Material for three-dimensional molding

Abstract

To provide a material for three-dimensional molding that retains a thermal property of a thermoplastic resin while excelling in molding performance in a three-dimensional printer and in a hue of a molded product.SOLUTION: In a material for three-dimensional molding comprising a resin composition containing a thermoplastic resin (A) and a non-halogen flame retardant (B), the non-halogen flame retardant (B) has a flow initiation temperature of 400°C or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a material for three-dimensional modeling, and more particularly to a material for three-dimensional modeling containing a non-halogen flame retardant. In particular, the present invention relates to a filament for material extrusion modeling and a powder for powder deposition modeling. The present invention also relates to a modeling method and a modeled product using these materials for three-dimensional modeling. [Background technology]

[0002] Today, three-dimensional printers (hereinafter sometimes referred to as "3D printers") that use various additive manufacturing methods (e.g., binder jetting, material extrusion, liquid vat photopolymerization, etc.) are available on the market. Among these, 3D printer systems using the material extrusion method (for example, a system manufactured by Stratasys Inc. in the United States) are used to extrude a fluid raw material from a nozzle part of an extrusion head to build a three-dimensional object in layers based on a computer-aided design (CAD) model. This system is becoming widely used because it is a simple system in which a raw material made of a thermoplastic resin is inserted into the extrusion head as a filament, and while being heated and melted, it is continuously extruded from the nozzle part of the extrusion head onto an XY-plane base in a chamber, and the extruded resin is deposited on and fused to an already deposited resin laminate, which solidifies as it cools. In the material extrusion method, the nozzle position relative to the base is usually raised in the Z-axis direction perpendicular to the XY plane, and the extrusion process is repeated to build a three-dimensional object similar to the CAD model. In addition, 3D printer systems using the Powder Bed Fusion method, such as those manufactured by 3D Systems in the United States, use high-power CO 2The resin powder is heated to a temperature close to its melting point using a heating means such as a laser, and melted, and used to build a three-dimensional object in layers based on a computer-aided design (CAD) model. In this case, the laser used as the heating means scans the cross section in the XY direction on the surface of the powder bed to selectively melt the powder material. From the 3D CAD data, one layer at a time can be stacked, and this process is repeated to form a laminate, resulting in a three-dimensional object. This system does not require the use of molds, can use a variety of resin powders as raw materials as long as they have a certain degree of heat resistance, and the resulting molded objects are highly reliable, making it a technology that has attracted attention in recent years.

[0003] Thermoplastic resins used in 3D printers are generally resins with relatively good moldability and fluidity, such as acrylonitrile-butadiene-styrene (ABS) resin, polypropylene resin (PP), and polylactic acid (PLA), as filament materials for 3D printers. In addition, polyamide resins such as nylon 12 and nylon 11 are widely used as materials for thermoplastic resin powders, but in recent years, polybutylene terephthalate resins have also been used as aromatic polyester resins that are less likely to absorb moisture than nylon 12 or nylon 11 and can be used to obtain molded products with high heat resistance.

[0004] 3D printers have been widely used for prototyping molded products, but in recent years, their application to functional parts for practical use has also been considered. In the case of practical use, for example, when used as components for home appliances, building materials, aircraft, automotive materials, etc., it is preferable that the molded product has high heat resistance and flame retardancy. As a study on imparting flame retardancy to thermoplastic resin materials for 3D printers, for example, Patent Document 1 discloses a method of melt-kneading a material with an oxygen index of 27 or more with a polyamide resin and pulverizing the mixture to obtain a flame-retardant powder. Patent Document 2 discloses a method for precipitating flame-retardant polymer microparticles from an oil-in-water (O / W) emulsion obtained by adding water containing an emulsifier to a flame-retardant-containing polymer solution, which is a mixture of a flame retardant, a thermoplastic resin, and an organic solvent, under stirring. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2017 / 158688 [Patent Document 2] JP 2020-7529 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above Patent Document 1, the thermoplastic resin is limited to polyamide 12, and in Patent Document 2, fine particles are precipitated from an oil-in-water (O / W) emulsion, so the particle size is small and when used in large quantities as a material for 3D printers, production takes time and effort.

[0007] In order for 3D printers to be widely used for functional parts that are also used for practical purposes, it is preferable that they can impart flame retardancy to thermoplastic resin materials other than polyamide 12, and it is also preferable that the manufacturing method for the materials be simple.

[0008] Furthermore, it is preferable to use non-halogen compounds such as phosphorus compounds as flame retardants. Conventionally, a method of blending halogen compounds, especially bromine compounds, has been generally used. However, it has been pointed out that halogen compounds are a cause of the generation of harmful gases such as dioxins when burned, and not only are there safety issues during waste incineration and thermal recycling, but the generation of harmful gases during fires may also have an adverse effect on the human body.

[0009] The present invention solves the above-mentioned problems, and aims to provide a material for three-dimensional modeling that contains a resin composition containing a thermoplastic resin and a non-halogen-based flame retardant, and that retains the thermal properties of the thermoplastic resin while exhibiting excellent modeling properties in a 3D printer and excellent color of the modeled product. [Means for solving the problem]

[0010] As a result of intensive research by the present inventors to solve the above problems, they discovered that these problems could be solved by using a non-halogen flame retardant that meets specific requirements, and thus developed the present invention.

