3D printing materials and their applications

Abstract

This application provides a 3D printing material and its application. The 3D printing material of this application includes: a resin matrix, impact-resistant particles, and inorganic fillers; both the impact-resistant particles and the inorganic fillers are dispersed in the resin matrix. The impact-resistant particles have a core-shell structure, comprising a core and a shell, with the shell disposed on the surface of the core. The core comprises a first polymer, and the shell comprises a second polymer. The solubility parameter of the resin matrix is ​​δ1, and the solubility parameter of the second polymer is δ2, therefore 0.9 ≤ δ1 / δ2 ≤ 1.1. The 3D printing material of this application exhibits good impact resistance.

Description

Technical Field

[0001] This application relates to the field of electronics, specifically to a 3D printing material and its application. Background Technology

[0002] Fused Deposition Modeling (FDM) 3D printing involves two main processes. First, thermoplastic polymers are typically fed as filaments through multiple gear meshing points and motors before being melt-extruded into a hot end. This requires the material to successfully navigate multiple bending paths (angles exceeding 90°) under pressure for FDM printing. Second, increasingly complex 3D printing applications (such as automotive parts and kitchen utensils) place higher demands on the mechanical properties (especially interlayer bond strength and impact resistance) and printing performance (printing speed, appearance quality) of FDM materials. While polylactic acid (PLA) is used as a 3D printing material in some technologies, its impact resistance is insufficient to meet the aforementioned requirements of fused deposition modeling 3D printing. Summary of the Invention

[0003] This application provides a 3D printing material with good impact resistance.

[0004] The first aspect of this application provides a 3D printing material comprising: a resin matrix, impact-resistant particles, and inorganic fillers; the impact-resistant particles and the inorganic fillers are both dispersed in the resin matrix; the impact-resistant particles have a core-shell structure, comprising a core and a shell, the shell being disposed on the surface of the core; the core comprising a first polymer, the shell comprising a second polymer; the solubility parameter of the resin matrix is ​​δ1, and the solubility parameter of the second polymer is δ2, then 0.9 ≤ δ1 / δ2 ≤ 1.1.

[0005] Furthermore, the 3D printing material comprises, by mass fraction, 85% to 92% resin matrix, 5% to 13% impact-resistant particles, and 1% to 4.6% inorganic filler.

[0006] Furthermore, the impact-resistant particles are acrylate graft copolymer particles.

[0007] Furthermore, the impact-resistant particles are graft copolymers with a first polymer as the main chain and a second polymer as the branched chain.

[0008] Furthermore, both the first polymer and the second polymer are non-benzene toughening agents.

[0009] Furthermore, the resin matrix is ​​polylactic acid resin; the second polymer is a methacrylic acid polymer.

[0010] Furthermore, the first polymer is a random copolymer of butyl acrylate and octyl acrylate.

[0011] Furthermore, the impact-resistant particles comprise 75% to 85% of a first polymer and 15% to 25% of a second polymer by mass fraction.

[0012] Furthermore, the molar ratio of the butyl acrylate unit to the octyl acrylate unit in the first polymer ranges from 2:1 to 4:1.

[0013] Furthermore, the average particle size d of the impact-resistant particles is in the range of 150nm≤d≤500nm.

[0014] Furthermore, the average particle size d1 of the core is in the range of 120nm≤d1≤400nm; the thickness d2 of the shell is in the range of 15nm≤d2≤50nm.

[0015] Furthermore, the inorganic filler is lamellar talc powder, and the average width of the lamellar talc powder ranges from 3.5 μm to 7 μm.

[0016] Furthermore, the glass transition temperature of the core is lower than that of the outer shell.

[0017] Furthermore, the main components of the 3D printing material are all food contact grade materials, wherein the content of the main components is greater than 0.05% by mass fraction.

[0018] Furthermore, the 3D printing material comprises the resin matrix, the impact-resistant particles, the inorganic filler, and the colorant, wherein the content of the main components is greater than 0.05% by mass fraction.

[0019] A second aspect of this application provides an application of the 3D printing material described in this application, wherein the 3D printing material is printed using a 3D printer, and the printing temperature of the 3D printing material is a first temperature T1; The 3D printer includes a nozzle, and the 3D printing material is used to scour the nozzle. When scourting, the temperature of the 3D printing material is a second temperature T2, then T1-30℃≤T2≤T1+10℃.

[0020] The 3D printing material of this application includes: a resin matrix, impact-resistant particles, and inorganic fillers. The impact-resistant particles have a core-shell structure, comprising a core and a shell, with the shell disposed on the surface of the core. The core comprises a first polymer, and the shell comprises a second polymer. The solubility parameter of the resin matrix is ​​δ1, and the solubility parameter of the second polymer is δ2. Therefore, 0.9 ≤ δ1 / δ2 ≤ 1.1, meaning the solubility parameter of the shell of the impact-resistant particles is essentially the same as that of the resin matrix. The shell of the impact-resistant particles has good compatibility with the resin matrix, thus enabling good interfacial interaction between the impact-resistant particles and the resin matrix without the need for additional dispersants or compatibilizers for dispersion. This allows the impact-resistant particles to be uniformly dispersed in the resin matrix, reducing the possibility of localized stress concentration and resulting in good overall impact resistance of the 3D printing material. Furthermore, this application minimizes the use of additional additives (such as compatibilizers or dispersants), reducing the risk of clogging during 3D printing material extrusion and allowing for lower printing flushing temperatures, thus reducing printing emissions. Furthermore, the impact-resistant particles of this application have a core-shell structure comprising a core and an outer shell. The outer shell has good compatibility with the resin matrix, ensuring efficient energy absorption of the crazing-cavitation effect of the impact-resistant particles. This further enhances the impact resistance of the 3D printing material and results in higher interlayer bonding strength in the 3D printed parts. Adding inorganic fillers to the resin matrix provides numerous nucleation sites. When the 3D printing material is subjected to external forces, these fillers can induce crack propagation deflection within the material, thereby lengthening the crack propagation path. This improves the overall toughness of the 3D printing material without affecting the interlayer bonding strength, further enhancing its impact resistance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments 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 these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a 3D printing material according to an embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the structure of an impact-resistant particle according to an embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the structure of a 3D printed part according to an embodiment of this application.

[0025] Figure 4This is a product image of a 3D printed part according to an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures: 100 - 3D printing material, 10 - impact-resistant particles, 11 - core, 12 - shell, 200 - 3D printed parts. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0028] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0029] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0030] It should be noted that, for ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0031] Figure 1 This is a schematic diagram of the structure of a 3D printing material 100 according to an embodiment of this application. Figure 2 This is a schematic diagram of the structure of the impact-resistant particle 10 according to an embodiment of this application.

