Improved powder for additive manufacturing

Abstract

The present invention relates to a composition comprising at least one polymer, wherein the polymer is in powder form, and wherein the polymer comprises at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from at least one polyaryletherketone and / or copolymers thereof and / or block copolymers thereof and / or polymer blends thereof, wherein the composition has a melt volume rate (MVR) of at least 5 cm3 / 10 min, and a method of manufacturing and use thereof. The present invention also relates to a method for manufacturing a building element and a building element thereof. 3 / 10 min. The present invention also relates to a method for manufacturing a building element and a building element thereof.

Description

Technical Field

[0001] This invention relates to a composition comprising at least one thermoplastic polymer, wherein the composition exhibits a specific melt volume rate to allow for optimized additive manufacturing methods. Furthermore, this application relates to a method for preparing the compositions of the invention, an apparatus comprising the compositions of the invention, and the use of the compositions of the invention. Background Technology

[0002] Devices based on powder-based building materials and additive manufacturing methods for industrial production of prototypes allow for the production of plastic granules and are becoming increasingly important. Through this manufacturing process, layers are selectively melted and solidified, creating the desired structure by applying binders and / or adhesives. The method is also known as “additive manufacturing,” “digital construction,” or “3D printing.”

[0003] For decades, industrial development methods have been used to create prototypes (rapid prototyping). However, due to technological advancements in systems, the production of components to meet the quality requirements of the final product has begun, replacing or excluding prototypes (rapid manufacturing). In other words, current technological advancements in systems also allow for the production of components that meet the quality requirements of the final product.

[0004] In practice, the term "additive manufacturing" is often replaced by the terms "regenerative manufacturing" or "rapid technology." Additive manufacturing, which uses powdered materials, encompasses methods such as sintering, melting, or bonding with adhesives.

[0005] Polymer systems are typically used as powdered materials for manufacturing articles. Industrial users of these polymer systems require articles made from them to have good processability, shape accuracy, and good mechanical properties.

[0006] For the purpose of manufacturing such articles, it is advantageous to achieve bonding between the molten material and the lower layers of the 3D structure, since interdiffusion can only occur within the molten material. However, if insufficient bonding of one or more layers occurs due to inadequate polymer melting properties, the 3D article tends to delaminate and lose stability. Therefore, the build temperature during the manufacturing process should be guided to optimize the polymer melting properties during manufacturing.

[0007] Therefore, when manufacturing 3D products, the build temperature needs to be above the polymer's crystallization temperature. On the other hand, to prevent the powder from melting in the build area, the build temperature generally needs to be below the melting temperature. The temperature ranges typically used for building objects using additive manufacturing methods are named the polymer's process window or sintering window. Summary of the Invention

[0008] Therefore, the object of the present invention is to predict a composition suitable for use as a material in additive manufacturing methods for producing articles, exhibiting process-safe mechanical stability and high shape accuracy. In particular, the object of the present invention is to provide a composition exhibiting optimal process window and melting properties.

[0009] According to the present invention, such an objective is achieved by a composition according to the present invention comprising at least one polymer having a defined melt volume rate. Furthermore, the objective is achieved by a method according to the present invention for preparing the composition, a method according to the present invention for manufacturing an object, and the use of the composition according to the present invention.

[0010] Therefore, the present invention relates to a composition, particularly a building material for use in the above-described additive manufacturing method, comprising:

[0011] At least one polymer,

[0012] The polymer is in powder form, and

[0013] The polymer includes at least one thermoplastic polymer.

[0014] The thermoplastic polymer is selected from at least one polyarylether ketone and its copolymers and / or block copolymers and / or polymer blends, wherein the composition has a thickness of at least 5 cm. 3 / 10min, more preferably at least 10cm 3 / 10min, and / or no more than 55cm 3 / 10min, preferably not exceeding 40cm 3 / 10min, preferably not exceeding 30cm 3 / 10min, preferably not exceeding 26cm 3 / 10min, optimal value not exceeding 24cm 3 / 10min.

[0015] In its simplest embodiment, the compositions of the present invention comprise polymers or polymer systems selected from thermoplastic polymers.

[0016] According to the present invention, the term "composition" as used herein may include one or more additives. The term "additive" as used herein refers to a substance, which may in particular be an amorphous and / or semi-crystalline and / or crystalline polymer, a polyol, a surfactant, and / or a protective colloid.

[0017] As used herein, the term "powder" refers to a blocky solid composed of fine particles that can flow freely when shaken or tilted. According to the invention, such fine particles have a particle size d50 of less than 500 μm.

[0018] According to the present invention, the composition exhibits at least approximately 5 cm 3 / 10min, more preferably at least about 10cm 3 / 10min, especially more preferably at least about 15cm 3 / 10min, optimally at least approximately 20cm 3 / 10min, and / or no more than approximately 55cm 3 / 10min, more preferably not exceeding approximately 40cm 3 / 10min, preferably not exceeding approximately 30cm 3 / 10min, preferably not exceeding approximately 26cm 3 / 10min, optimally not exceeding approximately 24cm 3 Melt volumetric rate (MVR) per 10 min. The terms “about” or “approximately” as used herein indicate that a particular amount or range may vary by up to 10% to 15%.

[0019] The term “melt volume rate (MVR)” (synonym: melt volume index, MVI) as used herein is a measure of the flowability of the melt of a thermoplastic polymer. It is defined as measured in cm⁻¹. 3 MVR represents the volume of polymer that flows under pressure through a capillary of a specific diameter and length over ten minutes, the pressure being applied by alternating pre-set weights at preset alternating temperatures. MVR is expressed in cm. 3 / 10min is used as an expression. For example, the method is described in ASTM D1238-10.

