Three-dimensional molded object, method for manufacturing the same, and processing liquid

Abstract

To provide a method for efficiently removing an uncured photocurable resin composition from a three-dimensional molded object made of a resin containing inorganic particles to improve an appearance quality thereof.SOLUTION: There is provided a three-dimensional molded object having a laminate portion 9 in which a plurality of resin layers 91 to 94 are laminated, wherein the three-dimensional molded object contains a large number of inorganic particles 2, a plurality of the inorganic particles 2 among the large number of inorganic particles 2 are dispersed in the laminate portion 9, and a laminate molded surface 9a formed by each of the plurality of resin layers 91 to 94 of the laminate portion 9 has protrusions 8 formed by a resin film 7 covering some of the inorganic particles 2a in accordance with a shape of the some inorganic particles 2a among the large number of inorganic particles 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional object that is cured by using an active energy ray, a method for producing the same, and a treatment liquid used in the production method. [Background technology]

[0002] In recent years, 3D additive manufacturing (AM) has been increasingly used as a means of manufacturing products, driven by the diversification of modeling materials and advances in equipment technology. Among these are modeling methods known as vat photopolymerization and stereolithography. These methods involve hardening a liquid photopolymerizable compound using an LED light, laser light source, or projector to form a three-dimensional shape, and are characterized by their ability to produce high-definition, high-precision models. In the stereolithography method, when a stereolithography object is removed from a modeling tank filled with a photocurable resin composition containing a photopolymerizable compound after modeling is complete, uncured photocurable resin composition remains on the surface of the stereolithography object. The uncured photocurable resin composition adheres to the curved surface of the stereolithography object due to surface tension, hardens when post-cured, and causes uneven reflection. For this reason, in the past, the stereolithography object was washed with a treatment liquid to remove the uncured photocurable resin composition, but this method made it difficult to completely remove the uncured photocurable resin composition that adhered to the unevenness of the surface of the stereolithography object, as well as the recesses and corners of the unevenness. Patent Document 1 discloses a method for reliably and simply removing uncured photocurable resin composition adhering to a photo-fabricated object by spraying resin particles onto the surface of the object, and further discloses that the resin particles that have embedded in the surface of the photo-fabricated object by spraying are melted to form a resin coating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-318605 Summary of the Invention [Problem to be solved by the invention]

[0004] When a stereolithography product contains inorganic particles, completely removing the uncured photocurable resin composition adhering to the surface of the stereolithography product exposes the inorganic particles on the surface of the stereolithography product, resulting in color unevenness due to the difference in color between the inorganic particles and the remaining cured photocurable resin composition, which not only impairs the appearance quality of the product but also makes it difficult to determine the presence or absence of scratches or molding defects from the appearance. Furthermore, even if an attempt is made to form a resin coating on the inorganic particles using the method of Patent Document 1, the resin particles sprayed onto the inorganic particles exposed on the surface of the stereolithography product are repelled, making it difficult to embed the resin particles into the inorganic particles, and the inorganic particles cannot be coated with a resin coating. An object of the present invention is to efficiently remove uncured photocurable resin composition from a three-dimensionally shaped object made of a resin containing inorganic particles, thereby improving the appearance quality. [Means for solving the problem]

[0005] A first aspect of the present invention is a three-dimensionally shaped object having a laminated portion in which a plurality of resin layers are laminated, Contains a large number of inorganic particles, a plurality of inorganic particles among the plurality of inorganic particles are dispersed in the laminated portion; The additive manufacturing surface formed by each of the plurality of resin layers of the laminated portion is characterized by having convex portions formed of a resin film covering some of the inorganic particles, which corresponds to the shape of some of the inorganic particles of the large number of inorganic particles. A second aspect of the present invention is a method for manufacturing a three-dimensional object using a stereolithography method, comprising the steps of: a step of supplying a photocurable resin composition containing at least a photopolymerizable compound, a photopolymerization initiator, and a large number of inorganic particles in a layered form, and a step of irradiating the layered photocurable resin composition with an active energy ray to cure the composition, the step being repeated multiple times to form a laminated portion; treating the laminated portion with a treatment liquid containing a polymerizable compound and a polymerization initiator; and a step of hardening the treatment liquid attached to the laminated portion. A third aspect of the present invention is a treatment liquid for stereolithography, comprising: The composition contains a polymerizable compound, a polymerization initiator, and an alcohol-based organic solvent, The content of the polymerizable compound is 5% by mass or more and 50% by mass or less. [Effects of the Invention]

[0006] According to the present invention, a three-dimensional object having a good appearance quality and suppressing uneven reflection and color is provided. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a three-dimensionally shaped object of the present invention taken along a lamination direction; [Figure 2] FIG. 1 is a schematic diagram illustrating an example of the configuration of a stereolithography apparatus using a regulated liquid level method. [Figure 3] 1 is a flowchart of a method for manufacturing a three-dimensional object according to the present invention. [Figure 4] 1A to 1C are cross-sectional views illustrating a manufacturing process of a three-dimensional object according to the present invention. [Figure 5] FIG. 1 is a schematic diagram showing a measurement area of ​​a microscopic laser Raman spectrometry. DETAILED DESCRIPTION OF THE INVENTION

[0008] The three-dimensional object of the present invention has a laminated portion formed by stacking a plurality of resin layers and contains a large number of inorganic particles. Some of the inorganic particles are present on the layered manufacturing surface formed by each of the plurality of resin layers, and the surface has protrusions formed by a resin film covering the inorganic particles according to the shape of the inorganic particles. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0009] <Three-dimensional object> FIG. 1 shows a cross-sectional view of a three-dimensionally shaped object according to the present invention. This cross-sectional view is a cross-sectional view of a method for laminating a laminated portion. In the figure, 100 denotes a three-dimensionally shaped object, and laminated portion 9 comprises resin 1 and a large number of inorganic particles 2 dispersed in the resin 1. Note that "large number" means three or more, but in reality, it can be 100 or more, and even 10,000 or more. Laminated portion 9 is formed by laminating multiple resin layers (91 to 94 in FIG. 1) using a stereolithography method, which will be described later. As a result, laminated surface 9a has a shape in which irregularities are repeated in the lamination direction at a predetermined pitch P corresponding to the thickness of the resin layers. In the figure, 3 denotes the irregular portion of laminated portion 9, and 4 denotes the interior of laminated portion 9 excluding irregularities 3. The three-dimensional object in Figure 1 is an example of exposure from below, and the upper parts of each layer 91 to 94 are underexposed compared to the lower parts, resulting in tapered sides.However, when exposure is performed from above, the lower parts are underexposed compared to the upper parts, and the direction of the tapered sides is reversed.

