JP6798326B2 - Powder material, manufacturing method of three-dimensional model using this, and three-dimensional modeling device - Google Patents

Description

The present invention relates to a powder material, a method for producing a three-dimensional model using the powder material, and a three-dimensional model device.

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 a three-dimensional model, a powder bed fusion bonding method is known. In the powder bed melt-bonding method, a powder material containing particles made of a resin material or a metal material is spread flat to form a thin layer. Then, a laser beam is irradiated to a desired position of the thin layer to selectively sinter or melt-bond adjacent particles (hereinafter, also simply referred to as “melt-bond”). That is, a layer (hereinafter, also simply referred to as a "modeled object layer") is formed by subdividing the three-dimensional modeled object in the thickness direction. A powder material is further spread on the modeled object layer formed in this manner, and laser light irradiation is repeated to produce a three-dimensional modeled object having a desired shape.

The powder bed melt-bonding method has high molding accuracy and high adhesive strength between laminated shaped objects. Therefore, according to this method, there is an advantage that a three-dimensional model having high strength can be easily obtained. However, at present, the resin species used in the powder bed fusion bonding method are limited to polystyrene, polyamide 11, polyamide 12, and the like, and it is required to form a three-dimensional model using a wider variety of resins.

Here, in the powder bed fusion bonding method, a thin layer made of a powder material may be preheated before irradiation with a laser beam for the purpose of reducing warpage of a modeled object. By performing preheating, it is possible to suppress the occurrence of shrinkage strain due to non-uniform cooling, and it is possible to produce a modeled object with less warpage. In addition, there is an advantage that the amount of laser light can be reduced by performing preheating. It is desired that the preheating temperature be set to a higher temperature. On the other hand, the conventional powder material composed of thermoplastic resin particles may agglomerate when the preheating is increased. When such agglomeration occurs, the particles that have not been irradiated with the laser beam, that is, the particles that have not been used for producing the modeled object, must be discarded. Therefore, it is strongly required to raise the preheating temperature and to improve the reusability of the powder material not irradiated with the laser beam.

Here, in the field of the powder bed melt-bonding method, various coated particles have been developed in which the powder particles are used as core-shell particles and the functions are improved. For example, Patent Document 1 discloses particles having a core particle, a first coating containing a resin, and a second coating containing a surfactant. In this technique, a surfactant is added to the second coating film for the purpose of suppressing the aggregation of particles and improving the molding accuracy. Further, Patent Document 2 discloses that the shell contains a fine-grained material that can be sintered or glass-formed at a temperature lower than that of the core particles. In this technique, a fine-grained material is added to the shell for the purpose of enhancing the melt-bonding force between the particles. On the other hand, Patent Document 3 discloses particles having core particles containing a filler and shells containing a binder resin. In this technique, a filler is included in the core particles for the purpose of producing a laminated structure having a complicated three-dimensional shape with high strength and dimensional accuracy.

Special Table 2005-533877 Special Table 2006-521264 Japanese Unexamined Patent Publication No. 2016-40121

As described above, the powder material used in the powder bed melt-bonding method requires preheating to prevent warpage of the modeled object, and particles do not aggregate during preheating to improve the product yield. It has been demanded.

However, in the coating particles described in Patent Document 1 described above, the first coating film arranged between the core particles and the second coating film contains a material having a low softening point. Therefore, in the modeling method in which preheating is performed, there is a problem that particle agglutination is likely to occur even if the second coating film contains a surfactant layer. On the other hand, as described in Patent Document 2, it was difficult to sufficiently suppress the aggregation of the coated particles during preheating only by dispersing the fine particle material in the shell of the coated particles for the powder bed fusion bonding method. .. Further, the coating particles for the powder bed melt-bonding method described in Patent Document 3 are intended for sintering a filler having a small volume shrinkage, and are sintered without preheating. That is, the coated particles were not configured in consideration of preheating, and it was difficult for the coated particles to suppress the aggregation of the coated particles during the preheating.

The present invention has been made in view of the above problems. That is, the present invention can sufficiently perform preheating for preventing the occurrence of warpage of the modeled object, and further, a powder material having high reusability, a three-dimensional modeling method using the same, and the three-dimensional modeling method. An object of the present invention is to provide a three-dimensional modeling apparatus.

The first of the present invention is in the following powder materials.
[1] Preheating of the powder material containing the coated particles and selective laser light irradiation to the thin layer of the powder material are repeated, and a plurality of molded product layers in which at least a part of the coated particles are melt-bonded are laminated. A powder material used in a method for producing a three-dimensional molded product, wherein the coating particles include a core resin and a shell resin that coats the core resin, and is between the core resin and the shell resin. A powder material in which at least one of a metal oxide and a metal nitride is localized.

[2] The powder material according to [1], wherein the metal oxide or metal nitride is in the form of particles.
[3] The average particle size of the particulate metal oxide or the metal nitride is 5 nm to 100 nm, and the total amount of the metal oxide and the metal nitride with respect to 100 parts by mass of the core resin is 0. The powder material according to [2], which is 05 parts by mass to 1.0 part by mass.
[4] The powder material according to any one of [1] to [3], wherein the metal oxide is titanium oxide.
[5] The storage elastic modulus G of the shell resin 'temperature is ^{10 6.5} Pa TS (65), said core storage elastic modulus of the resin material G' is ^{10 6.5} Pa Temperature TC (65) The higher powder material according to any one of [1] to [4].
'And is ^{10 6.5} Pa Temperature TS (65), the storage modulus G of the core resin' [6] The storage elastic modulus of the shell resin G temperature is ^{10 6.5} Pa TC and (65) The powder material according to [5], wherein the difference between the two is 5 ° C. or higher and 70 ° C. or lower.

The second aspect of the present invention is the following method for manufacturing a three-dimensional model.
[7] A thin layer forming step of forming a thin layer made of the powder material according to any one of the above [1] to [6], a preheating step of preheating the powder material, and the preheated powder. The thin layer forming step includes a laser light irradiation step of selectively irradiating the thin layer made of a material with a laser beam to form a shaped object layer in which at least a part of the coating particles are melt-bonded to each other. A method for producing a three-dimensional model, wherein the preheating step and the laser light irradiation step are repeated a plurality of times to form a three-dimensional model by laminating the model layers.

