JP2017132246A - Powder material for three-dimensional molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder material for three-dimensional molding with high removability of excessive powder and low cohesiveness of excessive powder, the powder material capable of improving strength of a three-dimensional molding and suppressing deterioration of dimensional accuracy of the three-dimensional molding, and also to provide a three-dimensional sintered article made of a metal with high strength in a Z-axis direction and low anisotropy of strength in X, Y and Z axes.SOLUTION: A powder material for three-dimensional molding includes metal particles and water-soluble organic material particles. The content of the organic material particles is 2-18 vol.% with regard to the powder material for three-dimensional molding, and a volume average particle diameter of the organic material particles is 3-15 μm.SELECTED DRAWING: None

Description

  The present invention relates to a three-dimensional modeling powder material, a three-dimensional modeling kit, a three-dimensional model manufacturing method, a three-dimensional sintered model manufacturing method, and a three-dimensional model manufacturing apparatus.

  In place of the conventional method for producing a three-dimensional object using a mold, an additive manufacturing method using a three-dimensional (3D) printer capable of producing a more complicated and fine three-dimensional object on demand has recently been developed. Proposed. In particular, a powder lamination method is used in the case of producing a three-dimensional structure composed of a metal or an inorganic compound. As one of the powder lamination methods, three-dimensional modeling powder materials containing particles of metal, inorganic compounds, etc. are laminated, and a three-dimensional modeling liquid material is applied in a predetermined pattern for each layer or multiple layers. For example, a method for producing a three-dimensional model by adhering powder materials to each other. The three-dimensional molded article thus obtained can be degreased and then sintered to obtain a three-dimensional sintered article.

  As the powder lamination method, there is known a method of adding an organic material such as a binder resin to a three-dimensional modeling powder material in order to bond the three-dimensional modeling powder material to each other.

  Furthermore, as a method of adding an organic material to a three-dimensional modeling powder material, a method of mixing organic material particles with a three-dimensional modeling powder material is known.

  As an example, for example, Patent Document 1 discloses a three-dimensional modeling powder that generates a layer of a three-dimensional structure by adding a water-soluble polymer and using a water as a solvent to form a liquid that is dropped and dissolved in the liquid. Has been. At this time, the water-soluble polymer contains partially saponified polyvinyl alcohol. The three-dimensionally shaped powder contains an inorganic or organic substance having an average particle diameter of 9 μm or more and 40 μm or less as an filler.

  Patent Document 2 discloses a powder material used for three-dimensional modeling for modeling a three-dimensional structure by discharging a modeling liquid to a specific region of the powder material deposited on the deposition surface. At this time, the powder material includes a filler that is a particle forming a three-dimensional structure, and an adhesive that bonds the filler to each other by dissolving in a modeling liquid. Moreover, the specific gravity of the filler is larger than the specific gravity of the modeling liquid discharged to the powder material.

  However, in the techniques disclosed in Patent Documents 1 and 2, surplus powder that has not been used for modeling (three-dimensional modeling powder material to which the three-dimensional modeling liquid material has not been applied) aggregates in the modeling tank. There was a problem. As a result, it takes time to remove the excess powder, or the 3D object is deformed when removing the excess powder, or the excess powder cannot be completely removed and the dimensional accuracy of the 3D object is greatly reduced. There was a problem to do. This leads to a decrease in the dimensional accuracy of the three-dimensional sintered product. In addition, if excessive powder agglomerates are mixed, there is a problem that the reuse rate of the excess powder decreases because the strength and dimensional accuracy of the three-dimensional structure decrease when the excess powder is reused. .

  Furthermore, an important subject is that the intensity | strength of the Z-axis direction which is the lamination direction of a three-dimensional molded item is low. This is because when the powder material layer is formed, since the powder materials are in close contact with each other on the XY plane, high strength is easily obtained, whereas in the Z-axis direction, voids are likely to exist between the layers. This is also an issue of additive manufacturing in general.

  These problems are particularly important in producing a metal three-dimensional sintered product that requires high strength. Metal three-dimensional sintered products are used for applications that require high strength, such as mechanical parts, jigs, and prototypes for measuring mechanical strength. At this time, even if the strength of the XY plane is high, if the strength in the Z-axis direction is low, it may be damaged depending on how the force is applied, and cannot be used as a metal part or a prototype. . The interlaminar adhesive strength tends to be improved by increasing the amount of the organic material, but the effect of increasing the strength in the Z-axis direction is limited because the effect of reducing the voids between the layers is not sufficient. In addition, when the amount of organic material is increased, the organic material spreads to a region where it should not exist, which promotes the adhesion of surplus powder and greatly reduces the dimensional accuracy of the three-dimensional modeled object and also the three-dimensional sintered object. There was also. In addition, when the amount of the organic material is large, the volumetric shrinkage increases when the three-dimensional molded object is sintered, which is also a factor of reducing the dimensional accuracy of the three-dimensional sintered article. From the above, it is necessary to optimize the amount of the organic material in the three-dimensional model including metal and the three-dimensional sintered product made of metal in order to achieve both strength and dimensional accuracy.

  However, conventionally, the three-dimensional sintered product has a problem that the strength anisotropy is high, that is, the strength in the stacking direction (Z-axis direction) of the three-dimensional model is low. The fact was not revealed.

  Patent Documents 1 and 2 disclose a powder material in which a filler and an organic material are mixed, and it is described that the warpage of a three-dimensional structure can be reduced by adding the filler.

  However, Patent Documents 1 and 2 use calcium carbonate and various resin materials as fillers, and there is no description regarding a metal three-dimensional sintered material that requires high strength. Could not be applied.

  The present invention is for three-dimensional modeling that has high removability of surplus powder, low cohesiveness of surplus powder, can improve the strength of a three-dimensional structure, and can suppress a decrease in dimensional accuracy of the three-dimensional structure. The object is to provide a powder material.

  Another object of the present invention is to provide a metal three-dimensional sintered product having a high strength in the stacking direction of the three-dimensional modeled object, that is, the Z-axis direction, and low strength anisotropy in the X, Y, and Z axes. And

  The present invention is a three-dimensional modeling powder material including metal particles and water-soluble organic material particles, and the content of the organic material particles is 2% by volume or more and 18% by volume with respect to the three-dimensional modeling powder material. The volume average particle diameter of the organic material particles is 3 μm or more and 15 μm or less.

  According to the present invention, it is possible to improve the strength of the three-dimensional structure, to suppress the decrease in the dimensional accuracy of the three-dimensional structure, and to improve the strength of the three-dimensional structure. A powder material for modeling can be provided.

  Further, according to the present invention, it is possible to provide a metal three-dimensional sintered product having high strength in the Z-axis direction and low strength anisotropy in the X, Y, and Z axes.

It is the schematic for demonstrating the area envelope degree of particle | grains. It is the schematic which shows an example of the manufacturing method of the three-dimensional molded item of this embodiment. It is the schematic which shows another example of the manufacturing method of the three-dimensional molded item of this embodiment. It is the schematic which shows an example of the modeling tank and supply tank of FIG. It is a schematic diagram which shows the vertically stacked sample and horizontally stacked sample of an Example.

  Next, an example of the form for implementing this invention is demonstrated. However, the present invention is not limited to these embodiments.

(Powder material for 3D modeling)
The three-dimensional modeling powder material of the present embodiment (hereinafter simply referred to as a powder material) includes metal particles and water-soluble organic material particles, and if necessary, other components (hereinafter referred to as other components) are further included. May be included.

-Metal particles-
The material constituting the metal particles is not particularly limited as long as it is a metal having a powder or particle form, and can be appropriately selected according to the purpose.

  As a material constituting the metal particles, a conventionally known material can be appropriately selected according to the purpose without any particular limitation. For example, Mg, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu Zn, Y, Zr, Nb, Mo, Pd, Au, Ag, Pt, In, Sn, Ta, W, Sb, or alloys thereof.

  Examples of a particularly preferable material constituting the metal particles include stainless steel (SUS), iron, copper, titanium, silver, aluminum, zirconium, and alloys thereof.

  Examples of stainless steel (SUS) include SUS304, SUS316L, SUS317, SUS329, SUS410, SUS430, SUS440, and SUS630.

The density of the metal particles is preferably ³ g / cm ³ or more. When the density of the metal particles is 3 g / cm ³ or more, when the powder material is laid flat (sometimes referred to as recoating), the metal particles are likely to be densely packed, In some cases, the porosity can be reduced.

  These materials may be used alone or in combination of two or more.

  In the present embodiment, commercially available particles or powders formed of these materials can be used as the metal particles.

  The metal particles may be subjected to a known surface (modification) treatment for the purpose of increasing the affinity with the organic material particles.

  The volume average particle diameter of the metal particles is preferably 1 to 250 μm, more preferably 2 to 100 μm, further preferably 3 to 50 μm, and particularly preferably 5 to 25 μm. When the volume average particle diameter of the metal particles is 1 μm or more, the fluidity of the powder material is improved, a powder material layer described later is easily formed, and the smoothness of the surface of the powder material layer is improved. For this reason, the manufacturing efficiency of the three-dimensional model is improved, the handling and handling properties of the powder material are improved, and the dimensional accuracy of the three-dimensional model tends to be improved. On the other hand, if the volume average particle size of the metal particles is 250 μm or less, the number of contacts between the powder materials increases, and at the same time, the space in the three-dimensional structure becomes small. Will improve.

  As a method for controlling the volume average particle size of the metal particles, a method of classifying the metal particles using a sieve or the like and collecting a desired particle size distribution region, or a method of mechanically pulverizing and atomizing the metal particles Etc. By using these methods, even a commercial product of metal particles can be controlled to have a desired volume average particle size.

  In the present embodiment, the volume average particle size of the metal particles is preferably 0.5 times or more and 3.5 times or less than the volume average particle size of organic material particles described later. When the volume average particle diameter of the metal particles is 0.5 times or more than the volume average particle diameter of the organic material particles, the amount of the organic material can be prevented from being excessive, and the organic material is present in an area more than necessary. It becomes possible to permeate, and to suppress the volume shrinkage during drying or sintering of the three-dimensional model. As a result, a three-dimensional molded article or a three-dimensional sintered article with high dimensional accuracy can be obtained. On the other hand, when the volume average particle size of the metal particles is 3.5 times or less than the volume average particle size of the organic material particles, the variation in strength of the three-dimensional structure due to the bias of the organic material particles is suppressed, Adhesive strength between the layers of the powder material layer can be sufficiently exerted, and as a result, the strength anisotropy of the three-dimensional structure or three-dimensional sintered object can be reduced.

