WO2019013069A1 - Powder material and method for producing three-dimensional model - Google Patents

Abstract

The purpose of the present invention is to provide: a powder material which is not susceptible to aggregation of particles during preliminary heating, while enabling melt bonding of resin particles with a small amount of laser irradiation, and which is additionally capable of producing a three-dimensional model that is suppressed in deformation and has high impact strength; and a method for producing a three-dimensional model, which uses this powder material. The present invention relates to a powder material which is used for the production of a three-dimensional model, wherein a thin layer of a powder material containing resin particles is selectively irradiated with laser light, thereby forming a shaped article layer that is obtained by sintering or melt bonding the resin particles, and thus-formed shaped article layers are laminated to produce the three-dimensional model. Each of the resin particles has a core that contains a first amorphous resin and a shell that contains a second amorphous resin which has a glass transition temperature higher than the glass transition temperature of the first amorphous resin, and temperature T1 and temperature T2 as determined by a specific method satisfy the relational expression T2 - T1 ≤ 105°C.

Description

Powder material and method for producing three-dimensional object

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

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. A powder bed fusion bonding method is known as one of methods for producing a three-dimensional object, and the powder bed fusion bonding method is characterized in that the molding accuracy is high and the adhesive strength between laminated layers is high.

In the powder bed fusion bonding method, a powder material containing particles of a resin material or a metal material is spread flat to form a thin layer. Then, a desired position of the thin layer is irradiated with laser light to selectively sinter or melt bond (hereinafter also referred to simply as “melt bond”) adjacent particles. That is, a layer obtained by finely dividing the three-dimensional object in the thickness direction (hereinafter, also simply referred to as a "object layer") is formed. A powder material is further spread on the thus-formed object layer, and laser irradiation is repeated to produce a three-dimensional object having a desired shape. Patent Document 1 proposes a particle having a core-shell structure as one of resin particles used in such a powder bed fusion bonding method.

Here, in general, a molded article made of an amorphous resin has higher impact strength than a molded article made of a crystalline resin. In addition, warpage is less likely to occur during molding, and transparency is often present. Furthermore, there is also the advantage that the surface of the molded product can be appropriately dissolved with a solvent to bond the molded products together. In addition, in the case of a molded product made of a crystalline resin, crystallization of the resin may further proceed after molding, and dimensional change or deformation may occur. On the other hand, amorphous resin which does not have crystallinity does not easily cause such dimensional change and deformation.

However, resin particles used in the powder bed melt bonding method are usually particles made of a crystalline resin as represented by polyamide 11, polyamide 12 and the like, and particles made of non-crystalline resin are mostly used. Absent. Also in Patent Document 1, a crystalline resin is used for the core of resin particles having a core-shell structure. The reasons are as follows. In crystalline resins, a rapid viscosity drop occurs at temperatures above the melting point. That is, by heating to a temperature slightly higher than the melting point, the fluidity is sufficiently lowered, and it is possible to melt and bond adjacent resin particles. In addition, crystalline resins have the property of being difficult to deform due to their crystal structure at temperatures lower than the melting point. Therefore, even if preheating to a temperature near the melting point, adjacent resin particles are less likely to fuse. Therefore, with particles made of a crystalline resin, the preheating temperature can be set to a temperature slightly lower than the melting point, and at the time of producing a three-dimensional object, the temperature of the particles is selectively heated to a temperature slightly higher than the melting point It is possible to obtain a desired three-dimensional object.

In contrast, amorphous resins do not have a melting point, and their viscosity gradually decreases after exceeding the glass transition temperature. Therefore, when resin particles made of amorphous resin are used in the powder bed melt bonding method, it is necessary to heat them to a temperature much higher than the glass transition temperature by laser irradiation in order to melt bond adjacent resin particles. . At this time, if the laser irradiation amount is insufficient, it can not be formed into a desired shape, or even if it can be formed, the resin particles can not be sufficiently melt-bonded to each other, and a sufficient strength can not be obtained. Problems are likely to occur (see, for example, Non-Patent Document 1).

On the other hand, when the temperature of the resin particle exceeds the glass transition temperature, the surface of the resin particle is gradually softened and deformed. That is, when the preheating temperature is equal to or higher than the glass transition temperature, adjacent resin particles are easily fused to each other, and a surplus attached matter is easily generated. Therefore, when resin particles made of amorphous resin are to be used in the powder bed melt bonding method, it is necessary to set the preheating temperature lower, and the laser irradiation amount is increased to melt bond the resin particles. There is a need.

JP, 2016-40121, A

Shinno Toshiki, Powder Sintered Layer Forming of Amorphous Plastics-Consideration of Problems-, Proceedings of the 2007 Annual Meeting of the Precision Engineering Society Fall Meeting, P. 487

Here, it is also conceivable to increase the laser irradiation amount when selectively melting and bonding resin particles made of an amorphous resin. However, in this case, the resin locally becomes high temperature, and the resin is decomposed or foaming occurs. As a result, in the three-dimensional object to be obtained, a reduction in density and a reduction in strength tend to occur. It is also conceivable to lower the scanning speed of the laser to selectively melt the resin, but in this case not only the resin particles to be melted but also the temperature of the adjacent resin particles far exceeds the glass transition temperature. It is easy to become. Therefore, excess resin particles are fused and the dimensional accuracy of the three-dimensional object is significantly reduced. Therefore, in the conventional powder material containing the resin particle which consists of non-crystalline resin, it was difficult to make compatible suppression of particle aggregation at the time of preheating, and preparation of a three-dimensional molded article with a small laser irradiation amount.

The present invention has been made in view of the above problems. That is, according to the present invention, the powder material is less likely to agglomerate during preheating, and the resin particles can be melt-bonded with a smaller amount of laser irradiation, and further, a powder material capable of producing a three-dimensional object with little deformation and high impact strength; It aims at provision of the manufacturing method of the three-dimensional molded item using this.

