Filament manufacturing method and three-dimensional object manufacturing method

Abstract

To provide a method for manufacturing a filament, which can manufacture a filament with high precision and can suppress bubbles and burning during manufacturing of the filament. [Solution] A method for producing a filament includes step (1) of melt-spinning a resin composition containing a cyclic olefin polymer under temperature conditions such that the maximum temperature achieved is in the range of (Tx+80)°C to (Tx+220)°C (here, Tx means the melting point (°C) when the cyclic olefin polymer has both a melting point (°C) and a glass transition temperature (°C), or means either the melting point (°C) or the glass transition temperature (°C) when the cyclic olefin polymer has only one of the two).

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a filament and a method for manufacturing a three-dimensional object. [Background technology]

[0002] In recent years, a modeling method in which a 3D object is obtained using a manufacturing device for 3D modeling (for example, a 3D printer) has been attracting attention as one of the efficient modeling technologies. Among the above-mentioned modeling methods, the fused deposition modeling (FDM) method, which melts and layers thermoplastic resin, is advantageous in terms of cost in addition to being able to use a wide range of materials. For example, Patent Document 1 discloses a specific polyamide as a resin used in modeling with a 3D printer using a hot melt method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-109558 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have found that cyclic olefin polymers are resins that may be suitable for the hot melt method in terms of physical properties and the like. Therefore, in order to use a resin composition containing a cyclic olefin polymer in three-dimensional modeling by the hot melt method, we investigated the production of filaments from this resin composition. However, when attempts have been made to produce filaments using a resin composition containing a cyclic olefin polymer, the precision of the produced filaments (specifically, dimensional precision and shape precision) has been insufficient, and / or burning has occurred during the production of the filaments. Here, dimensional accuracy is evaluated by the smallness of deviation from a target dimension, and shape accuracy is evaluated by circularity (that is, the closer the circularity is to 1, the better the shape accuracy).

[0005] An object of one embodiment of the present disclosure is to provide a method for manufacturing a filament that can manufacture a filament with high precision and can prevent burning during manufacturing of the filament, and a method for manufacturing a three-dimensional object by a thermal melting method using the manufactured filament. [Means for solving the problem]

[0006] Specific means for solving the above problems are as follows. <1> A method for producing a filament, comprising: (1) melt-spinning a resin composition containing a cyclic olefin polymer under temperature conditions such that the maximum temperature achieved is in the range of (Tx+80)°C to (Tx+220)°C (where Tx means the melting point (°C) when the cyclic olefin polymer has both a melting point (°C) and a glass transition temperature (°C), or Tx means either the melting point (°C) or the glass transition temperature (°C) when the cyclic olefin polymer has only one of the melting point (°C) or the glass transition temperature (°C)), to obtain a filament. <2> In the step (1), the resin composition is melt-spun under a temperature condition in which the maximum temperature reaches a range of 155°C to 300°C to obtain a filament. <1> A method for producing the filament described in <3> The method further includes, after the step (1), a step (2) of winding the filament. <1> or <2> A method for producing the filament described in <4> In the step (2), the filament is wound at a speed of 0.05 kg / h to 100 kg / h. <3> A method for producing the filament described in <5> The diameter of the filament is 1.00 mm to 10.00 mm. <1> ~ <4> 10. A method for producing a filament according to any one of the preceding claims. <6> The content of the cyclic olefin polymer contained in the resin composition is 90 mass% or more based on the total amount of the resin composition. <1> ~ <5> 10. A method for producing a filament according to any one of the preceding claims. <7> <1> ~ <6> obtaining a filament by the filament manufacturing method according to any one of the above; performing three-dimensional modeling using the filament by a thermal fusion method to obtain a three-dimensional model; A method for manufacturing a three-dimensional object, comprising: [Effects of the Invention]

[0007] According to one aspect of the present disclosure, there is provided a method for manufacturing a filament that can accurately manufacture a filament and suppress burning during manufacturing of the filament, and a method for manufacturing a three-dimensional object by a thermal melting method using the manufactured filament. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In the present disclosure, when there are multiple substances corresponding to each component, the amount of each component means the total amount of the multiple substances unless otherwise specified.

