Resin composition for 3D printers, three-dimensional fabricated object, and production method therefor

Abstract

Provided are: a resin composition for 3D printers which minimizes the wear of a nozzle of a 3D printer and exhibits both warpage inhibition and high-speed fabrication properties; a method for producing a three-dimensional fabricated object using the resin composition; and a 3D fabricated object exhibiting little warpage.　The resin composition for 3D printers comprises: a styrene resin (A) containing a rubber component; and lamellar particles (B) having a Mohs hardness of at most 3 and having surfaces treated with a silane coupling agent (X). The lamellar particle (B) content is 10-30 mass% with respect to the total mass of the resin composition. The method for producing a three-dimensional fabricated object comprises: melting the resin composition for 3D printers; and extruding the molten resin composition through a nozzle to form a three-dimensional fabricated object. The three-dimensional fabricated object contains the resin composition for 3D printers.

Description

Resin composition for 3D printers, three-dimensional model and method for manufacturing the same

[0001] The present invention relates to a resin composition for 3D printers, a three-dimensional object, and a method for producing the same.

[0002] A 3D printer is a type of three-dimensional modeling machine that uses 3D data such as CAD and CG created on a computer as blueprints to produce three-dimensional objects made of plastic or other materials.

[0003] Generally, 3D printers are classified by the deposition method, and known methods include binder jetting, fused deposition modeling, liquid vat photopolymerization, and powder sintering (SLS (Selective Laser Sintering) or SLM (Selective Laser Melting)) methods.

[0004] 3D printers use resin materials to create three-dimensional objects. For example, in fused deposition modeling (FDM), filaments of thermoplastic resin are used as the material. These filaments are melted and extruded from the nozzle of the 3D printer, layering them to form the desired shape. Filaments for FDM 3D printers are primarily made of polylactic acid resin (PLA resin) and acrylonitrile-butadiene-styrene resin (ABS resin). While ABS resin is known for its excellent heat resistance and ease of post-processing, it suffers from the problem of warping during modeling. Therefore, a resin material for 3D printers has been proposed that incorporates glass fiber into ABS resin to reduce warping. However, research by the present inventors has revealed that while incorporating glass fiber reduces warping, it also causes wear on the 3D printer nozzle.

[0005] As another method for improving warpage of three-dimensionally molded objects, Patent Document 1 proposes using a styrene-based resin with a Tg of 50°C or higher but lower than 100°C. However, mixing a resin with a low Tg results in a deterioration in the heat resistance of the resulting three-dimensionally molded object. Patent Document 2 proposes a three-dimensionally molded material in which a specific amount of filler (including talc) is blended with a thermoplastic resin and a thermoplastic elastomer. However, according to studies by the present inventors, it was found that simply mixing general-purpose talc with a thermoplastic resin does not achieve both warpage suppression and high-speed moldability.

[0006] Patent No. 7136131 International Publication No. 2021 / 060278

[0007] Therefore, an object of the present invention is to provide a resin composition for 3D printers that reduces wear on the nozzle of the 3D printer and achieves both suppression of warping and high-speed modeling capabilities, a method for manufacturing a three-dimensional object using the same, and a three-dimensional object with little warping.

[0008] As a result of extensive research, the present inventors discovered that all of the above-mentioned problems can be solved by blending a specific amount of relatively soft, surface-treated plate-like particles with a rubber-component-containing styrene-based resin, and thus completed the present invention. Specifically, the present invention includes the following aspects: [1] A resin composition for 3D printers, comprising: a rubber-component-containing styrene-based resin (A); and plate-like particles (B) having a Mohs hardness of 3 or less and having surfaces treated with a silane coupling agent (X), wherein the content of the plate-like particles (B) is 10 to 30 mass% relative to the total mass of the resin composition.

[0009] According to the present invention, it is possible to provide a resin composition for 3D printers that reduces wear on the nozzle of the 3D printer and achieves both suppression of warping and high-speed modeling ability, a method for manufacturing a three-dimensional object using the same, and a three-dimensional object with little warping.

[0010] An embodiment of the present invention will be described in detail below. The present invention is not limited to the following embodiment, and can be implemented by making appropriate modifications within the scope that does not impair the effects of the present invention. When a specific explanation given for one embodiment also applies to other embodiments, that explanation may be omitted in other embodiments. In this disclosure, expressions such as "1 to 10" regarding a numerical range mean "1 or more and 10 or less." For example, "10 to 30 g / min" means "10 g / 10 min or more and 30 g / 10 min or less."

[0011] [Resin Composition for 3D Printers] The resin composition for 3D printers according to this embodiment comprises a rubber-containing styrene-based resin (A) and plate-like particles (B) having a Mohs hardness of 3 or less and having surfaces treated with a silane coupling agent (X), wherein the content of the plate-like particles (B) is 10 to 30 mass% relative to the total mass of the resin composition. The resin composition for 3D printers according to this embodiment (hereinafter sometimes simply referred to as the "resin composition" or "resin material") can suppress wear on the nozzle of a 3D printer, achieving both suppression of warpage and high-speed modeling performance.

