce losses, reduce production steps and improve production efficiency.

[0049] This application adds carbon fibers while the material is still molten after the polymerization reaction and before cooling. This allows for the mixing of polyetheretherketone (PEEK) and carbon fibers before the removal of diphenyl sulfone and inorganic salts, effectively improving the problems of high hardness, smooth surface, difficulty in uniform mixing with carbon fibers, and difficulty in refining particles after PEEK polymerization. In the final PEEK mixed resin formed in this application, carbon fibers are encapsulated within the PEEK, with uniform distribution and controllable length ratio. In contrast, in existing technologies, PEEK powder and carbon fiber powder are separated, resulting in uneven distribution, fixed lengths, and inability to be adjusted arbitrarily according to product requirements. Furthermore, the particle size of the PEEK mixed resin can be controlled from 200 mesh to 1000 mesh. In addition, the final PEEK mixed resin has high purity, with diphenyl sulfone content below 0.1 wt.% and inorganic salt content below 0.05 wt.%.

[0050] In another aspect of this application, a polyetheretherketone (PEEK) mixed resin is provided, which is prepared using the method described above. Therefore, this PEEK mixed resin has advantages such as stable performance, good appearance, small particle size, high sphericity, and high purity.

[0051] Example The following embodiments describe the contents disclosed in this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of the embodiments of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0052] Example 1 (1) Hydroquinone, difluorobenzophenone, potassium carbonate and diphenyl sulfone solvent are added to the reactor to carry out the polymerization reaction.

[0053] (2) Before cooling down after the polymerization reaction, carbon fiber powder is added directly to the reactor to mix with the reactants and obtain a mixture. The length of the carbon fiber powder is 0.06 mm, and the amount of carbon fiber powder added is 5% of the total mass of the mixture. During the addition of carbon fiber powder, the speed of the stirring paddle is increased to ensure that the polyether ether ketone formed by the reaction is evenly dispersed in the reactor so that the carbon fiber powder and polyether ether ketone are evenly mixed.

[0054] (3) Adjust the pressure inside the reactor to -0.09 MPa to evaporate a large amount of diphenyl sulfone.

[0055] (4) Close the vacuum of the reactor, open the discharge valve, and introduce nitrogen into the reactor to discharge the reactants after removing part of the diphenyl sulfone onto the agglomerated steel belt.

[0056] (5) The reactants discharged onto the agglomerating steel belt are crushed to obtain mixed coarse powder particles.

[0057] (6) The mixed coarse powder particles were pulverized using an air jet mill and then classified and screened to obtain mixed fine powder particles. The grinding air pressure of the air jet mill was 0.8 MPa.

[0058] (7) Use acetone to wash away diphenyl sulfone from the mixed fine powder particles, then use pure water to wash away inorganic salts and residual acetone from the mixed fine powder particles, and finally dry to obtain polyether ether ketone mixed resin with high purity.

[0059] Example 2 Example 2 is essentially the same as Example 1, except that the amount of carbon fiber powder added is 20% of the total mass of the mixture. Scanning electron microscope images of the obtained product are shown below. Figure 4 As shown.

[0060] Example 3 Example 3 is basically the same as Example 1, except that the amount of carbon fiber powder added is 35% of the total mass of the mixture.

[0061] Example 4 (1) Hydroquinone, difluorobenzophenone, potassium carbonate and diphenyl sulfone solvent are added to the reactor to carry out the polymerization reaction.

[0062] (2) After the polymerization reaction is completed, the discharge valve is opened and nitrogen gas is introduced into the reactor to allow the reactants to be discharged onto the agglomerated steel belt. Subsequently, the reactants discharged onto the agglomerated steel belt are crushed to obtain coarse powder particles. Then, the carbon fiber powder and coarse powder particles are extruded and granulated using a twin-screw extruder to obtain a mixture. During the extrusion granulation process, the feed section temperature is 280℃ and the melt section temperature is 290℃.

[0063] (3) During the extrusion granulation process, a vacuum volatilization device is used to volatilize diphenyl sulfone, thereby reducing the content of diphenyl sulfone in the mixture.

[0064] (4) The reactants from which some diphenyl sulfone has been removed are crushed to obtain mixed coarse powder particles.

[0065] (5) The mixed coarse powder particles were crushed using an air jet mill and then classified and screened to obtain mixed fine powder particles. The grinding air pressure of the air jet mill was 0.8 MPa.

[0066] (6) Use acetone to wash away diphenyl sulfone from the mixed fine powder particles, then use pure water to wash away inorganic salts and residual acetone from the mixed fine powder particles, and finally dry to obtain polyether ether ketone mixed resin with high purity.