[0009] [Filament manufacturing method] The method for producing a filament according to the present disclosure includes a step (1) of melt-spinning a resin composition containing a cyclic olefin polymer under temperature conditions such that the maximum temperature achieved is in the range of (Tx+80)°C to (Tx+220)°C to obtain a filament. Here, when the cyclic olefin polymer has both a melting point (°C) and a glass transition temperature (°C), Tx means the melting point (°C) of the cyclic olefin polymer; when the cyclic olefin polymer has only one of a melting point (°C) and a glass transition temperature (°C), Tx means either one of the two.

[0010] According to the filament manufacturing method of the present disclosure, the filament can be manufactured with high precision, and burning during manufacturing of the filament can be suppressed. The obtained filament is used to perform three-dimensional modeling using the hot melt method to obtain a three-dimensional object, which results in less uneven discharge during modeling and a good appearance for the resulting three-dimensional object.

[0011] <Process (1)> Step (1) in the filament production method of the present disclosure is a step of melt-spinning a resin composition containing a cyclic olefin polymer (hereinafter also referred to as "resin composition (A)") under temperature conditions such that the maximum temperature reaches a range of (Tx + 80)°C to (Tx + 220)°C to obtain a filament.

[0012] (Resin composition (A)) The resin composition (A) contains a cyclic olefin polymer. The resin composition (A) may contain only one type of cyclic olefin polymer, or may contain two or more types.

[0013] The cyclic olefin polymer contains at least one cyclic olefin unit (that is, a structural unit derived from a cyclic olefin). The cyclic olefin polymer may be a homopolymer of a cyclic olefin, a copolymer of two or more types of cyclic olefins, or a copolymer of at least one type of cyclic olefin and at least one type of other monomer.

[0014] There are no particular limitations on the type of polymerization for the cyclic olefin polymer, and various known polymerization types such as addition polymerization and ring-opening polymerization can be applied. Examples of addition polymerization include random copolymerization, block copolymerization, and cross copolymerization.

