Flame-retardant polyamide-based 3D printing extrusion material

Abstract

The present invention relates to a flame-retardant, smoke-suppressed, and toxicity-suppressed (FST) polyamide thermoplastic material useful for 3D printing, comprising at least one non-halogenated organic flame retardant in combination with at least one particulate inorganic flame retardant. Furthermore, the present invention refers to the use of such FST polyamide thermoplastic material in 3D printing. The present invention further relates to a method for preparing a three-dimensional molded article by 3D printing based on such FST polyamide thermoplastic material.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to a flame retardant, smoke suppressant, and toxicity suppressant (FST) polyamide thermoplastic material useful for 3D printing, comprising at least one non-halogenated organic flame retardant in combination with at least one particulate inorganic flame retardant. Furthermore, the present invention refers to the use of such FST polyamide thermoplastic material in 3D printing. The present invention further relates to a method for preparing a three-dimensional molded article by 3D printing based on such FST polyamide thermoplastic material.

[0002] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 62 / 896,763, filed September 6, 2019, and U.S. Provisional Patent Application No. 62 / 978,316, filed February 19, 2020, the entire contents of both of which are incorporated by reference in their entireties as if fully set forth herein.

[0003] [background] There is a wide range of commercially available products that are at least partially composed of various types of thermoplastic materials. Polyamides, such as nylon compositions, are used to manufacture many different products.

[0004] The mechanical properties of thermoplastics, including polyamides, can be enhanced by the addition of reinforcing materials such as glass fibers (e.g., as described in U.S. Patent Application Publication No. 2018 / 244899) and / or may be added with one or more fillers. However, the utility of most thermoplastics, including polyamide thermoplastics, is often limited by flammability.

[0005] Therefore, it has been considered to provide polyamide thermoplastics with flame retardants such as phosphorus agents. EP 3127937 and US 2018 / 244899 describe flame-retardant polyamide thermoplastics containing dialkyl phosphinates and / or diphosphinates as flame retardants. EP 3127937 describes that such flame-retardant polyamide thermoplastics may even be useful in sensitive applications such as railway parts. Even the flame retardant, smoke suppression, and toxicity suppression (FST) requirements of industrial standards EN 45545-2 and NFPA 131 are met. Some compositions may also meet the requirements of aerospace applications such as FAR 25.853.

[0006] US Pat. No. 7,317,044 describes phosphonate flame retardants in relation to nylon compositions.

[0007] EP 2318460 describes nylon fibers and nylon carpets with flame retardant compositions preferably containing clay and inorganic bromine-based compounds. EP 1576073 indicates that the use of phosphorus agents is undesirable, and instead describes flame retardant compositions containing inorganic-organic hybrids, which may be clay.

[0008] The technical drawback of the above flame retardants is that they may cause undesirably high smoke generation and may impair surface quality and / or processability. In particular, phosphorus flame retardants such as dialkylphosphinates and / or diphosphinates often tend to generate significant amounts of smoke at very high temperatures. In recent years, 3D printing has become increasingly interesting in the manufacture of products from thermoplastic materials. This makes it even more challenging to prepare products with the desired surface properties that maintain mechanical strength and flame retardancy. In particular, reducing smoke generation is even more challenging.

[0009] There remains an unmet need to provide polyamide materials suitable for 3D printing applications that may optionally be reinforced, while at the same time having good surface quality, being flame retardant, and producing reduced smoke upon heating.

[0010] The inventors have surprisingly found that a combination of a non-halogenated organic flame retardant and a particulate inorganic flame retardant leads to particularly good results in terms of flame retardancy, smoke suppression and toxicity suppression of polyamide thermoplastic materials, thereby resulting in flame retardant, smoke suppressed and toxicity suppressed (FST) reinforced or filled polyamide thermoplastic materials that are particularly useful for 3D printing.

[0011] [Brief Overview] The present invention therefore relates to a flame retardant, smoke suppressant, and toxicity suppressant (FST) polyamide thermoplastic material useful for 3D printing, comprising at least one non-halogenated organic flame retardant in combination with at least one particulate inorganic flame retardant. Furthermore, the present invention refers to the use of such FST polyamide thermoplastic material in 3D printing. The present invention further relates to a method for preparing a three-dimensional molded article by 3D printing based on such FST polyamide thermoplastic material.

[0012] [Detailed Description] A first aspect is a thermoplastic material useful for 3D printing, comprising: (A) at least one polyamide as component A; (B) at least one non-halogenated organic flame retardant as component B; (C) at least one particulate inorganic flame retardant as component C; (D) optionally, one or more reinforcing or filler materials as component D; (E) optionally, as component E, one or more polymer additives selected from the group consisting of stabilizers, antioxidants, dyes, pigments, release agents, fillers, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives (e.g., metals, carbon, etc.), insulating additives, anti-drip agents, additional flame retardants, and combinations of two or more thereof; "thermoplastic material" refers to a thermoplastic material comprising, consisting of, or consisting essentially of.

[0013] Those skilled in the art are aware of a wide variety of such additives. For example, the stabilizer may be selected from Nylostab® S-EED®, Hostanox® P-EPQ®, and combinations thereof. Color components may also be optionally introduced by masterbatches, such as those including black polyamide 6. It will be understood that these components may be added with or without a masterbatch.

[0014] As used herein, the term "3D printing" can be understood in its broadest sense as any process of constructing a three-dimensional (3D) object from a computer-aided design (CAD) model, from a scan or other information, or by 3D drawing / painting, or any other means for generating a specific 3D shape. Typically, but not necessarily, 3D printing is performed by adding material layer by layer, which is sometimes referred to as additive manufacturing. 3D printing can be distinguished from casting, forging, milling, and traditional machining processes.

[0015] In an embodiment of the present invention, 3D printing is 3D printing based on material extrusion (e.g. Fused Deposition Modeling (FDM), Composite Filament Fabrication (CFF), or Fused Filament Fabrication (FFF), or Fused Pellet Fabrication, or Fused Particle Fabrication), Powder-bed based 3D printing, also known as "powder bed fusion" (e.g. powder bed and inkjet head 3D printing (3DP), selective heat sintering (SHS), or selective laser sintering (SLS)); 3D printing based on thin-film deposition modeling (LOM) (also known as sheet deposition); 3D printing based on jetting methods (e.g., material jetting or binder jetting), and 3D printing based on radiation-induced polymerization, such as photopolymerization (e.g., stereolithography (SLA), computed axis lithography, digital light processing (DLP), continuous liquid interface manufacturing (CLIP), or directed energy deposition (DED)) may be selected from the group consisting of:

[0016] In an embodiment of the invention, the 3D printing is material extrusion (e.g., Fused Deposition Modeling (FDM), Composite Filament Fabrication (CFF), or Fused Filament Fabrication (FFF), or Fused Pellet Fabrication, or Fused Particle Fabrication).

[0017] In an embodiment of the invention, the 3D printing is as described in WO 2018 / 132157, including the use of an electric field applicator in the print head. Such 3D printing based on material extrusion also includes methods such as those including the use of an electric field applicator in the print head as described in WO 2018 / 132157. In an embodiment of the invention, the 3D printing is as described in WO 2018 / 132157, including the use of an electric field applicator in the print head.

[0018] As used herein, the term "thermoplastic material" can be understood in its broadest sense as a polymeric material that becomes flexible, plastic, or moldable at high temperatures and solidifies upon cooling. Typically, the physical properties of a thermoplastic material change significantly without a phase change at temperatures above its glass transition temperature (Tg) and below its melting point. Typically, it becomes flexible, plastic, or moldable in this temperature range. In the context of the present invention, this temperature range in which a thermoplastic material has significantly increased plasticity can be in the range of 100-360°C, 110-350°C, 120-340°C, 130-330°C, 140-320°C, 145-310°C, 150-320°C, 155-310°C, 160-300°C, in the range of 170-290°C, in the range of 180-280°C, in the range of 190-270°C, in the range of 200-260°C, in the range of 200-260°C. Such temperature ranges may also be used as processing temperatures. The terms "feed" and "material" may be used interchangeably herein.

[0019] Typically, components A, B, C, D, and E are each different from each other.

