Three-dimensional shaped article and method

Abstract

Provided are: a three-dimensionally shaped article which uses a crystalline thermoplastic resin and has excellent mechanical properties; and a method for producing the three-dimensionally shaped article. The three-dimensionally molded article is formed by a hot melt deposition method of a wire rod containing a crystalline thermoplastic resin, and the porosity in the three-dimensionally molded article is 5% or less. A method for manufacturing a three-dimensionally molded article includes forming a three-dimensionally molded article by depositing a wire material containing a crystalline thermoplastic resin by a hot melt deposition method using a 3D printer. It is preferable that the set value of the discharge amount input to the 3D printer or the data processing software for the 3D printer be a value greater than 100%.

Description

Technical Field

[0001] The present invention relates to a three-dimensional object and a method for manufacturing the three-dimensional object. Background Art

[0002] Since 3D printers can produce three-dimensional objects without the use of molds or large melting devices, they have rapidly become popular in recent years. As modeling methods using 3D printers, known methods include hot melt deposition (FFF (Fused Filament Fabrication) method), stereolithography (STL (Stereolithography) method) and selective laser sintering (SLS (Selective Laser Sintering) method). Hot melt deposition is a method of forming a three-dimensional object by heating and melting a thermoplastic resin and then depositing it (for example, Patent Documents 1 and 2). Due to the low cost of the device, it is becoming more and more popular not only for industrial use but also for personal use. Polyacetal resin, which is a crystalline thermoplastic resin, is useful if it can be used as a modeling material for a 3D printer because of its excellent mechanical properties.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-172084

[0004] Patent Document 2: Japanese Patent Application Publication No. 2019-131762 Summary of the invention

[0005] When a crystalline thermoplastic resin such as polyacetal resin is used as a molding material for a 3D printer using a thermal melt deposition method, the obtained three-dimensional molded object tends to have lower mechanical properties such as bending properties than injection molded products.

[0006] An object of the present invention is to provide a three-dimensional molded object having excellent mechanical properties using a crystalline thermoplastic resin and a method for producing the same.

[0007] The present invention has the following aspects.

[0008] [1] A three-dimensional object formed by a wire material comprising a crystalline thermoplastic resin by a thermal melt deposition method,

[0009] The porosity of the three-dimensional object is 5% or less [wherein the porosity is expressed by the following value: a portion or the entirety of the three-dimensional object is subjected to CT scanning using X-rays, and an image analysis is performed on a 10 mm × 10 mm region in one direction of the obtained cross-sectional data, and the area (A) of the region where the resin component exists is measured. resin ) and the area of ​​the pores (A void), the ratio of the area of ​​the region where the pores exist to the area of ​​the region where the resin component exists [A void / A resin ](%) value; or, a part or all of the three-dimensional object is scanned by X-ray CT, and a 10mm×10mm×10mm area in the obtained spatial data is analyzed to determine the volume (V) of the area where the resin component exists. resin ) and the volume of the region where the pores exist (V void ), the ratio of the volume of the region where the pores exist to the volume of the region where the resin component exists [V void / V resin ](%) value].

[0010] [2] The three-dimensional shaped object according to [1], wherein the porosity in the three-dimensional shaped object is 2% or less.

[0011] [3] The three-dimensional object described in [1] or [2], wherein the crystalline thermoplastic resin comprises one or more selected from the group consisting of polyacetal resin, polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin and polyamide resin.

[0012] [4] The three-dimensional shaped object according to any one of [1] to [3], comprising an inorganic or organic filler.

[0013] [5] A method for manufacturing a three-dimensional object, which is the method for manufacturing a three-dimensional object described in [1], comprising the following steps:

[0014] A 3D printer is used to deposit wires containing crystalline thermoplastic resin by a hot melt deposition method to form a three-dimensional object.

[0015] [6] The method for manufacturing a three-dimensional object as described in [5], wherein the step of forming the three-dimensional object comprises the following steps:

[0016] The 3D printer receives an input of a set value for the amount of molten crystalline thermoplastic resin ejected from a nozzle; or

[0017] The 3D printer is operated based on the slice data created by the 3D printer data processing software, and the 3D printer data processing software is capable of inputting a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle,

[0018] The setting value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is a value greater than 100%.

[0019] [7] The method for manufacturing a three-dimensional object as described in [5] or [6], wherein the step of forming the three-dimensional object comprises the following steps:

[0020] The 3D printer receives an input of a set value of a wire diameter; or

[0021] The aforementioned 3D printer operates based on the slice data created by the 3D printer data processing software capable of inputting the set value of the wire diameter.

[0022] The set value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is a value smaller than the average wire diameter of the wire.

[0023] [8] The method for manufacturing a three-dimensional object as described in any one of [5] to [7], wherein the step of forming the three-dimensional object comprises the following steps:

[0024] The 3D printer receives an input of a set value for the amount of molten crystalline thermoplastic resin ejected from a nozzle; or

[0025] The 3D printer is operated based on the slice data created by the 3D printer data processing software, and the 3D printer data processing software is capable of inputting a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle,

[0026] Before forming the three-dimensional object, the following steps are included: preparing the density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the aforementioned ejection amount set value known standard three-dimensional modeling sample density (g / cm 3 ) and the set value of the aforementioned discharge volume,

[0027] The setting value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is: the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponds to the set value of the aforementioned discharge amount.

[0028] [9] The method for manufacturing a three-dimensional object as described in any one of [5] to [8], wherein the step of forming the three-dimensional object comprises the following steps:

[0029] The 3D printer receives an input of a set value of a wire diameter; or

[0030] The aforementioned 3D printer operates based on the slice data created by the 3D printer data processing software capable of inputting the set value of the wire diameter.

[0031] Before forming the three-dimensional object, the following steps are included: preparing the density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the density (g / cm) of the standard three-dimensional modeling sample with a known set value of the wire diameter 3 ) and the set value of the wire diameter,

[0032] The setting value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is: the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) is the set value of the wire diameter corresponding to 95% to 100% of the above point.

[0033] According to the present invention, a three-dimensional molded object having excellent mechanical properties using a crystalline thermoplastic resin and a method for producing the same can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram showing a structural example of a 3D printer.

[0035] Figure 2 This is an explanatory diagram about a method of molding a three-dimensional object using a 3D printer.

[0036] Figure 3 The density (g / cm2) of the standard three-dimensional modeling sample with known set values ​​is shown in the wire material used in Example 1. 3 ) and the aforementioned set values.

[0037] Figure 4 The density (g / cm2) of the standard three-dimensional modeling sample with known set values ​​is shown in the wire material used in Example 2. 3 ) and the aforementioned set values.

[0038] In Figure 5, Figures 5A to 5C This is a CT scan image of the three-dimensional object obtained in Example 1. Figure 5A This is the cross-sectional data of a surface of 10 mm × 4 mm. Figure 5B This is the cross-sectional data of a surface of 80 mm × 40 mm. Figure 5C This is the cross-sectional data of a surface measuring 80 mm x 10 mm.

[0039] In Figure 6, Figures 6A to 6C This is a CT scan image of the three-dimensional object obtained in Comparative Example 1. Fig. 6A This is the cross-sectional data of a surface of 10 mm × 4 mm. Figure 6B This is the cross-sectional data of a surface of 80 mm × 40 mm. Figure 6CThis is the cross-sectional data of a surface measuring 80 mm x 10 mm.

[0040] In Figure 7, Figures 7A to 7C It is a schematic diagram of the bending test. DETAILED DESCRIPTION

[0041] Hereinafter, one embodiment of the present disclosure is described in detail, but the scope of the present disclosure is not limited to the one embodiment described herein, and various changes can be made within the scope of the spirit of the present disclosure. In addition, if multiple upper limits and lower limits are recorded for a specific parameter, any upper limit and lower limit can be combined within these upper limits and lower limits to form a suitable numerical range. In addition, the lower limit and / or upper limit of the numerical range recorded in the present disclosure is a numerical value within the numerical range, and can also be replaced by the numerical value shown in the embodiment. The expression "X~Y" indicating a numerical range means "above X and below Y". If the specific description recorded for one embodiment is also applicable to other embodiments, its description can be omitted in other embodiments.

[0042] [Three-dimensional objects]

[0043] The three-dimensional shaped object related to the present embodiment is a three-dimensional shaped object formed by a wire rod (hereinafter also referred to as a "wire rod") containing a crystalline thermoplastic resin by a hot melt deposition method. In other words, it is a three-dimensional shaped object obtained by depositing a wire rod containing a crystalline thermoplastic resin as a material by a hot melt deposition method. The three-dimensional shaped object obtained by the hot melt deposition method can be determined by confirming the molding line (drawing line) and the deposition mark when observing the surface of the three-dimensional shaped object visually or with a stereoscopic microscope. The thickness of the molding line (drawing line) is not limited, for example, it can be 100μm to 1000μm.

