Polyamide resin filament

Abstract

To provide a filament desirable in handleability and moldability.SOLUTION: A polyamide resin filament for additional production containing polyamide resin and reinforcement fibers includes: crystalline polyamide resin derived from a single monomer; and amorphous polyamide resin derived from a single monomer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyamide resin filament. [Background technology]

[0002] One additive manufacturing technology that uses 3D printers and other devices is the melt lamination of heated thermoplastic resin filaments (melt lamination deposition modeling). This melt lamination deposition modeling has the advantages of not requiring a mold for modeling and allowing a high degree of freedom in shape, and in recent years, further research and development has been conducted into improving materials and processes.

[0003] As thermoplastic resin filaments used in the melt lamination method, those with devised thermoplastic resin compositions (e.g., Patent Document 1) and those with devised filament viscosity (e.g., Patent Document 2) have been proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2021-521021 [Patent Document 2] JP 2023-53430 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, all of the filaments of the conventional technology have room for improvement in terms of the filament's handleability (reduced breakage when wound onto a spool, reduced buckling when fed to a 3D printer, etc.) and the modeling properties when using the filament to create objects (reduced nozzle clogging, stable discharge of molten resin, reduced modeling steps, etc.).

[0006] In view of the state of the prior art, the problem to be solved by the present invention is to provide a filament that has good handling and shapeability. [Means for solving the problem]

[0007] The inventors conducted intensive research and repeated experiments to solve these problems, and unexpectedly discovered that the above problems could be solved by using a polyamide resin as the thermoplastic resin contained in the filaments, and further by devising the composition of the polyamide resin, which led to the completion of the present invention. That is, the present invention is as follows.

[0008] [1] A polyamide resin filament for additive manufacturing, comprising a polyamide resin and a reinforcing fiber, The polyamide resin includes a crystalline polyamide resin derived from a single monomer and an amorphous polyamide resin derived from a single monomer. A polyamide resin filament.

[0009] [2] The polyamide resin filament according to [1], wherein the reinforcing fibers include short fibers having an average fiber length of 1.0 mm or less.

[0010] [3] The polyamide resin filament according to [2], wherein the content of the short fibers is 15 mass% or less.

[0011] [4] The polyamide resin filament according to any one of [1] to [3], wherein the reinforcing fibers include continuous fibers.

[0012] [5] The polyamide resin filament according to any one of [1] to [4], wherein a mass ratio of the crystalline polyamide resin to the amorphous polyamide resin (crystalline polyamide resin:amorphous polyamide resin) is 60:40 to 95:5.

[0013] [6] The melt flow rate of the crystalline polyamide resin at 275°C is VA (g / 10 min), the mass ratio of the crystalline polyamide resin to the entire polyamide resin is A (mass%), the melt flow rate of the amorphous polyamide resin at 275°C is VB (g / 10 min), the mass ratio of the amorphous polyamide resin to the entire polyamide resin is B (mass%), and the content of reinforcing fibers is C (mass%), and the following formula is used: Apparent viscosity = (VA x A / 100 + VB x B / 100) / C The polyamide resin filament according to any one of [1] to [5], having an apparent viscosity of 100 or less, as calculated by the following formula:

[0014] [7] The polyamide resin filament according to any one of [1] to [6], wherein the crystalline polyamide resin contains polyamide 6.

[0015] [8] The polyamide resin filament according to any one of [1] to [7], wherein the amorphous polyamide resin contains polyamide 6I.

[0016] [9] The polyamide resin filament according to any one of [1] to [8], wherein the reinforcing fibers are glass fibers or carbon fibers.

[0017]

[10] The polyamide resin filament according to any one of [1] to [9], further comprising carbon black. Effect of the Invention

[0018] According to the present invention, a filament having good handling properties and shapeability can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment for carrying out the present invention (hereinafter, referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and can be carried out in various modifications within the scope of the gist of the present invention.

[0020] [Polyamide resin filament] The polyamide resin filament of the present embodiment (hereinafter, sometimes simply referred to as "filament") is for additive manufacturing. The filament of the present embodiment contains a polyamide resin and a reinforcing fiber, and the polyamide resin contains a crystalline polyamide resin derived from a single monomer and an amorphous polyamide resin derived from a single monomer.

[0021] In this disclosure, "additive manufacturing" refers to a process of building three-dimensional objects by incrementally adding (building up) layers of material, as opposed to subtractive manufacturing, typically through machining.

[0022] In the present disclosure, "polyamide resin derived from a single monomer" refers to a polyamide resin obtained by condensation polymerization using one type of polyamine and one type of polycarboxylic acid as monomers, or by ring-opening polymerization using one type of lactam as monomer. That is, "polyamide resin derived from a single monomer" does not include, for example, polyamide resin obtained by condensation polymerization using two or more types of polyamines and one type of polycarboxylic acid, polyamide resin obtained by condensation polymerization using one type of polyamine and two or more types of polycarboxylic acid, polyamide resin obtained by condensation polymerization using two or more types of polyamines and two or more types of polycarboxylic acid, and polyamide resin obtained by ring-opening polymerization using two or more types of lactam.

[0023] In this disclosure, the term "crystalline polyamide resin" refers to a polyamide resin that has a heat of crystalline fusion of 1 cal / g or more when heated from 30°C to 330°C at a temperature increase rate of 20°C / min in differential scanning calorimetry (DSC) measurement.

[0024] In addition, in the present disclosure, "amorphous polyamide resin" refers to a polyamide resin whose heat of crystalline fusion is less than 1 cal / g when heated from 30°C to 330°C at a temperature increase rate of 20°C / min in differential scanning calorimetry (DSC) measurement.

[0025] (Polyamide resin) As described above, the filament of the present embodiment contains a polyamide resin, and the polyamide resin includes a crystalline polyamide resin derived from a single monomer and an amorphous polyamide resin derived from a single monomer. In other words, the filament of the present embodiment contains, as polyamide resins, a crystalline polyamide resin derived from a single monomer and an amorphous polyamide resin derived from a single monomer.

[0026] Since the filament of this embodiment contains both crystalline polyamide resin and amorphous polyamide resin as polyamide resin, buckling of the filament is unlikely to occur in an environment that may become high temperature such as inside a 3D printer and / or a room temperature environment during additive manufacturing. That is, in the filament of this embodiment, the coexistence of crystalline polyamide resin and amorphous polyamide resin contributes to improved handleability. In addition, since the filament of this embodiment contains both crystalline polyamide resin and amorphous polyamide resin, the solidification temperature can be adjusted during modeling, and the steps of the modeled product can be reduced. That is, in the filament of this embodiment, the coexistence of crystalline polyamide resin and amorphous polyamide resin contributes to improved modeling.

[0027] Moreover, in the filament of this embodiment, both the crystalline polyamide resin and the amorphous polyamide resin are derived from a single monomer (polyamide resin obtained by condensation polymerization using one type of polyamine and one type of polycarboxylic acid as monomers, or ring-opening polymerization using one type of lactam as monomer). As a result, the appropriate range of the discharge temperature during modeling is wider than when it is not derived from a single monomer, and as a result, the discharge is stable, and the modeling property is improved. In addition, in the filament of this embodiment, both the crystalline polyamide resin and the amorphous polyamide resin are derived from a single monomer, so that buckling of the filament is less likely to occur during additive manufacturing in a high-temperature environment such as inside a 3D printer and / or in a room temperature environment. That is, in the filament of this embodiment, the use of a polyamide resin derived from a single monomer contributes to improving the handleability.

[0028] For the above reasons, the filament of this embodiment can exhibit good handling properties and shapeability.

[0029] Furthermore, the filament of this embodiment can also have the effect of improving the interlayer adhesion of the molded product by, for example, being able to adjust the solidification temperature during molding as described above.