[0010] As will be described later, the pitch P of the irregularities 3 corresponds to the thickness d of the photocurable resin composition 21 cured by the active energy rays 30, which is determined based on the settings at the time of generating the modeling data when stacking the laminated layer 9 in the stereolithography device using the regulated liquid level method shown in Figure 2. The thickness d is achieved by the control unit 31 controlling the amount of elevation of the modeling stage 23 by the lifting device 24. The thickness d is adjusted within a range of 30 μm to 150 μm, preferably 40 μm to 100 μm, depending on the precision and modeling speed of the resulting article, and the adjusted thickness d here becomes the pitch P of the irregularities 3.

[0011] The formation of the irregularities 3 will now be described. The active energy rays 30 that have passed through the release transparent film 27 cure the photocurable resin composition to a thickness d. Because the active energy rays 30 attenuate as they pass through the photocurable resin composition, the photocurable resin composition near the release transparent film 27 cures quickly, while the photocurable resin composition away from the release transparent film 27 cures slowly and may not cure sufficiently. This is particularly likely to occur on the surface of the laminated portion 9, which is the boundary between the irradiated and unirradiated areas of the active energy rays 30. As a result, the uncured portions become uncured photocurable resin composition and are removed. Regular irregularities 3 are formed on the layered manufacturing surface 9a as traces of the removal. The height difference of these irregularities 3 corresponds to the height difference D of the irregularities of the final three-dimensional object, specifically, 1 μm to 30 μm.

[0012] The three-dimensionally shaped object 100 of the present invention has a resin film 7 on the additive manufacturing surface 9a. The resin film 7 continuously covers the additive manufacturing surface 9a of the laminated portion 9 and the surfaces of the inorganic particles 2a exposed from the additive manufacturing surface 9a, forming convex portions 8 corresponding to the shapes of the inorganic particles 2a. Note that in FIG. 1, the inorganic particles 2a directly below the resin film 7 that form the convex portions 8 are all embedded in the resin 1 of the laminated portion 9, and have portions that contact the resin 1 and portions that contact the resin film 7. However, the present invention is not limited to this configuration. In other words, the inorganic particles 2 contained in the uncured photocurable resin composition that remained on the additive manufacturing surface 9a during the lamination of the laminated portion 9 may remain as they are, not contacting the additive manufacturing surface 9a, and be encapsulated within the three-dimensionally shaped object 100 by the resin film 7. The resin film 7 may be the same or different photocurable resin as the resin 1 that constitutes the laminated portion 9. The resin film 7 is extremely thin, preferably with a thickness of less than 1 μm.

[0013] The regularly arranged linear irregularities 3 can suppress shine on the surface of a three-dimensional object, but without the protrusions 8, the regular structure can appear to have uneven color depending on the viewing angle. However, the presence of the irregularities 3 and the randomly arranged protrusions 8 eliminates the color unevenness caused by the regular structure, improving the appearance quality.

[0014] Furthermore, the resin film 7 covering the convex portions 8 is extremely thin, and when observed with an optical microscope using incident illumination, the inorganic particles 2a directly below the resin film 7 that constitutes the convex portions 8 appear to reflect strongly, making them distinguishable from the inorganic particles 2b that are buried near the surface of the three-dimensional object.

[0015] <Photocurable resin composition> The laminated portion 9 is formed by photocuring a photocurable resin composition containing a photopolymerizable compound, a photopolymerization initiator, and a large number of inorganic particles 2, and the photocurable resin composition may further contain a colorant and other additives as needed.

[0016] [Photopolymerizable compound] The photopolymerizable compound used in the present invention may be a radically polymerizable compound such as an acrylate, urethane acrylate, or vinyl compound, or an oligomer thereof, or a cationically polymerizable compound such as an epoxy, oxetane, or vinyl ether compound, or an oligomer thereof. Among these, acrylate and urethane acrylate polymerizable compounds are preferred because they have high polymerizability and can be imparted with various functions. These polymerizable compounds may be used alone or in combination of two or more.

[0017] [Photopolymerization initiator] The photopolymerization initiator is decomposed by an active energy ray to generate radicals and / or cations. The generated radicals and cations cause polymerization of the polymerizable compound, thereby curing the photocurable resin composition. The photopolymerization initiator can be appropriately selected depending on the curing conditions (irradiation wavelength, irradiation energy) of the photopolymerizable compound used.

[0018] The type of photopolymerization initiator that can be used includes photoradical polymerization initiators such as acetophenone-based, acylphosphine oxide-based, titanocene-based, and oxime ester-based initiators, and photocationic polymerization initiators such as triarylsulfonium salt-based, diaryliodonium salt-based, oxime sulfonate-based, imide sulfonate-based, and trichloromethyltriazine-based initiators. It is preferable to use a photopolymerization initiator that generates radicals when irradiated with active energy rays having a wavelength of 300 nm or more and 450 nm or less, since this allows the use of a highly versatile mercury lamp or LED.

[0019] The photopolymerization initiator can be used alone or in combination of two or more. The amount of the photopolymerization initiator added is preferably in the range of 0.01 to 10.00 parts by mass per 100 parts by mass of the photopolymerizable compound. The addition ratio of the photopolymerization initiator may be appropriately selected depending on the irradiation dose of the active energy ray and further the additional heating temperature. It may also be adjusted depending on the target average molecular weight of the resulting polymer.

[0020] [Inorganic particles] In the present invention, inorganic particles are added to the photocurable resin composition as a raw material in order to improve the mechanical properties, flame retardancy, electrical conductivity, and other properties of the three-dimensionally shaped object. The particle size of inorganic particles varies depending on the material, but the average particle size is preferably between 3 μm and 25 μm. When the average particle size is 3 μm or more, the amount of inorganic particles required to improve properties is appropriate, and when it is 25 μm or less, light scattering during photo-curing is suppressed, making it easier to achieve good molding.

[0021] When flame-retardant inorganic particles are added, phosphate-based flame retardant particles are preferably used. Suitable examples of phosphate-based flame retardant particles include polyphosphates such as ammonium polyphosphate. The amount of inorganic particles added is preferably in the range of 10.00 parts by mass or more and 40.00 parts by mass or less relative to 100 parts by mass of the total of the photopolymerizable compound and the photopolymerization initiator.

[0022] [Coloring Agent] A colorant can be added to the raw photocurable resin composition to adjust the UV absorption by the photocurable resin composition and thereby adjust the hardness and color of the three-dimensional object. Examples of colorants for adjusting UV absorption include carbon black. Various organic and inorganic pigments can also be used as colorants for adjusting color. The amount of the colorant added is preferably in the range of 0.001 to 1.00 parts by mass relative to 100 parts by mass of the total of the photopolymerizable resin, photopolymerization initiator, and inorganic particles.

