Thermoplastic polyester particles and methods of making and using the same

Abstract

The invention is entitled "Thermoplastic Polyester Pellets and Methods of Making and Using Them". The invention discloses a method of making thermoplastic particles, which may include: mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter (dP) of about 7 MPa; 0.5 or less of a carrier fluid, (b) a dispersed phase comprising a dP of about 8 MPa 0.5 or greater dispersed fluid, and (c) an internal phase comprising a thermoplastic polyester, the mixing being carried out at a temperature greater than the melting point or softening temperature of the thermoplastic polyester and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase; and cooling the molten emulsion to below the melting point or softening temperature of the thermoplastic polyester to form coagulated particles comprising the thermoplastic polyester.

Description

Technical Field

[0001] The present disclosure relates to thermoplastic polyester particles and methods for making such particles. Such particles, particularly highly spherical thermoplastic polyester particles, can be used, among other things, as raw materials for additive manufacturing. Background Art

[0002] Three-dimensional (3D) printing, also known as additive manufacturing, is a rapidly growing field of technology. Although traditionally used for rapid prototyping activities, 3D printing is increasingly being used to produce commercial and industrial objects that may have structural and mechanical tolerances that are significantly different from those required for rapid prototyping.

[0003] 3D printing operates by depositing either (a) small droplets or streams of molten or solidifiable material or (b) powder particles into precise deposition locations for subsequent consolidation into larger objects, which can have any number of complex shapes. Such deposition and consolidation processes are typically performed under computer control to provide layer-by-layer buildup of larger objects. In a specific example, the consolidation of powder particles can be performed in a 3D printing system using a laser to facilitate selective laser sintering (SLS). Incomplete interlayer fusion can create structural weaknesses, which can be problematic for printing objects with tight structural and mechanical tolerances.

[0004] Powder particles that can be used for 3D printing include thermoplastic polymers (including thermoplastic elastomers), metals and other solidifiable substances. Although a wide variety of thermoplastic polymers are known, relatively few have properties suitable for 3D printing, particularly when powder bed fusion (PBF) is used. Additive manufacturing methods using powder materials include PBF, selective laser sintering (SLS), selective heat sintering (SHM), selective laser melting (SLM), electron beam melting (EBM), binder jetting and multi-jet melting (MJF). In the SLS printing method, energy from a high-power laser causes the particles to fuse together. Typical thermoplastic polymers suitable for 3D printing include those with a well-defined melting point and a recrystallization point that is approximately 20°C to 50°C lower than the melting point. This difference allows more efficient coalescence between adjacent polymer layers, thereby promoting improved structural and mechanical integrity.

[0005] In order to achieve good printing performance using powder particles (particularly polymer powder particles), the powder particles need to maintain good flow properties in the solid state. Flow properties can be assessed, for example, by measuring the fraction of powder particles in a sample that can pass through a standard sieve of a specified size and / or measuring the angle of repose. A high fraction of sievable powder particles can indicate that the particles are present in the form of non-agglomerated, essentially individual particles, which can be a characteristic of a ready-to-use powder flow. In contrast, a lower value of the angle of repose can be a characteristic of a ready-to-use powder flow. A relatively narrow particle size distribution in the sample and the regularity of the particle shape can also help promote good powder flow properties.

[0006] Commercial powder particles are typically obtained through cryogenic grinding or precipitation processes, which can produce irregular particle shapes and wide particle size distributions. Irregular particle shapes can lead to poor powder flow properties during 3D printing. In addition, powder particles with irregular shapes (especially those obtained from current commercial processes) can lead to poor filling efficiency after deposition and consolidation, resulting in extensive formation of voids in the printed article due to the powder particles not being tightly packed together during deposition. Wide particle size distribution can similarly be problematic in this regard. Although poor powder flow properties can be addressed to a certain extent by dry mixing with fillers and flow aids, these techniques may have limited effectiveness for softer polymer materials (such as elastomers) due to particle aggregation. Summary of the Invention

[0007] The present disclosure relates to thermoplastic polyester particles and methods for making such particles. Such particles, particularly highly spherical thermoplastic polyester particles, can be used, among other things, as raw materials for additive manufacturing.

[0008] According to aspects described herein, a method is provided, comprising: mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter (d P ) is about 7MPa 0.5 or smaller carrier fluid, (b) a dispersed phase comprising d P About 8MPa 0.5 or greater dispersed fluid, and (c) an internal phase comprising a thermoplastic polyester, the mixing being carried out at a temperature greater than the melting point or softening temperature of the thermoplastic polyester and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase; and cooling the molten emulsion to below the melting point or softening temperature of the thermoplastic polyester to form coagulated particles comprising the thermoplastic polyester.

[0009] According to aspects presented herein, there is provided a composition comprising: particles comprising a thermoplastic polyester, wherein the particles have a sintering window that is within 5° C. of the sintering window of the thermoplastic polyester. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following figures are included to illustrate certain aspects of the embodiments and should not be construed as exclusive embodiments. The disclosed subject matter is capable of considerable modification, alteration, combination, and equivalents in form and function, as will occur to those skilled in the art having the benefit of this disclosure.

[0011] Figure 1 is a flow diagram of a non-limiting example of a multiphase molten emulsion.

[0012] Figure 2 is a flow chart of a non-limiting example method 100 of the present disclosure.

[0013] Figure 3A is an optical micrograph of the particles of Example 1.

[0014] Figure 3B is an optical micrograph of the particles of Example 2.

[0015] Figure 3C is an optical micrograph of the particles of Example 3.

[0016] Figure 3D is an optical micrograph of the particles of Example 4.

[0017] Figure 3E is an optical micrograph of the particles of Example 5.

[0018] Figure 3F is an optical micrograph of the particles of Example 6.

[0019] Figure 3G is an optical micrograph of the particles of Example 7.

[0020] Figure 3H is an optical micrograph of the particles of Example 8.

[0021] Figure 4A is a scanning electron micrograph of the particles of Example 3.

[0022] Figure 4B is a scanning electron micrograph of the particles of Example 4.

[0023] Figure 5A is a differential scanning calorimetry thermogram of the particles of Example 3.

[0024] Figure 5B is a differential scanning calorimetry thermogram of the particles of Example 4.

[0025] Figure 5C This is the differential scanning calorimetry thermogram of polybutylene terephthalate (PBT) raw material.

[0026] Figure 6Ais a graph of the particle size distribution (including particle size statistics) of Example 4.

[0027] Figure 6B is a graph of the particle size distribution (including particle size statistics) of Example 8.

[0028] Figure 7 Included are two images of the sintered layer from Example 9 at 45% laser power.

[0029] Figure 8 Included are two images of the sintered layer from Example 10 at 45% laser power.

[0030] Figure 9A-9B is a scanning electron micrograph of the particles of Example 11, and Figure 9C-9F is a scanning electron micrograph of a cross section of the particle.

[0031] Figures 10A-10B Included are two images of the sintered layer from Example 11 at 45% laser power.

[0032] Figures 11A-11B is a scanning electron micrograph of the particles of Example 12, and Figure 11C-11F is a scanning electron micrograph of a cross section of the particle.

[0033] Figures 12A-12B is a scanning electron micrograph of the particles of Example 13, and Figure 12C-12F is a scanning electron micrograph of a cross section of the particle.

[0034] Figures 13A-13B is a picture of the sintered layer from Example 13 at 45% laser power.

[0035] Figures 14A-14D Included are scanning electron micrographs at various magnifications of particles prepared in Example 17.

[0036] Figure 15 is a bar graph of the particle sizes of the particles prepared in Example 17.

[0037] Figures 16A-16E Included are scanning electron micrographs at various magnifications of particles prepared in Example 18.

[0038] Figure 17 is a bar graph of the particle sizes of the particles prepared in Example 18.

[0039] Figures 18A-18B are optical micrographs of particles prepared in Example 19 at various magnifications.

[0040] Figure 19 is a bar graph of the particle sizes of the particles prepared in Example 19. DETAILED DESCRIPTION

[0041] The present disclosure relates to polymer particles comprising thermoplastic polyesters and methods of making such particles. Such particles, particularly highly spherical polymer particles comprising thermoplastic polyesters, can be used, among other things, as raw materials for additive manufacturing.

[0042] More specifically, the polymer particles described herein are prepared by a melt emulsification process, wherein the melt emulsion has three or more phases. Figure 1 A three-phase molten emulsion is shown comprising: (a) a continuous phase 102 comprising a carrier fluid (e.g., polydimethylsiloxane), (b) a dispersed phase 104 comprising a dispersing fluid, and (c) an internal phase 106 comprising a thermoplastic polyester. The carrier fluid, the dispersing fluid, and the thermoplastic polyester are each immiscible with one another. Although Figure 1 Several internal phase droplets within the dispersed phase are shown, but the dispersed phase droplets may have a single internal phase droplet within them.

[0043] Without being limited by theory, it is believed that the hydrolysis and / or grafting of the polyester during the melt emulsification process can lead to a reduction in the sintering window of the resulting particles. That is, when the polyester is hydrolyzed and / or grafted, the temperature range over which sintering can be effectively performed decreases. Therefore, the composition of the dispersed phase is preferably selected to not be conducive to the hydrolysis and / or grafting of the thermoplastic polyester. For example, hydroxyl-terminated polyethylene glycol, which has been used in other melt emulsification methods, can cleave polyester bonds via an ester exchange mechanism. In addition, hydroxyl-terminated polyethylene glycol can be able to graft onto polyester or byproducts of polyester hydrolysis. Therefore, alkyl-terminated polyethylene glycol is preferred in the dispersed phase because the polymer is inert to the ester exchange and cleavage of polyester chains. Additionally, the methods described herein can be tailored to further mitigate hydrolysis by one or more of: (a) performing the melt emulsification in an inert gas environment when not performed in an apparatus (e.g., an extruder), wherein no additional gas environment is present; and (b) using a less hygroscopic carrier fluid (if any) to minimize hydrolysis due to the lower water content.

[0044] In the methods described herein, a sufficient amount of shear is applied to disperse the dispersing fluid in the carrier fluid and to cause the polymer melt to form droplets in the dispersing fluid. As further described herein, to achieve an emulsion having three or more phases, the composition of the phases is selected based on (a) solubility parameters and / or (b) viscosity at processing temperature.

[0045] Emulsion stabilizers (e.g., nanoparticles and / or surfactants, in some cases including one or more members of each type) can be used to influence the surface tension at the interface between the carrier fluid and the polymer melt. Once the melt emulsification process is complete, the dispersion is cooled to solidify the polymer into polymer particles. Without being limited by theory, during the melt emulsification process, the emulsion stabilizer is primarily located at the interface between the polymer melt and the carrier fluid. Therefore, when the mixture is cooled, the emulsion stabilizer remains at the interface. Advantageously, the emulsion stabilizer at the surface of the resulting particles can contribute to the flow characteristics of the resulting particles.

[0046] Definition and test methods

[0047] As used herein, the term "immiscible" refers to a mixture of components that, when combined, form two or more phases that have less than 5% solubility by weight in one another at ambient pressure and room temperature or the melting point of the components if they are solid at room temperature. For example, polyethylene oxide having a molecular weight of 10,000 g / mol is solid at room temperature and has a melting point of 65° C. Thus, if a material that is liquid at room temperature and the polyethylene oxide have less than 5% solubility by weight in one another at 65° C., the polyethylene oxide is immiscible with the material.

[0048] As used herein, the term "thermoplastic polymer" refers to a plastic polymer material that reversibly softens / melts and hardens / solidifies upon heating and cooling. Thermoplastic polymers encompass thermoplastic elastomers.

[0049] As used herein, the term "elastomer" refers to a copolymer comprising a crystalline "hard" segment and an amorphous "soft" segment. For example, in the case of a polyurethane, the crystalline segment may comprise a portion of a polyurethane having carbamate functional groups and optional chain extender groups, and the soft segment may comprise a polyol.

[0050] As used herein, the term "polyurethane" refers to the polymer reaction product between a diisocyanate, a polyol, and optionally a chain extender.

[0051] As used herein, the term "oxide" refers to both metal oxides and non-metal oxides.For the purposes of this disclosure, silicon is considered a metal.

[0052] As used herein, the terms "associated," "associated," and grammatical variations thereof between an emulsion stabilizer and a surface refer to chemical bonding and / or physical adhesion of the emulsion stabilizer to the surface. Without being limited by theory, it is believed that the association between the polymers described herein and the emulsion stabilizers is primarily physical adhesion via hydrogen bonding and / or other mechanisms. However, chemical bonding may occur to some extent.

[0053] As used herein, the term "embedded" with respect to the surface of nanoparticles and polymer particles means that the nanoparticles extend at least partially into the surface such that the polymer contacts the nanoparticles to a greater extent than would be achieved if the nanoparticles were simply laid down on the surface of the polymer particle.

