JP2019001154A - Resin powder for stereoscopic shaping, stereoscopic shaping apparatus, production method for stereoscopic shaping article, and resin powder - Google Patents

Abstract

To solve a problem of causing a surface defect called orange peel such as a rough surface, a pore or distortion in a shaped article by shaping using a recycled resin powder for stereoscopic shaping, or decreasing tensile strength of the shaped article.SOLUTION: There is provided resin powder for stereoscopic shaping, comprising: a melting point of 100°C or higher by measuring in accordance with ISO 3146; and a ratio of greater than 0.80 and less than 1.20 in dividing of a melt mass flow rate after keeping a temperature by a melt mass flow rate before keeping the temperature, when the melt mass flow rates before and after keeping at a temperature of 15°C lower than a melting point at a pressure of 0.1 kPa for 4 hours are measured under conditions of a load of 2.16 kg and a temperature of 15°C higher than the melting point in accordance with JIS K7210.SELECTED DRAWING: None

Description

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

  A method of manufacturing a three-dimensional object such as a prototype or a final product by selectively melting and sintering a resin powder is known. For example, in the powder bed fusion (PBF) method, a thin layer of resin powder is irradiated with a laser to selectively melt and sinter the resin powder, and the obtained layers are repeatedly laminated. And shaping. The PBF method includes an SLS (Selective Laser Sintering) method for selectively irradiating a resin powder with a laser, and an SMS (Selective Mask Sintering) for partially irradiating the resin powder with a flat mask. Includes methods. Further, as an application of the PBF method, there is also known an MJF (Multi Jet Fusion) method in which a resin powder is melted selectively by dropping a liquid containing a heat absorbent into the resin powder and heating it with infrared light. .

  When modeling using resin powder, modeling may be performed using resin powder adjusted to a temperature near the softening point in order to maintain and relax (relax) the internal stress between the modeling layers. When the resin powder adjusted to a temperature near the softening point is irradiated with a laser, the resin powder is heated to a temperature equal to or higher than the softening point and melted.

  As the resin powder, for example, Patent Document 1 discloses a semi-aromatic polyamide resin composition used in a hot melt lamination method such as laser irradiation.

  In the method of selectively melting and molding the three-dimensional modeling resin powder, the three-dimensional modeling resin powder that has not been melted in the modeling process may be recycled. However, by modeling using recycled resin powder for three-dimensional modeling, surface defects called orange peel such as rough surfaces, pores, or distortion occur in the modeled object, and the tensile strength of the modeled object decreases. Issue arises.

  The resin powder for three-dimensional modeling of the invention according to claim 1 has a melting point measured in accordance with ISO 3146 of 100 ° C. or higher, and before and after being kept at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. , A ratio obtained by dividing the melt mass flow rate after the heat retention by the melt mass flow rate before the heat retention when the melt mass flow rate is measured under the condition of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point according to JIS K7210 Is greater than 0.80 and less than or equal to 1.20.

  ADVANTAGE OF THE INVENTION According to this invention, when modeling using the recycled resin powder, there exists an effect that it can reduce that a surface defect generate | occur | produces in a molded article or the tensile strength of a molded article falls.

FIG. 1A is a schematic perspective view showing an example of a substantially cylindrical resin powder. 1B is a schematic side view of the substantially cylindrical resin powder shown in FIG. 1A. FIG. 1C is a schematic side view showing an example of a shape that does not have an apex at the end of a substantially cylindrical resin powder. FIG. 1D is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 1E is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 1F is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 1G is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 1H is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 1I is a schematic side view showing another example of a shape that does not have a vertex at an end portion of a substantially cylindrical resin powder. FIG. 2 is a photograph showing an example of a substantially cylindrical resin powder. FIG. 3 is a schematic diagram illustrating a three-dimensional modeling apparatus according to an embodiment of the present invention. FIG. 4 is a conceptual diagram for explaining a manufacturing method of a three-dimensional structure. FIG. 5 is a conceptual diagram for explaining a method of manufacturing a three-dimensional structure.

  Hereinafter, modes for carrying out the present invention will be described, but the present invention is not limited to the following embodiments.

<<< Resin powder for three-dimensional modeling >>>
The resin powder for three-dimensional modeling according to an embodiment of the present invention has a melting point measured in accordance with ISO 3146 of 100 ° C. or higher, and is kept warm for 4 hours at a temperature 15 ° C. lower than the melting point under a pressure of 0.1 kPa. In addition, when the melt mass flow rate was measured under conditions of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point according to JIS K7210, the melt mass flow rate after the heat retention was divided by the melt mass flow rate before the heat retention. The ratio is greater than 0.80 and less than 1.20. Hereinafter, the resin powder for three-dimensional modeling is simply referred to as a resin powder.

  The melting point of the resin powder is determined by differential scanning calorimetry (DSC). In this case, according to ISO 3146 (plastic transition temperature measurement method, JIS K7121), for example, a differential scanning amount measuring device such as DSC-60A manufactured by Shimadzu Corporation is used, and the temperature is increased at 10 ° C./min. The DSC measurement of the resin powder is performed, and the temperature at the top of the obtained endothermic peak or the top of the melting point peak is defined as the melting point. When the resin powder has a plurality of melting points, the melting point in the present embodiment refers to the melting point on the high temperature side.

  The melting point of the resin powder is 100 ° C. or higher, preferably 150 ° C. or higher, and more preferably 200 ° C. or higher in consideration of the heat-resistant temperature when used for modeling the exterior of the product.

The resin powder is heated at a temperature 15 ° C. lower than the melting point under a pressure of 0.1 kPa. In the present invention, a DP610 vacuum heating device manufactured by Yamato Scientific Co., Ltd. is exemplified as a device capable of setting a reduced pressure. In the resin powder according to one embodiment of the present invention, the melt mass flow rate (A) before being kept warm by this vacuum heating device and the melt mass flow rate (B) after being kept warm are measured and compared before and after. (Formula 1)
(Formula 1) (Ratio of melt mass flow rate after heat retention divided by melt mass flow rate before heat retention) = (B) / (A)

  Melt mass flow rate (MFR) is an opening provided at the bottom of a container when a certain amount of resin powder is heated to a predetermined temperature in a cylindrical container heated by a heater and then pressurized. Nozzle) is the amount of resin extruded per 10 minutes. MFR is measured in accordance with JIS K7210 (ISO 1133), for example, using a melt mass flow rate measuring device (manufactured by Dynasco, type D405913) at a load of 2.16 kg and at a temperature 15 ° C. higher than the melting point. The

According to JIS K7210, the MFR of the resin powder when the melt mass flow rate is measured under a load of 2.16 kg and a temperature 15 ° C. higher than the melting point is 0.5 g / 10 min or more and 50 g / 10 min or less. It is preferable from the viewpoint of modeling by laser, and is preferably 1.0 g / 10 min or more and 40 g / 10 min or less, more preferably from the point of suppressing orange peel, and 1.5 g / 10 min or more and 30 g / 10 min or less. It is more preferable in terms of the strength of the shaped object.
In addition, the ratio obtained by dividing the MFR (B) after the warming by the MFR (A) before the warming is greater than 0.80 and 1.20 or less. If the ratio of MFR (B) after heat retention divided by MFR (A) before heat insulation is less than 0.80 or greater than 1.20, the resin surface becomes very rough and molding failures occur frequently. This is outside the scope of the present invention. Further, the ratio obtained by dividing MFR (B) after heat retention by MFR (A) before heat insulation is preferably larger than 0.90 and preferably 1.10 or less from the viewpoint of stability.

