Liquid crystal polyester resin composition for 3D printer and liquid crystal polymer filament for 3D printer

Abstract

This liquid crystal polyester resin composition for a 3D printer contains a liquid crystal polyester resin having repeating units represented by formulas (1), (2), and (3). (In formulas (1) to (3), Ar1 represents a phenylene group, a naphthylene group, or a biphenylylene group; Ar2 and Ar3 are each independently a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by formula (4); X and Y are each independently an oxygen atom or an imino group; and one or more hydrogen atoms in Ar1, Ar2, and Ar3 may be each independently substituted with a halogen atom, an alkyl group, or an aryl group.) (In formula (4), Ar4 and Ar5 each independently represent a phenylene group or a naphthylene group; and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

Description

Liquid crystal polyester resin composition for 3D printer and liquid crystal polymer filament for 3D printer

[0001] The present disclosure relates to a liquid crystal polyester resin composition for a 3D printer and a liquid crystal polymer filament for a 3D printer.

[0002] In recent years, 3D printers that can create three-dimensional shaped objects in a desired shape without using a mold have been used in various fields.

[0003] For example, Patent Document 1 describes a mounting table including a base. The second member of the base constituting the mounting table is formed by a 3D printer, and the linear expansion coefficient of the second member is a positive value as shown in FIG. 3 of Patent Document 1.

[0004] As in Patent Document 1, although the shaped object formed by a 3D printer is 5.0×10 －６ / K or less, it has a positive linear expansion coefficient as shown in FIG. 3. Therefore, there are limitations in the application of the shaped object formed by a 3D printer.

[0005] Japanese Patent Application Laid-Open No. 2021-197457

[0006] An object of the present disclosure is to provide a liquid crystal polyester resin composition for a 3D printer and a liquid crystal polymer filament for a 3D printer, which can be formed by a 3D printer and has a shaped object with an improved linear expansion coefficient.

[0007] [1] A liquid crystal polyester resin composition for a 3D printer containing a liquid crystal polyester resin having repeating units represented by the following formulas (1), (2), and (3).

[0008] (In the above formulas (1) to (3), Ar1 is a phenylene group, a naphthylene group or a biphenylylene group; Ar2 and Ar3 are each independently a phenylene group, a naphthylene group, a biphenylylene group or a group represented by the following formula (4); X and Y are each independently an oxygen atom or an imino group; one or more hydrogen atoms in Ar1, Ar2 and Ar3 may each independently be substituted with a halogen atom, an alkyl group or an aryl group.)

[0009] (In formula (4), Ar4 and Ar5 are each independently a phenylene group or a naphthylene group; Z is an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylidene group.) [2] The liquid crystal polyester resin composition for 3D printers according to [1] above, wherein the ratio of the total amount of repeating units containing 2,6-naphthylene groups in the liquid crystal polyester resin to the total amount of all repeating units constituting the liquid crystal polyester resin is 40 mol% or more. [3] The liquid crystal polyester resin composition for 3D printers according to [1] or [2] above, wherein the ratio of the total amount of repeating units represented by formula (1) to the total amount of all repeating units constituting the liquid crystal polyester resin is 30 mol% or more and 80 mol% or less, the ratio of the total amount of repeating units represented by formula (2) to the total amount of all repeating units constituting the liquid crystal polyester resin is 10 mol% or more and 35 mol% or less, and the ratio of the total amount of repeating units represented by formula (3) to the total amount of all repeating units constituting the liquid crystal polyester resin is 10 mol% or more and 35 mol% or less. [4] The liquid crystal polyester resin composition for 3D printers according to any one of [1] to [3] above, wherein in formula (3), X and Y are oxygen atoms. [5] A liquid crystal polyester resin composition for 3D printers according to any one of [1] to [4] above, wherein the melt viscosity of the liquid crystal polyester resin at a temperature 20°C higher than the flow temperature of the liquid crystal polyester resin and at a shear rate of 1000 / s is 10 Pa·s or more and 200 Pa·s or less. [6] A liquid crystal polyester resin composition for 3D printers according to any one of [1] to [5] above, wherein the melt tension of the liquid crystal polyester resin at a temperature 20°C higher than the flow temperature of the liquid crystal polyester resin is 5 mN or more and 150 mN or less. [7] A liquid crystal polyester resin composition for 3D printers according to any one of [1] to [6] above, wherein the liquid crystal polyester resin composition for 3D printers contains 0.01 parts by mass or more and 10.00 parts by mass or less of filler per 100 parts by mass of the liquid crystal polyester resin.[8] The liquid crystal polyester resin composition for 3D printers according to any one of [1] to [7] above, wherein the liquid crystal polyester resin composition for 3D printers contains 0.01 parts by mass to 200.00 parts by mass of thermoplastic resin per 100 parts by mass of the liquid crystal polyester resin, and the thermoplastic resin is at least one selected from the group consisting of polyester resin, polyacetal resin, polycarbonate resin, aliphatic polyamide resin, semi-aromatic polyamide resin, polyphenylene sulfide resin, polyethersulfone resin, polyether aromatic ketone resin, polyetherimide resin, polyamideimide resin, and thermoplastic polyimide resin. [9] A liquid crystal polymer filament for 3D printers comprising the liquid crystal polyester resin composition for 3D printers according to any one of [1] to [8] above.

[10] The liquid crystal polymer filament for 3D printers according to [9] above, wherein the diameter of the liquid crystal polymer filament for 3D printers is 1.00 mm to 5.00 mm.

[11] The liquid crystal polymer filament for 3D printers is a filament for a fused deposition modeling (FDM) 3D printer as described in [9] or

[10] above.

[0010] According to this disclosure, it is possible to provide a liquid crystal polyester resin composition for 3D printers and a liquid crystal polymer filament for 3D printers that can be fabricated by a 3D printer and have a more improved coefficient of thermal expansion.

[0011] The following will provide a detailed explanation based on the embodiments.

[0012] As a result of diligent research, the inventors have discovered that by using a liquid crystal polyester resin composition for 3D printers containing a liquid crystal polyester resin having a predetermined repeating unit as a raw material, the coefficient of linear expansion of objects fabricated by a 3D printer can be improved compared to the conventional technology. Based on this finding, the inventors have completed the present invention.