  The particle size distribution of the metal particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably sharp.

  The volume average particle size and particle size distribution of the metal particles can be measured using a known particle size distribution measuring apparatus.

  An example of the particle size distribution measuring device is a particle size distribution measuring device Microtrac MT3000II series (manufactured by Microtrac Bell).

  Although various shapes of particles can be used as the metal particles, the metal particles are preferably spherical and have a high aspect ratio and circularity expressed by the minor axis / major axis of the particles. preferable. Thereby, when the powder material layer containing metal particles is formed (recoating), the filling rate of the metal particles is increased. As a result, it is possible not only to reduce the voids of the resulting three-dimensional molded article, and also the three-dimensional sintered product, but also to reduce the gaps between layers, improving the strength of the three-dimensional molded product and the three-dimensional sintered product. It becomes possible to make it. In particular, by reducing the gaps between the layers, it is possible to improve the strength in the Z-axis direction, and it is possible to reduce the anisotropy of the strength of the three-dimensional structure and the three-dimensional sintered body.

  In the present embodiment, the aspect ratio (average value) of the metal particles is preferably 0.85 or more, and more preferably 0.90 or more. When the aspect ratio (average value) of the metal particles is 0.85 or more, the porosity of the three-dimensional structure or three-dimensional sintered object is reduced, and the strength of the three-dimensional structure or three-dimensional sintered object is improved. Variations in strength due to the location of the three-dimensional object are reduced.

  In the present embodiment, the aspect ratio (average value) of the particles can be obtained by the following method.

  That is, the aspect ratio (average value) of the particles is determined by determining the aspect ratio (minor axis / major axis) of each particle used in the analysis, and how much the particles having the aspect ratio of the predetermined value are present in the entire analyzed particle. It is a value weighted depending on whether or not it can be calculated by the following equation (1).

Aspect ratio (average value) = (X1 × Y1 + X2 × Y2 +... + Xn × Yn) / 100 (1)
Where X is the aspect ratio (minor axis / major axis) of the particles, Yi is the abundance [%] of the particles having an aspect ratio of Xi, i is an integer of 1 to n, and Y1 + Y2 + ... + Yn = 100.

  The aspect ratio of the particles can be measured using a known particle shape measuring device.

  Examples of the particle shape measuring device include Morphologi G3-SE (Spectres).

  The measurement conditions for the aspect ratio of the particles are not particularly limited and can be appropriately selected. For example, filtering by the area envelope degree of particles is performed with a dispersion pressure of 4 bar, a pressure air application time of 10 ms, a stationary time of 60 sec, and a measured number of particles of 50,000, and the aspect ratio is analyzed only with particles assumed to be primary particles. The number of particles assumed to be primary particles is preferably 15,000 or more, and more preferably 20,000 or more.

As shown in FIG. 1, the area envelope degree of the particle A is a value obtained by dividing the area (S ₁ ) of the particle A by the area (S ₁ + S ₂ ) of the convex hull of the particle A. ). The area envelope degree of the particle A is indicated by a value of 0 to 1, and indicates how jagged the particle A is.

Degree of area envelope of particle A = S ₁ / (S ₁ + S ₂ ) (2)
Filtering by the area envelope of the particle is, for example, the formula: Area envelope of the particle>0.99> 100 pixels
To do.

  In the present embodiment, the circularity of the metal particles is preferably 0.90 or more, and more preferably 0.95 or more. When the circularity of the metal particles is 0.90 or more, the metal particles are closely packed, the strength of the three-dimensional structure or three-dimensional structure is improved by reducing the porosity of the metal particles, or the place of the three-dimensional structure The variation in strength due to this can be reduced.

  The circularity of the metal particles can be measured using a known circularity measuring device.

  As an example of the circularity measuring device, a flow type particle image analyzer FPIA-3000 (manufactured by Malvern Instruments Inc.) and the like can be mentioned.

  The metal particles can be produced using a conventionally known method.

  Examples of the method for producing metal particles include, for example, a pulverization method in which a solid is subdivided by applying compression, impact, friction, etc., an atomizing method in which a molten metal is sprayed to obtain a quenched powder, and a precipitation method in which components dissolved in a liquid are precipitated. For example, a gas phase reaction method of vaporizing and crystallizing may be used.

  In the present embodiment, the method for producing metal particles is not particularly limited, but as a more preferred method for producing metal particles, spherical metal particles are obtained, and there is little variation in the particle size of the metal particles. Atomization method is mentioned.

  Examples of the atomizing method include a water atomizing method, a gas atomizing method, a centrifugal atomizing method, a plasma atomizing method, and the like, and any of them is preferably used.

-Organic material particles-
The material constituting the organic material particles is not particularly limited as long as the material is water-soluble and has a powder or particle form, and can be appropriately selected according to the purpose.

  In the present specification and claims, the term “water-soluble” means that it is substantially soluble in water. Here, substantially being easily soluble in water means, for example, when 1 g of organic material particles are mixed and stirred in 100 g of a solvent contained in a modeling liquid at 30 ° C., 90% by mass or more is dissolved. To do.

  Examples of the organic material include water-soluble resins and water-soluble prepolymers. Among these, a water-soluble resin is more preferable.

  Specific examples of the water-soluble resin include polyvinyl alcohol (PVA) resin, polyvinyl pyrrolidone, polyamide, polyacrylamide, polyethyleneimine, polyethylene oxide, polyacrylic acid resin, cellulose resin, and gelatin. Among these, polyvinyl alcohol is more preferably used for increasing the strength and dimensional accuracy of the three-dimensional structure.

  The water-soluble resin may be a homopolymer (homopolymer), a heteropolymer (copolymer), or may be modified as long as it shows water solubility. These functional groups may be introduced, or may be in the form of a salt.

  For example, the polyvinyl alcohol resin may be polyvinyl alcohol, or modified polyvinyl alcohol modified with acetoacetyl group, acetyl group, silicone or the like (acetoacetyl group modified polyvinyl alcohol, acetyl group modified polyvinyl alcohol, silicone modified polyvinyl alcohol). Alcohol). The polyvinyl alcohol resin may be a butenediol-vinyl alcohol copolymer or the like.

  The polyacrylic acid resin may be polyacrylic acid or a salt such as sodium polyacrylate. The polyacrylic acid resin may be an acrylic acid / maleic anhydride copolymer.

  Examples of the cellulose resin include sodium carboxymethyl cellulose (CMC).

  As a water-soluble prepolymer, the adhesive water-soluble isocyanate prepolymer etc. which are contained in a water stop agent etc. are mentioned, for example.

  In the present embodiment, the water-soluble resin contained in the organic material particles can have a crosslinkable functional group, which is preferable for increasing the strength of the three-dimensional structure.

  The crosslinkable functional group is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a hydroxyl group, a carboxyl group, a carbonyl group, an amide group, a phosphate group, a thiol group, an acetoacetyl group, and an ether bond. Is mentioned.

  Further, the water-soluble resin contained in the organic material particles is preferably a modified polyvinyl alcohol having a crosslinkable functional group, for example, acetoacetyl group-modified polyvinyl alcohol, carbonyl group-modified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol. Etc. are particularly preferred.

  Thus, when the water-soluble resin contained in the organic material particles has a crosslinkable functional group, it is preferable because the organic material particles are easily cross-linked and the strength of the three-dimensional structure is increased. When a cross-linking agent is added to the liquid material described later, when the liquid material comes into contact with the powder material, the organic material particles contained in the powder material are dissolved in the water contained in the liquid material, and at the same time, the cross-linking agent contained in the liquid material is powdered. It crosslinks with the crosslinkable functional group of the organic material particle contained in the material. For this reason, when the solvent contained in the liquid material evaporates, the metal particles contained in the powder material can be joined more firmly. As a result, the strength of the three-dimensional model can be further increased.

  For example, when the modified polyvinyl alcohol contained in the organic material particles has an acetoacetyl group or a carbonyl group, and the crosslinking agent contained in the liquid material is an organic metal salt, the acetoacetyl group or the carbonyl group of the modified polyvinyl alcohol A complex three-dimensional network structure, that is, a crosslinked structure is easily formed through the metal ion of the organometallic salt. That is, since the organic material particles and the crosslinking agent are excellent in crosslinking reactivity, the strength of the three-dimensional structure can be greatly increased.

  As the modified polyvinyl alcohol, one kind may be used alone, or two or more kinds having different properties such as viscosity and saponification degree may be used in combination.

  The average degree of polymerization of the modified polyvinyl alcohol is preferably 100 to 1100, and more preferably 200 to 500.

  The saponification degree of the modified polyvinyl alcohol is not particularly limited and can be appropriately selected according to the purpose, but is preferably 80% or more. For this reason, general modified saponification type and complete saponification type modified polyvinyl alcohol can be effectively used as the modified polyvinyl alcohol.

  The water-soluble resin contained in the organic material particles may be used alone or in combination of two or more. Further, the water-soluble resin contained in the organic material particles may be appropriately synthesized or may be a commercially available product.

  Examples of commercially available water-soluble resins contained in the organic material particles include polyvinyl alcohol PVA-205C, PVA-220C (manufactured by Kuraray Co., Ltd.), polyacrylic acid durimer AC-10 (manufactured by Toagosei Co., Ltd.), and polyacrylic. Sodium acid durimer AC-103P (manufactured by Toagosei Co., Ltd.), acetoacetyl-modified polyvinyl alcohol Gohsenx Z-300, Gohsenx Z-100, Gohsenx Z-200, Gohsenx Z-205, Gohsenx Z-210, Gohsenx Z-220 (Nippon Synthetic Chemical Industry Co., Ltd.), carboxyl group-modified polyvinyl alcohol Gohsenx T-330, Gohsenx T-350, Gohsenx T-330T (Nippon Gosei Chemical Co., Ltd.), butenediol-vinyl alcohol copolymer Nichigo G-polymer OKS-8041 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), carbonyl group-modified polyvinyl alcohol D polymer DF-05 (manufactured by Nihon Vinegar Bipoval), Poval JMR series (manufactured by Nihon Vinegar Bipoval), cellogen 5A of carboxymethylcellulose sodium (Daiichi Kogyo Seiyaku Co., Ltd.), Starch Hustard PSS-5 (Sanwa Starch Co., Ltd.), Gelatin Bematrix Gelatin (Nitta Gelatin Co., Ltd.) and the like.