[0023] <Method of manufacturing three-dimensional objects> FIG. 3 shows a flowchart of the manufacturing process of the three-dimensional object of the present invention. As shown in FIG. 3, in this manufacturing process, a laminated portion is first formed using a photocurable resin composition by stereolithography, and then an application process is performed. The application process may be a cleaning process in which the laminated portion is washed with a treatment liquid to remove uncured photocurable resin composition, or other processes may be performed after the cleaning process. Finally, the polymerizable compound in the cleaning liquid that has adhered to the surface of the laminated portion is cured to form a resin film on the surface.

[0024] [Formation of laminated portion] The laminated portion can be formed by repeating a step of supplying a photocurable resin composition to a predetermined thickness based on modeling data generated based on three-dimensional shape data of the object to be manufactured (a three-dimensional model) and a step of curing the supplied photocurable resin composition multiple times. Such stereolithography methods are broadly divided into two types: a free liquid level method and a restricted liquid level method.

[0025] FIG. 2 shows an example of the configuration of a modeling apparatus 200 using the controlled liquid level method. The modeling apparatus 200 has a container 25 that contains a liquid photocurable resin composition 21. Inside the container 25, a modeling stage 23 is provided so as to be movable up and down in the vertical direction by an elevator device 24 and a control unit 31. Active energy rays 30 for curing the photocurable resin composition 21 are emitted from a light source 28 by the control unit 31 and are magnified by a lens unit 29. The irradiation area is then controlled by a liquid crystal shutter 26, which is controlled in accordance with the control unit 31 and modeling data. The active energy rays 30 that have passed through the liquid crystal shutter 26 pass through a release transmission film 27 to cure the photocurable resin composition 21.

[0026] The thickness d of the photocurable resin composition 21 cured by the active energy rays 30 is a value determined based on the settings made when the modeling data was generated, and affects the accuracy of the resulting article (the reproducibility of the three-dimensional shape data of the article to be modeled). The thickness d is achieved by the control unit 31 controlling the amount of elevation of the modeling stage 23 by the elevator device 24. At this time, the lamination unit 9 forms irregularities on the surface in the direction perpendicular to the elevation direction of the modeling stage 23, with the irregularities being repeated at a predetermined pitch corresponding to the thickness d.

[0027] First, the control unit 31 controls the lifting device 24 based on the settings, and the modeling surface of the modeling stage 23 is set at a predetermined distance from the release transparent film 27, and a photocurable resin composition is supplied between the modeling surface of the modeling stage 23 and the release transparent film 27. Next, active energy rays 30 are irradiated from below the container 25 containing the photocurable resin composition. The irradiation of the active energy rays 30 cures the photocurable resin composition between the modeling surface of the modeling stage 23 and the release transparent film 27, forming a solid cured layer. After a predetermined amount of active energy rays 30 is irradiated and the photocurable resin composition is cured, the modeling stage 23 is raised, and the cured layer is peeled off from the release transmission film 27 .

[0028] Next, the height of the modeling stage 23 is adjusted so that a predetermined distance is formed between the cured layer formed below the modeling stage 23 and the release transmission film 27. Then, as before, a photocurable resin composition is supplied between the cured layer and the release transmission film 27, and active energy rays 30 are irradiated in accordance with the modeling data, thereby forming a new cured layer between the previous cured layer and the release transmission film 27. By repeating this process multiple times, a laminated part 9 can be obtained in which multiple cured layers are integrally laminated.

[0029] In addition to LED lights, other light sources include laser light sources and projectors. In the case of a laser light source, the amount of irradiation per unit area is controlled by the illuminance and scanning speed, so there is no need to provide a liquid crystal shutter 26. In addition to the liquid crystal shutter 26, a digital micromirror shutter may also be used.

[0030] A modeling apparatus using the free liquid surface method is configured such that the modeling stage 23 of the modeling apparatus 200 in Figure 2 is arranged to pull the stacked portion 9 below the liquid surface, the light source 28 is arranged above the container 25, and the hardened layer is formed on the modeling stage 23. A typical example of the free liquid level method is as follows: First, the modeling surface of a modeling stage that can be raised and lowered is lowered to a predetermined distance d from the liquid surface of the photocurable resin composition contained in a container. The modeling stage is then lowered, supplying the uncured photocurable resin composition to a thickness d on the surface of the cured layer. Then, based on the modeling data, active energy rays are irradiated to form a cured product integrated with the previously formed cured layer. By repeating this layer-by-layer curing process, the desired three-dimensional photo-fabricated object can be obtained. Subsequent processes are the same as those in the controlled liquid level method.

[0031] In both the controlled liquid level method and the free liquid level method, examples of active energy rays include ultraviolet rays, electron beams, X-rays, radioactive rays, high frequency waves, etc. Among these, ultraviolet rays having a wavelength of 300 nm or more and 450 nm or less are preferably used from an economical viewpoint, and in this case, examples of light sources that can be used include ultraviolet LEDs (light-emitting diodes), ultraviolet lasers (e.g., semiconductor-pumped solid-state lasers, Ar lasers, He—Cd lasers, etc.), high-pressure mercury lamps, ultra-high-pressure mercury lamps, mercury lamps, xenon lamps, halogen lamps, metal halide lamps, and fluorescent lamps.

[0032] [Surface treatment of laminated portion] After removing the laminated portion 9 obtained as described above from the container 25, the laminated portion 9 is subjected to a surface treatment (cleaning) using a treatment liquid for photolithography, and then subjected to a hardening treatment (post-cure) by light irradiation, heat irradiation, or both, to obtain a three-dimensional object of the present invention.

[0033] FIG. 4 is a cross-sectional schematic diagram showing the steps from surface treatment to curing of the laminated portion 9 in the lamination method of the laminated portion 9. FIG. 4(a) shows the state in which the laminated portion 9 has been pulled out of the container 25 immediately after formation, with uncured photocurable resin composition 41 adhering to the surface of the laminated portion 9. A treatment liquid 42 is brought into contact with the surface of the laminated portion 9 in this state, and the uncured photocurable resin composition 41 is removed (FIG. 4(b)). Next, a curing treatment is performed with the treatment liquid 42 adhering to the surface of the laminated portion 9, thereby forming a resin film 7 on the additive manufacturing surface 9a of the laminated portion 9 and on the surfaces of the inorganic particles 2 exposed on the additive manufacturing surface 9a (FIG. 4(c)).

[0034] The treatment liquid used for surface treatment should contain at least a polymerizable compound and a polymerization initiator, and preferably a photopolymerizable compound is used as the polymerizable compound. Furthermore, an alcohol-based organic solvent, preferably a primary alcohol, specifically ethyl alcohol or isopropyl alcohol, is preferably used, and the photopolymerizable compound and photopolymerization initiator are added to the alcohol-based organic solvent. The photopolymerizable compound and photopolymerization initiator are preferably the same types as those used to form the laminated portion. The content of the photopolymerizable compound in the treatment liquid is 5% by mass or more and 50% by mass or less, preferably 7% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or less.