[0020] MVR measurements of polyaryletherketones (PAEKs), particularly PEKKs, were performed on a Ceast apparatus equipped with Ceast-View 6.3.1 software. Prior to measurement, 4.8 g of powder was pre-dried at 120°C for 11 minutes using a Satorius MA 100 high-temperature balance. The powder was then filled into the MVR cell within 30 seconds. A 5 kg weight was applied, and the measurement was performed at 380°C according to ASTM D1238-10.

[0021] Surprisingly, according to the invention, the advantageous compositions exhibit excellent flowability and melting characteristics, as well as a uniform structure, characteristic of porous materials such as powders, resulting in improved rheological properties such as viscosity, thus allowing for material deposition and improved mechanical properties. Good flowability of porous materials is assumed when they are free and easily flowable.

[0022] The term "flowability" as used herein is used synonymously with the term "pouring ability". Pouring ability of powder is measured using a millimeter funnel according to DIN EN ISO 6186 and / or by a shear unit according to ASTM D 7891-15 and / or the Hausner Factor (as described in the Methods section). According to this application, the term "Hausner Factor" is used synonymously with the term "Hausner Ratio".

[0023] As used herein, the term "polymer" or "polymer system" refers to at least one homopolymer and / or hybrid polymer composed of several monomers. Homopolymers comprise covalent bonds of the same monomers, while hybrid polymers (also called copolymers) comprise different monomers having covalent bonds. According to the invention, a polymer or polymer system may comprise a mixture of the aforementioned homopolymers and / or hybrid polymers, or may comprise more than one polymer system, respectively. In this application, such a mixture is referred to as a polymer blend.

[0024] In the context of this invention, the hybrid polymer may be selected from the following: statistical copolymers having randomly distributed monomers; gradient copolymers that are similar in principle to statistical copolymers but wherein the monomer content in the chain increases or decreases; alternating copolymers comprising alternating monomers; block copolymers or segment copolymers comprising a longer sequence or block of each monomer; and graft copolymers wherein a block of each monomer is grafted onto the backbone of a different monomer.

[0025] Advantageously, the compositions of the present invention can be used in additive manufacturing methods. In the context of the present invention, additive manufacturing methods particularly include methods suitable for producing prototypes (rapid prototyping) and articles (rapid manufacturing), preferably selected from powder bed methods, including laser sintering, high-speed sintering, multi-jet melting, binder jetting, selective mask sintering, or selective laser melting. In particular, the compositions of the present invention can be used for laser sintering. The term "laser sintering" as used herein is similar to the term "selective laser sintering"; the latter refers to an earlier designation.

[0026] Furthermore, this application relates to a method for manufacturing the composition of the present invention, wherein the method includes the following steps:

[0027] (i) Providing at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from at least one polyarylether ketone and / or its copolymers and / or block copolymers and / or polymer blends.

[0028] (ii) Optionally, the polymer is ground.

[0029] (iii) Optionally, the polymer particles are prepared by thermomechanical treatment in a mixer at a temperature of at least 30°C and below the melting point Tm of the polymer.

[0030] As used herein, the term “providing” means the manufacture of a polymer or polymer system on-site and / or alternatively or additionally, the provision of a polymer or polymer system from an external location.

[0031] Preferably, polymer particles are obtained by grinding polymer granules or polymer flakes from the polymerization process. These polymer flakes are coarse, porous shavings obtained from the polymerization process; preferably, this powder has a particle size exceeding 1 μm. 2 / g BET specific surface area. When using polymer granules, this grinding step is preferably carried out at room temperature, or even more preferably by adding liquid nitrogen. Advantageously, the use of liquid nitrogen results in a higher yield of powder (for a given particle size).

[0032] To obtain spherical particles, the polymer particles are processed, preferably by thermomechanical treatment. This treatment is preferably carried out in a mixer, preferably a high-speed mixer, at a preferred temperature of at least 30°C and below the polymer's melting point Tm.

[0033] The terms mixing, blending, co-blending, and compounding are used synonymously below. The processes of mixing, blending, co-blending, and compounding can be carried out by extrusion in an extruder, kneader, disperser, and / or mixer, and may include one or more operations such as melting, dispersing, etc., if appropriate.

[0034] If the compositions of the present invention are to be packaged, such packaging process is preferably carried out under conditions of either humidity exclusion or humidity limitation.

[0035] The composition prepared according to the invention is advantageously used as a powder material, which is cured in a method for layering three-dimensional objects, wherein a series of layers of the object are continuously generated by the powder to be selectively cured at predetermined locations by energy, preferably by electromagnetic radiation, and especially preferably by laser.

[0036] Furthermore, the present invention relates to a composition obtained by or through the aforementioned method, particularly for laser sintering.

[0037] Finally, the compositions of the present invention manufacture objects, particularly three-dimensional objects, by layering and selectively curing the building materials, preferably by powdering. The term "curing" as used herein refers to at least partial melting of the building material followed by solidification or re-curing, and may also be referred to as sintering.

[0038] An advantageous method for manufacturing building elements, preferably 3D objects, comprising at least the following steps:

[0039] (i) Applying a layer of the composition according to the invention and / or a layer of the composition prepared by the manufacturing method according to the invention onto a production panel, wherein the composition is preferably applied in the form of a powder layer.

[0040] (ii) Selectively curing the applied layer of the composition at a location representing a cross-section of the object to be manufactured, preferably by using an irradiation unit, and

[0041] (iii) Lower the support and repeat the application and curing steps until the component, preferably a 3D object, is constructed, and the process is complete.