The third aspect of the present invention lies in the following three-dimensional modeling apparatus.
[8] A molding stage, a thin layer forming portion for forming a thin layer of the powder material according to any one of [1] to [6] on the molding stage, and a preheating portion for preheating the powder material. A laser irradiation unit that irradiates the thin layer made of the preheated powder material with a laser to form a model layer formed by melt-bonding at least a part of the coating particles, and the modeling stage. By controlling the stage support portion that variably supports the vertical position thereof, the thin layer forming portion, the preheating portion, the laser irradiation portion, and the stage support portion, the modeled object layer is repeatedly formed. A three-dimensional modeling device including a control unit for stacking.

According to the present invention, a powder material that can be sufficiently preheated to prevent warpage of the modeled object and has high reusability, a method for producing a three-dimensional modeled object using the powdered material, and A three-dimensional modeling apparatus for carrying out the manufacturing method can be provided.

FIG. 1A is a schematic cross-sectional view of the coated particles according to an embodiment of the present invention. FIG. 1B is a schematic cross-sectional view of the coated particles in another embodiment of the present invention. FIG. 2 is a side view schematically showing a configuration of a three-dimensional modeling apparatus according to an embodiment of the present invention. FIG. 3 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.

In order to solve the above-mentioned problems, the present inventors have conducted diligent studies and experiments on powder materials for the powder bed fusion bonding method. The present inventors have adopted coating particles containing a core resin and a shell resin coating the core resin, and further containing a metal oxide and / or a metal nitride between them, as a powder material for a powder bed melt bonding method. It was found that the above-mentioned problems can be solved by doing so. According to the coated particles contained in the powder material of the present invention, the core resin and the shell resin can be physically phase-separated by a metal oxide and / or a metal nitride. Therefore, even if the core resin is melted or softened by preheating, the shell resin is not easily affected by the preheating, and the aggregation of the coating particles is suppressed. As a result, the coated particles that are not irradiated with the laser beam at the time of producing the modeled object and are not used for forming the modeled object can be used for producing another modeled object.

Hereinafter, the powder material according to one embodiment of the present invention will be described, and then a method for producing a three-dimensional model using the powder material will be described.

1. 1. Powder material The powder material of the present embodiment is used for producing a three-dimensional model by the powder bed fusion bonding method. More specifically, the preheating of the powder material containing the coating particles and the selective laser irradiation of the thin layer are repeated, and a plurality of shaped object layers in which at least a part of the coating particles are melt-bonded are laminated. It is used in the method of manufacturing a three-dimensional model.

The powder material may contain at least coating particles and may consist only of coating particles. On the other hand, the powder material may further contain a material other than the coating particles containing the laser absorber and the flow agent as long as the melt bonding due to the laser irradiation is not hindered.

1-1. Coated particles The coated particles have a core resin and a structure in which the shell resin coats the core resin (hereinafter, the structure is also referred to as a “core-shell structure”). In addition, metal oxides and / or metal nitrides are localized between the core resin and the shell resin. In the present specification, the core-shell structure means that the ratio of the area of the portion covered with the shell resin to the surface of the core particles basically composed of the core resin is 90% or more. The metal oxide and / or the metal nitride is localized between the core resin and the shell resin, but when confirming the core-shell structure, the metal oxide and / or the metal nitride is the core. Treat as part of the particle. Practically, the cross sections of a large number of coated particles are imaged with a transmission electron microscope (TEM), and the ratio of the coated area of the shell resin to the surface area of the core particles is calculated for 10 arbitrarily selected coated particles. Then, if their average value is 90% or more, it is considered that those coated particles have a core-shell structure.

Here, as shown in the schematic cross-sectional view of FIG. 1A, the coated particles 100 having the core-shell structure may be coated with the core particles 101 by the sheet-shaped shell resin 102. Further, as shown in the schematic cross-sectional view of FIG. 1B, the particulate shell resin 102 may be the coated particles 100 in which the core particles 101 are coated. Although metal oxides and / metal nitrides are not shown in FIGS. 1A and 1B for convenience, in actual coating particles, metal oxides and / metals are formed between the core particles 100 and the shell resin 102. Nitride is localized.

Here, in the present specification, at least one of the metal oxide and the metal nitride is localized between the core resin and the shell resin, that is, the metal oxide and / / between the core resin and the shell resin. Alternatively, it means that there is a region where the metal nitride is observed by TEM. In addition, a part of the metal oxide and / or the metal nitride may be contained in the core particles made of the core resin or the shell resin covering the core particles, but when the cross section of the coated particles is confirmed by TEM, If a region consisting substantially of a metal oxide and / or a metal nitride is present between the core particles and the shell resin, it is treated as if the metal oxide and / or the metal nitride is localized in the region. ..

Here, the metal oxide and / or the metal nitride contained between the core resin and the shell resin may be in the form of particles or may be in the form of a film. The metal oxide and / or metal nitride is preferably in the form of particles from the viewpoint that coated particles can be easily produced by dry mixing.

The metal oxide and / or the metal nitride may be contained so as to cover only a part of the core resin, but it should be contained so as to cover substantially the entire surface of the core resin. Is preferable. When the metal oxide and / or the metal nitride covers substantially the entire surface of the core resin, the core resin and the shell resin can be physically separated as described above. Then, even if the core resin is melted by the preheating, it is possible to prevent the shell resin from being dissolved in the core resin, and it is possible to prevent the coating particles from aggregating during the preheating.

Here, when the metal oxide and / or the metal nitride is a particle, the average particle diameter thereof is preferably 1 nm to 350 nm, more preferably 3 nm to 200 nm, and further preferably 5 nm to 100 nm. preferable. When the average particle size is less than 1 nm, the surface coverage of the core particles by the metal oxide and / or the metal nitride is high, but the distance between the core resin and the shell resin is short, and the above-mentioned aggregation suppressing effect is obtained. Hard to get. On the other hand, when the average particle size is more than 350 nm, it becomes difficult for the metal oxide and / or the metal nitride to coat the core resin, and in this case as well, it becomes difficult to obtain the above-mentioned agglutination suppressing effect. The average particle size is the volume average particle size measured by the dynamic light scattering method. The volume average particle diameter can be measured by, for example, the Microtrack MT3300 II manufactured by Microtrac Bell Co., Ltd., a laser diffraction type particle size distribution measuring device equipped with a wet disperser. When measuring the average particle size of the metal oxide and / or the metal nitride in the coated particles, the measurement can be performed by dissolving the core resin and the shell resin in a solvent or the like and taking out the metal oxide and / or the metal nitride. It is possible.