The first of the present invention is the following powder material.
[1] A thin layer of a powder material containing resin particles is selectively irradiated with a laser beam to form a shaped object layer in which the resin particles are sintered or melt-bonded, and the shaped object layer is laminated. A powder material used for producing a three-dimensional object according to claim 1, wherein the resin particles have a core containing a first non-crystalline resin, and a second non-crystalline material having a glass transition temperature higher than that of the first non-crystalline resin. A powder material having a shell containing a hydrophobic resin, and the temperature T1 and the temperature T2 specified in the following method satisfy T2-T1 ≦ 105 ° C.
(Temperature T1)
0.2 g of the resin particles in a cylindrical opening glass bottle having an outer diameter of 20 mm or less, an inner diameter of 10 mm or more, a height of 45 mm or less, and an inner volume of 7 cc or less in an oven at Ta ° C (Ta is an integer that is a multiple of 5) And the weight of the resin particles passing through the sieve is 0.1 g or more when sieved with a 500 μm sieve, and the open glass bottle containing the resin particles is placed in an oven at Ta + 5 ° C. A temperature Ta at which the mass of the resin particles passing through the sieve is less than 0.1 g when held for 30 minutes and sieved is T1 (temperature T2)
A plurality of the resin particles are laid in a layer so as to contact each other in an aluminum plate having a flat bottom and a thickness of 0.1 mm or more and 1 mm or less, Tb ° C. (Tb is an integer that is a multiple of 5) The plate is heated for 30 seconds on a hot plate, cooled to room temperature, and observed with a microscope. Association between adjacent resin particles is confirmed, and the aluminum plate covered with the resin particles is heated at a Tb-5 ° C. hot plate When heating for 30 seconds above, let T2 be the temperature Tb at which no association between adjacent resin particles is confirmed

[2] The powder material according to [1], wherein the glass transition temperature Tg (c) of the first amorphous resin and the glass transition temperature Tg (s) of the second amorphous resin satisfy the following formula: .
Tg (s) -Tg (c) 3030 ° C.
[3] The powder material according to [1] or [2], wherein an average thickness of a shell of the resin particle is 0.05 μm or more and 2 μm or less.
[4] The powder material according to any one of [1] to [3], wherein an average particle diameter (D50) of the resin particles is 10 μm to 100 μm.
[5] The volume fraction of the shell material relative to the total volume of the resin particles, the glass transition temperature Tg (c) of the first non-crystalline resin, and the glass transition temperature Tg (s) of the second non-crystalline resin The powder material according to any one of [1] to [4], which satisfies the following formula.
100 / {Tg (s) -Tg (c)} ≦ volume fraction of shell material ≦ 500 / {Tg (s) -Tg (c)}
[6] The first amorphous resin and / or the second amorphous resin may be polystyrene, polyvinyl chloride, acrylonitrile / butadiene / styrene copolymer resin, acrylonitrile / styrene copolymer resin, acrylic resin, polycarbonate, poly At least one amorphous resin selected from the group consisting of arylates, modified polyphenylene ethers, polysulfones, polyethersulfones, polyetherimides, cycloolefin polymers, cycloolefin copolymers, and amorphous polyamides [1] The powder material in any one of [5].

The second of the present invention resides in the following method for producing a three-dimensional object.
[7] A thin layer forming step of forming a thin layer comprising the powder material according to any one of the above [1] to [6], a preheating step of preheating the powder material, and the powder preheated A laser beam irradiating step of selectively irradiating the thin layer of material with a laser beam to form a shaped object layer in which at least a part of the resin particles are melt-bonded to each other; The manufacturing method of the three-dimensional molded item which forms a three-dimensional molded item by repeating the said preheating process and the said laser beam irradiation process in multiple times, and laminating | stacking the said molded article layer.
[8] The method for producing a three-dimensional object according to [7], wherein the preheating step is a step of heating the powder material to a temperature equal to or lower than the above-mentioned temperature T1.

According to the method for producing a three-dimensional object using the powder material of the present invention, it is possible for the particles to be difficult to aggregate at the time of preheating and for the resin particles to be sufficiently melt bonded with a smaller laser irradiation amount. Still further, according to the powder material, it is possible to produce a three-dimensional object with little deformation and high impact strength.

1A and 1B are schematic cross-sectional views of resin particles in an embodiment of the present invention. FIG. 2: is a side view which shows roughly the structure of the three-dimensional model | molding apparatus in one Embodiment of this invention. FIG. 3 is a view showing the main part of the control system of the three-dimensional structure forming apparatus according to an embodiment of the present invention.

1. Powder material The powder material of this embodiment is used for manufacture of the three-dimensional object by the powder bed fusion bonding method. More specifically, formation of a thin layer made of a powder material containing resin particles, preheating of the powder material, and selective laser light irradiation to the thin layer are repeated to form a shaped layer in which resin particles are melt-bonded to each other. It is used in a method of producing a three-dimensional object by laminating a plurality of layers.

Here, the powder material of the present embodiment only needs to contain at least resin particles, and may be made of only resin particles. On the other hand, the powder material may further contain materials other than resin particles, such as a laser absorber and a flow agent, as long as fusion bonding by laser light irradiation is not hindered.

As described above, the amorphous resin does not have a melting point, and the viscosity gradually decreases after exceeding the glass transition temperature. Therefore, when applying an amorphous resin to resin particles for powder bed melt bonding, it is necessary to set the preheating temperature lower, while heating to a high temperature for melt bonding of the resin particles, ie There is a problem that it is necessary to increase the laser irradiation amount.

In order to solve such problems, the present inventors conducted intensive studies and experiments on powder materials for powder bed fusion bonding. As a result, by combining at least two types of non-crystalline resins and forming them into a core-shell structure, the upper limit of the preheatable temperature (hereinafter also referred to as "preheat upper limit temperature") T1 and melting of resin particles It is possible to reduce the difference (T2-T1) from the lower limit value of temperature required for bonding (hereinafter also referred to as "lower limit melting temperature") T2 and melt resin particles with high dimensional accuracy with low laser irradiation amount. It has been found that it is possible to combine. Since a three-dimensional object obtained from a powder material containing such resin particles contains an amorphous resin, its impact strength is high, and warpage and the like are less likely to occur. Furthermore, it is also possible to appropriately dissolve the surface of the three-dimensional object with a solvent to bond the formed products together. Hereinafter, the resin particle which the said powder material contains, and another component are demonstrated in detail.

1-1. Resin Particles The resin particles contained in the powder material of the present embodiment have a core containing a first amorphous resin and a second glass transition temperature (hereinafter, also simply referred to as “Tg”) higher than that of the first amorphous resin. It has a structure covered by a shell containing an amorphous resin (hereinafter, the structure is also referred to as “core-shell structure”). In the present specification, the core-shell structure means that the ratio of the area of the portion covered by the shell to the surface of the core particle basically composed of the core is 90% or more. Practically, the cross section of a large number of resin particles is imaged with a transmission electron microscope (TEM), and the ratio of the coated area of the shell to the surface area of the core particles is calculated for 10 resin particles selected arbitrarily. And if those average values are 90% or more, those resin particles are considered to have a core-shell structure.

The resin particle 100 having a core-shell structure may have a structure in which a sheet-like shell 102 covers the core 101 as shown in FIG. 1A. A schematic cross-sectional view of another embodiment of the core-shell structure is also shown in FIG. 1B. As shown in FIG. 1B, a particulate shell 102 may cover the core particle 101.

Here, the first non-crystalline resin contained in the core of the resin particle and the second non-crystalline resin contained in the shell of the resin particle are the difference between the preheating upper limit temperature T1 and the lower melting limit temperature T2 (T2-T1) Should be selected so as to be 105 ° C. or less, and they are respectively selected from known amorphous resins. T2-T1 is preferably 70 ° C. or less from the viewpoint of reducing the amount of energy (laser light quantity) required for producing a three-dimensional object. Here, the preheating upper limit temperature T1 and the melting lower limit temperature T2 are temperatures specified by the following method, respectively.

