Filament, resin composition, method for manufacturing a three-dimensional object, and three-dimensional object

Abstract

The present invention provides a filament containing polyolefin resin that exhibits reduced coefficient of thermal expansion and excellent dimensional accuracy. [Solution] A filament used in three-dimensional printing by fused deposition modeling, comprising a filler and a polyolefin resin, wherein the filler content relative to the entire filament is 12% by mass or less.

Description

[Technical Field]

[0001] This disclosure relates to a filament, a resin composition, a method for manufacturing a three-dimensional object, and a three-dimensional object. [Background technology]

[0002] In recent years, 3D printers (i.e., devices for manufacturing three-dimensional objects) have been utilized in various fields, including ICT (Information and Communication Technology) and medicine. For example, Patent Document 1 discloses a polypropylene monofilament resin composition containing two specific polypropylene resin compositions, which can stably mold thick monofilaments, such as those used in 3D printers, even when using a polypropylene resin composition with a high MFR (Metal Fiber Retention Rate). Furthermore, Patent Document 2 discloses a 3D printer material that can produce a molded object possessing both strength and flexibility, comprising a wire containing carbon nanotube threads and a thermoplastic resin. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-203228 [Patent Document 2] International Publication No. 2020 / 241615 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Through our research, we have found that when using a filament containing polyolefin resin as a filament for three-dimensional printing using the Fused Deposition Modeling (FDM) method, which involves melting and layering thermoplastic resins, the linear expansion coefficient of the filament may become high due to the high linear expansion coefficient of the polyolefin resin. If the linear expansion coefficient of the filament is too high, differences in thermal shrinkage occur between layers during three-dimensional printing using this filament, which may result in unintended bending of the resulting three-dimensional object. Furthermore, it was found that with filaments containing polyolefin resin, the dimensional accuracy of the resulting filament is sometimes insufficient (i.e., there is a large discrepancy between the target dimensions and the actual finished dimensions when forming the filament).

[0005] This disclosure was made in light of the above-mentioned issues. One aspect of this disclosure aims to solve the problem of providing a filament and resin composition that contain a polyolefin resin, yet have a reduced coefficient of thermal expansion and excellent dimensional accuracy, as well as a three-dimensional molded object using the above filament and a method for manufacturing the same. [Means for solving the problem]

[0006] The specific means for solving the aforementioned problems are as follows: <1> A filament used in three-dimensional fabrication using the fused deposition modeling method, It contains a filler and a polyolefin resin, and the content of the filler relative to the entire filament is 12% by mass or less. filament. <2> The filler includes at least one of a tubular filler and a fibrous filler. <1> The filament described above. <3> The filler comprises at least one of carbon nanotubes and cellulose nanofibers. <1> or <2> The filament described above. <4> The number-average diameter of the filler is 1 nm to 300 nm. <1> ~ <3> The filament listed in any one of the following. <5> The average aspect ratio of the fillers is 50 or more. <1> ~ <4> The filament listed in any one of the following. <6> The polyolefin resin contains structural units derived from α-olefins having 2 to 6 carbon atoms. <1> ~ <5> The filament listed in any one of the following. <7> The content of the polyolefin resin relative to the entire filament is 80% by mass or more. <1> ~ <6> The filament listed in any one of the following. <8> A resin composition used in the manufacture of filaments used in three-dimensional manufacturing by fused deposition modeling, It contains a filler and a polyolefin resin, and the content of the filler relative to the entire filament is 12% by mass or less. Resin composition. <9> <1> ~ <7> A method for manufacturing a three-dimensional object, comprising the step of manufacturing a three-dimensional object by thermal fusion molding using a filament described in any one of the above. <10> <1> ~ <7> A three-dimensional object manufactured by fused deposition modeling using one of the filaments described in any one of the above. [Effects of the Invention]

[0007] According to one aspect of this disclosure, a filament and resin composition containing a polyolefin resin are provided, which have a reduced coefficient of thermal expansion and excellent dimensional accuracy, as well as a three-dimensional molded object using the filament and a method for manufacturing the same. [Modes for carrying out the invention]

[0008] In this disclosure, a numerical range indicated using "~" means a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In the present disclosure, the term "process" includes not only an independent process but also a process whose intended purpose is achieved even if it cannot be clearly distinguished from other processes. In the present disclosure, the amount of each component means the total amount of a plurality of substances corresponding to each component unless otherwise specified when there are a plurality of substances corresponding to each component. In the present disclosure, the "(meth)acryloyl group" means an acryloyl group and a methacryloyl group, and the "(meth)acrylate" means an acrylate and a methacrylate.