[0020] In an embodiment of the invention, materials useful for 3D printing of the invention meet the flame retardant, smoke suppressant, and toxicity suppressant (FST) requirements of industry standards EN 45545-2 and NFPA 131. As used herein, industry standards refer to the actual September 2019 versions.

[0021] In an embodiment of the invention, the polyamide (PA) component (component A) is the major component of the material useful for 3D printing, i.e., it constitutes at least 40% by weight of the material for 3D printing.

[0022] As used herein, the term "polyamide" and its abbreviation "PA" can be understood in the broadest sense as any macromolecule having at least four units linked by amide bonds (#-NH-CO-# and / or #-CO-NH-#, respectively, i.e., in the same or different orientation(s), where each # is independently a bond site to the remainder of the polyamide or a capping group at the end of the polyamide). Typically, polyamides have more than 10, more than 50, more than 100, more than 500, more than 1000, more than 5000, more than 10000 units linked by amide bonds. Thus, component A may be any polyamide (PA), or a copolymer and / or blend of two or more thereof. Polyamides may contain one or more aliphatic monomers, one or more aromatic monomers, or combinations of two or more thereof (e.g., as alternating two or more monomers (e.g., as semi-aromatic alternating aromatic and aliphatic monomers), as random polymers, as block polymers, or as combinations of two or more thereof). Polyamides as used herein may be crystalline, partially crystalline, or amorphous.

[0023] Typically, the monomers or polyamides used herein have a molecular weight of less than 500 Daltons (Da), often less than 250 Da. The aliphatic monomers may contain, for example, a molecular residue selected from the group consisting of linear alkylene, branched alkylene, cycloalkylene, and combinations of two or more thereof. The aliphatic monomers may be unsubstituted or substituted with one or more halogens (e.g., F, Cl, Br, and / or I), alkyloxy groups (e.g., methoxy), amino groups, carboxy groups, and the like.

[0024] The polyamide may be an aliphatic polyamide, a semi-aromatic polyamide (e.g., polyphthalamide), an aromatic polyamide (aramid), or a blend of two or more thereof. In an embodiment of the invention, the polyamide is composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of one monomer. In another embodiment of the invention, the polyamide is composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of two monomers. In yet a further embodiment of the invention, the polyamide is composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of at least three monomers.

[0025] In an embodiment of the present invention, the polyamide is an aliphatic polyamide. In an embodiment of the present invention, the polyamide is an aliphatic polyamide composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of one monomer. In another embodiment of the present invention, the polyamide is an aliphatic polyamide composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of two monomers. In yet a further embodiment of the present invention, the polyamide is an aliphatic polyamide composed of at least 98% by weight, at least 99%, at least 99.9%, or 100% by weight of at least three monomers.

[0026] In an embodiment of the invention, the polyamide is (a) General formula #-NH-R a -CO-# (a) One or more monomeric moieties of (b) General formula #-CO-R b1 -CO-# (b1) and #-NH-R b2 -NH-# (b2) and a combination of one or more monomer moieties of (c) a combination of species of monomer moieties (a) and (b); containing or consisting essentially of one or more monomers selected from the group consisting of: R a is linear or branched C1-C 20 -Alkylene, C5~C 10 -Cycloalkylene, linear or branched C1-C 20 -Alkenylene, C5-C 10 -Cycloalkenylene, C6-C 10 -Arylene, linear or branched C1-C 20 -Heteroalkylene, C5-C 10 -Heterocycloalkylene, linear or branched C1-C 20 -Heteroalkenylene, C5-C 10 -Heterocycloalkenylene, C6-C 10 -heteroarylene, and combinations of two or three thereof; R a is optionally substituted with one or more halogens, one or more alkyloxy groups, one or more amino groups, or one or more carboxy groups; R b1 is linear or branched C1-C 20 -Alkylene, C5~C 10 -Cycloalkylene, linear or branched C1-C 20 -Alkenylene, C5-C 10 -Cycloalkenylene, C6-C 10 -Arylene, linear or branched C1-C 20 -Heteroalkylene, C5-C 10 -Heterocycloalkylene, linear or branched C1-C 20 -Heteroalkenylene, C5-C 10 -Heterocycloalkenylene, C6-C 10 -heteroarylene, and combinations of two or three thereof; R b1 is optionally substituted with one or more halogens, one or more alkyloxy groups, one or more amino groups, or one or more carboxy groups; R b2 is linear or branched C1-C20 -Alkylene, C5~C 10 -Cycloalkylene, linear or branched C1-C 20 -Alkenylene, C5-C 10 -Cycloalkenylene, C6-C 10 -Arylene, linear or branched C1-C 20 -Heteroalkylene, C5-C 10 -Heterocycloalkylene, linear or branched C1-C 20 -Heteroalkenylene, C5-C 10 -Heterocycloalkenylene, C6-C 10 -heteroarylene, and combinations of two or three thereof; R b2 is optionally substituted with one or more halogens, one or more alkyloxy groups, one or more amino groups, or one or more carboxy groups; Each # is independently an attachment site to the remainder of the polyamide or a capping group at the terminus of the polyamide.

[0027] In an embodiment of the present invention, in formulae (a), (b1) and (b2), R a is linear or branched C1-C 12 -alkylene, C5-C7-cycloalkylene, phenylene, and combinations of any two thereof; R b1 is linear or branched C1-C 12 -alkylene, C5-C7-cycloalkylene, phenylene, and combinations of any two thereof; and / or R b2 is linear or branched C1-C 12 -alkylene, C5-C7-cycloalkylene, phenylene, and a combination of any two thereof.

[0028] In an embodiment of the present invention, component A is a polyamide (PA) component selected from the group consisting of PA6 / 6.6 (also called PA6 / 66), PA6, PA6.6 (also called PA66), PA4.6 (also called PA46), PA6.10 (also called PA610), PA12, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, and blends of two or more thereof. The polyamides may be freshly synthesized or recycled.

[0029] In other words, component A may be a polyamide (PA) component selected from the group consisting of polycaprolactam, poly-(N,N'-hexamethylene adipamide), poly-(hexamethylene adipamide), poly-(hexamethylene sebacamide), poly-(hexamethylene dodecane diamide), poly-undecano-11-lactam, poly-undecano-12-lactam (polylauryl lactam), copolymers of two or more thereof, and blends of two or more thereof. In an embodiment of the present invention, component A is nylon.

[0030] As used herein, the term "non-halogenated organic flame retardant" can be understood in the broadest sense as any organic flame retardant that preferably does not contain halogens.

[0031] When used herein in connection with a compound, the term "organic" can be understood in the broadest sense as generally understood in the art. In general, non-halogenated organic compounds contain one or more covalently bonded carbon atoms, typically contain at least one hydrogen atom, and optionally contain one or more heteroatoms. Typically, non-halogenated organic flame retardants contain at least one heteroatom, such as one or more phosphorus atoms.

[0032] The term "non-halogenated" may be understood interchangeably with "halogen-free" as a compound that does not contain halogens (i.e., fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At)). Optionally, the non-halogenated flame retardant may be phosphinate-based and / or nitrogen-based (e.g., based on melamine cyanurate).

[0033] Component B may be any non-halogenated organic flame retardant or a mixture of two or more non-halogenated organic flame retardants. In an embodiment of the invention, component B is a phosphinate-based flame retardant. The flame retardant component B is different from the flame retardant of component C.

[0034] In an embodiment of the present invention, component B comprises or consists of a dialkylphosphine compound, a diphosphine compound, or a combination thereof. In an embodiment of the present invention, component B comprises a dialkylphosphinic acid salt of formula (I), a diphosphinic acid salt of formula (II), or a combination thereof. [ka] [In the formula, R 1 and R 2 are the same or different and are linear or branched C1-C6-alkyl or H, R 3 is a linear or branched C1-C 10 -Alkylene, C6~C 10 -Arylene, C7~C 20 -Alkylarylene, or C7-C 20 -arylalkylene, M is selected from the group consisting of magnesium (Mg), calcium (Ca), aluminum (Al), antimony (Sb), tin (Sn), germanium (Ge), titanium (Ti), zinc (Zn), iron (Fe), zirconium (Zr), cerium (Ce), bismuth (Bi), strontium (Sr), manganese (Mn), lithium (Li), sodium (Na), potassium (K), and protonated nitrogen bases; m is 1 to 4; n is 1 to 4; x is 1 to 4. It comprises or consists of:

[0035] Further examples of such compounds useful as component B are given in US Patent Application Publication No. 2018 / 244899. Still further examples of phosphinate-based flame retardant compounds useful as component B are given in EP Patent Application Publication No. 3127937.