[0035] When the laminated part is immersed in the treatment solution, it may be immersed in the treatment solution as is and then removed, depending on the shape of the laminated part, or it may be immersed in the treatment solution while being subjected to stirring or ultrasonic vibration and then removed. The immersion time is adjusted depending on the shape of the laminated part. The curing treatment can cure the polymerizable compound in the treatment liquid adhered to the surface of the laminate, and at the same time, cure any unreacted photopolymerizable compound remaining inside the laminate, thereby improving the initial strength of the laminate.

[0036] The wavelength of light irradiation for the curing treatment is preferably a wavelength that promotes the curing of the polymerizable compound in the treatment liquid, and among these, ultraviolet light with a wavelength of 300 nm or more and 450 nm or less is preferably used from an economical viewpoint. The irradiation time is adjusted within a range of 1 to 2 hours depending on the shape of the object and the mechanical strength of the target object. The temperature and irradiation time for thermal irradiation are adjusted depending on the shape of the laminate and the mechanical strength of the target three-dimensional object, as long as there is no significant change in the shape of the laminate.

[0037] By doing so, the three-dimensionally shaped object of the present invention has an uneven surface on the laminated surface of the laminated portion that is repeated at a predetermined pitch, and the uneven surface has convex portions that correspond to the shapes of the inorganic particles and are made of a resin film that covers the inorganic particles. In this way, the surface has unevenness that is repeated at a predetermined pitch, and the uneven surface has the convex portions, so that light that is incident on the surface of the three-dimensionally shaped object is scattered, and reflection unevenness that causes light to be strongly reflected in a specific direction is suppressed.

[0038] When the layered product surface of the laminated part has only irregularities and no resin film, regular lines caused by the irregularities may be visible. However, by having the above-mentioned convex portions on the irregular surface, these regular lines become less visible. Furthermore, for the inorganic particles directly below the resin film that constitutes the convex portions, their surfaces are covered with the resin film, thereby suppressing color unevenness. This results in a three-dimensional object with excellent appearance quality. Furthermore, when inorganic particles are coated with a resin film, the inorganic particles are less likely to fall off, and when the inorganic particles are used as a flame retardant, this also has the effect of suppressing a decrease in the flame retardancy of the three-dimensional object due to the fall off of the flame retardant.

[0039] <Measurement of unevenness pitch and height difference> In the present invention, the shape of the unevenness of the additively manufactured surface of the laminated portion is measured using a laser microscope for three-dimensional objects, but other methods that can evaluate the surface shape, such as an optical microscope, SEM, SPM, AFM, or surfcorder, may also be used.

[0040] <Observation of convex parts> In the present invention, the protrusions on the surface of a three-dimensional object are observed using an optical microscope with epi-illumination. Specifically, an area with repeated irregularities at a predetermined pitch is defined using a laser microscope, SEM, or the like. This area is observed using an optical microscope to observe the protrusions on the irregular surface. Here, inorganic particles coated with a resin film on the irregular surface are inorganic particles whose light reflection, under optical microscope observation, is equivalent to that of a cross section of a single inorganic particle located inside (4 in Figure 1) the irregularities on the additive manufacturing surface of the three-dimensional object.

[0041] The inorganic particles 2 located inside 4, beyond the irregularities 3, on the additive manufacturing surface 9a of the three-dimensionally molded object 100 shown in Fig. 1 are exposed by the following method: The three-dimensionally molded object 100 is cut, and the cut surface located inside 4, beyond the irregularities 3, is cross-sectioned using ion milling, a microtome, FIB, or the like, to expose the inorganic particles 2. The exposed inorganic particles may then be collected from the cut surface or the cross-section using a micromanipulator probe, a hand-held needle, or the like.

[0042] Another method involves excavating the three-dimensional object with a micromanipulator to collect the inorganic particles. For example, the surface of the three-dimensional object may be excavated with a micromanipulator, and once the excavation depth reaches the interior beyond the uneven portion, the inorganic particles may be collected using the probe of the micromanipulator. Furthermore, inorganic particles may be excavated with a micromanipulator from a cut surface or a cross section of the three-dimensional object described above, and then the inorganic particles may be collected using the probe of the micromanipulator.

[0043] The inorganic particles with exposed cross sections or the collected inorganic particles are observed under an optical microscope after removing any contaminants adhering to the surface with an organic solvent such as ethyl alcohol. The protrusions on the uneven surface of the three-dimensional object may be observed by other methods that can evaluate the surface shape and exposure state, such as a laser microscope or SEM.

[0044] <Cross-section observation of convex part> In the present invention, the cross-section of the convex portions on the uneven surface is observed using an SEM. Specifically, the three-dimensional object including the concave and convex portions is cut, and the cut surface is cross-sectioned using ion milling, a microtome, FIB, or the like to expose the cross-section of the convex portions on the uneven surface. This cross-section is observed using an SEM.

[0045] <Measurement of the degree of resin film coverage on convex parts> In the present invention, the degree of coverage of the resin film on the convex portions of the uneven surface is measured by microscopic laser Raman spectroscopy, as follows: On the surface of the three-dimensional object, an area with repeated irregularities at a predetermined pitch is determined using a laser microscope or SEM. In this area, five relatively bright spots are measured using a spectrophotometer, and the L * The 300μm x 300μm area at the center of the measurement location where the maximum is determined as the microscopic laser Raman measurement area. However, the measurement locations of the spectrophotometer must be at least 10mm apart from each other. If the three-dimensional object is small and the number of areas that can be measured by the spectrophotometer is less than five, the maximum number of points that can be measured is determined as the maximum number of points that can be measured. * The area of ​​300 μm × 300 μm at the center of the measurement location where the maximum value is reached is defined as the microscopic laser Raman measurement area. In an area with irregularities repeated at a predetermined pitch, if the brightness is uniform overall and it is unclear which areas have relatively high and low brightness, five arbitrary points are measured and the L * The microscopic laser Raman measurement area is defined as 300 μm × 300 μm at the center of the measurement location where the maximum is obtained.

[0046] Within the microscopic laser Raman measurement area, inorganic particles that are located at the apex of a convex portion and that have light reflection equivalent to the cross section of a single inorganic particle located inside the unevenness of the additive manufacturing surface of a 3D model under optical microscope observation with epi-illumination are measured using microscopic laser Raman. The laser spot diameter is set to the size of a single inorganic particle, and the irradiation time and number of integrations are adjusted to obtain sufficient Raman intensity.