[0054] As used herein, D10, D50, D90, and diameter span are primarily used herein to describe particle size. As used herein, the term "D10" refers to the diameter at which 10% of a sample (on a volume basis, unless otherwise specified) consists of particles having a diameter less than the stated diameter value. As used herein, the term "D50" refers to the diameter at which 50% of a sample (on a volume basis, unless otherwise specified) consists of particles having a diameter less than the stated diameter value. As used herein, the term "D90" refers to the diameter at which 90% of a sample (on a volume basis, unless otherwise specified) consists of particles having a diameter less than the stated diameter value.

[0055] As used herein, the terms "diameter span" and "span" and "span size" when referring to diameter provide an indication of the breadth of the particle size distribution and are calculated as (D90-D10) / D50 (again, unless otherwise indicated, each D value is based on volume).

[0056] By using the Malvern MASTERSIZER TM Particle size was determined by light scattering techniques or analysis of optical digital micrographs using a 3000. Unless otherwise indicated, light scattering techniques were used to analyze particle size.

[0057] For light scattering techniques, the control sample is the product of the trade name Quality Audit Standards QAS4002 TM Glass microspheres with diameters ranging from 15 μm to 150 μm were purchased from Malvern Analytical Ltd. Samples were analyzed as dry powders unless otherwise indicated. TM The particles to be analyzed were dispersed in air and analyzed using the 3000. The particle size was determined from a plot of bulk density versus size using the instrument software.

[0058] Particle size measurements and diameter spans can also be determined by optical digital microscopy.Optical images were acquired using a Keyence VHX-2000 digital microscope and version 2.3.5.1 software for particle size analysis (system version 1.93).

[0059] As used herein, when referring to sieving, the hole / sieve size is described in terms of United States Standard Sieve (ASTM E11-17).

[0060] As used herein, the terms "roundness" and "sphericity" with respect to particles refer to how closely the particles approximate a perfect sphere. To determine roundness, an optical microscopic image of the particles is taken. The perimeter (P) and area (A) of the particles in the plane of the microscopic image are calculated (e.g., using a SYSMEX FPIA3000 particle shape and size analyzer, available from Malvern Instruments). The roundness of a particle is C EA / P, where C EA It is the circumference of a circle whose area is equal to the area of ​​the actual particle (A).

[0061] As used herein, the term "sintering window" refers to the difference between the melting temperature (Tm) onset and the crystallization temperature (Tc) onset, or (Tm-Tc) onset. Tm, Tm(onset), Tc, and Tc(onset) are determined by differential scanning calorimetry according to ASTM E794-06 (2018) with a ramp rate of 10°C / min and a cooling rate of 10°C / min.

[0062] As used herein, the term "shear" refers to stirring or similar processes that cause mechanical agitation in a fluid.

[0063] As used herein, the term "aspect ratio" refers to the length divided by the width, wherein the length is greater than the width.

[0064] Unless otherwise indicated, the melting point of the polymers was determined by ASTM E794-06 (2018) with a 10°C / min ramp rate and cooling rate.

[0065] Unless otherwise indicated, the softening temperature or softening point of a polymer is determined by ASTM D6090-17.The softening temperature can be measured using a cup and ball apparatus commercially available from Mettler-Toledo using a 0.50 gram sample at a heating rate of 1°C / min.

[0066] The angle of repose is a measure of the flowability of a powder. Angle of repose measurements were determined using ASTM D6393-14 "Standard Test Method for Bulk Solids Characterized by Carr Indices" using a Hosokawa Micron Powder Characterization Tester PT-R.

[0067] Hausner ratio (Hausner ratio, Hr ) is a measure of the flowability of the powder and is given by H r =ρ 振实 / ρ 堆积 Calculate, where ρ 堆积 is the bulk density according to ASTM D6393-14, and ρ 振实 is the tap density according to ASTM D6393-14.

[0068] As used herein, unless otherwise indicated, the viscosity of a carrier fluid is the kinematic viscosity at 25° C., measured according to ASTM D445-19. For commercially available carrier fluids (e.g., PDMS oil), the kinematic viscosity data cited herein are those provided by the manufacturer, whether measured according to the aforementioned ASTM or another standard measurement technique.

[0069] As used herein, the Hansen solubility parameters are based on Hansen Solubility Parameters: User Manual Solubility Parameters:A User's Handbook) (Charles M. Hansen. CRC Press, Boca Raton, FL, 2nd ed. 2007). Alternatively, the Hansen solubility parameter of a mixture can be calculated by taking the volume-weighted average of the Hansen solubility parameters of each component in the mixture. The total Hansen solubility parameter is the geometric mean of the three Hansen solubility components: d D (from dispersion interactions), d P (from polarity attraction) and d H (from hydrogen bonding).

[0070] Polymer particles and preparation method

[0071] Figure 2 2 is a flow chart of a non-limiting exemplary method 200 of the present disclosure. At 208, polymer 202, carrier fluid 204, dispersing fluid 206, and an optional emulsion stabilizer (not shown) are combined to produce mixture 210. Polymer 202 comprises a thermoplastic polyester and, optionally, one or more additional thermoplastic polymers. Components 202, 204, and 206 may be added in any order and may include mixing and / or heating during the process of combining components 202, 204, and 206 at 208.

[0072] Examples of thermoplastic polyesters include, but are not limited to, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, and the like, and any combination thereof.

[0073] The mixture 210 is then processed at 212 by applying sufficiently high shear to the mixture 210 at a temperature greater than the melting point or softening temperature of the polymer 202 to form a molten emulsion 214 having three or more phases. More specifically, the molten emulsion may include: (a) a continuous phase including a carrier fluid 204 (e.g., polydimethylsiloxane), (b) a dispersed phase including a dispersing fluid 206, and (c) an internal phase including the polymer 202. To achieve separate continuous and dispersed phases (with the internal phase dispersed in the dispersed phase), the carrier fluid 204 preferably has a pressure of about 7 MPa. 0.5 or smaller (or 0MPa 0.5 to 7MPa 0.5 , or 0MPa 0.5 to 5MPa 0.5 , or about 3MPa 0.5 to 7MPa 0.5 ) of the polar Hansen solubility parameter (d P ), and the dispersion fluid 206 preferably has a pressure of about 8 MPa 0.5 or greater (or 8MPa 0.5 to 30MPa 0.5 , or 8MPa 0.5 to 15MPa 0.5 , or 13MPa 0.5 to 20MPa 0.5 , or about 15MPa 0.5 to 30MPa 0.5 ) P In addition, the dispersion fluid 206 has a d P and carrier fluid 204 P The difference between the two values ​​is preferably 3 MPa. 0.5 or greater (or 3MPa 0.5 to 30MPa 0.5 , or 3MPa 0.5 to 10MPa 0.5 , or about 5MPa 0.5 to 15MPa 0.5 , or about 10MPa 0.5 to 20MPa 0.5 , or about 15MPa 0.5 to 30MPa 0.5 ).

[0074] Because the temperature is above the melting point or softening temperature of polymer 202, polymer 202 becomes a polymer melt. As a non-limiting example, PBT has a softening temperature of approximately 170°C and a melting temperature of approximately 223°C. Therefore, the temperature at which PBT is mixed to form molten emulsion 214 can be from about 180°C to about 320°C (or from about 180°C to about 250°C, or from about 200°C to about 300°C, or from about 225°C to about 300°C). If additional thermoplastic polymers and / or additional thermoplastic polyesters are used in addition to PBT, the temperature may vary. More generally, the temperature at which molten emulsion 214 is mixed to form can be from about 150°C to about 350°C (or from about 150°C to about 250°C, or from about 200°C to about 300°C, or from about 250°C to about 350°C). Likewise, temperatures outside these ranges may also be suitable, depending on the polymers included in the process. The mixture 210 is preferably substantially free of water (e.g., less than 1% by weight of water) to mitigate hydrolysis of the thermoplastic polyester. Additionally, the mixture can be heated in an inert gas environment (e.g., using nitrogen or argon) to mitigate the introduction of additional water into the mixture 200.

[0075] Additionally, the shear rate should be high enough to disperse the polymer melt in the form of droplets in the dispersion fluid 206. Without being limited by theory, it is believed that, all other factors being equal, increasing shear should reduce the size of the polymer melt droplets in the carrier fluid 204. However, at some point, increasing shear and reducing droplet size may have diminishing returns, or there may be damage to the droplet contents, thereby reducing the quality of the particles produced therefrom.

[0076] The molten emulsion 214 inside and / or outside the mixing vessel is then cooled at 216 to solidify the polymer droplets into polymer particles (also referred to as solidified polymer particles). The cooled mixture 218 can then be processed at 220 to separate the polymer particles 222 from other components 224 (e.g., carrier fluid 204, dispersion fluid 206, excess emulsion stabilizer when used, etc.), and to wash or otherwise purify the polymer particles 222. The polymer particles 222 comprise the polymer 202 and at least a portion of the emulsion stabilizer that coats the outer surface of the polymer particles 222 when used. The emulsion stabilizer, or a portion thereof, can be deposited as a uniform coating on the polymer particles 222. In some cases, which may depend on non-limiting factors such as temperature (including cooling rate), the type of polymer 202, and the type and size of the emulsion stabilizer, the nanoparticles of the emulsion stabilizer can at least partially embed within the outer surface of the polymer particles 222 during association with the outer surface. Even if embedding does not occur, at least the nanoparticles within the emulsion stabilizer 206 can remain robustly associated with the polymer particles 222 to facilitate further use. In contrast, dry blending already formed polymer microparticles (eg, formed by cryogenic grinding or precipitation processes) with a glidant (such as silica nanoparticles) does not produce a robust, uniform coating of the glidant on the polymer microparticles.

[0077] Advantageously, the carrier fluid, dispersion fluid, and wash solvent of the systems and methods described herein (e.g., method 200) can be recycled and reused. One skilled in the art will recognize any necessary cleaning of the spent carrier fluid, dispersion fluid, and solvent required during recycling.

[0078] The polymer 202, carrier fluid 204, and dispersion fluid 206 should be selected so that they are immiscible with one another at various processing temperatures (e.g., from room temperature to the processing temperature). An additional factor that may be considered is the difference (e.g., difference or ratio) in viscosity between the molten polymer 202, carrier fluid 204, and dispersion fluid 206 at the processing temperature. This viscosity difference can affect droplet breakup and particle size distribution. Without being limited by theory, it is believed that when the viscosities of the molten polymer 202, carrier fluid 204, and dispersion fluid 206 are too similar, the roundness of the product as a whole can be reduced, with particles becoming more oval and a more elongated structure observed.

[0079] Examples of thermoplastic polymers that can be used in combination with thermoplastic polyesters include, but are not limited to, polyamides, polyurethanes, polyethylenes, polypropylenes, polyacetals, polycarbonates, polystyrenes, polyvinyl chlorides, polytetrafluoroethylenes, polyesters (e.g., polylactic acid), polyethers, polyethersulfones, polyetheretherketones, polyacrylates, polymethacrylates, polyimides, acrylonitrile butadiene styrene (ABS), polyphenylene sulfide, vinyl polymers, polyarylene ethers, polyarylene sulfide, polysulfones, polyetherketones, polyamide-imides, polyetherimides, polyetheresters, copolymers comprising polyether blocks and polyamide blocks (PEBA or polyether block amides), grafted or non-grafted thermoplastic polyolefins, functionalized or non-functionalized ethylene / vinyl monomer polymers, functionalized or non-functionalized ethylene / vinyl monomer polymers. Alkyl (meth)acrylates, functionalized or non-functionalized (meth)acrylic polymers, functionalized or non-functionalized ethylene / vinyl monomer / alkyl (meth)acrylate terpolymers, ethylene / vinyl monomer / carbonyl terpolymers, ethylene / alkyl (meth)acrylate / carbonyl terpolymers, methyl methacrylate-butadiene-styrene (MBS) core-shell polymers, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymers, chlorinated or chlorosulfonated polyethylene, polyvinylidene fluoride (PVDF), phenolic resins, poly(ethylene / vinyl acetate), polybutadiene, polyisoprene, styrenic block copolymers, polyacrylonitrile, silicones, and the like, and any combination thereof. Copolymers comprising one or more of the foregoing can also be used in the methods and systems of the present disclosure.

[0080] The thermoplastic polymers in the compositions and methods of the present disclosure can be elastomeric or non-elastomeric. Some of the aforementioned examples of thermoplastic polymers can be elastomeric or non-elastomeric, depending on the exact composition of the polymer. For example, polyethylene, which is a copolymer of ethylene and propylene, can be elastomeric regardless of the amount of propylene in the polymer.

[0081] Thermoplastic elastomers generally fall into one of six categories: styrenic block copolymers, thermoplastic polyolefin elastomers, thermoplastic vulcanizates (also known as elastomeric alloys), thermoplastic polyurethanes, thermoplastic copolyesters, and thermoplastic polyamides (typically block copolymers comprising polyamides).