[0012] Here, "warping" refers to a phenomenon in which, when a three-dimensional object is formed using a 3D printer, at least a portion of a resin material layered on a substrate (hereinafter sometimes referred to as "laminate") peels off from the surface of the substrate, creating a gap (floating) between the substrate and the laminate. When this phenomenon occurs, problems arise, such as difficulty in obtaining a three-dimensional object of the desired shape, or the laminate coming into contact with the nozzle of the 3D printer, making further modeling impossible. The resin composition according to this embodiment can suppress warping during modeling, allowing a three-dimensional object of the desired shape to be obtained. It can also prevent problems during modeling caused by warping. In this specification, "laminate" refers to a three-dimensional object in the middle of being modeled.

[0013] The resin composition according to this embodiment can achieve high-speed modeling properties in addition to suppressing warpage. Here, "high-speed modeling properties" refers to the ability to model a three-dimensional object at a modeling speed of, for example, 80 to 150 mm / s. Resin materials with poor high-speed modeling properties will experience uneven discharge at the above-mentioned modeling speeds, or will develop holes or other defects in the appearance of the resulting three-dimensional object. The resin composition according to this embodiment can produce three-dimensional objects with excellent appearance, even when modeled at high speed. Note that a resin composition "for 3D printers" according to the present disclosure means that it can be used as a filament when modeling three-dimensional objects with a 3D printer.

[0014] <Rubber component-containing styrene-based resin (A)> The resin composition according to this embodiment contains a rubber component-containing styrene-based resin (A) (hereinafter referred to as "resin (A)"). The "rubber component-containing styrene-based resin" refers to a resin obtained by copolymerizing or blending a rubber component with a styrene-based resin. By combining the resin (A) with the plate-like particles (B) described below, a resin composition is obtained that suppresses nozzle wear while simultaneously suppressing warpage and achieving high-speed modeling properties.

[0015] "Styrene-based resin" refers to a polymer containing, as a main component, a compound having a styrene skeleton. "Containing, as a main component, a compound having a styrene skeleton" means that the proportion of the compound having a styrene skeleton relative to the total amount (100% by mass) of raw material monomers is greater than 50% by mass. This proportion may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or even 95% by mass or more. Examples of compounds having a styrene skeleton include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene, with styrene being preferred.

[0016] In one embodiment, the styrene-based resin may be a copolymer obtained by copolymerizing the above-described compound having a styrene skeleton with another monomer. Examples of such copolymers include acrylonitrile-styrene copolymer (AS resin) and maleic anhydride-styrene copolymer (maleic anhydride-modified polystyrene resin).

[0017] Examples of the rubber component include conjugated diene rubber and non-diene rubber. Examples of conjugated diene rubber include conjugated diene hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. Examples of non-diene rubber include silicone rubber, ethylene-propylene rubber, acrylic rubber, and urethane rubber. Examples of styrene-based resins containing such conjugated diene rubber or non-diene rubber include high impact polystyrene (HIPS); acrylonitrile-butadiene-styrene copolymers (ABS resins); AXS resins such as acrylonitrile-acrylic rubber-styrene copolymers (AAS resins), acrylonitrile-chlorinated polyethylene-styrene copolymers (ACS resins), and acrylonitrile-(ethylene-propylene-diene rubber)-styrene copolymers (AES resins); and methyl methacrylate-butadiene-styrene copolymers (MBS resins). As the resin (A), these styrene-based resins containing rubber components can be used alone or in combination of two or more.

[0018] In one embodiment, the resin (A) preferably contains a conjugated diene rubber as a rubber component. When the resin (A) contains a styrene-based resin containing a conjugated diene rubber, molding processability is improved. In a more preferred embodiment, the resin (A) may contain at least one resin selected from HIPS and ABS resin. In a particularly preferred embodiment, the resin (A) is an ABS resin.

[0019] In one embodiment, from the viewpoint of easily ensuring the fluidity required for 3D printing using a 3D printer, the mass average molecular weight (Mw) of resin (A) is preferably 110,000 to 150,000. Furthermore, from the viewpoint of easily obtaining a 3D-modeled object with good impact resistance and heat resistance, the Mw may be 140,000 to 170,000. Two or more ABS resins with different Mws may be mixed to achieve the above-mentioned fluidity, heat resistance, impact resistance, and the like. When two or more ABS resins are mixed, it is preferable to adjust the average Mw of the mixture to be within the aforementioned range (e.g., 110,000 to 170,000). Furthermore, when using a single ABS resin, from the viewpoint of the above-mentioned fluidity, heat resistance, and impact resistance, it is particularly preferable to use an ABS resin with a Mw of 130,000 to 150,000. The Mw of resin (A) refers to a value measured using GPC, solvent: THF, measurement temperature: 40°C, and standard: polystyrene.

