Photocurable oligomer for 3D printing and shape memory polymer composition for 3D printing, comprising same

Abstract

The present invention relates to a photocurable oligomer produceable as a photocurable composition for 3D printing so as to be capable of maintaining a 3D-printable viscosity and exhibiting physical properties for being usable as a dental material. In addition, the present invention, by applying 3D printing technology, may be produced so as to be outputted in a form suitable for the oral structure of a patient, may increase orthodontic force by having excellent mechanical properties, and when heat is provided, may have the shape thereof changed and restored, thereby increasing user convenience while being providable as various personalized dental products.

Description

Photocurable oligomer for 3D printing and shape memory polymer composition for 3D printing comprising the same

[0001] The present invention relates to a photocurable oligomer for 3D printing and a shape memory polymer composition for 3D printing comprising the same.

[0002] 3D printers include the FDM (Fused Deposition Modeling) method, which draws out solid plastic materials that melt in heat like threads and builds them up by melting them little by little; the SLA (StereoLithography Apparatus) method, which utilizes the principle of hardening the injected part by injecting laser light into photocurable resin; the SLS (Selective Laser Sintering) method, which uses the principle of using functional polymers or metal powders instead of photocurable resin in the SLA method and injecting laser light to solidify and form; and the DLP (Digital Light Processing) method, which utilizes the principle of partially hardening by irradiating light to the bottom of a storage tank where photocurable resin is stored.

[0003] Among these, both SLA and DLP 3D printers use photocurable compositions.

[0004] 3D printers can be used in a variety of fields, enabling the production of customized products. This is particularly true in the medical field.

[0005] For example, they can be manufactured as custom-made transparent orthodontic devices. Transparent orthodontic devices, like conventional orthodontic devices, attach to the teeth and protrude, without any visible structures or metal wires. Their nearly transparent color offers superior aesthetics compared to conventional orthodontic devices. Therefore, many people who want orthodontic treatment but are hesitant due to concerns about the negative impact of having orthodontic devices attached to their teeth on their work, interpersonal relationships, and self-confidence, are reluctant to pursue it. Transparent orthodontic devices avoid this burden, allowing patients to receive treatment comfortably.

[0006] To manufacture the above-described transparent orthodontic device, a 3D image is acquired using a scanner. Using this image, the desired tooth movement direction and the elasticity of the resin are considered, and a computer program is used to simulate the step-by-step tooth movement. The movement of each tooth is then implemented step-by-step, from the initial position to the final position. Then, a mold for thermo-pressure molding of the resin is printed for each step using a 3D printer. Thermo-pressure molding is then performed on the printed mold to manufacture the transparent orthodontic device for each step of tooth movement.

[0007] The transparent orthodontic treatment manufactured as described above uses a hard sheet to induce tooth alignment due to the nature of the material to ensure aesthetics, so the transparent orthodontic device is hard due to the nature of the hard material, so there is a lot of pain inflicted on the patient.

[0008] Despite the many advantages of clear aligners, they have a disadvantage over fixed aligners: if the device doesn't fit properly during tooth movement, it won't settle properly, hindering proper tooth movement. In particular, using clear aligners to straighten teeth can lead to unintended tooth tilting.

[0009] As previously explained, 3D printing technology is being utilized in a variety of medical fields and offers significant efficiency compared to conventional machining in terms of production time, cost, and process. In particular, DLP technology offers superior surface roughness, making it ideal for use in the medical field, where complex shapes require molding.

[0010] However, as mentioned above, when using conventional 3D printer materials, there is a problem in applying them to the medical field due to limitations in the physical properties of the output, so there is an urgent need to develop photocurable polymer 3D printer materials that can be applied to various medical fields.

[0011] [Prior Art Literature]

[0012] [Patent Document]

[0013] (Patent Document 1) KR 10-2020-0120992

[0014] The purpose of the present invention is to provide a photocurable oligomer for 3D printing and a shape memory polymer composition for 3D printing comprising the same.

