Propylene resin compositions for three dimensional printers, filaments for three dimensional printers, and three dimensional printed modeling objects

Abstract

To provide a propylene resin composition for three-dimensional printers with high carbon fiber content that does not impair moldability, such as filament winding ability, and that is capable of producing moldable objects with excellent mechanical strength and does not impair the moldability of moldable objects by three-dimensional printers.SOLUTION: A propylene resin composition for three-dimensional printers containing 15 to 45 mass% carbon fiber and 55 to 85 mass% resin component, containing polypropylene and olefinic elastomer in the resin component, the total content of polypropylene and olefinic elastomer in the resin component is in the range of 80 to 100 mass%, and the ratio of polypropylene and olefinic elastomer in the resin component is 50 / 50 to 90 / 10 by mass.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a propylene resin composition for 3D printers, a filament for 3D printers, and a 3D printed object. [Background technology]

[0002] Methods using fiber-reinforced resin compositions, in which various reinforcing fibers are dispersed in thermoplastic resins, are generally known and used in a variety of applications to improve the mechanical properties such as strength, rigidity, impact resistance, and heat resistance of materials and molded products made of thermoplastic resins. Among these, carbon fiber-reinforced resin compositions are attracting attention as industrially important materials because they exhibit excellent mechanical properties such as strength and rigidity despite their low specific gravity.

[0003] One known method for molding the aforementioned thermoplastic resins is fused deposition modeling (FDM) using a 3D printer capable of creating complex shapes. Examples of thermoplastic resins used in this FDM method include polylactic acid (PLA), acrylonitrile butadiene styrene copolymer (ABS), nylon, and polypropylene. Among these, polypropylene is industrially useful in many aspects, including price, processing performance, heat resistance, and safety, and research is underway to utilize it as a material for 3D printers.

[0004] On the other hand, materials using polypropylene as a thermoplastic resin have drawbacks such as poor mechanical properties, high shrinkage rates, and a tendency to undergo severe distortion deformation, especially when 3D printing complex shapes, resulting in low product dimensional accuracy. Therefore, there is a demand for carbon fiber reinforced polypropylene resin compositions that can be used in 3D printers. For example, a carbon fiber reinforced polypropylene composite material for use in 3D printing, containing polypropylene and carbon fibers, has been disclosed (see Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Chinese Patent Application Publication No. 109679207 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] While it is preferable for the thermoplastic resin to contain a relatively large amount of carbon fiber to improve mechanical properties such as strength and rigidity, Patent Document 1 reports that when a polypropylene composition with a high carbon fiber content (for example, a carbon fiber content of 15 wt%) is used, although the mechanical strength is excellent, problems such as the resulting filament being too stiff to be wound into a coil and 3D printed objects having defects occur.

[0007] The present invention has been made in view of the above problems, and aims to provide a propylene resin composition for 3D printers with a high carbon fiber content that does not impair moldability such as filament winding properties, enables the manufacture of molded objects with excellent mechanical strength, and does not impair the moldability of objects manufactured by a 3D printer. [Means for solving the problem]

[0008] As a result of the inventors' investigations, they found that when carbon fibers are used in a relatively high content, the above problem can be solved by using a specific resin component containing a predetermined amount of polypropylene and an olefin-based elastomer.

[0009] In other words, the present invention includes the following: [1] A propylene resin composition for 3D printers comprising 15 to 45% by mass of carbon fiber and 55 to 85% by mass of resin components, The aforementioned resin component includes polypropylene and an olefin-based elastomer. The total content of polypropylene and olefin-based elastomer in the aforementioned resin component is in the range of 80 to 100% by mass. The aforementioned resin component contains polypropylene and olefin-based elastomer in a mass ratio of 50 / 50 to 90 / 10. Propylene resin composition for 3D printers. [2] The propylene resin composition for 3D printers according to [1], wherein the polypropylene comprises at least one selected from the group consisting of homopolypropylene and random polypropylene. [3] The propylene resin composition for 3D printers according to [1] or [2], wherein the olefin elastomer is at least one selected from the group consisting of ethylene elastomers or propylene elastomers. [4] A propylene resin composition for 3D printers according to any one of [1] to [3], wherein part or all of the polypropylene is polypropylene modified with an anhydride. A 3D printer filament comprising a propylene resin composition for 3D printers as described in any of [5] [1] to [4]. [6] A 3D printed object manufactured from a propylene resin composition for 3D printers described in any of [1] to [4], or from a 3D printer filament described in [5]. [Effects of the Invention]

[0010] By using the propylene resin composition for 3D printers of the present invention, a 3D printer filament containing the propylene resin composition can be manufactured without impairing physical properties such as spool winding properties, even though the carbon fiber content is relatively high relative to the resin components. Furthermore, 3D printed objects containing the propylene resin composition or filament exhibit excellent moldability and superior mechanical strength after molding due to the high carbon fiber content. [Modes for carrying out the invention]

[0011] [Propylene resin composition for 3D printers] The propylene resin composition for 3D printers of the present invention includes carbon fibers and a resin component having polypropylene and an olefin-based elastomer.

[0012] <Carbon fiber> As the carbon fiber used in the present invention, various known carbon fibers can be used. Specific examples include carbon fibers such as polyacrylonitrile-based, rayon-based, pitch-based, polyvinyl alcohol-based, regenerated cellulose, and pitch-based carbon fibers produced from mesophase pitch. The carbon fiber may contain a recycled material.

[0013] The fiber diameter of the carbon fiber is preferably 3 to 30 μm, more preferably 4 to 10 μm. The lower limit value of the above range of the fiber diameter is significant in terms of preventing fiber breakage and the productivity of fiber bundles. For example, when continuously producing pellets, if the fiber diameter is appropriately thickened, the number of fibers to be bundled does not increase, and the complicated work of connecting fiber bundles becomes unnecessary, improving productivity. On the other hand, the upper limit value of the above range is significant in suppressing the decrease in the aspect ratio of the fiber and maintaining the reinforcing effect when the pellet length is determined.

[0014] The aspect ratio of the carbon fiber is preferably 5 to 500. The lower limit value is significant in suppressing the decrease in strength, and the upper limit value is significant in terms of moldability. The aspect ratio of the carbon fiber is obtained by the formula (average fiber length) ÷ (average fiber diameter) from the average fiber diameter and the average fiber length.

[0015] The fiber density of the carbon fiber is preferably 1.00 to 10 g / cm 3 and more preferably 1.50 to 5.0 g / cm 3 Moreover, the TEX number, which is the number of grams per 1 km of fiber, is preferably 300 to 3000 g / 1000 m, more preferably 500 to 2000 g / 1000 m. When these values are within the above ranges, there is a tendency to exhibit the effects peculiar to carbon fibers, such as excellent mechanical properties such as strength and rigidity despite having a low specific gravity.