  When the resin powder is heated to a temperature close to the melting point, radicals are generated, and molecules are crosslinked or decomposed by the generated radicals. The inventors have confirmed that surface defects are generated in the molded article or the strength is reduced by modeling using the resin powder whose MFR is changed by crosslinking or decomposition. Therefore, the inventors repeatedly evaluated a molded article obtained from resin powders having various melting characteristics, and when using the resin powder having the predetermined melting characteristics described above, not only new resins but also recycled resins were used. It has been found that even when used, it is possible to solve the problem of surface defects of the molded article or a decrease in strength. That is, the melt mass flow rate was measured under conditions of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210 before and after holding at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. The ratio of the melt mass flow rate after heat retention divided by the melt mass flow rate before heat retention is greater than 0.80, not greater than 1.20, preferably not less than 0.85 and not greater than 1.15, more preferably 0. When it is .90 or more and 1.10 or less, it is possible to prevent a surface defect from occurring in the modeled object or a decrease in the strength of the modeled object.

  The resin powder includes a thermoplastic resin, and is made of a resin composition in which any other component is added inside or outside the thermoplastic resin. Hereinafter, each component of the resin powder will be described.

<Resin powder>
The resin powder contains a thermoplastic resin as a resin component. A thermoplastic resin is a resin that plasticizes and melts when heat is applied. The thermoplastic resin may be a crystalline resin or an amorphous resin. The crystalline resin is a resin in which a melting point peak is detected in measurement based on ISO 3146 (Plastic Transition Temperature Measurement Method, JIS K7121).

  Examples of the resin component in the resin powder include polyolefin, polyamide, polyester, polyether, polyphenylene sulfide, liquid crystal polymer (LCP), polyacetal (POM: Polyoxymethylene, melting point: 175 ° C.), polyimide, and fluororesin. Is done. A thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  Examples of the polyolefin include polyethylene and polypropylene (PP, melting point: 180 ° C.).

  Polyamides 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). And semi-aromatic polyamides such as polyamide 4T (PA4T), polyamide MXD6 (PAMXD6), polyamide 6T (PA6T), polyamide 9T (PA9T, melting point: 300 ° C.), and polyamide 10T (PA10T) . PA9T is also called polynonamethylene terephthalamide, which is composed of nine diamines and terephthalic acid monomers, and is semi-aromatic with aromatic carboxylic acid side. Aramids produced from p-phenylenediamine and terephthalic acid monomer as a wholly aromatic aromatic compound on the diamine side as well as the carboxylic acid side are also included in the polyamide.

  Examples of the polyester include polyethylene terephthalate (PET, melting point: 260 ° C.), polybutadiene terephthalate (PBT, melting point: 218 ° C.), polylactic acid (PLA), and the like. In order to impart heat resistance, a polyester containing an aromatic partially containing terephthalic acid or isophthalic acid is also preferably used in the present invention.

  As the polyether, polyetheretherketone (PEEK, melting point: 343 ° C.), polyetherketone (PEK), polyetherketoneketone (PEKK), polyaryletherketone (PAEK), polyetheretherketoneketone (PEEKK), And polyaryl ketones such as polyether ketone ether ketone ketone (PEKEKK). Moreover, polyether sulfone can also be used as a resin component.

  The thermoplastic resin may have two melting point peaks such as PA9T. A thermoplastic resin having two melting point peaks is completely melted at a temperature higher than the melting point peak on the high temperature side. The resin powder preferably contains at least one thermoplastic resin having a melting point of 100 ° C. or higher.

  In order to prevent warping of the modeled object, it is preferable that the temperature width (temperature window) for the crystal layer change, that is, the difference between the melting start temperature and the recrystallization point during cooling is larger than 3 ° C. More preferably, it is more preferable that the size is 5 ° C. or higher because a high-definition shaped article can be formed. Moreover, smoke generation by laser irradiation can be suppressed by selecting a resin having a decomposition temperature higher than the heating temperature by the laser and other components.

<Other ingredients>
Examples of other components in the resin powder include additives such as deterioration inhibitors, fluidizers, reinforcing agents, flame retardants, plasticizers, and crystal nucleating agents, and amorphous resins. Other components may be used by mixing with the particles, or may be used by coating the surface of the particles. When other components are included in the resin powder, the other components may be used alone or in combination of two or more.

(Deterioration inhibitor)
In order to maintain the thermal stability of the molecule and suppress resin degradation such as crosslinking or decomposition, the resin powder may contain a degradation inhibitor. Examples of the deterioration inhibitor include metal chelate materials, ultraviolet absorbers, polymerization inhibitors, and antioxidants.

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

  Various additives such as radical scavengers are used as hindered phenol-based antioxidants. Specific examples of hindered phenol-based antioxidants include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). Propionate, 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'-methylene (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-methylphenyl) 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-butylphenol) ), 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-tris 2 [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) Cetate, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) acetyloxy} -1,1-dimethylethyl] -2,4,8,10-tetra Oxaspiro [5,5] undecane, tetrakis [methylene-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris Examples include (3-tert-butyl-4-hydroxy-5-methylbenzyl) benzene and tris (3-tert-butyl-4-hydroxy-5-methylbenzyl) isocyanurate.

  Among hindered phenolic antioxidants, tetrakis [methylene-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] methane, octadecyl-3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propionate and 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2 , 4,8,10-tetraoxaspiro [5,5] undecane and tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane are stable at high temperatures. 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} 1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane and tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl] ) Propionate] methane is more preferred. A hindered phenolic antioxidant may be used individually by 1 type, and may use 2 or more types together.

  Examples of phosphorous antioxidants include phosphorous acid, phosphoric acid, phosphonous acid, and phosphonic acid; esters such as phosphite compounds, phosphate compounds, phosphonite compounds, phosphonate compounds; and tertiary phosphines. Is done. Phosphorus-based deterioration inhibitors may be used alone or in combination of two or more.

  Examples of phosphite compounds include triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl Phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, tris (diethylphenyl) phosphite, tris (di-iso-propylphenyl) phosphite, tris (di-n-butylphenyl) Phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,6-di-tert-butylphenyl) phosphite, distearyl pentaeri Ritol 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 penta Examples include erythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, and dicyclohexylpentaerythritol diphosphite.

  Among these phosphite compounds, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methyl) Phenyl) pentaerythritol diphosphite and bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite are preferred in terms of high-temperature stability.

