JP2020185771A - Thermoplastic resin powder, resin powder for solid molding, manufacturing apparatus of solid molding, and manufacturing method of solid molding - Google Patents

Abstract

To provide a thermoplastic resin powder having excellent antistatic effect, capable of reducing adherence of the resin powder in the apparatus, and capable of molding a solid molding having a molding face with good appearance.SOLUTION: Provided is a thermoplastic resin powder: having 0.01 mass% or more and 30.0 mass% or more of a heat-resistant anti-static agent; having a 50% cumulative volume particle diameter of 5 μm or more and 200 μm or less; having a rate of a volume average particle diameter and a number average particle diameter, (Mv/Mn), of 2.00 or less and a melting point of 100°C or more; having a surface resistivity of 1×105 Ω or more and 1×1014 Ω or less; a specific volume resistance of 1×105 Ω cm or more and 1×1015 Ω cm or less; and a high temperature resistivity of 1×105 Ω cm or more and 1×1015 Ω cm or less; wherein the resin powder involves columnar body particles, with a rate of a height toward a diameter or a long side at a bottom face of the columnar body particle being 0.5 -fold or more and 2 -fold or less, a density of 0.8 g/cm3 or more and 1.4 g/cm3 or less, and a mass reduction rate after heating for 4 hours at a temperature lower by 10°C than a melting point of the powder of 0.65 mass% or less.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic resin powder, a resin powder for three-dimensional modeling, an apparatus for producing a three-dimensional model, and a method for producing a three-dimensional model.

In recent years, resin powder has been used as a raw material for plastic products in a wide variety of fields. For example, as a resin powder, for example, a semi-aromatic polyamide resin composition containing a semi-aromatic polyamide, a polyhydric alcohol, and a fibrous reinforcing material is disclosed (see, for example, Patent Document 1).

However, the semi-aromatic polyamide resin composition described in Patent Document 1 is prone to charge, and it has been difficult to obtain a high-quality plastic product.
An object of the present invention is to provide a thermoplastic resin powder which is excellent in antistatic effect, can reduce adhesion of resin powder in an apparatus, and can form a three-dimensional model having a beautiful modeling surface.

The thermoplastic resin powder of the present invention as a means for solving the above problems contains 0.01% by mass or more and 30.0% by mass or less of a heat-resistant antistatic agent.

According to the present invention, it is possible to provide a thermoplastic resin powder which is excellent in antistatic effect, can reduce adhesion of resin powder in an apparatus, and can form a three-dimensional model having a beautiful modeling surface.

FIG. 1A is a schematic perspective view showing an example of cylindrical resin particles. FIG. 1B is a schematic side view of the resin particles of the substantially cylindrical body shown in FIG. 1A. FIG. 1C is a schematic side view showing an example of a cylindrical resin particle having no apex at an end. FIG. 1D is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 1E is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 1F is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 1G is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 1H is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 1I is a schematic side view showing another example of a cylindrical resin particle having a shape having no apex at an end. FIG. 2 is a photograph showing an example of a cylindrical resin powder. FIG. 3 is a schematic view showing a three-dimensional modeling apparatus according to an embodiment of the present invention. FIG. 4 is a flowchart for explaining an example of the operation of the three-dimensional model manufacturing apparatus.

(Thermoplastic resin powder)
The thermoplastic resin powder of the present invention contains a heat-resistant antistatic agent in an amount of 0.01% by mass or more and 30.0% by mass or less, preferably contains resin particles, and further contains other components as necessary.

<Resin particles>
The shape of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include shapes such as a cylinder, a polygonal prism, and a sphere. Among these, the cylindrical body is more preferable because it has a very large contact area between particles and is easily charged, so that it has a high antistatic effect.

The columnar body is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a true columnar body and an elliptical columnar body. Among these, a true cylinder is preferable.
The columnar body includes a substantially cylindrical body. Here, the substantially circle means that the ratio of the major axis to the minor axis (major axis / minor axis) is 1 or more and 10 or less. Further, the circular portion of the cylinder may be partially missing.
The polygonal prism is not particularly limited as in the case of the cylinder, and can be appropriately selected depending on the intended purpose, and a part of the polygonal portion of the polygonal prism may be missing.
As with the cylindrical body, the sphere is not particularly limited and may be appropriately selected depending on the intended purpose, and a part of the sphere may be missing.

The diameter of the circular portion of the cylindrical body is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 200 μm or less. When the circular portion of the cylinder is elliptical, the diameter means the major axis.
The length of one side of the polygonal portion of the polygonal prism is not particularly limited and can be appropriately selected depending on the purpose, but the diameter of the smallest circle (minimum inclusion circle) including all the polygonal portions. Is preferably 5 μm or more and 200 μm or less.
The diameter of the sphere is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 200 μm or less.

The height of the cylinder, that is, the distance between the two opposing circular portions (distance between the upper surface and the bottom surface) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 200 μm or less.
The height of the polygonal prism, that is, the distance between the two opposing polygonal portions (distance between the upper surface and the bottom surface) is not particularly limited as in the height of the cylindrical body, and can be appropriately selected depending on the purpose. However, it is preferably 5 μm or more and 200 μm or less.

The areas of the two opposing circular portions (top and bottom) of the cylinder may be different from each other. However, as the ratio (r2 / r1) of the diameter r2 of the circular portion having the larger area to the diameter r1 of the circular portion having the smaller area, the bulk density can be increased when there is no difference in the areas of the two circular portions. In terms of possible, 1.5 or less is preferable, and 1.1 or less is more preferable.
The areas of the two opposing polygonal portions (top and bottom) in the polygonal prism may be different from each other. However, as the ratio (S2 / S1) of the larger area (S2) of the polygonal portion to the smaller area (S1) of the polygonal portion, the bulk density is higher when there is no difference in the areas of the two polygonal portions. It is preferably close to 1 in that it can be increased.
When modeling a three-dimensional model by the powder bed melt-bonding method (PBF; Part Bed Fusion), the accuracy of the model or the model can be improved by increasing the bulk density of the resin particles.

It is preferable that the resin particles of a column such as a cylinder or a polygonal column do not have vertices in order to increase the bulk density. The apex means a corner portion existing in the pillar body.

Here, the shape of the resin particles of the cylindrical body will be described with reference to FIGS. 1A to 1I.
FIG. 1A is a schematic perspective view showing an example of cylindrical resin particles. FIG. 1B is a schematic side view of the resin particles of the cylindrical body shown in FIG. 1A. FIG. 1C is a schematic side view showing an example of a cylindrical resin particle having no apex at an end. 1D to 1I are schematic side views showing another example of a cylindrical resin particle having no apex at an end.

When the cylindrical body shown in FIG. 1A is observed from the side surface, it has a rectangular shape as shown in FIG. 1B, and there are four corner portions, that is, four vertices. Examples of the shape having no apex at the end are shown in FIGS. 1C to 1I.
The presence or absence of the vertices of the resin particles of the pillar can be determined from the projected image of the resin particles of the pillar with respect to the side surface. For example, the side surface of the resin particles of the pillar is observed with a scanning electron microscope (device name: S4200, manufactured by Hitachi, Ltd.) or the like, and obtained as a two-dimensional image. In this case, the projected image is a quadrilateral, and the end is a portion composed of two adjacent sides. Then, when it is composed of only two adjacent straight lines, a corner is formed and it has a vertex, and when the end is composed of an arc as shown in FIGS. 1C to 1I, it has a vertex at the end. There will be no.

For example, as shown in FIG. 2, the resin particles 21 of the pillar body have a first surface 22, a second surface 23, and a side surface 24.
The first surface 22 has a first facing surface 22a and an outer peripheral region 22b of the first surface having a shape extending along the side surface 24. The outer peripheral region 22b of the first surface is a surface continuous with the first facing surface 22a via a curved surface, and is substantially orthogonal to the first facing surface 22a.
The second surface 23 has a second facing surface 23a facing the first facing surface 22a, and an outer peripheral region 23b of the second surface having a shape extending along the side surface 24. The outer peripheral region 23b of the second surface is a surface continuous with the second facing surface 23a via a curved surface, and is substantially orthogonal to the second facing surface 23a.
The side surface 24 is adjacent to the first surface 22 and the second surface 23. Further, the outer peripheral region 22b of the first surface and the outer peripheral region 23b of the second surface extend on the side surface 24.

The shapes of the outer peripheral region 22b of the first surface and the outer peripheral region 23b of the second surface (hereinafter, also referred to as “outer peripheral region”) are shapes that can be distinguished from the side surface 24 on the SEM (Scanning Electron Microscope) image. All you need is. Specifically, the shape of the outer peripheral region includes, for example, a shape in which a part of the outer peripheral region is integrated with the side surface 24, a shape in which the outer peripheral region is in contact with the side surface 24, and a space between the outer peripheral region and the side surface 24. The shape in which is present can be mentioned.
Further, it is preferable that the outer peripheral region is provided so as to have a surface direction substantially the same as the surface direction of the side surface 24.
Further, as shown in FIG. 2, the outer peripheral region extends along the side surface 24 and is located on the side surface 24. Further, the structure of the first surface and the second surface covering the vicinity of the connection region between the outer peripheral region and the side surface 24 is also referred to as a bottle cap shape.

The method for forming the resin particles into a shape having no vertices is not particularly limited and may be appropriately selected depending on the intended purpose. For example, high-speed rotary mechanical pulverization, high-speed impact mechanical pulverization, or mechanical friction is used. Examples thereof include a known method using a spheroidizing treatment device such as surface melting.

The melting point of the resin particles can be appropriately selected depending on the intended purpose, but considering the heat resistant temperature when used for modeling the molded product or the exterior of the molded product, 100 ° C. or higher is preferable, and 120 ° C. or higher is more preferable. It is preferable, and 140 ° C. or higher is more preferable.

The melting point of the resin particles can be measured by, for example, differential scanning calorimetry (DSC). Specifically, the melting point of the resin particles shall be measured according to ISO3146 (Plastic transition temperature measuring method, JIS K7121), for example, using a differential scanning calorimetry device such as DSC-60A manufactured by Shimadzu Corporation. Can be done. As a measuring method, for example, the temperature is raised at 10 ° C./min, DSC measurement of the resin particles is performed, and the temperature at the apex of the obtained endothermic peak or the temperature at the apex of the melting point peak is defined as the melting point. When the resin particles have a plurality of melting points, the melting point on the high temperature side may be used.

