JP7685124B2 - Resin composition for 3D printers, 3D model and its manufacturing method - Google Patents

Description

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

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 from plastic and other materials.

3D printers are generally classified according to the deposition method they use, and known methods include binder injection, fused deposition modeling, liquid vat photopolymerization, and powder sintering additive manufacturing (SLS: Selective Laser Sintering, or SLM: Selective Laser Melting).

In a 3D printer, a resin material is used to create a three-dimensional object. For example, in the fused deposition modeling method (hereinafter referred to as the "FDM method"), a filament-shaped thermoplastic resin is used as the material, and the filament is melted and extruded from the nozzle of the 3D printer, and laminated to form the desired shape. As filaments for FDM 3D printers, polylactic acid resin (PLA resin) and acrylonitrile-butadiene-styrene resin (ABS resin) are mainly used. Of these, ABS resin is easy to obtain three-dimensional objects with excellent heat resistance and has good post-processing properties, but is prone to warping during modeling. Therefore, a resin material for 3D printers has been proposed in which glass fiber is blended into ABS resin to reduce warping. However, according to the study by the present inventors, it was found that although warping is improved by blending glass fiber, the nozzle of the 3D printer is worn out.

As another method for improving warpage of a three-dimensional object, Patent Literature 1 proposes using a styrene-based resin having a Tg of 50° C. or more and less than 100° C. However, the method of mixing a resin with a low Tg deteriorates the heat resistance of the resulting three-dimensional object.
Patent Document 2 proposes a material for three-dimensional modeling in which a specific amount of filler (including talc) is blended with a thermoplastic resin and a thermoplastic elastomer. However, according to the study by the inventors of the present application, it was found that a resin composition in which a thermoplastic resin is mixed with general talc does not sufficiently suppress warping during modeling, and wear of the nozzle of the 3D printer occurs after long-term use. It was also found that such a method cannot achieve both warping suppression and high-speed modeling.

Patent No. 7136131 International Publication No. 2021/060278

A first objective of the present disclosure is to provide a resin composition for 3D printers that does not wear out the nozzle of a 3D printer and that can suppress warping during modeling, a method for manufacturing a three-dimensional object using the same, and a three-dimensional object with minimal warping.
A second object of the present disclosure is to provide a resin composition for 3D printers that reduces wear on the nozzle of a 3D printer, and achieves both suppression of warping and high-speed modeling ability, a method for producing a three-dimensional object using the same, and a three-dimensional object with minimal warping.

As a result of intensive investigations, the inventors of the present application have found that the first problem can be solved by a resin composition (1) according to the following first embodiment.
[1] A resin composition (1) for a 3D printer,
The resin composition (1) comprises a rubber component-containing styrene-based resin (A1),
and plate-like particles (B1) having a Mohs hardness of 3 or less,
The content of the plate-like particles (B1) relative to the total mass of the resin composition (1) is 10% by mass or more, and the proportion of crystalline silica relative to the total mass of the resin composition (1) is less than 0.02% by mass. Resin composition (1) for 3D printers.

In addition, it has been found that the second problem can be solved by using a resin composition (2) according to the second embodiment described below.
<1> A resin composition (2) for 3D printers,
A rubber component-containing styrene-based resin (A2),
and plate-like particles (B2) having a Mohs hardness of 3 or less and having a surface treated with a silane coupling agent (X2),
The content of the plate-like particles (B2) is 10 to 30% by mass relative to the total mass of the resin composition (2).

According to the first embodiment of the present disclosure, the first problem can be solved. That is, it is possible to provide a resin composition for 3D printers (1) that prevents wear on the nozzle of the 3D printer and suppresses warping during modeling, a method for producing a three-dimensional object using the same (1), and a three-dimensional object (1) with little warping.
According to the second embodiment of the present disclosure, the second problem can be solved. That is, it is possible to provide a resin composition for 3D printers (2) that suppresses wear on the nozzle of the 3D printer and achieves both suppressed warping and high-speed modeling properties, a method for producing a three-dimensional object using the same (2), and a three-dimensional object (2) with little warping.

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 description given for one embodiment also applies to other embodiments, the description may be omitted in the other embodiments.
In the present disclosure, the expression "1 to 10" regarding a numerical range means "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."
The configurations and combinations thereof in each embodiment are merely examples, and addition, omission, substitution, and other modifications of the configurations are possible as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited to the embodiments.
Each feature disclosed herein may be combined with any other feature disclosed herein.

[First embodiment]
First, a resin composition for 3D printers (1) according to a first embodiment, a method for producing a three-dimensional object using the same (1), and a three-dimensional object (1) will be described.

[Resin composition for 3D printers (1)]
The first embodiment of the present disclosure relates to a resin composition for 3D printers (1).
The resin composition for 3D printers (1) according to the first embodiment includes a rubber component-containing styrene-based resin (A1) and a plate-like particle (B1) having a Mohs hardness of 3 or less, and the content of the plate-like particle (B1) relative to the total mass of the resin composition (1) is 10% by mass or more, and the ratio of crystalline silica to the total mass of the resin composition (1) is less than 0.02% by mass. According to the resin composition for 3D printers (1) according to the first embodiment (hereinafter, sometimes simply referred to as "resin composition (1)" or "resin material (1)"), the first problem can be solved. That is, the nozzle of the 3D printer is not worn, and warping during modeling can be suppressed.

In the present disclosure, "warping" refers to a phenomenon in which, when a three-dimensional object is modeled using a 3D printer, at least a part of the resin material laminated on the substrate (hereinafter, the resin material laminated on the substrate and the three-dimensional object in the middle of modeling will be referred to as the "laminate") peels off from the substrate surface, causing a gap (floating) between the substrate and the laminate. If warping occurs during modeling, problems such as difficulty in obtaining a three-dimensional object of the desired shape, the laminate coming into contact with the nozzle of the 3D printer and making it impossible to model any further, and the appearance of the obtained three-dimensional object becoming worse occur. The resin composition (1) according to the first embodiment can suppress warping during modeling to obtain a three-dimensional object of the desired shape. It can also prevent problems during modeling caused by warping.
In addition, in the present disclosure, the resin composition (1) “for 3D printers” means that it can be used as a filament when forming a three-dimensional object with a 3D printer.

<Rubber component-containing styrene-based resin (A1)>
The resin composition (1) according to the first embodiment contains a rubber component-containing styrene-based resin (A1) (hereinafter referred to as "resin (A1)"). 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 (A1) with the plate-like particles (B1) described later, warping during molding can be suppressed and nozzle wear can also be prevented.

The term "styrene-based resin" refers to a polymer mainly composed of a compound having a styrene skeleton. The term "mainly composed of a compound having a styrene skeleton" refers to a ratio of the compound having a styrene skeleton to the total amount (100% by mass) of raw material monomers that is more than 50% by mass. The ratio may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.
Examples of compounds having a styrene skeleton include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene, with styrene being preferred.

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

Examples of the rubber component include conjugated diene rubber and non-diene rubber. Examples of the conjugated diene rubber include conjugated diene hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. Examples of the 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 copolymer (ABS resin); AXS resins such as acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS resin), and acrylonitrile-(ethylene-propylene-diene rubber)-styrene copolymer (AES resin); and methyl methacrylate-butadiene-styrene copolymer (MBS resin). The term "AXS resin" refers to a resin in which acrylonitrile (A component in AXS resin) and styrene (S component in AXS resin) are graft polymerized onto a rubber component (X component in AXS resin).
As the resin (A1), the above-mentioned styrene-based resins containing a rubber component can be used alone or in combination of two or more kinds.

In one embodiment, the resin (A1) preferably contains a conjugated diene rubber as a rubber component. When the resin (A1) contains a styrene-based resin containing a conjugated diene rubber, the molding processability using a 3D printer is improved. In a more preferred embodiment, the resin (A1) may contain at least one resin selected from HIPS and ABS resin. In a particularly preferred embodiment, the resin (A1) is an ABS resin.

In one embodiment, the Tg (glass transition temperature) of the resin (A1) is preferably 100° C. or higher. If the Tg of the resin (A1) is 100° C. or higher, the heat resistance is likely to be good. In the present disclosure, the Tg of the resin (A1) can be measured by DSC (differential scanning calorimetry) (for example, product name "DSCvesta" manufactured by Rigaku Corporation).
In one embodiment, it is preferable to use an ABS resin having a Tg of 100° C. or more as the resin (A1).

