Method for producing 3D additively manufactured objects, support materials and articles

Abstract

To provide a production method of a three-dimensional lamination molded body, a support material and an article, capable of reducing producing costs and enabling the recovery and reuse of the support material, while capable of properly supporting the three-dimensional lamination molded body in degreasing and firing in the fabrication of the three-dimensional lamination molded body by a material extrusion method.SOLUTION: This invention relates to a production method of a three-dimensional lamination molded body 1 for forming a support material 2 supporting the three-dimensional lamination molded body 1 at a lower part of the three-dimensional lamination molded body 1 when molding the three-dimensional lamination molded body 1 by a material extrusion method. The production method includes forming, as the support material 2, a shrinkage relaxation layer which shrinks following the shrinkage of the three-dimensional lamination molded body 1 in firing and is formed of a filament material of a mixture containing ceramic powder and thermoplastic resin, and a self-disintegrating layer which is composed of a filament material mixed with a high-melting point inorganic filler and thermoplastic resin, and can be peeled off from the three-dimensional lamination molded body 1 after firing.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for producing a three-dimensional additive manufacturing object using a support material that supports the three-dimensional additive manufacturing object below the three-dimensional additive manufacturing object during a manufacturing process using a material extrusion method, and to a supporting material and an article. [Background technology]

[0002] 3D additive manufacturing (AM) is a technology that creates three-dimensional shapes through additive processing based on 3D CAD data and other data. AM can be broadly categorized into seven types of methods, one of which is the material extrusion method, which creates objects by extruding plastic material from a nozzle and layering it. It is generally known that objects are created using a thermoplastic resin that melts when heated as the material. In addition, when creating a shape in which there is no support below the object (for example, an overhang or bridge shape) using the material extrusion method, a technology is known in which the object is created using a support material to support the object.

[0003] In this case, if the supporting material is made of the same material as the model, the supporting material will fuse to the model after degreasing and firing, making it impossible to remove the supporting material from the model. To address this issue, a method has been disclosed in which the supporting material is made of an interface layer (peeling layer) to prevent the supporting material from fusing with the model, and a supporting material body to absorb shrinkage during the degreasing and firing process of the model, and the supporting material is fired with the interface layer interposed between the supporting material body and the model, making it easier to remove the supporting material from the model after firing (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special publication 2019-522105 [Patent Document 2] JP 2020-501022 A Summary of the Invention [Problem to be solved by the invention]

[0005] The interface layer is made of a material different from that used for the shaped body so that it can be easily peeled off from the shaped body, and since it does not shrink to the same extent as the shaped body, a configuration has been adopted in which the interface layer is made thin and the supporting material body made of the same material as the shaped body (a material having the same shrinkage rate as the shaped body) is made thick in order to absorb the shrinkage of the shaped body. However, when the shaped body is made of an expensive material such as zirconia ceramics, the supporting material body is also made of the same expensive material as the shaped body, so if the interface layer is made thin, the supporting material body must be made thick accordingly, which raises the problem of high manufacturing costs for the shaped body. Furthermore, since the supporting material is discarded after firing, a large amount of waste material is generated, which also causes environmental problems.

[0006] The present invention aims to provide a method for producing a 3D additive manufacturing object using a material extrusion method, a supporting material, and an article that can adequately support the 3D additive manufacturing object during degreasing and sintering, while reducing production costs and enabling the support material to be recovered and reused. [Means for solving the problem]

[0007] The present invention relates to a method for producing a three-dimensional additive manufacturing object as described below in (1) to (12). (1) A method for producing a three-dimensional additive manufacturing object, comprising forming a support material that supports the three-dimensional additive manufacturing object under a lower portion of the three-dimensional additive manufacturing object during a manufacturing process of the three-dimensional additive manufacturing object by a material extrusion method, the support material including a shrinkage relaxation layer that shrinks in response to the shrinkage of the three-dimensional additive manufacturing object during firing, and a self-disintegrating layer that is made of a filament material that is a mixture containing a high-melting point inorganic filler and a thermoplastic resin and that can be peeled off from the three-dimensional additive manufacturing object after firing; The self-disintegrating layer shrinks in accordance with the shrinkage of the three-dimensional additive manufacturing object during firing, but has a smaller shrinkage rate during firing than the shrinkage relaxation layer.A method for producing a three-dimensional additively manufactured object by forming a three-dimensional additively manufactured object. (2) A method for producing a three-dimensional additive manufacturing object described in (1) above, wherein the three-dimensional additive manufacturing object is a ceramic manufacturing object and is manufactured using a ceramic material containing ceramic powder, and the shrinkage relaxation layer is formed from a filament material that is a mixture containing ceramic powder and a thermoplastic resin. (3) The method for producing a three-dimensional additive manufacturing object according to (2) above, wherein the filament material forming the shrinkage relaxation layer has a ceramic powder content of 30 volume % or more. ( 4 ) The filament material forming the self-disintegrating layer has a content of the high melting point inorganic filler of 30 volume % or more, 3 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11. ( 5 ) the high melting point inorganic filler has a melting temperature 100° C. or more higher than the firing temperature of the three-dimensional laminated object, 4 ) A method for producing a three-dimensional additive manufacturing object according to the present invention. ( 6 ) The high melting point inorganic filler has an average particle diameter of 1 μm or more and 40 μm or less, and the increase rate of the average particle diameter before and after firing is 150% or less, 5 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11. ( 7 ) The filament material forming the shrinkage relaxation layer and / or the self-disintegrating layer has a viscosity of 20 to 500 Pa·s at the molding temperature, 6 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11. ( 8 ) The self-disintegrating layer has a compressive strength of 5 MPa or less after firing, 7 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11. ( 9 ) The supporting material is such that the self-disintegrating layer accounts for 5% or more and 60% or less of the above (1) to ( 8 ) Support material described in any of the following. ( 10) The support material has a thermal deformation rate of 10% or less during degreasing, and the difference in shrinkage rate between the support material and the three-dimensional additive manufacturing body during firing is 4% or less. 9 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11. ( 11 ) The three-dimensional laminated object is an object formed into an overhang shape or a bridge shape, 10 2. A method for producing a three-dimensional layered object according to any one of claims 1 to 11.