[0047] In the measured Raman spectrum of inorganic particles, if cosmic rays are detected, they are removed and the data after baseline correction is used as the Raman spectrum measurement data. From this Raman spectrum measurement data, the five highest intensities of the Raman intensities originating from inorganic particles are selected and their average value is calculated.

[0048] However, if there is a measurement point within 50 μm of a Raman measurement point already used to calculate the average intensity, this area is excluded and the next intensity is taken. This is explained using Figure 5. Within the microscopic laser Raman measurement area 32, the inorganic particles measured are designated in order of highest intensity as first, second, third, fourth, fifth, and sixth. Of these, the fourth measurement point is within a range 33 within 50 μm of the third measurement point. However, since the third measurement point has already been used to calculate the average, the fourth measurement point is excluded. Since the fifth and sixth measurement points are not within 50 μm of the Raman measurement point already used to calculate the average, they are used to calculate the average. In this way, the measurement points used to calculate the average are the first, second, third, fifth, and sixth. This process is repeated until five intensities are calculated.

[0049] If there are fewer than five microscopic laser Raman measurement points within the 300 μm × 300 μm measurement area, a 300 μm × 300 μm area adjacent to the center is determined, and this process is repeated until there are five intensities to calculate the average value. * If there are fewer than five microscopic laser Raman measurement points at the measurement location where L is maximum, * The measurement location with the next largest value is determined as the microscopic laser Raman measurement area, and this process is repeated until there are five points of intensity for which the average value is to be calculated.

[0050] <Measurement of the average particle size of inorganic particles> In the present invention, the particle size of inorganic particles is measured by image processing of a cross-sectional image of a three-dimensionally shaped object. This measurement method is described below. The three-dimensional object is cut using a cutting machine, the cross section is polished, and the polished surface is processed using ion milling. Note that processing can also be performed using a microtome or FIB instead of ion milling. The processed surface is then coated with osmium using an osmium coater. Note that coating can also be performed with carbon using a carbon coater. The processed surface is observed with an SEM. Observation using backscattered electrons is preferable because it increases the compositional contrast between the inorganic particles and the resin, allowing for clear images of the inorganic particles. By using an FIB-SEM, cross-section extraction and SEM observation can be performed consecutively. The obtained observation image is processed using image processing software such as ImagePro to measure the circular area equivalent diameter of the inorganic particles, and the average particle diameter is obtained.

[0051] <Measurement of the average particle size of colorants> In the present invention, the particle size of the colorant is measured by image processing of a cross-sectional image of the three-dimensional object, using the same method as the method for measuring the average particle size of the inorganic particles described above.

[0052] <Spectrophotometer measurement> Of the uneven surface of the laminated part's additive manufacturing surface, three points with relatively high brightness and three points with relatively low brightness are measured with the spectrophotometer described above. If the brightness is uniform overall and the areas with relatively high and low brightness are unknown, six points are measured arbitrarily. The measurement points of the spectrophotometer should be at least 10 mm apart from each other.

[0053] <Application> The three-dimensionally shaped object of the present invention can be suitably used in three-dimensional additive manufacturing, particularly photolithography. Furthermore, the three-dimensionally shaped object of the present invention obtained by a 3D printer can be widely used in the field of optical three-dimensional modeling. While the application fields are not limited in any way, representative fields include prototype models, design models, working models, base models for producing molds, direct molds for prototype molds, service parts, housings, and industrial product components for industrial products, including electrical and electronic equipment, office automation equipment, cameras, computers, medical equipment, and industrial machinery. In particular, the three-dimensionally shaped object of the present invention has excellent appearance quality and can therefore be used in the manufacture of housings and parts for industrial products.

[0054] [Included components] The disclosure of this embodiment includes the following configuration. (Configuration 1) A three-dimensional object having a laminated portion in which a plurality of resin layers are laminated, Contains a large number of inorganic particles, a plurality of inorganic particles among the plurality of inorganic particles are dispersed in the laminated portion; A three-dimensional object characterized in that the additive manufacturing surface formed by each of the multiple resin layers of the laminated portion has convex portions composed of a resin film covering some of the inorganic particles, corresponding to the shape of the inorganic particles of the large number of inorganic particles.

[0055] (Configuration 2) The three-dimensional object according to configuration 1, wherein the surfaces of the inorganic particles have a portion that contacts a recess of one of the plurality of resin layers and a portion that contacts the resin film. (Configuration 3) 3. The three-dimensional object according to claim 1, wherein the resin film continuously covers the plurality of resin layers. (Configuration 4) 4. The three-dimensional object according to any one of Structures 1 to 3, wherein the resin film is made of a photocurable resin. (Configuration 5) The three-dimensional object according to configuration 4, wherein the resin film is made of the same photocurable resin as the resin layer. (Configuration 6) 6. The three-dimensional object according to any one of configurations 1 to 5, wherein the resin film has a thickness of less than 1 μm. (Configuration 7) A three-dimensional object according to any one of structures 1 to 6, characterized in that the average value of the five highest Raman measurement intensities of the inorganic particles is less than half of the average value of the five highest Raman measurement intensities of the inorganic particles located inside the stacked portion. (Configuration 8) 8. The three-dimensional object according to any one of configurations 1 to 7, wherein the average particle size of the large number of inorganic particles is 3 μm or more and 25 μm or less.

[0056] (Configuration 9) The three-dimensional object described in any one of structures 1 to 8, characterized in that the additive manufacturing surface has a shape in which unevenness is repeated in the direction in which the multiple resin layers are stacked, at a pitch corresponding to the thickness of each of the multiple resin layers. (Configuration 10) 10. The three-dimensional object according to configuration 9, wherein the pitch of the projections and recesses is 30 μm or more and 150 μm or less. (Configuration 11) 11. The three-dimensional object according to configuration 9 or 10, wherein the height difference of the projections and recesses is 1 μm or more and 30 μm or less.

[0057] (Configuration 12) 12. The three-dimensional object according to any one of configurations 1 to 11, wherein the numerous inorganic particles are flame retardant particles. (Configuration 13) 13. The three-dimensionally shaped object according to claim 12, wherein the flame retardant particles are phosphoric acid-based flame retardant particles. (Configuration 14) 14. The three-dimensional object according to any one of Structures 1 to 13, wherein the resin layer further contains a colorant. (Configuration 15) 15. The three-dimensional object according to claim 14, wherein the colorant is carbon black.

[0058] (Configuration 16) A method for manufacturing a three-dimensional object using a stereolithography method, comprising the steps of: a step of supplying a photocurable resin composition containing at least a photopolymerizable compound, a photopolymerization initiator, and a large number of inorganic particles in a layered form, and a step of irradiating the layered photocurable resin composition with an active energy ray to cure the composition, the step being repeated multiple times to form a laminated portion; treating the laminated portion with a treatment liquid containing a polymerizable compound and a polymerization initiator; and performing a hardening process on the treatment liquid attached to the laminated portion.