[0036] In an embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (I). In an alternative embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (II).

[0037] In an embodiment of the invention, in either formula (I) or (II), the residue R 1 and R 2 are the same or different and are linear alkyls selected from the group consisting of ethyl, methyl, n-propyl, and n-butyl. In an embodiment of the invention, in either formula (I) or (II), the residue R 1 and R 2 are each ethyl.

[0038] In an embodiment of the invention, in either formula (I) or (II), residue M is selected from the group consisting of Al, Mg, Ca, Sb, Sn, and Zn. In an embodiment of the invention, in either formula (I) or (II), residue M is Al. In an embodiment of the invention, in formula (I), residue m depends on the valence of the metal ion M. When residue M is Al, m can be 3. In an embodiment of the invention, in formula (II), residues x and n depend on the valence of the metal ion M. In an embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (I), residue M is selected from the group consisting of Al, Mg, Ca, Sb, Sn, and Zn.

[0039] In an embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (I) and has the residue R 1 and R 2 are the same or different and are linear alkyls selected from the group consisting of ethyl, methyl, n-propyl, and n-butyl. In an embodiment of the invention, in either formula (I) or (II), the residue R 1 and R 2 are each ethyl.

[0040] In an embodiment of the invention, component B comprises or consists of a diethylphosphinic acid (DEP) salt of formula (I). In an embodiment of the invention, component B comprises or consists of an aluminum salt of diethylphosphinic acid (DEPAL). DEPAL is commercially available, for example as Exolit® (e.g. OP 1230) from Clariant International Ltd, Switzerland.

[0041] In an embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (I) and has the residue R 1 and R 2 are the same or different and are linear alkyls selected from the group consisting of ethyl, methyl, n-propyl, and n-butyl, and the residue M is selected from the group consisting of aluminum (Al), magnesium (Mg), calcium (Ca), antimony (Sb), tin (Sn), and zinc (Zn).

[0042] For example, the non-halogenated organic flame retardant may be an organophosphorus compound, which may optionally also contain nitrogen. The organophosphorus compound may be, for example, a phosphase-based compound (e.g., based on bisphenol A), triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP), diphenyl phosphate (BADP), or tricresyl phosphate (TCP); a phosphonate-based compound (e.g., based on dimethyl methyl phosphonate (DMMP)), or a phosphinate-based compound (e.g., based on aluminum diethyl phosphinate (e.g., commercially available Exolit® OP 1230)).

[0043] In an embodiment of the invention, component B comprises or consists of a dialkylphosphinic acid salt of formula (I) and has the residue R 1 and R 2 are both ethyl, the residue M is Al and m is 3. Thus, in an embodiment of the invention, the non-halogenated organic flame retardant (used as component B) is aluminum diethylphosphinate.

[0044] Component C may be any particulate inorganic flame retardant or a mixture of two or more thereof. In an embodiment of the invention, component C is a particulate inorganic flame retardant comprising at least one metal ion selected from the group consisting of zinc, aluminum, calcium, molybdenum, and magnesium. Additionally or alternatively, component C may also comprise one or more further metals. The flame retardant component C is different from the flame retardant of component B.

[0045] As used herein, the term "particulate" can be understood in the broadest sense as a component that is primarily composed of particles. Preferably, such particles are solid particles or essentially solid particles. The particles of the particulate inorganic flame retardant may have any size. In an embodiment of the present invention, the particles of the particulate inorganic flame retardant have an average particle size (measurable by means of measuring light scattering, such as in accordance with ISO 13320:2020) in the range of 0.1 to 1000 μm, 1 to 500 μm, 2 to 250 μm, 5 to 100 μm, 10 to 50 μm, 20 to 30 μm, 22 to 28 μm, or (approximately 25 μm) D 50 has.

[0046] In an embodiment of the invention, component C is a particulate inorganic flame retardant comprising or consisting of an inorganic molybdate, such as an inorganic molybdate selected from the group consisting of basic zinc phosphate complexes (e.g., zinc molybdate complexes) (e.g., commercially available from Huber Engineered Materials under the name Kemgard® (e.g., Kemgard® 981), calcium molybdate, ammonium octamolybdate, and zinc molybdate-magnesium silicate.

[0047] In an embodiment of the present invention, component C is selected from the group consisting of particulate zinc phosphate complexes, Al(OH)O, zinc oxide / zinc phosphate complexes, basic zinc phosphate complexes (e.g., zinc molybdate complexes), calcium zinc molybdate complexes, and mixtures of two or more thereof. In an embodiment of the present invention, component C comprises or is a basic zinc phosphate complex (e.g., zinc molybdate complexes). In an embodiment of the present invention, component C comprises or is Al(OH)O (also called AlO(OH)), also known as boehmite and commercially available as Actilox® (e.g., Actilox® 200SM from Nabaltec AG, Germany). In an embodiment of the present invention, component C comprises or is a mixture of basic zinc phosphate complexes (e.g., zinc molybdate complexes) and Al(OH)O.

[0048] Component D may be any reinforcing material or filler material or a combination of both.

[0049] In a preferred embodiment, component D is or comprises at least one reinforcing material. In a preferred embodiment, the reinforcing material is or comprises at least one fibrous material. Thus, component D may be any fibrous material. Preferably, the fibrous material is a reinforcing fibrous material that reinforces materials useful for 3D printing.

[0050] In an embodiment of the present invention, component D is a fibrous material selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and combinations of two or more thereof. In an embodiment of the present invention, component D is a fibrous material, the fibers having an average length of 100 mm or less, 50 mm or less, 20 mm or less, 10 mm or less, 5 mm or less, 2 mm or less, or 1 mm or less. In an embodiment of the present invention, component D is a fibrous material, the fibers having an average length of at least 100 nm, at least 1 μm, at least 10 μm, at least 100 μm, or at least 900 μm. In an embodiment of the present invention, component D is a fibrous material, the fibers having an average diameter ranging from 0.1 to 100 μm, 0.5 to 50 μm, 1 to 20 μm, 2 to 18 μm, 5 to 15 μm, 6 to 14 μm, 7 to 13 μm, 8 to 12 μm, 9 to 11 μm, or (approximately 10 μm). As used herein, the average length or average diameter of the fibers may be determined by any known technique, such as the use of image analysis equipment on photomicrographs by a scanning electron microscope (SEM), or alternatively by laser diffraction techniques (such as static or dynamic light scattering techniques, including those conforming to ISO 13320:2020).

[0051] In an embodiment of the invention, component D is a fibrous material, the fibres having an average length of less than 10 mm and an average diameter in the range of 1 to 20 μm. In an embodiment of the invention, component D is a fibrous material, the fibres having an average length of 1 to 10 mm and an average diameter in the range of 5 to 15 μm. In an embodiment of the invention, component D is a fibrous material, the fibres having an average length of 2 to 5 mm and an average diameter in the range of 7 to 12 μm. In an embodiment of the invention, component D is a fibrous material, the fibres having an average length of (approximately) 4.5 mm and an average diameter in the range from 10 μm.

[0052] In an embodiment of the present invention, component D is a fiber material selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and combinations of two or more thereof, and the fibers preferably have an average length of 10 mm or less and an average diameter in the range of 1 to 20 μm. In particular, the fiber material is made of glass fibers having an average length of 5 mm or less and an average diameter in the range of 5 to 15 μm.

[0053] The fibres may optionally be continuous fibres (so-called "endless" fibres with a length of more than 100 mm). The fibres may also be comprised in tissues, meshes, knits etc. In an embodiment of the invention, component D is a continuous fibre material. In an embodiment of the invention, component D is a continuous fibre material obtainable or obtained by continuous co-extrusion of fibres into filaments.