  The volume average particle diameter of the organic material particles is 3 μm or more and 15 μm or less, and more preferably 5 μm or more and 12 μm or less. When the volume average particle diameter of the organic material particles is less than 3 μm, the organic material particles are aggregated, and as a result, the metal particles are aggregated. Moreover, the bias of the organic material particles occurs, and the metal particles and the organic material particles cannot be uniformly distributed. Thereby, the intensity | strength variation of the obtained three-dimensional molded item generate | occur | produces, and a partial breakage, a crack, and a chip | tip generate | occur | produce. On the other hand, when the volume average particle diameter of the organic material particles exceeds 15 μm, the distance between the metal particles is widened, so that when the liquid material adheres, voids are easily generated, and the metal particles are closely bonded to each other. I can't. As a result, the strength of the three-dimensional molded article decreases, and at the same time, the strength anisotropy of the three-dimensional sintered product also increases. In addition, the organic material becomes excessive, diffuses outside the necessary region, and surplus powder adheres, thereby reducing the dimensional accuracy of the three-dimensional structure.

  The volume average particle diameter of the organic material particles can be measured using a known particle size distribution measuring device.

  An example of the particle size distribution measuring device is a particle size distribution measuring device Microtrac MT3000II series (manufactured by Microtrac Bell).

  Further, as the organic material particles, particles having various shapes can be used, but the organic material particles are preferably spherical, and the aspect ratio represented by the minor axis / major axis of the organic material particles The circularity is preferably higher. Thereby, the effect which improves the fluidity | liquidity of a metal particle can be acquired, and the filling rate of the powder material at the time of forming the powder material layer mentioned later (recoating) increases. As a result, it becomes possible to reduce the voids of the resulting three-dimensional molded article and the three-dimensional sintered product, and to reduce the gaps between the layers, and the strength of the three-dimensional molded article and the three-dimensional sintered product is improved. The strength variation of the three-dimensional model and the strength anisotropy of the three-dimensional model may be reduced.

  The aspect ratio of the organic material particles can be measured using a known particle shape measuring device.

  Examples of the particle shape measuring device include Morphologi G3-SE (Spectres).

  The circularity of the organic material particles can be measured using a known circularity measuring device.

  As an example of the circularity measuring device, there is a flow type particle image analyzer FPIA-3000 (manufactured by Malvern Instruments).

  The content rate of the organic material particles is preferably 2% by volume or more and 18% by volume or less, and preferably 4% by volume or more and 12% by volume or less with respect to the powder material. When the content of the organic material particles is less than 2% by volume with respect to the powder material, the strength of the three-dimensional structure decreases, and the risk of deformation before sintering increases, and when the content exceeds 18% by volume, The size of the three-dimensional structure is increased by the organic material diffusing beyond the necessary area, and surplus powder adhering to areas that are not originally required, or by surplus powder agglomerating and increasing the surface roughness of the three-dimensional structure. Accuracy is reduced.

  As the organic material particles, general commercially available powder materials can be used. Moreover, organic material particle | grains can be manufactured by granulating resin etc ..

  As a method for producing the organic material particles, a general method such as a spray drying method or a freeze pulverization method can be used.

  The spray drying method is a method in which a liquid is made into a fine mist and ejected into hot air to instantaneously obtain a powdery dried product.

  The freeze pulverization method is a method in which a material is frozen instantaneously and pulverized under ultra-low temperature and oxygen-free conditions using the property of becoming hard and brittle at an extremely low temperature.

  In the present embodiment, any conventionally known production method can be used as a method for producing the organic material particles, but it is more preferable to use a spray drying method because spherical particles are easily obtained.

-Other ingredients-
There is no restriction | limiting in particular as another component, Although it can select suitably according to the objective, For example, a fluidizing agent, a filler, a leveling agent, a sintering aid, etc. are mentioned.

  It is preferable that the powder material contains a fluidizing agent in that a layer of the powder material can be easily and efficiently formed. Moreover, when a powder material contains a filler, it is preferable at the point which a space | gap etc. become difficult to produce in the three-dimensional molded item obtained. It is preferable that the powder material contains a leveling agent in that the wettability of the powder material is improved and handling becomes easy. When the powder material contains a sintering aid, it is preferable in that the three-dimensional structure can be sintered at a lower temperature.

  The powder material can be suitably used for simple and efficient production of various molded bodies and structures, and the three-dimensional modeling kit of the present embodiment described later, the method of manufacturing the three-dimensional molded object of the present embodiment, and the present The present invention can be particularly preferably applied to the manufacturing apparatus for a three-dimensional structure according to the embodiment.

  In the present embodiment, a three-dimensional structure having a complicated three-dimensional shape can be easily and efficiently manufactured with good dimensional accuracy by simply applying a liquid material to the powder material. Since the three-dimensional model obtained in this way has sufficient hardness, it will lose its shape even if it is held by hand, put in and out of the mold, or air blow treatment to remove excess powder material. No handling and excellent handling and handling. The three-dimensional model may be used as it is as a modeling model, or may be degreased as necessary and then subjected to a sintering treatment to form a three-dimensional model. When the sintering process is performed, unnecessary voids and the like are not generated, and a three-dimensional sintered product having a beautiful appearance can be easily obtained.

(Liquid material for 3D modeling)
The three-dimensional modeling liquid material of the present embodiment (hereinafter simply referred to as a liquid material) contains water, and may further contain other components as necessary.

-Water-
The water is not particularly limited as long as it can dissolve the organic material particles, and for example, ion exchange water, distilled water, or the like can be used.

  The water content is not particularly limited and may be appropriately determined as necessary, but is preferably 20 to 95% by mass, and 40 to 90% by mass with respect to the total mass of the liquid material. More preferably, it is more preferably 50 to 85% by mass. Thereby, the high solubility of the organic material particles contained in the powder material can be maintained. As a result, the remaining undissolved organic material particles can be prevented, and the strength of the three-dimensional structure can be increased. In addition, it is possible to prevent occurrence of liquid clogging or nozzle omission due to drying of the inkjet nozzles during standby when applying the liquid material by the inkjet method.

-Aqueous solvent-
The liquid material may further contain an aqueous solvent such as alcohol, polyhydric alcohol, ether, and ketone.

  Specific examples of the aqueous solvent include ethanol, propanol, butanol, 1,2,6-hexanetriol, 1,2-butanediol, 1,2-hexanediol, 1,2-pentanediol, 1,3- Dimethyl-2-imidazolidinone, 1,3-butanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1 , 3-propanediol, 2,3-butanediol, 2,4-pentanediol, 2,5-hexanediol, 2-ethyl-1,3-hexanediol, 2-pyrrolidone, 2-methyl-1,3- Propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,3-hexanediol, -Methyl-2-pyrrolidone, N-methylpyrrolidinone, β-butoxy-N, N-dimethylpropionamide, β-methoxy-N, N-dimethylpropionamide, γ-butyrolactone, ε-caprolactam, ethylene glycol, ethylene glycol n-butyl ether, ethylene glycol-n-propyl ether, ethylene glycol phenyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monoethyl ether, glycerin, diethylene glycol, diethylene glycol-n-hexyl ether, diethylene glycol methyl ether, diethylene glycol monoethyl Ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diglycerin, dipro Pyrene glycol, dipropylene glycol n-propyl ether, dipropylene glycol monomethyl ether, dimethyl sulfoxide, sulfolane, thiodiglycol, tetraethylene glycol, triethylene glycol, triethylene glycol ethyl ether, triethylene glycol dimethyl ether, triethylene glycol monobutyl ether , Triethylene glycol methyl ether, tripropylene glycol, tripropylene glycol-n-propyl ether, tripropylene glycol methyl ether, trimethylol ethane, trimethylol propane, propyl propylene diglycol, propylene glycol, propylene glycol-n-butyl ether, propylene Glycol-t-butyl ether, pro Glycol phenyl ether, propylene glycol monoethyl ether, hexylene glycol, and the like can be used polyethylene glycol, polypropylene glycol. However, this is an example, and the present invention is not limited to these.

-Crosslinking agent-
In the present embodiment, the liquid material is applied to the powder material, so that the organic material particles in the powder material are dissolved by the water in the liquid material, and the metal particles are bonded to each other by drying the water, so that the three-dimensional modeling Things are formed. When the organic material particles have a crosslinkable functional group, when a crosslinking agent that undergoes a crosslinking reaction with the organic material particles is added to the liquid material, a crosslinking structure with the organic material particles is formed by the crosslinking agent, and the strength of the three-dimensional structure is improved. . As a result, it is possible to suppress a decrease in the dimensional accuracy of the three-dimensional sintered product due to the deformation of the three-dimensional model by removing excess powder or the like.

  The cross-linking agent is not particularly limited as long as it cross-links with the cross-linkable functional group of the organic material particles, but is preferably selected appropriately from organic metal salts according to the purpose.

  Examples of the organic metal salt include a metal complex, a zirconia-based crosslinking agent, a titanium-based crosslinking agent, a water-soluble organic crosslinking agent, and a chelating agent.

  Examples of the zirconia-based crosslinking agent include zirconium oxychloride and ammonium zirconium carbonate.

  Examples of the titanium-based crosslinking agent include titanium acylate and titanium alkoxide.

  Examples of chelating agents include organic titanium chelates and organic zirconia chelates.

  These may be used individually by 1 type and may use 2 or more types together.

  Furthermore, preferred examples of the organic metal salt include those that ionize divalent or higher metal ions in water.

  Specific examples of organic metal salts include zirconium oxychloride octahydrate (tetravalent), titanium lactate ammonium (tetravalent), basic aluminum acetate (trivalent), zirconium ammonium oxycarbonate (tetravalent), and titanium triethanol. Aminates (tetravalent), glyoxylate, zirconium lactate ammonium and the like are preferable.