Further, the content of the metal oxide and / or the metal nitride in the coated particles is preferably 0.01 part by mass to 5.0 part by mass, and 0.03 part by mass with respect to 100 parts by mass of the core resin. It is more preferably ~ 3.0 parts by mass, and more preferably 0.05 parts by mass to 1.0 parts by mass. When the amount of the metal oxide and / or the metal nitride is less than 0.01 parts by mass, the coverage of the core resin by the metal oxide and / or the metal nitride becomes low, and it becomes difficult to obtain the aggregation suppressing effect. On the other hand, when the amount of the metal oxide and / or the metal nitride is larger than the above range, the effect of suppressing aggregation is high, but the metal oxide and / or the metal nitride inhibits the fusion of the particles by laser irradiation. May reduce the strength of the modeled object. The content of metal oxides and / or metal nitrides can be measured by thermogravimetric analysis.

The type of the metal oxide and / or the metal nitride is not particularly limited as long as it is a metal oxide or a metal nitride. Examples of metal oxides include iron oxide, copper oxide, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide and the like. Examples of metal nitrides include boron nitride and the like. In this specification, the metal constituting the metal oxide also includes a metalloid such as silicon and boron. Further, the metal is not limited to a single metal such as iron, copper, aluminum, silicon, titanium, zirconium, and boron, and an alloy containing the single metal (for example, a titanium alloy, a zirconium alloy, a cobalt-chromium alloy, etc.), and stainless steel. It may be steel or the like. Here, if the metal oxide and / or the metal nitride is a material that easily aggregates, the metal oxide and / or the metal nitride may be unevenly distributed between the core resin and the shell resin. Therefore, titanium oxide is particularly preferable among the above from the viewpoint that the dispersibility is good and aggregation is unlikely to occur.

Here, in the coated particles of the present embodiment, the storage elastic modulus G'c of the core resin is lower than the storage elastic modulus G's of the shell resin at the preheating temperature in the method for producing a three-dimensional model described later. Is preferable. When the storage elastic moduli (G'c and G's) of the core resin and the shell resin have such a relationship, it is possible to soften only the core resin by preheating. In the preheating temperature, the core resin and the or storage modulus of the shell resin (G'c and G's) satisfies the above relationship, the storage modulus of the shell resin G 'is 10 ^{6.5 Pa} Temperature TS ( It can be estimated to some extent from 65) and the temperature TC (65) at which the storage elastic modulus G'of the core resin becomes ^106.5 Pa. In this embodiment, TS (65) is higher than TC (65). Covered particles in which the temperature TS (65) at which the storage elastic modulus G'of the shell resin is ^106.5 Pa is higher than the temperature TC (65) at which the storage elastic modulus G'of the core resin is ^106.5 Pa. By adopting it, it becomes possible to further suppress particle agglomeration during preheating while suppressing modeling distortion. Further, by using such coated particles, the coated particles can be efficiently melt-bonded to each other by laser irradiation.

Here, the preheating temperature is appropriately set according to the type of coated particles and the like, and can be set in the same manner as the general powder bed melt bonding method. The preheating temperature is preferably 50 ° C. or higher and 300 ° C. or lower, more preferably 100 ° C. or higher and 300 ° C. or lower, further preferably 100 ° C. or higher and 250 ° C. or lower, and 140 ° C. or higher and 250 ° C. or lower. It is more preferable to have. It is more preferably 140 ° C. or higher and 200 ° C. or lower.

Here, the coated particles are formed by at least a part (at least a core) of the coated particles due to the shell resin softening, melting, disappearing, etc. when irradiated with laser light in the method for producing a three-dimensional model described later. Resin) melt-bonded to each other. At this time, the metal oxide and / or the metal sulfide is dispersed in the molded product in which at least a part of the coated particles are melt-bonded to each other.

Therefore, from the viewpoint of making the shell resin soften, melt, or disappear by laser light irradiation and producing a three-dimensional model in a shorter time, the temperature at which the shell resin softens, melts, or disappears, and the core resin It is preferable that the temperature at which the material softens or melts is close to the value. Further, during laser light irradiation, the specific volume of the core resin increases and the volume changes due to the laser light energy, but the volume change is preferably small from the viewpoint of improving the modeling accuracy of the three-dimensional modeled object. Therefore, it is preferable that the temperature difference is small in order to melt-bond at least a part (core resin) of the coated particles while the volume change of the core resin is small. On the other hand, from the viewpoint of suppressing deformation of the coating particles during preheating, that is, suppressing softening of the shell resin, it is preferable that the temperature difference is not too small.

Therefore, the difference between the above-mentioned TS (65) and TC (65) is preferably 5 ° C. or higher and 70 ° C. or lower, more preferably 10 ° C. or higher and 70 ° C. or lower, and 10 ° C. or higher and 60 ° C. or lower. It is more preferable that the temperature is 30 ° C. or higher and 60 ° C. or lower.

Further, the temperature TC (65) at which the storage elastic modulus G'of the core resin is ^106.5 Pa is preferably included in the range of the general preheating temperature in the powder bed melt bonding method. Therefore, TC (65) is preferably 50 ° C. or higher and 300 ° C. or lower, more preferably 100 ° C. or higher and 300 ° C. or lower, further preferably 100 ° C. or higher and 250 ° C. or lower, and 140 ° C. or higher and 250 ° C. or higher. It is more preferably ° C. or lower, and even more preferably 140 ° C. or higher and 200 ° C. or lower.

Further, the temperature TS (65) at which the storage elastic modulus G'of the shell resin is ^106.5 Pa is a temperature that facilitates melting by irradiation with laser light while ensuring the degree of freedom in selecting the core resin. It is preferably in the range. Therefore, TS (65) is preferably 100 ° C. or higher and 350 ° C. or lower, more preferably 150 ° C. or higher and 330 ° C. or lower, further preferably 250 ° C. or higher and 330 ° C. or lower, and 250 ° C. or higher and 300 ° C. or higher. It is more preferably below ° C.