[0009] 〔Filament〕 The filament of the present disclosure is a filament for three-dimensional modeling by a hot melt lamination method (FDM (Fused Deposition Modeling) method) in which a thermoplastic resin is melted and laminated, and contains a filler and a polyolefin resin, and the content of the filler in the whole filament is 12% by mass or less.

[0010] The filament of the present disclosure contains a polyolefin resin, but has a reduced linear expansion coefficient and excellent dimensional accuracy. Regarding the effect of reducing the linear expansion coefficient, specifically, through the study by the present inventors, it has been found that in a conventional filament containing a polyolefin resin, the linear expansion coefficient of the polyolefin resin is high, which may cause the linear expansion coefficient of the filament to increase. If the linear expansion coefficient of the filament is too high, a thermal shrinkage difference may occur between layers during three-dimensional modeling using this filament, and as a result, an unintended bend may occur in the obtained three-dimensional object. Regarding this point, in the filament of the present disclosure, by containing a polyolefin resin and a filler, the linear expansion coefficient is reduced by the action of the filler.

[0011] Regarding the effect of excellent dimensional accuracy, specifically, as a result of the study by the present inventors, it has also been found that, for conventional filaments containing a polyolefin resin, the dimensional accuracy of the obtained filaments may be insufficient (that is, when forming the filaments, the deviation between the target dimension and the actual finished dimension may be large). Regarding this point, in the filament of the present disclosure, since the content of the filler with respect to the entire filament is 12% by mass or less, it is also excellent in dimensional accuracy (that is, when forming the filament, the deviation between the target dimension and the actual finished dimension is reduced).

[0012] <Filler> The filament of the present disclosure contains at least one kind of filler. The filler may be an organic filler or an inorganic filler.

[0013] The content of the filler with respect to the entire filament is 12% by mass or less. Thereby, the effect that it is excellent in the dimensional accuracy of the filament (that is, the accuracy for obtaining a filament with a target dimension when forming the filament) is exhibited.

[0014] The content of the filler with respect to the entire filament is preferably 1% by mass to 12% by mass, more preferably 1% by mass to 10% by mass.

[0015] The filler preferably includes at least one of a tubular filler and a fibrous filler. In this case, the total content of the tubular filler and the fibrous filler is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 80% by mass to 100% by mass, with respect to the total amount of the filler.

[0016] Preferably, the tubular filler is a carbon nanotube. Preferably, the fibrous filler is a cellulose nanofiber.

[0017] The number-average diameter of the fillers is preferably 1 nm to 300 nm, more preferably 2 nm to 200 nm, and even more preferably 3 nm to 100 nm.

[0018] Here, the diameter of the filler refers to the thickness (i.e., width) of the filler in the projected image if the filler is tubular or fibrous, and to the equivalent diameter of the circle in the projected image if the filler is particulate.

[0019] Here, the number-mean diameter of the fillers refers to the value obtained by selecting 100 fillers from a microscopic image and taking the arithmetic mean of the diameters of those selected fillers.

[0020] The number-average length of the fillers is preferably 0.1 μm to 200 μm, more preferably 0.2 μm to 150 μm.

[0021] Here, the number-average length of the fillers refers to the value obtained by selecting 100 fillers from a microscopic image and taking the arithmetic mean of the lengths of those selected fillers.

[0022] The average aspect ratio of the fillers is preferably 50 or more, more preferably 100 to 1500, and even more preferably 100 to 1000.

[0023] Here, the average aspect ratio of the number of fillers is calculated as follows. One hundred fillers are selected from the microscope image, and the number-average diameter and number-average length of each of the selected 100 fillers are determined using the method described above. The number-mean aspect ratio is obtained by dividing the obtained number-mean length by the number-mean diameter (i.e., calculated using the formula "number-mean aspect ratio = number-mean length / number-mean diameter").

[0024] The filler preferably contains at least one of carbon nanotubes and cellulose nanofibers. In this case, the total content of carbon nanotubes and cellulose nanofibers is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 80% to 100% by mass, relative to the total amount of filler.