[0044] (Porosity)

[0045] The porosity of the three-dimensional object is 5% or less, preferably 2% or less, and more preferably 1% or less. By setting the porosity to 5%, the mechanical properties of the three-dimensional object can be excellent. To date, there is no known three-dimensional object with a porosity of 5% or less, especially in a wire material containing a crystalline thermoplastic resin formed by a hot melt deposition method.

[0046] "Porosity" refers to defects other than voids intentionally formed in the target three-dimensional object. Intentionally formed voids generally refer to voids formed inside the object based on a set value called infill, which can be confirmed on three-dimensional data. In one embodiment, the void can be an area surrounded by the three-dimensional object in all directions. In one embodiment, the void can be a defect generated between adjacent modeling lines (drawing lines) in the three-dimensional object.

[0047] The porosity is represented by the following (i) or (ii).

[0048] (i) A portion or the entirety of the three-dimensional object is subjected to CT scanning using X-rays, and an image analysis is performed on a 10 mm x 10 mm region in one direction of the obtained cross-sectional data to measure the area (A) of the region where the resin component exists. resin ) and the area of ​​the pores (A void ), the ratio of the area of ​​the region where the pores exist to the area of ​​the region where the resin component exists [A void / A resin ](%) value;

[0049] (ii) A portion or the entirety of the three-dimensional object is scanned by X-ray CT, and data analysis is performed on a 10 mm × 10 mm × 10 mm region in the obtained spatial data to measure the volume (V resin ) and the volume of the region where the pores exist (V void ), the ratio of the volume of the region where the pores exist to the volume of the region where the resin component exists [V void / V resin ](%) value.

[0050] "CT scanning" is to take pictures using an X-ray CT device composed of an X-ray tube and an X-ray detector. The range of the three-dimensional object scanned by CT is a part or the whole. In one embodiment, when the range of the CT scan is a part of the three-dimensional object, for example, it can be a range of 1 to 100 mm × 1 to 100 mm at any position of the three-dimensional object, for example, it can be a range of 10 mm × 10 mm. In one embodiment, from the viewpoint of easily measuring the area and / or volume of the region where pores exist, the range of the three-dimensional object scanned by CT is preferably a range that does not contain voids intentionally formed in the three-dimensional object.

[0051] The "area of ​​10 mm×10 mm" and the "area of ​​10 mm×10 mm×10 mm" refer to the dimensions within the field of view used for calculation.

[0052] In one embodiment, the cross-sectional data and / or spatial data of the image analysis or data analysis may be a portion of the cross-sectional data and / or spatial data obtained by CT scanning.

[0053] In one embodiment, the cross-sectional data and / or spatial data to be analyzed are cross-sectional data and / or spatial data including the surface (or near the surface) of the three-dimensional object among the cross-sectional data and / or spatial data obtained by CT scanning, and may be cross-sectional data and / or spatial data including the area from one surface to the center (or near the center) of the inside of the three-dimensional object. By analyzing the cross-sectional data and / or spatial data including the surface (or near the surface) of the three-dimensional object, the porosity on the surface of the three-dimensional object can be measured. By analyzing the cross-sectional data and / or spatial data including the area from one surface to the center (or near the center) of the inside of the three-dimensional object, the porosity inside the three-dimensional object can be measured.

[0054] The image analysis area is a 10 mm x 10 mm area in one direction of the cross-sectional data obtained by CT scanning. In one embodiment, the image analysis area may be an area along any direction of the cross-sectional data of the image analysis, for example, an area along the deposition direction in the hot melt deposition method, or an area along a direction perpendicular to the deposition direction in the hot melt deposition method. In one embodiment, the image analysis area may be an area along the height direction of the three-dimensional object, an area along the plane direction, or an area along the thickness direction.

[0055] In one embodiment, for cross-sectional data in one or more directions, two or more directions, or three directions obtained by CT scanning, image analysis is performed on a 10 mm×10 mm area along each direction, and the porosity ([A void / A resin ](%)). In one embodiment, when image analysis is performed on image data in two or more directions, the porosity in the region along at least one direction of the image analysis is less than 5%, preferably the porosity in each region along the two or more directions of the image analysis is less than 5%, and more preferably the porosity in each region along all directions of the image analysis is 5%.

[0056] The spatial data for data analysis is a 10 mm×10 mm×10 mm area in the cross-sectional data obtained by CT scanning. In one embodiment, the area for data analysis can perform data analysis on a 10 mm×10 mm×10 mm area in the spatial data obtained by CT scanning, and calculate the porosity ([V void / V resin](%)). In one embodiment, when data analysis is performed on spatial data of more than two positions, the porosity in at least one position of the data analysis is less than 5%, preferably the porosity in each of the two or more positions of the data analysis is less than 5%, and more preferably the porosity in each of all directions of the data analysis is less than 5%.

[0057] "Area where the resin component exists" refers to an area where the resin component of the crystalline thermoplastic resin constituting the wire exists. The area where the resin component exists can be an area observed as an area with a high brightness value (CT value) (e.g., white or gray) in the cross-sectional data or spatial data obtained by CT scanning. In one embodiment, the area where the resin component exists can be an area with a CT value of -400 to 1000 in the cross-sectional data or spatial data obtained by CT scanning.

[0058] "Area where pores exist" refers to an area where defects other than voids intentionally formed in a three-dimensional object exist. The area where pores exist may be an area surrounded by an area where a resin component containing a crystalline thermoplastic resin exists in all directions. In one embodiment, the area where pores exist may be an area where defects generated between two or more adjacent modeling lines (drawing lines) exist. In one embodiment, the area where pores exist may be an area where, when the cross-sectional data and / or spatial data obtained by CT scanning are compared with the three-dimensional data of the three-dimensional object, the area that appears as voids in the three-dimensional data is removed. The area where pores exist may be an area observed as an area with a low CT value (usually black) in the cross-sectional data and / or spatial data obtained by CT scanning. In one embodiment, the area where pores exist may be an area with a CT value of -400 to 1000 in the cross-sectional data and / or spatial data obtained by CT scanning.

[0059] The area value (A) of each region can be measured using image processing software. resin , A void ). For example, A can be determined by binarization using image processing software (open source software "ImageJ"). resin , A void .

[0060] Based on the multiple two-dimensional images obtained by X-ray CT scanning, the volume value of each area (V resin 、V void For example, V can be calculated by analyzing the reconstructed three-dimensional image using image processing software (Molcer Plus, manufactured by White Rabbit). resin 、V void .

[0061] As a method for making the porosity less than 5%, there is a method of optimizing the set value of the ejection amount of molten crystalline thermoplastic resin from the nozzle input into the 3D printer or the data processing software for the 3D printer when using a 3D printer using the hot melt deposition method. For example, there is a method of setting the set value of the ejection amount input into the 3D printer or the data processing software for the 3D printer to a value greater than the standard specified value (for example, 100% of the Flow value). By setting the set value of the ejection amount input into the 3D printer or the data processing software for the 3D printer to a value greater than the standard specified value, the porosity in the molded object can be easily made less than 5%. In addition, for example, there is a method of using the density (g / cm) of a standard three-dimensional modeling sample whose set value of the ejection amount is known and which shows the wire diameter. 3 ) and the above-mentioned set value, and optimize the set value of the ejection amount input to the 3D printer or the 3D printer data processing software. Specifically, the density (g / cm2) of the wire to be used can be measured in advance. 3 ) and prepare to display the density (g / cm2) of a standard three-dimensional modeling sample with a known setting value of the ejection amount 3 ) and the above-mentioned measured value, and the set value of the ejection amount input to the 3D printer or the 3D printer data processing software is set so that the density of the standard curve becomes the density of the wire (g / cm 3 ) The porosity in the molded object can be easily reduced to 5% or less by using a calibration curve to optimize the setting value of the ejection amount input to the 3D printer or the data processing software for the 3D printer.

[0062] In another embodiment, as a method for making the porosity less than 5%, there is a method of optimizing the set value of the wire diameter input to the 3D printer. For example, there is a method of making the set value of the wire diameter input to the 3D printer smaller than the average wire diameter (measured value) of the wire used. By making the set value of the wire diameter input to the 3D printer smaller than the average wire diameter (measured value), the porosity in the modeled object can be easily made less than 5%. In addition, for example, there is a method of using the density (g / cm 3 ) and the above-mentioned set value, and optimize the set value of the wire diameter input to the 3D printer. Specifically, the density (g / cm 3 ) and the density (g / cm2) of a standard three-dimensional modeling sample with a known set value of the wire diameter 3) and the above-mentioned measured values, so that the setting value of the wire diameter input to the 3D printer is the density of the standard curve that becomes the density of the wire (g / cm 3 ) The method of setting the value of the point with the same value, etc. By using the standard curve to optimize the setting value of the wire diameter input to the 3D printer, the porosity in the molded object can be easily reduced to 5% or less.