[0015] Another object of the present invention is to provide a photocurable oligomer that can be manufactured into a photocurable composition for 3D printing, which can maintain a viscosity that allows 3D printing and exhibit properties that can be utilized as a dental material.

[0016] Another object of the present invention is to provide a photocurable composition for 3D printing, which can be manufactured by applying 3D printing technology in a shape that fits the oral structure of a patient, has excellent mechanical properties to increase corrective force, and can change and restore its shape when heat is applied, thereby increasing user convenience, and can exhibit a high corrective effect when provided as an orthodontic device, can exhibit a high orthodontic retention effect when provided as an orthodontic retainer, and can exhibit an excellent arch expansion effect when provided as an arch expansion device.

[0017] In order to achieve the above purpose, the photocurable oligomer for 3D printing of the present invention may be a compound represented by the following chemical formula 1:

[0018] [Chemical Formula 1]

[0019]

[0020] [Chemical Formula 2]

[0021]

[0022] [Chemical Formula 3]

[0023]

[0024] [Chemical Formula 4]

[0025]

[0026] [Chemical Formula 5]

[0027]

[0028] [Chemical Formula 6]

[0029]

[0030] Here,

[0031] n is an integer from 1 to 100,

[0032] m is an integer from 1 to 50,

[0033] 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,

[0034] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0035] 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.

[0036] 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.

[0037] The above C may be a repeating unit selected from the group consisting of compounds represented by chemical formulas 4 to 6.

[0038] The above photocurable oligomer may have a number average molecular weight (Mn) of 1,500 to 6,000.

[0039] The above photocurable oligomer may have a weight average molecular weight (Mw) of 2,500 to 9,000.

[0040] The photocurable oligomer may have a viscosity of 2,000 psi to 3,500 psi.

[0041] According to another embodiment of the present invention, a shape memory polymer composition for 3D printing may include the photocurable oligomer for 3D printing; a monomer; a photoinitiator; and a stabilizer.

[0042] In the present invention, “hydrogen” is hydrogen, light hydrogen, deuterium or tritium, unless specifically limited.

[0043] In the present invention, “alkyl” refers to a monovalent substituent derived from a straight or branched saturated hydrocarbon having 1 to 40 carbon atoms. Examples thereof include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, and hexyl.

[0044] In the present invention, “alkenyl” refers to a monovalent substituent derived from a straight or branched unsaturated hydrocarbon having 2 to 40 carbon atoms and at least one carbon-carbon double bond. Examples thereof include, but are not limited to, vinyl, allyl, isopropenyl, and 2-butenyl.

[0045] In the present invention, “alkynyl” refers to a monovalent substituent derived from an unsaturated hydrocarbon having 2 to 40 carbon atoms and a straight or branched chain having at least one carbon-carbon triple bond. Examples thereof include, but are not limited to, ethynyl and 2-propynyl.

[0046] In the present invention, “aryl” refers to a monovalent substituent derived from an aromatic hydrocarbon having 6 to 60 carbon atoms, which is a single ring or a combination of two or more rings. In addition, it may also include a form in which two or more rings are simply attached to each other (pendant) or condensed, and specifically, it may be a naphthyl group, anthracenyl group, phenanthryl group, triphenyl group, pyrenyl group, phenalenyl group, perylenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto. The fluorenyl group may be substituted, and adjacent groups may be bonded to each other to form a ring.

[0047] In the present invention, “heteroaryl” refers to a monovalent substituent derived from a monoheterocyclic or polyheterocyclic aromatic hydrocarbon having 6 to 30 carbon atoms. At this time, at least one carbon atom in the ring, preferably 1 to 3 carbon atom(s), is substituted with a heteroatom such as N, O, S, or Se. In addition, a form in which two or more rings are simply attached to each other (pendant) or condensed may be included, and a form condensed with an aryl group may also be included. Examples of such heteroaryls include, but are not limited to, 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl; polycyclic rings such as phenoxathienyl, indolizinyl, indolyl, purinyl, quinolyl, benzothiazole, and carbazolyl; and 2-furanyl, N-imidazolyl, 2-isoxazolyl, 2-pyridinyl, and 2-pyrimidinyl.