[0011] That is, the gist of the present invention is as follows. [1] A material for three-dimensional modeling containing a resin composition, the resin composition comprising a thermoplastic resin (A) and a non-halogen-based flame retardant (B), the non-halogen-based flame retardant (B) having a flow initiation temperature of 400°C or lower. [2] The material for three-dimensional modeling according to the above [1], wherein the non-halogen flame retardant (B) is an organic phosphorus-containing compound. [3] The material for three-dimensional modeling according to the above [1] or [2], characterized in that the non-halogenated flame retardant (B) is a phosphorus-based spiro compound or a phosphate ester compound. [4] The material for three-dimensional modeling according to any one of [1] to [3] above, characterized in that it contains a non-halogenated flame retardant (B) in a ratio of 1 part by mass to 40 parts by mass per 100 parts by mass of the thermoplastic resin (A). [5] A filament for three-dimensional modeling, comprising the material for three-dimensional modeling described in any one of [1] to [4] above. [6] The filament for three-dimensional printing described in [5] above, having a filament diameter of 1.0 mm or more and 5.0 mm or less. [7] A powder for three-dimensional modeling, comprising the material for three-dimensional modeling described in any one of [1] to [4] above. [8] The powder for three-dimensional modeling according to the above item [7], having a particle size distribution D50 of 20 μm or more and 100 μm or less. [9] A molded body made of the material for three-dimensional modeling described in any one of [1] to [4] above.

[10] A molded article formed from the filament for three-dimensional modeling described in [5] or [6] above, or the powder for three-dimensional modeling described in [7] or [8] above. Effect of the Invention

[0012] According to the present invention, it is possible to provide a three-dimensional modeling material that contains a specific non-halogen flame retardant and has excellent modeling properties in a 3D printer, and a three-dimensional model made of the material.

[0013] (Why the present invention is effective) The reason why the present invention is effective is not yet clear, but it can be assumed that the reason is as follows: In other words, the three-dimensional modeling material containing the resin composition of the present invention maintains the flow characteristics of the resin composition when heated by adjusting the flow start temperature value of the non-halogen flame retardant contained in the resin composition within a specific range, so that a uniform molten state can be obtained when extruding the filament or irradiating the powder layer with a heating medium such as a laser during modeling using a 3D printer, and the desired three-dimensional modeled product can be manufactured with high accuracy. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out in various modifications within the scope of its gist.

[0015] [3D modeling materials] The three-dimensional modeling material of the present invention contains a resin composition. The resin composition will be described in detail below.

[0016] <Resin composition> The resin composition used in the three-dimensional modeling material of the present invention contains a thermoplastic resin (A) and a non-halogen flame retardant (B), and is characterized in that the flow initiation temperature of the non-halogen flame retardant (B) is 400° C. or lower. In addition, the resin composition may contain other resins, additives, reinforcing materials, etc. other than the thermoplastic resin (A) to the extent that the effects of the present invention are not impaired. The resin composition used in the three-dimensional modeling material of the present invention contains a thermoplastic resin (A) and a non-halogen flame retardant (B), and since the flow-start temperature of the non-halogen flame retardant (B) is 400° C. or less, it is believed that the present resin composition can maintain the same thermoplasticity as the thermoplastic resin (A). Since the present resin composition can maintain the same thermoplasticity as the thermoplastic resin (A), the present resin composition can impart flame retardancy to a molded product while maintaining its moldability, unlike general thermoplastic molding methods such as extrusion molding and injection molding, in three-dimensional modeling in which heat and light are directly applied to the material and a molded product is produced by layering layers based on 3D-CAD or 3D-CG data.

[0017] <Thermoplastic resin (A)> The thermoplastic resin (A) used in the present invention may be any material that exhibits thermoplasticity due to the heat or light of the 3D printer device, and may be appropriately selected depending on the function to be imparted to the molded article to be shaped. For example, polyacetal, polyacrylate, polyacrylic acid, polyamide, polyamideimide, polyacid anhydride, polyarylate, polyarylene ether, polyarylene sulfide, polybenzoxazole, polyester, polyetheretherketone, polyetherimide, polyetherketoneketone, polyetherketone, polyethersulfone, polyimide, polymethacrylate, polyolefin, polyphthalide, polysilazane, polysiloxane, polystyrene, polysulfide, polysulfonamide, polysulfonate, polythioester, polytriazine, polyurea, polyurethane, polyvinyl alcohol, polyvinyl ester, polyvinyl ether, polyvinyl halide, polyvinyl ketone, polyvinyl fluoride polyvinyl aromatic, polysulfone, polyarylene sulfonate ... Examples of the thermoplastic elastomer include polyaryletherketone, polylactic acid, polyglycolic acid, poly-3-hydroxybutyrate, polyhydroxyalkanoate, starch, cellulose ester, poly(phenylene ether), poly(methyl methacrylate), styrene-acrylonitrile, poly(ethylene oxide), epichlorohydrin polymer, polycarbonate homopolymer, copolycarbonate, poly(ester carbonate), poly(ester-siloxane-carbonate), poly(carbonate-siloxane), vinyl polymer, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), methyl methacrylate-butadiene-styrene copolymer resin (MBS resin), polyvinyl chloride, modified polyphenylene ether, olefin-based, styrene-based, and polyester-based thermoplastic elastomers. These resins may be used in combination of two or more kinds as appropriate. Furthermore, the thermoplastic resin (A) may be appropriately mixed with additives such as fillers such as carbon black, carbon fiber, glass fiber, talc, mica, nanoclay, magnesium, antioxidants, lubricants, colorants, etc.