[0063] (Crystalline thermoplastic resin)

[0064] The crystalline thermoplastic resin preferably includes one or more crystalline thermoplastic resins selected from the group consisting of polyacetal resins, polyethylene resins, polypropylene resins, polyethylene terephthalate resins, polybutylene terephthalate resins, and polyamide resins, and more preferably includes polyacetal resins. The crystalline thermoplastic resin may include one alone or two or more. In one embodiment, the crystalline thermoplastic resin preferably includes polyacetal resins, or may be composed of polyacetal resins.

[0065] The polyacetal resin may be a polyacetal homopolymer or a polyacetal copolymer. In one embodiment, from the viewpoint of the balance between mechanical properties and thermal properties, it is preferred to include a polyacetal copolymer. The molecules of the polyacetal resin may be not only linear, but also have a branched or cross-linked structure, or may be a known modified polyoxymethylene into which other organic groups are introduced. The polyacetal resin may include one alone or more than two.

[0066] The polyacetal homopolymer is a polymer having only oxymethylene units (-CH2O-) in the main chain.

[0067] The polyacetal copolymer is a copolymer resin containing an oxymethylene unit (-CH2O-) as a main structural unit and further containing a comonomer unit other than the aforementioned oxymethylene unit. "Main structural unit" refers to a monomer unit that accounts for more than 50% by mass, preferably 70% by mass or more, of all structural units (100% by mass) constituting the polyacetal copolymer.

[0068] The comonomer units included in the polyacetal copolymer can be one or more than two. The aforementioned comonomer units are preferably oxyalkylene units with a carbon number of 2 or more. By making the comonomer units oxyalkylene units with a carbon number of 2 or more, it is easy to make thermal stability good. In addition, the comonomer units are more preferably at least one oxyalkylene unit selected from oxyethylene, oxypropylene and oxytetramethylene, and particularly preferably include oxyethylene. As comonomer units, when including oxyethylene units, the proportion of oxyethylene units in all comonomer units (100% by mass) is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less.

[0069] The polyacetal copolymer may be any of a random copolymer, a block copolymer, and a graft copolymer, and is preferably a random copolymer from the viewpoint of thermal stability.

[0070] In one embodiment, the crystalline thermoplastic resin includes a polyacetal copolymer, and the comonomer units that can be included in the polyacetal copolymer in all structural units (100 mass%) are preferably 1.0 mass% or more and 6.0 mass% or less, more preferably 1.5 mass% or more and 5.5 mass% or less, further preferably 2.0 mass% or more and 5.0 mass% or less, and particularly preferably 2.5 mass% or more and 4.5 mass% or less. By including a polyacetal copolymer, the polyacetal copolymer preferably includes comonomer units of 1.0 mass% or more and 6.0 mass% or less, thereby making the dimensional stability of the three-dimensional object more excellent. The proportion of the comonomer units in the polyacetal copolymer can be expressed by 1 H-NMR method. For example, the sample is prepared by dissolving the sample in deuterated hexafluoroisopropanol to a concentration of 5 mass %. 1 The sample is analyzed by H-NMR to calculate the ratio of the integral ratio of the comonomer unit (for example, the oxyalkylene unit having 2 or more carbon atoms described later) to the integral ratio of the peak of all monomers of the polyacetal copolymer.

[0071] In one embodiment, the crystalline thermoplastic resin includes a polyacetal copolymer, and the comonomer unit in the polyacetal copolymer preferably includes an oxyalkylene unit having 2 or more carbon atoms, and more preferably includes at least one oxyalkylene unit selected from oxyethylene, oxypropylene, and oxytetramethylene.

[0072] Examples of the polyethylene resin include high-density polyethylene resin, low-density polyethylene resin, and linear low-density polyethylene resin.

[0073] Examples of the polypropylene resin include not only homopolymers of propylene but also polypropylene copolymers and branched polypropylene.

[0074] Examples of the polyethylene terephthalate resin include polyethylene terephthalate resins mainly composed of terephthalic acid or a derivative thereof capable of forming an ester thereof (C 1-6 A polyester resin composed of ethylene glycol or a derivative thereof (acetylated product, etc.) as a dicarboxylic acid component as well as ethylene glycol or a derivative thereof capable of forming an ester (acetylated product, etc.) as a diol component.

[0075] Examples of the polybutylene terephthalate resin include a polybutylene terephthalate resin containing terephthalic acid or an ester-forming derivative thereof (C 1-6Polybutylene terephthalate resins are obtained by polycondensing a dicarboxylic acid component (such as an alkyl ester, an acyl halide, etc.) containing at least 4 carbon atoms of an alkanediol (1,4-butanediol) or an ester-forming derivative thereof (such as an acetylated product). Examples include homopolyesters (polybutylene terephthalate) and / or copolyesters (polybutylene terephthalate copolymers, polybutylene terephthalate copolyesters, or modified PBT resins) containing butylene terephthalate as a main component.

[0076] Examples of the polyamide resin include polyamide 11 (PA11), polyamide 6 (PA6), polyamide 66 (PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 12 (PA12), polyamide 6T (PA6T), polyamide 6I, polyamide 9T, polyamide M5T, polyamide 1010 (PA1010), polyamide 1012 (PA1012), polyamide 10T, polyamide MXD6, polyamide 6T / 66, polyamide 6T / 6I, polyamide 6T / 6I / 66, polyamide 6T / 2M-5T, and polyamide 9T / 2M-8T.

[0077] The melt flow rate (MFR) of the crystalline thermoplastic resin under a load of 2.16 kg is preferably 1.0 g / 10 min or more and 8.0 g / 10 min or less, more preferably 1.2 g / 10 min or more and 7.0 g / 10 min or less, and further preferably 1.4 g / 10 min or more and 6.0 g / 10 min or less in the temperature range of the melting point Tm2 (°C) to the melting point Tm2+30°C. By making the MFR 1.0 g / 10 min or more and 8.0 g / 10 min or less, the modeling stability of the three-dimensional modeling object becomes good. It should be noted that the MFR can be measured based on ISO 1133-1:2011 (condition D) under the conditions of a load of 2.16 kg in the temperature range of the melting point Tm2 (°C) to the melting point Tm2+30°C (for example, when the crystalline thermoplastic resin is a polyacetal resin, the temperature is 190°C).

[0078] The melting point Tm2 of the crystalline thermoplastic resin measured by differential scanning calorimetry is preferably 160°C or more and 175°C or less, more preferably 162°C or more and 170°C or less. By making the melting point Tm2 160°C or more and 170°C or less, stable molding of a three-dimensional molded object becomes easy. The melting point Tm2 is based on the method of JIS K-7121 (2012), and is a method in which a crystalline thermoplastic resin is heated from 40°C to 200°C (1st RUN) at a heating rate of 20°C / min, then kept at 200°C for 5 minutes, then cooled to 40°C at a cooling rate of 10°C / min, then kept at 40°C for 5 minutes, and then heated from 40°C to 200°C (2nd RUN) at a heating rate of 10°C / min again. The peak top temperature of the endothermic peak of the 2nd RUN is observed.

[0079] The crystallization temperature Tc of the crystalline thermoplastic resin measured by a differential scanning calorimeter is preferably 130°C to 155°C, more preferably 135°C to 150°C. By setting the crystallization temperature Tc to 130°C to 155°C, a three-dimensional object can be molded with good operability. The crystallization temperature Tc is the temperature of the peak top of the exothermic peak observed when the crystalline thermoplastic resin is heated from 40°C to 200°C (1st RUN) at a heating rate of 20°C / min based on the method of JIS K-7121 (2012), maintained at 200°C for 5 minutes, and then cooled to 40°C at a cooling rate of 10°C / min.

[0080] In one embodiment, the content of the crystalline thermoplastic resin in the resin component constituting the three-dimensional object is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and may be 100% by mass, based on the total mass of the total resin component. When a polyacetal resin is included as the crystalline thermoplastic resin, the content of the polyacetal resin in the resin component is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, based on the total mass of the resin component constituting the three-dimensional object.

[0081] In one embodiment, the content of the crystalline thermoplastic resin in the three-dimensional molded object is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, based on the total mass of the three-dimensional molded object. When a polyacetal resin is included as the crystalline thermoplastic resin, the content of the polyacetal resin in the three-dimensional molded object is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, based on the total mass of the three-dimensional molded object.