[0082] Examples of polyamides include, but are not limited to, polycaprolactam (nylon 6, polyamide 6, or PA6), poly(hexamethylene succinamide) (nylon 4,6, polyamide 4,6, or PA4,6), polyhexamethylene adipamide (nylon 6,6, polyamide 6,6, or PA6,6), polypentamethylene adipamide (nylon 5,6, polyamide 5,6, or PA5,6), polyhexamethylene sebacamide (nylon 6,10, polyamide 6,10, or PA6,10), polyundecanamide (nylon 11, polyamide 11, or PA11), polydodecamide (nylon 12, polyamide 12, or PA12), and polyhexamethylene terephthalamide (nylon 6T, polyamide 6 T or PA6T), nylon 10,10 (polyamide 10,10 or PA10,10), nylon 10,12 (polyamide 10,12 or PA10,12), nylon 10,14 (polyamide 10,14 or PA10,14), nylon 10,18 (polyamide 10,18 or PA10,18), nylon 6,18 (polyamide 6,18 or PA6,18), nylon 6,12 (polyamide 6,12 or PA6,12), nylon 6,14 (polyamide 6,14 or PA6,14), nylon 12,12 (polyamide 12,12 or PA12,12), etc., and any combination thereof. Copolyamides may also be used. Examples of copolyamides include, but are not limited to, PA 11 / 10,10, PA 6 / 11, PA 6,6 / 6, PA 11 / 12, PA 10,10 / 10,12, PA 10,10 / 10,14, PA 11 / 10,36, PA 11 / 6,36, PA 10,10 / 10,36, PA 6T / 6,6, and the like, and any combination thereof. A polyamide followed by a first number of commas followed by a second number of commas is a polyamide having a first number of backbone carbons between nitrogens for segments without pendant =O groups and a second number of backbone carbons between two nitrogens for segments with pendant =O groups. As a non-limiting example, nylon 6,10 is [NH-(CH2)6-NH-CO-(CH2)8-CO] n A polyamide followed by a quantitative backslash number is a copolymer of the polyamide indicated by the numbers before and after the backslash.

[0083] Examples of polyurethanes include, but are not limited to, polyether polyurethanes, polyester polyurethanes, mixed polyether and polyester polyurethanes, and any combination thereof. Examples of thermoplastic polyurethanes include, but are not limited to, poly[4,4′-methylenebis(phenyl isocyanate)-alt-1,4-butanediol / di(propylene glycol) / polycaprolactone], ELASTOLLAN TM 1190A (a polyether polyurethane elastomer available from BASF), ELASTOLLAN TM1190A10 (a polyether polyurethane elastomer available from BASF), and the like, and any combination thereof.

[0084] Compatibilizers may optionally be used to improve the blending efficiency and effectiveness of the thermoplastic polyester with one or more thermoplastic polymers. Examples of polymer compatibilizers include, but are not limited to, PROPOLDER TM MPP202020 (polypropylene, available from Polygroup Inc.), PROPOLDER TM MPP2040 40 (polypropylene, available from Polygroup Inc.), NOVACOM TM HFS2100 (maleic anhydride functionalized high density polyethylene polymer, available from Polygroup Inc.), KEN-REACT TM CAPS TM L TM 12 / L (organic metal coupling agent, available from Kenrich Petrochemicals), KEN-REACT TM CAPOW TM L TM 12 / H (organic metal coupling agent, available from Kenrich Petrochemicals), KEN-REACT TM LICA TM 12 (organometallic coupling agent, available from Kenrich Petrochemicals), KEN-REACT TM CAPS TM KPR TM 12 / LV (organic metal coupling agent, available from Kenrich Petrochemicals), KEN-REACT TM CAPOW TM KPR TM 12 / H (organic metal coupling agent, available from Kenrich Petrochemicals), KEN-REACT TM Titanates and zirconates (organometallic coupling agents available from Kenrich Petrochemicals), VISTAMAXX TM(ethylene-propylene copolymer, available from ExxonMobil), SANTOPRENE TM (thermoplastic vulcanizate of EPDM and polypropylene, available from ExxonMobil), VISTALON TM (EPDM rubber, available from ExxonMobil), EXACT TM (plastomer, available from ExxonMobil), EXXELOR TM (polymer resin available from ExxonMobil), FUSABOND TM M603 (random ethylene copolymer, available from Dow Chemical Company (DOW)), FUSABOND TM E226 (anhydride-modified polyethylene, available from Dow Chemical Company (DOW)), BYNEL TM 41E710 (co-extrudable adhesive resin available from Dow Chemical Company (DOW)), SURLYN TM 1650 (ionomer resin, available from Dow Chemical Company (DOW)), FUSABOND TM P353 (a chemically modified polypropylene copolymer available from Dow Chemical Company (DOW)), ELVALOY TM PTW (ethylene terpolymer, available from Dow Chemical Company (DOW)), ELVALOY TM 3427AC (copolymer of ethylene and butyl acrylate, available from Dow Chemical Company (DOW)), LOTADER TM AX8840 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM 3210 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM 3410 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM 3430 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM 4700 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM AX8900 (ethylene-acrylate based terpolymer, available from Arkema), LOTADER TM4720 (ethylene-acrylate based terpolymer, available from Arkema), BAXXODUR TM EC 301 (amine for epoxy resin, available from BASF), BAXXODUR TM EC 311 (amine for epoxy resin, available from BASF), BAXXODUR TM EC 303 (amine for epoxy resin, available from BASF), BAXXODUR TM EC 280 (amine for epoxy resin, available from BASF), BAXXODUR TM EC201 (amine of epoxy resin, available from BASF), BAXXODUR TM EC 130 (amine for epoxy resin, available from BASF), BAXXODUR TM EC 110 (amine of epoxy resin, available from BASF), styrene, polypropylene, polyamide, polycarbonate, EASTMAN TM G-3003 (a maleic anhydride grafted polypropylene available from Eastman), RETAIN TM (polymer modifier, available from Dow Chemical Company (DOW)), AMPLIFY TY TM (maleic anhydride grafted polymer, available from Dow Chemical Company (DOW)), INTUNE TM (olefin block copolymer, available from The Dow Chemical Company (DOW)), etc. and any combination thereof.

[0085] The thermoplastic polymer may have a melting point or softening temperature of about 50°C to about 450°C (or about 50°C to about 125°C, or about 100°C to about 175°C, or about 150°C to about 280°C, or about 200°C to about 350°C, or about 300°C to about 450°C).

[0086] The thermoplastic polymer may have a glass transition temperature (derived according to ASTM E1356-08 (2014) using a 10°C / min ramp rate and cooling rate) of about -50°C to about 400°C (or about -50°C to about 0°C, or about -25°C to about 50°C, or about 0°C to about 150°C, or about 100°C to about 250°C, or about 150°C to about 300°C, or about 200°C to about 400°C).

[0087] Polymer 202 may optionally contain additives. Typically, the additives will be present before polymer 202 is added to mixture 210. Thus, the additives are dispersed throughout the polymer, both in the polymer melt droplets and in the resulting polymer particles. Therefore, for clarity, such additives are referred to herein as "internal additives." Internal additives can be blended with the polymer just prior to preparing mixture 210 or significantly in advance.

[0088] When describing the amounts of components in the compositions described herein (e.g., mixture 210 and polymer particles 222), internal additives are not accounted for based on the weight percentages of polymer 202. For example, a composition comprising 1 wt% emulsion stabilizer is a composition comprising 0.9 g of emulsion stabilizer, 90 g of polymer, and 10 g of internal additive, based on the weight of 100 g of polymer 202 comprising 10 wt% of internal additive and 90 wt% of polymer.

[0089] The internal additive may be present in the polymer 202 in an amount ranging from about 0.1% to about 60% by weight (or about 0.1% to about 5%, or about 1% to about 10%, or about 5% to about 20%, or about 10% to about 30%, or about 25% to about 50%, or about 40% to about 60% by weight) of the polymer 202. For example, the polymer 202 may include about 70% to about 85% by weight of the polymer and about 15% to about 30% by weight of the internal additive, such as glass fiber or carbon fiber.

[0090] Examples of internal additives include, but are not limited to, fillers, reinforcing agents, pigments, pH adjusters, and combinations thereof. Examples of fillers include, but are not limited to, glass fibers, glass particles, mineral fibers, carbon fibers, oxide particles (e.g., titanium dioxide and zirconium dioxide), metal particles (e.g., aluminum powder), and combinations thereof. Examples of pigments include, but are not limited to, organic pigments, inorganic pigments, carbon black, and combinations thereof.

[0091] Polymer 202 may be present in mixture 210 at about 5 wt % to about 60 wt % (or about 5 wt % to about 25 wt %, or about 10 wt % to about 30 wt %, or about 20 wt % to about 45 wt %, or about 25 wt % to about 50 wt %, or about 40 wt % to about 60 wt %) of the combined polymer 202, carrier fluid 204, and dispersing fluid 206.

[0092] Suitable carrier fluid 204 has a viscosity of about 1,000 cSt to about 150,000 cSt (or about 1,000 cSt to about 60,000 cSt, or about 40,000 cSt to about 100,000 cSt, or about 75,000 cSt to about 150,000 cSt) at 25°C.

[0093] Examples of the carrier fluid 204 include, but are not limited to, silicone oil, fluorinated silicone oil, perfluorinated silicone oil, paraffin, liquid petrolatum, vison oil, turtle oil, soybean oil, perhydrosqualene, sweet almond oil, calophyllum oil, palm oil, parleam oil, grapeseed oil, sesame oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, almond oil, castor oil, avocado oil, jojoba oil, olive oil, corn germ oil, esters of lanolic acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and the like, and any combination thereof. Examples of silicone oils include, but are not limited to, polydimethylsiloxane, methylphenylpolysiloxane, alkyl-modified polydimethylsiloxane, alkyl-modified methylphenylpolysiloxane, amino-modified polydimethylsiloxane, amino-modified methylphenylpolysiloxane, fluorine-modified polydimethylsiloxane, fluorine-modified methylphenylpolysiloxane, polyether-modified polydimethylsiloxane, polyether-modified methylphenylpolysiloxane, and the like, and any combination thereof. A suitable carrier fluid (alone or as a mixture) should be selected so as not to decompose at the molten emulsion processing temperature.

[0094] Suitable dispersion fluids 206 have a viscosity of about 1,000 cSt to about 150,000 cSt (or about 1,000 cSt to about 60,000 cSt, or about 40,000 cSt to about 100,000 cSt, or about 75,000 cSt to about 150,000 cSt) at 25°C.

[0095] Examples of the dispersing fluid 206 include, but are not limited to, polyethylene glycol, polyethylene glycol with an alkyl terminal end (e.g., a C1-C4 terminal alkyl group such as tetraethylene glycol dimethyl ether (TDG)), esters of lanolin acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and the like, and any combination thereof.

[0096] It should be noted that, in general, some of the carrier fluid 204 and dispersing fluid 206 compositions overlap, as some compositions within these general categories may be used as carrier fluid 204 and other compositions may be used as dispersing fluid 206 (e.g., based on the degree of modification and / or type of modification (e.g., carbon chain length)). p Will determine whether the composition is the carrier fluid 204 or the dispersion fluid 206.

[0097] Polyesters are susceptible to hydrolysis. Therefore, the presence of water-degradable thermoplastic polyesters during the melt-emulsification preparation of thermoplastic polyester particles can have consequences for the application of thermoplastic polyester particles (e.g., in additive manufacturing). Therefore, preferred carrier fluids 204 include, but are not limited to, silicone oils, fluorinated silicone oils, perfluorinated silicone oils, paraffins, liquid petrolatum, vison oil, turtle oil, soybean oil, perhydrosqualene, calophyllum oil, palm oil, parleam oil, corn oil, sunflower oil, almond oil, avocado oil, jojoba oil, olive oil, corn germ oil, esters of lanolic acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and the like, and any combination thereof. Additionally, preferred dispersing fluids 206 include, but are not limited to, polyethylene glycols terminated with alkyl groups. As a non-limiting example, the carrier fluid may comprise silicone oil and alkyl-terminated polyethylene glycol.

[0098] The weight ratio of the carrier fluid to the dispersing fluid may be from about 1:3 to about 10:1 (or from about 1:2 to about 5:1 or from about 1:1 to about 3:1). Without being limited by theory, it is believed that a higher concentration of the dispersing fluid may result in smaller diameter particles. While other conditions (e.g., viscosity of each fluid, temperature, mixing speed, etc.) may play a role in producing smaller diameter particles, a weight ratio of the carrier fluid to the dispersing fluid of from about 1:3 to about 3:1 may be suitable for producing smaller diameter particles.

