WO2018146281A1 - Additive manufacturing powder compositions including amorphous and semi-crystalline components - Google Patents

Abstract

According to some examples, a method of forming a three-dimensional article includes contacting a substrate with a first quantity of a powder composition. The powder composition includes an amorphous thermoplastic component. The powder composition further includes a semi-crystalline thermoplastic component. The method further includes fusing at least a portion the first quantity of the powder composition to form a first layer. The amorphous thermoplastic component and the semi-crystalline thermoplastic component are substantially free of phase separation when combined in a melt state.

Description

ADDITIVE MANUFACTURING POWDER COMPOSITIONS INCLUDING AMORPHOUS AND SEMI- CRYSTALLINE

COMPONENTS CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional

Patent Application Serial No. 62/457,194 entitled "ADDITIVE MANUFACTURING POWDER COMPOSITIONS INCLUDING AMORPHOUS AND SEMI-CRYSTALLINE COMPONENTS," filed February 10, 2017, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

[0002] Articles formed through additive manufacturing processes can include a plurality of adjacent layers adhering to each other. The properties of the article can be a function of the materials used to form each layer. However, certain materials may not form strong interlayer connections.

[0003] Polymers used for additive manufacturing can include neat polymers, such as polyamides or polyamide -based compounds. The choice of these materials can be driven by relative ease of processability in combination with good mechanical properties and dimension control in the final article. However, a problem with these materials is that they are not considered to be a type of material that is well suited for every application. Some materials may not provide an article having good interlayer adhesion or densities that approach those of an injection molded component.

SUMMARY

[0004] A solution to this problem, according to this disclosure, is to provide a powder formed from a semi-crystalline powder component and an amorphous powder component. The powder can be used in conjunction with an additive manufacturing process to form three dimensional articles that show good interlayer adhesion and integrity. The good interlayer adhesion and integrity can be caused in part by a lack of phase separation between the semi-crystalline powder component and an amorphous powder component in the layers of the three dimension article upon heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various examples discussed in the present document.

[0006] FIG. 1 is a DSC curve showing the thermal behaviors of a composition of Example 1.

[0007] FIG. 2 is a DSC curve showing the thermal behaviors of a composition of Example 2.

[0008] FIG. 3 is a photograph showing various examples of articles formed from the composition of Example 1.

DETAILED DESCRIPTION

[0009] The types of polymers used for additive manufacturing can include neat polymers such as polyamides or polyamide-based compounds. The choice of these materials can be driven by relative ease of processability in combination with good mechanical properties and dimension control in the final article. However, a problem with these materials is that they are not considered to be a type of material that is well suited for every application. For example, in injection molding, manufacturers may desire to have the opportunity to match the resin/grade to the application. A solution to this problem, according to this disclosure, is to provide a powder formed from a semi-crystalline powder component and an amorphous powder component.

[0010] Some examples of the present disclosure relate to a powder composition for use in additive manufacturing techniques. One example of a suitable technique that the composition can be applied to is a powder bed additive manufacturing method. The composition includes an amorphous thermoplastic powder component and a semi-crystalline thermoplastic powder component. The amount of each component in the composition can be selected from many suitable amounts. For example, the amorphous thermoplastic component can range from about 2.5 wt% to about 97.5 wt% of the powder composition, or from about 5 wt% to about 95 wt%, about 10 wt% to about 90 wt%, about 15 wt% to about 85 wt%, about 20 wt% to about 80 wt%, about 25 wt% to about 75 wt%, about 30 wt% to about 70 wt%, about 35 wt% to about 65 wt%, about 40 wt% to about 60 wt%, or about 45 wt% to about 55 wt%.

[0011] The glass transition temperature (T_g) of the amorphous thermoplastic component can be in a range of more than 50 °C and less than 350 °C, or from about 55 °C to about 345 °C, about 65 °C to about 340 °C, about 70 °C to about 335 °C, about 75 °C to about 330 °C, about 80 °C to about 325 °C, about 85 °C to about 320 °C, about 90 °C to about 315 °C, about 95 °C to about 315 °C, about 100 °C to about 310 °C, about 105 °C to about 300 °C, about 110 °C to about 290 °C, about 115 °C to about 285 °C, about 120 °C to about 280 °C, about 125 °C to about 275 °C, about 130 °C to about 270 °C, about 135 °C to about 265 °C, about 140 °C to about 260 °C, about 145 °C to about 255 °C, about 150 °C to about 250 °C, about 155 °C to about 245 °C, about 160 °C to about 240 °C, about 165 °C to about 235 °C, about 170 °C to about 230 °C, about 175 °C to about 225 °C, about 180 °C to about 220 °C, about 185 °C to about 215 °C, or about 190 °C to about 210 °C.

[0012] The amorphous thermoplastic component is formed from a first plurality of particles each including the amorphous thermoplastic component. The amorphous thermoplastic component can be 100 wt% of each of the particles of the first plurality of particles. Each particle of the amorphous thermoplastic component can have an average molecular weight in a range from about 1,000 Daltons to about 150,000 Daltons, about 2,000 Daltons to about 140,000 Daltons, about 3,000 Daltons to about 130,000 Daltons, about 4,000 Daltons to about 120,000 Daltons, about 5,000 Daltons to about 110,000 Daltons, about 6,000 Daltons to about 100,000 Daltons, about 7,000 Daltons to about 90,000 Daltons, about 8,000 Daltons to about 80,000 Daltons, about 9,000 Daltons to about 70,000 Daltons, about 10,000 Daltons to about 60,000 Daltons, about 15,000 Daltons to about 50,000 Daltons, or about 20,000 Daltons to about 40,000 Daltons.

[0013] The individual particles of the amorphous thermoplastic component can be monomodal in that each particle has substantially the same shape. The shape of each particle can be spherical. The shape of each particle may deviate from that of a perfect sphere, however, such that the shape can be substantially spherical. For example, each particle can have an oval or elliptical shape. An aspect ratio (length to width) of the substantially spherical particles can range from about 1.01 to about 2, about 1.05 to about 1.95, about 1.10 to about 1.90, about 1.15 to about 1.85, about 1.20 to about 1.80, about 1.25 to about 1.75, about 1.30 to about 1.70, about 1.35 to about 1.65, about 1.40 to about 1.60, or about 1.45 to about 1.55. Additionally, in further examples, the individual particles can have an irregular shape.

[0014] Though the individual particles of the amorphous thermoplastic component are monomodal, the diameter of the particles can be selected from various suitable diameters. A median diameter size of about 50% of the individual particles of the amorphous thermoplastic component (D50) can range from about 10 microns to about 100 microns, about 10 microns to about 95 microns, about 10 microns to about 90 microns, about 10 microns to about 85 microns, about 10 microns to about 80 microns, about 10 microns to about 75 microns, about 10 microns to about 70 microns, about 10 microns to about 60 microns, about 10 microns to about 50 microns, about 10 microns to about 40 microns, about 10 microns to about 30 microns, about 15 microns to about 95 microns, about 20 microns to about 90 microns, about 25 microns to about 85 microns, about 30 microns to about 80 microns, about 35 microns to about 75 microns, about 40 microns to about 70 microns, about 45 microns to about 65 microns, or about 50 microns to about 60 microns. Larger particle sizes are possible for example, but in general a D98 of the particles of the amorphous thermoplastic component is about 150 microns. Given the micron-level diameters of the individual particles, the particles can be referred to as ultrafine amorphous particles. The combination of the amorphous thermoplastic polymer component and the semi-crystalline polymer component allows for individual D50 values as low as 10 microns. Surprisingly, such particles having such a small D50 value are viable and do not burn during the additive manufacturing process.