[0082] (Other ingredients)

[0083] The three-dimensional object may also contain other components as required. As other components, fibrous, powdery, plate-like inorganic or organic fillers, thermoplastic resins other than crystalline thermoplastic resins (other thermoplastic resins), etc. may be listed. The three-dimensional object may also contain one or more additives commonly used for thermoplastic resins as required, such as weather (light) stabilizers, dyes, pigments and other colorants, lubricants, nucleating agents, release agents, antistatic agents, surfactants, etc.

[0084] (Inorganic or organic fillers)

[0085] In one embodiment, the three-dimensional object may contain an inorganic or organic filler. As the inorganic or organic filler, for example, a powdery filler with an average particle size of 2nm to 400μm, preferably 20nm to 100μm, a plate-like filler, an average fiber length of 0.1 to 600μm, preferably 1 to 300μm, an average fiber diameter of 0.001 to 20μm, preferably 0.01 to 15μm, and a fibrous filler. By including an inorganic or organic filler, the strength of the three-dimensional object can be made better. It should be noted that the average particle size of the inorganic or organic filler refers to the particle size D50 when the cumulative frequency is 50% in the volume-based arithmetic average particle size measured by the laser diffraction / scattering particle size distribution measurement method. The average particle size can be measured, for example, using a laser diffraction / scattering particle size distribution measurement device (manufactured by Kuba Seisakusho Co., Ltd., product name: LA-960). The average fiber length is the arithmetic mean of the values ​​measured by an image measuring device (manufactured by Nireco Co., Ltd., product name: LUZEXFS) for 500 fibrous fillers. The average fiber diameter is the arithmetic mean of the values ​​measured by an image measuring device (manufactured by Nireco Co., Ltd., product name: LUZEXFS) for 500 fibrous fillers, and the longest straight line distance in the cross section perpendicular to the longitudinal direction.

[0086] Examples of the powdery filler include carbon black, graphite, silicon dioxide, quartz powder, glass beads, glass spheres, glass powder, silicates such as calcium silicate, aluminum silicate, kaolin, clay, diatomaceous earth, and wollastonite, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony trioxide, and aluminum oxide, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, other ferrites, silicon carbide, silicon nitride, boron nitride, and various metal powders. These powdery fillers may be used alone or in combination of two or more.

[0087] As fibrous fillers, for example, glass fiber, milled glass fiber, carbon fiber, asbestos fiber, silica fiber, silica·alumina fiber, alumina fiber, zirconium oxide fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, silicate fiber such as wollastonite, magnesium sulfate fiber, aluminum borate fiber, and inorganic fibrous substances such as fibrous materials of metals such as stainless steel, aluminum, titanium, copper, and brass can be listed. A particularly typical fibrous filler is glass fiber. High melting point organic fibrous substances such as polyamide, fluororesin, polyester resin, and acrylic resin can also be used. These fibrous fillers can be used alone or in combination of two or more.

[0088] Examples of the plate-like filler include mica, glass flakes, talc, and various metal foils. These plate-like fillers may be used alone or in combination of two or more.

[0089] When the three-dimensional object contains an inorganic or organic filler, its content can be, for example, 0 to 30 parts by mass, or 5 to 20 parts by mass relative to 100 parts by mass of the crystalline thermoplastic resin. The content of the inorganic or organic filler can be, for example, 0 to 30% by mass, or 5 to 20% by mass in the total mass of the three-dimensional object.

[0090] (Three-dimensional objects)

[0091] The three-dimensional object obtained according to the present disclosure has excellent various mechanical properties, including bending properties, tensile properties, etc. In one embodiment, the bending strength of the three-dimensional object measured according to ISO178 can be more than 80% or more than 85% of the bending strength of a standard injection molded product made of the same material. In a preferred embodiment, the bending strength of the three-dimensional object measured according to ISO178 can be a value higher than that of a standard injection molded product.

[0092] In one embodiment, the flexural modulus of the three-dimensional object measured according to ISO 178 may be 80% or more or 85% or more of the flexural modulus of a standard injection molded product made of the same material. In a preferred embodiment, the flexural modulus of the three-dimensional object measured according to ISO 178 may be a value higher than the flexural modulus of the standard injection molded product.

[0093] In addition, the flexural strength of the three-dimensional shaped object and the flexural modulus described later used a test piece produced by the thermal fusion deposition method.

[0094] The size and shape of the three-dimensional object are not limited and may be a size and a shape according to the intended use.

[0095] [Method for producing three-dimensional object]

[0096] The method for manufacturing a three-dimensional object related to the present embodiment includes the following steps: using a 3D printer and data processing software for the 3D printer as required, depositing a wire material containing a crystalline thermoplastic resin by a hot melt deposition method to form a three-dimensional object. The 3D printer is not limited, and a commercially available hot melt deposition 3D printer can be used.

[0097] (Wire preparation process)

[0098] "Wire" is a solid material used for three-dimensional modeling. The material commonly used for 3D printers is a continuous fiber shape with a circular or nearly circular cross-sectional shape perpendicular to the length direction of the wire.

[0099] The wire material comprises a crystalline thermoplastic resin. The type and content of the crystalline thermoplastic resin and other characteristics are the same as those described in the above-mentioned three-dimensional object, so the description is omitted here. The wire material may comprise one or more crystalline thermoplastic resins. In one embodiment, the content of the crystalline thermoplastic resin in the wire material is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, relative to the total mass of the wire material. When a polyacetal resin is included as the crystalline thermoplastic resin, the content of the polyacetal resin in the wire material is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, relative to the total mass of the wire material.

[0100] The wire material may also contain other components as required. As other components, fibrous, powdery, plate-like inorganic or organic fillers, thermoplastic resins other than crystalline thermoplastic resins (other thermoplastic resins), etc. may be listed. The three-dimensional object may also contain one or more additives commonly used for thermoplastic resins as required, such as weather (light) stabilizers, dyes, pigments and other colorants, lubricants, nucleating agents, release agents, antistatic agents, surfactants, etc.

[0101] Examples and contents of inorganic or organic fillers and other thermoplastic resins are the same as those described above for other components that may be contained in the three-dimensional object.

[0102] In one embodiment, the average diameter of the wire (also referred to as the "average wire diameter") is preferably 1 to 3 mm, more preferably 1 to 2.5 mm, and even more preferably 1.5 to 2 mm. By making the average wire diameter 1 to 3 mm, it can be used as a material suitable for commercially available 3D printing device standards. The average wire diameter is the arithmetic mean of the values ​​obtained by taking out a 5m sample, randomly selecting 20 positions, and measuring its diameter (or the longest straight line distance in the cross section) to the third decimal place with a micrometer, and rounding the value to the third decimal place.

[0103] In one embodiment, the wire material may be a winding body wound around a core material. By making it a winding body, it can be easier to install it in a 3D printer and easier to shape it with a 3D printer.

[0104] From the viewpoint of easily forming a stable three-dimensional shape, the melting point Tm2 of the wire measured by a differential scanning calorimeter is preferably 160°C or more and 175°C or less, and more preferably 162°C or more and 173°C or less. The melting point Tm2 is the temperature of the peak top of the endothermic peak of the 2nd RUN observed when the wire is heated from 40°C to 200°C (1st RUN) at a heating rate of 20°C / min by a method based on JISK-7121 (2012), then held at 200°C for 5 minutes, then cooled to 40°C at a cooling rate of 10°C / min, then held at 40°C for 5 minutes, and then heated from 40°C to 200°C (2nd RUN) at a heating rate of 10°C / min again.

[0105] From the viewpoint of easily forming a stable three-dimensional shape, the crystallization temperature Tc of the wire measured by a differential scanning calorimeter is preferably 130°C or more and 155°C or less, and more preferably 135°C or more and 150°C or less. The crystallization temperature Tc is the temperature of the peak top of the exothermic peak observed when the wire is heated from 40°C to 200°C (1stRUN) at a heating rate of 20°C / min according to JIS K-7121 (2012), then maintained at 200°C for 5 minutes, and then cooled to 40°C at a cooling rate of 10°C / min.

[0106] The method for producing the wire is not limited. The wire can be produced by extruding a crystalline thermoplastic resin together with other components that may be contained as needed through an extruder, cooling and solidifying the extruded wire, and then winding it with a winder at a winding speed that allows the wire diameter to reach a desired value.

[0107] In the method for producing a wire rod, the crystalline thermoplastic resin may be used alone or in combination of two or more.

[0108] (Three-dimensional object forming process)

[0109] In the process of forming a three-dimensional object, a wire material containing a crystalline thermoplastic resin is supplied to a 3D printer and deposited by a hot melt deposition method to form a three-dimensional object. The hot melt deposition method is a method of producing a three-dimensional object by ejecting a molten material of the wire material from an ejection nozzle onto a molding table in a linear shape, so that molding lines (drawing lines) are deposited in the plane direction and the height direction.

