Method for forming three-dimensional structure using UV parallel light in multi-layer stacked structure and three-

Abstract

The present invention relates to a method for forming a three-dimensional structure using UV parallel light in a multilayer stacked structure, and a three-dimensional structure formed by the method, and more particularly, to a method for forming a three-dimensional structure using UV parallel light, the present invention relates to a method for forming a three-dimensional structure using UV parallel light in a multilayer stacked structure having improved impact resistance, restoring force, extension force, and restoring force and having a low-reflection coating effect by irradiating a photomask with parallel light and UV, a three-dimensional structure formed by the method, and an element using the three-dimensional structure, and more particularly, to a method for forming a three-dimensional structure using UV parallel light in a multilayer stacked structure having improved impact resistance, restoring force, extension force, and restoring force, a three-dimensional structure formed by the method, and an element using the three-dimensional structure. The three-dimensional structure according to the manufacturing method of the present invention is composed of an impact-absorbing layer skeleton scaffold and an impact-buffering part around the skeleton scaffold, and has different modulus values. Since the skeleton scaffold maintains high structural hardness and the impact-absorbing portion disperses the internal / external impact, it is possible to manufacture a three-dimensional impact-absorbing layer having excellent impact resistance, restoring force, and extension force. The impact absorbing layer can also be used for a stacked structure, and can also be used for an element or a foldable display employing the stacked structure.

Description

Technical Field

[0001] The present invention relates to a method for forming a three-dimensional structure using ultraviolet (UV) parallel light in a multi-layer stacked structure and a three-dimensional structure formed by the method. Specifically, the present invention relates to a method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure having improved impact resistance, resilience, extensibility, and resilience and having the effect of low-reflection coating by irradiating parallel light and UV to a photomask, a three-dimensional structure formed by the method, and a component using the three-dimensional structure. Background Art

[0002] Recently, as society enters the formal information age, the display field for processing and displaying a large amount of information has developed rapidly. Correspondingly, various flat display devices have been developed and received much attention. As the display changes from a flat form to a bent or folded form, existing cover windows have changed to a very thin form such as a film (CPI) or an ultra-thin glass (UTG) in order to be easily folded and unfolded in glass.

[0003] Therefore, instead of the existing inflexible glass substrate, a flexible display device that uses a flexible material such as plastic to manufacture and can maintain its display performance intact even when bent like paper is rapidly becoming the new generation of flat display devices.

[0004] Flexible display devices use a plastic thin-film transistor substrate instead of a glass substrate and can be divided into unbreakable, bendable, rollable, and foldable types with high durability. Such flexible display devices can have the advantages of space utilization, decoration, and design, and can have a variety of application fields.

[0005] However, since flexible display devices need to be able to be folded and unfolded, both the backplane and the cover window including the display panel are formed in a very thin film form, and the thin film form transmits most of the impact transmitted from the outside vertically.

[0006] That is, when an impact is applied from the outside to the cover window or the backplane, as the cover window and the backplane are formed in a thin film form, the impact applied from the outside is directly transmitted to the display panel located between the cover window and the backplane.

[0007] This ultimately leads to damage to the display panel, thereby reducing the display quality of the display panel.

[0008] Korean Patent No. 10-1707138 discloses the following: A hard film is formed on the surface of a template, and by removing the solid-phase resin inside that is exposed by removing a part of the hard film, separate surface elements are added to the upper and lower surfaces or the upper and lower surfaces and the side surfaces of the micro-lattice structure. However, this process has the problem of treating the process of adding surface elements as a separate requirement. Summary of the Invention

[0009] Technical Problem

[0010] To solve the above problems, an object of the present invention is to provide a method for forming a three-dimensional structure by improving impact resistance, resilience, and elongation and using UV parallel light capable of low-reflection coating.

[0011] Moreover, an object of the present invention is to provide a three-dimensional structure manufactured by the above method.