[0054] In an alternative embodiment of the present invention, component D is or includes one or more fillers. Thus, component D can be any filler. For example, such fillers can be selected from the group consisting of glass beads, one or more non-glass inorganic fillers, and combinations thereof. The non-glass inorganic fillers can be any filler known in the art, including, but not limited to, those selected from the group consisting of talc, insulating materials (such as boron nitride, etc.), and others, and combinations of two or more thereof.

[0055] It will be understood that component D may also comprise or consist of a combination of one or more reinforcing materials and one or more fillers.

[0056] Thus, in an embodiment of the invention, the thermoplastic material of component D is (a) a reinforcing fiber material, preferably a fiber material selected from the group consisting of glass fiber, carbon fiber, aramid fiber, and a combination of two or more thereof, the fiber preferably having an average length of 10 mm or less and an average diameter in the range of 1 to 20 μm, and in particular the fiber material is a glass fiber having an average length of 5 mm or less and an average diameter in the range of 5 to 15 μm; (b) a filler material, preferably selected from the group consisting of glass beads, one or more non-glass inorganic fillers, and combinations thereof; or (c) A combination of (a) and (b).

[0057] Optionally, the material useful for 3D printing may contain one or more polymer additives as component E. Such polymer additives may be any polymer additive known in the art. For example, the polymer additives may be selected from the group consisting of stabilizers, antioxidants, dyes, pigments, release agents, fillers, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives (e.g., metals, carbon, etc.), insulating additives (e.g., boron nitride, etc.), anti-dripping agents, additional flame retardants, and combinations of two or more thereof. The polymer additives of component E are different from each of components A-D. In particular, the polymer additives of component E are different from the flame retardants of each of components B or C, in other words, are not the flame retardants of components B or C.

[0058] In an embodiment of the invention, the thermoplastic material comprises, as one component of component E, one or more aromatic di- or tricarboxylic acid esters / amides, such as N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,3-benzene-dicarboxamide.

[0059] In an embodiment of the present invention, the thermoplastic material is one of the components of component E, such as 119345-01-6, 2082-79-3, 6683-19-8, 32509-66-3, 90498-90-1, 40601-76-1, 27676-62-6, 10191-41-0, 10081-67-1, 181314-48-7, 143925-92-2, 31570-04-4, 26741-53-7, 693-36-7, 2500-88-1, 1843-05-6, 25973-55-1, 147-75-1, 1511- ...2, 1511-11-3, 1511-11-4, 1511-11-1, 1511-11-1, 1 3,411-8, 3864-99-1, 2440-22-4, 155633-54-8, 70321-86-7, 2725-22-6, 147315-50-2, 14516-71-3, 2403-88-5411, 52829-07-9, 167078-06-0 (24860-22-8), 124172-53-8, 65447-77-0, 71878-19-8 (and 70624-18-9), 82451-48-7, and 106990-43-6.

[0060] In an embodiment of the invention, the thermoplastic material comprises as component E one or more copper-based stabilizers, such as those selected from the group consisting of one or more copper fatty acids (e.g. copper stearates) and one or more copper halides (e.g. copper iodides and / or copper bromides), optionally in combination with metal sulfonates, as described in EP 2271710. For example, such stabilizers can be obtained commercially, such as Bruggolen H320.

[0061] In an embodiment of the invention, the thermoplastic material includes, as one component of component E, tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenyl diphosphonite.

[0062] In one embodiment, component E is 0-20% by weight or 0-2% by weight of a salt of phosphorous acid, based on the total amount of thermoplastic material; 0 to 2% by weight or 0.1 to 2% by weight of a carboxylic acid ester amide, based on the total amount of the thermoplastic material; 0-1% by weight or 0.1-1% by weight of phosphonites or mixtures of phosphonites and phosphites, based on the total amount of thermoplastic material, and / or 0 to 1% by weight or 0.1 to 1% by weight based on the total amount of thermoplastic material, 14 ~C 40 Esters or salts of long-chain aliphatic carboxylic acids (fatty acids) having a chain length of may also include

[0063] In an embodiment of the present invention, the thermoplastic material is At least one aromatic di- or tricarboxylic acid ester / amide, in particular N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,3-benzenedicarboxamide), 119345-01-6, 2082-79-3, 6683-19-8, 32509-66-3, 90498-90-1, 40601-76-1, 27676-62-6, 10191-41-0, 10081-67-1, 181314-48-7, 143925-92-2, 31570-04-4, 26741-53-7, 693-36-7, 2500-88-1, 1843-05-6, 25973-55-1, 05.11.3896, 147-75-9, 3864-99-1, 2440-22-4, 155633-54-8, 703 at least one stabilizer having a CAS number selected from the group consisting of 21-86-7, 2725-22-6, 147315-50-2, 14516-71-3, 2403-88-5411, 52829-07-9, 167078-06-0 (24860-22-8), 124172-53-8, 65447-77-0, 71878-19-8 (and 70624-18-9), 82451-48-7, and 106990-43-6, in particular tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenyl diphosphonite; Includes.

[0064] In an embodiment of the invention, the thermoplastic material includes an anti-drip agent as a component of component E. The anti-drip agent may comprise or consist of silica particles and / or polytetrafluoroethylene (PTFE), such as commercially available as Teflon. The anti-drip agent of component E is different from the flame retardant of each of components B or C, in other words, it is not a flame retardant of components B or C.

[0065] In an embodiment of the invention, the thermoplastic material comprises a further flame retardant as one component of component E. Such further flame retardant of component E is different from the respective flame retardant of component B or C, in other words is not a flame retardant of component B or C. Such further flame retardant of component E is therefore neither a non-halogenated organic flame retardant (component B) nor a particulate inorganic flame retardant (component C). In an embodiment of the invention, the further flame retardant of component E is a halogenated organic flame retardant or a non-particulate inorganic flame retardant. Such further flame retardant may also be a halogenated flame retardant (e.g. polytetrafluoroethylene-based (PTFE-based) such as commercially available as Teflon).

[0066] Further examples of compounds useful as polymer additives of component E are given in EP 3127937 and U.S. 2018 / 244899.

[0067] Components A-D, and, if present, component E, may be present in any content ratio. In one embodiment, the polyamide or polyamides of component A are the major components of the material useful for 3D printing. Thus, preferably, component A constitutes at least 50% by weight of the material useful for 3D printing.

[0068] In an embodiment of the invention, the thermoplastic material comprises 38.9-98.9 wt.% of component A, 38.9-80 wt.% of component A, 40-80 wt.% of component A, 50-80 wt.% of component A, 55-80 wt.% of component A, or 55-60 wt.% of component A.

[0069] In an embodiment of the invention, the thermoplastic material comprises 1-30 wt. % of component B, 1-30 wt. % of component B, 10-20 wt. % of component B, or 12-19 wt. % of component B.

[0070] In an embodiment of the invention, the thermoplastic material comprises 0.01-40 wt% of component C, 0.1-35 wt% of component C, 0.1-25 wt% of component C, 1-10 wt% of component C, 10-40 wt% of component C, 20-35 wt% of component C, 25-30 wt% of component C, 1-10 wt% of component C, 1.2-32 wt% of component C, 28-32 wt% of component C, or 1.2-8 wt% of component C.

[0071] In an embodiment of the invention, the thermoplastic material comprises 0-60 wt% of component D, 1-58 wt% of component D, 5-30 wt% of component D, 10-25 wt% of component D, or 15-22 wt% of component D.

[0072] In an embodiment of the invention, the thermoplastic material comprises 0-5 wt% of component E, 0-2 wt% of component E, 0-1 wt% of component E, 0.1-1 wt% of component E, 0.2-0.8 wt% of component E, 0.3-0.7 wt% of component E, or 0.4-0.6 wt% of component E.