[0025] (Carbon nanotubes (CNTs)) The filler may contain carbon nanotubes (hereinafter also referred to as CNTs). CNTs have a shape in which graphene sheets are rolled into a single-layer or multi-layered tubular structure. The CNTs preferably include at least one of single-walled carbon nanotubes (hereinafter also referred to as "single-walled CNTs") and multi-walled carbon nanotubes (hereinafter also referred to as "multi-walled CNTs"), more preferably include multi-walled CNTs, and even more preferably be multi-walled CNTs. When the CNTs include at least one of single-walled carbon nanotubes (SLAs) and multi-walled carbon nanotubes (in particular, multi-walled carbon nanotubes), the melt viscosity of the resin composition used in the manufacture of the filament is further reduced, and as a result, the manufacturability of the resin composition or the filament is further improved. Furthermore, if the CNTs include at least one of single-walled CNTs and multi-walled CNTs (especially multi-walled CNTs), the electromagnetic wave absorption performance of the electromagnetic wave absorbing member will be further improved when the electromagnetic wave absorbing member is manufactured as a three-dimensional object as described later.

[0026] "Single-walled carbon nanotubes" refer to carbon nanotubes that have a shape in which a single layer of graphene sheet is rolled up into a cylindrical shape. "Multilayer carbon nanotubes" refer to carbon nanotubes that have a shape in which graphene sheets are rolled into multiple tubular layers.

[0027] If the filler contains carbon nanotubes, the number-average diameter of the carbon nanotubes may be, for example, 7 nm to 100 nm. If the filler contains carbon nanotubes, the number-average length of the carbon nanotubes may be, for example, 1 μm to 120 μm. If the filler contains carbon nanotubes, the number-mean aspect ratio of the carbon nanotubes may be, for example, 150 to 1000.

[0028] CNTs may be commercially available products. Commercially available CNTs include Nanocyl's "NC7000," Seena Nanotechnology Co., Ltd.'s "FLOTUBE9000," and OCSiAl's "Tubal."

[0029] (Cellulose nanofiber (CNF)) The filler may contain cellulose nanofibers (hereinafter also referred to as CNF). In this disclosure, cellulose nanofiber means cellulose fibers including cellulose microfibers with a fiber diameter of nanoscale (1 nm to 1000 nm). Cellulose nanofibers are obtained by defibrating pulp (pulp fibers), which is a plant-based raw material.

[0030] If the filler contains cellulose nanofibers, the number-average diameter of the cellulose nanofibers may be, for example, 3 nm to 50 nm. If the filler contains cellulose nanofibers, the number-average length of the cellulose nanofibers may be, for example, 0.5 μm to 10 μm. If the filler contains cellulose nanofibers, the number-mean aspect ratio of the cellulose nanofibers may be, for example, 10 to 100.

[0031] CNF can be a commercially available product. Examples of commercially available CNF products include Selenpia (Nippon Paper Industries), AUROVISCO (Oji Holdings), AUROVEIL (Oji Holdings), Leocrista (Daiichi Kogyo Seiyaku), Serish (Daicel Mirise), ELLEX (Daio Paper Corporation), nanoforet (Chuetsu Pulp & Paper Co., Ltd.), XCNF (Rengo), RCNF (Rengo), Stellafine (Marusumi Paper Co., Ltd.), Aronfibro (Toagosei Co., Ltd.), S-CNF (Yokogawa Biofrontier Co., Ltd.), Binfis (Sugino Machinery Co., Ltd.), Cellfim (Mori Machinery Co., Ltd.), Fibrima (Masuko Sangyo Co., Ltd.), MaCSIE (Ehime Paper Co., Ltd.), Cellostar (Starlight Industries Co., Ltd.), and STARCEL (Seiko PMC Co., Ltd.).

[0032] <Polyolefin resin> The filament of this disclosure contains at least one polyolefin resin.

[0033] The polyolefin resin content relative to the entire filament is preferably 80% by mass or more, more preferably 85% by mass or more, and preferably 90% by mass or more.

[0034] In this disclosure, polyolefin resin means a resin containing structural units derived from olefins. The polyolefin resin may be a homopolymer of one olefin, a copolymer of two or more olefins, or a copolymer of one or more olefins and one or more non-olefin monomers. If the polyolefin resin is a copolymer, it may be a random copolymer or a block copolymer.

[0035] The polyolefin resin preferably contains structural units derived from α-olefins having 2 to 6 carbon atoms.

[0036] In this disclosure, α-olefin having 2 carbon atoms means ethylene.

[0037] Examples of α-olefins having 2 to 6 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, and 1-hexene.

[0038] Examples of polyolefin resins include, Ethylene-based polymers (i.e., polymers containing structural units derived from ethylene; for example, polyethylene, ethylene-propylene polymers, ethylene-α-olefin copolymers with 3-6 carbon atoms), Propylene polymers (i.e., polymers containing structural units derived from propylene; for example, polypropylene), 4-methyl-1-pentene polymers (i.e., polymers containing structural units derived from 4-methyl-1-pentene), These are some examples.