[0015] The ultrafine amorphous thermoplastic component can comprise different components. For example, the amorphous thermoplastic component can comprise one or more thermoplastic polymers. The amorphous thermoplastic polymer can be in a range of about 50 wt% to about 100 wt% of the ultrafine amorphous thermoplastic component, or from about 55 wt% to about 95 wt%, about 60 wt% to about 90 wt%, about 65 wt% to about 85 wt %, or about 70 wt% to about 80 wt%.

[0016] The thermoplastic polymer can be selected from many different types of thermoplastic polymers. Suitable examples of thermoplastic polymers include a polyamide-imide, a polyethersulphone, a polyetherimide, a polyacrylate, a polysulphone, a polymethacrylate, a polyvinylchloride, an acrylonitrile butadiene styrene, a polystyrene, a polyetherimide, or mixtures thereof.

[0017] The semi-crystalline thermoplastic component can range from about 2.5 wt% to about 97.5 wt% of the powder composition, or from about 5 wt% to about 95 wt%, 10 wt% to about 90 wt%, 15 wt% to about 85 wt%, 20 wt% to about 80 wt%, 25 wt% to about 75 wt%, 30 wt% to about 70 wt%, 35 wt% to about 65 wt%, 40 wt% to about 60 wt%, or 45 wt% to about 55 wt%.

[0018] The melting point (T_m) of the semi-crystalline thermoplastic component can be in a range of more than 150 °C and less than 350 °C, or from about 155 °C to about 345 °C, about 160 °C to about 340 °C, about 170 °C to about 335 °C, about 175 °C to about 330 °C, about 180 °C to about 325 °C, about 185 °C to about 320 °C, about 190 °C to about 315 °C, about 195 °C to about 310 °C, about 200 °C to about 305 °C, about 205 °C to about 300 °C, about 210 °C to about 295 °C, about 215 °C to about 290 °C, about 220 °C to about 285 °C, about 225 °C to about 280 °C, about 230 °C to about 275 °C, about 235 °C to about 270 °C, about 240 °C to about 265 °C, or about 245 °C to about 260 °C. In the powder mixture, the T_m of the semi-crystalline thermoplastic component can be chosen to be near the glass transition temperature of the amorphous thermoplastic component. In some examples, the T_m of the semi-crystalline thermoplastic component can be higher than the glass transition temperature of the amorphous thermoplastic component (e.g., 0.5 °C to 10 °C higher).

[0019] The semi-crystalline thermoplastic component can be formed from a second plurality of particles each comprising the semi-crystalline component. Similar to the amorphous thermoplastic component, the semi-crystalline thermoplastic component can be 100 wt% of each of the individual particles of the second plurality of particles.

[0020] Each particle of the semi-crystalline thermoplastic polymer powder component can have an average molecular weight in a range from about 1,000 Daltons to about 250,000 Daltons, about 2,000 Daltons to about 240,000 Daltons, about 3,000 Daltons to about 230,000 Daltons, about 4,000 Daltons to about 220,000 Daltons, about 5,000 Daltons to about 210,000 Daltons, about 6,000 Daltons to about 200,000 Daltons, about 7,000 Daltons to about 190,000 Daltons, about 8,000 Daltons to about 180,000 Daltons, about 9,000 Daltons to about 170,000 Daltons, about 10,000 Daltons to about 160,000 Daltons, about 15,000 Daltons to about 150,000 Daltons, about 20,000 Daltons to about 140,000 Daltons, about 30,000 Daltons to about 130,000 Daltons, about 40,000 Daltons to about 120,000 Daltons, about 50,000 Daltons to about 110,000 Daltons, about 60,000 Daltons to about 100,000 Daltons, or about 70,000 Daltons to about 90,000 Daltons.

[0021] The individual particles of the amorphous thermoplastic component can be monomodal in that each particle has substantially the same shape. The shape of each particle can be spherical. The shape of each particle can deviate from that of a perfect sphere, however, such that the shape can be substantially spherical or elongated. For example, each particle can have an oval, elliptical, rod, or cylindrical shape.

[0022] Though the substantially spherical individual particles of the semi- crystalline thermoplastic component can be monomodal, the diameter of the particles can be selected from a number of suitable diameters. For example, a D50 of the individual particles of the semi-crystalline thermoplastic component can range from about 10 microns to about 100 microns, about 10 microns to about 95 microns, about 10 microns to about 90 microns, about 10 microns to about 85 microns, about 10 microns to about 80 microns, about 10 microns to about 75 microns, about 10 microns to about 70 microns, about 10 microns to about 60 microns, about 10 microns to about 50 microns, about 10 microns to about 40 microns, about 10 microns to about 30 microns, about 15 microns to about 95 microns, about 20 microns to about 90 microns, about 25 microns to about 85 microns, about 30 microns to about 80 microns, about 35 microns to about 75 microns, about 40 microns to about 70 microns, about 45 microns to about 65 microns, or about 50 microns to about 60 microns. Larger particle sizes are possible for example, but in general a D98 of the particles of the semi-crystalline thermoplastic component is about 150 microns. Given the micron diameters of the individual particles, the particles can be referred to as ultrafine semi-crystalline particles. The combination of the amorphous thermoplastic polymer component and the semi-crystalline polymer component allows for D50 values as low as 10 microns. Surprisingly, particles having such a small D50 value are viable and do not burn during the additive manufacturing process. [0023] An aspect ratio (length to width) of the elongated individual particles of the semi-crystalline powder component can range from about 1.01 to about 5, about 1.05 to about 4.95, about 1.10 to about 4.90, about 1.15 to about 4.85, about 1.20 to about 4.80, about 1.25 to about 4.75, about 1.30 to about 4.70, about 1.35 to about 4.65, about 1.40 to about 4.60, about 1.45 to about 4.55, about 1.50 to about 4.50, about 1.55 to about 4.45, about 1.60 to about 4.40, about 1.65 to about 4.35, about 1.70 to about 4.30, about 1.75 to about 4.25, about 1.80 to about 4.20, about 1.85 to about 4.15, about 1.90 to about 4.10, about 1.95 to about 4.05, about 2.00 to about 4.00, about 2.05 to about 3.95, about 2.10 to about 3.90, about 2.15 to about 3.85, about 2.20 to about 3.80, about 2.25 to about 3.75, about 2.30 to about 3.70, about 2.35 to about 3.65, about 2.40 to about 3.60, about 2.45 to about 3.55, about 2.50 to about 3.50, about 2.55 to about 3.45, about 2.60 to about 3.35, about 2.65 to about 3.30, about 2.70 to about 3.25, about 2.75 to about 3.20, about 2.80 to about 3.15, about 2.85 to about 3.10, or about 2.90 to about 3.05.

[0024] The semi-crystalline thermoplastic component can comprise different components. For example, the semi-crystalline thermoplastic component can comprise one or more thermoplastic polymers. The semi-crystalline thermoplastic polymer can be in a range of about 50 wt% to about 100 wt% of the ultrafine semi-crystalline thermoplastic component, or from about 55 wt% to about 95 wt%, about 60 wt% to about 90 wt%, about 65 wt% to about 85 wt %, or about 70 wt% to about 80 wt%.

[0025] The one or more semi-crystalline thermoplastic polymers can be selected from many suitable polymers. Suitable semi-crystalline thermoplastic polymers include a polyetheretherketone, a polyphenylene ether, a polytetrafluoroethylene, a Nylon 6,6, a Nylon 11, a polyphenylene sulphide, a polyethylene terephthalate, a polyoxymethylene, a polypropylene, a high density polyethylene, a low density polyethylene, or mixtures thereof.