Further, from the viewpoint of making it more difficult for the modeled object to be deformed after the laser beam irradiation, it is preferable that the core resin hardens in a shorter time during cooling after the laser beam irradiation. From the above viewpoint, the temperature at which the core resin softens (temperature TC (65) at which the storage elastic modulus ^G'is 106.5 Pa) and the temperature at which the core resin becomes hard enough not to be deformed (storage elastic modulus G') are It is preferable that the temperature difference from the temperature at which it reaches 10 ^7.0 Pa (TC (70)) is small. Specifically, | TC (70) -TC (65) | is 10 ° C. or higher and 100 ° C. or lower. It is more preferably 10 ° C. or higher and 80 ° C. or lower, further preferably 15 ° C. or higher and 80 ° C. or lower, further preferably 20 ° C. or higher and 80 ° C. or lower, and 20 ° C. or higher and 50 ° C. or lower. Is even more preferable.

Here, each of the storage elastic moduli can be a value measured by a known method. In the present specification, the value obtained by measuring by a method using a storage elastic modulus measuring device (ARES-G2 rheometer manufactured by TA Instruments) is referred to as the storage elastic modulus. The specific method is shown below.

(Preparation of sample for storage elastic modulus measurement)
The core resin or shell resin constituting the coating particles is separated and extracted with a solvent that dissolves only one of the core resin and the shell resin, and dried to be powdered. Using a pressure molding machine (NT-100H, manufactured by NPA System Co., Ltd.), the obtained powder is pressurized to 30 kN at room temperature for 1 minute to form a columnar sample having a diameter of about 8 mm and a height of about 2 mm. ..

(Measurement procedure of storage elastic modulus)
After adjusting the temperature of the parallel plate of the above device to 150 ° C. and heating and melting the prepared columnar sample, a load is applied in the vertical direction so that the axial force does not exceed 10 (g weight). Then, the above sample is fixed to the parallel plate. In this state, the parallel plate and the columnar sample are heated to a measurement start temperature of 250 ° C., and the viscoelastic data is measured while slowly cooling. The measured data is transferred to a computer equipped with Microsoft Windows 7 (“Windows” is a registered trademark of the company), and the data is transferred through the control, data collection and analysis software (TRIOS) operating on the computer, and desired. The value of the storage elasticity G'(Pa) at the temperature of is read.

(Measurement conditions for storage elastic modulus)
Measurement frequency: 6.28 radians / second Measurement distortion setting: Set the initial value to 0.1% and perform measurement in the automatic measurement mode.
Sample elongation correction: Adjust in automatic measurement mode.
Measurement temperature: Slowly cool from 250 ° C to 100 ° C at a rate of 5 ° C per minute.
Measurement interval: Viscoelastic data is measured every 1 ° C.

Here, the average particle size of the coated particles 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 coated particles is 2 μm or more, the thickness of each 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 diameter of the coated particles is 210 μm or less, it is possible to produce a three-dimensional model having a complicated shape.

At this time, the average particle size of the core is preferably 1 μm or more and 200 μm or less, more preferably 2 μm or more and 150 μm or less, further preferably 5 μm or more and 100 μm or less, and 5 μm or more and 70 μm or less. Is more preferable, and it is further preferable that it is 10 μm or more and 60 μm or less. When the average particle size of the core is 1 μm or more, the powder material has sufficient fluidity, so that the powder material can be easily handled when producing a three-dimensional model. Further, when the average particle size is 1 μm or more, the core resin can be easily produced, and the production cost of the powder material does not increase. When the average particle size is 200 μm or less, a higher-definition three-dimensional model can be manufactured.

On the other hand, the thickness of the shell (thickness of the layer made of the shell resin) is preferably 10 to 500 nm, more preferably 15 to 400 nm, and even more preferably 20 to 300 nm.

The average particle size of the coated particles is 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 (HELOS manufactured by SIMPATEC) equipped with a wet disperser. The average particle size of the core and the thickness of the shell are the thickness of the layer made of shell resin for 10 randomly selected coated particles in the image obtained by imaging the cross sections of a large number of coated particles with TEM. It is possible to actually measure 10 points and adopt the average value thereof. In the observation using the image taken by the TEM, a metal oxide and / or a metal nitride is also confirmed between the core particles and the shell resin. The thickness of the region where the metal oxide and / or the metal nitride is localized is appropriately selected according to the content of the metal oxide and / or the metal nitride, and is appropriately set within a range that does not impair the object of the present invention. Will be done.

The amount of the core resin and the shell resin in the coated particles may be any amount as long as the core-shell structure is formed. For example, the amount of the shell resin with respect to 100 parts by mass of the core resin is preferably 0.1 part by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 20 parts by mass or less, and 0.5 parts by mass or less. It is more preferably 1 part by mass or more and 15 parts by mass or less, further preferably 1 part by mass or more and 15 parts by mass or less, and further preferably 1 part by mass or more and 10 parts by mass or less.

The circularity of the coated particles is preferably 0.95 or more, more preferably 0.96 or more, and even more preferably 0.97 or more. When the circularity of the coating particles is 0.95 or more, the volumes of the individual coating particles tend to be uniform, and it becomes easy to form the modeled object layer in a desired shape. The circularity indicates the average circularity of the coated particles, and is a value measured using "FPIA-2100" (manufactured by Sysmex Corporation).

Specifically, the coated particles are moistened with an aqueous surfactant solution, and ultrasonic dispersion is performed for 1 minute. Then, using "FPIA-2100", measurement is performed at an appropriate density of 3000 to 10000 HPF detections in the measurement condition HPF (high-magnification imaging) mode. Within this range, reproducible measurements can be obtained. The circularity is calculated by the following formula.
Circularity = (peripheral length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)
The average circularity is an arithmetic mean value obtained by adding the circularity of each particle and dividing by the total number of measured particles.

Here, the core resin and shell resin of the coating particles described above are not particularly limited as long as they are resins that soften or melt by heating, and the above-mentioned TS (65), TC (65), storage elastic modulus, etc. are taken into consideration. Can be selected individually. As the shell resin, a resin that disappears by heating can also be selected. Examples of resins applicable to core resins and shell resins include crystalline resins such as polyethylene, polypropylene, nylon, polyacetal, polyethylene terephthalate (PET), polyphenyl sulfide, polyether ether ketone (PEEK), and crystalline polyester. Polystyrene, polyurethane, polyvinyl chloride, acrylic nitrile butadiene styrene copolyma (ABS), acrylic polymer, polycarbonate, ethylene vinyl acetate copolymer (EVA), styrene acrylonitrile copolymer (SAN), polyarylate, polyphenylene ether, polycaprolactone Non-crystalline resins such as;

Among these resins, it was difficult to increase the molding accuracy of the non-crystalline resin by the conventional method, but the coated particles having the core-shell structure of the present embodiment can improve the molding accuracy. Become. From this point of view, the material of the core resin may be a non-crystalline resin. It can be said that the particle structure is more useful when a non-crystalline resin is used as the material of the core resin.