[0013] The liquid crystal polyester resin composition for 3D printers of the embodiment (hereinafter also simply referred to as the liquid crystal polyester resin composition) comprises a liquid crystal polyester resin having a repeating unit represented by the following formula (1) (hereinafter also referred to as repeating unit (1)), a repeating unit represented by the following formula (2) (hereinafter also referred to as repeating unit (2)), and a repeating unit represented by the following formula (3) (hereinafter also referred to as repeating unit (3)).

[0014]

[0015] In the above formulas (1) to (3), Ar1 is a phenylene group, a naphthylene group, or a biphenylylene group; Ar2 and Ar3 are each independently a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4); X and Y are each independently an oxygen atom or an imino group (-NH-); and one or more hydrogen atoms in Ar1, Ar2, and Ar3 may each be independently substituted with a halogen atom, an alkyl group, or an aryl group.

[0016]

[0017] In formula (4) above, Ar4 and Ar5 are each independently a phenylene group or a naphthylene group; Z is an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.

[0018] The halogen atoms that can be substituted for one or more hydrogen atoms in Ar1, Ar2, and Ar3 are preferably fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0019] The alkyl group that can be substituted for one or more hydrogen atoms in Ar1, Ar2, and Ar3 is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group, ethyl group, 1-propyl group, isopropyl group, 1-butyl group, isobutyl group, sec-butyl group, tert-butyl group, 1-hexyl group, 2-ethylhexyl group, 1-octyl group, and 1-decyl group.

[0020] The aryl group that can be substituted for one or more hydrogen atoms in Ar1, Ar2, and Ar3 is preferably an aryl group having 6 to 20 carbon atoms, and more preferably a monocyclic aromatic group such as a phenyl group, orthotolyl group, metatolyl group, or paratolyl group, or a fused aromatic group such as a 1-naphthyl group or a 2-naphthyl group.

[0021] When one or more hydrogen atoms in Ar1, Ar2, and Ar3 are substituted with the above substituents, the number of such substituents is preferably one or two, and more preferably one, for each group represented by Ar1, Ar2, Ar3, Ar4, or Ar5, independently of each other.

[0022] The alkylidene group of Z is preferably an alkylidene group having 1 to 10 carbon atoms, and more preferably a methylene group, ethylidene group, isopropylidene group, 1-butylidene group, or 2-ethylhexylidene group.

[0023] One or more hydrogen atoms in Ar4 and Ar5 may be independently substituted with a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0024] The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid.

[0025] In this specification, "derived from" means that the chemical structure of the raw material monomer changes due to polymerization, but no other structural changes occur.

[0026] Preferred aromatic hydroxycarboxylic acids include 4-hydroxybenzoic acid, meta-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 2-hydroxy-3-naphthoic acid, 1-hydroxy-5-naphthoic acid, 4-hydroxy-4'-carboxydiphenyl ether, and aromatic hydroxycarboxylic acids in which some of the hydrogen atoms in the aromatic ring of these aromatic hydroxycarboxylic acids are substituted with substituents selected from the group consisting of alkyl groups, aryl groups, and halogen atoms.

[0027] In the production of liquid crystal polyester resins, aromatic hydroxycarboxylic acids may be used individually or in combination of two or more types.

[0028] The repeating unit (1) is preferably a unit in which Ar1 is a 1,4-phenylene group (a repeating unit derived from 4-hydroxybenzoic acid) and a unit in which Ar1 is a 2,6-naphthylene group (a repeating unit derived from 6-hydroxy-2-naphthoic acid), and more preferably a unit in which Ar1 is a 1,4-phenylene group.

[0029] The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid.

[0030] Preferably, the aromatic dicarboxylic acids are terephthalic acid, isophthalic acid, biphenyl-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylthioether-4,4'-dicarboxylic acid, or aromatic dicarboxylic acids in which some of the hydrogen atoms in the aromatic ring of these aromatic dicarboxylic acids are substituted with substituents selected from the group consisting of alkyl groups, aryl groups, and halogen atoms.

[0031] Aromatic dicarboxylic acids may be used individually or in combination of two or more in the production of liquid crystal polyester resins.

[0032] The repeating unit (2) is preferably a unit in which Ar2 is a 1,4-phenylene group (for example, a repeating unit derived from terephthalic acid), a unit in which Ar2 is a 1,3-phenylene group (for example, a repeating unit derived from isophthalic acid), a unit in which Ar2 is a 2,6-naphthylene group (for example, a repeating unit derived from 2,6-naphthalenedicarboxylic acid), and a unit in which Ar2 is a diphenyl ether-4,4'-diyl group (for example, a repeating unit derived from diphenyl ether-4,4'-dicarboxylic acid), with units in which Ar2 is a 1,4-phenylene group and units in which Ar2 is a 1,3-phenylene group being preferred.

[0033] The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxyamine, or aromatic diamine.

[0034] Preferably, the aromatic diol, aromatic hydroxyamine, or aromatic diamine is 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, bis(4-hydroxyphenyl)methane, 1,2-bis(4-hydroxyphenyl)ethane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl thioether, 2,6-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 4-aminophenol, 1,4-phenylenediamine, 4-amino-4'-hydroxybiphenyl, or 4,4'-diaminobiphenyl.

[0035] Aromatic diols, aromatic hydroxyamines, or aromatic diamines may be used individually or in combination of two or more in the production of liquid crystal polyester resins.

[0036] The repeating unit (3) is preferably a unit in which Ar3 is a 1,4-phenylene group (for example, a repeating unit derived from hydroquinone, 4-aminophenol, or 1,4-phenylenediamine), and preferably a unit in which Ar3 is a 4,4'-biphenylylene group (for example, a repeating unit derived from 4,4'-dihydroxybiphenyl, 4-amino-4'-hydroxybiphenyl, or 4,4'-diaminobiphenyl), and more preferably a unit in which Ar3 is a 4,4'-biphenylylene group.

[0037] As the repeating unit (3), a unit in which X and Y are each oxygen atoms is preferred.