[0016] From the viewpoint of enhancing mechanical strength, the tensile strength of the carbon fiber is preferably 2500 to 6000 MPa, more preferably 3500 to 6000 MPa, and particularly preferably 4000 to 6000 MPa.

[0017] Also, the carbon fiber may be a long fiber, a short fiber, or chopped fiber. As the raw material of the long fiber, a continuous fiber bundle can be used, which is commercially available as tow. Usually, its average fiber diameter is 3 to 30 μm, and the number of filament bundles is 500 to 80,000. Preferably, the average fiber diameter is 4 to 10 μm, and the number of bundles is 12,000 to 50,000. The length of the chopped strand is usually 1 to 20 mm, and the fiber diameter is usually 3 to 30 μm, preferably 4 to 10 μm.

[0018] Also, the carbon fiber is preferably a carbon fiber bundle bundled using a sizing agent. Specifically, it is preferable to use a state in which a large number of carbon fibers are integrally bundled with a sizing agent. The sizing agent constituting the carbon fiber bundle is preferably a urethane-based emulsion, an epoxy-based emulsion, or a nylon-based emulsion from the viewpoint of enhancing mechanical strength. More preferably, it is an emulsion-based adhesive such as a urethane-based emulsion or an epoxy-based emulsion, and particularly preferably an epoxy-based emulsion from the viewpoint of further improving mechanical strength. The number of carbon fibers constituting the carbon fiber bundle is not particularly limited, but can be, for example, 6,000 to 48,000.

[0019] The surface of the carbon fiber is preferably one that has been surface-treated by oxidation etching, coating, etc. Examples of the oxidation etching treatment include air oxidation treatment, oxygen treatment, treatment with an oxidizing gas, treatment with ozone, corona treatment, flame treatment, (atmospheric pressure) plasma treatment, and oxidizing liquids (nitric acid, aqueous solution of alkali metal hypochlorite, potassium dichromate-sulfuric acid, potassium permanganate-sulfuric acid). Examples of the substance for coating the carbon fiber include carbon, silicon carbide, silicon dioxide, silicon, plasma monomer, ferrocene, iron trichloride, etc. Also, a sizing agent such as urethane-based, olefin-based, acrylic-based, nylon-based, butadiene-based, and epoxy-based may be used as needed.

[0020] The propylene resin composition for 3D printers of the present invention contains 15 to 45% by mass of carbon fibers and 55 to 85% by mass of resin components. Preferably, it contains 17 to 40% by mass of carbon fibers and 60 to 83% by mass of resin components, and more preferably, it contains 19 to 35% by mass of carbon fibers and 65 to 81% by mass of resin components. By including carbon fibers and resin components within the above ranges, it is possible to produce a filament with sufficient windability, and to produce molded objects with excellent mechanical strength without compromising their moldability.

[0021] The carbon fiber content within the aforementioned range is higher in proportion to the resin component compared to conventional propylene resin compositions for 3D printers. As mentioned above, simply increasing the carbon fiber content can be expected to improve the mechanical strength of the fabricated object, but it leaves unresolved issues such as problems with the physical properties of the filament material used in the preceding stage and defects during fabrication. Conventional technologies have not been able to solve these problems with carbon fiber content within the aforementioned range. In the present invention, these problems are overcome by using a specific resin component. The resin component will be described in detail below.

[0022] <Resin components> The resin component used in the present invention is characterized by containing polypropylene and an olefin-based elastomer in predetermined proportions.

[0023] The total content of the polypropylene and olefin-based elastomer in the resin component is in the range of 80 to 100% by mass, preferably 85 to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 94 to 100% by mass. Furthermore, the mass ratio of the polypropylene to the olefin-based elastomer is 50 / 50 to 90 / 10, preferably 60 / 40 to 90 / 10, more preferably 70 / 30 to 87 / 13, and even more preferably 75 / 25 to 85 / 15. When the polypropylene and olefin-based elastomer are included in the resin component within the above range, the effects described above are achieved.

[0024] 〔polypropylene〕 The polypropylene includes at least one selected from the group consisting of a homopolymer of propylene (homopolypropylene), a random copolymer of propylene and α-olefin (random polypropylene), and a block copolymer of propylene and α-olefin (block polypropylene). A preferred embodiment is one in which at least one homopolypropylene is included, and a more preferred embodiment is one in which only at least one homopolypropylene is included, or one in which at least one homopolypropylene and at least one random polypropylene are included.

[0025] The α-olefin copolymerized with propylene is preferably an α-olefin having 2 or 4 to 20 carbon atoms. Examples of α-olefins having 2 or 4 to 20 carbon atoms include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. The α-olefin may be used alone or in combination of two or more.

[0026] When using a random polypropylene composed of propylene and an α-olefin having 2 or 4 to 20 carbon atoms as the polypropylene, the polypropylene contains 70 mol% to 99 mol%, preferably 80 mol% to 99 mol%, more preferably 90 mol% to 99 mol%, of structural units derived from propylene, and 1 mol% to 30 mol%, preferably 1 mol% to 20 mol%, more preferably 1 mol% to 10 mol%, of structural units derived from α-olefin (provided that the total of structural units derived from propylene and structural units derived from α-olefin is 100 mol%). Here, "structural units derived from propylene" specifically refers to structural units represented by -CH2-CH(-CH3)-.

[0027] The aforementioned polypropylene has a melting point (Tm) of preferably 130 as measured by differential scanning calorimetry (DSC). The temperature is above ℃, more preferably above 140℃, preferably below 180℃, and more preferably below 170℃. The melting point (Tm) of the polypropylene is a value measured by the following method in accordance with JIS K7121.

[0028] Approximately 5 mg of polypropylene is sealed at room temperature in the measuring aluminum pan of a differential scanning calorimeter (DSC220C) manufactured by Seiko Instruments Inc., and heated from room temperature to 260°C at a rate of 10°C / min. To completely melt the polypropylene, it is held at 260°C for 5 minutes, and then cooled to -50°C at a rate of 10°C / min. The temperature at which a peak is observed during this cooling process is defined as the crystallization temperature (Tc). After holding at -50°C for 5 minutes, a second heating is performed to 260°C at a rate of 10°C / min, and the temperature at which a peak is observed during this second heating is defined as the melting point (Tm) of the polymer. If multiple peaks are detected, the peak detected at the highest temperature is adopted.

