WO2019117015A1

WO2019117015A1 - Method for producing three-dimensional molded object, and powder material used therein

Info

Publication number: WO2019117015A1
Application number: PCT/JP2018/044956
Authority: WO
Inventors: 和也磯部
Original assignee: コニカミノルタ株式会社
Priority date: 2017-12-13
Filing date: 2018-12-06
Publication date: 2019-06-20
Also published as: JPWO2019117015A1; JP7205492B2

Abstract

The present invention addresses the problem of providing: a powder material that can be efficiently cured by irradiation with infrared light and that makes it possible to produce a three-dimensional molded object having high strength and high dimensional precision; and a method for producing a three-dimensional molded object using the powder material. In order to solve the abovementioned problem, a powder material according to the present invention is used in a method for a producing a three-dimensional molded object that includes formation of a thin layer containing the powder material, application of a bonding fluid to the thin layer, and irradiation of the thin layer with infrared light. The powder material contains molding particles comprising a thermoplastic resin and an inorganic filler that has a thermal conductivity of 2W/mK or more and a band gap of 1.59 eV or more.

Description

Method for producing three-dimensional object and powder material used therefor

The present invention relates to a method of producing a three-dimensional object and a powder material used therefor.

In recent years, various methods capable of relatively easily producing a three-dimensional object having a complicated shape have been developed, and rapid prototyping and rapid manufacturing using such a method are attracting attention.

As one of methods for producing such a three-dimensional object, a thin layer formed of resin particles containing a thermoplastic resin is formed, and resin particles in a desired region are sintered or melt bonded (hereinafter simply referred to as "melt bonding") Methods are also proposed to obtain a three-dimensional object. For example, various treatments are performed so that the degree of absorption of energy differs between a region in which resin particles are melt-bonded (hereinafter also referred to as “cured region”) and other regions (hereinafter also referred to as “non-cured region”). It is proposed that energy be applied to the entire surface of the thin layer after performing (see Patent Document 1). According to the method, since energy irradiation can be performed collectively, there is an advantage that the three-dimensional object can be formed much faster than the conventional method. In addition, it is described in the following patent document 1 that the energy absorbing agent is applied only to the cured region as a method of raising the degree of energy absorption of the cured region more than the degree of energy absorption of the non-cured region.

Japanese Patent Application Publication No. 2007-533480

In recent years, in the method for producing a three-dimensional object described in Patent Document 1, a bonding fluid containing an infrared light absorbing agent is applied to the cured region, and for the non-cured region, for peeling with low energy absorption as required. It has been studied to apply a fluid (hereinafter, the method is also referred to as "MJF method"). In the MJF method, when the binding fluid and the peeling fluid are applied and the entire surface is irradiated with infrared light, the infrared light absorbing agent in the cured region absorbs infrared light and generates heat. Thereby, the temperature of the resin particle in a hardening area | region rises, and resin particles melt-bond. However, in the method, it takes time to transfer the heat to the inside of the resin particles. Therefore, a method of melting the thermoplastic resin more efficiently has been desired.

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

The first of the present invention is a powder material.
[1] A powder material used in a method for producing a three-dimensional object, comprising forming a thin layer containing a powder material, applying a bonding fluid to the thin layer, and irradiating the thin layer with infrared light. A powder material comprising: a shaping particle comprising: 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 average particle diameter of the inorganic material is 0.01 to 50 μm.
[3] The powder material according to [1] or [2], wherein the inorganic material is scaly.

The second of the present invention resides in the following method for producing a three-dimensional object.
[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], a bonding fluid containing an infrared light absorbent, and Irradiating the infrared light to the thin layer after the fluid application step of applying to a specific area and the fluid application step, and melting the thermoplastic resin in the shaping particles of the area to which the binding fluid is applied And an infrared light irradiation step of forming a shaped object layer.

[5] The method according to [4], wherein the three-dimensional object is formed by laminating the three-dimensional object by repeating the thin layer formation step, the fluid application step, and the infrared light irradiation step a plurality of times. A method of manufacturing a three-dimensional object.
[6] The fluid application process according to [4] or [5], wherein a peeling fluid with less infrared light absorption than the bonding fluid is applied to a region adjacent to the application region of the bonding fluid. A method of manufacturing a three-dimensional object.
[7] The method for producing a three-dimensional object according to [6], wherein in the fluid applying step, the bonding fluid and the peeling fluid are applied by an inkjet method.

