Materials for three-dimensional modeling, methods for three-dimensional modeling, and three-dimensional models.

Abstract

To provide a three-dimensional modeling material that can enhance the mechanical properties of three-dimensional objects. [Solution] A three-dimensional modeling material 1 used for creating three-dimensional objects, comprising a thermosetting resin 2 in a liquid phase and reinforcing fibers 3 dispersed in the thermosetting resin 2, wherein the reinforcing fibers 3 have a release-restricting portion 3a on their surface, and the release-restricting portion 3a bites into the cured thermosetting resin 2, thereby restricting the release of the reinforcing fibers 3 in the fiber direction.

Description

Technical Field

[0001] The present invention relates to a three-dimensional shaping material, a three-dimensional shaping method, and a three-dimensional shaped object. More specifically, the present invention relates to a three-dimensional shaping material, a three-dimensional shaping method, and a three-dimensional shaped object used for shaping a three-dimensional shaped object using an additive manufacturing technology such as 3D printing.

Background Art

[0002] As a name for a manufacturing apparatus using 3D printing technology, the term "3D printer" is widely used. A 3D printer is a three-dimensional shaping apparatus that calculates the cross-sectional shape of a shaped object by computer based on three-dimensional CAD data, divides the shaped object into thin ring-shaped cross-sectional components, forms the cross-sectional components in various ways, and stacks them to shape the target shaped object. 3D printing technology is often used as a synonym for Additive Manufacturing Technology internationally, and the Japanese translation uses the term "additive manufacturing technology".

[0003] In recent years, for shaped objects formed by a 3D printer, not only appearance but also rigidity and strength are required for evaluation purposes before mass production of actual products, and metal 3D printers, composite material 3D printers, etc. have attracted attention. As one of the related technologies, the applicant of the present application has proposed a three-dimensional shaping method described in Patent Document 1 below.

[0004] Patent Document 1 describes a three-dimensional shaping method in which shaping of a shell layer that becomes an outer shell layer of a three-dimensional shaped object and filling of a core material into a core part inside the shaped shell layer are repeatedly performed a plurality of times in the stacking direction in a shaping tank in which a shell material is stored, and then the core material is cured in a lump by applying thermal energy. The core material is a thermosetting resin in which fibrous reinforcing materials are dispersed. According to such a three-dimensional shaping method, since there is no lamination interface in the portion of the cured core material, it has become possible to shape a three-dimensional shaped object having no directionality in rigidity and strength. [Problems to be Solved by the Invention]

[0005] The applicant fabricated a three-dimensional object using the three-dimensional fabrication method described in Patent Document 1, and performed a bending test on the hardened core material of the fabricated object as a test specimen, observing the fracture surface after the bending test. The results are shown in Figure 5.

[0006] Figure 5 is a photograph of the fracture surface of the hardened core material, taken with a scanning electron microscope. According to photograph 50 shown in Figure 5, multiple black holes 51 are formed across the entire fracture surface. These black holes 51 indicate the traces of fibrous reinforcing material 52 that have come loose. Multiple pieces of reinforcing material 52 are also visible exposed from the fracture surface, and gaps 54 are formed at the boundary between the exposed reinforcing material 52 and the resin 53. These gaps 54 indicate that the interface between the resin 53 and the reinforcing material 52 has delaminated.

[0007] Observation of the fracture surface suggests that the following phenomenon occurs inside the fabricated object when external forces such as bending deformation are applied. Specifically, when an external force that causes bending deformation is applied to the test specimen (hardened core material), a localized tensile force acts at the interface between the resin 53 and the reinforcing material 52. When this tensile force exceeds the allowable value, the interface between the resin 53 and the reinforcing material 52 begins to delaminate, causing the reinforcing material 52 to slip. When such slippage of the reinforcing material 52 occurs, the tensile force described above, i.e., the resistance to bending deformation, ceases to act. If the bending deformation increases further, cracks propagate in the resin 53, causing fracture, and it can be inferred that the reinforcing material 52 present at the fracture surface is removed from the resin 53.