[0059] (Configuration 17) 17. The method for manufacturing a three-dimensional object according to Configuration 16, wherein the treatment liquid contains an alcohol-based organic solvent. (Configuration 18) 18. The method for producing a three-dimensionally shaped object according to claim 17, wherein the alcohol-based organic solvent is a primary alcohol. (Configuration 19) 19. The method for producing a three-dimensional object according to configuration 18, wherein the primary alcohol is ethyl alcohol. (Configuration 20) 20. The method for manufacturing a three-dimensional object according to any one of Structures 16 to 19, wherein the content of the polymerizable compound in the treatment liquid is 5% by mass or more and 50% by mass or less. (Configuration 21) 21. The method for manufacturing a three-dimensional object according to any one of Configurations 16 to 20, wherein the polymerizable compound is a photopolymerizable compound. (Configuration 22) 22. The method for manufacturing a three-dimensional object according to claim 21, wherein the photopolymerizable compound contained in the treatment liquid is the same as the photopolymerizable compound contained in the photocurable resin composition.

[0060] (Configuration 23) A processing liquid for stereolithography, The composition contains a polymerizable compound, a polymerization initiator, and an alcohol-based organic solvent, The treatment liquid has a polymerizable compound content of 5% by mass or more and 50% by mass or less. (Configuration 24) 24. The treatment liquid according to claim 23, wherein the polymerizable compound is a photopolymerizable compound. [Example]

[0061] <Manufacturing of 3D objects> The following materials were mixed in the following composition to prepare a photocurable resin composition. 〔material〕 Polymerizable compound (A): 2-(allyloxymethyl)methyl acrylate (manufactured by Nippon Shokubai Co., Ltd., trade name "FX-AO-MA") Polymerizable compound (B): urethane acrylate (manufactured by Nippon Kayaku Co., Ltd., product name "KAYARAD UC-6101") Polymerizable compound (C): tris-(2-acryloxyethyl) isocyanurate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "A-9300" Photopolymerization initiator (D): bis(2,4,6-trimethylbenzoyl)phenyl phosphate oxide (manufactured by IGM Resins, trade name "Omnirad819") Inorganic particles (E): ammonium polyphosphate (manufactured by Clariant, trade name "Exolit AP423") Colorant (F): Carbon black (manufactured by Mitsubishi Chemical Corporation, product name "Mitsubishi Chemical MA-100")

[0062] 〔composition〕 Polymerizable compound (A): 25 parts by mass Polymerizable compound (B): 35 parts by mass Polymerizable compound (C): 40 parts by mass Photopolymerization initiator (D): 3 parts by mass Inorganic particles (E): 30 parts by mass based on the total amount of (A) + (B) + (C) + (D) Colorant (F): 0.02 parts by mass relative to the total amount of (A) + (B) + (C) + (D) + (E)

[0063] The photocurable resin composition was used to form a laminated layer using a 3D printer (manufactured by SUMAOPAI, product name "M1370") The thickness of each layer was 50 μm, and the irradiation time per layer was 4 seconds. The resulting laminate was removed from the modeling stage and immersed in an ultrasonic cleaner (manufactured by AS ONE, product name "ASU-20D") filled with a treatment solution. The treatment solution was a mixture of 25 parts by weight of polymerizable compound (A), 35 parts by weight of (B), 40 parts by weight of (C), and 3 parts by weight of photopolymerization initiator (D), diluted with ethyl alcohol to a concentration of 15% by weight. The laminate was then treated by applying 43 kHz ultrasonic waves for 1 minute at a temperature range of 20 to 30°C. The curing process was carried out for 1 hour using a secondary curing device (manufactured by 3D SYSTEMS, product name "LC-3DPrint Box"), followed by a 2-hour heat treatment in a 100°C oven to obtain a 3D model.

[0064] <Measurement of unevenness> The surface of the three-dimensional object was measured using a laser microscope (manufactured by Lasertec, product name "OPTELICS HYBRID+"). Repeated irregularities at a predetermined pitch corresponding to the thickness of one layer were confirmed on the surface in the direction perpendicular to the ascending and descending direction of the modeling stage, and this shape was measured. The irregularity pitch P was 45 μm to 55 μm, and the irregularity height difference D was 5 μm to 25 μm.

[0065] <Observation of convex parts> The convex portions of the surface irregularities of the 3D model were observed using a laser microscope. The observations were carried out using an optical microscope with epi-illumination attached to a laser Raman microscope (manufactured by Renishaw, product name "inVia Qontor"). Under optical microscope observation, it was confirmed that there were inorganic particles whose light reflection was equivalent to the cross section of a single inorganic particle inside the model, rather than the irregularities on the additive manufacturing surface of the 3D model.

[0066] The inorganic particles located deeper than the irregularities on the additive manufacturing surface of the 3D-printed object were exposed using the following method. The 3D-printed object was cut using a cutting machine (Buehler, product name "IsoMet"), and the cut surface was then finish-polished using a polishing machine (Ikegami Seiki, product name "ISSP-1000") with colloidal silica slurry (Buehler, product name "MasterMet"). This polished surface was then processed using ion milling (Hitachi High-Tech, product name "IM4000 PLUS"). After removing any contamination adhering to the processed surface with ethyl alcohol, the inorganic particles were observed under an optical microscope.

[0067] <Cross-section observation of convex part> The uneven surface of the 3D model was cut using a cutting machine (Buehler, product name "IsoMet"), and the cut surface was then polished using a colloidal silica slurry (Buehler, product name "MasterMet") and a polishing machine (Ikegami Seiki, product name "ISSP-1000"). This polished surface was then processed using an ion milling machine (Hitachi High-Tech, product name "IM4000 PLUS"). The processed surface was then coated with a 5 nm thick osmium coating using an osmium coater (Meiwa Force Systems, product name "Tennant20"). The processed surface was observed using an SEM (manufactured by FEI, product name "Teneo"), and the results showed that the thickness of the resin film on the convex parts was less than 1 μm.

[0068] <Measurement of the degree of resin film coverage on convex parts> To measure the degree of resin film coverage on the convex portions, first, a cross section of a single inorganic particle located inside the unevenness of the additive manufacturing surface of the three-dimensional object described above was measured using a microscopic laser Raman microscope (manufactured by Renishaw, product name "inVia Qontor"). The Raman measurement conditions were an objective lens magnification of 100x, a laser wavelength of 532 nm, grading of 1800 l / mm, and the center of the measurement spectrum range was set at 1000 cm with the grading in a fixed position. -1 The irradiation time was 10 seconds, the laser power was 0.009375%, and the number of accumulations was 50.