[0012] Furthermore, an object of the present invention is to apply the three-dimensional structure manufactured by the above manufacturing method or manufacturing methods to a display.

[0013] Technical Solution

[0014] To achieve the above object, the present invention provides a method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, including the following steps:

[0015] (a) Coating a bone scaffold-forming composition including a polymer, a photoinitiator, and a curing agent on the upper part of a substrate;

[0016] (b) Forming a polymer layer on the upper part of the composition;

[0017] (c) Placing a photomask on the upper part of the polymer layer;

[0018] (d) Irradiating UV parallel light from directions 2 to 8 at an angle greater than 0° and less than 90° with respect to the surface perpendicular to the exposure surface to the photomask, so that the bone scaffold is cured parallel to the angle of the parallel light; and

[0019] (e) Forming a buffer part of a cured structure having a hardness lower than that of the bone scaffold by removing the photomask and irradiating UV light with an intensity lower than that of the UV parallel light.

[0020] To achieve the above another object, the present invention provides a method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, including the following steps:

[0021] (a) Coating a bone scaffold-forming composition including a polymer, a photoinitiator, and a curing agent on a substrate;

[0022] (b) Form a polymer layer on top of the composition;

[0023] (c) Place a half-cut mask on top of the polymer layer; and

[0024] (d) With the surface perpendicular to the exposure surface as a reference, irradiate the half-cut mask with UV parallel light from the 2 to 8 directions at an angle greater than 0° and less than 90°. The UV parallel light passing through the holes of the half-cut mask cures the bone scaffold in parallel with the angle of the parallel light, and the UV parallel light passing through the parts other than the holes of the half-cut mask forms a buffer part with a hardness lower than that of the bone scaffold.

[0025] To achieve another object as described above, the present invention provides a bone scaffold of a three-dimensional structure manufactured by the above manufacturing method.

[0026] To achieve another object as described above, the present invention provides an element adopting a stacked structure including the bone scaffold of the three-dimensional structure.

[0027] Technical effects

[0028] The bone scaffold of the three-dimensional structure according to the manufacturing method of the present invention is composed of a bone scaffold and a buffer part around the bone scaffold, and each modulus value is different. Since the bone scaffold maintains a high structural hardness and the buffer part dissipates internal / external impacts, it is possible to manufacture a bone scaffold of a three-dimensional structure with excellent impact resistance, resilience, and extensibility. The bone scaffold can also be used for a stacked structure body, and can also be used for an element adopting the stacked structure or a foldable display. Description of the drawings

[0029] Figure 1 Images of (a) a triangular prism structure, (b) a conical shape (cone array), (c) a triangular structure, and (d) a pyramid structure formed according to the angle of the parallel light when irradiating the parallel light according to an embodiment of the present invention.

[0030] Figure 2 As an image showing the pattern of the photomask according to an embodiment of the present invention, it is an image showing a rectangular pattern (a) and a triangular pattern (b).

[0031] Figure 3 An image that schematizes the manufacturing method of the absorption layer of the three-dimensional thin film sandwich structure formed by measuring the parallel light according to an embodiment of the present invention.

[0032] Figure 4It is a graph showing the stress-strain curve according to the usage time of the curing agent TMPTA when only parallel light is irradiated, according to an embodiment of the present invention.

[0033] Figure 5 It is a graph measuring the modulus of the absorption layer when only parallel light is irradiated, according to an embodiment of the present invention.

[0034] Figure 6 It is a graph showing the stress-strain curve when parallel light and UV are irradiated without using a photomask, according to an embodiment of the present invention.

[0035] Figure 7 It is a graph measuring the modulus according to time when parallel light and UV are irradiated without using a photomask, according to an embodiment of the present invention.

[0036] Figure 8 It is a graph showing the stress-strain curve when only overall UV is irradiated without a photomask, according to an embodiment of the present invention.

[0037] Figure 9 It is a graph measuring the modulus when only overall UV is irradiated without a photomask, according to an embodiment of the present invention.

