JP2019081958A - Sintering shaping method, liquid binder, and sintered shaped article - Google Patents

Abstract

To provide a three-dimensional shaped article having higher strength and higher definition.SOLUTION: A sintering shaping method includes: a shaping layer formation step of forming a shaping layer 5 using a sintering shaping material containing inorganic particles 2a; a step of applying a liquid binder 8 containing inorganic particles 8a to a desired region of the shaping layer 5; a step of curing the applied liquid binder 8 to form a shaping cross-sectional layer (shaping part 5a); a step of removing that region (non-shaping part 5b) of the shaping layer 5 to which the liquid binder 8 is not applied; and a step of heating the stacked shaping cross-sectional layers to sinter them.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a sinter molding method, a liquid binder used for sinter molding, and a sinter molded article.

  One of the modeling methods for forming a three-dimensional three-dimensional model (shaped object) is the layered modeling method. As the layer-forming method, for example, an optical forming method of selectively curing by a laser while laminating a photocurable resin to form cross-sectional layers of a shaped object, and selectively welding and solidifying a laser while laminating a powder material Powder formation method to form each layer, melt deposition method to form each layer by extruding and depositing thermoplastic material by heating and extruding thermoplastic material, sheet material such as paper is cut into a cross-sectional shape of the model and laminated A sheet laminating method formed by bonding has been proposed.

Patent Document 1 discloses the following three-dimensional printing technique (a method of manufacturing a three-dimensional structure).
First, a powder material containing ceramic, metal, etc. is deposited in layers. A binder material is then applied to selected areas of the layer of powder material, which bonds the powder materials together. Then, the binder material that has penetrated into the voids between the powder materials joins the powder materials to form a shaped object corresponding to the two-dimensional cross-sectional layer of the three-dimensional object. By alternately repeating the deposition of the powder material and the application of the binder material, a two-dimensional cross-sectional layer is laminated, and a three-dimensional shaped object is formed (shaped).

JP 6-218712 A

  However, the method for producing a three-dimensional structure of Patent Document 1 is to bond powder materials together with a binder material applied to a powder material (shape material), and for example, it is possible to selectively apply laser light. The method of welding and solidifying the metal material (the molding material) is different from the method of solidifying the molding material, that is, the form in which the molding material is connected. The strength of the obtained three-dimensional structure differs greatly depending on the form of connection of the structure. In general, the forming method of bonding powder materials as in Patent Document 1 with a binder material is inferior in strength as compared with a method of welding and solidifying a metal material. Therefore, it has been considered to increase the strength of the three-dimensional structure by using a ceramic or metal material as the powder material and introducing a sintering process to improve the bond between the powder materials. However, according to this method, the material for bonding the powder materials to each other is removed (degreased) by thermal decomposition and the powder materials sinter together, so the dimensional shrinkage of the three-dimensional structure becomes large, causing a change in shape. There was a problem that it was easy. That is, when sintered to increase its strength, it is difficult to maintain the dimensions of the base, and the three-dimensional structure formed by the method of manufacturing a three-dimensional structure of Patent Document 1 has high strength and high strength. There has been a problem that the formation of a fine three-dimensional structure can not be stabilized.

  The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following applications or embodiments.

  Application Example 1 In the sinter modeling method according to this application example, in a forming layer forming step of forming a forming layer using a sinter forming material containing a first inorganic particle, and a desired region of the forming layer. A step of applying a liquid binder containing second inorganic particles, a step of curing the applied liquid binder to form a shaped cross-sectional layer, and the liquid binder of the shaped layer is not applied It is characterized by including the process of removing a field, and the process of heating and sintering processing the above-mentioned modeling section layer.

  In the sintering and shaping method of this application example, a second inorganic particle is contained in a desired region of a modeling layer forming step of forming a modeling layer using a sintered modeling material containing a first inorganic particle, and Applying the liquid binder, and curing the applied liquid binder to form the shaped cross-section layer. By including these steps, the shaped cross-sectional layer can further include a second inorganic particle in addition to the first inorganic particle. Moreover, the process of removing the area | region to which the liquid binder of the modeling layer is not provided, and the process of heating and sintering the laminated modeling cross section layer are included. By including these steps, the three-dimensional structure is formed by the laminated forming cross-sectional layer, and the strength can be enhanced by performing a sintering process.

  According to this application example, in order to further include the second inorganic particles in addition to the first inorganic particles, the density of the inorganic particles (first and second inorganic particles) (volume filling) Three-dimensional object with a high rate) can be obtained. As a result, the dimensional change (shrinkage) of the three-dimensional structure in the sintering process is further suppressed, and a three-dimensional structure with higher dimensional accuracy can be formed.

  Application Example 2 In the sintering and shaping method according to the application example, in the step of performing the sintering process, the second inorganic particle is lower than a sintering start temperature at which the first inorganic particle starts sintering. The method is characterized by including a heating step of fusing the first inorganic particles at a temperature.

  According to this application example, the step of performing the sintering process fuses the second inorganic particle to the first inorganic particle at a temperature lower than the sintering start temperature at which the first inorganic particle starts sintering. Thus, the second inorganic particles can function as a binder for binding the first inorganic particles to each other. As a result, the dimensional change (shrinkage) of the three-dimensional structure in the sintering process is further suppressed, and a three-dimensional structure with higher dimensional accuracy can be formed.

  Application Example 3 In the sinter modeling method according to the application example, the sinter modeling material includes a thermoplastic binder that bonds the first inorganic particles to each other, and the sinter forming step includes the sintering step. The method is characterized in that the shaping material is heated to a temperature equal to or higher than the melting point of the thermoplastic binder.

  According to this application example, the sintered and shaped material contains a thermoplastic binder that bonds the first inorganic particles to each other. In the shaping layer forming step, the sintered shaping material is heated to a temperature equal to or higher than the melting point of the thermoplastic binder. By heating the sintered shaped material to a temperature higher than the melting point of the thermoplastic binder, the flowability of the sintered shaped material is increased, so that the sintered shaped material can be spread more easily, and the dimensional accuracy is higher. It is possible to form a shaping layer. In addition, in the heating process in which the sintering process proceeds, the thermoplastic binder contributes to the binding between the first inorganic particles until the thermoplastic binder is thermally decomposed (until the degreasing is completed). According to this application example, as a result of these, it is possible to form a three-dimensional structure with higher dimensional accuracy.

  Application Example 4 In the sintering and shaping method according to the application example, the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles contained in the shaped cross-sectional layer is 400: 1 to 3: It is characterized by being in the range of 1.

