Resin powder composition, three-dimensional molded body, and method for manufacturing a three-dimensional molded body

Abstract

To provide a resin powder composition, a three-dimensional molded body, and a method for producing a three-dimensional molded body, which are suitable for producing a three-dimensional molded body excellent in impact strength and tensile modulus of elasticity. 【Solution means】(a-1) MFR (230 ° C, 2.16 kg load) is 0.1 g / 10 min to 20 g / 10 min, (a-2) the amount of the 23 ° C n-decane soluble part (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23 ° C n-decane soluble part amount (D sol ) and the 23 ° C n-decane insoluble part amount (D insol ), and (a-3) the powder aggregation stress at 160 ° C is 0 N to 2.5 N A resin powder (A) containing a propylene-based polymer powder that satisfies the above conditions, (b-1) MFR (230 ° C, 2.16 kg load) is 25 g / 10 min to 150 g / 10 min, (b-2) the amount of the 23 ° C n-decane soluble part (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23 ° C n-decane soluble part amount (D sol ) and the 23 ° C n-decane insoluble part amount (D insol ), and (b-3) the powder aggregation stress at 160 ° C is 0 N to 2.5 N. A resin powder composition comprising a resin powder (B) containing a propylene-based polymer powder that satisfies the above conditions, wherein the mass ratio of the resin powder (B) to the resin powder (A) is 30 / 70 to 70 / 30.

Description

[Technical Field]

[0001] This disclosure relates to a resin powder composition, a three-dimensional molded article, and a method for producing a three-dimensional molded article. [Background technology]

[0002] Representative examples of 3D printing methods using thermoplastic resins include material extrusion (MEX) and powder bed fusion (PBF) using powder materials. Because the PBF method offers high molding accuracy and allows for the creation of fine objects, various methods have been proposed.

[0003] Patent Document 1 discloses a "powder material for three-dimensional molding, comprising a first resin powder containing homopolypropylene and nanofibers, and a second resin powder containing block polypropylene," which is used in powder bed fusion bonding. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2024 / 075711 [Overview of the project] [Problems that the invention aims to solve]

[0005] In powder bed fusion bonding, it is required to recoat the powder material at a temperature close to its melting point. While powder compositions containing polypropylene resin powder have been proposed, at high temperatures close to the powder's melting point, powders containing block polypropylene with rubber components are prone to agglomeration. On the other hand, the presence of rubber components is important for improving the impact resistance of the fabricated object. One embodiment of the present disclosure aims to provide a resin powder composition, a three-dimensional molded body, and a method for manufacturing a three-dimensional molded body that are suitable for manufacturing a three-dimensional molded body excellent in impact strength and tensile modulus of elasticity using two or more resin powders having a rubber component.

Means for Solving the Problems

[0006] The means for solving the above problems include the following aspects. <1> The following requirements (a-1), (a-2), and (a-3): (a-1) The MFR (230°C, 2.16 kg load) is 0.1 g / 10 min to 20 g / 10 min. (a-2) The amount of the 23°C n-decane soluble part (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23°C n-decane soluble part (D sol ) and the 23°C n-decane insoluble part (D insol ). (a-3) The powder aggregation stress at 160°C is 0 N to 2.5 N. A resin powder (A) containing a propylene-based polymer powder that satisfies the above requirements, and The following requirements (b-1), (b-2), and (b-3): (b-1) The MFR (230°C, 2.16 kg load) is 25 g / 10 min to 150 g / 10 min. (b-2) The amount of the 23°C n-decane soluble part (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23°C n-decane soluble part (D sol ) and the 23°C n-decane insoluble part (D insol ). (b-3) The powder aggregation stress at 160°C is 0 N to 2.5 N. A resin powder (B) containing a propylene-based polymer powder that satisfies the above requirements, and Including, A resin powder composition in which the mass ratio of the resin powder (B) containing the propylene-based polymer powder to the resin powder (A) containing the propylene-based polymer powder (mass of the resin powder (B) containing the propylene-based polymer powder / mass of the resin powder (A) containing the propylene-based polymer powder) is 30 / 70 to 70 / 30. <2> The volume-average particle size of both the resin powder (A) containing the propylene polymer powder and the resin powder (B) containing the propylene polymer powder is 1 μm to 200 μm. <1> The resin powder composition described above. <3> The melting points of resin powder (A) containing the propylene polymer powder and resin powder (B) containing the propylene polymer powder, as measured by DSC, are both 150°C to 170°C. <1> or <2> The resin powder composition described above. <4> Measured according to ISO 179-1 standard, 25 kJ / m³ at 23°C. 2 Having the above Charpy impact strength (without notches), <1> ~ <3> A resin powder composition as described in any one of the following. <5> It has a tensile modulus of 1,300 MPa or higher at 23°C, as measured according to the ISO 527-1 standard. <1> ~ <4> A resin powder composition as described in any one of the following. <6> D of resin powder (A) containing the propylene polymer powder and resin powder (B) containing the propylene polymer powder 90 All of these are between 75 μm and 200 μm. <1> ~ <5> A resin powder composition as described in any one of the following. <7> Used in three-dimensional molding, <1> ~ <6> A resin powder composition as described in any one of the following. <8> <1> ~ <7> A three-dimensional molded article formed using any one of the resin powder compositions described in that one. <9> <1> ~ <7> A method for producing a three-dimensional molded article, comprising producing a three-dimensional molded article by powder bed fusion bonding using a resin powder composition described in any one of the following. [Effects of the Invention]

[0007] According to one embodiment of the present disclosure, a resin powder composition, a three-dimensional molded article, and a method for manufacturing a three-dimensional molded article are provided that are suitable for producing a three-dimensional molded article having excellent impact strength and tensile modulus. [Modes for carrying out the invention]

[0008] In the present disclosure, a numerical range indicated using "~" represents a range that includes the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerically described stepwise range. In the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, the term "step" includes not only an independent step but also a step that is not clearly distinguishable from other steps as long as the intended purpose of the step is achieved.