  Moreover, as an organometallic salt, a commercial item can be used.

  Commercially available products include, for example, zirconium oxychloride octahydrate zirconium oxychloride (Daiichi Rare Element Chemical Industries), aluminum hydroxide (Wako Pure Chemical Industries), magnesium hydroxide (Wako Pure Chemical Industries) ), Titanium lactate ammonium Olga-Tix TC-300 (Matsumoto Fine Chemical Co., Ltd.), zirconium lactate ammonium Olga-Tix ZC-300 (Matsumoto Fine Chemical Co., Ltd.), basic aluminum acetate (Wako Pure Chemical Industries, Ltd.), bisvinyl Sulfone compound VS-B (K-FJC) (Fuji Film Fine Chemicals Co., Ltd.), zirconium zirconium oxycarbonate zircozol AC-20 (Daiichi Rare Element Chemical Co., Ltd.), Titanium triethanolaminate ORGATICS TC-400 (Matsumoto Fine Chemi Le Co., Ltd.).

  When the metal valence in the organic metal salt is 2 or more, the cross-linking strength of the three-dimensional structure can be improved, and the obtained three-dimensional structure is preferable in that it has a good strength.

  Moreover, as a ligand of a metal ion, a lactate ion is preferable in terms of excellent discharge stability of the liquid material.

-Other ingredients-
The other components can be appropriately selected in consideration of various conditions such as the type of means for applying the liquid material, the usage frequency, and the amount.

  For example, when a liquid material is applied to a powder material using an inkjet method, the selection can be made in consideration of the influence of clogging on a nozzle head in an inkjet printer or the like.

  Examples of other components include preservatives, preservatives, stabilizers, pH adjusters, wetting agents, penetrating agents, drying inhibitors, viscosity modifiers, surfactants, antifoaming agents, antifungal agents, and dispersants. , Coloring agents and the like, and conventionally known materials can be added without limitation.

  The method for preparing the liquid material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of adding a crosslinking agent in water, mixing other components as necessary, and dissolving them by mixing. Is mentioned.

  The mass ratio of the crosslinking agent to the organic material particles when the liquid material is applied to the powder material is preferably 0.1 to 50% by mass, more preferably 0.5 to 40% by mass, It is especially preferable that it is 35 mass%. When the mass ratio is 0.1% by mass or more, the strength of the three-dimensional structure is improved, and problems such as loss of shape are less likely to occur during subsequent processing such as sintering or handling, and the mass ratio is 50% by mass or less. And the dimensional accuracy of a three-dimensional molded item improves.

(3D modeling kit)
The three-dimensional modeling kit of the present embodiment (hereinafter simply referred to as a kit) includes a powder material and a liquid material including water, and may further include other components as necessary.

  Furthermore, the kit can add a crosslinking agent capable of reacting with the crosslinkable functional group of the organic material particles to the liquid material. Thereby, the intensity | strength of a three-dimensional molded item can be raised.

  The kit containing a liquid material containing a crosslinking agent may be a kit for preparing a liquid material by adding a crosslinking agent at the time of use.

  The kit can be suitably used for manufacturing various molded bodies and structures, and is particularly preferably applied to the method for manufacturing a three-dimensional object according to the present embodiment, which will be described later, and the apparatus for manufacturing a three-dimensional object according to the present embodiment. Can do.

  When a three-dimensional structure is manufactured using a kit, a liquid material is applied to the powder material, and if necessary, a three-dimensional structure having a complex three-dimensional shape can be easily and efficiently obtained with good dimensional accuracy. Can be manufactured. The three-dimensional model obtained in this way has sufficient strength, so even if you hold it by hand, put it in and out of the mold, or remove excess powder material by air blowing, it will lose its shape. No handling and excellent handling and handling. The three-dimensional model may be used as it is, or may be further subjected to a sintering process to form a three-dimensional model. When the sintering process is performed, unnecessary voids and the like are not generated, and a three-dimensional sintered product having a beautiful appearance can be easily obtained.

(Method for manufacturing a three-dimensional model)
The manufacturing method of the three-dimensional structure according to the present embodiment includes a step of forming a powder material layer using a powder material (hereinafter referred to as a powder material layer forming step) and a step of applying a liquid material to a predetermined region of the powder material layer. (Hereinafter referred to as a liquid material application step). Here, a three-dimensional molded item can be manufactured by repeating the powder material layer forming step and the liquid material applying step. The manufacturing method of the three-dimensional molded item of this embodiment may further include other processes as needed.

  When a three-dimensional object is manufactured using the method for manufacturing a three-dimensional object according to the present embodiment, excess powder can be easily and cleanly removed, and a three-dimensional object having high dimensional accuracy can be obtained. The resulting three-dimensional model has sufficient strength, and even if it is removed by excess powder or carried by hand, it does not show any change in shape, and until it is sintered The shape can be maintained firmly, and a three-dimensional sintered product having high dimensional accuracy can be obtained.

  Further, the surplus powder is less aggregated and can be reused. In addition, a three-dimensional structure manufactured using a powder material that reuses surplus powder has the same dimensional accuracy and modeling quality as compared to a three-dimensional structure manufactured using an unused powder material.

  Furthermore, the three-dimensional sintered product obtained by sintering these three-dimensional shaped products has not only high strength, but also small strength anisotropy in the XY axis direction and the Z axis direction. It can be used effectively as metal parts, jigs, and prototypes without being damaged even if added.

  In FIG. 2, an example of the manufacturing method of the three-dimensional molded item of this embodiment is shown.

  First, the manufacturing apparatus of the three-dimensional molded item shown by FIG. 2 is demonstrated.

  The manufacturing apparatus for a three-dimensional model has a modeling powder storage tank 1 for molding a three-dimensional model and a supply powder storage tank 2 for supplying the powder material P to the modeling powder storage tank 1, and stores the modeling powder. The tank 1 and the supply powder storage tank 2 each have a support (stage) 3 on which the powder material P is placed and which can move up and down. Here, a powder material layer is formed on the stage 3 of the modeling powder storage tank 1. The apparatus for manufacturing a three-dimensional model is provided with an inkjet head 5 that discharges a liquid material L to a powder material layer formed on the stage 3 of the modeling powder storage tank 1 above the modeling powder storage tank 1. . Further, the three-dimensional structure manufacturing apparatus supplies the powder material P from the stage 3 of the supply powder storage tank 2 to the stage 3 of the modeling powder storage tank 1 and is supplied to the stage 3 of the modeling powder storage tank 1. The powder material P has a leveling mechanism (recoater) 4 for leveling the surface of the powder material P to form a powder material layer.

  Next, each process of the manufacturing method of the three-dimensional molded item shown by FIG. 2 is demonstrated.

  2A and 2B, the powder material P is supplied from the stage 3 of the supply powder storage tank 2 to the stage 3 of the modeling powder storage tank 1, and the powder material layer having a smooth surface is provided. The process to form is shown. At this time, after controlling the gap between the stage 3 of the modeling powder storage tank 1 and the stage 3 of the supply powder storage tank 2, the gap between the modeling powder storage tank 1 and the stage 3 is controlled and the recoater 4 is supplied. By moving from the powder storage tank 2 to the modeling powder storage tank 1, a powder material layer having a desired layer thickness is formed on the stage 3 of the modeling powder storage tank 1.

  FIG. 2C shows a process of discharging the liquid material L to the powder material layer formed on the stage 3 of the modeling powder storage tank 1 using the inkjet head 5. At this time, the position at which the liquid material L is discharged is determined by two-dimensional image data (slice data) obtained by slicing a three-dimensional model to be modeled into a plurality of planes.

  2D and 2E, the powder material P is supplied from the stage 3 of the supply powder storage tank 2 to the stage 3 of the modeling powder storage tank 1, and the powder material layer having a smooth surface is provided. The process to form is shown. At this time, after the stage 3 of the powder storage tank 2 for supply is raised and the stage 3 of the powder storage tank 1 for molding is lowered, the gap with the stage 3 of the powder storage tank 1 for molding is controlled, and the recoater 4 Is moved from the supply powder storage tank 2 to the modeling powder storage tank 1, whereby a powder material layer having a desired layer thickness is newly formed on the stage 3 of the modeling powder storage tank 1.

  FIG. 2 (f) shows a step of discharging the liquid material L onto the powder material layer formed on the stage 3 of the modeling powder storage tank 1 using the inkjet head 5. At this time, the position at which the liquid material L is discharged is determined by two-dimensional image data (slice data) obtained by slicing a three-dimensional model to be modeled into a plurality of planes.

  By repeating these series of steps, if necessary, the powder material P to which the liquid material L is adhered is dried, and the powder material P to which the liquid material L is not adhered, that is, excess powder is removed, A three-dimensional model can be obtained.

  In FIG. 3, another example of the manufacturing method of the three-dimensional molded item of this embodiment is shown.

  The manufacturing apparatus of the three-dimensional structure shown in FIG. 3 is in principle the same as the manufacturing apparatus of the three-dimensional structure shown in FIG. 1, but the supply mechanism of the powder material P is different.

  3 (a) and 3 (b), the powder material P is supplied from the movable supply powder storage tank 2 'to the stage 3 of the modeling powder storage tank 1, and the powder material layer having a smooth surface is provided. The process to form is shown. At this time, after the powder material P is supplied from the supply powder storage tank 2 ′ onto the stage 3 of the modeling powder storage tank 1, the gap with the stage 3 of the modeling powder storage tank 1 is adjusted, and the recoater 4 is By moving, a powder material layer having a desired layer thickness is formed on the stage 3 of the modeling powder storage tank 1.

  FIG. 3C shows a process of discharging the liquid material L to the powder material layer formed on the stage 3 of the modeling powder storage tank 1 using the inkjet head 5. At this time, the position at which the liquid material L is discharged is determined by two-dimensional image data (slice data) obtained by slicing a three-dimensional model to be modeled into a plurality of planes.