[0039] (Ethylene polymer) Ethylene polymers contain ethylene units (i.e., structural units derived from ethylene). The ethylene-based polymer may be a homopolymer of ethylene or a copolymer of ethylene and another monomer.

[0040] Examples of ratios of ethylene units to total structural units in ethylene polymers include 50 mol% to 100 mol%, 60 mol% to 100 mol%, and 80 mol% to 100 mol%. When an ethylene polymer is a copolymer with other monomers, the ratio of ethylene units to the total structural units in the ethylene polymer may be 99 mol% or less, 95 mol% or less, 90 mol% or less, or 80 mol% or less. These ratios are related to carbon-13C nuclear magnetic resonance (hereinafter, 13 It can be calculated by a measurement method called ¹¹C-NMR.

[0041] When an ethylene-based polymer is a copolymer with another monomer, the other monomer can be an α-olefin having 3 to 20 carbon atoms. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, and 1-eicosene.

[0042] Ethylene polymers may have only one of the melting point (°C) and / or the glass transition temperature (°C), or they may have both the melting point (°C) and / or the glass transition temperature (°C). The Tx of the ethylene polymer (i.e., the melting point (°C) of the ethylene polymer if it has both a melting point (°C) and a glass transition temperature (°C), or the one of the two if it has only one of the melting point (°C) and a glass transition temperature (°C)) may be, for example, 100°C to 200°C, and preferably 100°C to 150°C. Tx can be measured using a differential scanning calorimeter (DSC).

[0043] The melt flow rate (MFR) of ethylene-based polymers, measured at 190°C in accordance with JIS K7210, is, for example, 0.01 g / 10 min to 250 g / 10 min, preferably 1 g / 10 min to 230 g / 10 min, more preferably 1 g / 10 min to 200 g / 10 min, and even more preferably 1 g / 10 min to 210 g / 10 min.

[0044] The ethylene polymer has a density of preferably 820 kg / m³. 3 ~1000kg / m 3 More preferably 850 kg / m 3 ~1000kg / m 3 It is within the range.

[0045] Ethylene-based polymers can be produced, for example, by polymerizing ethylene with α-olefins having 3 to 20 carbon atoms, if necessary. Alternatively, it may be produced by thermally decomposing a high molecular weight ethylene-based polymer. Furthermore, ethylene polymers may be purified by methods such as solvent fractionation, which separates them based on differences in solubility in a solvent, or molecular distillation, which separates them based on differences in boiling points.

[0046] Ethylene polymers can be obtained by polymerizing ethylene and, if necessary, an α-olefin having 3 to 20 carbon atoms using conventionally known catalysts for olefin polymerization, such as vanadium-based catalysts, titanium-based catalysts, magnesium-supported titanium catalysts, metallocene catalysts described in International Publication No. 01 / 53369, International Publication No. 01 / 27124, Japanese Patent Publication No. 3-193796, or Japanese Patent Publication No. 2-41303.

[0047] Ethylene-based polymers can be commercially available, such as Lubmer® manufactured by Mitsui Chemicals, Inc.

[0048] (Propylene polymer) Propylene polymers contain propylene units (i.e., structural units derived from propylene). The propylene polymer may be a homopolymer of propylene or a copolymer of propylene and another monomer.

[0049] Examples of ratios of propylene units to total structural units in propylene polymers include 50 mol% to 100 mol%, 60 mol% to 100 mol%, and 80 mol% to 100 mol%. When the propylene polymer is a copolymer with other monomers, the ratio of propylene units to the total structural units in the propylene polymer may be 99 mol% or less, 95 mol% or less, 90 mol% or less, or 80 mol% or less. These ratios are related to carbon-13C nuclear magnetic resonance (hereinafter, 13 It can be calculated by a measurement method called ¹¹C-NMR.

[0050] When the propylene-based polymer is a copolymer with other monomers, examples of the other monomers include ethylene and α-olefins having 4 to 20 carbon atoms. Examples of the α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1-octadecene, and 1-eicosene.

[0051] The propylene-based polymer may have only one of the melting point (°C) and the glass transition temperature (°C), or may have both the melting point (°C) and the glass transition temperature (°C). Tx of the propylene-based polymer (that is, when the propylene-based polymer has both the melting point (°C) and the glass transition temperature (°C), the melting point (°C) of the propylene-based polymer; when the propylene-based polymer has only one of the melting point (°C) and the glass transition temperature (°C), this one) may be, for example, 100°C to 200°C, preferably 100°C to 150°C. Tx can be measured by a differential scanning calorimeter (DSC).

