Photocurable composition for 3D printer, comprising zwitterions, and transparent dental aligner comprising same

Abstract

The present invention relates to a photocurable composition for a 3D printer, comprising zwitterions, and a transparent dental aligner comprising same. The photocurable composition, which can be used to manufacture a transparent dental aligner by means of a 3D printer, and the transparent dental aligner manufactured using the photocurable composition, comprise zwitterions, and thus can prevent the attachment of microbial organisms to the surface of the transparent dental aligner and the formation of biofilms thereon, which can lead to infections and complications. In addition, the transparent dental aligner can be manufactured by being output in a form suitable for the oral structure of a patient through the application of 3D printing technique, the transparent dental aligner has excellent mechanical properties, and thus can increase orthodontic force, and when heat is provided, the shape of the transparent dental aligner can be changed and restored such that high orthodontic efficacy can be exhibited.

Description

Photocurable composition for 3D printer containing zwitterionic and transparent orthodontic device containing the same

[0001] The present invention relates to a photocurable composition for a 3D printer containing a zwitterionic agent and a transparent orthodontic device containing the same.

[0002] 3D printing is a process technology that uses digitally designed data to repeatedly layer two-dimensional cross-sections to create a three-dimensional shape. This allows for significant freedom in design planning and modification, and can significantly reduce the cost and time required for prototype production.

[0003] Furthermore, because 3D printing technology allows for the simple production of even the most complex shapes, the range of products it can produce is virtually limitless. Consequently, 3D printing technology is expected to shift technological paradigms and drive industrial innovation across diverse sectors, including manufacturing, healthcare, and IT.

[0004] 3D printer technology can be divided into photocuring lamination, laser sintering lamination, resin extrusion lamination, inkjet lamination, polyjet lamination, and thin film lamination depending on the material.

[0005] The double photocuring lamination method is a method of manufacturing a molded product by hardening a photocurable liquid resin with a laser beam or strong ultraviolet rays (UV, Ultraviolet rays). Examples of this photocuring lamination method include stereolithography apparatus (SLA) and digital light processing (DLP).

[0006] Recently, 3D printing technology has been utilized in various medical fields, offering significant efficiency in terms of production time, cost, and process compared to conventional subtractive machining. In particular, photocurable additive manufacturing offers superior surface roughness, making it ideal for medical applications requiring the production of complexly shaped molded products.

[0007] However, as mentioned above, when using conventional 3D printer materials, there are problems such as limitations in the physical properties of the output and problems such as bacterial growth when used inside the mouth, making it difficult to apply them to the medical field. Therefore, there is an urgent need to develop photocurable polymer 3D printer materials that can be applied to various medical fields.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] KR 10-2020-0120992 A1

[0011] The purpose of the present invention is to provide a photocurable composition for a 3D printer containing a zwitterionic ion and a transparent orthodontic device containing the same.

[0012] Another object of the present invention is to provide a photocurable composition that can be manufactured into a transparent orthodontic device using a 3D printer, wherein the transparent orthodontic device manufactured using the photocurable composition contains zwitterionic ions, thereby preventing the attachment of microbial organisms to the surface of the transparent orthodontic device and the formation of a biofilm that can cause infection and complications.

[0013] Another object of the present invention is to provide a transparent orthodontic device that can be manufactured by applying 3D printing technology to a shape that fits the oral structure of a patient, and that has excellent mechanical properties to increase orthodontic power, and can exhibit a high orthodontic effect by changing and restoring its shape when heat is applied.

[0014] In order to achieve the above object, the present invention relates to a photocurable composition for a 3D printer, comprising: a photocurable oligomer represented by the following chemical formula 1; a reactive monomer; and a zwitterion, wherein the zwitterion may be a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), carboxybetaine acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and combinations thereof:

[0015] [Chemical Formula 1]

[0016]

[0017] [Chemical Formula 2]

[0018]

[0019] [Chemical Formula 3]

[0020]

[0021] [Chemical Formula 4]

[0022]

[0023] [Chemical Formula 5]

[0024]

[0025] [Chemical Formula 6]

[0026]

[0027] Here,

[0028] n is an integer from 1 to 100,

[0029] m is an integer from 1 to 50,

[0030] A, B, C and D are the same or different from each other and are repeating units each independently selected from the group consisting of compounds represented by chemical formulas 2 to 6,

[0031] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0032] R1 and R2 are the same or different, and can each be independently selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0033] The above A, B and D are the same or different from each other, and may be repeating units independently selected from compounds represented by chemical formula 2 or 3.