  These phosphite compounds may be commercially available products. Examples of commercially available products of distearyl pentaerythritol diphosphite include ADK STAB PEP-8 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) and JPP681S (trademark, manufactured by Johoku Chemical Co., Ltd.). Commercial products of bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite include ADK STAB PEP-24G (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.), Alkanox P-24 (trademark, Great Lakes) ), Ultranox P626 (trademark, manufactured by GE Specialty Chemicals), Doverphos S-9432 (trademark, manufactured by Dover Chemical), and Irgafos126 and 126FF (trademark, manufactured by CIBA SPECIALTY CHEMIC). As a commercially available product of bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, ADK STAB PEP-36 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) is exemplified. Commercially available products of bis {2,4-bis (1-methyl-1-phenylethyl) phenyl} pentaerythritol diphosphite include ADK STAB PEP-45 (trademark, manufactured by Asahi Denka Kogyo Co., Ltd.) and Doverphos S- 9228 (trademark, manufactured by Dober Chemical) is exemplified.

  Examples of other phosphite compounds include compounds that react with dihydric phenols and have a cyclic structure. Compounds having a cyclic structure that react with dihydric phenols 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 and 2,2-methylenebis (4,6-di-tert-butylphenyl) Examples include octyl phosphite.

  Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, Examples include octadecyl phosphate and diisopropyl phosphate. Of these phosphate compounds, triphenyl phosphate, octadecyl phosphate, and trimethyl phosphate are preferable in terms of high temperature stability.

  Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3′-biphenylenedi. Phosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite Tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3′-biphenylene diphosphonite, 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)- Examples thereof include 4-phenyl-phenylphosphonite and bis (2,6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite.

  Among the phosphonite compounds, tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite and bis (di-tert-butylphenyl) -phenyl-phenylphosphonite are preferable in that they can be used in combination with a phosphite compound. Tetrakis (2,4-di-tert-butylphenyl) -biphenylene diphosphonite and bis (2,4-di-tert-butylphenyl) -phenyl-phenylphosphonite are preferred.

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

  Tertiary phosphine includes triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, tri-p-tolyl. Examples include phosphine, trinaphthylphosphine, and diphenylbenzylphosphine. Of the tertiary phosphines, triphenylphosphine is preferable in terms of long-term stability at high temperatures.

  When two or more kinds of deterioration inhibitors are used in combination, there are also combinations that can obtain more remarkable effects. For example, by using a combination of hindered phenol and phosphorus antioxidant 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 more preferably 0.05% by mass or more and 5% by mass or less with respect to the total amount of the resin powder from the viewpoint of preventing long-term deterioration. Preferably, 0.1 mass% or more and 5 mass% or less are still more preferable. The suitable 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 is within the above range, the effect of preventing the thermal deterioration of the resin is sufficiently obtained, the physical properties of the molded product are improved when the resin powder used for modeling is recycled, and the resin powder is discolored by heat. The effect which prevents is also acquired.

(Fluidizer)
Although it does not specifically limit as a fluidizing agent, The spherical particle which consists of inorganic materials is illustrated. The volume average particle diameter of the spherical particles made of an inorganic material is not particularly limited, but is preferably less than 10 μm. The content of the fluidizing agent may be sufficient to cover the particle surface, and is preferably 0.1% by mass or more and 10% by mass or less with respect to the total amount of the resin powder.

  Examples of inorganic materials in spherical particles include silica, alumina, titania, zinc oxide, magnesium oxide, tin oxide, iron oxide, copper oxide, hydrated silica, silica modified with a silane coupling agent, and magnesium silicate. Is exemplified. Among these, silica, titania, hydrated silica, and silica modified with a silane coupling agent are preferable from the viewpoint of improving fluidity, and the surface is hydrophobicized with a silane coupling agent from the viewpoint of cost. Silica modified in nature is more preferable.

(Strengthening agent)
Examples of the reinforcing agent include fiber fillers, bead fillers, glass fillers described in International Publication No. 2008/057844 pamphlet, glass beads, carbon fibers, and aluminum balls from the viewpoint of improving strength. A reinforcing agent may be used individually by 1 type, and may use 2 or more types together.

  Although it does not specifically limit as a fiber filler, A carbon fiber, an inorganic glass fiber, and a metal fiber are illustrated. Although it does not specifically limit as a bead filler, A carbon bead, an inorganic glass bead, and a metal bead are illustrated.

  Since the thermal conductivity of the fiber filler or the bead filler is higher than the thermal conductivity of the resin powder, when the surface of the resin powder is irradiated with laser in SLS modeling, the heat of the irradiated portion diffuses outside the laser irradiated portion. For this reason, when fiber filler or bead filler is mixed with resin powder that does not have sharp melt properties, the resin powder outside the laser irradiation area is heated by thermal diffusion and melted excessively, resulting in molding accuracy. Becomes 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, even if the resin powder outside the laser irradiation part is heated by thermal diffusion, Since it becomes difficult to melt, high modeling accuracy can be maintained.

  The average fiber diameter of the fiber filler is preferably 1 μm or more and 30 μm or less, and the average fiber length of the fiber filler is preferably 30 μm or more and 500 μm or less. By using a fiber filler having an average fiber diameter and an average fiber length within the above ranges, the strength of the model is improved, and the surface roughness of the model is the same as the surface roughness of the model without the fiber filler. Can be maintained to a degree.

  The circularity of the bead filler is preferably 0.8 or more and 1.0 or less, and the volume average particle size of the bead filler is preferably 10 μm or more and 200 μm or less. The circularity can be obtained by the following equation when the area (number of pixels indicating the bead filler when the bead filler is imaged) is S and the perimeter is L.

Circularity = 4πS / L2 (formula)
The volume average particle diameter can be measured, for example, using a particle size distribution measuring device (Microtrac MT3300EXII, manufactured by Microtrac Bell Co., Ltd.).

  As content of a fiber filler, 5 mass% or more and 60 mass% or less are preferable with respect to the resin powder whole quantity. If the content is 5% by mass or more, the strength of the shaped article is improved, and if it is 60% by mass or less, the formability is improved.

  As content of a bead filler, 5 mass% or more and 60 mass% or less are preferable with respect to the resin powder whole quantity. If the content is 5% by mass or more, the strength of the shaped article is improved, and if it is 60% by mass or less, the formability is improved.

(Flame retardants)
Examples of the flame retardant include various flame retardants such as halogen series, phosphorus series, inorganic hydrated metal compound series, nitrogen series, and silicone series. Various flame retardants such as those for building, vehicles, or ship rigging may be used for the resin powder. When two or more flame retardants are used in combination, the flame retardant performance is improved by combining the halogen-based and inorganic hydrated metal compound-based.

  The resin particles may also contain an inorganic reinforcing agent such as a fibrous substance such as glass fiber, carbon fiber, or aramid fiber; or an inorganic layered silicate such as talc, mica, or montmorillonite. According to such an embodiment, it is possible to achieve both physical property enhancement and flame retardancy enhancement.

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

  As content of a flame retardant, 1 mass% or more and 50 mass% or less are preferable with respect to the resin powder whole quantity, and 10 mass% or more and 30 mass% or less are more preferable from the point which improves a flame retardance more. When the content is 1% by mass or more, sufficient flame retardancy is obtained. When the content is 50% by mass or less, a change in the melt-solidification characteristics of the resin powder is suppressed, and a decrease in modeling accuracy and a deterioration in physical properties of the modeled object can be prevented.