In one embodiment, from the viewpoint of easily securing the fluidity required for modeling by a 3D printer, the mass average molecular weight (Mw) of the resin (A1) is preferably 100,000 to 150,000. From the viewpoint of easily obtaining a three-dimensional model with good impact resistance and heat resistance, the Mw may be 110,000 to 140,000. Note that two or more types of ABS resins with different Mw may be mixed to achieve both the fluidity, heat resistance, and impact resistance. When two or more types of ABS resins are mixed and used, it is preferable to adjust the average Mw of the mixture to be in the above-mentioned range (for example, 110,000 to 140,000). Also, when one type of ABS resin is used, it is particularly preferable to use an ABS resin with a Mw of 130,000 to 150,000 from the viewpoint of the above-mentioned fluidity, heat resistance, and impact resistance. Note that the Mw of the resin (A1) refers to a value measured using GPC, solvent: THF, measurement temperature: 40°C, and standard substance: polystyrene conversion.

(ABS resin)
When resin (A1) contains an ABS resin, the ABS resin preferably contains a conjugated diene rubber (butadiene) in an amount of 12 to 22% by mass, more preferably 16 to 20% by mass, based on the total mass of the ABS resin. Also, as described above, resin (A1) may be a mixture of two or more types of ABS resins.

In one embodiment, the MFR (220°C, 10 kg load) of the ABS resin is preferably 10 to 30 g/10 min, more preferably 10 to 25 g/10 min, and even more preferably 10 to 20 g/10 min. By using an ABS resin having such an MFR (220°C, 10 kg load), high-speed modeling properties are improved.
In one embodiment, when two or more kinds of ABS resins are used as the resin (A1), the blending ratio of each ABS resin may be adjusted so that the MFR (220°C, 10 kg load) of the mixture of ABS resins is 10 to 30 g/10 min, preferably 10 to 25 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 range of ABS resin 1:ABS resin 2 of 3 to 7:7 to 3. In the present disclosure, the MFR of the resin (A1) can be measured according to the A method of JIS K 7210-1.

When resin (A1) contains ABS resin, the proportion of ABS resin in resin (A1) is preferably 50% by mass or more, more preferably 80% by mass or more, based on the total mass of resin (A1). Resin (A1) may also contain only ABS resin. That is, the proportion of resin (A) in resin (A1) may be 50 to 100% by mass, 80 to 100% by mass, or 50 to 80% by mass.

The proportion of resin (A1) in resin composition (1) is preferably 50 to 90% by mass, more preferably 70 to 90% by mass, based on the total mass of resin composition (1). In one embodiment, the proportion of resin (A1) in resin composition (1) may be 50 to 70% by mass, based on the total mass of resin composition (1).

<Plate-like particles (B1)>
The resin composition (1) according to the first embodiment contains 10% by mass or more of plate-like particles (B1) having a Mohs hardness of 3 or less, based on the total mass of the resin composition (1). In the present disclosure, the term "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 contain particles other than spherical particles, such as particles expressed as scale-like particles, rod-like particles, or needle-like (fibrous) particles. Whether the resin composition (1) according to the first embodiment contains plate-like particles can be determined, for example, by observing the particles (100 or more) contained in the resin composition (1) according to the first embodiment with an electron microscope such as a SEM, and determining whether the particles are thin and have an aspect ratio of 1.0 or more and whether more than 50% by number of particles are contained.
In one embodiment, the aspect ratio of the plate-like particles (B1) may be 10-90, 10-80, or 20-70.

The plate-like particles (B1) according to the first embodiment are plate-like inorganic particles having a Mohs hardness of 3 or less, and have a low content of crystalline silica, or are particles that are substantially free of crystalline silica. By combining such plate-like particles (B1) with the above-mentioned resin (A1) and setting the ratio of crystalline silica in the resin composition (1) to a certain value or less, the nozzle of the 3D printer is not worn, and warping during modeling can be suppressed.
In addition, "particles with a low content of crystalline silica or particles that do not substantially contain crystalline silica" refers to particles with a crystalline silica content of less than 0.2% by mass or particles in which crystalline silica is not substantially detected, as measured by the X-ray diffraction method described below. As such plate-like particles (B1), for example, boron nitride, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, calcium carbonate, graphite, sepiolite, talc (synthetic smectite, etc.), mica, clay, etc. are preferred examples. Among these, from the viewpoint of the particles having low water absorption and more easily obtaining the warpage suppression effect, it is more preferable that the plate-like particles (B1) contain at least one plate-like particle selected from the above talc, mica, and clay, and more preferably contain talc and/or mica. In addition, commercially available products may be used as the plate-like particles (B1). Examples of commercially available products include those manufactured by Nippon Talc Co., Ltd. under the product names "MS-SF", "MicroAce (registered trademark) K-1#90-SF", and "FG-15F"; and those manufactured by IMI-FABI under the product name "HTP1LPultra5L".

The content of crystalline silica in the plate-like particles (B1) can be measured by X-ray diffraction (base standard absorption correction method). Specifically, first, the free silicic acid qualitative analysis of the plate-like particles (B1) is performed by an X-ray diffraction analyzer. At this time, quartz, cristobalite, and tridymite (manufactured by the Japan Working Environment Measurement Association, a public interest incorporated association) are used as standard samples for free silicic acid analysis. Then, the crystalline silica in the plate-like particles (B1) is quantitatively analyzed by X-ray diffraction (base standard absorption correction method). The measurement conditions in the X-ray diffraction method are as follows.
Measuring device: X-ray generator (for example, a tabletop rotating anode type X-ray generator manufactured by Rigaku Corporation, product name "Ultrax 18")
Target: Cu
Scanning angle: 5° to 60°
Step width: 0.02 degrees Measurement time: 0.6 seconds Tube voltage: 40 kV
Tube current: 30mA
Divergence slit: 1.00 degrees, scattering slit: 1.00 degrees, receiving slit: 0.3 mm

In addition, the detection limit of the content of crystalline silica in the plate-like particles (B1) under the above measurement conditions is 0.1% by mass. The content of crystalline silica in general talc and mica measured by the above method is about 1% by mass. The plate-like particles (B1) according to the first embodiment have a lower content of crystalline silica than general talc and mica. In a preferred embodiment, the content of crystalline silica in the plate-like particles (B1) is less than 0.2% by mass, and in a more preferred embodiment, it is 0.1% by mass or less. In a further preferred embodiment, the plate-like particles (B1) are at least one particle selected from talc, mica, and clay in which crystalline silica is not detected under the above measurement conditions.

"Mohs hardness" is a hardness index expressed on a 10-point scale, and is a value obtained by rubbing the corresponding standard substance with the substance being measured and evaluating the hardness of the substance relative to the standard substance based on whether scratches are left. The standard substances are, in order from soft (Mohs hardness 1) to hard (Mohs hardness 10), 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-surfaced plates with known Mohs hardness, placing the particle to be measured between the two plates, and rubbing the two plates together to check for scratches on the plate surface. If scratches are left on the plate surface, a plate with a lower Mohs hardness is used and the same procedure is repeated to determine the Mohs hardness.

(Average particle diameter (D50))
In one embodiment, the average particle diameter (D50) of the plate-like particles (B1) is preferably 1 to 50 μm, more preferably 1 to 40 μm, even more preferably 1 to 30 μm, and particularly preferably 1 to 20 μm. In one embodiment, the average particle diameter (D50) of the plate-like particles (B1) may be 1.5 to 13 μm. If the average particle diameter (D50) is within the above range, the MFR of the resin composition (1) is unlikely to decrease. Therefore, it is easy to obtain a filament that can achieve a high MFR required for a filament for a 3D printer. Furthermore, since the elastic modulus is unlikely to increase during mixing, the filament is unlikely to break during filament production, and the productivity is likely to be good. The average particle diameter (D50) of the plate-like particles (B1) refers to the volume-based cumulative diameter (D50) evaluated by a laser diffraction scattering method. In addition, the "volume-based cumulative diameter (D50)" means a particle diameter corresponding to a cumulative value of 50% in a volume-based cumulative particle size distribution measured by a laser diffraction scattering method. The cumulative particle size distribution is represented by a distribution curve with the particle size (μm) on the horizontal axis and the cumulative value (%) on the vertical axis.

(Silane coupling agent (X1))
The plate-like particle (B1) according to the first embodiment may have its surface treated with a silane coupling agent (X1). "The surface is treated with a silane coupling agent (X1)" means that at least a part of the surface of the plate-like particle (B1) is coated with the silane coupling agent (X1). By treating the surface of the plate-like particle (B1) with the silane coupling agent (X1), the resin composition (1) is less likely to thicken, the warping suppression effect during modeling is more likely to be obtained, and high-speed modeling properties are also likely to be good. In the present disclosure, "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 cause uneven discharge at the above-mentioned modeling speed, or will cause holes or the like in the appearance of the obtained three-dimensional object. By using particles whose surfaces have been treated with a silane coupling agent (X1) as the plate-like particles (B1), a three-dimensional object having excellent appearance can be easily obtained even when modeled at high speed.
The silane coupling agent (X1) is not particularly limited. In one embodiment, a silane coupling agent containing a functional group such as a vinyl group, an amino group, a styryl group, an epoxy group, or a mercapto group in the structure may be used alone or in combination of two or more kinds.