[0018] In order to obtain a molded product having high heat resistance and flame retardancy using a 3D printer, the thermoplastic resin (A) can be selected from those having a melting point or glass transition temperature of 50°C or higher depending on the application. Specifically, vinyl polymers, polyesters (hereinafter sometimes referred to as "polyester resins"), polyamides (hereinafter sometimes referred to as "polyamide resins"), polyarylene ethers, polyarylene sulfides, polyethersulfones, polysulfones, polyether ketones, polyether ether ketones, polyurethanes, polycarbonates (hereinafter sometimes referred to as "polycarbonate resins"), polyamideimides, polyimides, polyetherimides, polyacetals, and copolymers thereof can be mentioned. Among these, polyesters, polycarbonates, and polyamides are more preferable because of their excellent processability and heat resistance.

[0019] <Polyester resin> The polyester resin used in the present invention is not particularly limited in type as long as it is a resin having an ester bond in the main chain. Examples of the polyester resin include polyester resins derived from dicarboxylic acid residues and diol residues, such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene succinate, and polybutylene succinate, polyester resins obtained by polymerizing monomers having carboxylic acid residues and alcohol residues in one molecule, such as polylactic acid and poly-ε-caprolactam, and copolymers thereof. These polyester resins may be used alone or in combination of two or more kinds.

[0020] The polyester resin used in the present invention is preferably an aromatic polyester resin from the viewpoint of thermal properties and mechanical properties, and the aromatic polyester resin may be a resin made of condensation polymerization of an aromatic dicarboxylic acid component and a diol component, and among them, one or both of the aromatic dicarboxylic acid component and the diol component are preferably made of a single compound. Among the aromatic polyester resins, polyethylene terephthalate resin, polypropylene terephthalate resin, and polybutylene terephthalate resin are preferred, polyethylene terephthalate resin and polybutylene terephthalate resin are more preferred, and polybutylene terephthalate resin (hereinafter, polybutylene terephthalate) is particularly preferred. As the polybutylene terephthalate resin, the "NovaDuran (registered trademark)" series manufactured by Mitsubishi Engineering Plastics Corporation and the like are commercially available.

[0021] <Polycarbonate resin> The polycarbonate resin used in the present invention is preferably an aromatic polycarbonate resin, but may be an aliphatic polycarbonate resin. It may be either a homopolymer or a copolymer with other copolymerizable monomers. Furthermore, the structure may be a branched structure, a straight-chain structure, or a mixture of a branched structure and a straight-chain structure. The polycarbonate resin used in the present invention may be produced by any known method such as a phosgene method, an ester exchange method, or a pyridine method.

[0022] The weight average molecular weight of the polycarbonate resin used in the present invention is usually in the range of 10,000 to 100,000, preferably 20,000 to 40,000, and particularly preferably 22,000 to 28,000. The polycarbonate resin may be used alone or in combination of two or more. If the weight average molecular weight is in the above range, impact resistance is ensured and extrusion moldability is also good, which is preferable. The weight average molecular weight was measured using GPC (HLC-8120GPC manufactured by Tosoh Corporation) and calculated in terms of polystyrene.

[0023] The polycarbonate resin used in the present invention may be a commercially available product, and specific examples of aromatic polycarbonate resins include "SD POLYCA" manufactured by Sumika Polycarbonate Co., Ltd., "Iupilon" and "NOVAREX" manufactured by Mitsubishi Engineering Plastics Corporation, and "Panlite" manufactured by Teijin Ltd. In addition, specific examples of aliphatic polycarbonate resins include "DURABIO" manufactured by Mitsubishi Chemical Corporation.

[0024] <Polyamide resin> The polyamide resin used in the present invention may be either a crystalline polyamide resin or an amorphous polyamide resin. It can be polymerized by a known method, and a commercially available product can be used. Here, examples of the polymerization method include the following methods (1) to (6). In addition, either a batch method or a continuous method can be appropriately selected. [1] A method in which an aqueous solution or suspension of a dicarboxylic acid / diamine salt or a mixture thereof is heated and polymerized while maintaining the molten state (thermal melt polymerization method). [2] A method of increasing the degree of polymerization of polyamide obtained by thermal melt polymerization while maintaining it in a solid state at a temperature below the melting point (thermal melt polymerization / solid-state polymerization method). [3] A method in which an aqueous solution or suspension of a dicarboxylic acid / diamine salt or a mixture thereof is heated, and the precipitated prepolymer is melted again in an extruder such as a kneader to increase the degree of polymerization (prepolymer extrusion polymerization method). [4] A method in which an aqueous solution or suspension of a dicarboxylic acid / diamine salt or a mixture thereof is heated, and the degree of polymerization of the precipitated prepolymer is increased while maintaining it in a solid state at a temperature below the melting point of the polyamide (prepolymer solid-state polymerization method). [5] A method in which a dicarboxylic acid / diamine salt or a mixture thereof is polymerized in one step while maintaining it in a solid state (single-step solid-state polymerization method). [6] A method of polymerization using a dicarboxylic acid halide equivalent to a dicarboxylic acid and a diamine (solution method).