[0009] <Resin powder composition> The resin powder composition of the present disclosure satisfies the following requirements (a-1), (a-2), and (a-3): (a-1) The MFR (at 230°C, 2.16 kg load) is 0.1 g / 10 min to 20 g / 10 min (a-2) The amount of the 23°C n-decane soluble portion (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23°C n-decane soluble portion (D sol ) and the 23°C n-decane insoluble portion (D insol ) (a-3) The powder aggregation stress at 160°C is 0 N to 2.5 N and includes a resin powder (A) containing a propylene-based polymer powder that satisfies the following requirements (b-1), (b-2), and (b-3): (b-1) The MFR (at 230°C, 2.16 kg load) is 25 g / 10 min to 150 g / 10 min (b-2) The amount of the 23°C n-decane soluble portion (D sol ) is 6% by mass to 15% by mass with respect to the total mass of the 23°C n-decane soluble portion (D sol ) and the 23°C n-decane insoluble portion (D insol ) (b-3) The powder aggregation stress at 160°C is 0 N to 2.5 N and includes a resin powder (B) containing a propylene-based polymer powder that Includes, The mass ratio of resin powder (B) containing propylene polymer powder to resin powder (A) containing propylene polymer powder (mass of resin powder (B) containing propylene polymer powder / mass of resin powder (A) containing propylene polymer powder is 30 / 70 to 70 / 30.

[0010] With the above configuration, the three-dimensional molded articles obtained using the resin powder composition of this disclosure exhibit excellent impact strength and tensile modulus by mixing MFR and two or more resin powders in which the content of n-decane soluble portion (rubber component) and powder cohesive stress are controlled within a predetermined range. The resin powder composition of this disclosure is suitable for use in three-dimensional molding and has an excellent balance between non-cohesiveness and fusion properties by lasers, etc., making it more suitable for manufacturing three-dimensional molded articles by powder bed fusion bonding.

[0011] -Resin powder containing propylene polymer powder- Resin powder containing propylene polymer powder (hereinafter also referred to as "resin powder") contains propylene polymer powder. Examples of propylene polymers include propylene homopolymers, propylene random copolymers containing constituent units derived from propylene and constituent units derived from olefin monomers other than propylene, and propylene block copolymers.

[0012] From the viewpoint of obtaining a three-dimensional molded article with excellent impact strength and tensile modulus, the propylene-based polymer is preferably a propylene-based block copolymer.

[0013] Propylene-based block copolymers have a propylene-derived skeleton as an essential skeleton, and are composed of skeletons derived from ethylene and one or more olefins selected from α-olefins having 4 to 20 carbon atoms. Examples of α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0014] When the propylene copolymer is a propylene-based block copolymer, the propylene-based block copolymer contains constituent units derived from ethylene and one or more olefins selected from α-olefins having 4 to 20 carbon atoms, and the total content of olefins other than propylene may be 4 mol% to 30 mol% relative to the propylene-based block copolymer.

[0015] The propylene polymer may have either an isotactic or syndiotactic stereoregularity in the portion where the propylene-derived structural units are repeatedly bonded. However, from the viewpoint of obtaining a three-dimensional molded article with excellent impact strength and tensile modulus, an isotactic structure is preferred.

[0016] In this disclosure, the MFR (Melt Flow Rate) of the resin powder (Resin Powder (A)) containing one of the propylene polymer powders in the resin powder composition, measured at 230°C and a 2.16 kg load in accordance with ASTM D1238, is between 0.1 g / 10 min and 20 g / 10 min. When the MFR (230°C, 2.16 kg load) of the resin powder (Resin Powder (A)) containing one of the propylene polymer powders in the resin powder composition is within the above range, the resin powder composition can weld to the other resin powder (B) when mixed, while maintaining the high impact strength of resin powder (A). This imparts excellent impact strength and tensile modulus to the three-dimensional molded body formed by the powder bed fusion method. If the MFR of resin powder (A) is lower than 0.1 g / 10 min, the weldability of the resin decreases, and if the MFR of resin powder (A) exceeds 20 g / 10 min, the impact strength of the resulting molded object decreases. The MFR is preferably 0.1g / 10 min to 18g / 10 min, and more preferably 0.2g / 10 min to 15g / 10 min.

[0017] In this disclosure, the MFR (Melt Flow Rate) of the resin powder (resin powder (B)) containing the other propylene polymer powder contained in the resin powder composition, measured at 230°C and a 2.16 kg load in accordance with ASTM D1238, is between 25 g / 10 min and 150 g / 10 min. When the MFR (230°C, 2.16 kg load) of the resin powder (resin powder (B)) containing the other propylene polymer powder contained in the resin powder composition is within the above range, the viscosity of the resin powder composition decreases during melting, resulting in high fluidity. Due to the high fluidity, the voids between the resin powders are reduced and the filling efficiency increases during the welding process of the powder bed fusion method, so that the three-dimensional molded body formed by the powder bed fusion method is given excellent impact strength and tensile modulus. If the MFR of resin powder (B) exceeds 150 g / 10 min, the impact strength of the resin powder itself decreases, and the impact strength of the resulting molded body also decreases.

[0018] In this disclosure, the resin powder containing propylene polymer powder (preferably composed of propylene block copolymer powder) has a portion that is soluble at 23°C n-decane and a portion that is insoluble at 23°C n-decane. The "23°C n-decane soluble portion" refers to the portion of the resin powder that is dissolved in the n-decane solution after being heated and dissolved in n-decane at 145°C for 30 minutes and then cooled to 23°C, as described in the examples below.

[0019] The 23°C n-decane soluble portion is preferably mainly composed of a copolymer (rubber component) consisting of propylene and one or more olefins selected from ethylene and α-olefins having 4 to 20 carbon atoms. In this case, the olefin content other than propylene in the 23°C n-decane soluble portion (total content of ethylene and one or more olefins selected from α-olefins having 4 to 20 carbon atoms) may be 4 mol% to 30 mol% relative to the 23°C n-decane soluble portion.

[0020] In this disclosure, the soluble portion (D) of the resin powder containing propylene polymer powder at 23°C n-decane is defined as sol ) is the soluble portion (D) of n-decane at 23℃. sol ) and the insoluble portion of n-decane at 23°C (D insol The amount is 6% to 15% by mass relative to the total mass of the resin powder containing propylene polymer powder (D sol The fact that the above range is present imparts impact resistance to the resin powder composition and the three-dimensional molded body formed by the powder bed fusion method using the same. On the other hand, in the recoating step of the method for manufacturing a three-dimensional molded body by powder bed fusion bonding, the powder has low cohesiveness, making it possible to suitably mold (shape) the three-dimensional molded body. sol If it is lower than 6% by mass, the impact strength of the resin composition decreases, D sol When the amount exceeds 15% by mass, the cohesiveness of the powder increases, reducing the filling properties of the molded object and thus decreasing its impact strength. D sol The amount is preferably 7% to 15% by mass, and more preferably 8% to 15% by mass.