[0008] The present invention also provides the following: 12 ) or ( 15 ) support material. ( 12 ) a support material that supports the three-dimensional additive manufacturing object under the three-dimensional additive manufacturing object during a manufacturing process of the three-dimensional additive manufacturing object by a material extrusion method, the support material having a shrinkage relief layer that shrinks in accordance with the shrinkage of the three-dimensional additive manufacturing object during firing, and a self-disintegrating layer that is formed from a filament material that is a mixture containing a high-melting point inorganic filler and a thermoplastic resin, prevents adhesion between the three-dimensional additive manufacturing object and the shrinkage relief layer, and is peelable from the three-dimensional additive manufacturing object after firing. The self-disintegrating layer shrinks in accordance with the shrinkage of the three-dimensional additive manufacturing body during firing, but the shrinkage rate during firing is smaller than that of the shrinkage relaxation layer. , support materials. ( 13 ) The three-dimensional laminated object is an overhang-shaped or bridge-shaped object, 12 ) Support material as described in. ( 14 ) The material extrusion method is a method for producing a molded object by extruding a plastic material from a nozzle in a three-dimensional additive manufacturing (AM) technology. 12 )or( 13 ) Support material as described in. ( 15 ) The material of the support material is a mixture containing ceramic powder and a thermoplastic resin for the shrinkage relaxation layer, and a mixture containing a high melting point inorganic filler and a thermoplastic resin for the self-disintegrating layer. 12 ) or ( 14 ) Support material described in any of the following.

[0009] Furthermore, the present invention relates to the following: 16 ) or ( 19 ) items are the gist of the present invention. ( 16 ) a ceramic three-dimensional additive manufacturing object shaped by an extrusion method with a shaping material including a sinterable ceramic powder material for forming a final part at a sintering temperature, the shaping material including one or more resin binders that hold the powder material in a net-shape object before densifying the powder material into a final part; and a support material for the ceramic three-dimensional additive manufacturing object, the support material being disposed adjacent to a surface of the ceramic three-dimensional additive manufacturing object and supporting the ceramic three-dimensional additive manufacturing object under the ceramic three-dimensional additive manufacturing object during at least one of debinding and sintering of the shaping object. , grilled The three-dimensional laminated body has a shrinkage relief layer that shrinks in accordance with the shrinkage of the three-dimensional laminated body during formation, and a self-disintegrating layer that prevents adhesion between the three-dimensional laminated body and the shrinkage relief layer and can be peeled off from the three-dimensional laminated body after firing. The self-disintegrating layer shrinks in accordance with the shrinkage of the three-dimensional additive manufacturing object during firing, but the shrinkage rate during firing is smaller than that of the shrinkage relaxation layer. and a composite support material. ( 17 ) the support material is a material made of a mixture containing a ceramic powder of the shrinkage relaxation layer or a high melting point inorganic filler of the self-disintegrating layer and a thermoplastic resin, and the content of the ceramic powder of the shrinkage relaxation layer or the high melting point inorganic filler of the self-disintegrating layer is 30 volume % or more, Things The stranded filament is made of a material that has a fluidity of 20 to 500 Pa·s at the heating temperature during modeling. 16 ) the item described in. ( 18 ) The high melting point inorganic filler of the self-disintegrating layer has a melting temperature 100°C or higher than the desired sintering temperature of the shaped body, an average particle size of 1 μm or more and 40 μm or less, the relative density of the ceramic shaped body when the support is removed in the firing process is 50% or more, the compressive strength of the self-disintegrating layer at that time is 5 MPa or less, and the degree of adhesion of the inorganic filler of the self-disintegrating layer is such that the change in the average particle size before firing is 150% or less, and the self-disintegrating layer can be recovered and recycled, 16 )or( 17 ) the item described in. ( 19The composition ratio of the self-disintegrating layer in the composite support material is 5% or more and 60% or less, the thermal deformation of the composite support material during degreasing is 10% or less, and the difference in the shrinkage rate between the ceramic model and the composite support during firing is within 4%. 16 ) or ( 18 ) An article described in any one of the above. Effect of the Invention

[0010] According to the present invention, it is possible to provide a method for producing a three-dimensional additive manufacturing object using a material extrusion method, which is capable of adequately supporting the three-dimensional additive manufacturing object during degreasing and sintering, while also reducing production costs and enabling the support material to be recovered and reused, as well as a supporting material and article for the same. [Brief description of the drawings]

[0011] [Figure 1] 1A to 1C are diagrams for explaining a method for producing a ceramic body according to an embodiment of the present invention. [Diagram 2] 2A to 2C are diagrams illustrating the states of the ceramic body 1 and the supporting material 2 before and after degreasing and firing. [Diagram 3] FIG. 2 is a schematic diagram showing a configuration of a supporting material according to the present embodiment. [Figure 4] 1 is a graph showing the relationship between the average particle size of the silica powder used in the self-collapsing layer and the thermal deformation rate of the self-collapsing layer due to heating. [Diagram 5] 1 is a graph showing the relationship between the average particle size of silica powder, the firing temperature, and the compressive strength after firing in a self-disintegrating layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, in the following, a ceramic shaped body made of a ceramic material will be described as a preferred example of a three-dimensional additive manufacturing object according to the present invention, but the present invention is not limited to a ceramic shaped body as long as the shaped body is made of a material that can be used to manufacture a three-dimensional additive manufacturing object by a material extrusion method.

[0013] FIG. 1 is a diagram for explaining a method for producing a ceramic shaped body 1 according to the present embodiment, and FIG. 2 is a diagram for explaining the state of the ceramic shaped body 1 and the supporting material 2 before and after degreasing and firing. As shown in FIG. 1, the supporting material 2 supports the ceramic shaped body 1 so that the ceramic shaped body 1 does not deform during degreasing and firing when the ceramic shaped body 1 is shaped into a shape that is not supported at the bottom of the ceramic shaped body 1 (for example, a bridge shape shown in FIG. 1 or an overhang shape not shown). Here, the ceramic shaped body 1 is produced as the final product ceramic shaped body 1 by performing degreasing and firing after shaping. When the ceramic shaped body 1 is degreased and fired, the ceramic shaped body 1 shrinks after degreasing and firing compared to before degreasing and firing, as shown in FIG. 2. For this reason, it is desirable for the supporting material 2 to be able to continuously support the ceramic shaped body 1 by not melting or collapsing (collapse due to thermal deformation) during degreasing and firing, and by shrinking in accordance with the shrinkage of the ceramic shaped body 1, as shown in Fig. 2. Furthermore, since it is necessary to remove the supporting material 2 from the ceramic shaped body 1 after firing of the ceramic shaped body 1, it is desirable for the supporting material 2 to be a member that can be easily removed from the ceramic shaped body 1 after firing. In order to have such characteristics, the supporting material 2 according to this embodiment has the following configuration.

[0014] Fig. 3 is a schematic diagram showing the configuration of the supporting material 2 according to this embodiment. As shown in Fig. 3, the supporting material 2 according to this embodiment has a shrinkage relaxation layer 10 and a self-collapsing layer 20. In this embodiment, as shown in Fig. 3, both ends of the supporting material 2 that are in contact with the ceramic shaped body 1 are formed with the self-collapsing layer 20, and the shrinkage relaxation layer 10 is formed at a position that is not in contact with the ceramic shaped body 1 and is sandwiched between the self-collapsing layers 20.