[0008] Thus, although the three-dimensional objects produced by the three-dimensional printing method described in Patent Document 1 above are reinforced with reinforcing materials and have non-directional rigidity and strength, there was still room for further improvement to enhance their mechanical properties. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2019-136923 [Overview of the project] Means for solving the problem and their effects

[0010] The present invention has been made in view of the above problems, and aims to provide a three-dimensional molding material, a three-dimensional molding method, and a three-dimensional molded object that can improve the mechanical properties of the three-dimensional molded object.

[0011] To achieve the above objective, the three-dimensional molding material (1) according to the present invention is A three-dimensional modeling material used for creating three-dimensional objects, A thermosetting resin in liquid phase, The thermosetting resin contains reinforcing fibers dispersed within it. The reinforcing fiber has a shedding-restricting portion on its surface, The release-restricting portion is characterized by its ability to prevent the reinforcing fibers from coming out in the fiber direction by biting into the hardened thermosetting resin.

[0012] According to the three-dimensional molding material (1) described above, the reinforcing fibers having the release-restricting portion are dispersed in the thermosetting resin in a liquid phase state. Therefore, when an external force that causes bending deformation or tensile deformation is applied to a three-dimensional molded object obtained by curing the three-dimensional molding material, the release-restricting portion can increase the resistance to the tensile force in the fiber direction that occurs at the interface between the reinforcing fiber and the thermosetting resin. Consequently, the effect of suppressing deformation and fracture of the three-dimensional molded object can be enhanced, and the mechanical properties of the three-dimensional molded object can be improved.

[0013] Furthermore, the three-dimensional molding material (2) according to the present invention is, in the three-dimensional molding material (1) described above, The aforementioned shedding-restricting portion is characterized by being a fuzzy portion in which the surface of the reinforcing fiber is frayed.

[0014] According to the three-dimensional molding material (2) described above, since the release-restricting portion is a fuzzy portion formed by fuzzing the surface of the reinforcing fiber, it is possible to harden the thermosetting resin with the fuzzy portion embedded in it. Therefore, the fuzzy portion can increase the resistance to the tensile force in the fiber direction generated at the interface, thereby enhancing the effect of suppressing deformation and fracture of the three-dimensional molded object.

[0015] Furthermore, the three-dimensional molding material (3) according to the present invention is characterized in that, in the three-dimensional molding material (1) or (2) above, the reinforcing fiber is carbon fiber, glass fiber, aramid fiber, or cellulose fiber.

[0016] According to the three-dimensional molding material (3) described above, since the reinforcing fibers are carbon fibers, glass fibers, aramid fibers, or cellulose fibers, the effect of suppressing deformation and fracture of the three-dimensional molded object described above can be reliably enhanced.

[0017] Furthermore, the three-dimensional molding material (4) according to the present invention is characterized in that, in any of the three-dimensional molding materials (1) to (3) above, the reinforcing fiber is a milled fiber having an average fiber diameter of 2 to 20 μm and an average fiber length of 20 to 500 μm.

[0018] According to the above-mentioned three-dimensional molding material (4), since the reinforcing fibers are milled fibers with an average fiber diameter of 2 to 20 μm and an average fiber length of 20 to 500 μm, they have excellent fluidity and dispersibility in the thermosetting resin in the liquid phase, and also exhibit less anisotropy compared to long fibers or chopped fibers, i.e., excellent isotropy, which facilitates the formation of the release-restricting portion that can be uniformly and reliably embedded in the thermosetting resin, thereby reliably enhancing the effect of suppressing deformation and fracture of the three-dimensional molded object.

