JP2018058235A - Powder material, method for manufacturing solid molded object and solid molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder material including resin particles containing polyamide resin for a powder bed type melt bonding method, the powder material being capable of producing a solid molded object having higher impact resistance than the solid molded object manufactured from resin particles consisting only of polyamide resin.SOLUTION: The present invention relates to a powder material which is used for manufacturing a solid molded object provided by selectively irradiating laser light to a thin layer of the powder material containing resin particles to form a molded object layer resulting from sintering or fusion bonding of the composite particles and to laminate the molded object layer. The resin particle is a core-shell type particle having a shell portion containing a polyamide resin as a main component and a shell portion containing a thermoplastic resin having a functional group reactive with an amide group as a main component. The content of the thermoplastic resin in the powder material is 1.0 mass% or more and 30 mass% or less with respect to the total mass of the polyamide resin in the powder material.SELECTED DRAWING: Figure 1

Description

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

  In recent years, various methods have been developed that can relatively easily manufacture a three-dimensional object having a complicated shape. As one of methods for producing a three-dimensional structure, a powder bed fusion bonding method is known. The powder bed fusion bonding method is characterized by high modeling accuracy and high adhesion strength between laminated layers. Therefore, the powder bed fusion bonding method can be used not only for manufacturing a prototype for confirming the shape or properties of the final product, but also for manufacturing the final product.

  In the powder bed fusion bonding method, a powder material containing particles containing resin material or metal material is laid flat to form a thin film, and a laser is irradiated to a desired position on the thin film to select particles contained in the powder material. Sintered or melted and bonded (hereinafter, the bonding of particles by sintering or melting is also simply referred to as “melt bonding”), thereby finely dividing the three-dimensional object in the thickness direction (hereinafter referred to as “melt bonding”) , Simply referred to as “modeled object layer”). A powder material is further spread on the layer thus formed, and laser irradiation is performed to selectively melt bond particles contained in the powder material, thereby forming the next modeled object layer. By repeating this procedure and stacking the modeling object layers, a three-dimensional modeling object having a desired shape is manufactured.

  Resin materials such as polyamide may be used for the particles contained in the powder material from the viewpoints of ease of handling and the range of objects to be applied.

  Regarding the polyamide resin, Patent Document 1 describes that a molded product obtained by injection molding from a composition obtained by melt-kneading a polyamide resin and a polyarylate resin has high mechanical strength such as impact strength. Patent Document 1 suggests that the amino group of the polyamide resin causes some chemical reaction with the polyarylate resin in the above composition, thereby increasing the impact strength.

  Patent Document 2 describes a composition containing a thermoplastic resin such as a polyamide resin and a compound having a functional group that reacts with the thermoplastic resin. Patent Document 2 describes that a molded product having good heat resistance and impact resistance can be obtained by melt-kneading the above composition under conditions in which the pressure difference before and after melt-kneading is constant. .

JP-A-5-132614 International Publication No. 2009/119624

  As the three-dimensional modeling becomes widespread, the performance required for the three-dimensional model is also increasing. For example, there is a desire to manufacture a three-dimensional model having higher impact resistance using a polyamide resin.

  Here, as described in Patent Document 1 and Patent Document 2, it is expected that the impact resistance of the three-dimensional structure to be obtained is increased by reacting the polyamide resin with another resin. However, Patent Document 1 and Patent Document 2 describe a composition for producing a molded product by injection molding, extrusion molding, or the like, and a similar structure is a resin for three-dimensional modeling by a powder bed fusion bonding method. There is no mention of whether it can be applied to particles and what conditions are required for application.

  The present invention has been made in view of the above problems, and is a powder material for a powder bed fusion bonding method including resin particles containing a polyamide resin, and is a three-dimensional structure manufactured from resin particles made of only a polyamide resin. It is an object of the present invention to provide a powder material capable of producing a three-dimensional structure having higher impact resistance. The present invention further provides a method for producing a three-dimensional structure using such a powder material, and a three-dimensional structure apparatus capable of producing a three-dimensional structure using such a powder material. To do.

The present invention relates to the following powder materials, methods for producing powder materials, and methods for producing three-dimensional structures.
[1] A thin layer of a powder material containing resin particles is selectively irradiated with laser light to form a shaped article layer formed by sintering or melt bonding the resin particles, and the shaped article layer is laminated. The resin particles are used in the manufacture of a three-dimensional molded article by the above, wherein the resin particles are a shell mainly composed of a thermoplastic resin having a core part mainly composed of a polyamide resin and a functional group that reacts with an amide group. And the content of the thermoplastic resin in the powder material is 1.0% by mass or more and 30% by mass or less with respect to the total mass of the polyamide resin in the powder material. , Powder material.
[2] The powder material according to [1], wherein the functional group that reacts with the amide group is a carbonyl group.
[3] The thermoplastic resin is selected from the group consisting of a polyester resin, a polycarbonate resin, a polylactic acid resin, and a polyarylate resin having a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyhydric alcohol. The powder material according to [1] or [2], comprising one or more resins.
[4] The powder material according to any one of [1] to [3], wherein the polyamide resin contained in the resin particles has a terminal amino group concentration of 10 μeq / g or more and 100 μeq / g or less.
[5] The storage modulus G of the thermoplastic resin 'temperature _TS which is ^{10 _6.5} Pa _^(6.5) has a storage modulus G of the polyamide resin' is ^{10 6.5} Pa Temperature TC ₍ The powder material according to any one of [1] to [4], which is higher than _6.5) .
[6] The powder material according to any one of [1] to [5], wherein the volume average particle diameter of the resin particles is 1 μm or more and 100 μm or less.
[7] A step of forming a thin layer of the powder material according to any one of [1] to [6] and a laser beam is selectively irradiated to the formed thin layer to be included in the powder material The step of forming a shaped product layer formed by sintering or melt bonding resin particles, the step of forming the thin layer, and the step of forming the shaped product layer are repeated a plurality of times in this order, and the shaped product layer The manufacturing method of the three-dimensional molded item containing the process of laminating | stacking.
[8] A modeling stage; a thin film forming unit that forms a thin film of the powder material according to any one of [1] to [6] on the modeling stage; A laser irradiation unit that forms a model layer formed by sintering or melt-bonding resin particles contained therein, a stage support unit that variably supports the vertical position of the modeling stage, the thin film forming unit, A three-dimensional modeling apparatus comprising: a control unit that controls a laser irradiation unit and the stage support unit to repeatedly form and stack the modeled object layer.

  According to the present invention, a three-dimensional modeling is a powder material for a powder bed fusion bonding method including resin particles containing a polyamide resin, and has a higher impact resistance than a three-dimensional model manufactured from resin particles made of only a polyamide resin. There are provided a powder material capable of manufacturing an object, a method of manufacturing a three-dimensional object using such a powder material, and a three-dimensional object forming apparatus capable of manufacturing a three-dimensional object using such a powder material.