  According to this application example, since the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles contained in the shaped cross-sectional layer is in the range of 400: 1 to 3: 1, the first inorganic particles are Can be shaped as a main material. Moreover, a three-dimensional structure having a higher density of inorganic particles can be obtained by the second inorganic particles applied to the main material. As a result, the dimensional change (shrinkage) of the three-dimensional structure in the sintering process is further suppressed, and a three-dimensional structure with higher dimensional accuracy can be formed.

  Application Example 5 In the sintering method according to the application example, the ratio of the average particle diameter of the first inorganic particles to the average particle diameter of the second inorganic particles is in the range of 50000: 1 to 10: 1. It is characterized by being.

  According to this application example, the ratio of the average particle diameter of the first inorganic particles to the average particle diameter of the second inorganic particles is in the range of 50000: 1 to 10: 1. It can be shaped as a material, and the second inorganic particles to be applied easily penetrate between the main material (first inorganic particles) together with the liquid binder. As a result, it is possible to form a shaped cross-section layer in which the density of inorganic particles is more uniformly increased, and to obtain a three-dimensional structure in which the density of inorganic particles is more uniformly increased. As a result, the dimensional change (shrinkage) of the three-dimensional structure in the sintering process is further suppressed, and a three-dimensional structure with higher dimensional accuracy can be formed.

Application Example 6 In the sintering and shaping method according to the application example, an average particle diameter of the second inorganic particles is 0.001 μm to 10 μm.

  According to this application example, the average particle diameter of the second inorganic particles is 0.001 μm to 10 μm. That is, since the second inorganic particle is an inorganic particle having a size of the nanoparticle level (1 to 10,000 nm), the liquid binder is applied to a desired region of the sintered and shaped material containing the first inorganic particle. When it does, it can be easily inserted in the void of the 1st inorganic particle. That is, the density of the inorganic particles (first and second inorganic particles) can be increased more uniformly, and a three-dimensional structure with the density of the inorganic particles increased more uniformly can be obtained. In addition, since the second inorganic particle is an inorganic particle having a size at the nanoparticle level, the sintering start temperature of the three-dimensional structure can be lowered by applying the second inorganic particle. That is, because sintering of the second inorganic particle and the first inorganic particle is started at a lower temperature due to the size effect of the second inorganic particle, for example, the first inorganic particle and the second inorganic particle When the same metal is used, sintering can be started at a lower temperature as compared to the sintering start temperature of the first inorganic particle alone. As a result, it is possible to suppress the change in dimension in the heating step for the sintering process (for example, the change in dimension due to the thermal decomposition (defatting) of the binder material included in the sintered shaped material) from a lower temperature. The dimensional change (shrinkage) of the three-dimensional structure is further suppressed, and a three-dimensional structure with higher dimensional accuracy can be formed.

Application Example 7 In the sintering and shaping method according to the application example, the first inorganic particles and the second inorganic particles are ceramic particles or metal particles.

  According to this application example, since the first inorganic particles and the second inorganic particles are ceramic particles or metal particles, they can perform a sintering process on the three-dimensional structure of the main material, As a result, a stronger three-dimensional object can be obtained.

  Application Example 8 The liquid binder according to this application example applies a liquid binder to a desired region of the sintered shaped material containing the first inorganic particles, and hardens the applied liquid binder. And a second inorganic particle is included in the production of the three-dimensional structure including the steps.

  The liquid binder of this application example is a liquid binder used in the production of a three-dimensional structure, which is applied to a desired region of the sintered shaped material including the first inorganic particles, and the applied region is cured. Thus, an area constituting the three-dimensional structure is formed. Further, the liquid binder contains second inorganic particles. That is, according to the liquid binder of this application example, in addition to the first inorganic particles, the second inorganic particles can be further contained in the desired region for forming the three-dimensional structure. As a result, a three-dimensional structure with a higher density of inorganic particles can be obtained.

  Application Example 9 In the liquid binder according to the application example described above, an average particle diameter of the second inorganic particles is 0.001 μm to 10 μm.

  According to this application example, the average particle diameter of the second inorganic particles contained in the liquid binder is 0.001 μm to 10 μm. That is, since the second inorganic particle is an inorganic particle having a size of the nanoparticle level, the first binder particle is applied when a liquid binder is applied to a desired region of the sintered and shaped material containing the first inorganic particle. Can be easily inserted into the voids of the inorganic particles of That is, the density of the inorganic particles (first and second inorganic particles) can be increased more uniformly, and a three-dimensional structure with the density of the inorganic particles increased more uniformly can be obtained.

  Application Example 10 In the liquid binder according to the application example, the second inorganic particles are ceramic particles or metal particles.

  According to this application example, for example, the first inorganic particle is a ceramic particle similar to the second inorganic particle, or the first inorganic particle is a metal particle similar to the second inorganic particle In the above, it is possible to carry out a sintering process of a three-dimensional structure mainly composed of these, and as a result, it is possible to obtain a stronger three-dimensional structure.

  Application Example 11 A sintered molded article according to this application example is characterized in that it is shaped by the sinter molding method described in any one of application examples 1 to 7.

  The three-dimensional object of the sinter object formed by the sinter object forming method according to the application example is further suppressed in dimensional change (shrinkage) of the three-dimensional object when the sinter process is performed. Provided as a shaped object.

  Application Example 12 The sintered molded article according to this application example is characterized in that it is shaped using the liquid binder described in any one of Application Examples 8 to 10.

  The sintered shaped object shaped using the liquid binder described in the application example is provided as a three-dimensional shaped object with higher dimensional accuracy.

  Application Example 13 The sintered molded article according to this application example is included in the first inorganic particles contained in advance in the sintered molded material to be laminated, and in the liquid binder to be applied to the laminated sintered molded material. And a second inorganic particle.

  According to this application example, the sintered shaped article is the first inorganic particles contained in advance in the sintered shaped material to be laminated, and the second inorganic substance contained in the liquid binder applied to the sintered shaped material on the laminated side. And particles. That is, since the sintered molded article is configured to include the second inorganic particles in addition to the first inorganic particles, it is more inorganic than the sintered molded article configured of only the first inorganic particles. It is possible to obtain a sintered shaped article having a high packing ratio of particles.

Conceptual diagram showing the state of sintered shaped material at normal temperature A schematic diagram for explaining a sintering molding apparatus Conceptual diagram of the liquid binder according to the first embodiment Conceptual diagram showing application of a liquid binder to the desired area of the shaped layer Conceptual diagram comparing heat treatment process of degreasing and sintering with the prior art

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following is one embodiment of the present invention, and not intended to limit the present invention. In addition, in each following figure, in order to make an explanation intelligible, it may be described in the scale different from actual.

