Polycarbonate resin composition for 3D printers

Abstract

The present invention provides a polycarbonate resin-based composition for 3D printers that has good filament diameter accuracy and roundness, and high strength, mainly when used with FFF-type general-purpose 3D printers. [Solution] A polycarbonate resin composition for 3D printers containing (A) a polycarbonate resin, (B) a resin-modifying polymer, and (C) a heat-sealable polymer. The polycarbonate resin (A) is a polycarbonate resin or a mixture of a polycarbonate resin and PBT resin or a mixture of a polycarbonate resin and ASA resin, with a mixing ratio of 100 to 55% by weight of polycarbonate resin and 0 to 45% by weight of PBT resin or ASA resin, the polycarbonate resin being an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin, the resin-modifying polymer (B) being a core-shell type polymer, and the heat-sealable polymer (C) being polycaprolactone or a crystalline copolymer polyester resin.

Description

[Technical Field]

[0001] This invention relates to a polycarbonate resin composition for 3D printers using the Material Extrusion Fabrication (MEX) method. Here, the MEX extrusion fabrication method includes the Fused Filament Fabrication (FFF) method and the Fused Granular Fabrication (FGF) method. This invention relates to a polycarbonate resin composition for 3D printers (hereinafter referred to as "3D printers") that employ these methods to output three-dimensionally shaped objects.

[0002] Furthermore, among the MEX extrusion layering methods, FFF type 3D printers are commercially available in both relatively inexpensive [general-purpose 3D printers] and expensive [high-temperature 3D printers], as shown in Table 1.

[0003] [Table 1]

[0004] In this invention, the main application area is a polycarbonate-based resin composition for forming 3D-molded objects with high strength using a general-purpose 3D printer. However, it is not limited to this, and this polycarbonate-based resin composition can also be applied to high-temperature 3D printers and even to fused granular fabrication (FGF) methods. [Background technology]

[0005] Traditionally, many types of thermoplastic resins have been used for applications such as automotive interior materials, and injection molding has been employed as the molding method. In injection molding, molten thermoplastic resin is injected into a heated mold under pressure, thereby enabling the production of molded articles with high strength.

[0006] On the other hand, 3D printing using the MEX extrusion method involves heating and melting thermoplastic resin at the nozzle of the 3D printer and layering it onto a heated molding plate using only the weight of the resin itself. As a result, no pressure is applied between the layered resin layers. In other words, there is no pressure between the layered resin layers.

[0007] Therefore, in 3D printing using the MEX extrusion method, the only pressure applied between the layered resin layers is the weight of the resin itself. This is significantly different from injection molding, where molten thermoplastic resin is injected and pressed into a closed space such as a mold, resulting in a state where the thermoplastic resin is firmly fused together. Consequently, the strength of 3D printed objects using the MEX extrusion method is considerably inferior to that of objects produced by injection molding. In particular, the strength of 3D printed objects in the longitudinal axis direction is inferior to that in the transverse axis direction, which is a major problem with 3D printing using the MEX extrusion method.

[0008] Patent Document 1 discloses a thermoplastic resin filament consisting of two layers, an inner layer and an outer layer. It states that the main component resins of both the inner and outer layers are polycarbonate-based resins with a viscosity-average molecular weight of 18,000 to 28,000, and that the difference in melt flow rates (ASTMD1238, load of 1.2 kg at the melting point of the resin) between the resin compositions constituting the inner and outer layers is 30 (g / 10 min) or less. It is disclosed that by making the difference in melt flow rates between the resin compositions of the inner and outer layers 30 (g / 10 min) or less, the two layers can be integrated without delamination, but nothing is described regarding 3D printed objects.

[0009] Patent Document 2 discloses a polycarbonate resin composition for 3D printers that exhibits excellent tensile strength and appearance in 3D printed molded products manufactured by fused deposition modeling. This polycarbonate resin composition for 3D printers contains 5 to 50 parts by weight of an inorganic filler (component B) per 100 parts by weight of an aromatic polycarbonate resin (component A).

[0010] Although the examples of the polycarbonate resin composition for 3D printers described in Patent Document 2 state that the 3D printer was used to create the object at a cylinder temperature of 300°C, there is no mention of the build plate or chamber temperature. Furthermore, while Patent Document 2 describes the tensile fracture stress in the X and Z axes of the 3D printed object in Examples 1 to 16, the Z-axis / X-axis ratio of the tensile fracture stress is always only 0.44 to 0.25. Therefore, the technology described in Patent Document 2 cannot be considered as providing a polycarbonate resin composition for forming a 3D object with high strength using a general-purpose 3D printer, which is the main objective of this application.

[0011] Patent Document 3 discloses that a composition containing a thermoplastic polyester resin (polycaprolactone resin, polyester-based resin) with a glass transition temperature of 100°C or lower that is compatible with polycarbonate resin and an aromatic polycarbonate resin can provide a filament for 3D printing that has good heat resistance and impact resistance, suppresses warping of 3D molded bodies, and has excellent interlayer adhesion.

[0012] Furthermore, although Patent Document 3 states that it is preferable to improve the accuracy and roundness of the filament diameter, it does not mention the accuracy of the filament diameter in its examples. Moreover, Patent Document 3 does not describe the tensile speed in the tensile test described in its examples. Anyone skilled in the art working in the plastics industry knows that the tensile speed has a significant effect on tensile strength. From this perspective, the technology described in Patent Document 3 cannot be used to provide a polycarbonate-based resin composition for molding 3D objects with high strength using a general-purpose 3D printer, which is the main objective of the present invention.

[0013] Patent Document 4 discloses a filament for three-dimensional modeling composed of a polycarbonate-based resin (A) and a polyester-based resin (B), and describes that the polyester-based resin (B) is a polybutylene terephthalate-based resin. According to this Patent Document 4, it is described that the resin composition for three-dimensional modeling composed of the polycarbonate-based resin (A) and the polybutylene terephthalate-based resin (B) can provide a filament for three-dimensional modeling that suppresses warpage of modeled objects and has excellent adhesion to the table of a 3D printer, without impairing the inherent properties of polycarbonate resin such as heat resistance and impact resistance.

[0014] In the Examples of this Patent Document 4, it is described that a filament with a diameter of 1.75 mm was produced using a twin-screw kneader, but there is no description regarding the diameter accuracy and roundness of the filament. Therefore, it must be said that based on the technique described in Patent Document 4, it is impossible to provide a thermoplastic resin composition for molding a 3D modeled body having high strength using a general-purpose 3D printer, which is the main object of the present application.

