FLAME-RETARDANT COMPOSITIONS FOR ADDITIVE MANUFACTURING AND RELATED PRINTED 3D ARTICLES COMPRISING OXYGEN BARRIERS - Patent application

Abstract

Described herein are compositions for additive manufacturing applications that, in some embodiments, impart flame retardancy and / or flame resistance to articles printed or formed from the compositions. The compositions may also impart desired mechanical properties to the articles. In some embodiments, the compositions include a sinterable powder or a thermoplastic polymer in an amount of 10 to 99% by weight, based on the total weight of the composition, and an oxygen barrier in an amount of up to 25%, up to 15%, or up to 10% by weight, based on the total weight of the composition. The oxygen barrier includes at least one of (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority pursuant to 35 U.S.C. Section 119 to U.S. Provisional Patent Application No. 63 / 397,628, filed August 12, 2022, which is incorporated herein by reference in its entirety. [Technical Field]

[0002] The present invention relates to compositions for additive manufacturing, and in particular to compositions that impart flame retardancy or flame resistance to articles printed or formed from the compositions. [Background technology]

[0003] Three-dimensional (3D) printers and systems use various types of materials to form various 3D objects, articles, or parts according to computer-generated files. Such materials can include build materials used to form the object itself, as opposed to sacrificial support materials that may be used to support the object during the additive manufacturing process but are subsequently removed from the final printed object. Some build materials are also known as inks, for example, when they are polymerizable liquids or other fluids that are jetted or otherwise selectively deposited to form 3D objects. In some such instances, the build material is solid at ambient temperature and turns liquid at elevated jetting temperatures. In other instances, the build material is liquid at ambient temperature. The build material can also be a powder or dry particulate material, as opposed to a polymerizable liquid. Such powders can be used in selective laser sintering (SLS) and similar additive manufacturing techniques.

[0004] Build materials can include a variety of chemical species. The chemical species included in the build material can be selected according to various considerations, including, but not limited to, the desired chemical and / or mechanical properties of the printed article and the operating parameters of the 3D printing device. Unfortunately, some build materials and products printed from build materials may be unsuitable for electronics and transportation applications and / or other applications requiring flame retardancy. Summary of the Invention [Problem to be solved by the invention]

[0005] As a result, 3D printing technology may have limited application in areas requiring flame-retardant or flame-resistant materials and articles, and improved materials for forming flame-retardant or flame-resistant articles by additive manufacturing are needed. [Means for solving the problem]

[0006] In light of the above, compositions (or build materials) for additive manufacturing applications are described herein, which, in some embodiments, impart flame retardancy and / or flame resistance to articles printed or formed from the compositions. The compositions may also impart or maintain desirable mechanical properties to the articles. In some embodiments, the compositions described herein include a sinterable powder in an amount of 10 to 99% or 10 to 99.9% by weight, based on the total weight of the composition, and an oxygen barrier in an amount of up to 25%, up to 15%, or up to 10% by weight, based on the total weight of the composition. The oxygen barrier includes at least one of (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component. In some cases, the oxygen barrier includes only the organophosphorus component and the heptazine or melamine-derived component. In other examples, the oxygen barrier also includes the organophosphorus component, the heptazine or melamine-derived component, and the polymeric organobromine component.

[0007] In some embodiments of the compositions described herein, the organophosphorus component comprises a species further described below, such as a species of Formula Ia, Formula Ib, Formula II, and / or Formula III: Further, in some examples, the oxygen barrier of the compositions described herein comprises a combination of two, three, or all four of a species of Formula Ia, a species of Formula Ib, a species of Formula II, and a species of Formula III.

[0008] Additionally, in some cases, the heptazine or melamine-derived component includes a heptazine derivative or heptazine-based species, such as melem, melam, or melon. As further described below, other species can also be used. In some cases, the heptazine or melamine-derived component does not include melamine itself.

[0009] The polymeric organobromine component of the compositions described herein can include species further described below, such as brominated polystyrene, brominated polyacrylate, brominated epoxy, end-capped brominated epoxy, or a combination of two or more thereof.

[0010] The sinterable powders of the compositions described herein, in some cases, include a semi-crystalline polymer, which in some instances is included as a major or primary component. For example, in some embodiments, the sinterable powder includes polyamide (PA), polyesters (PEs), polyurethane (PU), polyethylene (PE), polypropylene (PP), poly(butylene terephthalate) (PBT), poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK), or a combination of two or more of the foregoing. In some embodiments, the sinterable powders described herein further include a filler component or material, such as glass, ceramic, or carbon fiber.

[0011] Additionally, in some cases, the compositions described herein are free or substantially free of phosphate.

[0012] Some compositions described herein are particularly suitable for forming 3D articles using SLS and other additive manufacturing techniques that use powder or dry particulate build materials. However, the compositions and methods described herein are not necessarily limited to SLS or other sintering applications or uses. The present disclosure also contemplates compositions and methods for forming articles using other additive manufacturing techniques. For example, in some examples, compositions and methods for fused deposition modeling (FDM) are also described. In such embodiments, the sinterable powders described above can be replaced with different materials, such as thermoplastic polymers, that can be extruded, sprayed, or otherwise deposited in a layer-by-layer manner to form 3D articles.

[0013] Thus, in some cases, compositions for additive manufacturing are described herein, which include a thermoplastic polymer in an amount of 10 to 99% by weight or 10 to 99.9% by weight, based on the total weight of the composition, and an oxygen barrier in an amount of up to 25%, up to 15%, or up to 10% by weight, based on the total weight of the composition. The oxygen barrier may include at least one of (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component. In some preferred embodiments, the oxygen barrier includes an organophosphorus component and a heptazine or melamine-derived component, but does not necessarily include a polymeric organobromine species. Additionally, the oxygen barrier may include any of the components, species, or combinations and species combinations described above for compositions including a sinterable powder instead of a non-particulate or non-powdered thermoplastic polymer. Thermoplastic polymers, in some embodiments, include acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), nylon, polycarbonate, or combinations, block copolymers, or melts of two or more of the foregoing.

[0014] Also described herein are methods for printing or forming 3D articles. In some embodiments, such methods include providing a composition described herein and selectively solidifying layers of the composition to form the article. In some cases, the composition is provided in a layer-by-layer process. Furthermore, in some examples, the compositions and methods described herein provide printed articles that are flame-retardant and / or flame-resistant. For example, in some embodiments, articles formed from the compositions and / or methods described herein pass the FAR 25.853 test (60 seconds and 12 seconds).

[0015] Additionally, articles formed from the compositions and / or methods described herein can provide flame retardancy and / or flame resistance while maintaining other desirable mechanical properties. For example, in some instances, the article has a tensile modulus that is at least 90% of the tensile modulus of a reference article formed from a reference composition excluding the oxygen barrier. Further, in some embodiments, the article has a tensile strength that is at least 70% of the tensile strength of a reference article formed from a reference composition excluding the oxygen barrier. Further, in some embodiments, the article has an elongation to break that is at least 70% of the elongation to break of a reference article formed from a reference composition excluding the oxygen barrier component.

