JPWO2019117015A1 - Manufacturing method of three-dimensional model and powder material used for it - Google Patents

Abstract

An object of the present invention is to provide a powder material that can be efficiently cured by infrared light irradiation and can produce a three-dimensional model having high strength and high dimensional accuracy, and a method for producing the three-dimensional model using the powder material. To do. In order to solve the above problems, it is used in a method for manufacturing a three-dimensional model including forming a thin layer containing a powder material, applying a binding fluid to the thin layer, and irradiating the thin layer with infrared light. It is a powder material. The powder material contains molding particles including a thermoplastic resin and an inorganic material having a thermal conductivity of 2 W / mK or more and a band gap of 1.59 eV or more.

Description

The present invention relates to a method for producing a three-dimensional model and a powder material used therein.

In recent years, various methods have been developed that can relatively easily produce three-dimensional objects having complicated shapes, and rapid prototyping and rapid manufacturing using such methods are attracting attention.

As one of the methods for producing such a three-dimensional model, a thin layer made of resin particles containing a thermoplastic resin is formed, and the resin particles in a desired region are sintered or melt-bonded (hereinafter, simply "melt-bonded"). (Also referred to as), a method of obtaining a three-dimensional model has been proposed. For example, various treatments are performed so that the degree of energy absorption differs between the region where the resin particles are melt-bonded (hereinafter, also referred to as “cured region”) and the other region (hereinafter, also referred to as “non-cured region”). It has been proposed to irradiate the entire surface of the thin layer with energy after performing the above (Patent Document 1). According to this method, since energy irradiation can be performed collectively, there is an advantage that a three-dimensional model can be formed much faster than the conventional method. In addition, Patent Document 1 below describes that an energy absorber is applied only to the cured region as a method of increasing the degree of energy absorption in the cured region to be higher than the degree of energy absorption in the non-cured region.

Special Table 2007-533480

In recent years, in the method for producing a three-dimensional model described in Patent Document 1, a binding fluid containing an infrared light absorber is applied to a cured region, and a non-cured region is used for peeling with low energy absorption as necessary. It is being considered to apply a fluid (hereinafter, the method is also referred to as "MJF method"). In the MJF method, when the entire surface is irradiated with infrared light after the coupling fluid and the peeling fluid are applied, the infrared light absorber in the cured region absorbs the infrared light and generates heat. As a result, the temperature of the resin particles in the cured region rises, and the resin particles are melt-bonded to each other. However, in this method, it takes time for heat to be transferred to the inside of the resin particles. Therefore, there has been a demand for a method for melting the thermoplastic resin more efficiently.

The present invention has been made in view of the above problems. That is, the present invention provides a powder material that can be efficiently cured by infrared light irradiation and can produce a three-dimensional model having high strength and high dimensional accuracy, and a method for producing the three-dimensional model using the powder material. provide.

The first of the present invention lies in the powder material.
[1] A powder material used in a method for producing a three-dimensional model including the formation of a thin layer containing a powder material, the application of a binding fluid to the thin layer, and the irradiation of the thin layer with infrared light. A powder material containing molding particles, which comprises a thermoplastic resin and an inorganic material having a thermal conductivity of 2 W / mK or more and a band gap of 1.59 eV or more.

[2] The powder material according to [1], wherein the inorganic material has an average particle size of 0.01 to 50 μm.
[3] The powder material according to [1] or [2], wherein the inorganic material is scaly.

The second aspect of the present invention is the following method for manufacturing a three-dimensional model.
[4] A thin layer forming step of forming a thin layer containing the powder material according to any one of the above [1] to [3] and a binding fluid containing an infrared light absorber are applied to the thin layer. The fluid coating step of applying to a specific region and the thin layer after the fluid coating step are irradiated with infrared light to melt the thermoplastic resin in the molding particles of the region to which the binding fluid is applied. A method for manufacturing a three-dimensional model, including an infrared light irradiation step of forming a model layer.

[5] The step according to [4], wherein the thin layer forming step, the fluid coating step, and the infrared light irradiation step are repeated a plurality of times to stack the shaped object layers to form a three-dimensional shaped object. A method for manufacturing a three-dimensional model.
[6] The method according to [4] or [5], wherein in the fluid coating step, a peeling fluid having less infrared light absorption than the coupling fluid is applied to a region adjacent to the coating region of the coupling fluid. A method for manufacturing a three-dimensional model.
[7] The method for producing a three-dimensional model according to [6], wherein in the fluid coating step, the bonding fluid and the peeling fluid are coated by an inkjet method.

The powder material of the present invention can be efficiently cured by infrared light irradiation. Further, according to the powder material of the present invention, a three-dimensional model having high strength and high dimensional accuracy can be obtained.

FIG. 1 is a side view schematically showing a configuration of a three-dimensional modeling apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a main part of a control system of a three-dimensional modeling apparatus according to an embodiment of the present invention.

The powder material of the present invention is a material applied to the above-mentioned MJF method. As described above, in the MJF method, a binding fluid containing an infrared light absorber and, if necessary, a peeling fluid having less infrared light absorption than the binding fluid are applied to the thin layer containing the resin particles. Then, by irradiating the entire surface with infrared light, only the temperature of the region to which the bonding fluid is applied is raised, and the resin particles are melt-bonded. However, the conventional resin particles have a problem that heat is not easily transferred to the inside when irradiated with infrared light, and it takes time to sufficiently melt the resin particles.