[0048] In the present invention, "substitution" means that a hydrogen atom bonded to a carbon atom of a compound is replaced with another substituent, and the position of substitution is not limited as long as it is a position where a hydrogen atom is replaced, i.e., a position where a substituent can be substituted, and when two or more are substituted, the two or more substituents may be the same or different from each other. The above substituent is hydrogen, a cyano group, a nitro group, a halogen group, a hydroxy group, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 24 carbon atoms, a heteroalkyl group having 2 to 30 carbon atoms, an aralkyl group having 6 to 30 carbon atoms, an aryl group having 5 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, a heteroarylalkyl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an arylamino group having 6 to 30 carbon atoms, an aralkylamino group having 6 to 30 carbon atoms, a heteroarylamino group having 2 to 24 carbon atoms, a substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkyl group having 6 to It may be substituted with one or more substituents selected from the group consisting of 30 arylsilyl groups and substituted or unsubstituted aryloxy groups having 6 to 30 carbon atoms, but is not limited to the above examples.

[0049] In the present invention, “halogen group” is fluorine, chlorine, bromine or iodine.

[0050] In the present invention, “alkylthio” means the above-described alkyl group bonded via a sulfur linkage (-S-).

[0051] In the present invention, “aryloxy” is a monovalent substituent represented by RO-, wherein R represents aryl having 6 to 60 carbon atoms. Examples of such aryloxy include, but are not limited to, phenyloxy, naphthyloxy, and diphenyloxy.

[0052] In the present invention, “alkyloxy” is a monovalent substituent represented by R'O-, wherein R' means alkyl having 1 to 40 carbon atoms, and may include a linear, branched, or cyclic structure. Examples of alkyloxy include, but are not limited to, methoxy, ethoxy, n-propoxy, 1-propoxy, t-butoxy, n-butoxy, and pentoxy.

[0053] In the present invention, “alkoxy” may be straight chain, branched chain, or cyclic chain. The carbon number of the alkoxy is not particularly limited, but is preferably 1 to 20 carbon atoms. Specifically, it may be methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, p-methylbenzyloxy, etc., but is not limited thereto.

[0054] As used herein, "aralkyl" refers to an aryl-alkyl group, where aryl and alkyl are as defined above. Preferred aralkyl groups include lower alkyl groups. Non-limiting examples of suitable aralkyl groups include benzyl, 2-phenethyl, and naphthalenylmethyl. Bonding to the parent moiety is via the alkyl group.

[0055] In the present invention, “arylamino group” means an amine substituted with an aryl group having 6 to 30 carbon atoms.

[0056] In the present invention, “alkylamino group” means an amine substituted with an alkyl group having 1 to 30 carbon atoms.

[0057] In the present invention, “aralkylamino group” means an amine substituted with an aryl-alkyl group having 6 to 30 carbon atoms.

[0058] In the present invention, “heteroarylamino group” means an amine group substituted with an aryl group and a heterocyclic group having 6 to 30 carbon atoms.

[0059] In the present invention, “heteroaralkyl group” means an aryl-alkyl group substituted with a heterocyclic group.

[0060] In the present invention, “cycloalkyl” refers to a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 40 carbon atoms. Examples of such cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantine.

[0061] In the present invention, “heterocycloalkyl” means a monovalent substituent derived from a non-aromatic hydrocarbon having 3 to 40 carbon atoms, wherein at least one carbon atom in the ring, preferably 1 to 3 carbon atom(s), is substituted with a heteroatom such as N, O, S or Se. Examples of such heterocycloalkyl include, but are not limited to, morpholine and piperazine.

[0062] In the present invention, “alkylsilyl” means silyl substituted with alkyl having 1 to 40 carbon atoms, and “arylsilyl” means silyl substituted with aryl having 6 to 60 carbon atoms.