[0015] As the cyclic olefin, an olefin containing an alicyclic structure (hereinafter also referred to as an alicyclic olefin) is preferred. Examples of alicyclic olefins include: Bicyclo[2.2.1]-hept-2-ene (common name: norbornene), 5-methyl-bicyclo[2.2.1]-hept-2-ene, 5,5-dimethyl-bicyclo[2.2.1]-hept-2-ene, 5-ethyl-bicyclo[2.2.1]-hept-2-ene, 5-butyl-bicyclo[2.2.1]-hept-2-ene, 5-hexyl-bicyclo[2.2.1]-hept-2-ene, 5-octyl-bicyclo[2.2.1]-hept-2-ene, 5-octadecyl-bicyclo[2.2.1]-hept-2-ene, 5-ethylidene-bicyclo[2.2.1]-hept-2-ene, 5-methylidene-bicyclo[2.2.1]-hept-2-ene, 5-vinyl-bicyclo[2.2.1]-hept-2-ene, 5-propenyl-bicyclo[2.2.1]-hept-2-ene, 5-Methoxy-carbinyl-bicyclo[2.2.1]-hept-2-ene, 5-cyano-bicyclo[2.2.1]-hept-2-ene, 5-methyl-5-methoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, 5-ethoxycarbonyl-bicyclo[2.2.1]-hept-2-ene, bicyclo[2.2.1]-hept-5-enyl-2-methylpropionate, bicyclo[2.2.1]-hept-5-enyl-2-methyloctanate, Bicyclo[2.2.1]-hept-2-ene-5,6-dicarboxylic acid anhydride, 5-hydroxymethylbicyclo[2.2.1]-hept-2-ene, 5,6-di(hydroxymethyl)-bicyclo[2.2.1]-hept-2-ene, 5-hydroxy-i-propylbicyclo[2.2.1]-hept-2-ene, 5,6-dicarboxy-bicyclo[2.2.1]-hept-2-ene, bicyclo[2.2.1]-hept-2-ene-5,6-dicarboxylic acid imide, 5-cyclopentyl-bicyclo[2.2.1]-hept-2-ene, 5-cyclohexyl-bicyclo[2.2.1]-hept-2-ene, 5-cyclohexenyl-bicyclo[2.2.1]-hept-2-ene, 5-phenyl-bicyclo[2.2.1]-hept-2-ene, Tricyclo[4.3.0.1 2,5 ) Deca-3,7-diene (trivial name: dicyclopentadiene), Tricyclo[4.3.0.1 2,5 ) dec-3-ene, Tricyclo[4.4.0.1 2,5 ]Undeca-3,7-diene, Tricyclo[4.4.0.1 2,5 ]Undeca-3,8-diene, Tricyclo[4.4.0.1 2,5 ]undec-3-ene, Tetracyclo[7.4.0.1 10,13 .0 2,7 )-trideca-2,4,6-11-tetraene (synonym: 1,4-methano-1,4,4a,9a-tetrahydrofluorene), Tetracyclo[8.4.0.1 11,14 .0 3,8 )-Tetradeca-3,5,7,12-11-tetraene (synonym: 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene), Tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene (common name: tetracyclododecene), 8-Methyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Ethyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Methylidene-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Ethylidene-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Vinyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Propenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Methoxycarbonyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Methyl-8-methoxycarbonyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Hydroxymethyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Carboxy-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Cyclopentyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Cyclohexyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-Cyclohexenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, 8-phenyl-tetracyclo[4.4.0.1 2,5 .1 7,10 )-dodec-3-ene, Pentacyclo[6.5.1.1 3,6 .0 2,7 .0 9,13 )-pentadeca-3,10-diene, Pentacyclo[7.4.0.1 3,6 .1 10,13 .0 2,7 norbornene-based monomers such as ]-pentadeca-4,11-diene; Monocyclic cycloalkenes such as cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2-(2-methylbutyl)-1-cyclohexene, cyclooctene, 3a,5,6,7a-tetrahydro-4,7-methano-1H-indene, and cycloheptene; vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane; Alicyclic conjugated diene monomers such as cyclopentadiene and cyclohexadiene; etc. The cyclic olefins (preferably alicyclic olefins) can be used either alone or in combination of two or more.

[0016] The ratio of the cyclic olefin units to all structural units in the cyclic olefin polymer may be 50 mol % to 100 mol %, 60 mol % to 100 mol %, or 80 mol % to 100 mol %, for example. When the cyclic olefin polymer is a copolymer with other monomers, the ratio of cyclic olefin units to all structural units in the cyclic olefin polymer may be 99 mol% or less, 95 mol% or less, 90 mol% or less, or 80 mol% or less. These ratios are determined by carbon 13C nuclear magnetic resonance (hereinafter referred to as 13 It can be calculated using a measurement method called C-NMR.

[0017] When the cyclic olefin polymer is a copolymer of a cyclic olefin and another monomer, the other monomer may be ethylene or an α-olefin having 3 to 20 carbon atoms. Examples of the α-olefin 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.

[0018] The cyclic olefin polymer may have either a melting point (° C.) or a glass transition temperature (° C.), or may have both a melting point (° C.) and a glass transition temperature (° C.). The Tx of the cyclic olefin polymer (i.e., the melting point (°C) of the cyclic olefin polymer when the cyclic olefin polymer has both a melting point (°C) and a glass transition temperature (°C); when the cyclic olefin polymer has only one of a melting point (°C) and a glass transition temperature (°C), either one of them) may be, for example, 10°C to 200°C, 50°C to 150°C, or 60°C to 100°C, and is preferably 70°C to 90°C. Tx can be measured by differential scanning calorimetry (DSC).

[0019] The cyclic olefin polymer can be produced, for example, by polymerizing a cyclic olefin and, if necessary, an α-olefin having 3 to 20 carbon atoms. Alternatively, it may be produced by pyrolysis of a high molecular weight cyclic olefin polymer. The cyclic olefin polymer may be purified by solvent fractionation, which separates the polymers based on the difference in solubility in a solvent, or molecular distillation, which separates the polymers based on the difference in boiling point.