[0026] In addition to the amorphous thermoplastic component and the semi-crystalline thermoplastic component, the composition can include additive components. Examples of additive components include flow agents (e.g., inorganic flow promoters), fillers, UV agents, flame retardants, anti-static agents, plasticizers, or mixtures thereof. The additive components, individually or in total, can range from about 0.05 wt% to about 50 wt% of the composition, or from about I wt% to about 45.5 wt%, about 1.5 wt% to about 45 wt%, about 2 wt% to about 44.5 wt%, about 2.5 wt% to about 44 wt%, about 3 wt% to about 43.5 wt%, about 3.5 wt% to about 43 wt%, about 4 wt% to about 42.5 wt%, about 4.5 wt% to about 42 wt%, about 5 wt% to about 41.5 wt%, about 5.5 wt% to about 41 wt%, about 6 wt% to about 40.5 wt%, about 6.5 wt% to about 40 wt%, about 7 wt% to about 39.5 wt%, about 7.5 wt% to about 39 wt%, about 8 wt% to about 38.5 wt%, about 8.5 wt% to about 38 wt%, about 9 wt% to about 37.5 wt%, about 9.5 wt% to about 37 wt%, about 10 wt% to about 36.5 wt%, about 10.5 wt% to about 36 wt%, about

I I wt% to about 35.5 wt%, about 11.5 wt% to about 35 wt%, about 12 wt% to about 34.5 wt%, about 12.5 wt% to about 34 wt%, about 13 wt% to about 33.5 wt%, about 13.5 wt% to about 33 wt%, about 14 wt% to about 32.5 wt%, about 14.5 wt% to about 32 wt%, about 15 wt% to about 31.5 wt%, about 15.5 wt% to about 31 wt%, about 16 wt% to about 30.5 wt%, about 16.5 wt% to about 30 wt%, about 17 wt% to about 29.5 wt%, about 17.5 wt% to about 29 wt%, about 18 wt% to about 28.5 wt%, about 18.5 wt% to about 28 wt%, about 19 wt% to about 27.5 wt%, about 19.5 wt% to about 27 wt%, about 20 wt% to about 26.5 wt%, about 20.5 wt% to about 26 wt%, about 21 wt% to about 25.5 wt%, about 21.5 wt% to about 25 wt%, about 22 wt% to about 24.5 wt%, about 22.5 wt% to about 24 wt%, or about 23 wt% to about 23.5 wt%.

[0027] Suitable examples of inorganic flow agents include a hydrated silica, an amorphous alumina, a glassy silica, a glassy phosphate, a glassy borate, a glassy oxide, a titania, a talc, a mica, a fumed silica, a kaolin, an attapulgite, a calcium silicate, an alumina, a magnesium silicate, or a mixture thereof.

[0028] Suitable examples of plasticizers include ester-based plasticizers, which are esters of mono- or di -basic acids such as myristate esters, phthalate esters, adipate esters, phosphate esters, citrates, trimellitates, glutarates, and sebacate esters (e.g., dialkyl phthalates, such as dibutyl phthalate, diisoctyl phthalate, dibutyl adipate, and dioctyl adipate; 2-ethylhexyl diphenyl diphosphate; t-butylphenyl diphenyl phosphate; butyl benzylphthalates; dibutoxyethoxyethyl adipate; dibutoxypropoxypropyl adipate; acetyltri-n-butyl citrate; dibutylsebacate; etc.). Phosphate ester plasticizers are commercially sold under the trade designation SANTICIZER from Monsanto, St. Louis, MO. Glutarate plasticizers are commercially sold under the trade designation PLASTHALL 7050 from CP. Hall Co., Chicago, IL. [0029] Additional examples of ester-based plasticizers include aliphatic monoalkyl esters, aromatic monoalkyl esters, aliphatic polyalkyl esters, aromatic polyalkyl esters, polyalkyl esters of aliphatic alcohols, phosphonic polyalkyl esters, aliphatic poly(alkoxylated) esters, aromatic poly(alkoxylated) esters, poly(alkoxylated) ethers of aliphatic alcohols, and poly(alkoxylated) ethers of phenols. In some examples, the esters are derived from an alcohol or from a renewable source, such as 2-octanol, citronellol, dihydrocitronellol, or 2-alkyl alkanols.

[0030] Fillers may be selected from one or more of a wide variety of materials, as known in the art, and include organic and inorganic fillers. Inorganic filler particles include silica, submicron silica, zirconia, submicron zirconia, non- vitreous microparticles, nanosized silica particles, nanosized metal oxide particles, and combinations thereof.

[0031] UV agents can include thermal initiators including peroxides such as benzoyl peroxide, dibenzoyl peroxide, dilauryl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide, hydroperoxides (e.g., tert-butyl hydroperoxide and cumene hydroperoxide), dicyclohexyl peroxydicarbonate, 2,2,-azo-bis(isobutyronitrile), and t-butyl perbenzoate. Examples of commercially available thermal initiators include initiators available from DuPont Specialty Chemical (Wilmington, Del.) under the VAZO trade designation including VAZO™ 67 (2,2'-azo-bis(2-methybutyronitrile)), VAZO™ 64 (2,2'-azo- bis(isobutyronitrile)), and VAZO™ 52 (2,2'-azo-bis(2,2-dimethyvaleronitrile)); and LUCIDOL™ 70 from Elf Atochem North America, Philadelphia, Pa.

[0032] Examples of flame retardants include, for example, organophosphorous compounds such as organic phosphates (including trialkyl phosphates such as triethyl phosphate and tris(2-chloropropyl)phosphate, triaryl phosphates such as triphenyl phosphate and diphenyl cresyl phosphate, resorcinol bis-diphenylphosphate, resorcinol diphosphate, and aryl phosphate); phosphites (including trialkyl phosphites, triaryl phosphites, and mixed alkyl-aryl phosphites); phosphonates (including diethyl ethyl phosphonate and dimethyl methyl phosphonate); polyphosphates (including melamine polyphosphate and ammonium polyphosphates); polyphosphites; polyphosphonates; phosphinates (including aluminum tris(diethyl phosphinate); halogenated fire retardants such as chlorendic acid derivatives and chlorinated paraffins; organobromines such as decabromodiphenyl ether (decaBDE); decabromodiphenyl ethane; polymeric brominated compounds such as brominated polystyrenes, brominated carbonate oligomers (BCOs), brominated epoxy oligomers (BEOs), tetrabromophthalic anhydride, tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HBCD); metal hydroxides such as magnesium hydroxide, aluminum hydroxide, cobalt hydroxide, and hydrates of the foregoing metal hydroxides; and combinations thereof. The flame retardant can be a reactive type flame-retardant (including polyols which contain phosphorus groups, 10-(2,5-dihydroxyphenyl)- 1 OH-9-oxa- 10-phospha-phenanthrene- 10-oxide, phosphorus-containing lactone- modified polyesters, ethylene glycol bis(diphenyl phosphate), neopentylglycol bis(diphenyl phosphate), amine- and hydroxyl-functionalized siloxane oligomers). These flame retardants can be used alone or in conjunction with other flame retardants.

[0033] The composition can be used to form a three-dimensional article through an additive manufacturing process such as a powder bed fusing or powder bed fusion process in which the components, and amounts thereof, of the composition (e.g., amorphous thermoplastic polymers, semi-crystalline polymer, and optional additives) can be selected based on desired characteristics (e.g., density, thermal properties, and mechanical properties) of the resulting three- dimensional article. The article can be produced, at least in part, by producing a digital model (e.g., a CAD file) of the article. Within the digital model of the article digital models of each layer can be created. The digital file can be used to a control an additive manufacturing apparatus to produce each layer of the product thus forming the article.