[0038] Figure 10 It is a graph showing the stress-strain curve when UV is irradiated after parallel light is irradiated onto a photomask, according to an embodiment of the present invention.

[0039] Figure 11 It is a graph measuring the modulus of the absorption layer when UV is irradiated after parallel light is irradiated onto a photomask, according to an embodiment of the present invention.

[0040] Best Mode

[0041] Hereinafter, the present invention will be described in more detail.

[0042] According to one aspect of the present invention, there is provided a method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, comprising the following steps: (a) coating a composition for forming a bone scaffold including a polymer, a photoinitiator, and a curing agent on an upper portion of a substrate; (b) forming a polymer layer on the composition; (c) placing a photomask on the polymer layer; (d) irradiating UV parallel light from 2 to 8 directions at an angle greater than 0° and less than 90° with respect to a surface perpendicular to the exposure surface to the photomask, so that the bone scaffold is cured parallel to the angle of the parallel light; and (e) forming a buffer portion of a cured structure having a hardness lower than that of the bone scaffold by removing the photomask and irradiating UV light having an intensity lower than that of the UV parallel light.

[0043] In the present invention, the bone scaffold of the three-dimensional structure can be formed by two processes including an exposure process using a photomask and an exposure process after removing the photomask. Specifically, the bone scaffold of the present invention is composed of a bone scaffold and a buffer portion around the bone scaffold. The "bone scaffold" refers to a portion where the composition for curing the absorption layer is transmitted by UV parallel light and cured at the same angle and shape as the parallel light. Therefore, the structure and shape of the bone scaffold can be regarded as directly reflecting the shape, size, and interval of the holes of the photomask.

[0044] The three-dimensional structure of the present invention is formed by separating the bone scaffold and the buffer portion, so their hardnesses are different from each other, and thus the impact absorption can be maximized within the multi-layer stacked structure. It is characterized in that during the process of forming such a bone scaffold and a buffer portion, the types of UV and photomasks are selectively and diversely used.

[0045] A three-dimensional shape is manufactured by irradiating UV parallel light and introducing the composition for forming a bone scaffold between the substrate and the polymer, so that the bone scaffold as a cured structure can be formed parallel to the angle of the UV parallel light. In the absorption layer, a buffer portion can be formed in the remaining regions other than the bone scaffold generated by the UV parallel light by irradiating UV light having an intensity lower than that of the UV parallel light.

[0046] In the present invention, the "UV light having an intensity lower than that of the UV parallel light" refers to UV light having an intensity lower than that of the UV parallel light during the process of removing the photomask and achieving exposure. Due to the UV light having an intensity lower than that of the UV parallel light, a buffer portion formed around the cured bone scaffold can form a cured structure having a relatively low hardness. Due to the difference in the reflection force between the bone scaffold and the buffer portion caused by UV parallel light having different intensities, low-reflection coating using parallel light can also be performed.

[0047] In this specification, the portion thus formed is referred to as a "buffer portion". In the three-dimensional structure of the present invention including a bone scaffold and an impact buffer portion, the buffer portion may be a peripheral portion surrounding the bone scaffold. Since the structure cured by UV parallel light is hard, durability is improved. The buffer portion of the remaining portion other than the cured structure dissipates impact, thereby improving impact resistance, resilience, and extensibility, and enabling low-reflection coating using UV parallel light.

[0048] When the three-dimensional structure of the present invention is applied to the hinge portion of a foldable display, compared with existing filling materials, due to the three-dimensional bone scaffold with a relatively large modulus, the shape stability and wrinkle resilience can be improved. Also, by diversifying the shape of the three-dimensional bone structure, the path difference of light gradually passing in the thickness direction of the film can be controlled, thereby enabling the expansion of application fields such as effective low-reflection coating.