[0021] The intrinsic viscosity [η] of the n-decane soluble portion at 23°C may be between 1.0 dl / g and 10 dl / g.

[0022] The weight-average molecular weight of the n-decane insoluble portion at 23°C is not particularly limited. The weight-average molecular weight can be calculated from the molecular weight distribution converted to polypropylene (PP) using gel permeation chromatography (GPC). The molecular weight distribution (weight-average molecular weight: Mw / number-average molecular weight: Mn) may be between 1.0 and 10.

[0023] In this disclosure, the powder cohesive stress of the resin powder containing propylene polymer powder at 160°C is 0N to 2.5N. Because the powder cohesive stress of the resin powder at 160°C is within the above range, the resin powder or resin powder composition is non-cohesive, and in the recoating step of the method for manufacturing a three-dimensional molded body by powder bed fusion bonding, the resin powder or resin powder composition has fluidity and can be suitably molded (formed) into a three-dimensional molded body. The powder cohesive stress is preferably 0N to 2.3N, and more preferably 0N to 2.1N. The powder cohesive stress is a value measured by a force gauge (e.g., Nidec FGP-0.2), and is measured in detail by the method described in the examples.

[0024] The volume-average particle size of the resin powder containing propylene polymer powder is preferably 1 μm to 200 μm, more preferably 10 μm to 150 μm, even more preferably 25 μm to 100 μm, and particularly preferably 35 μm to 70 μm, from the viewpoint of ensuring good fluidity of the resin powder or resin powder composition in the recoating step of the powder bed fusion bonding method for producing a three-dimensional molded article, and contributing to three-dimensional molding by powder bed fusion bonding.

[0025] D of resin powder containing propylene polymer powder 90 In the recoating step of the method for manufacturing a three-dimensional molded body by powder bed fusion bonding, the fluidity and filling properties of the resin powder are good, and from the viewpoint of contributing to three-dimensional molding by powder bed fusion bonding, the particle size is preferably 75 μm to 200 μm, more preferably 100 μm to 180 μm, and even more preferably 125 μm to 160 μm.

[0026] Volume average particle size and D of resin powder 90 For example, this can be achieved by performing grinding treatments such as mechanical grinding or wet grinding, particle spheroidization, and classification on resin powder particles containing particles whose particle size has been controlled by polymerization or prepared propylene polymer powder.

[0027] The particle size is measured using a particle size distribution analyzer (for example, the MT3300EXII manufactured by Microtrac-Bell Corporation), employing the refractive index of each powder particle, and measured using a dry (air) method without the use of solvents. Details will be explained in the examples.

[0028] The shape of the resin powder particles containing propylene polymer powder is preferably spherical in the recoating step of the powder bed fusion bonding method for manufacturing three-dimensional molded articles, as this ensures good filling of the powder layer and contributes to three-dimensional molding by the powder bed fusion bonding method.

[0029] From the viewpoint of the heat resistance of the resin powder, the melting point measured by DSC of the resin powder containing propylene polymer powder is preferably 160°C to 170°C, more preferably 162°C to 169°C, and even more preferably 164°C to 168°C.

[0030] The tensile modulus of resin powder containing propylene polymer powder, as measured according to ISO 527-1, may be between 1,000 MPa and 2,000 MPa. The method for measuring the tensile modulus according to ISO 527-1 is shown in detail in the examples.

[0031] The Charpy impact strength (with notch) of resin powder containing propylene polymer powder, as measured according to ISO 179-1 standard, is 2 kJ / m². 2 ~70kJ / m 2 This may be the case. The method for measuring Charpy impact strength (with notch) according to the ISO 179-1 standard is shown in detail in the examples.

[0032] In the resin powder composition of this disclosure, the mass ratio of resin powder (B) containing propylene polymer powder to resin powder (A) containing propylene polymer powder (mass of resin powder (B) containing propylene polymer powder / mass of resin powder (A) containing propylene polymer powder) is 30 / 70 to 70 / 30. The masses of resin powder (A) containing propylene polymer powder and resin powder (B) can be arbitrarily combined within the upper and lower limits of the above mass ratio. As long as the mass ratio of resin powder (A) and resin powder (B) is within the above range, it is possible to mold (form) a three-dimensional molded body by powder bed fusion bonding, and the resulting three-dimensional molded body has excellent impact strength.

[0033] -Other ingredients- The resin powder composition of this disclosure may also contain other components besides the resin powder containing the propylene polymer powder, to the extent that it does not impair the effects of the invention. Examples of other components include resin components such as thermoplastic resins other than propylene polymers, elastomer components (for example, propylene-based elastomers such as polyisobutylene, butyl rubber, propylene-ethylene copolymer rubber, propylene-butene copolymer rubber, and propylene-butene-ethylene copolymer rubber, and ethylene-based elastomers such as ethylene-propylene copolymer rubber), thermosetting resins, additive components, and the like. Biomass-derived raw materials may be incorporated into the resin powder composition.

[0034] Examples of additive components include heat stabilizers, antistatic agents, weather stabilizers, light stabilizers, UV absorbers, anti-aging agents, antioxidants, neutralizing agents, fatty acid metal salts, softeners, dispersants, colorants, lubricants, pigments, dyes, fillers, whitening agents, antistatic agents, solvents, wetting agents, antimicrobial agents, chelating agents, flow aids, reinforcing agents, energy absorption enhancers, energy absorption inhibitors, laser absorbers, fusion agents, and finish enhancers. The aforementioned other components may be used individually or in combination of two or more. When preparing a resin powder composition by mixing the other components, the mixing order is arbitrary; they may be mixed simultaneously, or a multi-stage mixing method may be employed, such as mixing some components before mixing others.

[0035] The resin powder composition of this disclosure may contain a flow aid. Preferably, the flow aid is dry-blended with the resin powder. In this disclosure, a flow aid refers to a substance that suppresses the aggregation of resin powder due to the adhesive force between the resin powder particles. By including a flow aid, the fluidity of the resin powder can be improved, and the filling of the resin powder becomes more uniform when forming a three-dimensional molded body. As a result, the resulting three-dimensional molded body tends to have less warping.