[0030] Furthermore, in this embodiment, since both the above-mentioned crystalline polyamide resin and the amorphous polyamide resin are derived from a single monomer, the appropriate range of temperature and humidity conditions during filament production is wide, and therefore, the effect of obtaining a filament with a stable wire diameter can be achieved. For example, when the maximum, minimum and average values ​​of the wire diameter of the filament of this embodiment are obtained using a sample of 10 m in length, the value obtained by dividing the maximum value by the average value (maximum wire diameter (index)) is preferably 1.100 or less, more preferably 1.050 or less, and even more preferably 1.020 or less. Similarly, for example, the value obtained by dividing the minimum value by the average value (minimum wire diameter (index)) is preferably 0.955 or more, more preferably 0.965 or more, and even more preferably 0.980 or more.

[0031] Furthermore, in the filament of the present embodiment, since both the above-mentioned crystalline polyamide resin and the amorphous polyamide resin are derived from a single monomer, when modeling is performed in combination with other types of filaments during additive manufacturing, the appropriate range of the discharge temperature during modeling is widened and / or the compatibility with other types of filaments is improved. As a result, the filament of the present embodiment can also have the effect of being able to obtain a modeled product with excellent adhesion even when modeling is performed in combination with various types of filaments.

[0032] Furthermore, the filament of the present embodiment has the effect of being excellent in heat resistance and ultraviolet resistance. Therefore, the filament of the present embodiment and a shaped product using the filament can be suitably used for manufacturing space equipment such as artificial satellites.

[0033] In the filament of this embodiment, the mass ratio of the crystalline polyamide resin to the amorphous polyamide resin (crystalline polyamide resin: amorphous polyamide resin) is preferably 60:40 to 95:5, more preferably 65:35 to 90:10, and even more preferably 70:30 to 80:20. When the mass ratio of the crystalline aliphatic polyamide resin derived from a single monomer to the amorphous polyamide resin derived from a single monomer is within this range, the balance between the stability of the filament diameter, the shaping stability, the appearance of the shaped article, and the heat resistance of the filament and the shaped article can be improved.

[0034] Examples of the crystalline polyamide resin derived from a single monomer include, but are not limited to, polyamide 6, polyamide 66, polyamide 46, polyamide 612, polyamide 610, polyamide 12, polyamide 4T, polyamide 6T, and polyamide 11. The crystalline polyamide resin derived from a single monomer may be used alone or in combination of two or more. Among these, from the viewpoint of more effectively improving the handling property and the moldability, the crystalline polyamide resin preferably contains polyamide 6.

[0035] Examples of the amorphous polyamide resin derived from a single monomer include, but are not limited to, polyamide 6I, polyamide MACM12, polyamide MC12, polyamide PACM12, polyamide MACM10, polyamide MACM14, polyamide PACM14, etc. The amorphous polyamide resin derived from a single monomer may be used alone or in combination of two or more. Among these, from the viewpoint of more effectively improving the handling property and the moldability, the amorphous polyamide resin preferably contains polyamide 6I.

[0036] (Reinforced Fiber) As described above, the filament of the present embodiment contains reinforcing fibers. Such reinforcing fibers may be short fibers or continuous fibers.

[0037] When the reinforcing fibers include short fibers, the discharge of the molten resin during filament production is stable, and a filament with a stable wire diameter can be obtained. In addition, the discharge during additive manufacturing is stable, and the resin is well cut when the molded product and the nozzle are separated during additive manufacturing, so that stable molding can be performed.

[0038] When the reinforcing fibers include short fibers, the average fiber length is preferably 1.0 mm or less, more preferably 500 μm or less, even more preferably 200 μm or less, and even more preferably 90 μm or less. If the average fiber length of the short fibers is within this range, the balance between the toughness of the filament and the strength of the shaped article using the filament is good, the filament becomes less likely to break, and a shaped article with high strength can be obtained.

[0039] When the reinforcing fibers include short fibers, the content of the short fibers is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 4% by mass or less, and even more preferably 2% by mass or less, based on the mass of the entire filament, from the viewpoint of further improving the handleability of the filament. Also, when the reinforcing fibers are short fibers, the content of the reinforcing fibers is preferably 0.5% by mass or more, more preferably 0.7% by mass or more, even more preferably 0.8% by mass or more, and even more preferably 1% by mass or more, based on the mass of the entire filament, from the viewpoint of further improving the discharge stability during shaping and the strength of the obtained shaped product.

[0040] On the other hand, as described above, it is also preferable that the reinforcing fibers contained in the filament of the present embodiment include continuous fibers. When the reinforcing fibers include continuous fibers, the physical properties of the obtained shaped article can be improved.

[0041] In this disclosure, the term "continuous fiber" refers to a fiber that is substantially uninterrupted in the filament. In addition, in this disclosure, "substantially uninterrupted" refers to a state in which reinforcing fibers are included in all cross sections perpendicular to the longitudinal direction of the filament. In addition, while it is ideal for continuous fibers to have all of the reinforcing fiber single threads uninterrupted within the filament, if 80% or more of the number of single threads are uninterrupted for 1 m on one or both sides along the longitudinal direction of the filament from any point, the fiber may be considered to be continuous.

[0042] When the reinforcing fibers include continuous fibers, the content of the continuous fibers is preferably 5 to 70 volume % relative to the total volume of the filaments, more preferably 15 to 65 volume %, and even more preferably 20 to 60 volume %, from the viewpoint of the physical properties of the shaped article. When the reinforcing fibers include continuous fibers, the content of the continuous fibers is preferably 15% by mass or more, more preferably 30% by mass or more, and preferably 80% by mass or less, more preferably 65% ​​by mass or less, based on the mass of the entire filament, from the viewpoint of the physical properties of the shaped article. Furthermore, when the reinforcing fibers include continuous fibers, the content of components other than the polyamide resin and the reinforcing fibers in the filament of this embodiment is preferably 0 to 2 parts by mass, more preferably 0 to 1 part by mass, based on 100 parts by mass of the polyamide resin.

[0043] The filament of this embodiment may contain both short fibers and continuous fibers as the reinforcing fibers.

[0044] Examples of reinforcing fibers include, but are not limited to, glass fibers, carbon fibers, plant fibers, aramid fibers, ultra-high strength polyethylene fibers, polybenzazole-based fibers, liquid crystal polyester fibers, polyketone fibers, metal fibers, ceramic fibers, etc. The reinforcing fibers may be used alone or in combination of two or more. Among these, the reinforcing fibers are preferably glass fibers, carbon fibers, plant fibers, or aramid fibers, and more preferably glass fibers or carbon fibers, from the viewpoints of mechanical properties, thermal properties, and versatility.

[0045] The reinforcing fibers may be treated with a surface treatment agent. The surface treatment agent is not particularly limited, but a suitable example is a sizing agent.

[0046] -Bundling agent- The reinforcing fibers are preferably treated with a sizing agent. In other words, the reinforcing fibers are preferably attached with a sizing agent. The sizing agent can be attached to the reinforcing fibers by using it as a water dispersion, for example.

[0047] The sizing agent may include one or more selected from the group consisting of a coupling agent (e.g., a silane coupling agent), a lubricant, and a binder. More specifically, the sizing agent may be composed of a coupling agent and a binder, or may be composed of a coupling agent, a lubricant, and a binder. By using a sizing agent that forms a strong bond between the reinforcing fiber and the resin that coats the periphery, a filament with a low void ratio can be obtained.

[0048] The sizing agent may be added externally to the material to be used, or may be contained internally in the material to be used. For example, the lubricant may be contained in a commercially available product of the thermoplastic resin to be used (e.g., polyamide resin). Also, for example, the coupling agent may be contained on the surface of the reinforcing fiber (e.g., carbon fiber). Furthermore, when the reinforcing fiber is carbon fiber, the type of sizing agent is not particularly limited, and a known one may be used, specifically, for example, one described in JP 2015-101794 A may be used.