[0019] Furthermore, the three-dimensional molding method (1) according to the present invention is a three-dimensional molding method that molds a three-dimensional object using any of the three-dimensional molding materials (1) to (4) described above, The process includes a shell fabrication step in which the shell, which is the outer shell layer of the three-dimensional object, is fabricated using shell material, A core material filling step of filling the three-dimensional modeling material as a core material into a core part which is a part surrounded by the shell; It is characterized by including a core material curing step of curing the core material filled in the core part.

[0020] According to the three-dimensional modeling method (1) described above, since the three-dimensional modeling material is filled as the core material in the core part and cured, the effect of suppressing deformation and breakage when an external force acts is enhanced. That is, a three-dimensional object with improved mechanical properties can be modeled.

[0021] Further, the three-dimensional object (1) according to the present invention is a three-dimensional object modeled using any one of the above three-dimensional modeling materials (1) to (4), A shell forming an outer shell layer, It is characterized by including a core modeling part in which the three-dimensional modeling material is filled and cured in a core part which is a part surrounded by the shell.

[0022] According to the three-dimensional object (1) described above, since it includes the core modeling part in which the three-dimensional modeling material is filled and cured in the core part, the effect of suppressing deformation and breakage when an external force acts is enhanced. That is, it can be made into a modeled object with improved mechanical properties.

[0023] Further, the three-dimensional object (2) according to the present invention is as described in the above three-dimensional object (1) It is characterized by having a form in which at least a part of the shell is removed and at least a part of the core modeling part is exposed.

[0024] According to the three-dimensional object (2) described above, since it has a form in which at least a part of the shell is removed and at least a part of the core modeling part is exposed, it can be made into a three-dimensional object mainly composed of the core modeling part, and can be made into a three-dimensional object with a high effect of suppressing deformation and breakage when an external force acts.

Brief Description of Drawings

[0025] [Figure 1] This figure illustrates the structure of a three-dimensional molding material according to an embodiment of the present invention, where (a) schematically shows the form of the three-dimensional molding material and (b) schematically shows an example of the form of the reinforcing fibers contained in the three-dimensional molding material. [Figure 2] This is a schematic diagram showing an example of the configuration of a three-dimensional modeling apparatus used in the three-dimensional modeling method according to the embodiment. [Figure 3] This figure illustrates an example of a three-dimensional molding method according to an embodiment, where (a) illustrates the shell molding process and (b) illustrates the core material filling process. [Figure 4] This figure illustrates an example of the core material hardening process in the three-dimensional fabrication method according to the embodiment, where (a) is a cross-sectional view showing the state before the core material hardening, (b) is a cross-sectional view showing the state after the core material hardening, and (c) is a schematic diagram showing the microscopic structure of the core fabricated part. [Figure 5] This is a photograph taken with a scanning electron microscope of the fracture surface of a hardened core material of a three-dimensional object fabricated using a conventional three-dimensional printing method. [Modes for carrying out the invention]

[0026] The embodiments of the three-dimensional molding material, three-dimensional molding method, and three-dimensional molded object according to the present invention will be described below with reference to the drawings. Note that the forms of the various components of the three-dimensional molding material and three-dimensional molded object shown in the drawings are schematic representations intended to facilitate understanding of the spirit of the present invention, and are not limited to these forms.

[0027] [3D modeling materials] Figure 1 is a diagram illustrating the structure of a three-dimensional molding material according to an embodiment of the present invention, where (a) schematically shows the form of the three-dimensional molding material and (b) schematically shows an example of the form of the reinforcing fibers contained in the three-dimensional molding material. The three-dimensional modeling material 1 is used for creating three-dimensional objects and contains a thermosetting resin 2 in a liquid phase and reinforcing fibers 3 dispersed in the thermosetting resin 2, and has a paste-like form. The thermosetting resin 2 contained in the three-dimensional modeling material 1 can be composed of, for example, epoxy resin, acrylic resin, as well as unsaturated polyester resin, vinyl ester resin, phenolic resin, urethane resin, alkyd resin, phenoxy resin, melamine resin, or polyimide resin. The thermosetting resin 2 may be composed of one or more of these types. In addition to a curing agent and a curing accelerator, the thermosetting resin 2 may also contain commonly used colorants and various additives.