[0052] The melt flow rate (MFR) of the propylene-based polymer measured at 230°C in accordance with JIS K7210 is, for example, 0.01 g / 10 min to 250 g / 10 min, preferably 1 g / 10 min to 230 g / 10 min, more preferably 1 g / 10 min to 200 g / 10 min, and still more preferably 1 g / 10 min to 210 g / 10 min.

[0053] The density of the propylene-based polymer is preferably 820 kg / m 3 ~1000 kg / m 3 and more preferably 850 kg / m 3 ~1000 kg / m 3 within the range.

[0054] The propylene-based polymer can be produced, for example, by polymerizing propylene and, if necessary, ethylene or an α-olefin having 4 to 20 carbon atoms. Alternatively, it may be produced by thermally decomposing a high molecular weight propylene polymer. Furthermore, propylene polymers may be purified by methods such as solvent fractionation, which separates them based on differences in solubility in a solvent, or molecular distillation, which separates them based on differences in boiling points.

[0055] Propylene polymers can be obtained by polymerizing ethylene and, if necessary, an α-olefin having 3 to 20 carbon atoms using conventionally known catalysts for olefin polymerization, such as vanadium-based catalysts, titanium-based catalysts, magnesium-supported titanium catalysts, metallocene catalysts described in International Publication No. 01 / 53369, International Publication No. 01 / 27124, Japanese Patent Publication No. 3-193796, or Japanese Patent Publication No. 2-41303.

[0056] Furthermore, commercially available propylene polymers can be used, such as homopolypropylene manufactured by Prime Polymer.

[0057] (4-methyl-1-pentene polymer) 4-methyl-1-pentene polymers contain 4-methyl-1-pentene units (i.e., structural units derived from 4-methyl-1-pentene). The 4-methyl-1-pentene polymer may be a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another monomer.

[0058] Examples of ratios of 4-methyl-1-pentene units to total structural units in 4-methyl-1-pentene polymers include 50 mol% to 100 mol%, 60 mol% to 100 mol%, and 80 mol% to 100 mol%. When the 4-methyl-1-pentene polymer is a copolymer with other monomers, the ratio of 4-methyl-1-pentene units to the total structural units in the 4-methyl-1-pentene polymer may be 99 mol% or less, 95 mol% or less, 90 mol% or less, or 80 mol% or less. These ratios are related to carbon-13C nuclear magnetic resonance (hereinafter,13 It can be calculated by a measurement method called ¹¹C-NMR.

[0059] When a 4-methyl-1-pentene polymer is a copolymer with another monomer, the other monomer may be an α-olefin having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene). Examples of α-olefins having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene) include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Of these, ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene are preferred. These α-olefins may be used individually or in combination of two or more.

[0060] The 4-methyl-1-pentene polymer preferably has a content of 90 mol% to 100 mol% of constituent units derived from 4-methyl-1-pentene, and a content of 0 mol% to 10 mol% of constituent units derived from at least one olefin (hereinafter also referred to as a comonomer) selected from α-olefins having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene). Furthermore, from the viewpoint of transparency and heat resistance, the content of structural units derived from 4-methyl-1-pentene relative to the total structural units contained in the 4-methyl-1-pentene polymer is preferably 92 mol% to 100 mol%, more preferably 95 mol% to 100 mol%, and the content of structural units derived from at least one olefin selected from α-olefins having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene) is preferably 0 mol% to 8 mol%, more preferably 0 mol% to 5 mol%.

[0061] A 4-methyl-1-pentene polymer may have only one of the melting point (°C) and / or the glass transition temperature (°C), or it may have both the melting point (°C) and / or the glass transition temperature (°C). The Tx of the 4-methyl-1-pentene polymer (i.e., the melting point (°C) of the 4-methyl-1-pentene polymer if the 4-methyl-1-pentene polymer has both a melting point (°C) and a glass transition temperature (°C), or the one of the melting point (°C) and glass transition temperature (°C) if the 4-methyl-1-pentene polymer has only one of these) is preferably 200°C to 250°C, more preferably 200°C to 245°C, and even more preferably 200°C to 240°C. Tx can be measured using a differential scanning calorimeter (DSC).

[0062] The melt flow rate (MFR) of 4-methyl-1-pentene polymers, measured at 260°C and a 5.0 kg load in accordance with ASTM D1238, is, for example, 0.01 g / 10 min to 250 g / 10 min, preferably 5 g / 10 min to 230 g / 10 min, more preferably 10 g / 10 min to 220 g / 10 min, and even more preferably 15 g / 10 min to 200 g / 10 min.