[0049] --Coupling agent-- A coupling agent is a compound that bonds materials with different properties, mainly inorganic materials and organic materials. Examples of coupling agents include, but are not limited to, silane coupling agents, polymer coupling agents, polymerizable coupling agents, etc. In particular, when the reinforcing fibers are carbon fibers, it is preferable to select a coupling agent that is compatible with the hydroxyl groups present on the surface of the carbon fibers.

[0050] Silane coupling agents are usually used as surface treatment agents for reinforcing fibers (e.g., glass fibers and carbon fibers), and contribute to improving the interfacial adhesive strength. Examples of silane coupling agents include, but are not limited to, aminosilanes such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes, maleic acids, and the like. When polyamide is used as the thermoplastic resin, it is preferable to select a silane coupling agent that is easily bonded to a carboxyl group or amino group, which is the terminal group of the polyamide resin, and aminosilanes are preferred.

[0051] Examples of the polymer coupling agent include, but are not limited to, diamines (1,6-hexadiamine, etc.), polycarboxylic acids, epoxies, etc. Among these, diamines and polycarboxylic acids are preferred as the polymer coupling agent from the viewpoint of compatibility with thermoplastic resins (polyamide resins).

[0052] Examples of the polymerizable coupling agent include, but are not limited to, epoxies, phenols, ethers, lactones, etc. Among these, phenols and lactones are preferred as the polymerizable coupling agent from the viewpoint of compatibility with thermoplastic resins (polyamide resins).

[0053] --Lubricant-- The lubricant contributes to improving the opening property of reinforcing fibers (e.g., carbon fibers and glass fibers). As the lubricant, any ordinary liquid or solid lubricating material according to the purpose can be used, and in particular, when a silane coupling agent and a binder are used in combination, a lubricating material that does not inhibit them is preferable. Specific examples of the lubricant include, but are not limited to, animal, vegetable or mineral waxes such as carnauba wax and lanolin wax; surfactants such as fatty acid amides, fatty acid esters, fatty acid ethers, aromatic esters, and aromatic ethers.

[0054] --Binding agent-- The binder contributes to improving the bundling property and / or interfacial adhesive strength of reinforcing fibers (e.g., carbon fibers and glass fibers). As the binder, a polymer according to the purpose and a thermoplastic resin other than the thermoplastic resin as the main material of the filament can be used. In addition, a polyamide resin can also be used as the binder.

[0055] Examples of the polymer as a binder include, but are not limited to, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, copolymers of acrylic acid esters and / or methacrylic acid esters and copolymerizable monomers, and salts of these with primary, secondary, and tertiary amines. In addition, examples of the polymer that can be suitably used include polyurethane resins synthesized from isocyanates such as m-xylylene diisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), and isophorone diisocyanate, and diols such as polyester diols and polyether diols.

[0056] The homopolymer of acrylic acid preferably has a weight average molecular weight of 1,000 to 90,000, and more preferably 1,000 to 25,000. Regarding the copolymer of acrylic acid and other copolymerizable monomers, the copolymerizable monomers constituting the copolymer are not limited to the following, but may be, for example, one or more selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, vinylacetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid, among monomers having a hydroxyl group and / or a carboxyl group (excluding the case of only acrylic acid). In addition, the copolymerizable monomer preferably has one or more ester monomers. Examples of the salts of the homopolymer and copolymer of acrylic acid with primary, secondary and tertiary amines include, but are not limited to, triethylamine salt, triethanolamine salt, glycine salt, etc. The degree of neutralization is preferably 20 to 90%, more preferably 40 to 60%, from the viewpoints of improving the stability of the mixed solution with other concomitant chemicals (silane coupling agents, etc.) and reducing the amine odor. The weight average molecular weight of the acrylic acid polymer that forms the salt is preferably 3,000 or more from the viewpoint of improving the bundling ability of reinforcing fibers (e.g., carbon fibers and glass fibers), and is preferably 50,000 or less from the viewpoint of improving the properties when made into a shaped article.

[0057] As the binder, it is preferable to use a resin having good wettability or a surface tension similar to that of the polyamide resin contained in the filament of the present embodiment, particularly a thermoplastic resin. Specifically, for example, an emulsion of a polyurethane resin, an emulsion of a polyamide resin, or modified products thereof can be selected.

[0058] Thermoplastic resins used as binders include, but are not limited to, polyolefin resins, polyamide resins, polyurethane resins, polyacetal resins, polycarbonate resins, polyester resins, polyether ketones, polyether ether ketones, polyether sulfones, polyphenylene sulfide, thermoplastic polyetherimides, thermoplastic fluorine resins, and modified thermoplastic resins obtained by modifying these. The thermoplastic resin used as binder is preferably the same type as the polyamide resin contained in the filament of this embodiment, particularly the crystalline polyamide resin, or a modified form thereof (modified polyamide resin). In this case, when a composite material is formed, the adhesion between the reinforcing fiber and the polyamide resin can be improved.

[0059] Furthermore, when the bundling agent is used as an aqueous dispersion (emulsion) and attached to the reinforcing fibers (e.g., carbon fibers or glass fibers) in order to further improve the adhesion between the reinforcing fibers and the polyamide resin that coats them, it is preferable to use a modified thermoplastic resin as the bundling agent from the viewpoint of reducing the ratio of the emulsifier component for forming the emulsion or making the emulsifier component unnecessary.

[0060] Here, the modified thermoplastic resin means a resin obtained by copolymerizing a different monomer component other than a monomer component capable of forming the main chain of the thermoplastic resin, for the purpose of changing the properties of the thermoplastic resin, thereby modifying the hydrophilicity, crystallinity, thermodynamic properties, etc. The modified thermoplastic resin is not limited to the following, but examples thereof include modified polyolefin resins, modified polyamide resins, modified polyester resins, etc.

[0061] The modified polyolefin resin as a binder may be a copolymer of an olefin monomer and a monomer copolymerizable with the olefin monomer, or a homopolymer of one type of monomer copolymerizable with the olefin monomer, or a copolymer of two or more types of the copolymerizable monomer, all of which can be produced by a known method. The copolymer of the olefin monomer and the monomer copolymerizable with the olefin monomer may be a random copolymer obtained by copolymerizing the olefin monomer and the monomer copolymerizable with the olefin monomer, or a graft copolymer obtained by grafting the monomer copolymerizable with the olefin to the olefin.

[0062] Examples of the olefin monomer include, but are not limited to, ethylene, propylene, 1-butene, etc. These olefin monomers may be used alone or in combination of two or more.

[0063] Examples of monomers copolymerizable with olefin monomers include unsaturated carboxylic acids such as acrylic acid, maleic acid, maleic anhydride, methacrylic acid, vinylacetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid, and esters of these unsaturated carboxylic acids (methyl esters, ethyl esters, etc.), etc. These monomers may be used alone or in combination of two or more.

[0064] When the modified polyolefin resin is a copolymer of an olefin monomer and a monomer copolymerizable with the olefin monomer, the monomer ratio is preferably 60-95% by mass of the olefin monomer and 5-40% by mass of the monomer copolymerizable with the olefin monomer, and more preferably 70-85% by mass of the olefin monomer and 15-30% by mass of the monomer copolymerizable with the olefin monomer, based on 100% by mass of the total mass of the copolymerization components. If the olefin monomer is 60% by mass or more, the affinity with the matrix is ​​good, and if the mass% of the olefin monomer is 95% by mass or less, the water dispersibility of the modified polyolefin resin is good, and it is easy to apply it uniformly to the reinforcing fibers.

[0065] In the modified polyolefin resin used as a binder, the modified group such as a carboxyl group introduced by copolymerization may be neutralized with a basic compound. Examples of the basic compound include, but are not limited to, alkalis such as sodium hydroxide and potassium hydroxide, ammonia, and amines such as monoethanolamine and diethanolamine.