[0029] The melt flow rate (MFR) of the polypropylene is measured in accordance with ASTM D1238 under conditions of 230°C and a 2.16 kg load, and is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, even more preferably 1.5 g / 10 min or more, preferably 500 g / 10 min or less, more preferably 400 g / 10 min or less, and even more preferably 300 g / 10 min or less. If the MFR is lower than the lower limit, the resin flowability during molding will be poor, and the resin may not be able to impregnate the carbon fiber details. Also, if the MFR is higher than the upper limit, the molded product may not have sufficient mechanical strength.

[0030] The aforementioned polypropylene has a tensile modulus measured in accordance with JIS K7161, preferably in the range of 200 MPa to 5,000 MPa. More preferably, this tensile modulus is in the range of 300 MPa to 3,000 MPa, and even more preferably in the range of 500 MPa to 2,000 MPa. Furthermore, the tensile fracture stress measured in accordance with JIS K7161 is preferably in the range of 10 MPa to 50 MPa. Having the tensile modulus and tensile fracture stress within the above ranges results in excellent physical properties of the filament and balance during molding.

[0031] In the present invention, homopolypropylene, random polypropylene, or block polypropylene can be prepared by copolymerization in the presence of a known olefin polymerization catalyst. Specifically, as the olefin polymerization catalyst, for example, a so-called Ziegler-Natta catalyst containing a solid titanium catalyst component and an organometallic compound catalyst component, or a metallocene catalyst can be used.

[0032] Furthermore, the homopolypropylene, random polypropylene, or block polypropylene can also be commercially available products, such as J13B, J105G, J106G, J106MG, J107G, J137G, J108M, F113G, F-300SP, F-704NP homopolypropylenes from Prime Polymer, and J-2021GRP, J-3021GRP, F- Examples include random polypropylenes such as 724NPC, F-730NV, F-744NO, F227D, F219DA, and F329RA, and block polypropylenes from Prime Polymer such as J704UG, J705UG, J715M, J707G, J707EG, J708UG, J709QG, J739E, J-452HP, J466HP, J762HP, J-750HP, and J-3051HP. The homopolypropylene, random polypropylene, or block polypropylene may be used individually or in combination of two or more types.

[0033] In this invention, it is preferable to use polypropylene that is partially or entirely modified with carboxylic acid anhydride as the polypropylene. More preferably, it is polypropylene that is partially modified with carboxylic acid anhydride. The inclusion of the carboxylic acid anhydride-modified polypropylene in the resin component improves the interfacial adhesion between the component and the carbon fiber, contributing to an improvement in the strength of the resulting molded product.

[0034] The carboxylic acid anhydride-modified polypropylene is obtained by modifying the polypropylene with at least one selected from carboxylic acids anhydride. One or more types of polypropylene can be used for modification.

[0035] Specific examples of the carboxylic anhydride include unsaturated dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid anhydride. Among these, maleic anhydride, itaconic anhydride, and tetrahydrophthalic anhydride are more preferred, with maleic anhydride being even more preferred. One or more types of the carboxylic anhydride can be used.

[0036] Conventional methods can be used for the above modification, for example, by grafting carboxylic anhydride onto polypropylene. Specifically, carboxylic anhydride is grafted onto polypropylene, which will serve as the graft main chain, in the presence of a radical polymerization initiator.

[0037] Conventional methods known as grafting methods can be used, such as the solution method and the melt-kneading method. For example, one method involves suspending or dissolving polypropylene in a solvent and adding and mixing a carboxylic anhydride and a radical polymerization initiator at a temperature of typically 80 to 200°C to carry out graft polymerization; another method involves contacting the carboxylic anhydride and the radical polymerization initiator under melt-kneading at a temperature above the melting point of polypropylene, for example, 180 to 300°C.

[0038] Examples of solvents used in the solution method include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, heptane, octane, and decane; alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; chlorinated hydrocarbon solvents such as trichloroethylene, perchloroethylene, dichloroethylene, dichloroethane, and chlorobenzene; aliphatic alcohol solvents such as ethanol and isopropanol; ketone solvents such as acetone, methyl isobutyl ketone, and methyl ethyl ketone; and ester solvents such as methyl acetate, ethyl acetate, and butyl acetate. One or more solvents can be used.

[0039] Examples of radical polymerization initiators include organic peroxides and azo compounds. Examples of organic peroxides include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-trioyl peroxide, di-t-butyl peroxide, dicumyl peroxide, (2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, lauroyl peroxide, t-butyl peroxyacetate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, t-butyl peroxyisobutyrate, t-butyl peroxyphenyl acetate, t-butyl peroxy-s-octate, t-butyl peroxypivalate, cumyl peroxypivalate, and t-butyl peroxyethyl acetate. Examples of azo compounds include azoisobutyronitrile and dimethylazoisobutyrate. One or more radical polymerization initiators can be used.

[0040] Carboxylic acid-modified polypropylene can also be obtained, for example, by copolymerizing an olefin with a carboxylic acid anhydride. The olefin used to form the polypropylene described above can be used as the olefin. As for the copolymerization method, for example, a conventionally known radical copolymerization method can be used.

[0041] The content of structures derived from carboxylic acid anhydride in carboxylic acid anhydride-modified polypropylene is preferably 0.1% by mass or more, more preferably 0.8% by mass or more, preferably 5.0% by mass or less, and more preferably 4.0% by mass or less. The above content is determined, for example, in the case of maleic acid-modified polypropylene, by measuring the infrared absorption (IR) spectrum of the resin and measuring the content between 1670 and 1810 cm⁻¹. -1 The content can be determined from a calibration curve created separately based on the peak area. Even when using carboxylic anhydrides other than maleic acid, the above content can be determined by infrared absorption spectroscopy or the like.

[0042] The polypropylene-based weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of carboxylic acid anhydride-modified polypropylene are determined by gel permeation chromatography (GPC). Mw is preferably 2,000 to 200,000, more preferably 4,000 to 180,000, and even more preferably 6,000 to 160,000. Mn is preferably 500 to 50,000, more preferably 1,000 to 45,000, and even more preferably 1,500 to 40,000. The Mw / Mn is preferably 1.0 to 8.0, more preferably 1.0 to 5.0.

[0043] [Olefin-based elastomers] The resin component used in the present invention includes an olefin-based elastomer as an essential component. The olefin-based elastomer used in the present invention is not particularly limited in terms of the type of olefin that constitutes the monomer, and may be any olefin-based elastomer that is commonly used.