[0016] These and other embodiments are further described in the detailed description that follows. DETAILED DESCRIPTION OF THE INVENTION

[0017] The embodiments described herein can be more readily understood by reference to the following detailed description and examples. However, the elements, devices, and methods described herein are not limited to the specific embodiments presented in the detailed description and examples. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Many modifications and adaptations will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

[0018] Furthermore, all ranges disclosed herein should be understood to encompass any and all subranges subsumed therein. For example, a stated range of "1.0 to 10.0" should be deemed to include any and all subranges beginning with a minimum value greater than or equal to 1.0 and ending with a maximum value less than or equal to 10.0, such as 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.

[0019] All ranges disclosed herein should also be considered to include the endpoints of the range, unless otherwise specified. For example, the range "between 5 and 10" should generally be considered to include the endpoints 5 and 10.

[0020] Furthermore, when the term "up to" is used in reference to an amount or quantity, it is understood that the amount is at least a detectable amount or quantity. For example, a substance present in an amount "up to" a particular amount can be present in an amount from a detectable amount (or non-zero amount) up to and including the particular amount.

[0021] Additionally, in any disclosed embodiment, the terms "substantially," "approximately," and "about" may be substituted with "within [a percentage]" as specified, where the percentage may be 0.1, 1, 5, or 10 percent, unless the use of such terminology in a given instance indicates otherwise.

[0022] The article "a" or "an" should also be understood to refer to "at least one," unless the context of the particular use requires otherwise.

[0023] Terms such as "three-dimensional printing system," "three-dimensional printer," and "printing" generally describe various solid freeform manufacturing techniques for creating three-dimensional articles or objects by selective laser sintering (SLS), stereolithography (SLA), dynamic light projection (DLA), selective deposition, jetting, fused deposition modeling (FDM), multi-jet modeling (MJM), and other additive manufacturing techniques currently known or that may become known in the art that use build materials or inks to fabricate three-dimensional objects.

[0024] Further definitions include: The term "alkyl," as used herein, alone or in combination, refers to a straight-chain or branched-chain saturated hydrocarbon group optionally substituted with one or more substituents. For example, alkyl includes C1 to C6 30 or C1~C 18 may be.

[0025] The term "alkenyl," as used herein, alone or in combination, refers to a straight-chain or branched-chain hydrocarbon group having at least one carbon-carbon double bond and optionally substituted with one or more substituents.

[0026] The term "alkynyl," as used herein, alone or in combination, refers to a straight-chain or branched-chain hydrocarbon group having at least one carbon-carbon triple bond and optionally substituted with one or more substituents.

[0027] The term "aryl," as used herein, alone or in combination, refers to an aromatic monocyclic or polycyclic ring system optionally substituted with one or more ring substituents.

[0028] The term "heteroaryl," as used herein, alone or in combination, refers to an aromatic monocyclic or polycyclic ring system in which one or more of the ring atoms is an element other than carbon, such as nitrogen, boron, oxygen, and / or sulfur.

[0029] The term "heterocycle," as used herein, alone or in combination, refers to a monocyclic or polycyclic ring system in which one or more atoms of the ring system are elements other than carbon, such as boron, nitrogen, oxygen, and / or sulfur or phosphorus, and the ring system is optionally substituted with one or more ring substituents. Heterocyclic ring systems can include aromatic and / or non-aromatic rings, including rings with one or more points of unsaturation.

[0030] The term "heteroalkyl," as used herein, alone or in combination, refers to an alkyl moiety as defined above having one or more carbon atoms, e.g., 1, 2, or 3 carbon atoms, substituted with one or more heteroatoms, which may be the same or different.

[0031] The term "heteroalkenyl," as used herein, alone or in combination, refers to an alkenyl moiety as defined above having one or more carbon atoms, e.g., 1, 2, or 3 carbon atoms, substituted with one or more heteroatoms, which may be the same or different.

[0032] The term "cycloalkyl," as used herein, alone or in combination, refers to a non-aromatic, monocyclic or polycyclic ring system optionally substituted with one or more ring substituents.

[0033] In one aspect, compositions for use in additive manufacturing applications are described herein. The compositions can be used, for example, in SLS and FDM printing applications.

[0034] In some embodiments, the compositions described herein include a sinterable powder in an amount of 10 to 99 wt. % based on the total weight of the composition, and an oxygen barrier in an amount of up to 25 wt. %, up to 15 wt. %, or up to 10 wt. % based on the total weight of the composition. The oxygen barrier includes at least one of (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component. In some cases, the oxygen barrier includes only the organophosphorus component and the heptazine or melamine-derived component. In other examples, the oxygen barrier also includes the organophosphorus component, the heptazine or melamine-derived component, and the polymeric organobromine component.

[0035] As further described herein, compositions according to the present disclosure can provide flame retardancy and / or flame resistance while also maintaining other desirable mechanical properties. More specifically, in some cases, the compositions described herein can provide or impart oxygen barrier properties to articles formed from the compositions. Fire typically requires three elements: fuel, oxygen, and a flame or ignition. Flame-retardant or flame-resistant solutions for flames and fires, such as those described herein, can eliminate or suppress one or more of the aforementioned elements of the so-called "fire triangle." In some embodiments, the compositions or printed 3D articles described herein eliminate or suppress the supply of oxygen to a fire or flame and are "gas-phase" or "vapor-phase" flame-retardant or flame-resistant compositions or articles. Such oxygen-barrier compositions or articles can suppress or disrupt the radical gas phase of a fire, thereby cooling the fire / flame / environment and reducing the supply of flammable gases to the fire / flame / environment.

[0036] When referring to specific components herein, the organophosphorus component of the oxygen barrier can include any organophosphorus species not inconsistent with the technical objectives described herein. In some embodiments, the organophosphorus component includes one or a mixture of specific organophosphorus species, including mixtures of specific species described below.

[0037] In some embodiments, the organophosphorus component comprises a species of Formula Ia or Formula Ib: [ka] In the formula, R 1 , R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl (e.g., having 1 to 20 carbon atoms or 1 to 10 carbon atoms); and [ka] In the formula, R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl (e.g., having 1 to 20 carbon atoms or 1 to 10 carbon atoms); M is a metal; n is an integer of 1 to 3. For example, in some cases, M is aluminum (Al) and n is 3. Other species of formula Ib can also be used. For example, in some cases, M n+ Na + or Zn 2+ Counterion M n+ It is also possible to replace with a different cation that does not necessarily contain or consist of metal ions, for example an organic cation or a cation complex.

[0038] In still other cases, the organophosphorus component described herein includes a phosphonate. In other examples, the phosphonate is excluded or is present in an amount less than 0.5% by weight. In some embodiments, the organophosphorus component includes a species of Formula II or a species of Formula III: [ka] and [ka]

[0039] In some examples, the organophosphorus component includes an oligomeric non-halogen phosphate ester, such as Fyrolflex® RDP, available from ICL Industrial Products.