[0028] The reinforcing fibers 3 contained in the three-dimensional molding material 1 are, for example, carbon fibers, glass fibers, aramid fibers, or cellulose fibers, and are preferably carbon fibers. The reinforcing fiber 3 includes, for example, milled fibers with an average fiber diameter of 2 to 20 μm and an average fiber length of 20 to 500 μm, preferably with an average fiber diameter of 5 to 15 μm and an average fiber length of 50 to 300 μm. More preferably, it includes milled fibers with a median average fiber diameter of approximately 8 μm and a median average fiber length of approximately 100 μm. The milled fibers are short fibers in powder form, i.e., microfibers, obtained by crushing the reinforcing fiber 3. The average fiber diameter and average fiber length are the average values ​​obtained when observing the reinforcing fiber 3 to be used under an optical microscope and measuring a predetermined number of arbitrarily selected fiber diameters and fiber lengths using an image analysis device or the like, i.e., number-average fiber diameter and number-average fiber length. Furthermore, the content of reinforcing fibers 3 in the three-dimensional molding material 1 is 2 to 50 volume%, preferably 5 to 30 volume%, and more preferably 10 to 20 volume%. The reinforcing fibers 3 may include nanofibers of carbon fibers, glass fibers, aramid fibers, or cellulose fibers.

[0029] Furthermore, the reinforcing fiber 3 has pull-out restricting portions 3a on its surface. The pull-out restricting portions 3a are designed to restrict the pull-out of the reinforcing fiber 3 in the fiber direction by biting into the cured thermosetting resin 2. Therefore, it is preferable that multiple pull-out restricting portions 3a are formed on the surface of the reinforcing fiber 3.

[0030] Such shedding-restricting portion 3a is composed of, for example, a fuzzy portion 3b formed by fuzzing the surface of the reinforcing fiber 3. The fuzzy portion 3b functions as a return portion that restricts the shedding of the reinforcing fiber 3 in the fiber direction. The morphology of the fuzzy portion 3b, such as the direction, length, and thickness of the fuzz from the surface of the reinforcing fiber 3, is not particularly limited, but includes forms in which at least a part of the surface of the reinforcing fiber 3 is roughened or protruding.

[0031] The fuzzy portions 3b may be formed on the surface of the reinforcing fibers 3 so that they all face the same direction, as shown in Figure 1(b), or they may be formed so that they face different directions from one another. For example, the fluffy portions 3b may all be formed in the same direction so as to rise in one direction of the fiber direction of the reinforcing fiber 3, or they may be formed in alternating directions so as to rise in the fiber direction of the reinforcing fiber 3. Alternatively, the fluffy portions 3b may be formed in different directions so as to rise from both ends of the reinforcing fiber 3 toward the center in the fiber direction, or they may be formed in different directions so as to rise toward both ends of the reinforcing fiber 3.

[0032] Such a shedding-restricting portion 3a consisting of a fuzzy portion 3b can be formed on the surface of the reinforcing fiber 3 by various methods. For example, the fuzzy portion 3b may be formed by mechanical treatment such as friction treatment on the reinforcing fiber 3, or by chemical treatment such as oxidation treatment or plasma treatment on the reinforcing fiber 3, or by heat treatment on the reinforcing fiber 3. Furthermore, the fuzzy portion 3b may be formed by a combination of the above-mentioned mechanical treatment and chemical treatment, or by a combination of the above-mentioned chemical treatment and heat treatment, or by a combination of other treatments.