[0049] UV parallel light is irradiated onto the photomask from directions 2 to 8. Preferably, it is irradiated onto the photomask from directions 2 to 6. More preferably, it is irradiated onto the photomask from directions 2 to 4. Also, the UV parallel light is irradiated at an angle greater than 0° and less than 90° with respect to the surface perpendicular to the exposure surface. Preferably, it is irradiated at an angle of 10° to 80°. According to the angle at which the UV parallel light is irradiated, the shape of the bone scaffold in the three-dimensional structure of the present invention formed on the substrate can be manufactured in various ways.

[0050] That is, the cross-sectional shape of the holes in the photomask can be various forms such as a circle, an ellipse, a straight line, a curve, or a plane. Also, the size of the mask holes, the interval between the holes, and the depth of the holes can be changed diversely. Since the degree of exposure and curing varies according to the shape, interval, and depth of the mask holes, the physical properties of the absorption layer can be changed. And when an absorption layer is to be formed and used in this way, the cross-sectional shape, interval, and depth (thickness) of the holes can be designed considering the impact absorption strength.

[0051] In the absorption layer, preferably, the shape of the bone scaffold formed according to the angle of the parallel light exhibits various forms such as a sandwich panel, a pyramid structure, or a conical shape (cone array), etc., but the shape is not limited thereto. According to the cross-sectional shape, size, interval, depth of the mask holes, the intensity of the UV parallel light, and the irradiation angle of the UV parallel light, various shapes are possible.

[0052] The absorption layer can be used for various purposes. For example, by using a bonding component, it can be used as a 3D binder having a three-dimensional shape.

[0053] Figure 1Images of (a) a triangular prism structure, (b) a conical shape (corn array), (c) a triangular structure, and (d) a pyramid structure formed according to the angle of the parallel light when the parallel light according to an embodiment of the present invention is irradiated. Refer to Figure 1 , various patterns can be formed while changing the shape of the photomask or the shape of the control.

[0054] Moreover, even when UV parallel light is irradiated, each modulus is different according to the curing time. If the irradiation time of the parallel light becomes longer, complete cross-linking occurs and the modulus increases. Therefore, as Figure 1 shown, a specific shape or structure is exhibited. On the contrary, if the irradiation time of the parallel light is short or the parallel light is not irradiated, curing occurs locally, and thus a buffer portion with a small modulus can be formed.

[0055] Figure 2 As an image showing the pattern of the photomask according to an embodiment of the present invention, it is an image showing a rectangular pattern (a) and a triangular pattern (b). Refer to Figure 2 for the description. D represents the diameter of the photomask hole, and L represents the interval between the photomask holes. Figure 2 In (a), it shows the case where four holes of the photomask form a rectangle, and in (b), it shows the case where the intervals of L connected from the center points of the holes are all the same. However, it is not limited thereto. When D and L are at the same interval, when the interval of L is changed, when the pattern of the photomask holes is changed, etc., the shape of the photomask can be variously changed for use. Regardless of the shape or size of the photomask, the size and interval of the holes, a structure (bone scaffold) with a high modulus is generated in parallel with the parallel light passing through the photomask holes, and a buffer portion can be formed in the portion where the light does not pass through the photomask.

[0056] Preferably, the modulus of the absorption layer is 0.1 KPa to 1 KPa, and more preferably, the modulus of the absorption layer is 0.3 KPa to 1 KPa. Preferably, the modulus of the bone scaffold forming the three-dimensional structure of the present invention is 0.15 KPa to 0.4 KPa, and more preferably, the modulus of the bone scaffold forming the three-dimensional structure of the present invention is 0.2 KPa to 0.35 KPa. Preferably, the modulus of the three-dimensional structure of the present invention in which a buffer portion is formed around the bone scaffold is 0.10 KPa to 0.30 KPa.