(Preheating upper limit temperature T1)
0.2 g of resin particles are placed in a cylindrical opening glass bottle having an outer diameter of 20 mm or less, an inner diameter of 10 mm or more, a height of 45 mm or less, and an inner volume of 7 cc or less. Then, the glass bottle is held for 30 minutes in an oven at Ta ° C. (Ta is an integer that is a multiple of 5), and sieved with a 500 μm mesh. Then, the temperature at which the mass of resin particles passing through the sieve becomes 0.1 g or more is specified. Similarly, an open glass bottle containing resin particles is held in an oven at Ta + 5 ° C. for 30 minutes and sieved through a 500 μm mesh. Then, when the mass of the passing particles is less than 0.1 g, the temperature Ta is specified as T1. In addition, also in Ta + 5 degreeC, when mass of the resin particle which passes a sieve will be 0.1 g or more, temperature Ta of oven is raised and the same test is performed and T1 is specified.

(Lower melting limit temperature T2)
A plurality of resin particles are placed in a layer so as to be in contact with each other in an aluminum plate having a flat bottom and a thickness of 0.1 mm or more and 1 mm or less. Then, the aluminum plate is heated for 30 seconds on a hot plate at Tb ° C. (Tb is an integer that is a multiple of 5), and allowed to cool to room temperature. Then, when the resin particles on the aluminum plate are observed with a microscope, the temperature at which the association between adjacent resin particles is confirmed is specified. Similarly, the aluminum plate covered with resin particles is heated on a hot plate at Tb-5 ° C. for 30 seconds, cooled to room temperature, and the resin particles on the aluminum plate are observed with a microscope. At this time, when the association of adjacent resin particles is not confirmed, the temperature Tb is specified as T2. In addition, also in Tb-5 ° C, when association of resin particles is seen, temperature Tb ° C of a hot plate is lowered, the same test is performed, and T2 is specified. Note that “adjacent particles are associated with each other” means that the interface between adjacent particles disappears when observed with a microscope.

Here, the types of the first amorphous resin and the second amorphous resin contained in the core and the shell are not particularly limited. For example, polystyrene (PS), polyvinyl chloride (PVC), acrylonitrile butadiene styrene copolymer Resin (ABS), acrylonitrile-styrene copolymer resin (AS), acrylic resin, polycarbonate (PC), polyarylate (PAR), modified polyphenylene ether (PPE), polysulfone (PSU), polyether sulfone (PES), poly It can be ether imide (PEI), cycloolefin polymer (COP), cycloolefin copolymer (COC), amorphous polyamide and so on.

The core of the resin particles may contain only one type of amorphous resin (first amorphous resin), or may contain two or more types. In addition, the core may contain various additives, various fillers, and the like. In addition, although the core may partially contain a crystalline resin, it is preferable that at least 50% by mass of the first amorphous resin is contained with respect to the total mass of the core when the three-dimensional object is manufactured. Is preferable from the viewpoint of sufficient melt bonding, and it is more preferable to contain 70 to 100% by mass of the first amorphous resin. The amount of the first amorphous resin contained in the core is such that the resin particles are immersed in a solvent in which only the shell dissolves, the shell is dissolved, and so forth. And it can specify by analyzing the composition of the remaining core by various methods.

On the other hand, the shell may also contain only one type of amorphous resin (second amorphous resin) or may contain two or more types. Furthermore, the shell may contain various additives, various fillers, and the like. The shell may partially contain a crystalline resin, but containing 50% by mass or more of the second amorphous resin with respect to the total mass of the shell causes adhesion of particles during preheating. It is preferable from the viewpoint of suppressing, and it is more preferable to contain 70 to 100% by mass of the second amorphous resin. The amount of the second amorphous resin contained in the shell is such that the resin particles are immersed in a solvent in which only the core dissolves, and the core is dissolved, for example, to form the shell only. And it can specify by analyzing the composition of the remaining shell by various methods.

In addition, the glass transition temperature (Tg (c)) of the first amorphous resin contained in the core and the glass transition temperature (Tg (s)) of the second amorphous resin are the glass transition temperature of the first amorphous resin. If (Tg (c)) is lower, the difference is not particularly limited, but Tg (s) −Tg (c) is preferably 30 ° C. or more, and more preferably 50 to 100 ° C. When the glass transition temperature (Tg (s)) of the second amorphous resin contained in the shell becomes high, the preheating upper limit temperature T1 of the resin particles tends to be high. On the other hand, when the glass transition temperature (Tg (c)) of the first non-crystalline resin contained in the core is lowered, the melting lower limit temperature T2 tends to be lowered. Therefore, it becomes possible to make these differences (T2-T1) sufficiently small.

Here, the average particle diameter (D50) of the resin particles is preferably 10 μm to 100 μm, more preferably 20 to 80 μm, and still more preferably 30 to 70 μm. When the average particle diameter of the resin particles is 10 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 a three-dimensional shaped object can be efficiently produced. On the other hand, when the average particle diameter of the resin particles is 100 μm or less, it is possible to produce a three-dimensional object having a complicated shape.

At this time, the average particle diameter of the core is preferably 9 to 99 μm, more preferably 19 to 79 μm, and still more preferably 29 to 79 μm. When the average particle size of the core is 60 μm or more, the preparation of the core (particles) is facilitated, and the production cost of the powder material is not excessively increased. On the other hand, when the average particle diameter is 50 μm or less, the average particle diameter of the resin particles can be relatively reduced, and it becomes possible to manufacture a high-definition three-dimensional object.

On the other hand, the thickness of the shell (the thickness of the layer comprising the shell) is preferably 0.05 μm or more and 2 μm or less, more preferably 0.06 to 1.6 μm, and 0.08 to 1.2 μm. Is more preferred. When the shell is composed of a plurality of particles, the average particle diameter of the particles constituting the shell is preferably smaller than the average particle diameter of the particles consisting of the core, and more than half the average particle diameter of the core preferable. When the thickness of the shell is 0.05 μm or more, it is difficult for the core to be eluted on the surface of the resin particles during preheating, and the aggregation of the resin particles is less likely to occur. On the other hand, when the thickness is 2 μm or less, the shell is decomposed, lost, melted, etc. by the laser irradiation, and the resin particles (mainly the core) are easily melt-bonded.

The average particle size of the resin particles is a volume average particle size measured by a dynamic light scattering method. The volume average particle diameter can be measured by a laser diffraction type particle size distribution measuring apparatus (manufactured by Sympatic (SYMPATEC), HEROS (HELOS)) equipped with a wet disperser. In addition, the average particle diameter of the core and the thickness of the shell are prepared by preparing an image obtained by imaging cross sections of a large number of resin particles by TEM, and measuring the particle diameter of the core and the thickness of the shell for 10 resin particles randomly selected. Do. And these average values can be adopted as the average particle diameter of the core and the thickness of the shell, respectively.