[0042] As used herein, the term "construction material" preferably refers to a powder or powder material that is suitably solidified by additive manufacturing methods, preferably by applying a powder bed method, and especially by laser sintering or laser melting, to form construct elements or 3D objects. The compositions of the invention described above are particularly suitable as construct materials.

[0043] The method or part thereof for manufacturing building elements is preferably carried out under a nitrogen atmosphere.

[0044] The production panel according to the invention relates to a panel placed on a carrier within an additive manufacturing machine and positioned at a predetermined location relative to an irradiation unit adapted for curing the carrier material. A build material is applied to the panel such that the upper layer of the panel corresponds to the level to be cured. During the build process, particularly in laser sintering, the carrier can be adjusted such that the most recently applied layer of build material has the same distance from the irradiation unit, preferably a laser, thereby being cured by exposure to the irradiation unit.

[0045] Articles made from the compositions of the present invention, particularly 3D objects, exhibit advantageous tensile strength and elongation at break. The term "tensile strength" as used herein refers to a measure of the maximum force required to pull a material to its breaking point. The determination of tensile strength is known to those skilled in the art and can be measured according to DIN EN ISO 527. The term "elongation at break" as used herein refers to the ratio of the length changed after the test specimen breaks to its original length. It expresses the material's ability to resist shape change without cracking. Elongation at break can be determined, for example, according to DIN EN ISO 527-2.

[0046] Furthermore, build elements manufactured from the compositions of the present invention exhibit improved dimensional stability and / or reduced shape distortion. As used herein, the term "dimensional stability" refers to the degree to which a material retains its original dimensions when subjected to changes in temperature, pressure, force, alteration, or humidity. For laser sintering methods, dimensional stability can be determined by the manner in which the build element undergoes shape distortion.

[0047] Therefore, this part relates to a building element obtained by or through the manufacturing method described above.

[0048] The uses of the compositions of the present invention can be achieved through rapid prototyping and manufacturing. Therefore, additive manufacturing is preferably used to produce three-dimensional objects by selectively projecting a laser beam with a predetermined energy onto layers of powdered material. This additive manufacturing method is preferably selected from powder bed methods, including laser sintering, high-speed sintering, binder jetting, selective grinding sintering, selective laser melting, and especially laser sintering. By applying this method, prototypes and building blocks can be manufactured quickly and cost-effectively.

[0049] The term "rapid manufacturing" as used herein specifically refers to the manufacture of building components, such as producing more than one identical article, where production, for example, by means of mold assembly, is uneconomical or otherwise more complex or infeasible due to the geometry of the building component. In short, this is true when the article exhibits a complex shape. Examples are components for high-end automobiles, racing cars, or rally cars manufactured in small quantities, or spare parts for motorsports, where availability is crucial in addition to the small quantity. The articles of this invention can be applied to industries such as aerospace, medical engineering, mechanical engineering, automotive, sports, household goods, electronics, or lifestyle. More importantly, it is suitable for producing similar building components, such as personalized components like prostheses, (inner ear) hearing devices, etc., whose geometry can be individually tailored to the user's needs.

[0050] Finally, the present invention includes a composition in the form of a powder material suitable for curing in a method of manufacturing a three-dimensional object by layering such powder material, and subsequently constructing a series of layers of the object at specific locations by applying energy, preferably electromagnetic radiation, and especially by applying laser.

[0051] More preferred embodiments of the invention are derived from the dependent claims together with the following description, thereby allowing a class of patent claims to be constituted by dependent claims of different classes, and allowing features of different embodiments to be combined to form new embodiments. It should be understood that the definitions and interpretations of terms used above and below apply accordingly to all embodiments described in this specification and the appended claims. Specific embodiments of the method of the invention will be further described below.

[0052] Preferably, at least one polyaryletherketone is selected from the group consisting of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), and / or PRKK copolymers or PEEK copolymers, such as the group consisting of polyetheretherketone-polyetherdiphenyletherketone (PEEK-PEDEK) and / or polyetheretherketone-polyethervinyletherketone (PEEK-PEmEK).

[0053] More preferably, at least one polyaryletherketone is selected from the group consisting of polyetherketoneketone (PEKK) and / or polyetheretherketone-polyetherdiphenyletherketone (PEEK-PEDEK) and / or polyetheretherketone-polyethervinyletherketone (PEEK-PEmEK), as follows:

[0054]

[0055] More preferably, the at least one polymer is selected from at least one homopolymer and / or hybrid polymer and / or polymer blend, wherein the at least one homopolymer and / or hybrid polymer and / or polymer blend preferably includes semi-crystalline homopolymer and / or hybrid polymer and / or amorphous homopolymer and / or hybrid polymer. Particularly preferably, the at least one homopolymer and / or hybrid polymer and / or polymer blend is selected from at least one semi-crystalline polymer or a semi-crystalline polymer blend of at least one semi-crystalline polymer and at least another semi-crystalline polymer or a semi-crystalline polymer blend of at least one semi-crystalline polymer and an amorphous polymer.

[0056] The term "semi-crystalline" as used herein should be understood to include both crystalline and amorphous regions. A polymer is considered substantially amorphous if its crystallinity in the solid phase is about 5% by weight or less, particularly about 2% by weight or less. In particular, a polymer is considered substantially amorphous if its melting point cannot be determined by dynamic differential calorimetry (DSC) and / or its enthalpy of fusion in the first heating is below 1 J / g. Semi-crystalline materials may contain up to 70% by weight, preferably up to 90% by weight, and particularly up to 95% by weight of crystalline regions.

[0057] Preferably, the hybrid polymer or copolymer comprises at least two different repeating units and / or at least one polymer blend based on the aforementioned polymers and copolymers. Advantageously, such hybrid polymers or copolymers and / or polymer blends are semi-crystalline.