[0038] When a molded object obtained using a 3D printer with the liquid crystal polyester resin composition of the embodiment as a raw material (hereinafter also referred to as a molded object made by a 3D printer) is required to have particularly good heat resistance and thermal stability, it is preferable that the number of substituents on the repeating units (1) to (3) be small. Furthermore, when a molded object made by a 3D printer is required to have particularly good heat resistance and thermal stability, it is preferable that it does not have heat-sensitive substituents (for example, alkyl groups).

[0039] The heat resistance of the above-mentioned shaped object refers to the property that the resin, which is the forming material of the shaped object, is difficult to soften under a high-temperature environment. The heat resistance of the shaped object can be clarified by measuring the deflection temperature under load of the shaped object. The deflection temperature under load is measured under a load of 1.82 MPa in accordance with ASTM D648. It can be said that the higher the deflection temperature under load of the shaped object measured in this way, the higher the heat resistance of the shaped object.

[0040] Further, the thermal stability of the shaped object refers to the property that resin decomposition and deterioration are unlikely to occur when the shaped object is held at the temperature (melting temperature) at which the resin is molded.

[0041] Further, from the viewpoint of improving the tensile strength of the shaped object, it is preferable that the liquid crystal polyester resin contains a naphthalene skeleton.

[0042] Hereinafter, regarding the liquid crystal polyester resin that is particularly suitable for application to the liquid crystal polyester resin composition of the embodiment, the combination of its structural units will be described in detail based on the above examples of the structural units.

[0043] Specific examples of preferable liquid crystal polyester resins include, for example, resins composed of structural units (repeating units) derived from the following monomers.

[0044] (a) 6-hydroxy-2-naphthoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer (b) 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer (c) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer (d) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer (e) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone copolymer (f) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / hydroquinone / 4,4'-dihydroxybiphenyl copolymer (g) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl copolymer (h) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer (i) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer (j) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer (k) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone copolymer (l) 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol copolymer (r) 4-hydroxybenzoic acid / 6-hydroxy-2-naphthoic acid / terephthalic acid / 4-aminophenol copolymer (m) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl copolymer.

[0045] Among the above examples, (a), (c), and (j) are preferred, with (a) being more preferred. Specifically, it is more preferable that Ar1 is a 2,6-naphthylene group, Ar2 is a 2,6-naphthylene group and a 1,4-phenylene group, Ar3 is a 1,4-phenylene group, and X and Y are oxygen atoms, respectively.

[0046] Furthermore, the proportion of the total amount of repeating units containing 2,6-naphthylene groups in the liquid crystal polyester resin is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and particularly preferably 70 mol% or more, relative to the total amount of all repeating units constituting the liquid crystal polyester resin. The total amount of all repeating units constituting the liquid crystal polyester resin is the sum of the amounts of substance (moles) of each repeating unit obtained by dividing the mass of each repeating unit constituting the liquid crystal polyester resin by the formula weight of each repeating unit.

[0047] When the proportion of repeating units containing 2,6-naphthylene groups is 40 mol% or more, orientation is more likely to occur when the object is fabricated with a 3D printer, which further improves the tensile strength of the fabricated object and makes the coefficient of thermal expansion of the fabricated object more likely to be negative.

[0048] The proportion of the total amount of repeating units (1) of the liquid crystal polyester resin is preferably 30 mol% or more, more preferably 30 mol% to 80 mol%, even more preferably 30 mol% to 70 mol%, and particularly preferably 35 mol% to 65 mol%, relative to the total amount of all repeating units constituting the liquid crystal polyester resin.

[0049] When the proportion of repeating units (1) of the liquid crystal polyester resin is 30 mol% or more, the heat resistance and hardness of the molded object tend to improve. Furthermore, when the proportion of repeating units (1) is 80 mol% or less, the melt viscosity can be lowered. As a result, the temperature required for molding the liquid crystal polyester resin tends to be lower.

[0050] From the viewpoint of improving the heat resistance of the above-mentioned molded product, the ratio of the total amount of repeating units (2) of the liquid crystal polyester resin is preferably 35 mol% or less, more preferably 10 mol% to 35 mol%, even more preferably 15 mol% to 35 mol%, and particularly preferably 17.5 mol% to 32.5 mol% or less, relative to the total amount of all repeating units constituting the liquid crystal polyester resin.

[0051] From the viewpoint of improving the heat resistance of the above-mentioned molded product, the ratio of the total amount of repeating units (3) of the liquid crystal polyester resin is preferably 35 mol% or less, more preferably 10 mol% to 35 mol%, even more preferably 15 mol% to 35 mol%, and particularly preferably 17.5 mol% to 32.5 mol% or less, relative to the total amount of all repeating units constituting the liquid crystal polyester resin.

[0052] In liquid crystal polyester resin, the ratio of the total amount of repeating units (2) to the total amount of repeating units (3) ([total amount of repeating units (2)] / [total amount of repeating units (3)] (moles / moles)) is preferably 0.90 or more and 1.10 or less, more preferably 0.95 or more and 1.05 or less, and even more preferably 0.98 or more and 1.02 or less.

[0053] In liquid crystal polyester resin, the ratio of the total amount of repeating units (3) to the total amount of repeating units (1) ([total amount of repeating units (3)] / [total amount of repeating units (1)] (moles / moles)) is preferably 0.20 or more and 1.00 or less, more preferably 0.25 or more and 0.85 or less, and even more preferably 0.30 or more and 0.75 or less.

[0054] In the liquid crystal polyester resin, the molar ratio y / x of repeating units (2) is preferably greater than 0 and 1.0 or less, more preferably between 0.1 and 0.9, and even more preferably between 0.2 and 0.8. Here, x represents the molar content of repeating units in which Ar2 is a 1,4-phenylene group. Also, y represents the molar content of repeating units in which Ar2 is a 1,3-phenylene group.

[0055] The liquid crystal polyester resin may have only one type of repeating unit (1) to (3), independently of each other, or it may have two or more types. In addition, the liquid crystal polyester resin may have one or more types of repeating units other than repeating units (1) to (3), but the proportion of the total amount of repeating units other than repeating units (1) to (3) is preferably 10 mol% or less, more preferably 5 mol% or less, with respect to the total amount of all repeating units constituting the liquid crystal polyester resin.