  3D and 3E, supplying the powder material P from the supply powder storage tank 2 ′ to the stage 3 of the modeling powder storage tank 1 and forming a powder material layer having a smooth surface. Indicates. At this time, the stage 3 of the modeling powder storage tank 1 is lowered, and the powder material P is supplied from the movable supply powder storage tank 2 ′ onto the stage 3 of the modeling powder storage tank 1, and then the molding powder. By controlling the gap between the storage tank 1 and the stage 3 and moving the recoater 4, a powder material layer having a desired layer thickness is newly formed on the stage 3 of the modeling powder storage tank 1.

  FIG. 3F shows a process of discharging the liquid material L to the powder material layer formed on the stage 3 of the modeling powder storage tank 1 using the inkjet head 5. At this time, the position at which the liquid material L is discharged is determined by two-dimensional image data (slice data) obtained by slicing a three-dimensional model to be modeled into a plurality of planes.

  By repeating these series of steps, if necessary, the powder material P to which the liquid material L is adhered is dried, and the powder material P to which the liquid material L is not adhered, that is, excess powder is removed, A three-dimensional model can be obtained.

  The manufacturing apparatus for a three-dimensional structure shown in FIG. 3 has an advantage that it can be made more compact.

  The manufacturing method of the three-dimensional structure shown in FIGS. 2 and 3 is an example of the manufacturing method of the three-dimensional structure according to the present embodiment, and the manufacturing method of the three-dimensional structure according to the present embodiment is limited to these. It is not something.

(Manufacturing device for 3D objects)
The three-dimensional structure manufacturing apparatus according to the present embodiment uses a powder material to form a powder material layer (hereinafter referred to as a powder material layer forming means) and a means for applying a liquid material to a predetermined region of the powder material layer. (Hereinafter referred to as liquid material applying means). The manufacturing apparatus of the three-dimensional molded item of this embodiment may further include other means as necessary.

  Examples of other means include a supply powder storage tank, a modeling powder storage tank, a powder material container, a liquid material container, a support (stage), and a leveling mechanism (recoater).

-Powder storage tank-
The powder storage tank is classified into a supply powder storage tank (hereinafter also referred to as a supply tank) and a modeling powder storage tank (hereinafter also referred to as a modeling tank).

  Hereinafter, the supply tank and the modeling tank shown in FIG. 2 will be described as examples of the supply tank and the modeling tank.

  Each of the supply tank and the modeling tank has a tank shape or a box shape, and a support (stage) on the bottom surface thereof is vertically movable up and down. Moreover, the supply tank and the modeling tank are provided adjacent to each other, and a three-dimensional model is formed on the stage of the modeling tank.

  The stage of the supply tank is raised, and the placed powder material is supplied onto the stage of the supply tank using a flattening roller as a recoater. The recoater flattens the upper surface of the powder material placed on the stage of the supply tank and the modeling tank to form a powder material layer.

  Using an inkjet head, a liquid material is discharged onto the powder material layer formed on the stage of the modeling tank. At this time, the head cleaning mechanism adheres to the ink jet head to suck the liquid material and wipes the discharge port.

  FIG. 4 shows an example of the modeling tank 1 and the supply tank 2 of FIG.

  Each of the modeling tank 1 and the supply tank 2 has a box shape, and two upper surfaces of the supply tank 2 and the modeling tank 1 are open. The supply tank 2 and the modeling tank 1 are held inside each so that the stage can be moved up and down. The stage is arranged so that the side faces the frames of the modeling tank 1 and the supply tank 2, and the upper surface is held horizontally. Around the modeling tank 1 and the supply tank 2, a powder drop port 6 having a concave shape with an open upper surface is provided. When the powder material layer is formed, surplus powder accumulated by the flattening roller falls on the powder dropping port 6. The surplus powder that has fallen to the powder dropping port 6 is returned to the powder supply unit located above the modeling tank 1 by an operator, a suction mechanism, or the like as necessary.

-Support (stage)-
The support is not particularly limited as long as the powder material can be placed thereon, and can be appropriately selected according to the purpose. Japanese Patent Application Laid-Open No. 2000-328106 Examples thereof include a base plate in the apparatus described in FIG.

  The surface of the support, that is, the placement surface on which the powder material is placed may be, for example, a smooth surface or a rough surface. The surface of the support may be a flat surface or a curved surface.

  The surface of the support preferably has a low affinity with the three-dimensional structure. When the affinity between the three-dimensional structure and the surface of the support is lower than the affinity between the metal particles and the organic material particles, it is easy to remove the obtained three-dimensional structure from the surface of the support.

-Powder material layer forming step and powder material layer forming means-
There is no restriction | limiting in particular as a method of forming a powder material layer on a support body, According to the objective, it can select suitably. For example, as a method of forming a thin powder material layer on a support, a known counter rotation mechanism (counter roller) used in the selective laser sintering method described in Japanese Patent No. 3607300 is used. Preferred examples include a method used, a method using a member such as a brush, a roller, and a blade, a method using a pressing member, and a method using a known powder laminating apparatus.

  An example of a method for forming a thin powder material layer on a support using a counter rotating mechanism (counter roller), a brush, a blade, a pressing member, and the like will be described below.

  That is, the counter rotation mechanism is placed on a support body that is arranged so as to be able to move up and down while sliding on the inner wall of the outer frame in the outer frame (sometimes referred to as a mold, a hollow cylinder, or a cylindrical structure). (Counter roller)), a powder material layer is formed using a brush, a roller, a blade, a pressing member, or the like. At this time, when a support that can move up and down in the outer frame is used, the support is arranged at a position slightly lower than the upper end opening of the outer frame, that is, the powder material layer The powder material is placed on the support while being positioned below the thickness. As described above, a thin powder material layer can be formed on the support.

  Note that when a liquid material is applied to the thin powder material layer formed in this way, the organic material particles in the portion to which the liquid material is applied are dissolved, so that the metal particles are bonded to each other.

  Here, when the liquid material is applied to the thin powder material layer formed by placing the powder material on the powder material layer in the same manner as described above, the metal particles in the portion to which the liquid material is applied Adhere to each other. At this time, the adhered metal particles also adhere to the metal particles present in the lower powder material layer. As a result, a shaped article having a thickness of about two thin powder material layers is obtained.

  In addition, a thin powder material layer can be formed on a support automatically and simply using a known powder laminating apparatus.

  A powder laminating apparatus generally includes a recoater for laminating a powder material, a movable supply tank for supplying the powder material onto a support, and a thin powder material layer on the support for laminating. A movable molding tank. The powder laminating apparatus can always arrange the surface of the supply tank slightly higher than the surface of the modeling tank by raising the supply tank, lowering the modeling tank, or both. Further, the powder laminating apparatus can place a powder material on a support using a recoater, and a thin powder material layer can be laminated by repeatedly moving the recoater.

  The average thickness of the powder material layer is preferably 30 to 500 μm, more preferably 40 to 300 μm, and still more preferably 50 to 150 μm. When the average thickness of the powder material layer is 30 μm or more, the strength of the three-dimensional structure is improved, and it is difficult to cause problems such as loss of shape during subsequent processing such as sintering or handling, and when the average thickness is 500 μm or less. The dimensional accuracy of the shaped object is improved.

  The average thickness of the powder material layer is not particularly limited and can be measured according to a known method.

-Liquid material application step and liquid material application means-
There is no restriction | limiting in particular as a method of providing a liquid material to a powder material layer, According to the objective, it can select suitably, For example, a dispenser system, a spray system, an inkjet system etc. are mentioned. In order to carry out these methods, a known apparatus can be suitably used as the liquid material applying means. Among these, the inkjet method is particularly preferable. The ink jet method is preferable in that the quantitative property of droplets is better than that of the spray method, and there is an advantage that the application area can be widened compared with the dispenser method, and a complicated three-dimensional shape can be formed accurately and efficiently.

  The ink jet type liquid material applying means has a nozzle capable of applying the liquid material to the powder material layer by an ink jet method. In addition, as a nozzle, the nozzle in the inkjet head of a well-known inkjet printer can be used conveniently. Moreover, an inkjet printer can be used suitably as a liquid material provision means. In addition, as an inkjet printer, SG7100 (made by Ricoh) etc. are mentioned suitably, for example. Ink jet printers are preferable in that the amount of ink that can be dropped from an ink jet head at a time is large and the coating area is large, so that the coating speed can be increased.

  In the liquid material, the crosslinking agent can also function as a pH adjuster.

  The pH of the liquid material is 5 (weakly acidic) to 12 (basic) from the viewpoint of preventing corrosion and clogging of the nozzle head portion of the nozzle used when the liquid material is applied to the powder material layer by the inkjet method. It is preferably 8 to 10 (weakly basic).

  A known pH adjusting agent may be used to adjust the pH of the liquid material.

-Powder material container-
The manufacturing apparatus of the three-dimensional molded item of this embodiment may have a powder material accommodating part as needed.

  The powder material container is a member that accommodates the powder material, and its size, shape, material, and the like are not particularly limited and can be appropriately selected according to the purpose.

  Examples of the powder material container include a storage tank, a bag, a cartridge, and a tank.

-Liquid material container-
The manufacturing apparatus of the three-dimensional molded item of this embodiment may have a liquid material accommodating part as needed.

  The liquid material container is a member that stores the liquid material, and the size, shape, material, and the like of the liquid material container are not particularly limited, and can be appropriately selected according to the purpose.

  Examples of the liquid material container include a storage tank, a bag, a cartridge, and a tank.

-Other processes and other means-
Examples of other processes include a drying process, a sintering process, a surface protection treatment process, and a painting process.

  Examples of other means include drying means, sintering means, surface protection treatment means, and painting means.

  A drying process is a process of drying the powder material layer to which the liquid material was given. By removing the solvent contained in the powder material layer to which the liquid material has been applied by the drying process, the metal particles are bonded to each other to form a three-dimensional structure.

  Examples of the drying means include known dryers.

  In the drying step, organic substances may be further removed, that is, degreased.

  Degreasing refers to a treatment for removing the resin component. By sufficiently removing the resin component from the powder material layer to which the liquid material is applied by degreasing, deformation and cracking of the three-dimensional sintered product in the subsequent sintering process can be suppressed.

  Examples of the degreasing method include a sublimation method, a solvent extraction method, a natural drying method, and a heating method, and among them, the heating method is preferable.