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

  In order to solve the above-mentioned problems, the present inventors diligently studied and experimented on resin particles containing polyamide that can be included in a powder material capable of producing a three-dimensional structure by a powder bed fusion bonding method. As a result, the inventors of the present invention have a thermoplastic resin in which the resin particles have a core portion mainly composed of a polyamide resin and a functional group that reacts with an amide group (hereinafter also simply referred to as “reactive functional group”). A core-shell type particle having a shell portion mainly composed of a resin (hereinafter also referred to simply as “reactive resin”), and the content of the thermoplastic resin in the powder material is It has been found that a three-dimensionally shaped article with improved impact resistance can be produced when the content is 1.0% by mass to 30% by mass with respect to the total mass of the polyamide resin.

  When the resin particle is a core-shell type particle having a core part mainly composed of a polyamide resin and a shell part mainly composed of a reactive resin, a minute amount is contained in the melted polyamide resin when irradiated with a laser. The reactive resin is finely dispersed, and many reaction fields are generated between the terminal amine group of the polyamide resin and the reactive functional group of the reactive resin. Therefore, when a three-dimensional structure is manufactured from a powder material containing the resin particles by a powder bed fusion bonding method, a structure in which a plurality of polyamide resins are combined with each reactive resin is intricately entangled, and a random network structure is three-dimensional. Formed in the modeled object. When the random network structure is formed, cracks due to stress applied to the three-dimensional structure are difficult to propagate in the three-dimensional structure, so that the three-dimensional structure manufactured from the powder particles is subjected to an impact. It is considered that cracks are less likely to occur (high impact resistance).

  When the content of the reactive resin in the powder material is 0.1% by mass or more with respect to the total mass of the polyamide resin, a sufficient amount of the network structure is formed and the stress is sufficiently dispersed. Therefore, it is considered that the impact resistance is increased. On the other hand, if the content of the reactive resin in the powder material is 30% by mass or less with respect to the total mass of the polyamide resin, the amount of the polyamide resin relative to the reactive resin does not become excessive, and each reactive resin However, since a plurality of polyamide resins can react, the network structure is sufficiently formed and stress is sufficiently dispersed.

  As described in Patent Document 1 and Patent Document 2, when two types of resins are melted and kneaded and are allowed to react with each other, the resin having the higher melting point is used in order to sufficiently react without the interface between the resins. It is necessary to perform kneading for a relatively long time at a temperature higher than the melting point. At this time, even if kneading is performed in an inert gas environment or the like, random thermal decomposition or random cross-linking occurs, and the impact resistance of the molded product is reduced, and in particular, the extensibility is reduced. There is. However, when a powder material containing core-shell type resin particles having a core part composed mainly of a polyamide resin and a shell part composed mainly of a reactive resin is irradiated with a laser, a minute reaction occurs in the molten polyamide resin. A state in which the conductive resin is finely dispersed can be formed even by a short laser irradiation. Therefore, when a three-dimensional structure is manufactured by irradiating the powder material according to the present invention with a laser, the above-described random thermal decomposition and random cross-linking are less likely to occur, and the impact resistance of the manufactured three-dimensional structure is not reduced without reducing elongation. The sex can be enhanced sufficiently.

  In particular, when the particles are of the core-shell type, as will be described later, it is possible to produce particles in which the terminal amine group of the polyamide resin and the reactive functional group of the reactive resin are unreacted. Therefore, when a laser is irradiated, a structure in which a minute reactive resin is finely dispersed in a molten polyamide resin is likely to be formed, and the above-described random network structure is likely to be formed in a three-dimensional structure. .

  Hereinafter, representative embodiments of the present invention will be described in detail.

1. Powder Material In this embodiment, a thin layer of a powder material containing resin particles is selectively irradiated with laser light to form a modeled object layer formed by fusion bonding of the resin particles, and the modeled object layer is laminated. This relates to a powder material (hereinafter also simply referred to as “powder material”) used for manufacturing a three-dimensional structure. The resin particles are core-shell type particles having a core part mainly composed of polyamide resin and a shell part mainly composed of reactive resin. Moreover, content of the said reactive resin in powder material is 1.0 mass% or more and 30 mass% or less with respect to the total mass of the said polyamide resin in powder material. The above powder material does not significantly hinder the fusion bonding by laser irradiation and the dense filling of resin particles when forming a thin layer, and does not significantly reduce the accuracy of the three-dimensional structure, such as a laser absorber or a flow agent. A material other than the resin particles may be further included.

1-1. Resin Particles The resin particles are core-shell type particles having a core portion mainly composed of polyamide resin and a shell portion mainly composed of reactive resin.

  The fact that the resin particles contain a polyamide resin and a reactive resin means that the reactive resin such as toluene is eluted with a soluble solvent, and the residual line segment and the infrared absorption spectrum (IR spectrum) of the eluted component are obtained. Using a Fourier transform infrared spectrophotometer (for example, Nicolet 380 manufactured by Thermo Fisher Scientific), measurement can be performed by the total reflection (ATR) method. At this time, Ge can be used for the infrared transmission prism, the incident angle can be 60 °, and the number of reflections can be one.

1-1-1. Polyamide resin The polyamide resin may be a polymer in which structural units constituting the main chain are bonded by an amide bond. The resin particles may contain only one type of polyamide resin, or may contain a combination of two or more types of polyamide resins. Moreover, the powder material may contain only a single type of resin particles having the same polyamide resin, or a combination of two or more types of resin particles having different types of polyamide resin.

  Examples of polyamide resins include polycapramide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polycoupleramide / polyhexamethylene adipamide copolymer (nylon 6/66) , Polyundecamide (nylon 11), polycapramide / polyundecamide copolymer (nylon 6/11), polydodecamide (nylon 12), polycoupler / polydodecamide copolymer (nylon 6/12), polyhexamethylene sebamide (nylon 610) Polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthalamide (nylon 6T), poly Hexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polycapramide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polycapramide / polyhexamethylene isophthalamide copolymer (nylon 6 / 6I), polyhexa Methylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polytrimethylhexamethylene terephthalamide (nylon TMDT), polybis (4-Aminocyclohexyl) methane dodecamide (nylon PACM12), polybis (3-methyl-4-aminocyclohexyl) methane dodeca (Nylon dimethyl PACM12), polymetaxylylene adipamide (nylon MXD6), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), and polyundecamethylene terephthalamide (nylon 11T) and These copolymers are included. Of these, nylon 6 and nylon 66 are preferred because they are readily available and have a wide range of uses.

  Usually, the polyamide resin has only one or several terminal amide groups per molecular chain that contribute to the reaction between the polyamide resin and the reactive resin. On the other hand, the reactive resin can have a large number of reactive functional groups contributing to the above reaction in the main chain or the like. Therefore, it is preferable that the concentration of the amide group in the powder material is high from the viewpoint of sufficiently generating the above reaction and facilitating the formation of a random network structure. On the other hand, if the concentration of the amide group in the powder material is too high, the polyamide resin has many branched structures and the molecular weight of the polyamide resin becomes small, so that the composition inside the three-dimensional structure to be manufactured is not good. It tends to be uniform and may reduce mechanical strength such as impact resistance. From such a viewpoint, the terminal amide group concentration of the polyamide resin is preferably 10 μeq / g or more and 100 μeq / g or less.