(Embodiment 1)
As Embodiment 1, a sinter modeling material, a sinter modeling apparatus, a “sinter modeling method”, a sinter modeling used in lamination modeling as one method for forming a three-dimensional model (sinter-shaped object) of a three-dimensional shape A "liquid binder" and a "sintered shaped article" shaped by these will be described.
As a method of additive manufacturing, a liquid binder is selectively applied to a thin layer made of a sintered modeling material by an inkjet method so as to form a cross-sectional shape of a three-dimensional structure, and a portion to which the liquid binder is applied is The method of forming a three-dimensional structure by laminating one after another while curing is used.
Each of these will be specifically described below.

<Sintered molding material>
FIG. 1 is a conceptual view showing a state of the sintered and shaped material 1 at normal temperature (15 to 25 ° C.).
The sintered molding material 1 is a material (main material) used when molding a three-dimensional three-dimensional model (sintered molding) by the lamination molding method, and the basics of the sintered molding by the sintered modeling material 1 To form each layer (hereinafter referred to as a shaped layer) for forming each cross-sectional shape of the sintered shaped article.
The sintered shaped material 1 is constituted of a powder material 2 composed of powder "first inorganic particles", a binder material 3 as a "thermoplastic binder", and the like.

Powder material 2 is a main constituent material of a sintered shaped product formed using sintered shaped material 1.
The powder material 2 is configured as an aggregate of inorganic particles 2a as "first inorganic particles". Metal particles and ceramic particles can be used for the inorganic particles 2a. The inorganic particles 2a have a substantially spherical shape with an average particle diameter of 0.1 μm to 30 μm. The average particle size is more preferably 1 μm or more and 15 μm or less. Moreover, it is more preferable that it is close to a true sphere shape. As a result, the controllability of the shape of the sintered formed article, in particular, the controllability of the shape of the side or the corner that defines the outer shape of the sintered formed thing is improved.

  In addition, the particle diameter of the inorganic particles 2a is preferably equal to or less than the average thickness of the shaped layer formed by the sintered and shaped material 1, and is more preferably 1/2 or less of the average thickness of the shaped layer. . Thereby, the density (volume filling rate) of the inorganic particle 2a in a modeling layer can be improved, and the mechanical strength of a sintered molded article can be improved by extension.

  In addition, it is preferable that the powder material 2 contain inorganic particles 2 a having particle sizes different from each other within the above range of particle sizes. The distribution of the particle size of the inorganic particles 2a may be a distribution close to a Gaussian distribution (normal distribution), or a distribution having a maximum value of the particle size distribution on the maximum diameter side or the minimum diameter side (piece Distribution).

  When the particle size of the inorganic particle 2a is a single value, the volume filling ratio by the inorganic particle 2a when forming the sintered shaped article exceeds 69.8% which is the theoretical value at the closest packing. In fact, the filling rate is about 50 to 60%. On the other hand, if inorganic particles 2a of different particle sizes are contained in powder material 2 (the particle sizes are distributed with a range), for example, inorganic particles 2a having relatively large particle sizes By arranging the inorganic particles 2 a having a relatively small particle diameter in the formed void, the volume filling rate is improved. Thereby, the mechanical strength of a sintered molded article can be improved. In this way, specifically, it is preferable that the volume filling rate be about 70%.

  For the powder material 2 (inorganic particles 2a), a stainless alloy powder is used as a preferred example. The powder material 2 is not limited to stainless alloy powder, and, for example, copper, bronze (Cu / Sn), brass (Cu / Zn), tin, lead, gold, silver, platinum, palladium, iridium, titanium Powders such as tantalum, iron and carbonyl iron, and metal alloy powders such as titanium alloy, cobalt alloy, aluminum alloy, magnesium alloy, magnesium alloy, iron alloy, nickel alloy, chromium alloy, silicon alloy, zirconium alloy, gold alloy, etc. It may be a magnetic alloy powder containing Fe / Ni, Fe / Si, Fe / Al, Fe / Si / Al, Fe / Co, Fe / Co / V, etc., or an intermetallic compound powder such as titanium aluminum. Moreover, in the case of a ceramic powder, an alumina powder, a zirconia powder, etc. may be sufficient.

  The binder material 3 is a thermoplastic polymer compound, and when the powder material 2 and the binder material 3 are mixed in the sintered and shaped material 1 and the inorganic particles 2a are dispersed substantially uniformly, the inorganic particles 2a are bound to each other. Have a function to As shown in FIG. 1, when the powder material 2 and the binder material 3 are mixed so as to be dispersed substantially uniformly, the binder material 3 binds, for example, the inorganic particles 2a as a flake-like binder flake 3a. There is.

For example, as a preferable example, polycaprolactone diol having a melting point of 55 ° C. to 58 ° C. and a thermal decomposition start temperature of about 200 ° C. is used as the binder material 3.
In addition, the binder material 3 is not limited to polycaprolactone diol, It has thermoplasticity solid at normal temperature, and the thing whose thermal decomposition start temperature is 50 degreeC or more and lower than the sintering temperature of the inorganic particle 2a is used. For example, ethylene vinyl acetate copolymer having a melting point of 50 to 100 ° C. and a thermal decomposition start temperature of about 250 ° C., polyethylene having a melting point of about 120 ° C. and a thermal decomposition start temperature of about 400 ° C. may be used.
Each is a solid such as waxy, vaseline-like or flake-like at normal temperature, and melts and becomes liquid when it exceeds the melting point.

  The higher the filling factor of the inorganic particles 2a constituting the powder material 2 in the sintered shaped article, the higher the accuracy concerning the shape of the sintered shaped article. Therefore, in order to increase the precision of the shape of the sintered shaped article, the volume occupied by the binder material 3 is smaller than the voids of the densely packed inorganic particles 2a so that the inorganic particles 2a are densely packed. A compounding ratio is preferred. Therefore, as a volume ratio of powder material 2: binder material 3, the range of 7: 3 to 9: 1 is preferable.

  The sintered molding material 1 may contain a solvent. As the solvent, an aqueous solvent containing a non-organic solvent such as water and an aqueous solution of an inorganic salt is preferable. As the aqueous solvent, water is more preferably used. By containing the solvent in the sintered modeling material 1, it is possible to more easily obtain a paste-like sintered modeling material in which the powder material 2 is uniformly dispersed. Moreover, since it becomes easy to spread a paste-like sintered modeling material more depending on a solvent, a modeling layer can be formed thinner.