[0058] A material that is at least partially semi-crystalline, preferably a powder material, can be produced by using one or more of the above-mentioned polymers (homopolymers, copolymers, or polymer blends).

[0059] Advantageous compositions preferably comprise a polymer and / or copolymer and / or polymer blend having a melt temperature of at least about 120°C, preferably at least about 150°C, and particularly preferably at least about 180°C. However, the preferred polymer and / or copolymer and / or polymer blend has a melt temperature not exceeding about 320°C, preferably not exceeding about 300°C, and particularly preferably not exceeding about 280°C.

[0060] As used herein, the term “melting temperature” refers to a temperature or range in which a substance, preferably a polymer, copolymer, or polymer blend, transforms from a solid state into a liquid state.

[0061] Alternatively or additionally, advantageous compositions preferably comprise a polymer and / or copolymer and / or polymer blend having a glass transition temperature of at least about -10°C, preferably at least about 50°C, more preferably at least about 90°C, particularly preferably at least about 120°C and / or not exceeding about 250°C, preferably not exceeding about 225°C, more preferably not exceeding about 200°C, particularly preferably not exceeding about 175°C.

[0062] As used herein, the term "glass transition temperature" refers to the temperature at which a polymer becomes in a gel-like, viscous state. The determination of the glass transition temperature is known to those skilled in the art and can be performed, for example, by DSC (according to DIN EN ISO 11357).

[0063] According to preferred embodiments and advantageous compositions, the extrapolated onset temperature of the melting peak is increased by at least 1°C, preferably at least 5°C, compared to thermoplastic polymers not subjected to annealing treatment. T eim And / or increase the crystallization temperature (Tc) and melting temperature (Tm) by at least 1°C, preferably at least 5°C. T eim The difference in / Tc.

[0064] Surprisingly, the inventors discovered that annealing of the composition led to T eim Increase and / or T eim An increase in the difference between / Tc and the temperature leads to an increase in the process window. As used herein, the term "process window" refers to the difference between the lowest possible temperature (non-coiling temperature: NCT) and the highest possible temperature (maximum build temperature: UBT). The terms "crystallization temperature" and "extrapolated onset temperature of melting peak" are used herein. eim "" refers to the peak temperature as defined in DIN EN ISO 11357.

[0065] Methods for determining the extrapolated onset temperature of crystallization temperature, melting temperature, and melting peak are known to those skilled in the art and can be performed using dynamic differential calorimetry (DSC) as described in DIN EN ISO 11357. To allow for comparison of measurements with and without annealing, the same holding time, heating rate, onset temperature, and final temperature are considered when applying the same method.

[0066] The degree of crystallinity can be measured using various analytical methods, such as DSC or X-ray diffraction. Therefore, the degree of crystallinity is calculated by the enthalpy of melting in [J / g] (compared to a polymer with a theoretical crystallinity of 100%).

[0067] As used in this article, the term "enthalpy of fusion" refers to the energy required to melt a substance from its solid state to its liquid state at its melting temperature and constant pressure (isobars).

[0068] Furthermore, the inventors have surprisingly discovered that the process window can be increased not only by means of a specific temperature range below the melting point Tm, but also alternatively or additionally by means of changing the melt volumetric rate (MVR) of the polymer. Advantageously, within the aforementioned specific MVR range, for primary powders, i.e., unused powders, the process window is at least about 1°C, preferably at least about 3°C, more preferably at least about 5°C and most preferably about 9°C, and / or not exceeding about 200°C, preferably not exceeding about 100°C, more preferably not exceeding about 50°C.

[0069] According to a preferred embodiment, the above-mentioned polyether ketone includes the following repeating units:

[0070] Repeating unit A

[0071]

[0072] Repeating unit B

[0073] ,

[0074] The ratio of repeating unit A to repeating unit B is preferably between approximately 80:20 and 10:90, more preferably between 70:30 and 40:60, and particularly preferably between 60:40.

[0075] According to a particularly preferred embodiment, the polyaryletherketone has a melting temperature Tm of at least about 250°C, preferably at least about 260°C, particularly preferably at least about 270°C, and / or at most about 320°C, preferably at most about 310°C, particularly at most about 300°C, and / or wherein the polyaryletherketone has a glass transition temperature of at least about 120°C, preferably at least about 140°C, particularly preferably at least about 150°C.

[0076] According to a next preferred embodiment, the polyetherimide preferably comprises repeating units according to Formula I.

[0077] Formula I

[0078]

[0079] and / or repeating units according to Equation II

[0080] Formula II

[0081]

[0082] and / or repeating units according to Equation III

[0083] Formula III

[0084] .

[0085] According to a next preferred embodiment, the polymer blend comprises polyaryletherketone-polyetherimide.

[0086] Even more preferably, the polyaryletherketone comprises a polyetherketone having a repeating unit A and a repeating unit B in a ratio of 60:40.

[0087] Repeating unit A

[0088]

[0089] Repeating unit B

[0090]

[0091] And / or polyetherimides include repeating units of formula I.

[0092] Formula I

[0093] .

[0094] A more preferred composition comprises a polyether ketone having the following repeating units:

[0095] Repeating unit A

[0096]

[0097] Repeating unit B

[0098] .

[0099] Preferably, the ratio of 1,4-phenylene units in repeating unit A to 1,3-phenylene units in repeating unit B is from 90:10 to 10:90, more preferably from 70:30 to 10:90, particularly preferably from 60:40 to 10:90, and most preferably 60:40. The number of repeating units A and repeating units B, n1 or n2, can preferably be at least 10 and / or no more than 2000, respectively.