<Particulate>
The resin particles are preferably pulverized or cut. As a method of pulverizing the resin, for example, it is obtained by pulverizing a pellet-shaped resin composition containing the above thermoplastic resin with a pulverizer and classifying or filtering particles other than a predetermined particle size with a filter. It is done. When pulverizing using the brittleness of the resin, the environment during pulverization is not more than the brittle temperature of the resin, preferably not more than room temperature, more preferably not more than 0 ° C, and still more preferably not more than -25 ° C. Yes, more preferably −100 ° C. or lower. In order to improve the fluidity of the resin particles, it is preferable to remove particles of, for example, 80 μm or more and 25 μm or less by a sphering operation. The resin powder is preferably dried to such an extent that does not affect the modeling. For this reason, you may shape | mold using the resin powder dried with the vacuum dryer or the silica gel. As a method of cutting the resin, the fiberized resin may be cut.

<Crystallinity control>
By controlling the crystal size and crystal orientation of the crystalline resin in the resin powder, errors due to the recoating process are reduced in the modeling process under a high temperature environment. Methods for controlling crystal size and crystal orientation include heat treatment, stretching treatment, treatment using ultrasonic waves, a method using an external stimulus such as an external electric field application treatment, a method using a crystal nucleating agent, and a resin as a solvent. Examples include a method that does not use external stimulation, such as a method of increasing crystallinity by dissolving and slowly evaporating the solvent.

  An example of the heat treatment is an annealing treatment in which the resin is heated to a temperature equal to or higher than the glass transition temperature to enhance crystallinity. In order to further enhance the crystallinity, an annealing treatment may be performed on the resin to which the crystal nucleating agent is added. An example of the annealing treatment procedure is to keep the resin at a temperature 50 ° C. higher than the glass transition temperature for 3 days and then slowly cool it to room temperature.

  The stretching treatment is performed in order to increase the orientation of the resin by stretching the resin and increase the crystallinity. As a procedure of the stretching process, using an extruder, the resin is melted at a temperature 30 ° C. or more higher than the melting point and stirred, and the melt is stretched 1 to 10 times to be fibrous. Illustrated. The maximum draw ratio in the drawing treatment is appropriately set according to the melt viscosity of the resin. When using an extruder, the number of nozzle openings is not particularly limited, but the productivity increases as the number increases. The stretched resin is subjected to processing such as pulverization and cutting to form a resin powder.

  As a treatment using ultrasonic waves, glycerin (manufactured by Tokyo Chemical Industry Co., Ltd., reagent grade) solvent is added to the resin powder about 5 times the resin powder, and then heated to a temperature 20 ° C. higher than the melting point of the resin, An example is a process of applying an ultrasonic wave at 24 kHz and an amplitude of 60% for 2 hours with an ultrasonic generator such as Ultrasonicator UP200S manufactured by Hielscher. After the treatment for applying ultrasonic waves, it is preferable to wash the resin powder with a solvent of isopropanol at room temperature and vacuum-dry it.

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

(shape)
Each particle shape of the resin powder is preferably a substantially cylindrical body. The term “substantially circle” means that the ratio of the major axis to the minor axis (major axis / minor axis) is 1 to 10. In the present embodiment, “˜” indicates a range including numerical values before and after. Although there is no restriction | limiting in particular as a substantially cylindrical body, A true cylinder, an elliptic cylinder, etc. are illustrated and a true cylinder is preferable. Note that a part of the circular portion of the substantially cylindrical body may be missing. In addition, when performing said extending | stretching process, the shape of resin powder is decided by the shape of the nozzle opening of an extruder. For example, in order to obtain a substantially cylindrical resin powder, the nozzle opening may be substantially circular, and in order to obtain a rectangular parallelepiped resin powder, the nozzle opening may be rectangular or square.

  The size of the circle on each face in the substantially cylindrical body may be different. However, since the bulk density can be increased if the shape is unified, the ratio of the diameter of the circle between the large surface and the small surface (large surface / small surface) is preferably 1.5 times or less. .1 times or less is more preferable.

  There is no restriction | limiting in particular as a diameter of a substantially cylindrical body, Although it selects suitably according to the objective, 5 micrometers or more and 200 micrometers or less are preferable. In addition, when the circular part of a substantially cylindrical body is an ellipse, a diameter means a major axis. There is no restriction | limiting in particular as the height (distance between both surfaces) of a substantially cylindrical body, Although it can select suitably according to the objective, 5 micrometers or more and 200 micrometers or less are preferable.

  The substantially cylindrical resin powder has a columnar shape having a bottom surface and an upper surface, but preferably has no apex in order to increase the bulk density. A vertex means a corner portion existing in the column. The shape of the columnar particles will be described with reference to FIGS. 1A to 1I. FIG. 1A is a schematic perspective view showing an example of a substantially cylindrical resin powder. 1B is a schematic side view of the substantially cylindrical resin powder shown in FIG. 1A. FIG. 1C is a schematic side view showing an example of a shape that does not have an apex at the end of a substantially cylindrical resin powder. FIG. 1D to FIG. 1I are schematic side views showing other examples of shapes that do not have vertices at the ends of the substantially cylindrical resin powder.

  When the cylindrical body shown in FIG. 1A is observed from the side, it has a rectangular shape as shown in FIG. 1B, and there are four corner portions, that is, vertices. An example of a shape having no apex at the end is shown in FIGS. 1C to 1I. Confirmation of the presence or absence of the apex of the columnar particles can be determined from the projection image on the side surface of the columnar particles. For example, the side surfaces of the columnar particles are observed using a scanning electron microscope (device name: S4200, manufactured by Hitachi, Ltd.) or the like, and acquired as a two-dimensional image. In this case, the projected image has a quadrilateral shape, and assuming that a portion constituted by two adjacent sides is an end, if it is constituted by only two adjacent straight lines, a corner is formed and has a vertex. 1C to FIG. 1I, when the end portion is constituted by an arc, the end portion does not have a vertex.

For example, as shown in FIG. 2, the column 21 has a first surface 22, a second surface 23, and a side surface 24. The first surface 22 includes a first facing surface 22 a and an outer peripheral region 22 b 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 that is 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 includes a second facing surface 23 a facing the first facing surface 22 a, and a second surface outer peripheral region 23 b having a shape extending along the side surface 24. The outer peripheral area 23b of the second surface is a surface that is 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. On the side surface 24, an outer peripheral region 22b of the first surface and an outer peripheral region 23b of the second surface extend.
The shape 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”) may be any shape that can be distinguished on the side surface 24 and the SEM image. A shape in which a part of the region is integrated with the side surface 24, a shape in which the outer peripheral region is in contact with the side surface 24, a shape in which a space exists between the outer peripheral region and the side surface 24, and the like are included. Moreover, it is preferable that the outer peripheral area 22 b of the first surface and the outer peripheral area 23 b of the second surface are provided so as to be substantially the same surface direction as the surface direction of the side surface 24.
As shown in FIG. 2, the outer peripheral region 22 b of the first surface and the outer peripheral region 23 b of the second surface are extended along the side surface 24 and located on the side surface 24. Further, the characteristic structures of the first surface and the second surface that cover the vicinity of the connection region between the outer peripheral region 22b of the first surface, the outer peripheral region 23b of the second surface, and the side surface 24 are bottle cap shapes. Also called.