[0066] The weight average molecular weight of the modified polyolefin resin as a binder is not particularly limited, but is preferably 5,000 or more from the viewpoint of improving the bundling property of reinforcing fibers (e.g., carbon fibers and glass fibers), and is preferably 200,000 or less from the viewpoint of emulsion stability when made into a water dispersion. From the same viewpoint, the weight average molecular weight of the modified polyolefin resin is more preferably 50,000 or more, and more preferably 150,000 or less.

[0067] The modified polyamide resin as a binder is a modified polyamide compound in which a hydrophilic group such as a polyalkylene oxide chain or a tertiary amine component is introduced into the molecular chain of a polyamide resin, and can be produced by a known method. When a polyalkylene oxide chain is introduced into the molecular chain, for example, a modified polyamide resin is produced by copolymerizing a part or all of polyethylene glycol, polypropylene glycol, etc., which is modified into a diamine or dicarboxylic acid. When a tertiary amine component is introduced into the molecular chain, for example, aminoethylpiperazine, bisaminopropylpiperazine, α-dimethylamino ε-caprolactam, etc. are copolymerized to produce a modified polyamide resin.

[0068] The modified polyester resin used as a binder is a copolymer of polycarboxylic acid or its anhydride and polyol, and has hydrophilic groups in the molecular skeleton including the terminals, and can be produced by a known method. Examples of the hydrophilic groups include polyalkylene oxide groups, sulfonates, carboxyl groups, and neutralized salts thereof.

[0069] Examples of the polycarboxylic acid or anhydride thereof include aromatic dicarboxylic acids, sulfonate-containing aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, trifunctional or higher polycarboxylic acids, and the like. Examples of aromatic dicarboxylic acids include, but are not limited to, phthalic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and phthalic anhydride. Examples of sulfonate-containing aromatic dicarboxylic acids include, but are not limited to, sulfoterephthalate, 5-sulfoisophthalate, and 5-sulfoorthophthalate. Examples of the aliphatic dicarboxylic acid or alicyclic dicarboxylic acid include, but are not limited to, fumaric acid, maleic acid, itaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, succinic anhydride, and maleic anhydride. Examples of tri- or higher functional polycarboxylic acids include, but are not limited to, trimellitic acid, pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, and the like.

[0070] Among these, the polycarboxylic acid or its anhydride is preferably such that 40 to 99 mol % of the total polycarboxylic acid component is an aromatic dicarboxylic acid from the viewpoint of improving the heat resistance of the modified polyester resin, and further, the polycarboxylic acid or its anhydride is preferably such that 1 to 10 mol % of the total polycarboxylic acid component is a sulfonate-containing aromatic dicarboxylic acid from the viewpoint of emulsion stability when the modified polyester resin is made into an aqueous dispersion.

[0071] Examples of the polyol include diols and polyols having three or more functional groups. Examples of the diol include, but are not limited to, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, polybutylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, polytetramethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A or its alkylene oxide adduct, etc. Examples of the polyol having three or more functional groups include trimethylolpropane, glycerin, pentaerythritol, etc.

[0072] In the copolymer of polycarboxylic acid or its anhydride and polyol as the modified polyester resin, the copolymerization ratio of the polycarboxylic acid or its anhydride and the polyol is preferably 40 to 60 mass% of the polycarboxylic acid or its anhydride and 40 to 60 mass% of the polyol, and more preferably 45 to 55 mass% of the polycarboxylic acid or its anhydride and 45 to 55 mass% of the polyol, relative to 100 mass% of the total mass of the copolymerization components.

[0073] The weight average molecular weight of the modified polyester resin as a binder is not particularly limited, but is preferably 3,000 or more from the viewpoint of improving the bundling property of reinforcing fibers (e.g., carbon fibers or glass fibers), and is preferably 100,000 or less from the viewpoint of emulsion stability when made into a water dispersion. From the same viewpoint, the weight average molecular weight of the modified polyester resin is more preferably 10,000 or more, and more preferably 30,000 or less.

[0074] The polymers and thermoplastic resins that can be used as binders may be used alone or in combination of two or more kinds. The binder preferably contains one or more polymers selected from homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, copolymers of acrylic acid esters and / or methacrylic acid esters and copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines, with the total amount being 100% by mass, and more preferably contains one or more polymers selected from homopolymers of acrylic acid, copolymers of acrylic acid esters and / or methacrylic acid esters and copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines, with the total amount being 100% by mass.

[0075] When the sizing agent is composed of a silane coupling agent and a binder, the amount of the binder attached is preferably 0.1 to 3 mass% as the total mass of the silane coupling agent and the binder relative to 100 mass% of the reinforcing fiber (e.g., glass fiber). If the total mass of the silane coupling agent and the binder is 0.1 mass% or more, it is possible to control the bundling property of the reinforcing fiber (e.g., carbon fiber or glass fiber) and improve the interfacial adhesive strength, and if it is 3 mass% or less, it is advantageous in terms of the handleability of the thread (reinforcing fiber). From the same viewpoint, the amount of the binder attached to 100 mass% of the reinforcing fiber can be more preferably 0.2 to 2 mass%, and even more preferably 0.2 to 1 mass%, as the total mass of the silane coupling agent and the binder.

[0076] In addition, when the sizing agent is composed of a silane coupling agent, a lubricant, and a binder, the amount of the binder attached is preferably 0.01 to 3 mass% as the total mass of the silane coupling agent, the lubricant, and the binder relative to 100 mass% of the reinforcing fiber (e.g., carbon fiber or glass fiber). If the total mass of the silane coupling agent, the lubricant, and the binder is 0.01 mass% or more, it is possible to control the bundling property of the reinforcing fiber (e.g., carbon fiber or glass fiber) and improve the interfacial adhesive strength, and if it is 3 mass% or less, it is advantageous in terms of the handleability of the thread (reinforcing fiber). Also, if it is 3 mass% or less, it is advantageous in terms of the handleability of the thread (reinforcing fiber). From a similar viewpoint, the amount of the sizing agent adhered to 100% by mass of the reinforcing fibers, expressed as the total mass of the silane coupling agent, lubricant and binder, is more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and is more preferably 2% by mass or less, even more preferably 1% by mass or less.

[0077] The amount of the coupling agent attached is preferably 0.05 to 1 mass %, and more preferably 0.1 to 0.9 mass %, relative to 100 mass % of the reinforcing fibers.

[0078] --Form of sizing agent-- The sizing agent may be adjusted to any form, such as an aqueous solution, a colloidal dispersion, or an emulsion using an emulsifier, depending on the mode of use. However, from the viewpoint of improving the dispersion stability and heat resistance of the sizing agent, it is preferable to use the sizing agent in the form of an aqueous solution. In addition, the reinforcing fiber treated with the sizing agent can be continuously obtained, for example, in a known manufacturing process, by applying the above-mentioned sizing agent to the reinforcing fiber using a known method such as a roller-type applicator, and then drying. In addition, the reinforcing fiber treated with the sizing agent can also be obtained, for example, by a method of immersing the reinforcing fiber in a liquid containing the sizing agent, or a method of immersing the reinforcing fiber substrate in a liquid containing the sizing agent.

[0079] - Shape of reinforcing fiber - The reinforcing fiber is preferably a multifilament consisting of a plurality of filaments. From the viewpoint of ease of handling, the number of single threads of the multifilament is preferably 30 to 15,000. The filament of the present embodiment may contain a plurality of the multifilaments as reinforcing fibers.

[0080] From the viewpoints of strength and ease of handling, the single filament diameter R of the reinforcing fiber is preferably from 2 to 30 μm, more preferably from 4 to 25 μm, and even more preferably from 6 to 20 μm.