[0057] In the polymer layer on the composition for forming the bone scaffold, although the type of the polymer is not limited, it is preferably polyethylene terephthalate (PET). Although the polymer itself can be used as the polymer layer, preferably, it is applied after corona treatment. Preferably, the thickness of the polymer layer is 30 μm to 100 μm, and more preferably, the thickness of the polymer layer is 30 μm to 50 μm.

[0058] According to another aspect of the present invention, there is provided a method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, comprising the following steps: (a) coating a composition for forming a bone scaffold including a polymer, a photoinitiator, and a curing agent on a substrate; (b) forming a polymer layer on the composition; (c) placing a half-cut mask on the polymer layer; and (d) irradiating UV parallel light from 2 to 8 directions at an angle greater than 0° and less than 90° with respect to a surface perpendicular to the exposure surface to the half-cut mask. The UV parallel light passing through the holes of the half-cut mask cures the bone scaffold in parallel with the angle of the parallel light, and a buffer portion having a hardness lower than that of the bone scaffold is formed by the UV parallel light in a portion other than the holes of the half-cut mask.

[0059] In another embodiment of the present invention, the two processes of using a photomask and removing the photomask can be shortened to one process, and a three-dimensional structure can also be formed. In this process, in addition to the photomask as a conventional pattern mask, a pattern mask that adjusts the transmittance of UV light to an appropriate level in an on / off form rather than 100% or 0% can be used, and the term "half-cut mask" is used.

[0060] Different from a photomask, when irradiating UV parallel light, 100% of the strong UV parallel light transmits through the holes of the half-cut mask, thereby forming a bone scaffold. However, in a region other than the holes of the mask, only a part of the UV parallel light can transmit rather than complete transmission of the UV parallel light. Therefore, due to a single exposure, a portion with a UV parallel light transmittance of 100% forms a bone scaffold, and a portion less than 100% forms a buffer portion. Therefore, compared with a conventional photomask, the manufacturing process can be shortened. At this time, the transmittance of a portion other than the holes of the half-cut mask can be appropriately adjusted in consideration of the curing rate of the shock buffer portion and used.

[0061] Since the curing speed of the composition for forming a bone scaffold increases with the increase in the intensity of UV parallel light and the concentration of the photoinitiator, the curing speed can be adjusted by adjusting the intensity of the parallel light or the concentration of the photoinitiator.

[0062] According to still another aspect of the present invention, there is provided a three-dimensional structure manufactured by the manufacturing method of the present invention.

[0063] The composition for forming a bone scaffold may include a polymer and / or copolymer, a photoinitiator, and a curing agent.

[0064] As the block copolymer, for example, polystyrene-polymethylmethacrylate copolymer, polybutadiene-polybutylmethacrylate copolymer, polybutadiene-polydimethylsiloxane copolymer, polybutadiene-polymethylmethacrylate copolymer, polybutadiene-polyvinylpyridine copolymer, polybutylacrylate-polymethylmethacrylate, polybutylacrylate-polyvinylpyridine, polyisoprene-polyvinylpyridine, polyisoprene-polymethylmethacrylate, polyhexylacrylate-polyvinylpyridine, polyisobutylene-polybutylmethacrylate, polyisobutylene-polymethylmethacrylate, polyisobutylene-polybutylmethacrylate, polyisobutylene-polydimethylsiloxane, polybutylmethacrylate-polybutylacrylate, polyethylethylene-polymethylmethacrylate, polystyrene-polybutylmethacrylate, polystyrene-polybutadiene, polystyrene-polyisoprene,polystyrene-polydimethylsiloxane, polystyrene-polyvinylpyridine, polyethylethylene-polyvinylpyridine, polyethylene-polyvinylpyridine, polyvinylpyridine-polymethylmethacrylate, polyethyleneoxide-polyisoprene, polyethyleneoxide-polybutadiene, polyethyleneoxide-polystyrene, polyethyleneoxide-polymethylmethacrylate, polyethyleneoxide-polydimethylsiloxane, polystyrene-polyethyleneoxide, etc.