[0015] Patent Document 5 was previously filed by the applicant of the present application, and aims to provide a resin composition for additive manufacturing having sufficient adhesive strength in the height direction, and relates to a resin composition for additive manufacturing containing a polycarbonate-based resin, an impact modifier which is a styrene-based thermoplastic elastomer or a core-shell polymer, and a heat-softening material having at least one of a crystalline copolyester resin, polycaprolactone, and a polyester-based thermoplastic elastomer.

[0016] With respect to the technique described in this Patent Document 5, the inventors of the present application have conducted further research and studies, and as a result, have found that there are technical matters to be improved. That is, although the technique described in Patent Document 5 contains three components of a polycarbonate-based resin, an impact modifier and a heat-softening material, it has been found that many of the specific materials specified in Patent Document 5 cannot provide the physical properties required for a 3D printed modeled body.

[0017] Further, among the three components, the polycarbonate-based resin has an excessively wide range of melt volume rate (MVR), and it has been found that among the materials defined as thermal softening materials, only specific crystalline copolyester resins and polycaprolactone can provide the physical properties required for a 3D printed shaped article.

Prior Art Documents

Patent Documents

[0018]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of Invention

Problems to be Solved by the Invention

[0019] The present inventor further studied polycarbonate-based resin compositions suitable for 3D printers, and as a result, found that it is important to solve the problems described below.

[0020] That is, the dimensional accuracy of the filament wire diameter is extremely important. Regarding wire diameter accuracy, among commercially available filaments, the most excellent PC filament has a wire diameter accuracy of 1.75±0.05 mmφ for a 1.75 mmφ filament, which is excellent, but generally, the accuracy is approximately 1.75±0.10 mmφ.

[0021] Consequently, if the filament diameter exceeds 1.85 mm, for example, the filament will clog the nozzle of the 3D printer at the filament entry point (inlet), making 3D printing difficult. Similarly, even if the average wire diameter is 1.75 ± 0.10 mm, if the filament is elliptical, clogging will occur if the longer (thicker) portion exceeds 1.85 mm.

[0022] On the other hand, if the wire diameter is thinner than 1.65 mmφ, the aforementioned clogging does not occur, but a problem arises where the molten filament breaks between the object on the build plate and the nozzle when the 3D printer nozzle moves at high speed in the XY direction (horizontal direction) to perform 3D printing using heated and melted filament, causing the 3D printing to stop. Thus, the accuracy of the filament's wire diameter is extremely important when performing 3D printing.

[0023] In view of the conventional problems described above, the object of the present invention is to provide a polycarbonate-based resin composition that has the physical properties necessary for a 3D printed body, such as good filament diameter accuracy and roundness, and has high strength mainly when printed with a general-purpose FFF 3D printer. [Means for solving the problem]

[0024] The inventors of this invention have conducted extensive research to solve the above problems and have found a polycarbonate-based resin composition that can solve the above problems, thereby completing the present invention as described below.

[0025] [1] A polycarbonate resin composition for 3D printers comprising (A) a polycarbonate resin, (B) a resin-modifying polymer, and (C) a heat-sealable polymer, The polycarbonate resin (A) is a polycarbonate resin or a mixture of a polycarbonate resin and polybutylene terephthalate resin (hereinafter referred to as "PBT resin") or a mixture of a polycarbonate resin and acrylonitrile-styrene-acrylic terpolymer (hereinafter referred to as "ASA resin"), wherein the mixing ratio of the polycarbonate resin to the PBT resin or ASA resin is 100 to 55% by weight of the polycarbonate resin and 0 to 45% by weight of the PBT resin or ASA resin, and the polycarbonate resin is an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin. The aforementioned resin-modified polymer (B) is a core-shell type polymer, The heat-sealable polymer (C) is polycaprolactone or a crystalline copolymer polyester resin. A polycarbonate resin composition for 3D printers, wherein, when the total weight of the polycarbonate resin (A), the resin-modified polymer (B), and the heat-sealable polymer (C) is 100% by weight, the ratio of the polycarbonate resin (A) to the total weight is in the range of 65% to 92% by weight, the ratio of the resin-modified polymer (B) to the total weight is in the range of 5% to 20% by weight, and the ratio of the heat-sealable polymer (C) to the total weight is in the range of 3% to 15% by weight.

[0026] [2] The polycarbonate resin composition for 3D printers according to [1], wherein the polycarbonate resin (A) is a mixture of polycarbonate resin and PBT resin or a mixture of polycarbonate resin and ASA resin, and the mixing ratio of the polycarbonate resin to the PBT resin or the ASA resin is 95 to 55% by weight of the polycarbonate resin and 5 to 45% by weight of the PBT resin or the ASA resin.

[0027] [3] The polycarbonate resin composition for 3D printers according to [1] or [2], wherein the polycarbonate resin (A) has an MVR of 8 to 19 g / min measured at 300°C and a load of 1.2 kg, the core material of the core-shell type polymer which is the resin-modified polymer (B) is acrylic rubber or silicone-acrylic composite rubber with an average particle diameter of 100 to 700 nmφ, the number average molecular weight of the polycaprolactone which is the heat-fusible polymer (C) is 10,000 to 25,000, and the glass transition temperature of the crystalline copolymer polyester resin is 5°C or less.

[0028] [4] A polycarbonate resin composition for 3D printers according to any one of [1] to [3], wherein the tensile breaking strength in the longitudinal axis (ZX) direction of a molded object produced by a general-purpose FFF 3D printer of the polycarbonate resin composition is 35 MPa or more.

[0029] [5] A polycarbonate resin composition for 3D printers according to any one of [1] to [4], wherein the ratio of the tensile breaking strength along the vertical axis (ZX) to the horizontal axis (XY) of a molded object made with a general-purpose FFF 3D printer of the polycarbonate resin composition is 0.6 or more.