[0099] The weight ratio of the dispersion fluid to the thermoplastic polyester can be from about 1:5 to about 10:1 (or from about 1:3 to about 1:1, or from about 1:2 to about 3:1, or from about 1:1 to about 5:1, or from about 3:1 to about 10:1). Without being limited by theory, it is believed that higher concentrations of thermoplastic polyester can result in smaller diameter particles. While other conditions (e.g., viscosity of each fluid, temperature, mixing speed, etc.) can play a role in producing smaller diameter particles, a weight ratio of the dispersion fluid to the thermoplastic polyester of from about 1:5 to about 2:1 can be suitable for producing smaller diameter particles.

[0100] The carrier fluid 204 can be present in the mixture 210 at about 40% to about 95% by weight (or about 75% to about 95% by weight, or about 70% to about 90% by weight, or about 55% to about 80% by weight, or about 50% to about 75% by weight, or about 40% to about 60% by weight) of the combined polymer 202, carrier fluid 204, and dispersing fluid 206. The dispersing fluid 204 can be present in the mixture 210 at about 5% to about 40% by weight (or about 5% to about 15% by weight, or about 10% to about 25% by weight, or about 15% to about 30% by weight, or about 20% to about 40% by weight) of the combined polymer 202, carrier fluid 204, and dispersing fluid 206.

[0101] In some cases, the carrier fluid 204 may have a viscosity of about 0.6 g / cm 3 to about 1.5g / cm 3 The dispersion fluid 206 may have a density of about 0.6 g / cm 3 to about 1.5g / cm 3 and polymer 202 has a density of about 0.7 g / cm 3 to about 1.7g / cm 3 wherein the polymer has a similar, lower, or higher density than the density of the carrier fluid and / or the dispersion fluid.

[0102] Emulsion stabilizers are useful in the methods and compositions of the present disclosure and can include nanoparticles (eg, oxide nanoparticles, carbon black, polymer nanoparticles, and combinations thereof), surfactants, and the like, and any combination thereof.

[0103] Oxide nanoparticles can be metal oxide nanoparticles, non-metal oxide nanoparticles or their mixtures. Examples of oxide nanoparticles include, but are not limited to, silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, iron oxide, copper oxide, tin oxide, boron oxide, cerium oxide, thallium oxide, tungsten oxide, etc. and any combination thereof. Mixed metal oxides and / or non-metal oxides such as aluminosilicates, borosilicates and aluminoborosilicates are also included in the term metal oxide. Oxide nanoparticles can be hydrophilic or hydrophobic, which may be natural to the particles or the result of surface treatment of the particles. For example, silicon dioxide nanoparticles with a hydrophobic surface treatment (such as dimethylsilyl, trimethylsilyl, etc.) can be used in the methods and compositions of the present invention. In addition, silicon dioxide with a functional surface treatment (such as methacrylate functionality) can be used in the methods and compositions of the present invention. Non-functionalized oxide nanoparticles may also be suitable for use.

[0104] Commercially available examples of silica nanoparticles include, but are not limited to, AEROSIL available from Evonik.TM Particles (e.g., AEROSIL TM R812S (with hydrophobic modified surface and 260±30m 2 / g BET surface area of ​​about 7nm average diameter silica nanoparticles), AEROSIL TM RX50 (with hydrophobic modified surface and 35±10m 2 / g BET surface area of ​​about 40nm average diameter silica nanoparticles), AEROSIL TM 380 (with hydrophilic modified surface and 380±30m 2 / g of BET surface area of ​​silica nanoparticles) and the like and any combination thereof.

[0105] Carbon black is another type of nanoparticle that can be present as an emulsion stabilizer in the compositions and methods disclosed herein. Various grades of carbon black are familiar to those of ordinary skill in the art, and any of these grades can be used herein. Other nanoparticles capable of absorbing infrared radiation can similarly be used.

[0106] Polymer nanoparticles are another type of nanoparticle that can be present as an emulsion stabilizer in the present disclosure. Suitable polymer nanoparticles can comprise one or more polymers that are thermosetting and / or cross-linked so that they do not melt when processed by melt emulsification according to the present disclosure. High molecular weight thermoplastic polymers with high melting points or decomposition points can similarly comprise suitable polymer nanoparticle emulsion stabilizers.

[0107] The nanoparticles can have an average diameter (volume-based D50) of about 1 nm to about 500 nm (or about 10 nm to about 150 nm, or about 25 nm to about 100 nm, or about 100 nm to about 250 nm, or about 250 nm to about 500 nm).

[0108] Nanoparticles can have a size of about 10 m 2 / g to about 500m 2 / g (or about 10m 2 / g to about 150m 2 / g, or about 25m 2 / g to about 100m 2 / g, or about 100m 2 / g to about 250m 2 / g, or about 250m 2 / g to about 500m 2 / g) of BET surface area.

[0109] The nanoparticles can be included in the mixture 210 at a concentration of about 0.01 wt % to about 10 wt % (or about 0.01 wt % to about 1 wt %, or about 0.1 wt % to about 3 wt %, or about 1 wt % to about 5 wt %, or about 5 wt % to about 10 wt %) based on the weight of the polymer 202.

[0110] The surfactant may be anionic, cationic, nonionic, or zwitterionic. Examples of surfactants include, but are not limited to, sodium lauryl sulfate, sorbitan oleate, poly[dimethylsiloxane-co-[3-(2-(2-hydroxyethoxy)ethoxy)propylmethylsiloxane], sodium docusate (sodium 1,4-bis(2-ethylhexyloxy)-1,4-dioxobutane-2-sulfonate), and the like, and any combination thereof. Commercially available examples of surfactants include, but are not limited to, CALFAX®. TM DB-45 (sodium dodecyl diphenyl ether disulfonate, available from Pilot Chemicals), SPAN TM 80 (sorbitan maleate nonionic surfactant), MERPOL TM Surfactants (available from Stepan Company), TERGITOL TM TMN-6 (a water-soluble, nonionic surfactant available from Dow Chemical Company), TRITON TM X-100 (octylphenol ethoxylate, available from Sigma Aldrich), IGEPAL TM CA-520 (polyoxyethylene (5) isooctylphenyl ether, available from Sigma Aldrich), BRIJ TM S10 (polyethylene glycol octadecyl ether, available from Sigma Aldrich), etc. and any combination thereof.

[0111] The surfactant may be included in mixture 210 at a concentration of about 0.01 wt % to about 10 wt % (or about 0.01 wt % to about 1 wt %, or about 0.5 wt % to about 2 wt %, or about 1 wt % to about 3 wt %, or about 2 wt % to about 5 wt %, or about 5 wt % to about 10 wt %) based on the weight of polymer 202. Alternatively, mixture 210 may not include (or be absent) a surfactant.

[0112] The weight ratio of nanoparticles to surfactant can be from about 1:10 to about 10:1 (or from about 1:10 to about 1:1, or from about 1:5 to about 5:1, or from about 1:1 to about 10:1).

[0113] As described above, components 202, 204, and 206, and the emulsion stabilizer (when used), can be added in any order and mixed and / or heated during the process of combining components 202, 204, and 206 at 208. For example, dispersion fluid 206 can be dispersed in carrier fluid 204 before adding polymer 202 and emulsion stabilizer, and the dispersion can be optionally heated. In another non-limiting example, polymer 202 can be heated to produce a polymer melt, to which carrier fluid 204, dispersion fluid 106, and emulsion stabilizer can be added together or sequentially. In yet another non-limiting example, dispersion fluid 206 and carrier fluid 204 can be mixed at a temperature greater than the melting point or softening temperature of polymer 202 and at a sufficient shear rate to disperse the polymer melt in dispersion fluid 206. The emulsion stabilizer can then be added to form mixture 210 and maintained under suitable processing conditions for a set period of time.

[0114] Components 202, 204, and 206, and an emulsion stabilizer (if used), may be combined at 208 in any combination in a mixing device and / or another suitable container for process 212. As a non-limiting example, polymer 202 may be heated to a temperature greater than the melting point or softening temperature of polymer 202 in a mixing device for process 212, and dispersion fluid 206 may be dispersed in carrier fluid 204 in another container. The dispersion may then be added to the melt of polymer 202 in a mixing device for process 212.

[0115] The mixing apparatus used for processing 212 to produce molten emulsion 214 should be capable of maintaining molten emulsion 214 at a temperature greater than the melting point or softening temperature of polymer 202 and applying sufficient shear rate to disperse the polymer melt in the form of droplets in dispersion fluid 206 .

[0116] Examples of mixing devices for use in processing 212 to produce the molten emulsion 214 include, but are not limited to, extruders (e.g., continuous extruders, batch extruders, etc.), stirred reactors, mixers, reactors with in-line homogenizer systems, and the like, and devices derived therefrom.

[0117] The molten emulsion 214 is processed 212 and formed under suitable processing conditions (eg, temperature, shear rate, etc.) for a set period of time.

[0118] The temperature for processing 212 and forming molten emulsion 214 should be a temperature greater than the melting point or softening temperature of polymer 202 and less than the decomposition temperature of any components 202, 204, and 206 in mixture 210. For example, the temperature for processing 212 and forming molten emulsion 214 can be about 1°C to about 50°C (or about 1°C to about 25°C, or about 5°C to about 30°C, or about 20°C to about 50°C) greater than the melting point or softening temperature of polymer 202, provided that the temperature for processing 212 and forming molten emulsion 214 is less than the decomposition temperature of any components 202, 204, and 206 in mixture 210.

[0119] The shear rate of processing 212 and forming the molten emulsion 214 should be high enough to disperse the polymer melt in the form of droplets in the dispersion fluid 206. The droplets should include droplets having a diameter of about 1000 μm or less (or about 1 μm to about 1000 μm, or about 1 μm to about 50 μm, or about 10 μm to about 100 μm, or about 10 μm to about 250 μm, or about 50 μm to about 500 μm, or about 250 μm to about 750 μm, or about 500 μm to about 1000 μm).

[0120] The time for maintaining the temperature and shear rate for processing 212 and forming molten emulsion 214 can be from 10 seconds to 18 hours or longer (or from 10 seconds to 30 minutes, or from 5 minutes to 1 hour, or from 15 minutes to 2 hours, or from 1 hour to 6 hours, or from 3 hours to 18 hours). Without being limited by theory, it is believed that a steady state of droplet size will be reached, at which point processing 212 can be stopped. This time may also depend on, among other things, the temperature, shear rate, the composition of polymer 202, the composition of carrier fluid 204, the composition of dispersion fluid 206, and the composition of the emulsion stabilizer.

[0121] The molten emulsion 214 may then be cooled at 216. Cooling 216 may range from slow (e.g., allowing the molten emulsion to cool under ambient conditions) to fast (e.g., quenching). For example, the cooling rate may range from about 10°C / hour to about 100°C / second to almost instantaneous when quenching (e.g., in dry ice) (or about 10°C / hour to about 60°C / hour, or about 0.5°C / minute to about 20°C / minute, or about 1°C / minute to about 5°C / minute, or about 10°C / minute to about 60°C / minute, or about 0.5°C / second to about 10°C / second, or about 10°C / second to about 100°C / second).

[0122] During cooling, little or no shear may be applied to the molten emulsion 214. In some cases, the shear applied during heating may also be applied during cooling.

[0123] The cooled mixture 218 resulting from cooling 216 the molten emulsion 214 comprises solidified polymer particles 222 (or simply polymer particles) and other components 224 (e.g., carrier fluid 204, dispersion fluid 206, excess emulsion stabilizer, etc.) The polymer particles may be dispersed in the carrier fluid or settled in the carrier fluid.

[0124] The cooled mixture 218 may then be processed at 220 to separate the polymer particles 222 (or simply polymer particles 222) from other components 224. Suitable processing includes, but is not limited to, washing, filtering, centrifuging, decanting, and the like, and any combination thereof.

[0125] The solvent used to wash the polymer particles 222 should generally be (a) miscible with the carrier fluid 204 and / or the dispersion fluid 206 and (b) non-reactive with (e.g., non-swelling and non-dissolving) the polymer 202. The choice of solvent will depend on, among other things, the composition of the carrier fluid, the composition of the dispersion fluid, and the composition of the polymer 202.

[0126] Examples of solvents include, but are not limited to, hydrocarbon solvents (e.g., pentane, hexane, heptane, octane, cyclohexane, cyclopentane, decane, dodecane, tridecane, and tetradecane), aromatic hydrocarbon solvents (e.g., benzene, toluene, xylene, 2-methylnaphthalene, and cresol), ether solvents (e.g., diethyl ether, tetrahydrofuran, diisopropyl ether, and dioxane), ketone solvents (e.g., acetone, and methyl ethyl ketone), alcohol solvents (e.g., methanol, ethanol, isopropanol, and n-propanol), ester solvents (e.g., ethyl acetate, methyl acetate, butyl acetate, butyl propionate, and butyl butyrate), halogenated solvents (e.g., chloroform, bromoform, 1,2-dichloromethane, 1,2-dichloroethane, carbon tetrachloride, chlorobenzene, and hexafluoroisopropanol), water, and the like, and any combination thereof.