[0025] The crystalline polyamide resin is not particularly limited, but specific examples include the following: polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polybis(4-aminocyclohexyl)methandecamide (polyamide PACM12), polybis(3-methyl-4-aminocyclohexyl)methandecamide (polyamide dimethyl PACM12), polynonamethylene terephthalamide (polyamide 9T), polydeca Examples of the crystalline polyamide resin include methylene terephthalamide (polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), polyundecamethylene hexahydroterephthalamide (polyamide 11T(H)), polyundecamethylene (polyamide 11), polydodecamide (polyamide 12), polytrimethylhexamethylene terephthalamide (polyamide TMDT), polyhexamethylene isophthalamide (polyamide 6I), polyhexamethylene terephthalic / isophthalamide (polyamide 6T / 6I), polymetaxylylene adipamide (polyamide MXD6), and copolymers thereof. The crystalline polyamide resin may be used alone or in combination of two or more.

[0026] The amorphous polyamide resin is preferably a polycondensate containing 30 to 70 mol %, more preferably 40 to 60 mol %, of isophthalic acid as a dicarboxylic acid component.

[0027] Examples of such polycondensates include the following: a polycondensate of isophthalic acid / α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms / metaxylylenediamine, a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine, a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane, a polycondensate of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, a polycondensate of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane, Examples of the polycondensate include a polycondensate of isophthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, a polycondensate of isophthalic acid / terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, and a polycondensate of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam. Also included are those in which the benzene ring of the terephthalic acid component and / or isophthalic acid component constituting these polycondensates is substituted with an alkyl group or a halogen atom. Furthermore, two or more of these amorphous polyamide resins can be used in combination.

[0028] Preferably, a polycondensate of isophthalic acid / α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms / metaxylylenediamine, a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane, a polycondensate of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, or a mixture of a polycondensate of isophthalic acid / terephthalic acid / hexamethylenediamine / bis(3-methyl-4-aminocyclohexyl)methane and a polycondensate of terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine is used.

[0029] The relative viscosity of the polyamide resin used in the present invention is not particularly limited, but the relative viscosity measured using 96% by mass concentrated sulfuric acid as a solvent at a temperature of 25°C and a concentration of 1 g / dl is preferably in the range of 1.5 to 5.0. This range is preferable because it provides an excellent balance of take-up properties after melt kneading, mechanical strength, moldability, etc. For these reasons, the relative viscosity is more preferably in the range of 2.0 to 4.0.

[0030] The polyamide resin used in the present invention may be a commercially available product. Specific examples of crystalline polyamide resins include those available from Daicel-Evonik Ltd. under the trade names "DAIAMID" and "VESTOSINT." Specific examples of amorphous polyamide resins include "TROGAMID" (trade name) manufactured by Daicel-Evonik Ltd. and "Selar" (trade name) manufactured by DuPont.

[0031] <Non-halogen flame retardants (B)> In this invention, the flame retardant refers to a substance that is added to flammable materials such as plastics, rubber, fibers, and wood to make them less flammable or less likely to spread flames.

[0032] The non-halogen flame retardant (B) used in the present invention is required to have a flow initiation temperature of 400° C. or less. If the flow initiation temperature exceeds 400° C., the non-halogen flame retardant (B) will not exhibit thermoplasticity when exposed to heat or light during three-dimensional modeling, and when a model (resin molded product) is modeled using a 3D printer, materials (for example, deposited strands or powders) will not bond sufficiently to each other, resulting in low interlayer adhesion in the model. The flow initiation temperature of the non-halogen flame retardant (B) is preferably 100° C. or higher, more preferably 120° C. or higher, from the viewpoint of heat resistance of the molded article to which flame retardancy is to be imparted, and is preferably 350° C. or lower, more preferably 300° C. or lower, from the viewpoint of processability.

[0033] As the non-halogen flame retardant (B) used in the present invention, various known ones can be used, including phosphorus-based organic flame retardants (organic phosphorus-containing compounds), nitrogen-based organic flame retardants (melamine cyanurate, triazine compounds, guanidine compounds), silicon-based organic flame retardants (silicon polymers), etc. These non-halogen flame retardants may be used by mixing two or more kinds as appropriate. Furthermore, the non-halogen flame retardant (B) may be appropriately mixed with additives such as flame retardancy-improving resins such as phenolic resins, epoxy resins, or styrene-based resins, anti-dripping agents such as polytetrafluoroethylene (PTFE) particles, and fillers. Furthermore, the non-halogen flame retardant (B) may be an inorganic flame retardant, so long as it has a flow-initiation temperature of 400° C. or lower.

[0034] Among these, phosphorus-based organic flame retardants (organic phosphorus-containing compounds) are preferred because they have excellent radical trapping effect and oxidation reaction suppression effect. Examples of organic phosphorus-containing compounds are not particularly limited, but include carboxymethylphenyl phosphate, (2-carboxyethyl)phenyl phosphate, (2-carboxyethyl)toluyl phosphate, (2-carboxyethyl)2,5-dimethylphenyl phosphate, (2-carboxyethyl)cyclohexyl phosphate, (carboxypropyl)phenyl phosphate, (4-carboxyphenyl)phenyl phosphate, (3-carboxyphenyl)phenyl phosphate, (2-carboxyethyl)methyl phosphate, (2-carboxyethyl)ethyl phosphate, triphenyl phosphate, tributyl phosphate, t-butyl diphenyl phosphate, tris(2-ethylhexyl)phosphate, bisphenol A bis(diphenyl phosphate)-1.3-phenyl bis(diphenyl phosphate), phosphoric acid diphenyl ester and other phosphoric acid ester compounds, phosphorus spiro compounds, etc. In the present invention, from the viewpoint of flame retardancy and thermal properties, it is preferable to use a phosphate ester compound or a phosphorus-based spiro compound, and it is more preferable to use a phosphorus-based spiro compound.