1-2. Other Materials As described above, the powder material may contain components other than the above-mentioned coated particles, and examples thereof include a laser absorber, a flow agent, and the like.

1-2-1. Laser Absorbent The powder material may further contain a laser absorber from the viewpoint of more efficiently converting the light energy of the laser into thermal energy. The laser absorber may be a material that absorbs a laser having a wavelength to be used and generates heat. Examples of such laser absorbers include carbon powders, nylon resin powders, pigments, and dyes. These laser absorbers may be used alone or in combination of two.

The amount of the laser absorber can be appropriately set within a range in which the melt bonding of the coating particles is facilitated. For example, it can be more than 0% by mass and less than 3% by mass with respect to the total mass of the powder material.

1-2-2. Flow Agent The powder material may further include a flow agent from the viewpoint of improving the fluidity of the powder material and facilitating the handling of the powder material during the production of the three-dimensional model. 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 type of these flow agents may be used, or two types may be used in combination.

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 coating particles having a core-shell structure (at least the core resin) are sufficiently melt-bonded. It can be more than 0% by mass and less than 2% by mass with respect to the mass.

2. 2. Method for Producing Powder Material The method for producing the powder material is not particularly limited, and can be produced by a known method. For example, when the powder material contains only the above-mentioned coated particles, the coated particles can be used as they are as the powder material. On the other hand, when the powder material contains the coated particles and other materials, the powdered other material and the coated particles can be mixed and mixed for production. Hereinafter, a method for preparing coated particles will be described.

(Preparation method of coated particles)
The method for preparing the above-mentioned coated particles will be described below.
The coating particles include a step of preparing particles made of a core resin, a step of adhering a metal oxide and / or a metal nitride to the surface of the particles made of the core resin, and the step of adhering the metal oxide and / or the metal nitride. It can be prepared by performing a step of adhering a shell resin so as to cover it.

The particles made of the core resin may be prepared or a commercially available product may be used. The preparation method can be the same as the known method for preparing resin particles.

Further, the method of adhering the metal oxide and / or the metal nitride to the surface of the particles made of the core resin is not particularly limited. An example of the method of adhering the metal oxide and / or the metal nitride is a method of applying a dispersion liquid in which the particles of the metal oxide and / or the metal nitride are dispersed on the surface of the particles made of the core resin. It may be a method of adhering a metal oxide and / or a metal nitride to the surface of the particles made of the core resin by a vapor deposition method, a sputtering method or the like, and the particles made of the core resin and the metal oxide and / Or a method may be used in which the particles made of metal nitride are dry-mixed and the metal oxide particles are physically adhered to the surface of the core resin. Among these, dry mixing is preferable from the viewpoint that metal oxides and / or metal nitrides can be efficiently adhered.

Further, as a method for adhering the shell resin, a wet coating method in which a coating liquid in which the shell resin is dissolved is applied, particles to which a metal oxide and / or a metal nitride is attached, and particles made of the shell resin are used. A dry coating method in which the shell resin is bonded to the surface by stirring and mixing and mechanical impact, and a method in which these are combined are included.

When the wet coating method is adopted, the coating liquid may be spray-coated on the surface of the core resin to which the metal oxide and / or the metal nitride is attached, and the metal oxide and / or the metal nitride is attached. The core resin may be immersed in the coating liquid. According to the wet coating method, coated particles in which the core particles are coated with the sheet-shaped shell resin as shown in FIG. 1A can be obtained. On the other hand, according to the dry coating method, coated particles in which the core particles are coated with the particulate shell resin as shown in FIG. 1B can be obtained. According to the wet coating method, it is easy to form a layer made of a shell resin having a uniform thickness, and since the dry coating method does not require a drying step, the manufacturing process can be simplified.

As described above, the core resin and the shell resin are selected in consideration of the storage elastic modulus. Commercially available core resins and shell resins may be used. Further, those prepared by polymerizing a monomer, a prepolymer or the like may be used.

On the other hand, if a specific resin is selected as the core resin and a material having a higher Tg than the resin is selected as the shell resin, the above-mentioned relationship between TC (65) and TS (65) can be easily satisfied. For example, if polyethylene, polypropylene, and polystyrene, which tend to have a low Tg, are selected as the core resin, and polyetheretherketone (PEEK), polycarbonate, and an acrylic polymer, which tend to have a high Tg, are selected as the shell resin, the above-mentioned TC The relationship between (65) and TS (65) can be easily satisfied. The Tg of a commercially available resin is often published by each manufacturer.

Further, the storage elastic modulus G'of the resin to be prepared can be controlled within a desired range by changing the average molecular weight of the resin. Specifically, if the average molecular weight of the resin to be prepared is increased, the storage elastic modulus G'of the resin is increased, and if the average molecular weight of the resin to be prepared is decreased, the storage elastic modulus G'of the resin is decreased. For each type of resin to be used, the relationship between the molecular weight and the storage elastic modulus G'at the preheating temperature is investigated in advance, and the molecular weight of the resin to be prepared is determined by referring to the above relationship in the next production of the resin. May be good.

3. 3. Method for manufacturing a three-dimensional model Next, a method for manufacturing a three-dimensional model using the above-mentioned powder material will be described. In the method for producing a three-dimensional model of the present embodiment, it can be carried out in the same manner as the usual powder bed fusion bonding method except that the powder material is used. Specifically, it comprises (1) a thin layer forming step of forming a thin layer made of the above-mentioned powder material, (2) a preheating step of preheating the powder material, and (3) a preheated powder material. The method can include a laser light irradiation step of selectively irradiating the thin layer with laser light to form a molded product layer in which the coating particles contained in the powder material are melt-bonded to each other. Then, the three-dimensional model can be manufactured by repeating the steps (1) to (3) a plurality of times and laminating the model layers. Either step (1) or step (2) may be performed first.