[0127] The solvent can be removed from the polymer particles 222 by drying using an appropriate method such as air drying, heat drying, reduced pressure drying, freeze drying, or a mixture thereof. Heating can preferably be performed at a temperature below the glass transition point of the polymer (e.g., about 50°C to about 150°C).

[0128] The polymer particles 222 separated from the other components 224 may optionally be further classified to produce purified polymer particles 228. For example, to narrow the particle size distribution (or reduce the diameter span), the polymer particles 222 may be passed through a sieve having a pore size of about 10 μm to about 250 μm (or about 10 μm to about 100 μm, or about 50 μm to about 200 μm, or about 150 μm to about 250 μm).

[0129] In another example of a purification technique, the polymer particles 222 can be washed with water to remove the surfactant while retaining substantially all of the nanoparticles associated with the surface of the polymer particles 222. In yet another example of a purification technique, the polymer particles 222 can be blended with additives to achieve a desired end product. For clarity, such additives are referred to herein as "external additives" because they are blended with the particles 222 or other particles obtained by the methods described herein after the particles have solidified. Examples of external additives include glidants, other polymer particles, fillers, and the like, as well as any combination thereof.

[0130] In some cases, the surfactant used to prepare the polymer particles 222 may be undesirable in downstream applications. Thus, yet another example of a purification technique may include at least substantially removing the surfactant from the polymer particles 222 (eg, by washing and / or pyrolysis).

[0131] Polymer particles 222 and / or purified polymer particles 228 (referred to as particles 222 / 228) can be characterized by composition, physical structure, and the like.

[0132] As described above, the emulsion stabilizer is located at the interface between the polymer melt and the carrier fluid. Thus, when the mixture is cooled, the emulsion stabilizer remains at or near the interface. Thus, the structure of the particles 222 / 228 generally includes the emulsion stabilizer (a) dispersed on the outer surface of the particles 222 / 228 and / or (b) embedded in the exterior of the particles 222 / 228 (e.g., the exterior 1% by volume).

[0133] In addition, in the case where voids are formed inside the polymer melt droplets, the emulsion stabilizer should generally be at the interface between the interior of the void and the polymer (and / or embedded in the interface). The voids generally do not contain polymer. Instead, the voids may contain, for example, a carrier fluid, air, or be empty. The particles 222 / 228 may contain a carrier fluid at about 5% or less (or about 0.001% to about 5% by weight, or about 0.001% to about 0.1% by weight, or about 0.01% to about 0.5% by weight, or about 0.1% to about 2% by weight, or about 1% to about 5% by weight) of the particles 222 / 228.

[0134] The polymer 202 may be present in the particles 222 / 228 at about 90% to about 99.5% by weight (or about 90% to about 95% by weight, or about 92% to about 97% by weight, or about 95% to about 99.5% by weight) of the particles 222 / 228.

[0135] When used, the emulsion stabilizer may be present in the particles 222 / 228 at about 10% or less by weight (or about 0.01% to about 10% by weight, or about 0.01% to about 1% by weight, or about 0.5% to about 5% by weight, or about 3% to about 7% by weight, or about 5% to about 10% by weight) of the particles 222 / 228. When purified to at least substantially remove a surfactant or another emulsion stabilizer, the emulsion stabilizer 206 may be present in the particles 228 at less than 0.01% by weight (or 0% to about 0.01% by weight, or 0% to 0.001% by weight).

[0136] After forming the polymer microparticles according to the present disclosure, at least a portion of the nanoparticles (such as silica nanoparticles) can be disposed as a coating on the outer surface of the polymer microparticles. At least a portion of the surfactant (if used) can also be associated with the outer surface. The coating can be disposed substantially uniformly on the outer surface. As used herein with respect to a coating, the term "substantially uniform" refers to a uniform coating thickness across the surface locations (particularly across the outer surface) covered by the coating composition (e.g., nanoparticles and / or surfactant). The emulsion stabilizer 206 can form a coating that covers at least 5% (or about 5% to about 100%, or about 5% to about 25%, or about 20% to about 50%, or about 40% to about 70%, or about 50% to about 80%, or about 60% to about 90%, or about 70% to about 100%) of the surface area of ​​the particles 222 / 228. When purified to at least substantially remove a surfactant or another emulsion stabilizer, the emulsion stabilizer 206 may be present in the particle 228 at less than 25% (or 0% to about 25%, or about 0.1% to about 5%, or about 0.1% to about 1%, or about 1% to about 5%, or about 1% to about 10%, or about 5% to about 15%, or about 10% to about 25%) of the surface area of ​​the particle 228. The coverage of the emulsion stabilizer 206 on the outer surface of the particle 222 / 228 can be determined using image analysis of scanning electron microscope images (SEM micrographs). The emulsion stabilizer 206 may form a coating that covers at least 5% (or about 5% to about 100%, or about 5% to about 25%, or about 20% to about 50%, or about 40% to about 70%, or about 50% to about 80%, or about 60% to about 90%, or about 70% to about 100%) of the surface area of ​​the particle 222 / 228. When purified to at least substantially remove a surfactant or another emulsion stabilizer, the emulsion stabilizer 206 may be present in the particles 228 at less than 25% (or 0% to about 25%, or about 0.1% to about 5%, or about 0.1% to about 1%, or about 1% to about 5%, or about 1% to about 10%, or about 5% to about 15%, or about 10% to about 25%) of the surface area of ​​the particles 228. Image analysis of SEM micrographs can be used to determine the coverage of the emulsion stabilizer 206 on the exterior surfaces of the particles 222 / 228.

[0137] The particles 222 / 228 may have a D10 of about 0.1 μm to about 125 μm (or about 0.1 μm to about 5 μm, about 1 μm to about 10 μm, about 5 μm to about 30 μm, or about 1 μm to about 25 μm, or about 25 μm to about 75 μm, or about 50 μm to about 85 μm, or about 75 μm to about 125 μm), a D50 of about 0.5 μm to about 200 μm (or about 0.5 μm to about 10 μm, or about 5 μm to about 50 μm, or about 30 μm to about 100 μm, or about 30 μm to about 70 μm, or about 25 μm to about 50 μm, or about 50 μm to about 100 μm, or about 75 μm to about 150 μm, or about 100 μm to about 200 μm), and a D90 of about 3 μm to about 300 μm (or about 3 μm to about 15 μm, or about 10 μm to about 50 μm, or about 25 μm to about 75 μm, or about 70 μm to about 200 μm, or about 60 μm to about 150 μm, or about 150 μm to about 300 μm), where D10 < D50 < D90. The particles 222 / 228 may also have a diameter span of about 0.4 to about 3 (or about 0.6 to about 2, or about 0.4 to about 1.5, or about 1 to about 3). Without limitation, a diameter span value of 1.0 or greater is considered wide, and a diameter span value of 0.75 or less is considered narrow. For example, the particles 222 / 228 may have a D10 of about 5 μm to about 30 μm, a D50 of about 30 μm to about 100 μm, and a D90 of about 70 μm to about 120 μm, where D10 < D50 < D90. The particles 222 / 228 may have a diameter span of about 0.5 to about 2.5.

[0138] The particles 222 / 228 may have a roundness of about 0.7 or greater (or about 0.7 to about 0.95, or about 0.90 to about 1.0, or about 0.93 to about 0.99, or about 0.95 to about 0.99, or about 0.97 to about 0.99, or about 0.98 to 1.0).

[0139] The particles 222 / 228 may have a static angle of about 20° to about 45° (or about 20° to about 30°, or about 25° to about 35°, or about 30° to about 40°, or about 35° to about 45°).

[0140] The particles 222 / 228 may have a Hausner ratio of about 1.0 to about 1.5 (or about 1.0 to about 1.2, or about 1.1 to about 1.3, or about 1.2 to about 1.35, or about 1.3 to about 1.5).

[0141] The particles 222 / 228 may have about 0.3 g / cm 3 to about 0.8 g / cm 3 (or about 0.3 g / cm 3 to about 0.6 g / cm3 , or about 0.4g / cm 3 to about 0.7g / cm 3 , or about 0.5g / cm 3 to about 0.6g / cm 3 , or about 0.5g / cm 3 to about 0.8g / cm 3 ) of the bulk density.

[0142] Depending on the temperature and shear rate of processing 212 and the composition and relative concentrations of components 202, 204, and 206, different shapes of the structures comprising particles 222 / 228 have been observed. Typically, particles 222 / 228 comprise substantially spherical particles (having a roundness of approximately 0.97 or greater). However, other structures have been observed within particles 222 / 228, including discs and elongated structures. Thus, particles 222 / 228 may comprise one or more of the following: (a) substantially spherical particles having a roundness of 0.97 or greater, (b) disc structures having an aspect ratio of approximately 2 to approximately 10, and (c) elongated structures having an aspect ratio of 10 or greater. Each of the (a), (b), and (c) structures has an emulsion stabilizer dispersed on an outer surface of the (a), (b), and (c) structures and / or embedded within the exterior of the (a), (b), and (c) structures. At least some of the (a), (b), and (c) structures may agglomerate. For example, (c) elongated structures may be laid on the surface of (a) substantially spherical particles.

[0143] The sintering window of particles 222 / 228 can be within 10° C., preferably within 5° C., of the sintering window of polymer 202 (comprising thermoplastic polyester and optionally one or more additional thermoplastic polymers). Likewise, polyesters are susceptible to hydrolysis, especially at the temperatures of the melt emulsification process.

[0144] Application of polymer particles comprising thermoplastic polyesters

[0145] The polymer particles described herein, comprising a thermoplastic polyester and optionally one or more additional thermoplastic polymers, can be used in 3D printing processes, particularly those employing selective laser sintering to facilitate particle consolidation. The polymer particles disclosed herein can exhibit properties superior to polymer particles having irregular shapes or wider particle distributions, such as those commercially available. In a non-limiting example, the polymer particles disclosed herein can consolidate at lower laser powers and provide reduced void formation in 3D printed articles.

[0146] The 3D printing process of the present disclosure may include depositing the polymer particles of the present disclosure onto a surface in a specified shape, and once deposited, heating at least a portion of the polymer particles to promote consolidation and form a consolidated body (article), wherein the consolidated body has a void percentage of approximately 1% or less after consolidation. For example, the heating and consolidation of the polymer particles may be performed in a 3D printing device using a laser, such that the heating and consolidation are performed by selective laser sintering.

[0147] Any polymer particles disclosed herein can be formulated to be suitable for 3D printing. The composition and type of polymer particles can be selected based on various factors, such as, but not limited to, the laser power used for selective laser sintering, the type of article to be prepared, and the intended use conditions of the article.

[0148] Examples of items that can be 3D printed using the polymer particles of the present disclosure include, but are not limited to, containers (e.g., for food, beverages, cosmetics, personal care compositions, pharmaceuticals, etc.), shoe soles, toys, furniture parts and decorative household items, plastic gears, screws, nuts, bolts, cable ties, automotive parts, medical supplies, prostheses, orthopedic implants, aviation / aircraft related parts, preparation of artifacts to assist learning in education, 3D anatomical models to assist surgery, robots, biomedical devices (orthotics), household appliances, dental, electronic devices, sporting goods, etc.

[0149] Other applications of the disclosed microparticles may include, but are not limited to, use as fillers in paints and powder coatings, inkjet materials, and electrophotographic toners, etc. In some cases, the microparticles may have other preferred properties, such as diameter and span, that may be useful for such other applications.

[0150] Terms

[0151] Item 1. A method comprising: mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter (d P ) is about 7MPa 0.5 or smaller carrier fluid, (b) a dispersed phase comprising d P About 8MPa 0.5 or greater dispersed fluid, and (c) an internal phase comprising a thermoplastic polyester, the mixing being conducted at a temperature greater than the melting point or softening temperature of the thermoplastic polyester and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase; and cooling the molten emulsion to below the melting point or softening temperature of the thermoplastic polyester to form coagulated particles comprising the thermoplastic polyester.

[0152] Clause 2. The method of Clause 1, wherein the temperature of the mixing is from about 200°C to about 320°C.

[0153] Clause 3. The method of Clause 1, wherein the cooling is to a temperature below 160°C.

[0154] Item 4. The method according to Item 1, wherein the carrier fluid comprises one selected from the group consisting of silicone oil, fluorinated silicone oil, perfluorinated silicone oil, paraffin, liquid petrolatum, mink oil, turtle oil, soybean oil, perhydrosqualene, sweet almond oil, crabapple oil, palm oil, parleam oil, grapeseed oil, sesame oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, almond oil, castor oil, avocado oil, jojoba oil, olive oil, corn germ oil, esters of lanolin acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof.