[0015] The shrinkage relaxation layer 10 is preferably formed from a material that shrinks at approximately the same rate as the ceramic shaped body 1 during the degreasing and firing process, and can be formed from the same material as the ceramic shaped body 1. For example, when a mixture containing zirconia ceramic powder and a thermoplastic resin is used as the material of the ceramic shaped body 1, a mixture containing zirconia ceramic powder and a thermoplastic resin can also be used as the material of the shrinkage relaxation layer 10. In this way, by forming the shrinkage relaxation layer 10 from the same material as the ceramic shaped body 1, the shrinkage relaxation layer 10 can shrink at approximately the same rate as the ceramic shaped body 1 during firing, and as a result, the difference in shrinkage rate between the ceramic shaped body 1 and the support material 2 during firing can be reduced.

[0016] In this embodiment, the filament material, which is a mixture of zirconia ceramic powder and thermoplastic resin with the same composition as the ceramic shaped body 1, is inserted into the extrusion head as a filament, and is continuously extruded from a nozzle part of the extrusion head while being heated and melted, and laminated to form the shrinkage relaxation layer 10. In the filament material of the shrinkage relaxation layer 10, the ceramic powder content is preferably 30 volume % or more. If the ceramic powder content is less than 30% or less, the difference in shrinkage rate with the ceramic shaped body 1 becomes too large (the firing shrinkage becomes too large compared to the ceramic shaped body 1), and there is a possibility that the function as a support is lost (melted down). In addition, it is preferable to adjust the filament material of the shrinkage relaxation layer 10 so that the viscosity at the shaping temperature is 20 to 500 Pa·s. The viscosity of the filament material can be adjusted by adjusting the type of resin in addition to the ceramic powder content.

[0017] The shrinkage relaxation layer 10 and the ceramic shaped body 1 may be formed from different materials or with different compounding ratios. When the materials of the shrinkage relaxation layer 10 and the ceramic shaped body 1 are different, it is preferable that they have approximately the same shrinkage behavior during firing (for example, the difference in shrinkage rate is within 4%). The shrinkage relaxation layer 10 and the ceramic shaped body 1 may also be formed from the same raw materials with different compounding ratios of the raw materials.

[0018] The self-disintegrating layer 20 is formed by extruding and laminating a filament material made of a mixture containing a high-melting-point inorganic filler and a thermoplastic resin. In particular, the high-melting-point inorganic filler used in the self-disintegrating layer 20 is characterized by having a melting temperature 100°C or more higher than the planned sintering temperature of the ceramic shaped body 1 so that it can be reused even after the ceramic shaped body 1 is fired. For example, when zirconia ceramics is used as the material for the ceramic shaped body 1, the ceramic shaped body 1 is often fired at 1150°C at which the relative density of the ceramic shaped body 1 is 50% or more so that the ceramic shaped body 1 does not deform. In this case, silica powder having a melting point of 1250°C or more (melting point is 1650°C) can be used as the high-melting-point inorganic filler of the self-disintegrating layer 20.

[0019] The particle size of the high melting point inorganic filler used in the self-disintegrating layer 20 is not particularly limited, but the average particle size is preferably 1 μm or more, more preferably 2 μm or more. If the average particle size of the high melting point inorganic filler is less than 1 μm, as described later, the compressive strength of the self-disintegrating layer 20 after firing will be high, and the support material 2 may not be easily removed from the ceramic shaped body 1. In addition, the particle size of the high melting point inorganic filler is preferably 40 μm or less, more preferably 30 μm or less. As described later, the higher the average particle size of the high melting point inorganic filler, the greater the thermal deformation of the self-disintegrating layer 20 during degreasing tends to be, and if the average particle size exceeds 40 μm, the support material 2 may melt down and the support material 2 may not be able to support the ceramic shaped body 1.

[0020] In addition, the supporting material 2 according to the present embodiment is also characterized in that the high melting point inorganic filler contained in the self-disintegrating layer 20 can be recovered and reused. Here, when recovering and reusing the high melting point inorganic filler, if the particle size of the high melting point inorganic filler to be reused varies widely, it becomes difficult to control the thermal deformation of the self-disintegrating layer 20 in the degreasing process and the contraction of the self-disintegrating layer 20 in the firing process during reuse. Therefore, the ceramic shaped body 1 is manufactured so that the increase rate of the average particle size of the high melting point inorganic filler contained in the self-disintegrating layer 20 before and after firing is 150% or less. Specifically, when the temperature at which the supporting material 2 is fired is equal to or higher than a predetermined temperature, the average particle size of the high melting point inorganic filler after firing tends to increase. Therefore, for example, in the supporting material 2 having the self-disintegrating layer 20 using silica powder as the high melting point inorganic filler, the increase rate of the average particle size of the silica powder before and after firing can be suppressed to approximately 150% or less by setting the firing temperature of the supporting material 2 to less than 1400°C.

[0021] In this embodiment, the self-disintegrating layer 20 is formed by laminating a filament material, which is a mixture of silica powder and thermoplastic resin in a strand shape, by a material extrusion method. The filament material of the self-disintegrating layer 20 preferably has a silica powder (high melting point inorganic filler) content of 30% by volume or more. In addition, in order to easily form the self-disintegrating layer 20 by laminating the filament material of the self-disintegrating layer 20, it is preferable to adjust the viscosity of the filament material of the self-disintegrating layer 20 to 20 to 500 Pa·s at the molding temperature. Furthermore, in this embodiment, the self-disintegrating layer 20 is configured so that the compressive strength of the self-disintegrating layer 20 after firing is 5 MPa or less so that the support material 2 can be easily peeled off from the ceramic shaped body 1 after firing. As will be described later, the compressive strength of the self-disintegrating layer 20 after firing can be adjusted by the firing temperature and the average particle size of the high melting point inorganic filler of the self-disintegrating layer 20, so that the compressive strength of the self-disintegrating layer 20 is 5 MPa or less, depending on the planned firing temperature.

[0022] It is desirable that the supporting material 2 has little thermal deformation in the degreasing process and shrinks to the same extent as the ceramic shaped body 1 in the firing process so that the supporting material 2 can continuously support the ceramic shaped body 1 during degreasing and firing. It is also desirable that the supporting material 2 can reduce the amount of waste material while reducing the manufacturing cost. Therefore, the supporting material 2 according to this embodiment is configured such that the thermal deformation rate in the degreasing process is within 10% and the difference in the shrinkage rate between the supporting material 2 and the ceramic shaped body 1 in the firing process is within 4%. In addition, the supporting material 2 according to this embodiment is configured such that the composition ratio of the self-disintegrating layer 20, which can be made of a relatively inexpensive material, is increased and the high melting point inorganic filler used in the self-disintegrating layer 20 can be reused in order to reduce the manufacturing cost while reducing waste material. Below, a configuration example of the supporting material 2 according to this embodiment will be described.