[0035] Commercially available phosphorus spiro compounds include, but are not limited to, Fireguard FCX-210 manufactured by Teijin Ltd. Commercially available phosphate esters include, but are not limited to, Nofia HM1100 manufactured by FRX.

[0036] The amount of the non-halogen flame retardant (B) used may be selected so as to satisfy sufficient flame retardancy and physical properties required in the scene of use, and specifically, from the viewpoint of imparting flame retardancy, it is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin (A). Also, from the viewpoint of moldability, it is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0037] <Flame retardant synergist> The resin composition according to the present invention may contain a flame retardant assistant. The flame retardant assistant is not particularly limited as long as it improves flame retardancy by combining with the flame retardant. For example, fluorine-based flame retardant assistant, phosphate ester-based flame retardant assistant, nitrogen-based flame retardant assistant, etc. are mentioned. Among these, fluorine-based flame retardant assistant is preferable, fluoroolefin resin is preferable, and tetrafluoroethylene resin can be exemplified. The fluorine-based flame retardant assistant may be in any form such as powder or dispersion, or powder in which a fluororesin is coated with another resin. The content of the flame retardant auxiliary is preferably in the range of 0.001 to 1 part by mass, and more preferably in the range of 0.01 to 0.5 parts by mass, based on 100 parts by mass of the flame retardant.

[0038] <Other ingredients> In the present invention, the resin composition of the present invention may contain additives that are generally blended as appropriate within the range that does not significantly impair the effects of the present invention. Examples of the additives include inorganic particles such as silica, alumina, and kaolin, organic particles such as acrylic resin particles and melamine resin particles, pigments such as titanium oxide and carbon black, weather resistance stabilizers, heat resistance stabilizers, antistatic agents, melt viscosity improvers, crosslinking agents, lubricants, nucleating agents, plasticizers, antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, neutralizers, antifogging agents, antiblocking agents, slip agents, and colorants, which are added for the purpose of improving and adjusting the modeling properties, the stability of the three-dimensional model, and various physical properties of the three-dimensional model.

[0039] The content of the additive in the resin composition of the present invention is not particularly specified, but from the viewpoint of the stability of the 3D modeling material and the 3D model to be produced, it is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.08 parts by mass or more, and particularly preferably 0.1 parts by mass or more, relative to 100 parts by mass of the 3D modeling material in total. Also, from the viewpoint of suppressing a decrease in interlayer adhesion of the 3D model to be produced, the upper limit of the content of the additive is preferably 30 parts by mass or less, more preferably 28 parts by mass or less, and even more preferably 25 parts by mass or less.

[0040] Furthermore, in addition to the above-mentioned components, the resin composition of the present invention may appropriately contain a reinforcing material that is generally blended within a range that does not significantly impair the effects of the present invention. Specific examples of reinforcing materials include inorganic fillers and inorganic fibers. Specific examples of inorganic fillers include calcium carbonate, zinc carbonate, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, potassium titanate, glass balloons, glass flakes, glass powder, silicon carbide, silicon nitride, boron nitride, gypsum, calcined kaolin, zinc oxide, antimony trioxide, zeolite, hydrotalcite, wollastonite, silica, talc, metal powder, alumina, graphite, carbon black, and carbon nanotubes. Specific examples of inorganic fibers include glass cut fibers, glass milled fibers, glass fibers, gypsum whiskers, metal fibers, metal whiskers, ceramic whiskers, carbon fibers, and cellulose nanofibers.

[0041] Here, the content of the reinforcing material is not particularly specified, but from the viewpoint of the strength of the three-dimensional object to be produced, the content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the total material for three-dimensional printing. Also, from the viewpoint of suppressing a decrease in interlayer adhesion of the three-dimensional object to be produced, the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0042] The resin composition used in the present invention can be produced by adding and mixing the thermoplastic resin (A), the non-halogen flame retardant (B), and the other components described above. The method for producing the resin composition is not particularly limited as long as it contains each component. For example, the thermoplastic resin (A) and other components such as additives that are mixed as necessary are premixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder, kneader, or the like to produce the resin composition of the present invention. When the material for three-dimensional modeling is used in the form of powder or pellets, the non-halogenated flame retardant (B), inorganic particles, organic particles, and reinforcing materials may be mixed with the powder produced by the method described below and formulated as a powder mixture without being kneaded with the thermoplastic resin (A) and additives, etc.

[0043] <3D modeling materials> The three-dimensional modeling material of the present invention is a material used for modeling a three-dimensional object (resin molded body) by a 3D printer. The three-dimensional modeling material may be composed of the above-mentioned resin composition for three-dimensional modeling alone, that is, may have a single-layer structure composed of a single resin layer composed of the above-mentioned resin composition for three-dimensional modeling. The three-dimensional modeling material of the present invention may also have a multi-layer structure including at least a resin layer composed of the above-mentioned resin composition for three-dimensional modeling.