[0033] [Methods for creating three-dimensional objects, and three-dimensional objects] Next, we will explain a method for creating three-dimensional objects using the three-dimensional modeling material 1 described above. Figure 2 is a schematic diagram showing an example of the configuration of a three-dimensional modeling apparatus used in the three-dimensional modeling method according to the embodiment. In the following description, one direction of the horizontal plane is defined as the X-axis direction, the direction perpendicular to this in the horizontal plane is defined as the Y-axis direction, and the direction perpendicular to the XY plane (horizontal plane) is defined as the Z-axis direction.

[0034] The 3D modeling apparatus 20 functions as a composite material 3D printer and mainly consists of a build tank 21 where modeling is performed by liquid vat polymerization (also known as stereolithography), a laser optical system 22, a core material supply system 23, and a thermosetting device 26, with the above-mentioned 3D modeling material 1 being used as the core material 16 in the core material supply system 23.

[0035] The build tank 21 contains a shell material 12, which is, for example, a photocurable resin, a liquid phase material. The liquid level can be maintained and adjusted to a predetermined position by a photocurable resin adjustment system (not shown). For the shell material 12, known UV-curable resins such as epoxy or acrylic resins can be used. A build platform 25 is also provided inside the build tank 21. The build platform 25 is for supporting the object being built and can be moved (raised and lowered) and set to any position in the Z-axis direction in the figure by a drive mechanism (not shown).

[0036] The laser optical system 22 comprises an ultraviolet laser light source 22a and a scanning optical system 22b. The ultraviolet laser light source 22a emits ultraviolet laser light 22c, which is one of the active energy rays, and the scanning optical system 22b drives the ultraviolet laser light 22c to be scanned on the liquid surface of the shell material 12 (i.e., the XY plane).

[0037] The shell material 12 hardens to a predetermined depth from the liquid surface by irradiation with ultraviolet laser light 22c, as shown in Figure 2 as a hardened ultraviolet-curable resin layer 13. This hardening depth can be adjusted within a predetermined range, for example, of about 0.1 mm to 0.4 mm, by adjusting the output of the ultraviolet laser light source 22a.

[0038] Therefore, by positioning the upper surface of the build plate 25 at a depth submerged by a predetermined curing depth from the liquid surface of the shell material 12, and irradiating the liquid surface of the shell material 12 with ultraviolet laser light 22c at any position, a cured ultraviolet-curable resin layer 13 of any area is formed on the build plate 25. Subsequently, the build plate 25 is lowered by the curing depth, the liquid surface of the shell material 12 is leveled with a liquid surface leveling tool (not shown), and then ultraviolet laser light 22c is irradiated at an arbitrary position on the liquid surface of the shell material 12, thereby laminating a new cured ultraviolet-curable resin layer 13 on top of the cured ultraviolet-curable resin layer 13.

[0039] Then, by repeatedly lowering the build plate 25 and irradiating the liquid surface of the shell material 12 with ultraviolet laser light 22c, the cured ultraviolet-curable resin layer 13 is stacked, and a three-dimensional shell 14 (see Figure 3) is fabricated. The shell 14, formed by hardening the shell material 12, becomes the outer shell layer of the three-dimensional object. The portion of the shell 14 surrounded by its inner surface that has a bottom surface is called the core portion 15 (see Figure 3).

[0040] The core material supply system 23 includes a core material tank 23a that stores the three-dimensional molding material 1 described above as core material 16, piping systems 23c and 23d connected to the core material tank 23a, a pump 23b installed in the middle of the piping systems 23c and 23d, and a nozzle 24 attached to the outlet of the piping system 23d. The nozzle 24 can be moved and fixed in the XYZ directions by a nozzle movement mechanism (not shown). For this reason, the piping system 23d is made of a flexible structure and material so as to follow the movement of the nozzle 24.

[0041] The core material supply system 23 is configured to drive a pump 23b to supply core material 16 from the core material tank 23a to the nozzle 24 via piping systems 23c and 23d, and to discharge the core material 16 from the tip of the nozzle 24. The nozzle 24 is composed of, for example, a needle nozzle with a diameter small enough to prevent clogging of the core material 16.