[0036] Examples of fluidizing agents include silica (silicon dioxide) such as fused silica, crystalline silica, and amorphous silica; alumina (aluminum oxide), alumina colloid (alumina sol), and alumina white; calcium carbonate such as light calcium carbonate, heavy calcium carbonate, finely powdered calcium carbonate, and special calcium carbonate-based fillers; clay (aluminum silicate powder) such as nepheline syenite fine powder, calcined clay such as montmorillonite and bentonite, and silane-modified clay; silica-containing compounds such as talc, diatomaceous earth, and silica sand; crushed natural minerals such as pumice powder, pumice balloons, slate powder, and mica powder; and sulfur Examples include minerals such as barium acid, lithopone, calcium sulfate, molybdenum disulfide, and graphite; glass-based fillers such as glass fibers, glass beads, glass flakes, and foamed glass beads; fly ash spheres, volcanic glass hollow bodies, synthetic inorganic hollow bodies, single-crystal potassium titanate, carbon fibers, carbon nanotubes, carbon hollow spheres, fullerenes, anthracite powder, artificial cryolite, titanium dioxide, magnesium oxide, basic magnesium carbonate, dolomite, potassium titanate, calcium sulfite, mica, asbestos, calcium silicate, molybdenum sulfide, boron fibers, and silicon carbide fibers. Among these, silica, alumina, calcium carbonate, glass-based fillers, and titanium dioxide are preferred, with silica being more preferred. Commercially available silica products include the "AEROSIL" (registered trademark) series of fumed silica manufactured by Nippon Aerosil Co., Ltd., the "Rheoroseal" (registered trademark) series of dry silica manufactured by Tokuyama Corporation, and the X-24 series of sol-gel silica powder manufactured by Shin-Etsu Chemical Co., Ltd.

[0037] The resin powder composition of this disclosure may contain a reinforcing material. Examples of reinforcing materials include inorganic reinforcing materials composed of inorganic compounds and organic reinforcing materials composed of organic compounds. The inorganic reinforcing material may be dry-blended with the resin powder or may be contained within the resin powder. In terms of controlling the spherical shape of the resin powder and improving fluidity, it is preferable that the inorganic reinforcing material is dry-blended with the resin powder. The reinforcing material may also serve as the aforementioned flow aid.

[0038] Reinforcement materials include, for example, glass-based fillers such as glass fibers, glass beads, glass flakes, and foamed glass beads; clays such as nepheline syenite fine powder, calcined clay such as montmorillonite and bentonite, and silane-modified clay (aluminum silicate powder); silica-containing compounds such as talc, diatomaceous earth, and silica sand; crushed natural minerals such as pumice powder, pumice balloons, slate powder, and mica powder; minerals such as barium sulfate, lithopone, calcium sulfate, molybdenum disulfide, and graphite; silica (silicon dioxide) such as fused silica, crystalline silica, and amorphous silica; alumina (aluminum oxide), alumina colloid (alumina sol), and alumina white; light calcium carbonate, heavy calcium carbonate, and fine powders. Examples include calcium carbonate, special calcium carbonate-based fillers, fly ash spheres, volcanic glass hollow bodies, synthetic inorganic hollow bodies, single-crystal potassium titanate, potassium titanate fibers, carbon fibers, carbon nanotubes, carbon hollow spheres, fullerenes, anthracite powder, cellulose nanofibers, artificial cryolite, titanium dioxide, magnesium oxide, basic magnesium carbonate, dolomite, calcium sulfite, mica, asbestos, calcium silicate, molybdenum sulfide, boron fibers, silicon carbide fibers, polypropylene fibers, polyamide fibers, polyoxymethylene fibers, ultra-high molecular weight polyethylene fibers, polytetrafluoroethylene fibers, liquid crystal (LCP) fibers, and Kevlar registered trademark fibers. Among these, glass-based fillers, minerals, and carbon fibers are preferred due to their hardness and significant strength-enhancing effect.

[0039] Surface-treated reinforcing materials (especially inorganic reinforcing materials) may be used. This makes it possible to improve the adhesion between the reinforcing material and the resin powder. Examples of surface treatment agents used for surface treatment include silane coupling agents such as aminosilane, epoxysilane, and acrylicsilane. These surface treatment agents may be immobilized on the surface of the inorganic reinforcing material by a coupling reaction, or they may coat the surface of the inorganic reinforcing material. When recycling the powder used in three-dimensional molding, it is preferable to use a material immobilized by a coupling reaction, as it is less likely to be modified by heat or other factors.

[0040] The resin powder composition of this disclosure may contain an energy absorption enhancer. The energy absorption enhancer is a substance that absorbs electromagnetic radiation. The energy absorption enhancer may also function as a flow aid or reinforcing agent.

[0041] Examples of energy absorption enhancers include pigments, carbon black, carbon fibers, copper hydroxyphosphate, near-infrared absorbing dyes, near-infrared absorbing pigments, metal nanoparticles, polythiophene, poly(p-phenylene sulfide), polyaniline, poly(pyrrole), polyacetylene, poly(p-phenylene vinylene), polyparaphenylene, poly(styrene sulfonate), poly(3,4-ethylenedioxythiophene)-poly(styrenephosphonate)p-diethylaminobenzaldehyde diphenylhydrazone, anti-9-isopropylcarbazole-3-, or conjugated polymers consisting of combinations thereof.

[0042] The resin powder composition of this disclosure may contain an energy absorption inhibitor. The energy absorption inhibitor is a substance that does not readily absorb electromagnetic radiation. The energy absorption inhibitor may also function as a flow aid or reinforcing agent.

[0043] Examples of energy absorption inhibitors include materials that reflect particulate electromagnetic radiation such as titanium, heat-insulating powders such as mica powder and ceramic powder, and water. Either an energy absorption enhancer or an energy absorption inhibitor may be used, or both may be used in combination to adjust the degree of absorption of electromagnetic radiation.