[0030] [6] A polycarbonate resin composition for 3D printers according to any one of [1] to [4], wherein the ratio of the tensile breaking strength along the horizontal axis (XY) of a molded object made with a general-purpose FFF 3D printer using the polycarbonate resin composition to the tensile breaking strength of a molded product formed by injection molding is 0.6 or more. [Effects of the Invention]

[0031] According to the polycarbonate resin composition for 3D printers of the present invention, in the case of the FFF method, it is possible to mold 3D objects that have good diameter accuracy and roundness of the filament and have high strength. [Brief explanation of the drawing]

[0032] [Figure 1A] This is a plan view showing an example of a multi-purpose test specimen (full-size dumbbell-shaped test specimen). [Figure 1B] Figure 1A is a side view of the multipurpose test specimen. [Figure 2A] This is a plan view showing an example of a load deflection temperature test specimen. [Figure 2B] Figure 2A is a side view of the load deflection temperature test specimen. [Figure 3] This is an explanatory diagram showing the maximum and minimum diameters in the cross-section of the filament. [Figure 4A] This is a plan view showing an example of a multi-purpose test specimen (short-size dumbbell-shaped test specimen). [Figure 4B] Figure 4A is a side view of the multipurpose test specimen shown. [Modes for carrying out the invention]

[0033] The following describes embodiments for carrying out the present invention, but the present invention is not limited to the following embodiments. That is, within the scope that does not depart from the spirit of the present invention, the following embodiments may be modified, improved, etc., as appropriate, based on the ordinary knowledge of those skilled in the art.

[0034] 1. Polycarbonate resin composition for 3D printers A polycarbonate-based resin composition for 3D printers according to one embodiment of the present invention (hereinafter sometimes referred to as the "resin composition") mainly comprises (A) a polycarbonate-based resin, (B) a resin-modified polymer, and (C) a heat-fusible polymer, and is mainly usable as a filament for FFF-type 3D printers.

[0035] In this polycarbonate resin composition for 3D printers, the polycarbonate resin (A) is a polycarbonate resin (hereinafter referred to as "PC resin") or a mixture of PC resin and PBT resin or a mixture of PC resin and ASA resin, and the mixing ratio of the PC resin to the PBT resin or ASA resin is 100 to 55% by weight of the PC resin and 0 to 45% by weight of the PBT resin or ASA resin. Furthermore, the PC resin is an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin, the resin modifier polymer (B) is a core-shell type polymer, and the heat-seal polymer (C) is polycaprolactone or a crystalline copolymer polyester resin.

[0036] Here, as one embodiment, the PC resin that constitutes one component of the resin composition usable as a filament is a type of engineering plastic having excellent characteristics such as heat resistance and impact resistance, and is widely used as an industrial material for various applications. In the present invention, aromatic polycarbonate resin or siloxane copolymer polycarbonate resin is preferably used as the PC resin.

[0037] Aromatic polycarbonate resins are obtained by reacting aromatic divalent phenolic compounds with phosgene or diester carbonate. The method for producing aromatic polycarbonate resins is not particularly limited, and known methods can be employed. Examples include a method of directly reacting aromatic divalent phenolic compounds with phosgene (interfacial polymerization) or a method of transesterification of aromatic divalent phenolic compounds with diester carbonate such as diphenyl carbonate in a molten state (melt method).

[0038] Regarding the melt volume rate (MVR), a numerical value representing the fluidity of thermoplastic resins during melting, for PC-based resins, the MVR measured at 300°C and a load of 1.2 kg was 8 to 19 cm³. 3 The range is preferably / 10min. The MVR value of the PC resin is 8cm 3By setting the MVR to 10 min or more, good fusion between the resin layers of the 3D printed object can be obtained. On the other hand, an MVR value of 19 cm² is achieved. 3 By setting the time to 10 min or less, good filament diameter accuracy and roundness can be obtained.

[0039] Examples of commercially available aromatic polycarbonate resins include Panlite L-1225L, L-1225Y, L-1250Y (manufactured by Teijin Limited), Europin S-2000, S-3000 (manufactured by Mitsubishi Engineering Plastics Corporation), and Toughlon 1900, 2200, 2500 (manufactured by Idemitsu Kosan Co., Ltd.).

[0040] Furthermore, siloxane copolymer polycarbonate resins are high-performance polycarbonate resins obtained by chemically bonding (copolymerizing) polydimethylsiloxane to polycarbonate resin. Examples of commercially available siloxane copolymer polycarbonate resins include Toughlon Neo AG1950, AG2030, VG1950, RC2031 (manufactured by Idemitsu Kosan Co., Ltd.), and Panlite SS1230 (manufactured by Teijin Limited).

[0041] PBT resin is a thermoplastic crystalline resin produced by polycondensation reaction using terephthalic acid and 1,4-butanediol as basic raw materials. It has a melting point of 224°C, a crystallization temperature of 170-175°C, and a glass transition temperature of 37-53°C. In addition to excellent chemical resistance and UV resistance, low water absorption, and dimensional stability, it also has good melt-mixability with polycarbonate resin. Examples of commercially available products include NOVADURAN5510R1, 5010TRXA (manufactured by Mitsubishi Chemical Corporation) and DURANEX2002EF2001 (manufactured by Polyplastics Co., Ltd.).

[0042] ASA resin is an acrylonitrile-styrene-acrylic ternary copolymer, and is a thermoplastic resin with particularly excellent UV resistance and good melt-mixability with polycarbonate resin. Examples of commercially available products include DIALACS210B, DIALACS310, DIALACS510, and DIALACS411A (manufactured by Techno UMG Co., Ltd.).

[0043] Furthermore, the resin-modifying polymer, which constitutes one component of the resin composition, is used to improve the mechanical strength of the resin. Generally, rubber-containing graft polymers are used, but a "core-shell type graft polymer" can be suitably used. As a core-shell type graft polymer, a "core-shell type graft polymer" in which the core component is acrylic rubber or silicone-acrylic composite rubber and the shell component is acrylic polymer is particularly preferred. Moreover, since this "core-shell type graft polymer" exhibits a fine particle structure, its average particle size is preferably 100 to 700 μm.

[0044] Core-shell type graft polymers are impact-resistant modifiers obtained by polymerizing vinyl monomers in the presence of rubber, where the rubber component acts as the core and the polymerized vinyl monomers form the shell.

[0045] Examples of rubber components include silicone rubber made from organosiloxanes, acrylic rubber made from alkyl acrylates and alkyl methacrylates, and composite rubbers thereof. These rubbers are used individually or in combination with two or more other types.

[0046] Examples of vinyl monomers that form the shell include methacrylates such as methyl methacrylate and ethyl methacrylate. Examples of these core-shell type graft polymers include silicone-acrylic composite rubber systems (such as Metabren S-2100 (manufactured by Mitsubishi Chemical Corporation)) and acrylic rubber impact-resistant modifiers (such as Metabren W-600A (manufactured by Mitsubishi Chemical Corporation)).

[0047] Next, the heat-fusible polymer, which is a component of the resin composition, is composed of at least one of a crystalline copolymer polyester resin and polycaprolactone.