On the other hand, the molding particles contained in the powder material of the present invention include an inorganic material having a thermal conductivity of 2 W / mK or more and a band gap of 1.59 eV or more, together with a thermoplastic resin. When the molding particles contain an inorganic material having relatively high thermal conductivity, the heat from the generated infrared light absorber is transferred to the thermoplastic resin via the inorganic material. That is, the thermoplastic resin is efficiently melted by transferring heat to the inside of the molding particles. In addition, the inorganic material has a sufficiently large bandgap and hardly absorbs infrared light. Therefore, when producing a three-dimensional model, infrared light can be irradiated not only to the surface of the cured region but also to the inside, and the particles for modeling can be sufficiently melt-bonded. Further, since the inorganic material does not absorb infrared light, even if the entire surface is irradiated with infrared light, the non-cured region does not generate heat, and the powder material only in the cured region can be cured. Hereinafter, the powder material will be described first, and then a method for manufacturing a three-dimensional model using the powder material will be described.

1. 1. About powder material The powder material of the present invention includes at least molding particles. The powder material may contain various additives, a flow agent, a filler, and the like, if necessary.

The molding particles are particles containing a thermoplastic resin and an inorganic material. The shape of the molding particles is not particularly limited, and may be any shape such as spherical or prismatic. However, from the viewpoint of improving the fluidity of the powder material and producing a three-dimensional model with high dimensional accuracy, it is preferable that the powder material has a spherical shape. Further, the inorganic material may be contained only in a part of the modeling particles, for example, only on the surface side, but from the viewpoint of thermal conductivity, it is preferable that the modeling particles uniformly contain the inorganic material. ..

Here, the average particle size of the modeling particles is not particularly limited, but is preferably 2 μm or more and 210 μm or less, and more preferably 10 μm or more and 80 μm or less. When the average particle size of the modeling particles is 2 μm or more, the thickness of the modeled object layer produced by the method for producing a three-dimensional object described later tends to be sufficiently thick, and it becomes possible to efficiently produce a three-dimensional object. .. On the other hand, when the average particle size of the modeling particles is 210 μm or less, it is possible to produce a three-dimensional model having a complicated shape.

The average particle size of the modeling particles shall be the volume average particle size measured by the dynamic light scattering method. The volume average particle size can be measured by a laser diffraction type particle size distribution measuring device (MT3300EXII manufactured by Microtrac Bell) equipped with a wet disperser.

The thermal conductivity of the inorganic material contained in the molding particles is 2 W / mK or more, more preferably 2 to 250 W / mK, and further preferably 4 to 250 W / mK. When the thermal conductivity of the inorganic material is within the above range, heat is easily transferred from the infrared light absorber to the inorganic material, and further, heat is easily transferred from the inorganic material to the thermoplastic resin. The thermal conductivity is measured by using the MTPS (Unsteady Plane Heat Source) method using a thermal conductivity measuring device TCi or the like manufactured by C-THERM.

On the other hand, the band gap of the inorganic material is 1.59 eV or more, more preferably 2 to 10 eV, and even more preferably 5 to 10 eV. Since the inorganic material has a band gap that is not excited by infrared light, it does not generate heat even when it receives infrared light. The "infrared light" referred to in the present specification is light having a diameter of 780 nm to 3000 nm. Therefore, when the band gap is 1.59 eV or more, it is difficult for the inorganic material to absorb infrared light by infrared light irradiation. The band gap of the inorganic material is measured by observing the emission of photoelectrons corresponding to the energy of the ultraviolet light to be irradiated using AC3 or the like manufactured by RIKEN Keiki Co., Ltd.

The shape of the inorganic material contained in the molding particles is not particularly limited as long as it has the above-mentioned thermal conductivity and band gap, and may be, for example, particulate, fibrous, or scaly. It may be. From the viewpoint of thermal conductivity, it is particularly preferable that it is scaly. In addition, in this specification, "scaly" means a flat or curved plate shape.

The average particle size of the inorganic material is not particularly limited as long as the thermal conductivity can be exhibited, but is preferably 0.01 to 50 μm, more preferably 0.01 to 30 μm, and 0.01. It is more preferably ~ 20 μm. When the average particle size of the inorganic material is 0.01 μm or more, heat can be efficiently transferred in the molding particles. On the other hand, when the average particle diameter is 50 μm or less, the thermoplastic resin melts, and it is difficult to hinder the bonding when the modeling particles are bonded to each other, and it becomes easy to obtain a high-strength three-dimensional model. The average particle size of the inorganic material is the volume average particle size, and can be specified by removing the thermoplastic resin in the molding particles with a solvent or the like and then measuring with the laser diffraction type particle size distribution measuring device or the like.

When the inorganic material is scaly, the shape of the inorganic material when viewed in a plane is not particularly limited, and may be circular, elliptical, polygonal, or the like. Good. At this time, the ratio of the thickness to the major axis (major axis / thickness) is preferably 2 to 100, and more preferably 5 to 100. The thickness is preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm. When the thickness is 10 μm or less, the surface area of the inorganic material tends to be large, and the inorganic material facilitates efficient heat transfer. On the other hand, when the inorganic material is fibrous, the fiber length is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm. The fiber diameter is preferably 0.02 to 5 μm, more preferably 0.02 to 3 μm.