[0100] More preferably, the viscosity of the polymer used in PAEK is from 0.7 dl / g to 1.2 dl / g, more preferably from 0.78 dl / g to 1.1 dl / g, measured according to ISO 307 in a 96% by weight sulfuric acid solution at 25°C.

[0101] For example, preferred polyether ketone polymers are available in the series under the trade name Kepstan 600 (Arkema, France).

[0102] According to a more preferred embodiment, the polyaryletherketone has a melting temperature Tm of at least about 250°C, preferably at least about 260°C, particularly preferably at least about 270°C, and / or at most about 320°C, preferably at most about 310°C, particularly at most about 300°C.

[0103] In addition, the preferred polyaryletherketone has a glass transition temperature Tg of at least about 120°C, preferably at least about 140°C, particularly preferably at least about 150°C and / or no more than about 200°C, preferably no more than about 180°C, particularly preferably no more than about 170°C.

[0104] According to the next preferred embodiment, the polyetherketoneketone (PEKK) has an extrapolated onset melt temperature (T0) of at least 250°C, preferably at least 260°C, particularly preferably at least 265°C, and / or at most 285°C, preferably at most 280°C, particularly at most 275°C. eim ).

[0105] The extrapolated onset temperature of melting temperature Tm and the peak melting point (T) eim The determination of Tm and T can be made, for example, by DSC (differential scanning calorimetry). This is used to determine Tm and T. eim The corresponding DSC measurements are preferably performed according to DIN EN ISO 11357 (determined by the first heating curve of the DSC) on an apparatus such as the Mettler Toledo DSC 823 (for PAEK, especially PEKK, the starting temperature is 0°C, the maximum temperature is 360°C and the minimum temperature is 0°C; heating or cooling rate: 20 K / min, weight: 4.5 mg to 5.5 mg).

[0106] Such melting temperature and / or glass transition temperature of at least one polyaryletherketone advantageously allows for improved melting and bonding properties, especially for laser sintering, thus resulting in improved mechanical properties of building elements made from such polymers.

[0107] In the next preferred composition, the thermoplastic polymer is selected from at least one polyetherimide. Particularly preferred is that this polyetherimide comprises repeating units of Formula I.

[0108] Formula I

[0109]

[0110] and / or repeating units of Formula II

[0111] Formula II

[0112]

[0113] and / or repeating units of Formula III

[0114] Formula III

[0115] .

[0116] The number of repeating units in Formula I, Formula II, and Formula III is preferably at least 10 and / or no more than 1000.

[0117] Preferably, the number average molecular weight (Mn) of this polyetherimide is at least 10,000D, more preferably at least 15,000D and / or no more than 200,000D, and particularly preferably at least 15,000D and / or no more than 100,000D. The weight average molecular weight (Mw) of this preferred polymer is preferably at least 200,000D, more preferably at least 30,000D and / or no more than 500,000D, and particularly preferably at least 30,000D and / or no more than 200,000D.

[0118] Preferred polyetherimides of Formula I are available from the trade names Ultem® 1000, Ultem® 1010 and Ultem® 1040 (Sabic, Germany); preferred polyetherimides of Formula II are available from the trade names Ultem® 5001 and Ultem® 5011 (Sabic, Germany).

[0119] More preferred compositions include polymer blends comprising polyaryletherketone-polyetherimide, preferably polyetherketone having a repeating unit A to repeating unit B ratio of 60:40. Preferred compositions may also include polyetherimide, preferably comprising repeating units of formula I.

[0120] As described above, advantageous compositions may include one or more additives. According to preferred embodiments, the additives may be semi-crystalline polymers and / or semi-crystalline polyols and / or semi-crystalline surfactants and / or semi-crystalline protective colloids. Preferably, the additives are water-soluble and / or immiscible with at least one thermoplastic polymer at room temperature.

[0121] Advantageously, the additives appropriately protect the polymer pellet cake and form cavities during the pouring of the composition in the additive manufacturing process, thereby actively increasing the bulk density of the composition.

[0122] As used herein, the term "bulk density" refers to the mass of a material's many particles divided by the total volume they occupy. The total volume includes the particle volume, the interparticle volume, and the internal pore volume. The determination of bulk density is known to those skilled in the art and can be performed according to DIN EN ISO 60:2000-01.

[0123] According to a preferred embodiment, the composition has at least about 30 kg / m³ 3 and / or not exceeding approximately 65 kg / m 3 Preferably at least 35kg / m 3 and / or not exceeding 55 kg / m 3 Especially at least about 40kg / m 3 and / or not exceeding approximately 50 kg / m 3 The packing density.

[0124] When the polymer comprises polyaryletherketone prepared by milling polymer sheets, this composition preferably exhibits at least about 30 kg / m³. 3 and / or not exceeding approximately 50 kg / m 3 Preferably at least 32kg / m 3 and / or not exceeding 45 kg / m 3 Especially at least about 34 kg / m 3 and / or not exceeding approximately 40 kg / m 3 The bulk density. This is especially preferred if the composition is prepared from polymer sheets.

[0125] For compositions used in laser sintering, particle size or particle size distribution, suitable bulk density, and sufficient pourability are generally important.

[0126] As used herein, the term "particle size" refers to the size of an individual particle in a composition. Therefore, particle size distribution affects the properties of loose materials that exist in a pourable form, such as compositions existing in powder form.

[0127] According to another preferred embodiment, the polymer particles of the composition have the following particle size distribution:

[0128] -d10 = at least 10 μm, preferably at least 20 μm and / or no more than 50 μm, preferably no more than 40 μm

[0129] -d50 = at least 25 μm and / or no more than 100 μm, preferably at least 30 μm and / or no more than 80 μm, especially at least 40 μm and / or no more than 60 μm

[0130] -d90 = at least 50 μm and / or no more than 150 μm, preferably no more than 120 μm.