[0044] The resin powder composition of this disclosure may contain a fusing agent. The fusing agent may be, for example, a dispersion containing a radiation absorber (e.g., an active material). The active material may be any infrared light absorbing colorant. The solvent of the fusing agent may be water or a non-aqueous solvent (e.g., ethanol, acetone, n-methylpyrrolidone, aliphatic hydrocarbon, etc.). For example, the fusing agent may be a mixture of the active material and the solvent (preferably a mixture that does not contain other components). The fusion agent may, for example, include at least one cosolvent; at least one surfactant; at least one anticoagulation agent; at least one chelating agent; at least one buffer; at least one biocide; and water.

[0045] The resin powder composition of this disclosure may contain a finish enhancer. The finish enhancer may contain a surfactant, a cosolvent, and a balanced amount of water. The finish enhancer may be a mixture consisting of a surfactant, a cosolvent, and a balanced amount of water, and not containing other components. The finish enhancer may contain a colorant, or it may be a mixture consisting of a colorant, a surfactant, a cosolvent, and a balanced amount of water, and not containing other components. The finish enhancer may contain one or more components such as an anticoagulant, an antimicrobial agent, or a chelating agent. The resin powder composition and resin powder containing propylene polymer powder of this disclosure may be coated with any surface-active coating. Examples of surface-active coatings include coatings containing surfactants, acidic polymers, salts of acidic polymers, inorganic particles, etc., and the coating may use one of these or two or more of these.

[0046] Examples of surfactants used in surface-active coatings include anionic surfactants, nonionic surfactants, and cationic surfactants. Examples of anionic surfactants include sodium lauryl sulfate and linear or branched alkylbenzene sulfonates.

[0047] The surface-active coating may be an inorganic granular coating using inorganic particles, for example, an inorganic granular coating using fumed metal oxide nanoparticles. Examples of inorganic particles used in the inorganic granular coating include silicon dioxide, e.g., AEROSIL® 200, aluminum oxide, e.g., AEROXIDE® AluC and its aqueous dispersions, e.g., AERODISP® W1824, AERODISP® W440, etc.

[0048] Surface-active coatings are applied using appropriate methods. Examples include spray coating, pan coating, air or gas suspension coating, liquid phase coating, liquid dispersion coating, and immersion. Reactions such as polymerization may also be carried out after coating.

[0049] If the resin powder composition of this disclosure contains other components, the proportion of the propylene polymer to the total resin powder composition may be 80% by mass or more and less than 100% by mass, or 90% by mass or more and less than 100% by mass.

[0050] -Method for producing resin powder composition- The resin powder composition of this disclosure is produced by mixing resin powder (A) containing the propylene polymer powder and resin powder (B) containing the propylene polymer powder in the predetermined ratio. Mixing may be carried out using, for example, a V blender, a Henschel mixer, a Redigge mixer, etc. If necessary, coarse particles of the resin powder may be removed using a vibrating screen separator, a wind screen separator, etc.

[0051] The method for producing resin powder containing propylene polymer powder is not particularly limited. For example, propylene polymer powder and resin powder containing it can be produced by referring to the catalysts, production methods, etc., described in paragraphs 0022 to 0082 of International Publication No. 2012 / 102050.

[0052] The resin powder containing the propylene polymer powder of this disclosure can also be manufactured by referring to catalysts, manufacturing methods, etc., as described in, for example, International Publication No. 2009 / 011231, Japanese Patent Publication No. 2011-57789, Japanese Patent Publication No. 2019-206616, International Publication No. 2012 / 102050, etc.

[0053] -Applications- The resin powder composition disclosed herein can be used for the three-dimensional molding of three-dimensional molded articles. It is particularly suitable for the three-dimensional molding of three-dimensional molded articles by powder bed fusion bonding.

[0054] The three-dimensional molded articles that can be molded using the resin powder composition of this disclosure are not particularly limited and include, but are, automotive molded articles (e.g., console parts, switch parts, door trim parts, instrument panel parts, clips, covers, etc.), electrical appliance molded articles (electrical appliance parts, housings, etc.), furniture components, building components, construction materials, aircraft components, toys, shoes, sporting goods, ornaments, cases, etc.

[0055] -Physical Properties- The resin powder composition disclosed herein, from the viewpoint of excellent impact resistance, when formed into a three-dimensional molded article, has an impact resistance of 25 kJ / m³ at 23°C, as measured according to ISO 179-1 standard. 2 Preferably, it has a Charpy impact strength (without notches) of 30 kJ / m². 2 It is more preferable to have a Charpy impact strength (without notches) of 35 kJ / m² or higher. 2 It is even more preferable to have a Charpy impact strength (without notches) of 40 kJ / m². 2 It is particularly preferable to have the above Charpy impact strength (without notches). The method for measuring the Charpy impact strength (without notches) according to the ISO 179-1 standard is shown in detail in the examples.

[0056] From the viewpoint of excellent rigidity, the resin powder composition of this disclosure preferably has a tensile modulus of 1,300 MPa or more at 23°C when formed into a three-dimensional molded article, more preferably 1,350 MPa or more, even more preferably 1,400 MPa or more, and particularly preferably 1,450 MPa or more, as measured according to ISO 527-1. The method for measuring the tensile modulus according to ISO 527-1 is shown in detail in the examples.

[0057] <Three-dimensional molded object> The three-dimensional molded articles of this disclosure are molded using the aforementioned resin powder composition. Examples of three-dimensional molded articles include the aforementioned automotive molded articles and other molded articles. The three-dimensional molded articles of this disclosure may be sintered or molten bodies of the aforementioned resin powder composition.

[0058] The three-dimensional molded articles of this disclosure can be manufactured, for example, by three-dimensional molding using the aforementioned resin powder composition by powder bed fusion bonding.

[0059] <Method for manufacturing a three-dimensional molded body> The method for manufacturing a three-dimensional molded article according to this disclosure is a method for manufacturing a three-dimensional molded article by powder bed fusion bonding using the resin powder composition of this disclosure described above. Aside from using the resin powder composition of this disclosure described above, the three-dimensional molded article can be manufactured by the same method as the conventional powder bed fusion bonding method.

[0060] For example, the method for manufacturing a three-dimensional molded article according to the present disclosure may include: step 1 (recoating step) of forming a thin layer of a resin powder composition; step 2 (welding step) of selectively irradiating the preheated thin layer with laser light to form a molded layer in which the resin powder containing the propylene polymer powder in the resin powder composition is melt-bonded; and step 3 of repeating steps 1 and 2 in this order to build up molded layers.