[0032] Please see Figure 1 and Figure 2This application provides a 3D printing material 100, which includes: a resin matrix, impact-resistant particles 10, and inorganic fillers; the impact-resistant particles 10 and the inorganic fillers are dispersed in the resin matrix, the impact-resistant particles 10 have a core-shell structure, the impact-resistant particles 10 include a core 11 and a shell 12, the shell 12 is disposed on the surface of the core 11, the core 11 includes a first polymer, the solubility parameter of the resin matrix is ​​δ1, the solubility parameter of the second polymer is δ2, then 0.9≤δ1 / δ2≤1.1.

[0033] Understandably, the impact-resistant particles 10 and inorganic fillers are uniformly dispersed in the resin matrix. This ensures that when the 3D printing material is subjected to external force, the stress is more evenly distributed across all locations, with no typical stress concentration.

[0034] The 3D printing material 100 of this application can be printed using fused deposition modeling 3D printing technology, and can be used to prepare 3D printed parts such as automotive parts, kitchen utensils, toys, models, figurines, and prototypes.

[0035] It should be noted that the 3D printing material 100 can be, but is not limited to, filament, block, granular, sheet, etc. In the accompanying drawings of this application, the 3D printing material 100 is illustrated using filament as an example, and should not be construed as a limitation on the 3D printing material 100 of the embodiments of this application.

[0036] The solubility parameter is a physical constant characterizing the square root of the cohesive energy density of a substance, used to measure the compatibility and solubility between materials. Its core principle is "like dissolves like," meaning the smaller the difference in solubility parameters between the solute and solvent, the more compatible the system. The compatibility of the impact-resistant particles 10 was determined by dissolving them in solvents with different solubility parameters, thus providing a basic assessment of their δ value.

[0037] Understandably, the ratio δ1 / δ2 of the solubility parameter of the resin matrix to the solubility parameter of the shell 12 ranges from 0.9 to 1.1.

[0038] Specifically, δ1 / δ2 can be, but is not limited to, 0.9, 0.92, 0.94, 0.96, 0.98, 1.0, 1.02, 1.04, 1.06, 1.08, 1.1, etc. It should be noted that the uniformity of the dispersion of the impact-resistant particles in the resin matrix can be observed using a transmission electron microscope (TEM). If the impact-resistant particles 10 are uniformly dispersed in the resin matrix and there is no obvious delamination or cracks at the interface between the impact-resistant particles 10 and the resin matrix, then the bonding between the impact-resistant particles and the resin matrix (PLA matrix) is good, i.e., the condition 0.9 ≤ δ1 / δ2 ≤ 1.1 is satisfied. In this embodiment, if δ1 / δ2 is too large or too small, the solubility parameters of the resin matrix and the second polymer will differ too much, which is detrimental to the interfacial compatibility between the impact-resistant particles 10 and the resin matrix. The closer δ1 / δ2 is to 1, the better the interfacial compatibility between the impact-resistant particles 10 and the resin matrix, and the better the dispersion of the impact-resistant particles 10 in the resin matrix.

[0039] Optionally, the resin matrix is ​​polylactic acid, and the solubility parameter δ1 of the resin matrix is ​​9.5 (cal / cm³)^(1 / 2), and the second polymer is polymethyl methacrylate, and the solubility parameter δ2 of the second polymer is approximately 9.1 (cal / cm³)^(1 / 2) to 9.5 (cal / cm³)^(1 / 2).

[0040] Compared to methods that add toughening modifiers to polylactic acid, such as polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), thermoplastic polyurethane elastomer (TPU), methyl methacrylate-butadiene-styrene copolymer (MBS), ethylene-octene copolymer (POE), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), ethylene-methyl acrylate copolymer (EMA), and natural rubber (NR), this application, although they can... While these toughening agents can improve the brittleness and impact resistance of PLA to some extent, they also have poor compatibility with PLA, which can easily lead to a rapid decrease in interlayer bonding strength or even interlayer cracking. On the other hand, these toughening agents usually contain small molecule monomer residues from the synthesis end and some contain benzene (such as PBAT, MBS, SBS, SEBS, etc.). At the printing temperature of 220℃ (the printing temperature of PLA), they are very likely to volatilize a large number of harmful substances, including volatile organic compounds (VOCs) and particulate matter, and some even have a pungent odor, affecting user experience and health.

[0041] In this application, the solubility parameter of the resin matrix is ​​δ1, and the solubility parameter of the second polymer is δ2. Therefore, 0.9 ≤ δ1 / δ2 ≤ 1.1, meaning the solubility parameter of the shell 12 of the impact-resistant particle 10 is essentially the same as that of the resin matrix. The shell 12 of the impact-resistant particle 10 has good compatibility with the resin matrix, thus enabling good interfacial interaction between the impact-resistant particle 10 and the resin matrix without the need for additional dispersants or compatibilizers for dispersion. This allows the impact-resistant particle 10 to be uniformly dispersed in the resin matrix, reducing the possibility of localized stress concentration and resulting in better overall impact resistance for the 3D printing material 100. Furthermore, this application minimizes the use of additional additives (such as compatibilizers or dispersants), reducing the risk of clogging during printing material extrusion and allowing for lower printing flushing temperatures, thus reducing printing emissions. Furthermore, the impact-resistant particles 10 of this application have a core-shell structure including a core 11 and a shell 12. The shell 12 has good compatibility with the resin matrix, which can ensure efficient energy absorption of the crazing-cavitation effect of the impact-resistant particles 10, further enabling the 3D printing material 100 to have better impact resistance and enabling the 3D printed parts made from the 3D printing material 100 to have higher interlayer bonding strength.

[0042] In related technologies, inorganic fillers such as calcium carbonate, wollastonite, and barium sulfate are added to PLA. These inorganic fillers are usually used to reduce the cost of PLA consumables and also act as nucleating agents to improve the crystallization behavior of PLA. However, their effect on optimizing printing quality is extremely limited (due to low specific surface area, few nucleation sites, and high nucleation barriers). In fact, they may even cause surface roughness, white spots, and other appearance abnormalities. On the other hand, the introduction of high-content inorganic fillers also causes an order-of-magnitude increase in the concentration of particulate matter emitted during printing. The 3D printing material 100 of this application adds inorganic fillers to the resin matrix. Inorganic fillers can provide more nucleation sites. When the 3D printing material 100 is subjected to external force, it can induce the deflection of internal crack propagation, thereby increasing the side length of the crack propagation path. Without affecting the interlayer bonding strength of the 3D printed part, it improves the overall toughness of the 3D printing material 100 and further improves the impact resistance of the 3D printing material 100.

[0043] In some embodiments, the outer shell 12 comprises a second polymer, and the glass transition temperature (Tg) of the core 11 is lower than that of the outer shell 12. In this embodiment, the core 11 has a lower glass transition temperature, which allows the core 11 to have better toughness and can better improve the impact resistance of the 3D printing material 100. The outer shell 12 has a higher glass transition temperature, which allows the outer shell 12 to have higher hardness and better fix the particle morphology of the core-shell structure during the preparation of the impact-resistant particles 10.