  In addition, in this embodiment, since the content rate of the organic material particle in a powder material is very small, the time required for degreasing is very small and effective.

  A sintering process is a process of sintering a three-dimensional molded item.

  Sintering refers to a method in which powder is consolidated at a high temperature. A three-dimensional sintered product can be obtained by sintering the powder material in a sintering furnace. By sintering the powder material, the metal particles contained in the powder material are diffused and grain-grown to obtain a high-strength three-dimensional sintered product that is dense and has few voids as a whole.

  By a sintering process, it can be set as the metal three-dimensional sintered product with which the three-dimensional molded item was integrated.

  Examples of the sintering means include a known sintering furnace.

  Conditions such as temperature, time, atmosphere, and heating rate during sintering are appropriately set depending on the composition of the powder material, the degreasing state of the three-dimensional structure, size, shape, and the like.

  Although it does not specifically limit as sintering atmosphere, In addition to air atmosphere, it is also possible to use inert gas atmosphere, such as vacuum or pressure reduction atmosphere, non-oxidizing atmosphere, nitrogen gas, argon gas.

  Sintering may be performed in two or more stages. For example, primary sintering and secondary sintering with different sintering conditions may be performed. In this case, the sintering temperature, sintering time, and sintering atmosphere of the primary sintering and the secondary sintering can be changed.

  The surface protection treatment step is a step of forming a protective layer on the three-dimensional structure or the three-dimensional sintered body. By the surface protection treatment step, for example, the durability of the three-dimensional structure or the three-dimensional sintered product can be imparted to the surface of the three-dimensional structure or the three-dimensional sintered product.

  Specific examples of the protective layer include a water resistant layer, a weather resistant layer, a light resistant layer, a heat insulating layer, and a glossy layer.

  Examples of the surface protection treatment means include known surface protection treatment devices such as a spray device and a coating device.

  A painting process is a process of painting on a three-dimensional molded item or a three-dimensional sintered product. A three-dimensional molded item or a three-dimensional sintered product can be colored in a desired color by the painting process.

  Examples of the coating means include known coating apparatuses such as sprays, rollers, and brushes.

  Examples of the present invention will be described below, but the present invention is not limited to the examples.

Example 1
-Preparation of organic material particles 1-
As a water-soluble resin, polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nippon Vinegar Bipvar) was spray-dried to prepare organic material particles 1. The organic material particles 1 had a volume average particle size of 7.6 μm.

-Production of powder material 1-
Stainless steel particles (SUS316L) PSS316L (volume average particle size 8.1 μm, aspect ratio 0.93, density 7.98 g / cm ³ , Sanyo Special Steel Co., Ltd.) 99 parts by mass (93.7 volumes) as metal particles 1 %)), 1 part by mass (6.3% by volume) of organic material particles 1 was added, and the mixture was well stirred and mixed with a stirrer to prepare powder material 1.

<Volume average particle diameter>
The volume average particle size of the organic material particles and the metal particles was measured using a particle size measuring device Microtrac HRA (manufactured by Nikkiso Co., Ltd.).

<Aspect ratio>
The aspect ratio (average value) of the metal particles was measured using a particle shape measuring apparatus Morphologi G3-SE (Spectris). At this time, the area envelope degree of the formula particles>0.99> 100 pixels
The aspect ratio was analyzed using only particles assumed to be primary particles. The measurement conditions are as follows.

Dispersion pressure: 4 bar
Pressure application time: 10 ms
Incubation time: 60s
Number of particles assumed to be primary particles: 50,000 -Preparation of liquid material 1-
A liquid material 1 was prepared by mixing and stirring 70 parts by mass of water and 30 parts by mass of 1,2-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) as an aqueous solvent.

-Production of three-dimensional model 1-
As the recoater 4, a three-dimensional object 1 was produced according to the following method using a three-dimensional object manufacturing apparatus (see FIG. 2) using a counter roller and an inkjet head 5.

  The powder material 1 is put into the powder material container of the three-dimensional model manufacturing apparatus, the liquid material 1 is put into the liquid material container, 3D data is input, and the process shown in FIG. Two types of samples were prepared. At this time, the average thickness of one layer of the powder material layer was adjusted to be about 100 μm.

  At this time, as a strip-shaped sample, a horizontally stacked sample (see FIG. 5A) in which the length direction was shaped in the XY axis direction was produced.

  On the other hand, as a dumbbell-shaped sample, a horizontally stacked sample and a vertically stacked sample formed in the Z-axis direction (see FIG. 5B) were prepared.

  Next, the strip-shaped sample and the dumbbell-shaped sample were air-dried for about 3 hours, put in a dryer, and dried at 50 ° C. for 3 hours. Thereafter, the powder material (excess powder) to which the liquid material 1 is not adhered is blown off with air, and then again put into a dryer, dried at 100 ° C. for 12 hours, and allowed to cool to room temperature as it is to produce a three-dimensional structure 1 did.

(Example 2)
-Preparation of organic material particles 2-
An organic material except that polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval) was changed to polyvinyl alcohol JMR-10HH (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval). Organic material particles 2 were produced in the same manner as particles 1. The organic material particle 2 had a volume average particle size of 3.3 μm.

-Production of powder material 2-
A powder material 2 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 2.

-Production of three-dimensional model 2-
A three-dimensional model 2 was produced in the same manner as the three-dimensional model 1 except that the powder material 1 was changed to the powder material 2.

(Example 3)
-Preparation of organic material particles 3-
Organic material particles, except that polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval) was changed to Gocenex Z-100 (manufactured by Nippon Synthetic Chemical Industry), an acetoacetyl group-modified polyvinyl alcohol. In the same manner as in Example 1, organic material particles 3 were produced. The organic material particles 3 had a volume average particle size of 5.8 μm.

-Production of powder material 3-
A powder material 3 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 3.

-Preparation of liquid material 2-
Liquid material 2 was prepared in the same manner as liquid material 1, except that 3 parts of zirconium zirconium oxycarbonate zircosol AC-20 (manufactured by Daiichi Rare Element Chemical Co., Ltd.) was further added as a crosslinking agent.

-Production of three-dimensional model 3-
The three-dimensional structure 3 was produced in the same manner as the three-dimensional structure 1 except that the powder material 1 was changed to the powder material 3 and the liquid material 1 was changed to the liquid material 2.

Example 4
-Preparation of organic material particles 4-
Diacetone acrylamide-modified polyvinyl alcohol DF-05 (density 1.2 g / cm ³ , Japanese vinegar) as a carbonyl group-modified polyvinyl alcohol using polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval). Organic material particles 4 were produced in the same manner as the organic material particles 1 except that the material was changed to Bipobar). The organic material particles 4 had a volume average particle size of 10.5 μm.

-Production of powder material 4-
A powder material 4 was produced in the same manner as the powder material 1 except that the organic material particles 3 were changed to the organic material particles 4.

-Preparation of liquid material 3-
Liquid material 3 was prepared in the same manner as liquid material 1 except that 3 parts of adipic acid dihydrazide ADH (manufactured by Nippon Kasei Co., Ltd.) was further added as a crosslinking agent.

-Production of three-dimensional model 4-
The three-dimensional structure 4 was produced in the same manner as the three-dimensional structure 1 except that the powder material 1 was changed to the powder material 4 and the liquid material 1 was changed to the liquid material 3.

(Example 5)
-Preparation of organic material particles 5-
Organic material particles 5 were produced in the same manner as the organic material particles 4 except that the spray drying conditions were changed. The organic material particles 5 had a volume average particle size of 12.0 μm.

-Production of powder material 5-
A powder material 5 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 5.

-Production of three-dimensional model 5-
A three-dimensional model 5 was produced in the same manner as the three-dimensional model 4 except that the powder material 4 was changed to the powder material 5.

(Example 6)
-Production of organic material particles 6-
Organic material particles 6 were produced in the same manner as the organic material particles 4 except that the spray drying conditions were changed. The organic material particles 6 had a volume average particle diameter of 14.8 μm.

-Production of powder material 6-
A powder material 6 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 6.

-Production of three-dimensional model 6-
A three-dimensional model 6 was produced in the same manner as the three-dimensional model 4 except that the powder material 4 was changed to the powder material 6.

(Example 7)
-Production of powder material 7-
Powder was changed except that the addition amount of metal particles 1 was changed to 99.6 parts by mass (97.4% by volume) and the addition amount of organic material particles 1 was changed to 0.4 parts by mass (2.6% by volume). A powder material 7 was produced in the same manner as the material 1.

-Production of three-dimensional model 7-
A three-dimensional object 7 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 7.

(Example 8)
-Production of powder material 8-
Same as powder material 1 except that the addition amount of metal particles 1 is changed to 98 parts by mass (88.1% by volume) and the addition amount of organic material particles 1 is changed to 2 parts by mass (11.9% by volume). Thus, a powder material 8 was produced.

-Production of three-dimensional model 8-
A three-dimensional object 8 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 8.

Example 9
-Production of powder material 9-
Same as powder material 1 except that the addition amount of metal particles 1 is changed to 97 parts by mass (82.9% by volume) and the addition amount of organic material particles 1 is changed to 3 parts by mass (17.1% by volume). Thus, a powder material 9 was produced.

-Production of three-dimensional model 9-
A three-dimensional object 9 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 9.

(Example 10)
-Production of powder material 10-
Metal particle 1 was changed to stainless steel particle (SUS316L) PSS316L (volume average particle diameter 12.0 μm, aspect ratio 0.93, density 7.98 g / cm ³ , manufactured by Sanyo Special Steel Co., Ltd.) as metal particle 2. Except for the above, a powder material 10 was produced in the same manner as the powder material 5.

-Production of three-dimensional model 10-
The three-dimensional structure 10 was produced in the same manner as the three-dimensional structure 5 except that the powder material 5 was changed to the powder material 10.

(Example 11)
-Production of powder material 11-
Metal particle 1 was changed to stainless steel particle (SUS316L) PSS316L (volume average particle diameter 44.7 μm, aspect ratio 0.91, density 7.98 g / cm ³ , manufactured by Sanyo Special Steel Co., Ltd.) as metal particle 3. Except for the above, a powder material 11 was produced in the same manner as the powder material 5.