The terminal amino group concentration of the polyamide resin can be measured by a known method such as ¹ H-NMR or neutralization titration. For example, the measurement of the terminal amino group concentration by the neutralization titration method is as follows. 0.5 g of a sample (polyamide resin) is dissolved in 30 mL of a mixed solution of phenol / ethanol = 4/1 (volume ratio), and 5 mL of methanol is dissolved. In addition, it can be measured by neutralization titration with 0.05N hydrochloric acid.

  The number average molecular weight of the polyamide resin is not particularly limited, but is preferably 500 or more and 70000 or less, and preferably 3000 or more and 50000 or less. The number average molecular weight of the polyamide resin can be measured by a known method such as gel permeation chromatography (GPC).

1-1-2. Reactive resin The said reactive resin should just be resin which has a reactive functional group. The resin particles may contain only one type of reactive resin, or may contain a combination of two or more types of reactive resins. Moreover, the powder material may contain only a single type of resin particles having the same reactive resin, or may contain a combination of two or more types of resin particles having different types of reactive resin.

  The reactive resin may have a reactive functional group in the main chain or in a side chain. Among these, from the viewpoint of distributing a sufficient amount of reactive functional groups more uniformly in the reactive resin to form a denser network structure, the reactive resin has reactive functional groups as the main chain. It is preferable to have.

  The reactive functional group is a functional group that can react with an amide group to form a covalent bond. Examples of the reactive functional group include a carbonyl group. The carbonyl group is a functional group possessed by a general-purpose polymer and is preferred because there are many types of resins that can be used.

  Examples of reactive resins having a carbonyl group in the main chain as a reactive functional group include polyester resins, polycarbonate resins, and polylactic acid resins having a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyhydric alcohol. And polyarylate resins. Of these, polycarbonate resins and polyarylate resins are preferred because of their high heat resistance, solubility in solvents, and ease of processing.

  Examples of the structural unit derived from the polyvalent carboxylic acid constituting the polyester resin include oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, and dimer acid. Aliphatic dicarboxylic acids including, alicyclic dicarboxylic acids including 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids including phthalic acid, isophthalic acid and terephthalic acid, and the like Constituent units derived from ester derivatives and the like are included.

  Examples of structural units derived from the polyhydric alcohol constituting the polyester resin include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, C2-C20 aliphatic glycols such as 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, and dimer diol, and polyethylene glycols having a molecular weight of 200-100,000, poly-1,3-propylene Constituent units derived from long chain glycols such as glycol, poly 1,2-propylene glycol, and polytetramethylene glycol are included.

  Polyethylene terephthalate (PET) resin and polybutylene terephthalate (PBT) resin are preferable because the polyester resin is easily available and has a wide range of uses.

  Further, the number average molecular weight of the reactive resin is not particularly limited, but is preferably 500 or more and 70000 or less, and more preferably 3000 or more and 50000 or less, although it depends on the type of the reactive resin. The number average molecular weight of the reactive resin can be measured by a known method such as gel permeation chromatography (GPC).

1-1-3. Combination of polyamide resin and reactive resin The polyamide resin and the reactive resin can be in any combination.

Note that the temperature TS _{(6.5) at which} the storage elastic modulus G ′ of the reactive resin becomes 10 ^6.5 Pa is equal to the temperature TC _{(6 ) at which} the storage elastic modulus G ′ of the polyamide resin becomes 10 ^6.5 Pa. Higher than _.5) . In addition, the temperature at which the storage elastic modulus G ′ of the resin becomes 10 ^6.5 Pa is a temperature at which the resin starts to soften when heated.

By adopting such a configuration, the powder material has a temperature of the surface of a thin layer formed of the powder material that is waiting before laser irradiation (hereinafter, also simply referred to as “standby temperature”). The polyamide resin can be preheated so that the storage elastic modulus G ′ of the polyamide resin becomes a temperature around TC _{(6.5) at which} the storage elastic modulus G ′ becomes 1 × 10 ^6.5 Pa or higher. At this time, since the temperature TS _{(6.5) at which} the storage elastic modulus G ′ of the reactive resin constituting the shell portion becomes 1 × 10 ^6.5 Pa is higher, the shell resin is constituted in the vicinity of the standby temperature. The storage modulus G ′ of the material is higher than 1 × 10 ^6.5 Pa. For this reason, the powder material having such a structure has a lower weight due to the weight of the resin particles laminated on the upper layer in order to maintain the hardness of the outer film formed by the shell resin even when the standby temperature is set to such a high temperature. It is considered that the deformation of the resin particles contained in the layer is less likely to occur, and the accuracy of the three-dimensional structure is not easily lowered due to the deformation of the resin particles before the laser irradiation. On the other hand, the pre-heating causes the resin particles to reach a temperature near the temperature TC _{(6.5) at which} the storage elastic modulus G ′ of the polyamide resin constituting the core portion becomes around 1 × 10 ^6.5 Pa or higher. Since it is heated, it can be heated to a temperature at which the polyamide resin melts with a smaller amount of energy irradiation, and it becomes possible to produce a three-dimensionally shaped article in a shorter time. Furthermore, since the polyamide resin constituting the core part is heated to the above-mentioned relatively high temperature, the specific volume of the polyamide resin constituting the core part even when heated to a temperature at which the resin particles are fused by laser irradiation. It does not change so much, and it is considered that deformation of the resin particles due to volume change during laser irradiation hardly occurs.

The temperature at which the storage elastic modulus G ′ becomes 1 × 10 ^6.5 Pa can be a value obtained by measurement by a known method. In this specification, the storage elastic modulus G ′ is a value obtained by measuring with the following method using a storage elastic modulus measuring apparatus (ARES-G2 rheometer, manufactured by TA Instruments Inc.).

(Sample preparation)
With a solvent that dissolves only one of the polyamide resin that constitutes the core part and the reactive resin that constitutes the shell part, the polyamide resin or reactive resin that constitutes the resin particles is separated and extracted, and dried to form a powder. To do. Using a pressure molding machine (NT-100H, manufactured by NP System Co., Ltd.), the resulting powder is pressed at 30 kN for 1 minute at room temperature to form a cylindrical sample with a diameter of about 8 mm and a height of about 2 mm. To do.

(Measurement procedure)
The temperature of the parallel plate of the device is adjusted to 150 ° C., the molded cylindrical sample is heated and melted, and then a load is applied in the vertical direction so that the axial force does not exceed 10 (g weight). Then, the 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 viscoelasticity data is measured while gradually cooling. The measured data is transferred to a computer equipped with Microsoft Windows 7 ("Windows" is a registered trademark of the company), and is transferred through control, data collection and analysis software (TRIOS) operating on the computer. Read the value of storage modulus G ′ (Pa) at temperature.

(Measurement condition)
Measurement frequency: 6.28 radians / second.
Measurement strain setting: The initial value is set to 0.1%, and measurement is performed in the automatic measurement mode.
Sample extension correction: Adjust in automatic measurement mode.
Measurement temperature: Slow cooling from 250 ° C. to 100 ° C. at a rate of 5 ° C. per minute.
Measurement interval: Viscoelasticity data is measured every 1 ° C.