[0044] The shape of the material for 3D modeling may be any shape that can be applied to various types of 3D printers such as fused deposition modeling (ME), powder bed fusion (PBF), multi-jet fusion, etc. Specific shapes of the material for 3D modeling include powder, pellets, granules, filaments, etc.

[0045] <Filament for 3D modeling> The filament for three-dimensional modeling of the present invention may be used as either a modeling material or a supporting material, which are roughly classified as raw materials used in the material extrusion method, but it is preferable to use it as a modeling material. Note that the modeling material is the main body of the model, and the supporting material is what supports the layered modeling material until it hardens into the desired shape.

[0046] <Method of manufacturing filaments for 3D modeling> The filament for three-dimensional modeling of the present invention is produced by melt-kneading a thermoplastic resin (A) and a non-halogen flame retardant (B). The kneading method is not particularly limited, and known methods, for example, melt-kneading devices such as a single-screw extruder, a multi-screw extruder, a Banbury mixer, and a kneader, can be used. In the present invention, it is preferable to use a co-rotating twin-screw extruder from the viewpoint of dispersibility and miscibility of each component. Excellent dispersibility and miscibility are preferable because they can increase the accuracy and roundness of the filament diameter.

[0047] The method for producing the filament for three-dimensional shaping of the present invention is not particularly limited, but it can be obtained by a method of molding the thermoplastic resin (A), the non-halogen-based flame retardant (B), etc., by a known molding method such as extrusion molding. For example, when the filament for three-dimensional shaping of the present invention is obtained by extrusion molding, the conditions are appropriately adjusted depending on the flow characteristics and molding processability of the thermoplastic resin (A) and the non-halogen-based flame retardant (B) used, but are usually 200 to 400°C, preferably 220 to 350°C.

[0048] <Physical properties of filaments for 3D modeling> The diameter of the filament for three-dimensional modeling of the present invention depends on the specifications of the system used for molding a resin molded body by the material extrusion method, but is usually 1.0 mm or more, preferably 1.5 mm or more, more preferably 1.6 mm or more, and particularly preferably 1.7 mm or more, while the upper limit is 5.0 mm or less, preferably 4.0 mm or less, more preferably 3.5 mm or less, and particularly preferably 3.0 mm or less. Furthermore, it is preferable from the viewpoint of stability of raw material supply that the accuracy of the diameter is within an error of ±5% for any measurement point of the filament. In particular, it is preferable that the standard deviation of the diameter of the filament for three-dimensional modeling of the present invention is 0.07 mm or less, particularly 0.06 mm or less.

[0049] In addition, the filament for three-dimensional printing of the present invention preferably has a circularity of 0.93 or more, particularly 0.95 or more. The upper limit of the circularity is 1.0. In this way, if the filament for three-dimensional printing has a small standard deviation of the diameter and a high circularity, uneven discharge during printing can be suppressed, and a resin molded product with excellent appearance and surface properties can be stably produced. By using the above-mentioned resin composition, a filament for three-dimensional printing that satisfies such standard deviation and circularity can be relatively easily produced.

[0050] <3D modeling powder> The powder for three-dimensional modeling of the present invention is a modeling material used in powder bed fusion (PBF) system. The production method, physical properties, etc. of the powder for three-dimensional modeling will be described in detail below.

[0051] <Method of manufacturing powder for 3D modeling> The powdering means for producing the powder for three-dimensional modeling of the present invention include melt granulation, in which the resin composition of the present invention melted near the melting point is made into a fibrous form and then cut, and pulverization, in which the resin composition of the present invention is cut or destroyed by applying impact or shear. In order to improve the coatability of the powder in powder layered modeling, it is preferable that the powder does not contain fine powder of about 10 μm and has a certain particle size and particle size distribution, so that a suitable powder method is selected to obtain powder of such a suitable shape.

[0052] As the pulverizing means, for example, a stamp mill, a ring mill, a stone mill, a mortar, a roller mill, a jet mill, a high-speed rotary mill, a hammer mill, a pin mill, a container-driven mill, a disk mill, a media stirring mill, or the like can be used.

[0053] In addition, in order to prevent the resin material from stretching due to shear heat during grinding, there is a method in which the resin temperature during grinding is lowered by cooling the powder system with liquid nitrogen or the like, and powder is produced by brittle fracture rather than ductile fracture. This is called low-temperature grinding or freeze grinding. Among them, it is preferable to use a high-speed rotary mill for pulverization, which can obtain powder with a particle size distribution and shape suitable for powder additive manufacturing, because this improves the flowability and powder application properties during pulverization. In addition, it is preferable to use liquid nitrogen to produce powder by brittle fracture of the resin material, in order to suppress changes in the physical properties and color of the resin material due to pulverization.

[0054] In addition, from the viewpoint of removing elongated powder from the pulverized powder to increase the circularity and from the viewpoint of removing fine powder to prevent the powder from flying up during handling, it is preferable to carry out a classification process after pulverization. In this case, classification methods include air classification, sieve classification, etc. In addition, the above-mentioned inorganic particles and reinforcing materials may be added to the obtained powder as necessary.