The material constituting the inorganic material is not particularly limited as long as it satisfies the thermal conductivity and the band gap, and examples thereof include metal oxides such as aluminum oxide, magnesium oxide, and talc; silicon carbide and boron nitride. And semi-metals such as aluminum nitride and carbides of metals and nitrides are included. The molding particles may contain only one kind of inorganic material, or may contain two or more kinds of inorganic materials. Among these, a white inorganic material is preferable from the viewpoint that it is difficult to absorb infrared light. Further, magnesium oxide, talc, boron nitride, or aluminum nitride is more preferable, and boron nitride is particularly preferable.

The inorganic material is preferably contained in an amount of 1 to 60% by mass, more preferably 3 to 60% by mass, and further preferably 5 to 60% by mass with respect to the molding particles. preferable. When 1% by mass or more of an inorganic material is contained in the modeling particles, heat is easily transferred in the modeling particles when producing a three-dimensional modeled object. On the other hand, when the amount of the inorganic material in the molding particles is 60% by mass or less, the amount of the thermoplastic resin is relatively sufficient, and it becomes easy to obtain a three-dimensional model having high strength.

On the other hand, the thermoplastic resin contained in the molding particles is appropriately selected according to the method for forming the three-dimensional model. As the thermoplastic resin, the same resin as that contained in the resin particles for a general MJF method can be used. The molding particles may contain only one type of thermoplastic resin, or may contain two or more types of thermoplastic resin.

However, if the melting temperature of the thermoplastic resin is too high, it will be necessary to irradiate infrared light for a long time in order to melt the modeling particles when producing the three-dimensional model, and it will take time to produce the three-dimensional model. There are things to do. Therefore, the melting temperature of the thermoplastic resin is preferably 300 ° C. or lower, more preferably 230 ° C. or lower. On the other hand, from the viewpoint of heat resistance of the obtained three-dimensional model, the melting temperature of the thermoplastic resin is preferably 100 ° C. or higher, more preferably 150 ° C. or higher. The melting temperature can be adjusted depending on the type of thermoplastic resin and the like.

Here, the thermoplastic resin may be a crystalline resin or an amorphous resin. Examples of thermoplastic resins include polyamide 12, polyamide 6, polycarbonate, polyoxymethylene, polymethylmethacrylate, polyethylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polysulfone, polyacrylonitrile, poly2-ethylhexyl. Includes methacrylate, polyphenylene sulfide and the like. Among these, polyamide 12 or polypropylene is preferable from the viewpoint of versatility and handleability.

Here, the thermoplastic resin is preferably contained in an amount of 40 to 99% by mass, more preferably 40 to 97% by mass, based on the molding particles. When 40% by mass of the thermoplastic resin is contained, it becomes easy to obtain a three-dimensional model having high strength. On the other hand, when the amount of the thermoplastic resin is 97% by mass or less, the amount of the inorganic material is relatively large, and the thermoplastic resin can be efficiently melted.

Further, the powder material may contain components other than the molding particles as long as the object and effect of the present invention are not impaired, and for example, various additives may be contained. Examples of various additives include antioxidants, acidic compounds and derivatives thereof, lubricants, UV absorbers, light stabilizers, nucleating agents, flame retardants, impact improvers, foaming agents, colorants, organic peroxides, and exhibitions. Includes adhesives, adhesives, etc. The powder material may contain only one kind of these, or may contain two or more kinds of these.

Further, the powder material may contain a filler as long as the object and effect of the present invention are not impaired. Examples of fillers are talc, calcium carbonate, zinc carbonate, wallastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, glass cut. Fiber, glass milled fiber, glass flakes, glass powder, silicon carbide, silicon nitride, gypsum, gypsum whiskers, calcined kaolin, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fibers, metal whiskers, metal powder , Ceramic whiskers, potassium titanate, boron nitride, graphite, carbon fibers and other inorganic fillers; polysaccharide nanofibers; various polymers and the like. The powder material may contain only one kind of these, or may contain two or more kinds of these.

In addition, the powder material may contain a flow agent as long as the object and effect of the present invention are not impaired. The flow agent may be a material having a small coefficient of friction and self-lubricating property. Examples of such flow agents include silicon dioxide and boron nitride. Only one of these flow agents may be included, or both may be included. The amount of the flow agent can be appropriately set within a range in which the fluidity of the powder material is improved and the melt bond of the powder material is sufficiently generated, for example, more than 0% by mass with respect to the total mass of the powder material. It can be less than 2% by mass.

The method for preparing the powder material is not particularly limited, and for example, the following method can be used. First, a thermoplastic resin and an inorganic material are prepared. As the thermoplastic resin, a thermoplastic resin may be prepared, or a commercially available product may be used. Further, since the inorganic materials have the same average particle size, they may be mechanically pulverized or classified as necessary. Then, the thermoplastic resin and the inorganic material are heated and mixed. The heating temperature is appropriately selected according to the type of the thermoplastic resin, and is preferably at least the temperature at which the thermoplastic resin melts, for example. Then, after cooling the mixture, it is pulverized to a desired size to obtain a powder material. At this time, classification or the like may be performed as necessary.

2. 2. Method for manufacturing a three-dimensional model Next, a method for manufacturing a three-dimensional model using the above powder material will be described. In the method for producing the three-dimensional model, (1) a thin layer forming step of forming a thin layer containing the powder material, and (2) a binding fluid containing an infrared light absorber are applied to a specific region of the thin layer. The fluid coating step of coating and (3) the thin layer after the fluid coating step are irradiated with infrared light to melt the thermoplastic resin in the modeling particles in the region to which the binding fluid is applied. At least the infrared light irradiation step of forming the modeled object layer is performed. In the above-mentioned fluid coating step, if necessary, a peeling fluid having less infrared light absorption than the coupling fluid may be coated on the region adjacent to the coating region of the coupling fluid.