[0048] As a crystalline copolymer polyester resin that can be used as a heat-fusible polymer, a crystalline copolymer polyester with a glass transition temperature of 5°C or lower is preferred. A crystalline copolymer polyester is a crystalline copolymer polyester composed of a polyvalent carboxylic acid component and a polyvalent glycol component. Examples of polyvalent carboxylic acid components include terephthalic acid, isophthalic acid, and hexahydroterephthalic acid, while examples of polyvalent glycol components include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, all of which possess properties such as heat resistance and weather resistance.

[0049] The glass transition temperature of these crystalline copolymer polyesters is preferably 5°C or lower, and more preferably in the range of 5 to -70°C. Examples of commercially available crystalline copolymer polyesters include Byron GM913, Byron GM920, and Byron GM6400 (manufactured by Toyobo Co., Ltd.).

[0050] Polycaprolactone is a type of biodegradable plastic. Polycaprolactone can be produced by ring-opening polymerization of caprolactone in the presence of a catalyst such as an acid, base, or organometallic compound. The ends of the polycaprolactone may be subjected to end treatment such as esterification. The melting point of polycaprolactone is 60°C, and the glass transition temperature is approximately -60°C. The number-average molecular weight (hereinafter sometimes referred to as "molecular weight") of these polycaprolactones is preferably in the range of 9,000 to 30,000, and more preferably in the range of 10,000 to 25,000.

[0051] As commercially available polycaprolactones, Praxel H1P (number average molecular weight 10,000: manufactured by Daicel Corporation), Capa2803 (number average molecular weight 10,000: manufactured by Ingevity), and Capa6250 (number average molecular weight 25,000: manufactured by Ingevity) can be suitably used.

[0052] The resin composition of this embodiment is composed of the three components mentioned above (polycarbonate resin, resin-modified polymer, and heat-fusible polymer), and these three components are mixed in a predetermined ratio (by weight), heated, and then molded into a filament shape using well-known resin molding techniques so that it can be used as a filament for a 3D printer.

[0053] Here, when the total weight of the polycarbonate resin, resin-modified polymer, and heat-seal polymer is set to 100% by weight, the weight ratio of the polycarbonate resin to the total weight can be set to a range of 65% to 92% by weight, more preferably 75% to 90% by weight. The weight ratio of the resin-modified polymer shown in the total weight can be set to a range of 5% to 20% by weight, more preferably 5% to 15% by weight. The weight ratio of the heat-seal polymer to the total weight can be set to a range of 3% to 15% by weight, more preferably 3% to 10% by weight.

[0054] Furthermore, the mixing ratio of PC resin and PBT resin, or PC resin and ASA resin, is 100 to 55% by weight of PC resin, preferably 100 to 60% by weight, and 0 to 45% by weight of PBT resin or ASA resin, preferably 0 to 40% by weight.

[0055] Furthermore, it is preferable to use a mixture of PC resin and PBT resin, or a mixture of PC resin and ASA resin, rather than PC resin alone. The mixing ratio is preferably 95-55% by weight of PC resin and 5-45% by weight of PBT resin or ASA resin, and more preferably 90-56% by weight of PC resin and 10-44% by weight of PBT resin or ASA resin. In this way, when a mixture of PC resin and PBT resin, or a mixture of PC resin and ASA resin is used, the tensile breaking strength in the longitudinal axis (ZX) direction is higher compared to PC resin alone, and the ratio of tensile breaking strength in the longitudinal axis (ZX) direction to the transverse axis (XY) direction, and the ratio of tensile breaking strength in the transverse axis (XY) direction to the tensile breaking strength of the molded product formed by injection molding are higher, resulting in a 3D printed object with an excellent balance of tensile breaking strength in the longitudinal axis and transverse axis directions.

[0056] By adjusting the weight ratios of the three components—(A) polycarbonate resin, (B) resin-modified polymer, and (C) heat-fusible polymer—to within the above weight ratio range, it is possible to obtain a 3D printer filament with excellent moldability (diameter accuracy and roundness) and superior strength in the longitudinal axis direction (ZX) of 3D printed objects.

[0057] In addition, in the resin composition of the present invention, other components may be added in addition to the three components described above, as long as they do not impair its physical properties or basic functions, and for the purpose of adding other functions.

[0058] For example, carbon fiber (CF) or cellulose nanofiber (CNF) can be added to the resin composition to form a composite. In this case, an appropriate amount of addition is approximately 5 to 30% by weight. Furthermore, an antistatic agent can be mixed into the resin composition. As an antistatic agent, ionic liquids are preferred due to their excellent transparency, heat resistance, and antistatic properties.

[0059] 2. Properties of the resin composition The resin composition of this embodiment is composed of the three components in the weight ratios described above, and exhibits excellent moldability of the filament (diameter accuracy and roundness) and excellent strength in the longitudinal axis direction (ZX) of the 3D printed object. (Details will be described later).

[0060] Furthermore, preferably, the tensile breaking strength in the longitudinal axis (ZX) direction of the 3D printed object obtained using the polycarbonate resin composition of this embodiment is 35 MPa or more, the ratio of the tensile breaking strength in the longitudinal axis (ZX) direction to the transverse axis (XY) direction is 0.6 or more, the ratio of the tensile breaking strength in the transverse axis (XY) direction of the 3D printed object to the tensile breaking strength of the injection molded product is 0.6 or more, and the load deflection temperature at a load of 0.45 MPa is 100°C or more.

[0061] Furthermore, the tensile breaking strength was measured in accordance with "ISO 527," and the temperature of deflection under load was measured in accordance with "ISO 75 Method for measuring temperature of deflection under load." [Examples]

[0062] The resin compositions of the present invention will be described in more detail below based on the following examples, but the present invention is not limited to these examples. In addition to the following examples, various modifications and improvements can be made to the present invention based on the knowledge of those skilled in the art, without departing from the spirit of the invention.

[0063] First, the materials used and their properties for each component of the PC-based resin, resin-modified polymer, and heat-sealable polymer used in the examples and comparative examples are shown below.