[0044] Understandably, the toughness of the core 11 is greater than that of the outer shell 12. The hardness of the outer shell 12 is greater than that of the core 11. Thus, the core 11 has better toughness, which can better improve the impact resistance of the 3D printing material 100, while the outer shell 12 has higher hardness, which can better fix the particle morphology of the core-shell structure during the preparation of the impact-resistant particles 10.

[0045] Understandably, the elastic modulus of the first polymer is less than that of the second polymer. That is, the elastic modulus of the core 11 is less than that of the outer shell 12. The elastic modulus measures the ability to deform under external force. The core 11 has a smaller elastic modulus, which allows for better deformation performance and thus improves the impact resistance of the 3D printing material 100.

[0046] Optionally, the core 11 has greater toughness than the resin matrix. The core 11 has less hardness than the resin matrix.

[0047] Optionally, the elastic modulus of the first polymer is less than that of the resin matrix. That is, the elastic modulus of the core 11 is less than that of the resin matrix. The core 11 has a smaller elastic modulus, which can result in better deformation performance, while the resin matrix has a higher elastic modulus, which can better improve the overall elasticity and impact resistance of the 3D printing material.

[0048] Optionally, the kernel 11 is resilient.

[0049] In some embodiments, both the first polymer and the second polymer are non-benzene toughening agents. In this embodiment, both the first polymer and the second polymer are non-benzene toughening agents, free from harmful monomers remaining at the synthesis end, which can greatly reduce the release of harmful substances during 3D printing.

[0050] In some embodiments, the 3D printing material 100 comprises, by mass fraction, 85% to 92% resin matrix, 5% to 13% impact-resistant particles 10, and 1% to 4.6% inorganic filler.

[0051] In the embodiments of this application, when the numerical range a to b is involved, unless otherwise specified, the numerical value can be any value between a and b, including the endpoint value a and the endpoint value b.

[0052] Specifically, the mass fraction of the resin matrix in the 3D printing material 100 can be, but is not limited to, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, etc.

[0053] Specifically, the mass fraction of impact-resistant particles 10 in the 3D printing material 100 can be, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, etc. If the mass fraction of impact-resistant particles 10 in the 3D printing material 100 is too low, it will not be conducive to improving the toughness of the 3D printing material 100, resulting in high filament modulus, high brittleness, low elongation at break, and unsuitability for printing. If the mass fraction of impact-resistant particles 10 in the 3D printing material 100 is too high, although it can provide toughness, it reduces the interlayer adhesion of the 3D printing material 100, reduces the interlayer bonding strength of the 3D printed part, and reduces the strength and elastic modulus and other mechanical properties of the 3D printing material 100.

[0054] Specifically, the mass fraction of inorganic filler in the 3D printing material 100 can be, but is not limited to, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.6%, etc. In this embodiment, if the mass fraction of inorganic filler in the 3D printing material 100 is too low, the cooling and crystallization of the 3D printing material 100 will be slow during 3D printing, resulting in poor heat dissipation and making the printed part prone to deformation. If the mass fraction of inorganic filler in the 3D printing material 100 is too high, the interlayer bonding strength of the 3D printed part will be reduced, and particulate matter emissions will increase.

[0055] In this embodiment of the application, by designing the proportion of impact-resistant particles 10 and inorganic fillers in the 3D printing material 100, the 3D printing material 100 is made to have high toughness, and the 3D printed parts have good impact resistance and high interlayer bonding strength.

[0056] In some embodiments, the decomposition temperature of the impact-resistant particles 10 is greater than or equal to 250°C. Specifically, the decomposition temperature of the impact-resistant particles 10 can be, but is not limited to, greater than or equal to 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, etc. The impact-resistant particles 10 of this application have a high decomposition temperature, which improves the impact resistance and interlayer bonding strength of 3D printed parts. Furthermore, they are stable during 3D printing, are not prone to decomposition, and there is no need to worry about VOC / particulate matter emissions during printing or the migration of harmful substances during use.

[0057] It should be noted that the decomposition temperature can be measured using thermogravimetric analysis (TGA) curves. Specifically, the 3D printing material 100 is pulverized and placed in an organic solvent such as dichloromethane or trichloromethane. At this point, the resin matrix is ​​completely dissolved, while the impact-resistant particles 10 and inorganic fillers are not dissolved. However, the impact-resistant particles will partially swell, resulting in a decrease in density. After separating the insoluble matter (including the swollen impact-resistant particles 10 and inorganic fillers), the insoluble matter can be further centrifuged at high speed, causing the inorganic fillers to settle to the bottom and the impact-resistant particles 10 to remain in the middle or upper part. Finally, drying yields the impact-resistant particles 10. Thermogravimetric analysis is then performed on the obtained impact-resistant particles 10 to determine their decomposition temperature.

[0058] In some embodiments, the impact-resistant particles 10 are acrylate graft copolymer particles.

[0059] Related technologies use additives such as epoxidized soybean oil, tri-n-butyl acetylglucosinolate, glycidyl methacrylate, and tetrabutyl titanate to improve the mechanical properties of PLA, including toughness and interlayer bonding strength. However, most of these additives are liquids with high activity (i.e., poor stability) and are not included in the food contact compliance list (for example, GB 4806 / 9685 and EU No 10 / 2011, regulations limit the list of materials that can be used in food contact plastics). Therefore, they are very easy to volatilize or decompose toxic VOCs during high-temperature extrusion, and small molecule harmful substances also migrate during the use of printed products, affecting the health and life of users.

[0060] In this embodiment, acrylate graft copolymer particles are used as impact-resistant particles 10. These impact-resistant particles 10 are non-benzene toughening agents and do not contain harmful monomers remaining at the synthesis end. During 3D printing, the release of harmful substances can be greatly reduced. In addition, acrylate graft copolymer particles are stable and do not easily decompose during 3D printing, so there is no need to worry about VOC / particulate matter emissions during the printing process or the migration of harmful substances during use.

[0061] In some embodiments, the first polymer is an acrylate copolymer. The second polymer is a methacrylate polymer.

[0062] Related technologies use additives such as epoxidized soybean oil, tri-n-butyl acetylglucosinolate, glycidyl methacrylate, and tetrabutyl titanate to improve the mechanical properties of PLA, including toughness and interlayer bonding strength. However, most of these additives are liquids with high activity (i.e., poor stability) and are not included in the food contact compliance list (for example, GB 4806 / 9685 and EU No 10 / 2011, regulations limit the list of materials that can be used in food contact plastics). Therefore, they are very easy to volatilize or decompose toxic VOCs during high-temperature extrusion, and small molecule harmful substances also migrate during the use of printed products, affecting the health and life of users.

[0063] In this embodiment, acrylate and methacrylate polymers are used as the impact-resistant particles 10. These impact-resistant particles 10 are non-benzene toughening agents and do not contain harmful monomers remaining at the synthesis end, which can greatly reduce the release of harmful substances during 3D printing. Furthermore, acrylate and methacrylate polymers are stable and do not easily decompose during 3D printing, eliminating concerns about VOC / particulate emissions during printing and the migration of harmful substances during use. Moreover, the methacrylate polymer of the outer shell 12 has better compatibility with the polylactic acid resin matrix. Furthermore, when polylactic acid is used as the resin matrix, the uniformity of the dispersion of the impact-resistant particles 10 in the resin matrix can be improved, further enhancing the impact resistance and interlayer bonding strength of the 3D printed part.