<Thermoplastic resin>
Thermoplastic resin means a resin that plasticizes and melts when heat is applied.
The thermoplastic resin is not particularly limited and may be appropriately selected depending on the intended purpose, and may be a crystalline resin or a non-crystalline resin.
The crystalline resin is a resin in which a melting point peak is detected in a measurement based on ISO 3146 (Plastic transition temperature measuring method, JIS K7121).

Examples of the thermoplastic resin include polyolefin, polyamide, polyester, polyether, polyphenylene sulfide, liquid crystal polymer (LCP: Liquid Crystal Polymer), polyacetal (POM: Polyoxymethylene), polyimide, fluororesin and the like. The seeds may be used alone or in combination of two or more.

Examples of the polyolefin include polyethylene, polypropylene, polymethylpentene and the like. The polypropylene may be a block body, a random body, or a homo body, and may contain a composite material such as talc or glass fiber.

Examples of the polyamide include polyamide 410 (PA410), polyamide 6 (PA6), polyamide 66 (PA66, melting point: 265 ° C.), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), and polyamide 12 ( PA12); Semi-aromatic polyamides such as polyamide 4T (PA4T), polyamide MXD6 (PAMXD6), polyamide 6T (PA6T), polyamide 9T (PA9T, melting point: 300 ° C.), polyamide 10T (PA10T) can be mentioned.

PA9T is also called polynonamethylene terephthalamide, and is a semi-aromatic substance containing 9 diamines of carbon and a terephthalic acid monomer, and the carboxylic acid side is aromatic. Polyamide also contains aramid produced from p-phenylenediamine and a terephthalic acid monomer as a total aromatic that is aromatic not only on the carboxylic acid side but also on the diamine side.

Examples of the polyester include polyethylene terephthalate (PET, melting point: 260 ° C.), polybutadiene terephthalate (PBT), polylactic acid (PLA) and the like. Among these, those having an aromatic component containing terephthalic acid or isophthalic acid as a part are preferable in terms of imparting heat resistance.

Examples of the polyether include polyaryl ketone and polyether sulfone.
Examples of the polyarylketone include polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone ketone (PEKK), polyaryletherketone (PAEK), polyetheretherketone ketone (PEEKK), and polyether. Examples thereof include ketone ether ketone ketone (PEKEKK).

The thermoplastic resin may have two melting point peaks, for example, PA9T. A thermoplastic resin having two melting point peaks melts completely when the temperature becomes higher than the melting point peak on the high temperature side. The thermoplastic resin powder preferably contains at least one type of thermoplastic resin having a melting point of 100 ° C. or higher.

[Manufacturing method of resin particles]
The method for producing the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but a method of pulverizing or cutting the resin composition to a predetermined particle size or the like is preferable.

As a method of pulverizing the resin composition to a predetermined particle size, for example, a pellet-shaped resin composition containing a thermoplastic resin is pulverized by a pulverizer, and resin particles having a particle size other than the predetermined particle size are classified or filtered. Examples include a method of filtering. Further, when pulverizing by utilizing the vulnerability of the resin composition, the environmental temperature at the time of pulverization is preferably not less than the brittle temperature of the resin composition, preferably room temperature (25 ° C) or less, more preferably 0 ° C or less. -25 ° C or lower is more preferable, and -100 ° C or lower is particularly preferable. In the classification operation, for example, it is preferable to collect resin particles of 25 μm or more and 80 μm or less in order to improve the fluidity of the resin particles.

Examples of the method of cutting the resin composition to a predetermined particle size include a method of cutting the resin composition fiberized by extrusion molding so as to have a predetermined particle size.

Among these, a method of cutting the resin composition fiberized by extrusion molding so as to have a predetermined particle size is preferable. When the method for producing the resin particles is a method of cutting the resin composition fiberized by extrusion molding so as to have a predetermined particle size, the fiber diameter (area of the upper surface and the bottom surface) and the cut width (the height of the pillar) are used. It is advantageous in that the shape of the resin particles can be changed relatively easily depending on (corresponding).

-Crystalline control-
By controlling the crystal size and crystal orientation of the crystalline resin in the resin particles, for example, when modeling a three-dimensional model by the PBF method, a recoating process for forming a powder material layer in the modeling process under a high temperature environment is performed. The occurrence of errors can be reduced.
As a method for controlling the crystal size and crystal orientation, for example, a method using an external stimulus such as heat treatment, stretching treatment, sonication treatment, and external electric field application treatment; a method using a crystal nucleating agent; There is a method of slowly volatilizing the solvent to increase the crystallinity.

Examples of the heat treatment include an annealing treatment in which the resin composition is heated to a temperature equal to or higher than the glass transition temperature in order to enhance crystallinity.
Examples of the annealing treatment include a treatment in which the resin composition to which the crystal nucleating agent is added is kept warm at a temperature 50 ° C. higher than the glass transition temperature for 3 days, and then slowly cooled to room temperature (25 ° C.). ..

The stretching treatment is performed in order to increase the orientation of the resin by stretching the resin and enhance the crystallinity. The stretched resin is subjected to processing such as crushing and cutting to become resin particles.
The stretching treatment includes, for example, a treatment in which the resin is melted at a temperature higher than the melting point by 30 ° C. or more using an extruder and stirred while stretching the melt to a fibrous form by 1 to 10 times or less. Can be mentioned.
The maximum draw ratio in the stretching treatment is appropriately set according to the melt viscosity of the resin composition and the like. When an extruder is used, the number of nozzle openings is not particularly limited, but the larger the number, the higher the productivity.
The higher the stretching ratio, the better the crystal orientation. Therefore, 2.0 times or more is preferable, and 2.5 times or more is more preferable in that ideal crystal / orientation can be easily obtained. After the stretching treatment, an annealing step or a relaxing step may be added to prevent deformation of the fibers during heating.

Further, when the stretching process is performed, the shape of the resin particles is determined by the shape of the nozzle port of the extruder. For example, in order to obtain the resin particles of the cylindrical body, the shape of the nozzle mouth may be circular, and in order to obtain the shape of the resin particles of the polygonal prism, the shape of the nozzle mouth may be polygonal.

For ultrasonic treatment, for example, glycerin (reagent grade, manufactured by Tokyo Kasei Kogyo Co., Ltd.) solvent is added about 5 times to the resin particles, and then heated to a temperature 20 ° C. higher than the melting point of the resin, manufactured by Heelscher. , Ultrasonicator UP200S and other ultrasonic generators can be used to apply ultrasonic waves at 24 kHz and an amplitude of 60% for 2 hours. In this case, it is preferable to wash the resin particles with an isopropanol solvent and vacuum dry them at room temperature after the treatment of applying ultrasonic waves.

Examples of the external electric field application treatment include a treatment in which resin particles are heated at a glass transition temperature or higher, an AC electric field (500 Hz) of 600 V / cm is applied for 1 hour, and then the resin particles are slowly cooled.

As for the temperature range (temperature window) for the crystal phase change, that is, the difference between the melting start temperature during heating and the recrystallization temperature during cooling, a value larger than 3 ° C. is preferable in terms of preventing warpage of the modeled object. It is more preferable that the temperature is higher than ° C. in that a high-definition model can be formed. Further, when a three-dimensional model is formed by a laser by the PBF method, smoke generation due to laser irradiation can be suppressed by selecting a resin or other components having a decomposition temperature higher than the heating temperature by the laser.

The height of the cylindrical or polygonal columnar resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 200 μm or less, and when a three-dimensional model is formed by the PBF method. Is more preferably 30 μm or more and 200 μm or less in terms of matchability with the PBF method. When the height of the resin particles is in a preferable range, it is advantageous in that the strength of the molded product can be improved and the warpage of the molded product or the molded product can be suppressed.

When the resin particles are cylindrical, the ratio of the height to the diameter of the circular portion on the upper surface or the bottom surface of the resin particles is preferably 0.5 times or more and 2 times or less, and 1 time or more and 2 times or less is workability. It is more preferable in that respect. When the resin particles are polygonal prisms, the height ratio to the diameter of the smallest circle (minimum inclusion circle) that includes all the polygonal portions on the upper surface or bottom surface of the resin particles is 0.5. It is preferably more than twice and less than twice, more preferably in terms of workability.

<Heat-resistant antistatic agent>
The heat-resistant antistatic agent means a heat-resistant antistatic agent having a 5% mass reduction temperature of 150 ° C. or higher according to a measuring method based on ISO 7111-1987.
The thermoplastic resin powder preferably contains a heat-resistant antistatic agent in an amount of 0.01% by mass or more and 30.0% by mass or less, and preferably 0.1% by mass or more and 5.0% by mass or less.
By containing 0.01% by mass or more and 30.0% by mass or less of the heat-resistant antistatic agent, the thermoplastic resin powder has an excellent antistatic effect, can reduce the adhesion of the resin powder in the apparatus, and has a beautiful shaped surface. It is possible to model a three-dimensional model having the above.

The heat-resistant antistatic agent may be added internally or externally to the resin powder. In the case of internal addition, a heat-resistant antistatic agent is kneaded into the resin composition in the method for producing resin particles.
It has been confirmed that it is particularly effective for light thermoplastic resins such as polyethylene and polypropylene having a density of less than 1 g / cm ³ because the influence of electrostatic force as a force applied to the resin powder is relatively large. .. It has also been confirmed that the resin powder, which has no polarity on the surface and is hydrophobic, is particularly effective because the surface of the resin particles is easily charged and is easily affected by electrostatic force.
For example, in a PBF type three-dimensional modeling device, it is common to perform residual heat on the resin powder surface during modeling, and in such a high temperature and low humidity environment, antistatic action is given to have a surface active action. The effect of the agent becomes unstable. Therefore, an antistatic agent that directly lowers the resistivity of the resin is preferable. As the antistatic agent that directly lowers the resistivity of the resin, for example, an external agent may be used, and an external agent having a pair of charges that easily charges the resin may be added. With external additives, the antistatic effect is weakened due to the effect of the external additive falling off when molding is repeated, and the effect of burial due to the softening of the resin powder due to heat, leading to a decrease in recyclability. The agent is more preferable. Further, the internal additive for the purpose of lowering the resistivity of the resin preferably has an antistatic effect by adding a small amount. This is because as the addition ratio of the internal additive increases, the original physical properties of the resin are impaired, which leads to a decrease in strength such as tensile strength.