[0064] 1.PC resin [PC-1] Idemitsu Kosan Toughlon 1900: Aromatic polycarbonate resin, MVR = 19cm 3 / 10 min (300℃, load 1.2kg) [PC-2] Idemitsu Kosan Toughlon 2200: Aromatic polycarbonate resin, MVR = 12cm 3 / 10 min (300℃, load 1.2kg) [PC-3] Tarflon 2500 manufactured by Idemitsu Kosan: aromatic polycarbonate resin, MVR=8cm 3 / 10min (300°C, load 1.2kg) [PC-4] Tarflon Neo AG1950 manufactured by Idemitsu Kosan: siloxane copolymerized polycarbonate resin, MVR=13cm 3 / 10min (300°C, load 1.2kg) [PC-5] Tarflon Neo AG2030 manufactured by Idemitsu Kosan: siloxane copolymerized polycarbonate resin, MVR=9cm 3 / 10min (300°C, load 1.2kg)

[0065] [PC-6] Tarflon 1700 manufactured by Idemitsu Kosan: aromatic polycarbonate resin, MVR=27cm 3 / 10min (300°C, load 1.2kg) [PC-7] Panlite K-1300Y manufactured by Teijin: aromatic polycarbonate resin, MVR=2.8cm 3 / 10min (300°C, load 1.2kg) [PC-8] Panlite SS1230 manufactured by Teijin: siloxane copolymerized polycarbonate resin, MVR=20.4cm 3 / 10min (300°C, load 1.2kg) [PC-9] Tarflon Neo VC2260 manufactured by Idemitsu Kosan: siloxane copolymerized polycarbonate resin, MVR=4cm 3 / 10min (300°C, load 1.2kg)

[0066] 2. PBT resin [PBT-1] NOVADURN 5510R1 manufactured by Mitsubishi Chemical: polybutylene terephthalate resin, MVR=90cm 3 / 10min (250°C, load 1.2kg) [PBT-2] NOVADURN 5010TRXA manufactured by Mitsubishi Chemical: polybutylene terephthalate resin, MVR=19cm 3 / 10min (250°C, load 1.2kg)

[0067] 3. ASA resin [ASA-1] Techno UMG DIALAC S5110: ASA resin, MVR=14cm 3 / 10 min (220℃, load 98N) [ASA-2] Techno UMG DIALAC S210B: ASA resin, MVR = 25cm 3 / 10 min (220℃, load 98N)

[0068] 4. Resin-modified polymers [Core Shell-1] Mitsubishi Chemical Metabrane W600A: Core material = acrylic rubber, Shell material = (meth)acrylic polymer, Average particle size = 100~200 μm [Core Shell-2] Mitsubishi Chemical Metabrane S2100: Core material = silicone / acrylic composite rubber, Shell material = (meth)acrylic polymer, Average particle size = 600-700 μm

[0069] 5. Heat-sealable polymers [PCL-1] Daicel Praxel H1P: Polycaprolactone, Molecular weight = 10,000, Granular [PCL-2] Ingevity Capa6250: Polycaprolactone, Molecular weight = 25,000, Granular [PCL-3] Ingevity Capa6500: Polycaprolactone, Molecular weight = 50,000, Granular [PCL-4] Daicel Praxel 240: Polycaprolactone diol, molecular weight = 4000, waxy.

[0070] [GM-1] GM913 manufactured by Toyobo: Crystalline copolymer polyester resin, molecular weight = 35,000, glass transition temperature = -70°C [GM-2] GM350 manufactured by Toyobo: Crystalline copolymer polyester resin, molecular weight = 35,000, glass transition temperature = 3°C [GM-3] GM400 manufactured by Toyobo: Crystalline copolymer polyester resin, molecular weight = 25,000, glass transition temperature = 19°C [RV-1] RV103 manufactured by Toyobo: Amorphous copolymer polyester resin, molecular weight = 23,000, glass transition temperature = 47°C [RV-2] RV200 manufactured by Toyobo: Amorphous copolymer polyester resin, molecular weight = 17,000, glass transition temperature = 7°C

[0071] (Manufacturing of polycarbonate resin compositions) Various raw materials for the polycarbonate resin composition were weighed according to the mixing ratios (by weight) listed in Tables 2 to 9, placed in a mixer (Super Mixer SMV-10: manufactured by Kawata Co., Ltd.), and stirred for 5 minutes. Then, using a twin-screw extruder with vacuum vent and strand die (TEX30α, manufactured by Japan Steel Works Ltd.), the extrusion temperature was adjusted to 260°C for melt extrusion and pelletization.

[0072] (Preparation of test specimens by injection molding) Polycarbonate resin composition (pellets) manufactured using a twin-screw extruder was placed in a vacuum dryer and dried at 110°C for more than 2 hours. Then, using an injection molding machine (manufactured by Shibaura Machinery Co., Ltd.) with a clamping force of 980kN, the injection molding temperature was set to 285°C and the mold temperature to 85°C, and a multi-purpose test specimen (full-size dumbbell-shaped test specimen) conforming to ISO standards was molded as shown in Figures 1A and 1B. This multi-purpose test specimen 1 was set to have a length L: 170 mm, a thickness T: 4 ± 0.2 mm, a width W: 10 ± 0.2 mm, an edge width EW: 20 mm, a first length L1: 114 mm, and a second length L2: 80 mm.

[0073] (Measurement of physical properties of test specimens by injection molding) (1) Measurement of tensile breaking strength: Using multipurpose test specimens compliant with ISO standards, the specimens were conditioned for 24 hours in a laboratory at 23±2℃, and then the tensile breaking strength was measured at a tensile speed of 50 mm / min in accordance with ISO-527.

[0074] (2) Measurement of load deflection temperature: From a multipurpose test specimen conforming to ISO standards, test specimens with a length L = 80 ± 2.0 mm, a width W = 10 ± 0.2 mm, and a thickness T = 4 ± 0.2 mm were cut out as shown in Figures 2A and 2B. The load deflection temperature (DTUL) was measured in accordance with ISO 75 using an HDT testing machine 3M-2 (manufactured by Toyo Seiki Seisakusho Co., Ltd.) with a load of 0.45 MPa and a heating rate of 10°C / min.

[0075] (Filament molding and measurement of diameter accuracy and roundness) Polycarbonate resin composition (pellets) manufactured using a twin-screw extruder was placed in a vacuum dryer and dried at 110°C for more than 2 hours. Then, using a 30mmφ single-screw extruder with a vacuum vent monofilament die (manufactured by Plastic Technology Co., Ltd.), the monofilament was melt-extruded at an extrusion temperature of 250°C. After cooling, a 1.75mmφ monofilament was produced using a take-up and wind-up machine.