As described above, the molding particles contained in the powder material can efficiently transfer the heat generated by the infrared light absorber. Therefore, the powder material in the region coated with the bonding fluid can be efficiently cured by infrared light irradiation. Further, by using the molding particles of the powder material, infrared light can be irradiated not only to the surface of the thin layer but also to the inside, and the thermoplastic resins can be sufficiently bonded to each other in the cured region. it can. As a result, a three-dimensional model having high strength and excellent dimensional accuracy can be obtained. Hereinafter, a method for manufacturing the three-dimensional model will be described in detail.

(1) Thin layer forming step In the thin layer forming step, a thin layer mainly containing the above-mentioned powder material is formed. The method for forming the thin layer is not particularly limited as long as a layer having a desired thickness can be formed. For example, this step can be a step of laying the powder material supplied from the powder supply unit of the three-dimensional modeling apparatus flat on the modeling stage by a recorder. The thin layer may be formed directly on the modeling stage or may be formed so as to be in contact with the already spread powder material or the already formed modeling layer.

The thickness of the thin layer is the same as the thickness of the desired model layer. The thickness of the thin layer can be arbitrarily set according to the accuracy of the three-dimensional model to be manufactured, but is usually 0.01 mm or more and 0.30 mm or less. By setting the thickness of the thin layer to 0.01 mm or more, the modeled object already produced by infrared light irradiation (infrared light irradiation in the infrared light irradiation step described later) for forming a new modeled object layer. It is possible to prevent the layer from melting. Further, when the thickness of the thin layer is 0.01 mm or more, it becomes easy to spread the powder material uniformly. Further, by setting the thickness of the thin layer to 0.30 mm or less, it is possible to irradiate the lower part of the thin layer with infrared light in the infrared light irradiation step described later, and the thermoplastic resin in the cured region is thickened. It is possible to melt in the entire direction. From the above viewpoint, the thickness of the thin layer is more preferably 0.01 mm or more and 0.20 mm or less.

Preheating may be performed, if necessary, to heat the powder material after the formation of the thin layer or before the formation of the thin layer. When preheating is performed, the amount of energy required for melting the powder material (thermoplastic resin) in the infrared light irradiation step is reduced, and the amount of light irradiated in the infrared light irradiation step is reduced or the time is shortened. It becomes possible. The preheating temperature is a temperature lower than the temperature at which the thermoplastic resin contained in the molding particles melts, and is lower than the boiling point of the solvent contained in the bonding fluid or the peeling fluid to be applied in the fluid coating step described later. Is preferable. Specifically, when T (° C.) is the lowest temperature of the melting point of the thermoplastic resin and the boiling point of the solvent contained in the bonding fluid and the stripping fluid, (T-50) ° C. or higher (T-). 5) The temperature is preferably 1 ° C. or lower, and more preferably (T-30) ° C. or higher and (T-5) ° C. or lower. At this time, the heating time is preferably 1 to 60 seconds, more preferably 3 to 20 seconds. By setting the heating temperature and the heating time within the above ranges, the amount of infrared light irradiation in the infrared light irradiation step can be reduced.

(2) Fluid coating step In the fluid coating step, the binding fluid is applied to a specific region of the thin layer formed in the thin layer forming step. Further, as described above, the peeling fluid may be applied to the region adjacent to the coating region of the coupling fluid, if necessary. For example, the bonding fluid can be selectively applied to the region where the modeled object layer should be formed (cured region), and the peeling fluid can be applied to the region where the modeled product layer is not formed (non-cured region). Either the binding fluid or the peeling fluid may be applied first, but from the viewpoint of the dimensional accuracy of the obtained three-dimensional model, it is preferable to apply the bonding fluid first.

The method of applying the binding fluid and the peeling fluid is not particularly limited, and for example, coating by a dispenser, coating by an inkjet method, spray coating, or the like can be performed, but the bonding fluid and the peeling fluid can be applied to a desired region at high speed. From the viewpoint that the above can be applied, it is preferable to apply at least one of them by an inkjet method, and it is more preferable to apply both by an inkjet method.

The coating amounts of the binding fluid and the peeling fluid are preferably 0.1 to 50 μL, and more preferably 0.2 to 40 μL, respectively, per 1 mm ^{3 of the} thin layer. When the coating amounts of the binding fluid and the peeling fluid are within the above range, the powder material in the cured region and the non-cured region can be sufficiently impregnated with the binding fluid and the peeling fluid, respectively, and the dimensional accuracy is good. It is possible to form a three-dimensional model.

The binding fluid applied in this step contains at least an infrared light absorber and a solvent. The binding fluid may contain a known dispersant or the like, if necessary.

The infrared light absorber is particularly limited as long as it can absorb the infrared light irradiated in the infrared light irradiation step described later and can efficiently raise the temperature of the region to which the coupling fluid is applied. Not done. Specific examples of infrared light absorbers include infrared light absorbers such as carbon black, ITO (indium tin oxide), and ATO (antimony tin oxide); cyanine pigments; phthalocyanine pigments mainly composed of aluminum and zinc; Phthalocyanine compounds; nickel dithiolene complexes having a planar tetracoordinate structure; squalium dyes; quinone compounds; diynemonium compounds; infrared light absorbing dyes such as azo compounds are included. Among these, carbon black is more preferable from the viewpoint of versatility and the ability to efficiently increase the temperature of the region to which the bonding fluid is applied.