[0063] The 4-methyl-1-pentene polymer has an intrinsic viscosity [η] measured at 135°C in decalin solvent, preferably 0.5 dl / g to 4.0 dl / g, more preferably 0.6 dl / g to 3.5 dl / g, and even more preferably 0.8 dl / g to 3.0 dl / g.

[0064] The 4-methyl-1-pentene polymer has a molecular weight distribution (Mw / Mn), which is the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), measured by gel permeation chromatography (GPC), preferably between 1.0 and 7.0, more preferably between 1.2 and 6.0, and even more preferably between 1.5 and 5.0.

[0065] The 4-methyl-1-pentene polymer has a density of preferably 820 kg / m³. 3 ~860 kg / m 3 , more preferably 825 kg / m 3 ~850kg / m 3 It is within the range.

[0066] 4-methyl-1-pentene polymers can be produced, for example, by polymerizing 4-methyl-1-pentene with, optionally, α-olefins having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene). Alternatively, it may be produced by thermal decomposition of a high molecular weight 4-methyl-1-pentene polymer. Furthermore, 4-methyl-1-pentene polymers may be purified by methods such as solvent fractionation, which separates them based on differences in solubility in a solvent, or molecular distillation, which separates them based on differences in boiling points.

[0067] 4-methyl-1-pentene polymers can be obtained by polymerizing 4-methyl-1-pentene and, if necessary, α-olefins having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene) using conventionally known catalysts for olefin polymerization, such as vanadium-based catalysts, titanium-based catalysts, magnesium-supported titanium catalysts, metallocene catalysts described in International Publication No. 01 / 53369, International Publication No. 01 / 27124, Japanese Patent Publication No. 3-193796, or Japanese Patent Publication No. 2-41303.

[0068] A commercially available 4-methyl-1-pentene polymer can be used, for example, TPX® manufactured by Mitsui Chemicals, Inc.

[0069] <Other ingredients> The filaments of this disclosure may contain other components besides fillers and polyolefin resins. Other components include, for example, colorants (e.g., pigments or dyes), weather stabilizers, UV absorbers, antistatic agents, anti-slip agents, anti-blocking agents, anti-fogging agents, crystal nucleating agents, lubricants, anti-aging agents, hydrochloric acid absorbers, fillers, foaming agents, crosslinking agents, crosslinking aids, adhesives, softeners, flame retardants, and so on.

[0070] [Resin composition] The resin compositions disclosed herein are A resin composition used in the manufacture of filaments used in three-dimensional manufacturing by fused deposition modeling, It contains a filler and a polyolefin resin, and the filler content relative to the total filament is 12% by mass or less. It is a resin composition.

[0071] The resin composition of this disclosure is preferably in the form of pellets. The resin compositions of this disclosure are preferably used in the manufacture of the filaments of this disclosure as described above.

[0072] A preferred embodiment of the resin composition of this disclosure (e.g., a preferred composition) is the same as a preferred embodiment of the filament of this disclosure, except for its shape.

[0073] [Three-dimensional molded objects and methods for manufacturing them] The method for manufacturing a three-dimensional object according to the present disclosure includes the step of manufacturing a three-dimensional object using the filament of the present disclosure by a fused deposition modeling method.

[0074] The three-dimensional object described herein is a three-dimensional object manufactured using the filament described herein by fused deposition modeling.

[0075] The manufacture of intraoral instruments using fused deposition modeling (FDM) three-dimensional fabrication should be carried out in accordance with publicly known techniques. Prior to three-dimensional printing, the filament of this disclosure may be pre-dried.

[0076] Three-dimensional printing is performed by melting the filament of this disclosure and extruding the molten filament from an extruder.

[0077] Three-dimensional fabrication using the fused deposition modeling (FDM) method can be performed using a FDM 3D printer.

[0078] There are no particular restrictions on the shape of the three-dimensional object in the three-dimensional object and the method for manufacturing the same as disclosed herein. According to the manufacturing method for three-dimensional objects of this disclosure, three-dimensional objects having various three-dimensional shapes can be manufactured by fused deposition modeling (FDM).

[0079] Examples of three-dimensionally fabricated objects include dental components, molds, and electromagnetic wave absorbing components. Examples of electromagnetic wave absorbing materials include: Components for absorbing electromagnetic waves inside electronic devices, electronic control units, unmanned aerial vehicles, or lithium-ion battery enclosures; A component that also serves as a Thermal Interface Material (TIM) to mitigate radiated noise; A component for absorbing electromagnetic waves leaking from a contactless power supply device that performs contactless power supply; These are some examples. [Examples]

[0080] The following are examples of the embodiments described herein, but the disclosure is not limited to these embodiments. In Tables 1 and 3, the numbers in the column for each component represent the mass percentage of that component relative to the total filament, and "-" means that the component was not present.