[0023] (1) Thermal deformation during the degreasing process The degreasing process is a process in which organic matter such as the binder resin contained in the ceramic body 1 and the supporting material 2 is removed by heating and pyrolyzing and burning it. In the degreasing process, the binder resin softens, causing deformation in the ceramic body 1 and the supporting material 2, and materials with a large amount of deformation are not suitable for use as the supporting material 2. For this reason, the supporting material 2 according to this embodiment is configured so that the thermal deformation rate during degreasing is within 10% at the end of degreasing (usually 600°C). The following describes the results of verifying the configuration of the supporting material 2 that results in a thermal deformation amount of within 10% during degreasing.

[0024] The self-disintegrating layer 20 was prepared by using silica powders of different particle sizes (2 to 35 μm) and setting the content of these silica powders at 40 volume %, and the thermal deformation rate (%) of each sample during heating was measured using a thermomechanical analyzer. In addition, as a comparative example, the thermal deformation rate (%) of a sample using zirconia (content was set to 40 volume %) used in the ceramic shaped body 1 and the shrinkage relaxation layer 10 was also measured during heating. The evaluation results are shown in FIG. 4. In FIG. 4, (A) shows the evaluation result of a sample using 2.3 μm silica powder, and (B) shows the evaluation result of a sample using 4.0 μm silica powder. In addition, (C) shows the evaluation result of a sample using 8.5 μm silica powder, and (D) shows the evaluation result of a sample using 34.5 μm silica powder. Furthermore, (X) shows the evaluation result of a comparative example using zirconia.

[0025] As shown in Fig. 4, when silica powder having an average particle size of 2 to 4 µm is used for the self-collapsing layer 20, the deviation in the thermal deformation rate is small compared to the comparative example using zirconia, and it is found that it is difficult to deform during degreasing. In particular, when silica powder having an average particle size of 2 to 4 µm is used, the deformation rate during degreasing is within 10%, and there is little risk that the support material 2 will melt down due to thermal deformation, and it is found that it is suitable as the support material 2. On the other hand, when silica powder having an average particle size of 8 to 35 µm is used, it is found that the thermal deformation rate is large compared to the comparative example using zirconia.

[0026] However, even when the silica powder having an average particle diameter of 8 to 35 μm is used for the self-collapsing layer 20, the influence of thermal deformation of the supporting material 2 can be reduced by adjusting the composition ratio of the shrinkage relaxation layer 10 using zirconia and the self-collapsing layer 20 using silica powder. For example, when the average particle diameter of the silica powder contained in the self-collapsing layer 20 is 2.3 μm or 4.0 μm, the thermal deformation during degreasing is small, so that the composition ratio of the self-collapsing layer 20 in the supporting material 2 can be increased up to 60%. On the other hand, when the average particle diameter of the silica powder in the self-collapsing layer 20 is 8.5 μm and 34.5 μm, the thermal deformation during the degreasing process is large, so that the composition ratio of the self-collapsing layer 20 in the supporting material 2 is set to a maximum of 20%. In this way, in the supporting material 2 according to this embodiment, the average particle diameter of the silica powder used in the self-collapsing layer 20 and the composition ratio of the self-collapsing layer 20 can be adjusted to within 10% in the degreasing process.

[0027] (2) Shrinkage rate of Support Material 2 during firing In this embodiment, in order to shrink the support material 2 following the ceramic shaped body 1 in the firing process, it is preferable to use the same material for the shrinkage relaxation layer 10 as for the ceramic shaped body 1. Here, when a ceramic material such as zirconia ceramics is used for the ceramic shaped body 1 and the shrinkage relaxation layer 10, it is preferable to make the composition ratio of the shrinkage relaxation layer 10 in the support material 2 as small as possible and the composition ratio of the self-disintegrating layer 20 as large as possible, since ceramic materials such as zirconia ceramics are often very expensive. However, if the composition ratio of the self-disintegrating layer 20 is too large, the support material 2 cannot follow the shrinkage of the ceramic shaped body 1 during firing (cannot absorb the shrinkage of the ceramic shaped body 1), and there is a risk that the ceramic shaped body 1 will be destroyed. Therefore, it is preferable to set the composition ratio of the shrinkage relaxation layer 10 and the self-disintegrating layer 20 of the support material 2 to an appropriate range that can realize low cost while preventing destruction of the ceramic shaped body 1.

[0028] Therefore, in the supporting material 2 according to this embodiment, the shrinkage rate of the supporting material 2 is adjusted to be within 4%, preferably within 3%, of the shrinkage rate of the ceramics shaped body 1 when the supporting material 2 and the ceramics shaped body 1 are fired. Here, in the firing process of the ceramics shaped body 1, when the relative density of the ceramics shaped body 1 reaches 50% or more, the ceramics shaped body 1 and the supporting material 2 are removed from the firing furnace, the supporting material 2 is removed from the ceramics shaped body 1 and recovered, and then the ceramics shaped body 1 alone can be heated again to a target temperature and sintered. This is because if the supporting material 2 is removed when the relative density of the ceramics shaped body 1 is less than 50%, the ceramics shaped body 1 may lose support and deform in the subsequent firing process. When the material of the ceramics shaped body 1 is zirconia ceramic, the firing temperature at which the relative density reaches 50% is about 1150°C. Therefore, when the material of the ceramic body 1 is zirconia ceramics, it is desirable to keep the difference in shrinkage rate between the ceramic body 1 and the supporting material 2 within 4%, preferably within 3%, until firing at 1150°C.

[0029] In the supporting material 2, by adjusting the composition ratio of the shrinkage relaxation layer 10 and the self-disintegrating layer 20, it is possible to control the difference in shrinkage rate between the ceramic shaped body 1 and the supporting material 2 during firing to within 4%. Specifically, the composition ratio of the self-disintegrating layer 20 is preferably 5% or more and 60% or less, and more preferably 10% or more and 50% or less. The reason why the composition ratio of the self-disintegrating layer 20 is set to 5% or more is that if the composition ratio of the self-disintegrating layer 20 is less than 5%, some burning occurs at the interface between the ceramic shaped body 1 and the self-disintegrating layer 20, and when the supporting material 2 is removed from the ceramic shaped body 1, a part of the self-disintegrating layer 20 is fused to the ceramic shaped body 1, and the recovery amount of the high melting point inorganic filler contained in the self-disintegrating layer 20 is significantly reduced, which may result in a large amount of the supporting material 2 being discarded. On the other hand, if the composition ratio of the self-collapsing layer 20 is greater than 60%, the self-collapsing layer 20 has a lower shrinkage rate during firing than the shrinkage relaxation layer 10, which increases the shrinkage difference between the support material 2 and the ceramic body 1, and this may induce defects such as firing cracks.