The shape of the infrared light absorber is not particularly limited, but it is preferably in the form of particles. The average particle size is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm. If the average particle size of the infrared light absorber is excessively large, it becomes difficult for the infrared light absorber to enter the gaps between the molding particles when the bonding fluid is applied onto the thin layer. On the other hand, when the average particle size is 1.0 μm or less, the infrared light absorber easily enters between the modeling particles. On the other hand, when the average particle size of the infrared light absorber is 0.1 μm or more, heat can be efficiently transferred to the molding particles (thermoplastic resin or inorganic material) in the infrared light irradiation step described later. It becomes possible to melt-bond the molding particles.

The binding fluid preferably contains an infrared light absorber in an amount of 0.1 to 10.0% by mass, more preferably 1.0 to 5.0% by mass. When the amount of the infrared light absorber is 0.1% by mass or more, it is possible to sufficiently raise the temperature of the region to which the bonding fluid is applied in the infrared light irradiation step described later. On the other hand, when the amount of the infrared light absorber is 10.0% by mass or less, the infrared light absorber is less likely to aggregate in the binding fluid, and the coating stability of the binding fluid is likely to be improved.

On the other hand, the solvent is not particularly limited as long as it can disperse the infrared light absorber and further dissolves the components in the molding particles, and can be, for example, an aqueous solvent. As used herein, the term "aqueous solvent" refers to water or an organic solvent miscible with water. Examples of organic solvents to be mixed with water include alcohol solvents such as methanol, ethanol and propanol, isopropyl alcohol and triethylene glycol; nitrile alcohol solvents such as acetonitrile; ketone alcohol solvents such as acetone; 1,4- Ether alcohol solvents such as dioxane and tetrahydrofuran (THF); amide alcohol solvents such as dimethylformamide (DMF) and the like are included. The binding fluid may contain only one of these, or may contain two or more of them. Further, among these, a mixed solution of water and triethylene glycol is particularly preferable.

The binding fluid preferably contains 90.0 to 99.9% by mass of the solvent, more preferably 95.0 to 99.0% by mass. When the amount of the solvent in the binding fluid is 90.0% by mass or more, the fluidity of the binding fluid becomes high, and it becomes easy to apply by, for example, an inkjet method.

The viscosity of the binding fluid is preferably 0.5 to 50.0 mPa · s, more preferably 1.0 to 20.0 mPa · s. When the viscosity of the binding fluid is 0.5 mPa · s or more, diffusion when the binding fluid is applied to the thin layer is more likely to be suppressed. On the other hand, when the viscosity of the binding fluid is 50.0 mPa · s or less, the coating stability of the binding fluid tends to increase.

On the other hand, the peeling fluid applied in this step may be a fluid that absorbs infrared light less than the coupling fluid, and may be, for example, a fluid containing an aqueous solvent as a main component. The peeling fluid may contain only one kind of these, or may contain two or more kinds of them. Further, the peeling fluid is particularly preferably a mixed solution of water and triethylene glycol.

The stripping fluid preferably contains 90% by mass or more of the solvent, and more preferably 95% by mass or more. When the amount of the solvent in the peeling fluid is 90% by mass or more, it becomes easy to apply by, for example, an inkjet method.

The viscosity of the peeling fluid is preferably 0.5 to 50.0 mPa · s, more preferably 1.0 to 20.0 mPa · s. When the viscosity of the peeling fluid is 0.5 mPa · s or more, diffusion when the peeling fluid is applied to the thin layer is likely to be appropriately suppressed. On the other hand, when the viscosity of the peeling fluid is 50.0 mPa · s or less, the coating stability of the peeling fluid tends to increase.

(3) Infrared light irradiation step In the infrared light irradiation step, infrared light is collectively irradiated to the thin layer after the fluid coating step, that is, the thin layer coated with the binding fluid (and the exfoliating fluid). At this time, in the region where the binding fluid is applied, the infrared light absorber absorbs the infrared light, and the temperature of the region rises. Then, the thermoplastic resin in the modeling particles in the region is melted to form a modeling object layer.

The infrared light irradiated in this step may be light having a wavelength of 780 to 3000 nm, and more preferably light having a wavelength of 800 to 2500 nm.

The time for irradiating infrared light in this step is appropriately selected according to the type of the thermoplastic resin contained in the powder material, but is usually preferably 5 to 60 seconds, preferably 10 to 30 seconds. More preferably. By setting the infrared light irradiation time to 5 seconds or more, it is possible to sufficiently melt the thermoplastic resin and bond adjacent molding particles. On the other hand, if the time is 60 seconds or less, it becomes possible to efficiently manufacture a three-dimensional model.

3. 3. Three-dimensional modeling device A three-dimensional modeling device that can be used in the method for manufacturing a three-dimensional model will be described. The three-dimensional modeling apparatus can have the same configuration as a known three-dimensional modeling apparatus. As shown in the schematic side view of FIG. 1, the three-dimensional modeling apparatus includes a modeling stage 210 located in the opening, a thin layer forming portion 220 for forming a thin layer made of a powder material, and a thin layer for preheating the thin layer. Preheating unit 230, fluid coating unit 300 for applying binding fluid (and exfoliating fluid) to the thin layer, infrared irradiation unit 240 for irradiating the thin layer with infrared light, and variable vertical position A stage support portion 250 that supports the modeling stage 210 and a base 290 that supports each of the above portions are provided.