<Sintering molding apparatus>
FIG. 2 is a schematic view for explaining the sinter modeling apparatus 100. As shown in FIG.
In FIG. 2, the Z-axis direction is the vertical direction, the -Z direction is the vertical direction, the Y-axis direction is the longitudinal direction, the + Y direction is the near direction, the X-axis direction is the lateral direction, the + X direction is the left direction, and the XY plane is The plane is parallel to the plane on which the sinter molding apparatus 100 is installed.

The sinter molding apparatus 100 is an apparatus for forming a three-dimensional three-dimensional model (sinter-shaped product) by the layered manufacturing method using the sinter molding material 1.
The sintering and shaping apparatus 100 controls the material supply unit 10, the heating unit 20, the spreading unit 30, the shaping unit 40, the drawing unit 50, the hardening unit 60, the revealing unit 70, the degreasing and sintering unit 80, and the like. A unit (not shown) is provided.

The material supply part 10 is a part which supplies the accommodated sintered modeling material 1 to the heating part 20, for example, is provided with the hopper 11 as shown in FIG. The hopper 11 supplies the sintered and shaped material 1 accommodated in the interior to the heating unit 20 from the material discharge port 12 located above the heating unit 20.
The material supply unit 10 is not limited to this configuration. For example, the material supply unit 10 includes a loading unit that loads and heats a cartridge containing the sintered modeling material 1, and sets the loaded cartridge to a temperature above the melting point of the binder material 3. It may be a configuration (not shown) in which the sintered modeling material 1 is rendered fluid and supplied to the heating unit 20 by heating.

  The heating unit 20 includes a hot plate 21 for heating and maintaining the sintered and shaped material 1 at a temperature equal to or higher than the melting point of the binder material 3. The sintered shaped material 1 supplied from the material supply unit 10 melts the binder material 3 on the hot plate 21 to form the flowable shaped material 4 having fluidity.

The spreader 30 includes a squeegee 31.
The squeegee 31 is an elongated plate member movable in the X-axis direction and extending in the Y-axis direction, and moves the fluid modeling material 4 to slide in the -X direction on the XY plane. Thus, the fluid modeling material 4 can be spread thinly.
The spreader 30 spreads the fluid modeling material 4 on the stage 41 of the modeling unit 40 to form the modeling layer 5.
In addition, the method of spreading the flowable modeling material 4 thinly is not limited to the method of spreading by the squeegee 31. For example, a method of spreading by pressing with air or a method of spreading by centrifugal force by rotating a stage provided with a heating unit may be used.

  The modeling unit 40 includes a stage 41, a stage elevating mechanism 42 that raises and lowers the stage 41 in the Z-axis direction, and the like. The stage 41 forms an XY plane in which the flowable molding material 4 is spread by the squeegee 31 at an initial position located in the same plane (the same height) as the hot plate 21.

  The stage 41 is maintained at normal temperature (for example, room temperature), and the fluid modeling material 4 spread on the stage 41 loses fluidity when it is below the melting point, and is modeled newly on the modeling layer 5 previously formed. It is laminated as layer 5. The spreadable flowable molding material 4 may be left until it is below the melting point or may be cooled. As a cooling method, a method of blowing a cooled air at normal temperature or cooling to the shaping layer 5 using a fan or a method of bringing a cooling plate into contact with the shaping layer 5 can be used.

  The stage lifting mechanism 42 lowers the stage 41 according to the layer thickness of the shaping layer 5 which is spread and formed on the stage 41. As the stage 41 descends, the surface of the shaping layer 5 is positioned in the same plane (at the same height) as the hot plate 21, and the flowable shaping material 4 is spread again by the squeegee 31 to form the shaping An XY plane to be stacked as the layer 5 is configured.

The drawing unit 50 includes a discharge head 51, a cartridge loading unit 52, a carriage 53, a carriage moving mechanism 54 (not shown), and the like.
The ejection head 51 is provided with a nozzle (not shown) for ejecting the liquid binder 8 onto the shaping layer 5 on the stage 41 by an inkjet method.
The cartridge loading unit 52 loads the ink cartridge containing the liquid binder 8 and supplies the liquid binder 8 to the ejection head 51.
The carriage 53 mounts the ejection head 51 and the cartridge loading unit 52 (that is, an ink cartridge), and moves the upper surface of the stage 41 by the carriage moving mechanism 54.
The carriage moving mechanism 54 has an X-Y axis linear motion conveying mechanism, and moves (scans) the carriage 53 in the XY plane.

  The drawing unit 50 forms a desired image (image reflecting the cross-sectional shape of the sintered formed article) by the liquid binder 8 on the shaped layer 5 spread on the stage 41 under the control of the control unit. Specifically, the control unit has the image information of each cross-sectional layer constituting the sintered molded article input in advance, and the position to move the discharge head 51, the liquid binder 8 according to the image information. The timing of discharge is controlled, and the liquid binder 8 is applied to the corresponding modeling layers 5.

  The curing unit 60 includes a liquid binder curing mechanism 61 that cures the liquid binder 8 applied to the shaped layer 5 to form the shaped cross section layer 6. For example, when using a material containing an ultraviolet curable resin as the liquid binder 8, the liquid binder curing mechanism 61 is constituted by an ultraviolet irradiator, and for example, the liquid binder 8 contains a thermosetting resin. In the case of using a material, the liquid binder curing mechanism 61 is configured by a heating device.

The revealing part 70 is a part that removes the area (non-shaped part 5b) to which the liquid binder 8 of the shaped layer 5 is not applied to reveal the shaped object 7, and is disposed on the −X side of the shaped part 40. It is done. The revealing portion 70 includes unnecessary portion removing means (not shown) such as a cutting knife and a rotating brush, and the forming portion 70 (laminate of the forming layer 5) is transported by the transport mechanism 43 from the modeling portion 40. Perform appearance processing.
In addition, since the development process may be a method of washing away the non-modeling part 5b by water washing etc. when the binder material 3 is water-soluble, it is a structure provided with a water washing tank etc. as an unnecessary part removal means. It is good.

  The degreasing / sintering portion 80 is a portion for degreasing and sintering the shaped object 7 (the layered shaped sectional layer 6) from which the non-shaped portion 5b is removed, and is disposed on the −X side of the revealing portion 70 ing. The degreasing / sintering unit 80 includes a degreasing / sintering furnace 81, a heating heater 82, a degreasing gas supply facility 83, an exhaust facility 84, and the like, with respect to the object 7 transported from the revealing unit 70 by the transport mechanism 43. A degreasing and sintering process is performed.