[0155] Clause 5. The method according to Clause 1, wherein the dispersing fluid comprises one selected from the group consisting of polyethylene glycol, alkyl-terminated polyethylene glycol (e.g., a C1-C4-terminated alkyl group such as tetraethylene glycol dimethyl ether (TDG)), esters of lanolin acid, esters of oleic acid, esters of lauric acid, esters of stearic acid, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof.

[0156] Item 6. The method of Item 1, wherein the carrier fluid comprises silicone oil and the dispersing fluid comprises alkyl-terminated polyethylene glycol.

[0157] Item 7. The method of Item 1, wherein the weight ratio of the carrier fluid to the dispersing fluid is from about 1:3 to about 100:1.

[0158] Clause 8. The method of Clause 1, wherein the thermoplastic polyester is present in an amount of 90% to 99.5% by weight of the coagulated particles.

[0159] Clause 9. The method of Clause 1, wherein the mixture further comprises an emulsion stabilizer.

[0160] Item 10. The method of Item 9, wherein the emulsion stabilizer is associated with the surface of the coagulated particles.

[0161] Clause 11. The method of Clause 10, wherein at least a portion of the emulsion stabilizer is embedded in the surface of the solidified particles.

[0162] Item 12. The method of Item 9, wherein the emulsion stabilizer comprises nanoparticles.

[0163] Clause 13. The method of Clause 9, wherein the solidified particles comprise voids, the voids comprising an emulsion stabilizer at the void / thermoplastic polyester interface.

[0164] Clause 14. The method of Clause 1, wherein the sintering window of the solidified particles is within 5°C of the sintering window of the thermoplastic polyester.

[0165] Clause 15. The method of Clause 1, wherein the solidified particles have a D10 of about 0.1 μm to about 125 μm, a D50 of about 0.5 μm to about 200 μm, and a D90 of about 3 μm to about 300 μm, wherein D10 <D50<D90。

[0166] Clause 16. The method of Clause 15, wherein the solidified particles have a diameter span of about 0.4 to about 3.

[0167] Clause 17. The method of Clause 1, wherein the solidified particles have a D10 of about 0.5 μm to about 5 μm, a D50 of about 0.5 μm to about 10 μm, and a D90 of about 3 μm to about 15 μm, wherein D10 <D50<D90。

[0168] Clause 18. The method of Clause 1, wherein the solidified particles have a D10 of about 1 μm to about 50 μm, a D50 of about 25 μm to about 100 μm, and a D90 of about 60 μm to about 300 μm, wherein D10 <D50<D90。

[0169] Clause 19. The method of Clause 1, wherein the solidified particles have a D10 of about 5 μm to about 30 μm, a D50 of about 30 μm to about 100 μm, a D90 of about 70 μm to about 120 μm, and a diameter span of about 0.5 to about 2.5, wherein D10 <D50<D90。

[0170] Item 20. The method of Item 1, wherein the mixing occurs in an extruder.

[0171] Item 21. The process according to Item 1, wherein the mixing is performed in a stirred reactor under an inert gas atmosphere.

[0172] Clause 22. The method of Clause 1, wherein the solidified particles have a roundness of about 0.90 to about 1.0.

[0173] Item 23. The composition of Item 1, wherein the solidified particles have a Hausner ratio of about 1.0 to about 1.5.

[0174] Clause 24. The method of Clause 1, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, and any combination thereof.

[0175] Clause 25. The method of clause 1, wherein the mixture further comprises a thermoplastic polymer selected from the group consisting of polyamide, polyurethane, polyethylene, polypropylene, polyacetal, polycarbonate, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polyester (e.g., polylactic acid), polyether, polyethersulfone, polyetheretherketone, polyacrylate, polymethacrylate, polyimide, acrylonitrile butadiene styrene (ABS), polyphenylene sulfide, vinyl polymer, polyarylene ether, polyarylene sulfide, polysulfone, polyetherketone, polyamide-imide, polyetherimide, polyetherester, copolymers comprising polyether blocks and polyamide blocks (PEBA or polyether block amide), grafted or non-grafted thermoplastic polyolefins, functionalized or non-functionalized ethylene / vinyl monomer polymers, functionalized or non-functionalized functionalized ethylene / alkyl (meth)acrylate, functionalized or non-functionalized (meth)acrylic polymer, functionalized or non-functionalized ethylene / vinyl monomer / alkyl (meth)acrylate terpolymer, ethylene / vinyl monomer / carbonyl terpolymer, ethylene / alkyl (meth)acrylate / carbonyl terpolymer, methyl methacrylate-butadiene-styrene (MBS) type core-shell polymer, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymer, chlorinated or chlorosulfonated polyethylene, polyvinylidene fluoride (PVDF), phenolic resin, poly(ethylene / vinyl acetate), polybutadiene, polyisoprene, styrenic block copolymer, polyacrylonitrile, silicone, and any combination thereof.

[0176] Item 26: The method of Item 1, wherein the weight ratio of carrier fluid to dispersing fluid is from about 1:3 to about 10:1 (or from about 1:2 to about 5:1 or from about 1:1 to about 3:1).

[0177] Item 27: The method of Item 1, wherein the weight ratio of carrier fluid to dispersing fluid is from about 1:3 to about 3:1.

[0178] Item 28. The method of Item 1, wherein the weight ratio of the dispersing fluid to the thermoplastic polyester is from about 1:5 to about 10:1 (or from about 1:3 to about 1:1, or from about 1:2 to about 3:1, or from about 1:1 to about 5:1, or from about 3:1 to about 10:1).

[0179] Item 29. The method of Item 1, wherein the weight ratio of the dispersing fluid to the thermoplastic polyester is from about 1:5 to about 2:1.

[0180] Clause 29.5: Solidified particles prepared by the method according to Clause 1.

[0181] Item 30. A composition comprising: particles comprising a thermoplastic polyester, wherein the particles have a sintering window that is within 5°C of the sintering window of the thermoplastic polyester.

[0182] Item 31. The composition of Item 30, wherein the particle further comprises an emulsion stabilizer associated with an outer surface of the particle.

[0183] Clause 32. The composition of Clause 31, wherein the emulsion stabilizer comprises nanoparticles and at least some of the nanoparticles are embedded in the outer surface of the particles.

[0184] Item 33. The composition of Item 31, wherein at least some of the particles have voids comprising an emulsion stabilizer at the void / thermoplastic polymer interface.

[0185] Item 34. The composition of Item 31, wherein the emulsion stabilizer forms a coating that covers at least 50% of the surface of the particle.

[0186] Item 35. The composition of Item 30, wherein the thermoplastic polyester is present in an amount of 90% to 99.5% by weight of the particle.

[0187] Clause 36. The composition of Clause 30, wherein the solidified particles have a D10 of about 0.1 μm to about 125 μm, a D50 of about 0.5 μm to about 200 μm, and a D90 of about 3 μm to about 300 μm, wherein D10 <D50<D90。

[0188] Clause 37. The composition of Clause 36, wherein the solidified particles have a diameter span of about 0.4 to about 3.

[0189] Clause 38. The composition of clause 30 or clause 31 or clause 32 or clause 33 or clause 34 or clause 35, wherein the solidified particles have a D10 of about 0.5 μm to about 5 μm, a D50 of about 0.5 μm to about 10 μm, and a D90 of about 3 μm to about 15 μm, wherein D10 <D50<D90。

[0190] Item 39. The composition of Item 30, wherein the solidified particles have a D10 of about 1 μm to about 50 μm, a D50 of about 25 μm to about 100 μm, and a D90 of about 60 μm to about 300 μm, wherein D10 <D50<D90。

[0191] Clause 40. The composition of Clause 30, wherein the solidified particles have a D10 of about 5 μm to about 30 μm, a D50 of about 30 μm to about 100 μm, a D90 of about 70 μm to about 120 μm, and a diameter span of about 0.5 to about 2.5, wherein D10 <D50<D90。

[0192] Clause 41. The composition of Clause 30, wherein the particles have a Hausner ratio of about 1.0 to about 1.5.

[0193] Clause 42. The composition of Clause 30, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, and any combination thereof.

[0194] Item 43. The composition of Item 30, wherein the particles further comprise a thermoplastic polymer selected from the group consisting of polyamide, polyurethane, polyethylene, polypropylene, polyacetal, polycarbonate, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polyester (e.g., polylactic acid), polyether, polyethersulfone, polyetheretherketone, polyacrylate, polymethacrylate, polyimide, acrylonitrile butadiene styrene (ABS), polyphenylene sulfide, vinyl polymer, polyarylene ether, polyarylene sulfide, polysulfone, polyetherketone, polyamide-imide, polyetherimide, polyetherester, copolymers comprising polyether blocks and polyamide blocks (PEBA or polyether block amide), grafted or non-grafted thermoplastic polyolefins, functionalized or non-functionalized ethylene / vinyl monomer polymers, functionalized or non-functionalized functionalized ethylene / alkyl (meth)acrylate, functionalized or non-functionalized (meth)acrylic polymer, functionalized or non-functionalized ethylene / vinyl monomer / alkyl (meth)acrylate terpolymer, ethylene / vinyl monomer / carbonyl terpolymer, ethylene / alkyl (meth)acrylate / carbonyl terpolymer, methyl methacrylate-butadiene-styrene (MBS) type core-shell polymer, polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) block terpolymer, chlorinated or chlorosulfonated polyethylene, polyvinylidene fluoride (PVDF), phenolic resin, poly(ethylene / vinyl acetate), polybutadiene, polyisoprene, styrenic block copolymer, polyacrylonitrile, silicone, and any combination thereof.

[0195] Unless otherwise indicated, all numbers used in this specification and the associated claims expressing the quantity of ingredients, characteristics (such as molecular weight), process conditions, etc. should be understood as being modified in all cases by the term "about". Therefore, unless otherwise indicated, the numerical parameters listed in the following specification and the appended claims are approximate values, which may vary depending on the desired properties sought to be obtained by the embodiments of the present invention. At a minimum, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of reported significant digits and by applying customary rounding techniques.

[0196] One or more exemplary embodiments of the embodiments of the present invention disclosed herein are presented herein. For the sake of clarity, all features of physical implementation are not described or shown in this application. It should be understood that in the development of the physical implementation of the embodiments of the present invention, many specific decisions must be made to achieve the developer's goal, such as meeting system-related constraints, business-related constraints, government-related constraints and other constraints, which vary and change over time due to implementation. Although the effort made by the developer may be time-consuming, such effort will be a routine task for those of ordinary skill in the art who benefit from the disclosure.

[0197] Although compositions and methods are described herein as "comprising" various components or steps, the compositions and methods may also "consist essentially of" or "consist of" the various components and steps.

[0198] In order to facilitate a better understanding of the embodiments of the present invention, the following examples of preferred or representative embodiments are given. The following examples should in no way be construed as limiting or defining the scope of the present invention.

[0199] Example

[0200] Example 1. 14.97 g of PDMS oil (from Clearco Inc.) with a viscosity of 10,000 cSt and 5.15 g of tetraethylene glycol dimethyl ether (TGD) (from Sigma Aldrich) were added to a 100 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and an electronic thermometer. The mixture was heated to between 250° C. and 255° C. while stirring at 350 rpm under a slow N2 flow. Then, 10.02 g of polybutylene terephthalate (PBT) pellets (melt viscosity 6,000 p-bar, from Scientific Polymer Inc.) were slowly added (about 10 min) while maintaining the reactor temperature between 250° C. and 255° C. and stirring at 350 rpm. The weight ratios of the components of PDMS oil, PBT, and TGD were 3:2:1, respectively. The mixture was stirred at 250°C and 600 rpm for 1 hour and then discharged into dry ice, while keeping the hot paste away from oxygen to prevent TGD autoignition. After the dry ice sublimated, the silicone oil was removed by washing with hexane followed by centrifugation, with three wash / centrifugation cycles performed. Spherical PBT particles with an average size of 30-40 μm were obtained. Figure 3A is an optical micrograph of the particles of Example 1.

[0201] Example 2. 150.0g of PDMS oil with a viscosity of 10,000cSt and 50.0g of TGD were added to a 500mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and an electronic thermometer, and heated to between 250°C and 255°C while stirring at 350rpm under a slow N2 stream. Then, 100.0PBT pellets (melt viscosity 6,000p) were added slowly (in about 10min) while maintaining the reactor temperature between 250°C and 255°C and stirring at 350rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 600rpm at 250°C for 1 hour and then discharged into dry ice while keeping the hot paste away from oxygen to avoid TGD spontaneous combustion. After dry ice sublimation, silicone oil was removed by washing / filtering three times with hexane. PBT spherical particles with an average size of 100 μm-150 μm were obtained. Figure 3B is an optical micrograph of the particles of Example 2.