[0061] A single molded layer constituting the three-dimensional molded body is formed by going through steps 1 and 2, and by repeating steps 1 and 2, the molded layers are sequentially stacked to form the three-dimensional molded body. From the viewpoint of achieving high-precision molding, the manufacturing method of the three-dimensional molded body of this disclosure preferably includes step 4, in which a thin layer of the resin powder composition is preheated before the laser is irradiated in step 2.

[0062] Each of the aforementioned steps may be carried out with reference to, for example, the method for manufacturing a three-dimensional molded body described in International Publication No. 2020 / 213586, HP Multi Jet Fusion technology, or 3D printing using the molding material described in Japanese Patent No. 7071532. [Examples]

[0063] The embodiments of this disclosure will be described in detail below with reference to examples. The embodiments of this disclosure are not limited to the following examples. The physical properties of the resin powder and resin powder composition in the examples were measured by the following methods, respectively.

[0064] (1) Volume average particle size and D 90 Volume average particle size and D of resin powder 90 The particle size distribution was determined using a particle size analyzer (Microtrac-Bell Co., Ltd., MT3300EXII), employing the refractive index of each powder particle, and using a dry (air) method without solvents to determine the volume-average particle size and D 90 The following measurements were taken. The particle refractive index was set to 1.5. A sample was used in which 0.1 g of powder particles was added to 0.2 g of surfactant (Kao Corporation, Emal E-27C) and 30 mL of water, and ultrasonically dispersed for 10 minutes.

[0065] (2) Tensile modulus Test specimens were obtained by molding the resin powder at a molding temperature of 210°C using an injection molding machine (NEX140, manufactured by Nissei Plastic Industrial Co., Ltd.). A three-dimensional molded body was prepared from the resin powder composition as follows. First, a 0.2 mm thick layer of resin powder or resin powder composition was spread on the build stage using a 3D 3D printer (SINTERSTATION 2500 plus, manufactured by 3D SYSTEMS) at a predetermined recoating speed (160 mm / s). A CO2 laser equipped with a CO2 laser wavelength galvanometer scanner was used to irradiate this thin layer with laser light in a 360 mm x 310 mm area under the following conditions to create a molded layer. Subsequently, the resin powder or resin powder composition was further spread on the molded layer, and laser light was irradiated to build up another molded layer. These processes were repeated to create a three-dimensional molded body (a stack of molded layers). -Laser light emission conditions- Laser output: 40W Laser light wavelength: 10.6 μm Beam diameter: 500 μm on thin-layer surfaces Number of lines: 1 line

[0066] Using the three-dimensional molded body prepared as described above, the following test specimens were prepared. The tensile modulus of the test specimens was measured under the following conditions in accordance with ISO 527-1. -Measurement conditions- Test specimen: ISO 527-1 Tensile speed: 0.5 mm / min Distance between gauge lines: 25mm

[0067] (3) Charpy impact strength Using test specimens prepared in accordance with ISO 179-1 and molded in the same manner as the measurement of the tensile modulus described above, the following conditions were used to measure the Charpy impact strength (kJ / m²) for resin powder with a notch and for resin powder composition without a notch. 2 ) was measured. -Measurement conditions- Temperature: 23℃ Test specimen: 10mm (width) x 80mm (length) x 4mm (thickness)

[0068] (4) MFR The melt flow rate (MFR) of the resin powder was measured in accordance with ASTM D1238 under conditions of 230°C and a load of 2.16 kg.

[0069] (5) Melting point In accordance with the measurement method of ISO 3146 (Method for determining the transition temperature of plastics, JIS K7121), a differential scanning calorimetry device (Diamond DSC, manufactured by PerkinElmer) was used to heat the resin powder to 230°C at a rate of 10°C / min, and the endothermic peak temperature was defined as the melting point of the resin powder.

[0070] (6) 23℃ n-decane soluble portion 5 g of resin powder sample was mixed with 200 mL of n-decane and heated at 145°C for 30 minutes until dissolved. The mixture was cooled to 20°C over approximately 3 hours and allowed to stand for 30 minutes. The precipitate (α) was then filtered off. The filtrate was placed in approximately three times its volume of acetone to precipitate the components dissolved in the n-decane. Precipitate (β) (hereinafter, n-decane soluble portion: D) sol The filtrate, n-decane, and acetone were filtered off, and the precipitate was dried. No residue was observed even after concentrating and drying the filtrate. The precipitate (α) was added again to 200 mL of n-decane, heated at 145°C for 30 minutes, the solution was filtered, and the inorganic filler was filtered off. The filtrate was cooled to 20°C over approximately 3 hours, left to stand for 30 minutes, and then precipitate (γ) (hereinafter referred to as the n-decane-insoluble portion of the resin powder: D) was removed. insol ) was filtered out. In the separation of n-decane from resin powder, the precipitate (γ) is the n-decane-insoluble portion (D insol Since this corresponds to ), the amount of n-decane soluble was calculated as follows. Amount of n-decane soluble portion (mass%) = [amount of precipitate (β) / (amount of precipitate (γ) + precipitate (β))] × 100

[0071] (7) Powder coagulation stress A cylindrical stainless steel container measuring 22mm in height and 15mm in diameter contains a bulk density of 0.33g / cm³. 3 The container was filled to the brim with resin powder. The container filled with resin powder was heated in an oven at 160°C for 9 minutes, and then cooled at room temperature for 15 minutes. The cylindrical resin was removed from the container, and the cohesive stress of the powder was measured from above using a force gauge (Nidec, FGP-0.2, attachment: press type).

[0072] [Manufacturing Example 1] A prepolymerization catalyst was prepared as follows, and a resin powder containing a propylene-based polymer powder was prepared using the prepolymerization catalyst. (1) Preparation of solid titanium catalyst components 952 g of anhydrous magnesium chloride, 4420 mL of decane, and 3906 g of 2-ethylhexyl alcohol were heated at 130°C for 2 hours to obtain a homogeneous solution. 213 g of phthalic anhydride was added to this solution, and the mixture was stirred at 130°C for a further 1 hour to dissolve the phthalic anhydride. The homogeneous solution obtained in this manner was cooled to 23°C, and 750 mL of this homogeneous solution was added dropwise over 1 hour to 2000 mL of titanium tetrachloride maintained at -20°C. After the dropwise addition, the temperature of the resulting mixture was raised to 110°C over 4 hours. At 110°C, 52.2 g of diisobutyl phthalate (DIBP) was added, and the mixture was maintained at the same temperature for 2 hours with stirring. The solid portion was then collected by hot filtration, and this solid portion was resuspended in 2750 mL of titanium tetrachloride, and then heated again at 110°C for 2 hours. After heating, the solid portion was again collected by hot filtration and washed with decane and hexane at 110°C until no titanium compounds were detected in the washing solution. The solid titanium catalyst component prepared as described above was stored as a hexane slurry, and a portion of it was dried to examine the catalyst composition. The solid titanium catalyst component contained 2% by mass of titanium, 57% by mass of chlorine, 21% by mass of magnesium, and 20% by mass of DIBP.