[0081] [Examples 1-4] <Preparation of Masterbatch (PPCNT) for Pellet Production> Fifteen parts by mass of carbon nanotubes (CNTs) as fillers and eighty-five parts by mass of polypropylene (PP) as a polyolefin resin were placed in an FM mixer (FM10C / I, manufactured by Nippon Coke Industries Co., Ltd., capacity: 9L). The added CNTs and PP were stirred and mixed under the following conditions: stirring temperature of 140°C, stirring time of 60 minutes, and screw rotation speed of 1000 rpm (revolutions per minute). This yielded a masterbatch (PPCNT) for pellet production with a CNT content of 15% by mass and a PP content of 85% by mass.

[0082] The details of CNT and PP used here are as follows: CNT… Carbon nanotubes manufactured by Nanocyl (number-average diameter 9.5 nm, number-average length 1.5 μm, number-average aspect ratio 158, powder form, multi-walled) PP… Homopolypropylene manufactured by Prime Polymer (MFR 7g / 10min (2.16kg, 230℃))

[0083] <Preparation of pellets for filament fabrication> A masterbatch for pellet production (PPCNT) and PP as a polyolefin resin were mixed so that the respective mass percentages of PP and CNT relative to the total amount of pellets were as shown in Table 1, thereby obtaining pellets for filament production as a resin composition. The detailed procedure for preparing the pellets is as follows: A twin-screw extruder (TEM-35B, manufactured by Toshiba Machine Co., Ltd., screw diameter: 35 mm, L / D: 32, vented type) was prepared. A die with a 3 mm diameter hole for strand removal was attached to the outlet of the twin-screw extruder. A dry blend of the pellet production masterbatch (PPCNT) and PP was fed into the twin-screw extruder and melt-kneaded at a mixing temperature of 230°C and a screw rotation speed of 100 rpm. The resulting molten mixture was extruded through the die to obtain strands. The strands were cooled in a water bath and cut with a strand cutter. This obtained pellets.

[0084] <Making filaments> Using the above pellets, filaments were manufactured using a filament maker (Composer450, 3devo). The nozzle temperature settings and melt prevention conditions in the filament maker were as shown in the table below. The above resin composition was put into the hopper of a filament extruder (3devo), melt-spinned to produce filaments, and the produced filaments were wound up. Here, the cylinders are arranged in the following order from the upstream side in the resin flow direction: cylinder 4, cylinder 2, cylinder 2, and cylinder 1. The target diameter was adjusted by the melting temperature and / or the rotation speed of the extruder. Table 1 shows the type and amount of polyolefin resin, the type and amount of filler, the cylinder temperature, the single-screw extrusion rotation speed, and the target diameter.

[0085] <Evaluation of the linear thermal expansion coefficient of filaments> The coefficient of thermal expansion was evaluated using the obtained filament as follows. The filament was cut to an appropriate length with scissors, and a pressed piece was produced using a vacuum press (manufactured by Kansai Roll Co., Ltd.) under the conditions of a vacuum atmosphere, temperature of 260°C, pressure of 7MPa, and pressing time of 10 minutes, using a spacer of appropriate thickness to achieve a thickness of 3mm. The coefficient of thermal expansion was measured using the TMA method with the obtained pressed pieces. In detail, the coefficient of linear thermal expansion was measured using a TMA402 F1 Hyperion (manufactured by NETZSCH) under a load of 50 mN, a heating rate of 5°C / min, and in a helium atmosphere. The coefficient of thermal expansion was measured in the same manner in Comparative Example 1, described later. The coefficient of linear expansion in Comparative Example 1 (relative value) was determined when the coefficient of linear expansion in Comparative Example 1 described later was set to 100. Based on the results obtained, the coefficient of linear expansion was evaluated according to the following criteria. The evaluation results for the coefficient of linear expansion are shown in Table 2.

[0086] -Evaluation Criteria for Linear Expansion Coefficient- A... Less than 90 B… 90 or more but less than 100 C…100 or more

[0087] [Comparative Example 1] The procedure was the same as in Example 1, except that a pellet manufacturing masterbatch (PPCNT) was not used in the stage of preparing pellets for filament production, and pellets were prepared using only PP, and the filament manufacturing conditions (specifically, at least one of the cylinder temperature, unscrew extrusion speed, and target diameter; the same applies hereinafter) were changed as shown in Table 1. The evaluation results for the coefficient of linear expansion are shown in Table 2.