[0073] For example, component E is 0-2 wt%, 0.01-1 wt%, 0.05-1 wt%, 0.1-0.8 wt%, 0.15-0.7 wt%, or 0.2-0.6 wt% of one or more processing stabilizers, such as Hostanox P-EPQ, 0-2 wt%, 0.01-1 wt%, 0.05-1 wt%, 0.1-0.8 wt%, 0.15-0.7 wt%, or 0.2-0.6 wt% of one or more modifiers and stabilizers, such as Nylostab S-EED, and optionally 0 to 2% by weight, 0.01 to 1% by weight, 0.05 to 1% by weight, 0.1 to 0.8% by weight, 0.15 to 0.7% by weight, or 0.2 to 0.6% by weight of one or more dyes; It may contain or consist of:

[0074] In an embodiment of the invention, the thermoplastic material is (A) 38.9 to 98.9% by weight of component A; (B) 1 to 30% by weight of component B; (C) 0.01 to 35% by weight of component C; (D) 0 to 60% by weight of component D; (E) 0 to 20% by weight of component E; It comprises or consists of:

[0075] In an embodiment of the invention, the thermoplastic material is (A) 38.9 to 98.9% by weight of component A; (B) 1 to 30% by weight of component B; (C) 0.01 to 35% by weight of component C; (D) 0 to 60% by weight of component D; (E) 0 to 5% by weight of component E; It comprises or consists of:

[0076] It will be understood that each percentage range is based on the total weight of the thermoplastic material. In embodiments of the present invention, and throughout the present invention, the contents of components A through D, and E, if present, add up to 100%. Thus, a thermoplastic material may consist of such components.

[0077] In an embodiment of the invention, the thermoplastic material is (A) 50 to 80% by weight of component A; (B) 1 to 30% by weight of component B; (C) 0.1 to 35% by weight of component C; (D) 0 to 60% by weight of component D; (E) 0 to 2% by weight of component E; It comprises or consists of:

[0078] In an embodiment of the invention, the thermoplastic material is (A) 50 to 80% by weight of component A; (B) 1 to 30% by weight of component B; (C) 0.1 to 35% by weight of component C; (D) 0.1 to 60% by weight of component D; (E) 0 to 2% by weight of component E; It comprises or consists of:

[0079] In an embodiment of the invention, the thermoplastic material is (A) 44.9 to 78.9% by weight of component A; (B) 10 to 20% by weight of component B; (C) 1 to 35% by weight of component C; (D) 10 to 25% by weight of component D; (E) 0.1 to 1% by weight of component E; It comprises or consists of:

[0080] In an embodiment of the invention, the thermoplastic material is 40 to 60% by weight of component A; 12 to 19% by weight of component B; 1.2 to 32% by weight of component C; 15 to 22% by weight of component D; 0.1 to 1% by weight of component E; It comprises or consists of:

[0081] In an embodiment of the invention, the thermoplastic material is 55 to 60% by weight of component A; 12 to 19% by weight of component B; 1.2 to 8 weight percent of component C; 15 to 22% by weight of component D; 0.1 to 1% by weight of component E; It comprises or consists of:

[0082] In a preferred embodiment, the thermoplastic material is (A) 55 to 78.9 wt. % of at least one polyamide (PA) component selected from the group consisting of PA6 / 6.6 (also referred to as PA6 / 66), PA6, PA6.6 (also referred to as PA66), PA4.6 (also referred to as PA46), PA6.10 (also referred to as PA610), PA12, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, and blends of two or more thereof; (B) 10 to 20% by weight of at least one phosphinate-based flame retardant, in particular aluminum diethylphosphinate; (C) 1 to 10% by weight of at least one particulate inorganic flame retardant containing at least one metal ion selected from the group consisting of zinc, aluminum, calcium, molybdenum, and magnesium, in particular selected from the group consisting of particulate zinc phosphate complexes, Al(OH)O, zinc oxide / zinc phosphate complexes, basic zinc phosphate complexes (e.g., zinc molybdate complexes), calcium zinc molybdate complexes, and mixtures of two or more thereof; (D) 10 to 25% by weight of at least one reinforcing or filler material, in particular a fiber material selected from the group consisting of glass fiber, carbon fiber, aramid fiber, and combinations of two or more thereof, the fiber having an average length of 10 mm or less and an average diameter in the range of 1 to 20 μm; (E) 0.1 to 1 wt. % of at least one polymer additive selected from the group consisting of stabilizers, antioxidants, dyes, pigments, release agents, fillers, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives (e.g., metals, carbon, etc.), insulating additives, anti-dripping agents, further flame retardants, and combinations of two or more thereof, in particular containing at least one aromatic di- or tricarboxylic acid ester / amide and / or one or more stabilizers; It comprises or consists of:

[0083] The materials useful for 3D printing of the present invention may be provided in any form: as 3D printing filaments, powders useful for powder bed fusion 3D printing, as granules, as a melt, or in any other form.

[0084] Therefore, a further aspect of the present invention relates to a 3D printing filament comprising or consisting (essentially) of the thermoplastic material of the present invention.

[0085] It will be understood that all descriptions and embodiments described above in relation to the material itself also apply mutatis mutandis to 3D printing filaments.

[0086] Such 3D printing filaments may have any diameter. The diameter depends on the 3D printing device with which it is intended to be used. In an embodiment of the invention, the 3D printing filaments have a diameter in the range of 0.5-5 mm. Such 3D printing filaments may have any length. Preferably, the length is greater than 1 m, more preferably greater than 2 m, greater than 5 m, greater than 10 m, greater than 20 m, greater than 50 m, greater than 20 m, or even greater than 100 m in length.

[0087] Another aspect of the invention relates to a powder for powder bed fusion 3D printing comprising or consisting essentially of the thermoplastic material of the invention.

[0088] It will be understood that all descriptions and embodiments described above in relation to the material itself also apply mutatis mutandis to the powder for powder bed fusion 3D printing.

[0089] Such powders may have any properties suitable for this purpose. The size and shape of the powder will also depend on the 3D printing device it is intended to be used with. In embodiments of the invention, the powder has an average diameter of less than 5 mm, less than 2 mm, or less than 1 mm.

[0090] As mentioned above, the material of the invention can be used in 3D printing. Thus, a further aspect of the invention relates to the use of the thermoplastic material of the invention in 3D printing.

[0091] It will be understood that all descriptions and embodiments described above in relation to the material itself also apply mutatis mutandis to the use of the thermoplastic material of the present invention in 3D printing.

[0092] Thus, the present invention also refers to the use of the 3D printing filaments of the present invention (e.g., having a diameter in the range of 0.5-5 mm) in 3D printing (e.g., any extrusion-based 3D printing described herein). The present invention further refers to the use of the powder bed fusion 3D printing powders of the present invention in 3D printing (e.g., powder bed fusion 3D printing).

[0093] The invention also refers to a method for preparing a three-dimensional molded article by 3D printing, in which a preferably small part of a material is heated at least until it becomes plastic (optionally (partially) melted), whereby the product is prepared in layers, while the material is cooled and thereby solidified again.

[0094] A further aspect of the invention relates to a method for preparing a three-dimensional part by 3D printing, said method comprising the steps of: (i) providing a thermoplastic material of the present invention; (ii) heating a predetermined portion of the thermoplastic material of step (i) above its glass transition temperature to obtain a plastic material; (iii) preparing a three-dimensional molded article from the plastic mass of step (ii); (iv) cooling the heated thermoplastic mass of step (iii) to obtain a solid product. Includes.

[0095] It will be understood that all descriptions and embodiments described above relating to the material itself, the 3D printing filaments, and the powders for powder bed fusion 3D printing, and the use of the material, also apply mutatis mutandis to the method of preparing a three-dimensional molded article by 3D printing.

[0096] Step (ii) may comprise heating to a temperature in the range 180-265°C, 190-260°C, 200-255°C, 210-250°C, 220-245°C, 230-245°C or (approximately) 240°C. These temperatures may also be used as nozzle temperatures. These may be suitable for certain polyamides and polyamide blends, such as PA6 / 66.

[0097] Step (ii) may include using heating chamber conditions of 25-250°C, 30-200°C, 30-150°C, 40-120°C, 50-100°C, 60-100°C, or 70-90°C.