[0044] The olefin-based elastomer preferably includes at least one selected from the group consisting of ethylene-based elastomers and propylene-based elastomers. Among these, including at least one propylene-based elastomer as the olefin-based elastomer is a preferred embodiment.

[0045] In the present invention, a first embodiment of an exemplary olefin-based elastomer that can be used as an olefin-based elastomer is a copolymer of one or more selected from the group consisting of ethylene and propylene and other olefins. In the present invention, a copolymer in which ethylene is selected is called an ethylene-based elastomer, and a copolymer in which propylene is selected is called a propylene-based elastomer.

[0046] In one exemplary embodiment of the present invention, the olefin elastomer is a copolymer of a first copolymer portion consisting of one selected from the group consisting of polyethylene and polypropylene, and a second copolymer portion consisting of one selected from the group consisting of polybutadiene, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, polyisobutylene, and α-olefin.

[0047] An example of such a copolymer is a copolymer of a first copolymer portion consisting of one selected from the group consisting of polyethylene and polypropylene, and a second copolymer portion consisting of poly-α-olefin. The copolymerization of the first copolymer portion and the second copolymer portion may be either block copolymerization or graft copolymerization.

[0048] In another exemplary embodiment of the present invention, the olefin-based elastomer is a random copolymer comprising one or more selected from the group consisting of ethylene and propylene, and α-olefin (excluding ethylene and propylene). The α-olefins mentioned above are olefins having a double bond at one end of their molecular chain, and preferred examples include 1-butene and 1-octene.

[0049] For example, a block copolymer can be made of a polyolefin block that forms a highly crystalline polymer such as polypropylene as the hard part, and an amorphous monomer copolymer that forms the soft part. Specifically, examples include olefin (crystalline)-ethylene-butylene-olefin block copolymer, polypropylene-polyolefin (amorphous)-polypropylene block copolymer, etc. Specific examples include the product name "DYNARON" (registered trademark) from JSR Corporation, the product names "Tafmer" (registered trademark) and "Notio" (registered trademark) from Mitsui Chemicals, Inc., and the product name "ENGAGE" from Dow Chemical Company Limited. TM "VERSIFY TM ", a product name manufactured by ExxonMobil Chemicals Corporation, "Vistamaxx TM Examples include those sold commercially as "[product name]".

[0050] A second embodiment of the olefin-based elastomer that can be used as an olefin-based elastomer in the present invention is a blend of one selected from the group consisting of polyethylene and polypropylene and one selected from the group consisting of ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-butene copolymer, and hydrogenated styrene-butadiene. In this case, the ethylene-propylene copolymer, ethylene-propylene-diene copolymer, and ethylene-butene copolymer may be partially or completely crosslinked.

[0051] Specific examples include the product name "Milastomer (registered trademark)" from Mitsui Chemicals, the product name "Esporex (registered trademark)" from Sumitomo Chemical, the product names "Thermoran (registered trademark)" and "Zelus (registered trademark)" from Mitsubishi Chemical, and the product name "Santoplene (registered trademark)" from ExxonMobil Chemicals Ltd.

[0052] Furthermore, in the present invention, the olefin elastomer may be an unmodified olefin elastomer, or it may be a modified olefin elastomer obtained by modifying the olefin elastomer with at least one functional group selected from the group consisting of acid anhydride groups, carboxyl groups, amino groups, imino groups, alkoxysilyl groups, silanol groups, silyl ether groups, hydroxyl groups, and epoxy groups.

[0053] The aforementioned olefin-based elastomer has a melting point (Tm) that is either not observed or is in the range of 50 to 162°C as measured by differential scanning calorimeter (DSC). Meeting this requirement suppresses deformation during heating. Here, "not observed melting point (Tm)" for olefin-based elastomers means that the heat of fusion (ΔH) (unit: J / g) measured by differential scanning calorimeter (DSC) is substantially not measured. Substantially not measuring the heat of fusion (ΔH) means that no peak is observed in the differential scanning calorimeter (DSC) measurement, or the observed heat of fusion is 1 J / g or less. The melting point (Tm) of olefin-based elastomers is a value measured in accordance with JIS K7121, using the same method as the measurement of the melting point (Tm) of polypropylene described above.

[0054] In this case, in one preferred embodiment of the present invention, when a propylene-based elastomer is used, the olefin-based elastomer used in the present invention preferably contains 50 mol% or more and less than 90 mol% of structural units derived from propylene. Furthermore, in another preferred embodiment of the present invention, when an ethylene-based elastomer is used, the ethylene-based elastomer used in the present invention preferably contains 50 mol% or more and less than 90 mol% of structural units derived from ethylene. Here, "structural units derived from ethylene" specifically refers to structural units represented by -CH2-CH2-.

[0055] The olefin-based elastomer has a tensile modulus measured in accordance with ASTM D638, preferably in the range of 1 MPa to 500 MPa. More preferably, this tensile modulus is in the range of 1 MPa to less than 200 MPa, even more preferably in the range of 1 MPa to 100 MPa, even more preferably in the range of 1 MPa to 50 MPa, and particularly preferably in the range of 1 MPa to 40 MPa. Furthermore, the olefin-based elastomer preferably has a tensile fracture nominal strain exceeding 1000%, as measured in accordance with ASTM D638. Having a tensile modulus within this range allows the resulting filament to possess appropriate flexibility. It also helps to suppress filament breakage at the printer exit.

[0056] 〔polyamide〕 Furthermore, the resin components contained in the propylene resin composition for 3D printers of the present invention may also include polyamide to improve interfacial adhesion between polypropylene, olefin-based elastomer, and carbon fibers.

[0057] As the polyamide, for example, an amino acid lactam or a melt-mold polymer obtained by a melt polycondensation reaction between a diamine and a dicarboxylic acid can be used. Specifically, the following polyamides can be mentioned.

[0058] (1) Polycondensates of organic dicarboxylic acids having 4 to 12 carbon atoms and organic diamines having 2 to 13 carbon atoms, for example, polyhexamethylene adipamide [6,6 nylon], which is a polycondensate of hexamethylenediamine and adipic acid; polyhexamethylene azelamide [6,9 nylon], which is a polycondensate of hexamethylenediamine and azelaic acid; and polyhexamethylene sebakami, which is a polycondensate of hexamethylenediamine and sebaic acid. Examples of organic dicarboxylic acids include do[6,10 nylon], polyhexamethylene dodecanoamide[6,12 nylon] which is a polycondensate of hexamethylenediamine and dodecanedionic acid, semi-aromatic polyamides (PA6T, PA9T, PA10T, PA11T) which are polycondensates of aromatic dicarboxylic acids and aliphatic diamines, and polybis(4-aminocyclohexyl)methanedodecane which is a polycondensate of bis-p-aminocyclohexylmethane and dodecanedionic acid.Specific examples of organic dicarboxylic acids include adipic acid, pimelic acid, suberic acid, phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, phenylenedioxydiacetic acid, oxydibenzoic acid, diphenylmethanedicarboxylic acid, diphenylsulfondicarboxylic acid, biphenyldicarboxylic acid, sebacic acid, and dodecanediic acid. Specific examples of organic diamines include hexamethylenediamine, octamethylenediamine, nonanediamine, octanediamine, decanediamine, undecadiamine, undecanediamine, and dodecanediamine.