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.

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, and N-phenyl-3-aminopropyltrimethoxysilane. These may be used alone or in combination of two or more.

Examples of silane coupling agents containing an epoxy group in the 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 types.

Examples of silane coupling agents that contain a styryl group in their structure (styryl-based silane coupling agents) include p-styryltrimethoxysilane.

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 types.

In one embodiment, the silane coupling agent (X1) is preferably a silane coupling agent containing an amino group or an epoxy group in the structure, and more preferably contains a silane coupling agent containing an epoxy group (epoxy-based silane coupling agent). In a particularly preferred embodiment, the silane coupling agent (X1) can contain 3-glycidoxypropyltrimethoxysilane. It is presumed that by containing plate-like particles (B1) having a Mohs hardness of 3 or less and having a surface treated with such a silane coupling agent (X1), the adhesiveness derived from the functional group in the silane coupling agent (X1), preferably the epoxy group, becomes more likely to be expressed, and warping is more likely to be suppressed. It is also presumed that the reaction between the carbonyl group derived from the oxidation of the resin (A1) and the functional group in the silane coupling agent (X1) (preferably an amino group or an epoxy group) makes it easier to suppress thermal shrinkage.

In one embodiment, when the plate-like particle (B1) is used whose surface is treated with a silane coupling agent (X1), the amount of the silane coupling agent (X1) added to the plate-like particle (B1) may be 0.1 to 3 mass%, 0.1 to 2 mass%, 0.5 to 1.5 mass%, or 0.5 to 1 mass% based on the total mass (100 mass%) of the plate-like particle (B1). By setting the ratio of the silane coupling agent (X1) within the above range, the effect of suppressing warpage during molding is more easily obtained.
As the plate-like particle (B1) whose surface is treated with a silane coupling agent (X1), it is preferable to use at least one selected from the above-mentioned talc, mica, and clay having a crystalline silica content of less than 0.2% by mass, and it is more preferable to use talc and/or mica. By using such plate-like particle (B1), it is easy to obtain a resin composition (1) that does not wear out the nozzle of a 3D printer, can suppress warping during modeling, and can also be modeled at high speed.

The method for treating the surface of the raw material particles with the silane coupling agent (X1) is not particularly limited, and a general method can be adopted, such as dissolving the silane coupling agent (X1) in an organic solvent such as ethanol, spraying the resulting solution onto the raw material particles, and heating the mixture while stirring.
Whether the surface of the plate-like particle (B1) has been treated with a silane coupling agent may be determined by analyzing the surface of the plate-like particle (B1) in the resin composition (1) by TEM-EDX and detecting Si element.

The ratio of the plate-like particles (B1) to the total mass of the resin composition (1) according to the first embodiment is 10% by mass or more. The ratio of the plate-like particles (B1) in the resin composition (1) can be adjusted arbitrarily within a range of 10% by mass or more. From the viewpoint of making it easier to suppress warping during molding, the ratio of the plate-like particles (B1) to the total mass of the resin composition (1) may be 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more. In one embodiment, the ratio of the plate-like particles (B1) to the total mass of the resin composition (1) may be 10 to 40% by mass, or 10 to 30% by mass.

<Crystalline Silica>
The ratio of crystalline silica to the total mass of the resin composition (1) according to the first embodiment is less than 0.02% by mass. By including the resin (A1) and the plate-like particles (B1) and by having the ratio of crystalline silica in the resin composition (1) being less than 0.02% by mass, warping during modeling can be suppressed, and wear of the nozzle of the 3D printer can also be suppressed.
The proportion of crystalline silica in the resin composition (1) may be 0.015% by mass or less, or 0.01% by mass or less, from the viewpoint of more easily suppressing the wear of the nozzle. In addition, it is preferable that crystalline silica is not detected when measured under the above-mentioned measurement conditions for the content of crystalline silica in the plate-like particles (B1). The proportion of crystalline silica in the resin composition (1) may be obtained by heating the resin composition (1) at 500 ° C. in a nitrogen atmosphere to incinerate it, and then measuring the proportion of crystalline silica in the resulting residue under the above-mentioned measurement conditions, or the proportion of crystalline silica in the resin composition (1) may be calculated from the content of crystalline silica in the plate-like particles (B1).

Through the study of the present inventors, it has been found that even when a resin composition containing particles with a relatively low Mohs hardness, such as common talc or mica, is used as a filament for a 3D printer, the nozzle of the 3D printer wears out after long-term use. As a result of intensive study of the reason for this, the present inventors have found that the nozzle wears out due to the crystalline silica contained in the particles. The resin composition (1) according to the first embodiment is a combination of plate-shaped particles (B1) (preferably plate-shaped inorganic particles with a low content of crystalline silica) having a Mohs hardness of 3 or less and the above-mentioned resin (A1), and the proportion of crystalline silica in the resin composition (1) is less than 0.02% by mass, thereby preventing the nozzle of the 3D printer from wearing out and suppressing warping during modeling. In this disclosure, "the nozzle of a 3D printer does not wear out" may include when the 3D printer is used for an extended period of time (for example, when 10 m of filament is ejected from the nozzle to form a three-dimensional object), the amount of nozzle wear before and after use is less than 0.01 mm, or the inside of the nozzle is not scratched (nozzle wear is 0 mm).

<Other ingredients>
The resin composition (1) according to the first embodiment can contain components (other components) other than the above-described resin (A1) and plate-like particles (B1) within the range that does not impair the effects of the present invention.
Examples of other components include thermoplastic resins other than the resin (A1) (e.g., PLA resin, PC resin, etc.); inorganic particles other than the plate-like particles (B1) (e.g., inorganic particles having a Mohs hardness of 4 or more); 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. One or more of these other components can be blended into the resin composition (1). On the other hand, from the viewpoint of preventing nozzle wear of the 3D printer, it is preferable that the resin composition (1) according to the first embodiment does not contain inorganic particles other than the plate-like particles (B1). In one embodiment, when the resin composition (1) contains other components (excluding inorganic particles other than the plate-like particles (B1)), they may be blended in a range of 2 mass% or less with respect to the total mass of the resin composition (1).

<Physical Properties of Resin Composition (1)>
In one embodiment, from the viewpoint of easily obtaining the effect of suppressing warping during molding, the MFR (220°C, 10 kg load) of the resin composition (1) is preferably 10 g/10 min or more, more preferably 10 to 19 g/10 min. The MFR (220°C, 10 kg load) of the resin composition (1) can be measured according to Method A of JIS K 7210-1.

[Method for producing resin composition (1)]
The method for producing the resin composition (1) according to the first embodiment is not particularly limited as long as it has the effect of the present invention, and for example, the resin (A1), the plate-like particles (B1), and other components as necessary are mixed in a twin-screw kneader or the like, and then extruded into a desired shape to obtain the resin composition (1). When the resin composition (1) is molded into a filament, the kneader is preferably equipped with a strand spooler for producing filaments, a gear pump, or the like.
The resin composition (1) according to the first embodiment is also excellent in mixability. In one embodiment, when using a twin-screw kneader (for example, manufactured by Shibaura Machine Co., Ltd., product name "TEM-26SX"), mixing can be performed under the conditions of 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. It is presumed that the improved dispersibility of the plate-like particles (B1) in the resin composition (1) makes it easier to exhibit the warpage suppression effect during molding. From these viewpoints, it is preferable to set the rotation speed of the twin-screw kneader to 300 rpm or more. In one embodiment, from the viewpoint of the dispersibility and shape maintenance of the plate-like particles (B1), the rotation speed may be set to 300 to 600 rpm.

In one embodiment, when the plate-like particles (B1) are used whose surfaces have been treated with a silane coupling agent (X1), the method may include surface-treating the plate-like particles (B1) with the silane coupling agent (X1). That is, the method may include surface-treating the plate-like particles (B1) as raw material particles with the above-mentioned silane coupling agent (X1) to obtain plate-like particles (B1) whose surfaces have been treated with the silane coupling agent (X1), and mixing the resin (A1) and the plate-like particles (B1) treated with the silane coupling agent (X1) and extruding them into a desired shape to obtain the resin composition (1) according to the first embodiment.