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

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

The powder material of the present invention is a material applied to the aforementioned MJF method. As described above, in the MJF method, a bonding fluid containing an infrared light absorbing agent and, if necessary, a peeling fluid with less infrared light absorption than the bonding fluid are applied to a thin layer containing 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 to melt and bond the resin particles. However, in the case of conventional resin particles, there is a problem that heat is not transmitted to the inside at the time of infrared light irradiation, and it takes a long time to sufficiently melt.

On the other hand, the shaping particles contained in the powder material of the present invention include, together with the thermoplastic resin, an inorganic material having a thermal conductivity of 2 W / mK or more and a band gap of 1.59 eV or more. When the modeling particles contain a relatively high thermal conductivity inorganic material, the heat from the heat-generating infrared light absorbing agent is transmitted to the thermoplastic resin through the inorganic material. That is, when the heat is transmitted to the inside of the shaping particles, the thermoplastic resin is efficiently melted. In addition, the above-mentioned inorganic material has a sufficiently large band gap and hardly absorbs infrared light. Therefore, when producing a three-dimensional molded item, infrared light can be irradiated to the inside as well as the surface of the cured region, and the particles for shaping 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-hardened area does not generate heat and the powder material of only the hardened area can be hardened. Hereinafter, a powder material is demonstrated previously, and the manufacturing method of the three-dimensional object which used the said powder material is demonstrated after that.

1. Powder Material The powder material of the present invention contains at least shaping particles. The powder material may contain, if necessary, various additives, a flow agent, a filler and the like.

The shaping particles are particles containing a thermoplastic resin and an inorganic material. The shape of the shaping particles is not particularly limited, and may be any shape such as spherical or prismatic. However, from the viewpoint of improving the flowability of the powder material and producing a three-dimensional object with high dimensional accuracy, it is preferable to be spherical. Moreover, although an inorganic material may be contained only in a part of particle | grains for modeling, for example, surface side, it is preferable that an inorganic material is uniformly contained in the particle | grains for modeling from a heat conductivity viewpoint. .

Here, the average particle size of the shaping 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 diameter of the particles for shaping is 2 μm or more, the thickness of a shaped object layer produced by the method for producing a three-dimensional shaped object described later tends to be sufficiently thick, and it becomes possible to efficiently produce a three-dimensional shaped object . On the other hand, when the average particle diameter of the particles for shaping is 210 μm or less, it is possible to produce a three-dimensional shaped object having a complicated shape.

The average particle size of the shaping particles is a volume average particle size measured by a dynamic light scattering method. The volume average particle size can be measured by a laser diffraction type particle size distribution measuring apparatus (manufactured by Microtrack Bell, MT3300EXII) equipped with a wet disperser.

The thermal conductivity of the inorganic material contained in the shaping particles is 2 W / mK or more, more preferably 2 to 250 W / mK, and still more preferably 4 to 250 W / mK. When the thermal conductivity of the inorganic material is in the above range, heat is easily transmitted from the infrared light absorber to the inorganic material, and further, heat is easily transmitted efficiently from the inorganic material to the thermoplastic resin. The thermal conductivity is measured using a thermal conductivity measuring apparatus TCi manufactured by C-THERM Co., Ltd. and the like, using an MTPS (unsteady planar heat source) method.

On the other hand, the band gap of the inorganic material is 1.59 eV or more, more preferably 2 to 10 eV, and still more preferably 5 to 10 eV. With the band gap such that the inorganic material is not excited by infrared light, it does not generate heat even when it receives infrared light. As used herein, “infrared light” is light of 780 nm to 3000 nm. Therefore, if 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 above-mentioned inorganic material is measured by observing emission of photoelectrons corresponding to the energy of 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 particles for formation is not particularly limited as long as it has the above-described thermal conductivity and band gap, and may be, for example, in the form of particles or fibers. It may be From the viewpoint of thermal conductivity, it is particularly preferable to be scaly. In the present specification, "scale-like" refers to a flat or curved plate-like shape.

The average particle diameter of the inorganic material is not particularly limited as long as the thermal conductivity can be exhibited, but it is preferably 0.01 to 50 μm, more preferably 0.01 to 30 μm, and 0.01 More preferably, it is ̃20 μm. When the average particle diameter of the inorganic material is 0.01 μm or more, heat can be efficiently transmitted in the particles for shaping. On the other hand, when the average particle diameter is 50 μm or less, the thermoplastic resin is melted, and it is difficult to inhibit the binding when the particles for shaping are bound, and a three-dimensional object with high strength is easily obtained. The average particle diameter of the inorganic material is a volume average particle diameter, and can be specified by measuring the above-mentioned laser diffraction type particle size distribution measuring device or the like after removing the thermoplastic resin in the particles for shaping by a solvent or the like.