[0065] Preferably, the photoinitiator is selected from one or more of the group consisting of benzyldimethyl ketal (photoinitiator #651), 2-methyl-1-(4-(methythio)phenyl)-2-morpholino-propan-1-on (photoinitiator #907), α,α-methoxy-α-hydroxyacetophenone (Irgacure #651), and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (photoinitiator #1173).

[0066] The solvent for the composition for forming a bone scaffold is not particularly limited. If only some examples of suitable solvents are cited, the following solvents can be used alone or as a mixture thereof: ethylene glycol monomethylethyl, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol, propylene glycol monoacetate, toluene, xylene, methyl ethyl ketone, methyl isopentyl ketone, cyclohexanone, dioxane, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate, 2-heptanone, γ-butyrolactone, 2-hydroxyethyl propionate, 2-hydroxy-2-methylethyl propionate, ethyl ethoxyacetate, ethyl glycolate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxy-2-methylpropionate, 3-ethoxy and propionic acid, methyl 3-methoxy-2-methylethyl propionate, 4-methyl-2-pentanol, 4-methyl-2-pentanol acetate, isopropyl alcohol, methanol, ethanol, n-butanol, cyclopentanol, cyclopentanone, ethyl acetate, butyl acetate, etc.

[0067] The composition for forming a bone scaffold of the present invention may further include additives such as surfactants. As the surfactant, surfactants used in the present technical field (for example, fluorosurfactants, anionic surfactants, cationic surfactants, nonionic surfactants, etc.) can be used without particular limitation.

[0068] According to another aspect of the present invention, there is provided a device (device) employing a stacked structure including the three-dimensional structure of the present invention. The device can also be applied to a display panel, for example, it can correspond to all elements for all foldable, rollable, and flat displays such as organic light-emitting diodes (OLEDs: organic light-emitting diodes).

[0069] The three-dimensional structure of the present invention includes both a bone scaffold and a buffer portion around the bone scaffold, thereby increasing the durability of the device, and improving impact resistance, resilience, and tensile strength, so that it is strong against internal and external impacts. Therefore, it can also be applied to other application fields such as display protection films, various packaging materials, home appliance protectants, and protective films for electronic devices. And, low-reflection coating using UV parallel light can be performed.

[0070] In this specification, when it is mentioned that a certain part "includes" a certain component, it means that other components can be included without excluding other components. And, the terms used in this specification are for explaining the embodiments and are not for limiting the present invention. In this specification, unless otherwise stated in the sentence, the singular form also includes the plural form.

[0071] In this specification, expressions such as "A or B", "at least one of A and / or B", or "one or more of A and / or B" may include all possible combinations of the items listed together. For example, "A or B", "at least one of A and B", or "at least one of A or B" may mean: (1) a case including at least one A; (2) a case including at least one B; or (3) a case including both at least one A and at least one B.

[0072] Hereinafter, preferred embodiments will be given to explain the present invention in more detail. However, these embodiments are used to more specifically explain the present invention, and it is obvious to those of ordinary skill in the technical field to which the present invention belongs that the scope of the present invention is not limited thereto. Detailed Description of the Invention

[0073] <Example 1>

[0074] Example 1

[0075] As the composition of the binder, 30 g of photoinitiator (irgacure) 980, 9 g of isobornyl acrylate (IBOA), 0.3 g of acetic acid (AA), and 0.4 g of photoinitiator (irgacure) 651 were used. As the curing agent, 0.04 g of 1,6-hexanediol diacrylate (HDDA) or 0.04 g of TMPTA (trimethylolpropane triacrylate) was used. A binder with a thickness of 1 mm was coated. It was confirmed how the cured shape changes according to the film thickness and UV irradiation time. For the cured shape (3D pattern), ethyl acetate (EAC) or toluene, which can dissolve the uncured binder after curing, was used as the solvent, and the binder was washed and removed using the solvent, thereby confirming the pattern morphology. A photomask with a hole diameter of 800 μm and a hole pitch of 1200 μm was used.