[0020] (ABS Resin) When resin (A) contains an ABS resin, the ABS resin preferably contains butadiene in an amount of 12 to 22% by mass, more preferably 16 to 20% by mass, relative to the total mass of the ABS resin. Furthermore, as described above, resin (A) may be a mixture of two or more types of ABS resins.

[0021] In one embodiment, the ABS resin preferably has an MFR (220°C, 10 kg load) of 10 to 30 g / 10 min, more preferably 15 to 30 g / 10 min, and even more preferably 20 to 30 g / 10 min. Using an ABS resin with such an MFR (220°C, 10 kg load) improves high-speed molding properties. When two or more types of ABS resins are used as resin (A), the blending ratio of each ABS resin may be adjusted so that the MFR (220°C, 10 kg load) of the ABS resin blend is 10 to 30 g / 10 min. For example, ABS resin 1 having an MFR (220°C, 10 kg load) of 30 to 45 g / 10 min and ABS resin 2 having an MFR (220°C, 10 kg load) of 10 to 15 g / 10 min may be combined in a ratio of ABS resin 1:ABS resin 2 in the range of 3 to 7:7 to 3.

[0022] When resin (A) contains an ABS resin, the proportion of the ABS resin in resin (A) is preferably 50% by mass or more, more preferably 80% by mass or more, relative to the total mass of resin (A). Resin (A) may also contain only ABS resin. That is, the proportion of resin (A) in resin (A) may be 50 to 100% by mass, or 80 to 100% by mass.

[0023] The proportion of resin (A) in the resin composition can be adjusted arbitrarily within a range of 70 to 90% by mass relative to the total mass of the resin composition. In one embodiment, the proportion of resin (A) in the resin composition may be 70 to 85% by mass, 73 to 83% by mass, or 73 to 80% by mass relative to the total mass of the resin composition.

[0024] <Plate-like particles (B)> The resin composition according to this embodiment contains 10 to 30 mass% of plate-like particles (B) having a Mohs hardness of 3 or less and having surfaces treated with a silane coupling agent (X), relative to the total mass of the resin composition. By combining such plate-like particles (B) with the resin (A), it is possible to achieve both suppression of warpage and high-speed modeling, and also suppress wear on the nozzle of a 3D printer.

[0025] Here, "plate-like particles" refers to particles that are thin and have an aspect ratio of 1.0 or more. Therefore, the plate-like particles may include particles other than spherical particles, such as those described as scaly particles, rod-like particles, or needle-like (fibrous) particles. In a preferred embodiment, the plate-like particles include scaly particles such as talc, clay (kaolin, bentonite), and mica. Whether the particles in the resin composition are plate-like particles can be determined, for example, by observing the particles (100 or more) contained in the resin composition according to this embodiment with an electron microscope such as an SEM and determining whether more than 50% by number of particles have a thin thickness and an aspect ratio of 1.0 or more. In one embodiment, the aspect ratio of the plate-like particles (B) may be 10 to 90, 10 to 80, or 20 to 70.

[0026] "Mohs hardness" is a hardness index expressed on a scale of 10, and is a value obtained by rubbing a material to be measured against a corresponding standard material and evaluating the hardness relative to the standard material based on whether scratches are left. The standard materials, in order from softest (Mohs hardness 1) to hardest (Mohs hardness 10), are 1: talc, 2: gypsum, 3: calcite, 4: fluorite, 5: apatite, 6: feldspar, 7: quartz, 8: topaz, 9: corundum, and 10: diamond. The Mohs hardness is measured by preparing two smooth plates with known Mohs hardness, placing the foreign object to be measured between the two plates, and rubbing the two plates together to check for scratches on the plate surface.

[0027] The particles constituting the plate-like particles (B) according to this embodiment (hereinafter sometimes referred to as "raw material particles") are not particularly limited as long as they are inorganic particles having a Mohs hardness of 3 or less, and examples thereof include at least one selected from the group consisting of diatomaceous earth, bentonite, boron nitride, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, calcium carbonate, talc, kaolin, clay, and mica. Among these, from the viewpoint of water absorption of the particles and warpage suppression effect, it is preferable that the raw material particles include at least one plate-like particle selected from talc and mica. That is, in a preferred embodiment, the plate-like particles (B) include at least one plate-like particle selected from talc and mica, the surface of which is treated with a silane coupling agent (X).