[0034] The term "powder bed fusing" or "powder bed fusion" is used herein to mean processes in which the composition is selectively sintered or melted and fused, layer by layer, to provide an article. Use of the composition as described herein can facilitate production of articles having densities close to that of a corresponding article formed by injection molding.

[0035] One factor driving the selection of the components, described further herein, of the composition is whether the pair of amorphous thermoplastic polymer component and semi-crystalline thermoplastic polymer component are miscible with each other such that once they mix and are fused to form a layer there is substantially no phase separation upon subsequent heating. [0036] Powder bed fusing or powder bed fusion further includes all laser sintering and all selective laser sintering processes as well as other powder bed fusing technologies as defined, for example, by ASTM F2792-12a. For example, sintering of the powder composition can be accomplished via application of electromagnetic radiation produced, for example, by a laser, with the selectivity of the sintering achieved, for example, through selective application of inhibitors, absorbers, susceptors, or the electromagnetic radiation (e.g., through use of masks or directed laser beams). Any other suitable source of electromagnetic radiation can be used, including, for example, infrared radiation sources, microwave generators, lasers, radiative heaters, lamps, or a combination thereof. In some examples, selective mask sintering (SMS) techniques can be used to produce three-dimensional articles. Briefly stated, in an SMS technique, an SMS machine is used in conjunction with a shielding mask to selectively block infrared radiation, resulting in the selective irradiation of a portion of a powder layer. In using an SMS process to produce articles from powder compositions of the disclosure, it can be desirable to include one or more materials in the composition that enhance the infrared absorption properties of the powder composition. For example, the powder composition can include one or more heat absorbers or dark-colored materials (e.g., carbon black, carbon nanotubes, or carbon fibers).

[0037] Powder bed fused (e.g., laser-sintered) articles can be produced from the composition using any suitable powder bed fusing processes including laser sintering processes. These articles can include a plurality of overlying and adhering sintered layers that include a polymeric matrix which, in some examples, has reinforcement particles dispersed throughout the polymeric matrix. Laser sintering processes are known, and are based on the selective sintering of polymer particles, where layers of polymer particles are briefly exposed to laser light and the polymer particles exposed to the laser light are thus bonded to one another. Successive sintering of layers of polymer particles produces three-dimensional objects.

[0038] By way of example, in a process as described above, a quantity of the composition can be placed on a support surface or substrate. Both the amorphous thermoplastic powder component and the semi-crystalline thermoplastic component are separated prior to use in the additive manufacturing process. For example, they are not compounded or extruded prior to being placed on the support surface. The composition can be subsequently leveled to form a substantially smooth surface. A laser source can then be directed over at least a portion of the composition to form an integral or initial layer. Additional layers are formed by depositing an amount of the composition on the integral layer and directing energy onto those layers. In depositing subsequent layers the previously formed layer becomes a substrate. For example the integral layer becomes a substrate for a subsequently deposited layer.

[0039] In some examples of the method, a plurality of layers are formed in a preset pattern by an additive manufacturing process. The number of layers forming the plurality of layers can vary, but for example, the plurality of layers can include 5 or more layers, or 20 or more layers. The maximum number of layers can vary greatly, determined, for example, by considerations such as the size of the article being manufactured, the technique used, the capabilities of the equipment used, and the level of detail desired in the final article. For example, 5 to 100,000 layers can be formed, or 20 to 50,000 layers can be formed, or 50 to 50,000 layers can be formed.

[0040] It is to be understood that "layer" includes a layer having any shape, regular or irregular, and having at least a predetermined thickness. The thickness of each layer can vary widely depending on the additive manufacturing method. For example, the individual layers can be each, on average, at least 50 microns thick, at least 80 microns thick, or at least 100 microns thick. In some examples, the plurality of sintered layers are each, on average, less than 500 microns thick, less than 300 microns thick, or less than 200 microns thick. Thus, the individual layers in some examples can be 50 to 500 microns thick, 80 to 300 microns thick, or 100 to 200 microns thick. Three-dimensional articles produced from powder compositions using a layer-by-layer powder bed fusing processes other than selective laser sintering can have layer thicknesses that are the same as or different from those described above.

[0041] In operation, the amorphous thermoplastic powder component and the semi-crystalline thermoplastic powder are not compounded prior to exposure to the electromagnetic radiation source. Because the components of the composition are not compounded, the amorphous thermoplastic powder and the semi-crystalline thermoplastic powder retain their individual T_g and T_m, respectively. [0042] The composition is placed on the powder bed and heated (e.g., by the laser) to a predetermined temperature exceeding both the T_g of the amorphous thermoplastic component and the T_m of the semi-crystalline thermoplastic component. When the predetermined temperature is reached, the individual components mix to form an amorphous thermoplastic layer including the amorphous thermoplastic component and the semi-crystalline thermoplastic component. Upon subsequent reheating (e.g., when subsequent layers are formed), the T_g of the amorphous layer will either be higher or lower than that of the amorphous thermoplastic component. Whether the T_g of the amorphous component is higher or lower than that that of the amorphous thermoplastic layer depends on the relative amounts of the amorphous thermoplastic component and the semi-crystalline thermoplastic component in the composition.

[0043] When the semi-crystalline thermoplastic component comprises the majority of the composition, the T_g of the resulting amorphous thermoplastic layer, and subsequently of the formed article, is lower than that of the amorphous thermoplastic component. The extent to which the T_g of the amorphous thermoplastic layer is lower than the T_g of the amorphous thermoplastic component can range, for example, from about 2 °C to about 50 °C, 3 °C to about 49 °C, 4 °C to about 48 °C, 5 °C to about 47 °C, 6 °C to about 46 °C, 7 °C to about 45 °C, 8 °C to about 44 °C, 9 °C to about 43 °C, 10 °C to about 42 °C, 11 °C to about 41 °C, 12 °C to about 40 °C, 13 °C to about 39 °C, 14 °C to about 38 °C, 15 °C to about 37 °C, 16 °C to about 36 °C, 17 °C to about 35 °C, 18 °C to about 34 °C, 19 °C to about 33 °C, 20 °C to about 32 °C, 21 °C to about 31 °C, 22 °C to about 30 °C, 23 °C to about 29 °C, 24 °C to about 28 °C, or about 25 °C to about 27 °C.

[0044] As a result of the lower T_g, the amorphous thermoplastic layer remains in a viscous or liquid phase throughout most of the additive manufacturing process. This is because each additional layer is formed by heating a deposited layer of the composition to the predetermined temperature, which is above the T_g of the amorphous thermoplastic layer. Thus, during heating, what will become adjacent layers are able to interact in a liquid or at least semi-liquid phase, which promotes better interlayer adhesion in the final amorphous three- dimensional product. [0045] Conversely, when the amorphous thermoplastic component comprises the majority of the composition, the T_g of the resulting amorphous thermoplastic layer, and subsequently of the formed article, is higher than that of the amorphous thermoplastic component. This can result in the amorphous article having a higher heat deflection temperature, as determined by the ISO/FDIS 178 test, than a corresponding article comprising less or none of the semi-crystalline powder component. The extent to which the T_g of the amorphous thermoplastic layer is higher than the T_g of the amorphous thermoplastic component can range, for example, from about 2 °C to about 50 °C, 3 °C to about 49 °C, 4 °C to about 48 °C, 5 °C to about 47 °C, 6 °C to about 46 °C, 7 °C to about 45 °C, 8 °C to about 44 °C, 9 °C to about 43 °C, 10 °C to about 42 °C, 11 °C to about 41 °C, 12 °C to about 40 °C, 13 °C to about 39 °C, 14 °C to about 38 °C, 15 °C to about 37 °C, 16 °C to about 36 °C, 17 °C to about 35 °C, 18 °C to about 34 °C, 19 °C to about 33 °C, 20 °C to about 32 °C, 21 °C to about 31 °C, 22 °C to about 30 °C, 23 °C to about 29 °C, 24 °C to about 28 °C, or about 25 °C to about 27 °C.