  There is no restriction on the method of making the resin powder of a substantially cylindrical body without a vertex, as long as the vertex of the resin powder is rounded off, there is no limitation, and high-speed rotary mechanical pulverization, high-speed impact mechanical pulverization, or mechanical friction Examples of various known methods using a spheroidizing apparatus such as surface melting by the above-mentioned method are exemplified.

<Characteristics>
The specific gravity of the resin powder is preferably 0.8 g / mL or more. When the specific gravity of the resin powder is 0.8 g / mL or more, secondary agglomeration of particles can be suppressed in the recoating process for forming a resin layer during modeling. On the other hand, in applications such as metal replacement, the specific gravity of the resin powder is preferably 3.0 g / mL or less because of light weight needs. The specific gravity is obtained by measuring the true specific gravity. The true specific gravity is, for example, the volume of the sample by changing the volume and pressure of the gas (He gas) at a constant temperature using a dry automatic densimeter using a gas phase substitution method (Accumic 1330, manufactured by Shimadzu Corporation). And measuring the mass of this sample and calculating the density.

  The 50% cumulative volume particle size of the 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. Further, 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, and preferably 1.50 or less in terms of improvement in modeling accuracy. More preferred is 1.20 or less. The 50% cumulative volume particle size and the Mv / Mn can be measured using, for example, a particle size distribution measuring device (Microtrac MT3300EXII, manufactured by Microtrac Bell Co., Ltd.).

The ratio of the length to the diameter in the resin powder is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 or more and 2.0 or less, more preferably 0.8 or more and 1.2 or less. preferable. When the ratio of the length to the diameter in the resin powder is within a preferable range, it is advantageous in terms of improving the filling rate.
Examples of the method for measuring the ratio of the length to the diameter of the resin powder include a method of deriving from an image taken at a magnification of about 100 times.

<Application>
The resin powder of the present embodiment has an appropriate balance for parameters such as particle size, particle size distribution, heat transfer characteristics, melt viscosity, bulk density, fluidity, melting temperature, and recrystallization temperature, and the SLS method and the SMS method. , MJF (Multi Jet Fusion) method, or BJ (Binder Jetting) method and other three-dimensional modeling methods using resin powder. The resin powder of this embodiment 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 used in the fields of automobiles, precision equipment, semiconductors, aerospace, medicine, and metal substitutes.

  The three-dimensional structure formed by laser sintering using the resin powder of the present embodiment is smooth, the generation of orange peel is suppressed, and the surface has sufficient resolution. The orange peel is a surface defect such as a rough surface, a hole, or a distortion on the surface of the three-dimensional structure formed by laser sintering in the PBF method. Of these surface defects, for example, vacancies not only reduce aesthetics but also affect mechanical strength.

  The resin powder of this embodiment has excellent long-term recyclability. By using the new resin powder and recycled powder of the present embodiment to form by PBF method, MJF method, etc., (a) orange peel property, or (b) remarkable decrease in mechanical performance due to recycling (tensile strength A three-dimensional product that does not show any of the above (reduction of 30% or more) is obtained.

  The recycled powder is, for example, a resin powder that has not been used for modeling when it is modeled for 50 hours using a PBF modeling apparatus (manufactured by Ricoh Co., Ltd., AM S5500P). Even if 30% by mass of new resin powder is added to the recycled powder and the molding for 50 hours is further repeated twice, a three-dimensional object which does not show any of the above-described decreases in (a) and (b) is obtained. In addition, evaluation of (a) and (b) can be implemented using the ISO (International Organization for Standardization) 3167 Type1A 150 mm length multipurpose dog bone-like test specimen formed of resin powder.

<3D modeling equipment>
The three-dimensional modeling apparatus which models using said resin powder is demonstrated using FIG. FIG. 3 is a schematic diagram illustrating a three-dimensional modeling apparatus according to an embodiment of the present invention.

  As illustrated in FIG. 3, the modeling apparatus 1 includes a supply tank 11 as an example of a storage unit that stores the resin powder P for modeling, a roller 12 that supplies the resin powder P stored in the supply tank 11, and a roller 12. A laser scanning space 13 in which the resin powder P supplied by the laser beam L is scanned, an electromagnetic irradiation source 18 that is an irradiation source of the laser L as electromagnetic rays, and a laser L irradiated by the electromagnetic irradiation source 18. A reflection mirror 19 that reflects the laser scanning space 13 to a predetermined position is provided. The modeling apparatus 1 also includes heaters 11H and 13H that heat the resin powder P accommodated in the supply tank 11 and the laser scanning space 13, respectively.

The electromagnetic irradiation source 18 is not particularly limited, and examples thereof include a CO ₂ laser, an infrared irradiation source, a microwave generator, a radiant heater, an LED lamp, and a combination thereof.
While the electromagnetic irradiation source 18 is irradiating the laser L, the reflecting surface of the reflecting mirror 19 is 3D (three-dim
ensional) move based on the two-dimensional data of the model. The two-dimensional data of the 3D model indicates each cross-sectional shape when the 3D model is sliced at a predetermined interval. Thereby, by changing the reflection angle of the laser L, a portion of the laser scanning space 13 indicated by the two-dimensional data is selectively irradiated with the laser L. The resin powder at the laser L irradiation position is melted and sintered to form a layer. That is, the electromagnetic irradiation source 18 functions as a layer forming unit that forms each layer of the modeled article from the resin powder P.

  Pistons 11 </ b> P and 13 </ b> P are provided in the supply tank 11 and the laser scanning space 13 of the modeling apparatus 1. When the modeling of the layers 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 modeling object. This makes it possible to supply new resin powder P used for modeling a new layer from the supply tank 11 to the laser scanning space 13.

  Although the modeling apparatus 1 selectively melts the resin powder P by changing the laser irradiation position by the reflecting mirror 19, the present invention is not limited to such an embodiment. The resin powder of the present invention is also preferably used in a selective mask sintering (SMS) type modeling apparatus. In the SMS method, for example, a part of the resin powder is masked with a shielding mask, electromagnetic rays are irradiated, electromagnetic rays such as infrared rays are irradiated to the unmasked portion, and the resin powder is selectively melted to form To do. When the SMS process is used, the resin powder P preferably contains one or more heat absorbers that enhance infrared absorption characteristics, dark substances, or the like. Examples of the heat absorbing agent or dark substance include carbon fiber, carbon black, carbon nanotube, and cellulose nanofiber. For the SMS process, for example, those described in US Pat. No. 6,531,086 can be suitably used.

<Method for manufacturing a three-dimensional model>
4 and 5 are conceptual diagrams for explaining a method of manufacturing a three-dimensional structure. The manufacturing method of the three-dimensional molded item using the modeling apparatus 1 is demonstrated using FIG.4 and FIG.5.

  The resin powder P accommodated in the supply tank 11 is heated by the heater 11H. The temperature of the supply tank 5 is preferably as high as possible below the melting point of the resin particles P in terms of suppressing warping when the resin particles P are melted by laser irradiation, but the melting of the resin powder P in the supply tank 11 is preferable. In terms of prevention, it is preferably 10 ° C. or more lower than the melting point of the resin powder P. As shown in FIG. 4A, the engine of the modeling apparatus 1 drives the roller 12 as an example of a supply process, supplies the resin powder P in the supply tank 5 to the laser scanning space 13, and levels the ground. Thus, a powder layer having a thickness T corresponding to one layer is formed. The resin powder P supplied to the laser scanning space 13 is heated by the heater 13H. The temperature of the laser scanning space 13 is preferably as high as possible in terms of suppressing warping when the resin particles P are melted by laser irradiation, but in terms of preventing the resin powder P from melting in the laser scanning space 13, The temperature is preferably 5 ° C. or more lower than the melting point of the resin powder P.