[0063] The present invention relates to a photocurable oligomer that can be manufactured into a photocurable composition for 3D printing, so as to maintain a viscosity that allows 3D printing and exhibit properties that can be utilized as a dental material.

[0064] In addition, by applying 3D printing technology, it can be manufactured in a shape that fits the patient's oral structure, has excellent mechanical properties to increase corrective power, and can change and restore its shape when heat is applied, thereby increasing user convenience and providing various customized dental products.

[0065] Figure 1 is a flowchart illustrating a process for manufacturing a photocurable oligomer according to one embodiment of the present invention.

[0066] Figure 2 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0067] Figure 3 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0068] Figure 4 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0069] Figure 5 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0070] Figure 6 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0071] Figure 7 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0072] Figure 8 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0073] Figure 9 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0074] Figure 10 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0075] Figure 11 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0076] Fig. 12 is a photograph of a transparent orthodontic device according to one embodiment of the present invention.

[0077] FIG. 13 is a drawing of a three-dimensional shape of a dental orthodontic device according to one embodiment of the present invention.

[0078] Fig. 14 is a photograph of a correction maintenance device according to one embodiment of the present invention.

[0079] The present invention relates to a photocurable oligomer for 3D printing, which is a compound represented by the following chemical formula 1:

[0080] [Chemical Formula 1]

[0081]

[0082] [Chemical Formula 2]

[0083]

[0084] [Chemical Formula 3]

[0085]

[0086] [Chemical Formula 4]

[0087]

[0088] [Chemical Formula 5]

[0089]

[0090] [Chemical Formula 6]

[0091]

[0092] 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 each independently a repeating unit selected from the group consisting of compounds represented by chemical formulas 2 to 6, a, b, c and d are the same or different from each other and are each independently an integer from 1 to 30, R1 and R2 are the same or different from each other and are each independently 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] A photocurable oligomer for 3D printing according to one embodiment of the present invention may be a compound represented by the following chemical formula 1:

[0097] [Chemical Formula 1]

[0098]

[0099] [Chemical Formula 2]

[0100]

[0101] [Chemical Formula 3]

[0102]

[0103] [Chemical Formula 4]

[0104]

[0105] [Chemical Formula 5]

[0106]

[0107] [Chemical Formula 6]

[0108]

[0109] Here,

[0110] n is an integer from 1 to 100,

[0111] m is an integer from 1 to 50,

[0112] 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,

[0113] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] The above C may be a repeating unit selected from the group consisting of compounds represented by chemical formulas 4 to 6.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] The diols used for the preparation of the above oligomers are as follows:

[0130]

[0131] In addition, the diisocyanate for reacting with the above diol is as follows:

[0132]

[0133]

[0134] Additionally, monomers that may be included to terminate the urethane reaction or increase the molecular weight are as follows:

[0135]

[0136]

[0137] 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:

[0138]

[0139]

[0140]

[0141]

[0142]

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] In addition, by utilizing these characteristics, it can be used in various dental products such as orthodontic retainers and arch expanders.

[0148] As described above, when various oligomers are selected according to the physical properties required for each product, such as tensile strength, flexural strength, flexural elasticity, and flexural strength, and a photocurable composition for 3D printing is manufactured using the same, it is possible to manufacture excellent dental products.

[0149] 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 manufactured using an oligomer having a viscosity within the above range, it can be provided with a viscosity suitable for use in a 3D printer.

[0150] A photocurable composition for a 3D printer according to one embodiment of the present invention may include the photocurable oligomer for D printing; a monomer; a photoinitiator; and a stabilizer.

[0151] The above monomer is a reactive monomer, and may specifically be an acrylate monomer.

[0152] More specifically, the acrylate monomer may be selected from the group consisting of a compound represented by the following chemical formula 7, a compound represented by the following chemical formula 8, and a mixture thereof:

[0153] [Chemical Formula 7]

[0154]

[0155] [Chemical Formula 8]

[0156]

[0157] The photoinitiator may be BP, TPO, DCP, BPO, DPPO, etc., and preferably DPPO (2-hydroxy-2-methylpropiophenone) may be used. However, the present invention is not limited to the above examples, and any photoinitiator capable of producing a photocurable composition may be used without limitation.