The ratio of the core and the shell in the resin particle may be a ratio such that the difference (T2-T1) between the above-mentioned melting lower limit temperature T2 and the preheating upper limit temperature T1 is 105.degree. C. or less. It is preferable that the ratio, that is, the ratio of the volume of the shell to the volume of the entire resin particle, satisfy the following equation.
100 / {Tg (s) -Tg (c)} ≦ volume fraction of shell material ≦ 500 / {Tg (s) -Tg (c)}
When the volume fraction of the shell is 100 / {Tg (s) -Tg (c)} or more, the core is covered with a sufficient amount of shell, so that resin particles are difficult to fuse together during preheating. As a result, the preheating upper limit temperature T1 tends to increase. On the other hand, when the volume fraction of the shell is 500 / {Tg (s) -Tg (c)} or less, when the laser irradiation is performed, the melting lower limit temperature T2 tends to be low, and the flow of the resin particles It is possible to improve the sex sufficiently. The volume fraction can be calculated based on the particle size of the core and the thickness of the shell obtained from the above-mentioned TEM image.
The core particle diameter = 2r, when shell thickness = t, a, becomes the volume of the core particle and Vc and ^{Vc = 4/3 · πr 3} . On the other hand, when the volume of the resin particle is Vcs, Vcs = 4/3 · π (r + t) ³ .
Then, assuming that the volume of the shell is Vs, Vs = volume of core-shell particles-volume of core particles. Therefore, the volume fraction of the shell can be specified by determining the core particle diameter and the shell thickness from the TEM image and calculating Vs / Vcs × 100.

The shape of the resin particles is not particularly limited, but is preferably spherical from the viewpoint of producing a three-dimensional object with high accuracy. At this time, the circularity of the resin particles is preferably 0.95 or more, more preferably 0.96 or more, and still more preferably 0.97 or more. When the degree of circularity of the resin particles is 0.95 or more, the volumes of the individual resin particles are likely to be uniform, and it becomes easy to form a shaped object layer in a desired shape. The degree of circularity indicates the average degree of circularity of resin particles, and is measured using “FPIA-2100” (manufactured by Sysmex). Specifically, resin particles are wetted with a surfactant aqueous 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 detection numbers in the measurement condition HPF (high magnification imaging) mode. Within this range, reproducible measurement values can be obtained. The roundness is calculated by the following equation.
Circularity = (perimeter of a circle with the same projected area as the particle image) / (perimeter of particle projection)
The mean circularity is an arithmetic mean value obtained by adding the circularity of each particle and dividing by the total number of particles measured.

It is preferable that 95 mass% or more is contained with respect to the total mass of powder material, and, as for the said resin particle, it is more preferable that 97 mass% or more is contained. When the resin particles are included in the above range, the strength of the three-dimensional object tends to increase.

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

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

The amount of the laser absorber can be appropriately set within the range in which the melt bonding of the resin 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 From the viewpoint of improving the flowability of the powder material and facilitating the handling of the powder material at the time of production of the three-dimensional object, the powder material may further include a flow agent. 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. These flow agents may be used alone or in combination of two.

The amount of the flow agent can be appropriately set within a range in which the flowability of the powder material is improved and the melt bonding of the resin particles is sufficiently generated, for example, 0% by mass with respect to the total mass of the powder material Many can be less than 2% by mass.

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 resin particles described above, the resin particles can be used as the powder material as it is. On the other hand, when the powder material contains resin particles and other materials, it can be manufactured by stirring and mixing other materials in powder form and resin particles. Hereinafter, the method for preparing resin particles will be described.

(Method of preparing resin particles)
The aforementioned resin particles can be produced by known methods. Examples of a method of preparing resin particles include a wet coating method in which a coating solution in which a second non-crystalline resin is dissolved is applied to particles containing the first non-crystalline resin, and particles comprising the first non-crystalline resin And dry coating methods in which particles made of the second amorphous resin and the like are mixed by stirring and bonded by mechanical impact, and methods combining these. When the wet coating method is employed, the coating solution may be spray coated on the surface of the particles containing the first amorphous resin, and the particles containing the first amorphous resin may be dipped in the coating solution. It is also good. According to the wet coating method, resin particles in which a sheet-like shell covers a core as shown in FIG. 1A are obtained. On the other hand, according to the dry coating method, as shown in FIG. 1B, resin particles in which a particulate shell covers the core can be obtained. According to the wet coating method, it is easy to form a shell having a uniform thickness, and the dry coating method does not require a drying step, so the manufacturing process can be simplified.

As described above, the first amorphous resin and the second amorphous resin are selected in consideration of the preliminary heating upper limit temperature T1 and the melting lower limit temperature T2, respectively. A commercially available thing may be used for the 1st amorphous resin and the 2nd amorphous resin. Moreover, you may use what was prepared by polymerizing a monomer, a prepolymer, etc. When a commercially available resin is used, commercially available materials may be used in combination such that the difference (T2-T1) between the melting lower limit temperature T2 and the preheating upper limit temperature T1 is 105 ° C. or less.

3. Next, a method of producing a three-dimensional object by using the above-mentioned powder material will be described. In the method for producing a three-dimensional object of the present embodiment, the method can be carried out in the same manner as an ordinary powder bed melt bonding method except that the powder material is used. Specifically, it comprises (1) a thin layer forming step of forming a thin layer of the above-mentioned powder material, (2) a preheating step of preheating the powder material, and (3) preheating the powder material. And a laser beam irradiation step of selectively irradiating the thin layer with a laser beam to form a shaped object layer in which the resin particles contained in the powder material are melt-bonded to each other. The three-dimensional object can be manufactured by repeating the steps (1) to (3) a plurality of times to laminate the object layer. Any of the step (1) and the step (2) may be performed first.

3-1. Thin layer formation process (process (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 laid flat on the shaping 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, it is possible to prevent the resin particles of the lower layer from being melted and bonded by the laser light irradiation for forming the next shaped object layer. It is possible to spread the powder uniformly. 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 resin 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. In addition, from the viewpoint of making the resin particles melt and bond more sufficiently throughout the thickness direction of the thin layer and making the formation layer more difficult to crack, the thickness of the thin layer corresponds to the beam spot diameter of the laser light described later Is preferably set to be 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 prior to preheating the powder material.

The preheating temperature is preferably a temperature not more than the preheating upper limit temperature T1 of the resin particles of the powder material described above, and more preferably T1-20 ° C. or more and T1 or less. By setting the preheating temperature to the preheating upper limit temperature T1 or less, it is possible to suppress the fusion of resin particles at the time of preheating.