In the present invention, in order to improve the antistatic effect, TG / DTA is used as a measurement method based on ISO 7111-1987, the temperature is raised at 10 ° C./min, and the 5% by mass reduction temperature is 150 ° C. or higher. A heat resistant antistatic agent is preferably used.
Such heat-resistant antistatic agents are used for the purpose of leaking the surface potential so that electric charges do not accumulate, but in general coating types such as surfactants and kneading types, they are three-dimensionally placed at high temperatures. Volatilizes during modeling, and the antistatic effect at high temperatures is reduced.
Examples of the heat-resistant antistatic agent include carbon black, ketchon black, carbon nanotubes, polypyrrole, polythiophene, cationic surfactants, anionic surfactants, amphoteric ionic surfactants, and nonionic surfactants.
As the heat-resistant antistatic agent, for example, a conductive compound (CA6141 grade), which is a registered trademark of CABELEC, may be used.

Further, for the purpose of long-term use, a high molecular weight antistatic agent is more preferable than a low molecular weight antistatic agent. Examples of the polymer antistatic agent include polyethylene oxide, polyacrylic acid salt, quaternary ammonium salt copolymer, and the like. Chemical names include glycerin monofatty acid ester, fatty acid diethanolamide, alkyldiethanolamine, and alkylsulfonic acid. Examples thereof include salts, alkylbenzene sulfonates, alkyltrimethylammonium salts, alkylbenzyldimethylammonium salts, alkylbetaines, alkylimidazolium betaines, and boronamine amphoteric ion polyethylene polymers.
Examples of the polymer antistatic agent include a heat-resistant antistatic agent having a special structure such as AS113 and AS310E manufactured by ADEKA Co., Ltd., and Biomicelle BN105 manufactured by Boron Research Institute Co., Ltd. from the viewpoint of stability.
The heat-resistant antistatic agent may be an inorganic substance, and examples thereof include carbon black, graphene, carbon nanotubes; and metal oxide fine particles such as zinc oxide and titanium oxide.

The heat-resistant antioxidant is a semi-polar organic compound having one atomic group represented by the following structural formula (1) and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. From a composition containing one or more of the basic organic compounds having one or more basic nitrogen atomic groups and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. A donor-acceptor hybrid antistatic agent is preferable from the viewpoint of antistatic effect.

A semi-polar organic compound having at least one atomic group represented by the above structural formula (1) and one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule has the following structural formula (2). ) To (8) and the like.

The basic organic compounds having one basic nitrogen atomic group and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule are represented by the following structural formulas (9) to (18). Things and so on.

<Other ingredients>
The other components in the resin powder are not particularly limited and may be appropriately selected depending on the intended purpose. For example, addition of a deterioration inhibitor, a fluidizing agent, a strengthening agent, a flame retardant, a plasticizer, a crystal nucleating agent and the like. Examples include agents and non-crystalline resins. These may be used alone or in combination of two or more. Further, other components may be mixed with each resin particle and used, or may be used by coating the surface of each resin particle.

<< Deterioration inhibitor >>
The thermoplastic resin powder may contain a deterioration inhibitor in order to maintain the thermal stability of the molecule and suppress resin deterioration such as cross-linking or decomposition.
Examples of the deterioration inhibitor include a metal chelating material, an ultraviolet absorber, a polymerization inhibitor, an antioxidant and the like. The powdered antioxidant used as an antioxidant can be mixed uniformly without making a masterbatch of the antioxidant by coating the resin pellets with an oily component such as a lubricant and then mixing them. it can.

Examples of the metal chelating material include hydrazide-based, phosphate-based, and phosphite-based compounds.
Examples of the ultraviolet absorber include triazine-based compounds and the like.
Examples of the polymerization inhibitor include copper acetate and the like.
Examples of the antioxidant include hindered phenol-based, phosphorus-based and sulfur-based compounds.

Examples of the hindered phenol-based antioxidant include various additives such as radical scavengers.
Examples of the hindered phenol-based antioxidant include α-tocopherol, butylhydroxytoluene, cinapyl alcohol, vitamin E, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and the like. 2-tert-Butyl-6- (3'-tert-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 2,6-di-tert-butyl-4- (N, N) -Dimethylaminomethyl) phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis ( 4-Ethyl-6-tert-butylphenol), 4,4'-methylenebis (2,6-di-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-cyclohexylphenol), 2,2' -Dimethylene-bis (6-α-methyl-benzyl-p-cresol), 2,2'-ethylidene-bis (4,6-di-tert-butylphenol), 2,2'-butylidene-bis (4-methyl) -6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), triethylene glycol-N-bis-3- (3-tert-butyl-4-hydroxy-5-methyl) Phenyl) propionate, 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl 6- (3-) tert-Butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1, 1,-Dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 4,4'-thiobis (6-tert-butyl-m-cresol), 4,4'-thiobis ( 3-Methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-6-tert-butylphenol), bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4, 4'-di-thiobis (2,6-di-tert-butylphenol), 4,4'-tri-thiobis (2,6-di-tert-butylpheno) , 2,2-thiodiethylenebis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-) Hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, N, N'-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N , N'-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) ) Butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-) Hydroxyphenyl) isocyanurate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) ) Isocyanurate, 1,3,5-tris2 [3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanurate, tetrakis [methylene-3- (3,5-di-) tert-Butyl-4-hydroxyphenyl) propionate] methane, triethylene glycol-N-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, triethylene glycol-N-bis-3 -(3-tert-Butyl-4-hydroxy-5-methylphenyl) acetate, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) acetyloxy}- 1,1-Dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, tetrakis [methylene-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] Methane, 1,3,5-trimethyl-2,4,6-tris (3-tert-butyl-4-hydroxy-5-methylbenzyl) benzene, tris (3-tert-butyl-4-hydroxy-5-methyl) Benzyl) isocyanurate, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5) − Methylphenyl Le) Propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, tetrakis [methylene-3- (3', 5'-di-t-butyl) -4'-Hydroxyphenyl) propionate] Methane, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) -2,4,6-trimethylbenzene and the like. These may be used alone or in combination of two or more.
Among these, tetrakis [methylene-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] methane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetra Oxaspiro [5,5] undecane and tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane are preferred in terms of high temperature stability.

Examples of phosphorus-based antioxidants include phosphorous acid, phosphoric acid, phosphonic acid, phosphonic acid; these esters such as phosphite compounds, phosphate compounds, phosphonite compounds, and phosphonate compounds; tertiary phosphine and the like. Be done. These may be used alone or in combination of two or more.

Examples of the phosphite compound include triphenylphosphite, tris (nonylphenyl) phosphite, tridecylphosphite, trioctylphosphite, trioctadecylphosphite, didecylmonophenylphosphite, dioctylmonophenylphosphite, and diisopropyl. Monophenylphosphite, monobutyldiphenylphosphite, monodecyldiphenylphosphite, monooctyldiphenylphosphite, tris (diethylphenyl) phosphite, tris (di-iso-propylphenyl) phosphite, tris (di-n-butyl) Phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, distearylpentaerythritol diphosphite, bis (2,4) -Di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4) -Ethylphenyl) pentaerythritol diphosphite, bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, bis (nonylphenyl) penta Examples thereof include erythritol diphosphite and dicyclohexylpentaerythritol diphosphite. These may be used alone or in combination of two or more.
Among these, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol Diphosphite and bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite are preferred in terms of high temperature stability.

Commercially available products may be used as these phosphite compounds.
Examples of commercially available products of distearyl pentaerythritol diphosphite include ADEKA STAB PEP-8 (registered trademark, manufactured by ADEKA Corporation) and JPP681S (registered trademark, manufactured by Johoku Chemical Industry Co., Ltd.).
Commercially available products of bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite include, for example, Adecastab PEP-24G (registered trademark, manufactured by ADEKA Co., Ltd.) and Alkanox P-24 (registered trademark, Great Lakes). , Ultranox P626 (registered trademark, manufactured by GE Specialty Chemicals), Doverphos S-9432 (registered trademark, manufactured by Dover Chemicals), Irgaofos126, 126FF (registered trademark, manufactured by CIBA SPECIAL), etc.
Examples of commercially available products of bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite include ADEKA STAB PEP-36 (registered trademark, manufactured by ADEKA Corporation).
As commercially available products of bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite, for example, ADEKA STAB PEP-45 (registered trademark, manufactured by ADEKA Corporation), Doverphos S-9228 (Registered trademark, manufactured by Dover Chemical Co., Ltd.) and the like.

Examples of other phosphite compounds include compounds that react with divalent phenols and have a cyclic structure.
Examples of the compound that reacts with divalent phenols and has a cyclic structure include 2,2'-methylenebis (4,6-di-tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite. , 2,2'-Methylenebis (4,6-di-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2-Methylenebis (4,6-di-tert-butylphenyl) ) Octylphosphite and the like.

Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresil phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate and dioctyl. Examples include phosphate, octadecyl phosphate, diisopropyl phosphate and the like. These may be used alone or in combination of two or more.
Among these, triphenyl phosphate, octadecyl phosphate, and trimethyl phosphate are preferable from the viewpoint of high temperature stability.

Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite and tetrakis (2,4-di-tert-butylphenyl) -4,3'-. Biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylenedi Phenylonite, tetrakis (2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite , Bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, Bis (2,4-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, Bis (2,6) −Di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,6-di-tert-butyl) Phenyl) -3-phenyl-phenylphosphonite and the like. These may be used alone or in combination of two or more.
Among these, tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite, bis (di-tert-butylphenyl) -phenyl-phenylphosphonite, tetrakis (2,4-di-tert-butylphenyl) -bipheni Range phosphonite and bis (2,4-di-tert-butylphenyl) -phenyl-phenylphosphonite are preferable because they can be used in combination with a phosphite compound.

Examples of the phosphonate compound include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate.

Examples of the tertiary phosphine include triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, and try-p. -Trilphosphine, trinaphthylphosphine, diphenylbenzylphosphine and the like. These may be used alone or in combination of two or more. Among these, triphenylphosphine is preferable from the viewpoint of long-term stability at high temperatures.

When two or more kinds of deterioration inhibitors are used in combination, there are some combinations in which a more remarkable effect can be obtained. For example, by using a hindered phenol-based and phosphorus-based antioxidant in combination as a deterioration inhibitor, there is an effect of complementarily improving the stability, so that an effect of improving long-term thermal stability can be obtained.