[0034] The above C may be a repeating unit selected from the group consisting of compounds represented by chemical formulas 4 to 6.

[0035] The above amphoteric ion may be included in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the reactive monomer.

[0036] The photocurable oligomer may have a viscosity of 2,000 psi to 3,500 psi.

[0037] A transparent orthodontic device according to another embodiment of the present invention may include the photocurable composition for a 3D printer.

[0038] The present invention relates to a photocurable composition that can be manufactured into a transparent orthodontic device using a 3D printer. The transparent orthodontic device manufactured using the photocurable composition contains zwitterionic ions, thereby preventing the attachment of microbial organisms to the surface of the transparent orthodontic device and the formation of a biofilm that can cause infection and complications.

[0039] In addition, by applying 3D printing technology, it can be manufactured into a transparent orthodontic device that is output in a shape that fits the patient's oral structure, and the transparent orthodontic device has excellent mechanical properties, so that it can increase the orthodontic power, and when heat is provided, its shape can be changed and restored, so that it can exhibit a high orthodontic effect.

[0040] Figure 1 is a flowchart illustrating a process for manufacturing a photocurable oligomer according to one embodiment of the present invention.

[0041] Figure 2 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0042] Figure 3 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0043] Figure 4 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0044] Figure 5 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0045] Figure 6 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0046] Figure 7 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0047] Figure 8 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0048] Figure 9 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0049] Figure 10 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0050] Figure 11 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0051] Figure 12 shows the results of protein adsorption performance evaluation for a specimen according to one embodiment of the present invention.

[0052] Figure 13 shows the results of evaluating bacterial adsorption performance for a specimen according to one embodiment of the present invention.

[0053] The present invention relates to a photocurable composition for a 3D printer, comprising: a photocurable oligomer represented by the following chemical formula 1; a reactive monomer; and a zwitterion, wherein the zwitterion is a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), carboxybetaine acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and combinations thereof:

[0054] [Chemical Formula 1]

[0055]

[0056] [Chemical Formula 2]

[0057]

[0058] [Chemical Formula 3]

[0059]

[0060] [Chemical Formula 4]

[0061]

[0062] [Chemical Formula 5]

[0063]

[0064] [Chemical Formula 6]

[0065]

[0066] Here,

[0067] n is an integer from 1 to 100,

[0068] m is an integer from 1 to 50,

[0069] A, B, C and D are the same or different from each other and are repeating units each independently selected from the group consisting of compounds represented by chemical formulas 2 to 6,

[0070] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0071] R1 and R2 are the same or different, and can each be independently selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0072] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0073] The 3D printing of the present invention refers to a process of manufacturing a three-dimensional object by layering materials using 3D digital data. This specification focuses on 3D printing technologies such as DLP (Distal Light Processing), SLA (Stereo Lithography Apparatus), and PolyJet, but it should be understood that the technology can be applied to other 3D printing technologies as well.

[0074] The photocurable composition of the present invention refers to a polymer that is crosslinked and polymerized into a polymer network structure, and is a material that is cured by light irradiation. While the present specification focuses on UV light, the present invention is not limited to UV light and can be applied to other types of light.

[0075] A photocurable composition for a 3D printer according to one embodiment of the present invention may include a photocurable oligomer represented by the following chemical formula 1; a reactive monomer; and a zwitterionic ion:

[0076] [Chemical Formula 1]

[0077]

[0078] [Chemical Formula 2]

[0079]

[0080] [Chemical Formula 3]

[0081]

[0082] [Chemical Formula 4]

[0083]

[0084] [Chemical Formula 5]

[0085]

[0086] [Chemical Formula 6]

[0087]

[0088] Here,

[0089] n is an integer from 1 to 100,

[0090] m is an integer from 1 to 50,

[0091] A, B, C and D are the same or different from each other and are repeating units each independently selected from the group consisting of compounds represented by chemical formulas 2 to 6,

[0092] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0093] R1 and R2 are the same or different, and can each be independently selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0094] The above photocurable oligomer is characterized by including a urethane acrylate structure as a main chain, a photocurable functional group bonded to the urethane structure, and including a soft functional group and a hard functional group in the compound.