[0055] <Physical properties of powders for 3D modeling> When used as a material for powder bed fusion (PBF), D50, which accounts for 50% by volume of the powder particle size distribution, depends on the specifications of the system used to mold resin molded bodies by powder bed fusion (PBF), but from the viewpoint of applying the powder to a thickness within a specified range during molding, it is preferably 20 μm or more, more preferably 30 μm or more, even more preferably 40 μm or more, particularly preferably 50 μm or more, and most preferably 55 μm or more, and is preferably 100 μm or less, more preferably 80 μm or less, even more preferably 75 μm or less, and particularly preferably 70 μm or less.

[0056] The above D50 is determined by weighing out 5 g of powder and measuring the powder particle size distribution (volume basis) using a particle size distribution measuring device (HORIBA, LA-960). The particle size at 50% of the frequency distribution of the powder among the detected particle size distribution is determined as D50.

[0057] [Molded body] The molded article of the present invention is made of the above-mentioned material for three-dimensional modeling. As a method for producing the molded article, it is preferable to use a three-dimensional printer for molding. The detailed production method will be described below.

[0058] <Manufacturing method for 3D objects> In the method for producing a molded product made of the material for three-dimensional modeling of the present invention, the material for three-dimensional modeling of the present invention is used and molded by a three-dimensional printer to obtain a resin molded product. Examples of molding methods using a three-dimensional printer include the material extrusion method (ME method), powder sintering method (PBF method, SLS method), inkjet method, and stereolithography method (SLA method). Among them, it is preferable to use the material extrusion method (ME method) and powder sintering method (PBF method) in which a molded product is produced by melting a thermoplastic resin.

[0059] The material extrusion method (ME method) is a method in which a filament-like resin composition that has been melted or softened at high temperature is extruded from a nozzle and arranged in a planar shape, forming layers that are divided in the height direction to obtain a molded product. In the powder sintering method (PBF method), a laser or an electron beam is irradiated to particles of a resin composition spread on a stage to sinter or fuse the particles and form a layer in the height direction. Next, the particles of the resin composition are spread in contact with the layer formed above and irradiated with a laser or an electron beam to form the next layer. By stacking layers in this way, a molded body of a desired shape can be obtained. EXAMPLES

[0060] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples as long as it does not depart from the gist of the present invention.

[0061] <Physical property measurement method> (flow start temperature) The flow starting temperature of the flame retardant (B) was measured by the following method. Using a Shimadzu Corporation high-performance flow tester (product name: Flow Tester CFT-500C), 1.0 g of the measurement sample was heated at a constant rate of 3°C / min using a nozzle (inner diameter 1 mm, length 2 mm) and a load of 40 kg / cm. 2 When the measurement was performed under the above conditions, the temperature at which the measurement sample started to flow from the nozzle was measured, and this was determined as the flow initiation temperature.

[0062] (Melting point Tm) The melting point (Tm) or glass transition temperature (Tg) of the flame retardant (B) and the resin composition was measured by the following method. Using a differential scanning calorimeter manufactured by PerkinElmer Co., Ltd., product name "Pyris1 DSC", in accordance with JIS K7121, about 10 mg of powder sample was heated from room temperature to the crystal melting temperature (melting point Tm) + 20 ° C. at a heating rate of 10 ° C. / min, held at that temperature for 1 minute, cooled to 30 ° C. at a cooling rate of 10 ° C. / min, and then heated again to 280 ° C. at a heating rate of 10 ° C. / min. The crystal melting temperature (melting point Tm) (° C.) (reheating process) was obtained from the thermogram measured when. Each value was rounded to one decimal place.

[0063] (glass transition temperature Tg) Using a differential scanning calorimeter manufactured by PerkinElmer Co., Ltd., trade name "Pyris1 DSC", in accordance with JIS K7121, approximately 10 mg of a sample was heated from 0°C to 250°C at a heating rate of 10°C / min, held at that temperature for 1 minute, cooled to 0°C at a cooling rate of 10°C / min, and then heated again to 250°C at a heating rate of 10°C / min. From the thermograms measured at these times, the glass transition temperature (Tg) (°C) (reheating process) was determined.

[0064] (Color) When the thermoplastic resin (A) and the non-halogen flame retardant (B) were compounded, the color of the resulting resin composition pellets was visually observed and evaluated according to the following criteria. Evaluation criteria A: Shows the same whiteness as thermoplastic resin (A) alone B: Thermoplastic resin (A) is yellowish in color than the resin alone.

[0065] (particle size distribution) 5 g of powder material was weighed out, and the particle size distribution of the powder was measured on a volume basis using a particle size distribution measuring device (Microtec Co., Ltd.). The particle size D50 at 50% of the frequency distribution of the powder was obtained from the detected particle size distribution, and the particle size distribution was evaluated according to the following criteria. A: D50 is less than 100 μm B: D50 is 100μm or more

[0066] (Formability) Using a powder bed fusion printer Lisa Pro (Sinterit), the printing area (Print bed) was set to a temperature above the crystallization temperature and below the crystal melting temperature of the powder sample, and the material supply area (Feed bed) was set to a temperature above the crystallization temperature of the powder sample, and a 1BA type tensile test piece conforming to JIS K7161 was produced with a layer pitch of 0.125 mm, and the presence or absence of molding defects was checked by visual observation. The moldability was evaluated according to the following criteria. A: It is possible to model the object, and the mechanical properties can be evaluated using the obtained sample. B: Can be molded, but very fragile C: Cannot be modeled