[0098] Step (ii) may include heating the build plate of the 3D printer to a temperature above or below the glass transition temperature of the polymer to ensure ideal properties for adhesion and maintaining adhesion to the plate. Further methods of ensuring adhesion of the polymer to the build plate may include the use of vacuum-type build plates or specific build plate adhesives, such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or one or more other chemical-based adhesives / glues, or combinations of two or more thereof. Adhesion may optionally occur near, below, or above the glass adhesion temperature.

[0099] In steps (iii) and (iv), the temperature may be reduced to any temperature below the glass transition temperature, for example, in the range of room temperature (i.e. (approximately) 20°C) to 120°C, 20°C to 110°C, 30°C to 90°C, 40°C to 100°C, 60°C to 100°C, 70°C to 90°C, or (approximately) 80°C, etc. Such a temperature may be the printing bed temperature. It will be understood that the product may finally be reduced to room temperature (i.e. (approximately) 20°C) or a temperature below room temperature.

[0100] The method for preparing the three-dimensional molded article may be carried out by any means. For example, 3D printing based on material extrusion (e.g. Fused Deposition Modeling (FDM), Composite Filament Fabrication (CFF), or Fused Filament Fabrication (FFF), or Fused Pellet Fabrication, or Fused Particle Fabrication), Powder-bed based 3D printing, also known as "powder bed fusion" (e.g. powder bed and inkjet head 3D printing (3DP), selective heat sintering (SHS), or selective laser sintering (SLS)); 3D printing based on thin-film deposition modeling (LOM) (also known as sheet deposition); 3D printing based on jetting methods (e.g., material jetting or binder jetting), and 3D printing based on radiation-induced polymerization, such as photopolymerization (e.g., stereolithography (SLA), computed axis lithography, digital light processing (DLP), continuous liquid interface manufacturing (CLIP), or directed energy deposition (DED)) The 3D printing method may be selected from the group consisting of:

[0101] In an embodiment of the invention, the method comprises the steps of: (i) providing a 3D printing filament of the present invention; (ii) extruding the 3D printing filament and thereby heating it to obtain a plastic mass at an exit die of the extruder; (iii) applying the plastic mass from the extruder exit die to a desired three-dimensional shape of the product; (iv) cooling the heated thermoplastic mass of step (iii) to obtain a portion of a solid product; (v) continuing steps (i) to (iv) until a three-dimensional molded product is obtained; Includes.

[0102] The extrusion in step (ii) of the procedure may be carried out by any means, for example such a process may be Fused Deposition Modeling (FDM), Composite Filament Fabrication (CFF), or Fused Filament Fabrication (FFF), or Fused Pellet Fabrication, or Fused Particle Fabrication.

[0103] In another embodiment of the invention, the method comprises the steps of: (i) providing a powder for powder bed fusion 3D printing of the present invention and contacting the powder with a solid support; (ii) heating selected portions of the powder in contact with the solid surface of step (i) to obtain a plastic mass in the desired three-dimensional shape of the product, preferably by irradiation with light applied to the desired shape, in particular by irradiation with a laser beam or light selectively applied through selected openings in a radiation opaque mask; (iii) adhering the plastic material to a material with which it comes into contact; (iv) cooling the heated thermoplastic mass of step (iii) to obtain a portion of a solid product; (v) continuing steps (i) to (iv) until a three-dimensional molded product is obtained; Includes.

[0104] For example, such a method may be powder bed based 3D printing, also known as "powder bed fusion". Such a method may be selected from the group consisting of powder bed and inkjet head 3D printing (3DP), selective heat sintering (SHS), or selective laser sintering (SLS).

[0105] As used herein, the term "consisting essentially of" can be understood to mean that the respective composition is composed of at least 95% by weight, at least 98% by weight, at least 99% by weight, at least 99.5% by weight, at least 99.8% by weight, or at least 99.9% by weight of the specified component, and optionally, additional components that do not (significantly) affect the properties of the composition. Such additional components may be, for example, trace amounts of water, trace amounts of one or more salts, and / or trace amounts of one or more impurities of the component.

[0106] Further embodiments of the invention are presented in the examples and claims. The examples are intended to further illustrate the invention but do not limit the scope of the claims. EXAMPLES

[0107] 1.) Components used to prepare the flame retardant polyamide composition The following ingredients were used: Commercially available polyamides (as component A): Polyamide 6 / 66 (also called PA6 / 66, PA6 / 6.6), Flame retardant (as component B): aluminium salt of diethylphosphinic acid, hereafter referred to as DEPAL (Clariant International Ltd, Switzerland); Flame retardant (as component C-1): basic zinc phosphate complex (Cemguard® 981, Huber Engineered Materials, USA); Flame retardant (as component C-2): boehmite (Actilox® 200SM, Nabaltec AG, Germany); Glass fiber (as component D): ECS301 (HP-3-M4) glass fiber, diameter 10 μm, length 4.5 mm (Chongqing Polycomp International Corporation, China); Stabilizer (as component E-1): Nylostab® S-EED® (Clariant International Ltd, Switzerland); Stabilizer (as component E-2): Hostanox® P-EPQ® (Clariant International Ltd, Switzerland), and Optionally, a color masterbatch could be added (as component E-3): a mixture of polyamide 6, one or more additives, and one or more colorants / dyes.

[0108] 2. Manufacturing, Processing, and Testing of 3D Printed Compositions with Flame Retardant Polyamide Flame retardants (components B and C) and other components were mixed in the ratios listed in Table 1 by first premixing pellets and powders (powder to powder, pellet to pellet) using a standard mixing device. Once the components in the same form were mixed, they were further incorporated together into polyamide 6 / 66 (component A) at a temperature of 200-250 °C by the main and side feeders of a twin screw extruder (Leistritz ZSE 27 iMAXX 48D). Glass fiber (component D) was added further downstream in the barrel of the extruder through a heated die of appropriate size for the intended filament diameter and cooled in a continuous temperature controlled water bath. The polymer strand was pulled through the die by a rotary pull device and measured for diameter using a 3-axis laser measuring device just before this device. The diameter was maintained within a tolerance of at least + / - 0.05 mm of the desired diameter. The filament was further wound onto a spool to allow printing on an extrusion type 3D printer.

[0109] Following winding onto the spool, the filaments were dried in a vacuum oven at 80° C. until the desired moisture level was achieved (approximately 2-14 hours). The filaments were then packaged in plastic bags with an appropriate size desiccant and vacuum sealed to prevent exposure to moisture.

[0110] The filament compositions were tested in an extrusion-type 3D printer (Ultimaker S5 with aftermarket top cover) using a suitable glass print bed surface coated with adhesive to allow the first layer to adhere properly to the glass print bed (e.g. PVP-based glue or a commercially available polyamide-targeted print adhesive). The filaments were extruded at temperatures between 220 and 250°C and molded into test specimens including those for UL 94, NFPA 130 (ASTM E162-15b, ASTM E662-17), SMP 800c, and EN 45545-2 (ISO 4589-2, ISO 5659-2).

[0111] All 3D printed specimens were produced under conditions that allowed for the best printed specimens with the particular composition (print temperature of approximately 240° C.). In some cases, slightly varying print temperatures and speeds were used. The print bed temperature was maintained at 80° C.

[0112] Examples IE1 and IE2 were prepared as defined in Table 1. All amounts are defined as weight percent and are based on the 3D printed composition including flame retardants, additives, and reinforcing materials.

[0113] [Table 1]

[0114] The polyamide 6 / 66 (PA6 / 66-GF20) composition without other components had a higher mass density, especially the specific optical density D of smoke upon flame exposure at 4.0 seconds. s (ASTM E662-17) was quite high. Both IE1 and IE2 were off-white to beige. The mass density of IE2 was 1293 kg / m 3and its melting point is 195°C. In comparison, both glass fiber reinforced IE1 and IE2 proved to be quite useful in the 3D printing process and obtained desirable surfaces. Especially IE2 printed well and obtained a very smooth surface for the glass fiber reinforced 3D printer extruded material.

[0115] Therefore, the combination of polyamide, glass fiber, DEPAL, and stabilizer reduces surface flammability (I s ≦35, ideally ≦25) and smoke density (D s Polyamide 3D printing compositions were obtained that achieved the NFPA 130 requirements for modulus of elasticity (≦200, ideally ≦165).