[0081] Reinforcement fiber single yarn diameter R (μm) and density D (g / cm 3 From the viewpoint of the ease of handling of the reinforcing fibers and the strength of the composite material, the product RD is preferably 5 to 100 μm g / cm 3 , more preferably 10 to 50 μm g / cm 3 , and more preferably 15 to 45 μm g / cm 3 , more preferably 20 to 45 μm g / cm 3 It is.

[0082] The density D can be measured using a specific gravity meter. On the other hand, the single fiber diameter R (μm) is related to the density D (g / cm 3 ) and the number of single yarns (dtex), the following formula:

[0083]

number

[0084] In order to set the product RD of the reinforcing fibers within a predetermined range, the fineness (dtex) and the number of single yarns (pieces) of commercially available reinforcing fibers may be appropriately selected according to the density of the reinforcing fibers. For example, when glass fiber is used as the reinforcing fiber, the density is about 2.5 g / cm 3Therefore, it is sufficient to select one with a single filament diameter of 2 to 40 μm. Specifically, when the single filament diameter of the glass fiber is 9 μm, the product RD becomes 23 by selecting glass fiber having a fineness of 660 dtex and a single filament number of 400. When the single filament diameter of the glass fiber is 17 μm, the product RD becomes 43 by selecting glass fiber having a fineness of 11,500 dtex and a single filament number of 2,000. For example, when carbon fiber is used as the reinforcing fiber, the density is about 1.8 g / cm 3 Therefore, a carbon fiber having a single filament diameter of 2.8 to 55 μm should be selected. Specifically, when the single filament diameter of the carbon fiber is 7 μm, the product RD becomes 13 by selecting a carbon fiber having a fineness of 2,000 dtex and 3,000 single filaments. For example, when aramid fiber is used as the reinforcing fiber, the density is about 1.45 g / cm 3 Therefore, it is sufficient to select one with a single yarn diameter of 3.4 to 68 μm. Specifically, when the single yarn diameter of the aramid fiber is 12 μm, the product RD becomes 17 by selecting an aramid fiber with a fineness of 1,670 dtex and 1,000 single yarns.

[0085] Reinforcing fibers, for example, glass fibers, are produced by weighing and mixing raw glass, molten glass in a melting furnace, spinning the glass filaments, applying a sizing agent, and passing through a spinning machine to take up a winding form such as a direct wind roving (DWR), cake, or twisted yarn. The reinforcing fibers before the filament production may be in any form, but a form taken up into a yarn, cake, or DWR is preferred because it increases productivity and production stability in the process of coating with resin (mixing with polyamide resin). Among the above, DWR is more preferred from the viewpoint of productivity.

[0086] (Other ingredients) The filament of this embodiment may contain other components such as additives as necessary in addition to the above-mentioned polyamide resin and reinforcing fiber (including various components constituting the surface treatment agent such as a bundling agent). Examples of such additives include colorants, antiaging agents, antioxidants, weathering agents, metal deactivators, light stabilizers, heat stabilizers, UV absorbers, antibacterial and antifungal agents, deodorizers, conductivity imparting agents, dispersants, softeners, plasticizers, crosslinking agents, co-crosslinking agents, vulcanizing agents, vulcanization assistants, foaming agents, foaming assistants, flame retardants, vibration dampers, nucleating agents, neutralizing agents, lubricants, antiblocking agents, dispersants, flow improvers, and mold release agents.

[0087] Examples of the colorant include carbon black, nigrosine, aluminum pigment, titanium dioxide, ultramarine, cyanine blue, cyanine green, quinacridone, diatomaceous earth, monoazo salt, perylene, disazo, condensed azo, isoindoline, red iron oxide, nickel titanium yellow, diketone pyrrolopyrrole, metal salt, perylene red, metal oxide, bismuth vanadate, cobalt green, cobalt blue, anthraquinone, phthalocyanine green, phthalocyanine blue, etc. Among these, black colorants are preferred, and carbon black and nigrosine are more preferred.

[0088] In particular, the filament of the present embodiment preferably further contains carbon black. This not only further improves the stability of the filament diameter and the stability of the shaping, but also further improves properties such as heat resistance, ultraviolet resistance, vacuum resistance, and radiation resistance. Therefore, the filament of the present embodiment further containing carbon black and the shaped product using the filament can be suitably used in the manufacture of space equipment such as artificial satellites.

[0089] When the filament of this embodiment further contains carbon black, the content of the carbon black is preferably 0.2% by mass or more with respect to the mass of the entire filament. In this case, the effect of further improving the stability of the filament's wire diameter and the stability of the shape, as well as the effect of further improving properties such as heat resistance, ultraviolet resistance, vacuum resistance, and radiation resistance can be sufficiently obtained. In addition, when the filament of this embodiment further contains carbon black, the content of the carbon black is preferably 5.0% by mass or less with respect to the mass of the entire filament. In this case, for example, when the filament of this embodiment is used for manufacturing space equipment such as artificial satellites, overheating due to the influence of infrared rays in outer space can be suppressed. From the same viewpoint, the content of the carbon black is more preferably 0.5% by mass or more, more preferably 0.8% by mass or more, more preferably 4.5% by mass or less, and even more preferably 4.0% by mass or less with respect to the mass of the entire filament.

[0090] When the filament of the present embodiment contains an additive other than carbon black, the content of the additive may be, for example, 3 mass % or less, preferably 1.5 mass % or less, relative to the mass of the entire filament (100 mass %).

[0091] (Apparent viscosity of filament) The filament of the present embodiment is expressed by the following formula, where VA (g / 10 min) is the melt flow rate of the crystalline polyamide resin at 275° C., A (mass %) is the mass ratio of the crystalline polyamide resin to the entire polyamide resin, VB (g / 10 min) is the melt flow rate of the amorphous polyamide resin at 275° C., B (mass %) is the mass ratio of the amorphous polyamide resin to the entire polyamide resin, and C (mass %) is the content of the reinforcing fiber: Apparent viscosity = (VA x A / 100 + VB x B / 100) / C It is preferable that the apparent viscosity calculated by the above formula is 100 or less. If the apparent viscosity is in this range, the resin dripping from the nozzle during modeling is reduced, and modeling properties tend to be improved, and the filament diameter tends to be stable. From the same viewpoint, the apparent viscosity of the filament of this embodiment is more preferably 90 or less, even more preferably 80 or less, and even more preferably 60 or less.

[0092] (Filament manufacturing method) The filament of this embodiment can be manufactured using the above-mentioned polyamide resin and reinforcing fiber, and other components that are blended as necessary. The polyamide resin, reinforcing fiber, and other components that are blended as necessary may be mixed in advance before the filament is manufactured, or may be mixed during the filament manufacturing process. The method of mixing the polyamide resin, reinforcing fiber, and other components that are blended as necessary is not particularly limited, but may be a known method, such as a method of mixing using a melt kneading device such as a single-screw extruder, a multi-screw extruder, a Banbury mixer, or a kneader.

[0093] The method for producing the filament of the present embodiment is not particularly limited, and examples thereof include a method in which the above-mentioned polyamide resin and reinforcing fiber, and other components blended as necessary, are molded by a known molding method such as extrusion molding. For example, when the filament of the present embodiment is obtained by extrusion molding, the conditions are appropriately adjusted depending on the flow characteristics and moldability of the polyamide resin used, and are usually 80 to 330°C, preferably 150 to 300°C.

[0094] (Modeling using filaments) The filament of this embodiment can be used in various known additive manufacturing methods, and is particularly suitable for fused deposition modeling.