[Method for manufacturing three-dimensional object (1)]
The method for producing a three-dimensional object (1) according to the first embodiment includes forming a three-dimensional object using the resin composition for a 3D printer (1) according to the first embodiment.
More specifically, the manufacturing method (1) according to the first embodiment preferably includes melting the resin composition (1) according to the first embodiment, and extruding the melted resin composition (1) according to the first embodiment from a nozzle to form a three-dimensional object. The manufacturing method (1) according to the first embodiment is preferably a method for manufacturing a three-dimensional object using an FDM 3D printer. When the resin composition (1) according to the first embodiment is used as a raw material resin for an FDM 3D printer, a filament-shaped product is used.

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 parts. Some FDM 3D printers have an integrated nozzle and heat melter.

The nozzle is installed in a gantry structure, allowing it to move freely on the XY plane of the substrate. The substrate is a platform for constructing the desired three-dimensional object, support material, etc. There are no particular limitations on the configuration of the substrate, but a configuration that can be heated and kept warm is preferable from the viewpoint of making it easier to improve the adhesion and dimensional stability of the laminate. Usually, at least one of the nozzle and the substrate is movable in the Z-axis direction perpendicular to the XY plane.

In a preferred embodiment, a filament made of the resin composition (1) according to the first embodiment is unwound from a raw material supply section and fed into a nozzle by a pair of opposing rollers or gears. It is then heated and melted in the nozzle, and the molten filament is extruded from the tip of the nozzle. In response to a signal transmitted based on a CAD model, the nozzle moves its position while supplying and stacking the molten filament onto the substrate to form a three-dimensional object. After this process is completed, the stacked object is removed from the substrate, and the desired three-dimensional object can be obtained by peeling off support materials, etc., or cutting off excess portions as necessary.

One way to supply the filament to the nozzle is, for example, to unwind and supply the filament. It is preferable that the filament is stored in a cartridge wound into a bobbin, from the standpoints of stable unwinding, protection from environmental factors such as moisture, and prevention of twisting and kinking.

A preferred method of feeding the filament to the nozzle while unwinding it is to engage the filament with a driving roll such as a nip roll or gear roll, and feed the filament to the nozzle while pulling it up. From the viewpoint of stabilizing the filament feed by making the filament gripped by the engagement of the driving roll stronger, a fine uneven shape may be transferred to the surface of the filament.

In the manufacturing method (1) according to the first 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 (1) according to the first embodiment. The substrate temperature is preferably set to 110°C or less, more preferably 100°C or less.

In one embodiment, the build speed may be 80 to 150 mm/s, or may be 90 to 120 mm/s.

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

According to the manufacturing method (1) of the first embodiment, warping during modeling can be suppressed. In addition, it is possible to manufacture a three-dimensional object with less warping and excellent appearance.

[3D object (1)]
The three-dimensional object (1) according to the first embodiment includes the resin composition (1) according to the first embodiment. In a preferred embodiment, the three-dimensional object (1) is composed only of the resin composition (1) according to the first embodiment. Such a three-dimensional object (1) has little warping and a good appearance. Therefore, the three-dimensional object (1) according to the first embodiment can be suitably used for applications such as stationery; toys; covers for electronic devices such as smartphones; parts such as grips; school teaching materials, home appliances, repair parts for office automation equipment, various parts for automobiles, motorcycles, bicycles, etc.; building materials; plastic shaping molds, etc.

In one embodiment, when the three-dimensional object (1) is placed on a horizontal plate, the maximum value of the gap (floating amount) between the bottom surface of the three-dimensional object (1) and the horizontal plate is preferably less than 1 mm, more preferably 0.5 mm or less, and even more preferably 0.3 mm or less. The floating amount can be determined from the maximum value of the gap distance between the horizontal plate and the three-dimensional object (1) at a point where the bottom of the three-dimensional object (1) is separated from the horizontal plate and floating, measured with a curved ruler, while the three-dimensional object (1) is placed on the horizontal plate.

Another aspect of the first embodiment is the use of the resin composition (1) according to the first embodiment as a resin raw material (filament) for a three-dimensional object manufactured using a 3D printer (1), or a method of using the same (1).
An example of the method (1) for using the resin composition (1) according to the first embodiment as a resin raw material (filament) for a 3D printer is a method including obtaining the resin composition (1) according to the first embodiment by the above-described method for producing a resin composition (1), supplying the resin composition (1) to a 3D printer, and extruding the resin composition (1) from a nozzle while melting it to form a three-dimensional object.

A non-limiting list of exemplary aspects and exemplary combinations of aspects of the first embodiment are set forth below.
[1] A resin composition (1) for a 3D printer,
The resin composition (1) comprises a rubber component-containing styrene-based resin (A1),
and plate-like particles (B1) having a Mohs hardness of 3 or less,
The content of the plate-like particles (B1) relative to the total mass of the resin composition (1) is 10% by mass or more, and the proportion of crystalline silica relative to the total mass of the resin composition (1) is less than 0.02% by mass. Resin composition (1) for 3D printers.
[2] The resin composition for 3D printers (1) described in [1], wherein the average particle diameter (D50) of the plate-like particles (B1) is 1 to 50 μm.
[3] The resin composition for 3D printers (1) according to [1] or [2], wherein the rubber component-containing styrene-based resin (A1) contains a conjugated diene rubber.
[4] The resin composition for 3D printers according to any one of [1] to [3], wherein the rubber component-containing styrene-based resin (A1) has a Tg of 100 ° C. or higher.
[5] The content of the crystalline silica in the plate-like particles (B1) is less than 0.2% by mass relative to the total mass of the plate-like particles (B1). [1] The resin composition for 3D printers according to any one of [1] to [4].
[6] The resin composition (1) for 3D printers according to any one of [1] to [5], wherein the plate-like particles (B1) include at least one plate-like particle selected from talc, mica, and clay.
[7] The resin composition for 3D printers (1) according to any one of [1] to [6], wherein the rubber component-containing styrene-based resin (A1) contains an acrylonitrile-butadiene-styrene resin.
[8] A method for producing a three-dimensional object (1), comprising the steps of: forming a three-dimensional object using the resin composition for a 3D printer (1) according to any one of [1] to [7].
[9] A three-dimensional object (1) comprising the resin composition for 3D printers (1) according to any one of [1] to [7].

Moreover, preferred aspects of the first embodiment are as follows.
<1> A resin composition (1) for a 3D printer,
The resin composition (1) contains a rubber component-containing styrene-based resin (A1) and, as inorganic particles, only plate-like particles (B1) having a Mohs hardness of 3 or less,
The content of the plate-like particles (B1) relative to the total mass of the resin composition (1) is 10% by mass or more, and the proportion of crystalline silica relative to the total mass of the resin composition (1) is less than 0.02% by mass. Resin composition (1) for 3D printers.
<2> The plate-like particles (B1) are at least one plate-like particle selected from talc, mica, and clay having a crystalline silica content of less than 0.2% by mass, or boron nitride. The resin composition (1) for 3D printers according to <1>.
<3> The resin composition for 3D printers according to <1> or <2>, wherein the rubber component-containing styrene-based resin (A1) contains an ABS resin having an MFR (220 ° C., 10 kg load) of 10 g / 10 min or more.
<4> A method for producing a three-dimensional object (1), comprising the step of forming a three-dimensional object using the resin composition for a 3D printer (1) according to any one of <1> to <3>.
<5> A three-dimensional object (1) comprising the resin composition for 3D printers (1) according to any one of <1> to <3>.

Second Embodiment
Next, a resin composition for 3D printers (2) according to a second embodiment, a method for producing a three-dimensional object using the resin composition (2), and a three-dimensional object (2) will be described.

[Resin composition for 3D printers (2)]
The resin composition for 3D printers (2) according to the second embodiment includes a rubber component-containing styrene-based resin (A2) and a plate-like particle (B2) having a Mohs hardness of 3 or less and a surface treated with a silane coupling agent (X2), and the content of the plate-like particle (B2) is 10 to 30% by mass with respect to the total mass of the resin composition (2). According to the resin composition for 3D printers (2) according to the second embodiment (hereinafter, sometimes simply referred to as "resin composition (2)" or "resin material (2)"), the second problem can be solved. That is, it is possible to suppress the wear of the nozzle of the 3D printer, and to achieve both suppression of warping and high-speed modeling.