  In addition, although the sinter shaping | molding apparatus 100 demonstrated to the example the structure by which the appearance part 70 and the degreasing sintering part 80 were continuously provided from the shaping | molding part 40, it does not limit to this. For example, the revealing portion 70 and the degreasing / sintering portion 80, or each of the revealing portion 70 and the degreasing / sintering portion 80 may be configured separately.

Liquid Binder
FIG. 3 is a conceptual view of a liquid binder 8 as a “liquid binder” according to the first embodiment.
The liquid binder 8 is characterized in that the liquid portion 9 contains the inorganic particles 8 a as “second inorganic particles”. The liquid portion 9 also contains a curing agent 8 b.

  As the inorganic particles 8a, metal particles or ceramic particles can be used as in the case of the inorganic particles 2a. As a preferred example, a stainless alloy powder is used as in the inorganic particles 2a. In addition, the inorganic particles 8a are not limited to stainless steel alloys, and for example, copper, bronze (Cu / Sn), brass (Cu / Zn), tin, lead, gold, silver, platinum, palladium, iridium, titanium, Metals such as tantalum, iron, carbonyl iron, etc., titanium alloys, cobalt alloys, aluminum alloys, magnesium alloys, iron alloys, nickel alloys, chromium alloys, silicon alloys, zirconium alloys, gold alloys, etc., also Fe / Ni, It may be a magnetic alloy containing Fe / Si, Fe / Al, Fe / Si / Al, Fe / Co, Fe / Co / V, or an intermetallic compound such as titanium aluminum. In the case of ceramic, alumina, zirconia or the like may be used.

  The inorganic particles 8a have a substantially spherical shape with an average particle diameter of 0.001 μm to 10 μm. The average particle diameter of the inorganic particles 8a is more preferably 0.001 μm or more and 5 μm or less, and more preferably closer to a true sphere shape. The ratio of the average particle size of the inorganic particles 2a to the average particle size of the inorganic particles 8a is in the range of 50000: 1 to 10: 1. Thereby, the inorganic particles 8a can be easily inserted into the voids of the inorganic particles 2a. That is, the density of the inorganic particles (inorganic particles 2a and inorganic particles 8a) can be increased more uniformly, and a three-dimensional structure with the density of inorganic particles increased more uniformly can be obtained.

  As the curing agent 8b, although a UV curable resin (UV polymerizable compound) is used as a suitable example, it is not limited thereto. For example, thermoplastic resin, thermosetting resin, light of visible light region is used. Various light-curable resins such as visible light-curable resins (light-curable resins in a narrow sense) to be cured, various light-curable resins such as infrared-curable resins, X-ray-curable resins and the like, and one or more selected from these It may be a configuration.

  In addition, the liquid binder 8 (liquid portion 9) is, for example, a dispersant, a surfactant, a polymerization initiator, a polymerization accelerator, a solvent, a penetration accelerator, a wetting agent (humectant), an adhesion promoter, a mildew agent, It may contain ingredients such as preservatives, antioxidants, ultraviolet light absorbers, chelating agents, pH adjusters, thickeners, anticoagulants, antifoaming agents and the like.

<Sintered molding method>
Next, a “sinter molding method” will be described that shapes a “sinter-shaped product” using the sintering and shaping material 1 and the liquid binder 8 described above and using the sintering and shaping apparatus 100.
The sinter molding method according to the present embodiment includes the following steps.
(1) A forming layer forming step of forming the forming layer 5 using the sintered and shaped material 1 containing the inorganic particles 2a (2) A liquid binder 8 containing the inorganic particles 8a is applied to a desired region of the forming layer 5 Step (3) Step of curing the applied liquid binder 8 to form the shaped cross-sectional layer 6 (4) step of removing the region of the shaped layer 5 to which the liquid binder 8 is not applied (5) laminated A step of heating and sintering the formed sectional layer 6

Hereinafter, description will be made in order with reference to FIG.
In addition, from the process after supplying the sintering modeling material 1 to the sintering modeling apparatus 100 to the process of performing the sintering process of the three-dimensional object 7, it is performed by control of the control part with which the sintering modeling apparatus 100 is provided.

  First, the sintered and shaped material 1 including the inorganic particles 2a and the binder material 3 is prepared, and filled in the material supply unit 10 (hopper 11). Each ratio is appropriately determined according to the forming specification of the sintered formed article, such as the particle size of the inorganic particles 2a, the distribution of the particle size, the volume filling ratio by the inorganic particles 2a, the layer thickness of the forming layer 5 formed by spreading It is desirable to set. Specifically, for example, the volume filling rate of the inorganic particles 2a is about 70%. Moreover, it is preferable that each dispersion becomes uniform.

In addition, a liquid binder 8 containing inorganic particles 8 a and a curing agent 8 b is prepared, filled in an ink cartridge, and set in the cartridge loading unit 52.
Although the inorganic particle of the same raw material as the inorganic particle 2a is used as a suitable example for the inorganic particle 8a, it does not limit to this. In the amount of the inorganic particles 8a contained in the liquid binder 8, the ratio of the weight of the inorganic particles 2a to the weight of the inorganic particles 8a contained in the formed sectional layer 6 is in the range of 400: 1 to 3: 1. Adjust to become Specifically, as a preferred example, the ratio of the weight of the inorganic particles 2a to the weight of the inorganic particles 8a with respect to the inorganic particles 2a adjusted so that the volume filling rate is about 70% in the sintered and shaped material 1 The content of the inorganic particles 8a is adjusted so that
For the curing agent 8b, an ultraviolet curable resin is used as a preferred example.

Next, the sintered and shaped material 1 is supplied from the material supply unit 10 to the heating unit 20 (hot plate 21). The amount of the sintered molding material 1 supplied to the heating unit 20 at one time is controlled to an amount corresponding to the amount of one forming layer 5.
The heating unit 20 heats the sintered and shaped material 1 to a temperature equal to or higher than the melting point of the binder material 3 by the hot plate 21 and melts the binder material 3 to form the flowable shaped material 4.

  Next, the flowable molding material 4 is spread on the stage 41 by the spreading unit 30. Specifically, the squeegee 31 brought into contact with the + X side of the flowable sintered shaped material 1 (flowable shaped material 4) is stretched on the surface of the stage 41 by moving in the −X direction.