  The volume average particle diameter of the resin particles is preferably 1 μm or more and 100 μm or less. When the volume average particle diameter is 1 μm or more, the fluidity of the powder material is sufficiently enhanced, and the handling of the powder material when producing a three-dimensional structure is facilitated. Further, when the volume average particle diameter is 1 μm or more, it is easy to produce resin particles, and the production cost of the powder material does not increase. When the volume average particle diameter is 100 μm or less, it is possible to produce a relatively high-definition three-dimensional modeled object. From the viewpoint of easier handling of the powder material, easier production of the resin particles, and higher accuracy of the three-dimensional structure, the average particle diameter of the resin particles is more preferably 5 μm or more and 70 μm or less. Preferably, it is 20 μm or more and 60 μm or less. From the viewpoint of further increasing the accuracy of the three-dimensional structure, the upper limit of the average particle diameter of the resin particles is preferably 50 μm, more preferably 40 μm, and further preferably 30 μm.

  In this specification, the volume average particle size of the particles is, for example, a laser diffraction / scattering type particle size distribution measuring device equipped with a wet disperser (manufactured by Microtrack Bell Co., Ltd., Microtrack MT3000II ("MICROTRAC" is registered by the company). Trademark))). In addition, the particle diameter of 100 particles arbitrarily selected from a microscope image of a resin imaged by a scanning electron microscope (SEM) or a transmission electron microscope (TEM) was measured, and the average value was determined as a volume average particle particle size. The diameter may be estimated.

  It is preferable that the resin particles substantially contain only the polyamide resin and the reactive resin. However, as long as the three-dimensional structure can have desired characteristics, the components used when producing the resin particles. In addition to the polyamide resin or the reactive resin, it may contain a component such as a residue.

1-1-4. The amount of the polyamide resin and the reactive resin The content of the reactive resin in the powder material is 1.0% by mass or more and 30% by mass or less with respect to the total mass of the polyamide resin in the powder material. When the content is within the above range, the impact resistance of the three-dimensional structure manufactured from the powder material can be increased more than the impact resistance of the three-dimensional structure formed only of the polyamide resin. From the viewpoint of further improving the impact resistance of the three-dimensional structure, the content of the reactive resin in the powder material is 1.5% by mass or more and 20% by mass or less based on the total mass of the polyamide resin in the powder material. It is preferable that it is 2.0 mass% or more and 15 mass% or less, and it is more preferable that it is 3.0 mass% or more and 15 mass% or less.

  The amount of polyamide resin in the powder material and the amount of the above-mentioned reactive resin are determined by eluting the reactive resin with a soluble solvent such as toluene, and heating and drying the residue line segment and the eluted component respectively under reduced pressure. It can be determined by weighing.

1-1-5. Form of Resin Particles Resin particles are core-shell type particles in which at least a part of the surface of the core part mainly composed of the polyamide resin is coated with a shell part mainly composed of the reactive resin.

  The shell part preferably covers 90% or more and 100% or less of the surface of the core part, more preferably 95% or more and 100% or less, and even more preferably 100%. In the present specification, the above-mentioned coverage in the core-shell type particles is about 100 resin particles arbitrarily selected from a microscopic image of a powder material imaged by a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The ratio of the length covered with the shell portion of the outer peripheral length of the core portion can be measured, and these measured values can be averaged.

1-2. Other materials 1-2-1. Laser absorber From the viewpoint of more efficiently converting laser light energy into thermal energy, the powder material may further include a laser absorber. 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 powder, nylon resin powder, pigments and dyes. These laser absorbers may be used alone or in combination of two kinds.

  The amount of the laser absorber can be appropriately set within a range in which the resin particles can be easily melted and bonded. For example, the amount of the laser absorber may be more than 0% by mass and less than 3% by mass with respect to the total mass of the powder material. it can.

1-2-2. Flow Agent From the viewpoint of further improving the fluidity of the powder material and facilitating the handling of the powder material during the production of the three-dimensional structure, the powder material may further include a flow agent. The flow agent may be a material having a small coefficient of friction and self-lubricating properties. Examples of such flow agents include silicon dioxide and boron nitride. These flow agents may be used alone or in combination. Even if the fluidity of the powder material is increased by the flow agent, the resin particles are not easily charged, and the resin particles can be filled more densely when forming a thin film.

  The amount of the flow agent can be appropriately set as long as the fluidity of the powder material is further improved and the resin particles are sufficiently melt-bonded. For example, the amount of the flow agent is 0% by mass with respect to the total mass of the powder material. It can be more than 2% by mass.

2. Method for Producing Powder Material The powder material can be produced by producing the resin particles and, if necessary, stirring and mixing with materials other than the resin particles.

  The resin particles can be produced by a known method for producing particles containing a resin as a main component.

  Moreover, when the said resin particle is a core-shell type particle | grain, it can manufacture using the well-known method for manufacturing the particle | grains which have a core-shell structure from multiple types of resin material.

  Examples of the above method include a wet coating method using a coating solution in which a reactive resin constituting the shell portion is dissolved, and a polyamide resin constituting the core and a reactive resin constituting the shell portion, which are mechanically mixed by stirring. It can be performed by a dry coating method in which bonding is performed by impact, a combination thereof, or the like. When the wet coating method is employed, the coating solution may be spray-coated on the surface of the polyamide resin, or the polyamide resin may be immersed in the coating solution. According to the wet coating method, resin particles in which a sheet-like reactive resin uniformly coats a particulate polyamide resin can be obtained. According to the dry coating method, resin particles in which a particulate reactive resin is coated with a particulate polyamide resin are obtained. The wet coating method easily forms a shell portion having a uniform thickness, and the dry coating method does not require a drying process and can simplify the manufacturing process.

  In addition, since the core-shell type particles produced by the above-described method are not heated in the state in which the polyamide resin and the reactive resin coexist during the production, the terminal amine group of the polyamide resin and the reactive resin have Reactive functional groups tend to remain unreacted. Therefore, when irradiated with a laser, a structure in which a minute reactive resin is finely dispersed in a molten polyamide resin is formed, and the above-described random network structure is easily formed in a three-dimensional structure.

  Commercially available polyamide resins and reactive resins may be used, or one or both resins may be synthesized from suitable monomers, prepolymers, and the like.

3. The manufacturing method of a three-dimensional molded item This embodiment concerns on the manufacturing method of the three-dimensional molded item using the said powder material. The method according to the present embodiment can be performed in the same manner as the ordinary powder bed fusion bonding method, except that the powder material is used. Specifically, the method according to the present embodiment includes (1) a step of forming a thin layer of the powder material, and (2) selectively irradiating a laser beam to the preheated thin layer, and the powder. A step of forming a shaped article layer formed by melt-bonding resin particles contained in the material, a step of (3) repeating the step (1) and the step (2) a plurality of times in this order, and laminating the shaped article layer; including. By the step (2), one of the three-dimensional objects constituting the three-dimensional object is formed, and the next layer of the three-dimensional object is further performed by repeating the steps (1) and (2) in the step (3). It is laminated and the final three-dimensional model is manufactured. The manufacturing method according to this embodiment may further include (4) a step of preheating the thin layer of the formed powder material at least before step (2).