Examples

[0046] Various embodiments of the present disclosure can be better understood by reference to the following Examples, which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.

Example 1

[0047] A composition having 90 wt polyetherimide and 10 wt polyethylene terephthalate was formed. The polyetherimide and the polyethylene terephthalate were not compounded. The composition was placed on a powder bed and a laser was used to increase the temperature of the composition to an initial temperature below the T_g of the polyetherimide. The temperature was further increased beyond the T_g of the polyetherimide. This process sinters the composition and forms a first layer. After the first layer of the composition is sintered, the powder bed piston is lowered with a predetermined increment (e.g., 100 μιη), and another layer of the composition is spread over the previous sintered layer by a roller. The process then repeats as the laser melts and fuses each successive layer to the previous layer until the entire part is completed. [0048] FIG. 1 is a DSC curve showing the thermal behaviors of the composition of Example 1. In the first heating cycle (line 10), an exotherm around 243.85 °C can be seen, which is attributed to the T_m of polyethylene terephthalate. The glass T_g also can be seen around 213.63°C, which is attributed to polyetherimide. In the second heating cycle (line 12), the single T_g of the amorphous first layer, which is a mixture of both components, can be seen at around 187 °C. Because of the decrease of the T_g of the amorphous first layer compared to the T_g of the polyetherimide, the sintering window becomes broad. This results in improved processability. The improved sintering window also suggests that interlayer adhesion will be enhanced because the layers remain in a liquid phase during the SLS process.

Example 2

[0049] A composition having 10 wt% polyetherimide and 90 wt% polyethylene terephthalate was formed. The polyetherimide and the polyethylene terephthalate were not compounded. The composition was placed on a powder bed and a laser was used to increase the temperature of the composition to an initial temperature below the T_g of the polyetherimide. The temperature was further increased beyond the T_g of the polyetherimide. This process sinters the composition and forms a first layer. After the first layer of the composition is sintered, the powder bed piston is lowered with a predetermined increment (e.g., 100 μιη), and another layer of the composition is spread over the previous sintered layer by a roller. The process then repeats as the laser melts and fuses each successive layer to the previous layer until the entire part is completed.

[0050] FIG. 2 is a DSC curve showing the thermal behaviors of the composition of Example 2. In the first heating cycle (line 20), an exotherm around 245.82 °C can be seen which is attributed to the T_m of polyethylene terephthalate. The T_g also can be seen around 76.85 °C which is attributed to the mobile amorphous phase of the polyethylene terephthalate. In the second heating cycle (line 22), the single T_g of the amorphous first layer can be seen at around 84.31 °C. Because of the increase of the T_g of the amorphous first layer compared to the T_g of the polyethylene terephthalate, the layer and the subsequent article have a higher heat deflection test value. This can mean that the article's flame resistivity can be increased by varying the contents of the composition. Example 3

[0051] FIG. 3 is a photograph showing various examples of articles (30A and 30B) formed from the composition of Example 1. As shown, the articles can be formed with control in the x-, y-, and z-directions. Additionally, the articles are substantially free of gaps and corrugations. The density of these articles is about 95% of the density of a corresponding article formed by injection molding.

[0052] The terms and expressions that have been employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the examples of the present disclosure. Thus, it should be understood that although the present disclosure has been specifically disclosed by specific examples and optional features, modifications and variations of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of examples of the present disclosure.

Additional Embodiments.

[0053] The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance:

[0054] Embodiment 1 provides a method of forming a three-dimensional article, the method comprising:

disposing a quantity of a powder composition on a substrate, the powder composition comprising:

a first plurality of particles each comprising an amorphous thermoplastic component; and

a second plurality of particles each comprising a semi-crystalline thermoplastic component; and

fusing at least a portion of the quantity of the powder composition to form a layer, wherein the amorphous thermoplastic component and the semi- crystalline thermoplastic component of the layer are substantially free of phase separation when combined in a melt state following fusion. [0055] Embodiment 2 provides the method of Embodiment 1 , wherein the amorphous thermoplastic component is about 2.5 wt% to about 97.5 wt% of the powder composition.

[0056] Embodiment 3 provides the method of any one of Embodiments 1 or 2, wherein the first plurality of the particles each comprising the amorphous thermoplastic component is about 2.5 wt% to about 97.5 wt% of the powder composition.

[0057] Embodiment 4 provides the method of any one of Embodiments 1-

3, wherein the first plurality of the particles each comprising the amorphous thermoplastic component is about 2.5 wt% to about 15 wt% of the powder composition.

[0058] Embodiment 5 provides the method of any one of Embodiments 1-

4, wherein the first plurality of the particles each comprising the amorphous thermoplastic component is about 5 wt% to about 95 wt% of the powder composition.

[0059] Embodiment 6 provides the method of any one of Embodiments 1-

5, wherein the amorphous thermoplastic component has a glass transition temperature of more than 50 °C and less than 350 °C.

[0060] Embodiment 7 provides the method of any one of Embodiments 1- 6, wherein the amorphous thermoplastic component has an average molecular weight of between 1,000 and 150,000 Daltons.

[0061] Embodiment 8 provides the method of any one of Embodiments 1-

7, wherein the amorphous thermoplastic component is 100 wt% of each of the first plurality of particles.

[0062] Embodiment 9 provides the method of Embodiment 8, wherein the first plurality of the particles each comprising the amorphous thermoplastic component are monomodal and have a D50 of about 10 to about 100 microns.

[0063] Embodiment 10 provides the method of Embodiment 9, wherein the first plurality of particles each comprising the amorphous thermoplastic component have a D98 of 150 microns.

[0064] Embodiment 11 provides the method of any one of Embodiments

8-10, wherein each of the first plurality of particles each comprising the amorphous thermoplastic component has a substantially spherical shape. [0065] Embodiment 12 provides the method of any one of Embodiments

1-11, wherein the amorphous thermoplastic component comprises an amorphous thermoplastic polymer.

[0066] Embodiment 13 provides the method of Embodiment 12, wherein the amorphous thermoplastic polymer is about 60 wt% to about 100 wt% of the amorphous thermoplastic component.

[0067] Embodiment 14 provides the method of Embodiment 12, wherein the amorphous thermoplastic polymer is about 90 wt% to about 100 wt% of the amorphous thermoplastic component.

[0068] Embodiment 15 provides the method of any one of Embodiments

12-14, wherein the amorphous thermoplastic polymer is polyamide-imide, polyethersulphone, polyetherimide, polyarylate, polysulphone, polymethacrilate, polyvinylchloride, acrylonitrile butadiene styrene, polystyrene, polyetherimide, or mixtures thereof.

[0069] Embodiment 16 provides the method of Embodiment 15, wherein the amorphous thermoplastic polymer is polyetherimide.

[0070] Embodiment 17 provides the method of any one of Embodiments

1-16, wherein the second plurality of the particles each comprising the semi- crystalline thermoplastic component is about 5 wt% to about 95 wt% of the powder composition.

[0071] Embodiment 18 provides the method of any one of Embodiments

1-17, wherein the second plurality of the particles each comprising the semi- crystalline thermoplastic component is about 50 wt% to about 95 wt% of the powder composition.

[0072] Embodiment 19 provides the method of any one of Embodiments

1-18, wherein the second plurality of the particles each comprising the semi- crystalline thermoplastic component is about 5 wt% to about 15 wt% of the powder composition.