[0064] It should be noted that the composition of the impact-resistant particles 10 can be measured using Fourier transform infrared spectroscopy (FT-IR) and semi-quantitative pyrolysis-gas chromatography-mass spectrometry (Py GC-MS). Specifically, the characteristic peaks of acrylate are observed by Fourier transform infrared spectroscopy (FT-IR) to determine the type of impact-resistant particles 10 in the 3D printing material 100. Py GC-MS and / or other testing methods can be used to determine whether the resin matrix is ​​polylactic acid resin and to identify the composition of the impact-resistant particles 10.

[0065] In some embodiments, the impact-resistant particles 10 are a first polymer as the main chain and a second polymer as a graft copolymer with branched chains.

[0066] Understandably, the first polymer and the second polymer are connected by chemical bonds.

[0067] Optionally, the main chain is an acrylate copolymer and the side chains are methacrylate polymers.

[0068] In this embodiment, the impact-resistant particle 10 has a first polymer as its main chain and a second polymer as a branched graft copolymer, meaning that the core 11 and the outer shell 12 are connected by chemical bonds. This results in better bonding between the core and shell structures of the impact-resistant particle 10, thus improving the toughness and interlayer bonding strength of the 3D printed part when the 3D printing material 100 is subjected to external force. It should be noted that the molecular chain structure of the impact-resistant particle 10 (such as the graft copolymer structure) can be measured using nuclear magnetic resonance.

[0069] In some embodiments, the resin matrix is ​​polylactic acid resin; the first polymer is butyl acrylate-octyl acrylate random copolymer (BA-OA copolymer); and the second polymer is polymethyl methacrylate (PMMA).

[0070] It should be noted that the second polymer has a cross-linked network structure, meaning the graft copolymer has a cross-linked network of butyl acrylate-octyl acrylate random copolymer as the main chain and polymethyl methacrylate as the side chain. Understandably, the main chain is a cross-linked network structure.

[0071] Understandably, the core 11 of the impact-resistant particle 10 is a random copolymer backbone of butyl acrylate-octyl acrylate, and the outer shell 12 is a polymethyl methacrylate branch.

[0072] In this embodiment, polylactic acid (PLA) is used as the resin matrix, resulting in virtually no odor during printing. It exhibits excellent printing performance: a low melting point (approximately 190-220°C), eliminating the need for a heated bed, minimizing cooling shrinkage, and reducing the likelihood of warping or cracking. The resulting 3D printed parts possess high hardness, fine layer textures, and easily render sharp edges and intricate details, making them suitable for display models, figurines, and prototypes. The first polymer is a random copolymer of butyl acrylate and octyl acrylate; the second polymer is polymethyl methacrylate (PMMA). The PMMA of the outer shell 12 has excellent compatibility with the PLA resin matrix, allowing the impact-resistant particles 10 to be more uniformly dispersed within the resin matrix, thus better toughening and reinforcing the 3D printing material 100 and improving the impact resistance and interlayer bonding strength of the 3D printed parts. The impact-resistant particles 10 are non-benzene toughening agents, free of harmful monomers remaining at the synthesis end, significantly reducing the release of harmful substances during 3D printing. Furthermore, the butyl acrylate unit in the butyl acrylate-octyl acrylate random copolymer is the core toughening component of the impact-resistant particle 10. The carbon chain of the substituents in polyoctyl acrylate is longer, resulting in a lower glass transition temperature, which can provide better toughening effect at low temperatures. Moreover, the butyl acrylate-octyl acrylate random copolymer and polymethyl methacrylate are stable and do not easily decompose during 3D printing, eliminating concerns about VOC / particulate emissions during printing and the migration of harmful substances during use. Furthermore, using the butyl acrylate-octyl acrylate random copolymer as the core allows for a more uniform distribution of butyl acrylate and octyl acrylate units within the molecular chain, resulting in better toughening effect and avoiding the microphase separation and stress concentration problems that are common in block copolymers. Additionally, random copolymers are easier to prepare, have lower preparation costs, and are more economical and efficient from a synthetic polymerization perspective.

[0073] In some embodiments, the impact-resistant particles 10 comprise 75% to 85% of a first polymer and 15% to 25% of a second polymer by mass fraction.

[0074] Understandably, the impact-resistant particles 10 comprise, by mass fraction, 75% to 85% butyl acrylate-octyl acrylate random copolymer and 15% to 25% polymethyl methacrylate.

[0075] Understandably, the impact-resistant particles 10 comprise, by mass fraction, 75% to 85% core 11 and 15% to 25% shell 12.

[0076] Specifically, the mass fraction of the first polymer in the impact-resistant particles 10 can be, but is not limited to, 75%, 76%, 78%, 80%, 82%, 84%, 85%, etc.

[0077] Specifically, the mass fraction of the second polymer in the impact-resistant particles 10 can be, but is not limited to, 15%, 16%, 18%, 20%, 22%, 24%, 25%, etc.

[0078] The core 11 (i.e., the first polymer) of the impact-resistant particle 10 is used to provide cavitation-shear yield toughening; the outer shell 12 of the impact-resistant particle 10 is used to improve the interfacial compatibility between the impact-resistant particle 10 and the resin matrix. If the mass fraction of the first polymer in the impact-resistant particle 10 is too high and the mass fraction of the second polymer is too low, the interfacial compatibility between the impact-resistant particle 10 and the resin matrix is ​​reduced, and the coating process becomes difficult to control, leading to easy damage to the core-shell structure. If the mass fraction of the first polymer in the impact-resistant particle 10 is too low and the mass fraction of the second polymer is too high, the core 11 portion is too small, and the cavitation-shear yield toughening effect of the 3D printing material 100 is not obvious, which is not conducive to improving the impact resistance of the 3D printed part.

[0079] In some embodiments, the molar ratio of the butyl acrylate unit to the octyl acrylate unit in the first polymer ranges from 2:1 to 4:1.

[0080] Understandably, the molar ratio of butyl acrylate units to octyl acrylate units in the butyl acrylate-octyl acrylate random copolymer ranges from 2:1 to 4:1.

[0081] Specifically, the molar ratio of butyl acrylate units (BA units) to octyl acrylate units (OA units) in the first polymer can be, but is not limited to, 2:1, 2.3:1, 2.5:1, 2.8:1, 3:1, 3.3:1, 3.5:1, 3.8:1, 4:1, etc.

[0082] In this embodiment, the butyl acrylate unit is the core toughening component of the core 11 of the impact-resistant particle 10. The carbon chain of the substituent of polyoctyl acrylate is longer, resulting in a lower glass transition temperature, which can achieve better toughening effect at low temperatures. If the molar ratio of the butyl acrylate unit to the octyl acrylate unit in the first polymer is too low, the stronger hydrophobicity of the octyl acrylate unit increases the difficulty of the emulsion polymerization process of the first polymer, and also increases the cost of the impact-resistant particle 10. If the molar ratio of the butyl acrylate unit to the octyl acrylate unit in the first polymer is too high, the content of octyl acrylate unit in the first polymer is too low, which is not conducive to the low-temperature toughening effect of the impact-resistant particle 10.