When the inorganic material is scaly, the shape of the inorganic material in plan view 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, and more preferably 0.1 to 5 μm. If the thickness is 10 μm or less, the surface area of the inorganic material is likely to be large, and heat can be efficiently conducted by the inorganic material. On the other hand, when the inorganic material is in the form of fibers, the fiber length is preferably 0.1 to 100 μm, and 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 above-mentioned inorganic material is not particularly limited as long as it satisfies the above-mentioned thermal conductivity and band gap, and examples thereof include metal oxides such as aluminum oxide, magnesium oxide and talc; silicon carbide and boron nitride And metal carbides or nitrides of metalloids such as aluminum nitride. The particles for formation may contain only one type of inorganic material, or may contain two or more types. Among these, a white-based inorganic material is preferable from the viewpoint of difficulty in absorbing 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, still more preferably 5 to 60% by mass, based on the particles for formation. preferable. When the inorganic particles are contained in an amount of 1% by mass or more in the particles for shaping, heat is easily transmitted in the particles for shaping in producing a three-dimensional object. On the other hand, when the amount of the inorganic material in the shaping particles is 60% by mass or less, the amount of the thermoplastic resin is relatively sufficient, and a three-dimensional object with high strength is easily obtained.

On the other hand, the thermoplastic resin contained in the particles for formation is suitably selected according to the formation method of a three-dimensional object. As the said thermoplastic resin, the thing similar to resin contained in the resin particle for general MJF system can be used. The particles for shaping may contain only one kind of thermoplastic resin, or may contain two or more kinds.

However, if the melting temperature of the thermoplastic resin is too high, it may be necessary to irradiate infrared light for a long time to melt the particles for shaping at the time of producing the three-dimensional object, and it takes time to produce the three-dimensional object There is something to do. Then, it is preferable that it is 300 degrees C or less, and, as for the melting temperature of a thermoplastic resin, it is more preferable that it is 230 degrees C or less. On the other hand, the melting temperature of the thermoplastic resin is preferably 100 ° C. or more, and more preferably 150 ° C. or more, from the viewpoint of the heat resistance and the like of the three-dimensional object to be obtained. The melting temperature can be adjusted by 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, polymethyl methacrylate, polyethylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polysulfone, polyacrylonitrile, poly 2-ethylhexyl These include 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 particles for formation. When the thermoplastic resin is contained in 40% by mass, a three-dimensional object with high strength is easily obtained. On the other hand, when the amount of the thermoplastic resin is 97% by mass or less, the amount of the inorganic material relatively increases, and the thermoplastic resin can be efficiently melted.

Moreover, components other than the particle | grains for modeling may be contained in the powder material in the range which does not impair the objective and effect of this invention, 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 modifiers, blowing agents, colorants, organic peroxides, Adhesives, adhesives and the like are included. The powder material may contain only one of them, or two or more of them.

Furthermore, the powder material may contain a filler as long as the purpose and effect of the present invention are not impaired. Examples of fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, glass cut Fiber, glass milled fiber, glass flake, glass powder, silicon carbide, silicon nitride, gypsum, gypsum whisker, calcined kaolin, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, metal powder And inorganic fillers such as ceramic whiskers, potassium titanate, boron nitride, graphite and carbon fibers; polysaccharide nanofibers; various polymers and the like. The powder material may contain only one of them, or two or more of them.

In addition, the powder material may include a flow agent as long as the purpose and effect of the present invention are not impaired. The flow agent may be a material having a small coefficient of friction and having self-lubricity. Examples of such flow agents include silicon dioxide and boron nitride. Only one type of flow agent may be included, or both may be included. The amount of the flow agent can be appropriately set within a range in which the flowability of the powder material improves and the melt bonding of the powder material occurs sufficiently, 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 may be, for example, the following method. First, a thermoplastic resin and an inorganic material are prepared. The thermoplastic resin may be a thermoplastic resin, or a commercially available product may be used. Further, in order to make the average particle diameter of the inorganic material uniform, mechanical crushing, classification, etc. may be performed as necessary. Then, the thermoplastic resin and the inorganic material are heated and mixed. The heating temperature is appropriately selected in accordance with the type of the thermoplastic resin, and is preferably, for example, a temperature at which the thermoplastic resin melts. The mixture is then cooled and ground to the desired size to form a powder material. At this time, classification etc. may be performed as needed.