[0131] Methods for determining particle size distribution or particle size distribution separately are known to those skilled in the art and can be determined by DIN ISO 13322-2.

[0132] Particularly preferred compositions comprise polymer particles selected from polyaryletherketones, wherein the polymer particles of the composition have the following particle size distribution:

[0133] -d10 = at least 15 μm, preferably at least 20 μm, especially at least 25 μm and / or no more than 50 μm, preferably no more than 40 μm, especially no more than 30 μm

[0134] -d50 = at least 40 μm and / or no more than 100 μm, preferably at least 45 μm and / or no more than 80 μm, especially at least 50 μm and / or no more than 65 μm

[0135] -d90 = at least 70 μm and / or no more than 150 μm, preferably at least 80 μm and / or no more than 130 μm, more preferably no more than 120 μm, and especially preferably no more than 110 μm.

[0136] Even more preferably, this preferred polyaryletherketone powder is obtained by grinding polymer sheets.

[0137] According to a more preferred embodiment, the advantageous composition exhibits a distribution width (d90-d10) / d50 of no more than 3, preferably no more than 2, especially no more than 1.5, and particularly preferably no more than 1.

[0138] A more preferred composition comprises a fine particle content of no more than about 5% by weight, preferably no more than about 3% by weight, particularly preferably no more than about 2% by weight, and most preferably no more than 1% by weight. The term "fine particle content" as used herein refers to particles having a particle size of less than 10 μm.

[0139] The polymer particles of the compositions of the present invention preferably exhibit a substantially spherical to lentil-shaped form. Particularly preferably, the polymer particles exhibit a sphericity of at least about 0.8, preferably at least about 0.85, particularly preferably at least about 0.90, and most preferably at least about 0.95. The determination of sphericity can be made, for example, by microscopic examination according to DIN ISO 13322-1 or DIN ISO 13322-2 (on a Camsizer XT device (Retsch Technology, Germany)).

[0140] According to a particularly preferred embodiment, the advantageous composition has a pourability of at least 1 second, preferably at least 2 seconds, most preferably at least 3 seconds and / or no more than 12 seconds, preferably no more than 9 seconds, most preferably no more than 8 seconds (the pourability is measured with a 25 mm funnel according to DINEN ISO 6186).

[0141] More particularly preferred compositions show a Hausner factor of at least 1.01 and / or no more than 1.7, preferably no more than about 1.5, more preferably no more than about 1.4, especially preferably no more than about 1.3, even more preferably no more than about 1.2, and most preferably no more than about 1.18.

[0142] It has also been found that exhibiting a small surface area is advantageous for the polymer particles of the compositions of the present invention. The surface area of ​​these polymer particles can be determined, for example, by gas adsorption according to Brunauer, Emmet and Teller (BET) (as per DIN EN ISO 9277). The particle surface area measured according to this method is also called the BET specific surface area.

[0143] According to a preferred embodiment, the advantageous composition has a BET specific surface area of ​​at least about 0.1 m². 2 / g and / or no more than about 10m 2 / g, preferably not exceeding 5m 2 / g, more preferably not exceeding 2m 2 / g, especially preferably not exceeding 1.5m 2 / g, optimal value not exceeding 1m 2 / g. In particular, this composition comprises polymer particles selected from polyaryletherketones.

[0144] In cases where polyaryletherketone particles are particularly preferably made from polymer sheets, these polyaryletherketone particles preferably have a particle size of at least 0.5 μm. 2 The BET specific surface area is approximately 1 / g. Particularly preferred is that these polyaryletherketone particles are obtained by grinding.

[0145] The method for preparing the composition according to the present invention has been initially described. According to another preferred embodiment for preparing the composition, the polymer is preferably selected from polyaryletherketones or copolymers or blends thereof with another polymer, more preferably in powder form. Particularly preferred is that the polymer is provided in the form of polymeric sheets from the polymerization process.

[0146] The preparation of an advantageous composition may include, for example, the melting and dispersion of the polymer provided in step i) described above in an additive, such as a dispersant. Preferably, this dispersant is selected from polyols, more preferably semi-crystalline polyols. In particular, this polyol is selected from at least one semi-crystalline polyethylene glycol and / or at least one semi-crystalline polyethylene oxide and / or at least one polyvinyl alcohol, especially preferably selected from at least one semi-crystalline polyethylene glycol. Preferably, this additive or dispersant is removed by centrifugation and / or filtration.

[0147] The dispersion step is preferably carried out in a dispersion device, more preferably in an extruder. Alternatively, the dispersion step can be carried out in a kneader. Preferably, the dispersion device includes several continuous zones, particularly in the direction of travel.

[0148] In another method, polymers or polymer particles are separated from the mixture or dispersion, and the separated polymers or polymer particles may then be washed and / or dried.

[0149] The separation of the respective components of a mixture or dispersion is preferably carried out by centrifugation and / or filtration. For example, a dry composition can be obtained by drying the solid composition in an oven such as a vacuum desiccant.

[0150] Alternatively or additionally, advantageous compositions can be obtained by melt compounding of the polymer provided in step i), by spinning fibers and further processing the polymer by spun fibers into microspheres.

[0151] Alternatively or additionally, advantageous compositions can be obtained by melting and compounding the polymer provided in step i) and, in a melt spraying process, preferably by applying high pressure through a nozzle to spray the melt.

[0152] Alternatively or additionally, advantageous compositions can be obtained by dissolving the polymer in a solvent, preferably at an elevated temperature, and preferably by precipitating the polymer from the solvent to form a powder through cooling and stirring.