[0030] In addition, the composition ratio of the self-disintegrating layer 20 must also be adjusted depending on the particle diameter of the high-melting-point inorganic filler contained in the self-disintegrating layer 20. For example, when zirconia powder is used for the ceramic shaped body 1 and the shrinkage relaxation layer 10, silica powder is used for the self-disintegrating layer 20, the firing temperature is 1150°C, and the support material 2 is removed after firing, in order to keep the difference in shrinkage rate between the ceramic shaped body 1 and the support material 2 during firing within 3%, when the particle diameter of the silica powder is 2.3 μm, 4.0 μm, or 8.5 μm, the composition ratio of the self-disintegrating layer 20 can be increased to 60%. On the other hand, when the particle diameter of the silica powder is 34.5 μm, the composition ratio of the self-disintegrating layer 20 can be increased to 50%.

[0031] In this way, in the supporting material 2 according to this embodiment, by adjusting the composition of the self-disintegrating layer 20 (for example, the average particle size and content of the high-melting-point inorganic filler used in the self-disintegrating layer 20) and the composition ratio of the shrinkage relaxation layer 10 and the self-disintegrating layer 20, the rate of thermal deformation during degreasing can be controlled to within 10%, and the shrinkage rate of the supporting material 2 during firing can be controlled to within 4%, more preferably within 3%, of the shrinkage rate of the ceramic shaped body 1. As a result, the supporting material 2 does not melt down during the degreasing process, and shrinks in accordance with the shrinkage of the ceramic shaped body 1 during the firing process, thereby enabling the ceramic shaped body 1 to be continuously supported.

[0032] (3) The degree of adhesion and self-destruction strength suitable for recovery and reuse of the support material 2 It is desirable that the support material 2 can be easily removed from the ceramic shaped body 1 after firing. In the firing process, the high-melting-point inorganic filler contained in the self-disintegrating layer 20 is also sintered, so if the self-disintegrating layer 20 after firing has a high compressive strength, it becomes difficult to remove the self-disintegrating layer 20 from the ceramic shaped body 1. Therefore, in this embodiment, the self-disintegrating layer 20 is configured so that the compressive strength of the self-disintegrating layer 20 after firing is 5 MPa or less, which allows the self-disintegrating layer 20 to be easily disintegrated and recovered.

[0033] 5 shows the compressive strength of the self-disintegrating layer 20 produced using silica powder (high melting point inorganic filler) of various average particle sizes, when fired at each firing temperature. In the case of the self-disintegrating layer 20 (A) fired at 1400°C using silica powder with an average particle size of 2.3 μm, the compressive strength of the self-disintegrating layer 20 exceeds 5 MPa, making it difficult to remove the self-disintegrating layer 20 from the ceramic shaped body 1. On the other hand, in the case of the self-disintegrating layer 20 (B) to (D) fired at 1400°C using silica powder with an average particle size of 4 μm or more, the compressive strength of the self-disintegrating layer 20 is 5 MPa or less, making it easy to remove the self-disintegrating layer 20 from the ceramic shaped body 1. Similarly, when fired at 1300°C, the compressive strength of the self-disintegrating layer 20 (E) using silica powder with an average particle size of 2.3 μm exceeds 5 MPa, making it difficult to remove the self-disintegrating layer 20 from the ceramic shaped body 1, but the compressive strength of the self-disintegrating layer 20 (F) to (H) using silica powder with an average particle size of 4 μm or more is 5 MPa or less, making it possible to easily remove the self-disintegrating layer 20 from the ceramic shaped body 1. Furthermore, as shown in FIG. 4, when the self-disintegrating layer 20 is fired at 1200°C and when fired at 1100°C, the compressive strength of the self-disintegrating layers 20 (I) to (L), (M) to (P) is 5 MPa or less, making it possible to easily remove the self-disintegrating layer 20 from the ceramic shaped body 1 even when silica powder with an average particle size of 2.3 μm is used. Thus, in the self-disintegrating layer 20 according to this embodiment, it is preferable to use silica powder having an average particle size of 4 μm or more in order to make the compressive strength after firing 5 MPa or less. However, even when silica powder having an average particle size of less than 4 μm is used, the compressive strength after firing can be made 5 MPa or less by controlling the firing temperature.

[0034] In addition, in the support material 2 according to this embodiment, in order to reduce the amount of waste material, it is preferable that the self-disintegrating layer 20 is made of a material suitable for recovery and reuse. Here, in order to recover and reuse the self-disintegrating layer 20, it is required that there is no significant change in the particle diameter of the high-melting-point inorganic filler before and after firing. If the variation in the particle diameter of the high-melting-point inorganic filler after firing becomes large, it becomes difficult to control the thermal deformation and firing shrinkage, and it becomes unsuitable for reuse. Therefore, in this embodiment, as the high-melting-point inorganic filler of the self-disintegrating layer 20, one is used that has an increase rate of the average particle diameter (cumulative 50%) after firing of 150% or less and an average particle diameter of 40 μm or less. EXAMPLES

[0035] In this example, 3 mol Y-zirconia powder (average particle size: 0.71 μm) was used as the ceramic powder for the ceramic shaped body 1 and the shrinkage relaxation layer 10, and silica powder (average particle size: 2.3 to 34.5 μm) was used as the high melting point inorganic filler for the self-collapsing layer 20. In addition, the resin binder used was an acrylic resin, an ethylene-vinyl acetate copolymer resin, or a polyethylene resin to which an appropriate amount of a lubricant and a plasticizer had been added.

[0036] A resin binder was mixed so that the zirconia powder or silica powder was 40% by volume, and the mixture was heated and kneaded at 150°C using a pressure kneader (Toshin, TD0.3-3). Zirconia filament material and silica filament material were prepared by extruding the mixture into rods with a diameter of approximately 3 mm using an extruder (product name "Noztek Pro HT", Noztek Corporation).

[0037] The ceramic model 1 and the support material 2 were modeled using a fused deposition modeling desktop 3D printer (product name "MF-2200D", manufactured by Muto Industries). This device has two modeling nozzles, and the ceramic model 1 and shrinkage relaxation layer 10 can be modeled by extruding ceramic filament material from one nozzle 1, and the self-disintegrating layer 20 can be modeled by extruding silica filament material from the other nozzle 2.

[0038] In this embodiment, the support material 2 of Examples 1 to 8 and Comparative Examples 1 to 4 was produced by using the above-mentioned fused deposition model desktop 3D printer to form the shrinkage relaxation layer 10 using the above-mentioned zirconia filament material and the self-disintegrating layer 20 using the above-mentioned silica filament material in the composition ratio shown in Table 1 below. In addition, in the support material 2 of Examples 1 to 8 and Comparative Examples 1 to 4, the self-disintegrating layer 20 is formed using silica powder having the average particle size shown in Table 1 below. [Table 1]

[0039] Next, based on the above Table 1, the thermal deformation rate L of the supporting material 2 during degreasing in Examples 1 to 8 and Comparative Examples 1 to 4 is D , the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S The results of measuring the compressive strength of the self-disintegrating layer 20 after firing and the rate of change in particle size of the self-disintegrating layer 20 before and after firing will be described below.