-Production of three-dimensional model 11-
The three-dimensional structure 11 was produced in the same manner as the three-dimensional structure 5 except that the powder material 5 was changed to the powder material 11.

(Example 12)
-Production of powder material 12-
Other than changing the metal particles 1 to titanium alloy particles TILOP64-45 (volume average particle size 34.5 μm, aspect ratio 0.90, density 4.43 g / cm ³ , Osaka Titanium Technologies, Inc.) as metal particles 4 Produced powder material 12 in the same manner as powder material 4.

-Production of three-dimensional model 12-
The three-dimensional model 12 was produced in the same manner as the three-dimensional model 4 except that the powder material 4 was changed to the powder material 12.

(Example 13)
-Production of powder material 13-
Except for changing the addition amount of the metal particles 4 to 95 parts by mass (83.7% by volume) and the addition amount of the organic material particles 4 to 5 parts by mass (16.3% by volume), the same as the powder material 12, A powder material 13 was produced.

-Production of three-dimensional model 13-
A three-dimensional object 13 was produced in the same manner as the three-dimensional object 12 except that the powder material 12 was changed to the powder material 13.

(Example 14)
-Production of powder material 14-
Powder material except that the metal particles 1 are changed to aluminum particles TFS-A10P (volume average particle size 10 μm, aspect ratio 0.88, density 2.7 g / cm ³ , manufactured by Toyo Aluminum Co., Ltd.) as the metal particles 5 In the same manner as in Example 4, a powder material 14 was produced.

-Production of three-dimensional model 14-
A three-dimensional object 14 was produced in the same manner as the three-dimensional object 4 except that the powder material 4 was changed to the powder material 14.

(Example 15)
-Production of powder material 15-
Except for changing the addition amount of the metal particles 5 to 95 parts by mass (89.4% by volume) and changing the addition amount of the organic material particles 4 to 5 parts by mass (10.6% by volume), the same as the powder material 14 Thus, a powder material 15 was produced.

-Production of three-dimensional model 15-
A three-dimensional object 15 was produced in the same manner as the three-dimensional object 14 except that the powder material 14 was changed to the powder material 15.

(Example 16)
-Production of powder material 16-
Except for changing the metal particles 1 to copper particles Type-T (volume average particle size 6.0 μm, aspect ratio 0.86, density 8.9 g / cm ³ , manufactured by DOWA Electronics Co., Ltd.) as the metal particles 6, A powder material 16 was produced in the same manner as the powder material 4.

-Production of three-dimensional model 16-
The three-dimensional model 16 was produced in the same manner as the three-dimensional model 4 except that the powder material 4 was changed to the powder material 16.

(Example 17)
-Production of powder material 17-
Except for changing the addition amount of the metal particles 6 to 98 parts by mass (86.9% by volume) and changing the addition amount of the organic material particles 4 to 2 parts by mass (13.1% by volume), the same as the powder material 16 Thus, a powder material 17 was produced.

-Production of three-dimensional model 16-
A three-dimensional model 17 was produced in the same manner as the three-dimensional model 16 except that the powder material 16 was changed to the powder material 17.

(Example 18)
-Preparation of organic material particles 7-
Except for changing polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval) to Alcox L-11 (density 1.1 g / cm ³ , manufactured by Meisei Chemical Industry) of polyethylene oxide. Organic material particles 7 were produced in the same manner as the organic material particles 1. The organic material particles 7 had a volume average particle size of 3.3 μm.

-Production of powder material 18-
A powder material 18 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 7.

-Production of three-dimensional model 18-
A three-dimensional object 18 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 18.

(Example 19)
-Production of powder material 19-
A powder material 19 was produced in the same manner as the powder material 18 except that the metal particles 1 were changed to the metal particles 3.

-Production of three-dimensional model 19-
A three-dimensional object 19 was produced in the same manner as the three-dimensional object 18 except that the powder material 18 was changed to the powder material 19.

(Example 20)
-Preparation of organic material particles 8-
Polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval) was changed to polyacrylic acid Aquaric AS (manufactured by Nippon Shokubai Co., Ltd.), and spray drying was changed to freeze pulverization. Organic material particles 8 were produced in the same manner as the organic material particles 1. The organic material particles 8 had a volume average particle size of 14.3 μm.

-Production of powder material 20-
A powder material 20 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 8.

-Production of three-dimensional model 20-
A three-dimensional object 20 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 20.

(Example 21)
-Production of powder material 21-
A powder material 21 was produced in the same manner as the powder material 20 except that the metal particles 1 were changed to the metal particles 6.

-Production of three-dimensional model 21-
A three-dimensional object 21 was produced in the same manner as the three-dimensional object 20 except that the powder material 20 was changed to the powder material 21.

(Example 22)
-Preparation of organic material particles 9-
Polyvinyl alcohol JMR-20H (density 1.2 g / cm ³ , manufactured by Nihon Vinegar Bipoval) was replaced with butenediol-vinyl alcohol copolymer G-polymer OKS-8041 (density 1.2 g / cm ³ , Nippon Synthetic Chemical Industry Co., Ltd.). Organic material particles 9 were produced in the same manner as the organic material particles 1 except that the material was changed to “made”. The organic material particles 9 had a volume average particle size of 8.8 μm.

-Production of powder material 22-
A powder material 22 was produced in the same manner as the powder material 12 except that the organic material particles 4 were changed to organic material particles 9.

-Production of three-dimensional model 22-
A three-dimensional model 22 was produced in the same manner as the three-dimensional model 12 except that the powder material 12 was changed to the powder material 22.

(Example 23)
-Production of metal particles 7-
The metal particles 2 were subjected to vibration milling using zirconia beads to produce metal particles 7. The metal particles 7 had a volume average particle size of 9.2 μm and an aspect ratio of 0.81.

-Production of powder material 23-
A powder material 23 was produced in the same manner as the powder material 10 except that the metal particles 2 were changed to the metal particles 7.

-Production of three-dimensional model 23-
A three-dimensional object 23 was produced in the same manner as the three-dimensional object 10 except that the powder material 10 was changed to the powder material 23.

(Comparative Example 1)
-Production of three-dimensional model 24-
Except for changing the powder material 1 to the metal particles 1, the three-dimensional object 24 was tried to be produced in the same manner as the three-dimensional object 1. However, when excess powder was blown off with air, the structure could not be confirmed. The three-dimensional model 24 could not be produced.

(Comparative Example 2)
-Production of powder material 24-
Except for changing the organic material particles 1 to water-insoluble silicone resin fine particles (Tospearl 2000B, volume average particle size 6.0 μm, density 1.32 g / cm ³ ) as organic material particles 10, Similarly, the powder material 24 was produced.

-Production of three-dimensional model 25-
Except for changing the powder material 1 to the powder material 24, the three-dimensional object 25 was prepared in the same manner as the three-dimensional object 1. However, when surplus powder was blown off with air, the structure could not be confirmed. The three-dimensional model 25 could not be produced.

(Comparative Example 3)
-Preparation of liquid material 4-
A liquid material 4 was prepared in the same manner as the liquid material 1 except that 6 parts by mass of the organic material particles 1 were added and dissolved.

-Production of three-dimensional model 26-
A three-dimensional object 26 was produced in the same manner as the three-dimensional object 24 except that the liquid material 1 was changed to the liquid material 4.

(Comparative Example 4)
-Production of powder material 25-
Powder was changed except that the addition amount of metal particles 1 was changed to 96.5 parts by mass (80.6% by volume) and the addition amount of organic material particles 1 was changed to 3.5 parts by mass (19.4% by volume). In the same manner as Material 1, a powder material 25 was produced.

-Production of three-dimensional model 27-
A three-dimensional object 27 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 25.

(Comparative Example 5)
-Production of powder material 26-
Same as powder material 1 except that the addition amount of the metal particles 1 is changed to 90 parts by mass (57.5% by volume) and the addition amount of the organic material particles 1 is changed to 10 parts by mass (21.7% by volume). Thus, a powder material 26 was produced.

-Production of three-dimensional model 28-
A three-dimensional object 28 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 26.

(Comparative Example 6)
-Production of organic material particles 11-
Organic material particles 11 were produced in the same manner as the organic material particles 1 except that the spray drying was changed to freeze pulverization. The organic material particles 11 had a volume average particle diameter of 19.8 μm.

-Production of powder material 27-
A powder material 27 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 11.

-Production of three-dimensional model 29-
A three-dimensional object and 29 were produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 27.

(Comparative Example 7)
-Preparation of organic material particles 12-
Organic material particles 12 were produced in the same manner as the organic material particles 11 except that the freeze-grinding conditions were changed. The organic material particles 12 had a volume average particle size of 50.3 μm.

-Production of powder material 28-
A powder material 28 was produced in the same manner as the powder material 1 except that the organic material particles 1 were changed to the organic material particles 12.

-Production of three-dimensional model 30-
A three-dimensional object 30 was produced in the same manner as the three-dimensional object 1 except that the powder material 1 was changed to the powder material 28.

  Tables 1 to 4 show the characteristics of the organic material particles 1 to 12, the metal particles 1 to 7, the powder material 1 to 28, and the liquid materials 1 to 4, respectively.

次に、立体造形物１〜２３、２６〜３０の曲げ応力、余剰粉の除去性、余剰粉の凝集性、寸法精度を評価した。

Next, the bending stress of the three-dimensional molded items 1 to 23 and 26 to 30, the removability of excess powder, the cohesiveness of excess powder, and the dimensional accuracy were evaluated.

<Bending stress>
Using a precision universal testing machine Autograph AGS-J (manufactured by Shimadzu Corporation), the three-point bending stresses of the three-dimensional structures 1 to 23 and 26 to 30 were measured. Specifically, a strip-shaped horizontal sample was used as the three-dimensional model, and the maximum stress when the three-dimensional model was broken was measured. The evaluation criteria for bending stress are shown below.

  A: The maximum stress is 9.0 MPa or more.

  ○: The maximum stress is 5.0 MPa or more and less than 9.0 MPa.

  Δ: The maximum stress is 1.0 MPa or more and less than 5.0 MPa.

  X: The maximum stress is less than 1.0 MPa.