[0028] The inventors' studies have revealed that simply combining plate-like particles (such as untreated talc or mica) with a Mohs hardness of 3 or less with resin (A) results in nozzle wear during modeling. Furthermore, resin compositions incorporating such particles tend to leave coarse particles, which can easily cause defects during modeling. The inventors' studies have also revealed that the above-mentioned problems can be solved by combining plate-like particles (B) with resin (A) that have a Mohs hardness of 3 or less and whose surfaces have been treated with a silane coupling agent (X). The reason that combining plate-like particles (B) with resin (A) can simultaneously reduce nozzle wear, warpage, and achieve high-speed modeling is presumably because, when the resin material is melted, the functional groups contained in the silane coupling agent (X) on the surface of the plate-like particles (B) exhibit adhesiveness, making the laminate less likely to peel from the substrate, thereby facilitating warpage suppression. Even more surprisingly, it is believed that such plate-like particles (B) are likely to have the effect of reducing thermal shrinkage, and that by combining them with resin (A), the interaction (including chemical reaction) makes it easier to suppress thermal shrinkage, thereby achieving both warpage suppression and high-speed molding capabilities.

[0029] (Average Particle Diameter (D50)) In one embodiment, the average particle diameter (D50) of the plate-like particles (B) is preferably 1 to 50 μm, more preferably 5 to 40 μm, and even more preferably 10 to 35 μm. In one embodiment, the average particle diameter (D50) of the plate-like particles (B) may be 1 to 10 μm, 7 to 30 μm, 10 to 50 μm, 20 to 50 μm, or 20 to 35 μm. If the average particle diameter (D50) is within the above range, the decrease in MFR during mixing is small, making it easy to adjust the filament to achieve the high MFR required for 3D printer filaments. Furthermore, since the increase in elastic modulus during mixing is small, the filament does not break during production, and productivity is likely to be good. The average particle diameter (D50) of the plate-like particles (B) refers to the volume-based cumulative diameter (D50) evaluated by a laser diffraction scattering method. Furthermore, the term "volume-based cumulative diameter (D50)" refers to the particle diameter at which the cumulative value is 50% in the volume-based cumulative particle size distribution measured by a laser diffraction scattering method. The cumulative particle size distribution is expressed by a distribution curve with the particle diameter (μm) on the horizontal axis and the cumulative value (%) on the vertical axis.

[0030] (Silane Coupling Agent (X)) The surface of the plate-like particle (B) according to this embodiment is treated with a silane coupling agent (X). "Surface treated with a silane coupling agent (X)" means that at least a portion of the surface of the plate-like particle (B) is coated with the silane coupling agent (X). By treating the surface of the plate-like particle with the silane coupling agent (X), thickening of the resin composition is suppressed, and a resin composition excellent in high-speed molding ability is obtained. As the silane coupling agent (X), for example, a silane coupling agent containing a vinyl group, an amino group, a styryl group, an epoxy group, a mercapto group, or the like as a functional group in the structure can be used alone or in combination of two or more.

[0031] Examples of silane coupling agents containing a vinyl group in the structure (vinyl-based silane coupling agents) include vinyltrimethoxysilane, vinyltriethoxysilane, etc. These may be used alone or in combination of two or more.

[0032] Examples of silane coupling agents containing an amino group in the structure (amino-based silane coupling agents) include N-2-(aminoethyl)-3-aminopropylmethyldimethoxylane, N-2-(aminoethyl)-3-aminopropylmethyltrimethoxylane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, etc. These may be used alone or in combination of two or more.

[0033] Examples of silane coupling agents containing an epoxy group in their structure (epoxy-based silane coupling agents) include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc. These may be used alone or in combination of two or more.

[0034] Examples of silane coupling agents containing a styryl group in the structure (styryl-based silane coupling agents) include p-styryltrimethoxysilane.

[0035] Examples of silane coupling agents containing a mercapto group in the structure (mercapto-based silane coupling agents) include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc. These may be used alone or in combination of two or more.

[0036] In one embodiment, the silane coupling agent (X) is preferably a silane coupling agent containing an amino group or an epoxy group, and more preferably a silane coupling agent containing an epoxy group (epoxy-based silane coupling agent). In a particularly preferred embodiment, the silane coupling agent (X) contains 3-glycidoxypropyltrimethoxysilane. It is presumed that the inclusion of plate-like particles (B) having a Mohs hardness of 3 or less and having their surfaces treated with such a silane coupling agent (X) facilitates the development of adhesiveness derived from the functional group, preferably the epoxy group, in the silane coupling agent (X), and thus facilitates the suppression of warpage. It is also presumed that the reaction between the carbonyl group derived from the oxidation of the resin (A) and the functional group (preferably an amino group or an epoxy group) in the silane coupling agent (X) further facilitates the suppression of thermal shrinkage.

[0037] In one embodiment, the proportion of the silane coupling agent (X) in the plate-like particles (B) is preferably 0.1 to 3 mass%, more preferably 0.1 to 2 mass%, more preferably 0.5 to 1.5 mass%, and even more preferably 0.5 to 1 mass%, relative to the total mass of the raw material particles. By setting the proportion of the silane coupling agent (X) within the above range, the effect of suppressing warpage is more easily achieved. The method for treating the surfaces of the raw material particles with the silane coupling agent (X) is not particularly limited, and a common method can be used, such as dissolving the silane coupling agent in an organic solvent such as ethanol, spraying it onto the raw material particles, and heating while stirring. Whether the surfaces of the plate-like particles (B) in the resin composition have been treated with the silane coupling agent can be determined, for example, by measuring the particles dispersed in the resin using TEM-EDX to detect Si elements.