3-1. Step of forming a thin layer made of a powder material (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 laid flat on a 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 can be set according to the thickness of the shaped article layer. Although the thickness of a thin layer can be arbitrarily set according to the precision of the three-dimensional molded item to manufacture, it is 0.01 mm or more and 0.30 mm or less normally. By setting the thickness of the thin layer to 0.01 mm or more, the resin particles of the lower layer are melt-bonded or the modeling layer of the lower layer is re-melted by laser irradiation for forming the next layer. Can be prevented. By making the thickness of the thin layer 0.30 mm or less, the laser energy is conducted to the lower part of the thin layer, and the resin particles contained in the powder material constituting the thin layer are sufficiently melted throughout the thickness direction. Can be combined. 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 more sufficiently melting and bonding the resin particles throughout the thickness direction of the thin layer and making cracks between the laminates less likely to occur, the thickness of the thin layer is different from the laser beam spot diameter described later. Is preferably set to be within 0.10 mm.

3-2. A step of forming a shaped article layer formed by fusion bonding of resin particles (step (2))
In this step, a laser is selectively irradiated to the position where the shaped article layer is to be formed in the formed thin layer, and the resin particles at the irradiated position are melt-bonded. Thereby, adjacent resin particles are melted together to form a melt-bonded body, thereby forming a shaped article layer. At this time, the resin particles that have received the energy of the laser are melt-bonded to the already formed layer, and thus adhesion between adjacent layers also occurs.

  When the resin particles are irradiated with a laser, the reactive resin constituting the shell portion is considered to be decomposed and finely dispersed in the polyamide resin. Thereby, many reaction fields between the terminal amine group of the polyamide resin and the reactive functional group of the reactive resin are generated, and the structure in which a plurality of polyamide resins are bonded to each reactive resin is intricately entangled. It is considered that a random network structure is formed in the three-dimensional structure. Since the random network structure prevents the propagation of cracks due to stress applied to the three-dimensional structure in the three-dimensional structure, the three-dimensional structure manufactured in this way is less likely to crack even when subjected to an impact. (High impact resistance). In addition, since the reactive resin is easily finely dispersed by laser irradiation, the above reaction can occur even in a short laser irradiation. Therefore, random thermal decomposition and random cross-linking by heating the resin for a long time are unlikely to occur, and the impact resistance of the manufactured three-dimensional model can be sufficiently increased without reducing the elongation.

What is necessary is just to set the wavelength of a laser within the range which the said polyamide resin absorbs. At this time, it is preferable to reduce the difference between the wavelength of the laser and the wavelength at which the absorption rate of the polyamide resin is highest. However, since the resin can absorb light in various wavelength ranges, a CO ₂ laser or the like It is preferable to use a laser having a wide wavelength band. For example, the wavelength of the laser is preferably 0.8 μm or more and 12 μm or less.

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

  The laser scanning speed 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 mm / second to 100 mm / second, more preferably 1 mm / second to 80 mm / second, further preferably 2 mm / second to 80 mm / second, and more preferably 3 mm. / Mm or more and 80 mm / second or less is more preferable, and 3 mm / second or more and 50 mm / second or less is further preferable.

  The beam diameter of the laser can be appropriately set according to the accuracy of the three-dimensional structure to be manufactured.

3-3. A step of preheating the thin layer of the formed powder material (step (3))
In this step, the step (1) and the step (2) are repeated to laminate the shaped article layer formed by the step (2). A desired three-dimensional modeled object is manufactured by laminating the modeled object layers.

3-4. A step of preheating the thin layer of the formed powder material (step (4))
In this step, the thin layer of the powder material is preheated prior to step (2). For example, the surface temperature (standby temperature) of the thin layer can be heated to 15 ° C. or lower, preferably 5 ° C. or lower, than the melting point of the polyamide resin with a heater or the like.

Note that the standby temperature is set to 15 ° C. or less, preferably 5 ° C. or less than the temperature TS _{(6.5) at} which the storage elastic modulus G ′ of the reactive resin constituting the shell portion becomes 10 ^6.5 Pa. it can. In particular, the temperature _{TC (6} to 'the storage modulus G of the temperature _{TS (6.5)} said polyamide resin is ^{10 6.5} Pa' storage modulus of the reactive resin G becomes ^{10 6.5} _Pa. When the temperature is higher than ₅₎ , the standby temperature may be near or higher than the temperature TC _(6.5) at which the storage elastic modulus G ′ of the polyamide resin becomes 10 ^6.5 Pa. Therefore, when using such a powder material containing resin particles, by setting the standby temperature to the above temperature, the resin particles can be heated to a temperature at which the resin particles are melt-bonded with a smaller amount of energy irradiation. It is considered that the production can be performed in a shorter time, and the deformation of the resin particles due to the volume change at the time of laser irradiation can be hardly caused.

3-5. Other From the viewpoint of preventing the strength of the three-dimensional structure from decreasing due to oxidation of the resin particles during the melt bonding, at least step (2) is preferably performed under reduced pressure or in an inert gas atmosphere. The pressure when reducing the pressure is preferably 10 ⁻² Pa or less, and more preferably 10 ⁻³ Pa or less. Examples of the inert gas that can be used in the present embodiment include nitrogen gas and rare gas. 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, all of the steps (1) to (3) (when including the step (4), all of the steps (1) to (4)) are performed under reduced pressure or an inert gas. It is preferable to carry out in an atmosphere.

4). Three-dimensional modeling apparatus This embodiment concerns on the apparatus which manufactures a three-dimensional molded item using the said powder material. The apparatus which concerns on this embodiment can be set as the structure similar to the well-known apparatus which manufactures the three-dimensional molded item by the powder bed melt-bonding method except using the said powder material. Specifically, as shown in FIG. 1 which is a side view schematically showing the configuration of the three-dimensional modeling apparatus 100 according to the present embodiment, a modeling stage 110 located in the opening, a powder material containing resin particles A thin film forming part 120 for forming a thin film on the modeling stage, a laser irradiation part 130 for irradiating the thin film with a laser to form a model layer formed by melting and bonding the resin particles, and a variable position in the vertical direction Are provided with a stage support part 140 for supporting the modeling stage 110 and a base 145 for supporting the above parts.

  As shown in FIG. 2 showing the main part of the control system, the three-dimensional modeling apparatus 100 controls the thin film forming unit 120, the laser irradiation unit 130, and the stage support unit 140 to repeatedly form the modeled object layer. A control unit 150 to be stacked, a display unit 160 for displaying various information, an operation unit 170 including a pointing device for receiving an instruction from a user, and various types of information including a control program executed by the control unit 150 are stored. You may provide the data input part 190 containing the interface etc. for transmitting / receiving various information, such as 3D modeling data, with the memory | storage part 180 and an external device. The three-dimensional modeling apparatus 100 may be connected to a computer device 200 for generating data for three-dimensional modeling.

  On the modeling stage 110, a modeling material layer is formed by forming a thin layer by the thin film forming unit 120 and irradiating the laser by the laser irradiation unit 130, and the modeling material layer is stacked to form a three-dimensional modeled object. .