[0040] The organophosphorus component (or any combination of organophosphorus components) of the oxygen barriers described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some cases, for example, the organophosphorus component is present in an amount of up to 10% by weight or up to 5% by weight, based on the total weight of the composition. In some cases, the organophosphorus component is present in an amount of 1-10% by weight, 1-8% by weight, 1-5% by weight, 1-3% by weight, 3-10% by weight, 3-8% by weight, 5-10% by weight, or 5-8% by weight, based on the total weight of the composition.

[0041] The oxygen barrier of the compositions described herein can also include a heptazine or melamine-derived component. Any heptazine or melamine-derived component that is consistent with the technical objectives of the present disclosure can be used. In some examples, the heptazine or melamine-derived component is a derivative of or contains one or more structural units corresponding to heptazine or melamine. In some embodiments, for example, the heptazine or melamine-derived component includes melem, melam, or melon. In some cases, the heptazine or melamine-derived component does not include melamine itself.

[0042] In some cases, the heptazine or melamine derived component comprises a species of formula IV: [ka] In the formula, X, Y, and Z are each independently H and NR 6 R 7 selected from; and In the formula, R 6 and R 7 are each independently selected from H and C1-C5 alkyl. For example, in some embodiments, X, Y, and Z are each H. In other cases, X, Y, and Z are each NH2.

[0043] "Cn" (or "C n It is further understood that a species (such as a "Cn" alkyl) is a species (such as an alkyl moiety) that includes or contains exactly "n" carbon atoms. Thus, a C1-C5 alkyl group can include any alkyl group having exactly 1, 2, 3, 4, or 5 carbons, respectively.

[0044] In some embodiments described herein, R 6 and R 7 are each H, and one or more of X, Y, and Z contains NH. In some cases, R 5 and R 7 are each independently H, methyl, or ethyl.

[0045] In other embodiments, the heptazine or melamine derived component comprises a species of formula V: [ka] In the formula, n is an integer of 2 to 1,000.

[0046] In some embodiments, the heptazine or melamine derived component comprises a species of formula VI: [ka] In the formula, W, X, Y, and Z are each independently H and NR 6 R 7 selected from; and In the formula, R 6 and R 7are each independently selected from H and C1-C5 alkyl. For example, in some cases, W, X, Y, and Z are each NH2.

[0047] Furthermore, in some cases, the heptazine or melamine-derived component of the oxygen barrier described herein includes a heptazine or melamine-derived oligomer. As known to those skilled in the art, an oligomer includes multiple chemically bonded monomers. Thus, the heptazine or melamine-derived oligomer includes multiple chemically bonded heptazine or melamine-derived units. In some cases, the heptazine or melamine-derived oligomer includes highly condensed g-CN. In some embodiments, the heptazine or melamine-derived component includes a species of Formula VII: [ka] In the formula, the dashed bonds indicate crosslinks between repeat units. Heptazine- or melamine-derived oligomers, such as highly condensed g-CN, can be prepared according to methods such as those found in Ping, N.; Zhang, L.; Gang, L.; Cheng, H.I., Graphene-Like Carbon Nitride Nanosheets for Improved Photocatalytic Activities, Adv. Funct. Mater. 2012 (22), 4763-4770. Other heptazine- or melamine-derived oligomers can also be used in the compositions described herein.

[0048] The heptazine or melamine-derived component (or the total amount of heptazine or melamine-derived components) of the oxygen barriers described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some cases, for example, the heptazine or melamine-derived component is present in an amount of up to 24% by weight, up to 20% by weight, up to 15% by weight, up to 10% by weight, or up to 5% by weight, based on the total weight of the composition. In some examples, the heptazine or melamine-derived component is present in an amount of 1-24% by weight, 1-20% by weight, 1-15% by weight, 1-10% by weight, 1-5% by weight, 5-24% by weight, 5-20% by weight, 5-15% by weight, 10-24% by weight, 10-20% by weight, or 15-24% by weight, based on the total weight of the composition.

[0049] The oxygen barrier of the compositions described herein, in some embodiments, comprises a polymeric organobromine component. Any polymeric organobromine component not inconsistent with the technical objectives of the present disclosure may be used. Furthermore, a "polymeric" organobromine component may include a polymer whose repeating units are organobromine units, as opposed to, for example, a polymer that is terminally brominated but does not contain organobromine moieties in the repeating units of the polymer itself. The polymeric organobromine species described herein, in some cases, have a weight average molecular weight ranging from 500 to 100,000; 500 to 5,000; 1,000 to 10,0000; or 1,000 to 5,000. Furthermore, it should be understood that the polymeric organobromine component of the compositions described herein may be different from the organophosphorus component of the composition. In some cases, the polymeric organobromine component comprises one or more of FR-122P, FR-803P (brominated polystyrene), FR-1025 (brominated polyacrylate), F-2001 (brominated epoxy), F-2200 HM (brominated epoxy), F-1600 (brominated epoxy), F-2100L (brominated epoxy), F-2100 (brominated epoxy), F-2100H (brominated epoxy), F-2400E (brominated epoxy), F-2400 (brominated epoxy), F-2400H (brominated epoxy), F-3014 (end-capped brominated epoxy), F-3020 (end-capped brominated epoxy), and F-3100 (end-capped brominated epoxy), all of which are commercially available from ICI Industrial Products.

[0050] The polymeric organobromine component (or a combination of all polymeric organobromine species) of the oxygen barriers described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some cases, for example, the polymeric organobromine component is present in an amount of up to 10% by weight, up to 5% by weight, up to 3% by weight, or up to 1% by weight, based on the total weight of the composition. In some cases, the polymeric organobromine component is present in an amount of 1-25% by weight, 1-20% by weight, 1-15% by weight, 1-10% by weight, 1-5% by weight, 5-25% by weight, 5-20% by weight, 5-15% by weight, 10-25% by weight, 10-20% by weight, or 15-25% by weight.

[0051] In some embodiments, the oxygen barrier of the composition described herein may also contain one or more additional components. For example, in some cases, the oxygen barrier further contains a dispersant component. Any dispersant component that is not inconsistent with the technical objectives of the present disclosure may be used. For example, in some cases, the dispersant component includes fumed silica.

[0052] The dispersant component of the oxygen barriers described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some cases, for example, the dispersant component is present in an amount of up to 0.1 wt.%, up to 0.05 wt.%, or up to 0.01 wt.%, based on the total weight of the composition. In some examples, the dispersant component is present in an amount of 0.01-0.1 wt.%, 0.01-0.05 wt.%, or 0.05-0.1 wt.%, based on the total weight of the composition. In some embodiments, the oxygen barriers of the compositions described herein are free of a dispersant component or contain less than 0.01 wt.% of a dispersant component.