[0202] Example 3. To a 100 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and electronic thermometer, 15.05 g of PDMS oil with a viscosity of 10,000 cSt and 5.30 g of TGD were added and heated to between 250°C and 255°C while stirring at 300 rpm under a slow stream of N2. Then, 10.02 g of PBT pellets (melt viscosity 6,000 pF) were slowly added (over about 10 minutes) while maintaining the reactor temperature between 250°C and 255°C and stirring at 300 rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 400 rpm at 250°C for 1 hour. Then, 0.05 g (0.5 wt% of the PBT content) of AEROSIL TM R812S silica additive (from Evonik) was added and stirred at 500 rpm for 15 minutes at 250 ° C. The final product was cooled to 200 ° C and discharged in dry ice. At this temperature, it can be discharged safely. After the dry ice sublimation, the silicone oil was removed by washing with hexane and then centrifuging, wherein the washing / centrifugation cycle was performed three times. PBT spherical particles with an average size of 30 μm-40 μm were obtained. The sintering window [(Tm-Tc) onset] was 26 ° C and (Tm-Tc) was 38.4 ° C. Figure 3C is an optical micrograph of the particles of Example 3. Figure 4A is a scanning electron micrograph of the particles of Example 3. Figure 5A is a differential scanning calorimetry thermogram of the particles of Example 3, showing the sintering window and Figure 5C The PBT raw material shown has no significant changes.

[0203] Example 4. To a 500 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and electronic thermometer, 75.38 g of PDMS oil with a viscosity of 10,000 cSt and 25.58 g of TGD were added and heated to between 250°C and 255°C while stirring at 300 rpm under a slow stream of N2. Then, 50.03 g of PBT pellets (melt viscosity 6,000 pF) were slowly added (over about 10 minutes) while maintaining the reactor temperature between 250°C and 255°C and stirring at 300 rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 400 rpm at 250°C for 85 minutes. Then, 0.28 g (0.5 wt% of the PBT content) of AEROSIL TMR812S silica additive and stirring at 500 rpm at 250 ° C for 30 minutes. The final product was cooled to 200 ° C and discharged in dry ice. At this temperature, it can be discharged safely. After the dry ice sublimation, the silicone oil was removed by washing with hexane and then centrifuging, wherein the washing / centrifugation cycle was performed three times. PBT spherical particles with an average size of 30 μm-40 μm were obtained. The sintering window [(Tm-Tc) onset] was 17.9 ° C and (Tm-Tc) was 30.5 ° C. Figure 3D is an optical micrograph of the particles of Example 4. Figure 4B is a scanning electron micrograph of the particles of Example 4. Figure 5B is a differential scanning calorimetry thermogram of the particles of Example 4, showing the sintering window and Figure 5C The PBT raw material shown has no significant changes. Figure 6A is a graph of the particle size distribution (including particle size statistics) of Example 4.

[0204] Example 5. To a 500 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and electronic thermometer, 75.55 g of PDMS oil with a viscosity of 10,000 cSt and 25.42 g of TGD were added and heated to between 250° C. and 255° C. while stirring at 350 rpm under a slow stream of N2. Then, 50.07 g of PBT pellets (melt viscosity 6,000 pF) were slowly added (over about 10 minutes) while maintaining the reactor temperature between 250° C. and 255° C. and stirring at 350 rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 500 rpm at 250° C. for 85 minutes. Then, 0.28 g (0.5 wt% of the PBT content) of AEROSIL TM RX50 silica additive (from Evonik) was added and stirred at 500 rpm for 30 minutes at 250°C. The final product was cooled to 200°C and discharged into dry ice. At this temperature, it can be discharged safely. After the dry ice sublimated, the silicone oil was removed by washing with hexane and then centrifuging. The washing / centrifugation cycle was performed three times. Spherical PBT particles with an average size of 30-40 μm were obtained. Figure 3E is an optical micrograph of the particles of Example 5.

[0205] Example 6. To a 500 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and electronic thermometer, 75.06 g of PDMS oil with a viscosity of 10,000 cSt and 26.07 g of TGD were added and heated to between 250°C and 255°C while stirring at 350 rpm under a slow stream of N2. Then, 50.04 g of PBT pellets (melt viscosity 8,500 pF) were slowly added (over about 10 minutes) while maintaining the reactor temperature between 250°C and 255°C and stirring at 350 rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 500 rpm at 250°C for 85 minutes. Then, 0.28 g (0.5 wt% of the PBT content) of AEROSIL TM R812S silica additive was added and stirred at 500 rpm for 30 minutes at 250°C. The final product was cooled to 200°C and discharged into dry ice. At this temperature, it can be discharged safely. After the dry ice sublimated, the silicone oil was removed by washing with hexane and then centrifuging. The washing / centrifugation cycle was performed three times. Spherical PBT particles with an average size of 80 μm were obtained. Figure 3F is an optical micrograph of the particles of Example 6.

[0206] Example 7. To a 500 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating jacket, condenser, nitrogen inlet and outlet, and electronic thermometer, 75.35 g of PDMS oil with a viscosity of 10,000 cSt and 25.94 g of TGD were added and heated to between 250° C. and 255° C. while stirring at 350 rpm under a slow stream of N2. Then, 50.09 g of PBT pellets (melt viscosity 8,500 pF) were slowly added (over about 10 minutes) while maintaining the reactor temperature between 250° C. and 255° C. and stirring at 350 rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 500 rpm at 250° C. for 85 minutes. Then, 0.28 g (0.5 wt% of the PBT content) of AEROSIL TM RX50 silica additive was added and stirred at 500 rpm for 30 minutes at 250°C. The final product was cooled to 200°C and discharged into dry ice. At this temperature, it could be safely discharged. After the dry ice sublimed, the silicone oil was removed by washing with hexane followed by centrifugation, with three wash / centrifugation cycles performed. Spherical PBT particles with an average size of 80 μm were obtained. Figure 3G is an optical micrograph of the particles of Example 7.

[0207] Example 8. A 500 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating mantle, condenser, nitrogen inlet and outlet, and electronic thermometer was charged with 82.55 g of 10,000 cSt PDMS oil (from Clearco Inc.) and 28.09 g of tetraethylene glycol dimethyl ether (TGD) (from Sigma Aldrich) and heated to between 250° C. and 255° C. while stirring at 350 rpm under a slow stream of N2. A blend of 49.50 g of PBT pellets (melt viscosity 8,500 pF, from Scientific Polymer Inc.) and 5.50 g of nylon 6 pellets (from Sigma Aldrich) was then slowly added (over approximately 10 minutes) while maintaining the reactor temperature between 250° C. and 255° C. and stirring at 350 rpm (PBT / nylon 6 ratio of 9:1). The ratio of the components of PDMS oil, polymer and TGD was 3:2:1 respectively. The mixture was stirred at 250°C and 500 rpm for 85 minutes. Then 0.28 g (0.5 wt% of PBT content) of AEROSIL TM RX50 silica additive was added and stirred at 250°C at 500 rpm for 30 minutes. The final product was cooled to 200°C and discharged into dry ice. At this temperature, it could be safely discharged. After the dry ice sublimed, the silicone oil was removed by washing with hexane followed by centrifugation, with three wash / centrifugation cycles performed. Spherical PBT particles with an average size of 120 μm were obtained. Figure 3H is an optical micrograph of the particles of Example 8. Figure 6B is a graph of the particle size distribution (including particle size statistics) of Example 8.

[0208] Example 9. A 500 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating mantle, a nitrogen inlet / outlet, and an electronic thermometer. 75.5 g of 30 kcSt PDMS oil (from Clearco Inc.) and 49.50 g of PBT pellets (melt viscosity 6000 pF; Scientificpolymer Inc.) were added to the reactor and heated to 250° C. to 255° C. while stirring at 150 rpm for 45 minutes under a slow stream of N 2 . 0.28 g (0.56 wt % of PBT content) of AEROSIL was then added. TM R812S silica additive was added and stirred at 500 rpm / 250°C for 10 minutes. The hot final product was discharged into dry ice and washed three times with hexane after the dry ice sublimated. The obtained PBT spherical particles were dried in an electric oven at 50°C overnight, and the particle size was measured to be 110 μm (D50).

[0209] Selective laser sintering (SLS) was performed using a Snow White SLS printer system (Sharebot). The thermoplastic polyurethane microparticles of Example 9-3 were deposited in 30 mm x 30 mm squares using the SLS printer system and then sintered under various laser power conditions specified in Table 1 below. The post-sintering void percentage was calculated using digital microscope software (Table 1). Figure 7 Included are two pictures of the sintered layer at 45% laser power.

[0210] Table 1

[0211] Laser power (%) Scan rate Temperature (℃) Void% 20 40,000 170 NS 25 40,000 170 NS 30 40,000 170 5.1 35 40,000 170 2.7 40 40,000 170 1.8 45 40,000 170 2.0

[0212] NS - Not successfully sintered into a single piece.

[0213] Example 10. A 500 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating mantle, a nitrogen inlet / outlet, and an electronic thermometer. 82.74 g of 5 KcSt PDMS oil (from Clearco Inc.) and 0.55 g of AEROSIL TM R812S silica additive (1.0 wt % of PBT content) was added and heated to 250°C while stirring at 300 rpm. 55.0 g of PBT pellets (melt viscosity 6000 p; Scientificpolymer Inc.) were then added while the temperature was 240 to 250°C at 300 rpm. When the PBT addition was complete, the rpm was increased to 500 rpm and stirred for 60 minutes. The hot final product was discharged in dry ice and washed three times with hexane after the dry ice sublimated. The obtained PBT spherical particles were dried in an electric oven at 50°C overnight and the particle size was measured to be 86 μm (D50) after screening with a sieve with an aperture of 250 μm.

[0214] The particles of Example 10 were sintered as described in Example 9. The sintering conditions and results are presented in Table 2. Figure 8 Included are two pictures of the sintered layer at 45% laser power.

[0215] Table 2

[0216] Laser power (%) Scan rate Temperature (℃) Void% 20 40,000 170 NS 25 40,000 170 NS 30 40,000 170 NS 35 40,000 170 7.6 40 40,000 170 5.3 45 40,000 170 4.2 50 40,000 170 2.9 55 40,000 170 2.7

[0217] NS - Not successfully sintered into a single piece.

[0218] Example 11. A 500 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating mantle, a nitrogen inlet / outlet, and an electronic thermometer. 100.23 g of PDMS oil (Sigma Aldrich) with a viscosity of 18-22 KcSt, 5.12 g of TGD, 50.05 g of PBT pellets (MFI: 18 g / 10 min, DuPont), and 0.51 g of AEROSIL were added to the reactor. TM R812S silica additive (1.0 wt % of PBT content). It is then heated to 250°C while stirring at 300 rpm under a slow N2 stream. Once the temperature reaches 250°C (in about 20 min-25 min), rpm is increased to 620. After 75 min, the hot final product is discharged in dry ice and washed three times with hexane. The PBT spherical particles obtained are dried overnight at 50°C in an electric oven and before and after screening with a sieve of 250 μm in aperture, the particle size is measured to be 83 μm and 93 μm (D50), respectively. FIG9 includes three SEM micrographs (top) of the particles and three SEM micrographs (bottom) of the cross section of the particles (samples intercepted using cryomicrotomy).

[0219] The particles of Example 11 were sintered as described in Example 9. The sintering conditions and results are presented in Table 3. Figure 10 includes two pictures of sintered layers at 45% laser power.

[0220] Table 3

[0221]

[0222]

[0223] NS - Not successfully sintered into a single piece.

[0224] Example 12. A 500 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating mantle, a nitrogen inlet / outlet, and an electronic thermometer. 100.25 g of PDMS oil (from Clearco Inc.) with a viscosity of 10 KcSt, 5.14 g of TGD, 50.1 g of PBT pellets (MFI: 18 g / 10 min, from DuPont), and 0.50 g of AEROSIL TMR812S silica additive (1.0 wt % of PBT content). It is then heated to 250°C while stirring at 300 rpm under a slow N2 stream. Once the temperature reaches 250°C (in about 20-25 min), rpm is increased to 620. After 75 min, the hot final product is discharged in dry ice and washed three times with hexane. The PBT spherical particles obtained are dried overnight at 50°C in an electric oven and before and after screening with a sieve of 250 μm in aperture, the particle size is measured to be 83 μm and 93 μm (D50), respectively. Figure 11 includes three SEM micrographs (top) of the particles and three SEM micrographs (bottom) of the cross section of the particles (samples intercepted using cryomicrotomy).

[0225] Example 13. A 500 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating mantle, a nitrogen inlet / outlet, and an electronic thermometer. 100.56 g of PDMS oil (from Clearco Inc.) with a viscosity of 30 KcSt, 5.16 g of TGD, 50.12 g of PBT pellets (MFI: 18 g / 10 min, from DuPont), and 0.50 g of AEROSIL TM R812S silica additive (1.0 wt % of PBT content). It is then heated to 250°C while stirring at 300 rpm under a slow N2 stream. Once the temperature reaches 250°C (in about 20 min-25 min), rpm is increased to 620. After 75 min, the hot final product is discharged in dry ice and washed three times with hexane. The PBT spherical particles obtained are dried overnight at 50°C in an electric oven and before and after screening with a sieve of 250 μm in aperture, the particle size is measured to be 123 μm and 85 μm (D50) respectively. Figure 12 includes three SEM micrographs (top) of the particles and three SEM micrographs (bottom) of the cross section of the particles (samples intercepted using cryomicrotomy).