The specific preheating temperature is appropriately selected depending on the preheating upper limit temperature T1, the type of the first noncrystalline resin and the second noncrystalline resin contained in the resin particles, etc. The temperature is preferably the following, more preferably 100 ° C. or more and 250 ° C. or less, still more preferably 140 ° C. or more and 250 ° C. or less, and still more preferably 140 ° C. or more and 200 ° C. or less.

At this time, the heating time is preferably 1 to 60 seconds, more preferably 5 to 30 seconds. By making heating temperature and heating time into the said range, the core in a resin particle can fully be softened or melt | dissolved, and a three-dimensional object can be manufactured by a low laser irradiation amount.

3-3. Laser light irradiation process (process (3))
In this step, the laser beam is selectively irradiated to the position where the shaped object layer is to be formed in the thin layer made of the preheated powder material, and the resin particles at the desired position are melted and bonded. The melted resin particles (in particular, the core) melt together with the adjacent resin particles to form a shaped object layer. At this time, the resin particles that have received the energy of the laser beam also melt and bond with the already formed shaped material layer, and adhesion between adjacent layers also occurs.

The wavelength of the laser light may be set within the range of the wavelength absorbed by the resin particles. In this case, the wavelength of the laser beam, it is preferable to make the difference in absorption rate and becomes highest wavelength of the resin particles (especially shell material) is reduced, for example, a wide laser beam having a wavelength band of CO ₂ laser or the like It can be used. The wavelength of the laser light 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 in a range in which the temperature of the resin particles can be raised 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 reducing the energy of the laser beam to reduce the manufacturing cost and simplifying the configuration of the manufacturing apparatus, the power at the output of the laser beam is preferably 30 W or less, and is 20 W or less It is more preferable that

The scanning speed of the laser light 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 to 10 m / sec, more preferably 2 m / sec to 8 m / sec, and still more preferably 3 m / sec to 7 m / sec. The beam diameter of the laser beam can be appropriately set according to the accuracy of the three-dimensional object to be manufactured.

3-4. Repetition of Steps (1) to (3) In the production of a three-dimensional object, the above steps (1) to (3) are repeated any number of times. Thereby, a modeling thing layer will be laminated | stacked and a desired three-dimensional modeling thing will be obtained.

3-5. Others Note that at least the step (3) should be performed under reduced pressure or in an inert gas atmosphere from the viewpoint of preventing the strength of the three-dimensional object from being reduced by the oxidation of the resin particles (particularly the core) during melt bonding. Is preferred. The pressure when decompressing is preferably 10 ⁻² Pa or less, more preferably 10 ⁻³ Pa or less. Examples of inert gases that can be used in the present embodiment include nitrogen gas and noble gases. Among these inert gases, nitrogen (N ₂ ) gas, helium (He) gas or argon (Ar) gas is preferable from the viewpoint of availability. From the viewpoint of simplifying the production process, it is preferable to carry out all of the steps (1) to (3) under reduced pressure or in an inert gas atmosphere.

4. Three-dimensional modeling device
The three-dimensional modeling apparatus which can be used for the manufacturing method of the said three-dimensional model is demonstrated. The three-dimensional model | molding apparatus which can be used for this embodiment can be made into the structure similar to a well-known three-dimensional model | molding apparatus. Specifically, as shown in the schematic side view of FIG. 2, the three-dimensional modeling apparatus 200 according to the present embodiment includes a modeling stage 210 positioned in the opening, and a thin layer formation for forming a thin layer of powder material. Part 220, Preheating part 230 for preheating powder material, Laser irradiation part 240 for irradiating a thin layer with laser light, Stage supporting part 250 for supporting modeling stage 210 with variable vertical position, and A base 290 is provided to support the above components.

On the other hand, the main part of the control system of the three-dimensional model formation 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 a three-dimensional object. A display unit 270 for displaying various information, an operation unit 275 including a pointing device or the like for receiving an instruction from a user, a storage unit 280 storing various information including a control program executed by the control unit 260, and A data input unit 285 including an interface and the like for transmitting and receiving various information such as three-dimensional modeling data and the like 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 300 for generating data for three-dimensional modeling may be connected to the three-dimensional modeling apparatus 200.

The modeling stage 210 is controlled to be movable up and down, and on the modeling stage 210, formation of a thin layer by the thin layer forming unit 220, preheating of the powder material by the preheating unit 230, and irradiation of laser light by the laser irradiation unit 240 Is done. 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 present embodiment, 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 raising and lowering 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 powder materials, and can maintain the temperature. In this 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 second heater heats the powder material before being supplied onto the modeling stage. And the heater 232, but 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 the thin layer, particularly the surface temperature of the area where the shaped object layer is to be formed without contact, and may be, for example, an infrared sensor or an optical pyrometer.

The laser irradiation part 240 can be set as the structure containing the laser light source 241 and the galvano mirror 242a. The laser irradiation part 240 may be equipped with the laser window 243 which permeate | transmits a laser beam, and the lens (not shown) for adjusting the focal distance of a laser beam to the surface of a thin layer. The laser light source 241 may be any light source that emits the 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 configured 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 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.

In addition, 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 300 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 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 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. 2). 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 only the powder material in a predetermined area or the entire inside of the apparatus according to the temperature information output from the control unit 260. The temperature information may be, for example, a temperature determined by the control unit 260 based on the preliminary heating upper limit temperature T1 or the like input from the data input unit 285. 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 laser irradiation information output from the control unit 260, the laser irradiation unit 240 emits a laser beam from the laser light source 241 on the thin layer, adapted to the area constituting the three-dimensional object in each slice data. The galvano mirror drive unit 242 drives the galvano mirror 242 a to scan a laser beam. At least a part (at least the core) of the resin particles contained in the powder material is melted and bonded by the irradiation of the laser light, and a shaped object 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 powder material 1-1. Preparation of Raw Materials The resins listed in Table 1 below were prepared as core and shell materials. In addition, when the average particle diameter of commercially available resin is larger than the numerical value of Table 1, it measures with the laser diffraction type particle size distribution measuring apparatus (The Sympatic (SYMPATEC company make, HEROS (HELOS)) equipped with the wet dispersing machine. The resin fine particles were ground by a mechanical grinding method until the average particle diameter (D50) obtained was the value described in Table 1.

1-2. Preparation of Powdered Material (Comparative Example 1 and Comparative Example 8)
The above-mentioned PC1 (polycarbonate particles, Iupilon S-3000 manufactured by Mitsubishi Gas Chemical Co., Ltd.) or ABS (Stylac A4130 manufactured by Asahi Kasei Corporation) was used as it was as a powder material.

(Comparative example 2)
Dissolve 30 g of PC4 (polycarbonate resin, manufactured by Mitsubishi Gas Chemical Company, FPC-0220) while stirring 1000 g of toluene in a beaker, and then add 1000 g of PC1 (polycarbonate particles, Iupilon S-3000 manufactured by Mitsubishi Gas Chemical Company) Stir for 10 minutes to obtain a suspension of particles. This suspension was then added in one go, with stirring, to 4000 g of ethanol prepared in another beaker. The mixed suspension was stirred for 30 minutes, filtered, and the obtained particles were further washed with ethanol and dried to obtain a powder material.