[0095] The output exhibits flexible properties due to the soft functional group included in the photocurable composition, and can also exhibit heat resistance due to the hard functional group.

[0096] That is, by combining a photocurable functional group with a photocurable oligomer and utilizing a soft functional group and a hard functional group, a flexible effect can be exhibited by utilizing a carbon skeleton having a soft property at room temperature, and heat-resistant properties can also be exhibited by utilizing a carbon skeleton having a hard property at room temperature.

[0097] Since the above photocurable oligomer includes a carbon skeleton having hard properties, it can produce a 3D printing output that has excellent physical properties such as thermal properties, strength, elastic modulus, and tensile elongation, and can be restored to its original shape by heat.

[0098] In addition, since the photocurable oligomer contains a carbon skeleton with soft properties, its shape can be deformed by an external force after heat is provided.

[0099] In general, a composition for a 3D printer may include a photocurable oligomer for 3D printing; a monomer; a photoinitiator; and a stabilizer, as described below. The oligomer, monomer, photoinitiator, and stabilizer included in the composition all affect the physical properties of the output, but the oligomer has the greatest effect. Accordingly, in general, in order to improve the physical properties of a 3D output, only a carbon skeleton having a hard property is included, which can improve the physical properties of the output, but conversely, if the shape is deformed due to use, the shape cannot be restored, which is a problem in that it cannot be used multiple times.

[0100] The composition for a 3D printer of the present invention includes a carbon skeleton having a hard property and a carbon skeleton having a soft property, so that not only is it excellent in physical properties such as thermal properties, strength, elasticity, and tensile elongation, but also the flexible property of the soft functional group can be utilized together, so that when the shape is deformed by an external force in a state where heat is provided, it can be fixed in the deformed shape, and when heat is provided again, it can be restored to the original shape.

[0101] The above A, B and D are the same or different from each other, and may be repeating units independently selected from compounds represented by chemical formula 2 or 3.

[0102] The above C may be a repeating unit selected from the group consisting of compounds represented by chemical formulas 4 to 6.

[0103] Specifically, the photocurable oligomer represented by the above chemical formula 1 can be manufactured by a method for synthesizing a urethane acrylate series. Basically, it proceeds through a stepwise polymerization reaction of a diol and a diisocyanate, and in order to prevent gelation of the material due to an increase in molecular weight during the polymerization process of the material, an acrylic monomer without a reaction site is used as a suspension. The monomer used in the synthesis of the oligomer of the present invention as an available acrylic monomer may be Isobornyl acrylate, Cyclic Trimethylolpropane Formal Acrylate, Lauryl acrylate, Lauryl methacrylate, 3,5,3-trimethelhexyl acrylate, Tetrahydrofurfuryl acrylate, Tetrahydrofurfuryl methacrylate, Benzyl methacrylate, etc.

[0104] More specifically, diol was pre-introduced into the monomer base used as the primary monomer to stabilize it, and then diisocyanate was added. As the urethane reaction progressed, heat of reaction was generated, the urethane chain lengthened, and the molecular weight increased.

[0105] As the molecular weight increases, the viscosity of the material may also increase. If the above-mentioned increase in molecular weight proceeds rapidly, the temperature rises rapidly, which also causes the urethane reaction to proceed more quickly, and as a result, the oligomer gels before reaching a sufficient molecular weight, making it unusable as a material. Therefore, in the present invention, in order to prevent this reaction, a solvent selected from the group consisting of Isobornyl acrylate, Cyclic Trimethylolpropane Formal Acrylate, Lauryl acrylate, Lauryl methacrylate, 3,5,3-trimethelhexyl acrylate, Tetrahydrofurfuryl acrylate, Tetrahydrofurfuryl methacrylate, Benzyl methacrylate, and mixtures thereof is used as a solvent for introducing the diol. The solvent does not participate in the reaction, and is used to control the reaction speed of the material and prevent a rapid increase in viscosity due to an increase in molecular weight. Additionally, the monomers used to synthesize the oligomer of the present invention must be free of functional groups capable of reactive urethane reactions, such as hydroxyl groups or urethane groups. Under the above conditions, the present invention can produce oligomers with excellent mass production and process stability.