3-1. Thin layer forming step (step (1))
In this step, a thin layer of the powder material is formed. For example, the powder material supplied from the powder supply unit is spread flat on the modeling stage by a recoater. 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, it is possible to prevent the coating particles of the lower layer from being melt-bonded by the laser irradiation for forming the next modeled object layer. It is possible to spread uniform powder. Further, by setting the thickness of the thin layer to 0.30 mm or less, the energy of the laser beam is conducted to the lower part of the thin layer, and the coating particles contained in the powder material constituting the thin layer are spread over the entire thickness direction. It can be sufficiently melt-bonded. From the above viewpoint, the thickness of the thin layer is more preferably 0.01 mm or more and 0.10 mm or less. Further, from the viewpoint of more sufficiently melt-bonding the coating particles over the entire thickness direction of the thin layer and making it more difficult for the modeled object layer to crack, the thickness of the thin layer is the beam spot diameter of the laser beam described later. It is preferable to set so that the difference between the two is within 0.10 mm.

3-2. Preheating step (step (2))
In this step, the powder material is preheated. As described above, either step (1) or step (2) may be performed first. For example, the powder material may be preheated to form a thin layer, or the thin layer may be formed and then the powder material may be preheated.

Preheating temperature is a temperature higher than the glass transition temperature of the core resin, and can be lower than the glass transition temperature of the shell resin temperature, the storage modulus G'c the core resin of the above coated particles 10 6 ^Pa or less and it is preferably a temperature at which the storage modulus G's of the shell resin is 10 8 ^Pa or more. Further, from the viewpoint of suppressing the heat of the preheated powder material from remelting and distorting the modeled object layer and lowering the modeling accuracy, the surface temperature of the powder material after preheating is the storage elastic modulus of the core resin. Preheating is preferably performed so that the rate G'is 5 ° C. or higher and 50 ° C. or lower higher than the temperature TC (65) at which the rate G'is 10 ^6.5 Pa. The preheating temperature is preferably 50 ° C. or higher and 300 ° C. or lower, more preferably 100 ° C. or higher and 250 ° C. or lower, further preferably 140 ° C. or higher and 250 ° C. or lower, and 140 ° C. or higher and 200 ° C. or lower. The following is more preferable.

At this time, the heating time is preferably 1 to 30 seconds, more preferably 5 to 20 seconds. By setting the heating temperature and the heating time within the above ranges, the core resin in the coated particles can be sufficiently softened or melted, and a three-dimensional model can be produced with the amount of laser energy.

3-3. Laser light irradiation step (step (3))
In this step, among the thin layers made of the preheated powder material, the laser beam is selectively irradiated to the position where the model layer should be formed, and at least a part of the coated particles at the irradiated position (at least the core) are irradiated. Resins) are melt-bonded. The melted coated particles (core resin) melt with the adjacent coated particles (core resin) to form a melt-bonded body, which becomes a modeled object layer. At this time, the coating particles that have received the energy of the laser beam are also melt-bonded to the already formed model layer, so that adhesion between adjacent layers also occurs.

The wavelength of the laser beam may be set within the wavelength range absorbed by the shell resin. At this time, it is preferable that the difference between the wavelength of the laser beam and the wavelength at which the absorption rate of the shell resin is the highest is small. However, since the resin generally absorbs light in various wavelength ranges, CO ₂ It is preferable to use a laser beam having a wide wavelength band such as a laser. For example, the wavelength of the laser beam can be, for example, 0.8 μm or more and 12 μm or less.

The power at the time of output of the laser light may be set within a range in which the shell resin is sufficiently melt-bonded at the scanning speed of the laser light described later. Specifically, it can be 5.0 W or more and 60 W or less. From the viewpoint of lowering the energy of the laser beam, lowering the manufacturing cost, and simplifying the configuration of the manufacturing apparatus, the power at the time of outputting the laser beam is preferably 30 W or less, preferably 20 W or less. More preferably.

The scanning speed of the laser beam may be set within a range that does not increase the manufacturing cost and does not excessively complicate the apparatus configuration. Specifically, it is preferably 1 m / sec or more and 10 m / sec or less, more preferably 2 m / sec or more and 8 m / sec or less, and further preferably 3 m / sec or more and 7 m / sec or less.
The beam diameter of the laser beam can be appropriately set according to the accuracy of the three-dimensional model to be manufactured.

3-4. Repeating steps (1) to (3) When manufacturing a three-dimensional model, the above steps (1) to (3) are repeated an arbitrary number of times. As a result, the modeled object layers are laminated to obtain a desired three-dimensional modeled object.

3-5. In addition, from the viewpoint of preventing the strength of the three-dimensional model from being lowered due to oxidation of the coated particles during melt bonding, it is preferable that at least step (3) is performed under reduced pressure or in an inert gas atmosphere. Preferably the pressure is less than or equal to ¹⁰ -2 Pa at the time of ^{decompression,} and more preferably ¹⁰ -3 Pa or less. Examples of the inert gas that can be used in this embodiment include nitrogen gas and rare gas. Of these inert gases, nitrogen (N ₂ ) gas, helium (He) gas, or argon (Ar) gas is preferable from the viewpoint of easy availability. From the viewpoint of simplifying the manufacturing process, it is preferable that all of the steps (1) to (3) are performed under reduced pressure or in an inert gas atmosphere.

4. Three-dimensional modeling equipment
A three-dimensional modeling apparatus that can be used in the above-mentioned method for manufacturing a three-dimensional model will be described. The three-dimensional modeling apparatus that can be used in the present embodiment can have the same configuration as the known three-dimensional modeling apparatus. Specifically, as shown in the schematic side view of FIG. 2, the three-dimensional modeling apparatus 200 according to the present embodiment forms a thin layer for forming a thin layer made of a modeling stage 210 and a powder material located in the opening. Part 220, preheating part 230 for preheating the powder material, laser irradiation part 240 for irradiating the thin layer with laser light, stage support part 250 for supporting the modeling stage 210 in a variable vertical position, and A base 290 for supporting each of the above parts is 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. 3, the three-dimensional modeling apparatus 200 controls the thin layer forming unit 220, the preheating unit 230, the laser irradiation unit 240, and the stage support unit 250 to form and stack the modeled objects 260. , A display unit 270 for displaying various information, an operation unit 275 including a pointing device for receiving instructions from a user, a storage unit 280 for storing various information including a control program executed by the control unit 260, and a storage unit 280. 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 300 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 powder material, and the laser irradiation unit 240 irradiates the laser beam on the modeling stage 210. Is done. 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 present embodiment, 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 powder material that can heat the region where the model layer is to be formed and maintain the temperature. In the present embodiment, 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 powder material before being supplied onto the modeling stage 210. The heater 232 and the like, 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 sensor or an optical thermometer.