[0083] Please see again Figure 2 In some embodiments, the average particle size d of the impact-resistant particles 10 is in the range of 150nm ≤ d ≤ 500nm.

[0084] Specifically, the average particle size d of the impact-resistant particles 10 can be, but is not limited to, 150nm, 180nm, 200nm, 230nm, 250nm, 280nm, 300nm, 330nm, 350nm, 380nm, 400nm, 430nm, 450nm, 480nm, 500nm, etc.

[0085] In this embodiment, if the average particle size d of the impact-resistant particles 10 is too small, the crazing-cavitation effect of the impact-resistant particles 10 will be insignificant or difficult to achieve, making it difficult to effectively induce yielding of the resin matrix and reducing the toughening effect of the impact-resistant particles 10. If the average particle size d of the impact-resistant particles 10 is too large, the impact-resistant particles 10 will easily generate stress concentration. Moreover, if the average particle size d of the impact-resistant particles 10 is too large, the impact-resistant particles 10 will be unevenly dispersed, reducing the toughening effect of the impact-resistant particles 10 on the 3D printing material 100 and hindering the improvement of the impact resistance of the 3D printing material 100 and the 3D printed parts.

[0086] Please see again Figure 2 In some embodiments, the average particle size d1 of the core 11 ranges from 120nm to 400nm. Specifically, the average particle size d1 of the core 11 can be, but is not limited to, 120nm, 150nm, 180nm, 200nm, 230nm, 250nm, 280nm, 300nm, 330nm, 350nm, 380nm, 400nm, etc. If the average particle size d1 of the core 11 is too small, the craze-cavitation effect is not obvious, reducing the difficulty in inducing the yield of the resin matrix and reducing the toughening effect of the impact-resistant particles 10. If the average particle size d1 of the core 11 is too large, the impact-resistant particles 10 are prone to forming stress concentration points, reducing the impact resistance and strength of the 3D printing material 100.

[0087] Please see again Figure 2 In some embodiments, the thickness d2 of the outer shell 12 is in the range of 15nm ≤ d2 ≤ 50nm. Specifically, the thickness d2 of the outer shell 12 can be, but is not limited to, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, etc.

[0088] If the thickness d2 of the outer shell 12 is too thin, it reduces the interfacial compatibility between the impact-resistant particles 10 and the resin matrix, and also makes the coating process difficult to control, leading to easy damage to the core-shell structure. If the thickness d2 of the outer shell 12 is too thick, the core 11 portion becomes too small, resulting in an insignificant cavitation-shear yielding toughening effect on the 3D printing material 100, which is detrimental to improving the impact resistance of the 3D printed part.

[0089] Optionally, when copolymerizing butyl acrylate monomer and octyl acrylate monomer, the crosslinking agent added is 1% to 3% by mass. It should be noted that when copolymerizing butyl acrylate monomer and octyl acrylate monomer, more than 98% of the added crosslinking agent participates in the crosslinking reaction.

[0090] In some embodiments, the inorganic filler is lamellar talc, and the average width of the lamellar talc ranges from 3.5 μm to 7 μm.

[0091] Specifically, the average width of the lamellar talc powder can be, but is not limited to, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, etc.

[0092] In this embodiment, by adding lamellar talc as an inorganic filler, lamellar talc has a high specific surface area and a large number of nucleation micro-points. Even at a low addition amount, it can promote rapid cooling and crystallization of the resin matrix (e.g., PLA) (this process can be characterized by differential scanning calorimetry (DSC) curves), improve the printing performance and appearance quality of the 3D printing material 100 during melt extrusion, and enhance its overall appearance quality. Furthermore, lamellar talc is stable, releases no VOCs, and poses no migration risk. If the average width of the lamellar talc is too small, its nucleation effect will be poor, reducing the cooling rate of the 3D printing material 100 during printing. This makes it prone to deformation during printing, affecting the accuracy of the supported 3D printed part and the quality of the 3D printing material 100's overhang heat dissipation. If the average width of the flaky talc is too large, the flaky talc will have a certain reinforcing effect on the resin matrix, reducing the toughening effect of the flaky talc on the resin matrix. In addition, too many nucleation sites of the flaky talc will cause the 3D printing material 100 to cool too quickly during printing, weakening the adhesion between layers and reducing the interlayer bonding strength of the obtained 3D printed parts.

[0093] Optionally, the characteristic peaks of acrylate can be observed using Fourier transform infrared spectroscopy (FT-IR) to determine the type of impact-resistant particles 10 in the 3D printing material 100. X-ray fluorescence spectroscopy (XRF) can be used to identify the corresponding elements Mg and Si in talc (inorganic filler). By combining infrared spectral peaks, thermogravimetric analysis, or scanning electron microscopy, it can be determined whether Mg and Si elements are present in the 3D printing material 100, thus determining whether the 3D printing material 100 contains talc. The mass fraction of inorganic filler in the 3D printing material 100 can be determined by thermogravimetric analysis (TGA). The crystallization characteristics and crystallization temperature of the 3D printing material 100 can be determined by differential scanning calorimetry (DSC). Thus, it can be determined whether the glass transition temperature of the core 11 of the impact-resistant particles 10 is lower than that of the outer shell 12 by differential scanning calorimetry (DSC) and / or other testing methods. Pyrolysis-gas chromatography-mass spectrometry (PyGC-MS) can be used to determine / semi-quantitatively identify small molecule fragments, namely the types and contents of monomers such as lactic acid, lactide, and acrylate. PyGC-MS and / or other testing methods can be used to determine whether the resin matrix is ​​polylactic acid resin and to identify the components of impact-resistant particles 10. Nuclear magnetic resonance spectroscopy (1H NMR) can analyze the characteristic peaks of PLA and acrylate, and the mass ratio of PLA to impact-resistant particles 10 can be quantitatively analyzed based on the peak area.

[0094] In some embodiments, the 3D printing material 100 comprises food contact grade materials as its main components, wherein the content of the main components is greater than 0.05% by mass fraction.

[0095] "Food-grade contact materials" refers to materials that are 100% derived from the EU No 10 / 2011 authorized positive list and relevant regulations.

[0096] In this embodiment, the main components of the 3D printing material 100 are all food contact grade materials, which results in the release of less volatile organic compounds (VOCs) and particulate matter during printing, thus providing higher safety and benefiting health.

[0097] In some embodiments, the 3D printing material 100 comprises a resin matrix, impact-resistant particles, inorganic fillers, and colorants as its main components, wherein the content of the main components is greater than 0.05% by mass fraction. In this embodiment, the 3D printing material 100 also includes colorants, which allows the 3D printing material 100 to have more colors and better meet the needs of users.