[0153] According to a particularly preferred embodiment, an advantageous method for preparing the composition includes annealing the polymer particles to a temperature above Tg and below Tm. Preferably, the annealing of the polymer particles is carried out in a furnace.

[0154] Annealing can be performed in the same steps as the spheroidizing steps described above. Alternatively, annealing can be performed before or even after the polymer particles are spheroidized.

[0155] According to a particularly preferred embodiment, the annealing of the polymer, especially PAEK, is carried out in the same step as the rounding step described above. This particularly preferred method is preferably carried out at an annealing temperature of at least about 30°C, more preferably at least about the glass transition temperature of the polymer, and / or not exceeding about the melting temperature of the polymer.

[0156] Therefore, the present invention relates to a composition, particularly a composition comprising a PAEK polymer, which is obtained by the method described above including such an annealing step or by means of the method described above including such an annealing step.

[0157] According to the most preferred embodiment, the method for preparing the advantageous composition includes an annealing step of polymer particles, preferably PEKK particles, at a preferred temperature of at least 250°C, more preferably at least about 260°C, particularly preferably at least about 265°C and / or preferably not more than 285°C, more preferably not more than 280°C, particularly preferably not more than 275°C.

[0158] In the next step, an advantageous method includes adding an additive. In particular, this additive is selected from flow agents. Preferably, the addition of the additive, especially the flow agent, is carried out in a mixer.

[0159] The manufacture of the building elements of the present invention has been initially described. The inventors have now surprisingly discovered that, even more advantageously, a method for manufacturing the building elements utilizes the updating of the composition. Advantageously, the use of an updated composition improves the mechanical stability of the building elements. Furthermore, the use of an updated composition advantageously leads to a cost-effective manufacturing method.

[0160] As used herein, the term "updating of composition" refers to a portion of the total composition, i.e., a portion of the composition not previously used in the laser sintering process, or a portion of the composition used at least once in the laser sintering process. In the context of this invention, the portion of the composition not previously used in the laser sintering process is referred to as the "primary composition" or "main composition." This main composition preferably comprises 10% by weight or more and 60% by weight or less of the total composition, more preferably 50% by weight or less, even more preferably 40% by weight or less, and particularly preferably 30% by weight or less.

[0161] Based on the working volume dimensions, especially in the xy direction, high component warpage exceeding 60% by weight can be observed. Therefore, according to a particularly preferred embodiment, the number of updates is preferably within the above range. This is particularly advantageous for PEKK, and most preferably for copolymers of PEKK with a 60:40 ratio (repeating unit A:repeating unit B).

[0162] Therefore, according to an advantageous embodiment, the preferred refill is below 50% by weight, preferably below 40% by weight, and especially preferably below 30% by weight. However, due to the potential reduction in particle surface area (“orange peel” effect), the refill should be above 10% by weight. This is particularly relevant when using machines with large build volumes, such as the EOS P800 or P810, and even more relevant when operating buildings with a z-height greater than approximately 100 mm, or most relevant when operating buildings with a z-height greater than approximately 200 mm. Advantageously, this refill is used for PEKK, and most preferably for copolymers of PEKK with a 60:40 ratio (repeating unit A: repeating unit B).

[0163] Furthermore, surprisingly, it has been found that in an advantageous method for manufacturing building elements, preferably 3D objects, the aforementioned layer application step i) is applied by at least two layers, wherein the layer application is subdivided into a step of applying a first layer having a first height H1 and a step of applying a second layer having a second height H2, wherein the second layer with height H2 is applied on the first layer with height H1, preferably wherein the height H1 of the first layer is equal to the height H2 of the second layer.

[0164] According to a next preferred embodiment, such a layer has a thickness preferably at least about 60 μm and / or no more than 120 μm, more preferably about 100 μm. Surprisingly, when a layer of such thickness is applied, the bonding of the layer is improved.

[0165] Particularly preferably, the advantageous method for manufacturing the building elements uses roof blades with a preferred angle of 1.9°.

[0166] Therefore, the present invention covers a building element, preferably a 3D object, wherein the building element is obtained by or can be obtained by the manufacturing method described above.

[0167] Finally, advantageous methods may include packaging the composition. The packaging of compositions prepared according to the method of the invention, especially powders, is preferably carried out under conditions that exclude atmospheric moisture. Such packaged materials can be stored under reduced humidity conditions to prevent clumping, thereby improving the storage stability of the compositions of the invention. Furthermore, advantageous packaging materials can prevent moisture, especially atmospheric moisture, from entering the compositions of the invention.

[0168] As described above, the compositions of the present invention are suitable for use in additive manufacturing methods, particularly for laser sintering methods. Typically, the target area of ​​the powder bed in an irradiation apparatus, especially a laser beam, is heated prior to use such that the temperature of the primary powder material is close to its melting temperature and only marginal energy input is sufficient to increase the total energy input of the particles to aggregate and solidify. Therefore, energy-absorbing and / or energy-reflecting materials can be applied to the target area of ​​the irradiation unit, as known, for example, from high-speed sintering or multi-jet melting methods, respectively.

[0169] As used herein, “melting” refers to the melting of at least a portion of powder in a method (during additive manufacturing processes), for example, in a powder bed, by inputting energy, preferably electromagnetic radiation, and especially laser radiation. Therefore, the compositions of the present invention allow for the method-safe fabrication of at least partially melted and manufactured components with high mechanical stability and shape accuracy.

[0170] It was also found that the determination of tensile strength and elongation at break can be used as a measure of the processability of the compositions of the present invention or, in particular, the building elements manufactured therefrom.