[0056] Furthermore, the flow initiation temperature of the liquid crystal polyester resin is preferably 270°C or higher, more preferably 270°C to 400°C, and even more preferably 280°C to 380°C. By using a liquid crystal polyester resin with a flow initiation temperature within the above range, the heat resistance of the molded object obtained using the liquid crystal polyester resin composition of the embodiment can be improved. In addition, in 3D printing when obtaining a molded object from the liquid crystal polyester resin composition, the thermal stability of the liquid crystal polyester resin is improved, and thermal degradation can be avoided.

[0057] The flow initiation temperature, also called the flow temperature or fluid temperature, is the temperature at which a liquid crystal polyester resin exhibits a viscosity of 4800 Pa·s (48000 poise) when melted under a load of 9.8 MPa and heated at a rate of 4°C / min using a capillary rheometer, and extruded from a nozzle with an inner diameter of 1 mm and a length of 10 mm. This temperature serves as an indicator of the molecular weight of the liquid crystal polyester resin (see, for example, Naoyuki Koide (ed.), "Liquid Crystal Polymers - Synthesis, Molding, and Applications," pp. 95-105, CMC, published June 5, 1987).

[0058] A liquid crystal polyester resin with a suitable flow initiation temperature can be easily obtained by appropriately optimizing the structural units that make up the liquid crystal polyester resin. In other words, improving the linearity of the molecular chains of the liquid crystal polyester resin tends to increase its flow initiation temperature.

[0059] For example, structural units derived from terephthalic acid improve the linearity of the molecular chains of liquid crystal polyester resin. On the other hand, structural units derived from isophthalic acid improve the flexibility (decreases linearity) of the molecular chains of liquid crystal polyester resin. Therefore, by controlling the copolymerization ratio of terephthalic acid and isophthalic acid, a liquid crystal polyester resin with a desired flow initiation temperature can be obtained.

[0060] Furthermore, it is preferable to optimize the copolymerization ratio of terephthalic acid and isophthalic acid in the liquid crystal polyester resin. This allows for control of the linearity of the molecular chains of the liquid crystal polyester resin, as described above. As a result, multiple types of liquid crystal polyester resins with different flow initiation temperatures can be produced.

[0061] Furthermore, at a temperature 20°C higher than the flow temperature (flow start temperature) of the liquid crystal polyester resin (flow temperature + 20°C), and at a shear rate of 1000 / s, the melt viscosity of the liquid crystal polyester resin is preferably 10 Pa·s or more and 200 Pa·s or less, and more preferably 70 Pa·s or more and 150 Pa·s or less. When the melt viscosity of the liquid crystal polyester resin is within the above range, even better molding becomes possible.

[0062] Furthermore, the lower limit of the melt tension of the liquid crystal polyester resin at a temperature 20°C higher than the flow temperature of the liquid crystal polyester resin is preferably 5 mN or more, more preferably 50 mN or more, and the upper limit of the melt tension is preferably 150 mN or less, more preferably 100 mN or less. When the melt tension of the liquid crystal polyester resin is 5 mN or more, filament sagging during molding can be suppressed, and when the melt tension is 150 mN or less, filament breakage during molding can be suppressed. Thus, when the melt tension is within the above range, even better molding can be achieved.

[0063] The liquid crystal polyester resin composition may contain only one type of liquid crystal polyester resin. Alternatively, the liquid crystal polyester resin composition may contain a mixture of multiple types of liquid crystal polyester resins, which further improves the melt-flow properties of the liquid crystal polyester resin composition and effectively suppresses warping of the resulting molded object.

[0064] Here, we assume a mixture of liquid crystal polyester resins having different flow initiation temperatures. In this mixture, the one with the higher flow initiation temperature is designated as the first liquid crystal polyester resin, and the one with the lower flow initiation temperature is designated as the second liquid crystal polyester resin.

[0065] The flow initiation temperature of the first liquid crystal polyester resin is preferably 300°C or higher, more preferably 310°C or higher, and even more preferably 315°C or higher. Furthermore, the flow initiation temperature of the first liquid crystal polyester resin is preferably 400°C or lower, more preferably 360°C or lower, and even more preferably 345°C or lower. The upper and lower limits of the flow initiation temperature can be arbitrarily combined.

[0066] When the flow initiation temperature of the first liquid crystal polyester resin is within the above range, it tends to be possible to achieve both the melting fluidity of the resin and the heat resistance of the resulting molded object.

[0067] The flow initiation temperature of the second liquid crystal polyester resin is preferably 260°C or higher, more preferably 270°C or higher, and even more preferably 285°C or higher. Furthermore, the flow initiation temperature of the second liquid crystal polyester resin is preferably 350°C or lower, more preferably 320°C or lower, and even more preferably 315°C or lower. The upper and lower limits of the flow initiation temperature can be arbitrarily combined.

[0068] When the flow initiation temperature of the second liquid crystal polyester resin is within the above range, the fluidity in the thin-walled sections of the mold (thin-wall fluidity) tends to be good, and the load deflection temperature of the resulting molded object tends to be sufficiently high.

[0069] Furthermore, in the liquid crystal polyester resin mixture, the content of the second liquid crystal polyester resin is preferably 10 parts by mass or more and 150 parts by mass or less, more preferably 30 parts by mass or more and 120 parts by mass or less, and even more preferably 50 parts by mass or more and 100 parts by mass or less, per 100 parts by mass of the first liquid crystal polyester resin.

[0070] The above-mentioned content of the second liquid crystal polyester resin relative to the first liquid crystal polyester resin should be set appropriately so that the balance between the load deflection temperature and thin-wall fluidity of the liquid crystal polyester resin mixture is in a desired state.

[0071] Furthermore, the liquid crystal polyester resin mixture may also contain liquid crystal polyester resins other than the first and second liquid crystal polyester resins. In this case, the resin with the highest flow initiation temperature in the liquid crystal polyester resin mixture is designated as the first liquid crystal polyester resin, and the resin with the lowest flow initiation temperature is designated as the second liquid crystal polyester resin. In substance, a liquid crystal polyester resin mixture consisting of the first liquid crystal polyester resin and the second liquid crystal polyester resin is preferred.

[0072] In the liquid crystal polyester resin mixture, α / β is preferably 0.1 to 0.6, and more preferably 0.3 to 0.6. α represents the molar ratio y / x of the first liquid crystal polyester resin. β represents the molar ratio y / x of the second liquid crystal polyester resin. As described above, x represents the molar content of repeating units where Ar2 is a 1,4-phenylene group, and y represents the molar content of repeating units where Ar2 is a 1,3-phenylene group.