[0038] The proportion of the plate-like particles (B) relative to the total mass of the resin composition can be adjusted arbitrarily within the range of 10 to 30% by mass. If the proportion of the plate-like particles (B) is 10 to 30% by mass, it is possible to achieve both high-speed modeling performance and warpage suppression while suppressing nozzle wear. From the viewpoint of making it easier to adjust the MFR (220°C, 10 kg load) of the resin composition described below to 30 g / 10 min or less and making it easier to obtain a resin composition with better high-speed modeling performance, the proportion of the plate-like particles (B) may be 11 to 27% by mass or may be 15 to 25% by mass.

[0039] <Other Components> The resin composition according to this embodiment may contain components (other components) other than the resin (A) and the plate-like particles (B) described above, as long as the effects of the present invention are not impaired. Examples of other components include thermoplastic resins other than the resin (A) (e.g., PLA resin, PC resin, etc.); inorganic particles other than the plate-like particles (B); polymer fillers; additives such as ultraviolet absorbers, stabilizers, antioxidants, plasticizers, colorants, tinting agents, flame retardants, antistatic agents, fluorescent brighteners, matting agents, and impact strength improvers. These may be used alone or in combination of two or more. When the resin composition contains other components, they may be blended in an amount of 2% by mass or less relative to the total mass of the resin composition.

[0040] <Physical properties of resin composition> In one embodiment, from the viewpoint of being more excellent in high-speed molding ability and likely to become a resin composition with good warpage suppression, the MFR (220 ° C, 10 kg load) of the resin composition is preferably 30 g / 10 min or less, more preferably 6 g / 10 min or more and less than 30 g / 10 min, and even more preferably 8 to 28 g / 10 min. In one embodiment, the MFR (220 ° C, 10 kg load) of the resin composition may be in the range of 10 to 30 g / 10 min. The MFR (220 ° C, 10 kg load) of the resin composition can be measured, for example, using a product name "Melt Indexer G-02" manufactured by Toyo Seiki Seisakusho, Ltd., in accordance with Method A of JIS K7210-1.

[0041] [Method for Producing Resin Composition] The method for producing the resin composition according to this embodiment is not particularly limited as long as it achieves the effects of the present invention. For example, a method can be used in which the resin (A), the plate-like particles (B), and, if necessary, other components are mixed in a twin-screw kneader or the like, and then extruded into the desired shape to obtain a resin composition. When molding the resin composition into a filament, the kneader is preferably equipped with a strand spooler, gear pump, or the like for producing filaments. Since the resin composition according to this embodiment contains specific surface-treated plate-like particles (B), it also has good mixability with the resin (A). In one embodiment, when using a twin-screw kneader (e.g., manufactured by Shibaura Machine Co., Ltd., product name "TEM-26SX"), mixing can be performed under the following conditions: a set temperature of 200 to 220°C, a discharge rate of 30 to 40 kg / hr, and a rotation speed of 250 to 350 rpm.

[0042] In one embodiment, the method for producing a resin composition may include preparing plate-like particles (B), that is, surface-treating raw material particles with the silane coupling agent (X) to obtain plate-like particles (B), and mixing the resin (A) and the plate-like particles (B) and extruding the mixture into a desired shape to obtain a resin composition.

[0043] [Method for Manufacturing a Three-Dimensional Model] The method for manufacturing a three-dimensional model according to the present embodiment includes, as a raw resin, a resin composition according to the present embodiment, which comprises a rubber component-containing styrene-based resin (A) and plate-like particles (B) having a Mohs hardness of 3 or less and whose surfaces are treated with a silane coupling agent (X), the plate-like particles (B) being present in an amount of 10 to 30 mass% relative to the total mass of the resin composition. In a preferred embodiment, the raw resin consists solely of the resin composition according to the present embodiment. The manufacturing method according to the present embodiment includes melting the resin composition and extruding the molten resin composition through a nozzle to form a three-dimensional model. The manufacturing method according to the present embodiment is preferably a method for manufacturing a three-dimensional model using an FDM 3D printer. When the resin composition according to the present embodiment is used as a raw resin for an FDM 3D printer, it is formed into a filament shape.

[0044] FDM 3D printers generally include a heatable substrate (modeling table), an extrusion head (nozzle), a heat melter, a filament guide, a filament installation, and other raw material supply units. Some FDM 3D printers have an integrated nozzle and heat melter.