2. Next, a method of manufacturing a three-dimensional object using the above powder material will be described. In the method of manufacturing the three-dimensional object, (1) a thin layer forming step of forming a thin layer containing the above-mentioned powder material, and (2) a bonding fluid containing an infrared light absorber in a specific region of the thin layer. And (3) irradiating the thin layer after the fluid application step with infrared light to melt the thermoplastic resin in the shaping particles in the area where the bonding fluid is applied. At least an infrared light irradiation step of forming a shaped object layer. In the fluid application step, if necessary, a peeling fluid with less infrared light absorption than the binding fluid may be applied to the region adjacent to the binding fluid application region.

As described above, the shaping particles contained in the powder material can efficiently transmit the heat generated by the infrared light absorbent. Therefore, the infrared light irradiation can efficiently cure the powder material in the area to which the bonding fluid is applied. Further, by using the shaping 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 in the curing region. it can. As a result, a three-dimensional object having high strength and excellent dimensional accuracy can be obtained. Hereinafter, the manufacturing method of the said three-dimensional molded item is demonstrated 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 of forming the thin layer is not particularly limited as long as a layer having a desired thickness can be formed. For example, this process can be a process of laying the powder material supplied from the powder supply unit of the three-dimensional model forming device flatly on the modeling stage by the recoater. The thin layer may be formed directly on the shaping stage, or may be formed on a powder material that has already been spread or may be in contact with the already formed shaped material layer.

The thickness of the thin layer is the same as the thickness of the desired shaped object layer. The thickness of the thin layer can be optionally set according to the accuracy of the three-dimensional object to be produced, 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, a shaped object already produced by infrared light irradiation (infrared light irradiation in an infrared light irradiation step described later) for forming a new shaped object layer It is possible to prevent the layer from melting. Moreover, it becomes easy to spread powder material uniformly as the thickness of a thin layer is 0.01 mm or more. Further, by setting the thickness of the thin layer to 0.30 mm or less, it becomes possible to irradiate infrared light to the lower part of the thin layer in the infrared light irradiation step described later, and the thermoplastic resin in the cured region is made thick It is possible to melt throughout the 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.

After formation of the thin layer, or before forming the thin layer, preheating may be performed to heat the powder material, if necessary. If preheating is performed, the amount of energy required to melt the powder material (thermoplastic resin) in the infrared light irradiation step decreases, 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 shaping particles is melted, and is a temperature lower than the boiling point of the solvent contained in the bonding fluid and the peeling fluid applied in the fluid application step described later. Is preferred. Specifically, when the lowest temperature of the melting point of the thermoplastic resin and the boiling point of the bonding fluid and the solvent contained in the peeling fluid is T (° C.), the temperature is (T-50) ° C. or more (T−) 5) ° C or less is preferable, and (T-30) ° C or more and (T-5) ° C or less are more preferable. At this time, the heating time is preferably 1 to 60 seconds, more preferably 3 to 20 seconds. By making heating temperature and heating time into the said range, the infrared-light irradiation amount in an infrared-light irradiation process can be reduced.

(2) Fluid Application Step In the fluid application step, the binding fluid is applied to a specific area of the thin layer formed in the thin layer forming step. As described above, if necessary, the release fluid may be applied to the area adjacent to the application area for the binding fluid. For example, the bonding fluid can be selectively applied to the area (cured area) where the shaped article layer is to be formed, and the release fluid can be applied to the area (non-cured area) where the shaped article layer is not formed. Either of the bonding fluid and the release fluid may be applied first, but it is preferable to apply the bonding fluid first from the viewpoint of the dimensional accuracy of the resulting three-dimensional object.

The method of applying the binding fluid and the release fluid is not particularly limited, and may be, for example, application by a dispenser, application by an inkjet method, spray application, etc. It is preferable to apply at least one of them by the inkjet method from the viewpoint of being able to be applied, and it is more preferable to apply both by the inkjet method.

The application amount of the binding fluid and the peeling fluid is preferably 0.1 to 50 μL, and more preferably 0.2 to 40 μL, per mm ^{3 of the} thin layer. When the application amount of the bonding fluid and the peeling fluid is within the above range, the powder material in the hardened region and the non-hardened region can be sufficiently impregnated with the bonding fluid and the peeling fluid, respectively, and the dimensional accuracy is good. Can form a three-dimensional object.

The bonding fluid applied in this step contains at least an infrared light absorbing agent and a solvent. The coupling fluid may contain a known dispersant and the like as necessary.