Example 1
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 2, except that the addition amount of PC4 (FPC-0220 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 55 g.

(Example 2)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 2, except that the addition amount of PC4 (FPC-0220 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 85 g.

(Example 3)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 2, except that the addition amount of PC4 (FPC-0220 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 130 g.

(Comparative example 3)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 2, except that the addition amount of PC4 (FPC-0220 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 160 g.

(Comparative example 4)
Dissolve 11 g of PAR (polyarylate resin, M-2040 manufactured by Unitika) while stirring 1000 g of tetrahydrofuran in a beaker, add another 1000 g of PC1 (polycarbonate particles), and stir for 10 minutes to suspend the particles I got a liquid. This suspension was then added in one go, with stirring, to 4000 g of ethanol prepared in another beaker. The mixed suspension was stirred for 30 minutes, filtered, and the obtained particles were further washed with ethanol and dried to obtain a powder material.

(Example 4)
A powder material was obtained by the same operation as in the preparation method of Comparative Example 4, except that the amount of PAR (M-2040, manufactured by Unitika) was changed to 23 g.

(Examples 5 to 8)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 4, except that the amount of PAR (M-2040, manufactured by Unitika) was 32 g.

(Example 9)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 4, except that the amount of PAR (M-2040, manufactured by Unitika) was 64 g.

(Comparative example 5)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 4, except that the amount of PAR (M-2040 manufactured by Unitika) was changed to 75 g.

(Example 10)
In the preparation method of Comparative Example 4, PC2 (polycarbonate particles, Eupilon S-3000 (average particle diameter 40 μm) manufactured by Mitsubishi Gas Chemical Co., Ltd.) having an addition amount of PAR (M-2040 manufactured by Unitika Co., Ltd.) of 19 g was used. A powder material was obtained by performing the same operation except using polycarbonate particles and Iupilon S-3000 (average particle size 10 μm) manufactured by Mitsubishi Gas Chemical Co., Ltd.

(Example 11)
In the preparation method of Comparative Example 4, the amount of PAR (M-2040) added is 60 g, and PC3 (polycarbonate particles, instead of PC1 (polycarbonate particles, Eupilon S-3000 (average particle diameter 40 μm) manufactured by Mitsubishi Gas Chemical Co., Ltd.)) A powder material was obtained by performing the same operation except using Iupilon S-3000 (average particle diameter 100 μm) manufactured by Mitsubishi Gas Chemical Co., Ltd.).

(Comparative example 6)
Dissolve 8 g of PC5 (polycarbonate resin, M-2000H manufactured by Unitika) while stirring 1000 g of toluene in a beaker, and then add 1000 g of PC1 (polycarbonate particles, Iupilon S-3000 manufactured by Mitsubishi Gas Chemical Co., Ltd.) 10 Stirring for a minute gave a suspension of particles. This suspension was then added in one go, with stirring, to 4000 g of ethanol prepared in another beaker. The mixed suspension was stirred for 30 minutes, filtered, and the obtained particles were further washed with ethanol and dried to obtain a powder material.

(Example 12)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 6, except that the addition amount of PC5 (M-2000H manufactured by Unitika) was 13 g.

(Examples 13 and 14)
A powder material was obtained by the same operation as in the preparation method of Comparative Example 6, except that the addition amount of PC5 (M-2000H manufactured by Unitika) was changed to 23 g.

(Example 15)
A powder material was obtained by the same operation as in the preparation method of Comparative Example 6, except that the addition amount of PC5 (M-2000H manufactured by Unitika Co., Ltd.) was 34 g.

(Comparative example 7)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 6, except that the addition amount of PC5 (M-2000H manufactured by Unitika Co., Ltd.) was 43 g.

(Comparative example 9)
After dissolving 18 g of PC6 (polycarbonate resin, PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) while stirring 1000 g of toluene in a beaker, add 1000 g of ABS particles (Stylac A4130 manufactured by Asahi Kasei Corp.) and stir for 10 minutes. , Obtained a suspension of particles. This suspension was then added in one go, with stirring, to 4000 g of ethanol prepared in another beaker. The mixed suspension was stirred for 30 minutes, filtered, and the obtained particles were further washed with ethanol and dried to obtain a powder material.

(Example 16)
A powder material was obtained by the same operation as in the preparation method of Comparative Example 9, except that the addition amount of PC6 (PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 27 g.

(Examples 17 to 19)
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 9, except that the addition amount of PC6 (PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 43 g.

Example 20
A powder material was obtained by performing the same operation as in the preparation method of Comparative Example 9, except that the addition amount of PC6 (PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 87 g.

(Comparative example 10)
A powder material was obtained by the same operation as in the preparation method of Comparative Example 9, except that the addition amount of PC6 (PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was 104 g.

(Example 21)
While dissolving 1000 g of dichloromethane in a beaker while dissolving 30 g of PC7 (polycarbonate resin, S-3000 made by Mitsubishi Gas Chemical Co., Ltd.), add 1000 g of PS particles (H450 made by Toyo Styrene Co., Ltd.) and stir for 30 seconds, A suspension of particles was obtained. This suspension was then added in one go, with stirring, to 4000 g of ethanol prepared in another beaker. The mixed suspension was stirred for 30 minutes, filtered, and the obtained particles were further washed with ethanol and dried to obtain a powder material.

(Example 22)
A powder material is obtained by the same operation as in Example 21 except that PC7 is changed to PC6 (PCZ-200) and PS particles are changed to AS particles (Stylac T8701 manufactured by Asahi Kasei Corporation). Obtained.

(Example 23)
The same procedure as in Example 21 is repeated, except that PC7 is changed to modified PPE (Zylon 200H manufactured by Asahi Kasei Corp.) and PS particles are changed to PVC particles (PVICA CA 70 GC manufactured by Mitsubishi Chemical Corp.). A powder material was obtained.

(Example 24)
The same procedure as in Example 21 is repeated, except that PC7 is changed to PSU (U-Dell P-1700 manufactured by Solvay Specialty Polymers) and PS particles are changed to PMMA particles (Acripet MD001 manufactured by Mitsubishi Rayon). By doing, a powder material was obtained.

(Example 25)
A powder is obtained by the same procedure as in Example 21 except that PC7 is changed to PES (4100G manufactured by Sumitomo Chemical Co., Ltd.) and PS particles are changed to COP particles (Zeonex E480 manufactured by Zeon Corporation). I got the material.

(Example 26)
In the production method of Example 21, the same operation is performed except that PC7 is changed to PEI (Ultem 1010 manufactured by Subic Innovative Plastics Co., Ltd.) and PS particles are changed to COC particles (Apel 5014 DP manufactured by Mitsui Chemicals, Inc.) Thus, a powder material was obtained.