[0110] In the previous method, after measuring the diameter of the wire used as the material (the general standard value is 1.75mm), this measured value is input as the set value of the wire diameter into the 3D printer or the data processing software for the 3D printer. In addition, the set value of basically 100% is used as the ejection amount for modeling. However, when using a wire containing a crystalline thermoplastic resin, there is a problem of defects (gaps) or pores between the modeling lines due to the shrinkage when ejected from the nozzle. In addition, there is also the problem that the mechanical properties of the obtained three-dimensional modeling object are significantly lower than those of the injection molded product. In this embodiment, by adjusting the set value input into the 3D printer or the data processing software for the 3D printer, a three-dimensional modeling object with excellent mechanical properties can be manufactured.

[0111] In one embodiment, the 3D printer is configured to be able to input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, or the 3D printer is configured to operate based on slice data established by the data processing software for the 3D printer, the data processing software for the 3D printer is able to input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, and the set value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is preferably a value greater than 100%. That is, in this embodiment, the process of forming a three-dimensional object includes the following steps: the 3D printer receives an input of a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle; or the 3D printer is operated based on the slice data established by the data processing software for the 3D printer, the data processing software for the 3D printer is able to input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, and the set value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is preferably a value greater than 100%. By inputting a value greater than 100% as the set value of the ejection amount into a 3D printer or 3D printer data processing software, a three-dimensional object having excellent mechanical properties can be easily manufactured. The generation of voids in the obtained three-dimensional object is suppressed.

[0112] "3D printer data processing software" is software that has the function of dividing three-dimensional data into multiple layers (slicing processing) to create slice data. The structure of 3D printer data processing software is usually to be able to set and change the modeling conditions of the 3D printer while previewing the slice data. The obtained slice data is converted into a language that can be operated by the 3D printer and sent to the 3D printer, and the 3D printer operates based on the sent slice data.

[0113] In addition, in another embodiment, the 3D printer is configured to be capable of inputting a set value of the wire diameter, or the 3D printer is configured to operate based on slice data established by a 3D printer data processing software capable of inputting a set value of the wire diameter, and the set value of the wire diameter input to the 3D printer or the 3D printer data processing software is preferably smaller than the average wire diameter (measured value) of the wire used. That is, in this embodiment, the process of forming a three-dimensional object includes the following steps: the 3D printer receives an input of a set value of the wire diameter; or the 3D printer operates based on slice data established by a 3D printer data processing software capable of inputting a set value of the wire diameter, and the set value of the wire diameter input to the 3D printer or the 3D printer data processing software is preferably smaller than the average wire diameter of the wire.

[0114] By inputting a value smaller than the average wire diameter (actually measured value) as the set value of the wire diameter into a 3D printer or 3D printer data processing software, a three-dimensional object with excellent mechanical properties can be manufactured more easily. The generation of voids in the obtained three-dimensional object is suppressed.

[0115] The “average wire diameter” is the arithmetic mean of the values ​​obtained by measuring the diameter (or the longest straight line distance in the cross section) to the third decimal place using a micrometer at 20 randomly selected locations of a 5 m sample taken from the wire, and rounding off to the third decimal place.

[0116] In one embodiment, the set value of the discharge amount input to the 3D printer or the data processing software for the 3D printer may be greater than 100% and less than 150%, or greater than 100% and less than 125%.

[0117] In another embodiment, the wire diameter setting value input to the 3D printer or the 3D printer data processing software may be 70% to 100% of the average wire diameter of the wire used, or 80% to 100%.

[0118] In a method for manufacturing a three-dimensional object according to an embodiment of the present invention, the 3D printer is configured to input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, or the 3D printer is configured to operate based on slice data established by data processing software for the 3D printer, and the data processing software for the 3D printer is capable of inputting a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle. Before forming the three-dimensional object, the method comprises the following steps: preparing a density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the density of the standard three-dimensional modeling sample (g / cm) with a known set value of the ejection amount; 3) and the set value of the ejection amount (hereinafter referred to as the "standard curve") (hereinafter, the density of the prepared wire (g / cm 3 ) and preparing the standard curve are collectively referred to as the "standard curve preparation process"). The setting value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is preferably such that the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponds to a set value of the ejection amount corresponding to 95% to 100% of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle. That is, in this embodiment, the process of forming a three-dimensional object includes the following steps: the 3D printer receives an input of a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle; or the 3D printer operates based on the slice data established by the data processing software for the 3D printer, and the data processing software for the 3D printer can input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle. Before forming the three-dimensional object, the process includes the following steps: preparing the density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the aforementioned ejection amount set value known standard three-dimensional modeling sample density (g / cm 3 ) and the set value of the ejection amount, the set value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is preferably such that the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 The above-mentioned setting value of the discharge amount corresponding to 95% to 100% of the above-mentioned point. The setting value of the discharge amount input to the 3D printer or the data processing software for the 3D printer is the density (g / cm) of the wire in the standard curve. 3 ) is set to a discharge amount of 95% to 100%, and it becomes easy to manufacture a three-dimensional molded object with excellent mechanical properties. The generation of voids in the obtained three-dimensional molded object is suppressed.

[0119] (Standard curve preparation process)

[0120] In another embodiment of the method for manufacturing a three-dimensional object, the 3D printer is configured to be capable of inputting a set value of the wire diameter, or the 3D printer is configured to operate based on slice data established by a 3D printer data processing software capable of inputting a set value of the wire diameter, and before forming the three-dimensional object, the method includes the following steps: preparing a density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the density (g / cm) of a standard three-dimensional modeling sample with a known set value of the wire diameter 3 ) and the set value of the wire diameter (hereinafter also referred to as the "standard curve") (hereinafter, the prepared wire density (g / cm3 ) and preparing the standard curve are collectively referred to as the "standard curve preparation process"). The set value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is preferably such that the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponding to the set value of the wire diameter. That is, in this embodiment, the process of forming a three-dimensional object includes the following steps: the 3D printer receives the input of the set value of the wire diameter; or the 3D printer operates based on the slice data established by the 3D printer data processing software capable of inputting the set value of the wire diameter, and before forming the three-dimensional object, includes the following steps: preparing the density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the density (g / cm) of a standard three-dimensional modeling sample having a known set value of the aforementioned wire diameter 3 ) and the set value of the wire diameter, the set value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is preferably such that the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponding to 95% to 100% of the wire diameter. The wire diameter setting value input to the 3D printer or the 3D printer data processing software is the density (g / cm2) of the wire in the standard curve. 3 ) is set to 95% to 100% of the wire diameter, making it easy to manufacture a three-dimensional object with excellent mechanical properties. The generation of voids in the obtained three-dimensional object is suppressed.

[0121] The standard curve preparation process can be performed before the three-dimensional object formation process or before or after the wire preparation process. The density (g / cm 3 ) and a standard curve, you can also prepare the previously measured wire density (g / cm 3 ) and a pre-established standard curve. Density of the wire (g / cm 3 ) and the standard curve are preferably re-measured or re-established each time the composition of the wire and / or the model of the 3D printer changes.

[0122] Density of wire (g / cm 3) is a value measured by a method generally referred to as a water displacement method, Archimedes method, etc. First, the weight of a 5 cm long wire sheet is measured in the air. Next, the weight of the wire sheet is measured while being completely immersed in water. Since the difference between the weight in the air and the weight in the water represents the buoyancy in the water, the substantial volume of the wire sheet can be calculated. The density of the wire sheet is calculated based on the weight in the air and the substantial volume thus obtained.

[0123] Taking the case where the object of the changed setting value is the wire diameter as an example, a standard curve can be established by the following method. First, prepare a standard three-dimensional modeling sample with a known setting value of the wire diameter in the 3D printer. For example, if a wire with the same composition as the target three-dimensional modeling object is used, and the setting value of the wire diameter in the 3D printer is set to 1.55mm, 1.65mm, or 1.75mm, then three standard three-dimensional modeling samples of three sizes of 80mm×10mm×4mm thick are manufactured. Next, the density of three standard three-dimensional modeling samples of each type is measured by the water substitution method, and the arithmetic mean is taken as the density (g / cm 3 ). The density obtained (g / cm 3 ) as the vertical axis and the set value of the wire diameter (1.55mm, 1.65mm or 1.75mm) as the horizontal axis, a standard curve can be established from the drawn approximate straight line. If it is not an approximate straight line, check the set value to obtain an approximate straight line and perform the modeling and density evaluation again.