[0106] In addition, the equivalent ratio of diol and diisocyanate was set to a state where the equivalent of diisocyanate was higher than that of diol, so that the oligomer terminal exists as an isocyanate group. A reaction catalyst including a Zn-based catalyst can be used during the reaction process. The catalyst may or may not be included. The catalyst is included to proceed the reaction more quickly, and the reaction can proceed even if it is not necessarily included, but even if it is included, the reaction can proceed with a very small amount added.

[0107] After the temperature increase was stopped due to the completion of the urethane reaction, 2-hydroxy acrylate and 2-hydroxy methacrylate were added dropwise to end-cap the ends of the oligomers.

[0108] The diols used for the preparation of the above oligomers are as follows:

[0109]

[0110]

[0111] In addition, the diisocyanate for reacting with the above diol is as follows:

[0112]

[0113]

[0114] Additionally, monomers that may be included to terminate the urethane reaction or increase the molecular weight are as follows:

[0115]

[0116]

[0117]

[0118]

[0119] The compound represented by the above chemical formula 1 manufactured by the above manufacturing method can be selected from the group consisting of the following compounds:

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] Here, p, p', p", q, q', q", r, s, t, u and v are integers from 1 to 100.

[0126] The photocurable oligomer may have a number average molecular weight (Mn) of 1,500 to 6,000, 1,500 to 5,500, or 1,600 to 5,000. The photocurable oligomer may have a weight average molecular weight (Mw) of 2,500 to 9,000, 3,000 to 8,500, or 3,500 to 8,000.

[0127] When a photocurable composition for 3D printing, described below, is manufactured using an oligomer having a number average molecular weight and a weight average molecular weight within the above range, and a transparent orthodontic device is manufactured using the same, the transparent orthodontic device can be printed in a manner customized to the patient's oral structure, and the orthodontic force can be increased using the same. In addition, when the transparent orthodontic device is immersed in water at 50 to 100°C and then deformed, the shape changes to the deformed shape, but when used while fitted on a tooth, the orthodontic device, which has been deformed by body temperature, gradually returns to its original shape, thereby exhibiting orthodontic force.

[0128] That is, conventional transparent orthodontic devices are manufactured from transparent plastic materials and can transmit sufficient force for correcting teeth. However, as described above, the transparent orthodontic devices are printed in accordance with the gradual movement state of the teeth, and are different from the current tooth structure of the patient. Therefore, they are not easy to wear when fitted to the teeth and can cause great pain even after wearing them.

[0129] On the other hand, when using the photocurable composition for 3D printing of the present invention, if the printed transparent orthodontic device is immersed in water at 50 to 100°C before use and then positioned on the patient's teeth to change its shape to fit the current, the shape of the orthodontic device gradually changes due to body temperature, so that it can exert a large orthodontic force without the patient feeling great pain.

[0130] The above photocurable oligomer may have a viscosity of 2,000 psi to 3,500 psi, 2,100 psi to 3,200 psi, or 2,200 psi to 3,000 psi. When a photocurable composition is prepared using an oligomer having a viscosity within the above range, it can be provided with a viscosity suitable for use in a 3D printer.

[0131] The photocurable composition of the present invention comprises a zwitterion, and the zwitterion may be a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), carboxybetaine acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and combinations thereof.

[0132] The photocurable composition according to one embodiment of the present invention may additionally include nanoclay, and the nanoclay is characterized in that it is sepiolite. However, the nanoclay is not limited to sepiolite, and any nanoclay that can be included in the photocurable composition for a 3D printer and enhance mechanical properties can be used without limitation.

[0133] Polymer composite technology can be applied to overcome the mechanical strength limitations of 3D printing materials. However, applying these composite materials to 3D printing poses several challenges. The most critical issue is the size of the additives used in the composite material. As the additive size increases, the printing gap also increases, potentially resulting in lower printing resolution.