[0073] Furthermore, in a liquid crystal polyester resin mixture, if at least one of the liquid crystal polyester resins is a polymer obtained by polymerizing raw material monomers containing aromatic hydroxycarboxylic acid in the presence of an imidazole compound, the liquid crystal polyester resin mixture exhibits very high fluidity in melt and excellent thermal stability.

[0074] Furthermore, the liquid crystal polyester resin composition may also contain fillers and thermoplastic resins in addition to the liquid crystal polyester resin.

[0075] The filler material may be used alone or in combination of two or more types.

[0076] The filler may be a fibrous filler, a plate-shaped filler, or other granular fillers such as spherical ones other than fibrous or plate-shaped ones.

[0077] Preferred examples of fibrous fillers include glass fibers; carbon fibers such as pan-carbon fibers and pitch-carbon fibers; ceramic fibers such as silica fibers, alumina fibers, and silica-alumina fibers; and metal fibers such as stainless steel fibers. Whiskers such as potassium titanate whiskers, barium titanate whiskers, wollastonite whiskers, aluminum borate whiskers, silicon nitride whiskers, and silicon carbide whiskers are also preferred, with glass fibers being the most preferred among them.

[0078] Suitable examples of plate-shaped fillers include talc, mica, graphite, wollastonite, glass flakes, barium sulfate, and calcium carbonate. Among these, talc or mica are preferred.

[0079] Suitable examples of granular fillers include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide, and calcium carbonate.

[0080] Furthermore, from the viewpoint of improving the mechanical strength of the molded object, it is preferable that the content of the filler in the liquid crystal polyester resin composition is 0.01 parts by mass or more per 100 parts by mass of liquid crystal polyester resin. Furthermore, from the viewpoint of maintaining high interlayer adhesion in the molded object, it is preferable that the content of the filler be 10.00 parts by mass or less, more preferably 5.00 parts by mass or less, and even more preferably 3.00 parts by mass or less.

[0081] Furthermore, from the viewpoint of improving interlayer adhesion in the molded object, it is preferable that the content of thermoplastic resin in the liquid crystal polyester resin composition is 0.01 parts by mass or more per 100 parts by mass of liquid crystal polyester resin. Furthermore, from the viewpoint of maintaining high interlayer adhesion in the molded object, it is preferable that the content of the thermoplastic resin is 200.00 parts by mass or less, and more preferably 50.00 parts by mass or less.

[0082] The thermoplastic resin contained in the liquid crystal polyester resin composition is preferably at least one selected from the group consisting of polyester resins, polyacetal resins, polycarbonate resins, aliphatic polyamide resins, semi-aromatic polyamide resins, polyphenylene sulfide resins, polyethersulfone resins, polyether aromatic ketone resins, polyetherimide resins, polyamideimide resins, and thermoplastic polyimide resins.

[0083] Furthermore, the liquid crystal polyester resin composition may also contain biomass-derived materials or recycled materials.

[0084] Next, we will describe an example of a method for manufacturing liquid crystal polyester resin.

[0085] The liquid crystal polyester resin contained in the liquid crystal polyester resin composition of the embodiment is preferably produced by the following acylation and polymerization steps.

[0086] The acylation process is a process in which an acylated product is obtained by acyling the phenolic hydroxyl group of a raw material monomer with a fatty acid anhydride (for example, acetic anhydride).

[0087] In the polymerization process, a liquid crystal polyester resin is obtained by polymerizing the acyl group of the acylated product obtained in the acylation process with the carboxyl group of the acylated products of aromatic dicarboxylic acid and aromatic hydroxycarboxylic acid through transesterification.

[0088] The acylation and polymerization steps may be carried out in the presence of a heterocyclic organic base compound as represented by the following formula (5).

[0089]

[0090] In the above formula (5), R １ ~R ４Each of these is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxymethyl group, a cyano group, a cyanoalkyl group having 1 to 4 carbon atoms, a cyanoalkoxy group having 1 to 4 carbon atoms, a carboxyl group, an amino group, an aminoalkyl group having 1 to 4 carbon atoms, an aminoalkoxy group having 1 to 4 carbon atoms, a phenyl group, a benzyl group, a phenylpropyl group, or a formyl group.

[0091] The heterocyclic organic base compound in formula (5) above is R １ is an alkyl group having 1 to 4 carbon atoms, and R ２ ~R ４ Preferably, each of these is an imidazole derivative in which each atom is a hydrogen atom. This can further improve the reactivity of the acylation reaction in the acylation step and the transesterification reaction in the polymerization step. In addition, it can improve the color tone of molded products obtained using the liquid crystal polyester resin composition.

[0092] Among heterocyclic organic base compounds, 1-methylimidazole and 1-ethylimidazole, or both, are particularly preferred due to their availability.

[0093] Furthermore, the amount of heterocyclic organic base compound used is preferably 0.005 parts by mass or more and 1.000 parts by mass or less, when the total amount of raw material monomers of the liquid crystal polyester resin is 100 parts by mass. Moreover, from the viewpoint of the color tone of the molded product and productivity, the amount of heterocyclic organic base compound used is more preferably 0.050 parts by mass or more and 0.500 parts by mass or less, per 100 parts by mass of raw material monomers.

[0094] The heterocyclic organic base compound only needs to be present at a specific point during the acylation and transesterification reactions. Its addition can occur immediately before the start of the acylation reaction, during the acylation reaction, or between the acylation and transesterification reactions. The resulting liquid crystal polyester resin exhibits very high melt fluidity and excellent thermal stability.

[0095] The amount of fatty acid anhydride used is determined considering the amount of aromatic diol and aromatic hydroxycarboxylic acid used as raw material monomers. Specifically, the amount of fatty acid anhydride used is preferably 1.00 equivalent to 1.20 equivalents, more preferably 1.00 equivalent to 1.15 equivalents, even more preferably 1.03 equivalent to 1.12 equivalents, and particularly preferably 1.05 equivalent to 1.10 equivalents, relative to the total amount of phenolic hydroxy groups contained in these raw material monomers.