[0059] (2) Polycondensates of ω-amino acids, for example, polyundecaneamide [11 nylon] which is a polycondensate of ω-aminoundecanoic acid.

[0060] (3) Ring-opened polymers of lactams, for example, polycapramid[6 nylon], a ring-opened polymer of ε-aminocaprolactam, and polylauric lactam[12 nylon], a ring-opened polymer of ε-aminolaurolactam.

[0061] (4) A polyamide produced from adipic acid, isophthalic acid, and hexamethylenediamine.

[0062] Furthermore, specific examples of commercially available polyamides include 3012U, 3014U, 3024U, 3024NUX, 1013B, 1013NW8, 1013NW9, 1013IU50, 1018I, 1022B, 1030B, NAP1400F, etc. from Ube Industries; CM1007, CM1017, CM1017XL2, CM1017XL3, CM1017-K, CM1026, CM3007, CM3001-N, CM3006, CM3301L from Toray Industries; and LV-2H, LV-3H, LV-5H, LV-3AH, LKN-5H, LC-3H, L20EC, XE3925, etc. from EMS. The polyamides may be used individually or in mixtures of two or more types.

[0063] From the viewpoint of strength of the molded article of the carbon fiber reinforced resin composition, it is preferable that the polyamide has excellent fluidity when melted. From this viewpoint, the polyamide is measured in accordance with ASTM D1238 under conditions of 190°C and a 2.16 kg load, preferably 5 g / 10 min or more, more preferably 10 g / 10 min or more, even more preferably 12 g / 10 min or more, and usually 500 g / 10 min or less.

[0064] Furthermore, if the resin component contains polyamide, its content is 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 6% by mass or less.

[0065] <Other ingredients> The propylene resin composition for 3D printers of the present invention may contain various additives depending on the application, as long as they do not hinder the objectives of the present invention. These additives may include, for example, dispersants, lubricants, plasticizers, flame retardants, antioxidants (phenolic antioxidants, phosphoric acid antioxidants, sulfuric acid antioxidants, etc.), antistatic agents, light stabilizers, UV absorbers, crystallization accelerators (nucleating agents, etc.), foaming agents, crosslinking agents, antibacterial agents, and other modifying additives; colorants such as pigments and dyes; particulate fillers such as carbon black, titanium dioxide, red iron oxide, azo pigments, anthraquinone pigments, phthalocyanine, talc, calcium carbonate, mica, and clay; short fibrous fillers such as wollastonite; and whiskers such as potassium titanate. One or more of these may be used.

[0066] <3D printer filament> The 3D printer filament containing the propylene-based resin composition for 3D printers of the present invention exhibits excellent moldability, including extrusion stability, dimensional stability, and spool winding properties, even with a high carbon content in the resin composition. The 3D printer filament is manufactured by melt-spinning the propylene-based resin composition and then stretching it. A known melt-spinning method can be used for melt-spinning. The same applies to stretching.

[0067] Examples of methods for manufacturing 3D printer filaments according to the present invention include an extrusion step in which the propylene-based resin composition is extruded as a molten strand from the die hole of a single-screw or twin-screw extruder and guided into a cooling water tank to obtain the strand; a stretching step in which the strand is stretched; and a winding step in which the stretched filament is wound up.

[0068] Extrusion is carried out at a temperature in the range of the melting point (Tm) to the melting point (Tm) + 130°C of the propylene resin composition, and the molten strand extruded from the die is cooled by immersion in a water bath. The water temperature depends on the diameter of the target filament, but is preferably in the range of 5 to 60°C, more preferably 7 to 50°C, and even more preferably 10 to 40°C. If the water temperature is too high, the strand will not cool sufficiently and will be introduced to the next stretching process while still soft, which may cause poor winding at the take-up roll (stretching roll).

[0069] In this invention, stretching refers to the operation of mechanically stretching a filament at a temperature below the melting point of the material, thereby orienting the molecular chains parallel to the tensile direction. This operation significantly improves tensile strength and increases toughness. After the stretching process, if the material is reheated above the stretching temperature, it will tend to shrink back to its original dimensions. Therefore, to ensure dimensional and strength stability, heat treatment (heat setting) may be performed at a temperature slightly lower than the stretching temperature.

[0070] In this invention, the strand obtained in the extrusion process is heated to a specific temperature and stretched. The stretching is performed by the speed ratio (stretching ratio) between the take-up roll on the inlet side and the take-up roll on the outlet side, and the stretching ratio is preferably 2 to 15 times. Any of the heating methods used during stretching, such as a hot water bath, oven, or heated roll, may be used and there are no restrictions, but a hot water bath is more preferable for more uniform heating and stretching.

[0071] Stretching using a hot water tank can be achieved by using a water tank with a length and depth that allows for temperature control, and arranging take-up rolls at both ends. Stretching using an oven can be achieved by using an oven several meters long with an electric heater (infrared heater) as the heat source, positioned in the take-up direction for temperature control, and arranging take-up rolls at both ends. Furthermore, stretching using heat rolls can be achieved by installing multiple take-up rolls whose temperature is controlled by water piping, oil piping, and electric heaters placed inside, and adjusting the rotation speed of the rolls.

[0072] The temperature conditions during stretching are almost the same regardless of which device and method is selected, such as a hot water bath, oven, or heated roll. The surface temperature of the filament before stretching is preferably in the range of the glass transition temperature (Tg) to the melting point (Tm) of the olefin-based elastomer composition, more preferably in the range of Tg to Tm-30°C, and even more preferably in the range of Tg to Tm-60°C. If the surface temperature is below Tg, stretching breakage may occur, or stretching by more than twice the original length may become impossible. Conversely, if it exceeds Tm, the effect of strength development due to stretching will be reduced.

[0073] The stretching ratio is typically 2 to 15 times, preferably 3 to 12 times, and more preferably 4 to 10 times. If the stretching ratio is less than 2 times, the strength development due to the stretching operation may be insufficient. Conversely, if the stretching ratio exceeds 15 times, problems such as breakage during stretching, whitening due to void formation, and the filament becoming prone to longitudinal splitting may occur.