(Example 27)
The same procedure as in Example 21 is repeated, except that PC7 is changed to PEI (Ultem 1010 manufactured by Subic Innovative Plastics Co., Ltd.) and PS particles are changed to amorphous PA particles (Rilsanclear G120 manufactured by Arkema). To obtain a powder material.

2. Evaluation The obtained powder material and the three-dimensional object obtained from the powder material were evaluated as follows. The results are shown in Tables 2 and 3.

2-1. Evaluation of powder material (1) Measurement of shell thickness The powder material (resin particles) prepared in each of the examples and comparative examples is dispersed in a photocurable resin (D-800 manufactured by Nippon Denshi Co., Ltd.), and then photocured. Let form a block. Then, using a microtome equipped with diamond teeth, a flaky sample with a thickness of 100 to 200 nm was cut out from the above block and placed on a grid with a support film for transmission electron microscope observation. The above grid was placed on a scanning transmission electron microscope (JSM-7401F, manufactured by JEOL Ltd.), and bright field images were taken under the following conditions.

(Imaging method)
Acceleration voltage: 30kV
Magnification: 10000 times

The interface between the core and the shell of 10 resin particles randomly selected from the obtained images was confirmed, the thickness of the shell of each resin particle was measured, and the average was determined to determine the average thickness of the shell. .

(2) Identification of T1 (preheating upper limit temperature) 0.2 g of resin particles was placed in a cylindrical opening glass bottle having an outer diameter of 20 mm or less, an inner diameter of 10 mm or more, a height of 45 mm or less, and an inner volume of 7 cc or less. Then, the glass bottle was held for 30 minutes in an oven at Ta ° C. (Ta is an integer that is a multiple of 5) and sieved with a 500 μm mesh. Then, the temperature at which the mass of resin particles passing through the sieve was 0.1 g or more was specified. Similarly, an open glass bottle containing resin particles was held for 30 minutes in a Ta + 5 ° C. oven and sieved through a 500 μm mesh. And when the mass of the particle | grains to pass passes less than 0.1 g, the said temperature Ta was specified as T1.

(3) Identification of T2 (lower limit temperature of melting) A plurality of resin particles were laid in one layer so as to be in contact with each other in an aluminum pan having a flat bottom and having a thickness of 0.1 mm or more and 1 mm or less. Then, the aluminum plate was heated for 30 seconds on a hot plate at Tb ° C. (Tb is an integer that is a multiple of 5) and allowed to cool to room temperature. Then, when the resin particles on the aluminum plate were observed with a microscope, the temperature at which the association between adjacent resin particles was confirmed was specified. Similarly, the aluminum plate covered with resin particles was heated on a hot plate at Tb-5 ° C. for 30 seconds, cooled to room temperature, and the resin particles on the aluminum plate were observed with a microscope. At this time, when the association of adjacent resin particles was not confirmed, the temperature Tb was specified as T2.

(4) Volume fraction of shell The volume fraction of the shell of the resin particle of the powder material produced in the example and the comparative example was calculated based on the particle diameter of the core and the thickness of the shell obtained from the above-mentioned TEM image. did.
The core particle diameter = 2r, when shell thickness = t, a, becomes the volume of the core particle and Vc and ^{Vc = 4/3 · πr 3} . On the other hand, when the volume of the resin particle is Vcs, Vcs = 4/3 · π (r + t) ³ . Then, assuming that the volume of the shell is Vs, Vs = volume of core-shell particles-volume of core particles. Therefore, the volume fraction of the shell was specified by determining the core particle diameter and the shell thickness from the TEM image, and calculating Vs / Vcs × 100. From the volume fraction, it was determined whether the resin particles produced in each Example and Comparative Example satisfied the following formula, and the case where the following formula was satisfied was evaluated as 、, and the case not satisfied was evaluated as x.
100 / {Tg (s) -Tg (c)} ≦ volume fraction of shell material ≦ 500 / {Tg (s) -Tg (c)}

2-2. Preparation and Evaluation of Three-Dimensional Shaped Article (1) Preparation of Three-Dimensional Shaped Article The powder material prepared in each of the Examples and Comparative Examples was spread on a forming stage placed on a hot plate to form a thin layer having a thickness of 0.1 mm. . Then, by adjusting the temperature of the hot plate, each was heated to the preheating temperature described in Table 2 and Table 3. This thin layer is irradiated with laser from a 50 W fiber laser (manufactured by SPI Lasers) equipped with a galvanometer scanner for YAG wavelength under the following conditions 1 to 4 in a range of 15 mm long × 90 mm wide, and this is 10 layers The three-dimensional object was produced by laminating.

[Condition 1]
Laser power: 20 W
Laser light wavelength: 1.07 μm
Beam diameter: 170 μm on thin layer surface
Operation interval: 0.2 mm
Scanning speed: 4000 mm / sec
Number of lines: 1 Line Ambient temperature: Preheating temperature Atmosphere: Nitrogen (N ₂ ) 100%

[Condition 2]
Laser power: 20 W
Laser light wavelength: 1.07 μm
Beam diameter: 170 μm on thin layer surface
Operation interval: 0.2 mm
Scanning speed: 2000 mm / sec
Number of lines: 1 Line Ambient temperature: Preheating temperature Atmosphere: Nitrogen (N ₂ ) 100%

[Condition 3]
Laser power: 20 W
Laser light wavelength: 1.07 μm
Beam diameter: 170 μm on thin layer surface
Operation interval: 0.2 mm
Scanning speed: 1000 mm / sec
Number of lines: 1 Line Ambient temperature: Preheating temperature Atmosphere: Nitrogen (N ₂ ) 100%

[Condition 4]
Laser power: 40 W
Laser light wavelength: 1.07 μm
Beam diameter: 170 μm on thin layer surface
Operation interval: 0.2 mm
Scanning speed: 2000 mm / sec
Number of lines: 1 Line Ambient temperature: Preheating temperature Atmosphere: Nitrogen (N ₂ ) 100%

(2) Preparation of Injection Molded Product The powder material prepared in Examples and Comparative Examples was molded into a test piece measuring 15 mm long × 90 mm wide × 1 mm thick using an injection molding machine with a maximum clamping force of 30 tons and a screw diameter of 22 mm. . The cylinder temperature was set to T2 + 10 ° C., the mold temperature was set to Tg (c) -30 ° C., the injection pressure was 100 MPa, and the injection speed was 20 mm / s.

(3) Evaluation of density ratio The weight in air and the weight in water of each of the three-dimensional object and the injection molded product produced in the same shape were measured under the above conditions 1 to 4, respectively, The density of the three-dimensional object or injection molded article was specified. Then, the density of the shaped article to the density of the injection molded article was specified as a density ratio (density of the shaped article / density of the injection molded article × 100).