In addition, the "warping" referred to here refers to a phenomenon in which, when a three-dimensional object is formed using a 3D printer, at least a part of the resin material (hereinafter sometimes referred to as "laminate") laminated on a substrate peels off from the substrate surface, causing a gap (floating) between the substrate and the laminate. When such a phenomenon occurs, problems occur, such as it being difficult to obtain 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, and can obtain a three-dimensional object of the desired shape. It can also prevent problems during modeling caused by warping. In this disclosure, the "laminate" refers to a three-dimensional object in the middle of being modeled.

The resin composition (2) according to the second embodiment can achieve high-speed modeling properties in addition to suppressing warping. 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 be discharged unevenly at the above-mentioned modeling speed, or will have holes or the like in the appearance of the obtained three-dimensional object. With the resin composition (2) according to the second embodiment, it is possible to model a three-dimensional object with excellent appearance, even when modeled at high speed.
In addition, the resin composition (2) “for 3D printers” in the present disclosure means that it can be used as a filament when forming a three-dimensional object with a 3D printer.

<Rubber component-containing styrene-based resin (A2)>
The resin composition (2) according to the second embodiment contains a rubber component-containing styrene-based resin (A2) (hereinafter referred to as "resin (A2)"). 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 (A2) with the plate-like particles (B2) described later, a resin composition is obtained that suppresses nozzle wear while simultaneously suppressing warpage and achieving high-speed modeling properties.

The term "styrene-based resin" refers to a polymer mainly composed of a compound having a styrene skeleton. The term "mainly composed of a compound having a styrene skeleton" refers to a ratio of the compound having a styrene skeleton to the total amount (100% by mass) of raw material monomers that is more than 50% by mass. The ratio may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.
Examples of compounds having a styrene skeleton include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene, with styrene being preferred.

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

Examples of the rubber component include conjugated diene rubber or non-diene rubber. Examples of the conjugated diene rubber include conjugated diene hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. Examples of the 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 copolymer (ABS resin); AXS resins such as acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS resin), and acrylonitrile-(ethylene-propylene-diene rubber)-styrene copolymer (AES resin); and methyl methacrylate-butadiene-styrene copolymer (MBS resin). As the resin (A2), one type of styrene-based resin containing these rubber components can be used alone or two or more types can be used in combination.

In one embodiment, the resin (A2) preferably contains a conjugated diene rubber as a rubber component. When the resin (A2) contains a styrene-based resin containing a conjugated diene rubber, the molding processability is improved. In a more preferred embodiment, the resin (A2) may contain at least one resin selected from HIPS and ABS resin. In a particularly preferred embodiment, the resin (A2) is an ABS resin.

In one embodiment, from the viewpoint of easily securing the fluidity required for modeling by a 3D printer, the mass average molecular weight (Mw) of the resin (A2) is preferably 110,000 to 150,000. From the viewpoint of easily obtaining a three-dimensional model with good impact resistance and heat resistance, the Mw may be 140,000 to 170,000. Note that two or more types of ABS resins with different Mw may be mixed to achieve both the fluidity, heat resistance, and impact resistance. When two or more types of ABS resins are mixed and used, it is preferable to adjust the average Mw of the mixture to be in the above-mentioned range (for example, 110,000 to 170,000). Also, when one type of ABS resin is used, it is particularly preferable to use an ABS resin with a Mw of 130,000 to 150,000 from the viewpoint of the above-mentioned fluidity, heat resistance, and impact resistance. Note that the Mw of the resin (A2) refers to a value measured using GPC, solvent: THF, measurement temperature: 40°C, and standard substance: polystyrene conversion.

(ABS resin)
When resin (A2) 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, based on the total mass of the ABS resin. Furthermore, as described above, resin (A2) may be a mixture of two or more types of ABS resins.

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. By using an ABS resin having such an MFR (220°C, 10 kg load), high-speed molding properties are improved. When two or more types of ABS resins are used as resin (A2), the blending ratio of each ABS resin may be adjusted so that the MFR (220°C, 10 kg load) of the ABS resin mixture 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 of 3-7:7-3.

When resin (A2) contains ABS resin, the proportion of ABS resin in resin (A2) is preferably 50% by mass or more, and more preferably 80% by mass or more, based on the total mass of resin (A2). Resin (A2) may also contain only ABS resin. In other words, the proportion of resin (A2) in resin (A2) may be 50 to 100% by mass, or 80 to 100% by mass.

The proportion of resin (A2) in resin composition (2) can be adjusted arbitrarily within the range of 70 to 90% by mass, based on the total mass of resin composition (2). In one embodiment, the proportion of resin (A2) in resin composition (2) may be 70 to 85% by mass, 73 to 83% by mass, or 73 to 80% by mass, based on the total mass of resin composition (2).

<Plate-like particles (B2)>
The resin composition (2) according to the second embodiment contains 10 to 30% by mass of plate-like particles (B2) having a Mohs hardness of 3 or less and having a surface treated with a silane coupling agent (X2) relative to the total mass of the resin composition (2). By combining such plate-like particles (B1) with the above-mentioned resin (A1), it is possible to achieve both suppression of warping and high-speed modeling properties, and also to suppress wear of the nozzle of the 3D printer.

Here, the term "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 expressed 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 SEM, and determining whether the particles are thin and have an aspect ratio of 1.0 or more at more than 50% by number.
In one embodiment, the aspect ratio of the plate-like particles (B2) may be 10-90, 10-80, or 20-70.

"Mohs hardness" is a hardness index expressed on a 10-point scale, and is a value obtained by rubbing the material being measured against a corresponding standard material and evaluating the hardness of the material relative to the standard material based on whether or not it is scratched. The standard materials are, in order from softest (Mohs hardness 1) to hardest (Mohs hardness 10), 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.

The particles constituting the plate-like particles (B2) according to the second 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. Of 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 (B2) include at least one plate-like particle selected from talc and mica, the surface of which is treated with a silane coupling agent (X2).

The inventors of the present application have found that simply combining plate-like particles (untreated talc, mica, etc.) with a Mohs hardness of 3 or less with resin (A2) causes nozzle wear during modeling. In addition, resin compositions combining such particles tend to leave coarse particles, which are prone to defects during modeling. As a result of the inventors' studies, it has been found that the above-mentioned problems can be solved by combining plate-like particles (B2) with resin (A2) that have a Mohs hardness of 3 or less and whose surfaces have been treated with a silane coupling agent (X2). The reason why the combination of plate-like particles (B2) with resin (A2) can achieve both nozzle wear, warpage suppression, and high-speed modeling is presumably because, when the resin material is melted, the functional groups contained in the silane coupling agent (X2) on the surface of the plate-like particles (B2) exert adhesive properties, making it difficult for the laminate to peel off from the substrate, which makes it easier to suppress warpage. Even more surprisingly, it is presumed that such plate-like particles (B2) are likely to have the effect of reducing thermal shrinkage, and that by combining them with resin (A2), the interaction (including chemical reaction) makes it easier to suppress thermal shrinkage, thereby enabling both warpage suppression and high-speed moldability to be achieved.

(Average particle diameter (D50))
In one embodiment, the average particle diameter (D50) of the plate-like particles (B2) 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 (B2) may be 1 to 10 μm, may be 10 to 50 μm, may be 20 to 50 μm, or may be 20 to 35 μm. If the average particle diameter (D50) is within the above range, the decrease in MFR during mixing is small, so it is 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 the productivity is likely to be good. The average particle diameter (D50) of the plate-like particles (B2) refers to the volume-based cumulative diameter (D50) evaluated by a laser diffraction scattering method. The term "volume-based cumulative diameter (D50)" refers to a particle diameter at which the cumulative value is 50% in a 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.

(Silane coupling agent (X2))
The plate-like particle (B2) according to the second embodiment has its surface treated with a silane coupling agent (X2). "Surface treated with a silane coupling agent (X2)" means that at least a part of the surface of the plate-like particle (B2) is coated with a silane coupling agent (X2). By treating the surface of the plate-like particle with a silane coupling agent (X2), the viscosity of the resin composition is suppressed, and a resin composition (2) having excellent high-speed molding properties is obtained.
As the silane coupling agent (X2), for example, a silane coupling agent containing a functional group such as a vinyl group, an amino group, a styryl group, an epoxy group, a mercapto group, etc. in the structure can be used alone or in combination of two or more kinds.

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.

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, and N-phenyl-3-aminopropyltrimethoxysilane. These may be used alone or in combination of two or more.

Examples of silane coupling agents containing an epoxy group in the 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 types.

Examples of silane coupling agents that contain a styryl group in their structure (styryl-based silane coupling agents) include p-styryltrimethoxysilane.

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 types.