[0095] (Use of filaments and shaped products) The filament of the present embodiment and a shaped article using the filament can be suitably used for space equipment such as rockets and artificial satellites, aircraft, drones, braces, assist suits, wearable devices and other wearable members and equipment, sporting goods such as soles, rackets, and fishing tackle, infrastructure such as utility poles, electric wires, and underground trenches, cars, construction materials, robots, electrical and electronic components, various containers, daily necessities, household goods, sanitary products, tools, jigs, cases, connectors, welfare equipment, medical equipment, housings for analytical equipment, and the like.

[0096] In automotive applications, the material can be used in, but is not limited to, the chassis / frame, undercarriage, drivetrain parts, interior parts, exterior parts, functional parts, and other parts. Specifically, steering shafts, mounts, sunroofs, steps, suspension trim, door trim, trunks, boot lids, bonnets, seat frames, seat backs, retractors, retractor support brackets, clutches, gears, pulleys, cams, argons, elastic beams, baffling, lamps, reflectors, glazing, front end modules, back door inners, brake pedals, handles, electrical materials, sound absorbing materials, door exteriors, interior panels, instrument panels, rear gates, ceiling ridges, seats, seat frames, wiper pillars, EPS (Electric Power Steering), small motors, heat sinks, ECU (Engine Control Unit) boxes, ECU housings, steering gear box housings, plastic housings, EV (Electric Vehicle motor housings, wire harnesses, on-board meters, combination switches, small motors, springs, dampers, wheels, wheel covers, frames, subframes, side frames, motorcycle frames, fuel tanks, oil pans, intake manifolds, propeller shafts, drive motors, monocoques, hydrogen tanks, fuel cell electrodes, panels, floor panels, exterior panels, doors, cabins, roofs, hoods, valves, EGR (Exhaust GasRecirculation valves, variable valve timing units, connecting rods, cylinder bores, members (engine mountings, front floor cloths, footwell cloths, seat cloths, inner sides, rear cloths, suspensions, pillar reinforcement, front sides, front panels, uppers, dash panel cloths, steering), tunnels, fastening inserts, crash boxes, crash rails, corrugated panels, roof rails, upper bodies, side rails, braiding, door surround assemblies, airbag parts, body pillars, dash-to-pillar gussets, suspension towers, bumpers, body pillar lowers, front body pillars, reinforcements (instrument panels, rails, roofs, front body pillars, roof rails, roof side rails, lockers, door belt lines, front floor unders, front body pillar uppers, front body pillar lowers, centre pillars, centre pillar hinges, door outside panels), side outer panels, front door window frames, MICS (Minimum Intrusion CabinSystem) bulk, torque box, radiator support, radiator fan, water pump, fuel pump, electronically controlled throttle body, engine control ECU, starter, alternator, manifold, transmission, clutch, dash panel, dash panel insulator pad, door side impact protection beam, bumper beam, door beam, bulkhead, outer pad, inner pad, rear seat rod, door panel, door trim board sub-assembly, energy absorber (bumper, shock absorbing), shock absorber, shock absorbing garnish, pillar garnish, roof side inner garnish, resin rib, side rail front spacer, side rail rear spacer, seat belt pretensioner, airbag They can be suitably used as parts for sensors, arms (suspension, lower, hood hinges), suspension links, shock absorbing brackets, fender brackets, inverter brackets, inverter modules, hood inner panels, hood panels, cowl louvers, cowl top outer front panels, cowl top outer panels, floor silencers, dump seats, hood insulators, fender side panel protectors, cowl insulators, cowl top ventilator loopers, cylinder head covers, tire deflectors, fender supports, strut tower bars, transmission center tunnels, floor tunnels, radio core supports, luggage panels, luggage floors, accelerator pedals, accelerator pedal bases, and the like.

[0097] Specific examples of space equipment include rockets and artificial satellites, as well as space environment sensors and their casings, spacecraft attitude control devices, spacecraft communication equipment, rovers, space telescopes, experimental equipment for the space environment, and space debris tracking devices. EXAMPLES

[0098] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples and can be practiced in various modified forms within the scope of the present invention.

[0099] The following measurements and evaluations were carried out on the filaments obtained in each example, the shapes produced using the filaments, and the products produced by the shapes.

[0100] [Measurement of apparent viscosity of filament] For the filaments obtained in each example, the apparent viscosity was calculated according to the following formula, where the melt flow rate of the crystalline polyamide resin used at 275°C and a load of 1.2 kg was defined as VA (g / 10 min), the mass ratio of the crystalline polyamide resin to the entire resin was defined as A (mass %), the melt flow rate of the amorphous polyamide resin used at 275°C and a load of 1.2 kg was defined as VB (g / 10 min), the mass ratio of the amorphous polyamide resin to the entire resin was defined as B (mass %), and the content of reinforcing fibers was defined as C (mass %). Apparent viscosity = (VA x A / 100 + VB x B / 100) / C

[0101] [Filament evaluation] (Filament diameter stability) The diameter of 10 m of the filament wound on a spool was measured by passing it through a diameter measuring instrument (LS-9006MR, LS-9006MT, KEYENCE Corporation) at a speed of 1 m / min. The sampling interval was 5 points / sec. The maximum, minimum and average values ​​of the obtained diameters were obtained, and the maximum value was divided by the average value (maximum diameter (index)) and the minimum value was divided by the average value (minimum diameter (index)). The closer these values ​​were to 1, the more excellent the diameter stability was evaluated to be.

[0102] (Filament breakage) 10 m of the filament obtained in each example was wound on a spool with a diameter of 300 mm at 1 m / min, and the number of times the filament broke during the winding was measured. In addition, measurements were made in the same manner using a spool with a diameter of 90 mm and a spool with a diameter of 45 mm. The fewer the number of breaks, the better the filament was evaluated as being easy to handle.

[0103] [Evaluation during modeling] (Building stability) Using a 3D printer (Mark2, manufactured by Markforged), a cube with a length of 50 mm, a width of 50 mm, and a height of 50 mm was modeled at an ambient temperature of 23°C. The cube was made up of a total of 400 layers, and was modeled using the filaments obtained in each example as matrix filaments. In the example (Example 13) in which continuous fibers were used, four layers each from the upper and lower ends were modeled using filaments from polyamide resin pellets obtained as intermediate products in Example 13 as matrix filaments, and the remaining inner layers were modeled using the continuous fiber filaments finally obtained in Example 13. At this time, the number of times the filament clogged the nozzle was measured. It was evaluated that the fewer the number of cloggings, the better the modeling stability and, in turn, the better the modeling ability.

[0104] (Filament buckling) Using a 3D printer (Mark2, manufactured by Markforged), the filament obtained in each example was supplied at an environmental temperature of 23°C or 80°C. At this time, a filament supply tube capable of forming a loop with a diameter of 90 mm was prepared using a Teflon tube and attached to the 3D printer, and the number of times the filament buckled when 10 m of filament was supplied was measured. In addition, a filament supply tube capable of forming a loop with a diameter of 45 mm was prepared and measured in the same manner. The fewer the number of bucklings, the better the filament was evaluated to be in terms of ease of handling.

[0105] (Discharge stability) Using a 3D printer (Mark2, manufactured by Markforged), a cube with a length of 50 mm, a width of 50 mm, and a thickness of 50 mm was modeled at an environmental temperature of 23 ° C. The cube was composed of a total of 400 layers, and was modeled using the filaments of each example as matrix filaments. In the example (Example 13) using continuous fibers, four layers from each of the upper and lower ends were modeled using filaments from polyamide resin pellets obtained as intermediate products in Example 13 as matrix filaments, and the remaining inner layers were modeled using the continuous fiber filaments finally obtained in Example 13. The length a (mm) of the obtained cube was measured, and the value of a / 50 was calculated. The closer this value is to 1, the more stable the discharge is and the better the modeling accuracy is, that is, it was evaluated as being excellent in modeling ability.