[0076] Example 2 - Parallel Light Irradiation Experiment

[0077] Experiments were conducted by changing the UV irradiation amount, time, photoinitiator, and curing agent by multi-directional irradiation. To produce a 3D pattern, experiments were conducted to irradiate in one direction, two directions, and four directions by photometric measurement at 45 degrees to achieve the pattern. The more directions irradiated, the more times the UV is received repeatedly. Therefore, it is necessary to adjust the UV irradiation amount and time accordingly, and it is necessary to adjust the types and contents of the photoinitiator and curing agent accordingly.

[0078] <Results and Evaluation>

[0079] Results of Only Irradiating Parallel Light

[0080] Figure 4 It is a graph showing the stress-strain curve according to the use time of the curing agent TMPTA when only parallel light is irradiated according to an embodiment of the present invention.

[0081] Refer to Figure 4 For the description, only parallel light was irradiated without a photomask, and then overall UV irradiation for manufacturing the bone scaffold was not performed. The stress-strain curves according to the times of 140 seconds, 160 seconds, 180 seconds, 220 seconds, 260 seconds, 300 seconds, and 340 seconds were confirmed. For the parallel light machine, since 340 seconds is the maximum irradiation time, irradiation for more than 340 seconds cannot be performed. In the case of manufacturing a structure using a photomask, when 130 seconds of parallel light is irradiated, the structure performs best.

[0082] Figure 5 It is a graph measuring the modulus of the pressure-sensitive adhesive when only parallel light is irradiated according to an embodiment of the present invention. Each value is shown in Table 1 below:

[0083] [Table 1]

[0084]

[0085] Refer to Figure 5 And Table 1 for the description, when only parallel light is irradiated and no UV is irradiated without a photomask, the modulus of the pressure-sensitive adhesive is the highest at 300 seconds.

[0086] Parallel Light and Overall UV Irradiation

[0087] Parallel light was irradiated without a photomask, and then overall UV irradiation was performed.

[0088] Figure 6 It is a graph showing the stress-strain curve when parallel light and UV are irradiated without using a photomask according to an embodiment of the present invention.

[0089] Figure 7 It is a graph measuring the modulus according to time when parallel light and UV are irradiated without using a photomask in an embodiment of the present invention. Each value is shown in Table 2 below:

[0090] [Table 2]

[0091] 120s_60s 340s_90s Modulus (KPa) 0.234531 0.317365

[0092] Figure 7 And each time in Table 2 represents the parallel light irradiation time and the overall UV irradiation time respectively. The parallel light is irradiated to form a pyramid structure without a photomask, and an impact absorption surface is formed by irradiating UV on the part where the pyramid structure is not formed. After irradiating the parallel light for 120 seconds before the structure is optimized, the overall UV irradiation for 60 seconds shows the lowest modulus value. After irradiating for 340 seconds, which is the maximum irradiation time, the overall UV irradiation for 90 seconds shows the highest modulus value.

[0093] Overall UV Irradiation without Parallel Light

[0094] Figure 8 It is a chart showing the stress-strain curve when only the overall UV is irradiated without a photomask according to an embodiment of the present invention.

[0095] Figure 9 It is a chart measuring the modulus of the pressure-sensitive adhesive when only the overall UV is irradiated without a photomask according to an embodiment of the present invention. Each value is shown in Table 3 below:

[0096] [Table 3]

[0097]

[0098] Refer to Figure 8 、 Figure 9 and Table 3 for description. Without a photomask, the overall UV was irradiated for 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, 110 seconds, and 130 seconds. At this time, the parallel light was not irradiated. The shortest time for the manufactured adhesive not to adhere to the hand is about 45 - 50 seconds. Therefore, the experiment was carried out after 60 seconds. Since the modulus value is the highest when irradiated for 90 seconds, it is considered that there is no significant meaning to conduct the experiment under time conditions greater than 90 seconds.