On the other hand, the main part of the control system of the three-dimensional modeling apparatus 200 is shown in FIG. As shown in FIG. 2, the three-dimensional modeling apparatus 200 controls a thin layer forming unit 220, a preheating unit 230, a fluid coating unit 300, an infrared light irradiation unit 240, and a stage support unit 250 to form a modeled object. The control unit 260 for stacking, the display unit 270 for displaying various information, the operation unit 275 including a pointing device for receiving instructions from the user, and various information including the control program executed by the control unit 260. A storage unit 280 for storing and a data input unit 285 including an interface for transmitting and receiving various information such as three-dimensional modeling data to and from an external device may be provided. Further, the three-dimensional modeling apparatus 200 may include a temperature measuring device 235 for measuring the surface temperature of the thin layer formed on the modeling stage 210. Further, a computer device 310 for generating data for three-dimensional modeling may be connected to the three-dimensional modeling device 200.

The modeling stage 210 is controlled so as to be able to move up and down, and the thin layer forming unit 220 forms a thin layer, the preheating unit 230 preheats the thin layer, and the fluid coating unit 300 joins the fluid (and) on the modeling stage 210. The peeling fluid) is applied, and the infrared light irradiation unit 240 irradiates the infrared light. Then, the shaped objects formed by these are laminated to form a three-dimensional shaped object.

The thin layer forming unit 220 includes a powder material storage unit 221a for storing the powder material, a powder supply unit 221 provided at the bottom of the powder material storage unit 221a and a supply piston 221b for moving up and down in the opening, and a powder supply unit 221. The powder material supplied from the above can be spread flat on the molding stage 210 to include a recorder 222a for forming a thin layer of the powder material. In the device, the upper surface of the opening of the powder material storage portion 221a is arranged on substantially the same plane as the upper surface of the opening for raising and lowering the modeling stage 210 (for forming a three-dimensional model).

The powder supply unit 221 discharges a powder material storage unit (not shown) provided vertically above the modeling stage 210 and a powder material stored in the powder material storage unit in desired amounts. A nozzle (not shown) for the purpose may be provided. In this case, a thin layer can be formed by uniformly discharging the powder material from the nozzle onto the modeling stage 210.

The preheating unit 230 may be any one that can heat the region of the surface of the thin layer on which the modeled object layer should be formed and maintain the temperature. In the apparatus, the preheating unit 230 heats the first heater 231 capable of heating the surface of the thin layer formed on the modeling stage 210 and the second heater 231 capable of heating the powder material before being supplied onto the modeling stage. It includes a heater 232, but these may be only one of them. Further, the preheating unit 230 may be configured to selectively heat the region where the modeled object layer should be formed. Further, the entire inside of the apparatus may be preheated so that the surface of the thin layer is adjusted to a predetermined temperature.

The temperature measuring device 235 may be any one capable of measuring the surface temperature of the thin layer, particularly the surface temperature of the region where the modeled object layer should be formed, in a non-contact manner, and may be, for example, an infrared photosensor or an optical thermometer. it can.

The fluid coating unit 300 includes a coupling fluid coating unit 301 and a peeling fluid coating unit 302. When only the coupling fluid is applied, the peeling fluid application unit 302 may not be provided. The coupling fluid coating unit 301 and the peeling fluid coating unit 302 each include a storage unit (not shown) for storing the coupling fluid or the peeling fluid, and an inkjet nozzle (not shown) connected thereto. Can be.

The infrared light irradiation unit 240 can be configured to include an infrared lamp. The infrared lamp may be a light source capable of irradiating infrared light at a desired timing.

The stage support portion 250 may variably support the vertical position of the modeling stage 210. That is, the modeling stage 210 is configured to be precisely movable in the vertical direction by the stage support portion 250. Various configurations can be adopted for the stage support portion 250. For example, the stage support portion 250 is engaged with a holding member for holding the modeling stage 210, a guide member for guiding the holding member in the vertical direction, and a screw hole provided in the guide member. It can be configured with a matching ball screw or the like.

The control unit 260 includes a hardware processor such as a central processing unit, and controls the operation of the entire three-dimensional modeling device 200 during the modeling operation of the three-dimensional modeled object.

Further, the control unit 260 may be configured to convert, for example, the three-dimensional modeling data acquired from the computer device 310 by the data input unit 285 into a plurality of slice data sliced in the stacking direction of the modeling object layer. Slice data is modeling data of each modeling object layer for modeling a three-dimensional model. The thickness of the slice data, that is, the thickness of the modeled object layer corresponds to the distance (stacking pitch) corresponding to the thickness of one layer of the modeled object layer.

The display unit 270 can be, for example, a liquid crystal display or a monitor.

The operation unit 275 may include a pointing device such as a keyboard or a mouse, and may include various operation keys such as a numeric keypad, an execution key, and a start key.

The storage unit 280 may include various storage media such as ROM, RAM, magnetic disk, HDD, and SSD.

The three-dimensional modeling apparatus 200 receives the control of the control unit 260 to decompress the inside of the apparatus, a decompression unit such as a decompression pump (not shown), or the control unit 260 to inject an inert gas into the apparatus. It may be provided with an inert gas supply unit (not shown) for supplying.

Here, a three-dimensional modeling method using the three-dimensional modeling apparatus 200 will be specifically described. The control unit 260 converts the three-dimensional modeling data acquired from the computer device 310 by the data input unit 285 into a plurality of slice data sliced in the stacking direction of the modeling object layers. After that, the control unit 260 controls the following operations in the three-dimensional modeling apparatus 200.