[0067] Example 5 Example 5 is basically the same as Example 4, except that the amount of carbon fiber powder added is 20% of the total mass of the mixture.

[0068] Example 6 Example 6 is basically the same as Example 4, except that the amount of carbon fiber powder added is 35% of the total mass of the mixture.

[0069] Example 7 Example 7 is basically the same as Example 4, except that the short-cut carbon fibers and coarse powder particles are extruded and granulated using a twin-screw extruder to obtain a mixture.

[0070] Example 8 Example 8 is basically the same as Example 7, except that the amount of chopped carbon fiber powder added is 20% of the total mass of the mixture.

[0071] Example 9 Example 9 is basically the same as Example 7, except that the amount of chopped carbon fiber powder added is 35% of the total mass of the mixture.

[0072] Example 10 Example 10 is basically the same as Example 4, except that continuous carbon fibers and coarse powder particles are extruded and granulated using a twin-screw extruder to obtain a mixture.

[0073] Example 11 Example 11 is basically the same as Example 10, except that the amount of continuous carbon fiber powder added is 20% of the total mass of the mixture.

[0074] Example 12 Example 12 is basically the same as Example 10, except that the amount of continuous carbon fiber powder added is 35% of the total mass of the mixture.

[0075] Example 13 Example 13 is basically the same as Example 4, except that carbon fiber powder and chopped carbon fiber are extruded and granulated with coarse powder using a twin-screw extruder to obtain a mixture. The mass ratio of carbon fiber powder to chopped carbon fiber is 1:1, and the sum of the amounts of carbon fiber powder and chopped carbon fiber added is 5% of the total mass of the mixture.

[0076] Example 14 Example 14 is basically the same as Example 13, except that the sum of the amounts of carbon fiber powder and chopped carbon fiber added is 20% of the total mass of the mixture.

[0077] Example 15 Example 15 is basically the same as Example 13, except that the sum of the amounts of carbon fiber powder and chopped carbon fiber added is 35% of the total mass of the mixture.

[0078] Example 16 Example 16 is basically the same as Example 4, except that carbon fiber powder, continuous carbon fiber, and coarse carbon particles are extruded and granulated using a twin-screw extruder to obtain a mixture. The mass ratio of carbon fiber powder to continuous carbon fiber is 1:1, and the sum of the amounts of carbon fiber powder and continuous carbon fiber added is 5% of the total mass of the mixture.

[0079] Example 17 Example 17 is basically the same as Example 16, except that the sum of the amount of carbon fiber powder and continuous carbon fiber added is 20% of the total mass of the mixture.

[0080] Example 18 Example 18 is basically the same as Example 16, except that the sum of the amounts of carbon fiber powder and continuous carbon fiber added is 35% of the total mass of the mixture.

[0081] Example 19 Example 19 is basically the same as Example 4, except that carbon fiber powder, chopped carbon fiber, and continuous carbon fiber are extruded and granulated with coarse powder using a twin-screw extruder to obtain a mixture. The mass ratio of carbon fiber powder, chopped carbon fiber, and continuous carbon fiber is 1:1:1, and the sum of the amounts of carbon fiber powder, chopped carbon fiber, and continuous carbon fiber added is 5% of the total mass of the mixture.

[0082] Example 20 Example 20 is basically the same as Example 19, except that the sum of the amounts of carbon fiber powder, chopped carbon fiber and continuous carbon fiber added is 20% of the total mass of the mixture.

[0083] Example 21 Example 21 is basically the same as Example 19, except that the sum of the amounts of carbon fiber powder, chopped carbon fiber and continuous carbon fiber added is 35% of the total mass of the mixture.

[0084] Comparative Example 1 (1) Use any commercially available polyether ether ketone resin.

[0085] (2) Pulverize the polyether ether ketone resin into coarse powder particles with a median particle size of 3 mm.

[0086] (3) Use acetone to wash away diphenyl sulfone from the coarse powder particles, then use pure water to wash away inorganic salts and residual acetone from the coarse powder particles, and finally dry to obtain the finished polyether ether ketone coarse powder.

[0087] (4) The coarse polyether ether ketone powder is ground by impact mill to obtain fine polyether ether ketone powder.

[0088] (5) Mix the polyether ether ketone fine powder with the carbon fiber powder to obtain carbon fiber reinforced polyether ether ketone fine powder.

[0089] Comparative Example 2 Grind any commercially available polyetheretherketone resin into a fine powder.