[0124] In the above standard curve, density is the density of the above wire (g / cm 3 ) is used as the wire diameter setting value input to the 3D printer (or 3D printer data processing software). In one embodiment, the density in the standard curve is the wire density (g / cm 3 ) may be a value smaller than the average wire diameter of the wires used.

[0125] (3D Printer)

[0126] Figure 1 An example of a structure of a 3D printer that receives input of a set value of a wire diameter and a set value of an ejection amount ejected from a nozzle is shown. The structure of the 3D printer is not limited to Figure 1 The 3D printer may also be configured to receive either a set value of the wire diameter or a set value of the ejection amount ejected from the nozzle.

[0127] Figure 1The 3D printer 100 shown includes a wire supply unit 1 for setting the wire, a wire melting unit 2 for melting the wire, a nozzle 3, a modeling table 4, a casing 5, and a control unit 6 for controlling a scanning area of ​​the nozzle 3 and an ejection amount of the molten material of the wire 10 from the nozzle 3.

[0128] The wire supply unit 1 is configured to be able to provide a wire 10 for forming a three-dimensional object and, if necessary, an auxiliary wire 20 for forming an auxiliary component 40 for supporting a three-dimensional object 30. The wire melting unit 2 is integrally provided with a nozzle 3 and is provided with a heating mechanism (not shown). The nozzle 3 is configured to be able to scan the molding table 4 and eject the melt of the wire 10 from the ejection port at the front end. The molding table 4 is formed on a base that can adjust the height.

[0129] The control unit 6 is connected to the wire melting unit 2, and has a first input unit 7 for inputting three-dimensional data, a second input unit 8 for inputting a set value of the wire diameter, and a third input unit 9 for inputting a set value of the ejection amount ejected from the nozzle. In another embodiment, the control unit 6 can also be provided integrally with the nozzle 3, as in the wire melting unit 2. The control unit 6 controls the scanning area of ​​the nozzle 3 based on the three-dimensional data, and controls the ejection amount of the molten material of the wire 10 ejected from the nozzle 3 based on the set value of the wire diameter or the set value of the ejection amount. When the ejection amount of the molten material of the wire 10 ejected from the nozzle 3 is controlled based on the set value of the wire diameter, for example, the control unit 6 controls the ejection amount of the molten material of the wire 10 to increase as the set value of the wire diameter becomes smaller. The set value of the wire diameter and the set value of the ejection amount are as described above. The control of the ejection amount of the molten material of the wire 10 in the control unit 6 can also be realized by data processing software for a 3D printer. In one embodiment, the 3D printer 100 may be configured to operate based on slice data created by 3D printer data processing software that allows input of a set value of the wire diameter and / or a set value of the ejection amount.

[0130] In one embodiment, the inner diameter of the nozzle is not limited, and may be, for example, 0.1 to 1 mm, or 0.2 to 0.6 mm.

[0131] In one embodiment, the drawing speed of the molten wire is determined by the control unit, and may be, for example, 5 to 100 mm / sec, or 10 to 60 mm / sec.

[0132] In one embodiment, the 3D printer may also include an air duct for ejecting air, and the air is used to cool and solidify the modeling material accumulated near the nozzle.

[0133] (3D modeling)

[0134] Reference Figure 1 , 2, describes a method for manufacturing a three-dimensional object by a hot melt deposition method using a 3D printer. A wire 10 containing a crystalline thermoplastic resin is set in a wire supply unit 1 of a 3D printer 100. The three-dimensional data is input into a first input unit 7 of the 3D printer, and a set value of the wire diameter is input into a second input unit 8, and / or a set value of the amount of ejection from the nozzle is input into a third input unit 9. The set value of the wire diameter and the set value of the ejection amount are as described above. By optimizing the set value of the wire diameter and / or the set value of the ejection amount, it becomes easy to produce a three-dimensional object with excellent mechanical properties. In addition, a three-dimensional object with low porosity can be produced.

[0135] The control unit 6 determines the scanning area of ​​the nozzle 3 based on the three-dimensional data, and determines the discharge amount of the wire melt discharged from the nozzle 3 based on the set value of the wire diameter and / or the set value of the discharge amount.

[0136] When the 3D printer 100 is in operation, the wire 10 is supplied to the wire melting section 2 and melted, and is ejected from the ejection port 3a of the nozzle 3 onto the modeling table 4 based on the ejection amount output from the control section 6. The molten material of the wire 10 is ejected while the nozzle 3 scans the modeling table 4, thereby forming a bottom layer (base layer) in which the modeling lines 30a composed of the molten material of the wire 10 are gathered. By repeatedly reversing the scanning direction of the nozzle 3 and ejecting the molten material of the wire 10, a three-dimensional modeling object 30 in which the modeling lines 30a are sequentially stacked on the bottom layer is produced. The stacking pitch is not limited, and can be 0.05 to 0.4 mm, or 0.1 to 0.2 mm.

[0137] By better forming the bottom layer (base layer), the stacking structure constituting the three-dimensional modeling object 30 can be easily fixed to the modeling table 4 during the entire modeling process. In order to better form the bottom layer, in addition to leveling the modeling table 4, it is preferred to control the distance between the front end of the nozzle 3 and the surface of the modeling table 4 when forming the bottom layer. When forming the bottom layer, the distance between the front end of the nozzle 3 and the modeling table 4 is preferably greater than 50 μm and less than 200 μm. In fact, when forming the bottom layer, it is expected to consider in advance the optimal value that the modeling line 30a will not peel off from the modeling table 4 and the remaining ejected material will not accumulate on the peripheral portion of the bottom layer.

[0138] When the ground contact surface (surface contacting the molding table 4) of the three-dimensional molding object 30 to be manufactured is small and the height is high, the auxiliary component 40 supporting the three-dimensional molding object 30 may be molded before the molding of the three-dimensional molding object 30. When the auxiliary component 40 is molded, the wire 10 and the auxiliary wire 20 are set in the wire supply part 1. Before the molding of the wire 10, the auxiliary wire 20 is supplied to the wire melting part 2 and melted, and ejected on the molding table to form the auxiliary component 40. Thereafter, the three-dimensional molding object 30 is manufactured by ejecting the melt of the wire 10 on the auxiliary component 40.

[0139] In one embodiment, forming the three-dimensional object preferably includes forming the three-dimensional object on a molding table under the temperature condition represented by the following formula 1 (hereinafter also referred to as "first temperature adjustment step").

[0140] Tm2>Ts≥Tc and Tc>Ta>Tc-100 (Formula 1)

[0141] [In Formula 1, Ts is the temperature of the molding table (°C), Tc is the crystallization temperature of the wire (°C), Tm2 is the melting point of the wire (°C), and Ta is the ambient temperature of the molding area (°C)]

[0142] After the first step, the three-dimensional object is peeled off from the surface of the molding table under the temperature condition shown in the following formula 2 (hereinafter also referred to as "second temperature adjustment step").

[0143] Tc>Ts (Formula 2)

[0144] [In Formula 2, Ts and Tc are the same as in Formula 1]

[0145] The "modeling area" is a space on the modeling table where a three-dimensional model can be formed. In one embodiment, the modeling area is preferably a chamber that forms a closed space in order to facilitate temperature regulation.

[0146] The ambient temperature (Ta) of the molding area and the molding table temperature (Ts) can be adjusted by increasing or decreasing the settings on the hot melt deposition 3D printer. Neither the ambient temperature (Ta) of the molding area nor the molding table temperature (Ts) is the set value for the operation of the 3D printer, but refers to the actual measured values ​​of the molding table temperature and the ambient temperature of the molding area under certain set conditions.

[0147] The method for measuring the melting point Tm2 and the crystallization temperature Tc of the wire is the same as that described for the above-mentioned wire.

[0148] In the first temperature adjustment step, by setting the various temperatures during wire stacking within the range specified by Formula 1, the occurrence of warping of the deposited material caused by the temperature drop during stacking can be further suppressed, and the deposited material can be firmly fixed on the molding table, making it easier to mold a three-dimensional molded object. In the second temperature adjustment step, by setting the temperature of the molding table after molding within the range specified by Formula 2, the formed three-dimensional molded object becomes easier to peel off from the molding table.

[0149] In one embodiment, for example, when the melting point Tm2 of the crystalline thermoplastic resin is 162°C and the crystallization temperature Tc is 140°C, the temperature of the molding table in the first temperature adjustment process is preferably set to be above 140°C and below 162°C, and the ambient temperature of the molding area is preferably set to be above 40°C and below 140°C.

[0150] In the second temperature adjustment step, the temperature of the molding table after the three-dimensional molding is formed is lowered to below the crystallization temperature of the wire material, so that the bottom layer (base layer) crystallizes and the adhesion of the bottom layer to the molding table is reduced, so that the three-dimensional molding can be easily peeled off from the molding table.