The infrared light absorbing agent is particularly limited as long as it can absorb infrared light irradiated in an infrared light irradiation step described later and can efficiently increase the temperature of the region to which the binding fluid is applied. I will not. Specific examples of the infrared light absorber include infrared light absorbers such as carbon black, ITO (indium tin oxide), ATO (antimony tin oxide), etc .; cyanine dyes; phthalocyanine dyes mainly having aluminum or zinc; Phthalocyanine compounds; nickel dithiolene complexes having a planar four-coordinate structure; squalium dyes; quinone compounds; diimmonium compounds; and infrared light absorbing dyes such as azo compounds. 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 absorbing agent is not particularly limited, but is preferably in the form of particles. The average particle diameter is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm. If the average particle diameter of the infrared light absorbent is excessively large, the infrared light absorbent is less likely to enter the gaps of the modeling particles when the bonding fluid is applied on the thin layer. On the other hand, if the average particle size is 1.0 μm or less, the infrared light absorbing agent is likely to enter between the particles for shaping. On the other hand, when the average particle diameter of the infrared light absorbing agent is 0.1 μm or more, heat can be efficiently transmitted to the particles for modeling (thermoplastic resin and inorganic material) in the infrared light irradiation step described later, It becomes possible to melt bond the shaping particles.

The binding fluid preferably contains 0.1 to 10.0% by mass, and more preferably 1.0 to 5.0% by mass of the infrared light absorbing agent. It becomes possible to fully raise the temperature of the area | region where the fluid for coupling | bonding was apply | coated in the below-mentioned infrared light irradiation process as the quantity of an infrared light absorber is 0.1 mass% or more. On the other hand, when the amount of the infrared light absorbing agent is 10.0% by mass or less, aggregation of the infrared light absorbing agent in the bonding fluid is less, and the coating stability of the bonding fluid tends to be enhanced.

On the other hand, the solvent is not particularly limited as long as it is a solvent capable of dispersing the infrared light absorber and further difficult to dissolve the components in the shaping particles, and can be, for example, an aqueous solvent. As used herein, "aqueous solvent" refers to water or an organic solvent miscible with water. Examples of organic solvents miscible 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; 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 two or more of these. Among these, a mixture of water and triethylene glycol is particularly preferable.

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

The viscosity of the binding fluid is preferably 0.5 to 50.0 mPa · s, and more preferably 1.0 to 20.0 mPa · s. When the viscosity of the bonding fluid is 0.5 mPa · s or more, the diffusion at the time of applying the bonding fluid to the thin layer is further easily suppressed. On the other hand, when the viscosity of the bonding fluid is 50.0 mPa · s or less, the coating stability of the bonding fluid tends to be enhanced.

On the other hand, the release fluid to be applied in this step may be any fluid that absorbs less infrared light than the binding fluid, and can be, for example, a fluid containing an aqueous solvent as a main component. The peeling fluid may contain only one of these, or two or more of these. Further, it is particularly preferable that the peeling fluid be a mixed liquid of water and triethylene glycol.

The release fluid preferably contains 90% by mass or more of the solvent, and more preferably 95% by mass or more. It becomes easy to apply | coat, for example by the inkjet method etc. as the quantity of the solvent in the peeling fluid is 90 mass% or more.

The viscosity of the peeling fluid is preferably 0.5 to 50.0 mPa · s, and more preferably 1.0 to 20.0 mPa · s. When the viscosity of the peeling fluid is 0.5 mPa · s or more, the diffusion at the time of applying the peeling fluid to the thin layer tends 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 is likely to be enhanced.

(3) Infrared Light Irradiation Step In the infrared light irradiation step, the thin layer after the fluid application step, that is, the thin layer coated with the bonding fluid (and the peeling fluid), is collectively irradiated with infrared light. At this time, in a region where the binding fluid is applied, the infrared light absorbing agent absorbs infrared light, and the temperature of the region rises. Then, the thermoplastic resin in the shaping particles in the area is melted to form a shaped layer.

The infrared light to be 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.

In addition, 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 in general, it is preferably 5 to 60 seconds, and preferably 10 to 30 seconds. It is more preferable that By setting the infrared light irradiation time to 5 seconds or more, it is possible to melt the thermoplastic resin sufficiently to bond the adjacent modeling particles. On the other hand, by setting the time to 60 seconds or less, it is possible to efficiently manufacture a three-dimensional object.