[0020] The cyclic olefin polymer can be obtained by polymerizing a cyclic olefin and, if necessary, ethylene or an α-olefin having 3 to 20 carbon atoms using a conventionally known olefin polymerization catalyst, such as a vanadium-based catalyst, a titanium-based catalyst, a magnesium-supported titanium catalyst, or the metallocene catalysts described in WO 01 / 53369, WO 01 / 27124, JP-A 3-193796, or JP-A 2-41303. Furthermore, commercially available cyclic olefin polymers can be used, for example, APEL (registered trademark) manufactured by Mitsui Chemicals, Inc.

[0021] Examples of preferred physical properties of the cyclic olefin polymer are shown below. The melt mass flow rate (MFR) is preferably 5 cm 3 / 10min~100cm 3 / 10min range. The MFR is measured in accordance with ASTM D1238 at 260°C and a load of 2.16 kg. The density is preferably 0.90 g / cm 3 ~1.65g / cm 3 The range is. Density is measured in accordance with ISO 1183:2019. The water absorption is preferably 0.7% by mass or less. Water absorption is measured in accordance with ISO 62:2008 by immersing the material in water at 23°C for 24 hours. The moisture content is preferably 0.5% by mass or less. The moisture content is calculated based on the following formula. Water content (mass%)=((mass of resin composition before drying−mass of resin composition dried at 100°C for 24 hours) / mass of resin composition before drying)×100 The linear expansion coefficient is preferably 5×10 -4 (1 / ℃) or less. The coefficient of linear expansion is measured in accordance with ISO 11359:2023.

[0022] The resin composition (A) may or may not contain components other than the cyclic olefin polymer. Examples of components other than the cyclic olefin polymer that may be contained in the resin composition (A) include polymers other than the cyclic olefin polymer, coloring materials (e.g., pigments or dyes), weather stabilizers, ultraviolet absorbers, antistatic agents, antislip agents, antiblocking agents, antifogging agents, crystal nucleating agents, lubricants, antioxidants, hydrochloric acid absorbers, fillers, foaming agents, crosslinking agents, crosslinking aids, adhesives, softeners, and flame retardants.

[0023] The content of the cyclic olefin polymer contained in the resin composition (A) is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total amount of the resin composition (A).

[0024] (melt spinning) In step (1), the resin composition (A) is melt-spun under temperature conditions such that the maximum temperature reaches a range of (Tx+80)°C to (Tx+220)°C to obtain filaments. In step (1), the resin composition (A) is preferably melt-spun under temperature conditions such that the maximum temperature reaches a range of 155°C to 300°C (more preferably 160°C to 300°C) to obtain filaments.

[0025] The diameter of the filament obtained in step (1) is preferably 1.00 mm to 10.00 mm. The lower limit of the filament diameter is more preferably 1.00 mm, even more preferably 1.50 mm, and even more preferably 1.60 mm. The upper limit of the filament diameter is more preferably 4.00 mm, even more preferably 3.50 mm, and even more preferably 3.00 mm. Here, the diameter of the filament means the diameter of the cross section of the filament equivalent to a circle.

[0026] The roundness of the filament obtained in step (1) is preferably 1.00 to 1.20, more preferably 1.00 to 1.15, and even more preferably 1.00 to 1.10, since it is easy to obtain a three-dimensional shaped product with excellent appearance and surface properties. The closer the circularity is to 1.00, the closer the cross section of the filament is to a perfect circle. Here, the circularity of the filament is a value obtained by the following method. Ten measurement points are set at 3 cm intervals along the length of the filament, and the long and short diameters of the filament are measured at each measurement point. The average ratio of the long diameter to the short diameter is taken as the circularity of the filament.

[0027] In the melt spinning in step (1), for example, the resin composition (A) is fed into an extruder (for example, a single-screw extruder or a twin-screw extruder), and then extruded as a molten strand from a die hole of the extruder. The obtained molten strand is cooled to obtain a strand, and the obtained strand is stretched to obtain a filament. In this case, the maximum temperature of the resin composition (A) is the maximum temperature that can be reached in each cylinder of the extruder. The molten strand is cooled by air drying and / or in a water bath. When in a water bath, the water temperature is preferably in the range of 5°C to 60°C, more preferably 7°C to 50°C, and even more preferably 10°C to 40°C, although it depends on the diameter of the desired filament.