In one embodiment, the silane coupling agent (X2) is preferably a silane coupling agent containing an amino group or an epoxy group, and more preferably contains a silane coupling agent containing an epoxy group (epoxy-based silane coupling agent). In a particularly preferred embodiment, the silane coupling agent (X2) contains 3-glycidoxypropyltrimethoxysilane. It is presumed that by containing plate-like particles (B2) having a Mohs hardness of 3 or less and having a surface treated with such a silane coupling agent (X2), the adhesiveness derived from the functional group in the silane coupling agent (X2), preferably the epoxy group, becomes more likely to be expressed, and warping is more likely to be suppressed. It is also presumed that the reaction between the carbonyl group derived from the oxidation of the resin (A2) and the functional group in the silane coupling agent (X2) (preferably an amino group or an epoxy group) makes it easier to suppress thermal shrinkage.

In one embodiment, the ratio of the silane coupling agent (X2) in the plate-like particle (B2) 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%, based on the total mass of the raw material particles. By setting the ratio of the silane coupling agent (X2) within the above range, the effect of suppressing warpage is more easily obtained. The method of treating the surface of the raw material particles with the silane coupling agent (X2) is not particularly limited, and a general method can be adopted, such as dissolving the silane coupling agent in an organic solvent such as ethanol, spraying it on the raw material particles, and heating while stirring.
Whether the surfaces of the plate-like particles (B2) in the resin composition (2) have been treated with a silane coupling agent can be determined, for example, by measuring the particles dispersed in the resin with TEM-EDX and detecting the Si element.

The ratio of the plate-like particles (B2) to the total mass of the resin composition (2) can be adjusted arbitrarily within the range of 10 to 30% by mass. If the ratio of the plate-like particles (B2) is 10 to 30% by mass, it is possible to achieve both high-speed modeling properties 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 (2) described later to 30 g/10 min or less and making the resin composition (2) more excellent in high-speed modeling properties, the ratio of the plate-like particles (B2) may be 11 to 27% by mass or 15 to 25% by mass.

<Other ingredients>
The resin composition (2) according to the second embodiment can contain components (other components) other than the above-mentioned resin (A2) and plate-like particles (B2) within the range that does not impair the effects of the present invention.
Examples of other components include thermoplastic resins other than the resin (A2) (e.g., PLA resin, PC resin, etc.); inorganic particles other than the plate-like particles (B2); 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 mass% or less based on the total mass of the resin composition.

<Physical Properties of Resin Composition (2)>
In one embodiment, from the viewpoint of being more excellent in high-speed modeling and more favorable in warpage suppression, the MFR (220 ° C., 10 kg load) of the resin composition (2) 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 (2) may be in the range of 10 to 30 g / 10 min. The MFR (220 ° C., 10 kg load) of the resin composition (2) can be measured according to JIS K7210, for example, using a product name "Melt Indexer G-02" manufactured by Toyo Seiki Seisakusho Co., Ltd.

[Method for producing resin composition (2)]
The method for producing the resin composition (2) according to the second embodiment is not particularly limited as long as it has the effect of the present invention, and for example, the resin (A2), the plate-like particles (B2), and other components as necessary are mixed in a twin-screw kneader or the like, and then extruded into a desired shape to obtain a resin composition. When the resin composition (2) is molded into a filament shape, the kneader is preferably equipped with a strand spooler for producing filaments, a gear pump, or the like.
The resin composition (2) according to the second embodiment contains the specific surface-treated plate-like particles (B2), and therefore has good mixability with the resin (A2). In one embodiment, when a twin-screw kneader (for example, manufactured by Shibaura Machine Co., Ltd., product name "TEM-26SX") is used, mixing can be performed under the conditions of 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.

In one embodiment, the method for producing the resin composition (2) may include preparing plate-like particles (B2). That is, the method may include surface-treating the raw material particles with the above-mentioned silane coupling agent (X2) to obtain plate-like particles (B2), and mixing the resin (A2) and the plate-like particles (B2) and extruding them into a desired shape to obtain the resin composition (2).

[Method for manufacturing three-dimensional object (2)]
The method for producing a three-dimensional object (2) according to the second embodiment includes a rubber component-containing styrene-based resin (A2) and plate-like particles (B2) having a Mohs hardness of 3 or less and surface-treated with a silane coupling agent (X2), and the content of the plate-like particles (B2) is 10 to 30 mass% relative to the total mass of the resin composition (2). In a preferred embodiment, the raw resin is composed only of the resin composition (2) according to the second embodiment.
The manufacturing method (2) according to the second embodiment includes melting the resin composition (2) and extruding the melted resin composition (2) from a nozzle to form a three-dimensional object. The manufacturing method (2) according to the second embodiment is preferably a method for manufacturing a three-dimensional object using an FDM 3D printer. When the resin composition (2) according to the second embodiment is used as a raw material resin for an FDM 3D printer, a filament-shaped product is used.

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 parts. Some FDM 3D printers have an integrated nozzle and heat melter.

The nozzle is installed in a gantry structure, allowing it to move freely on the XY plane of the substrate. The substrate is a platform for constructing the desired three-dimensional object, support material, etc. There are no particular limitations on the configuration of the substrate, but a configuration that can be heated and kept warm is preferable from the viewpoint of making it easier to improve 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 perpendicular to the XY plane.

In a preferred embodiment, a filament made of the resin composition (2) of the second embodiment is unwound from a raw material supply section and fed into a nozzle by a pair of opposing rollers or gears. It is then heated and melted in the nozzle, and the molten filament is extruded from the tip of the nozzle. In response to a signal transmitted based on a CAD model, the nozzle moves its position while supplying and stacking the molten filament onto a substrate to form a three-dimensional object. After this process is completed, the stacked object can be removed from the substrate, and the desired three-dimensional object can be obtained by peeling off support materials, etc., or cutting off excess portions as necessary.

One way to supply the filament to the nozzle is, for example, to unwind and supply the filament. It is preferable that the filament is stored in a cartridge wound into a bobbin, from the standpoints of stable unwinding, protection from environmental factors such as moisture, and prevention of twisting and kinking.

A preferred method of feeding the filament to the nozzle while unwinding it is to engage the filament with a driving roll such as a nip roll or gear roll, and feed the filament to the nozzle while pulling it up. From the viewpoint of stabilizing the filament feed by making the filament gripped by the engagement of the driving roll stronger, a fine uneven shape may be transferred to the surface of the filament.

In the manufacturing method (2) according to the second 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.

In addition, since the resin composition (2) according to the second 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.

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

[3D object (2)]
The three-dimensional object (2) according to the second embodiment is formed using the resin composition (2) described above. That is, the three-dimensional object (2) according to the second embodiment contains the resin composition (2) described above. In a preferred embodiment, the three-dimensional object (2) is composed only of the resin composition (2) according to the second embodiment. Such a three-dimensional object (2) has little warping and a good appearance. Therefore, the three-dimensional object (2) according to the second embodiment can be suitably used for applications such as stationery; toys; covers for electronic devices such as smartphones; parts such as grips; school teaching materials, home appliances, repair parts for office automation equipment, various parts for automobiles, motorcycles, bicycles, etc.; building materials; plastic shaping molds, etc.

In one embodiment, when the three-dimensional object (2) is placed on a horizontal plate, the maximum value of the gap (floating amount) between the bottom surface of the three-dimensional object (2) and the horizontal plate is preferably less than 1 mm, and more preferably 0.3 mm or less. The floating amount can be determined from the maximum value of the gap distance between the horizontal plate and the three-dimensional object (2) at a point where the bottom of the three-dimensional object (2) is separated from the horizontal plate and floating, measured with a curved ruler, while the three-dimensional object (2) is placed on the horizontal plate.

Another aspect of the second embodiment is the use of the above-mentioned resin composition (2) as a resin raw material (filament) for a three-dimensional object (2) produced using a 3D printer (2), or a method for using the same (2).
An example of a method for using the resin composition (2) according to the second embodiment as a resin raw material (filament) for a 3D printer includes obtaining the resin composition (2) by the above-described method for producing a resin composition (2), supplying the resin composition (2) to a 3D printer, and extruding the resin composition (2) from a nozzle while melting it to form a three-dimensional object (2).