  The engine of the modeling apparatus 1 receives input of a plurality of two-dimensional data generated from the 3D model. As shown in FIG. 4 (B), the engine of the modeling apparatus 1 moves the reflecting surface of the reflecting mirror 19 based on the two-dimensional data on the most bottom side among the plurality of two-dimensional data, and the electromagnetic irradiation source. 18 is irradiated with a laser. There is no restriction | limiting in particular as an output of a laser, Although it selects suitably according to the objective, 10 watts or more and 150 watts or less are preferable. By the laser irradiation, the resin powder P at the position corresponding to the pixel indicated by the two-dimensional data on the most bottom surface side of the powder layer is melted. When the laser irradiation is completed, the molten resin is cured, and a sintered layer having a shape indicated by the two-dimensional data on the bottom side is formed (an example of a layer forming step).

  Although it does not specifically limit as thickness T of a sintered layer, As an average value, 10 micrometers or more are preferable, 50 micrometers or more are more preferable, and 100 micrometers or more are still more preferable. The thickness T of the sintered layer is not particularly limited, but the average value is preferably less than 200 μm, more preferably less than 150 μm, and still more preferably less than 120 μm.

  As shown in FIG. 5A, when the bottommost sintered layer is formed, the engine of the modeling apparatus 1 forms a modeling space having a thickness T corresponding to one layer in the laser scanning space 13. Thus, the laser scanning space 13 is lowered by the thickness T of one layer by the piston 13P. Further, the engine of the modeling apparatus 1 raises the piston 11 </ b> P so that new resin powder P can be supplied. Subsequently, as shown in FIG. 5A, the engine of the modeling apparatus 1 drives the roller 12 to supply the resin powder P in the supply tank 5 to the laser scanning space 13 to level the ground. A powder layer having a thickness T corresponding to the layer is formed.

  As shown in FIG. 5B, the engine of the modeling apparatus 1 moves the reflecting surface of the reflecting mirror 19 based on the two-dimensional data of the second layer from the bottom surface side among the plurality of two-dimensional data. Then, the electromagnetic irradiation source 18 is irradiated with a laser. As a result, the resin powder P at the position corresponding to the pixel indicated by the two-dimensional data of the second layer from the bottom side in the powder layer is melted. When the laser irradiation is completed, the molten resin is cured, and a sintered layer having the shape indicated by the two-dimensional data of the second layer from the bottom surface side is formed in a state of being laminated on the sintered layer on the bottom surface side. The

  The modeling apparatus 1 stacks the sintered layers by repeating the supply process and the layer formation process. When modeling based on all of the plurality of two-dimensional data is completed, a three-dimensional object having the same shape as the 3D model is obtained.

<3D objects>
The three-dimensional object formed by the resin powder is not particularly limited, but is a prototype of an electronic device part or an automobile part, a prototype for strength test, an aerospace, or a dress-up tool for the automobile industry, etc. Examples of small-quantity products used in The PBF method is expected to be superior in strength as compared with other methods such as the FFF (Fused Filament Fabrication) method and the ink jet method, so that it can be used as a practical product. The production speed is not suitable for mass production such as injection molding. For example, a necessary production amount can be obtained by making a large amount of small parts in a flat shape. In addition, since the method for manufacturing a three-dimensional structure in the PBF method used in the present invention does not require a mold such as injection molding, an overwhelming cost reduction and delivery time reduction can be achieved in trial production and prototype production. be able to.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by these Examples.

Example 1
To 99.8 parts by mass of polybutylene terephthalate (PBT) resin (trade name: Novaduran 5020, manufactured by Mitsubishi Engineering Plastics Co., Ltd., melting point: 218 ° C.), phenolic antioxidant (trade name: AO-330, 1, 3, 0.2 parts by mass of 5-tris (3,5-di-tert-butyl-4-hydroxyphenylmethyl) -2,4,6-trimethylbenzene, manufactured by ADEKA Corporation) was added, and a single screw extruder (Toyo Seiki Co., Ltd.) Using D2020), a fiber having a diameter of 60 μm was formed by winding at a stretch of 3 times or more. Thereafter, using a cutting device NZI0606 (manufactured by Hadano Seiki Co., Ltd.), the resin fibers were cut to a width of 60 μm or more and 70 μm or less to obtain a resin powder. When the shape was confirmed using a scanning electron microscope JSM-7800FPRIME manufactured by JEOL Ltd., in which the 50% cumulative volume particle size of the obtained resin powder was 65 μm, the wire diameter was 60 μm and the diameter was 60 μm. In order to melt the surface by mechanical friction, the obtained resin powder was treated for 20 minutes at a rotational speed of 1000 rpm using a Q mixer (manufactured by Mitsui Coke Co., Ltd.) to obtain substantially columnar particles. This was used as the resin powder of Example 1.

(Example 2)
The polybutylene terephthalate (PBT) resin used in Example 1 was changed to polyamide 66 (PA66) resin (trade name: Leona 1300S, manufactured by Asahi Kasei Chemicals Corporation, melting point: 265 ° C.), and a phosphite antioxidant ( Product Name: PEP-36, 3,9-Bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, Inc. A resin powder of Example 2 was obtained in the same manner as Example 1 except that 1.0 part by mass of ADEKA) and 0.1 part by mass of copper acetate as a polymerization inhibitor were added.

Example 3
In the same manner as in Example 2, except that the polyamide 66 (PA66) resin was changed to a polyamide 9T (PA9T) resin (trade name: Genesta N1000A, manufactured by Kuraray Co., Ltd., melting point: 306 ° C.) in Example 2. The resin powder of Example 3 was obtained.

(Example 4)
Except that the polybutylene terephthalate (PBT) resin in Example 1 was changed to a polypropylene (PP) resin (trade name: Novatec MA3, manufactured by Nippon Polypro Co., Ltd., melting point: 130 ° C., glass transition temperature: 0 ° C.) Resin powder of Example 4 was obtained in the same manner as Example 1.

(Example 5)
In Example 1, except that the polybutylene terephthalate (PBT) resin was changed to a polyether ether ketone (PEEK) resin (trade name: HT P22PF, manufactured by VICTREX, melting point: 343 ° C., glass transition temperature: 143 ° C.) Resin powder of Example 5 was obtained in the same manner as Example 1.

(Example 6)
Example 1 Example 1 except that polybutylene terephthalate (PBT) resin was changed to polyacetal (POM) resin (trade name: Tenac 4060, manufactured by Asahi Kasei Co., Ltd., melting point: 175 ° C.) in Example 1. 6 resin powder was obtained.