[0069] In the measured Raman spectrum of inorganic particles, if cosmic rays were detected, they were removed and baseline correction was performed. In this Raman spectrum measurement data, the maximum peak due to inorganic particles was at 1139 cm -1 Microscopic laser Raman measurements were performed on five cross sections of this inorganic particle, revealing a peak at 1139 cm -1 The average value (AVE internal The cross sections of the inorganic particles measured were spaced apart by 50 μm or more.

[0070] Next, the microscopic laser Raman measurement of the surface of the three-dimensional object was carried out as follows. Of the uneven surface confirmed by the laser microscope, five relatively bright areas were measured with a spectrophotometer (Konica Minolta, product name "CM-2600d"). The measurement conditions were φ3 mm, L * a * b * , D50, 10°, SCE method (specular reflection removed) * The measurement points of the spectrophotometer were set at least 10 mm apart. * The microscopic laser Raman measurement area was determined to be 300 μm × 300 μm at the center of the measurement location where the maximum value was reached. Note that, because the three-dimensional object is small, if the area that can be measured by the spectrophotometer is less than five points, the maximum number of points that can be measured is selected. * The microscopic laser Raman measurement area was determined to be 300 μm×300 μm at the center of the measurement location where the maximum value was obtained.

[0071] Within the microscopic laser Raman measurement area, inorganic particles that were located at the apex of the convex portion and that had light reflection equivalent to that of the cross-section of a single inorganic particle located inside the unevenness of the additive manufacturing surface of the 3D model under observation with an optical microscope using epi-illumination were measured using microscopic laser Raman. The Raman measurement conditions were the same as those for measuring the cross-section of the single inorganic particle described above.

[0072] In the measured Raman spectrum of inorganic particles, if cosmic rays were detected, they were removed and the data after baseline correction was used as Raman spectrum measurement data. In this Raman spectrum measurement data, the maximum peak of Raman intensity originating from inorganic particles was 1139 cm -1 In this test, five points are taken in order of intensity, and the average value (AVE step ) was sought.

[0073] The ratio (AVE) of the average value of the five cross-sections of the inorganic particle alone described above to the average value of the five cross-sections of the inorganic particle alone, which are located at the apex of the convex part within the microscopic laser Raman measurement area and are located inside the unevenness of the additive manufacturing surface of the three-dimensional object under optical microscope observation, isstep / AVE internal The results are shown in Table 1.

[0074] <Measurement of the average particle size of inorganic particles> The 3D model was cut using a cutting machine (Buehler, product name "IsoMet"), and the cut surface was then polished using a colloidal silica slurry (Buehler, product name "MasterMet") and a polishing machine (Ikegami Seiki, product name "ISSP-1000"). This polished surface was then processed using an ion milling machine (Hitachi High-Tech, product name "IM4000 PLUS"). The processed surface was then coated with a 5 nm thick osmium coating using an osmium coater (Meiwa Force Systems, product name "Tennant20").

[0075] The coated surface was observed using an SEM (FEI, product name "Teneo"). Observation was performed using backscattered electrons, resulting in a large contrast difference between the inorganic particles and the resin, allowing for clear images of the inorganic particles to be obtained. The observation magnification was 1000x. The obtained images were processed using image processing software (MEDIA CYBERNETICS, product name "Image-Pro 10") to measure the circular area equivalent diameter of the inorganic particles and obtain the average particle diameter. The result was 6.2 μm.

[0076] <Measurement of the average particle size of colorants> A coated surface was obtained in the same manner as in measuring the average particle size of inorganic particles. This coated surface was observed at 25,000x magnification using an SEM. The obtained image was processed using the image processing software mentioned above to measure the circular area equivalent diameter of the colorant, and this average particle size was obtained. The result was 50 nm.

[0077] <Spectrophotometer measurement> On the uneven surface of a three-dimensional object, we tried to measure three points with relatively high brightness and three points with low brightness using the spectrophotometer mentioned above. However, because the brightness was uniform overall, we measured six points, spaced at least 10 mm apart from each other. The measurement conditions were φ3 mm, L * a * b* , D50, 10°, SCE method (specular reflection removed) * As a result, L * The difference between the maximum and minimum values ​​was 0.2.

[0078] Example 2 A three-dimensionally shaped object was produced in the same manner as in Example 1, except that the concentration of the mixture of polymerizable compounds (A), (B), and (C) and photopolymerization initiator (D) diluted with ethyl alcohol was changed to 5% by mass, and an evaluation sample was produced in the same manner as in Example 1 and evaluated by the method described in Example 1. The results are shown in Table 1.

[0079] Example 3 A three-dimensional object was fabricated in the same manner as in Example 1, except that the thickness d of one resin layer when laminating the laminated portion was set to 100 μm, and the concentration of the mixture of polymerizable compounds (A), (B), (C), and photopolymerization initiator (D) diluted with ethyl alcohol was changed to 50 mass %. Evaluation samples were then prepared in the same manner as in Example 1 and evaluated using the method described in Example 1. The results are shown in Table 1. When the surface of the resulting three-dimensional object was observed with a laser microscope, repeated irregularities at a predetermined pitch were confirmed, and the shape of these irregularities was measured. The pitch of the irregularities was 100 μm to 105 μm, and the height difference between the irregularities was 3 μm to 15 μm.

[0080] In the microscopic laser Raman measurement of this evaluation sample, there were few inorganic particles at the apex of the convex portions, and under optical microscope observation, the light reflection was equivalent to the cross-section of the individual inorganic particles located inside the 3D object, rather than the unevenness of the additive manufacturing surface. Therefore, within the 300 μm × 300 μm measurement area, only three microscopic laser Raman measurement points were used to obtain intensity. Therefore, a new measurement area of ​​300 μm × 300 μm was selected adjacent to the initially selected 300 μm × 300 μm measurement area. By also measuring this new measurement area, the total intensity for calculating the average value was increased to five points.

[0081] (Comparative Example 1) A three-dimensional object was produced in the same manner as in Example 1, except that the treatment liquid was changed to ethyl alcohol, and an evaluation sample was produced in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1. Note that in the measurement with the spectrophotometer, L * The difference between the maximum and minimum values ​​was 4.7.

[0082] (Comparative Example 2) A three-dimensional object was produced in the same manner as in Example 1, except that the obtained laminated part was subjected to a curing treatment without surface treatment with a treatment liquid after removing the modeling support part, and was evaluated by the method described in Example 1. The results are shown in Table 1.

[0083] (Comparative Example 3) A three-dimensional object was produced in the same manner as in Example 1, except that the concentration of the mixture of polymerizable compounds (A), (B), (C), and photopolymerization initiator (D) diluted with ethyl alcohol was changed to 3% by mass. Evaluation samples were also produced in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1. Note that in the measurement with the spectrophotometer, L * The difference between the maximum and minimum values ​​was 3.1.