[0074] In addition to the single-stage method for stretching by 2 to 15 times, it is also possible to combine these methods as appropriate to create a 2-stage, 3-stage, or multi-stage configuration, performing a small-magnification stretch in each stage to achieve an overall stretching magnification of 2 to 15 times.

[0075] When performing multi-stage stretching, it is preferable to sequentially change the stretching ratio, for example, 1.1 to 10 times in the first stage, 1.5 to 12 times in the second stage, so that the overall stretching ratio is 2 to 15 times, and simultaneously, within the above temperature range, the heating temperature is set lowest for the first stage and progressively higher for each additional stage.

[0076] In this invention, the stretched filament can be further heat-treated (thermally fixed) to suppress changes in physical properties (e.g., shrinkage) at high temperatures. A method for heat-treating an olefin-based thermoplastic elastomer composition at a temperature between its glass transition temperature (Tg) and melting point (Tm) is preferably to introduce it into a heating bath set to 20 to 140°C, more preferably 30 to 120°C, perform heat treatment (thermally fixed), and then cool it in a cooling bath. For the heat treatment, any method such as a water bath, oven, or hot roll can be used, as in the stretching operation, and there are no restrictions. For cooling, either water cooling or air cooling can be used, and there are no restrictions. Finally, the stretched filament is wound into a dedicated cartridge, bobbin, and cone using a winding machine. It can be wound up in this manner to obtain a filament winding.

[0077] The diameter of the 3D printer filament of the present invention depends on the design specifications of the fused deposition modeling (FDM) method and the capabilities of the system used for printing, but is usually 1.0 mm or more, preferably 1.5 mm or more, and more preferably 1.6 mm or more. On the other hand, the upper limit is 4.0 mm or less, preferably 3.5 mm or less, and more preferably 3.0 mm or less.

[0078] The roundness of the 3D printer filament of the present invention is 0.93 or higher, preferably 0.95 or higher, with an upper limit of 1.0. The roundness in the present invention is measured by the method described in the examples below. Filaments with the diameter and roundness described above have excellent moldability, allowing for the stable production of molded products with superior appearance and surface properties.

[0079] <3D printed objects> The 3D printed object of the present invention is fabricated using a 3D printer with the propylene resin composition for 3D printers of the present invention, or a 3D printer filament containing the propylene resin composition. By using the resin composition or filament, high-strength objects can be manufactured without impairing moldability.

[0080] [Method for manufacturing 3D printed objects] The 3D printed object of the present invention is fabricated using a 3D printer by a known method called fused deposition modeling. Specifically, this manufacturing method comprises the steps of melting the resin composition or filament and extruding the resulting molten material from the nozzle of a 3D printed object manufacturing apparatus to fabricate a 3D printed object.

[0081] (Melting process) The melting step in the present invention involves melting the 3D printing material, which is either the propylene resin composition for 3D printers of the present invention or the filament for 3D printers of the present invention. The heating means for melting the 3D printing material is not particularly limited, and known heating means can be applied. In the melting step, it is preferable to use a 3D printing manufacturing apparatus equipped with a heating means such as an electric heater.

[0082] The melting temperature of the 3D printing material is not particularly limited and can be set appropriately according to the properties of the thermoplastic resin. For example, the melting temperature of the 3D printing material may be set to a temperature of +10 to 150°C, based on the higher of the melting point or glass transition temperature (Tg) of the thermoplastic resin.

[0083] In the melting process, for example, the 3D printing material may be melted and kneaded. When the 3D printing material is melted and kneaded, it tends to mix more uniformly. Therefore, material inconsistencies in the resulting 3D printed object are more easily suppressed. As a result, deformation of the 3D printed object tends to be further suppressed.

[0084] (modeling process) The fabrication process in this disclosure involves extruding the molten 3D printing material from a nozzle in the melting process to create a 3D printed object. In the fabrication process, for example, the molten 3D printing material is extruded from the nozzle of a 3D printing manufacturing apparatus, and a 3D printed object can be created by sequentially stacking 2D layers on a substrate based on multiple 2D data. Multiple 2D data are generated by slicer software, which slices the 3D coordinate data of the 3D printed object to be fabricated into cross-sections.

[0085] A 3D printing apparatus can be a material extrusion type 3D printing apparatus. There are no particular limitations on the material extrusion type 3D printing apparatus, and known apparatuses or known apparatus configurations can be applied. The 3D printing apparatus may be, for example, an apparatus comprising a cylinder, a nozzle, and a heating means. The cylinder is supplied with 3D printing material. The nozzle is provided on the downstream side of the cylinder in the direction of discharge of the 3D printing material. The nozzle discharges the 3D printing material. The heating means is provided on the cylinder. The heating means heats and melts the 3D printing material.

[0086] A 3D printing machine extrudes heated and molten 3D printing material from a nozzle, and builds up layers of this extruded material. This process creates a 3D printed object.

[0087] The cylinder may have a screw inside. The screw mixes the 3D printing material. The 3D printing apparatus may further include a table apparatus. The table apparatus is positioned opposite the nozzle. Molten 3D printing material extruded from the nozzle is deposited onto the table apparatus.

[0088] The 3D printing manufacturing apparatus may further include control means. The control means controls the spatial coordinates of the substrate and the nozzle, as well as the amount of 3D printing material extruded from the nozzle. Preferably, the control means controls the discharge of molten 3D printing material extruded from the nozzle, and controls the movement of the nozzle and / or table device in the X, Y, and Z axis directions relative to a reference plane.

[0089] (Other processes) The method for manufacturing a 3D printed object according to the present invention may further include, for example, a processing step. In the processing step, the 3D printed object created in the fabrication step is subjected to processing.

[0090] [Physical properties of 3D printed objects] The 3D printed objects of the present invention exhibit excellent mechanical strength. Specifically, the strength characteristics of the 3D printed objects can be evaluated by, for example, the following physical properties. In this specification, injection molded bodies described in the examples below were manufactured and their strength characteristics were evaluated.

[0091] (Tensile modulus of elasticity, tensile fracture stress, tensile fracture strain) The 3D printed object has a tensile modulus of elasticity measured in accordance with JIS K7161, preferably in the range of 1.0 to 40 GPa, more preferably in the range of 3.0 to 30 GPa, and even more preferably in the range of 5.0 to 20 GPa. Furthermore, the tensile breaking strength measured in accordance with JIS K7161 is preferably in the range of 1.0 to 200 MPa, more preferably in the range of 5.0 to 200 MPa, and even more preferably in the range of 10 to 200 MPa. Moreover, the tensile fracture strain required during the tensile test is preferably in the range of 1.0 to 20%, more preferably in the range of 2.0 to 20%, and even more preferably in the range of 3.0 to 10%.