3. Three-Dimensional Modeling Apparatus A three-dimensional modeling apparatus that can be used for the method of manufacturing the three-dimensional model is described. The three-dimensional model forming apparatus can have the same configuration as a known three-dimensional model forming apparatus. As shown in the schematic side view of FIG. 1, the three-dimensional shaping apparatus comprises a shaping stage 210 located in the opening, a thin layer forming portion 220 for forming a thin layer of powder material, and a preheating for the thin layer. Preheating unit 230, fluid application unit 300 for applying bonding fluid (and peeling fluid) to thin layer, infrared irradiation unit 240 for irradiating thin layer with infrared light, variable position in vertical direction And a stage support 250 for supporting the shaping stage 210, and a base 290 for supporting the above-described portions.

On the other hand, the main part of the control system of the three-dimensional model | molding apparatus 200 is shown in FIG. As shown in FIG. 2, the three-dimensional modeling apparatus 200 controls the thin layer forming unit 220, the preheating unit 230, the fluid coating unit 300, the infrared light irradiation unit 240, and the stage support unit 250 to form a shaped object. And a control unit 260 for stacking, a display unit 270 for displaying various information, an operation unit 275 including a pointing device for receiving an instruction from the user, and various information including a control program to be 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. Furthermore, the three-dimensional model forming apparatus 200 may include a temperature measuring device 235 that measures the surface temperature of the thin layer formed on the modeling stage 210. In addition, a computer device 310 for generating data for three-dimensional modeling may be connected to the three-dimensional modeling apparatus 200.

The shaping stage 210 is controlled to be movable up and down, and on the shaping stage 210, formation of a thin layer by the thin layer forming unit 220, preheating of the thin layer by the preheating unit 230, fluid for bonding by the fluid application unit 300 (and Application of the peeling fluid) and irradiation of infrared light by the infrared light irradiation unit 240 are performed. Then, the three-dimensional object is formed by laminating the three-dimensional object formed by these.

The thin layer forming unit 220 includes a powder material storage unit 221a for storing a powder material, a powder supply unit 221 provided with a supply piston 221b provided at the bottom of the powder material storage unit 221a and moving up and down in the opening, and a powder supply unit 221 The powder material supplied from the above can be laid flat on the shaping stage 210 to provide a recoater 222a that forms a thin layer of powder material. In the device, the upper surface of the opening of the powder material storage portion 221a is disposed on substantially the same plane as the upper surface of the opening (for forming a three-dimensional object) for moving up and down the modeling stage 210.

The powder supply unit 221 discharges the powder material storage unit (not shown) provided vertically above the modeling stage 210 and the powder material stored in the powder material storage unit by a desired amount. And a nozzle (not shown) may be provided. In this case, it is possible to form a thin layer by uniformly discharging the powder material from the nozzle onto the modeling stage 210.

The preheating part 230 should just heat the area | region which should form a modeling thing layer among the surfaces of a thin layer, and can 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 heating the powder material before being supplied onto the modeling stage. Although the heater 232 is provided, only one of them may be provided. In addition, the preheating unit 230 may be configured to selectively heat the area where the above-mentioned shaped object layer is to be formed. In addition, the entire inside of the device may be preheated, and the surface of the thin layer may be temperature-controlled to a predetermined temperature.

The temperature measuring device 235 may be any device that can measure the surface temperature of a thin layer, in particular, the surface temperature of the region where a shaped object layer is to be formed without contact, for example, an infrared light sensor or an optical pyrometer it can.

The fluid application unit 300 includes a coupling fluid application unit 301 and a peeling fluid application unit 302. When only the bonding fluid is applied, the peeling fluid application unit 302 may be omitted. The bonding fluid application unit 301 and the release fluid application unit 302 each include a reservoir (not shown) for storing the bonding fluid or the release fluid, and an inkjet nozzle (not shown) connected thereto. It 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 emitting infrared light at a desired timing.

The stage support part 250 should just support the position of the perpendicular direction of the modeling stage 210 variably. That is, the modeling stage 210 is configured to be precisely movable in the vertical direction by the stage support 250. Although various configurations can be adopted as the stage support portion 250, for example, 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 overall operation of the three-dimensional modeling apparatus 200 during the modeling operation of the three-dimensional object.

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

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

The operation unit 275 may include, for example, a pointing device such as a keyboard and a mouse, and may include various operation keys such as a ten key, an execution key, and a start key.

The storage unit 280 can include various storage media such as, for example, a ROM, a RAM, a magnetic disk, an HDD, and an SSD.

Under the control of the control unit 260, the three-dimensional model forming apparatus 200 decompresses the inside of the apparatus. Under the control of a pressure reducing unit (not shown) such as a pressure reducing pump or the control unit 260, inert gas is contained in the apparatus. You may provide the inert gas supply part (not shown) which supplies.