The content of the deterioration inhibitor is preferably 0.01% by mass or more and 10% by mass or less, and 0.05% by mass or more and 5% by mass or less, based on the total amount of the resin powder, in order to prevent deterioration for a long time. More preferably, it is 0.1% by mass or more and 0.4% by mass or less. The preferable range of the content of each deterioration inhibitor when two or more kinds of deterioration inhibitors are used in combination is the same as the above range. If the content of the deterioration inhibitor is within a preferable range, the effect of preventing thermal deterioration of the resin powder can be sufficiently obtained, the physical properties of the modeled object when the resin powder used for modeling is recycled are improved, and the resin powder is used. It also has the effect of preventing discoloration due to heat. Furthermore, since the stability of the polymer type antistatic agent can be further increased, it is more preferable to use the polymer antistatic agent together.

<< Fluidizer >>
The fluidizing agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include spherical particles made of an inorganic material.
The volume average particle diameter of the spherical particles made of an inorganic material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably less than 10 μm.
The content of the fluidizing agent may be an amount sufficient to cover the surface of the particles, and is not particularly limited and may be appropriately selected depending on the intended purpose. However, the content of the fluidizing agent is 0. It is preferably 1% by mass or more and 10% by mass or less.

Examples of the inorganic material in the spherical particles include silica, alumina, titania, zinc oxide, magnesium oxide, tin oxide, iron oxide, copper oxide, hydrated silica, silica whose surface is modified with a silane coupling agent, and magnesium silicate. And so on. Among these, silica, titania, hydrated silica, and silica whose surface has been modified with a silane coupling agent are preferable in terms of the effect of improving fluidity, and silica whose surface has been modified to be hydrophobic with a silane coupling agent. Is more preferable in terms of cost.

<< Strengthening agent >>
Examples of the reinforcing agent include inorganic fiber fillers, bead fillers, glass fillers described in Pamphlet No. 2008/05/7844, glass beads, carbon fibers, aluminum balls, and the like from the viewpoint of improving strength. These may be used alone or in combination of two or more.

The inorganic fiber filler is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include carbon fiber, inorganic glass fiber and metal fiber.

The bead filler is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include carbon beads, inorganic glass beads and metal beads.

Since the thermal conductivity of the inorganic fiber filler and the bead filler is higher than that of the resin powder, when the surface of the resin powder is irradiated with a laser in SLS (Selective Laser Sintering) and LS modeling, the heat of the irradiated part is irradiated by the laser. It spreads to the outside. Therefore, when a fiber filler or a bead filler is mixed with a resin powder having no sharp melt property, the resin powder outside the laser irradiation part is heated by thermal diffusion and excessively melted, so that the molding accuracy is improved. It gets lower. However, when a fiber filler or a bead filler is mixed with a resin powder containing a crystalline thermoplastic resin and having a sharp melt property, the resin powder outside the laser irradiation part melts even if it is heated by heat diffusion. Since it becomes difficult, high molding accuracy can be maintained.

The average fiber diameter of the inorganic fiber filler is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 μm or more and 30 μm or less.
The average fiber length of the inorganic fiber filler is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 30 μm or more and 500 μm or less.
When the average fiber diameter and the average fiber length of the inorganic fiber filler are in the preferable ranges, it is advantageous in that the strength of the modeled object can be improved and the surface roughness of the modeled object not containing the fiber filler can be made comparable. is there.

The content of the inorganic fiber filler is preferably 5% by mass or more and 60% by mass or less with respect to the total amount of the resin powder. When the content of the inorganic fiber filler is 5% by mass or more, the strength of the modeled object is improved, and when it is 60% by mass or less, the formability is improved.

The circularity of the bead filler is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.8 or more and 1.0 or less.
The circularity is obtained by the following equation, circularity = 4πS / L ² , where S is the area (the number of pixels indicating the bead filler when the bead filler is imaged) and L is the peripheral length.

The volume average particle diameter of the bead filler is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 μm or more and 200 μm or less.
The volume average particle size can be measured using, for example, a particle size distribution measuring device (microtrac MT3300EXII manufactured by Microtrac Bell Co., Ltd.).

The content of the bead filler is preferably 5% by mass or more and 60% by mass or less with respect to the total amount of the resin powder. When the content is 5% by mass or more, the strength of the modeled object is improved, and when it is 60% by mass or less, the formability is improved.

<< Flame Retardant >>
Examples of the flame retardant include various flame retardants such as halogen-based, phosphorus-based, inorganic hydrated metal compound-based, nitrogen-based, and silicone-based. Various flame retardants for construction, vehicles, or ship mounting may be used in the resin powder. When two or more kinds of flame retardants are used in combination, the flame retardant performance is improved by combining the halogen type and the inorganic hydrated metal compound type.

Further, the resin powder may contain a fibrous substance such as glass fiber, carbon fiber or aramid fiber; or an inorganic strengthening agent such as an inorganic layered silicate such as talc, mica or montmorillonite. According to such an embodiment, both physical property enhancement and flame retardancy enhancement can be achieved at the same time.

The flame retardancy of the resin powder can be evaluated by, for example, JIS K6911, JIS L1091 (ISO6925), JIS C3005, heat generation test (cone calorimeter) and the like.

The content of the flame retardant is preferably 1% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 30% by mass or less, based on the total amount of the resin powder. When the content of the flame retardant is 1% by mass or more, sufficient flame retardancy can be obtained. When the content of the flame retardant is 50% by mass or less, the change in the melt-solidification characteristics of the resin powder is suppressed, and the deterioration of the molding accuracy and the deterioration of the physical properties of the modeled object can be prevented.

The thermoplastic resin powder is preferably dried to such an extent that it does not affect the molding. Therefore, resin particles dried with a vacuum dryer or silica gel may be used for modeling.

<Characteristics of thermoplastic resin powder>
− Density −
The density of the thermoplastic resin powder is preferably 0.8 g / cm ³ or more and 1.4 g / cm ³ or less, and from the viewpoint of the effect of the antistatic agent, 0.8 g / cm ³ or more and 1.0 g / cm. ³ or less is more preferable. When the density of the thermoplastic resin powder is 0.8 g / cm ³ or more, it is possible to suppress the secondary agglutination of the particles in the recoating process for forming the powder material layer at the time of modeling. On the other hand, in applications such as metal substitution, the density of the thermoplastic resin powder is preferably 1.4 g / cm ³ or less from the viewpoint of weight reduction.
The density of the thermoplastic resin powder is obtained by measuring the true density. The true density is determined by, for example, changing the volume and pressure of a gas (He gas) at a constant temperature using a dry automatic density meter (Accupic 1330, manufactured by Shimadzu Corporation) using a gas phase replacement method to obtain a sample volume. And the mass of this sample can be measured to calculate the density.

-50% cumulative volume particle size D _50-
The 50% cumulative volume particle size D ₅₀ of the thermoplastic resin powder is preferably 5 μm or more and 200 μm or less, and more preferably 5 μm or more and 50 μm or less from the viewpoint of dimensional stability. The ratio (Mv / Mn) obtained by dividing the volume average particle size (Mv) of the resin powder by the number average particle size (Mn) is preferably 2.00 or less, preferably 1.50 or less, in terms of improving molding accuracy. More preferably, 1.20 or less is further preferable.
The 50% cumulative volume particle size and Mv / Mn can be measured using, for example, a particle size distribution measuring device (microtrac MT3300EXII manufactured by Microtrac Bell Co., Ltd.).

− Resistivity −
The thermoplastic resin powder has a room temperature of 25 ° C., a relative humidity of 65% to 67%, and an applied voltage of 250 V. By controlling the surface resistivity of the resin powder in the range of 1 × 10 ⁵ Ω or more and 1 × 10 ¹⁴ Ω or less. , The antistatic effect can be imparted, the soaring and adhesion of the resin powder can be significantly improved, and molding defects can be suppressed.
By lowering the surface resistance of the thermoplastic resin powder, it is possible to suppress the accumulation of electric charges generated due to friction between particles and between particle devices due to the movement of particles when powdered and applied to three-dimensional modeling. It is possible to obtain the effect of making it difficult for the powder to fly up due to the repulsion caused by the electrostatic force between the particles and to adhere to the metal part which is a conductor.
The surface resistivity of the thermoplastic resin powder is preferably controlled in the range of 1 × 10 ⁵ Ω or more and 1 × 10 ¹⁴ Ω or less, and the volume resistivity is 1 × 10 ⁵ Ω · cm or more 1 × 10 ¹⁵ Ω ·. It is preferably in the range of cm or less.
Further, it is more preferable that the surface resistivity is controlled in the range of 1 × 10 ⁵ Ω or more and 1 × 10 ¹³ Ω or less because the amount of adhesion is greatly reduced. However, since the resistance is deteriorated repulsion weakens fluidity between particles due to the electrostatic force between too low a particle, it is preferable that the surface resistivity is 1 × 10 ⁵ Ω or more.

The surface resistivity and volume resistivity of the thermoplastic resin powder are, for example, a resistance cell for high resistance (manufactured by Agilent Technologies, Agilent 16008B Bias RESISTIVELY CELL) as an electrode, and a high resistance meter (manufactured by Agilent Technologies) as a measuring device. It can be measured and discriminated by using an Agilent 4339B high resistivity meter).

The high-temperature resistivity was measured by the above device after being vacuum-heated at 150 ° C. and left for about 30 minutes.
The high temperature resistivity is preferably 1 × 10 ⁵ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less.

-Recyclability-
By using the thermoplastic resin powder, it is excellent in recyclability, and even if the surplus powder is repeatedly used, modeling can be performed without impairing the antistatic effect.
In order to prevent the resin powder from being charged, it is effective to add fine particles of material having the opposite polarity to the resin. However, the external fine particles are rubbed between the powder and the device or between the powders through the molding process. As a result, the antistatic effect is impaired due to the effect of falling off and the effect of burial due to the softening of the resin powder due to heat, and repeated modeling causes a decrease in recyclability.