[0053] Additionally, in some examples, the oxygen barriers of the compositions described herein contain no or less than 0.1 wt. % of a blowing agent component. Such excluded or minimally included blowing agent components can include, for example, urea, urea-formaldehyde resin, or dicyandiamide.

[0054] The oxygen barrier of the compositions described herein can be present in any amount consistent with the technical objectives of the present disclosure. In some embodiments, the oxygen barrier is present in the composition in an amount of 1 to 25 wt.%, 1 to 20 wt.%, 1 to 15 wt.%, or 1 to 10 wt.%, based on the total weight of the composition. In some cases, the oxygen barrier is present in the composition in an amount of 1 to 9 wt.%, 5 to 15 wt.%, 10 to 20 wt.%, or 15 to 25 wt.%, based on the total weight of the composition.

[0055] The compositions described herein also include, in some embodiments, sinterable powders. As will be appreciated by those skilled in the art, "sinterable" powders can be selectively sintered or fused by the application of energy, such as that provided by a laser beam or other electromagnetic radiation source. The application of energy (e.g., a selectively applied laser beam) can selectively heat powder particles, resulting in partial melting of the powder and fusing adjacent particles together. Thus, "sintering" can, in some cases, involve heating a powder to a temperature that induces viscous flow only at the adjacent boundaries of individual powder particles, with at least a portion of substantially all particles remaining solid. As discussed above, such sintering causes the particles to coalesce into a sintered solid mass, the bulk density of which increases compared to the bulk density of the powder particles before sintering. Such fusion can provide a solidified portion (e.g., a cross section or layer) of an article or object printed or formed by the process. Thus, an article or object formed by layer-by-layer or "slice-like" joining of vertically successive layers that are sintered into stacked "layers" or "slices" can be described as autogenously densified. Such slices or layers may, for example, have a thickness of up to about 250 μm, for example in the range of 50 μm to 180 μm.

[0056] Thus, the sinterable powders of the present disclosure can have optical, thermal, and other properties suitable for use in 3D printing systems or methods that selectively fuse or sinter individual powder particles to form an object. For example, the sinterable powders can have optical (e.g., absorbance) and / or thermal properties (e.g., glass transition temperature, Tg; melting point, MP; or crystallization temperature, Tc) selected for sintering with a particular electromagnetic radiation source. In some embodiments, the sinterable powders described herein have a non-zero absorbance or absorbance peak at a wavelength used in a 3D printing process (e.g., the peak wavelength of a laser, such as a CO2 laser used in an SLS process). Additionally, in some cases, the sinterable powders described herein have a sintering window (defined as the metastable thermodynamic region between melting and crystallization, or the difference between the MP onset and the Tc onset) of at least 10°C, as measured by differential scanning calorimetry (DSC) using a heating rate of 10°C / min, e.g., 10-30°C, 10-25°C, or 10-20°C. Additionally, in some examples, the sinterable powders described herein have an MP of 120-270°C, 150-250°C, 150-200°C, 150-180°C, 170-250°C, 170-220°C, 170-200°C, 190-250°C, 190-220°C, or 200-250°C.

[0057] Further, in some cases, the sinterable powders can have an average particle size and flowability suitable for use in such additive manufacturing processes. For example, in some embodiments, the sinterable powders described herein have an average particle size (D) of 60-300 μm, 60-250 μm, 60-200 μm, 60-150 μm, 60-100 μm, 80-300 μm, 80-250 μm, 80-200 μm, 80-150 μm, 80-100 μm, 100-300 μm, 100-250 μm, 100-200 μm, 150-300 μm, 150-250 μm, 150-200 μm, 200-300 μm, or 200-250 μm. 50). The particle sizes described herein can be measured using any suitable method known to one of ordinary skill in the art. For example, in some preferred embodiments, particle sizes are determined using sieve analysis in accordance with ASTM D1921. The sinterable powders described herein, in some implementations, have a monomodal particle size distribution (PSD), as opposed to a bimodal or other higher-order PSD.

[0058] Additionally, in some cases, the sinterable powders described herein have a normalized packing density of 20-45% or 25-40%. Additionally, in some embodiments, the sinterable powders described herein have an average circularity (defined as the ratio of the measured area of a particle to the area of an equivalent circle whose diameter is the maximum length of the particle) of 0.4-0.6. The average circularity can be measured by any method consistent with the technical objectives of the present disclosure. In some cases, for example, the average circularity is measured using dynamic image analysis in accordance with ISO 13322-2:2021.

[0059] Additionally, in some embodiments, the sinterable powders described herein have a bulk and / or tapped density of greater than 0.35 g / mL or greater than 0.4 g / mL, e.g., a bulk and / or tapped density of 0.35 to 1 g / mL or 0.4 to 1 g / mL, as measured according to ASTM D1895B (bulk density) or ASTM B527 (tapped density).

[0060] It is further noted that in some cases, the oxygen barriers described herein do not significantly alter the sintering functionality window of the sinterable powders described herein. For example, in some cases, the sintering functionality window of a composition including an oxygen barrier described herein has a width (in degrees Celsius) and / or one or more endpoints (in degrees Celsius) that is within 1°C, within 2°C, or within 5°C of an otherwise similar composition that does not include the oxygen barrier. Furthermore, in some examples, the compositions described herein that include an oxygen barrier do not emit or produce smoke when heated by a laser or other heat source in an additive manufacturing process as described herein. Thus, in some embodiments, performing the methods described herein does not produce smoke observable by a human observer with average visual acuity when observing the method without the use of any equipment or visual aids other than corrective lenses, such as glasses or contact lenses.

[0061] Any sinterable powder consistent with the objectives of the present disclosure can be used. In some cases, the sinterable powder includes a semi-crystalline polymer, and in some cases, it is included as the major or primary component (by mass or weight) of the sinterable powder. Any semi-crystalline polymer consistent with the objectives of the present disclosure can be used. In some implementations, the sinterable powder of the compositions described herein includes (or primarily includes as a major component) polyamide (PA), polyester (PEs), polyurethane (PU), polyethylene (PE), polypropylene (PP), poly(butylene terephthalate) (PBT), poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK), or a combination of two or more of the foregoing. When the sinterable powder includes polyamide (PA), any PA consistent with the objectives of the present disclosure can be used. For example, in some cases, the PA includes polyamide 11 (PA11), polyamide 12 (PA12), or a combination of PA11 and PA12.

[0062] In some cases, the sinterable powders described herein comprise up to 100%, up to 99%, up to 95%, or up to 90% by weight of semi-crystalline polymer, based on the total weight of the sinterable powder (rather than based on the total weight of the entire composition). In some examples, the sinterable powders comprise 50-100%, 50-99%, 50-90%, 50-80%, 50-70%, 60-100%, 60-99%, 60-90%, 70-100%, 70-99%, 70-90%, 80-100%, 80-99%, 80-95%, 85-100%, 85-99%, 85-95%, 90-100%, or 90-99% by weight of semi-crystalline polymer, based on the total weight of the sinterable powder.