  The thin film forming unit 120 includes, for example, an opening having an edge on the substantially same plane in the horizontal direction as the edge of the opening on which the modeling stage 110 moves up and down, a powder material storage unit extending vertically downward from the opening, and powder A powder supply unit 121 including a supply piston that is provided at the bottom of the material storage unit and moves up and down in the opening, and a recoater 122a that lays the supplied powder material flat on the modeling stage 110 to form a thin layer of the powder material. It can be set as the structure provided.

  The powder supply unit 121 includes a powder material storage unit and a nozzle provided vertically above the modeling stage 110, and discharges the powder material on the same plane as the modeling stage. It is good also as a structure.

The laser irradiation unit 130 includes a laser light source 131 and a galvanometer mirror 132a. The laser irradiation unit 130 may include a lens (not shown) for adjusting the focal length of the laser to the surface of the thin layer. The laser light source 131 may be a light source that emits a laser having the above wavelength with the above output. Examples of the laser light source 131 include a YAG laser light source, a fiber laser light source, and a CO ₂ laser light source. The galvanometer mirror 132a may be composed of an X mirror that reflects the laser emitted from the laser light source 131 and scans the laser in the X direction and a Y mirror that scans in the Y direction.

  The stage support unit 140 supports the modeling stage 110 variably in the vertical position. That is, the modeling stage 110 is configured to be precisely movable in the vertical direction by the stage support unit 140. Although various configurations can be adopted as the stage support unit 140, for example, the stage support unit 140 is engaged with a holding member that holds the modeling stage 110, a guide member that guides the holding member in the vertical direction, and a screw hole provided in the guide member. It can be composed of a ball screw or the like.

  The control unit 150 controls the entire operation of the 3D modeling apparatus 100 during the modeling operation of the 3D model.

  In addition, the control unit 150 includes a hardware processor such as a central processing unit. For example, the three-dimensional modeling data acquired from the computer device 200 by the data input unit 190 is sliced into a plurality of slices in the stacking direction of the modeling material layers. It may be configured to convert to data. Slice data is modeling data of each modeling material layer for modeling a three-dimensional modeled object. The thickness of the slice data, that is, the thickness of the modeling material layer coincides with the distance (lamination pitch) corresponding to the thickness of one layer of the modeling material layer.

  The display unit 160 can be, for example, a liquid crystal display or a monitor.

  The operation unit 170 may include a pointing device such as a keyboard and a mouse, and may include various operation keys such as a numeric keypad, an execution key, and a start key.

  The storage unit 180 can include various storage media such as a ROM, a RAM, a magnetic disk, an HDD, and an SSD.

  The three-dimensional modeling apparatus 100 receives the control of the control unit 150 and decompresses the inside of the apparatus. The decompression unit (not shown) such as a decompression pump or the control unit 150 controls the inert gas into the apparatus. You may provide the inert gas supply part (not shown) to supply. The three-dimensional modeling apparatus 100 may include a heater (not shown) that heats the inside of the apparatus, in particular, the upper surface of a thin layer made of a powder material, under the control of the control unit 150.

4-1. Example of 3D modeling using the 3D modeling apparatus 100 The control unit 150 converts the 3D modeling data acquired from the computer apparatus 200 by the data input unit 190 into a plurality of slice data sliced in the stacking direction of the modeling material layer. Thereafter, the control unit 150 controls the following operations in the three-dimensional modeling apparatus 100.

  The powder supply unit 121 drives a motor and a drive mechanism (both not shown) according to the supply information output from the control unit 150, moves the supply piston upward (in the direction of the arrow in the figure), and the modeling stage And extrude the powder material on the same horizontal plane.

  Thereafter, the recoater driving unit 122 moves the recoater 122a in the horizontal direction (arrow direction in the figure) according to the thin film formation information output from the control unit 150, conveys the powder material to the modeling stage 110, and the thin layer The powder material is pressed so that the thickness becomes the thickness of one layer of the shaped article layer.

  Thereafter, the laser irradiation unit 130 emits a laser from the laser light source 131 in accordance with the laser irradiation information output from the control unit 150, conforming to the region constituting the three-dimensional structure in each slice data on the thin film, and the galvano The mirror driving unit 132 drives the galvano mirror 132a to scan the laser. The resin particles contained in the powder material are melt-bonded by laser irradiation, and a shaped article layer is formed.

  Thereafter, the stage support unit 140 drives a motor and a drive mechanism (both not shown) according to the position control information output from the control unit 150, and moves the modeling stage 110 vertically downward (arrow direction in the figure) by the stacking pitch. )

  The display unit 160 displays various information and messages to be recognized by the user under the control of the control unit 150 as necessary. The operation unit 170 receives various input operations by the user and outputs operation signals corresponding to the input operations to the control unit 150. For example, a virtual three-dimensional object to be formed is displayed on the display unit 160 to check whether a desired shape is formed. If the desired shape is not formed, the operation unit 170 may be modified. Good.

  The control unit 150 stores data in the storage unit 180 or extracts data from the storage unit 180 as necessary.

  By repeating these operations, the modeled object layer is laminated and a three-dimensional modeled object is manufactured.

  In the following, specific examples of the present invention will be described. These examples do not limit the scope of the present invention.

1. Production of powder material A powder material containing resin particles was produced by the following procedure.

1-1. Powder material 1
In 100 parts by mass of toluene, 1 part by mass of polycarbonate (Mitsubishi Gas Chemical Co., Ltd., PCZ-200) and 2 parts by mass of emulsifier (Sakamoto Yakuhin Kogyo Co., Ltd., SY Glister CRS-75) are dissolved. Part of nylon 12 (manufactured by Arkema, ORGASOL 2003) was dispersed to obtain a first resin dispersion. A liquid obtained by dissolving 10 parts by weight of a nonionic surfactant (manufactured by Kao Corporation, Emanon C-25 (“Emanon” is a registered trademark of the company)) in 200 parts by weight of water. The mixture was poured into the container and subjected to ultrasonic treatment for 10 minutes to obtain a second resin dispersion. The second resin dispersion was put into an evaporator and the toluene was removed under reduced pressure to obtain a resin dispersion. Thereafter, the obtained resin dispersion was filtered under reduced pressure to obtain a powder material 1 composed of core-shell type resin particles in which nylon 12 was coated with polycarbonate.

1-2. Powder material 2
In 100 parts by mass of toluene, 0.5 parts by mass of polycarbonate (Mitsubishi Gas Chemical Co., Ltd., PCZ-200) and 2 parts by mass of emulsifier (Sakamoto Yakuhin Kogyo Co., Ltd., SY Grister CRS-75) are dissolved. Further, 10 parts by mass of nylon 12 (manufactured by Arkema, ORGASOL 2003) was dispersed to obtain a first resin dispersion. The first resin dispersion was poured into a liquid in which 10 parts by weight of a nonionic surfactant (Emanon C-25, manufactured by Kao Corporation) was dissolved in 200 parts by weight of water, and the dispersion exceeded 10 minutes. Sonication was performed to obtain a second resin dispersion. The second resin dispersion was put into an evaporator and the toluene was removed under reduced pressure to obtain a resin dispersion. Thereafter, the obtained resin dispersion was filtered under reduced pressure to obtain a powder material 2 composed of core-shell type resin particles in which nylon 12 was coated with polycarbonate.