[0226] The particles of Example 13 were sintered as described in Example 9. The sintering conditions and results are presented in Table 4. Figure 13 includes two pictures of sintered layers at 45% laser power.

[0227] Table 4

[0228] Laser power (%) Scan rate Temperature (℃) Void% 20 40,000 170 NS 25 40,000 170 3.0 30 40,000 170 1.0 35 40,000 170 0.7 40 40,000 170 0.4 45 40,000 170 0.3

[0229] NS - Not successfully sintered into a single piece.

[0230] Example 14. To a 2L Buchi reactor equipped with an anchor and 0.5D / T P4 impeller, a heating bath, and nitrogen inlet / outlet, 800.5g of PDMS oil with a viscosity of 30KcSt (from Clearco Inc.), 42.3g of TGD, 400.6g of PBT pellets (Crastin TM S600F20 NC010; MFI: 18 g / 10 min, from DuPont) and 4.1 g of AEROSIL TM R812S silica additive (1.0 wt % of PBT content). The reactor was purged with nitrogen, sealed, and heated to 245°C while stirring at 300 rpm. Once the temperature reached 240°C (in about 90 min), the rpm was increased to 650. After 75 min, the reactor was cooled to 75°C and 400 g of heptane was added to facilitate product discharge. The final product was washed three times with heptane and dried overnight at 50°C in an electric oven. The particle size was measured to be 66 μm (D50) with a span of 2.01.

[0231] Example 15. The same process was performed using a different grade of PBT, the same grade used in Example 16 (ResMart Ultra PBT 23). The results were comparable in terms of particle size and distribution (55 μm (D50), span of 2.43). The sintering window [(Tm-Tc) onset] was 21.5°C and the (Tm-Tc) was 30.3°C.

[0232] Example 16. PBT polymer pellets were prepared from ResMart Ultra PBT23 in a 27 mm twin-screw extruder (Leistritz ZSE 27HP). The carrier fluid was PDMS oil with a viscosity of 30,000 cSt at room temperature. The concentrations of the components in the final mixture in the extruder are given in Table 5. The polymer pellets were added to the extruder and brought to the temperature according to Table 5. Then, the AEROSIL TM A preheated carrier fluid of R812S silica nanoparticles was added to the molten polymer in the extruder. The screw speed was 1000 rpm. The mixture was then discharged into a container and allowed to cool to room temperature over several hours. Light scattering particle size data is also provided in Table 5.

[0233] Table 5

[0234]

[0235] Example 17. 150.0g of PDMS oil with a viscosity of 10,000cSt and 50.0g of TGD were added to a 500mL glass kettle reactor equipped with an overhead stirrer, a P4 impeller, a heating jacket, a condenser, a nitrogen inlet and outlet, and an electronic thermometer, and heated to 250°C to 255°C while stirring at 350rpm under a slow N2 stream. Then, 100.0PBT pellets (melt viscosity 6,000p) were added slowly (in about 10min) while maintaining the reactor temperature between 250°C and 255°C and stirring at 350rpm. The ratio of the components of PDMS oil, PBT, and TGD was 3:2:1, respectively. The mixture was stirred at 600rpm at 250°C for 1 hour and then discharged into dry ice while keeping the hot paste away from oxygen to avoid TGD spontaneous combustion. After dry ice sublimation, silicone oil was removed by washing / filtering three times with hexane. Spherical particles of PBT with an average size of 100-150 μm were obtained. Figure 14 includes SEM micrographs of the prepared particles at various magnifications. Figure 15 A histogram of granularity.

[0236] Example 18. A 100 mL glass kettle reactor was equipped with an overhead stirrer, a P4 impeller, a heating jacket, a nitrogen inlet / outlet, and an electronic thermometer. 10.85 g of PDMS oil (from Clearco Inc.) with a viscosity of 10 KcSt, 10.92 g of TGD (from Sigma Aldrich), and 10.85 g of PBT pellets (melt viscosity 6000 p; Scientificpolymer Inc.) were added to the reactor and heated to 250° C. to 255° C. while stirring at 350 rpm for 25 min under a slow stream of N2. The hot final product was discharged in dry ice and washed three times with hexane after sublimation of the dry ice. The obtained PBT spherical particles were dried in an electric oven at 50° C. overnight, and the average particle size was measured to be 30 μm-40 μm. FIG16 includes SEM micrographs of the prepared particles at various magnifications. Figure 17 A histogram of granularity.

[0237] Example 19. To a 100 mL glass kettle reactor equipped with an overhead stirrer, impeller, heating mantle, condenser, nitrogen inlet and outlet, and electronic thermometer were added 11.0 g of PDMS oil (from Sigma Aldrich) with a viscosity of 18,000 cSt-22,000 cSt, 0.05 g (0.6 wt% of PBT content) of AEROSIL TMR812S silica additive and 5.5g of TGD. It is then heated to 250°C to 255°C while stirring at 300rpm under a slow N2 flow. Then, 8.27g of PBT pellets (melt viscosity 6,000p) are slowly added while keeping the reactor temperature between 250°C and 255°C and stirring at 300rpm. The mixture is stirred at 400rpm at 250°C for 60 minutes. The hot final product is discharged in dry ice. After the dry ice is sublimated, the silicone oil is removed by washing with hexane and then centrifuging, wherein the washing / centrifugation cycle is repeated three times. PBT spherical particles with an average size of 2.5μm are obtained. Figure 18 includes optical micrographs of the prepared particles at various magnifications. Figure 19 A histogram of granularity.

[0238] The above examples show that PBT polymer particles can be prepared by the melt emulsification method.

[0239] Therefore, the present invention is well adapted to achieve the objects and advantages mentioned, as well as those inherent therein. The specific embodiments disclosed above are exemplary only, as the present invention may be modified and implemented in different but equivalent ways that will be apparent to those skilled in the art having the benefit of the teachings herein. In addition, no limitations are intended to the details of construction or design shown herein, except as described in the claims below. Therefore, it is apparent that the specific exemplary embodiments disclosed above may be altered, combined or modified, and all such variations are considered to be within the scope and spirit of the present invention. The present invention exemplarily disclosed herein may be appropriately implemented in the absence of any elements not specifically disclosed herein and / or any optional elements disclosed herein. Although compositions and methods are described by “comprising,” “containing,” or “including” various components or steps, compositions and methods may also be “essentially composed of” or “consisting of” various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. Specifically, each value range disclosed herein (in the form of "about a to about b," or equivalently, "about a to b," or equivalently, "about a b") should be understood to set forth each value and range encompassed within the broader value range. In addition, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. In addition, the indefinite articles "a" or "an" used in the claims are defined herein to mean that there is one or more than one of the element it introduces.

Claims

1. A method comprising: Mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter d P 7MPa 0.5 or less of a carrier fluid, (b) a dispersed phase comprising a dispersing fluid, and (c) an internal phase comprising a thermoplastic polyester, said mixing being conducted at a temperature greater than the melting point or softening temperature of the thermoplastic polyester and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase; and cooling the molten emulsion to below the melting point or softening temperature of the thermoplastic polyester to form coagulated particles comprising the thermoplastic polyester; wherein the dispersing fluid comprises one selected from the group consisting of polyethylene glycol, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof. 2 . The method according to claim 1 , wherein the temperature of the mixing is 200° C. to 320° C.

3. The method of claim 1, wherein cooling is to a temperature below 160°C.

4. The method of claim 1 , wherein the carrier fluid comprises one selected from the group consisting of silicone oil, paraffin, liquid petrolatum, mink oil, turtle oil, soybean oil, perhydrosqualene, sweet almond oil, crabapple oil, palm oil, parleam oil, grape seed oil, sesame oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, almond oil, castor oil, avocado oil, jojoba oil, olive oil, cereal germ oil, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof. The method according to claim 4 , wherein the silicone oil is a fluorinated silicone oil. The method according to claim 5 , wherein the fluorinated silicone oil is a perfluorinated silicone oil.

7. The method of claim 4, wherein the fatty acid ester is selected from the group consisting of esters of lanolin acid, esters of oleic acid, esters of lauric acid, and esters of stearic acid. The method according to claim 1 , wherein the polyethylene glycol is an alkyl-terminated polyethylene glycol.

9. The method according to claim 8, wherein the alkyl-terminated polyethylene glycol is a C1-C4 alkyl-terminated polyethylene glycol. 10 . The method according to claim 9 , wherein the polyethylene glycol having a terminal C1-C4 alkyl group is tetraethylene glycol dimethyl ether (TDG).

11. The method of claim 1, wherein the fatty acid ester is selected from the group consisting of esters of lanolin acid, esters of oleic acid, esters of lauric acid, and esters of stearic acid.

12. The method of claim 1, wherein the carrier fluid comprises silicone oil and the dispersing fluid comprises alkyl-terminated polyethylene glycol.

13. The method of claim 1, wherein the weight ratio of the carrier fluid to the dispersion fluid is 1:3 to 100:

1.

14. The method of claim 1, wherein the thermoplastic polyester is present in an amount of 90% to 99.5% by weight of the solidified particles.

15. The method of claim 1, wherein the mixture further comprises an emulsion stabilizer.

16. The method of claim 15, wherein the emulsion stabilizer is associated with the surface of the solidified particles.

17. The method of claim 16, wherein at least a portion of the emulsion stabilizer is embedded in the surface of the solidified particles.

18. The method of claim 1, wherein the sintering window of the solidified particles is within 5°C of the sintering window of the thermoplastic polyester.

19. The method of claim 1, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate (PTT), and any combination thereof.

20. A method comprising: Mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter d P 7MPa 0.5 or smaller carrier fluid, (b) a dispersed phase comprising d P 8MPa 0.5 or greater dispersed fluid, and (c) an internal phase comprising a thermoplastic polyester, said mixing being conducted at a temperature greater than the melting point or softening temperature of said thermoplastic polyester and at a shear rate sufficiently high to disperse said thermoplastic polyester in said dispersed phase; and The molten emulsion is cooled to below the melting point or softening temperature of the thermoplastic polyester to form coagulated particles comprising the thermoplastic polyester.

21. A method comprising: Mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter d P 7MPa 0.5 or smaller carrier fluid, (b) a dispersed phase comprising d P 8MPa 0.5 or greater dispersed fluid, and (c) an internal phase comprising a thermoplastic polyester, the mixing being conducted at 200° C. to 320° C. and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexylene terephthalate (PTT), and any combination thereof; and The molten emulsion is cooled to below 160°C to form coagulated particles comprising the thermoplastic polyester.

22. The method of claim 21, wherein the mixture further comprises an emulsion stabilizer, and wherein at least a portion of the emulsion stabilizer is embedded in the surface of the solidified particles.

23. A method comprising: Mixing a molten emulsion comprising: (a) a continuous phase comprising a polar Hansen solubility parameter d P 7MPa 0.5 or less of a carrier fluid, (b) a dispersed phase comprising a dispersing fluid, and (c) an internal phase comprising a thermoplastic polyester, the mixing being conducted at 200° C. to 320° C. and at a shear rate sufficiently high to disperse the thermoplastic polyester in the dispersed phase, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexylene terephthalate (PTT), and any combination thereof; and cooling the molten emulsion to below 160° C. to form coagulated particles comprising the thermoplastic polyester; wherein the dispersing fluid comprises one selected from the group consisting of polyethylene glycol, fatty acid esters, higher fatty acids, fatty alcohols, polysiloxanes modified with fatty acids, polysiloxanes modified with fatty alcohols, polysiloxanes modified with polyoxyalkylenes, and any combination thereof.

24. A composition comprising: Particles comprising a thermoplastic polyester obtained by the process of any one of claims 1 to 23, wherein the sintering window of the particles is within 5°C of the sintering window of the thermoplastic polyester, wherein the particles have a D10 of 5 µm to 30 µm, a D50 of 30 µm to 100 µm, a D90 of 70 µm to 120 µm, and a diameter span of 0.5 to 2.5, wherein D10 <D50<D90。 25. The composition of claim 24, wherein the particle further comprises an emulsion stabilizer associated with the outer surface of the particle.

26. The composition of claim 25, wherein the emulsion stabilizer comprises nanoparticles and at least some of the nanoparticles are embedded in the outer surface of the particles.

27. The composition of claim 25, wherein the emulsion stabilizer forms a coating that covers at least 50% of the surface of the particle.

28. The composition of claim 24, wherein the thermoplastic polyester comprises one selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polyhexamethylene terephthalate, and any combination thereof.

29. The composition of claim 24, wherein the particles have a roundness of 0.7 or greater.

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