[0073] Embodiment 20 provides the method of any one of Embodiments 1-19, wherein the second plurality of the particles each comprising the semi- crystalline thermoplastic component is about 8 wt% to about 95 wt% of the powder composition. [0074] Embodiment 21 provides the method of any one of Embodiments

1-20, wherein the semi-crystalline thermoplastic component has a melting temperature of more than 150 °C and less than 350 °C.

[0075] Embodiment 22 provides the method of Embodiments 21, wherein the melting temperature of the semi-crystalline thermoplastic component is higher than the glass transition temperature of the amorphous thermoplastic component.

[0076] Embodiment 23 provides the method of any one of Embodiments

1-22, wherein the semi-crystalline thermoplastic component has an average molecular weight of between 1,000 and 250,000 Daltons.

[0077] Embodiment 24 provides the method of any one of Embodiments

1-23, wherein the semi-crystalline thermoplastic component is 100 wt of each of the second plurality of particles.

[0078] Embodiment 25 provides the method of Embodiment 24, wherein the second plurality of the particles each comprising the semi-crystalline thermoplastic component are monomodal and have a D50 of about 10 to about 100 microns.

[0079] Embodiment 26 provides the method of any one of Embodiments

24 or 25, wherein the second plurality of the particles each comprising the semi- crystalline thermoplastic component have a D98 of about 150 microns.

[0080] Embodiment 27 provides the method of any one of Embodiments

24-26, wherein each of the second plurality of the particles each comprising the semi-crystalline thermoplastic component has a substantially elongated shape.

[0081] Embodiment 28 provides the method of any one of Embodiments

1-27, wherein the semi-crystalline thermoplastic component comprises a semi- crystalline thermoplastic polymer.

[0082] Embodiment 29 provides the method of Embodiment 28, wherein the semi-crystalline thermoplastic polymer is about 60 wt to about 100 wt of the semi-crystalline thermoplastic component.

[0083] Embodiment 30 provides the method of any one of Embodiments 28 or 29, wherein the semi-crystalline thermoplastic polymer is about 90 wt to about 100 wt of the semi-crystalline thermoplastic component.

[0084] Embodiment 31 provides the method of any one of Embodiments

28-30, wherein the semi-crystalline thermoplastic polymer is polyetheretherketone, polyphenylene ether, polytetrafluoroethylene, Nylon 6,6, Nylon 11, polyphenylene sulphide, polyethylene terephthalate, polyoxymethylene, polypropylene, high-density polyethylene, low-density polyethylene, or mixtures thereof.

[0085] Embodiment 32 provides the method of any one of Embodiments 1-31, wherein the powder composition further comprises an inorganic flow agent.

[0086] Embodiment 33 provides the method of Embodiment 32, wherein the inorganic flow agent is a hydrated silica, amorphous alumina, a glassy silica, a glassy phosphate, a glassy borate, a glassy oxide, titania, talc, mica, a fumed silica, kaolin, attapulgite, calcium silicate, alumina, magnesium silicate, or a mixture thereof.

[0087] Embodiment 34 provides the method of Embodiment 33, wherein the amorphous thermoplastic component is polyetherimide and the semi- crystalline thermoplastic component is polyethylene terephthalate.

[0088] Embodiment 35 provides the method of Embodiment 33, wherein the amorphous thermoplastic component is polystyrene and the semi-crystalline thermoplastic component is polyphenylene ether.

[0089] Embodiment 36 provides the method of any one of Embodiments

1-35, further comprising contacting the first layer with a second quantity of the powder composition.

[0090] Embodiment 37 provides the method of Embodiment 36, further comprising fusing at least a portion of the second quantity of the powder composition to form a second layer.

[0091] Embodiment 38 provides the method of any one of Embodiments

36 or 37, further comprising substantially leveling at least one of the first and second quantities of the powder composition to form a substantially smooth layer.

[0092] Embodiment 39 provides the method of any one of Embodiments

36-38, wherein fusing at least one of the first and second quantities of the powder composition comprises directing an energy beam over at least one of the first and second quantities.

[0093] Embodiment 40 provides the method of any one of Embodiments

1-39, wherein the substrate comprises at least one of a metallic or plastic material.

[0094] Embodiment 41 provides the method of any one of Embodiments

1-40, wherein the substrate is a powder bed.

[0095] Embodiment 42 provides a three-dimensional article comprising: a first layer comprising:

an amorphous thermoplastic component; and

a semi-crystalline thermoplastic component; and

a second layer adjacent to the first layer, the second layer comprising: an amorphous thermoplastic component; and

a semi-crystalline thermoplastic component,

wherein upon an increase in temperature the amorphous thermoplastic component and the semi-crystalline thermoplastic component of at least one of the first and second layers is substantially free of phase separation.

[0096] Embodiment 43 provides the three-dimensional article of

Embodiment 42, wherein the three-dimensional article is amorphous.

[0097] Embodiment 44 provides the three-dimensional article of any one of Embodiments 42 or 43, wherein a glass transition temperature of the three- dimensional article is higher than a glass transition temperature of the amorphous thermoplastic component.

[0098] Embodiment 45 provides the three-dimensional article of

Embodiment 44, wherein the glass transition temperature of the three-dimensional article ranges from about 5 °C to about 100 °C higher than the glass transition temperature of the amorphous thermoplastic component.

[0099] Embodiment 46 provides the three-dimensional article of any one of Embodiments 42 or 43, wherein a glass transition temperature of the three- dimensional article is lower than a glass transition temperature of the amorphous thermoplastic component.

[00100] Embodiment 47 provides the three-dimensional article of Embodiment 46, wherein the glass transition temperature of the three-dimensional article ranges from about 5 °C to about 50 °C lower than the glass transition temperature of the amorphous thermoplastic component.

[00101] Embodiment 48 provides a method of forming a three-dimensional article comprising:

(1) depositing a quantity of a powder composition on a substrate, the powder composition comprising:

A first plurality of particles each comprising an amorphous thermoplastic component; and a second plurality of particles each comprising a semi-crystalline thermoplastic component;

(2) directing a laser beam over a predetermined target area on the substrate to form an integral layer; and

optionally repeating (1) and (2) to form additional layers that are integrally bonded to adjacent layers to form a three-dimensional article,

wherein the amorphous thermoplastic component and the semi- crystalline thermoplastic component of the integral layer are substantially free of phase separation when combined in a melt state following fusion.

[00102] Embodiment 49 provides a method of producing an article, the method comprising:

producing a digital model of the article, producing the digital model of the article comprising:

producing a digital model of a first layer of the article; and producing a digital model of a second layer of the article;

using the digital model of the article to control an additive manufacturing apparatus to perform an additive manufacture process to produce the first layer and the second layer from the powder composition of claim 1, as specified by the digital model.

[00103] In this document, the terms "a," "an," or "the" are used to include one or more than one unless the context clearly dictates otherwise. The term "or" is used to refer to a nonexclusive "or" unless otherwise indicated. The statement "at least one of A and B" has the same meaning as "A, B, or A and B." In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[00104] In this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement "about X to Y" has the same meaning as "about X to about Y," unless indicated otherwise. Likewise, the statement "about X, Y, or about Z" has the same meaning as "about X, about Y, or about Z," unless indicated otherwise.

[00105] In the methods described herein, the acts can be carried out in any order without departing from the principles of the disclosure, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[00106] The term "about" as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[00107] The term "substantially" as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

[00108] The term "polyamide-imide" as used herein, generally refers to a polymer including amide and imide repeating units. Polyamide-imides can be prepared, for example, through condensation of an aromatic diamine, such as methylene dianiline (MDA) and trimellitic acid chloride (TMAC).