[0076] As shown in Figure 3, for each filament, the maximum diameter (2a) and minimum diameter (2b) were measured at five locations at 1m intervals, and the average, maximum, minimum, and flattening ratio (f) of the diameters were determined. The flattening ratio (f) = (ab) / a = 1 - (b / a) It can be calculated using this method. Therefore, when the maximum diameter (2a) and the minimum diameter (2b) are the same (a=b), the flattening ratio (f) is f=0, indicating that the cross-section is perfectly circular.

[0077] (3D printing) Using a general-purpose 3D printer (Rasise3D Pro3HS, sold by Japan 3D Printer Co., Ltd.), the "short-size dumbbell-shaped test specimens" shown in Figures 4A and 4B were fabricated in the longitudinal (ZX) and transverse (XY) directions of the object under the following fabrication conditions. The test specimen 10 shown in Figure 4 was set to have a length L: 130 mm, a thickness T: 4 ± 0.2 mm, a width W: 10 ± 0.2 mm, an edge width EW: 20 mm, a first length L1: 74 mm, and a second length L2: 40 mm. Nozzle temperature = 280°C, Build plate temperature = 120°C, Chamber temperature = 50-60°C

[0078] (Measurement of tensile fracture strength of 3D printed objects) In accordance with ISO-527, the tensile breaking strength was measured at a tensile speed of 50 mm / min.

[0079] (Examples 1-8) In Examples 1 to 8 shown in Table 2, (A) the polycarbonate resin is either an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin, with an MVR of 8 to 19 cm². 3 Using a 10 min solution, (B) a core-shell type polymer was used as the resin-modifying polymer, and (C) polycaprolactone (molecular weight 10,000) was used as the heat-sealing polymer. These three components were blended in the weight ratios shown in Table 2 to produce a resin composition (pellets).

[0080] Using the obtained resin composition (pellets), multipurpose test specimens were molded by injection molding as described above, and their physical properties were measured. Furthermore, filaments were prepared using the resin composition (pellets) as described above, and their physical properties (diameter accuracy and roundness (flatness)) were determined. In addition, a 3D-printed object (short-size dumbbell-shaped test specimen) was fabricated using a general-purpose 3D printer (Rasise3DPro3HS), and its physical properties were measured. These physical properties are shown in Table 2.

[0081] (Examples 9-18) In Examples 9 to 18, as shown in Table 3, (A) as the polycarbonate resin, aromatic polycarbonate resin (MVR12cm) was used. 3 (B) A core-shell type polymer was used as the resin modifier polymer, and (C) polycaprolactone (molecular weight 10,000, 25,000) or crystalline copolymer polyester resin (glass transition temperature -70°C, 3°C) was used as the heat-seal polymer. These three components were blended in the weight ratios shown in Table 2 to produce resin compositions (pellets).

[0082] Using the obtained resin composition (pellets), multipurpose test specimens, filaments, and molded objects were obtained by injection molding and a general-purpose 3D printer in the same manner as in Examples 1 to 8, and their physical properties were measured. These physical properties are shown in Table 3.

[0083] (Examples 19-22) In Examples 19-22, as shown in Table 4, (A) as the polycarbonate resin, aromatic polycarbonate resin (MVR12cm) was used. 3 (10 min) or a mixture of aromatic polycarbonate resin and ASA resin was used, (B) a core-shell type polymer was used as the resin modifier polymer, and (C) polycaprolactone (molecular weight 10,000) was used as the heat-seal polymer. These three components were blended in the weight ratios shown in Table 4 to produce resin compositions (pellets).

[0084] Using the obtained resin composition (pellets), multipurpose test specimens, filaments, and molded objects were obtained by injection molding and a general-purpose 3D printer in the same manner as in Examples 1 to 8, and their physical properties were measured. These physical properties are shown in Table 4.

[0085] (Comparative Examples 1-10) In Comparative Examples 1 to 10 shown in Table 5, (A) the polycarbonate resin is either an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin, and the MVR is 12 cm². 3 In addition to / 10min, MVR27cm 3 / 10 min, 2.8 cm 3 / 10 min, 20.4 cm 3 / 10 min, 4 cm 3 A mixture of aromatic polycarbonate resin and PBT resin was used, with (B) a core-shell type polymer as the resin modifier polymer, and (C) polycaprolactone (molecular weight 10,000, 50,000, 4,000), crystalline copolymer polyester resin (glass transition temperature 19°C), or amorphous copolymer polyester resin (glass transition temperature 47°C, 7°C) as the heat-sealable polymer. These three components were blended in the weight ratios shown in Table 5 to produce resin compositions (pellets).

[0086] Using the obtained resin composition (pellets), multipurpose test specimens, filaments, and molded objects were obtained by injection molding and a general-purpose 3D printer in the same manner as in Examples 1 to 8, and their physical properties were measured. These physical properties are shown in Table 5.

[0087] (Comparative Examples 11-15) In Comparative Examples 11 to 15 shown in Table 6, (A) the polycarbonate resin is an aromatic polycarbonate resin with an MVR of 12 cm². 3 Using a 10 min solution and a mixture of aromatic polycarbonate resin and ASA resin, (B) a core-shell type polymer was used as the resin modifier polymer, and (C) polycaprolactone (molecular weight 10,000) was used as the heat-seal polymer. These three components were blended in the weight ratios shown in Table 6 to produce resin compositions (pellets).

[0088] Using the obtained resin composition (pellets), multipurpose test specimens, filaments, and molded objects were obtained by injection molding and a general-purpose 3D printer in the same manner as in Examples 1 to 8, and their physical properties were measured. These physical properties are shown in Table 6.

[0089] [Table 2]

[0090] [Table 3]

[0091] [Table 4]

[0092] [Table 5]

[0093] [Table 6]

[0094] (Discussion: Evaluation of the resin compositions in the examples and comparative examples) (Evaluation of resin compositions in Examples 1-8) In the resin compositions of Examples 1 to 8, as described above, (A) the polycarbonate resin is an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin, and the MVR is 8 to 19 cm². 3 Within a range of / 10min, (B) a core-shell type polymer was used as the resin modifier polymer, and (C) polycaprolactone (molecular weight 10,000) was used as the heat-seal polymer, and these three components were blended in the weight ratios shown in Table 2. Multipurpose test pieces, filaments, and 3D printed objects obtained using these resin compositions (pellets) have good heat resistance, good filament diameter accuracy and roundness, and a high tensile breaking strength of 43 MPa or more in the longitudinal axis (ZX) direction, and a high ratio of tensile breaking strength in the longitudinal axis (ZX) direction to the transverse axis (XY) direction of 0.83 or more, showing an excellent balance of tensile breaking strength in the longitudinal and transverse axes.