<Removability of excess powder>
The dimensions and thicknesses of the three-dimensional objects 1 to 23 and 26 to 30 were measured, and the degree of reduction in dimensional accuracy due to the attachment of excess powder, that is, the removability of excess powder was evaluated. The evaluation criteria for the removal of excess powder are shown below.

  A: A desired size and thickness are obtained, and the surface is smooth.

  ○: The size and thickness are slightly different, but there is no problem with visual observation.

  (Triangle | delta): The surplus powder has adhered to the surface and the precision of a dimension and thickness and the smoothness of the surface are falling.

  X: A large amount of surplus powder adheres, the shape is changed, and it is necessary to scrape off the surplus powder.

<Cohesiveness of surplus powder>
At the time of producing the three-dimensional shaped objects 1 to 23 and 26 to 30, after collecting the surplus powder removed by blowing away with air, the surplus powder is passed through a sieve having an opening of 100 μm, and the aggregate of surplus powder remaining on the sieve From the amount, the cohesiveness of the excess powder was evaluated. The evaluation criteria for the cohesiveness of excess powder are shown below.

  (Double-circle): The aggregate of surplus powder hardly remains on a sieve, and the aggregate of surplus powder is hardly recognized.

  ○: Some agglomerates of excess powder remain on the sieve, but they are small enough to be easily crushed.

  Δ: A relatively large amount of surplus powder aggregate remains on the sieve, and pulverization is necessary for reuse.

  X: The aggregate of the surplus powder remaining on the sieve is a large lump and needs to be crushed for a long time to be reused.

<Dimensional accuracy>
Based on CAD data, the three-dimensional molded items 1-23 and 26-30 were produced, the dimension of the obtained three-dimensional molded item was measured, and the comparison with CAD data was performed. Moreover, linearity and surface unevenness were evaluated. The evaluation criteria for dimensional accuracy are shown below.

  A: Level where there is almost no difference from CAD data and the defect cannot be visually determined.

  ○: Although there is a slight difference in dimensions, it is difficult to distinguish and there is no problem with defects.

  Δ: A level in which there is a clear difference in dimensions, and defects can be easily distinguished visually.

  X: A level in which a large difference is recognized and a large defect is conspicuous.

-Production of three-dimensional sintered product 1-23, 26-30-
The three-dimensional objects 1 to 23 and 26 to 30 were heated to 400 ° C. in a nitrogen atmosphere using a dryer, degreased, and then sintered at 1300 ° C. under vacuum conditions in a sintering furnace. Three-dimensional sintered products 1 to 23 and 26 to 30 were produced.

  Next, the anisotropy of the tensile stress of the three-dimensional sintered products 1 to 23 and 26 to 30 was evaluated.

<Anisotropy of tensile stress of three-dimensional sintered product 1-23, 26-30>
Using a precision universal testing machine Autograph AGS-J (manufactured by Shimadzu Corporation), tensile stresses of the three-dimensional sintered products 1 to 23 and 26 to 30 were measured. Specifically, a dumbbell-shaped laterally stacked sample and a vertically stacked sample were used as the three-dimensional sintered product, and the maximum stress when each fractured was measured. The evaluation criteria for the anisotropy of tensile stress are shown below.

  A: The maximum stress of the vertically stacked sample is 90% or more with respect to the maximum stress of the horizontally stacked sample.

  A: The maximum stress of the vertically stacked sample is 80% or more with respect to the maximum stress of the horizontally stacked sample.

  Δ: The maximum stress of the vertically stacked sample is 70% or more with respect to the maximum stress of the horizontally stacked sample.

  X: The maximum stress of the vertically stacked sample is less than 70% with respect to the maximum stress of the horizontally stacked sample.

  Table 5 shows differences in bending stress, removal of excess powder, cohesiveness of excess powder, and dimensional accuracy of the three-dimensional molded objects 1 to 23 and 26 to 30, and tensile stresses of the three-dimensional sintered articles 1 to 23 and 26 to 30. The results of evaluation of directionality are shown.

表５から、実施例１〜２３における立体造形物１〜２３は、余剰粉の除去性が高く、かつ、余剰粉の凝集性が低く、立体造形物の強度が高いことがわかる。また、立体造形物１〜２３を焼結した立体焼結物１〜２３は、Ｚ軸方向の強度が高く、Ｘ、Ｙ、Ｚ軸における強度の異方性が低い。

From Table 5, it can be seen that the three-dimensional shaped objects 1 to 23 in Examples 1 to 23 have a high ability to remove surplus powder, a low agglomeration property of the surplus powder, and a high strength of the three-dimensional shaped article. The three-dimensional sintered products 1 to 23 obtained by sintering the three-dimensional molded products 1 to 23 have high strength in the Z-axis direction and low strength anisotropy in the X, Y, and Z axes.

  On the other hand, in the comparative example 1, since the metal particle 1 was used without using the powder material 1, the three-dimensional structure 24 could not be produced.

  In Comparative Example 2, since the powder material 24 containing water-insoluble silicone resin particles was used as the organic material particle 10, the three-dimensional structure 25 could not be produced.

  The three-dimensional structure 26 in Comparative Example 3 has a low strength because the powder material 1 is not used but the metal material 1 is used and the liquid material 4 in which the organic material particles 1 are dissolved is used. The three-dimensional sintered product 26 obtained by sintering the three-dimensional model 26 has low strength in the Z-axis direction and high strength anisotropy in the X, Y, and Z axes.

  Since the three-dimensionally shaped object 27 in Comparative Example 4 uses the powder material 25 in which the content of the organic material particles 1 is 19.4% by volume, the removal ability of the excess powder is low and the aggregation ability of the excess powder is high.

  Since the three-dimensional structure 28 in Comparative Example 5 uses the powder material 26 in which the content of the organic material particles 1 is 42.5% by volume, the removal ability of the excess powder of the three-dimensional structure 28 is low, and High cohesion. In addition, the three-dimensional sintered product 28 obtained by sintering the three-dimensional model 28 has low strength in the Z-axis direction and high strength anisotropy in the X, Y, and Z axes.

  Since the three-dimensional structure 29 in Comparative Example 6 uses the powder material 27 including the organic material particles 11 having a volume average particle diameter of 19.8 μm, the removal ability of the excess powder of the three-dimensional structure 29 is low. The three-dimensional sintered product 29 obtained by sintering the three-dimensional model 29 has a low strength in the Z-axis direction and a high strength anisotropy in the X, Y, and Z axes.

  Since the three-dimensional model 30 in Comparative Example 7 uses the powder material 28 including the organic material particles 12 having a volume average particle diameter of 50.3 μm, the removal ability of the excess powder of the three-dimensional model 30 is low. In addition, the three-dimensional sintered product 29 obtained by sintering the three-dimensional model 30 has low strength in the Z-axis direction and high strength anisotropy in the X, Y, and Z axes.

<Reuse of surplus powder>
In Example 1, when producing the three-dimensional structure 1, excess powder that was not used for modeling was collected, stirred with a stirrer, and then used as a reusable powder material. A sintered product was produced.

  When the bending stress was evaluated in the same manner as in Example 1 for the obtained three-dimensional modeled object and three-dimensionally sintered product, the same result as in Example 1 was obtained, and it was confirmed that the surplus powder could be reused. It was done.

1 Modeling powder storage tank (modeling tank)
2, 2 'supply powder storage tank (supply tank)
3 Support (Stage)
4 Leveling mechanism (recoater)
5 Inkjet head 6 Powder drop port P Powder material L Liquid material

JP 2011-230422 A JP 2012-125996 A

Claims (12)

A powder material for three-dimensional modeling including metal particles and water-soluble organic material particles,
The content of the organic material particles is 2% by volume or more and 18% by volume or less with respect to the powder material for three-dimensional modeling,
The volume average particle diameter of the organic material particles is 3 μm or more and 15 μm or less, and the three-dimensional modeling powder material.   3. The three-dimensional modeling powder according to claim 1, wherein the volume average particle size of the metal particles is 0.5 to 3.5 times the volume average particle size of the organic material particles. material. The aspect ratio (average value) calculated by the following formula (1) of the metal particles is 0.85 or more, and the three-dimensional modeling powder material according to claim 1 or 2.
Aspect ratio (average value) = (X1 × Y1 + X2 × Y2 +... + Xn × Yn) / 100 (1)
Where X is the aspect ratio (minor axis / major axis) of the particles, Yi is the abundance [%] of the particles having an aspect ratio of Xi, i is an integer of 1 to n, and Y1 + Y2 + ... + Yn = 100.   The powder material for three-dimensional modeling according to any one of claims 1 to 3, wherein the organic material particles include a polyvinyl alcohol resin.   The three-dimensional modeling powder material according to claim 4, wherein the polyvinyl alcohol resin has a crosslinkable functional group. Three-dimensional modeling powder material according to any one of claims 1 to 5,
A three-dimensional modeling kit comprising a three-dimensional modeling liquid material containing water.   The three-dimensional modeling kit according to claim 6, wherein the three-dimensional modeling liquid material further contains a crosslinking agent. A powder material layer forming step of forming a powder material layer using the three-dimensional powder material according to any one of claims 1 to 5,
Including a liquid material application step of applying a three-dimensional modeling liquid material to a predetermined region of the powder material layer,
The method for producing a three-dimensional structure, wherein the three-dimensional structure liquid material contains water.   The method for producing a three-dimensional structure according to claim 8, wherein the three-dimensional structure liquid material further contains a crosslinking agent.   The method for producing a three-dimensional structure according to claim 8 or 9, wherein an ink jet method is used when applying the three-dimensional structure liquid material. A three-dimensional object manufacturing process for manufacturing a three-dimensional object by the method for manufacturing a three-dimensional object according to any one of claims 8 to 10,
A method of manufacturing a three-dimensional sintered product, comprising: a three-dimensional sintered product manufacturing step of manufacturing the three-dimensional sintered product by sintering the three-dimensional modeled product. Powder material layer forming means for forming a powder material layer using the powder material for three-dimensional modeling according to any one of claims 1 to 5,
A liquid material applying means for applying a liquid material for three-dimensional modeling to a predetermined region of the powder material layer,
The apparatus for producing a three-dimensional structure, wherein the liquid material applying means is an ink jet system.

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