(Example 7)
In Example 1, instead of a phenolic antioxidant (trade name: AO-330) manufactured by ADEKA Corporation, a phenolic antioxidant (trade name: AO-80, 3,9-Bis {2- [3- 0.5 parts by mass of (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5.5] undecane, manufactured by ADEKA Corporation) In addition, phosphite antioxidants (trade name: PEP-36, 3,9-Bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa Resin powder of Example 7 was obtained in the same manner as Example 1 except that 1.0 part by mass of -3,9-diphosphaspiro [5.5] undecane, manufactured by ADEKA Corporation) was added.

(Example 8)
In Example 6, a sulfur-based antioxidant (trade name: AO-412S, 2,2-Bis {[3- (dodecylthio) -1-oxopropoxy] methyl} propane-1,3-diyl bis [3- ( dodecylthio) propionate], manufactured by ADEKA Co., Ltd.) 0.25 parts by mass, phosphate antioxidant (metal chelating agent) [A3] (trade name: AX-71, Octadecyl phosphate, manufactured by ADEKA Co., Ltd.) 0.25 A resin powder of Example 8 was obtained in the same manner as Example 6 except for adding part by mass.

(Comparative Example 1)
1 part by weight of calcium stearate made by Taihei Chemical Sangyo Co., Ltd. is added to 99 parts by weight of polybutylene terephthalate (PBT) resin (trade name: Novaduran 5020, manufactured by Mitsubishi Engineering Plastics Co., Ltd., melting point: 218 ° C.). Kneaded pellets were produced using D2020) manufactured by Toyo Seiki Co., Ltd. The MFR of the kneaded pellets was 10 g / 10 min. Thereafter, the kneaded pellets were freeze-ground at −200 ° C. to a width of 5 μm or more and 200 μm or less using a low temperature pulverization system (device name: Linlex Mill LX1, manufactured by Hosokawa Micron Corporation), and the resin of Comparative Example 1 A powder was obtained.

(Comparative Example 2)
Polybutylene terephthalate (PBT) resin (trade name: Novaduran 5020, manufactured by Mitsubishi Engineering Plastics Co., Ltd., melting point: 218 ° C.) was taken out after heating at 210 ° C. under reduced pressure of 0.1 kPa for 4 hours, and cooled sufficiently. The MFR was 0.1 g / 10 min. Thereafter, using a low temperature pulverization system (device name: Linlex Mill LX1, manufactured by Hosokawa Micron Corporation), freeze pulverization at −200 ° C. so as to have a width of 5 μm or more and 200 μm or less to obtain a resin powder of Comparative Example 2 It was.

(Comparative Example 3)
In Comparative Example 2, except that the polybutylene terephthalate (PBT) resin was changed to polyamide 66 (PA66) resin (trade name: Leona 1300S, manufactured by Asahi Kasei Chemicals Corporation, melting point: 265 ° C.), and the heating temperature was changed to 255 ° C. In the same manner as in Example 2, the resin powder of Comparative Example 3 was obtained.

(Comparative Example 4)
In Comparative Example 1, except that the polybutylene terephthalate (PBT) resin was changed to polyamide 9T (PA9T) resin (trade name: Genesta N1000A, manufactured by Kuraray Co., Ltd., melting point: 300 ° C.), the same as Comparative Example 1, The resin powder of Comparative Example 4 was obtained. The 50% cumulative volume particle size of the resin powder of Comparative Example 4 was 42 μm.

(Comparative Example 5)
In Comparative Example 1, except that the polybutylene terephthalate (PBT) resin was changed to a polypropylene (PP) resin (trade name: Novatec MA3, manufactured by Nippon Polypro Co., Ltd., melting point: 180 ° C., glass transition temperature: 0 ° C.) In the same manner as in Example 1, the resin powder of Comparative Example 5 was obtained.

(Comparative Example 6)
Comparative Example 2 except that the polybutylene terephthalate (PBT) resin was changed to a polyether ether ketone (PEEK) resin (trade name: HT P22PF, manufactured by VICTREX, melting point: 334 ° C.) and a heating temperature of 330 ° C. in Comparative Example 2. In the same manner as in Example 1, a resin powder of Comparative Example 6 was obtained.

(Comparative Example 7)
In Comparative Example 2, the polybutylene terephthalate (PBT) resin was changed to a polyacetal (POM) resin (trade name: Tenac 4060, manufactured by Asahi Kasei Corporation, melting point: 175 ° C.), and the heating temperature was changed to 165 ° C. In the same manner as in Comparative Example 2, the resin powder of Comparative Example 7 was obtained.

  For the resin powders obtained in each Example and Comparative Example, “melting point”, “50% cumulative volume particle size”, “volume average particle size (Mv)”, “number average particle size ( Mn) "," specific gravity ", and" MFR "were measured. The results are shown in Table 1.

[Melting point]
Based on ISO3146, melting | fusing point of the resin particle of each Example and a comparative example was measured.

[50% cumulative volume particle size, volume average particle size (Mv), number average particle size (Mn)]
50% cumulative volume particle size, volume average particle size, and number average particle size are measured using a particle refractive index for each resin powder using a particle size distribution analyzer (Microtrac MT3300EXII, manufactured by Microtrac Bell Co., Ltd.) The solvent was not used, and measurement was performed by a dry (atmospheric) method. The particle refractive indices are: polybutylene terephthalate (PBT) resin: 1.57, polyamide 66 (PA66) resin: 1.53, polyamide 9T (PA9T) resin: 1.53, polypropylene (PP) resin: 1.48, poly Ether ether ketone (PEEK) resin: 1.57 and polyacetal (POM) resin: 1.48 were set. The volume average particle size / number average particle size (Mv / Mn) was calculated from the obtained volume average particle size and number average particle size.

[specific gravity]
The specific gravity is obtained by changing the volume and pressure of the gas (He gas) at a constant temperature using a dry automatic densimeter using a vapor phase substitution method (Accumic 1330, manufactured by Shimadzu Corporation), and obtaining the volume of the sample. This was done by measuring the mass of the sample and measuring the density of the sample.

[Melt Mass Flow Rate (MFR)]
According to JIS7210 (ISO1133), melt mass flow rate (MFR) was measured with a load of 2.16 kg using a melt mass flow rate measuring device (model D405913 manufactured by Dynasco). The measurement temperature was set to the melting point + 15 ° C. described in Table 1. The measurement was performed after the resin powder was filled and heated for 2 minutes or longer to sufficiently melt the resin.

  About the resin powder obtained by each Example and the comparative example, "orange peel property", "long-term recyclability (retention rate%)", and "tensile strength" were evaluated as follows. The results are shown in Table 2.