Since the thermoplastic resin powder of the present invention is kneaded into the resin, it does not fall off or is buried due to repeated molding, and high recyclability is maintained.
As a method for confirming recyclability, it is effective to repeat the test of returning the unsintered and unmelted components of the resin powder used for modeling to the supply floor and performing the same modeling.
As the recycled powder used in the present invention, it is possible to suppress adhesion to metal parts even after the recycled powder has been tested at least once in a PBF type modeling machine (manufactured by Ricoh Co., Ltd., AMS5500P). It is possible that the resin powder adhered to the moving parts such as the recoater grows large, and eventually falls on the flatly formed powder surface, and the phenomenon of hindering the modeling is not observed.
When the large-grown powder mass falls on the powder surface, when laser irradiation or ink ejection is performed on that area, a locally raised model is formed and contacts the recorder when the powder surface of the next layer is formed. This causes a phenomenon in which the modeled object is displaced, or a phenomenon in which powder lumps are fused with the modeled object and unintended protrusions are formed on the surface layer of the modeled object.

<Use>
The thermoplastic resin powder of the present invention has an appropriate balance in parameters such as particle size, particle size distribution, heat transfer characteristics, melt viscosity, bulk density, fluidity, melt temperature, and recrystallization temperature, and has an SLS method, SMS. It is preferably used in various three-dimensional modeling methods using resin powder such as (Selective Mask Sintering) method, MJF (Multi Jet Fusion) method, HSS (High speed sintering) method, or BJ (Binder Jetting) method.
The thermoplastic resin powder of the present invention is suitably used in surface shrinkage agents, spacers, lubricants, paints, grindstones, additives, secondary battery separators, foods, cosmetics, clothes and the like. In addition, it may be used as a material or a metal substitute material used in fields such as automobiles, precision equipment, semiconductors, aerospace, and medical treatment. Among these uses, resin powder for three-dimensional modeling, which forms various articles in three dimensions, is particularly preferable.

(Resin powder for 3D modeling)
The resin powder for three-dimensional modeling of the present invention contains 0.01% by mass or more and 30.0% by mass or less of a heat-resistant antistatic agent.
The surface charging potential measured by the triboelectric charging method under the following conditions is ± 100V or less.
[Conditions] The stainless steel (SUS) recorder is rotated at 500 m / min for 10 minutes at the melting point of the thermoplastic resin powder at −10 ° C. to supply the thermoplastic resin powder from the supply tank to the modeling tank, and then 100 ° C. Measure the surface charge potential of the powder layer surface of the molding tank in.
The surface charging potential measured by the triboelectric charging method under the above conditions is ± 100V or less, preferably ± 40V or less, and more preferably ± 100V or less.
When the surface charging potential measured by the triboelectric charging method under the above conditions is ± 100V or less, the strength of the modeled object does not decrease, the amount of the additive added is reduced as much as possible, and an excellent effect of preventing recoat adhesion is obtained. Be done.

The three-dimensional model formed by laser sintering using the resin powder for three-dimensional modeling of the present invention has few internal defects, and stable strength and appearance of the model can be obtained. In addition to laser sintering, powder may be used for film processing, and even if it is difficult to make a general film, the powder can be drawn, so that a film can be obtained.

The resin powder for three-dimensional modeling of the present invention has excellent long-term recyclability. By using the new resin powder and the recycled powder of the present embodiment for modeling by the PBF method, the MJF, the HSS method, or the like, a stable model can be produced. With conventional powders, even if the adhesion due to recoating was low at the initial stage, adhesion occurred due to repeated specifications, and the modeling surface was not uniform, resulting in a decrease in the strength of the modeled object. However, in the three-dimensional modeling using the resin powder for three-dimensional modeling of the present invention, adhesion to the recoat can be suppressed not only at the initial stage but also continuously.

The recycled powder is, for example, a resin powder that was not used for modeling when it was modeled for 50 hours using an SLS-type modeling device (AMS5500P, manufactured by Ricoh Co., Ltd.). Even if 30% by mass of a new resin powder is added to the recycled powder and the molding for 50 hours is repeated twice more, a three-dimensional object having no molding defects can be obtained without showing an increase in the amount of adhesion to the recoat. The evaluation can be performed using an ISO (International Organization for Standardization) 3167 Type1A 150 mm long multipurpose dog bone-like test specimen formed of resin powder.

(Manufacturing method of three-dimensional model and equipment for manufacturing three-dimensional model)
The method for producing a three-dimensional model of the present invention includes a step of forming a powder material layer made of resin powder and a step of melting the powder material layer, and these steps are repeated to form the three-dimensional model.
The three-dimensional model manufacturing apparatus of the present invention includes a powder material layer forming means for forming a powder material layer made of resin powder, and a melting means for melting the powder material layer, and if necessary, other means. Have means.

<Powder material layer forming step and powder material layer forming means>
The powder material layer forming step is a step of forming a powder material layer made of resin powder, and is carried out by a powder material layer forming means.

The powder material layer is preferably formed on the support.
The support is not particularly limited as long as the resin powder can be placed on it, and can be appropriately selected depending on the intended purpose. A table having a surface on which the resin powder is placed, JP-A-2000-328106. Examples thereof include a base plate in the apparatus shown in FIG.
The surface of the support, that is, the mounting surface on which the resin powder is placed, may be, for example, a smooth surface, a rough surface, or a flat surface. It may be a curved surface, but when the organic material in the resin powder is heated and melted and cooled and solidified, it is easy to remove the obtained three-dimensional model from the above-mentioned mounting surface if the thermal expansion coefficient is different. It is preferable in that it is.

The method of arranging the resin powder on the support is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of arranging the resin powder in a thin layer is described in Japanese Patent No. 3607300. A method using a known counter rotation mechanism (counter roller) or the like used in the selective laser sintering method of the above, a method of spreading the resin powder into a thin layer using members such as a brush, a roller, and a blade, and a method of spreading the resin powder into a thin layer. A method of pressing the surface with a pressing member to spread it into a thin layer, a method of using a known powder laminating device, and the like are preferable.

In order to place the resin powder on the support in a thin layer by using the counter rotation mechanism (counter roller), the brush or blade, the pressing member, or the like, for example, the following can be performed. it can.
That is, the support arranged in the outer frame (sometimes referred to as "mold", "hollow cylinder", "cylindrical structure", etc.) so as to be able to move up and down while sliding on the inner wall of the outer frame. The resin powder is placed on the body using the counter rotation mechanism (counter roller), the brush, the roller or blade, the pressing member, and the like. At this time, when a support that can move up and down in the outer frame is used, the support is arranged at a position slightly lower than the upper end opening of the outer frame, that is, the resin powder. The resin powder is placed on the support so as to be positioned below by the thickness of the layer. As described above, the resin powder can be placed on the support in a thin layer.
The thickness of the powder material layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the average thickness per layer is preferably 1 μm or more and 500 μm or less, and more preferably 10 μm or more and 200 μm or less.

<Melting process and melting means>
The step of melting the powder material layer can be appropriately changed, and examples thereof include a method of electromagnetic irradiation and a method of using an inhibitor or an absorbent. Among these, electromagnetic irradiation is preferable, and it is more preferable to selectively perform electromagnetic irradiation.

The electromagnetic irradiation can be changed as appropriate, and examples thereof include a laser light source, an infrared irradiation source, a microwave generator, a radiant heater, and an LED lamp. These may be combined. When a laser light source is used, the laser may be selectively and directly irradiated, or the laser may be irradiated flatly using a mask. Among these, it is preferable to selectively irradiate the laser directly.

When a mask is used, the selective mask sintering (SMS) technique can be used to produce the three-dimensional model of the present embodiment. The SMS process is described, for example, in US Pat. No. 6,531,086. In the SMS process, a shielding mask is used to selectively block infrared radiation and a portion of the powder material layer is selectively irradiated.

As described above, the powder material layer is melted to form the sintered layer, and the thickness of the sintered layer can be appropriately changed by the modeling process. The plurality of sintered layers are preferably 10 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more per layer on average.

<Other processes and other means>
Examples of other steps include a sintering step and a control step.
Examples of other means include sintering means, control means, and the like.

Here, with reference to FIG. 3, a three-dimensional model manufacturing apparatus for modeling using resin powder will be described.

The three-dimensional model manufacturing apparatus 1 shown in FIG. 3 includes a supply tank 11, a roller 12, a laser scanning space 13, an electromagnetic irradiation source 18, a reflector 19, and heaters 11H and 13H.
The supply tank 11 stores the resin powder P as a modeling material, and is an example of the storage means.
The roller 12 supplies the resin powder P contained in the supply tank 11 to the laser scanning space 13, and is an example of the supply means. The roller 12 is made of, for example, stainless steel (SUS) or the like.
The laser scanning space 13 is a space in which the laser L as an electromagnetic ray is scanned. The rollers 12 form a powder material layer having a predetermined thickness.
The electromagnetic irradiation source 18 irradiates the laser L.
The reflecting mirror 19 reflects the laser L irradiated by the electromagnetic irradiation source 18 to a predetermined position in the laser scanning space 13. The electromagnetic irradiation source 18 and the reflecting mirror are examples of laser irradiation means. The reflecting surface of the reflecting mirror 19 moves based on the 3D data while the electromagnetic irradiation source 18 is irradiating the laser L.
The 3D data shows each cross-sectional shape when the 3D model is sliced at predetermined intervals. As a result, the reflection angle of the laser L changes, so that the predetermined layer represented by the 3D data in the laser scanning space 13 is selectively irradiated with the laser L. When the laser L is irradiated, the resin powder at the irradiation position is melted and sintered to form a modeling layer. That is, the electromagnetic irradiation source 18 functions as a layer forming means for forming each layer of the modeled object from the resin powder P. Further, the heaters 11H and 13H may heat the resin powder P housed in the supply tank 11 and the laser scanning space 13, respectively.
Further, pistons 11P and 13P are provided in the supply tank 11 and the laser scanning space 13 of the three-dimensional object manufacturing apparatus 1. When the formation of the layer is completed, the pistons 11P and 13P move the supply tank 11 and the laser scanning space 13 upward or downward with respect to the stacking direction of the modeled object. This makes it possible to supply the new resin powder P used for forming the new layer from the supply tank 11 to the laser scanning space 13.