The stage 41 is maintained at normal temperature (for example, room temperature), and the flowable modeling material 4 spread on the stage 41 is cooled to normal temperature. The flowable shaped material 4 is cooled to normal temperature, whereby the binder material 3 solidifies, the shaped layer 5 is formed, and the shaped layer forming step is completed.
The layer thickness of the shaping layer 5 is controlled by the specification of spreading by the squeegee 31. Specifically, the layer thickness of the shaping layer 5 is determined by the size of the gap between the lower end of the squeegee 31 and the XY plane (for example, the surface of the stage 41 at the initial position), the moving speed of the squeegee 31, the flowable modeling material 4 It is desirable to appropriately set the thickness so as to obtain a desired thickness because it changes depending on the viscosity of the ink.

  Next, the drawing unit 50 applies the liquid binder 8 containing the inorganic particles 8 a to a desired region of the shaped layer 5 formed on the stage 41, and forms a desired image by the liquid binder 8. Specifically, the liquid binder 8 is discharged while moving the discharge head 51 according to the image information of each of the cross-sectional layers constituting the sintered molded article input to the control unit in advance, and the sintered molded article A liquid binder 8 is applied at a position corresponding to the cross-sectional shape.

FIG. 4 is a conceptual view showing how the liquid binder 8 is applied to a desired region of the shaped layer 5 by the sintering and shaping apparatus 100.
The binder material 3 dispersed in the form of flakes in FIG. 1 is once melted and solidified to increase the volume filling ratio of the inorganic particles 2a to cover the surface of the inorganic particles 2a, thereby substantially covering the whole of the modeling layer 5 Distributed uniformly. As shown in FIG. 4, the liquid binder 8 selectively applied to the desired position penetrates into the region including the inorganic particles 2 a and the binder material 3 (voids of the inorganic particles 2 a covered with the binder material 3). And the shaped part 5a is formed. In addition, as the liquid binder 8 (liquid portion 9) penetrates into the interior of the modeling layer 5, the inorganic particles 8 a having a smaller particle diameter than the inorganic particles 2 a enter the gaps of the inorganic particles 2 a.

Next, the curing unit 60 cures the liquid binder 8 applied to the shaped layer 5 to form the shaped cross-sectional layer 6. Specifically, since the liquid binder 8 containing an ultraviolet curable resin is used as a preferable example, after the carriage 53 is retracted from the stage 41, the ultraviolet irradiator (liquid binder curing mechanism 61) is used. The modeling layer 5 is irradiated with ultraviolet light, and the liquid binder 8 applied to the modeling layer 5 is cured to cure the modeling portion 5a.
The liquid binder 8 is preferably cured to such an extent that the curing is not completed in order to maintain the bonding strength of the interface with the liquid binder 8 to be applied to the shaped layer 5 to be laminated next.

  Next, the stage lifting mechanism 42 lowers the stage 41 according to the layer thickness of the shaping layer 5 which is spread and formed on the stage 41. As the stage 41 descends, the surface of the shaping layer 5 is positioned in the same plane as the hot plate 21, and again, the flowable shaping material 4 is spread by the squeegee 31 and laminated as the shaping layer 5 An XY plane is constructed.

Thereafter, the process from the process of supplying the sintered modeling material 1 to the heating unit 20 from the material supply unit 10 to the above process is repeated, and the modeling layer 5 is laminated. That is, the second and subsequent shaped layers 5 are laminated on the previously formed shaped layer 5.
The step of forming the shaped layer 5 by spreading the flowable modeling material 4 may be performed at a place other than the stage 41, and the shaped layer 5 may be sequentially transferred to the stage 41 to be stacked.

  When the lamination of the forming layer 5 reaches a height corresponding to the formation of the object 7 and the layering is completed, the layer is taken out from the forming portion 40 to reveal the object 7. Specifically, the non-patterned portion 5b to which the shaped object (laminate of the shaped layer 5) is transported from the shaped portion 40 to the revealing portion 70 by the transport mechanism 43, and the liquid binder 8 is not applied by the unnecessary portion removing means Is removed to reveal the shaped object 7 (laminated shaped cross section layer 6).

  Next, the three-dimensional object 7 that has been revealed is transferred to the degreasing and sintering unit 80, and degreasing treatment is performed. Specifically, first, the shaped object 7 is transported from the developing unit 70 to the inside of the degreasing and sintering furnace 81 by the transport mechanism 43 to degrease the shaped object 7. Degreasing is performed for the purpose of thermally decomposing and removing the binder material 3 and the applied and hardened liquid binder 8 (hardening agent 8b). In the degreasing step, the binder material 3 is heat-treated at a temperature range where degreasing of the binder material 3 starts (in a preferred example, a temperature (300 ° C.) exceeding the thermal decomposition initiation temperature of polycaprolactone diol (about 200 ° C.)) And degreasing the liquid binder 8 (hardening agent 8b). Decomposed components generated by the thermal decomposition of the binder material 3 and the liquid binder 8 (hardening agent 8 b) are discharged from the exhaust equipment 84 by the degreasing gas supplied from the degreasing gas supply equipment 83.

  Next, a sintering process is performed on the degreased shaped object 7. Specifically, the temperature is gradually increased to a temperature further exceeding the temperature at which the degreasing treatment is performed, and the heat treatment is performed at a temperature at which the inorganic particles 2a are sintered. As a suitable example, when stainless steel alloy powder is used for inorganic particles 2a, for example, the heating temperature is gradually raised to 1300 ° C. at which the stainless steel alloy is sintered. Completion of the sintering of the inorganic particles 2a and the inorganic particles 8a provides a desired sintered shaped product.

  In the heating step of gradually raising the heating temperature, the inorganic particles 8a are lower than the sintering start temperature at which the inorganic particles 2a start sintering (the sintering start temperature when sintered only with the inorganic particles 2a) In the above, the inorganic particles 2a can be fused. This is due to the size effect (melting point decrease) in which the sintering start temperature can be lowered by applying the inorganic particles 8a because the inorganic particles 8a are inorganic particles having a size of the nanoparticle level.

FIG. 5 is a conceptual diagram comparing the heat treatment process of degreasing and sintering with the prior art (in the case where the liquid binder 8 does not contain the inorganic particles 8a). It shows that how the main material (inorganic particles) constituting the sintered shaped article changes in accordance with the transition of the heat treatment temperature.
The main material (inorganic particles 2a) is supported by the binder material and the applied and hardened liquid binder, but in the degreasing process (zone A shown in FIG. 5), the binder material and the applied and hardened liquid binder are As it is thermally decomposed gradually, the force to connect the main material (inorganic particles 2a) gradually weakens. This is the same in the prior art and in the present embodiment.