The laser irradiation unit 240 can be configured to include a laser light source 241 and a galvanometer mirror 242a. The laser irradiation unit 240 may include a laser window 243 that transmits the laser light and a lens (not shown) for adjusting the focal length of the laser light to the surface of the thin layer. The laser light source 241 may be a light source that emits laser light of the wavelength at the output. Examples of the laser light source 241 include a YAG laser light source, a fiber laser light source, and a CO ₂ laser light source. The galvano mirror 242a may be composed of an X mirror that reflects the laser light emitted from the laser light source 241 and scans the laser light in the X direction and a Y mirror that scans the laser light in the Y direction. The laser window 243 may be made of a material that transmits laser light.

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 300 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 of the present embodiment 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 300 into a plurality of slice data sliced thinly 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 the motor and the drive mechanism (both not shown) according to the supply information output from the control unit 260, and moves the supply piston upward in the vertical direction (in the direction of the up arrow in FIG. 2). The powder material is extruded on the same plane in the horizontal direction as the modeling 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 only the powder material in a predetermined region or the entire inside of the apparatus according to the temperature information output from the control unit 260. The temperature information is, for example, based on the data of the temperature TC (6.5) at which the storage elastic modulus G'of the material constituting the core resin input from the data input unit 285 becomes 10 ^6.5 Pa, the control unit 260. Can be used as information for heating the powder material to a temperature at which the difference from the above temperature is 5 ° C. or higher and 50 ° C. or lower, which is extracted from the storage unit 280. 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 laser irradiation unit 240 emits laser light from the laser light source 241 according to the laser irradiation information output from the control unit 260, conforming to the region constituting the three-dimensional model in each slice data on the thin layer. , The galvano mirror drive unit 242 drives the galvano mirror 242a to scan the laser beam. By irradiation with the laser beam, at least a part (at least the core resin) of the coating particles contained in the powder material is melt-bonded to form a modeled object layer.

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 pushes the modeling stage 210 vertically downward by the stacking pitch (lower part of FIG. 2). Move in the direction of the arrow).

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.

The control unit 260 receives information on the temperature of the region where the modeled object layer should be formed on the surface of the thin layer from the temperature measuring device 235, and the temperature of the region where the modeled object layer should be formed and the core resin. The difference between the temperature TC (6.5) at which the storage elastic modulus G'of the material constituting the material is 10 ^6.5 Pa and 5 ° C. or higher and 50 ° C. or lower, preferably 5 ° C. or higher and 30 ° C. or lower. The heating by the preheating unit 230 may be controlled.

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. Preparation of powder material 1-1. Preparation of raw materials The materials shown in Table 1 below were prepared as core resins and shell resins, and metal oxides or metal nitrides. Regarding the core resin and shell resin, when the average particle size of the commercially available resin is larger than the value shown in Table 1, a laser diffraction type particle size distribution measuring device (manufactured by SYMPATEC) equipped with a wet disperser, Commercially available resin particles were pulverized by a mechanical pulverization method until the average particle diameter measured with HELOS) reached the values shown in Table 1.

1-2. Preparation of powder material (1) Preparation of powder material 2500 2 g of PA12 particles and 5 g of titania 1 were put into an FM mixer (FM10C / I manufactured by Nippon Coke Industries Co., Ltd.), and the temperature was adjusted at 25 ° C. The mixture was mixed for 10 minutes at 35 m / s to prepare particles in which titania 1 was attached to the surface of PA12 particles. After that, 950 g of the particles were put into a rolling fluid coating device (MP-10 manufactured by Paulec Co., Ltd.), and the air supply temperature was 50 ° C., the static pressure in the layer was 1.8 kPa, the static pressure of exhaust gas was 2.1 kPa, and the rotor rotation speed was 400 rpm. It was made into a fluid state under the conditions. Then, a solution prepared by dissolving 50 g of a polycarbonate resin (FPC-0220 manufactured by Mitsubishi Gas Chemicals Co., Ltd.) in 1000 parts by mass of tetrahydrofuran (THF) was poured into the layer from a spray nozzle at a rate of 4 g / min. By spraying the solution from a total amount spray nozzle, a powder material 3 containing coated particles was obtained.

In the powder material, titania 1 was localized between the shell resin and the core resin. The localization of titania 1 was confirmed by a cross-sectional image of the coated particles imaged by TEM.

(2) Preparation of powder material 2 The powder material 2 was prepared in the same manner as the powder material 3 except that titania 1 was not attached to the polyamide 12 particles.

(3) Preparation of powder materials 4 to 21 As shown in Table 2, the powder materials 4 to 21 are prepared in the same manner as the powder material 3 except that the core resin, the shell resin, and the metal oxide or the metal nitride are combined. Prepared. When the obtained powder materials 4 to 21 were confirmed by the same method as that of the powder material 3, titanium oxide, aluminum oxide, silicon oxide, or boron nitride were localized between the shell resin and the core resin, respectively. It was.

(4) Preparation of Powder Material 1 Polyamide 12 particles were used as they were as powder material 1.

2. 2. Evaluation The three-dimensional model obtained from the above powder material was evaluated as follows. The results are shown in Table 3.