[0040] First, the thermal deformation rate L of the support material 2 during degreasing D , the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S The thermal deformation rate L of the support material 2 during degreasing is explained. D , the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S For the measurements, a modeling nozzle with a diameter of 1.0 mm was used, and support materials 2 for Examples 1 to 8 and Comparative Examples 1 to 4 were modeled to have dimensions of approximately 3 mm wide x 3 mm long x 3 mm high under conditions of a layer pitch of 150 μm, a modeling nozzle temperature of 120°C, and a modeling table temperature of 75°C.

[0041] In addition, the thermal deformation rate L D and the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing, L SFor the evaluation, a thermomechanical analyzer (product name "TMA402 F1 Hyperion", manufactured by NETZSCH) was used. Specifically, an alumina push rod was attached to the thermomechanical analyzer, and the lengths of the support materials 2 of Examples 1 to 8 and Comparative Examples 1 to 4 were measured under the conditions of a temperature rise rate of 5°C / min, nitrogen atmosphere, and load of 5mN in the range of 25°C to 600°C, a temperature rise rate of 5°C / min, air atmosphere, and load of 5mN in the range of 600°C to 1000°C, and a temperature rise rate of 1°C / min, air atmosphere, and load of 5mN in the range of 1000°C to 1400°C.

[0042] Based on the measured lengths of the supporting materials 2 in Examples 1 to 8 and Comparative Examples 1 to 4, the thermal deformation rates L of the supporting materials 2 during degreasing in Examples 1 to 8 and Comparative Examples 1 to 4 were calculated by the following formula (1). D was calculated. Thermal deformation rate L of support material 2 during degreasing D (%) = (L1 - L0) / L0 × 100 (1) In the above formula (1), L0 is the sample length (μm) of the support material 2 in Examples 1 to 8 and Comparative Examples 1 to 4 at room temperature, and L1 is the sample length (μm) of the support material 2 in Examples 1 to 8 and Comparative Examples 1 to 4 when the amount of deformation is largest in the range of 25 to 600°C.

[0043] Furthermore, the shrinkage rate L of the ceramic body 1 during firing is calculated by the following formulas (2) and (3). S1 and the shrinkage rate L of support material 2 during firing S2 By calculating the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing, L S (L S =L S1- L S2 ) was calculated. Shrinkage rate L of ceramic molded body 1 during firing S1 (%)=(L 31 -L 21 ) / L 21 ×100 …(2) Shrinkage rate L of support material 2 during firing S2 (%)=(L 32 -L 22 ) / L 22×100 …(3) In the above formula (2), L 21 is the sample length (μm) of the ceramic shaped body 1 at the temperature (1000°C) when zirconia begins to shrink during firing, and L 31 is the sample length (μm) of the ceramic shaped body 1 at the recovery temperature (1150 to 1400° C.) of the support material 2 shown in Table 1. In addition, in the above formula (3), L 22 is the sample length (μm) of the support material 2 in Examples 1 to 8 and Comparative Examples 1 to 4 at the temperature (1000 ° C.) at which zirconia begins to shrink during firing, and L 32 is the sample length (μm) of the supporting material 2 in Examples 1 to 8 and Comparative Examples 1 to 4 at the recovery temperature of the supporting material 2 (1150 to 1400° C.) shown in Table 1 above.

[0044] Here, the thermal deformation rate L of the support material 2 during degreasing D is calculated by the above formula (1). However, if the supporting material 2 is heated to 600°C or less in the degreasing process, the organic matter such as the binder resin in the supporting material 2 is thermally decomposed and burned by the heat, and the supporting material 2 shrinks. Therefore, in Table 1 above, the thermal deformation rate L D However, in the present invention, the "thermal deformation rate during degreasing of the supporting material 2" means the rate at which the supporting material 2 is deformed in the degreasing process, so in this embodiment, the thermal deformation rate L D In this case, as shown in Table 1 above, in Examples 1 to 8, the thermal deformation rate L D It was found that the absolute value of was within 10%. In addition, as shown in Table 1 above, the difference in shrinkage rate L between the support material 2 and the ceramic molded body 1 during firing S (L S1 -L S2) was within 4% at the recovery temperature (1150 to 1200°C) at which the supporting material 2 was removed. This shows that the supporting material 2 in Examples 1 to 8 was able to suppress melting during degreasing, was able to shrink in accordance with the ceramic shaped body 1 during firing, and was able to continuously support the ceramic shaped body 1 during the degreasing and firing processes.

[0045] On the other hand, in Comparative Examples 1 to 4, the thermal deformation rate L D The absolute value of exceeds 10%, or the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S (L S1 -L S2 ) exceeded 4% at the recovery temperature at which the supporting material 2 was removed, which raised the risk of not being able to continuously support the ceramic shaped body 1 in the degreasing and firing process. That is, in Comparative Examples 1 to 4, the supporting material 2 was produced in the same manner as in Examples 1 to 8, except for the following points. Specifically, in Comparative Example 1, the constituent ratio of the self-disintegrating layer 20 in the supporting material 2 was set to 80%, exceeding the upper limit of 60%, and in Comparative Examples 2 and 3, the recovery temperature of the supporting material 2 was set to 1300°C and 1400°C, respectively, which are higher than 1200°C, and in Comparative Example 4, the supporting material 2 was produced from only the self-disintegrating layer 20.

[0046] As shown in Table 1 above, in Comparative Examples 1 and 4, the thermal deformation amount L of the support material 2 during degreasing D The absolute value of the shrinkage ratio L between the ceramic body 1 and the support material 2 during firing was greater than 10%, and there was a risk of the support material 2 melting and collapsing. S (L S1 -L S2 ) became larger than 4%, and there was a risk of the ceramic body 1 being destroyed during firing. D The absolute value of exceeds 10%, or the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S (L S1 -L S2) exceeded 4% at the recovery temperature at which the support material 2 was removed, creating a risk that the ceramic body 1 would not be able to be continuously supported during the degreasing and firing process.

[0047] Next, the compressive strength of the self-disintegrating layer 20 (Examples 1 to 8 and Comparative Examples 1 to 4) after firing, which constitutes the support material 2, and the rate of change in particle size of the self-disintegrating layer 20 before and after firing will be described. In the evaluation of the compressive strength and rate of change in particle size of the self-disintegrating layer 20 after firing, a shaping nozzle with a diameter of 1.0 mm was used, and the self-disintegrating layer 20 was shaped to have a width of approximately 3 mm, a length of 3 mm, and a height of 3 mm under conditions of a layer pitch of 200 μm, a shaping nozzle temperature of 120 ° C, and a shaping table temperature of 75 ° C. Then, in an air atmosphere, the self-disintegrating layer 20 was sintered at a predetermined temperature for 1 hour at a heating rate of 1 ° C. / min to obtain the self-disintegrating layer 20 (Examples 1 to 8 and Comparative Examples 1 to 4) used in the support material 2 after firing.