[0042] The core material 16 is composed of the three-dimensional molding material 1 described above. Furthermore, the specific gravity of the core material 16 is higher than that of the shell material 12, and the viscosity of the core material 16 is higher than that of the shell material 12, preferably at least twice the viscosity of the shell material 12.

[0043] The thermosetting apparatus 26 is used in the core material curing process to cure the core material 16 filled in the core portion 15, and consists of a heating furnace with a sealable chamber. The thermosetting apparatus 26 is capable of raising and lowering the temperature inside its heating furnace to a temperature higher than the thermosetting temperature of the core material 16.

[0044] The operation of each part of the 3D printing apparatus 20 (the build plate 25, the laser optical system 22, and the core material supply system 23) is controlled by a control unit (not shown). This control unit consists of a computer device including an arithmetic processing unit and a memory unit. The memory unit stores programs for controlling the operation of each part of the 3D printing apparatus 20, 3D shape data (CAD data) of the 3D object to be printed, and various other setting data necessary for printing. The arithmetic processing unit executes processes to control the operation of each part of the 3D printing apparatus 20 based on the above programs.

[0045] Next, an example of a three-dimensional molding method according to the embodiment will be described using Figures 3 and 4. The three-dimensional molding method according to the embodiment includes a shell molding step, a core material filling step, and a core material hardening step. The shell fabrication process is a process in which the shell 14, which is the outer shell layer of the three-dimensional object, is fabricated by liquid bath polymerization in a fabrication tank 21 in which the shell material 12 is stored. The core material filling process is a process in which the three-dimensional molding material 1 is used as the core material 16 to fill the core portion 15, which is the part enclosed by the shell 14. The core material hardening process is a process of heat-curing the core material 16 that has been filled into the core portion 15.

[0046] In the three-dimensional molding method according to this embodiment, first, the three-dimensional molding apparatus 20 is used to mold the shell 14, and then the core material 16 is filled into the inside of the molded shell 14, that is, into the core portion 15. Specifically, in the shell fabrication process, as shown in Figure 3(a), the nozzle 24 is moved out of the irradiation range of the ultraviolet laser light 22c, and based on the three-dimensional shape data of the shell 14, the laser optical system 22 scans and irradiates the liquid surface of the shell material 12 on the build plate 25 with ultraviolet laser light 22c, and the build plate 25 is lowered by the curing depth to level the liquid surface of the shell material 12, and these operations are performed alternately. Through these operations, a shell 14 having a core part 15 is fabricated on the build plate 25 using the photopolymerization reaction of the shell material 12. The shell 14 exemplified in Figure 2 is fabricated in the shape of a bottomed box with an opening on the top surface. The thickness of the shell 14 can be appropriately designed depending on the type and shape of the fabricated object.

[0047] In the next core material filling step, as shown in Figure 3(b), with the shell 14 positioned below the liquid level of the shell material 12 in the molding tank 21, the nozzle 24 is inserted into the core section 15 where the shell material 12 is located, and the core material 16 is discharged from the tip of the nozzle 24. With at least the tip of the nozzle 24 inserted into the discharged core material 16, the core material 16 is filled into the core section 15, replacing the shell material 12 in the core section 15. The filling of the core material 16 may also be performed by moving the nozzle 24 in the horizontal (XY axis) and vertical (Z axis) directions within the core section 15 using a nozzle moving mechanism (not shown). Furthermore, since the three-dimensional molding material 1 described above is used for the core material 16, the reinforcing fibers 3 having the escape-restricting portion 3a are dispersed within the core section 15. Furthermore, when filling the core material 16, it is preferable to fill the core material 16 with the tip of the nozzle 24 inserted into the extruded core material 16, as shown in Figure 3(b). However, it is not always necessary to fill the core material 16 with the nozzle 24 inserted into the core material 16. Depending on the initial filling stage and the shape of the shell 14, it may be possible to fill the core material 16 without inserting the nozzle 24 into the core material 16.