[0096] When the amount of fatty acid anhydride used is 1.00 equivalent or more relative to the total amount of phenolic hydroxyl groups in the raw material monomers, the acylation reaction proceeds easily, and unreacted raw material monomers are less likely to remain in the subsequent polymerization step, resulting in efficient polymerization. Furthermore, when the acylation reaction proceeds sufficiently in this way, there is less possibility of unacylated raw material monomers sublimating and clogging the fractional distiller used during polymerization. On the other hand, when the amount of fatty acid anhydride used is 1.20 equivalent or less, the resulting liquid crystal polyester resin is less likely to be colored.

[0097] In the acylation step, the acylation reaction is preferably carried out at a temperature range of 130°C to 180°C for 30 minutes to 20 hours, and more preferably at a temperature range of 140°C to 160°C for 1 hour to 5 hours.

[0098] The aromatic dicarboxylic acid used in the polymerization step may be present in the reaction system during the acylation step. That is, the aromatic diol, aromatic hydroxycarboxylic acid, and aromatic dicarboxylic acid may be present in the same reaction system during the acylation step. This is because the carboxyl group and optionally substituted substituents on the aromatic dicarboxylic acid are not affected in any way by the fatty acid anhydride.

[0099] Therefore, the process can be carried out by sequentially performing the acylation step and polymerization step after charging the aromatic diol, aromatic hydroxycarboxylic acid, and aromatic dicarboxylic acid into the reactor, or by charging the aromatic diol and aromatic dicarboxylic acid into the reactor, performing the acylation step, and then charging the aromatic dicarboxylic acid into the reactor to perform the polymerization step. From the viewpoint of simplifying the manufacturing process, the former method is preferred.

[0100] The transesterification reaction in the polymerization step is preferably carried out while increasing the temperature from 130°C to 400°C at a heating rate of 0.1°C / min to 50.0°C / min, and more preferably while increasing the temperature from 150°C to 350°C at a heating rate of 0.3°C / min to 5.0°C / min.

[0101] Furthermore, when carrying out the transesterification reaction in the polymerization process, it is preferable to evaporate and distill off by-product fatty acids (e.g., acetic acid) and unreacted fatty acid anhydrides (e.g., acetic anhydride) to shift the equilibrium. At this time, by refluxing a portion of the distilled fatty acids back into the reactor, the raw material monomers that evaporated or sublimated along with the fatty acids can be condensed or back-sublimated and returned to the reactor.

[0102] In the acylation reaction of the acylation step and the transesterification reaction of the polymerization step, either a batch apparatus or a continuous apparatus may be used as the reaction apparatus. Regardless of which reaction apparatus is used, a liquid crystal polyester resin that can be used in the liquid crystal polyester resin composition of the embodiment can be obtained.

[0103] Furthermore, in the method for producing liquid crystal polyester resin, a step may be performed after the polymerization step to increase the molecular weight of the liquid crystal polyester resin obtained in the polymerization step.

[0104] For example, a liquid crystal polyester resin obtained in a polymerization process can be cooled and then pulverized to produce a powdered liquid crystal polyester resin, and this powder can then be heated to increase the molecular weight of the liquid crystal polyester resin. Alternatively, the powdered liquid crystal polyester resin obtained by cooling and pulverization can be granulated to produce a pelletized liquid crystal polyester resin, and this pelletized liquid crystal polyester resin can then be heated to increase its molecular weight. In this technical field, the process of increasing molecular weight using these methods is called solid-phase polymerization.

[0105] Solid-phase polymerization is particularly effective as a method for increasing the molecular weight of liquid crystal polyester resins. By increasing the molecular weight of liquid crystal polyester resins, it becomes easier to obtain liquid crystal polyester resins with a suitable flow initiation temperature.

[0106] The conditions for solid-phase polymerization typically involve heat-treating a solid resin under an inert gas atmosphere or reduced pressure for 1 to 20 hours. These polymerization conditions can be optimized after determining the flow initiation temperature of the resin obtained by melt polymerization. Examples of equipment used in solid-phase polymerization include known dryers, reactors, inert ovens, and electric furnaces.

[0107] When a liquid crystal polyester resin composition of this embodiment is used as a raw material for a 3D printer, the object produced by the 3D printer can have an improved coefficient of thermal expansion compared to conventional 3D printed objects. Furthermore, the coefficient of thermal expansion of the object is preferably smaller and negative than the coefficient of thermal expansion of the liquid crystal polyester resin and the liquid crystal polyester resin composition. Thus, the liquid crystal polyester resin composition is a composition suitable for 3D printing.

[0108] Next, the liquid crystal polymer filament for 3D printers according to this embodiment will be described.

[0109] The liquid crystal polymer filament for 3D printers of this embodiment (hereinafter also simply referred to as liquid crystal polymer filament) contains a liquid crystal polyester resin composition for 3D printers. The liquid crystal polyester resin composition for 3D printers contained in the liquid crystal polymer filament is the liquid crystal polyester resin composition of the above embodiment.

[0110] When a liquid crystal polymer filament of this embodiment is used as a raw material for a 3D printer, the liquid crystal polymer filament contains the liquid crystal polyester resin composition of the above embodiment, and the resulting object can have an improved coefficient of thermal expansion compared to conventional 3D printed objects. Furthermore, the coefficient of thermal expansion of the object is preferably smaller and negative than the coefficient of thermal expansion of the liquid crystal polymer filament. Thus, liquid crystal polymer filament is a filament suitable for 3D printing.

[0111] The method for producing liquid crystal polymer filaments is not particularly limited, but examples include an extrusion step in which the liquid crystal polyester resin composition produced by the above method is extruded as a molten strand from the die hole of an extruder and guided to a cooling water bath to obtain the strand, a stretching step in which the strand is stretched to obtain a filament, and a winding step in which the stretched filament is wound up.

[0112] Furthermore, from the viewpoint of further lowering the coefficient of thermal expansion of the fabricated object, the diameter of the liquid crystal polymer filament is preferably 1.00 mm or more and 5.00 mm or less, and more preferably 1.00 mm or more and 3.00 mm or less.

[0113] Furthermore, from the viewpoint of further reducing the coefficient of thermal expansion of the fabricated object, liquid crystal polymer filament is preferably a filament for fused deposition modeling (FDM) 3D printers.