[0098] Figure 3 This is a schematic diagram of the structure of a 3D printed part 200 according to an embodiment of this application. Figure 4 This is a product image of a 3D printed part 200 according to an embodiment of this application.

[0099] Please see Figure 3 and Figure 4 This application embodiment also provides a 3D printed part 200, which is made from the 3D printing material 100 described in this application.

[0100] Optionally, the 3D printed part 200 can be, but is not limited to, automotive parts, kitchen utensils, toys, models, figurines, prototypes, etc.

[0101] For a detailed description of other aspects of the 3D printing material 100, please refer to the description of the corresponding part of the above embodiments, which will not be repeated here.

[0102] The 3D printing material 100 of this application will be further described below through specific embodiments.

[0103] Examples 1 to 17, Comparative Examples 1 to 8 The 3D printing materials 100 of each embodiment and comparative example are prepared through the following steps. (1) Weigh polylactic acid (resin matrix), impact-resistant particles 10 (such as the acrylate graft copolymer particles of this application) and flaky talc (inorganic filler) according to the preset ratio. The composition of polylactic acid (resin matrix), impact-resistant particles 10 and flaky talc (inorganic filler) in each embodiment and comparative example, and the type of impact-resistant particles 10 are shown in Table 1 below. The average width of the flaky talc is 5 μm. (2) Polylactic acid, impact-resistant particles 10, and flaky talc are placed in a twin-screw extruder for extrusion granulation to obtain granules; and (3) The granules are extruded using a single screw extruder to obtain 3D printing material 100.

[0104] Comparative Example 9 The difference between this comparative example and Example 3 is that calcium carbonate is used as the inorganic filler in this comparative example.

[0105] Comparative Example 10 The difference between this comparative example and Example 3 is that the average width of the lamellar talc powder in this comparative example is 10 μm.

[0106] Comparative Example 11 The difference between this comparative example and Example 3 is that the inorganic filler in this comparative example includes 2.8% lamellar talc with an average width of 5 μm and 0.5% glycidyl methacrylate.

[0107] Comparative Example 12 The difference between this comparative example and Example 3 is that the inorganic filler in this comparative example includes 2.8% lamellar talc with an average width of 5 μm and 0.5% tetrabutyl titanate.

[0108] The composition of the 3D printing material 100 in each embodiment and comparative example is shown in Table 1 below.

[0109] Table 1. Composition of 3D printing material 100 in each embodiment and comparative example.

[0110] The following performance tests were performed on the 3D printing materials 100 of each embodiment and comparative example.

[0111] (1) Mechanical property test (XY bending strength, XY bending modulus, XY impact strength, Z bending strength, Z bending modulus, Z impact strength, XY elongation at break): Sample preparation: Tuozhu X1C printer, 0.4mm nozzle diameter, 220℃ printing temperature (for PLA), print 100% fill ratio samples one by one (concentric fill pattern, fill direction 90°), including two directions XY and Z, the size of which is 80mm×10mm×4mm; when performing XY direction performance test, the sample deposition direction is the thickness direction (i.e. 4mm direction), that is, the layers are arranged along the thickness direction; when performing Z direction performance test, the sample deposition direction is the length direction (i.e. 80mm direction), that is, the layers are arranged along the length direction; Z direction is the deposition direction of the sample, that is, the arrangement direction between the layers, XY direction refers to two mutually perpendicular directions on the plane perpendicular to Z direction.

[0112] Three-point bending (GB / T 9341): span 64mm, pressing speed 5mm / min, used to measure XY bending strength, XY bending modulus, Z bending strength, and Z bending modulus.

[0113] Simply supported beam impact (GB / T 1043): 5 Joule pendulum, 40mm span, used to measure XY impact strength and Z impact strength.

[0114] Uniaxial tensile test (GB / T 1040): gauge length 50 mm, tensile speed 50 mm / min, used to measure XY elongation at break.

[0115] (2) Crystallization temperature: DSC was used for testing. The scanning temperature was -20 to 250℃, 2℃ / min, N2 atmosphere. The test was conducted with the first heating, the first cooling and the second heating. The crystallization temperature was obtained from the DSC curve.

[0116] (3) 45° suspension angle mass, 60mm unsupported bridging mass: Printed at 220°C using a 3D printer as shown. Figure 4 Use the "OKT model" to observe the overhang and bridging print quality, such as whether there is sag, whether it is smooth, and whether the dimensional accuracy is OK.

[0117] (4) Printing emission test (220℃): in a closed 1m 3 Inside the environmental chamber, a Topzhu A1 open-type printer was used at 220°C (for PLA) to continuously print 120×120×120m. 3 The chamber is filled with 15% of the material for 4 hours. A handheld high-precision device (Ecofive, with particulate matter detection based on laser scattering principle and TVOC detection based on semiconductor sensing principle) is used to detect TVOC / PM2.5 levels inside the chamber (data after stabilization is used as the standard). The air environment inside the chamber is cleaned after each test. TVOC refers to total volatile organic compounds, and PM2.5 refers to particulate matter in the atmosphere with a diameter of less than or equal to 2.5 micrometers.

[0118] (5) Migration of hazardous substances (70℃, 2h): Print 100×100×20mm using a Tuozhu A1 printer. 3 A cube was immersed in 3% acetic acid (volume fraction) at 70°C for 2 hours for migration testing. The migration solution was then sampled, and the content of migrated harmful substances in the solution was determined by ICP-MS. The total migration amount was used as the standard (instrument detection limit: 3 mg / dm³). 2 ).

[0119] The performance parameters of the 3D printing materials 100 in each embodiment and comparative example are shown in Tables 2 and 3 below.

[0120] Table 2 Mechanical properties of 3D printing material 100 in each embodiment and comparative example

[0121] Table 3 shows other performance parameters of the 3D printing material 100 in each embodiment and comparative example.

[0122] The test results from Examples 1 to 5 and Comparative Examples 1 to 3 show that the 3D printed part 200 made from pure polylactic acid as 3D printing material 100 in Comparative Example 1 has low XY impact strength, Z impact strength and XY elongation; relatively high XY flexural strength, XY flexural modulus, Z flexural strength and Z flexural modulus. The 3D printed part 200 has a low crystallization temperature, rough overhang and obvious sagging. During 3D printing, the total volatile organic compounds (TVOC) and PM2.5 are low and there is less migration of harmful substances.

[0123] In Comparative Example 2, the addition of lamellar talc to the 3D printing material 100 in polylactic acid improved the XY impact strength, Z impact strength, and XY elongation of the resulting 3D printed part 200, but the improvement was not significant. The XY flexural strength, XY flexural modulus, Z flexural strength, and Z flexural modulus showed little overall change. The crystallization temperature of the 3D printed part 200 increased, resulting in smoother overhangs and more noticeable sagging. During 3D printing, the total volatile organic compounds (TVOC) and PM2.5 increased slightly, but the changes were minimal, and the migration of harmful substances was minimal.