The three-dimensional model manufacturing apparatus 1 may selectively melt the resin powder P by changing the laser irradiation position with the reflecting mirror 19. In addition, the resin powder of the present invention can be applied to various modeling devices such as a selective mask sintering (SMS: Selective Mask Sintering) method and a high speed sintering (HSS: High Speed Sintering) method. In the SMS method, for example, a part of the resin powder is masked with a shielding mask, the unmasked part is irradiated with electromagnetic rays, and the unmasked part is irradiated with electromagnetic rays such as infrared rays, and the resin powder is selectively melted for modeling. To do.
When the SMS method is used, it is preferable that the resin powder P contains at least one kind of a heat absorber that enhances infrared absorption characteristics, a dark-colored substance, or the like.
As the heat absorber or dark-colored substance, it is preferable to use carbon fiber, carbon black, carbon nanotube, cellulose nanofiber, or the like. In the HSS method, a modeling solution containing a radiant energy absorber is discharged into a modeling region on the powder material layer, and radiant energy is applied to fuse the powders containing the resin particles together.

FIG. 4 is a flowchart for explaining an example of the operation of the three-dimensional model manufacturing apparatus. Hereinafter, the three-dimensional modeling of the three-dimensional model manufacturing apparatus 1 will be described with reference to FIG.
In step S1, the modeling material is supplied (supply step). Specifically, as a modeling material, the resin powder P in the supply tank 5 is supplied to the laser scanning space 13 and flattened by driving the rollers 12. As a result, a powder material layer having a thickness T of one layer is formed.
Next, in step S2, the modeling material is irradiated with a laser (laser irradiation step). Based on the data of a predetermined layer of the modeling data, the electromagnetic irradiation source 18 is irradiated with the laser while moving the reflecting surface of the reflecting mirror 19. By irradiating the laser, the resin powder P at the position corresponding to the pixel indicated by the data of the predetermined layer in the powder material layer is melted. The resin melted by the irradiation of the laser is cured to form one modeling layer.
Next, in step S3, the three-dimensional model manufacturing apparatus 1 determines whether or not all the layers have been modeled. The modeling data includes data of a plurality of layers, and it is determined whether the data of all layers has completed modeling. When all is finished, the modeling is finished. If the modeling is not completed, the supply tank 11 and the laser scanning space 13 are moved upward or downward with respect to the stacking direction of the modeled objects.
Then, the process returns to step S1. By repeating the supply step (step S1) and the irradiation step (step S2), the modeling layers are laminated to form a three-dimensional modeled object. The resin powder P housed in the supply tank 11 and the laser scanning space 13 in steps S1 and S2, respectively, may be heated by the heaters 11H and 13H, respectively.

(Three-dimensional model)
The three-dimensional model formed by the thermoplastic resin powder of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a prototype of an electronic device part or an automobile part, or a prototype for a strength test. , Aerospace, or small quantities of products used in dress-up tools for the automobile industry. The PBF method is expected to have superior strength as compared with other methods such as the FFF (Fused Fused Fabrication) method and the inkjet method, and therefore can be used as a practical product.
The production speed is not comparable to mass production such as injection molding, but for example, the required production volume can be obtained by mass-producing small parts in a flat shape. Further, since the method for manufacturing a three-dimensional model in the PBF method used in the present invention does not require a mold unlike injection molding, overwhelming cost reduction and delivery time reduction are achieved in trial production and prototype production. be able to.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1)
Polypropylene (PP) resin (trade name: Prime Polypro J704UG, manufactured by Prime Polymer Co., Ltd., melting point: 160 ° C.) 99 parts by mass, Biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent, PP of the same grade 1 part by mass of a masterbatch added 10 times in 1 was used. After mixing them uniformly, they are added and put into a twin-screw extruder (device name: 2D25S, manufactured by Toyo Seiki Seisakusho Co., Ltd.). A 50 μm resin fiber was formed. Then, the formed resin fibers were cut into a size to achieve the desired particle size using an automatic cutting machine (device name: NZI-0606, manufactured by Ogino Seiki Seisakusho Co., Ltd.).
In Example 1, a resin powder was obtained by cutting into a cylinder having a height of 55 μm so that the 50% cumulative volume particle size (D ₅₀ ) was 80 μm. In the following examples, when the target value is 50% cumulative volume grain size (D ₅₀ ), the cut width, that is, the height of the cylinder is divided by the diagonal line √2. ..

Next, in order to melt the surface of the obtained resin powder by mechanical friction, a thermoplastic resin powder was treated for 20 minutes at a rotation speed of 1,000 rpm using a Q mixer (Mechanohybrid MH type, manufactured by Nippon Coke Co., Ltd.). Got
Various characteristics of the obtained thermoplastic resin powder were evaluated as follows. The results are shown in Table 1-1 and Table 1-2.

<Measurement of melting point of thermoplastic resin powder>
The melting point of the obtained thermoplastic resin powder was measured using a differential scanning calorimetry device (DSC-60A, manufactured by Shimadzu Corporation) in accordance with ISO 3146. Specifically, DSC measurement of the resin particles was performed with the temperature rise temperature gradient set to 10 ° C./min, and the temperature at the apex of the obtained endothermic peak or the temperature at the apex of the melting point peak was defined as the melting point. When the resin particles have a plurality of melting points, the melting point on the high temperature side is used.

<Density measurement of thermoplastic resin powder>
For the true density of the thermoplastic resin powder, determine the volume of the sample containing the resin powder in advance, and use a dry automatic density meter (device name: Accupic 1330, manufactured by Shimadzu Corporation) using the gas phase replacement method. The volume and pressure of the gas (He gas) were changed at a constant temperature, the mass was measured from the volume of the sample, and the density of the sample was measured.

<Shape of thermoplastic resin powder, diameter of bottom surface x height>
The shape of the resin particles of the obtained thermoplastic resin powder was observed with a scanning electron microscope (device name: JSM-7800FPRIME, manufactured by JEOL Ltd.). Further, in the case of a polygonal prism or a cylindrical shape, the diameter or diagonal length and height of the bottom surface were measured.

<50% cumulative volume particle size (D ₅₀ ), ratio (Mv / Mn)>
The 50% cumulative volume particle size (D ₅₀ ) of the thermoplastic resin powder was measured using a particle size distribution measuring device (microtrac MT3300EXII manufactured by Microtrac Bell Co., Ltd.). In addition, the volume average particle size Mv and the number average particle size Mn were measured using the same particle size distribution measuring device, and the ratio (Mv / Mn) was calculated.

<Pyrolysis measurement>
The Tg-DTA measurement was carried out according to ISO 7111-1987 using a differential thermal balance (Thermo plus EVO TG-DTA, manufactured by Rigaku Co., Ltd.) in a nitrogen atmosphere. The temperature at which the mass was reduced by 5% was measured as the 5% mass reduction temperature (Td5).
Further, using the differential thermal balance, the mass loss rate after 4 hours at −10 ° C. from the melting point of the thermoplastic resin powder was determined.

<Triboelectric charging method>
(1) Room temperature (25 ° C): Using an SLS type modeling device (AM S5500P manufactured by Ricoh Co., Ltd.), set the temperature of the supply tank and the modeling tank to room temperature (25 ° C), and set the stainless steel recorder at 500 m / min. After rotating and setting the lamination pitch to 100 μm, the thermoplastic resin powder was supplied from the supply tank to the modeling tank for 10 minutes. Then, using a surface electrometer (model 344, manufactured by Trek Japan Co., Ltd.), the surface potential was measured 2 mm above the surface of the powder layer in the modeling tank, and evaluated according to the following criteria.
(2) High temperature (100 ° C.): The same method as in (1) above, except that the temperature of the modeling tank and the supply tank is set to a temperature 10 ° C. lower than the melting point of the thermoplastic resin powder used. The test was conducted at. The measurement with the surface electrometer was performed when the temperatures of the supply tank and the modeling tank reached 100 ° C., and evaluated according to the following criteria.
[Evaluation criteria]
×: ± 100V or more ○: Less than ± 100V ◎: ± 10V or less

<Manufacturing of 3D objects>
Using the obtained thermoplastic resin powder, a three-dimensional model was manufactured by the SLS method using an SLS method modeling device (manufactured by Ricoh Co., Ltd., AM S5500P). As setting conditions, a layer average thickness of 0.1 mm was set to a laser output of 10 watts or more and 150 watts or less, a laser scanning space of 0.1 mm, and a component floor temperature at a temperature 3 ° C. lower than the melting point were used.

<Availability of 3D modeling>
The propriety of three-dimensional modeling was evaluated for the obtained three-dimensional model in the production of the above-mentioned three-dimensional model according to the following criteria.
[Evaluation criteria]
◯: Obtained without the shape being distorted ×: The modeled object because the powder surface was disturbed and modeling became impossible, the modeled object was dragged and modeling could not be continued, or the powder from the recorder fell off. Roughness and large vacancies occurred

<Amount of recoat attached after modeling>
After manufacturing the above three-dimensional model, remove the recorder bar, scrape off the attached thermoplastic resin powder, measure the weight of the attached thermoplastic resin powder, determine the amount of adhesion, and evaluate according to the following criteria. did.
[Evaluation criteria]
×: Adhesion amount is 1 g or more ○: Adhesion amount is less than 1 g ◎: Adhesion amount is 0.1 g or less

(Example 2)
In Example 1, a hindered phenolic antioxidant (trade name: AO-330, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) -2,4,6 -Trimethylbenzene, manufactured by ADEKA Co., Ltd., 0.1 parts by mass, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (Adecastab PEP-36,) as a phosphorus-based deterioration inhibitor A thermoplastic resin powder was obtained in the same manner as in Example 1 except that 0.2 parts by mass was added (manufactured by ADEKA Co., Ltd.).

(Example 3)
In Example 1, heat was obtained in the same manner as in Example 1 except that the content of biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was changed from 1 part by mass to 0.2 parts by mass. A thermoplastic resin powder was obtained.

(Example 4)
In Example 1, the content of biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was changed from 1 part by mass to 4.5 parts by mass, and a hindered phenol-based antioxidant (AO-330, Thermoplasticity in the same manner as in Example 1 except that ADEKA Co., Ltd.) was changed to 0.2 parts by mass and phosphorus-based deterioration inhibitor (Adecastab PEP-36, ADEKA Co., Ltd.) was changed to 0.4 parts by mass. A resin powder was obtained.

(Example 5)
In Example 4, the shape of the discharge port of the twin-screw extruder was changed from a round shape to a square shape, the fiber diameter was changed to 127 μm, the cut width was changed to 127 μm, and a hindered phenolic antioxidant (AO-330, stock). A thermoplastic resin powder was obtained in the same manner as in Example 4 except that a phosphorus-based deterioration inhibitor (ADEKA STAB PEP-36, manufactured by ADEKA Corporation) was added in an amount of 0.4 parts by mass without adding (manufactured by ADEKA Corporation). It was.