[0099] Irradiating the Photomask with Parallel Light and Overall UV

[0100] Figure 10 It is a chart showing the stress-strain curve when UV is irradiated after irradiating parallel light to a photomask according to an embodiment of the present invention.

[0101] Figure 11It is a graph measuring the modulus of the pressure-sensitive adhesive when irradiating UV after irradiating parallel light onto a photomask according to an embodiment of the present invention. Each value is shown in Table 4 below:

[0102] [Table 4]

[0103] 300s_90s 160s_45s Modulus (KPa) 0.613772 0.430539

[0104] Refer to Figure 10 、 Figure 11 and Table 4 for description. It is a diagram showing the case where parallel light is irradiated for 300 seconds using a photomask and then the entire UV is irradiated for 90 seconds, and the case where parallel light is irradiated for 160 seconds using a photomask and then the entire UV is irradiated for 45 seconds. Through the above experiments, by combining the condition with the highest modulus and the condition with the lowest modulus, the highest value and the lowest value of the modulus when forming the structure were measured. When using a photomask and irradiating both parallel light and UV, it can be confirmed that the highest modulus is formed when UV is irradiated for 90 seconds after irradiating parallel light for 300 seconds.

[0105] In summary, the following was found: A 3D structure spring was formed according to the size and interval of the photomask holes. Parallel light was irradiated onto the polymer and cured, thereby forming a 3D structure spring, and a 3D structure spring was formed according to the irradiation time of the parallel light. It has been confirmed that in the pressure-sensitive adhesive of the three-dimensional structure, the interval between the formed holes, the size of the holes, and the pattern of the holes can also vary.

[0106] For a better understanding of the claims of the present invention, the above content has described the features and technical points of the present invention somewhat broadly. Those with ordinary knowledge in the technical field to which the present invention pertains will be able to understand that it can be implemented in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the claims, not by the above detailed description, and should be interpreted as including all changes or modified forms derived from the scope of the claims and their equivalent concepts within the scope of the present invention.

Claims

1. A method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, comprising the following steps: (a) Coating a composition for forming a bone scaffold including a polymer, a photoinitiator, and a curing agent on an upper portion of a substrate; (b) Forming a polymer layer on the composition; (c) Placing a photomask on the polymer layer; (d) Irradiating the photomask with UV parallel light from 2 to 8 directions at an angle greater than 0° and less than 90° with respect to a surface perpendicular to the exposure surface, so that the bone scaffold is cured parallel to the angle of the parallel light; And (e) Forming a buffer portion of a cured structure having a hardness lower than that of the bone scaffold by removing the photomask and irradiating with UV light having an intensity lower than that of the UV parallel light.

2. A method for forming a three-dimensional structure using UV parallel light in a multi-layer stacked structure, comprising the following steps: (a) Coating a composition for forming a bone scaffold including a polymer, a photoinitiator, and a curing agent on a substrate; (b) Forming a polymer layer on the composition; (c) Placing a half-cut mask on the polymer layer; and (d) Irradiating the half-cut mask with UV parallel light from 2 to 8 directions at an angle greater than 0° and less than 90° with respect to a surface perpendicular to the exposure surface, curing the bone scaffold parallel to the angle of the UV parallel light passing through the holes of the half-cut mask, and forming a buffer portion of a cured structure having a hardness lower than that of the bone scaffold by the UV parallel light passing through portions other than the holes of the half-cut mask.

3. A three-dimensional structure, Wherein, The three-dimensional structure is manufactured using the method according to claim 1 or 2.

4. The three-dimensional structure according to claim 3, Characterized in that, The bone scaffold shows one or more structures selected from a sandwich panel, a pyramid structure, and a cone structure.

5. An element, Wherein, The element adopts a stacked structure including a three-dimensional structure having a three-dimensional shape according to claim 3.

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