[0158] 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.

[0159] In addition to the above photoinitiator and stabilizer, other additives may be additionally included.

[0160] 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.

[0161] A photocurable composition according to one embodiment of the present invention may contain 1 part by weight of a photoinitiator per 100 parts by weight of a UV resin. The UV resin may include a photocurable oligomer of the present invention and a monomer, and more specifically, may contain a compound represented by the following chemical formula 1, a compound represented by the following chemical formula 7, and a compound represented by the following chemical formula 8 in a weight ratio of 1:1:1 to 2:1:1.

[0162]

[0163] Manufacturing Example 1

[0164] Manufacturing of photocurable oligomers for 3D printing

[0165] 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.

[0166] The intermediate compounds produced by the above reaction are as follows:

[0167]

[0168] The oligomer finally produced by reacting the above intermediate compounds is as follows:

[0169]

[0170] The sequence of the manufacturing method of the above Manufacturing Example 1 is as shown in Fig. 1.

[0171] The GPC analysis results for the oligomer of the above manufacturing example 1 are as shown in Fig. 2. In addition, the NMR analysis results are as shown in Fig. 3.

[0172]

[0173] Manufacturing Example 2

[0174] An oligomer was prepared using the same method as in Manufacturing Example 1, but the monomers used during the reaction were different. The prepared oligomers are as follows:

[0175]

[0176] The GPC analysis results for the oligomer of the above manufacturing example 2 are as shown in Fig. 4. In addition, the NMR analysis results are as shown in Fig. 5.

[0177]

[0178] Manufacturing Example 3

[0179] An oligomer was prepared using the same method as in Manufacturing Example 1, but the monomers used during the reaction were different. The prepared oligomers are as follows:

[0180]

[0181] The GPC analysis results for the oligomer of the above manufacturing example 3 are as shown in Fig. 6. In addition, the NMR analysis results are as shown in Fig. 7.

[0182]

[0183] Manufacturing Example 4

[0184] An oligomer was prepared using the same method as in Manufacturing Example 1, but the monomers used during the reaction were different. The prepared oligomers are as follows:

[0185]

[0186] The GPC analysis results for the oligomer of the above manufacturing example 4 are as shown in Fig. 8. In addition, the NMR analysis results are as shown in Fig. 9.

[0187]

[0188] Manufacturing Example 5

[0189] An oligomer was prepared using the same method as in Manufacturing Example 1, but the monomers used during the reaction were different. The prepared oligomers are as follows:

[0190]

[0191] The GPC analysis results for the oligomer of the above manufacturing example 5 are as shown in Fig. 10. In addition, the NMR analysis results are as shown in Fig. 11.

[0192]

[0193] The results of the analysis of the oligomers of the above manufacturing examples 1 to 5 are summarized in Table 1 below:

[0194] Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 3 Manufacturing Example 4 Manufacturing Example 5 GPCMn41794102166347672691Mw69446763785575913703PDI1.681.651.681.591.38NMRA(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)OOOOO

[0195]

[0196] Experimental Example 1

[0197] Check physical properties

[0198] The viscosity of the oligomers of the above manufacturing examples 1 to 5 was measured, and the mechanical properties were measured after 3D printing.

[0199] In order to measure the mechanical properties, the oligomers of the above Preparation Examples 1 to 5, the compound represented by the following Chemical Formula 7, and the compound represented by the following Chemical Formula 8 were mixed in a weight ratio of 1:1:1, and 1 part by weight of DPPO was mixed with 100 parts by weight of the mixture to prepare a polymer composition, which was then placed in a 3D printer to prepare a specimen:

[0200] [Chemical Formula 7]

[0201]

[0202] [Chemical Formula 8]

[0203]

[0204] Specifically, flexural strength was measured according to ISO 20795-2 and ISO 10477, and tensile strength was measured according to ASTM D638.