[0048] The shell molding process and core material filling process described above may be performed alternately multiple times. That is, the process of molding a shell 14 to a predetermined height, filling the core material 16 into the core portion 15 formed by the shell 14, further adding to the shell 14, and then filling the core material 16 into the newly formed core portion 15 by the added shell 14 may be repeated. By dividing the molding of the shell 14 into multiple stages in this way, it becomes possible to fill every corner of the core portion 15 with core material 16 by filling it in stages, especially when the core portion 15 has a complex or large shape. The shell molding process and core material filling process described above are normally performed at room temperature (for example, 20°C to 30°C).

[0049] Then, once the core material filling process is complete, the build plate 25 inside the build tank 21 is raised above the liquid level of the shell material 12, the shell 14 with the core material 16 filled into the core section 15 is removed from the build plate 25, and the process proceeds to the next core material hardening process.

[0050] In the core material hardening process, as shown in Figure 4(a), the shell 14 with the core material 16 filled into the core portion 15 is placed into the thermosetting apparatus 26 to start the hardening process of the core material 16. In other words, the shell 14 is placed in the thermosetting apparatus 26, and the temperature inside the thermosetting apparatus 26 is raised to a temperature higher than the thermosetting temperature of the core material 16. This heats up the entire molded object, including the shell 14 and the core material 16, initiating the hardening of the core material 16, which is made of the three-dimensional molding material 1, and the hardening progresses. After a predetermined time has elapsed, the hardening of the entire core material 16 is completed, and as shown in Figure 4(b), a core molded part 17 made of hardened core material 16 is formed in the core part 15, and a three-dimensional molded object 10 consisting of the shell 14 and the core molded part 17 is created.

[0051] After the core material hardening process is complete, the three-dimensional object 10 is removed from the thermosetting apparatus 26. The extracted three-dimensional object 10 may be subjected to fine adjustments to its shape, etc., by using cutting tools or the like to remove material from the surface of the shell 14 or the core molded part 17, as needed. In another configuration, part or all of the shell 14 may be separated and removed from the core molding section 17 using a cutting tool or the like, and the core molding section 17 may be the main component of the three-dimensional object 11.

[0052] The core molding section 17 is formed by curing the three-dimensional molding material 1 described above. As shown in Figure 4(c), the microscopic structure within the core molding section 17 consists of reinforcing fibers 3 having release-restricting portions 3a dispersed within the cured thermosetting resin 4, with the fuzzy portions 3b of the reinforcing fibers 3a being embedded in the cured thermosetting resin 4.

[0053] According to the three-dimensional molding material 1 of the above embodiment, reinforcing fibers 3 having release-restricting portions 3a are dispersed in a thermosetting resin 2 in a liquid phase state. Since the release-restricting portion 3a is a fuzzy portion 3b formed by fuzzing the surface of the reinforcing fiber 3, it is possible to cure the thermosetting resin 2 with the fuzzy portion 3b embedded in the thermosetting resin 2. Therefore, when an external force that causes bending deformation or the like is applied to the three-dimensional molded objects 10 and 11 obtained by curing the three-dimensional molding material 1, the fuzzed portion 3b, which acts as a release-restricting portion 3a, can increase the resistance to the tensile force in the fiber direction that occurs at the interface between the reinforcing fiber 3 and the cured thermosetting resin 4. Consequently, the effect of suppressing deformation and fracture of the three-dimensional molded objects 10 and 11 can be enhanced, and the mechanical properties of the three-dimensional molded objects 10 and 11 can be improved.