[0063] In addition to the primary or main components described above, the sinterable powders described herein may also include one or more additional components. In some embodiments, for example, the sinterable powder includes a filler material. Any filler material consistent with the objectives of the present disclosure may be used. For example, in some cases, the filler material includes glass, ceramic, or carbon fiber. In some embodiments, the filler material is in the form of spheres, plates, or fibers, and the shape of any filler material is not particularly limited.

[0064] When a filler material is used, it can be present in the sinterable powder in any amount consistent with the technical objectives of the present disclosure. For example, in some cases, the sinterable powders described herein include up to 30%, up to 20%, up to 15%, or up to 10% by weight of filler material, based on the total weight of the sinterable powder (not based on the total weight of the entire composition). In some examples, the sinterable powder includes 1-30%, 1-25%, 1-20%, 1-15%, 1-10%, 1-5%, 5-30%, 5-25%, 5-20%, 5-15%, or 5-10% by weight of filler material, based on the total weight of the sinterable powder.

[0065] The sinterable powders described herein may also include a flow agent. Any flow agent consistent with the technical objectives of the present disclosure may be used. For example, in some cases, the flow agent comprises a nanoparticle coating or other coating, such as a silica nanoparticle coating, on the sinterable powder or on the semi-crystalline polymer of the sinterable powder. One example of a flow agent suitable for use in some embodiments described herein is Aerosil 200.

[0066] When used, a flow-regulating agent can be present in the sinterable powder in any amount consistent with the technical objectives of the present disclosure. For example, in some cases, the sinterable powders described herein include up to 10% by weight, up to 5% by weight, up to 1% by weight, or up to 0.5% by weight of flow-regulating agent, based on the total weight of the sinterable powder (not based on the total weight of the entire composition). In some examples, the sinterable powder includes 0.01-10% by weight, 0.01-5% by weight, or 0.01-1% by weight of flow-regulating agent, based on the total weight of the sinterable powder.

[0067] Furthermore, in some cases, the compositions described herein exclude certain ingredients or contain only small amounts.For example, in some cases, the compositions described herein are free of or substantially free of phosphate.In some embodiments, the compositions described herein that are "substantially free" of phosphate contain or can contain less than 5% by weight, less than 3% by weight, less than 1% by weight, or less than 0.5% by weight of phosphate based on the total weight of the composition.In some cases, the compositions that are substantially free of phosphate contain less than 0.1% by weight or less than 0.01% by weight of phosphate based on the total weight of the composition.

[0068] In addition to compositions for additive manufacturing, methods of additive manufacturing are also described herein. Such methods of forming or printing 3D articles, objects, or parts can include forming 3D articles from multiple layers of the compositions described herein as build materials, including layer-by-layer embodiments. Any of the compositions described above can be used. Furthermore, the layers of the compositions can be formed or provided according to an image of the 3D article in a computer-readable format, for example, according to preselected computer-aided design (CAD) parameters.

[0069] As previously mentioned, such methods can include SLS or other sintering methods. As will be understood by those skilled in the art, SLS methods can include holding a composition described herein in a container (such as a build bed or powder bed) and selectively applying energy to the composition in the container to solidify (or freeze or sinter) at least a portion of the layer of the composition, thereby forming a solidified (or frozen or sintered) layer that defines a cross-section of the 3D article. Furthermore, the methods described herein can further include raising or lowering the solidified layer of the composition to provide a new or second layer of unsolidified composition on the surface of the composition in the container, and then selectively applying energy again to the composition in the container to solidify (or freeze or sinter) at least a portion of the new or second layer of composition to form a second solidified layer that defines a second cross-section of the 3D article. Furthermore, the first and second cross-sections of the 3D article can be bonded or adhered to each other in the z-direction (or build direction corresponding to the above-mentioned direction of raising or lowering) by the application of energy to solidify (or freeze or sinter) the composition. Additionally, selectively applying energy to the composition within the container can include applying electromagnetic radiation having sufficient energy to solidify (or solidify or sinter) the composition. In some instances, the electromagnetic radiation has an average wavelength of 300 to 1500 nm. In some instances, the solidifying (or solidifying or sintering) radiation is provided by a computer-controlled laser beam. Furthermore, in some instances, raising or lowering the solidified layer of composition is accomplished using an elevator platform disposed within the container. The methods described herein can also include flattening the new layer of composition provided by raising or lowering the elevator platform, or rolling the new layer of composition. Such flattening or rolling can, in some instances, be accomplished by a wiper or roller.

[0070] It should be further understood that the foregoing process can be repeated as many times as desired to provide a 3D article. For example, in some cases, the process can be repeated "n" times, where n can be up to about 100,000, up to about 50,000, up to about 100,000, up to about 5000, up to about 1000, or up to about 500. Thus, in some embodiments, methods of printing a 3D article described herein can comprise selectively applying energy to the composition in the container to solidify (or coagulate or sinter) at least a portion of the nth layer of the composition, thereby forming an nth solidified layer that defines the nth cross-section of the 3D article; raising or lowering the nth solidified layer of the composition to provide an (n+1)th layer of unsolidified composition on a surface of the composition in the container; selectively applying energy to the (n+1)th layer of the composition in the container to solidify at least a portion of the (n+1)th layer of the composition to form the (n+1)th solidified layer that defines the (n+1)th cross-section of the 3D article; raising or lowering the (n+1)th solidified layer of the composition to provide an (n+2)th layer of unsolidified composition on a surface of the composition in the container; and continuing to repeat the foregoing steps to form the 3D article. Furthermore, it should be understood that one or more steps of the methods described herein, such as selectively applying energy to a layer of a composition, may be performed according to an image of the 3D article in a computer-readable format.

[0071] Thus, in some embodiments, a method for printing a 3D article described herein includes providing a composition described herein and selectively solidifying layers of the composition to form the article. Further, in some cases, the composition is provided in a layer-by-layer process. In some cases, the method is SLS or other particle sintering method of additive manufacturing.

[0072] The compositions and methods described herein are not necessarily limited to selective laser sintering (SLS) or other sintering applications or uses. The present disclosure also contemplates compositions and methods for forming articles using other additive manufacturing techniques. For example, in some examples, compositions and methods for fused deposition modeling (FDM) are also described. In such embodiments, the sinterable powders described above can be replaced with a different material, such as a thermoplastic polymer that can be extruded, sprayed, or otherwise deposited in a layer-by-layer manner to form a 3D article.

[0073] Thus, in some cases, compositions for additive manufacturing are described herein, including a thermoplastic polymer in an amount of 10 to 99 wt %, based on the total weight of the composition, and an oxygen barrier in an amount of up to 25 wt %, up to 15 wt %, or up to 10 wt %, based on the total weight of the composition. The oxygen barrier includes at least one of (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component. In such embodiments, it should be understood that the oxygen barrier and its components (e.g., the organophosphorus component, the heptazine or melamine-derived component, and the polymeric organobromine component) can be the same or have the same properties as those described above for compositions including a sinterable powder instead of a thermoplastic polymer. Furthermore, the thermoplastic polymer of the composition can include any thermoplastic polymer not inconsistent with the technical objectives of the present disclosure. For example, in some cases, the thermoplastic polymer includes acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), nylon, polycarbonate, or a combination, block copolymer, or melt of two or more thereof.