[0073] (2) Production of prepolymerization catalyst 87.5 g of solid titanium catalyst, 99.8 mL of triethylaluminum, 28.4 mL of diethylaminotriethoxysilane, and 12.5 L of heptane were placed in a 20 L autoclave equipped with a stirrer. Maintaining an internal temperature of 15°C to 20°C, 875 g of propylene was added, and the mixture was reacted with stirring for 100 minutes. After polymerization was complete, the solid components were allowed to settle, and the supernatant was removed and washed twice with heptane. The resulting prepolymerization catalyst was resuspended in purified heptane and adjusted with heptane to a solid titanium catalyst concentration of 0.7 g / L.

[0074] (3) Preparation of propylene polymer particles A jacketed, circulating tubular polymerization reactor with a capacity of 58 L was continuously supplied with 40 kg / hour of propylene, 123 NL / hour of hydrogen, 0.30 g / hour of prepolymerization catalyst, 2.1 mL / hour of triethylaluminum, and 0.88 mL / hour of diethylaminotriethoxysilane, and polymerization was carried out in a completely liquid state without a gas phase. The temperature of the tubular polymerization reactor was 70°C and the pressure was 3.3 MPa / G. The resulting slurry was sent to a 100L vessel polymerizer equipped with a stirrer for further polymerization. Propylene was supplied to the polymerizer at a rate of 15 kg / hour, and hydrogen was supplied to maintain a hydrogen concentration of 3.0 mol% in the gas phase. Polymerization was carried out at a temperature of 70°C and a pressure of 3.1 MPa / G. The obtained slurry was transferred to a 2.4 L transfer tube, where it was gasified and gas-solid separation was performed. Then, the polypropylene homopolymer powder was sent to a 480 L gas-phase polymerization reactor for ethylene-propylene copolymerization. Here, propylene, ethylene, and hydrogen were continuously supplied to the gas-phase polymerizer so that the gas composition was ethylene / (ethylene + propylene) = 0.18 (molar ratio of ethylene) and hydrogen / ethylene = 0.13 (molar ratio). Polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.9 MPa / G, followed by vacuum drying at 80°C to obtain propylene-based polymer particles composed of propylene-ethylene block copolymer.

[0075] (4) Mechanical crushing The propylene polymer particles obtained above were cooled to approximately -150°C with liquid nitrogen and pulverized using a pulverizer (Linlex mill) to obtain a resin powder (PP1) containing propylene polymer powder.

[0076] The physical properties of PP1 obtained in Manufacturing Example 1 are as follows: -Physical properties of PP1- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 1g / 10min Melting point: 165℃ 23℃ n-decane soluble portion: 12% by mass Powder cohesive stress: 1.2N Tensile modulus: 1,200 MPa Charpy impact strength (with notch): 30 kJ / m 2

[0077] [Manufacturing Example 2] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 2.5 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.18 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP2) containing propylene-based polymer powder.

[0078] The physical properties of PP2 obtained in Manufacturing Example 2 are as follows: -Physical properties of PP2- Volume-average particle size: 70 μm D 90 :160μm MFR (230℃, under 2.16kg load): 0.5g / 10min Melting point: 165℃ 23℃ n-decane soluble portion: 10% by mass Powder cohesive stress: 0.8N Tensile modulus: 1,350 MPa Charpy impact strength (with notch): 40 kJ / m 2

[0079] [Manufacturing Example 3] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 3.1 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.20 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP3) containing propylene-based polymer powder.

[0080] The physical properties of PP3 obtained in Manufacturing Example 3 are as follows: -Physical properties of PP3- Volume-average particle size: 70 μm D 90 :140μm MFR (230℃, under 2.16kg load): 5.0g / 10min Melting point: 165℃ 23℃ n-decane soluble portion: 13% by mass Powder cohesive stress: 1.3N Tensile modulus: 1,250 MPa Charpy impact strength (with notch): 35 kJ / m 2

[0081] [Manufacturing Example 4] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 5.0 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.15 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP4) containing propylene-based polymer powder.

[0082] The physical properties of PP4 obtained in Manufacturing Example 4 are as follows: -Physical properties of PP4- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 90g / 10min Melting point: 167℃ 23℃ n-decane soluble portion: 9% by mass Powder cohesive stress: 0.6N Tensile modulus: 1,350 MPa Charpy impact strength (with notch): 8kJ / m 2

[0083] [Manufacturing Example 5] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 4.0 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.21 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP5) containing propylene-based polymer powder.

[0084] The physical properties of PP5 obtained in manufacturing example 5 are as follows: -Properties of PP5- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 30g / 10min Melting point: 167℃ 23℃ n-decane soluble portion: 14% by mass Powder cohesive stress: 1.6N Tensile modulus: 1,300 MPa Charpy impact strength (with notch): 8kJ / m 2

[0085] [Manufacturing Example 6] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 5.5 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.15 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP6) containing propylene-based polymer powder.

[0086] The physical properties of PP6 obtained in manufacturing example 6 are as follows: -Physical properties of PP6- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 100g / 10min Melting point: 166℃ 23℃ n-decane soluble portion: 8% by mass Powder cohesive stress: 0.8N Tensile modulus: 1,590 MPa Charpy impact strength (with notch): 3 kJ / m 2

[0087] [Manufacturing Example 7] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 4.3 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.15 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP7) containing propylene-based polymer powder.

[0088] The physical properties of PP7 obtained in manufacturing example 7 are as follows: -Properties of PP7- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 45g / 10min Melting point: 167℃ 23℃ n-decane soluble portion: 8% by mass Powder cohesive stress: 0.7N Tensile modulus: 1,600 MPa Charpy impact strength (with notch): 4kJ / m 2

[0089] [Manufacturing Example 8] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 3.3 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.3 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP8) containing propylene-based polymer powder.