(Example 6)
In Example 1, the resin type was changed to PP random (J-721GR, manufactured by Prime Polymer Co., Ltd.), and the polyoxyalkylene alkyl ester as a heat-resistant antistatic agent (trade name: Emar 20C, manufactured by Kao Corporation). After changing to 8 parts by mass and making the fiber diameter 20 μm, a resin powder was obtained by a freeze pulverization method at −100 ° C.
In order to melt the surface of the obtained resin powder by mechanical friction, a Q mixer (Mechanohybrid MH type, manufactured by Nippon Coke Co., Ltd.) was used to spin the obtained spherical resin powder at a rotation speed of 1,000 rpm. Treatment for 20 minutes gave a thermoplastic resin powder.

(Example 7)
In Example 2, the thermoplasticity was changed to 4.8 parts by mass of a polyoxyalkylene alkyl ester (trade name: Emar 20C, manufactured by Kao Corporation) as a heat-resistant antistatic agent in the same manner as in Example 2. A resin powder was obtained.
(Example 8)
In Example 2, a thermoplastic resin powder was obtained in the same manner as in Example 2 except that AS301E (manufactured by ADEKA Corporation) was changed to 1 part by mass as a heat-resistant antistatic agent.

(Example 9)
A thermoplastic resin powder was obtained in the same manner as in Example 2 except that the resin type was changed to polymethylpentene (manufactured by Mitsui Chemicals, Inc., DX231) in Example 2.

(Example 10)
In Example 2, a thermoplastic resin powder was obtained in the same manner as in Example 2 except that the molding was changed to the HSS method shown below.
<HSS method>
Using the obtained three-dimensional modeling powder, an HSS method modeling device (HP Jet Fusion 3D 4200 printer manufactured by HP Co., Ltd.) was used to manufacture a three-dimensional model. As the setting conditions, the layer average thickness was set to 0.1 mm, the laser scanning space of 0.1 mm, and the component floor temperature was used at a temperature 20 ° C. lower than the melting point.

(Example 11)
In Example 1, heat was obtained in the same manner as in Example 1 except that the content of biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was changed from 1 part by mass to 5.1 parts by mass. A thermoplastic resin powder was obtained.

(Example 12)
In Example 1, heat was obtained in the same manner as in Example 1 except that the content of biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was changed from 1 part by mass to 0.01 part by mass. A thermoplastic resin powder was obtained.

(Comparative Example 1)
In Example 6, the thermoplastic resin powder was prepared in the same manner as in Example 6 except that the polyoxyalkylene alkyl ester (trade name: Emar 20C, manufactured by Kao Corporation) was not used as the heat-resistant antistatic agent. Obtained.

(Comparative Example 2)
A thermoplastic resin powder was obtained in the same manner as in Example 1 except that Biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was not used in Example 1.

(Comparative Example 3)
In Comparative Example 2, a thermoplastic resin powder was obtained in the same manner as in Comparative Example 2 except that the 50% cumulative volume particle size (D ₅₀ ) was changed to 300 μm.

(Comparative Example 4)
In Comparative Example 2, a thermoplastic resin powder was obtained in the same manner as in Comparative Example 2 except that the antistatic agent was changed to 4.8 parts by mass of Catanac SN (cationic surfactant, for vinyl chloride).

(Comparative Example 5)
In Comparative Example 4, a hindered phenolic antioxidant (trade name: AO-330, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) -2,4,6 -Trimethylbenzene, manufactured by ADEKA Co., Ltd.) with 0.1 parts by mass, and as a phosphorus-based deterioration inhibitor, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (Adecastab PEP-) A thermoplastic resin powder was obtained in the same manner as in Comparative Example 4 except that 0.2 parts by mass of (36, manufactured by ADEKA Co., Ltd.) was added.

(Comparative Example 6)
In Comparative Example 5, a thermoplastic resin powder was obtained in the same manner as in Comparative Example 5, except that the glycerin fatty acid ester (Rikemar, manufactured by RIKEN Vitamin Co., Ltd.) was changed to 4.8 parts by mass as an antistatic agent.

(Comparative Example 7)
A thermoplastic resin powder was obtained in the same manner as in Example 9 except that Biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) was not used as a heat-resistant antistatic agent in Example 9.

(Comparative Example 8)
In Example 1, the thermoplastic resin was obtained in the same manner as in Example 1 except that the content of biomicelle BN105 (manufactured by Boron Laboratory Co., Ltd.) as a heat-resistant antistatic agent was changed from 1 part by mass to 31 parts by mass. Obtained powder.

The contents of the abbreviations in Table 1-1 and Table 1-2 are as follows.
-Resin type-
* PP Random: Polypropylene resin (PP) (Product name: J-721GR, manufactured by Prime Polymer Co., Ltd.)
* PP block: Polypropylene (PP) resin (trade name: Prime Polypro J704UG, made by Prime Polymer Co., Ltd., melting point: 160 ° C)
* Polymethylpentene: manufactured by Mitsui Chemicals, Inc., DX231

-Antistatic agent-
* Biomicelle BN105: Heat-resistant antistatic agent manufactured by Boron Laboratory Co., Ltd. * Polyoxyalkylene alkyl ester, trade name: Emar 20C, manufactured by Kao Co., Ltd., heat-resistant antistatic agent * AS301E, manufactured by ADEKA Co., Ltd., heat-resistant antistatic agent Antistatic agent * Catanac SN, cationic surfactant, for vinyl chloride, not a heat-resistant antistatic agent * Glycerin fatty acid ester, manufactured by Riken Vitamin Co., Ltd., trade name: Rikemar, not a heat-resistant antistatic agent In addition, "Catanac SN ( "Cationic surfactant)" and "glycerin fatty acid ester (Rikemar)" do not meet the 5% mass reduction temperature of 150 ° C. or higher in the measurement method based on ISO 7111-1987, and are heat-resistant antistatic agents. Absent.

-Antioxidant-
* AO: Hindered phenolic antioxidant (trade name: AO-330, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) -2,4,6-trimethyl) Benzene, manufactured by ADEKA Corporation)
* PEP: As a phosphorus-based deterioration inhibitor, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (ADEKA STAB PEP-36, manufactured by ADEKA Corporation)

From the results in Table 1-1 and Table 1-2, by using an appropriate heat-resistant antistatic agent, it is possible to reduce the adhesion of the thermoplastic resin powder in the device, and a three-dimensional model with a beautiful model surface can be obtained. It was found that a modeled object that could be modeled and could not be modeled stably in the past can be obtained.

(Examples 13 to 19 and Comparative Examples 9 to 10)
A thermoplastic resin powder was obtained in the same manner as in Example 1 except that the resin types and antistatic agents shown in Table 2 were used in Example 1.

Details of each component in Table 2 are as follows.
-Thermoplastic resin-
* PP: Polypropylene resin, manufactured by Prime Polypro Co., Ltd., J704UG
* TPX: Mitsui Chemicals, Inc., TX845
* PBT: Polybutylene terephthalate resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd., 5010

-Heat-resistant antistatic agent-
The following carbon nanotubes, titanium oxide nanoparticles, or carbon black were used as the heat-resistant antistatic agent (internal additive).
-Carbon nanotubes (manufactured by Toyo Color Co., Ltd., PPM 0KC290 BLK)
-Titanium oxide nanoparticles (manufactured by Ishihara Sangyo Co., Ltd., TTO-51)
・ Carbon black (manufactured by Tokai Carbon Co., Ltd., TOKABLACK)

The following fumed silica was used as the heat-resistant antistatic agent (external additive).
・ Fumed silica (manufactured by Nippon Aerosil Co., Ltd., RA200H)

Next, various characteristics of each of the obtained thermoplastic resin powders were measured as follows. The results are shown in Table 3.

<Adhesion amount>
When the thermoplastic resin powder adheres to the moving parts including the periphery of the recorder mechanism, the resin powder that is scattered and adhered and accumulated due to the impact during movement falls on the component floor or the selectively sintered and melted component area, resulting in poor modeling. It is preferable that there is no such thing because it causes the occurrence.
The presence or absence of adhesion of the thermoplastic resin powder to the moving parts including the periphery of the recorder mechanism after the completion of the three-dimensional modeling was evaluated by the following adhesive tape test.

-Adhesive tape test-
A scotch tape (manufactured by 3M) is attached to the roller part of the recorder, which is a movable part after modeling, and the number of particles attached to the scotch tape when peeled off is measured by a scanning electron microscope (device name: S4200, manufactured by Hitachi, Ltd.). ) Was used to calculate the number of particles adhering to each area. The test was performed at three different locations, and the average value of the obtained measured values was used. The number of particles of 100 particles / cm ² or less is a level that can be actually used.

<Surface resistivity and volume resistivity of thermoplastic resin powder>
A resistance cell for high resistance (Agilent Technologies, Agilent 16008B Bias RESISTIVELY CELL) is used as an electrode, and a high resistance meter (Agilent Technologies, Agilent 4339B high resistance meter) is used as a measuring device. The rate and volume resistivity were measured.

<Three-dimensional modeling>
Each of the obtained thermoplastic resin powders was used to produce a three-dimensional model using an SLS method modeling device (AM S5500P, manufactured by Ricoh Co., Ltd.). The setting conditions are a layer average thickness of 0.1 mm, a recorder moving speed of 100 mm / s, a laser output of 10 watts or more and 150 watts or less, a laser scanning space of 0.1 mm, and ± 3 from the melting point of the thermoplastic resin powder. The component floor temperature was used at a temperature of ° C. The temperature of the supply tank was −10 ° C. or lower from the melting point.
Next, various characteristics of the obtained modeled object were evaluated as follows. The results are shown in Table 3.

-Tensile strength ratio-
Five pieces were modeled in the longitudinal direction of the tensile test specimen so that the long side faces the Z-axis direction with the tensile test specimen at the center. The tensile test specimen sample was performed using an ISO (International Organization for Standardization) 3167 Type1A 150 mm long multipurpose dog bone-like test specimen (the specimen has a central portion of 80 mm in length, 4 mm in thickness and 10 mm in width).
The obtained three-dimensional molded product (tensile test specimen sample) was subjected to a tensile test (manufactured by Shimadzu Corporation, AGS-5kN) according to ISO 527, and the tensile strength was the same grade without antistatic agent. The resin pellet material of No. 1 was divided by the tensile strength of the tensile test specimen injection-molded using the recommended conditions of the manufacturer, and the tensile strength ratio as a percentage was calculated. The test speed in the tensile test was 50 mm / min. In addition, the calculation was performed 5 times, and the average value of the obtained measured values was used. The tensile strength ratio of 70% or more is a level that can be actually used.