[0124] In Examples 1 to 5 and Comparative Example 3, the 3D printing material 100 contained the core-shell structured impact-resistant particles 10 and lamellar talc powder of this application. The XY impact strength, Z impact strength, and XY elongation of the resulting 3D printed parts 200 were significantly improved. The XY flexural strength, XY flexural modulus, Z flexural strength, and Z flexural modulus decreased slightly, but the decrease was not significant. The crystallization temperature of the 3D printed parts 200 was increased, and the overhang was smooth without sagging. During 3D printing, the total volatile organic compounds (TVOC) and PM2.5 increased slightly, but the changes were not significant, and the migration of harmful substances was minimal. Furthermore, the test results of Comparative Example 3 show that when the amount of core-shell impact-resistant particles 10 added is small, the improvement in XY impact strength, Z impact strength, and XY elongation of the 3D printing material 100 and the 3D printed part 200 is relatively limited. As the content of core-shell impact-resistant particles 10 in the 3D printing material 100 increases, the XY impact strength and XY elongation of the 3D printed part 200 gradually increase, while the Z impact strength of the 3D printed part 200 first gradually increases and then gradually decreases. The XY flexural strength, XY flexural modulus, Z flexural strength, and Z flexural modulus all gradually decrease, but the decrease is not significant, and the crystallization temperature of the 3D printed part 200 gradually decreases.

[0125] Examples 3, 6 to 10, Comparative Examples 4 and 5: In Comparative Example 4, the 3D printing material 100 was modified by adding the core-shell structured impact-resistant particles 10 of this application, but without adding lamellar talc. Compared with Comparative Example 1, the 3D printed part 200 made from the 3D printing material 100 of Comparative Example 4 showed a significant improvement in XY impact strength, Z impact strength and XY elongation. However, the XY flexural strength, XY flexural modulus, Z flexural strength and Z flexural modulus also decreased significantly. The 3D printed part 200 had rough overhangs and obvious sagging. During 3D printing, the total volatile organic compounds (TVOC) and PM2.5 increased, but the changes were not significant, and the migration of harmful substances was minimal. In Examples 3, 6 to 10, the 3D printing material 100 was supplemented with the core-shell structured impact-resistant particles 10 and lamellar talc powder of this application. The XY impact strength, Z impact strength and XY elongation of the 3D printed parts 200 were greatly improved. The XY flexural strength, XY flexural modulus, Z flexural strength and Z flexural modulus of the 3D printed parts 200 in Examples 3, 6 to 10 decreased slightly, but the decrease was not significant. The crystallization temperature of the 3D printed parts 200 was increased, the overhang was smooth and there was no sagging. During 3D printing, the total volatile organic compounds (TVOC) and PM2.5 increased slightly, but the change was not significant, and the migration of harmful substances was less. As the content of lamellar talc in the 3D printing material 100 increases, the XY impact strength, Z impact strength, and XY elongation of the resulting 3D printed part 200 gradually decrease, while the XY flexural strength, XY flexural modulus, Z flexural strength, and Z flexural modulus of the 3D printed part 200 gradually increase. The crystallization temperature of the 3D printed part 200 gradually increases, and the total volatile organic compounds (TVOC) and PM2.5 increase slightly, but the changes are not significant, and the migration of harmful substances is relatively small. When the content of lamellar talc in the 3D printing material 100 is too high (e.g., in Comparative Example 5), the Z impact strength and elongation at break decrease significantly, PM2.5 increases significantly, and the migration of harmful substances also increases.

[0126] The test results of Example 3 and Comparative Examples 6 to 8 show that Comparative Example 6, toughened with polybutylene adipate / terephthalate (PBAT), Comparative Example 7, toughened with methyl methacrylate-butadiene-styrene copolymer (MBS), and Comparative Example 8, toughened with polyolefin elastomer (POE), exhibited excessively low Z-impact strength and high emissions of total volatile organic compounds (TVOC) and PM2.5. Furthermore, Comparative Example 7 also showed significant migration of harmful substances. Compared to Comparative Examples 6 to 8, the 3D printed part 200 of Example 3 exhibited significantly improved Z-impact strength and significantly reduced emissions of total volatile organic compounds (TVOC) and PM2.5.

[0127] The test results from Example 3, Comparative Example 9, and Comparative Example 10 show that the 3D printing material 100 of Comparative Example 9, using 2500-mesh calcium carbonate as an inorganic filler, exhibits slow crystallization, poor printing quality, and poor heat dissipation during overhang; the 3D printed part 200 has rough overhang and significant sagging; and PM2.5 emissions are relatively high during printing. The 3D printing material 100 of Comparative Example 10, using lamellar talc powder with an average width of 10 μm as an inorganic filler, shows a significant decrease in the interlayer bonding strength of the 3D printed part 200, a substantial reduction in the XY and Z impact strengths, and a decrease in the XY flexural strength, XY elastic modulus, Z flexural strength, Z flexural modulus, and elongation at break.

[0128] The test results of Example 3, Comparative Example 11 and Comparative Example 12 show that Comparative Example 11 added 0.5% glycidyl methacrylate to Example 3, and Comparative Example 12 added 0.5% tetrabutyl titanate to Example 3. During printing, the emissions of total volatile organic compounds (TVOC) and PM2.5 of the 3D printing materials 100 of Comparative Example 11 and Comparative Example 12 increased significantly, and the migration of harmful substances increased significantly.

[0129] The test results from Examples 3, 10 to 13 show that as the mass fraction of the core 11 in the impact-resistant particles 10 increases and the mass fraction of the outer shell 12 decreases, the XY flexural strength, XY flexural modulus, Z flexural strength, Z flexural modulus, and Z impact strength of the resulting 3D printed part 200 gradually decrease; while the XY impact strength and XY elongation of the 3D printed part 200 gradually increase. Furthermore, as the mass fraction of the core 11 in the impact-resistant particles 10 increases and the mass fraction of the outer shell 12 decreases, the crystallization temperature of the 3D printing material 100 slightly decreases, and the emissions of total volatile organic compounds (TVOC) and PM2.5 slightly increase.

[0130] The test results from Examples 3, 14 to 17 show that as the molar ratio of butyl acrylate units to octyl acrylate units in the first polymer increases, the XY flexural strength and XY flexural modulus of the 3D printed part 200 gradually increase; the XY impact strength of the 3D printed part 200 gradually decreases; the Z flexural strength and Z flexural modulus of the 3D printed part 200 first gradually increase and then gradually decrease; and the Z impact strength and XY elongation of the 3D printed part 200 gradually decrease. Furthermore, as the molar ratio of butyl acrylate units to octyl acrylate units in the first polymer increases, the crystallization temperature of the 3D printing material 100 changes slightly, and the emissions of total volatile organic compounds (TVOC) and PM2.5 change slightly, but the overall changes are not significant.

[0131] In summary, the 3D printing material 100 of this application has better toughness and impact resistance, and when 3D printing is performed, it has lower emissions of total volatile organic compounds (TVOC) and PM2.5, which is beneficial to health.