[0092] (Charpy impact strength) The aforementioned 3D printed object preferably has a Charpy impact strength of 5 to 50 kJ / m², as measured in accordance with JIS K7111-1 / 1eA. 2is in the range of, more preferably 7 to 40 kJ / m 2 is in the range of, even more preferably 9 to 30 kJ / m 2 is in the range of.

Examples

[0093] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the descriptions of these examples.

[0094] [Equipment used] <Compound granulation equipment> When producing the resin composition for 3D printers in Examples and Comparative Examples, the compound granulation equipment and production conditions are as follows. Equipment: Co-rotating twin-screw extruder HK-25D (manufactured by Parker Corporation) Screw diameter: 25 mm Screw process length (L / D): 41 Barrel set temperature (taking the temperature at the nozzle tip as C8, setting the temperature step by step as C7 to C2 towards the hopper side, and the temperature directly below the hopper as C1): C8 / C7 / C6 / C5 / C4 / C3 / C2 / C1 = 200 / 200 / 200 / 200 / 200 / 210 / 210 / 80 °C Nozzle diameter: 3 mm × 2 holes Screw rotation speed: 150 rpm Cooling method: Water cooling (10 to 15 °C) Pre-drying: None

[0095] <Injection molding equipment> For the physical property evaluation of the molded body containing the resin composition for 3D printers, the equipment and production conditions when producing injection molded bodies in Examples and Comparative Examples are as follows. Equipment: Injection molding machine J100 ADS 180U (manufactured by Japan Steel Works, Ltd.) Barrel set temperature (taking the temperatures at the nozzle tip as NH2 and NH1, setting the temperature step by step as H4 to H1 towards the hopper side, and the temperature directly below the hopper as HP):

[0096]

具体的な実施例

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] NH2 / NH1 / H4 / H3 / H2 / H1 / HP =250 / 250 / 250 / 250 / 250 / 250 / 60℃ Holding time: 15 seconds Injection speed: 50mm / sec Cooling time: 30 seconds Holding pressure: 15~50MPa Mold temperature: 3mm x 2 holes Screw rotation speed: 50 min -1 Back pressure: 2 MPa

[0096] <3D Printing Equipment> To evaluate the formability of 3D printed objects containing a resin composition for 3D printers, the apparatus and manufacturing conditions used to produce the 3D printed objects in the examples and comparative examples are as follows. Equipment: 3D printer Raise3D Pro2 Plus (manufactured by Raise3D) Nozzle diameter: 0.8mm Nozzle temperature: 220℃ Stage temperature: 40℃ Layer thickness: 0.4mm

[0097] [evaluation] The methods for measuring the physical properties of the various materials used in the examples and comparative examples, as well as the methods for evaluating the manufactured filaments, injection molded articles, and printed objects, are as follows.

[0098] <Weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn)> The weight-average molecular weight (Mw), number-average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of carboxylic acid-modified polypropylene were measured by GPC under the following conditions. Equipment: Shodex GPC-101 (manufactured by Showa Denko Corporation) Detector: RI-71S Columns: GPCKF804L (Φ8.0mm x 300mm) x 3 (manufactured by Showa Denko Corporation) Measurement temperature: 40℃ Eluent: THF (tetrahydrofuran) Flow rate: 1.0ml / min

[0099] <Tensile modulus of elasticity, tensile fracture stress, tensile fracture nominal strain (material)> Tensile tests for polypropylene were conducted in accordance with JIS K7161, for olefin-based elastomers in accordance with ASTM D638, and for polyamides in accordance with ISO 527, under the following conditions. Equipment: Tensile testing machine Autograph AG-500C (manufactured by Shimadzu Corporation) Test speed: 300 mm / min Chuck spacing: 100mm Distance between gauge lines: 50mm A stress-strain curve was created to show the relationship between normal stress (in N) and normal strain (in %), and the tensile modulus, tensile fracture stress (in MPa), and tensile fracture nominal strain (in %) were determined. Measurements were taken five times, and the average value was used.

[0100] <Tensile modulus of elasticity, tensile fracture strength, tensile fracture strain (injection molded article)> Tensile tests of injection-molded articles were conducted in accordance with JIS K7161, under the following conditions. Equipment: Tensile testing machine AG-20kNXDPlus (manufactured by Shimadzu Corporation) Test speed: 5 mm / min Chuck spacing: 115mm Distance between gauge lines: 50mm A stress-strein curve was created to show the relationship between normal stress (in N) and normal strain (in %), and the tensile modulus (in GPa), tensile fracture strength (in MPa), and tensile fracture strain (in %) were determined. Measurements were taken five times, and the average value was used.

[0101] <Charpy impact strength> The Charpy impact test of the injection-molded parts was conducted in accordance with JIS K7111-1 / 1eA. The Charpy impact strength (unit: kJ / m²) at 23°C was measured for the cut-out test specimens of the injection-molded parts (specimen size = 10 mm × 80 mm × 4 mm, notched = machined).2 ) was sought.

[0102] <Extrusion stability, dimensional stability, spool winding properties> The various physical properties of the 3D printer filament were evaluated according to the following criteria. (Extrusion stability) ○: Can be made into a filament during filament fabrication. ×: Unable to form filament during filament production. (Dimensional stability) ○: The diameter falls within a tolerance of ±0.15 mm of the target diameter (1.75 mm). ×: The diameter is not within the tolerance of ±0.15 mm of the target diameter. (Spool winding performance) ○: Can be wound onto a spool (inner diameter 100mm x outer diameter 200mm), which is the common sales form of filament, or onto a spool with larger inner and outer diameters than the aforementioned spool. ×: Cannot be wound onto the aforementioned spool.

[0103] <Formability> The formability of 3D printed objects was evaluated according to the following criteria. ○: Can be molded onto ship models (60mm x 31mm x 48mm height). ×: The aforementioned ship model cannot be shaped.