While degreasing is completed, heating temperature is gradually increased, and heat treatment is continued until sintering is completed (zones of B and C shown in FIG. 5), a state in which the main material (inorganic particles) is supported, It differs from the prior art.
In the prior art, in the range (the zone B shown in FIG. 5) until the degreasing is completed and the sintering of the inorganic particles starts, the force connecting the main material (inorganic particles 2a) is minimized. Therefore, the dimensional change of the three-dimensional object 7 is likely to occur in combination with the influence of the volume filling rate of the inorganic particles being lower (only for the inorganic particles 2a) as compared with the present embodiment.
On the other hand, in the present embodiment, the fusion between the inorganic particles 8a and the inorganic particles 2a starts in the same zone B, and the volume filling ratio of the inorganic particles is higher than that in the prior art (inorganic particles Because the inorganic particles 8a are intruding into the voids of 2a), dimensional change of the shaped article 7 hardly occurs.

  In addition, fusion between the inorganic particles 8a and the inorganic particles 2a may start during the degreasing step (in this case, the fusion start temperature is the thermal decomposition start of the binder material 3 and the liquid binder 8 (hardening agent 8b) The temperature is low). By doing this, the binder material 3 and the liquid binder 8 (hardening agent 8b) are degreased and the fusion between the inorganic particles 8a and the inorganic particles 2a is minimized before the force connecting the main components (inorganic particles 2a) becomes minimal. Because dressing starts, dimensional change of the object 7 hardly occurs. In addition, fusion with the inorganic particles 2a may be started after the degreasing process is completed. (In this case, the fusion start temperature is lower than the thermal decomposition start temperature of the binder material 3 and the liquid binder 8 (hardener 8 b)). By doing this, the inorganic particles 2a are mixed in the voids of the main material (inorganic particles 2a) and the main material (inorganic particles 2a), so the binder material 3 and the liquid binder 8 (curing agent 8b) Even if it is degreased, the main material (inorganic particles 2a) does not move easily, and the dimensional change of the object 7 hardly occurs.

As described above, according to the sinter molding method, the liquid binder used for the sinter molding, and the sinter molded article according to the present embodiment, the following effects can be obtained.
In the sintering and shaping method of the present embodiment, the inorganic particle 8a is contained in a desired region of the shaping layer 5 in a shaping layer forming step of forming the shaping layer 5 using the sintered shaping material 1 in which the inorganic particles 2a are contained. A step of applying the liquid binder 8 and a step of curing the applied liquid binder 8 to form the shaped cross section layer 6 are included. In addition to the inorganic particles 2a, the inorganic particles 8a can be further included in the shaped cross-sectional layer 6 by including these steps. Moreover, the process of removing the area | region to which the liquid binder 8 of the modeling layer 5 is not provided, and the process of heating and sintering-processing the lamination | stacking modeling cross-section layer 6 are included. By including these steps, the three-dimensional structure (sintered structure) is shaped by the laminated shaped cross-sectional layer 6, and the strength can be enhanced by performing a sintering process.

  Moreover, in addition to the inorganic particles 2a, the modeling cross-sectional layer 6 further includes the inorganic particles 8a, so that it is possible to obtain a sintered shaped article having a higher density (volume filling rate) of the inorganic particles. As a result, the dimensional change (shrinkage) of the sintered shaped article in the sintering process is further suppressed, and a sintered shaped article with higher dimensional accuracy can be shaped.

  In addition, the inorganic particles 8a are fused to the inorganic particles 2a at a temperature lower than the sintering start temperature at which the inorganic particles 2a start sintering, thereby functioning as a binder for binding the inorganic particles 8a to each other. It can be done. As a result, the dimensional change (shrinkage) of the sintered shaped article in the sintering process is further suppressed, and a sintered shaped article with higher dimensional accuracy can be shaped.

  In addition, the sinter-shaped material 1 includes a thermoplastic binder material 3 for binding the inorganic particles 2 a to each other, and the shaped layer forming step heats the sinter-shaped material 1 to a temperature equal to or higher than the melting point of the binder material 3. Do. By heating the sinter shaped material 1 to a temperature higher than the melting point of the binder material 3, the flowability of the sinter shaped material 1 is enhanced, so that the sinter shaped material 1 can be spread more easily, and the size is further increased. It is possible to form the shaping layer 5 with high accuracy. In addition, in the heating process in which the sintering process proceeds, the binder material 3 contributes to the binding of the inorganic particles 2a until the binder material 3 is thermally decomposed (during the completion of the degreasing). According to this embodiment, as a result of these, it is possible to form a sintered shaped article with higher dimensional accuracy.

  Moreover, since the ratio of the weight of the inorganic particles 2a and the weight of the inorganic particles 8a included in the shaped cross-sectional layer 6 is in the range of 400: 1 to 3: 1, the inorganic particles 2a can be shaped as a main material. In addition, a sintered shaped article having a higher density of inorganic particles can be obtained by the inorganic particles 8a applied to the main material. As a result, the dimensional change (shrinkage) of the sintered shaped article in the sintering process is further suppressed, and a sintered shaped article with higher dimensional accuracy can be shaped.

  Further, since the ratio of the average particle size of the inorganic particles 2a to the average particle size of the inorganic particles 8a is in the range of 50000: 1 to 10: 1, the inorganic particles 2a can be shaped as a main material, and addition Inorganic particles 8 a easily penetrate between the main components (inorganic particles 2 a) together with the liquid binder 8. As a result, it is possible to form the shaped cross section layer 6 in which the density of the inorganic particles is increased more uniformly, and it is possible to obtain a sintered formed article in which the density of the inorganic particles is increased more uniformly. As a result, the dimensional change (shrinkage) of the sintered shaped article in the sintering process is further suppressed, and a sintered shaped article with higher dimensional accuracy can be shaped.