Here, the 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 by the data input unit 285 from the computer device 310 into a plurality of slice data sliced in the stacking direction of the three-dimensional object layer. Thereafter, the control unit 260 controls the following operation in the three-dimensional model forming apparatus 200.

The powder supply unit 221 drives the motor and the drive mechanism (both are not shown) according to the supply information output from the control unit 260 to move the supply piston vertically upward (in the direction of the arrow in FIG. 1). Push out the powder material on the same horizontal plane as the stage.

Thereafter, the recoater drive unit 222 moves the recoater 222a in the horizontal direction (in the direction of the arrow in the figure) in accordance with the thin layer formation information output from the control unit 260 to transport the powder material to the modeling stage 210 and thin layer The powder material is pressed so that the thickness of the layer is one layer of the shaped object layer.

The preheating unit 230 heats the surface of the thin layer formed in accordance with 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 performs heating in a portion corresponding to the surface of the thin layer to be formed before the thin layer is formed or in the apparatus. May be

Thereafter, according to the fluid application information output from the control unit 260, the fluid application unit 240 performs the bonding fluid from the thin layer 1 for bonding fluid application unit 30 on the thin layer of the region constituting the three-dimensional object in each slice data. Apply On the other hand, the peeling fluid is applied from the peeling fluid applying unit 302 to the thin layer in the region where the three-dimensional object is not formed.

Thereafter, the infrared light irradiation unit 240 irradiates the entire thin layer with infrared light in accordance with the infrared light irradiation information output from the control unit 260. Irradiation with infrared light causes the temperature of the region where the bonding fluid is applied to rise to a large extent partially, and the thermoplastic resin contained in the powder material is melted. Thereby, a shaped article 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 vertically lowers the modeling stage 210 by the stacking pitch (arrow direction in the figure) Move to).

The display unit 270 displays various information and messages to be recognized by the user under the control of the control unit 260 as necessary. 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, a virtual three-dimensional object to be formed is displayed on display portion 270 to confirm whether or not a desired shape is formed, and even if a desired shape is not formed, even if correction is made from operation portion 275 Good.

The control unit 260 stores data in the storage unit 280 or pulls out data from the storage unit 280 as necessary.

By repeating these operations, the three-dimensional object is manufactured by laminating the three-dimensional object layer.

Hereinafter, specific embodiments of the present invention will be described. The scope of the present invention is not interpreted as being limited by these examples.

1. Preparation of materials (Preparation of inorganic materials)
The inorganic materials shown in Table 1 below were used. The thermal conductivity was measured using a thermal conductivity measuring device TCi manufactured by C-THERM, using the MTPS method. On the other hand, the band gap was measured by observing emission of photoelectrons corresponding to the energy of ultraviolet light to be irradiated, using AC3 manufactured by Riken Keiki Co., Ltd. Further, the average particle diameter _{D 50} is used Microtrac Bell Co. MT-3000II, it was measured by laser diffraction measurements.

(Preparation of thermoplastic resin)
The following thermoplastic resin was used.
・ PA12 (polyamide 12) Daicel Evonik diamide L1600
・ PP (polypropylene) made by Sumitomo Chemical FLX80E4

2. Preparation of Powdered Material (Comparative Examples 1 and 4)
Particles made of polyamide 12 (PA12) or polypropylene (PP) were crushed with a lab jet manufactured by Nippon Pneumatic Mfg. Co., Ltd. and used as a powder material. The average particle diameter _{D 50} is used Microtrac Bell Co. MT-3000II, it was measured by laser diffraction measurements.

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

3. Preparation of Three-Dimensional Shaped Article The powder materials prepared in Examples 1 to 11 and Comparative Examples 1 to 4 were spread on a forming stage placed on a hot plate to form a thin layer having a thickness of 0.1 mm, 160 Preheating was done to ° C. A bonding fluid was applied to the thin layer in a test piece shape (maximum length: 75 mm, maximum width: 10 mm) of ISO 527-2-1BA by an inkjet method. The bonding fluid used contained 15 parts by mass of triethylene glycol, 5 parts by mass of an infrared light absorbent (carbon black (Mogul-L manufactured by Cabot)), and 80 parts by mass of water. The application amount of the binding fluid was 30 μL per 1 mm ³ . Next, the peeling fluid was applied by an inkjet method to the area other than the application of the binding fluid. As the peeling fluid, one containing 15 parts by mass of triethylene glycol and 85 parts by mass of water was used. In addition, the application amount of the peeling fluid was 30 μL per 1 mm ³ . Thereafter, the thin layer was irradiated with infrared light from an infrared lamp to heat the surface to which the bonding fluid was applied until the surface temperature reached 220.degree. Thereby, the powder material of the area | region which applied the binding fluid melt-bonded, and the three-dimensional object layer was produced. And the said process was repeated 10 times, and the three-dimensional molded article in which 10 layers of molded article layers were laminated was manufactured.