[0095] (Evaluation of resin compositions in Examples 9-10 and 15-18) Furthermore, Examples 9-10 shown in Table 3 are variations of Example 2 in which the blending ratio of (C) the heat-fusible polymer, polycaprolactone (molecular weight 10,000), is changed. Example 15 shown in Table 3 is a variation of Example 2 in which the type of (B) the resin-modifying polymer, core-shell type polymer, is changed. In addition, Examples 16-18 shown in Table 3 use (C) a polycaprolactone with a molecular weight of 25,000 (Example 16), (C) a crystalline copolymer polyester resin (glass transition temperature of -70°C) as the heat-fusible polymer (Example 17), and (C) a crystalline copolymer polyester resin (glass transition temperature of 3°C) as the heat-fusible polymer (Example 18).

[0096] The multipurpose test specimens, filaments, and 3D printed objects obtained using these resin compositions (pellets) exhibit good heat resistance, good filament diameter accuracy and roundness, and high tensile breaking strength in the longitudinal (ZX) direction of 36 MPa or more. Furthermore, the ratio of tensile breaking strength in the longitudinal (ZX) direction to the transverse (XY) direction is also high at 0.83 or more, demonstrating an excellent balance of tensile breaking strength in the longitudinal and transverse directions.

[0097] (Evaluation of the resin compositions of Examples 11-14) Examples 11-14 shown in Table 3 use a mixture of aromatic polycarbonate resin and PBT resin as the (A) polycarbonate resin among the three components of Example 2. Examples 11-13 use MVR90cm as the PBT resin. 3 The experiment used a mixture of 10 min (250°C, 1.2 kg load) and varied the mixing ratio. Example 14 used MVR19cm² as the PBT resin. 3 This test was conducted using a 10 min test (250°C, 1.2 kg load). The multipurpose test specimens, filaments, and 3D printed objects obtained using these resin compositions (pellets) had physical properties equivalent to or better than those of Example 2. In particular, the tensile breaking strength in the longitudinal (ZX) direction was high at 44-47 MPa, and the ratio of the tensile breaking strength in the longitudinal (ZX) direction to the transverse (XY) direction was 0.92 or higher. Furthermore, the ratio of the tensile breaking strength in the transverse (XY) direction to the tensile breaking strength of molded products formed by injection molding was also high at 0.88-0.98, indicating an excellent balance between the tensile breaking strength in the longitudinal and transverse directions.

[0098] (Evaluation of the resin compositions of Examples 19-22) Examples 19-22 shown in Table 4 use a mixture of aromatic polycarbonate resin and ASA resin as the (A) polycarbonate resin among the three components of Example 2. Examples 19-21 use MVR14cm as the ASA resin. 3 The experiment used a mixture of 10 min (220°C, 98 N load) and varied the mixing ratio. Example 22 used MVR25cm as the ASA resin. 3This test was conducted using a 10 min test (220°C, 98 N load). The multipurpose test specimens, filaments, and 3D printed objects obtained using these resin compositions (pellets) had physical properties equivalent to or better than those of Example 2. In particular, the tensile breaking strength in the longitudinal axis (ZX) direction was high at 43-46 MPa, and the ratio of the tensile breaking strength in the longitudinal axis (ZX) direction to the transverse axis (XY) direction was high at 0.92 or higher. Furthermore, the ratio of the tensile breaking strength in the transverse axis (XY) to the tensile breaking strength of molded products formed by injection molding was high at 0.85-0.96, indicating an excellent balance between the tensile breaking strength in the longitudinal and transverse axes.

[0099] (Evaluation of the resin compositions of Comparative Examples 1-4) On the other hand, Comparative Examples 1 to 4 shown in Table 5 use an aromatic polycarbonate resin as the (A) polycarbonate resin among the three components of Examples 1 to 5, with an MVR of 27 cm². 3 For the 10 min test (Comparative Example 1), the MVR was 2.8 cm. 3 / 10min (Comparative Example 2), (A) as the polycarbonate resin, siloxane copolymer polycarbonate resin, with an MVR of 20.4 cm 3 For the 10 min test (Comparative Example 3), the MVR was 4 cm. 3 This is a variation using the 10min version (Comparative Example 4).

[0100] Regarding the multipurpose test specimens, filaments, and 3D printed bodies obtained using these resin compositions (pellets), Comparative Example 1 showed good results in terms of heat resistance, tensile fracture strength in the longitudinal (ZX) direction, and the ratio of tensile fracture strength in the longitudinal (ZX) direction to the transverse (XY) direction of the 3D printed body, but the diameter accuracy and roundness of the filament were poor. Comparative Example 2 showed excellent heat resistance and filament properties, but the tensile fracture strength in the longitudinal (ZX) direction of the 3D printed body was low.

[0101] In Comparative Example 3, similar to Comparative Example 1, good results were obtained in terms of heat resistance, tensile fracture strength in the longitudinal (ZX) direction of the 3D printed object, and the ratio of tensile fracture strength in the longitudinal (ZX) direction to the transverse (XY) direction. However, the diameter accuracy and roundness of the filament were poor. In Comparative Example 4, similar to Comparative Example 2, although the heat resistance and filament properties were excellent, the tensile fracture strength in the longitudinal (ZX) direction of the 3D printed object was low.

[0102] (Evaluation of the resin composition of Comparative Example 5) In Comparative Example 5, compared to Example 13, a mixture of aromatic polycarbonate resin and PBT resin was used as (A) polycarbonate resin, with a mixing ratio of aromatic polycarbonate resin / PBT resin = 50 / 50. Regarding the multipurpose test pieces, filaments, and 3D printed objects obtained using this resin composition (pellets), the heat resistance was poor, with a load deflection temperature of less than 100°C, and the diameter accuracy and roundness of the filaments were poor.

[0103] (Evaluation of resin compositions of Comparative Examples 6-10) Comparative Examples 6 to 10, shown in Table 5, are variations of Example 2 in which (C) the heat-fusible polymer is changed to polycaprolactone (molecular weight 50,000) (Comparative Example 6), polycaprolactone diol (molecular weight 4,000) (Comparative Example 7), crystalline copolymer polyester resin (glass transition temperature 19°C) (Comparative Example 8), amorphous copolymer polyester resin (glass transition temperature 47°C) (Comparative Example 9), and amorphous copolymer polyester resin (glass transition temperature 7°C) (Comparative Example 10).