[0134] To avoid the above problems, nano-sized materials can be used as additives. Conventional nano-sized materials, such as graphene and carbon nanotubes (CNTs), can be price-competitive. On the other hand, nano-clays are more suitable for industrial applications due to their reasonable price. Among nano-clays, sepiolite is Mg8Si. 12 O 30 It is a hydrated magnesium silicate with a half unit cell formula of (OH)4·12H2O.

[0135] The above sepiolite is a needle-like or fiber-like structure composed of multiple blocks and tunnels parallel to the fiber direction. Each structural block contains a central octahedral magnesium (MgOH6) sheet sandwiched by two tetrahedral silica (SiO4) sheets. A single sepiolite fiber is 0.2 to 4 µm in length, 10 to 30 nm in width, and 5 to 10 nm in thickness.

[0136] Incorporating sepiolite into nanoclay can maintain a viscosity that allows 3D printing within a photocurable composition and exhibit high mechanical strength for the printed output.

[0137] That is, when a large amount of nano clay is included, the viscosity of the photocurable composition increases, and when the viscosity increases, there is a problem in that the composition cannot be manufactured into an output product through a 3D printer. When a certain amount of nano clay is included or more, the mechanical strength of the output product may increase, but because a composition with a high viscosity cannot be used for 3D printing, it is desirable that the viscosity of the photocurable composition be included within a certain range.

[0138] Accordingly, the photocurable composition may contain 90 to 120 parts by weight of the photocurable oligomer and 0.1 to 0.5 parts by weight of the zwitterion relative to 100 parts by weight of the reactive monomer. When mixed and used within the above range, not only can it be manufactured into an output product using a 3D printer, but the manufactured output product can exhibit excellent mechanical strength and can prevent the attachment of microbial organisms to the surface of the transparent orthodontic device and the formation of a biofilm that can cause infection and complications. The 3D printer is a DLP-type 3D printer.

[0139] The above reactive monomer may specifically be an acrylate monomer.

[0140] More specifically, the acrylate monomer may be selected from the group consisting of the following chemical formulas 7 to 13:

[0141] [Chemical Formula 7]

[0142]

[0143] [Chemical Formula 8]

[0144]

[0145] [Chemical Formula 9]

[0146]

[0147] [Chemical Formula 10]

[0148]

[0149] [Chemical Formula 11]

[0150]

[0151] [Chemical Formula 12]

[0152]

[0153] [Chemical Formula 13]

[0154]

[0155] In addition, a photoinitiator and a stabilizer may be additionally included, and the photoinitiator may be BP, TPO, DCP, BPO, DPPO, etc., and preferably DPPO (2-hydroxy-2-methylpropiophenone) may be used, but is not limited to the above examples, and any photoinitiator capable of producing a photocurable composition may be used without limitation.

[0156] The above stabilizer may be selected from the group consisting of tertiary amines such as diethylethanolamine and trihexylamine, hindered amines, organic phosphates, and hindered phenols, but is not limited to the above examples, and any stabilizer capable of producing a photocurable composition may be used without limitation.

[0157] In addition to the above photoinitiator and stabilizer, other additives may be additionally included.

[0158] The above additives may include conventional additives such as leveling agents, slip agents or stabilizers to improve thermal and oxidation stability, storage stability, surface properties, flow properties and process properties.

[0159] The photocurable composition for a 3D printer according to one embodiment of the present invention may be prepared by: dissolving a zwitterionic ion and a reactive monomer in a solvent to prepare a mixture including the zwitterionic ion; and mixing a photocurable oligomer into the mixture.

[0160] The above-mentioned amphoteric ion and reactive monomer are added to a solvent, and dispersed for 30 to 90 minutes by repeating the steps of ultrasonic dispersion for 1 to 5 seconds and pausing for 1 to 5 seconds. Preferably, the composition can be manufactured by repeating the steps of ultrasonic dispersion for 1 to 2 seconds and pausing for 1 to 2 seconds, and dispersing for 50 to 70 minutes.

[0161] As described above, in order to prepare a mixture containing zwitterionic ions, when ultrasonic dispersion is used to uniformly disperse the reactive monomer and zwitterionic ions in the solvent phase, the temperature rises to 50°C to 100°C. This is because the temperature increases as the photocurable monomer and zwitterionic ions are uniformly dispersed in the solvent by ultrasonic dispersion.