[0028] By stretching the strand as described above, the molecular chains can be oriented in a direction parallel to the pulling direction, and the tensile strength and toughness of the resulting filament can be improved. The above-mentioned strand drawing is carried out, for example, by adjusting the speed ratio (draw ratio) between the take-up roll on the inlet side and the take-up roll on the outlet side of the drawing device. The draw ratio of the above-mentioned strand is preferably 2 to 15 times.

[0029] The strand is usually stretched under heating. Heating during stretching may be carried out using any of a hot water bath, an oven, a heated roll, etc., without any particular limitation, but it is preferable to use a hot water bath from the viewpoint of more uniform stretching. The stretching using a hot water bath can be carried out, for example, by using a water bath having a length and depth that allow the water temperature to be adjusted, and take-up rolls disposed before and after the water bath. Stretching using an oven can be carried out, for example, using an electric heater (infrared heater) as a heat source arranged in the take-up direction, an oven with a length that allows the temperature to be adjusted, and take-up rolls arranged before and after the oven. Stretching using a heated roll can be carried out by, for example, installing multiple take-up rolls whose temperatures are controlled by water pipes, oil pipes, and electric heaters disposed inside, and adjusting the rotation speed of these take-up rolls.

[0030] When the cyclic olefin polymer has both a melting point (Tm) (°C) and a glass transition temperature (Tg) (°C), the heating temperature during stretching is preferably Tg to Tm, more preferably Tg to Tm-30°C, and even more preferably Tg to Tm-60°C.

[0031] The draw ratio of the strand is preferably 2 to 15 times, more preferably 3 to 12 times, and even more preferably 4 to 10 times. The strand may be stretched in a single-stage stretching process or in a multi-stage stretching process. When multi-stage stretching is performed, the stretching ratio may be changed sequentially, for example, 1.1 to 10 times in the first stage and 1.5 to 12 times in the second stage. It is preferable that the heating temperature during stretching is lowest in the first stage and is successively increased with each additional stage.

[0032] In step (1), the obtained filament may be heat-treated (heat-set). This makes it possible to suppress changes in physical properties (for example, shrinkage) at high temperatures. The temperature for the heat treatment is, for example, 20°C to 140°C, and preferably 30°C to 120°C. When the cyclic olefin polymer in the resin composition (A) used as the raw material for the filaments has both a melting point (°C) and a glass transition temperature (°C), the temperature of the heat treatment may be in the range of the glass transition temperature (°C) to the melting point (°C). As in the case of the stretching operation, the heat treatment may be carried out using any method such as a water bath, an oven, or a heated roll, and there is no limitation thereto.

[0033] In step (1), the obtained filament may be heat-treated (heat-set) and then cooled in a cooling bath. The cooling method may be either water cooling or air cooling, and there is no limitation.

[0034] <Process (2)> The method for producing a filament according to the present disclosure may further include a step (2) of winding the filament after the above-described step (1). The winding process involves winding the filament onto a cartridge, bobbin, or cone using a winding machine, for example, to obtain a roll of filament.

[0035] The winding speed is preferably 0.05 kg / h to 100 kg / h.

[0036] [Method for manufacturing 3D objects] The method for manufacturing a three-dimensional object according to the present disclosure includes: obtaining a filament by the filament manufacturing method described above; a step of performing 3D modeling using a filament by a thermal fusion method to obtain a 3D model; Includes.

[0037] As described above, the step of obtaining a filament in the method for producing a three-dimensionally shaped object according to the present disclosure makes it possible to obtain a filament that is excellent in accuracy (i.e., dimensional accuracy and shape accuracy) and that is inhibited from burning. In the step of obtaining a three-dimensional object in the method of manufacturing a three-dimensional object according to the present disclosure, such filaments are used to perform three-dimensional modeling by a thermal fusion method to obtain a three-dimensional object. This allows for the production of a three-dimensional object with excellent appearance.