[0205] Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 3 Manufacturing Example 4 Manufacturing Example 5 Batch Size 50L 50L 50L 50L 50L Mechanical Properties after Blending and 3D Printing Flexural Strength (20795-2 Specimen, MPa) 171 162 155 163 150 Flexural Elasticity (20795-2 Specimen, MPa) 393 93 80 73 80 0 365 53 59 4 Flexural Strength (104 77 Specimen, MPa) 146 122 162 158 143 Tensile Strength (D 638, MPa) 109 102 115 113 108 Elongation (D 638, %) 3.9 3.0 7.6 6.5 7.7 Viscosity (psi) 288 0 295 0 222 0 238 0 2380

[0206] It was confirmed that the specimens manufactured using the oligomers of the above manufacturing examples 1 to 5 exhibited excellent mechanical properties, and it was confirmed that printing using a 3D printer was possible through appropriate viscosity.

[0207]

[0208] Experimental Example 2

[0209] Manufacturing of transparent orthodontic devices

[0210] Fig. 13 is a diagram of a shape of a transparent orthodontic device using a computer program, and using this, a transparent orthodontic device was printed as in Fig. 12. Specifically, a polymer composition prepared by mixing the oligomer, monomer, and photoinitiator of Experimental Example 1 was placed in a 3D printer and printed as a transparent orthodontic device.

[0211] To confirm the shape memory characteristics, experiments were conducted to determine whether deformation and shape restoration occurred due to heat.

[0212] The experimental method was to immerse the sample in water at 50 to 100°C, apply an external force to deform the shape, and check whether the deformed shape was fixed, and whether the sample was immersed in water at 40 to 80°C again from the deformed shape and then restored to its original shape under conditions of 20 to 30°C.

[0213] If the shape is deformed by an external force after being immersed in water at 40 to 80°C for the first time, and the deformed shape is fixed, and then the shape is restored to its original shape at 20 to 30°C after being immersed in water at 50 to 100°C again, it is marked as O.

[0214] Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 3 Manufacturing Example 4 Manufacturing Example 5 Shape Memory Characteristics OOOOO

[0215] According to Table 3 above, it was confirmed that the shape could be deformed and fixed in the deformed shape after being placed in hot water temperature (50 to 70℃) of a generally easily accessible water purifier, and that it could be restored to its original shape when placed in water at hot water temperature again and no external force was applied.

[0216]

[0217] Experimental Example 3

[0218] Manufacturing of orthodontic retainers

[0219] Using the polymer compositions of Manufacturing Examples 1 to 5, a retainer as shown in Fig. 14 was manufactured by printing using the DLP method. Specifically, a polymer composition manufactured by mixing the oligomer, monomer, and photoinitiator of Experimental Example 1 was placed in a 3D printer and printed as an orthodontic retainer.

[0220] The above orthodontic retainer can be attached to the back of the patient's orthodontic teeth using dental adhesive after orthodontic treatment, and the orthodontic retainer can provide an orthodontic retention effect.

[0221]

[0222] 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.

[0223] The present invention relates to a photocurable oligomer for 3D printing and a shape memory polymer composition for 3D printing comprising the same.

Claims

1. A photocurable oligomer for 3D printing, which is a compound represented by the following chemical formula 1: [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 oligomers for 3D printing.

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 oligomers for 3D printing.

4. In paragraph 1, The above photocurable oligomer has a number average molecular weight (Mn) of 1,500 to 6,000. Photocurable oligomers for 3D printing.

5. In paragraph 1, The above photocurable oligomer has a weight average molecular weight (Mw) of 2,500 to 9,000. Photocurable oligomers for 3D printing.

6. In paragraph 1, The above photocurable oligomer has a viscosity of 2,000 mPa·s to 3,500 mPa·s. Photocurable oligomers for 3D printing.

7. Photocurable oligomer for 3D printing according to Article 1; monomer; photoinitiator; and Containing stabilizers Photocurable composition for 3D printing.

Images