[0088] [Examples 5-7] The same procedure as in Example 1 was followed, except that the combination of filler type and quantity, as well as the filament manufacturing conditions, were changed as shown in Table 1. The evaluation results for the coefficient of linear expansion are shown in Table 2.

[0089] The CNF used here is cellulose nanofiber, and the details are as follows. CNF… nanoforest-PDP (Chuetsu Pulp).

[0090] [Table 1]

[0091] [Table 2]

[0092] As shown in Table 2, the filaments of Examples 1 to 7, while containing PP (polypropylene) as a polyolefin resin, exhibited a reduced coefficient of thermal expansion compared to the filament of Comparative Example 1.

[0093] [Examples 101, 102, Comparative Example 101, and Comparative Example 102] Filaments were manufactured in the same manner as in Example 1, except that the type and amount of polyolefin resin, and the manufacturing conditions of the filament were changed as shown in Table 3.

[0094] Here, TPX as a polyolefin resin is a 4-methyl-1-pentene polymer, and the details are as follows. TPX… TPX(registered trademark) MX002O (21g / 10min (5kg, 260℃)) manufactured by Mitsui Chemicals, Inc. was prepared. This TPX is a 4-methyl-1-pentene polymer with a melting point of 224℃ (i.e., Tx is 224℃).

[0095] [Table 3]

[0096] In Examples 101, 102, and Comparative Example 101, the coefficient of linear expansion was evaluated in the same manner as in Example 1. The results are shown in Table 4.

[0097] [Table 4]

[0098] As shown in Table 4, the filaments of Examples 101 and 102, while containing TPX (4-methyl-1-pentene polymer) as a polyolefin resin, exhibited a reduced coefficient of thermal expansion compared to the filament of Comparative Example 101.

[0099] <Evaluation of filament dimensional accuracy> For each filament in Examples 1-7, Example 101, Example 102, and Comparative Example 102, 10 measurement points were set at 10 cm intervals along the length. At each measurement point, the major and minor axes of the filament's cross-section were measured, and the average value of these two values ​​was calculated as the diameter at that point. The average diameter at 10 measurement points was calculated and used as the actual measured diameter of the filament. For each filament, the deviation of the measured diameter from the target diameter (i.e., the difference between the measured diameter and the target diameter) was determined, and the percentage of the obtained deviation relative to the target diameter was calculated. Based on the results obtained, the dimensional accuracy of the filament was evaluated according to the following evaluation criteria. The results are shown in Table 5.

[0100] - Criteria for evaluating dimensional accuracy - A: The deviation of the measured diameter from the target diameter was less than 30% of the target diameter. B: The deviation of the measured diameter from the target diameter was between 30% and 50% of the target diameter. C: The deviation of the measured diameter from the target diameter was 50% or more relative to the target diameter. The results are shown in Table 5.

[0101] [Table 5]

[0102] As shown in Table 5, the filaments of Examples 1-7, 101, and 102, which had a filler content of 12% by mass or less, exhibited superior dimensional accuracy compared to the filament of Comparative Example 102, which had a filler content of 15% by mass.

Claims

1. A filament used in three-dimensional fabrication using the fused deposition modeling method, It contains a filler and a polyolefin resin, and the content of the filler relative to the entire filament is 12% by mass or less. filament.

2. The filament according to claim 1, wherein the filler comprises at least one of a tubular filler and a fibrous filler.

3. The filament according to claim 1, wherein the filler comprises at least one of carbon nanotubes and cellulose nanofibers.

4. The filament according to claim 1, wherein the number average diameter of the filler is 1 nm to 300 nm.

5. The filament according to claim 1, wherein the number-average aspect ratio of the fillers is 50 or more.

6. The filament according to claim 1, wherein the polyolefin resin contains structural units derived from α-olefins having 2 to 6 carbon atoms.

7. The filament according to claim 1, wherein the content of the polyolefin resin relative to the entire filament is 80% by mass or more.

8. A resin composition used in the manufacture of filaments used in three-dimensional manufacturing by fused deposition modeling, It contains a filler and a polyolefin resin, and the content of the filler relative to the entire filament is 12% by mass or less. Resin composition.

9. A method for manufacturing a three-dimensional object, comprising the step of manufacturing a three-dimensional object by thermal fusion molding using a filament described in any one of claims 1 to 7.

10. A three-dimensional object manufactured by fused deposition modeling using the filament described in any one of claims 1 to 7.

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