[0038] <Process for obtaining filaments> For the process of obtaining the filament, reference can be made to the above-mentioned method for producing the filament of the present disclosure.

[0039] <Process for obtaining 3D objects> In the process of obtaining a three-dimensional object, a filament is used to perform three-dimensional modeling using a thermal fusion method, thereby obtaining a three-dimensional object. The process for obtaining a three-dimensional object preferably includes a melting process in which the above-mentioned filament is melted as a three-dimensional object composition, and a modeling process in which the molten three-dimensional object composition is extruded from the nozzle of a three-dimensional printer to form a model.

[0040] (Melting process) In the melting step, the filament as the composition for three-dimensional modeling is melted. The heating means for melting the composition for three-dimensional modeling is not particularly limited, and known heating means can be used. In the melting step, it is preferable to use a three-dimensional printer equipped with a heating means such as an electric heater. The temperature at which the composition for three-dimensional modeling is melted is preferably set depending on the properties of the cyclic olefin polymer contained in the filament as the composition for three-dimensional modeling, and is preferably (Tx + 80)°C to (Tx + 220)°C, more preferably (Tx + 80)°C to (Tx + 210)°C, and even more preferably (Tx + 80)°C to (Tx + 200)°C.

[0041] In the melting step, for example, the filaments of the composition for three-dimensional modeling may be melted and kneaded.

[0042] (modeling process) In the modeling process, the 3D modeling composition melted in the melting process is extruded from the nozzle of a 3D printer to form a model. [Example]

[0043] Examples of the present disclosure will be shown below, but the present disclosure is not limited to the following examples.

[0044] Example 1 <Filament manufacturing> As a pellet-shaped resin composition containing a cyclic olefin polymer, APEL (registered trademark) APL6509T manufactured by Mitsui Chemicals, Inc. was prepared. This resin composition contains a cyclic olefin polymer A having a Tx (melting point in this example) of 80°C.

[0045] The physical properties of the cyclic olefin polymer A were as follows: Melt mass flow rate (MFR) is 5cm 3 / 10min~100cm 3 / 10min range. The MFR was measured in accordance with ASTM D1238 at 260°C under a load of 2.16 kg. The density is 0.90 g / cm 3 ~1.65g / cm 3 The range was. Density was measured according to ISO 1183:2019. The water absorption rate was 0.7% by mass or less. The water absorption rate was measured in accordance with ISO 62:2008 by immersing the sample in water at 23°C for 24 hours. The moisture content was 0.5% by mass or less. The moisture content was calculated based on the following formula. Water content (mass%)=((mass of resin composition before drying−mass of resin composition dried at 100°C for 24 hours) / mass of resin composition before drying)×100 The linear expansion coefficient is 5 x 10 -4 (1 / ℃) or less. The linear expansion coefficient was measured in accordance with ISO 11359:2023.

[0046] The above-mentioned resin composition APL6509T was charged into the hopper of a filament extruder (manufactured by 3devo) and melt-spun to produce filaments, which were then wound at a winding speed of 0.16 kg / h. The melt spinning conditions were as follows: single screw extrusion speed 4.0 rpm, cylinder 4 temperature 160°C, cylinder 3 temperature 160°C, cylinder 2 temperature 160°C, cylinder 1 temperature 160°C, and target diameter 6.47 mm. Here, the cylinders are arranged in the following order from the upstream side in the direction of resin flow: cylinder 4, cylinder 2, cylinder 2, cylinder 1. In this Example 1, the maximum temperature of the resin composition during melt spinning is 160°C. The target diameter was also adjusted by the melt temperature and / or the rotation speed of the extruder.

[0047] <Evaluation> The obtained filaments were subjected to the following evaluations. The results are shown in Table 1.

[0048] (dimensional accuracy) Ten measurement points were set at 10 cm intervals along the length of the obtained filament. At each measurement point, the major axis of the cross section of the filament was measured, and the average of the major axes at the 10 measurement points was taken as the actual measured diameter of the filament. Based on the obtained measured diameter and the target diameter, the dimensional accuracy was evaluated according to the following evaluation criteria. In the following evaluation criteria, the most excellent dimensional accuracy is ranked as A.