The powder supply unit 221 drives a motor and a drive mechanism (both not shown) according to the supply information output from the control unit 260, moves the supply piston upward in the vertical direction (in the direction of the arrow in FIG. 1), and forms the above-mentioned modeling. Extrude the powder material on the same plane horizontally as the stage.

After that, the recorder drive unit 222 moves the recorder 222a in the horizontal direction (in the direction of the arrow in the figure) according to the thin layer formation information output from the control unit 260, transports the powder material to the modeling stage 210, and makes the thin layer. The powder material is pressed so that the thickness of is one layer of the modeled object layer.

The preheating unit 230 heats the surface of the thin layer formed according to the temperature information output from the control unit 260 or the entire inside of the apparatus. The preheating unit 230 may start heating after the thin layer is formed, or heats a portion corresponding to the surface of the thin layer to be formed before the thin layer is formed or the inside of the apparatus. You may.

After that, the fluid coating unit 240 applies the coupling fluid from the coupling fluid coating unit 30 thin layer 1 on the thin layer of the region constituting the three-dimensional model in each slice data according to the fluid coating information output from the control unit 260. Apply. On the other hand, the peeling fluid is applied from the peeling fluid coating unit 302 to the thin layer in the region that does not form the three-dimensional model, if necessary.

After that, the infrared light irradiation unit 240 irradiates the entire thin layer with infrared light according to the infrared light irradiation information output from the control unit 260. The temperature of the region where the binding fluid is applied rises partially due to the irradiation of infrared light, and the thermoplastic resin contained in the powder material melts. As a result, a model layer is formed.

After that, the stage support unit 250 drives the motor and the drive mechanism (both not shown) according to the position control information output from the control unit 260, and the modeling stage 210 is moved downward by the stacking pitch in the vertical direction (arrow direction in the drawing). ).

The display unit 270 is controlled by the control unit 260 as necessary, and displays various information and messages to be recognized by the user. The operation unit 275 receives various input operations by the user and outputs an operation signal corresponding to the input operation to the control unit 260. For example, the virtual three-dimensional model to be formed is displayed on the display unit 270 to check whether or not the desired shape is formed, and if the desired shape is not formed, the operation unit 275 may make corrections. Good.

The control unit 260 stores the data in the storage unit 280 or retrieves the data from the storage unit 280, if necessary.

By repeating these operations, the modeled object layers are laminated to produce a three-dimensional modeled object.

Hereinafter, specific examples of the present invention will be described. It should be noted that these examples do not limit the scope of the present invention.

1. 1. Material preparation (preparation of inorganic material)
As the inorganic material, those shown in Table 1 below were used. The thermal conductivity was measured using the MTPS method using a thermal conductivity measuring device TCi manufactured by C-THERM. On the other hand, the band gap was measured by observing the emission of photoelectrons corresponding to the energy of the ultraviolet light to be irradiated using AC3 manufactured by RIKEN KEIKI. Further, the average particle size D ₅₀ was measured by a laser diffraction type measurement method using MT-3000II manufactured by Microtrac Bell.

(Preparation of thermoplastic resin)
The following thermoplastic resins were used.
-PA12 (Polyamide 12) Daicel Evonik's Daiamide L1600
・ PP (polypropylene) FLX80E4 manufactured by Sumitomo Chemical Co., Ltd.

2. 2. Preparation of powder material (Comparative Examples 1 and 4)
Particles made of polyamide 12 (PA12) or polypropylene (PP) were pulverized by a lab jet manufactured by Nippon Pneumatic Industries Co., Ltd. and used as a powder material. The average particle size D ₅₀ was measured by a laser diffraction measurement method using MT-3000II manufactured by Microtrac Bell.

(Comparative Examples 2 and 3 and Examples 1 to 11)
The inorganic material and the thermoplastic resin shown in Table 2 are mixed and charged into a small kneader manufactured by Xplore Instruments so that the ratio of the inorganic material to the total amount of the powder material is as shown in Table 2, and the temperature is 180 ° C. , Heated and mixed at 100 rpm. After cooling the mixture, it was pulverized using a lab jet manufactured by Nippon Pneumatic Industries Co., Ltd. to obtain a powder material containing molding particles having an average particle size shown in Table 2. The average particle size was measured by a laser diffraction measurement method using MT-3000II manufactured by Microtrac Bell.

3. 3. Preparation of three-dimensional model The powder materials prepared in Examples 1 to 11 and Comparative Examples 1 to 4 are spread on a modeling stage installed on a hot plate to form a thin layer having a thickness of 0.1 mm. Preheating was performed at ° C. A binding fluid was applied to this thin layer by an inkjet method in the shape of a test piece of ISO5272-1BA (maximum length: 75 mm, maximum width: 10 mm). As the binding fluid, a fluid containing 15 parts by mass of triethylene glycol, 5 parts by mass of an infrared light absorber (carbon black (Mogul-L manufactured by Cabot Corporation)), and 80 parts by mass of water was used. The coating amount of the coupling fluid, 1 mm ³ per set to 30 [mu] L. Next, the peeling fluid was applied to the area other than the area where the bonding fluid was applied by an inkjet method. As the stripping fluid, a fluid containing 15 parts by mass of triethylene glycol and 85 parts by mass of water was used. The coating amount of the stripping fluid, 1 mm ³ per set to 30 [mu] L. Then, the thin layer was irradiated with infrared light from an infrared lamp and heated until the surface temperature of the region coated with the coupling fluid reached 220 ° C. As a result, the powder material in the region coated with the binding fluid was melt-bonded to form a model layer. Then, the process was repeated 10 times to produce a three-dimensional model in which 10 layers of the model were laminated.