1-3. Powder material 3
Nylon 6 (made by Toray Industries, Inc., Amilan CM1001 (not strengthened with glass fiber (the same applies to Amilan CM1001 below), “Amilan” is a registered trademark of the same company)) was pulverized to a mean particle size of 50 μm by mechanical pulverization. Nylon 6 was obtained.

  100 parts by mass of toluene, 0.5 parts by mass of polyarylate synthesized according to the procedure described in JP-A-9-136946 and 2 parts by mass of an emulsifier (manufactured by Sakamoto Pharmaceutical Co., Ltd., CRS-75) Was dissolved, and 10 parts by mass of the particulate nylon 6 was dispersed to obtain a first resin dispersion. The resin dispersion 1 is injected into a liquid in which 10 parts by mass of a nonionic surfactant (Emanon C-25, manufactured by Kao Corporation) is dissolved in 200 parts by mass of water, and ultrasonic treatment is performed for 10 minutes. To obtain a second resin dispersion. The second resin dispersion was put into an evaporator and the toluene was removed under reduced pressure to obtain a resin dispersion. Thereafter, the obtained resin dispersion was filtered under reduced pressure to obtain a powder material 3 composed of core-shell type resin particles in which nylon 6 was coated with polyarylate.

1-4. Powder material 4
Nylon 12 (manufactured by Arkema, ORGASOL 2003) was used as it was to obtain a powder material 4.

1-5. Powder material 5
Nylon 6 (Amilan CM1001 manufactured by Toray Industries, Inc.) was pulverized to a mean particle size of 50 μm by a mechanical pulverization method, and the resulting particles containing nylon 6 were used as powder material 5.

1-6. Powder material 6
Particles obtained by pulverizing 100 parts by mass of nylon 12 (manufactured by Arkema Corporation, ORGASOL 2003) to an average particle size of 42 μm by mechanical pulverization method, and 10 parts by mass of polycarbonate (manufactured by Sumika Stylon Polycarbonate Co., Ltd., Caliber 301-4 (“ The powder material 6 was a mixture of the caliber “registered trademark of Trinceo Co., Ltd.)” and particles pulverized to a mean particle size of 50 μm by a mechanical pulverization method.

1-7. Powder material 7
In accordance with the procedure described in 100 parts by mass of nylon 6 (Amilan CM1001 manufactured by Toray Industries, Inc.) with an average particle size of 50 μm by mechanical pulverization and 5 parts by mass of JP-A-9-136946 A mixture of the synthesized polyarylate with particles pulverized to a mean particle size of 50 μm by a mechanical pulverization method was used as powder material 7.

1-8. Powder material 8
In 100 parts by mass of toluene, 3.5 parts by mass of polycarbonate (Mitsubishi Gas Chemical Co., Ltd., PCZ-200) and 2 parts by mass of emulsifier (Sakamoto Pharmaceutical Co., Ltd., SY Glister CRS-75) are dissolved. Further, 10 parts by mass of nylon 12 (manufactured by Arkema, ORGASOL 2003) was dispersed to obtain a first resin dispersion. The first resin dispersion was poured into a liquid in which 10 parts by weight of a nonionic surfactant (Emanon C-25, manufactured by Kao Corporation) was dissolved in 200 parts by weight of water, and the dispersion exceeded 10 minutes. Sonication was performed to obtain a second resin dispersion. The second resin dispersion was put into an evaporator and the toluene was removed under reduced pressure to obtain a resin dispersion. Thereafter, the obtained resin dispersion was filtered under reduced pressure to obtain a powder material 8 composed of core-shell type resin particles in which nylon 12 was coated with polycarbonate.

  Kind and amount of resin used for production of powder materials 1-8, form of resin particles contained in powder materials 1-8, and laser diffraction / scattering particle size distribution measuring device (manufactured by Microtrack Bell Co., Ltd., Measurement was performed using Microtrac MT3000II). Table 1 shows the volume average particle diameters of the powder materials 1 to 8. In Table 1, the column “form” includes “core shell” when the powder material includes resin particles formed by coating the core portion made of resin 1 with the shell portion made of resin 2, and the powder material is made of resin 1. When it is a mixture of particles and particles made of resin 2, “mixture” is described. In the column of “particle diameter”, when the powder material includes core-shell type resin particles, (average particle diameter of resin 1) / (average particle diameter of resin 2) is described.

The temperature TC _(6.5) at which the storage modulus G ′ of the nylon 12 used for the production of the powder material becomes 10 ^6.5 Pa when heated is 168 ° C., and the nylon 6 used for the production of the powder material. The temperature TC _(6.5) at which the storage elastic modulus G ′ reached 10 ^6.5 Pa during heating was 220 ° C. Moreover, the temperature TS _(6.5) at which the storage elastic modulus G ′ of the polycarbonate used for producing the powder material becomes 10 ^6.5 Pa when heated is 190 ° C., and the polycarbonate used for producing the powder material has The temperature TS _(6.5) at which the storage elastic modulus G ′ became 10 ^6.5 Pa during heating was 280 ° C.

2. Evaluation 2-1. Changes in the amount of carbonyl groups The infrared absorption spectra (IR spectra) of the powder materials 1 to 8 were subjected to total reflection (ATR) method using a Fourier transform infrared spectrophotometer (Nicolet 380 manufactured by Thermo Fisher Scientific). Measured with Ge was used for the infrared transmission prism, the incident angle was 60 °, and the number of reflections was one.

  Thereafter, the powder materials 1 to 8 were spread on a modeling stage of a three-dimensional modeling apparatus using a powder bed fusion bonding method having the basic configuration shown in FIG. 1 to form a thin layer having a thickness of 0.1 mm. This thin layer is irradiated with a laser in a range of 15 mm in length and 20 mm in width from a 50 W fiber laser (manufactured by SPI Lasers) equipped with a YAG wavelength galvanometer scanner under the following conditions to form single-layer shaped objects 1 to 8 Were prepared.

[Laser emission conditions]
Laser output: 20W
Laser wavelength: 1.07 μm
Beam diameter: 170 μm on the surface of the thin layer

[Laser scanning conditions]
Scanning speed: 3.0 mm / sec
Scanning interval: 0.2 mm

[Ambient atmosphere]
Temperature: Normal temperature Gas: Argon (Ar) 100%

  The IR spectra of the shaped objects 1 to 8 were measured in the same manner as the powder materials 1 to 8.

  The IR spectra of the powder materials 1 to 8 before dissolving and removing the resin 2 are compared with the IR spectra of the shaped objects 1 to 8 before dissolving and removing the resin 2, respectively, and the intensity of the peak corresponding to the carbonyl group is obtained. It was evaluated whether there was a change. In addition, from the IR spectrum measured from the powder material 4 and the powder material 5, and the shaped article 4 and the shaped article 5, no peak corresponding to the carbonyl group was detected.

  Further, the polyarylate contained in the powder material 2 is dissolved in toluene, which is a soluble solvent, and the polyarylate contained in the powder material 2 is dissolved and removed, and is contained in the powder material 2 and the removal liquid after the removal. The IR spectrum was similarly measured for the resin.