[0162] The solvent for preparing the above coating composition may be distilled water, but is not limited to the above examples and any solvent capable of preparing the coating composition may be used without limitation.

[0163] After preparing a mixture containing the above-mentioned amphoteric ions, a photocurable oligomer and a photoinitiator can be mixed into the mixture to prepare a photocurable composition.

[0164] A transparent orthodontic device according to another embodiment of the present invention can be manufactured by printing using a 3D printer using the photocurable composition.

[0165] In particular, the transparent orthodontic device of the present invention is a patient-customized transparent orthodontic device, and the patient-customized transparent orthodontic device utilizes accurate information about the patient's tooth structure using a 3D scanner, and can accurately derive the degree of tooth movement for each step based on the information about the tooth structure.

[0166] That is, when information about the patient's tooth structure is acquired using a 3D scanner and then input into a program that creates a 3D model, a 3D model is created that takes into account the degree of tooth movement for orthodontic treatment.

[0167] For the above program, you can purchase and use a commercially available program that creates 3D dental models.

[0168] As described above, after forming multiple 3D models for orthodontic treatment, an orthodontic device can be printed using a 3D printer using the 3D models.

[0169] As previously explained, the above 3D printer can be used with various types of 3D printers depending on the material, but in order to manufacture a transparent orthodontic device, a 3D printer using the DLP (Distal Light Processing), SLA (Stereo Lithography Apparatus), and PolyJet methods can be used.

[0170] The orthodontic device printed in this manner can be printed with the orthodontic device connected to the supporter on the plate portion within the 3D printer.

[0171] The orthodontic device combined with the supporter as described above can be manufactured into a final orthodontic device by removing the remaining resin, separating the supporter, and performing post-curing.

[0172] The above post-curing step is a process that can increase the transparency of transparent orthodontic devices. The output produced by the 3D printer has a conversion rate of approximately 60-70% because the oligomer in the photocurable composition is not completely cured. Accordingly, the post-curing process is a process for completely curing the oligomer and removing unreacted monomers, and the present invention can be performed in an inert gas environment.

[0173] The above inert gas is selected from the group consisting of nitrogen, argon, helium, krypton, neon and mixtures thereof, and is preferably characterized in that it is selected from the group consisting of nitrogen, argon, helium and mixtures thereof.

[0174] When performing the post-curing process in an inert gas environment under UV irradiation, not only does the curing speed of the 3D printed orthodontic device increase, but its strength is also enhanced, making it less susceptible to deformation even under higher levels of impact.

[0175] That is, when the curing process is carried out by irradiating UV in an inert gas environment, the curing speed is accelerated by the inert gas, and the strength of the output can be improved, compared to when the curing process is carried out by simply irradiating UV.

[0176] Additionally, if the post-curing process is performed in an inert gas environment, the transparency of the transparent orthodontic device is further improved.

[0177] When UV is irradiated in an inactive environment during the post-curing process, the UV irradiation not only enhances the curing speed and strength, but also improves the transparency of the orthodontic device. In other words, by utilizing the post-curing process of the present invention, a completely transparent orthodontic device can be manufactured.

[0178] Furthermore, when utilizing a post-curing process using UV in an inert gas environment, as in the present invention, the curing speed is enhanced, thereby increasing the production speed of the final product. Furthermore, the product exhibits superior strength, making it less susceptible to deformation due to external forces. Furthermore, transparency is improved, ensuring superior product quality.

[0179] Manufacturing example

[0180] Preparation of photocurable compositions

[0181] Manufacturing Example 1 (Example 1)

[0182] Isobornyl acrylate was used as a solvent, and polypropylene glycol, cyclohexanedimethanol, and BHT were added, and stirred at 10 to 200 rpm at 10 to 50°C. Isophorone diisocyanate was added, and stirring was performed under the same temperature conditions while changing the stirring speed from 50 to 200 rpm. Afterwards, HEMA was added, and stirring was performed at 150 to 500 rpm at 50 to 250°C to produce an oligomer.

[0183] The intermediate compounds produced by the above reaction are as follows:

[0184]

[0185] The oligomer finally produced by reacting the above intermediate compounds is as follows:

[0186]

[0187] The sequence of the manufacturing method of the above Example 1 is as shown in Fig. 1.