4. Evaluation The accuracy and strength of each three-dimensional model were evaluated by the following methods. The results are shown in Table 2.

(Evaluation of accuracy in 3D objects)
The dimensions of each three-dimensional model were measured in the length direction with a digital caliper (manufactured by Mitutoyo Co., Ltd., Super Caliper CD67-S PS / PM, "Super Caliper" is a registered trademark of the same company). The difference between the dimensions to be manufactured (maximum length 75 mm) and the dimensions of the manufactured three-dimensional model was averaged to obtain a deviation in modeling accuracy. At this time, the evaluation was performed according to the following criteria.
◯: Error less than ± 0.15 mm with respect to the reference length 75 mm Δ: Error ± 0.15 mm or more to less than ± 0.3 mm with respect to the reference length 75 mm ×: Error ± 0.3 mm or more with respect to the reference length 75 mm

(Strength evaluation in three-dimensional model)
The three-dimensional model produced by the above method and the injection-molded product produced in the same shape are subjected to the conditions of a tensile speed of 1 mm / min, a gripping distance of 60 mm, and a test temperature of 23 ° C. using a universal testing machine model-5582 manufactured by Inslon. The tensile strength was measured at. Based on the strength of the injection-molded product, the strength of the obtained three-dimensional model was evaluated according to the following criteria.
⊚: 90% or more with respect to the tensile strength of the injection-molded product ○: 80% or more and less than 90% with respect to the tensile strength of the injection-molded product ×: Less than 80% with respect to the tensile strength of the injection-molded product

As shown in Table 2 above, when the molding particles made of a thermoplastic resin were used, the strength of the obtained three-dimensional model was not sufficient (Comparative Examples 1 and 4). It is probable that the thermoplastic resin was not sufficiently melted and the bonding force between the molding particles was weak.

On the other hand, when modeling particles containing an inorganic material having a thermal conductivity of 2 W / mK or more and a band gap of 1.59 eV or more together with a thermoplastic resin are used, the strength and dimensional accuracy of the three-dimensional model are both. It was good (Examples 1 to 11). It is considered that the inorganic material sufficiently transferred heat to the inside of the modeling particles, and the modeling particles in the cured region could be sufficiently bonded. Further, especially when an inorganic material having a scaly shape or a high thermal conductivity was used (for example, Examples 4 to 7, 9, 10, 11), heat was easily transferred in the cured region and the strength was increased. Conceivable.

On the other hand, even if the inorganic material is contained together with the thermoplastic resin, when the thermal conductivity of the inorganic material is low, the result is the same as when the inorganic material is not added (Comparative Example 2). Further, even if an inorganic material having high thermal conductivity is contained, if the band gap is too small, the molding accuracy is lowered (Comparative Example 3). It is considered that the inorganic material generated heat due to the irradiation with infrared light, and the molding particles were bound to each other even in the uncured region.

This application claims priority under Japanese Patent Application No. 2017-238749 filed on December 13, 2017. All the contents described in the application specification and drawings are incorporated herein by reference.

The powder material of the present invention can be efficiently cured by infrared light irradiation. Further, according to the powder material, a three-dimensional model having high strength and high dimensional accuracy can be obtained. Therefore, the present invention is considered to contribute to the further spread of the three-dimensional modeling method.

200 Three-dimensional modeling device 210 Modeling stage 220 Thin layer forming unit 221 Powder supply unit 222 Recoater drive unit 222a Recoater 230 Preheating unit 231 First heater 232 Second heater 235 Temperature measuring device 240 Infrared light irradiation unit 250 Stage support unit 260 Control unit 270 Display unit 275 Operation unit 280 Storage unit 285 Data input unit 290 Base 300 Fluid coating unit 301 Coupling fluid coating unit 302 Peeling fluid coating unit 310 Computer device

Claims (7)

A powder material used in a method for producing a three-dimensional model including the formation of a thin layer containing a powder material, the application of a binding fluid to the thin layer, and the irradiation of the thin layer with infrared light.
Contains molding particles, including a thermoplastic resin and an inorganic material having a thermal conductivity of 2 W / mK or more and a bandgap of 1.59 eV or more.
Powder material. The average particle size of the inorganic material is 0.01 to 50 μm.
The powder material according to claim 1. The inorganic material is scaly,
The powder material according to claim 1 or 2. A thin layer forming step of forming a thin layer containing the powder material according to any one of claims 1 to 3.
A fluid coating step of applying a binding fluid containing an infrared light absorber to a specific region of the thin layer, and
Infrared light irradiation is performed on the thin layer after the fluid coating step, and the thermoplastic resin in the molding particles in the region to which the binding fluid is applied is melted to form a shaped object layer. Process and
A method for manufacturing a three-dimensional object, including. By repeating the thin layer forming step, the fluid coating step, and the infrared light irradiation step a plurality of times, the shaped object layers are laminated to form a three-dimensional shaped object.
The method for manufacturing a three-dimensional model according to claim 4. In the fluid coating step, a peeling fluid having less infrared light absorption than the coupling fluid is applied to a region adjacent to the coating region of the coupling fluid.
The method for manufacturing a three-dimensional model according to claim 4 or 5. In the fluid coating step, the bonding fluid and the peeling fluid are coated by an inkjet method.
The method for manufacturing a three-dimensional model according to claim 6.

Images