[0106] (Compatibility with other filaments) Using the filaments of each Example, a single layer was molded with a size of 50 mm in length and 50 mm in width using a 3D printer (Mark2, manufactured by Markforged), and ten types of filaments, namely polyamide 6, polyamide 6I, polyamide 66, polyamide 12, polyamide 612, polyamide 6I / 6T, polyamide 610, polyamide 612 / 6T, polyamide 610 / 6T, and polyamide 1010, were used on top of the filaments to mold them in the same size. Of the ten types, the types of filaments that were not peeled off and were in close contact were counted, and the more types, the better the compatibility with other filaments.

[0107] [Evaluation of the modeled product] (Interlaminar shear strength) Using the filaments produced in each Example, a strip-shaped test piece having a length of 25 mm, a width of 10 mm, and a thickness of 2 mm was printed at an ambient temperature of 23° C. using a 3D printer (Mark2, manufactured by Markforged). The test piece was made up of a total of 16 layers. In the Example (Example 13) using continuous fibers, four layers each from the upper and lower ends were printed using filaments from polyamide resin pellets obtained as intermediate products in Example 13 as matrix filaments, and the remaining inner layers were printed using the continuous fiber filaments finally obtained in Example 13. The test pieces of the molded product obtained were dried in a vacuum dryer at 80°C for 18 hours or more, and then tested in an Instron universal testing machine at a speed of 1 mm / min with an R2 three-point bending jig, with a span set to thickness x 5 (mm), at 23°C and 50% RH. The stress before the first decrease in stress of 2% or more after the strain reached 0.5% or more in the stress-strain curve was taken as the interlaminar shear strength (MPa), and the average value of the five samples was calculated. The higher the average value of the interlaminar shear strength, the better the interlaminar adhesion of the molded product was evaluated to be.

[0108] (Modeling step) Using the filaments produced in each Example, a strip-shaped test piece having a length of 25 mm, a width of 10 mm, and a thickness of 2 mm was printed at an ambient temperature of 23° C. using a 3D printer (Mark2, manufactured by Markforged). The test piece was made up of a total of 16 layers. In the Example (Example 13) using continuous fibers, four layers each from the upper and lower ends were printed using filaments from polyamide resin pellets obtained as intermediate products in Example 13 as matrix filaments, and the remaining inner layers were printed using the continuous fiber filaments finally obtained in Example 13. The obtained molded product was cut at a length of 10 mm, and the obtained cross section was polished with a polishing machine (IS-POLISHER ISPP-1000, manufactured by Ikegami Seiki Co., Ltd.) under the following conditions: 5 minutes with waterproof paper #400, 10 minutes with waterproof paper #2000, 5 minutes with silicon carbide film grain size 9 μm, 5 minutes with alumina film grain size 5 μm, and 5 minutes with alumina film grain size 3 μm, so that a force of 130 g / cm2 was applied to the polished surface, and the cross section was exposed. The obtained cross section was observed and photographed at a magnification of 20 times using a microscope (digital microscope VHX-5000, manufactured by Keyence Co., Ltd.). The length along the end face in the thickness direction of the obtained image was divided by the thickness of the molded product to calculate the value, and the molded step was evaluated as the average value of N5. The closer the obtained value is to 1, the smaller the molded step, that is, the better the moldability.

[0109] (UV resistance) Using the filaments prepared in each example, a strip-shaped test piece with a length of 150 mm, a width of 70 mm, and a thickness of 1 mm was printed using a 3D printer (Mark2, manufactured by Markforged) at an environmental temperature of 23° C. The test piece was observed after irradiating for 2200 hours at a black panel temperature of 63° C. and an irradiance of 255 W / m2 using a Sunshine Weather Meter (S80, Suga Test Instruments). In terms of UV resistance, the test piece was rated as A (best) if the appearance of the irradiated surface did not change, B (good) if the irradiated surface was rough, and C (bad) if cracks were present and / or the surface was significantly deformed.

[0110] Next, the materials used in the examples and comparative examples are as follows.

[0111] [Reinforced fiber] (Carbon Fiber) Carbon fiber 1: Manufactured as 100% by mass of carbon fiber with 1000 single fibers, diameter of 7 μm, and fineness of 69 tex, to which 0.45% by mass of a surface treatment agent was attached (continuous fiber). The surface treatment agent was prepared by adjusting with deionized water so that the ratios were 1% by mass of carnauba wax as a lubricant, 2% by mass of polyamide 6 as a binder, and 2.8% by mass of a copolymer (a compound having a weight average molecular weight of 20,000, obtained by copolymerizing 18% by mass of maleic anhydride, 57% by mass of methyl acrylate, and 25% by mass of methyl methacrylate). Carbon fiber 2: Produced by cutting carbon fiber 1 to an average fiber length of 90 μm. Carbon fiber 3: Produced by cutting carbon fiber 1 to an average fiber length of 1.5 mm.

[0112] (Glass fiber) Glass fiber 1: Manufactured as 100% by mass of glass fiber with a fineness of 68 tex and 700 single yarns, with 0.45% by mass of surface treatment agent attached (continuous fiber). The winding form was DWR, and the average single yarn diameter was about 9 μm. The above surface treatment agent was prepared by adjusting with deionized water so that the ratio of γ-aminopropyltriethoxysilane (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) as a coupling agent was 0.5% by mass, carnauba wax as a lubricant was 1% by mass, polyamide 6 as a binding agent was 2% by mass, and a copolymer compound (a copolymer compound having a weight average molecular weight of 20,000, obtained by copolymerizing 18% by mass of maleic anhydride, 57% by mass of methyl acrylate, and 25% by mass of methyl methacrylate) was 2.8% by mass. Glass fiber 2: Produced by cutting glass fiber 1 to an average fiber length of 90 μm. Glass fiber 3: Produced by cutting glass fiber 1 to an average fiber length of 1.5 mm.

[0113] [Thermoplastic resin] Resin 1: Polyamide 6 (crystalline polyamide resin derived from a single monomer, melt flow rate at 275°C = 5g / 10min) Resin 2: Polyamide 6I (amorphous polyamide resin derived from a single monomer, melt flow rate at 275°C = 266g / 10min) Resin 3: Polyamide 66 (crystalline polyamide resin derived from a single monomer, melt flow rate at 275°C = 55g / 10min) Resin 4: Polyamide 12 (crystalline polyamide derived from a single monomer, melt flow rate at 275°C = 1926g / 10min) Resin 5: Polyamide 6I / 6T (amorphous polyamide derived from multiple monomers, melt flow rate at 275°C = 98g / 10min) Resin 6: Polyamide 610 / 6T (crystalline polyamide derived from multiple monomers, melt flow rate at 275°C = 203g / 10min) Resin 7: Polyamide 610 (crystalline polyamide derived from a single monomer, melt flow rate at 275°C = 101g / 10min) Resin 8: Glycol modified polyethylene terephthalate resin (melt flow rate at 275°C = 4.7g / 10min) Resin 9: Isophthalic acid copolymerized polybutylene terephthalate resin (Melt flow rate at 275°C = 21.2 g / 10 min)

[0114] [Additives] Carbon black: Vulcan (Cabot Corporation)

[0115] [Example 1] Resin 1 was used as a crystalline polyamide resin, and resin 2 was used as an amorphous polyamide resin. The polyamide resin had a mass ratio of resin 1:resin 2=74.7:25.3, and glass fiber 2 as a reinforcing fiber and carbon black were mixed by dry blending so that glass fiber 2 was 1.1 mass% relative to the total mass and carbon black was 1.0 mass% relative to the total mass. The mixture was then fed into an extruder (SRV-L40 / 30, Nippon Yuki Co., Ltd.), and the two heaters closest to the feed port were set to 260°C and the remaining heaters to 250°C, the resin pressure was set to 0.1MPa, the discharge rate was set to 4.2kg / h, and the mixture was air-cooled and pelletized under the conditions of a pellet length of 4mm. The obtained pellets were used to filamentize the filament with a diameter of 1.75mmΦ in a filament manufacturing machine (3devo). The measurement and evaluation results of the obtained filament are shown in Table 1.