(Orange peel property)
About the resin powder of each Example and the comparative example, the SLS system modeling apparatus (the Ricoh Co., Ltd. make, AM S5500P) was used, and the three-dimensional molded item was manufactured. As the setting conditions, a laser output of 0.1 mm layer average thickness and 10 watts to 150 watts was set, and a laser scanning space of 0.1 mm and a temperature of −3 ° C. from the melting point was used as the part bed temperature. ISO (International Organization for Standardization) 3167 Type1A 150 mm long multipurpose canine bone-like test specimen (based on CAD, etc.) of a solid 3D model (sample for dimensions) (mm) with a side of 5 cm and an average thickness of 0.5 cm The specimen had a central portion of 80 mm long, 4 mm thick and 10 mm wide). About the obtained three-dimensional molded item, the surface was observed and "orange peel property" was evaluated based on the following evaluation criteria.
-Evaluation criteria-
○: No surface defects such as rough surfaces or vacancies or distortions ×: Surface defects such as rough surfaces or vacancies or distortions occur

(Tensile strength)
The long-term recyclability of the resin powder in the SLS process was measured as follows. Using an SLS modeling apparatus (Ricoh Co., Ltd., AM S5500P), 10 kg of powder was added into the supply floor of the SLS modeling apparatus. The setting conditions of the SLS modeling apparatus were the same as those for the “orange peel” evaluation. Using the resin powder of the example and the comparative example, the tensile test specimen is long in the Y-axis direction (the direction parallel to the rotation axis of the roller 12 in FIG. 3) in the center of the laser scanning space 13 using the SLS modeling apparatus. Five tensile test specimens were shaped so that the sides were facing. The interval between each modeled object layer is 5 mm. The tensile test specimen is an ISO (International Organization for Standardization) 3167 Type 1A 150 mm long multipurpose canine bone-like test specimen (the specimen has a central portion of 80 mm length, 4 mm thickness and 10 mm width). In this process, 20 modeling layers were first laminated to model a tensile test specimen, and an arbitrary sample was further modeled to set the modeling time to be 50 hours. About the tensile test specimen of the three-dimensional structure obtained at this time, the “tensile strength” was measured using a tensile tester (manufactured by Shimadzu Corporation, AGS-5 kN) according to ISO 527. The test speed in the tensile test was constant at 50 mm / min. Moreover, the initial value of the tensile strength in Table 2 is an average value of measured values obtained by conducting a test five times on the tensile test specimen. The initial value of the tensile strength is the result of a tensile test using a new powder (one that has never been shaped).

(Long-term recyclability)
About the resin powder of each Example and the comparative example, it heat-retained for 4 hours at the temperature 15 degreeC lower than melting | fusing point under the pressure of 0.1 kPa. Using the resin powder before and after the heat retention, the melt mass flow rate (g / 10 min) was measured under a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210. Table 1 shows the melt mass flow rate (g / 10 min) before heat insulation. A ratio obtained by dividing the melt mass flow rate after the heat retention by the melt mass flow rate before the heat insulation was evaluated according to the following evaluation criteria. Table 2 shows a ratio obtained by dividing the melt mass flow rate after the heat retention by the melt mass flow rate before the heat retention.
-Evaluation criteria-
○: Ratio is greater than 0.80 and less than or equal to 1.20 ×: Ratio is less than or equal to 0.80 or greater than 1.20

Japanese Patent No. 5911651

DESCRIPTION OF SYMBOLS 1 Modeling apparatus 11 Supply tank 11H Heater 11P Piston 12 Roller 13 Laser scanning space 13H Heater 13P Piston 18 Electromagnetic irradiation source 19 Reflection mirror

Claims (16)

The melting point measured according to ISO 3146 is 100 ° C. or higher,
When the melt mass flow rate is measured under the condition of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210 before and after holding at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. In addition,
A resin powder for three-dimensional modeling, wherein a ratio obtained by dividing the melt mass flow rate after heat retention by the melt mass flow rate before heat insulation is greater than 0.80 and equal to or less than 1.20.   The resin powder for three-dimensional model | molding of Claim 1 containing a deterioration inhibitor.   The resin powder for three-dimensional modeling according to claim 2, comprising at least two kinds of the deterioration preventing agents.   4. The resin powder for three-dimensional modeling according to claim 3, wherein the content of the at least two kinds of deterioration preventing agents is 0.05% by mass or more and 5% by mass or less, respectively.   5. The three-dimensional modeling according to claim 2, wherein the deterioration preventing agent is at least one selected from the group consisting of a metal chelate material, an ultraviolet absorber, a polymerization inhibitor, and an antioxidant. Resin powder.   The resin powder for three-dimensional model | molding as described in any one of Claims 2 thru | or 5 containing 1 or more types of compounds selected from the group which consists of a hindered phenol type | system | group, phosphorus type | system | group, sulfur type | system | group, and copper acetate.   The three-dimensional modeling resin powder according to any one of claims 1 to 6, wherein a ratio (Mv / Mn) obtained by dividing the volume average particle size by the number average particle size is 2.00 or less.   Specific gravity is 0.8 g / mL or more, The resin powder for three-dimensional modeling as described in any one of Claims 1 thru | or 7.   The resin powder for three-dimensional modeling according to any one of claims 1 to 8, wherein a 50% cumulative volume particle size is 5 µm or more and 200 µm or less.   The resin powder for three-dimensional modeling according to any one of claims 1 to 9, comprising at least one selected from polyolefin, polyamide, polyester, polyaryl ketone, polyphenylene sulfide, liquid crystal polymer, polyacetal, polyimide, and fluororesin. .   The polyamide is at least one selected from polyamide 410, polyamide 4T, polyamide 6, polyamide 66, polyamide MXD6, polyamide 610, polyamide 6T, polyamide 11, polyamide 12, polyamide 9T, polyamide 10T, and aramid. The resin powder for three-dimensional modeling according to 10.   The resin powder for three-dimensional modeling according to claim 10, wherein the polyester is at least one selected from polyethylene terephthalate, polybutylene terephthalate, and polylactic acid.   The resin powder for three-dimensional modeling according to claim 10, wherein the polyaryl ketone is at least one selected from polyether ether ketone, polyether ketone, and polyether ketone ketone. Storage means for storing the resin powder for three-dimensional modeling;
Supply means for supplying the resin powder for three-dimensional modeling housed in the housing means;
Among the three-dimensional modeling resin powders supplied by the supply unit, a layer forming unit that forms a layer by melting the three-dimensional modeling resin powder in a selected region, and
The supply of the three-dimensional image resin powder and the formation of the layer are repeated, and the layers are stacked and shaped,
The resin powder for three-dimensional modeling is
The melting point measured according to ISO 3146 is 100 ° C. or higher,
When the melt mass flow rate is measured under the condition of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210 before and after holding at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. The ratio of the melt mass flow rate after heat retention divided by the melt mass flow rate before heat retention is greater than 0.80 and equal to or less than 1.20. A supplying step of supplying the resin powder for three-dimensional modeling accommodated in the accommodating means;
Of the three-dimensional modeling resin powder supplied by the supplying step, the layer forming step of forming a layer by melting the three-dimensional modeling resin powder in a selected region is repeated, and the layers are stacked to be modeled,
The resin powder for three-dimensional modeling is
The melting point measured according to ISO 3146 is 100 ° C. or higher,
When the melt mass flow rate is measured under the condition of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210 before and after holding at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. The ratio of the melt mass flow rate after heat retention divided by the melt mass flow rate before heat retention is greater than 0.80 and equal to or less than 1.20. The melting point measured according to ISO 3146 is 100 ° C. or higher,
When the melt mass flow rate is measured under the condition of a load of 2.16 kg and a temperature 15 ° C. higher than the melting point in accordance with JIS K7210 before and after holding at a temperature 15 ° C. lower than the melting point for 4 hours under a pressure of 0.1 kPa. In addition,
A resin powder having a ratio obtained by dividing the melt mass flow rate after heat retention by the melt mass flow rate before heat retention is greater than 0.80 and not greater than 1.20.