[0114] Fused deposition modeling (FDM) is a method of creating a desired object by fluidizing thermoplastic resin, which has a shape such as pellets or filaments, using a heating means inside the extrusion head, then extruding it from a nozzle onto a platform, and gradually layering and cooling it to solidify it.

[0115] According to the embodiments described above, the coefficient of linear expansion of an object fabricated by a 3D printer using a liquid crystal polyester resin composition containing a liquid crystal polyester resin having a predetermined repeating unit can be improved compared to conventional 3D printed objects.

[0116] Although embodiments have been described above, the present invention is not limited to the embodiments described above, and includes all aspects included in the concepts and claims of this disclosure, and can be modified in various ways within the scope of this disclosure.

[0117] Examples and comparative examples will be described next, but this disclosure is not limited to these examples.

[0118] (Example 1) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer and reflux condenser, 6-hydroxy-2-naphthoic acid (1034.99 g, 5.5 mol), 2,6-naphthalenedicarboxylic acid (378.33 g, 1.75 mol), terephthalic acid (83.07 g, 0.5 mol), hydroquinone (272.52 g, 2.475 mol, 0.225 mol excess relative to the total amount of 2,6-naphthalenedicarboxylic acid and terephthalic acid), and acetic anhydride (1226.87 g, 12 mol) were charged, 0.17 g of 1-methylimidazole was added as a catalyst, and the reactor was thoroughly purged with nitrogen gas.

[0119] Subsequently, the mixture was heated from room temperature to 145°C over 15 minutes while being stirred with a nitrogen gas stream, and then refluxed at 145°C for 1 hour.

[0120] Next, while distilling off the by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 145°C to 310°C over 3.5 hours, and after being held at 310°C for 3 hours, the contents were removed and cooled to room temperature.

[0121] The obtained solid was pulverized to a particle size of 0.1 to 1 mm using a pulverizer, and then solid-phase polymerization was carried out under a nitrogen atmosphere by raising the temperature from room temperature to 250°C over 1 hour, raising the temperature from 250°C to 310°C over 10 hours, and holding at 310°C for 5 hours. After solid-phase polymerization, it was cooled to obtain a powdered liquid crystal polymer. The flow initiation temperature of the obtained liquid crystal polymer was 325°C. The obtained liquid crystal polymer was melt-kneaded at 340°C in an extruder, extruded from a die, and water-cooled to obtain a liquid crystal polymer filament with a diameter of Φ1.75 mm.

[0122] Using liquid crystal polymer filament, a JIS 7161-2 small test piece 1BA (thickness 1.6 mm) was fabricated using a fused deposition modeling (FDM) 3D printer with a bed temperature of 120°C, a nozzle diameter of Φ0.4 mm, a head relative speed along the stage surface to the stage of 150 mm / s, and a layer thickness of 0.2 mm.

[0123] (Example 2) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer and reflux condenser, 6-hydroxy-2-naphthoic acid (1034.99 g, 5.5 mol), 2,6-naphthalenedicarboxylic acid (378.33 g, 1.75 mol), terephthalic acid (83.07 g, 0.5 mol), hydroquinone (272.52 g, 2.475 mol, 0.225 mol excess relative to the total amount of 2,6-naphthalenedicarboxylic acid and terephthalic acid), and acetic anhydride (1226.87 g, 12 mol) were charged, 0.17 g of 1-methylimidazole was added as a catalyst, and the reactor was thoroughly purged with nitrogen gas.

[0124] Subsequently, the mixture was heated from room temperature to 145°C over 15 minutes while being stirred with a nitrogen gas stream, and then refluxed at 145°C for 1 hour.

[0125] Next, while distilling off the by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 145°C to 310°C over 3.5 hours, and after being held at 310°C for 3 hours, the contents were removed and cooled to room temperature.

[0126] The obtained solid was pulverized to a particle size of 0.1 to 1 mm using a pulverizer, and then solid-phase polymerization was carried out under a nitrogen atmosphere by raising the temperature from room temperature to 250°C over 1 hour, raising the temperature from 250°C to 320°C over 10 hours, and holding at 320°C for 5 hours. After solid-phase polymerization, it was cooled to obtain powdered liquid crystal polyester. The flow initiation temperature of the obtained liquid crystal polyester was 333°C. The obtained liquid crystal polyester was melt-kneaded at 350°C in an extruder and extruded from a die to obtain liquid crystal polymer filaments with a diameter of Φ1.75 mm.

[0127] Using liquid crystal polymer filament, a JIS 7161-2 small test piece 1BA (thickness 1.6 mm) was fabricated using a fused deposition modeling (FDM) 3D printer with a bed temperature of 120°C, a nozzle diameter of Φ0.4 mm, a head relative speed along the stage surface to the stage of 150 mm / s, and a layer thickness of 0.2 mm.

[0128] (Comparative Example 1) In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer, and reflux condenser, 994.5 g (7.2 mol) of 4-hydroxybenzoic acid, 446.9 g (2.4 mol) of 4,4'-dihydroxybiphenyl, 299.0 g (1.8 mol) of terephthalic acid, 99.7 g (0.6 mol) of isophthalic acid, and 1347.6 g (13.2 mol) of acetic anhydride were charged. 0.2 g of 1-methylimidazole was added as a catalyst, and the reactor was thoroughly purged with nitrogen gas.

[0129] Subsequently, the mixture was heated from room temperature to 150°C over 30 minutes while being stirred under a nitrogen gas stream, and then maintained at that temperature under reflux for 30 minutes.

[0130] Next, 2.4 g of 1-methylimidazole was added, and the temperature was raised from 150°C to 320°C over 2 hours and 50 minutes while distilling off the by-product acetic acid and unreacted acetic anhydride. After holding at 320°C for 30 minutes, the contents were removed and cooled to room temperature.

[0131] The obtained solid was pulverized to a particle size of 0.1 to 1 mm using a pulverizer, and then solid-phase polymerization was carried out under a nitrogen atmosphere by raising the temperature from room temperature to 250°C over 1 hour, raising the temperature from 250°C to 296°C over 5 hours, and holding at 296°C for 3 hours. After solid-phase polymerization, it was cooled to obtain powdered liquid crystal polyester. The flow initiation temperature of the obtained liquid crystal polyester was 328°C. The obtained liquid crystal polyester was melt-kneaded in an extruder and extruded from a die to obtain liquid crystal polymer filaments with a diameter of Φ1.75 mm.