[0054] Furthermore, the three-dimensional molding material 1 described above has reinforcing fibers 3 that are carbon fibers, glass fibers, or aramid fibers, and are milled fibers with an average fiber diameter of 2 to 20 μm and an average fiber length of 20 to 500 μm. Therefore, it has excellent fluidity and dispersibility in the liquid state thermosetting resin 2, and also has low anisotropy compared to long fibers or chopped fibers, i.e., it has excellent isotropy, making it easy to form release-restricting sections 3a that can be evenly and reliably embedded in the cured thermosetting resin 4, thereby reliably enhancing the effect of suppressing deformation and fracture of the three-dimensional molded objects 10 and 11 after curing.

[0055] Furthermore, according to the three-dimensional molding method of the above embodiment, the three-dimensional molding material 1 is filled into the core portion 15 as a core material 16 and hardened, so that the effect of suppressing deformation and fracture when an external force is applied is enhanced, that is, three-dimensional molded objects 10 and 11 with improved mechanical properties can be molded.

[0056] Furthermore, according to the above embodiment, the three-dimensional molded objects 10 and 11 are equipped with a core molded portion 17 in which the three-dimensional molding material 1 is filled and hardened in the core portion 15, so that the effect of suppressing deformation and fracture when an external force is applied is enhanced, that is, the molded object can be made in which the mechanical properties are improved.

[0057] Although embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible, all of which are also included within the scope of the present invention.

[0058] The present invention is widely applicable in the field of additive manufacturing technologies such as 3D printers. By applying the present invention to such fields, it becomes possible not only to prototype but also to mass-produce parts and products that require lightweight and high strength, such as parts used in various industrial equipment such as automobiles, aircraft, and robots, as well as nursing care products and sporting goods. [Explanation of symbols]

[0059] 1 Three-dimensional modeling materials 2 Thermosetting resin 3 Reinforced Fibers 3a Leaked regulatory section 3b Fuzzy area 4. Cured thermosetting resin 10, 11 Three-dimensional objects 12 Shell material 13. Cured UV-cured resin layer 14 Shells 15 Core section 16 Core material 17 Core molding section 20 Three-dimensional modeling equipment 21 Modeling tank 22 Laser Optics 22a Ultraviolet laser light source 22b Scanning optical system 22c ultraviolet laser light 23 Core material supply system 23a Core material tank 23b Pump 23c, 23d Piping System 24 nozzles 25 Build Table 26 Heat curing equipment

Claims

1. A three-dimensional modeling material used for creating three-dimensional objects, A thermosetting resin in liquid phase, The thermosetting resin contains reinforcing fibers dispersed within it. The reinforcing fiber has a shedding-restricting portion on its surface, The material for creating three-dimensional shapes is characterized in that the release-restricting portion prevents the reinforcing fibers from coming out in the fiber direction by biting into the hardened thermosetting resin.

2. The three-dimensional molding material according to claim 1, characterized in that the release-restricting portion is a fuzzy portion obtained by fuzzing the surface of the reinforcing fiber.

3. The three-dimensional molding material according to claim 1 or 2, characterized in that the reinforcing fiber is carbon fiber, glass fiber, aramid fiber, or cellulose fiber.

4. The three-dimensional molding material according to claim 1 or 2, characterized in that the reinforcing fibers are milled fibers having an average fiber diameter of 2 to 20 μm and an average fiber length of 20 to 500 μm.

5. A method for creating a three-dimensional object using the three-dimensional molding material described in claim 1, The process includes a shell fabrication step in which the shell, which is the outer shell layer of the three-dimensional object, is fabricated using shell material, A core material filling step in which the three-dimensional molding material is filled as a core material in the core portion which is the part enclosed by the shell, A method for creating a three-dimensional object, characterized by including a core material hardening step of hardening the core material filled in the core portion.

6. A three-dimensional object formed using the three-dimensional molding material described in claim 1, The shell that forms the outer layer, A three-dimensional object characterized by comprising a core portion, which is the part enclosed by the shell, and a core molded portion, which is filled with the three-dimensional molding material and hardened.

7. The three-dimensional object according to claim 6, characterized in that at least a portion of the shell is removed and at least a portion of the core molded portion is exposed.

Images