[0116] [Example 2] Except for not using carbon black, a filament was obtained in the same manner as in Example 1. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0117] [Example 3] A filament was obtained in the same manner as in Example 1, except that glass fiber 3 was used as the reinforcing fiber instead of glass fiber 2. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0118] [Example 4] A filament was obtained in the same manner as in Example 1, except that the glass fiber 2 was mixed in an amount of 20 mass % relative to the total mass. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0119] [Example 5] A filament was obtained in the same manner as in Example 1, except that the same amount of carbon fiber 2 was used as the reinforcing fiber instead of glass fiber 2. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0120] [Example 6] A filament was obtained in the same manner as in Example 1, except that the same amount of carbon fiber 3 was used as the reinforcing fiber instead of glass fiber 2. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0121] [Example 7] A filament was obtained in the same manner as in Example 1, except that the same amount of Resin 3 was used instead of Resin 1. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0122] [Example 8] A filament was obtained in the same manner as in Example 1, except that the same amount of Resin 4 was used instead of Resin 1. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0123] [Example 9] A filament was obtained in the same manner as in Example 1, except that the mass ratio of resin 1 to resin 2 was resin 1:resin 2=50:50. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0124] [Example 10] A filament was obtained in the same manner as in Example 1, except that the mass ratio of resin 1 to resin 2 was resin 1:resin 2=97:3. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0125] [Example 11] A filament was obtained in the same manner as in Example 1, except that the same amount of Resin 7 was used instead of Resin 1. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0126] [Example 12] A filament was obtained in the same manner as in Example 1, except that the carbon black was mixed in an amount of 5.0% by mass relative to the total mass. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0127] [Example 13] Resin 1 was used as a crystalline polyamide resin, and resin 2 was used as an amorphous polyamide resin. The polyamide resin had a mass ratio of resin 1 to resin 2 of resin 1:resin 2=74.7:25.3, and glass fiber 2 as a reinforcing fiber and carbon black were mixed by dry blending so that glass fiber 2 was 1.1% by mass relative to the total mass and carbon black was 1.0% by mass relative to the total mass. Then, the mixture was put into an extruder (SRV-L40 / 30, Nippon Yuki Co., Ltd.), and the two heaters closest to the inlet were set to 260°C and the remaining heaters to 250°C, the resin pressure was set to 0.1MPa, the discharge rate was set to 4.2kg / h, and the mixture was air-cooled and pelletized under the conditions of a pellet length of 4mm. Next, filaments were produced using the obtained polyamide resin pellets and carbon fiber 1 (continuous fiber). Specifically, first, a cylindrical die having a hollow part with an inner diameter of 5 mm and a length of 15 cm and a nozzle with a hole of Φ0.35 mm at the tip was attached to an extruder (Filabot EX2, manufactured by Filabot). The carbon fiber 1 and the polyamide resin composition extruded from the extruder are put into the hollow part (cavity) of this die. The extrusion temperature and the die temperature were set to 270 ° C., and the polyamide resin composition and the carbon fiber 1 extruded from the die were wound to obtain a filament (continuous fiber filament, 120 m). The content of the carbon fiber 1 in the obtained filament was 40 mass %. The measurement and evaluation results of the obtained filament are shown in Table 1. As described above, in the molding in this example, the filament produced using the polyamide resin pellet obtained as an intermediate product was used as the filament on the matrix resin side.

[0128] [Comparative Example 1] A filament was obtained in the same manner as in Example 1, except that Resin 6 was used instead of Resin 1 as the crystalline polyamide, Resin 5 was used instead of Resin 2 as the amorphous polyamide, and the mass ratio of these resins was Resin 6:Resin 5=70:30. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0129] [Comparative Example 2] A filament was obtained in the same manner as in Example 1, except that only Resin 1 was used in the same amount instead of the combination of Resin 1 and Resin 2. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0130] [Comparative Example 3] A filament was obtained in the same manner as in Example 1, except that only Resin 2 was used in the same amount instead of the combination of Resin 1 and Resin 2. The measurement and evaluation results of the obtained filament are shown in Table 1.

[0131] [Comparative Example 4] Resin 8 and resin 9 were used, and the mass ratio of these resins was resin 8: resin 9 = 70: 30, and mixed by a dry blend method. Next, the mixed raw material was made into a filament with a diameter of 1.75 mmΦ using a filament manufacturing machine (3devo). The measurement and evaluation results of the obtained filament are shown in Table 1. The filament of this example corresponds to the three-dimensional modeling material described in Patent Document 2 (JP Patent Publication No. 2023-53430).

[0132] [Table 1]

[0133] From Table 1, it can be seen that the filaments of the embodiments according to the present invention have excellent handleability due to the fewer number of bends and the fewer number of bucklings during modeling, and also have excellent modeling properties due to the fewer number of times the filaments clogged the nozzle during modeling, stable extrusion, and fewer modeling steps.

[0134] In contrast, the filament of Comparative Example 1 is found to have poor handling and shaping properties at least because the polyamide resin used is derived from multiple monomers. The filament of Comparative Example 2 is found to have poor handling and shaping properties at least because the polyamide resin used is only a crystalline polyamide resin. The filament of Comparative Example 3 is found to have poor handling and shaping properties at least because the polyamide resin used is only an amorphous polyamide resin. Furthermore, the filament of Comparative Example 4, which corresponds to the prior art, is also found to have poor handling and shaping properties at least.

[0135] Furthermore, Table 1 shows that the examples according to the present invention are superior to the comparative examples in terms of filament diameter stability, compatibility with other filaments during shaping, interlayer adhesion of the shaped product, and UV resistance. [Industrial Applicability]

[0136] According to the present invention, a filament having good handling properties and shapeability can be provided, and such a filament can be used for a wide range of applications, including not only automotive applications but also space equipment such as rockets and artificial satellites.

Claims

1. A polyamide resin filament for additive manufacturing comprising polyamide resin and reinforcing fibers, The polyamide resin includes a crystalline polyamide resin derived from a single monomer and an amorphous polyamide resin derived from a single monomer. A polyamide resin filament.

2. The polyamide resin filament according to claim 1, wherein the reinforcing fibers include short fibers having an average fiber length of 1.0 mm or less.

3. The polyamide resin filament according to claim 2 , wherein the content of the short fibers is 15 mass% or less.

4. The polyamide resin filament of claim 1 , wherein the reinforcing fibers comprise continuous fibers.

5. The polyamide resin filament according to any one of claims 1 to 4, wherein the mass ratio of the crystalline polyamide resin to the amorphous polyamide resin (crystalline polyamide resin: amorphous polyamide resin) is 60:40 to 95:

5.

6. The melt flow rate of the crystalline polyamide resin at 275° C. is VA (g / 10 min), the mass ratio of the crystalline polyamide resin to the entire polyamide resin is A (mass%), the melt flow rate of the amorphous polyamide resin at 275° C. is VB (g / 10 min), the mass ratio of the amorphous polyamide resin to the entire polyamide resin is B (mass%), and the content of reinforcing fibers is C (mass%), and the following formula is used: Apparent viscosity = (VA x A / 100 + VB x B / 100) / C The polyamide resin filament according to any one of claims 1 to 3, having an apparent viscosity of 100 or less as calculated by the following formula:

7. The polyamide resin filament according to claim 1 , wherein the crystalline polyamide resin comprises polyamide 6.

8. The polyamide resin filament according to claim 1 , wherein the amorphous polyamide resin comprises polyamide 6I.

9. The polyamide resin filament according to claim 1 , wherein the reinforcing fibers are glass fibers or carbon fibers.

10. The polyamide resin filament according to claim 1 , further comprising carbon black.

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