[0104] [Materials used] Details of the various materials used in the examples and comparative examples are as follows. <Carbon fiber> • Carbon fiber, epoxy sizing agent coated product (manufactured by Toray) <Homopolypropylene (h-PP)> • J13B (Made of Prime Polymer, MFR (2.16 kg load, 230°C): 220 g / 10 min, Tensile fracture stress: 35 MPa, Tensile modulus of elasticity: 1,800 MPa) • F113G (Made of Prime Polymer, MFR (2.16 kg load, 230°C): 3.0 g / 10 min, Tensile breaking stress: 35 MPa, Tensile modulus of elasticity: 1,600 MPa) <Random Polypropylene (r-PP)> • F227D (Made of Prime Polymer, MFR (2.16 kg load, 230°C): 6.7 g / 10 min, Tensile breaking stress: 24 MPa, Tensile modulus of elasticity: 800 MPa) <Carboxylic Acid Modified Polypropylene> Maleic acid-modified polypropylene (MAH-PP) (maleic anhydride content: 3.0% by mass, polypropylene-equivalent molecular weight Mw=37,800, Mn=17,400, Mw / Mn=2.18) <Polyamide (PA)> • 3012U (manufactured by Ube Industries, MFR (2.16 kg load, 190°C): 17 g / 10 min, tensile fracture stress: 47 MPa) <Olefin-based elastomer> • Toughmer (registered trademark) PN-0040 (Propylene-based elastomer manufactured by Mitsui Chemicals, tensile modulus: 37 MPa, tensile fracture nominal strain: >1000%) • Toughmer (registered trademark) PN-2060 (Propylene-based elastomer manufactured by Mitsui Chemicals, tensile modulus: 22 MPa, tensile fracture nominal strain: >1000%) • Toughmer (registered trademark) DF610 (Ethylene-based elastomer manufactured by Mitsui Chemicals, tensile modulus: 5 MPa, tensile fracture nominal strain: >1000%) <Polyamide (PA)> • 3012U (manufactured by Ube Industries, MFR (2.16 kg load, 190°C): 17 g / 10 min, tensile fracture stress: 47 MPa) <Carbon fiber-containing polypropylene resin> • FL900PP CF (Braskem, 14% carbon fiber by mass, using random polypropylene)

[0105] [Manufacturing Example 1] Carbon fiber-reinforced polypropylene pellets (LFT-1) with a pellet length of 9 mm were prepared by drawing using the above-mentioned carbon fibers, homopolypropylene (J13B), maleic acid-modified polypropylene, and polyamide in a mass ratio of 40:46:8.0:6.0.

[0106] [Manufacturing Example 2] Carbon fiber reinforced polypropylene pellets (LFT-2) with a pellet length of 9 mm were prepared by drawing using the above-mentioned carbon fiber, homopolypropylene (J13B), and maleic acid-modified polypropylene in a mass ratio of 40:52:8.0.

[0107] [Example 1] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), homopolypropylene (F113G), and olefin-based elastomer (PN-0040) were mixed in a mass ratio of 50:35:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition.

[0108] (2) Fabrication of injection molded products Test specimens for evaluating the physical properties of molded articles were prepared from the polypropylene resin composition obtained in (1) using the injection molding apparatus described above. Various physical properties of the obtained test specimens were evaluated according to the method described above. The results are shown in Table 1.

[0109] (3) Making filaments for 3D printers A 3D printer filament with a diameter of 1.75 mm was prepared from the polypropylene resin composition obtained in (1). The various physical properties of the obtained 3D printer filament were evaluated according to the method described above. The results are shown in Table 1.

[0110] (4) Fabrication of 3D printed objects (3) Using the 3D printer filament obtained in (3), a ship model (60mm x 31mm x 48mm high) was fabricated using the 3D printing apparatus described above. The 3D printing performance was evaluated according to the method described above. The results are shown in Table 1.

[0111] [Example 2] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), random polypropylene (F227D), and olefin-based elastomer (DF610) were mixed in a mass ratio of 50:35:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0112] [Example 3] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-2), homopolypropylene (F113G), and olefin-based elastomer (PN-2060) were mixed in a mass ratio of 50:35:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0113] [Example 4] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-2), random polypropylene (F227D), and olefin-based elastomer (DF610) were mixed in a mass ratio of 50:35:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0114] [Example 5] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), homopolypropylene (F113G), and olefin-based elastomer (PN-2060) were mixed in a mass ratio of 62.5:22.5:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0115] [Example 6] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), random polypropylene (F227D), and olefin-based elastomer (DF610) were mixed in a mass ratio of 62.5:22.5:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0116] [Example 7] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), homopolypropylene (F113G), and olefin-based elastomer (PN-2060) were mixed in a mass ratio of 75:10:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0117] [Example 8] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1), random polypropylene (F227D), and olefin-based elastomer (DF610) were mixed in a mass ratio of 75:10:15. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0118] [Comparative Example 1] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1) and homopolypropylene (F113G) were mixed in a mass ratio of 50:50. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0119] [Comparative Example 2] (1) Preparation of polypropylene resin composition Carbon fiber reinforced polypropylene pellets (LFT-1) and random polypropylene (F227D) were mixed in a mass ratio of 50:50. The mixture was then melt-kneaded and granulated using the compound granulation apparatus described above under the conditions described above to obtain a pelletized polypropylene resin composition. (2)~(4) Injection molded parts, 3D printer filaments, and 3D printed objects were obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded products are shown in Table 1.

[0120] [Comparative Example 3] (4) Fabrication of 3D printed objects Using a carbon fiber-containing polypropylene resin (FL900PP CF) as the polypropylene resin composition, a 3D printed object was obtained by manufacturing in the same manner as in Example 1. The various physical properties of the obtained molded product are shown in Table 1.

[0121] [Table 1]

Claims

1. A propylene resin composition for 3D printers containing 15 to 45% by mass of carbon fiber and 55 to 85% by mass of a resin component, The resin component contains polypropylene and an olefin-based elastomer, the total content of polypropylene and olefin-based elastomer in the resin component is in the range of 80 to 100 mass %, The resin component contains polypropylene and an olefin-based elastomer in a mass ratio of 50 / 50 to 90 / 10. Propylene resin composition for 3D printers.

2. The propylene resin composition for 3D printers according to claim 1, wherein the polypropylene comprises at least one selected from the group consisting of homopolypropylene and random polypropylene.

3. The propylene resin composition for 3D printers according to claim 1 or 2, wherein the olefin-based elastomer is at least one selected from the group consisting of ethylene-based elastomers and propylene-based elastomers.

4. The propylene resin composition for 3D printers according to any one of claims 1 to 3, wherein part or all of the polypropylene is polypropylene modified with carboxylic acid anhydride.

5. A filament for a 3D printer comprising the propylene resin composition for a 3D printer according to any one of claims 1 to 4.

6. A 3D printed object produced from the propylene resin composition for 3D printers according to any one of claims 1 to 4, or the filament for 3D printers according to claim 5.