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

(Evaluation of accuracy in three-dimensional object)
The dimensions in the longitudinal direction of each three-dimensional object were measured with a digital caliper (Supercaliper CD67-S PS / PM, "Supercaliper" is a registered trademark of the company) manufactured by Mitutoyo Co., Ltd.). The difference between the dimension to be produced (maximum length 75 mm) and the dimension of the produced three-dimensional object was averaged to obtain deviation of the shaping accuracy. At this time, the evaluation was performed based on the following criteria.
:: Less than ± 0.15 mm error for standard length 75 mm Δ: More than ± 0.15 mm to less than ± 0.3 mm error for standard length 75 mm ×: ± 0.3 mm or greater error for standard length 75 mm

(Strength evaluation in a three-dimensional object)
For a three-dimensional object manufactured by the above method and an injection molded product manufactured in the same shape, using an Instron universal tester model-5582, conditions of tensile speed 1 mm / min, gripper distance 60 mm, test temperature 23 ° C. The tensile strength was measured by The strength of the obtained three-dimensional object was evaluated based on the strength of the injection-molded article 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 shaping particles made of a thermoplastic resin were used, the strength of the obtained three-dimensional shaped article was not sufficient (Comparative Examples 1 and 4). It is considered that the melting of the thermoplastic resin was not sufficient, and the bonding force between the modeling particles was weak.

On the other hand, in the case of using a shaping particle 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, both the strength and dimensional accuracy of the three-dimensional object are Good (Examples 1 to 11). It is considered that the heat was sufficiently conducted to the inside of the shaping particles by the inorganic material, and the shaping particles in the hardened region could be sufficiently bonded. In particular, when an inorganic material having a scaly shape or a high thermal conductivity is used (for example, Examples 4 to 7, 9, 10, 11), heat is easily transmitted in the curing region, and the strength is increased. Conceivable.

On the other hand, even when the inorganic material was contained together with the thermoplastic resin, when the thermal conductivity of the inorganic material was low, the same result as in the case where the inorganic material was not added was obtained (Comparative Example 2). In addition, even when the inorganic material having a high thermal conductivity was included, when the band gap was too small, the shaping accuracy decreased (Comparative Example 3). It is considered that the irradiation of the infrared light causes the inorganic material to generate heat, and the particles for shaping are bound even in the non-hardened region.

This application claims the priority based on Japanese Patent Application No. 2017-238749 filed on Dec. 13, 2017. The contents described in the application specification and drawings are all 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 object with 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 apparatus 210 Modeling stage 220 Thin layer formation part 221 Powder supply part 222 Recoater drive part 222a Recoator 230 Preheating part 231 First heater 232 Second heater 235 Temperature measuring device 240 Infrared light irradiation part 250 Stage support part 260 control unit 270 display unit 275 operation unit 280 storage unit 285 data input unit 290 base 300 fluid application unit 301 coupling fluid application unit 302 peeling fluid application unit 310 computer device

Claims

A powder material for use in a method of producing a three-dimensional object, comprising: forming a thin layer containing a powder material; applying a bonding fluid to the thin layer; and irradiating infrared light to the thin layer,
Containing particles for shaping, comprising 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
Powder material.
The average particle size of the inorganic material is 0.01 to 50 μm,
A powder material according to claim 1.
The inorganic material is scaly,
A 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;
Applying a bonding fluid comprising an infrared light absorber to specific areas of the thin layer;
The thin layer after the fluid application step is irradiated with infrared light, and the thermoplastic resin in the modeling particles in the region to which the bonding fluid is applied is melted to form a shaped object layer Process,
A method of producing a three-dimensional object, comprising:
By repeating the thin layer formation step, the fluid application step, and the infrared light irradiation step a plurality of times, the three-dimensional object is formed by laminating the three-dimensional object layer.
The manufacturing method of the three-dimensional molded article of Claim 4.
In the fluid application step, a peeling fluid having less infrared light absorption than the bonding fluid is applied to a region adjacent to the application region of the bonding fluid.
The manufacturing method of the three-dimensional molded article according to claim 4 or 5.
In the fluid application step, the bonding fluid and the release fluid are applied by an inkjet method.
The manufacturing method of the three-dimensional molded article of Claim 6.