[0074] The compositions described above can be used in additive manufacturing material deposition methods, such as FDM. In material deposition methods, one or more layers of the compositions described herein are selectively deposited onto a substrate as a build material and solidified. In some cases, solidification involves rapid cooling of the composition or the composition undergoing a phase transition (e.g., from liquid to solid).

[0075] Thus, in some examples, the compositions (or build materials) described herein are selectively deposited in a fluid state onto a substrate, such as a build pad of a 3D printing system. Selective deposition can include, for example, depositing the build material according to preselected CAD parameters. For example, in some embodiments, a CAD file drawing corresponding to the desired 3D article to be printed is generated and sliced into a sufficient number of horizontal slices. The build material is then selectively deposited layer-by-layer according to the horizontal slices of the CAD file drawing to print the desired 3D article. A "sufficient" number of horizontal slices is, for example, the number necessary for successful printing of the desired 3D article to accurately and precisely manufacture the desired 3D article.

[0076] Further, in some embodiments, a preselected amount of the build material described herein is heated to an appropriate temperature and extruded or ejected from a suitable printer nozzle or print head or heads to form a layer on a print pad in a print chamber. In some embodiments, each layer of build material is deposited according to preselected CAD parameters. As described above, in some embodiments, the composition (or build material) described herein exhibits a phase change upon deposition and / or solidifies upon deposition. Furthermore, in some cases, the temperature of the printing environment can be controlled so that a deposited portion of the build material solidifies upon contact with a receiving surface. Furthermore, in some cases, after each layer is deposited, the deposited material is planarized before the deposition of the next layer. Optionally, multiple layers can be deposited before planarization. Planarization compensates for the thickness of one or more layers by leveling the dispensed material and removing excess material, forming a uniformly smooth, exposed, or flat, upward-facing surface on the printer's support platform. In some embodiments, planarization is achieved using a wiper device, such as a roller, that may counter-rotate in one or more printing directions but not in one or more other printing directions. In some cases, the wiper device comprises a roller and a wiper that removes excess material from the roller. Additionally, in some cases, the wiper device is heated. Note that the viscosity of the deposited build material described herein, in some embodiments, is desirably sufficient to retain its shape and not experience excessive viscous drag from the planarization device. Layer-by-layer deposition of build material can be repeated until the 3D article is formed.

[0077] The compositions and methods (e.g., SLS or FDM methods) described herein can form 3D articles that exhibit flame retardancy or flame resistance. For example, in some cases, the articles pass FAR 25.853 (60 seconds and 12 seconds). In some embodiments, the test sample thickness that passes FAR 25.853 (60 seconds and 12 seconds) can be less than 2 mm or less than 1 mm, for example, 0.8 mm or 0.4 mm.

[0078] Furthermore, the compositions and methods described herein can be used to provide 3D articles that not only exhibit flame retardancy or flame resistance but also have desirable mechanical properties.For example, 3D articles printed from the compositions described herein (and the compositions themselves when solidified as described herein) can have certain mechanical properties, such as tensile modulus (TM), tensile strength (TS), and elongation at break (EOB), that are close to those exhibited by otherwise similar 3D articles (or compositions) that do not contain oxygen barriers as described herein.For example, in some cases, the 3D articles or compositions described herein (depending on their composition / microstructure) can exhibit one, two, or all three of the following metrics: a tensile modulus (TM) ratio of at least 0.9, at least 0.95, or at least 0.98 (e.g., a TM ratio of 0.9 to 1 or 0.95 to 1); a tensile strength (TS) ratio of at least 0.6, at least 0.7, at least 0.75, or at least 0.8 (e.g., a TS ratio of 0.7 to 1, 0.75 to 0.85, or 0.8 to 0.95); and An elongation at break (EOB) ratio of at least 0.6, at least 0.7, at least 0.75, or at least 0.8 (e.g., an EOB ratio of 0.7-0.95, 0.7-0.9, 0.7-0.85, 0.8-1, or 0.8-0.9).

[0079] The above metrics are based on comparing a specified property (TM, TS, or EOB) of a 3D article formed from a composition described herein with a specified property (TM, TS, or EOB) of an otherwise identical 3D article formed in the same manner from the same composition described herein, except for omitting the oxygen barrier of the present invention. The relevant property (i.e., tensile modulus, tensile strength, or elongation at break) of a test sample (e.g., a 3D article formed from the composition) is measured after printing the 3D article (e.g., within 12 hours) and at the same time point after printing for comparison purposes. The same test method (e.g., ASTM D638) is used to test both samples / 3D articles in a set of samples / 3D articles being compared. The above ratios are based on a numerator that is the property value (e.g., TM, TS, or EOB) of a 3D article that includes an oxygen barrier, and a denominator that is the corresponding property value (e.g., TM, TS, or EOB) of an otherwise similar 3D article that does not include an oxygen barrier. [Example]

[0080] Tables 1-4 provide examples of possible formulations of compositions according to some embodiments described herein, where sinterable powders may be used (Tables 1 and 2) or non-particulate or non-powdered thermoplastic polymers may be used (Tables 3 and 4). The amounts listed in Tables 1 and 3 are weight percents based on the total weight of the relevant composition. A dash (--) indicates that the particular ingredient is not included. [Table 1] [Table 2] [Table 3] [Table 4]

[0081] Some additional non-limiting exemplary embodiments are described below.

[0082] Embodiment 1. A composition for additive manufacturing, comprising: a sinterable powder in an amount of 10 to 99% by weight, based on the total weight of the composition; and an oxygen barrier in an amount of up to 25% by weight, based on the total weight of the composition Including, The composition, wherein the oxygen barrier comprises at least one of (a) an organophosphorus component, (b) a heptazine or melamine derived component, and (c) a polymeric organobromine component.

[0083] Embodiment 2. The composition of embodiment 1, wherein the oxygen barrier comprises a heptadine or a melamine-derived component.

[0084] Embodiment 3. The composition of embodiment 1, wherein the oxygen barrier comprises an organophosphorus component.

[0085] Embodiment 4. The composition of embodiment 1, wherein the oxygen barrier comprises a polymeric organobromine component.

[0086] Embodiment 5. The organophosphorus component comprises a species of Formula Ia or Formula Ib: [ka] In the formula, R 1 , R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; and [ka] In the formula, R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; M is a metal; n is an integer between 1 and 3 The composition of any of the preceding embodiments.

[0087] Embodiment 6. The organophosphorus component comprises a species of Formula II: [ka] The composition of any of the preceding embodiments.

[0088] Embodiment 7. The organophosphorus component comprises a species of formula III: [ka] The composition of any of the preceding embodiments.