[0049] -Evaluation criteria for dimensional accuracy- A: The deviation (i.e., difference) of the measured diameter from the target diameter was within 15% of the target diameter, and the dimensional accuracy was excellent. B: The deviation (i.e., difference) of the measured diameter from the target diameter was more than 15% of the target diameter, and the dimensional accuracy was poor. C: Melt spinning was not possible (i.e., filaments were not obtained), and evaluation was not possible.

[0050] (Circularity (shape accuracy)) Ten measurement points were set at 3 cm intervals along the length of the obtained filament. At each measurement point, the major axis and minor axis of the filament were measured, and the major axis / minor axis ratio was calculated. The average ratio of the major axis to the minor axis at 10 measurement points was taken as the roundness. Based on the obtained circularity, the circularity (shape accuracy) was evaluated according to the following evaluation criteria. In the following evaluation criteria, the most excellent roundness (shape accuracy) is ranked A.

[0051] -Evaluation criteria for roundness (shape accuracy)- A: The circularity was 1.00 to 1.15. B: The circularity was greater than 1.15. C: Melt spinning was not possible (i.e., filaments were not obtained), and evaluation was not possible.

[0052] (burnt) The obtained filaments were visually observed and evaluated according to the following criteria. In the following evaluation criteria, the most excellent effect of inhibiting scorching is ranked as A.

[0053] - Burn evaluation results - A: No burns (i.e., black spots and / or black streaks) are observed on the filament. B: Burns (i.e., black spots and / or black streaks) are observed on the filament. C: Melt spinning was not possible (i.e., filaments were not obtained), and evaluation was not possible.

[0054] [Examples 2 to 10, Comparative Examples 1 and 2] The same procedure as in Example 1 was carried out except that the filament production conditions were changed as shown in Table 1. The results are shown in Table 1.

[0055] [Table 1]

[0056] As shown in Table 1, in Examples 1 to 10, in which filaments were obtained by melt spinning a resin composition containing a cyclic olefin polymer under temperature conditions in which the maximum temperature reached was in the range of (Tx + 80)°C to (Tx + 220)°C (Tx in this example is the melting point (°C) of the cyclic olefin polymer), the filaments produced had excellent dimensional accuracy and shape accuracy, and burning during filament production was suppressed. In contrast, in Comparative Example 1, in which the maximum temperature reached was less than (Tx+80)°C, melt spinning was not possible (that is, no filaments were obtained). Furthermore, in Comparative Example 2, in which the maximum temperature reached was more than (Tx+220)°C, the dimensional accuracy and shape accuracy decreased.

Claims

1. A method for producing a filament, comprising: (1) melt-spinning a resin composition containing a cyclic olefin polymer under temperature conditions such that the maximum temperature achieved is in the range of (Tx+80)°C to (Tx+220)°C (where Tx means the melting point (°C) when the cyclic olefin polymer has both a melting point (°C) and a glass transition temperature (°C), or Tx means either the melting point (°C) or the glass transition temperature (°C) when the cyclic olefin polymer has only one of the melting point (°C) and the glass transition temperature (°C)), to obtain a filament.

2. 2. The method for producing a filament according to claim 1, wherein in the step (1), the resin composition is melt-spun under temperature conditions such that the maximum temperature reaches a range of 155°C to 300°C to obtain a filament.

3. The method for producing a filament according to claim 1 , further comprising, after step (1), step (2) of winding the filament.

4. 4. The method for producing a filament according to claim 3, wherein in the step (2), the filament is wound at a speed of 0.05 kg / h to 100 kg / h.

5. The method for producing a filament according to claim 1, wherein the filament has a diameter of 1.00 mm to 10.00 mm.

6. The method for producing a filament according to claim 1, wherein the content of the cyclic olefin polymer contained in the resin composition is 90 mass% or more with respect to the total amount of the resin composition.

7. A step of obtaining a filament by the filament manufacturing method according to any one of claims 1 to 6; performing three-dimensional modeling by a thermal fusion method using the filament to obtain a three-dimensional model; A method for manufacturing a three-dimensional object, comprising:

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