A non-limiting list of exemplary aspects and combinations of exemplary aspects of the second embodiment is set forth below.
[1] A resin composition (2) for a 3D printer,
A rubber component-containing styrene-based resin (A2),
and plate-like particles (B2) having a Mohs hardness of 3 or less and having a surface treated with a silane coupling agent (X2),
The content of the plate-like particles (B2) is 10 to 30% by mass relative to the total mass of the resin composition (2).
[2] The resin composition (2) for 3D printers described in [1], wherein the rubber component-containing styrene-based resin (A2) contains a conjugated diene rubber.
[3] The plate-like particles (B2) include at least one plate-like particle selected from talc and mica, the surface of which is treated with the silane coupling agent (X2). [1] or [2] The resin composition (2) for 3D printers.
[4] The resin composition for 3D printers (2) according to any one of [1] to [3], wherein the rubber component-containing styrene-based resin (A2) contains an acrylonitrile-butadiene-styrene resin.
[5] The resin composition (2) for 3D printers according to any one of [1] to [4], wherein the silane coupling agent (X2) contains an amino group or an epoxy group.
[6] The resin composition (2) has an MFR of 10 to 30 g / 10 min at 220 ° C. and a load of 10 kg. Resin composition (2) for 3D printers according to any one of [1] to [5].
[7] The resin composition for 3D printers (2) according to any one of [1] to [6], wherein the average particle diameter (D50) of the plate-like particles (B2) is 1 to 50 μm.
[8] A method for producing a three-dimensional object (2), comprising: melting a resin composition for a 3D printer (2) according to any one of [1] to [7]; and extruding the molten resin composition (2) from a nozzle to form a three-dimensional object.
[9] A three-dimensional object (2) comprising the resin composition for 3D printers (2) according to any one of [1] to [7].

The present invention will be explained in more detail below with reference to examples, but the interpretation of the present invention is not limited to these examples.

The following raw materials were used according to the first embodiment.
<Raw materials>
The following was used as resin (A1).
(Resin (A1))
Resin (A1-1): ABS resin (manufactured by Denka Co., Ltd., product name "GR3500", MFR (220°C, 10 kg load): 14g/10min, Tg: 105°C, amount of conjugated diene rubber in resin: 18.1% by mass).
Resin (A1-2): ABS resin (manufactured by Denka Co., Ltd., product name "QF", MFR (220°C, 10 kg load): 44 g/10 min, Tg: 105°C, amount of conjugated diene rubber in resin: 15.8% by mass).
The MFR of the resin (A1) is a value measured in accordance with Method A of JIS K 7210-1.

The plate-like particles (B1) used were those shown in Table 1. The plate-like particles (B1-2-1) are particles obtained by treating the plate-like particles (B1-2) with 0.5% by mass of a silane coupling agent (X1) ((3-glycidoxypropyl)trimethoxysilane (manufactured by Shin-Etsu Silicones Co., Ltd., product name "KBM-403")).

The content of crystalline silica in the plate-like particles (B1) was measured under the following conditions.
<Measurement of Crystalline Silica Content>
The content of crystalline silica in each plate-like particle (B1) was measured by X-ray diffraction method (base standard absorption correction method). Specifically, first, the free silicic acid qualitative analysis of the plate-like particle (B1) was performed by an X-ray diffraction analyzer. At this time, quartz, cristobalite, and tridymite (manufactured by Japan Working Environment Measurement Association, a public interest incorporated association) were used as standard samples for free silicic acid analysis. Then, the crystalline silica in the plate-like particle (B1) was quantitatively analyzed by X-ray diffraction method (base standard absorption correction method). The measurement conditions in the X-ray diffraction method are as follows.
Measurement device: X-ray generator (a tabletop rotating anode type X-ray generator manufactured by Rigaku Corporation, product name "Ultrax18")
Target: Cu
Scanning angle: 5° to 60°
Step width: 0.02 degrees Measurement time: 0.6 seconds Tube voltage: 40 kV
Tube current: 30mA
Divergence slit: 1.00 degrees, scattering slit: 1.00 degrees, receiving slit: 0.3 mm

The detection limit for the crystalline silica content in the above measurement method is 0.1% by mass. Since no crystalline silica was detected (undetected) in plate-like particles (B1-1) to (B1-5) and plate-like particles (B1-2-1) using the above measurement method, the crystalline silica content in these plate-like particles (B1-1) to (B1-5) and plate-like particles (B1-2-1) is presumed to be equal to or greater than 0% by mass and less than 0.1% by mass.

[Example 1-1]
A twin-screw kneader (manufactured by Thermo Fisher Scientific, product name "Process 11") was equipped with a strand spooler for monofilament production and a gear pump, and 45 parts by mass of resin (A1-1), 45 parts by mass of resin (A1-2), and 10 parts by mass of plate-like particles (B1-1) were mixed, and pellets were sent into the device at 6 g / min with a feeder, and the mixture was mixed at a rotation speed of 300 rpm, a gear pump of 12 rpm, and a barrel temperature of 220 ° C., and then extruded to create a filament made of a resin composition for 3D printers (1) having a diameter of 1.75 mm. The MFR (220 ° C., 10 kg load) of the obtained filament was measured according to JIS K7210-1 A method using the product name "Melt Indexer G-02" manufactured by Toyo Seiki Seisakusho Co., Ltd.
In addition, a three-dimensional object was formed using the obtained filament, and the warpage during the formation and the wear resistance of the nozzle were evaluated under the following conditions. In addition, the proportion of crystalline silica in the resin composition (1) was calculated based on the content of crystalline silica in the plate-like particles (B1). The results are shown in Table 2.

<Warpage evaluation of 3D objects>
Using a 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2"), a sample plate for evaluation (three-dimensional object) measuring 200 mm wide x 50 mm long x 4 mm thick was modeled under the following conditions: substrate temperature: 100 ° C., nozzle temperature: 240 ° C., modeling speed: 30 mm/s, internal filling rate: 100%, and ambient temperature inside the 3D printer: about 30 ° C. The obtained sample plate was placed on a horizontal glass plate, and the maximum value of the gap distance at the contact surface between the sample plate and the glass plate was measured with a curved ruler, and 1 mm or less was measured with a high-precision contact digital sensor GT2 (manufactured by Keyence Corporation). If the maximum value was less than 1 mm (A rating and S rating), it was considered to have passed.
(Evaluation Criteria)
S: There is no gap between the sample plate and the glass plate (the gap distance is 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.

<3D printer nozzle wear resistance evaluation>
After replacing the nozzle of the 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2") with a brass nozzle with a diameter of 0.4 mm, a three-dimensional model was created using 10 m of a 1.75 mm diameter filament at a nozzle temperature of 240° C., modeling speed of 30 mm/s, and an ambient temperature inside the 3D printer of approximately 30° C. The nozzle diameter was then measured with an optical microscope to calculate the amount of nozzle wear, and an A rating was given for passing.
(Evaluation Criteria)
A: The amount of wear of the nozzle is 0 mm.
B: The amount of wear of the nozzle is more than 0 mm and less than 0.05 mm.
C: The amount of wear of the nozzle is 0.05 mm or more.

[Examples 1-2 to 1-8 and Comparative Examples 1-1 to 1-6]
A filament was produced under the same conditions as in Example 1-1, except that the composition of the resin composition (1) was as shown in Table 2. The MFR (220°C, 10 kg load) of the filament of each example was measured under the same conditions as in Example 1-1. In addition, the warping during molding and the abrasion resistance of the nozzle were evaluated under the same conditions as in Example 1-1. In addition, the proportion of crystalline silica in the resin composition (1) was calculated based on the content of crystalline silica in the plate-like particles (B1). The results are shown in Table 2.

The resin compositions (1) of Examples 1-1 to 1-8 contain plate-like particles (B1-1) to (B1-5) and plate-like particles (B1-2-1) in which crystalline silica was not detected, so the proportion of crystalline silica in the resin composition (1) was also evaluated as "not detected". When the resin compositions (1) of Examples 1-1 to 1-8, which satisfy the configuration of the first embodiment, were used as filaments for 3D printers, the nozzles were not worn and the amount of warping during modeling was small. In addition, the resin composition (1) of Example 1-8, which contains plate-like particles (B1) treated with a silane coupling agent (X1), produced a three-dimensional model with less warping than that of Example 1-4. On the other hand, the resin compositions of Comparative Examples 1-1 to 1-2, in which the amount of plate-like particles (B1) was less than 10 parts by mass, were rated A in the wear resistance evaluation of the nozzles, but had a large amount of warping. In addition, the resin compositions of Comparative Examples 1-3 to 1-6, in which the proportion of crystalline silica in the resin composition was 0.02% by mass or more, had a small amount of warping, but the nozzle was worn. From the above results, it was confirmed that the resin composition (1) according to the first embodiment does not wear out the nozzle of the 3D printer and can suppress warping during modeling. It was also confirmed that the manufacturing method (1) according to the first embodiment can suppress warping during modeling and obtain a three-dimensional object with little warping.