[0089] Embodiment 8. The composition of any of the preceding embodiments, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

[0090] Embodiment 9. The heptazine or melamine derived component comprises a species of formula IV: [ka] In the formula, X, Y, and Z are each independently H and NR 6 R 7 Selected from: In the formula, R 6 and R 7 are each independently selected from H and C1-C5 alkyl The composition of any of the preceding embodiments.

[0091] Embodiment 10. The heptazine or melamine derived component comprises a species of formula V: [ka] In the formula, n is an integer of 2 to 1000. The composition of any of the preceding embodiments.

[0092] Embodiment 11. The heptazine or melamine derived component comprises a species of formula VI: [ka] In the formula, W, X, Y, and Z are each independently H and NR 6 R 7 Selected from: In the formula, R 6 and R 7 are each independently selected from H and C1-C5 alkyl The composition of any of the preceding embodiments.

[0093] Embodiment 12. The composition of any of the preceding embodiments, wherein the heptadine or melamine-derived component does not comprise melamine.

[0094] Embodiment 13. The composition of any of the preceding embodiments, wherein the polymeric organobromine component comprises a brominated polystyrene, a brominated polyacrylate, a brominated epoxy, an end-capped brominated epoxy, or a combination of two or more of the foregoing.

[0095] Embodiment 14. The composition of any of the preceding embodiments, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

[0096] Embodiment 15. The composition of any of the preceding embodiments, wherein the composition is free or substantially free of phosphate.

[0097] Embodiment 16. The composition of any of the previous embodiments, wherein the sinterable powder comprises a semi-crystalline polymer.

[0098] Embodiment 17. The composition of any of the preceding embodiments, wherein the sinterable powder comprises polyamide (PA), polyesters (PEs), polyurethane (PU), polyethylene (PE), polypropylene (PP), poly(butylene terephthalate) (PBT), poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK), or a combination of two or more of the foregoing.

[0099] Embodiment 18. The composition of any of the previous embodiments, wherein the sinterable powder comprises a polyamide.

[0100] Embodiment 19. The composition of any of the previous embodiments, wherein the sinterable powder comprises a filler material.

[0101] Embodiment 20. A method of printing a three-dimensional article, comprising: providing a composition according to any one of embodiments 1 to 19; and Selectively solidifying the layer of composition to form the article. A method comprising:

[0102] Embodiment 21. The method of embodiment 20, wherein the composition is provided in a layer-by-layer process.

[0103] Embodiment 22. The method of embodiment 20 or 21, wherein the article passes FAR 25.853 (60 seconds and 12 seconds).

[0104] Embodiment 23. An article comprising: a tensile modulus (TM) ratio of at least 0.9; a tensile strength (TS) ratio of at least 0.7; and Elongation at break (EOB) ratio of at least 0.7 23. The method of any one of embodiments 20-22, having one, two, or three of:

[0105] Embodiment 24. A composition for additive manufacturing, comprising: a thermoplastic polymer in an amount of 10 to 99% by weight, based on the total weight of the composition; and an oxygen barrier in an amount of up to 25% by weight, based on the total weight of the composition Including, A composition, wherein the oxygen barrier comprises at least one of: (a) an organophosphorus component, (b) a heptazine or melamine derived component, and (c) a polymeric organobromine component.

[0106] Embodiment 25. The composition of embodiment 24, wherein the oxygen barrier comprises a heptadine or a melamine-derived component.

[0107] Embodiment 26. The composition of embodiment 24, wherein the oxygen barrier comprises an organophosphorus component.

[0108] Embodiment 27. The composition of embodiment 24, wherein the oxygen barrier comprises a polymeric organobromine component.

[0109] Embodiment 28. The organophosphorus component comprises a species of Formula Ia or Formula Ib: [ka] In the formula, R 1 , R 2 , and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; and [ka] In the formula, R 4 and R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; M is a metal; n is an integer between 1 and 3 28. The composition of any one of embodiments 24 to 27.

[0110] Embodiment 29. The organophosphorus component comprises a species of formula II: [ka] The composition of any one of embodiments 24 to 28.

[0111] Embodiment 30. The organophosphorus component comprises a species of Formula III: [ka] 30. The composition of any one of embodiments 24 to 29.

[0112] Embodiment 31. The composition of any of embodiments 24-30, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

[0113] Embodiment 32. The heptazine or melamine derived component comprises a species of formula IV: [ka] In the formula, X, Y, and Z are each independently H and NR 6 R 7 Selected from: In the formula, R 6 and R 7 are each independently selected from H and C1-C5 alkyl The composition of any one of embodiments 24 to 31.

[0114] Embodiment 33. The heptazine or melamine derived component comprises a species of formula V: [ka] In the formula, n is an integer of 2 to 1000. The composition of any one of embodiments 24 to 32.

[0115] Embodiment 34. The heptazine or melamine derived component comprises a species of formula VI: [ka] In the formula, W, X, Y, and Z are each independently H and NR 6 R 7 Selected from: In the formula, R 6 and R 7 are each independently selected from H and C1-C5 alkyl The composition of any one of embodiments 24 to 33.

[0116] Embodiment 35. The composition of any of embodiments 24-34, wherein the heptadine or melamine-derived component does not contain melamine.

[0117] Embodiment 36. The composition of any of embodiments 24-35, wherein the polymeric organobromine component comprises a brominated polystyrene, a brominated polyacrylate, a brominated epoxy, an end-capped brominated epoxy, or a combination of two or more of the foregoing.

[0118] Embodiment 37. The composition of any of embodiments 24-36, wherein the oxygen barrier is present in the composition in an amount of 1 to 30% by weight, based on the total weight of the composition.

[0119] Embodiment 38. The composition of any of embodiments 24-37, wherein the composition is free or substantially free of phosphate.

[0120] Embodiment 39. The composition of any of embodiments 24-38, wherein the thermoplastic polymer comprises acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), nylon, polycarbonate, or a combination, block copolymer, or melt of two or more of the foregoing.

[0121] Embodiment 40. A method of printing a three-dimensional article, comprising: providing a composition according to any one of embodiments 24 to 39; and Selectively solidifying the layer of composition to form the article. A method comprising:

[0122] Embodiment 41. The method of embodiment 40, wherein the composition is provided in a layer-by-layer process.

[0123] Embodiment 42. The method of embodiment 40 or 41, wherein the article passes FAR 25.85 (60 seconds and 12 seconds).

[0124] Embodiment 443. An article comprising: a tensile modulus (TM) ratio of at least 0.9; a tensile strength (TS) ratio of at least 0.7; and Elongation at break (EOB) ratio of at least 0.7 43. The method of any one of embodiments 40 to 42, having one, two, or three of:

[0125] All patent documents mentioned herein are incorporated by reference in their entirety. In accomplishing various objectives of the present invention, various embodiments of the present invention have been described. It is to be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. 1. A composition for additive manufacturing, comprising: sinterable powder in an amount of 10 to 99 wt. %, based on the total weight of the composition; and an oxygen barrier in an amount of up to 25% by weight based on the total weight of the composition; Including, The composition, wherein the oxygen barrier comprises at least one of: (a) an organophosphorus component, (b) a heptazine or melamine-derived component, and (c) a polymeric organobromine component.