[0188] The GPC analysis results for the oligomer of Example 1 are as shown in Fig. 2. In addition, the NMR analysis results are as shown in Fig. 3.

[0189] Example 2

[0190] Oligomers were prepared using the same method as in Example 1, but the monomers used in the reaction were different. The prepared oligomers are as follows:

[0191]

[0192] The GPC analysis results for the oligomer of Example 2 are as shown in Fig. 4. In addition, the NMR analysis results are as shown in Fig. 5.

[0193] Example 3

[0194] Oligomers were prepared using the same method as in Example 1, but the monomers used in the reaction were different. The prepared oligomers are as follows:

[0195]

[0196] The GPC analysis results for the oligomer of Example 2 are as shown in Fig. 6. In addition, the NMR analysis results are as shown in Fig. 7.

[0197] Example 4

[0198] Oligomers were prepared using the same method as in Example 1, but the monomers used in the reaction were different. The prepared oligomers are as follows:

[0199]

[0200] The GPC analysis results for the oligomer of Example 2 are as shown in Fig. 8. In addition, the NMR analysis results are as shown in Fig. 9.

[0201] Example 5

[0202] Oligomers were prepared using the same method as in Example 1, but the monomers used in the reaction were different. The prepared oligomers are as follows:

[0203]

[0204] The GPC analysis results for the oligomer of Example 2 are as shown in Fig. 10. In addition, the NMR analysis results are as shown in Fig. 11.

[0205]

[0206] The results of the analysis of the oligomers of Examples 1 to 5 are summarized in Table 1 below:

[0207] Example 1 Example 2 Example 3 Example 4 5GPCMn41794102166347672691Mw69446763785575913703PDI1.681.651.681.591.38NMRA(6.44)OOOOOB(5.89)OOOOOC(5.61)O(39.0)O(39.3)O(9.3)O(22.1)XD(4.91)O(87.9)O(89.6)O(77.6)O(86.4)O(61.0)E(6.48)XXO(16.1)XO(22.3)F(6.49)XXOXOG(3.41)OOOOOViscosity(psi)28802955221923842880

[0208] Manufacturing Example 2

[0209] Preparation of photocurable composition

[0210] 2-methacryloyloxyethyl phosphorylcholine (MPC) and a compound represented by the following chemical formula 7 were added to distilled water, and a mixture was prepared by dispersing the mixture for 1 second at 750 W output using a tip ultrasonic processor, followed by pausing for 1 second, repeating this process for 1 hour:

[0211] [Chemical Formula 7]

[0212]

[0213] Afterwards, DPPO was mixed with the photocurable oligomer and photoinitiator of Example 1, and a paste mixer was used to mix and defoame to prepare a photocurable composition.

[0214] MPC Chemical Formula 7 Photocurable Oligomer DPP0 Example 60.2 100 100 1 Example 70.2 4 100 100 1 Example 80.1 100 100 1 Example 90.3 100 100 1 Control-100 100 1

[0215] (unit weight)

[0216] Experimental example

[0217] Results of protein adsorption prevention experiment

[0218] The photocurable compositions of Examples 6 to 9 were placed in a 3D printer to prepare specimens, which were then immersed in phosphate-buffered saline (PBS, Gibco) at room temperature for 1 hour. Each sample was then immersed in bovine serum albumin (BSA; Pierce Biotechnology) broth (2 mg of protein / mL in PBS, 100 μL). After incubation at 37°C in 5% CO2 for 4 hours, any protein not bound to the sample was removed by washing twice with PBS. The amount of protein bound to the specimens was measured using microbicinchoninic acid (200 μL; Micro BCATM Protein Assay Kit, Pierce Biotechnology), followed by incubation at 37°C for 30 minutes. The amount of surface-adsorbed protein was quantified based on the optical density (OD) at 562 nm measured using a microplate reader (Epoch, BioTek Instruments). The experimental results are shown in Fig. 12.

[0219] Experimental results confirmed that a large amount of protein was adsorbed in the control group. In contrast, in the case of a specimen in which a coating layer was formed using a coating composition containing a zwitterionic compound within the scope of the present invention, the amount of adsorbed protein was significantly reduced, confirming the excellent effect of preventing protein adsorption.