[0090] The physical properties of PP8 obtained in manufacturing example 8 are as follows: -Physical properties of PP8- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 3g / 10min Melting point: 163℃ 23℃ n-decane soluble portion: 17% by mass Powder cohesive stress: 2.9N Tensile modulus: 1,000 MPa Charpy impact strength (with notch): 60 kJ / m 2

[0091] [Manufacturing Example 9] A resin powder (PP9) containing a propylene-based polymer powder composed of a propylene homopolymer manufactured by Prime Polymer Co., Ltd., having the following physical properties, was prepared.

[0092] The physical properties of PP9 obtained in manufacturing example 9 are as follows: -Physical properties of PP9- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 11g / 10min Melting point: 165℃ 23℃ n-decane soluble portion: 0% by mass Powder cohesive stress: 0N Tensile modulus: 1,650 MPa Charpy impact strength (with notch): 4kJ / m 2

[0093] [Manufacturing Example 10] A resin powder (PP10) containing a propylene-ethylene copolymer powder manufactured by Prime Polymer Co., Ltd., having the following physical properties, was prepared.

[0094] The physical properties of PP10 obtained in manufacturing example 10 are as follows: -Physical properties of PP10- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 10g / 10min Melting point: 140℃ 23℃ n-decane soluble portion: 0% by mass Powder cohesive stress: 4N Tensile modulus: 1,300 MPa Charpy impact strength (with notch): 15 kJ / m 2

[0095] [Manufacturing Example 11] Except for supplying hydrogen to the Vessel polymerizer to a concentration of 6.0 mol%, and setting the gas composition in the gas-phase polymerizer to ethylene / (ethylene + propylene) = 0.15 (ethylene content molar ratio), propylene-based polymer particles composed of propylene-ethylene block copolymer were obtained in the same manner as in Production Example 1. Furthermore, mechanical grinding treatment was performed in the same manner as in Production Example 1 to obtain resin powder (PP11) containing propylene-based polymer powder.

[0096] The physical properties of PP11 obtained in manufacturing example 11 are as follows: -Properties of PP11- Volume-average particle size: 70 μm D 90 :130μm MFR (230℃, under 2.16kg load): 200g / 10min Melting point: 165℃ 23℃ n-decane soluble portion: 9% by mass Powder cohesive stress: 1.6N Tensile modulus: 1,600 MPa Charpy impact strength (with notch): 1.0 kJ / m 2

[0097] Table 1 shows the physical properties, such as volume-average particle size, of the resin powders containing propylene-based polymer powders from Production Examples 1 to 11.

[0098] Next, the resin powders containing the propylene polymer powders from Production Examples 1 to 11 were dry-blended in a Henschel mixer (manufactured by Mitsui Miike Chemical Machinery Co., Ltd.) at the blending ratios (mass ratios) shown in Tables 2 and 3 to obtain resin powder compositions.

[0099] [Table 1]

[0100] [Table 2]

[0101] [Table 3]

[0102] As shown in Tables 2 and 3, the resin powder compositions of Examples 1 to 19 exhibited excellent impact strength and tensile modulus of elasticity in the molded three-dimensional articles. On the other hand, in Comparative Examples 1 to 8, molding itself was impossible, or even if molding was possible, the impact strength of the three-dimensional articles was significantly low. The resin powder compositions of Examples 1 to 19, with their excellent impact strength and tensile modulus of elasticity, can be suitably used as powders for three-dimensional molding by methods such as powder bed fusion bonding.

Claims

1. The following requirements (a-1), (a-2), and (a-3): (a-1) The MFR (at 230°C, with a 2.16 kg load) is between 0.1 g / 10 min and 20 g / 10 min. (a-2) 23°C n-decane soluble portion (D ｓｏｌ ) is the amount of n-decane soluble at 23°C (D ｓｏｌ ) and the insoluble portion of n-decane at 23°C (D ｉｎｓｏｌ It is 6% to 15% by mass relative to the total mass of ). (a-3) The powder cohesive stress at 160°C is 0 N to 2.5 N. A resin powder (A) containing a propylene polymer powder that satisfies the following conditions, The following requirements (b-1), (b-2), and (b-3): (b-1) The MFR (at 230°C, with a 2.16 kg load) is between 25 g / 10 min and 150 g / 10 min. (b-2) 23°C n-decane soluble portion (D ｓｏｌ ) is the amount of n-decane soluble at 23°C (D ｓｏｌ ) and the insoluble portion of n-decane at 23°C (D ｉｎｓｏｌ It is 6% to 15% by mass relative to the total mass of ). (b-3) The powder cohesive stress at 160°C is 0 N to 2.5 N. A resin powder (B) containing a propylene polymer powder that satisfies the following conditions, Includes, A resin powder composition in which the mass ratio of resin powder (B) containing the propylene polymer powder to resin powder (A) containing the propylene polymer powder is 30 / 70 to 70 / 30.

2. The resin powder composition according to claim 1, wherein the volume average particle size of both the resin powder (A) containing the propylene polymer powder and the resin powder (B) containing the propylene polymer powder is 1 μm to 200 μm.

3. The resin powder composition according to claim 1, wherein the melting points of the resin powder (A) containing the propylene polymer powder and the resin powder (B) containing the propylene polymer powder are both measured by DSC at 150°C to 170°C.

4. Measured according to ISO 179-1 standard, 25 kJ / m³ at 23°C. ２ The resin powder composition according to claim 1, having the above Charpy impact strength (without notches).

5. The resin powder composition according to claim 1, having a tensile modulus of 1,300 MPa or more at 23°C, as measured in accordance with ISO 527-1 standard.

6. D of resin powder (A) containing the propylene polymer powder and resin powder (B) containing the propylene polymer powder ９０ The resin powder composition according to claim 1, wherein all of the particles are 75 μm to 200 μm in size.

7. A resin powder composition according to claim 1, used for three-dimensional molding.

8. A three-dimensional molded article formed using the resin powder composition described in any one of claims 1 to 7.

9. A method for producing a three-dimensional molded article, comprising producing a three-dimensional molded article by a powder bed fusion bonding method using a resin powder composition according to any one of claims 1 to 7.

Images