[0045] The nozzle is installed in a gantry structure, allowing it to move freely on the X-Y plane of the substrate. The substrate is a platform for constructing the desired three-dimensional object, support material, etc. The substrate configuration is not particularly limited, but a configuration that can be heated and kept warm is preferable from the perspective of easily improving the adhesion and dimensional stability of the laminate. Typically, at least one of the nozzle and the substrate is movable in the Z-axis direction, which is perpendicular to the X-Y plane.

[0046] In a preferred embodiment, a filament made of the resin composition of this embodiment is unwound from a raw material supply unit and fed into a nozzle by a pair of opposing rollers or gears. The filament is then heated and melted in the nozzle, and the molten filament is extruded from the tip of the nozzle. The nozzle moves in response to a signal transmitted based on the CAD model, supplying and stacking the molten filament onto a substrate to form a three-dimensional object. After this process is complete, the stack is removed from the substrate, and the desired three-dimensional object can be obtained by peeling off support materials or trimming off excess portions as needed.

[0047] The filament may be supplied to the nozzle by unwinding it, for example. It is preferable that the filament be stored in a cartridge wound into a bobbin, from the viewpoints of stable unwinding, protection from environmental factors such as humidity, and prevention of twisting and kinking.

[0048] A preferred method for feeding the filament to the nozzle while unwinding it is to engage the filament with a driving roll such as a nip roll or a gear roll, and feed the filament to the nozzle while drawing it up. From the viewpoint of stabilizing the filament feeding by more firmly gripping the filament by the engagement between the filament and the driving roll, a fine concave-convex pattern may be transferred onto the surface of the filament.

[0049] In the manufacturing method according to the present embodiment, the nozzle temperature is preferably set to 220 to 260° C., more preferably 240 to 260° C., to melt the filaments made of the resin composition. The substrate temperature is preferably set to 110° C. or less, more preferably 100° C. or less.

[0050] In addition, since the resin composition according to this embodiment has excellent high-speed modeling properties, the modeling speed can be set high. In one embodiment, the modeling speed may be 80 to 150 mm / s, or 90 to 120 mm / s.

[0051] In one embodiment, from the viewpoint of obtaining a three-dimensionally shaped object with less warping, the shaping atmosphere temperature inside the 3D printer is preferably room temperature to 50°C, and more preferably 30 to 40°C.

[0052] [Three-dimensionally shaped object] The three-dimensionally shaped object according to this embodiment is formed using the resin composition described above. That is, the three-dimensionally shaped object according to this embodiment contains the resin composition described above. In a preferred embodiment, the three-dimensionally shaped object is composed solely of the resin composition according to this embodiment. Such a three-dimensionally shaped object has little warping and a good appearance. Therefore, the three-dimensionally shaped object according to this embodiment can be suitably used for applications such as stationery; toys; covers for electronic devices such as smartphones; parts such as grips; educational materials, repair parts for home appliances and office equipment, various parts for automobiles, motorcycles, bicycles, etc.; building materials; plastic shaping molds, etc.

[0053] In one embodiment, when the three-dimensional object is placed on a horizontal plate, the maximum value of the gap (floating amount) between the bottom surface of the three-dimensional object and the horizontal plate is preferably less than 1 mm, and more preferably 0.3 mm or less. The floating amount can be determined by measuring the distance of the gap between the horizontal plate and the three-dimensional object with a curved ruler at a point where the bottom of the three-dimensional object is separated from the horizontal plate and floating, while the three-dimensional object is placed on the horizontal plate.

[0054] Another embodiment of the present disclosure is a use of the aforementioned resin composition as a resin raw material (filament) for a three-dimensional object manufactured using a 3D printer, or a method of using the same. Examples of a method of using the resin composition according to this embodiment as a resin raw material (filament) for a 3D printer include, for example, a method of obtaining a resin composition by the aforementioned method of manufacturing a resin composition, supplying the resin composition to a 3D printer, and extruding the resin composition from a nozzle while melting it to form a three-dimensional object.

[0055] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is described below. [1] A resin composition for 3D printers, comprising: a rubber component-containing styrene-based resin (A); and plate-like particles (B) having a Mohs hardness of 3 or less and having surfaces treated with a silane coupling agent (X), wherein the content of the plate-like particles (B) is 10 to 30 mass% relative to the total mass of the resin composition. [2] The resin composition for 3D printers according to [1], wherein the rubber component-containing styrene-based resin (A) comprises a conjugated diene rubber. [3] The resin composition for 3D printers according to [1] or [2], wherein the plate-like particles (B) comprise at least one plate-like particle selected from talc and mica, the surface of which has been treated with the silane coupling agent (X). [4] The resin composition for 3D printers according to any one of [1] to [3], wherein the rubber component-containing styrene-based resin (A) comprises an acrylonitrile-butadiene-styrene resin. [5] The resin composition for 3D printers according to any one of [1] to [4], wherein the silane coupling agent (X) contains an amino group or an epoxy group. [6] The resin composition for 3D printers according to any one of [1] to [5], wherein the resin composition has an MFR of 10 to 30 g / 10 min at 220°C under a 10 kg load. [7] The resin composition for 3D printers according to any one of [1] to [6], wherein the plate-like particles (B) have an average particle size (D50) of 1 to 50 μm. [8] A method for producing a three-dimensionally shaped object, comprising melting the resin composition for 3D printers according to any one of [1] to [7], and extruding the molten resin composition through a nozzle to form a three-dimensionally shaped object. [9] A three-dimensionally shaped object comprising the resin composition for 3D printers according to any one of [1] to [7].