[0084] Comparative Example 4 A three-dimensionally shaped object was produced in the same manner as in Example 1, except that the concentration of the mixture of polymerizable compounds (A), (B), and (C) and photopolymerization initiator (D) diluted with ethyl alcohol was changed to 60% by mass, and an evaluation sample was produced in the same manner as in Example 1 and evaluated by the method described in Example 1. The results are shown in Table 1.

[0085] <Evaluation of unevenness> The surface of the three-dimensional object was measured with a laser microscope to confirm the presence of irregularities repeated at a predetermined pitch. The evaluation criteria were as follows: A (good): Repetitive irregularities at a given pitch are present. B (bad): There are no irregularities repeated at a predetermined pitch.

[0086] <Evaluation of Microscopic Laser Raman Measurements> The average maximum intensity (AVE) of the five convex portions of the surface was measured by microscopic laser Raman spectroscopy. step ) for the average maximum intensity (AVE) of five microscopic laser Raman measurements of inorganic particles located inside the irregularities on the additive manufacturing surface. internal ) was calculated and evaluated according to the following criteria. A (good): AVE step / AVE internal is less than 1 / 2. B(Bad):AVE step / AVE internal is greater than 1 / 2. - (Measurement not possible): There are no irregularities, and the microscopic laser Raman measurement area cannot be determined.

[0087] [Table 1]

[0088] Comparing Examples 1 to 3 with Comparative Examples 1 to 4 from Table 1, the three-dimensional objects of Examples 1 to 3 have irregularities on the surface that are repeated at a predetermined pitch, and the AVE step / AVE internal The reflection intensity was less than half of that of the conventional three-dimensionally molded object. Therefore, no color unevenness occurred on the surface, resulting in a three-dimensionally molded object with a high-quality appearance. In the three-dimensionally molded objects of Examples 1 to 3, the convex portions of the uneven surface that were subjected to microscopic laser Raman measurement had the same reflection intensity as the cross section of the inorganic particle alone when observed under an optical microscope with epi-illumination. However, because the surface of these convex portions was covered with a thin photocurable resin less than 1 μm thick, the Raman intensity was low.

[0089] The three-dimensional objects of Comparative Examples 1 and 3 had irregularities on the surface that were repeated at a predetermined pitch, but AVE step / AVE internal The three-dimensional objects of Comparative Examples 2 and 4 did not have repeated irregularities at a predetermined pitch on the surface, and therefore, uneven reflection occurred on the surface, which impaired the quality of their appearance. [Explanation of symbols]

[0090] 1: Resin, 2, 2a: Inorganic particles, 3: Concavoconvex, 4: Interior, 7: Resin film, 8: Convex portion, 9: Laminated portion, 9a: Laminated shaped surface, 21: Photocurable resin composition

Claims

1. A three-dimensional object having a laminated portion in which a plurality of resin layers are laminated, Contains a large number of inorganic particles, a plurality of inorganic particles among the plurality of inorganic particles are dispersed in the laminated portion; A three-dimensional object characterized in that the additive manufacturing surface formed by each of the multiple resin layers of the laminated portion has convex portions composed of a resin film covering some of the inorganic particles, corresponding to the shape of the inorganic particles of the large number of inorganic particles.

2. The three-dimensional object according to claim 1 , wherein the surfaces of the inorganic particles have a portion that contacts one of the recesses in the plurality of resin layers and a portion that contacts the resin film.

3. The three-dimensional object according to claim 1 , wherein the resin film continuously covers the plurality of resin layers.

4. The three-dimensional object according to claim 1 , wherein the resin film is made of a photocurable resin.

5. The three-dimensional object according to claim 4, wherein the resin film is made of the same photocurable resin as the resin layer.

6. The three-dimensional object according to claim 1 , wherein the resin film has a thickness of less than 1 μm.

7. The three-dimensional structure according to claim 1, characterized in that the average value of the five highest Raman measurement intensities of the inorganic particles is less than half of the average value of the five highest Raman measurement intensities of the inorganic particles located inside the laminate.

8. 2. The three-dimensional structure according to claim 1, wherein the average particle size of the inorganic particles is 3 μm or more and 25 μm or less.

9. The three-dimensional object according to claim 1, characterized in that the additive manufacturing surface has a shape in which unevenness is repeated in the direction in which the multiple resin layers are stacked, at a pitch corresponding to the thickness of each of the multiple resin layers.

10. 10. The three-dimensional structure according to claim 9, wherein the pitch of the projections and recesses is 30 μm or more and 150 μm or less.

11. The three-dimensional structure according to claim 9, wherein the height difference of the projections and recesses is 1 μm or more and 30 μm or less.

12. The three-dimensional structure according to claim 1 , wherein the plurality of inorganic particles are a flame retardant.

13. The three-dimensional structure according to claim 12, wherein the flame retardant is a phosphoric acid-based flame retardant.

14. The three-dimensional structure according to claim 1 , wherein the resin layer further contains a colorant.

15. 15. The three-dimensional object according to claim 14, wherein the colorant is carbon black.

16. A method for manufacturing a three-dimensional object using a stereolithography method, comprising the steps of: a step of supplying a photocurable resin composition containing at least a photopolymerizable compound, a photopolymerization initiator, and a large number of inorganic particles in a layered form, and a step of irradiating the layered photocurable resin composition with an active energy ray to cure the composition, the step being repeated multiple times to form a laminated portion; treating the laminated portion with a treatment liquid containing a polymerizable compound and a polymerization initiator; and performing a hardening process on the treatment liquid attached to the laminated portion.

17. The method for manufacturing a three-dimensional object according to claim 16, wherein the treatment liquid contains an alcohol-based organic solvent.

18. The method for manufacturing a three-dimensional object according to claim 17, wherein the alcohol-based organic solvent is a primary alcohol.

19. The method for manufacturing a three-dimensional object according to claim 18, wherein the primary alcohol is ethyl alcohol.

20. 17. The method for manufacturing a three-dimensional object according to claim 16, wherein the content of the polymerizable compound in the treatment liquid is 5% by mass or more and 50% by mass or less.

21. The method for manufacturing a three-dimensional object according to claim 16, wherein the polymerizable compound is a photopolymerizable compound.

22. The method for manufacturing a three-dimensional object according to claim 21 , wherein the photopolymerizable compound contained in the treatment liquid is the same as the photopolymerizable compound contained in the photocurable resin composition.

23. A processing liquid for stereolithography, The composition contains a polymerizable compound, a polymerization initiator, and an alcohol-based organic solvent, The treatment liquid has a polymerizable compound content of 5% by mass or more and 50% by mass or less.

24. 24. The treatment liquid according to claim 23, wherein the polymerizable compound is a photopolymerizable compound.

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