[0151] In one embodiment, for example, when the crystallization temperature Tc of the crystalline thermoplastic resin is 140° C., the temperature of the molding table after the three-dimensional molding is formed is preferably lowered to below 140° C. The bottom layer (base layer) may be removed by cutting, grinding, etc. as needed.

[0152] Example

[0153] Hereinafter, the present invention will be described in more detail with reference to Examples, but the interpretation of the present invention is not limited to these Examples.

[0154] [Production Example 1] (Step of preparing wire material (i))

[0155] Using POM resin (polyacetal resin, manufactured by Polyplastics Co., Ltd., DURACON (registered trademark) POM FP-15X), a wire (i) having an average wire diameter of 1.75 mm was prepared as follows. The method for measuring the average wire diameter will be described later.

[0156] POM resin pellets were put into a tabletop extruder (Apex Japan, AS-1) and extruded at a barrel temperature of 200°C and a screw speed of 40 rpm. The extruded wire was cooled and solidified with water, and then wound using a wire winder (Filabot, Spooler) at a winding speed that made the wire diameter 1.75 mm ± 0.1 mm, thereby obtaining a wire made of POM resin.

[0157] [Production Example 2] (Step of preparing wire material (ii))

[0158] A wire (ii) having an average wire diameter of 1.75 mm was prepared in the same manner as in Production Example 1 except that DURACON (registered trademark) POM KT-10H manufactured by Polyplastics Co., Ltd. was used as the POM resin (polyacetal resin). The average wire diameter was measured as follows.

[0159] (Measurement of average wire diameter)

[0160] A sample of 5 m was taken from the obtained wires (i) and (ii), and 20 locations were randomly selected and their diameters were measured to the third decimal place using a micrometer (manufactured by Mitutoyo Co., Ltd., product name: ABSOLUTE). Then, the third decimal place of the average value was rounded off to the average wire diameter.

[0161] [Example 1]

[0162] Using the wire material (i), a three-dimensional object is produced as follows.

[0163] (Standard curve preparation process)

[0164] The density (g / cm) of the wire (i) was determined as follows: 3 ) value, the result is 1.41g / cm 3 .

[0165] The density of the wire was measured by the water displacement method using an electronic densimeter (Alfa Mirage, SD-200L). Specifically, the weight of a 5 cm long wire sheet in air was first measured. Next, the weight of the wire sheet was measured while it was completely immersed in water. Based on these results, the density of the wire sheet was automatically calculated by the program of the electronic densimeter.

[0166] The density (g / cm2) of the standard three-dimensional modeling sample was prepared as follows: 3 ) and the set value.

[0167] The prepared wire (i) is placed in a 3D printer with hot melt deposition method (manufactured by INTAMSYS, trade name: FUNMAT HT Enhanced), and 1.75mm, 1.65mm or 1.55mm are input as the setting value of the wire diameter to shape three standard three-dimensional modeling samples (i-1) to (i-3) with dimensions of 80mm×40mm×10mm thick. The inner diameter of the nozzle that ejects the wire is 0.4mm, the stacking spacing is 0.2mm, and the drawing speed is 30mm / s. The temperature of the nozzle is 210℃, the temperature of the modeling table (Ts) is 155℃, the ambient temperature of the modeling area is 94℃, and the temperature of the modeling table drops to 100℃ after the three-dimensional modeling object is formed.

[0168] The density (g / cm2) of the obtained standard three-dimensional modeling samples (i-1) to (i-3) was measured as follows: 3 ) 5 times. The arithmetic mean values ​​are 1.19742 g / cm 3 (wire diameter setting value: 1.75mm), 1.31684g / cm 3 (wire diameter setting value: 1.65mm), 1.39636g / cm 3 (Set value of wire diameter: 1.55mm).

[0169] The density of the three-dimensional modeling sample was measured by a water displacement method using an electronic densitometer (Alfa Mirage, SD-200L) in the same manner as the density of the wire material. The details are the same as those described above and are omitted.

[0170] Using the obtained values, the density (g / cm 3 The standard curve of the correlation between ) and wire diameter. The results are as follows Figure 3 As shown. Figure 3 In the figure, the horizontal axis represents the known set value (the set value used for the standard curve), and the vertical axis represents the density (g / cm 3 ). The approximate straight line is represented by y=-0.7958x+2.5901.

[0171] In this calibration curve, the density value is set to the density value of the wire material obtained above (1.41 g / cm 3 ) corresponding to 99% of the point "1.50mm" is used as the wire diameter setting value input to the 3D printer.

[0172] (Three-dimensional object forming process)

[0173] The prepared wire (i) is placed in a 3D printer using hot melt deposition (manufactured by INTAMSYS, trade name: FUNMAT HT Enhanced), and 1.50 mm obtained from the above standard curve is input as the set value of the wire diameter input to the 3D printer to shape a three-dimensional object having dimensions of 80 mm long × 40 mm wide × 10 mm thick. It should be noted that the three-dimensional object does not have intentionally formed voids. When shaping the three-dimensional object, the stacking direction is changed to shape three three-dimensional objects (XZ, XY, ZX) having the same dimensions (refer to FIG7 ). The surfaces having a length of 80 mm and a thickness of 10 mm are used as the bottom layer, and the three-dimensional object (XZ) is shaped with the width direction (40 mm) as the stacking direction (refer to Fig. 7A). The bottom layer is formed with the two sides of 80 mm in length and 40 mm in width, and the thickness direction (10 mm) is used as the stacking direction to shape the three-dimensional object (XY) (refer to Figure 7B ). With the 40mm wide and 10mm thick sides as the bottom layer, and the length direction (80mm) as the stacking direction, a three-dimensional object (ZX) is formed (refer to Figure 7C ).

[0174] The inner diameter of the nozzle for ejecting the wire, the stacking pitch, the drawing speed, the nozzle temperature, the temperature of the modeling table (Ts), the ambient temperature of the modeling area, and the modeling table temperature after the three-dimensional modeling object is formed are the same values ​​as those when modeling the standard three-dimensional modeling sample.

[0175] [Example 2]

[0176] (Standard curve preparation process)

[0177] The density (g / cm 3 ) value, the result is 1.48g / cm 3 The standard three-dimensional modeling samples were prepared in the same way as in Example 1, and the density of each standard three-dimensional modeling sample was measured 5 times in the same way as in Example 1, and the arithmetic mean value was 1.3234 g / cm 3 (wire diameter setting value: 1.75mm), 1.3935g / cm 3 (wire diameter setting value: 1.65mm), 1.4775g / cm 3 (Set value of wire diameter: 1.55 mm). Based on the obtained value, the display density (g / cm 3 ) and the standard curve of the correlation between the set value. The results are as follows Figure 4 As shown. Figure 4 In the figure, the horizontal axis represents the known set value (the set value used for the standard curve), and the vertical axis represents the density (g / cm 3 ). The approximate straight line is represented by y=-0.7707x+2.6698.

[0178] In this calibration curve, the density value is set to the density value of the wire material obtained above (1.48 g / cm 3 ) is used as the setting value of the wire diameter input to the 3D printer.

[0179] (Three-dimensional object forming process)

[0180] Except that wire (ii) was used instead of wire (i), and 1.57 mm obtained from the above standard curve was input as the set value of the wire diameter input to the 3D printer, three three-dimensional objects (XZ, XY, ZX) with dimensions of 80 mm long × 40 mm wide × 10 mm thick and different stacking directions were molded in the same manner as in Example 1. The stacking direction of the three-dimensional objects (XZ, XY, ZX) was the same as in Example 1.

[0181] [Comparative Example 1]

[0182] Except that no standard curve is established and the wire diameter input to the 3D printer is set to the same value as the average wire diameter of wire (i) (measured value 1.75 mm), three three-dimensional objects (XZ, XY, ZX) with different stacking directions and dimensions of 80 mm long × 40 mm wide × 10 mm thick are molded in the same manner as in Example 1. The stacking direction of the three-dimensional objects (XZ, XY, ZX) is the same as in Example 1.

[0183] [Measurement and evaluation]

[0184] (CT scan using X-rays)

[0185] The three-dimensional objects XZ obtained in Example 1 and Comparative Example 1 were scanned with X-ray CT using the center as the field of view. The X-ray CT scanner "ScanXmate-D090SS270" manufactured by Comscan Tecno was used for the X-ray imaging. The results are shown in Figures 5 and 6. Figure 5A and Fig. 6A This is a part of the cross-sectional data of a surface of 10 mm×4 mm along the deposition direction (cross-sectional data viewed from the side surface of the three-dimensional modeled object). Figure 5B and Figure 6B It is in the center of the width direction of the 10mm×4mm surface (in Figure 5A and Fig. 6A Indicated by dotted line, Figure 5C and Figure 6C The cross section is taken near the center (indicated by a solid line in FIG), which is a part of the cross-sectional data of the 80 mm×40 mm surface along the stacking direction (cross-sectional data observed from the front side of the three-dimensional modeled object). Figure 5C and Figure 6C This is a part of the cross-sectional data of a surface of 80 mm×10 mm perpendicular to the deposition direction (cross-sectional data viewed from the top surface side of the three-dimensional modeled object).