A. Evaluation of three-dimensional modeled object (1) Preparation of three-dimensional modeled object Powder materials 1 to 21 are spread on a modeling stage installed on a hot plate to form a thin layer with a thickness of 0.1 mm, and the temperature of the hot plate is adjusted. As a result, they were heated to the preheating temperatures shown in Table 3, respectively. This thin layer was irradiated with laser light from a 50 W CO ₂ laser equipped with a galvanometer scanner for YAG wavelength according to the shape of a test piece of ISO 527-2-1BA under the following conditions to prepare a model layer. The above steps were repeated 10 times to produce laminated three-dimensional objects composed of 10 layers.
[Laser light emission conditions]
Laser output: 50W
Laser beam wavelength: 10 μm
Beam diameter: 170 μm on thin layer surface
[Laser light scanning conditions]
Scanning speed: 2000 mm / sec
Number of lines: 1 line [Ambient atmosphere]
Temperature: Preheating temperature Gas: Nitrogen (N ₂ ) 100%

(2) Measurement of strain of modeled object For the three-dimensional modeled object produced above, the length of the test piece in the longitudinal direction was measured using a Digimatic Height Gauge HD-AX manufactured by Mitutoyo Co., Ltd. for dimensional error. The dimensional error was evaluated according to the following criteria.
〇: Error less than ± 0.1 mm with respect to the reference length 75 mm Δ: Error ± 0.1 mm or more and less than 0.2 mm with respect to the reference length 75 mm ×: Error ± 0.3 mm or more with respect to the reference length 75 mm

(3) Measurement of the strength of the modeled object The three-dimensional modeled object produced above was subjected to the above-mentioned universal testing machine model-5582 manufactured by Inslon Co., Ltd. under the conditions of a tensile speed of 1 mm / min, a gripping tool distance of 60 mm, and a test temperature of 23 ° C. Was measured. The strength ratio was evaluated according to the following criteria.
〇: Tensile strength is 90% or more with respect to the tensile strength of the injection molded product manufactured using the core resin Δ: Tensile strength is 80% or more with respect to the tensile strength of the injection molded product manufactured using the core resin. Less than 90% ×: Tensile strength is less than 80% of the tensile strength of injection molded products made using core resin.

B. Evaluation of powder material (reusability)
1 g of each of the powder materials 1 to 21 was weighed in a 20 cc glass sample bottle, and left on a hot plate at the preheating temperature shown in Table 3 for 10 minutes. After being left to stand, the powder material was returned to room temperature, and then the powder material was transferred onto a metal mesh sieve having an opening diameter of 2 mm and vibrated for 20 seconds. The weight of the powder material remaining on the sieve was measured, and the reusability of the powder material was evaluated according to the following criteria.
⊚: Amount of particles remaining on the sieve is less than 3% by mass 〇: Amount of particles remaining on the sieve is 3% by mass or more and less than 7% by mass Δ: Amount of particles remaining on the sieve is 7% by mass or more 15 Less than mass% ×: The amount of particles remaining on the sieve is 15% by mass or more.

As shown in Table 3, in the powder materials 3 to 21 in which the metal oxide or metal nitride is localized between the core resin and the shell resin, the metal oxide and the metal nitride are located between the core resin and the shell resin. The reusability was good as compared with the case where no substance was contained (powder material 2) and the case where only the core resin was used (powder material 1). Since the core resin and the shell resin were physically phase-separated by the metal oxide or the metal nitride, it is presumed that the coated particles were difficult to aggregate during the preheating. However, when the amount of metal oxide or metal nitride is less than 0.05 mass with respect to 100 parts by mass of the core resin (powder materials 8 and 10), there is no practical problem, but the reusability is high. It tended to decline. Further, in the powder materials 3 to 21 in which the metal oxide or the metal nitride is localized between the core resin and the shell resin, the modeling distortion was small and the modeling object strength was sufficiently high within the practical problem. .. However, when the amount of the metal oxide or the metal nitride is more than 1.0% by mass with respect to 100 parts by mass of the total amount of the core resin and the shell resin (powder materials 9 and 11), there is a practical problem. Although there was no such thing, the strength of the modeled object tended to decrease.

Since the powder material according to the present invention does not easily aggregate even when preheated, it is possible to reuse the coated particles that were not used for modeling. Therefore, according to the present invention, it is considered that it contributes to the further spread of the powder bed melt bonding method.

100 Coated particles 101 Core particles 102 Shell resin 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 instrument 240 Laser irradiation unit 241 Laser light source 242 Galvano mirror drive unit 242a Galvano mirror 243 Laser window 250 Stage support unit 260 Control unit 270 Display unit 275 Operation unit 280 Storage unit 290 Base 285 Data input unit 300 Computer device

Claims (8)

Preheating of the powder material comprising coated particles, and the selective laser irradiation of the thin layer as many times as the powder material, at least a part each other is a plurality of layers stacked shaped object layer which is melted binding of said coated particles It is a powder material used in the method of manufacturing a three-dimensional model.
The coating particles include a core resin and a shell resin that coats the core resin.
A powder material in which at least one of a metal oxide and a metal nitride is localized between the core resin and the shell resin. The powder material according to claim 1, wherein the metal oxide or metal nitride is in the form of particles. The average particle size of the particulate metal oxide or metal nitride is 5 nm to 100 nm.
The powder material according to claim 2, wherein the total amount of the metal oxide and the metal nitride with respect to 100 parts by mass of the core resin is 0.05 parts by mass to 1.0 part by mass. The powder material according to any one of claims 1 to 3, wherein the metal oxide is titanium oxide. The storage elastic modulus of the shell resin G 'is ^{10 6.5} Pa Temperature TS (65) has a storage modulus G of the core resins' is higher than the temperature TC (65) to become ^{10 6.5} Pa,
The powder material according to any one of claims 1 to 4. The storage elastic modulus of the shell resin G 'is the temperature TS (65) to become ^{10 6.5} Pa, the storage modulus G of the core resin' is the difference between the temperature TC (65) to become ^{10 6.5} Pa The powder material according to claim 5, wherein the temperature is 5 ° C. or higher and 70 ° C. or lower. A thin layer forming step of forming a thin layer made of the powder material according to any one of claims 1 to 6.
A preheating step of preheating the powder material and
A laser light irradiation step of selectively irradiating the thin layer made of the preheated powder material with laser light to form a shaped object layer in which at least a part of the coating particles are melt-bonded to each other.
Including
The thin layer forming step, the preheating step, and the laser light irradiation step are repeated a plurality of times, and the three-dimensional model is formed by laminating the model layers.
A method for manufacturing a three-dimensional model. The modeling stage and
A thin layer forming portion for forming a thin layer of the powder material according to any one of claims 1 to 6 on the molding stage, and a thin layer forming portion.
A preheating unit that preheats the powder material and
A laser irradiation unit that irradiates the thin layer made of the preheated powder material with a laser to form a shaped object layer in which at least a part of the coating particles are melt-bonded to each other.
A stage support portion that variably supports the modeling stage in its vertical position, and
A control unit that controls the thin layer forming portion, the preheating portion, the laser irradiation portion, and the stage support portion to repeatedly form and stack the modeled object layer.
A three-dimensional modeling device equipped with.

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