  In the powder material 2 before the removal and the removal liquid after the removal, a peak was observed in the wave number corresponding to the carbonyl group, but in the powder material 2 after the removal, no peak was observed in the wave number corresponding to the carbonyl group.

  Furthermore, the polyarylate contained in the shaped article 2 was dissolved and removed with toluene, and the IR spectrum was similarly measured for the resin contained in the shaped article 2 and the removal liquid after the removal.

  In the powder material 2 before removal, no peak was observed in the wave number corresponding to the carbonyl group, and it was estimated that the carbonyl group of the polyarylate contained in the powder material 2 reacted with the terminal amide group of nylon 6. On the other hand, in the removal solution after removal, a peak was observed in the wave number corresponding to the carbonyl group, and it was speculated that some of the polyarylate did not react with nylon 6. In addition, in the molded article 2 after removal, no peak was observed in the wave number corresponding to the carbonyl group.

2-2. Tensile strength Test pieces 1 to 8 having the shape of type 1A described in JIS K 7181-2 were produced from powder materials 1 to 8 under the same production conditions as those described above for “change in carbonyl group amount”. The tensile strengths of the test pieces 1 to 8 were determined according to JIS K 7181-2.

  Test pieces 1 to 3 and test pieces 6 to 8 when compared with a case where a test piece is made using resin 1 alone (test piece 4 or test piece 5 made from powder material 4 or powder material 5) The tensile strength of the powder material is evaluated as `` ○ '' when the tensile strength is high or low, and when the tensile strength is low, the tensile strength of the powder material is “×”.

2-3. Defect of modeling object The modeling objects 1-8 produced on the same production conditions as the above "change of carbonyl group amount" are observed visually, and a defect (modeling) larger than the size (about 0.1 mm) of the resin particles on the modeling object It was confirmed whether or not there was a part that was not formed and became a void. When the number of defects is 1 or more and 10 or less, the defect of the model is evaluated as “◯”, and when the number of defects is 11 or more, the defect of the model is “x”. evaluated.

  Table 2 shows the evaluation results of the change in the amount of carbonyl groups, the tensile strength, and the defect of the molded product for the powder materials 1 to 8.

  A powder material comprising core-shell type resin particles having a core portion mainly composed of a polyamide resin and a shell portion mainly composed of a thermoplastic resin having a functional group that reacts with an amide group, wherein the powder material contains The powder materials 1 to 3 in which the content of the thermoplastic resin is 1.0% by mass or more and 30% by mass or less with respect to the total mass of the polyamide resin in the powder material are prepared The carbonyl group of the resin 2 is reacted with the terminal amide group of the resin 1, and the tensile strength of the modeled object is higher than the modeled articles (modeled article 4 and modeled article 5) made only from the polyamide resin, and It was difficult to cause defects in the shaped objects.

  Moreover, even if a molded article is manufactured from the powder material 6 and the powder material 7 that are simply mixed with a polyamide resin and a thermoplastic resin having a functional group that reacts with an amide group, the tensile strength of the molded article is a polyamide resin. It was lower than the modeled objects (modeled object 4 and modeled object 5) produced only from the above, and defects in the modeled object were also likely to occur. This is considered because the reaction field between the terminal amine group which the resin 1 has, and the carbonyl group which the resin 2 has does not generate so much, and the network structure is not formed sufficiently.

  Further, the powder material 8 in which the content of the thermoplastic resin in the powder material is more than 30% by mass with respect to the total mass of the polyamide resin in the powder material, the carbonyl group of the resin 2 is the terminal amide group of the resin 1 The tensile strength of the model was lower than that of the model (model 4 and model 5) produced only from the polyamide resin, and the model was easily damaged. This is probably because although the terminal amide group of the resin 1 and the carbonyl group of the resin 2 react, the amount of the resin 1 that reacts with each resin 2 is small, and the network structure is not sufficiently formed.

  According to the powder material according to the present invention, it is possible to manufacture a three-dimensional structure having higher impact resistance than a three-dimensional structure manufactured from a polyamide resin by a powder bed fusion bonding method. Therefore, this invention can expand the field | area which can utilize a powder bed melt-bonding method, and can contribute to the further spread of the three-dimensional modeling by a powder bed melt-bonding method.

DESCRIPTION OF SYMBOLS 100 Stereolithography apparatus 110 Modeling stage 120 Thin film formation part 121 Powder supply part 122 Recoater drive part 122a Recoater 130 Laser irradiation part 131 Laser light source 132 Galvano mirror drive part 132a Galvano mirror 140 Stage support part 145 Base 150 Control part 160 Display part 170 Operation Unit 180 storage unit 190 data input unit 200 computer device

Claims (8)

Three-dimensional modeling by selectively irradiating a thin layer of a powder material containing resin particles with laser light to form a modeled object layer formed by sintering or melt bonding the resin particles, and laminating the modeled object layer A powder material used in the manufacture of goods,
The resin particle is a core-shell type particle having a core part mainly composed of a polyamide resin and a shell part mainly composed of a thermoplastic resin having a functional group that reacts with an amide group.
The content of the thermoplastic resin in the powder material is 1.0% by mass or more and 30% by mass or less with respect to the total mass of the polyamide resin in the powder material.
Powder material.   The powder material according to claim 1, wherein the functional group that reacts with the amide group is a carbonyl group.   The thermoplastic resin is selected from the group consisting of a polyester resin having a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyhydric alcohol, a polycarbonate resin, a polylactic acid resin, and a polyarylate resin. The powder material according to claim 1 or 2, comprising a plurality of resins.   The powder material according to any one of claims 1 to 3, wherein the polyamide resin contained in the resin particles has a terminal amino group concentration of 10 µeq / g or more and 100 µeq / g or less. Storage modulus G of the thermoplastic resin 'temperature _TS which is ^{10 _6.5} Pa _^(6.5) has a storage modulus G of the polyamide resin' temperature _{TC (6.5} to become ^{10 6.5} Pa ₎ higher than the powder material according to any one of claims 1 to 4.   The powder material according to any one of claims 1 to 5, wherein a volume average particle diameter of the resin particles is 1 µm or more and 100 µm or less. Forming a thin layer of the powder material according to any one of claims 1 to 6;
A step of selectively irradiating the formed thin layer with laser light to form a shaped article layer in which resin particles contained in the powder material are sintered or melt-bonded;
The step of forming the thin layer and the step of forming the shaped article layer are repeated a plurality of times in this order, and the step of laminating the shaped article layer,
The manufacturing method of the three-dimensional molded item containing. Modeling stage,
A thin film forming section for forming a thin film of the powder material according to any one of claims 1 to 6 on the modeling stage;
A laser irradiation unit for irradiating the thin film with a laser to form a shaped article layer formed by sintering or fusion bonding resin particles contained in the powder material;
A stage support section that variably supports the vertical position of the modeling stage;
A control unit that controls the thin film forming unit, the laser irradiation unit, and the stage support unit to repeatedly form and stack the shaped article layer;
A three-dimensional modeling apparatus.

Images