[0186] like Figure 5A to Figure 5CAs shown, the three-dimensional object obtained in Example 1 has few pores in the cross-sectional data in any direction of the top view, the front view and the side view. The three-dimensional object obtained in Example 1 has few pores in any direction along the stacking direction and in the direction perpendicular to the stacking direction.

[0187] In contrast, Figure 6A to Figure 6C As shown, the three-dimensional modeled object obtained in Comparative Example 1 has defects (gaps) between adjacent drawing lines, and the number of voids is increased.

[0188] (Determination of Porosity)

[0189] for Figures 5A to 5C An arbitrary 10 mm × 10 mm area in the image processing software (Molcer Plus, manufactured by White Rabbit Co., Ltd.) was used to measure the area of ​​the region with a brightness value of -400 to 1000 as the area of ​​the resin region, and the area of ​​the region with a brightness value of -1000 to -800 as the area of ​​the pore region. The ratio of the area of ​​the pore region to the area of ​​the resin region was calculated from the obtained values ​​[A void / A resin ](%).

[0190] Figures 6A to 6C In the same way, [A void / A resin The results are shown in Table 1.

[0191] [Table 1]

[0192]

[0193] (Bending test)

[0194] Five three-dimensional objects XZ, XY, and ZX obtained in Examples and Comparative Examples were prepared, and their flexural strength and flexural modulus were measured according to ISO178. The arithmetic mean values ​​were taken as the flexural strength and flexural modulus of the three-dimensional objects XZ, XY, and ZX. Figures 7A to 7C The stacking direction of the three-dimensional object and the direction in which the bending test is performed are shown. Figures 7A to 7C Arrows representing mutually orthogonal x, y, and z directions are shown. The x and y directions are parallel to the horizontal plane of the modeling table of the 3D printer, and correspond to the width direction of the three-dimensional modeling object. The z direction is the opposite direction of the gravity direction, and corresponds to the accumulation direction of the molten wire. Figures 7A to 7C The black arrows in the figure indicate the stacking direction, and the white arrows indicate the direction of applied load.

[0195] like Figures 7A to 7CAs shown in FIG. 2 , a bending test was performed on any of the three-dimensional shaped objects of 80 mm×10 mm×4 mm thickness by applying a load in a direction perpendicular to the surface of 80 mm×10 mm. The results are shown in Table 2.

[0196] As a reference example, an injection molded product having a size of 80 mm×10 mm×4 mm thick was produced under the following conditions, and the flexural strength and flexural modulus were measured in accordance with ISO 178. The results are shown in Table 2.

[0197] <Injection molding conditions>

[0198] Material drying temperature and time: 80℃×3 hours or more

[0199] Barrel temperature: 205℃

[0200] Mold temperature: 90℃

[0201] Maintaining pressure: 70MPa

[0202] Injection speed: 13mm / s

[0203] [Table 2]

[0204]

[0205] As shown in Table 2, the three-dimensional objects XZ, XY and ZX of Example 1 are compared with the three-dimensional objects XZ, XY and ZX of Comparative Example 1, respectively, and it is found that they have higher bending strength and bending modulus measured according to ISO178, and have more excellent mechanical properties. The bending strength and bending modulus of the three-dimensional objects XZ, XY and ZX of Example 1 can achieve more than 85% of the injection molded products. The bending strength and bending modulus of the three-dimensional objects XZ and XY have exceeded the values ​​of the injection molded products.

[0206] Industrial Applicability

[0207] The three-dimensional shaped object disclosed in the present invention is excellent in mechanical properties such as bending properties, and therefore can be used for various purposes such as prototype production of parts utilizing spring properties, and has industrial applicability.

[0208] Description of Reference Numerals

[0209] 100: 3D printer

[0210] 1: Wire supply department

[0211] 2: Wire melting section

[0212] 3: Nozzle

[0213] 4: Styling table

[0214] 5: Casing

[0215] 10: Wire

[0216] 20: Auxiliary wire

[0217] 30: Three-dimensional objects

[0218] 40: Auxiliary parts

[0219] 6: Control Department

[0220] 7: First input part

[0221] 8: Second input section

[0222] 9: Third input unit

Claims

1. A three-dimensional object, which is a three-dimensional object formed by a wire material containing a crystalline thermoplastic resin by a hot melt deposition method, The porosity of the three-dimensional object is less than 5%, wherein: Porosity is expressed as the following value: A portion or the entirety of the three-dimensional object is scanned with X-ray CT, and an image analysis is performed on a 10 mm × 10 mm region in one direction of the obtained cross-sectional data to measure the area (A) of the region where the resin component exists. resin ) and the area of ​​the pores (A void ), the ratio of the area of ​​the region where the pores exist to the area of ​​the region where the resin component exists [A void / A resin ](%); or, A portion or the entirety of the three-dimensional object is scanned with X-ray CT, and data analysis is performed on a 10 mm × 10 mm × 10 mm area in the obtained spatial data to measure the volume (V resin ) and the volume of the region where the pores exist (V void ), the ratio of the volume of the region where the pores exist to the volume of the region where the resin component exists [V void / V resin ](%) value.

2. The three-dimensional object according to claim 1, wherein: The porosity in the three-dimensional object is 2% or less.

3. The three-dimensional object according to claim 1 or 2, wherein: The crystalline thermoplastic resin includes one or more selected from the group consisting of polyacetal resin, polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, and polyamide resin. The three-dimensional object according to claim 1 or 2, comprising an inorganic or organic filler.

5. A method for manufacturing a three-dimensional object, which is the method for manufacturing a three-dimensional object according to claim 1, comprising the following steps: A 3D printer is used to deposit wires containing crystalline thermoplastic resin by a hot melt deposition method to form a three-dimensional object.

6. The method for manufacturing a three-dimensional object according to claim 5, wherein: The steps of forming the three-dimensional object include the following steps: The 3D printer receives an input of a set value of an ejection amount of a molten crystalline thermoplastic resin ejected from a nozzle; or The 3D printer operates based on slice data created by data processing software for the 3D printer, and the data processing software for the 3D printer can input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, The set value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is a value greater than 100%.

7. The method for manufacturing a three-dimensional object according to claim 5 or 6, wherein: The steps of forming the three-dimensional object include the following steps: The 3D printer receives an input of a set value of a wire diameter; or The 3D printer operates based on slice data created by the 3D printer data processing software capable of inputting a set value of the wire diameter, The set value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is a value smaller than the average wire diameter of the wire.

8. The method for manufacturing a three-dimensional object according to claim 5 or 6, wherein: The steps of forming the three-dimensional object include the following steps: The 3D printer receives an input of a set value of an ejection amount of a molten crystalline thermoplastic resin ejected from a nozzle; or The 3D printer operates based on slice data created by data processing software for the 3D printer, and the data processing software for the 3D printer can input a set value of the ejection amount of the molten crystalline thermoplastic resin ejected from the nozzle, Before forming the three-dimensional object, the following steps are included: preparing the density (g / cm 3 ) value; and preparing a standard curve, the standard curve showing the density (g / cm) of a standard three-dimensional modeling sample of a known set value of the ejection amount 3 ) and the set value of the ejection amount, The setting value of the ejection amount input to the 3D printer or the data processing software for the 3D printer is: the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponds to a set value of the discharge amount corresponding to 95% to 100% of the above.

9. The method for manufacturing a three-dimensional object according to claim 5 or 6, wherein: The steps of forming the three-dimensional object include the following steps: The 3D printer receives an input of a set value of a wire diameter; or The 3D printer operates based on slice data created by the 3D printer data processing software capable of inputting a set value of the wire diameter, Before forming the three-dimensional object, the following steps are included: preparing the density (g / cm 3 ) value; and prepare a standard curve, the standard curve showing the density (g / cm) of a standard three-dimensional modeling sample with a known set value of the wire diameter 3 ) and the set value of the wire diameter, The set value of the wire diameter input to the 3D printer or the data processing software for the 3D printer is: the density of the standard three-dimensional modeling sample in the standard curve becomes the density of the wire (g / cm 3 ) corresponds to a set value of the wire diameter corresponding to 95% to 100%.

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