[0056] The present invention will be explained in more detail below by showing examples, but the interpretation of the present invention is not limited to these examples.

[0057] <Raw Materials> The following were used as resin (A). (Resin (A)) Resin (A-1): ABS resin (manufactured by Denka Company Limited, product name "GR3000", MFR (220°C, 10 kg load): 14 g / 10 min). Resin (A-2): ABS resin (manufactured by Denka Company Limited, product name "QF", MFR (220°C, 10 kg load): 44 g / 10 min). The MFR of resin (A) is a value measured at 220°C and 10 kg load.

[0058] As the plate-like particles (B), those shown in Table 1 were used.

[0059] The following raw material particles were used for each plate-like particle (B). In Table 1, the amount of silane coupling agent (X) added means the ratio to the total mass of the raw material particles. (Raw Material Particles) Plate-like particles (B-1) and (B-2): talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "P-2", average particle size (D50): 7 μm, aspect ratio: 20). Plate-like particles (B-3) and (B-4): talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "PAOG-R", average particle size (D50): 30 μm). Plate-like particles (B-5) and (B-6): mica (Mohs hardness: 3, manufactured by Yamaguchi Mica Co., Ltd., product name "A-21S", average particle size (D50): 23 μm). Plate-like particles (B'-1): Talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "P-2", average particle size (D50): 7 μm). Plate-like particles (B'-2): Talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "PAOG-R", average particle size (D50): 30 μm). Plate-like particles (B'-3): Mica (Mohs hardness: 3, manufactured by Yamaguchi Mica Co., Ltd., product name "A-21S", average particle size (D50): 23 μm). Plate-like particles (B'-4): Alumina (Mohs hardness: 8, manufactured by Kinseimatec Co., Ltd., product name "Seraph (registered trademark) (product number 10030)", average particle size (D50): 10 μm). Plate-like particles (B'-5): glass fiber (Mohs hardness: 5, manufactured by Central Glass Fiber Co., Ltd., product name "ECS03-70", average particle diameter (average value obtained by SEM observation): 13 μm). The average particle diameter of the glass fiber plate-like particles (B'-5) was determined by measuring the major axes of 100 particles at 40x magnification using an SEM (manufactured by Hitachi High-Technologies Corporation, product name "TM-1000"), and the average value was used.

[0060] Example 1 A twin-screw kneader (manufactured by Thermo Fisher Scientific, product name "Process 11") equipped with a monofilament production strand spooler and a gear pump was mixed with 80 parts by mass of resin (A-1) and 20 parts by mass of plate-like particles (B-1), and the mixture was extruded at 220 ° C. to produce a 1.75 mm diameter filament made of a resin composition for 3D printers. The MFR (220 ° C., 10 kg load) of the obtained filament was measured in accordance with JIS K7210-1 Method A using a Toyo Seiki Seisakusho Co., Ltd. product name "Melt Indexer G-02". In addition, a three-dimensional object was molded using the obtained filament, and warpage, high-speed moldability, and nozzle wear resistance were evaluated under the following conditions. The results are shown in Table 2.

[0061] <Evaluation of warpage of 3D-shaped objects> Using a 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2"), a substrate temperature of 100 ° C., a nozzle temperature of 240 ° C., a modeling speed of 30 mm / s, an internal filling rate of 100%, and an ambient temperature inside the 3D printer of approximately 30 ° C., a 200 mm wide x 50 mm long x 4 mm thick evaluation sample plate (3D-shaped object) was created. The obtained sample plate was placed on a horizontal glass plate, and the maximum gap distance at the contact surface between the sample plate and the glass plate was measured with a curved ruler (if the maximum gap distance was 1 mm or less, it was measured with a high-precision contact digital sensor GT2 (manufactured by Keyence Corporation)). If the maximum value was less than 1 mm (evaluated as A or higher in the evaluation criteria below), it was deemed to have passed. (Evaluation criteria) S: There was no gap between the sample plate and the glass plate (the gap distance was 0 mm). A: The gap distance (maximum value) between the sample plate and the glass plate is more than 0 mm and less than 1 mm. B: The gap distance (maximum value) between the sample plate and the glass plate is 1 mm or more and less than 3 mm. C: The gap distance (maximum value) between the sample plate and the glass plate is 3 mm or more.