[0048] The compressive strength (MPa) of the self-disintegrating layer 20 used in the support material 2 after firing was measured by applying pressure to Examples 1 to 8 and Comparative Examples 1 to 4 at a crosshead speed of 0.5 mm / min using a universal material testing machine (product name "5566", manufactured by Instron Corporation) and measuring the maximum load until the test pieces were compressed and broken (n=7). The compressive strength of the support material 2 after firing was calculated by the following formula (4). Compressive strength of support material 2 after firing (MPa) = breaking load (N) / cross-sectional area of ​​test piece (mm 2 ) …(4)

[0049] Furthermore, the self-disintegrating layers 20 of Examples 1 to 8 and Comparative Examples 1 to 4 used in the compressive strength measurements were collected, and the particle diameter of the high-melting-point inorganic filler in the self-disintegrating layers 20 was measured. The particle size change rate of the collected high-melting-point inorganic filler was measured using a particle size distribution measuring device (product name "Microtrac HRA9320", manufactured by Microtrac-Bell) with water as the dispersion medium and a refractive index of 1.54. The particle size change rate (%) of the high-melting-point inorganic filler before and after firing was calculated by the following formula (5). The rate of change in particle size of high melting point inorganic filler before and after firing (%) = x / x0 × 100 … (5) In the above formula (5), x0 is the average particle size (μm) of the high-melting point inorganic filler raw material powder, and x is the average particle size (μm) of the high-melting point inorganic filler after recovery.

[0050] As shown in Table 1 above, in Examples 1 to 8, the compressive strength of the self-disintegrating layer 20 after firing was 5 MPa or less. In addition, in Examples 1 to 8, the particle size change rate of the recovered high melting point inorganic filler was 150% or less. As described above, it was found that in the support material 2 of Examples 1 to 8, the self-disintegrating layer 20 can be easily removed from the ceramic shaped body 1, and the self-disintegrating layer 20 can be appropriately recovered and reused. On the other hand, as shown in Table 1 above, in Comparative Example 2, the compressive strength was greater than 5 MPa, and there was a risk that the self-disintegrating layer 20 could not be easily removed from the ceramic shaped body 1. In addition, in Comparative Example 3, the particle size change of the high melting point inorganic filler exceeded 150%, and the support material 2 was no longer suitable for reuse.

[0051] Next, Example 9 and Comparative Example 5 will be described. Table 2 below shows the composition ratio and each physical property value of the support material 2 of Example 9 and Comparative Example 5. In Example 9 and Comparative Example 5, a rectangular parallelepiped ceramic shaped body 1 with dimensions of 14 mm wide x 20 mm long x 12 mm high and a cavity of 10 mm wide x 20 mm long x 10 mm high inside was shaped while applying the support material 2 to the cavity part so that the width was 6 mm wide x 20 mm long x 10 mm high and the filling rate was 50%. The shaping conditions were as follows: a shaping nozzle with a diameter of 1.0 mm was used, the layer pitch was 200 μm, the shaping nozzle temperature was 120 ° C, and the shaping table temperature was 75 ° C. Then, the ceramic shaped body 1 was heated to a predetermined temperature under the conditions of an air atmosphere and a heating rate of 1 ° C. / min, and then cooled, and the support material 2 was appropriately recovered, and the deformation of the ceramic shaped body 1 during firing after the support material was recovered was evaluated. [Table 2]

[0052] In Example 9, the thermal deformation rate L of the support material 2 during degreasing DThe absolute value of is within 10%, and the difference in shrinkage rate between the support material 2 and the ceramic molded body 1 during firing L S (L S1 -L S2 ) was within 4%. Furthermore, the compressive strength of the supporting material 2 after firing was 5 MPa or less, and the particle size change rate of the recovered high melting point inorganic filler was 150% or less. In Example 9, the supporting material 2 was heated to the recovery temperature (1150°C) of the supporting material 2, and then cooled to room temperature, allowing the supporting material 2 to be easily recovered. Furthermore, after recovering the supporting material 2, the ceramic shaped body 1 was heated to 1400°C and fired at a holding temperature of 1 hour, but no deformation was observed in the ceramic shaped body 1.

[0053] In contrast, in Comparative Example 5, the ceramic body 1 and the supporting material 2 were heated to the recovery temperature (1150° C.) and then cooled to room temperature, and the supporting material 2 was recovered. In Comparative Example 5, the thermal deformation rate L D The absolute value of is within 10%, and the difference in shrinkage rate L between the support material 2 and the ceramic molded body 1 during firing is S (L S1 -L S2 ) was within 4%. In addition, the compressive strength of the supporting material 2 after firing was 5 MPa or less, and the particle size change rate of the recovered high melting point inorganic filler was 150% or less. However, in Comparative Example 5, since the composition ratio of the self-disintegrating layer 20 was less than 5%, the supporting material 2 was burned and caught on the ceramic shaped body 1, and as a result, the supporting material 2 could not be removed cleanly.

[0054] As described above, in this embodiment, the ceramic model 1 is produced using a support material 2 having a shrinkage relaxation layer 10 that shrinks in response to the shrinkage of the ceramic model 1 during firing, and a self-disintegrating layer 20 that is made of a filament material that is a mixture of a high-melting-point inorganic filler and a thermoplastic resin and can be peeled off from the ceramic model 1 after firing. In particular, the support material 2 according to this embodiment has a thermal deformation rate of the support material 2 during degreasing that is within 10%, and the difference in shrinkage rate between the ceramic model 1 and the support material 2 during firing, L S (L S1 -LS2 ) is within 4% at each temperature at which the supporting material 2 is removed, it is possible to prevent the supporting material 2 from melting and collapsing during degreasing, and it is possible for the supporting material 2 to shrink in accordance with the ceramics molded body 1 during firing, thereby continuously supporting the ceramics molded body 1 during the degreasing and firing steps. As a result, it is possible to appropriately fabricate ceramics molded bodies 1 having an overhang shape, a bridge shape, and the like.

[0055] Furthermore, in the supporting material 2 according to this embodiment, the compressive strength after firing is set to 5 MPa or less, and the particle size change rate of the recovered high-melting-point inorganic filler is set to 150% or less. This allows the supporting material 2 to be easily removed from the ceramic shaped body 1 after firing, and also allows the self-disintegrating layer 20 to be efficiently recovered and the high-melting-point inorganic filler used in the self-disintegrating layer 20 to be reused. As a result, the material can be recycled, and the manufacturing cost can be reduced while being environmentally friendly.