2. 10. The composition of claim 1, wherein the oxygen barrier comprises a heptadine or melamine-derived component.

3. 10. The composition of claim 1, wherein the oxygen barrier comprises an organophosphorus component.

4. 10. The composition of claim 1, wherein the oxygen barrier comprises a polymeric organobromine component.

5. The organophosphorus component comprises a species of formula Ia or Ib: 【Chemical 1】 In the formula, R １ , R ２ and R ３ are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; 【Chemistry 2】 In the formula, R ４ and R ５ are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; M is a metal; n is an integer from 1 to 3 The composition according to claim 3 .

6. The organophosphorus component comprises a species of formula II: 【Chemistry 3】 The composition according to claim 3 .

7. The organophosphorus component comprises a species of Formula III: 【Chemistry 4】 The composition according to claim 3 .

8. 4. The composition of claim 3, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

9. The heptazine or melamine derived component comprises a species of formula IV: 【Chemistry 5】 In the formula, X, Y, and Z are each independently H and NR ６ R ７ Selected from: In the formula, R ６ and R ７ are each independently selected from H and C1-C5 alkyl The composition according to claim 2 .

10. The heptazine or melamine derived component comprises a species of formula V: 【Chemistry 6】 In the formula, n is an integer from 2 to 1000. The composition according to claim 2 .

11. The heptazine or melamine derived component comprises a species of formula VI: 【Chemistry 7】 In the formula, W, X, Y, and Z are each independently H and NR ６ R ７ Selected from: In the formula, R ６ and R ７ are each independently selected from H and C1-C5 alkyl The composition according to claim 2 .

12. 3. The composition of claim 2, wherein the heptazine or melamine-derived component is melamine-free.

13. 5. The composition of claim 4, wherein the polymeric organobromine component comprises a brominated polystyrene, a brominated polyacrylate, a brominated epoxy, an end-capped brominated epoxy, or a combination of two or more of the foregoing.

14. 10. The composition of claim 1, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

15. 10. The composition of claim 1, wherein the composition is free or substantially free of phosphate.

16. The composition of claim 1 , wherein the sinterable powder comprises a semi-crystalline polymer.

17. 10. The composition of claim 1, wherein the sinterable powder comprises polyamide (PA), polyesters (PEs), polyurethane (PU), polyethylene (PE), polypropylene (PP), poly(butylene terephthalate) (PBT), poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK), or a combination of two or more of the foregoing.

18. The composition of claim 1 , wherein the sinterable powder comprises a polyamide.

19. The composition of claim 1 , wherein the sinterable powder comprises a filler material.

20. 1. A method for printing a three-dimensional article, comprising: Providing the composition of claim 1; and selectively solidifying said layer of composition to form said article. A method comprising:

21. 21. The method of claim 20, wherein the composition is applied in a layer-by-layer process.

22. 21. The method of claim 20, wherein the article passes FAR 25.853 (60 seconds and 12 seconds).

23. The article comprises: a tensile modulus (TM) ratio of at least 0.9; a tensile strength (TS) ratio of at least 0.7; and Elongation at break (EOB) ratio of at least 0.7 21. The method of claim 20, wherein the method comprises one, two, or three of:

24. 1. A composition for additive manufacturing, comprising: a thermoplastic polymer in an amount of 10 to 99% by weight, based on the total weight of the composition; and an oxygen barrier in an amount of up to 25% by weight, based on the total weight of the composition; Including, A composition wherein the oxygen barrier comprises at least one of: (a) an organophosphorus component, (b) a heptazine or melamine derived component, and (c) a polymeric organobromine component.

25. 25. The composition of claim 24, wherein the oxygen barrier comprises a heptadine or melamine-derived component.

26. 25. The composition of claim 24, wherein the oxygen barrier comprises an organophosphorus component.

27. 25. The composition of claim 24, wherein the oxygen barrier comprises a polymeric organobromine component.

28. The organophosphorus component comprises a species of formula Ia or Ib: 【Chemistry 8】 In the formula, R １ , R ２ , and R ３ are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; 【Chemistry 9】 In the formula, R ４ and R ５ are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalkyl, heteroalkenyl, heterocyclyl, aryl, and heteroaryl; M is a metal; n is an integer of 1 to 3.

27. The composition of claim 26.

29. The organophosphorus component comprises a species of formula II: 【Chemistry 10】 27. The composition of claim 26.

30. The organophosphorus component comprises a species of Formula III: 【Chemistry 11】 27. The composition of claim 26.

31. 27. The composition of claim 26, wherein the oxygen barrier is present in the composition in an amount of 1 to 10% by weight, based on the total weight of the composition.

32. The heptazine or melamine derived component comprises a species of formula IV: 【Chemistry 12】 In the formula, X, Y, and Z are each independently H and NR ６ R ７ is selected from; and In the formula, R ６ and R ７ is independently selected from H and C1-C5 alkyl.

33. The heptazine or melamine derived component comprises a species of formula V: 【Chemistry 13】 In the formula, n is an integer of 2 to 1,000.

26. The composition of claim 25.

34. The heptazine or melamine derived component comprises a species of formula VI 【Chemistry 14】 In the formula, W, X, Y, and Z are each independently H and NR ６ R ７ is selected from; and In the formula, R ６ and R ７ are each independently selected from H and C1-C5 alkyl 26. The composition of claim 25.

35. 26. The composition of claim 25, wherein the heptazine or melamine-derived component is melamine-free.

36. 30. The composition of claim 27, wherein the polymeric organobromine component comprises a brominated polystyrene, a brominated polyacrylate, a brominated epoxy, an end-capped brominated epoxy, or a combination of two or more of the foregoing.

37. 25. The composition of claim 24, wherein the oxygen barrier is present in the composition in an amount of 10 to 30% by weight, based on the total weight of the composition.

38. 25. The composition of claim 24, wherein the composition is free or substantially free of phosphate.

39. 25. The composition of claim 24, wherein the thermoplastic polymer comprises acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), nylon, polycarbonate, or a combination, block copolymer, or melt of two or more of the foregoing.

40. 1. A method for printing a three-dimensional article, comprising: Providing the composition of claim 24; and selectively solidifying said layer of composition to form an article. A method comprising:

41. 41. The method of claim 40, wherein the composition is applied in a layer-by-layer process.

42. 41. The method of claim 40, wherein the article passes FAR 25.853 (60 seconds and 12 seconds).

43. The article comprises: a tensile modulus (TM) ratio of at least 0.9; a tensile strength (TS) ratio of at least 0.7; and Elongation at break (EOB) ratio of at least 0.7 41. The method of claim 40, wherein the method comprises one, two, or three of:

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