[0220] Bacterial adsorption prevention experiment

[0221] Before conducting the bacterial adsorption inhibition experiment, all specimens were sterilized by ultraviolet irradiation. Actinomyces naeslundii (A. naeslundii) was cultured under anaerobic conditions using 3.8% BHI supplemented with 0.5% yeast extract (Becton Dickinson and Co. Sparks, MD, USA), 4 μg / mL resazurin (Sigma-Aldrich, St. Louis, MO, USA), 5 μg / mL hemin (Sigma-Aldrich, St. Louis, MO, USA), 0.05% L-cysteine ​​(Sigma-Aldrich, St. Louis, MO, USA), and 2 μg / mL vitamin K (Sigma-Aldrich, St. Louis, MO, USA).

[0222] After sufficient bacterial growth, 1 mL (108 cells / mL) of bacterial suspension was added to each sample in a 24-well plate and incubated at 37°C for 24 h. After incubation, the samples were gently washed twice with PBS to remove non-adherent bacteria. To assess bacterial colony forming units (CFU), attached bacteria were harvested by sonication (SH-2100, Saehan Ultrasonic, Seoul, Korea) in 1 mL of BHI for 5 min. 100 μL of this bacterial suspension was spread on an agar plate, incubated at 37°C for 24 h, and then colonies were counted.

[0223] The bacterial culture was centrifuged, and the bacterial pellet was resuspended in fresh medium until the optical density (OD) reached 0.55 (measured at a wavelength of 600 nm). The specimens were individually placed into each well of a 24-well plate containing 1 mL of medium and the bacterial cell suspension (OD = 0.55) and incubated for 24 h in a humidified atmosphere at 36°C. After incubation, each specimen was washed three times with Dulbecco's PBS (DBPS, Gibco BRL, USA) to remove loosely attached bacteria. Bacteria that were firmly attached to the substrate were fixed by passing the bottom of the sample over the flame of a Bunsen burner. The fixed sample was placed in 1 mL of a 0.1% gram crystal violet solution (Sigma-Aldrich, USA) and incubated at room temperature for 10 minutes. After the staining step, each sample was washed twice with 1 mL of DPBS and then placed in 1 mL of 95% ethanol to dissolve the crystal violet stain on the surface. 100 μL of the crystal violet solution dissolved for 10 minutes was added to each well of a 96-well plate, and the absorbance of the sample was measured at 570 nm using a microplate reader.

[0224] The experimental results are shown in Fig. 13. The experimental results confirm that a large amount of bacteria were adsorbed in the control group. Conversely, in the case of a specimen in which a coating layer was formed using a coating composition containing a zwitterionic compound within the scope of the present invention, the amount of adsorbed bacteria was significantly reduced, confirming the excellent effect of preventing bacterial adsorption.

[0225] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0226] The present invention relates to a photocurable composition for a 3D printer containing a zwitterionic agent and a transparent orthodontic device containing the same.

Claims

1. A photocurable oligomer represented by the following chemical formula 1; reactive monomer; and Contains zwitterionic ions, The above zwitterion is a monomer selected from the group consisting of sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), carboxybetaine acrylamide (CBAA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and combinations thereof. Photocurable composition for 3D printers: [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5] [Chemical Formula 6] Here, n is an integer from 1 to 100, m is an integer from 1 to 50, A, B, C and D are the same or different from each other and are repeating units each independently selected from the group consisting of compounds represented by chemical formulas 2 to 6, a, b, c and d are the same or different and are each independently an integer from 1 to 30, R1 and R2 are the same or different, and can each be independently selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

2. In paragraph 1, The above A, B and D are the same or different from each other, and are repeating units independently selected from compounds represented by chemical formula 2 or 3. Photocurable composition for 3D printers.

3. In paragraph 1, The above C is a repeating unit selected from the group consisting of compounds represented by chemical formulas 4 to 6. Photocurable composition for 3D printers.

4. In paragraph 1, The above amphoteric ion is included in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the reactive monomer. Photocurable composition for 3D printers.

5. In paragraph 1, The above photocurable oligomer has a viscosity of 2,000 psi to 3,500 psi. Photocurable composition for 3D printers.

6. A photocurable composition for a 3D printer according to any one of claims 1 to 5. Clear aligners.

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