[0056] Although the preferred embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the description of the above embodiment. Various modifications and improvements can be made to the above embodiment, and such modifications and improvements are also included in the technical scope of the present invention. [Explanation of symbols]

[0057] 1…Ceramics model 2…Support material 10...Shrinkage relief layer 20...Self-destruction layer

Claims

1. A method for producing a three-dimensional additive manufacturing object, comprising forming a support material that supports the three-dimensional additive manufacturing object below the three-dimensional additive manufacturing object during a manufacturing process of the three-dimensional additive manufacturing object by a material extrusion method, the method comprising the steps of: The method for producing a three-dimensional additive model includes forming a support material having a shrinkage relaxation layer that shrinks in response to the shrinkage of the three-dimensional additive model during firing, and a self-disintegrating layer that is made of a filament material that is a mixture containing a high-melting point inorganic filler and a thermoplastic resin and can be peeled off from the three-dimensional additive model after firing, wherein the self-disintegrating layer shrinks in response to the shrinkage of the three-dimensional additive model during firing, but has a smaller shrinkage rate during firing than the shrinkage relaxation layer.

2. The three-dimensional additively manufactured object is a ceramics manufactured object, and is manufactured using a ceramics material containing ceramic powder; The method for producing a three-dimensional additive manufacturing object according to claim 1 , wherein the shrinkage relaxation layer is formed from a filament material that is a mixture containing a ceramic powder and a thermoplastic resin.

3. The method for producing a three-dimensional additive manufacturing object according to claim 2 , wherein the filament material forming the shrinkage relaxation layer has a ceramic powder content of 30 volume % or more.

4. The method for producing a three-dimensional additive manufacturing object according to claim 1 , wherein the filament material forming the self-disintegrating layer has a content of the high melting point inorganic filler of 30 volume % or more.

5. The method for producing a three-dimensional additive manufacturing object according to claim 1 , wherein the high melting point inorganic filler has a melting temperature that is 100° C. or more higher than a firing temperature of the three-dimensional additive manufacturing object.

6. 6. The method according to claim 1, wherein the high melting point inorganic filler has an average particle size of 1 μm or more and 40 μm or less, and an increase in the average particle size before and after firing is 150% or less.

7. The method for producing a three-dimensional additive manufacturing object according to any one of claims 2 to 6, wherein the filament material forming the shrinkage relaxation layer and / or the self-disintegrating layer has a viscosity of 20 to 500 Pa·s at the modeling temperature.

8. The method for producing a three-dimensional additive manufacturing object according to claim 1 , wherein the self-disintegrating layer has a compressive strength of 5 MPa or less after firing.

9. The method for producing a three-dimensional additive manufacturing object according to claim 1 , wherein the self-disintegrating layer accounts for 5% to 60% of the supporting material.

10. The support material is The rate of thermal deformation during degreasing is within 10%. The method according to claim 1 , wherein a difference in shrinkage rate between the supporting material and the three-dimensional additive manufacturing object during firing is within 4%.

11. The method according to claim 1 , wherein the three-dimensional additive manufacturing object is a manufacturing object that is shaped into an overhang shape or a bridge shape.

12. A support material that supports a three-dimensional additive manufacturing object under a lower portion of the three-dimensional additive manufacturing object during a manufacturing process of the three-dimensional additive manufacturing object by a material extrusion method, a shrinkage relaxation layer that shrinks in response to shrinkage of the three-dimensional additive manufacturing body during firing; a self-disintegrating layer that is formed from a filament material that is a mixture containing a high melting point inorganic filler and a thermoplastic resin, prevents adhesion between the three-dimensional additive manufacturing object and the shrinkage relaxation layer, and is peelable from the three-dimensional additive manufacturing object after firing; The self-disintegrating layer shrinks in response to shrinkage of the three-dimensional additive manufacturing body during firing, but has a smaller shrinkage rate during firing than the shrinkage relaxation layer.

13. The supporting material according to claim 12 , wherein the three-dimensional additive manufacturing object is an overhang-shaped or bridge-shaped manufactured object.

14. 14. The supporting material according to claim 12 or 13, wherein the material extrusion method is a method for producing a molded object by extruding a plastic material from a nozzle and laminating it in a three-dimensional additive manufacturing (AM) technology.

15. The support material according to any one of claims 12 to 14, wherein the material of the support material is a mixture containing a ceramic powder and a thermoplastic resin for the shrinkage relaxation layer, and a mixture containing a high melting point inorganic filler and a thermoplastic resin for the self-disintegrating layer.

16. an article comprising: a ceramic three-dimensional additive manufactured body shaped by an extrusion method with a modeling material including a sinterable ceramic powder material for forming a final part at a sintering temperature, the ceramic three-dimensional additive manufactured body including one or more resin binders that hold the powder material into a net-shape object before densifying the powder material into a final part; and a support material for the ceramic three-dimensional additive manufactured body arranged adjacent to a surface of the ceramic three-dimensional additive manufactured body and supporting the ceramic three-dimensional additive manufactured body underside during at least one of degreasing and sintering of the manufactured body, the support material having both a shrinkage relief layer that shrinks in accordance with the shrinkage of the three-dimensional additive manufactured body during firing, and a self-disintegrating layer that prevents adhesion between the three-dimensional additive manufactured body and the shrinkage relief layer and is peelable from the three-dimensional additive manufactured body after firing, the self-disintegrating layer shrinking in accordance with the shrinkage of the three-dimensional additive manufactured body during firing, but having a smaller shrinkage rate during firing than the shrinkage relief layer.

17. The support material is a material made of a mixture containing a ceramic powder of the shrinkage relaxation layer or a high-melting point inorganic filler of the self-disintegrating layer and a thermoplastic resin, and the ceramic powder of the shrinkage relaxation layer or the high-melting point inorganic filler of the self-disintegrating layer is a mixture having a content of 30 volume % or more, and a filament made of this mixture in a strand shape is made of a material having a fluidity of a viscosity of 20 to 500 Pa s at the heating temperature during molding. The article according to claim 16.

18. The article according to claim 16 or 17, wherein the high-melting point inorganic filler of the self-disintegrating layer has a melting temperature 100° C. or more higher than the desired sintering temperature of the shaped body, has an average particle diameter of 1 μm or more and 40 μm or less, the relative density of the ceramic shaped body when the support is removed in the firing process is 50% or more, the compressive strength of the self-disintegrating layer at that time is 5 MPa or less, and the degree of adhesion of the inorganic filler that is the self-disintegrating layer is such that the change in the average particle diameter before firing is 150% or less, and the article can be recovered and recycled.

19. 19. An article according to any one of claims 16 to 18, which is a composite support material for ceramic modeling, in which the composition ratio of the self-disintegrating layer in the composite support material is 5% or more and 60% or less, the thermal deformation of the composite support material during degreasing is 10% or less, and the difference in shrinkage rate between the ceramic modeled body and the composite support during firing is within 4%.

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