  Moreover, the average particle diameter of the inorganic particle 8a is 0.001 micrometer or more and 10 micrometers or less. That is, since the inorganic particles 8a are inorganic particles having the size of the nanoparticle level (1 to 10,000 nm), when the liquid binder 8 is applied to a desired region of the sintered and shaped material 1 containing the inorganic particles 2a. Can be easily inserted into the voids of the inorganic particles 2a. That is, the density of the inorganic particles can be increased more uniformly, and a sintered shaped product with the density of the inorganic particles increased more uniformly can be obtained. Further, since the inorganic particles 8a are inorganic particles having a size of the nanoparticle level, the sintering start temperature of the sintered shaped article can be lowered by applying the inorganic particles 8a. That is, because sintering of the inorganic particles 8a and the inorganic particles 2a is started at a lower temperature due to the size effect of the inorganic particles 8a, for example, when the inorganic particles 2a and the inorganic particles 8a are the same metal, Sintering can be initiated at a lower temperature as compared to the sintering start temperature for particles 2a alone. As a result, it is possible to suppress the change in dimension in the heating step for the sintering process (for example, the change in dimension due to the thermal decomposition (defatting) of the binder material 3 contained in the sintered shaped material 1) from a lower temperature. Therefore, dimensional change (shrinkage) of the sintered shaped article is further suppressed, and a sintered shaped article with higher dimensional accuracy can be shaped.

  In addition, since the inorganic particles 2a and the inorganic particles 8a are ceramic particles or metal particles, they can perform a sintering process on the sintered shaped material of the main material, and as a result, a more robust sintered and shaped object You can get things.

  The liquid binder 8 of this embodiment is a liquid binder 8 used for producing a sintered shaped product, which is applied to a desired region of the sintered shaped material 1 including the inorganic particles 2a, and the applied region is cured. By doing this, a region that constitutes the sintered shaped product is formed. In addition, the liquid binder 8 contains inorganic particles 8 a. That is, according to the liquid binder 8 of the present embodiment, in addition to the inorganic particles 2a, the inorganic particles 8a can be further contained in the desired region for forming the sintered shaped article. As a result, it is possible to obtain a sintered shaped article having a higher density of inorganic particles.

  Moreover, the average particle diameter of the inorganic particle 8a contained in the liquid binder 8 is 0.001 micrometer or more and 10 micrometers or less. That is, since the inorganic particles 8a are inorganic particles of the size of the nanoparticle level, when the liquid binder 8 is applied to a desired region of the sintered and shaped material 1 containing the inorganic particles 2a, the inorganic particles 8a are It can be easily inserted into the air gap. That is, the density of the inorganic particles (inorganic particles 2a and inorganic particles 8a) can be increased more uniformly, and a sintered shaped product in which the density of the inorganic particles is increased more uniformly can be obtained.

  Also, for example, when the inorganic particles 2a contained in the sintered material 1 are ceramic particles similar to the inorganic particles 8a contained in the liquid binder 8, or the inorganic particles 2a contained in the sintered material 1 are liquid In the case of metal particles similar to the inorganic particles 8a contained in the binder 8, it is possible to carry out the sintering process of the sintered shaped product mainly composed of these, and as a result, a more robust sintered shaped product can be obtained. You can get it.

  That is, the sinter-shaped object formed by using the liquid binder 8 is, in other words, previously included in the sinter-shaped material 1 to be laminated. The sintered shaped object formed by including the inorganic particles 2a and the inorganic particles 8a contained in the liquid binder 8 to be applied to the laminated sintered shaped material 1 is sintered when the sintering process is performed. The dimensional change (shrinkage) of a shaped article is further suppressed, and a sintered shaped article with higher dimensional accuracy is provided.

  DESCRIPTION OF SYMBOLS 1 ... Sinter-shaped material, 2 ... powder material, 2a ... inorganic particle, 3 ... binder material, 3a ... binder flake, 4 ... fluid formable material, 5 ... formation layer, 5a ... formation part, 5b ... non- formation part, Reference Signs List 6 modeling cross section layer 7 modeling object 8 liquid binder 8a inorganic particle 8b curing agent 9 liquid portion 10 material supply portion 11 hopper 12 material discharge port 20 Reference numeral 21: hot plate, 30: spreader, 31: squeegee, 40: shaping unit, 41: stage, 42: stage elevating mechanism, 43: transport mechanism, 50: drawing unit, 51: discharge head, 52: Cartridge loading portion 53 Carriage 54 Carriage moving mechanism 60 Cured portion 61 Liquid binder hardening mechanism 70 Revealing portion 80 Degreasing sintering portion 81 Degreasing sintering furnace 82 Heating Heater, 83 ... Degreasing gas supply facility 84 ... exhaust equipment, 100 ... sintered molding apparatus.

Claims (13)

A forming layer forming step of forming a forming layer using a sintered forming material containing a first inorganic particle, a step of applying a liquid binder containing a second inorganic particle in a desired region of the forming layer ,
Curing the applied liquid binder to form a shaped cross section layer;
Removing the region of the shaped layer to which the liquid binder is not applied;
And heating the shaped cross-sectional layer to perform a sintering process.   The sintering step includes a heating step of fusing the second inorganic particle to the first inorganic particle at a temperature lower than a sintering start temperature at which the first inorganic particle starts sintering. The sinter molding method according to claim 1, characterized in that:   The sintered shaped material includes a thermoplastic binder that bonds the first inorganic particles, and the shaped layer forming step heats the sintered shaped material to a temperature equal to or higher than the melting point of the thermoplastic binder. The sinter molding method according to claim 1 or 2, wherein the method is performed.   The ratio of the weight of the first inorganic particles and the weight of the second inorganic particles contained in the shaped cross-sectional layer is in the range of 400: 1 to 3: 1. The sinter molding method according to any one of 3.   The ratio of the average particle size of the first inorganic particles to the average particle size of the second inorganic particles is in the range of 50000: 1 to 10: 1. The sintered molding method according to any one of the items.   The average particle diameter of said 2nd inorganic particle is 0.001 micrometer-10 micrometers, The sintering shaping method as described in any one of the Claims 1 thru | or 5 characterized by the above-mentioned.   The method according to any one of claims 1 to 6, wherein the first inorganic particles and the second inorganic particles are ceramic particles or metal particles. Used for producing a three-dimensional structure including applying a liquid binder to a desired region of the sintered shaped material containing the first inorganic particles, and curing the applied liquid binder;
A liquid binder characterized in that it contains a second inorganic particle.   The liquid binder according to claim 8, wherein an average particle diameter of the second inorganic particles is 0.001 μm or more and 10 μm or less.   The liquid binder according to claim 8 or 9, wherein the second inorganic particles are ceramic particles or metal particles.   A sintered shaped article characterized by being shaped by the sintered shaping method according to any one of claims 1 to 7.   A sintered shaped article characterized by being shaped using the liquid binder according to any one of claims 8 to 10.   It is characterized by including the first inorganic particles contained in advance in the sintered shaped material to be laminated, and the second inorganic particles contained in the liquid binder applied to the laminated sintered shaped material. Sinter-shaped object.

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