[0090] Please refer to the appendix for scanning electron microscope images of the polyetheretherketone mixed resins prepared in Example 1 and Comparative Example 1, respectively. Figure 2 and appendix Figure 3 A comparison reveals that in the polyetheretherketone (PEEK) mixed resin obtained in this application embodiment, most of the carbon fibers are in a bonded state with PEEK, with the carbon fibers encapsulated within the PEEK and evenly distributed. In contrast, the carbon fibers and PEEK in Comparative Example 1 are separated and unevenly mixed. Furthermore, the PEEK mixed resin obtained in this application embodiment has a concentrated particle size distribution with a span of less than 1.4.

[0091] The properties of the polyetheretherketone (PEEK) mixed resins prepared in the above embodiments and comparative examples were tested. Specifically: Dv50 particle size According to GB / T19077-2016, a laser diffraction particle size analyzer was used for detection.

[0092] Loose packing density According to GB / T1636, the fixed funnel method device is used for testing.

[0093] purity The contents of inorganic salts and diphenyl sulfone in polyether ether ketone mixed resin were detected by gas chromatography.

[0094] The results of the above tests are shown in the table below:

[0095]

[0096]

[0097] Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above embodiments should not be construed as limiting the present application, and that changes, substitutions and modifications can be made to the embodiments without departing from the spirit, principles and scope of the present application.

Claims

1. A method for preparing a polyetheretherketone (PEEK) mixed resin for 3D printing, characterized in that, include: Hydroquinone and difluorobenzophenone were mixed and an inorganic salt catalyst and diphenyl sulfone solvent were added to carry out a polymerization reaction; Before the polymerization reaction is completed, the carbon fiber is mixed with the reactants to obtain a mixture; The mixture is subjected to a first impurity removal treatment to remove a portion of the diphenyl sulfone; The reactants that have undergone the first impurity removal treatment are then subjected to pulverization and a second impurity removal treatment to obtain a polyether ether ketone mixed resin containing the carbon fibers.

2. The method according to claim 1, characterized in that, The mixture was obtained by adding carbon fibers to a reaction vessel and mixing them with the reactants. The first impurity removal process includes adjusting the pressure inside the reactor to a negative pressure to remove part of the diphenyl sulfone, introducing an inert gas into the reactor, and then discharging the reactants before performing the pulverization process.

3. The method according to claim 2, characterized in that, The pulverization process includes: The reactants that have undergone the first impurity removal treatment are subjected to a first pulverization treatment to obtain mixed coarse powder particles with a median particle size of 4-30 mesh. The mixed coarse powder particles are subjected to a second pulverization process to obtain mixed fine powder particles. The second pulverization process includes air jet milling.

4. The method according to claim 2, characterized in that, The reactor is equipped with a stirrer, and the mixing of carbon fibers and reactants is carried out under stirring conditions.

5. The method according to claim 1, characterized in that, The process of mixing carbon fibers with reactants to obtain a mixture includes: After the polymerization reaction is completed, an inert gas is introduced into the reactor to allow the reactants to be discharged onto the sheeted steel belt. The reactants discharged onto the agglomerated steel belt are subjected to a first crushing process to obtain coarse powder particles with a median particle size of 4-30 mesh. The carbon fiber is mixed with the coarse powder particles and extruded and granulated using a twin-screw extruder. During the extrusion granulation process, the first impurity removal treatment is performed, which includes controlling the ambient pressure to a negative pressure under vacuum to allow at least a portion of the diphenyl sulfone to volatilize.

6. The method according to claim 2 or 5, characterized in that, The removal of diphenyl sulfone comprises reducing the content of diphenyl sulfone in the system to 20%-70% of the content of diphenyl sulfone in the reactants.

7. The method according to claim 2 or 5, characterized in that, The second impurity removal process includes washing with acetone and then pure water in sequence.

8. The method according to claim 1, characterized in that, The carbon fiber satisfies at least one of the following conditions: The length of the carbon fiber is 0.06-0.08 mm; The amount of carbon fiber added is 5-50% of the total mass of the mixture; The carbon fiber includes at least one of chopped carbon fiber, carbon fiber powder, or continuous carbon fiber.

9. The method according to claim 1, characterized in that, The polyetheretherketone blend resin containing the carbon fibers satisfies at least one of the following conditions: The median particle size is 200-10000 mesh; In the polyether ether ketone mixed resin, the content of diphenyl sulfone is less than 0.1 wt.%, and the content of inorganic salt is less than 0.05 wt.%.

10. A polyetheretherketone blended resin, characterized in that, The polyetheretherketone mixed resin is prepared using the method described in any one of claims 1-9.

Images