[0062] <Evaluation of high-speed modeling ability> Using the same 3D printer as used in the warpage evaluation, cylinders with a diameter of 75 mm and a height of 120 mm were printed under the following conditions: substrate temperature: 100°C, nozzle temperature: 240°C, printing speed: 100 mm / s, and ambient temperature inside the 3D printer: approximately 30°C. The appearance of the obtained cylinders was visually inspected for holes or uneven discharge, and evaluated according to the following evaluation criteria. A rating of B or higher was deemed acceptable. Note that "uneven discharge" refers to streaks or fine irregularities resulting from uneven discharge. (Evaluation criteria) A: No holes or uneven discharge in the cylinder. B: Uneven discharge was observed in some parts of the cylinder, but no holes were present. C: Holes and uneven discharge were present in the cylinder.

[0063] <Evaluation of nozzle abrasion resistance of 3D printer> After replacing the nozzle of a 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2") with a brass nozzle having a diameter of 0.4 mm, a nozzle temperature of 240 ° C., a modeling speed of 30 mm / s, and an ambient temperature inside the 3D printer of approximately 30 ° C., a 3D model was created using 10 m of a 1.75 mm diameter filament. Then, the nozzle diameter was measured with an optical microscope to calculate the amount of nozzle wear. If no wear was detected (evaluation A in the evaluation criteria below), it was deemed to have passed. (Evaluation criteria) A: The amount of nozzle wear is 0 mm. B: The amount of nozzle wear is greater than 0 mm and less than 0.05 mm. C: The amount of nozzle wear is 0.05 mm or more.

[0064] [Examples 2 to 9 and Comparative Examples 1 to 7] Filaments were produced under the same conditions as in Example 1, except that the resin compositions were as shown in Table 1. The MFR (220°C, 10 kg load) of the filaments in each example was measured under the same conditions as in Example 1. Warpage, high-speed modeling ability, and nozzle abrasion resistance were also evaluated under the same conditions as in Example 1. The results are shown in Table 2.

[0065]

[0066] As shown in Table 2, when used as a filament for a 3D printer, the resin composition satisfying the configuration of this embodiment suppressed nozzle wear and achieved both suppressed warpage and high-speed modeling capabilities. On the other hand, the resin composition of Comparative Example 1, in which the amount of plate-like particles (B) was less than 10 parts by mass, resulted in significant warpage of the resulting 3D-modeled object. Furthermore, the resin composition of Comparative Example 2, in which more than 30 parts by mass of plate-like particles (B) were blended, exhibited poor high-speed modeling capabilities. Furthermore, the resin compositions of Comparative Examples 3 to 5, which contained untreated talc and mica, exhibited low nozzle wear, but the resulting 3D-modeled object exhibited significant warpage and poor high-speed modeling capabilities. These results demonstrate that even relatively soft plate-like particles without surface treatment cannot solve all of the problems of the present application. Furthermore, Comparative Examples 6 and 7 demonstrate that plate-like particles with a Mohs hardness of greater than 3, even when surface-treated with a silane coupling agent, failed to solve the problems of the present invention. From the above results, it was confirmed that the resin composition according to this embodiment can suppress wear on the nozzle of a 3D printer, and can achieve both suppression of warping and high-speed modeling ability.

[0067] The resin composition according to this embodiment has industrial applicability as a filament for forming a three-dimensional object using a 3D printer.

Claims

1. A resin composition for 3D printers, A rubber component-containing styrene-based resin (A), and plate-like particles (B) having a Mohs hardness of 3 or less and having a surface treated with a silane coupling agent (X), The content of the plate-like particles (B) is 10 to 30% by mass relative to the total mass of the resin composition, and the MFR of the resin composition at 220 ° C. and a load of 10 kg is 10 to 30 g / 10 min. Resin composition for 3D printers.

2. The resin composition for 3D printers according to claim 1, wherein the rubber component-containing styrene-based resin (A) contains a conjugated diene rubber.

3. The plate-like particles (B) include at least one plate-like particle selected from talc and mica, the surface of which is treated with the silane coupling agent (X). The resin composition for 3D printers according to claim 1 or 2.

4. The resin composition for 3D printers according to claim 1 or 2, wherein the rubber component-containing styrene-based resin (A) contains an acrylonitrile-butadiene-styrene resin.

5. The resin composition for 3D printers according to claim 1 or 2, wherein the silane coupling agent (X) contains an amino group or an epoxy group.

6. The resin composition for 3D printers according to claim 1 or 2, wherein the average particle diameter (D50) of the plate-like particles (B) is 1 to 50 μm.

7. A method for producing a three-dimensional object, comprising: melting the resin composition for a 3D printer according to claim 1 or 2; and extruding the molten resin composition from a nozzle to form a three-dimensional object.

8. A three-dimensional object comprising the resin composition for 3D printers according to claim 1 or 2.