[0067] (comprehensive evaluation) The above-mentioned color tone, particle size distribution and moldability were evaluated according to the following criteria. A: The formative evaluation is "B" or higher, and at least one of the following is "A". However, none of the evaluations is "B". B: The formative evaluation is "B" or higher, but not "C". C: Formability rating is "C"

[0068] [Example 1] A compound was prepared by adding 15 parts by mass of Fireguard FCX-210 (manufactured by Teijin) (B-1) as a non-halogen flame retardant to 100 parts by mass of polybutylene terephthalate (A-1) (Tm: 195°C, ΔHc: 34.6 J / g). The compound was then powdered by freeze-pulverization using liquid nitrogen and high-speed rotary pulverization. The resulting powder was made into 100 parts by mass, and 0.3 parts by mass of alumina particles (Alu CRK, manufactured by AEROSIL, average particle size 20 nm) as a flow aid and 0.3 parts by mass of carbon powder (Fine Powder SGP-10, manufactured by SEC Carbon, average particle size 10 μm) as an electromagnetic wave absorber were added to the powder, and a moldability evaluation was performed. Table 1 shows the non-halogen flame retardants used and the evaluation results of the properties, color, particle size distribution, and moldability of the obtained powder.

[0069] [Example 2] A powder was prepared in the same manner as in Example 1, except that 0.2 parts by mass of IT-1105-D (manufactured by ITAFlon) (C-1) was further added as an anti-dripping agent when compounding polybutylene terephthalate (A-1) and Fireguard FCX-210 (B-1), and various evaluations were performed.

[0070] [Example 3] Polybutylene terephthalate (A-1) (Tm: 195°C, ΔHc: 34.6 J / g) is powdered by freeze-pulverization using liquid nitrogen and high-speed rotary pulverization, and 15 parts by mass of Fireguard FCX-210 (B-1) as a non-halogen flame retardant is added to 100 parts by mass of the obtained powder and dry-blended to produce a powder. The composition of the obtained powder is the same as that of Example 1, and the color and moldability of the powder are similar. The results of various evaluations are shown in Table 1.

[0071] [Example 4] Powder was prepared in the same manner as in Example 1, except that Nofia HM1100 (manufactured by FRX Polymers) (B-2) was used as a non-halogen flame retardant instead of Fireguard FCX-210 (B-1), and various evaluations were performed.

[0072] [Comparative Example 1] A powder was prepared in the same manner as in Example 1, except that 7 parts by mass of Exolit AP422 (manufactured by Clariant) (B-3) was used as a non-halogen flame retardant instead of Fireguard FCX-210 (B-1), and various evaluations were performed.

[0073] [Comparative Example 2] A powder was prepared in the same manner as in Example 1, except that 10 parts by mass of Exolit OP1240 (manufactured by Clariant) (B-4) was used as a non-halogen flame retardant instead of Fireguard FCX-210 (B-1), and various evaluations were performed.

[0074] [Comparative Example 3] Powder is prepared in the same manner as in Example 3, except that Exolit OP1240 (manufactured by Clariant) (B-4) is used as a non-halogen flame retardant instead of Fireguard FCX-210 (B-1), and various evaluations are performed.

[0075] As is clear from the above results, if the flow initiation temperature of the non-halogenated flame retardant is 400°C or lower, it is possible to provide a material for 3D modeling that retains the thermal properties of thermoplastic resin while providing excellent modeling properties in 3D printers and excellent color of the modeled products.

[0076] [Table 1] [Industrial Applicability]

[0077] The three-dimensional modeling material of the present invention can provide a three-dimensional modeling material that retains the thermal properties of thermoplastic resin while exhibiting excellent modeling properties in 3D printers and excellent color in the modeled products. The material can be used not only for prototypes, but also for practical applications such as components for home appliances, building materials, aircraft, and automotive materials.

Claims

1. A material for three-dimensional modeling containing a resin composition, the resin composition comprising a thermoplastic resin (A) and a non-halogen-based flame retardant (B), the non-halogen-based flame retardant (B) having a flow initiation temperature of 400°C or lower.

2. The material for three-dimensional printing according to claim 1 , wherein the non-halogen flame retardant (B) is an organic phosphorus-containing compound.

3. 3. The material for three-dimensional modeling according to claim 1, wherein the non-halogen-based flame retardant (B) is a phosphorus-based spiro compound or a phosphoric acid ester compound.

4. The material for three-dimensional printing according to claim 1 , further comprising a non-halogenated flame retardant (B) in an amount of 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the thermoplastic resin (A).

5. A filament for three-dimensional modeling, comprising the material for three-dimensional modeling according to claim 1 .

6. The filament for three-dimensional modeling according to claim 5 , wherein the filament diameter is 1.0 mm or more and 5.0 mm or less.

7. A powder for three-dimensional modeling, comprising the material for three-dimensional modeling according to claim 1 .

8. The powder for three-dimensional modeling according to claim 7, wherein the particle size distribution D50 is 20 μm or more and 100 μm or less.

9. A molded body made of the material for three-dimensional modeling according to claim 1 .

10. A molded article formed from the filament for three-dimensional modeling according to claim 5 or 6, or the powder for three-dimensional modeling according to claim 7 or 8.

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