[0104] Regarding the multipurpose test specimens, filaments, and 3D printed objects obtained using these resin compositions (pellets), all of Comparative Examples 6 to 10 exhibited low tensile fracture strength in the longitudinal (ZX) direction of the 3D printed objects. Comparative Example 7 also showed poor filament properties (diameter accuracy and roundness).

[0105] (Evaluation of the resin compositions of Comparative Examples 11 and 13) Comparative Examples 11 and 13, shown in Table 6, are the same as those of Example 2, but (C) does not include the heat-fusible polymer (Comparative Example 11) and (B) does not include the resin-modifying polymer (Comparative Example 13). Regarding the multipurpose test specimens, filaments, and 3D printed bodies obtained using these resin compositions (pellets), Comparative Example 11 had extremely low tensile breaking strength in the longitudinal axis (ZX) direction of the 3D printed body, while Comparative Example 13 had poor filament properties (diameter accuracy and roundness) and low tensile breaking strength in the longitudinal axis (ZX) direction of the 3D printed body.

[0106] (Evaluation of the resin compositions of Comparative Examples 12 and 14) In Comparative Example 12, shown in Table 6, the proportion of (C) polycaprolactone (molecular weight 10,000), a heat-fusible polymer, among the three components of Example 2, is 20% by weight. The multipurpose test specimens, filaments, and 3D printed objects obtained using this resin composition (pellets) have poor heat resistance, with a load deflection temperature of less than 100°C, and poor filament properties (diameter accuracy and roundness). In Comparative Example 14, the proportion of (B) core-shell type polymer, a resin-modifying polymer, among the three components of Example 2, is 25% by weight. The multipurpose test specimens, filaments, and 3D printed objects obtained using this resin composition (pellets) have poor filament properties (diameter accuracy and roundness).

[0107] (Evaluation of the resin composition of Comparative Example 15) Comparative Example 15, shown in Table 6, differs from Example 21 in that the mixing ratio of aromatic polycarbonate resin and ASA resin is changed to aromatic polycarbonate resin / ASA resin = 50 / 50. The multipurpose test specimens, filaments, and 3D printed objects obtained using this resin composition (pellets) have poor heat resistance, with a load deflection temperature of less than 100°C, and poor filament properties (diameter accuracy and roundness).

[0108] As described in detail above, according to the resin composition of this embodiment, by blending three components—a polycarbonate resin, a resin-modified polymer, and a heat-fusible polymer—within a predetermined weight ratio range, it was possible to obtain a 3D printer filament with excellent moldability (diameter accuracy and roundness) and excellent longitudinal axis (ZX) strength of the 3D printed object.

[0109] In the above, polycarbonate resin compositions used in filament-melting type 3D printers have been described based on embodiments of the present invention, but the present invention is not limited to these embodiments. That is, in this embodiment, it is not only preferably applicable to filament-melting type 3D printers that use filaments, but can also be applied to molten granular type 3D printers that do not require filaments. [Industrial applicability]

[0110] The present invention provides a polycarbonate-based resin composition that can be suitably used not only in filament-melting type 3D printers but also in molten granular type 3D printers. [Explanation of Symbols]

[0111] 1: Multipurpose test specimen, L: length, L1: first length, L2: second length, T: thickness, W: width, EW: Edge width, a: Radius at the maximum diameter of the filament cross-section, b: Radius at the minimum diameter of the filament cross-section, 10: Test specimen

Claims

1. A polycarbonate resin composition for 3D printers comprising (A) a polycarbonate resin, (B) a resin-modifying polymer, and (C) a heat-sealable polymer, The polycarbonate resin (A) is a polycarbonate resin, a mixture of polycarbonate resin and PBT resin, or a mixture of polycarbonate resin and ASA resin, wherein the mixing ratio of the polycarbonate resin to the PBT resin or ASA resin is 100 to 55% by weight of the polycarbonate resin and 0 to 45% by weight of the PBT resin or ASA resin, and the polycarbonate resin is an aromatic polycarbonate resin or a siloxane copolymer polycarbonate resin. The aforementioned resin-modified polymer (B) is a core-shell type polymer, The heat-sealable polymer (C) is polycaprolactone or a crystalline copolymer polyester resin. A polycarbonate resin composition for 3D printers, wherein, when the total weight of the polycarbonate resin (A), the resin-modified polymer (B), and the heat-sealable polymer (C) is 100% by weight, the ratio of the polycarbonate resin (A) to the total weight is in the range of 65% to 92% by weight, the ratio of the resin-modified polymer (B) to the total weight is in the range of 5% to 20% by weight, and the ratio of the heat-sealable polymer (C) to the total weight is in the range of 3% to 15% by weight.

2. The polycarbonate resin composition for a 3D printer according to claim 1, wherein the polycarbonate resin (A) is a mixture of polycarbonate resin and PBT resin or a mixture of polycarbonate resin and ASA resin, and the mixing ratio of the polycarbonate resin to the PBT resin or ASA resin is 95 to 55% by weight of the polycarbonate resin and 5 to 45% by weight of the PBT resin or ASA resin.

3. A polycarbonate resin composition for a 3D printer according to claim 1 or 2, wherein the MVR of the polycarbonate resin (A), measured at 300°C and a load of 1.2 kg, is 8 to 19 g / min, the core material of the core-shell type polymer, which is the resin-modified polymer (B), is acrylic rubber or silicone-acrylic composite rubber with an average particle diameter of 100 to 700 nmφ, the number-average molecular weight of the polycaprolactone, which is the heat-fusible polymer (C), is 10,000 to 25,000, and the glass transition temperature of the copolymerized polyester resin is 5°C or less.

4. The polycarbonate resin composition for 3D printers according to any one of claims 1 to 3, wherein the tensile breaking strength in the longitudinal axis (ZX) direction of a molded object produced by a general-purpose FFF type 3D printer using the polycarbonate resin composition is 35 MPa or more.

5. A polycarbonate resin composition for 3D printers according to any one of claims 1 to 4, wherein the ratio of the tensile breaking strength along the vertical axis (ZX) to the horizontal axis (XY) of a molded object produced by a general-purpose FFF type 3D printer using the polycarbonate resin composition is 0.6 or more.

6. The polycarbonate resin composition for 3D printers according to any one of claims 1 to 4, wherein the ratio of the tensile breaking strength along the horizontal axis (XY) of a molded object produced by a general-purpose FFF 3D printer using the polycarbonate resin composition to the tensile breaking strength of a molded product produced by injection molding is 0.6 or more.

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