The following raw materials were used according to the second embodiment.
<Raw materials>
The following was used as resin (A2).
(Resin (A2))
Resin (A2-1): ABS resin (manufactured by Denka Co., Ltd., product name "GR3000", MFR (220°C, 10 kg load): 14g/10min).
Resin (A2-2): ABS resin (manufactured by Denka Co., Ltd., product name "QF", MFR (220°C, 10 kg load): 74g/10min).
The MFR of resin (A2) is a value measured at 220° C. under a load of 10 kg.

As the plate-like particles (B2), those shown in Table 3 were used.

The following raw material particles for each of the plate-like particles (B2) were used: In Table 3, the amount of silane coupling agent (X2) added means the ratio to the total mass of the raw material particles.
(raw material particles)
Plate-like particles (B2-1) and (B2-2): 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 (B2-3) and (B2-4): talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "PAOG-R", average particle size (D50): 30 μm).
Plate-like particles (B2-5) and (B2-6): Mica (Mohs hardness: 3, manufactured by Yamaguchi Mica Co., Ltd., product name "A-21S", average particle size (D50): 23 μm).
Plate-like particles (B'2-1): talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "P-2", average particle size (D50): 7 μm).
Plate-like particles (B'2-2): talc (Mohs hardness: 1, manufactured by Nippon Talc Co., Ltd., product name "PAOG-R", average particle size (D50): 30 μm).
Plate-like particles (B'2-3): mica (Mohs hardness: 3, manufactured by Yamaguchi Mica Co., Ltd., product name "A-21S", average particle size (D50): 23 μm).
Plate-like particles (B'2-4): alumina (Mohs hardness: 8, manufactured by Kinsei Matec Co., Ltd., product name "Seraph (registered trademark) (product number 10030)", average particle size (D50): 10 μm).
Plate-like particles (B'2-5): glass fiber (Mohs hardness: 5, manufactured by Central Glass Fiber Co., Ltd., product name "ECS03-70", average particle size (average value obtained by SEM observation): 13 μm).
The average particle size of the glass fiber of the plate-like particle (B'2-5) is the average value of the major axes of 100 particles measured at 40x magnification using a SEM (manufactured by Hitachi High-Technologies Corporation, product name "TM-1000").

[Example 2-1]
A twin-screw kneader (manufactured by Thermo Fisher Scientific, product name "Process 11") was equipped with a monofilament-producing strand spooler and a gear pump, and 80 parts by mass of resin (A1-1) and 20 parts by mass of plate-like particles (B2-1) were mixed and mixed at 220 ° C., and then extruded to produce a filament made of the resin composition (2) for 3D printers having a diameter of 1.75 mm. The MFR (220 ° C., 10 kg load) of the obtained filament was measured according to JIS K7210 using a product name "Melt Indexer G-02" manufactured by Toyo Seiki Seisakusho Co., Ltd.
In addition, a three-dimensional object was formed using the obtained filament, and the warpage, high-speed formability, and nozzle wear resistance were evaluated under the following conditions. The results are shown in Table 4.

<Warpage evaluation of 3D objects>
Using a 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2"), a sample plate for evaluation (three-dimensional object) measuring 200 mm wide x 50 mm long x 4 mm thick was modeled under the following conditions: substrate temperature: 100°C, nozzle temperature: 240°C, modeling speed: 30 mm/s, internal filling rate: 100%, and ambient temperature inside the 3D printer: about 30°C. The obtained sample plate was placed on a horizontal glass plate, and the maximum value of the gap distance at the contact surface between the sample plate and the glass plate was measured with a curved ruler, and 1 mm or less was measured with a high-precision contact digital sensor GT2 (manufactured by Keyence Corporation). If the maximum value was less than 1 mm, it was considered to have passed.
(Evaluation Criteria)
S: There is no gap between the sample plate and the glass plate (the gap distance is 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.

<Evaluation of high-speed modeling>
Using the same 3D printer as used in the warpage evaluation, a cylinder with a diameter of 75 mmφ x height of 120 mm was formed under the following conditions: substrate temperature: 100°C, nozzle temperature: 240°C, modeling speed: 100 mm/s, and ambient temperature inside the 3D printer: about 30°C. The appearance of the obtained cylinder was visually checked for holes or uneven discharge, and evaluated according to the following evaluation criteria. In addition, a rating of B or higher was considered to be acceptable. Note that "uneven discharge" refers to streaks and fine unevenness resulting from uneven discharge.
(Evaluation Criteria)
A: There are no holes or uneven discharge in the cylinder.
B: There is uneven discharge in some parts of the cylinder, but no holes.
C: The cylinder has holes and is unevenly discharged.

<3D printer nozzle wear resistance evaluation>
After replacing the nozzle of a 3D printer (manufactured by Japan 3D Printer Co., Ltd., product name "Raise3D Pro2") with a brass nozzle with a diameter of 0.4 mm, a three-dimensional model was created using 10 m of a 1.75 mm diameter filament at 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. The nozzle diameter was then measured with an optical microscope to calculate the amount of nozzle wear, and the nozzle was deemed to have passed if no wear was detected.
(Evaluation Criteria)
A: The amount of wear of the nozzle is 0 mm.
B: The amount of wear of the nozzle is more than 0 mm and less than 0.05 mm.
C: The amount of wear of the nozzle is 0.05 mm or more.

[Examples 2-2 to 2-10 and Comparative Examples 2-1 to 2-7]
Filaments were produced under the same conditions as in Example 2-1, except that the resin composition was as shown in Table 4. The MFR (220°C, 10 kg load) of the filaments of each example was measured under the same conditions as in Example 2-1. In addition, warping, high-speed modeling ability, and nozzle wear resistance were evaluated under the same conditions as in Example 2-1. The results are shown in Table 4.

As shown in Table 4, the resin composition (2) satisfying the configuration of the second embodiment, when used as a filament for a 3D printer, suppressed the wear of the nozzle, and was able to suppress warping and achieve both high-speed modeling properties. On the other hand, the resin composition of Comparative Example 2-1, in which the amount of plate-like particles (B2) was less than 10 parts by mass, had a large warp in the obtained three-dimensional model. In addition, the resin composition of Comparative Example 2-2, in which more than 30 parts by mass of plate-like particles (B2) were blended, had poor high-speed modeling properties.
In addition, the resin compositions of Comparative Examples 2-3 to 2-5, which contained talc and mica that were not surface-treated, had a small amount of nozzle wear, but the resulting three-dimensional objects had a large warp and poor high-speed modeling properties. From these results, it was found that even if the plate-like particles were relatively soft, those that were not surface-treated could not solve the second problem. Furthermore, from Comparative Examples 2-6 and 2-7, it was found that the second problem could not be solved with plate-like particles having a Mohs hardness of more than 3, even if the surface was treated with a silane coupling agent. From the above results, it was confirmed that the resin composition (2) according to the second embodiment can suppress the wear of the nozzle of the 3D printer, and can achieve both suppression of warping and high-speed modeling properties.

The resin composition (1) according to the first embodiment and the resin composition (2) according to the second embodiment have industrial applicability as filaments for producing three-dimensional objects using a 3D printer.

Claims (9)

A resin composition (1) for a 3D printer,
The resin composition (1) comprises a rubber component-containing styrene-based resin (A1),
and plate-like particles (B1) having a Mohs hardness of 3 or less,
The content of the plate-like particles (B1) relative to the total mass of the resin composition (1) is 10% by mass or more, and the proportion of crystalline silica relative to the total mass of the resin composition (1) is less than 0.02% by mass. Resin composition (1) for 3D printers. The resin composition (1) for 3D printers described in claim 1, wherein the average particle diameter (D50) of the plate-like particles (B1) is 1 to 50 μm. The resin composition (1) for 3D printers according to claim 1, wherein the rubber component-containing styrene-based resin (A1) contains a conjugated diene rubber. The resin composition (1) for 3D printers according to claim 1, wherein the Tg of the rubber component-containing styrene-based resin (A1) is 100°C or higher. The resin composition (1) for a 3D printer according to claim 1, wherein the content of the crystalline silica in the plate-like particles (B1) is less than 0.2 mass% relative to the total mass of the plate-like particles (B1). The resin composition (1) for a 3D printer according to claim 1, wherein the plate-like particles (B1) include at least one plate-like particle selected from talc, mica and clay. The resin composition (1) for 3D printers described in claim 1, wherein the rubber component-containing styrene-based resin (A1) contains acrylonitrile-butadiene-styrene resin. A method (1) for producing a three-dimensional object, comprising the steps of: forming a three-dimensional object using a resin composition (1) for a 3D printer according to any one of claims 1 to 7. A three-dimensional object (1) comprising a resin composition (1) for a 3D printer according to any one of claims 1 to 7.