[0132] Using liquid crystal polymer filament, a JIS 7161-2 small test piece 1BA (thickness 1.6 mm) was fabricated using a fused deposition modeling (FDM) 3D printer with a bed temperature of 120°C, a nozzle diameter of Φ0.4 mm, a head relative speed along the stage surface to the stage of 150 mm / s, and a layer thickness of 0.2 mm.

[0133] [Measurement and Evaluation] The molded objects obtained in the above examples and comparative examples, and the liquid crystal polyester resin compositions used to mold these objects, were subjected to the following measurements and evaluations. The results are shown in Table 1.

[0134] [1] Tensile strength was measured on a small test specimen 1BA in accordance with ISO 527.

[0135] [2] A 20 × 4.5 × 1.6 mm thick specimen was cut from the small specimen 1BA for measuring the coefficient of linear thermal expansion. The coefficient of linear thermal expansion in the Y-axis (forming direction) of the specimen at 50 to 150°C was measured in accordance with JIS 7197.

[0136] [3] Melt viscosity at a temperature 20°C higher than the flow temperature The melt viscosity of the liquid crystal polyester resin composition was measured in accordance with JIS K7199 using a Φ0.5 mm, 10 mm long capillary at an extrusion temperature 20°C higher than the flow temperature and a shear rate of 1000 / s.

[0137] [4] Melt tension at a temperature 20°C higher than the flow temperature A liquid crystal polyester resin composition was measured using a capillary rheometer melt tension measuring device (Capillograph 583 (manufactured by Toyo Seiki Seisakusho Co., Ltd.)) at an extrusion temperature 20°C higher than the flow temperature, when a strand extruded from a Φ1.0 mm × length 20 mm capillary at a piston speed of 5 mm / min was taken up with a draw ratio of 10.

[0138] [5] Appearance The appearance of the small test specimen 1BA was visually observed and ranked as ○ if no delamination was observed and △ if some delamination was observed.

[0139]

[0140] As shown in Table 1, in the above example, a liquid crystal polymer filament containing a liquid crystal polyester resin composition having a predetermined repeating unit was used as a raw material. As a result, the coefficient of linear expansion of the 3D-printed object was improved compared to the comparative example, and could even be made negative. Furthermore, in the above example, since the liquid crystal polyester resin contained a naphthalene skeleton, the tensile strength of the 3D-printed object could be significantly improved compared to the comparative example.

Claims

1. A liquid crystal polyester resin composition for 3D printers comprising a liquid crystal polyester resin having repeating units represented by the following formulas (1), (2), and (3). (In formulas (1) to (3) above, Ar1 is a phenylene group, a naphthylene group, or a biphenylylene group; Ar2 and Ar3 are each independently a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by formula (4) below; X and Y are each independently an oxygen atom or an imino group; one or more hydrogen atoms in Ar1, Ar2, and Ar3 may each be independently substituted with a halogen atom, an alkyl group, or an aryl group.) (In formula (4) above, Ar4 and Ar5 are each independently a phenylene group or a naphthylene group; Z is an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.) 2. The liquid crystal polyester resin composition for 3D printers according to claim 1, wherein the ratio of the total amount of repeating units containing 2,6-naphthylene groups in the liquid crystal polyester resin to the total amount of all repeating units constituting the liquid crystal polyester resin is 40 mol% or more.

3. The liquid crystal polyester resin composition for a 3D printer according to claim 1, wherein the ratio of the total amount of repeating units represented by formula (1) to the total amount of all repeating units constituting the liquid crystal polyester resin is 30 mol% or more and 80 mol% or less, the ratio of the total amount of repeating units represented by formula (2) to the total amount of all repeating units constituting the liquid crystal polyester resin is 10 mol% or more and 35 mol% or less, and the ratio of the total amount of repeating units represented by formula (3) to the total amount of all repeating units constituting the liquid crystal polyester resin is 10 mol% or more and 35 mol% or less.

4. The liquid crystal polyester resin composition for 3D printers according to claim 1, wherein in formula (3), X and Y are oxygen atoms.

5. The liquid crystal polyester resin composition for a 3D printer according to claim 1, wherein the melt viscosity of the liquid crystal polyester resin at a temperature 20°C higher than the flow temperature of the liquid crystal polyester resin and at a shear rate of 1000 / s is 10 Pa·s or more and 200 Pa·s or less.

6. The liquid crystal polyester resin composition for a 3D printer according to claim 1, wherein the melt tension of the liquid crystal polyester resin at a temperature 20°C higher than the flow temperature of the liquid crystal polyester resin is 5 mN or more and 150 mN or less.

7. The liquid crystal polyester resin composition for 3D printers according to claim 1, wherein the liquid crystal polyester resin composition for 3D printers contains 0.01 parts by mass or more and 10.00 parts by mass or less of a filler per 100 parts by mass of the liquid crystal polyester resin.

8. The liquid crystal polyester resin composition for 3D printers according to claim 1, wherein the liquid crystal polyester resin composition contains 0.01 parts by mass or more and 200.00 parts by mass or less of thermoplastic resin per 100 parts by mass of the liquid crystal polyester resin, and the thermoplastic resin is at least one selected from the group consisting of polyester resins, polyacetal resins, polycarbonate resins, aliphatic polyamide resins, semi-aromatic polyamide resins, polyphenylene sulfide resins, polyethersulfone resins, polyether aromatic ketone resins, polyetherimide resins, polyamideimide resins, and thermoplastic polyimide resins.

9. A liquid crystal polymer filament for a 3D printer comprising the liquid crystal polyester resin composition for 3D printers described in any one of claims 1 to 8.

10. The liquid crystal polymer filament for 3D printers according to claim 9, wherein the diameter of the liquid crystal polymer filament for 3D printers is 1.00 mm or more and 5.00 mm or less.

11. The liquid crystal polymer filament for 3D printers according to claim 9, wherein the liquid crystal polymer filament for 3D printers is a filament for fused deposition modeling (FDM) 3D printers.

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