-Recyclability-
The surplus powder of the thermoplastic resin powder used when the three-dimensional model used for the evaluation of the tensile strength was produced is returned to the supply tank of the three-dimensional model manufacturing device, and the three-dimensional model is used using the used thermoplastic resin powder. I made a model of the thing. This work was repeated 10 times, and the number of adhered particles in the adhesive tape test was about 100 particles / cm ² or less, which was a level that could be actually used, and the number of repetitions was determined so that molding defects due to powder falling did not occur.

Aspects of the present invention are, for example, as follows.
<1> A thermoplastic resin powder containing 0.01% by mass or more and 30.0% by mass or less of a heat-resistant antistatic agent.
<2> The thermoplastic resin powder according to <1>, which contains 0.1% by mass or more and 5.0% by mass or less of a heat-resistant antistatic agent.
<3> The above <1> to <2> containing 0.1% by mass or more and 5.0% by mass or less of a heat-resistant antistatic agent having a 5% mass reduction temperature of 150 ° C. or higher by a measurement method based on ISO 7111-1987. The thermoplastic resin powder according to any one of.
<4> The 50% cumulative volume particle size is 5 μm or more and 200 μm or less, and the ratio (Mv / Mn) of the volume average particle size (Mv) to the number average particle size (Mn) is 2.00 or less. The thermoplastic resin powder according to any one of 1> to <3>.
<5> The thermoplastic resin powder according to <4>, wherein the ratio (Mv / Mn) is 1.30 or less.
<6> The thermoplastic resin powder according to any one of <1> to <5>, which has a melting point of 100 ° C. or higher according to a measuring method based on ISO 3146.
<7> The thermoplastic resin powder according to any one of <1> to <6>, wherein the surface resistivity is 1 × 10 ⁵ Ω or more and 1 × 10 ¹⁴ Ω or less.
<8> The thermoplastic resin powder according to any one of <1> to <7>, wherein the volume resistivity is 1 × 10 ⁵ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less.
<9> The thermoplastic resin powder according to any one of <1> to <8>, wherein the high temperature resistivity is 1 × 10 ⁵ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less.
<10> The thermoplastic resin powder according to any one of <1> to <9>, which further contains an antioxidant.
<11> As the antioxidant, a phosphorus-based antioxidant is contained in an amount of 0.10% by mass or more and 0.8% by mass or less, and a phenol-based antioxidant is contained in an amount of 0.05% by mass or more and 0.2% by mass or less. 10> is the thermoplastic resin powder.
<12> The heat-resistant antioxidant has a semipolarity having one atomic group represented by the following structural formula (1) and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. A composition containing one or more organic compounds and one or more basic organic compounds having one basic nitrogen atom group and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. The thermoplastic resin powder according to any one of <1> to <11>, which is a donor-acceptor hybrid antistatic agent made of a substance.
<13> Any of the above <1> to <12>, wherein the resin powder contains columnar particles, and the ratio of the height of the columnar particles to the diameter or the long side at the bottom surface is 0.5 times or more and 2 times or less. It is the thermoplastic resin powder described in the above.
<14> The resin powder contains a substantially cylindrical body, and the diameter at the bottom surface of the substantially cylindrical body is 5 μm or more and 200 μm or less and the height is 5 μm or more and 200 μm or less, or the resin powder contains a rectangular parallelepiped and the rectangular parallelepiped. The thermoplastic resin powder according to any one of <1> to <13>, wherein each side of the bottom surface is 5 μm or more and 200 μm or less, and the height is 5 μm or more and 200 μm or less.
<15> The thermoplastic resin powder according to any one of <1> to <14>, wherein the density is 0.8 g / cm ³ or more and 1.4 g / cm ³ or less.
<16> The above-mentioned <1> to <15>, wherein the mass loss rate after heating the resin powder at a melting point of −10 ° C. for 4 hours by the TG-DTA method is 0.65% by mass or less. It is a thermoplastic resin powder.
<17> A resin powder for three-dimensional modeling, which comprises the thermoplastic resin powder according to any one of <1> to <16>.
<18> Contains a heat-resistant antistatic agent of 0.01% by mass or more and 30.0% by mass or less.
It is a resin powder for three-dimensional modeling characterized in that the surface charging potential measured by the triboelectric charging method under the following conditions is ± 100 V or less.
[Conditions] The stainless steel recorder is rotated at 500 m / min for 10 minutes at the melting point of the thermoplastic resin powder at −10 ° C. to supply the thermoplastic resin powder from the supply tank to the modeling tank, and then molding at 100 ° C. Measure the surface charge potential on the surface of the powder layer in the tank.
<19> A supply tank in which the thermoplastic resin powder according to any one of <1> to <16> is stored, and
A supply means for supplying the thermoplastic resin powder stored in the supply tank, and
A layer forming means for forming a layer containing the thermoplastic resin powder, and
A curing means for curing the layer and
It is a three-dimensional model manufacturing apparatus characterized by having.
<20> A layer forming step of forming a layer containing the thermoplastic resin powder according to any one of <1> to <16>.
This is a method for producing a three-dimensional model, which comprises repeating a curing step of curing the layer.

The thermoplastic resin powder according to any one of <1> to <16>, the three-dimensional modeling resin powder according to any one of <17> to <18>, and the three-dimensional modeling object according to <19>. According to the manufacturing apparatus and the method for manufacturing the three-dimensional model according to the above <20>, the conventional problems can be solved and the object of the present invention can be achieved.

1 Manufacturing equipment for 3D objects 11 Supply tank 11H Heater 11P Piston 12 Roller 13 Laser scanning space 13H Heater 13P Piston 18 Electromagnetic irradiation source 19 Reflector

International Publication No. 2015/159834 Pamphlet

Claims (19)

A thermoplastic resin powder containing 0.01% by mass or more and 30.0% by mass or less of a heat-resistant antistatic agent. The thermoplastic resin powder according to claim 1, which contains 0.1% by mass or more and 5.0% by mass or less of a heat-resistant antistatic agent. The invention according to any one of claims 1 to 2, which comprises 0.1% by mass or more and 5.0% by mass or less of a heat-resistant antistatic agent having a 5% mass reduction temperature of 150 ° C. or higher by a measuring method based on ISO 7111-1987. Thermoplastic resin powder. Claims 1 to 3 in which the 50% cumulative volume particle size is 5 μm or more and 200 μm or less, and the ratio (Mv / Mn) of the volume average particle size (Mv) to the number average particle size (Mn) is 2.00 or less. The thermoplastic resin powder according to any one of. The thermoplastic resin powder according to claim 4, wherein the ratio (Mv / Mn) is 1.30 or less. The thermoplastic resin powder according to any one of claims 1 to 5, which has a melting point of 100 ° C. or higher according to a measuring method based on ISO 3146. The thermoplastic resin powder according to any one of claims 1 to 6, wherein the surface resistivity is 1 × 10 ⁵ Ω or more and 1 × 10 ¹⁴ Ω or less. The thermoplastic resin powder according to any one of claims 1 to 7, wherein the volume resistivity is 1 × 10 ⁵ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less. The thermoplastic resin powder according to any one of claims 1 to 8, wherein the high-temperature resistivity is 1 × 10 ⁵ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less. The thermoplastic resin powder according to any one of claims 1 to 9, further comprising an antioxidant. The claim 10 contains 0.10% by mass or more and 0.8% by mass or less of a phosphorus-based antioxidant as the antioxidant, and 0.05% by mass or more and 0.2% by mass or less of a phenol-based antioxidant. Thermoplastic resin powder. The heat-resistant antioxidant is a semipolar organic compound having one atomic group represented by the following structural formula (1) and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. The composition comprises one or more kinds and one or more kinds of basic organic compounds having one basic nitrogen atomic group and at least one linear saturated hydrocarbon group having 11 to 22 carbon atoms in the molecule. The thermoplastic resin powder according to any one of claims 1 to 11, which is a donor-acceptor hybrid antistatic agent.
The thermoplastic according to any one of claims 1 to 12, wherein the resin powder contains columnar particles, and the ratio of the height of the columnar particles to the diameter or the long side at the bottom surface is 0.5 times or more and 2 times or less. Resin powder. The resin powder contains a substantially cylindrical body, and the diameter at the bottom surface of the substantially cylindrical body is 5 μm or more and 200 μm or less and the height is 5 μm or more and 200 μm or less, or the resin powder contains a rectangular parallelepiped and is on the bottom surface of the rectangular parallelepiped. The thermoplastic resin powder according to any one of claims 1 to 13, wherein each side is 5 μm or more and 200 μm or less, and the height is 5 μm or more and 200 μm or less. The thermoplastic resin powder according to any one of claims 1 to 14, which has a density of 0.8 g / cm ³ or more and 1.4 g / cm ³ or less. The thermoplastic resin powder according to any one of claims 1 to 15, wherein the mass loss rate after heating for 4 hours at a melting point of −10 ° C. of the resin powder by the TG-DTA method is 0.65% by mass or less. Contains 0.01% by mass or more and 30.0% by mass or less of heat-resistant antistatic agent
A resin powder for three-dimensional modeling, characterized in that the surface charging potential measured by the triboelectric charging method under the following conditions is ± 100 V or less.
[Conditions] The stainless steel recorder is rotated at 500 m / min for 10 minutes at the melting point of the thermoplastic resin powder at −10 ° C. to supply the thermoplastic resin powder from the supply tank to the modeling tank, and then molding at 100 ° C. Measure the surface charge potential on the surface of the powder layer in the tank. A supply tank in which the thermoplastic resin powder according to any one of claims 1 to 16 is stored, and
A supply means for supplying the thermoplastic resin powder stored in the supply tank, and
A layer forming means for forming a layer containing the thermoplastic resin powder, and
A curing means for curing the layer and
A three-dimensional model manufacturing device characterized by having. A layer forming step for forming a layer containing the thermoplastic resin powder according to any one of claims 1 to 16.
A method for producing a three-dimensional model, which comprises repeating a curing step of curing the layer.