[00109] The term "polyetherimide" as used herein, generally refers to a polymer having a repeating unit according to Structure I:

[00110] The term "polyacrylate" as used herein, refers to a polymer formed from acrylate monomers. Examples of acrylate monomers include methacrylates, methyl acrylate, ethyl acrylate, 2-chloroethyl vinyl ether, 2- ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate, and butyl methacrylate.

[00111] The term "polysulphone" as used herein, generally refers to a polymer including the subunit aryl-SO₂-aryl. Polysulphones can generally be prepared by the reaction of a diphenol and bis(4-chlorophenyl)sulphone, forming a polyether by elimination of sodium chloride. Examples of polysulphones include polyethersulfone.

[00112] The term "polymethacrylate" as used herein, refers generally to a polymer having a repeating unit according to Structure II:

[00113] The term "polyvinylchloride" as used herein, refers generally to a polymer having a repeating unit according to Structure III:

[00114] The term "acrylonitrile butadiene styrene" as used herein, refers generally to a terpolymer having the chemical formula

(C8H8)x- (C₄H6)y (C3H3N)z. Acrylonitrile butadiene styrene is generally formed by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The proportions can vary from 15 to 35% acrylonitrile, 5 to 30% butadiene, and 40 to 60% styrene.

[00115] The term "polystyrene" as used herein, refers generally to a polymer formed from a monomer styrene according to Structure IV:

[00116] The term "polyetheretherketone" as used herein, refers generally to a polymer having a repeating unit according to structure V:

[00117] The term "polyphenylene ether" as used herein, generally refers to a polymer including a phenoxy and/or thiophenoxy group as a repeating unit. The repeating unit can be represented according to Structure VI:

[00118] The term "polytetrafluoroethylene" as used herein, refers generally to a polymer formed from a repeating unit according to Structure VII:

[00119] The term "polyphenylene sulphide" as used herein, refers generally to polymers formed from aromatic rings linked with sulfides having a repeating unit according to Structure VIII:

[00120] The term "polyethylene terephthalate" as used herein, refers generally to a polymer having a repeating unit according to Structure IX:

[00121] The term "polyoxymethylene" as used herein, refers generally to a polymer having a repeating unit according to Structure X:

[00122] The term "polypropylene" as used herein, refers generally to a polymer having a repeating unit according to Structure XI:

[00123] The term "high-density polyethylene" as used herein, refers generally to a polymer formed from ethylene monomer repeating units and having a density ranging from about 0.93 to 0.97 g/cm³.

[00124] The term "low-density polyethylene" as used herein, refers generally to a polymer formed from ethylene monomer repeating units and having a density ranging from about 0.91 to 0.94 g/cm³.

[00125] The term "substituted" as used herein in conjunction with a molecule or an organic group as defined herein refers to the state in which one or more hydrogen atoms contained therein are replaced by one or more non- hydrogen atoms. The term "functional group" or "substituent" as used herein refers to a group that can be or is substituted onto a molecule or onto an organic group. Examples of substituents or functional groups include, but are not limited to, a halogen (e.g., F, CI, Br, and I); an oxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxyamines, nitriles, nitro groups, N-oxides, hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents that can be bonded to a substituted carbon (or other) atom include F, CI, Br, I, OR, OC(0)N(R)₂, CN, NO, N0₂, ON0₂, azido, CF₃, OCF₃, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy, ethylenedioxy, N(R)₂, SR, SOR, S0₂R, S0₂N(R)₂, S0₃R, C(0)R, C(0)C(0)R, C(0)CH₂C(0)R, C(S)R, C(0)OR, OC(0)R, C(0)N(R)₂, OC(0)N(R)₂, C(S)N(R)₂, (CH₂)₀-₂N(R)C(O)R, (CH₂)₀-₂N(R)N(R)₂, N(R)N(R)C(0)R, N(R)N(R)C(0)OR, N(R)N(R)CON(R)₂, N(R)S0₂R,

N(R)S0₂N(R)₂, N(R)C(0)OR, N(R)C(0)R, N(R)C(S)R, N(R)C(0)N(R)₂, N(R)C(S)N(R)₂, N(COR)COR, N(OR)R, C(=NH)N(R)₂, C(0)N(OR)R, and C(=NOR)R, wherein R can be hydrogen or a carbon-based moiety; for example, R can be hydrogen, (C₁-C₂₀)hydrocarbyl, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or to adjacent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl. [00126] The term "organic group" as used herein refers to any carbon- containing functional group. Examples can include an oxygen-containing group such as an alkoxy group, aryloxy group, aralkyloxy group, or oxo(carbonyl) group; a carboxyl group including a carboxylic acid, carboxylate, and a carboxylate ester; a sulfur-containing group such as an alkyl and aryl sulfide group; and other heteroatom-containing groups. Non-limiting examples of organic groups include OR, OOR, OC(0)N(R)₂, CN, CF₃, OCF₃, R, C(O), methylenedioxy, ethylenedioxy, N(R)₂, SR, SOR, S0₂R, S0₂N(R)₂, S0₃R, C(0)R, C(0)C(0)R, C(0)CH₂C(0)R, C(S)R, C(0)OR, OC(0)R, C(0)N(R)₂, OC(0)N(R)₂, C(S)N(R)₂, (CH₂)₀-₂N(R)C(O)R, (CH₂)₀-₂N(R)N(R)₂, N(R)N(R)C(0)R, N(R)N(R)C(0)OR, N(R)N(R)CON(R)₂, N(R)S0₂R, N(R)S0₂N(R)₂, N(R)C(0)OR, N(R)C(0)R, N(R)C(S)R, N(R)C(0)N(R)₂, N(R)C(S)N(R)₂, N(COR)COR, N(OR)R, C(=NH)N(R)₂, C(0)N(OR)R, C(=NOR)R, and substituted or unsubstituted (C₁-C₂₀)hydrocarbyl, wherein R can be hydrogen (in examples that include other carbon atoms) or a carbon-based moiety, and wherein the carbon-based moiety can be substituted or unsubstituted.

[00127] The term "weight- average molecular weight" as used herein refers to Mw, which is equal to∑Mi²ni / ΣΜinί, where n; is the number of molecules of molecular weight Mi. In various examples, the weight- average molecular weight can be determined using light scattering, small-angle neutron scattering, X-ray scattering, and sedimentation velocity.

[00128] The term "alkyl" as used herein refers to straight-chain and branched alkyl groups and cycloalkyl groups having from 1 to 20 carbon atoms, 1 to about 15 carbon atoms, 1 to 12 carbons, or, in some embodiments, from 1 to 8 carbon atoms. Examples of straight-chain alkyl groups include those with from 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n- heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec -butyl, t-butyl, neopentyl, isopentyl, and 2,2-dimethylpropyl groups. As used herein, the term "alkyl" encompasses n-alkyl, isoalkyl, and anteisoalkyl groups as well as other branched-chain forms of alkyl. Representative substituted alkyl groups can be substituted one or more times with any of the groups listed herein, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups. [00129] The term "cycloalkyl" as used herein refers to cyclic alkyl groups such as, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. In some embodiments, the cycloalkyl group can have 3 to about 8-12 ring members, whereas in other embodiments the number of ring carbon atoms ranges from 3 to 4, 5, 6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groups such as, but not limited to, norbornyl, adamantyl, bornyl, camphenyl, isocamphenyl, and carenyl groups, and fused rings such as, but not limited to, decalinyl, and the like. Cycloalkyl groups also include rings that are substituted with straight or branched-chain alkyl groups as defined herein. Representative substituted cycloalkyl groups can be mono -substituted or substituted more than once, such as, but not limited to, 2,2-, 2,3-, 2,4- 2,5- or 2,6- disubstituted cyclohexyl groups or mono-, di-, or tri- substituted norbornyl or cycloheptyl groups, which can be substituted with, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups. The term "cycloalkenyl" alone or in combination denotes a cyclic alkenyl group.