[0116] Further toxicity testing was performed, specifically Bombardier SMP 800-c toxicity test and NFPA 130 standard testing, and the results are shown in Tables 2 and 3 below.

[0117] [Table 2]

[0118] [Table 3]

[0119] Thus, the combination of polyamide, glass fiber, DEPAL, and stabilizers results in a polyamide 3D printing composition that achieves the NFPA 130 requirements for toxicity.

[0120] Further testing was performed for IE2 as required by EN 45545-2. 3D printed specimens with a thickness of 4 mm were prepared and tested. The results are shown in Table 4 below.

[0121] [Table 4]

[0122] Thus, the combination of IE2 polyamide, glass fiber, DEPAL, and stabilizer results in a polyamide 3D printing composition that achieves HL1, HL2, and HL3 hazard levels for the R22 requirements of EN 45545-2.

[0123] In summary, the thermoplastic materials useful for 3D printing of the present invention are highly advantageous, providing good printing properties, good physicochemical properties, good flame retardancy, and unexpectedly low specific optical density of smoke upon flame exposure, and therefore are particularly useful for 3D printing. (Appendix 1) A thermoplastic material useful for 3D printing, comprising: (A) at least one polyamide as component A; (B) at least one non-halogenated organic flame retardant as component B; (C) at least one particulate inorganic flame retardant as component C; (D) optionally, one or more reinforcing or filler materials as component D; (E) optionally, as component E, one or more polymer additives including stabilizers, antioxidants, dyes, pigments, release agents, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives, insulating additives, anti-drip agents, additional flame retardants, and combinations of two or more thereof; A thermoplastic material comprising, consisting of, or consisting essentially of. (Appendix 2) (A) 38.9 to 80% by weight of component A; (B) 1 to 30% by weight of component B; (C) 0.1 to 35% by weight of component C; (D) 0 to 60% by weight of component D; (E) 0 to 2% by weight of component E; 2. The thermoplastic material of claim 1, comprising, consisting of, or consisting essentially of: (Appendix 3) 3. The thermoplastic material according to claim 1 or 2, wherein component A comprises, consists of, or consists essentially of PA6 / 6.6, PA6, PA6.6, PA4.6, PA12, PA6.10, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, or blends of two or more thereof. (Appendix 4) 4. The thermoplastic material of claim 3, wherein the polyamide is recycled. (Appendix 5) 5. The thermoplastic material according to any one of claims 1 to 4, wherein component B comprises, consists of, or consists essentially of a phosphinate-based flame retardant. (Appendix 6) Component B is a dialkylphosphinic acid salt of formula (I), a diphosphinic acid salt of formula (II), or a combination thereof [ka] [In the formula, R 1 and R 2 are the same or different, and are linear or branched C 1 ~C 6 -alkyl or H, R 3 is linear or branched C 1 ~C 10 -Alkylene, C 6 ~C 10 -Arylene, C 7 ~C 20 -alkylarylene, or C 7 ~C 20 -arylalkylene, M is selected from the group consisting of Al, Mg, Ca, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and protonated nitrogen bases; m is 1 to 4; n is 1 to 4; x is 1 to 4. comprising, consisting of, or consisting essentially of In particular, the non-halogenated organic flame retardant is aluminum diethylphosphinate. 6. The thermoplastic material according to any one of claims 1 to 5. (Appendix 7) 7. The thermoplastic material according to any one of claims 1 to 6, wherein component C comprises, consists of or consists essentially of a particulate inorganic flame retardant comprising at least one metal ion selected from the group consisting of zinc, aluminum, calcium, molybdenum, and magnesium, in particular selected from the group consisting of particulate zinc phosphate complexes, Al(OH)O, zinc oxide / zinc phosphate complexes, basic zinc phosphate complexes, calcium zinc molybdate complexes, and mixtures of two or more thereof. (Appendix 8) Component D is (a) a reinforcing fiber material, preferably a fiber material selected from the group consisting of glass fiber, carbon fiber, aramid fiber, and combinations of two or more thereof; (b) a filler material, preferably selected from the group consisting of glass beads, one or more non-glass inorganic fillers, and combinations thereof; or (c) A combination of (a) and (b) The thermoplastic material of any one of claims 1 to 7, comprising, consisting of, or consisting essentially of (a), (b), or (c). (Appendix 9) The reinforcing fiber material has an average fiber length and / or an average fiber diameter, the average fibre length is 10 mm or less, preferably 5 mm or less; and / or The average fiber diameter is 1 to 20 μm, preferably 5 to 15 μm. A thermoplastic material as described in Appendix 8. (Appendix 10) The thermoplastic material is at least one aromatic di- or tricarboxylic acid ester / amide, in particular N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,3-benzenedicarboxamide, 119345-01-6, 2082-79-3, 6683-19-8, 32509-66-3, 90498-90-1, 40601-76-1, 27676-62-6, 10191-41-0, 10081-67-1, 181314-48-7, 143925-92-2, 31570-04-4, 26741-53-7, 693-36-7, 2500-88-1, 1843-05-6, 25973-55-1, 05.11.3896, 147-75-9, 3864-99-1, 2440-22-4, 155633-54-8, 703 at least one stabilizer having a CAS number selected from the group consisting of 21-86-7, 2725-22-6, 147315-50-2, 14516-71-3, 2403-88-5411, 52829-07-9, 167078-06-0 (24860-22-8), 124172-53-8, 65447-77-0, 71878-19-8 (and 70624-18-9), 82451-48-7, and 106990-43-6, in particular tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenyl diphosphonite; The thermoplastic material according to any one of claims 1 to 9, comprising, consisting of, or consisting essentially of: (Appendix 11) (A) 44.9 to 78.9% by weight of component A; (B) 10 to 20% by weight of component B; (C) 1 to 35% by weight of component C; (D) 10 to 25% by weight of component D; (E) 0.1 to 1% by weight of component E; The thermoplastic material according to any one of claims 1 to 10, comprising, consisting of, or consisting essentially of. (Appendix 12) (A) 55 to 78.9 wt. % of at least one polyamide (PA) component selected from the group consisting of PA6 / 6.6, PA6, PA6.6, PA4.6, PA12, PA6.10, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, and blends of two or more thereof; (B) 10 to 20% by weight of at least one phosphinate-based flame retardant, in particular aluminum diethylphosphinate; (C) 1 to 10% by weight of at least one particulate inorganic flame retardant containing at least one metal ion selected from the group consisting of zinc, aluminum, calcium, molybdenum, and magnesium, and in particular selected from the group consisting of particulate zinc phosphate complex, Al(OH)O, zinc oxide / zinc phosphate complex, basic zinc phosphate complex, calcium zinc molybdate complex, and mixtures of two or more thereof; (D) 10 to 25% by weight of at least one reinforcing or filler material, in particular a fiber material selected from the group consisting of glass fiber, carbon fiber, aramid fiber, and combinations of two or more thereof, the fiber preferably having an average length of 10 mm or less and an average diameter in the range of 1 to 20 μm; (E) 0.1 to 1% by weight of at least one polymer additive selected from the group consisting of stabilizers, antioxidants, dyes, pigments, release agents, fillers, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives, insulating additives, anti-dripping agents, further flame retardants, and combinations of two or more thereof, in particular containing at least one aromatic di- or tricarboxylic acid ester / amide and / or one or more stabilizers; 12. The thermoplastic material according to any one of claims 1 to 11, comprising, consisting of, or consisting essentially of: (Appendix 13) 3D printing filament comprising or consisting of a thermoplastic material according to any one of claims 1 to 12, in particular having a diameter in the range of 0.5 to 5 mm. (Appendix 14) A powder for powder bed fusion 3D printing, comprising or consisting of a thermoplastic material according to any one of claims 1 to 12. (Appendix 15) 13. Use of the thermoplastic material according to any one of claims 1 to 12 in 3D printing. (Appendix 16) A method for preparing a three-dimensional molded article by 3D printing, comprising the steps of: (i) providing a thermoplastic material according to any one of claims 1 to 12; (ii) heating a defined portion of the thermoplastic material of step (i) above its glass transition temperature to obtain a plastic material; (iii) preparing a three-dimensional shaped article from the plastic mass of step (ii); (iv) cooling the heated thermoplastic mass of step (iii) to obtain a solid product. A method comprising: (Appendix 17) (i) providing a 3D printing filament according to claim 13; (ii) extruding and thereby heating the 3D printing filament to obtain a plastic mass at an exit die of an extruder; (iii) applying the plastic mass from the exit die of the extruder to a desired three-dimensional shape of an article; (iv) cooling the heated thermoplastic mass of step (iii) to obtain a portion of a solid product; (v) continuing steps (i) to (iv) until a three-dimensional molded product is obtained; 17. The method of claim 16, comprising: (Appendix 18) (i) providing a powder for powder bed fusion 3D printing of claim 14 and contacting the powder with a solid support; (ii) heating selected portions of the powder in contact with the solid surface of step (i) to obtain a plastic mass in the desired three-dimensional shape of the product, preferably by irradiation of light applied to the desired shape, in particular by irradiation of a laser beam or light selectively applied through selected openings in a radiation opaque mask; (iii) adhering the plastic mass to a material with which it comes into contact; (iv) cooling the heated thermoplastic mass of step (iii) to obtain a portion of the solid product; (v) continuing steps (i) to (iv) until a three-dimensional molded product is obtained; 17. The method of claim 16, comprising:

Claims

1. 1. A thermoplastic material useful for 3D printing, comprising: (A) at least one polyamide as component A; (B) at least one non-halogenated organic flame retardant as component B; (C) at least one particulate inorganic flame retardant as component C; (D) optionally, one or more reinforcing or filler materials as component D; (E) optionally, as component E, one or more polymer additives including stabilizers, antioxidants, dyes, pigments, release agents, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives, insulating additives, anti-drip agents, additional flame retardants, and combinations of two or more thereof; Including, (A) 55 to 80% by weight of component A; (B) 13% by weight of component B; (C) 7% by weight of component C; (D) optionally, 10 to 25 weight percent of component D; (E) optionally, 0.1 to 1 wt. % of component E; Including, Component C comprises a particulate inorganic flame retardant selected from the group consisting of particulate zinc phosphate complexes, Al(OH)O, zinc oxide / zinc phosphate complexes, basic zinc phosphate complexes, calcium zinc molybdate complexes, and mixtures of two or more thereof; 1. A thermoplastic material in the form of a spooled filament for use in 3D printing, said material having a surface flammability of 25 or less and a specific optical density of 165 or less.

2. 2. The thermoplastic material of claim 1, wherein component A comprises PA6 / 6.6, PA6, PA6.6, PA4.6, PA12, PA6.10, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, or blends of two or more thereof.

3. A thermoplastic material as described in claim 1 or 2, wherein component A is PA6 / 6.

6.

4. The thermoplastic material according to any one of claims 1 to 3, wherein component B comprises a phosphinate-based flame retardant.

5. Component B is a dialkylphosphinic acid salt of formula (I), a diphosphinic acid salt of formula (II), or a combination thereof. 【Chemistry 1】 [In the formula, R １ and R ２ are the same or different, and are linear or branched C １ ~C ６ - alkyl or H, R ３ is linear or branched C １ ~C １０ -Alkylene, C ６ ~C １０ -Arylene, C ７ ~C ２０ - alkylarylene, or C ７ ~C ２０ -arylalkylene, M is selected from the group consisting of Al, Mg, Ca, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and protonated nitrogen bases; m is 1 to 4; n is 1 to 4; x is 1 to 4. Including, The thermoplastic material according to any one of claims 1 to 4.

6. A thermoplastic material described in any one of claims 1 to 5, wherein component B is aluminum diethylphosphinate.

7. The thermoplastic material according to any one of claims 1 to 6, wherein component C comprises Al(OH)O.

8. Component D is (a) a reinforcing fiber material selected from the group consisting of glass fiber, carbon fiber, aramid fiber, and combinations of two or more thereof; (b) a filler material selected from the group consisting of glass beads, one or more non-glass inorganic fillers, and combinations thereof; or (c) A combination of (a) and (b) The thermoplastic material according to any one of claims 1 to 7, comprising:

9. The reinforcing fiber material has an average fiber length and / or an average fiber diameter, the average fiber length is 10 mm or less; and / or The average fiber diameter is 1 to 20 μm. The thermoplastic material of claim 8.

10. The thermoplastic material is at least one aromatic di- or tricarboxylic acid ester / amide; 119345-01-6, 2082-79-3, 6683-19-8, 32509-66-3, 90498-90-1, 40601-76-1, 27676-62-6, 10191-41-0, 10081-67-1, 181314-48-7, 143925-92-2, 31570-04-4, 26741-53-7, 693-36-7, 2500-88-1, 1843-05-6, 25973-55-1, 05.11.3896, 147-75-9, 3864-99-1, 24 at least one stabilizer having a CAS number selected from the group consisting of 40-22-4, 155633-54-8, 70321-86-7, 2725-22-6, 147315-50-2, 14516-71-3, 2403-88-5411, 52829-07-9, 167078-06-0 (24860-22-8), 124172-53-8, 65447-77-0, 71878-19-8 (70624-18-9), 82451-48-7, and 106990-43-6; The thermoplastic material according to any one of claims 1 to 9, comprising:

11. (A) 59.4% by weight of component A; (B) 13% by weight of component B; (C) 7% by weight of component C; (D) 20% by weight of component D; (E) 0.6% by weight of component E; The thermoplastic material according to any one of claims 1 to 10, comprising:

12. (A) 55 to 78.9 wt. % of at least one polyamide (PA) component selected from the group consisting of PA6 / 6.6, PA6, PA6.6, PA4.6, PA12, PA6.10, PA6T / 66, PA6T / 6, PA6T, PA4T, PA9T, PA10T, high temperature polyamides, copolymers of two or more thereof, and blends of two or more thereof; (B) 13% by weight of aluminum diethylphosphinate; (C) 7% by weight of at least one particulate inorganic flame retardant selected from the group consisting of particulate zinc phosphate complexes, Al(OH)O, zinc oxide / zinc phosphate complexes, basic zinc phosphate complexes, calcium zinc molybdate complexes, and mixtures of two or more thereof; (D) 10 to 25% by weight of at least one fibrous material selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and combinations of two or more thereof, the fibers having an average length of 10 mm or less and an average diameter in the range of 1 to 20 μm; (E) 0.1 to 1 weight percent of at least one polymer additive selected from the group consisting of stabilizers, antioxidants, dyes, pigments, release agents, fillers, plasticizers, processing agents, antimicrobial agents, slip agents, antistatic agents, conductive additives, insulating additives, anti-drip agents, additional flame retardants, and combinations of two or more thereof, and containing at least one aromatic di- or tricarboxylic acid ester / amide and / or one or more stabilizers; The thermoplastic material of claim 1 comprising:

13. 13. A 3D printing filament comprising the thermoplastic material of any one of claims 1 to 12, optionally having a diameter in the range of 0.5 to 5 mm.

14. Use of the thermoplastic material according to any one of claims 1 to 12 in 3D printing.

15. 1. A method for preparing a three-dimensional molded article by 3D printing, comprising: (i) providing a thermoplastic material according to any one of claims 1 to 12; (ii) heating a defined portion of the thermoplastic material of step (i) above its glass transition temperature to obtain a plastic material; (iii) preparing a three-dimensional shaped article from the plastic mass of step (ii); (iv) cooling the heated thermoplastic mass of step (iii) to obtain a solid product; A method comprising:

16. (i) providing a 3D printing filament comprising the thermoplastic material; (ii) extruding and thereby heating the 3D printing filament to obtain a plastic mass at an exit die of an extruder; (iii) applying the plastic mass from the exit die of the extruder to a desired three-dimensional shape of an article; (iv) cooling the heated thermoplastic mass of step (iii) to obtain a portion of a solid product; (v) continuing steps (i) to (iv) until a three-dimensional molded article is obtained.

16. The method of claim 15, comprising:

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