(4) Evaluation of Strength Ratio A bending test was performed on the three-dimensional object manufactured by the above method and an injection molded product manufactured in the same shape. The measurement was performed using Tensilon RTC-1150A (manufactured by A & D Co.) at a distance between supporting points of 60 mm and a head speed of 2 mm / min. At this time, the maximum stress / cross-sectional area of the central portion of the test piece is taken as the bending strength, and the bending strength of the formed article to the bending strength of the injection molded article is the strength ratio (bending strength of the formed article / bending strength of the injection molded article × 100) As identified.

(5) Evaluation of dimensional increase rate The dimensional increase rate was specified for the three-dimensional object manufactured by the above method. Specifically, the dimensions of the three-dimensional object were measured with a caliper, and the larger one of the following A and B was identified as the dimension increase rate.
A: (maximum dimension of the three-dimensional object-design dimension) / design dimension × 100
B: (horizontal maximum dimension of three-dimensional object-designed dimension) / designed dimension x 100

(6) Individual Evaluation and Comprehensive Evaluation Evaluation under each condition was evaluated from the results of density ratio, strength ratio, and dimensional increase rate. Specifically, it was comprehensively evaluated based on the individual evaluation as follows.
(Individual evaluation)
:: When the density ratio is 70% or more, the strength ratio is 70% or more, and the dimensional increase due to the excess sintered product is less than 1% ○: Not applicable to ◎, but the density ratio exceeds 40% , When the strength ratio is 40% or more and the dimensional increase due to the excess sinter is 5% or less ×: Not applicable to 総 合 (Overall evaluation)
:: At least one つ evaluation under conditions 1 to 4 〇: There was no ◎ at conditions 1 to 4 but at least one 〇 evaluation at all x: conditions 1 to 4 all In case of evaluation

As shown in Tables 2 and 3 above, when the difference (T2-T1) between the melting lower limit temperature T2 and the preliminary heating upper limit temperature T1 is 105 ° C. or less, the overall judgment is ◎ or ((( Examples 1 to 27). On the other hand, when T2-T1 exceeds 105 ° C, it becomes difficult to melt and bond the resin particles sufficiently if the laser irradiation amount is small, or the resin particles are fused at the time of preheating, and dimensional accuracy Was easy to fall (Comparative Examples 1 to 10).

This application claims the priority based on Japanese Patent Application No. 2017-134706 filed on Jul. 10, 2017. The contents described in the application specification and drawings are all incorporated herein by reference.

According to the method for producing a powder material or a three-dimensional object according to the present invention, a powder bed fusion bonding method enables a more accurate formation with less amount of laser energy. Therefore, the present invention is considered to contribute to the further spread of the powder bed fusion bonding method.

DESCRIPTION OF SYMBOLS 100 resin particle 101 core particle 102 shell 200 three-dimensional shaping apparatus 210 modeling stage 220 thin film formation part 221 powder supply part 222 recoater drive part 222a recoater 230 preheating part 231 1st heater 232 2nd heater 235 temperature measurement device 240 laser irradiation Part 241 Laser light source 242 Galvano mirror drive part 242a Galvano mirror 243 Laser window 250 Stage support part 260 Control part 270 Display part 275 Operation part 280 Storage part 285 Data input part 290 Base 300 computer device

Claims (8)

A thin layer of powder material containing resin particles is selectively irradiated with laser light to form a shaped object layer in which the resin particles are sintered or melt-bonded, and three-dimensional shaping by laminating the shaped object layer Powder material used in the manufacture of
The resin particles have a core containing a first amorphous resin, and a shell containing a second amorphous resin having a glass transition temperature higher than that of the first amorphous resin, and are specified by the method described below Powder material in which the temperature T1 and the temperature T2 satisfy T2-T1 ≦ 105 ° C.
(Temperature T1)
0.2 g of the resin particles in a cylindrical opening glass bottle having an outer diameter of 20 mm or less, an inner diameter of 10 mm or more, a height of 45 mm or less, and an inner volume of 7 cc or less in an oven at Ta ° C (Ta is an integer that is a multiple of 5) And hold for 30 minutes, and the weight of the resin particles passing through the sieve is 0.1 g or more when subjected to a sieve with an aperture of 500 μm,
The open glass bottle containing the resin particles is held in an oven at Ta + 5 ° C. for 30 minutes, and when it is sieved, the temperature Ta at which the mass of the resin particles passing through the sieve becomes less than 0.1 g is T1. Do (temperature T2)
A plurality of the resin particles are laid in a layer so as to contact each other in an aluminum plate having a flat bottom and a thickness of 0.1 mm or more and 1 mm or less, Tb ° C. (Tb is an integer that is a multiple of 5) When heated on a hot plate for 30 seconds, cooled to room temperature and observed under a microscope, association between adjacent resin particles is confirmed,
When the aluminum dish covered with the resin particles is heated on a hot plate at Tb-5 ° C. for 30 seconds, a temperature Tb at which no association between adjacent resin particles is confirmed is set to T2. The powder material according to claim 1, wherein a glass transition temperature Tg (c) of the first amorphous resin and a glass transition temperature Tg (s) of the second amorphous resin satisfy the following formula.
Tg (s) -Tg (c) 3030 ° C. The average thickness of the shell of the resin particle is 0.05 μm or more and 2 μm or less.
A powder material according to claim 1 or 2. The powder material according to any one of claims 1 to 3, wherein an average particle diameter (D50) of the resin particles is 10 μm or more and 100 μm or less. The volume fraction of the shell material relative to the total volume of the resin particles, the glass transition temperature Tg (c) of the first amorphous resin, and the glass transition temperature Tg (s) of the second amorphous resin are represented by the following formulas The powder material according to any one of claims 1 to 4, wherein
100 / {Tg (s) -Tg (c)} ≦ volume fraction of shell material ≦ 500 / {Tg (s) -Tg (c)} The first non-crystalline resin and / or the second non-crystalline resin may be polystyrene, polyvinyl chloride, acrylonitrile butadiene styrene copolymer resin, acrylonitrile styrene copolymer resin, acrylic resin, polycarbonate, polyarylate, modified At least one amorphous resin selected from the group consisting of polyphenylene ether, polysulfone, polyether sulfone, polyether imide, cycloolefin polymer, cycloolefin copolymer, and amorphous polyamide,
Powder material according to any one of the preceding claims. A thin layer forming step of forming a thin layer comprising the powder material according to any one of claims 1 to 6;
A preheating step of preheating the powder material;
A laser beam irradiation step of selectively irradiating the thin layer of the preheated powder material with a laser beam to form a shaped object layer in which at least a part of the resin particles are melt-bonded to each other;
Including
The three-dimensional object is formed by repeating the thin layer formation step, the preheating step, and the laser light irradiation step a plurality of times to laminate the three-dimensional object layer.
A method of manufacturing a three-dimensional object. The preheating step is a step of heating the powder material to a temperature equal to or lower than the above-mentioned temperature T1.
The manufacturing method of the three-dimensional molded item of Claim 7.

Images