[00130] The term "aryl" as used herein refers to cyclic aromatic hydrocarbon groups that do not contain heteroatoms in the ring. Thus aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups. In some embodiments, aryl groups contain about 6 to about 14 carbons in the ring portions of the groups. Aryl groups can be unsubstituted or substituted, as defined herein. Representative substituted aryl groups can be mono-substituted or substituted more than once, such as, but not limited to, a phenyl group substituted at any one or more of the 2- , 3-, 4-, 5-, or 6-positions of the phenyl ring, or a naphthyl group substituted at any one or more of the 2- to 8-positions thereof.

[00131] The term "alkoxy" as used herein refers to an oxygen atom connected to an alkyl group, including a cycloalkyl group, as are defined herein. Examples of linear alkoxy groups include but are not limited to methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and the like. Examples of branched alkoxy groups include but are not limited to isopropoxy, sec -butoxy, tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclic alkoxy groups include but are not limited to cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can include about 1 to about 12, about 1 to about 15, or about 1 to about 20 carbon atoms bonded to the oxygen atom, and can further include double or triple bonds, and can also include heteroatoms. For example, an allyloxy group or a methoxyethoxy group is also an alkoxy group within the meaning herein, as is a methylenedioxy group in a context where two adjacent atoms of a structure are substituted therewith.

[00132] The term "amine" as used herein refers to primary, secondary, and tertiary amines having, e.g., the formula N(group)₃ wherein each group can independently be H or non-H, such as alkyl, aryl, and the like. Amines include but are not limited to R-NH₂, for example, alkylamines, arylamines, alkylarylamines; R₂NH wherein each R is independently selected, such as dialkylamines, diarylamines, aralkylamines, heterocyclylamines, and the like; and R₃N wherein each R is independently selected, such as trialkylamines, dialkylarylamines, alkyldiarylamines, triarylamines, and the like. The term "amine" also includes ammonium ions as used herein.

[00133] The terms "halo," "halogen," or "halide" group, as used herein, by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

[00134] The term "hydrocarbon" or "hydrocarbyl" as used herein refers to a molecule or functional group that includes carbon and hydrogen atoms. The term can also refer to a molecule or functional group that normally includes both carbon and hydrogen atoms but wherein all the hydrogen atoms are substituted with other functional groups.

[00135] The polymers described herein can terminate in any suitable way.

In some embodiments, the polymers can terminate with an end group that is independently chosen from a suitable polymerization initiator; -H; -OH; a substituted or unsubstituted (C₁-C₂₀)hydrocarbyl (e.g., (C₁-C₁₀)alkyl or (C₆- C₂₀)aryl) interrupted with 0, 1, 2, or 3 groups independently selected from -0-, substituted or unsubstituted -NH-, and -S-; a poly(substituted or unsubstituted (C₁- C₂₀)hydrocarbyloxy); and a poly(substituted or unsubstituted (C₁- C₂₀)hydrocarbylamino).

Claims

What is claimed is:

1. A method of forming a three-dimensional article, the method comprising: disposing a quantity of a powder composition on a substrate, the powder composition comprising:

a first plurality of particles each comprising an amorphous thermoplastic component; and

a second plurality of particles each comprising a semi-crystalline thermoplastic component; and

fusing the at least a portion of the quantity of the powder composition to form a layer, wherein the amorphous thermoplastic component and the semi- crystalline thermoplastic component of the layer are substantially free of phase separation when combined in a melt state following fusion.

2. The method of claim 1, wherein the first plurality of the particles each comprising the amorphous thermoplastic component is about 2.5 wt% to about

97.5 wt% of the powder composition.

3. The method of any one of claims 1 or 2, wherein the amorphous thermoplastic component has a glass transition temperature of more than 50 °C and less than 350 °C.

4. The method of any one of claims 1-3, wherein the amorphous

thermoplastic component is 100 wt% of each of the first plurality of particles. 5. The method of any one of claims 1-4, wherein the amorphous

thermoplastic component comprises an amorphous thermoplastic polymer.

6. The method of claim 5, wherein the amorphous thermoplastic polymer is polyamide-imide, polyethersulphone, polyetherimide, polyarylate, polysulphone, polymethacrilate, polyvinylchloride, acrylonitrile butadiene styrene, polystyrene, polyetherimide, or mixtures thereof.

7. The method of any one of claims 1-6, wherein the second plurality of the particles each comprising the semi-crystalline thermoplastic component is about 5 wt% to about 95 wt% of the powder composition. 8. The method of claim 3-7, wherein a melting temperature of the semi- crystalline thermoplastic component is higher than the glass transition temperature of the amorphous thermoplastic component.

9. The method of any one of claims 1-8, wherein the semi-crystalline thermoplastic component is 100 wt% of each of the second plurality of particles.

10. The method of claim 9, wherein the first plurality of the particles each comprising the semi-crystalline thermoplastic component are monomodal and have a D50 of about 10 to about 100 microns.

11. The method of claim 10, wherein the first plurality of the particles each comprising the amorphous thermoplastic component have D98 of about 150 microns.

12. The method of any one of claims 1-11, wherein the semi-crystalline thermoplastic component comprises a semi-crystalline thermoplastic polymer.

13. The method of claim 12, wherein the semi-crystalline thermoplastic polymer is polyetheretherketone, polyphenylene ether, polytetrafluoroethylene, Nylon 6,6, Nylon 11, polyphenylene sulphide, polyethylene terephthalate, polyoxymethylene, polypropylene, high-density polyethylene, low-density polyethylene, or mixtures thereof. 14. The method of claim 13, wherein the amorphous thermoplastic component is polyetherimide and the semi-crystalline thermoplastic component is polyethylene terephthalate.

A method of forming a three-dimensional article comprising: (1) depositing a quantity of a powder composition on a substrate, the powder composition comprising:

a first plurality of particles each comprising an amorphous thermoplastic component; and

a second plurality of particles each comprising a semi-crystalline thermoplastic component;

(2) directing a laser beam over a predetermined target area on the substrate to form an integral layer; and

optionally repeating (1) and (2) to form additional layers that are integrally bonded to adjacent layers to form a three-dimensional article

wherein the amorphous thermoplastic component and the semi- crystalline thermoplastic component of the integral layer are substantially free of phase separation when combined in a melt state following fusion. 16. A three-dimensional article comprising:

a first layer comprising:

an amorphous thermoplastic component; and

a semi-crystalline thermoplastic component; and

a second layer adjacent to the first layer, the second layer comprising: an amorphous thermoplastic component; and

a semi-crystalline thermoplastic component,

wherein upon an increase in temperature the amorphous thermoplastic component and the semi-crystalline thermoplastic component of at least one of the first and second layers is substantially free of phase separation.

17. The three-dimensional article of claim 16, wherein the three-dimensional article is amorphous.

18. The three-dimensional article of any one of claims 16 or 17, wherein a glass transition temperature of the three-dimensional article is higher than a glass transition temperature of the amorphous thermoplastic component.

19. The three-dimensional article of claim 18, wherein the glass transition temperature of the three-dimensional article ranges from about 5 °C to about 100 °C higher than the glass transition temperature of the amorphous thermoplastic component.

20. The three-dimensional article of any one of claims 16 or 17, wherein a glass transition temperature of the three-dimensional article is lower than a glass transition temperature of the amorphous thermoplastic component.