[0132] This application embodiment also provides an application of a 3D printing material 100, wherein the 3D printing material 100 is printed using a 3D printer, and the printing temperature of the 3D printing material 100 is a first temperature T1; the 3D printer includes a nozzle, and the 3D printing material 100 is used to scour the nozzle. When scourting, the temperature of the 3D printing material 100 is a second temperature T2, then T1-30℃≤T2≤T1+10℃.

[0133] Specifically, T2 can be, but is not limited to, T1-30℃, T1-25℃, T1-20℃, T1-15℃, T1-10℃, T1-5℃, T1, T1+5℃, T1+10℃, etc.

[0134] In one example, the first temperature T1 is 220℃, then 190℃≤T2≤230℃.

[0135] Optionally, the 3D printer also includes an airflow generating device (such as a fan) and a filtration system. During flushing, the airflow generating device is turned on, blowing airflow toward the nozzle to blow the exhaust gas into the filtration system. This ensures that the emitted materials quickly diffuse into the cavity and are collected by the 3D printer's filtration system, improving air quality and enhancing the user experience.

[0136] Optionally, when the airflow generating device is a fan, the fan speed can be from 2000 RPM to 4000 RPM, specifically, but not limited to, 2000 RPM, 2500 RPM, 3000 RPM, 33500 RPM, 4000 RPM, etc.

[0137] In one example, during the rinsing process, the temperature is directly raised to a second temperature T2 (e.g., 220°C), and the material is rapidly extruded and rinsed at this temperature (when the odor is most pronounced). During the rinsing and extrusion, the airflow generator is activated (its opening can be 20% to 40%, e.g., 20%, 30%, 40%). After rinsing for a period of time, the airflow generator is fully activated for 2 to 4 seconds, and the material is ejected (i.e., the 3D printing material 100 at the nozzle is ejected). This rinsing process can be performed once or repeatedly multiple times, such as 2, 3, 4, or 5 times.

[0138] In related technologies, when 3D printing material 100 is flushed against a 3D printer, in order to save time, it is usually extruded at the maximum volume speed of 3D printing material 100. At this time, the pressure on the nozzle is relatively high (there is a risk of nozzle blockage, that is, extrusion abnormality). Therefore, it is generally necessary to raise the temperature to 20°C to 30°C above the printing temperature (taking PLA as an example, the printing temperature is 220°C and the flushing temperature is generally 240°C). However, at this time, the flushing temperature is much higher than the melting point of PLA (160°C-170°C), which inevitably leads to partial volatilization and degradation of PLA itself and the additives for modifying PLA, that is, the emission of more harmful substances and a very obvious odor.

[0139] The 3D printing material 100 described in this embodiment includes a resin matrix, impact-resistant particles 10, and inorganic fillers. Safety is fully considered in the 3D printing material 100, and excessive additives, especially small-molecule modifiers, are not added (meaning that the formulation is designed to use as few additives as possible). This results in very low PLA Pure emissions and a lower risk of extrusion anomalies (clogging) at the same temperature. Therefore, we can reduce its rinsing temperature to T1-30℃≤T2≤T1+10℃ and rinsing at maximum volumetric speed without significantly increasing extrusion resistance. Compared to 3D printing materials 100 in related technologies, printing emissions are further reduced, alleviating the odor problem of 3D printing materials 100 during high-temperature rinsing in related technologies. In other words, the 3D printing material 100 of this application does not contain any small molecules and will not produce impurities from the degradation of small molecules. Therefore, the risk of clogging the nozzle of the 3D printer is low. When rinsing, it can be rinsed at a lower temperature, which can greatly reduce the emission of harmful substances. In addition, due to the lower rinsing temperature, the emission of harmful substances produced by the decomposition of some components in the 3D printing material 100 can be further reduced, thereby further reducing the emission of harmful substances.

[0140] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A 3D printing material, characterized in that, The 3D printing material includes: a resin matrix, impact-resistant particles, and inorganic fillers; the impact-resistant particles and the inorganic fillers are both dispersed in the resin matrix; the impact-resistant particles have a core-shell structure, comprising a core and a shell, with the shell disposed on the surface of the core; the core comprises a first polymer, and the shell comprises a second polymer; the solubility parameter of the resin matrix is ​​δ1, and the solubility parameter of the second polymer is δ2, then 0.9 ≤ δ1 / δ2 ≤ 1.

1.

2. The 3D printing material according to claim 1, characterized in that, The 3D printing material comprises, by mass fraction, 85% to 92% resin matrix, 5% to 13% impact-resistant particles, and 1% to 4.6% inorganic filler.

3. The 3D printing material of claim 1, wherein, The impact-resistant particles are acrylate graft copolymer particles.

4. The 3D printing material according to claim 1, characterized in that, The impact-resistant particles are a graft copolymer with a first polymer as the main chain and a second polymer as the branched chain.

5. The 3D printing material according to claim 1, characterized in that, Both the first polymer and the second polymer are non-benzene toughening agents.

6. The 3D printing material according to claim 1, characterized in that, The resin matrix is ​​polylactic acid resin; the second polymer is a methacrylic acid polymer.

7. The 3D printing material according to claim 6, characterized in that, The first polymer is a random copolymer of butyl acrylate and octyl acrylate.

8. The 3D printing material according to claim 1, characterized in that, The impact-resistant particles comprise 75% to 85% of a first polymer and 15% to 25% of a second polymer by mass fraction.

9. The 3D printing material according to claim 7, characterized in that, The molar ratio of butyl acrylate units to octyl acrylate units in the first polymer ranges from 2:1 to 4:

1.

10. The 3D printing material according to claim 1, characterized in that, The average particle size d of the impact-resistant particles is in the range of 150nm≤d≤500nm.

11. The 3D printing material according to claim 1, characterized in that, The average particle size d1 of the core is in the range of 120nm≤d1≤400nm; the thickness d2 of the shell is in the range of 15nm≤d2≤50nm.

12. The 3D printing material according to any one of claims 1-11, characterized in that, The inorganic filler is lamellar talc, and the average width of the lamellar talc ranges from 3.5 μm to 7 μm.

13. The 3D printing material according to any one of claims 1-11, characterized in that, The glass transition temperature of the core is lower than that of the outer shell.

14. The 3D printing material according to any one of claims 1-11, characterized in that, The 3D printing material contains food contact grade materials as its main components, and the content of the main components is greater than 0.05% by mass fraction.

15. The 3D printing material according to any one of claims 1-11, characterized in that, The 3D printing material comprises the resin matrix, the impact-resistant particles, the inorganic filler, and the colorant, wherein the content of the main components is greater than 0.05% by mass fraction.

16. An application of the 3D printing material according to any one of claims 1-15, characterized in that, The 3D printing material is printed using a 3D printer, and the printing temperature of the 3D printing material is a first temperature T1; The 3D printer includes a nozzle, and the 3D printing material is used to scour the nozzle. When scourting, the temperature of the 3D printing material is a second temperature T2, then T1-30℃≤T2≤T1+10℃.

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