[0171] Therefore, a more preferred embodiment covers a building element manufactured using the composition of the present invention. Advantageously, such a building element preferably exhibits a tensile strength of at least about 50 MPa in the xy direction, more preferably at least about 70 MPa, especially at least about 80 MPa, and most preferably at least about 90 MPa. Advantageously, the building element preferably has a tensile strength of no more than about 150 MPa, more preferably no more than about 120 MPa, and especially no more than about 110 MPa.

[0172] Alternatively or additionally, such building elements preferably exhibit an elongation at break of at least about 1%, more preferably at least about 2%, especially at least about 2.5%, most preferably at least about 3% and / or preferably no more than about 50%, more preferably no more than about 20%, and especially preferably no more than about 15%.

[0173] The determination of tensile strength and elongation at break is known to those skilled in the art and can be performed in accordance with DIN ENISO 527.

[0174] According to a more preferred embodiment, the advantageous composition includes at least one additive selected from one or more flow agents, heat stabilizers, oxidative stabilizers, ultraviolet stabilizers, colorants, and infrared absorbers. The preferred content of this additive in the composition may be at least about 0.005% by weight, preferably at least about 0.01% by weight, more preferably at least about 0.05% by weight, particularly preferably at least about 0.1% by weight, most preferably at least about 0.2% by weight, and / or the preferred composition may include one or more additives in a content preferably not exceeding about 3% by weight, more preferably not exceeding about 2% by weight, particularly preferably not exceeding about 1% by weight, and most preferably not exceeding about 0.5% by weight. The content of this additive refers to the content of each individual additive in the composition.

[0175] Other functional additives that may be used preferably in amounts exceeding 3% by weight are selected from softeners, fillers and reinforcing materials, flame retardants, reinforcing fibers, SiO2 particles, carbon particles, carbon fibers, glass fibers, carbon nanotubes, mineral fibers (e.g., Wollastonit), aramid fibers (especially Kevlar fibers), glass beads, mineral fillers, inorganic and / or organic pigments and / or flame retardants (especially those containing phosphates such as ammonium polyphosphate and / or bromine and / or other halogens and / or inorganic substances, such as magnesium hydroxide or aluminum hydroxide). Particularly preferred are additives including reinforcing fibers, especially carbon fibers.

[0176] More particularly preferred additives include polysiloxanes. Polysiloxanes can be used, for example, as flow agents to reduce the viscosity of polymer melts and / or, especially as softeners in polymer blends.

[0177] According to a more preferred embodiment, the advantageous composition includes at least one flow agent. This flow agent, which is typically present in particulate form, adheres to the polymer particles, thereby preventing the composition from clumping.

[0178] This flow agent is preferably selected from metal soaps, and more preferably from silica, stearates, tricalcium carbonate, calcium silicate, alumina, magnesium oxide, magnesium carbonate, zinc oxide, or mixtures thereof. More preferably, at least one flow agent is selected from silica (synonym: silica). Advantageous compositions comprise at least one flow agent in amounts of about 0.01% by weight and / or not exceeding about 1% by weight.

[0179] Further preferred embodiments of the present invention are derived from the dependent claims and the specification, wherein a patent claim of one class may be formed by dependent claims of different classes, and features of different embodiments may be combined to form new embodiments. It should be understood that the definitions and interpretations of the terms used above and below apply accordingly to all embodiments described in this specification and the appended claims. Specific embodiments of the present invention are further described below. Attached Figure Description

[0180] Figure 1 The image shows the location (left) of the cross-shaped test assembly and the pyrometer measurement spot (“P”, top right corner) on the EOS P800, which is affected by the reduced installation space.

[0181] Figure 2 Shown on a smaller P800 build platform (5 on xy) 2, Figure 2 The substrate in the middle of each sector.

[0182] Figure 3 The positions of the tensile specimens in the x-direction, z-direction, and density cubes in the powder box and EOS P800 are shown.

[0183] Figure 4 The positions of the tensile specimens in the x-direction, z-direction, and density cubes in the powder box and EOS P800 are shown.

[0184] Figure 5 The software's original configuration printout is displayed.

[0185] Figure 6 The original configuration printout of the software is displayed.

[0186] Figure 7 The software's original configuration printout is displayed. Detailed Implementation

[0187] Example

[0188] Example 1:

[0189] 1600 g of o-dichlorobenzene and 65 g of 1,4-(phenoxybenzoyl)benzene (EKKE) were placed in a 2 L reactor and stirred under a stream of dry nitrogen. The following acyl chlorides were added: terephthaloyl chloride (5.4 g), isophthaloyl chloride (22.2 g), and benzoyl chloride (0.38 g). The reactor was cooled to -5 °C. 115 g of AlCl3 was added while maintaining the reactor temperature below 5 °C. After a homogenization period (approximately 10 minutes), the reactor temperature was increased to 90 °C at a rate of 5 °C per minute (polymerization begins during this temperature increase). The reactor was maintained at 90 °C for 30 minutes and then cooled to 30 °C. 400 g of acidic water (3% HCl) was slowly added to keep the reactor temperature below 90 °C. The reactor was stirred for 2 hours and then cooled to 30 °C.

[0190] The reaction medium was removed from the reactor and filtered / purified according to the procedures performed by those skilled in the art. The purified wet PEKK was then dried overnight at 190°C under vacuum (30 mbar). Tablets were obtained.

[0191] Example 2:

[0192] The PEKK polymer sheet from Example 1 was appropriately ground and graded into a fine powder in air. Data for the powder are shown in Table A.

[0193] Table A

[0194]

[0195] Example 3

[0196] Polyetherketoneketone (PEKK) was prepared as in Examples 1 and 2.

[0197] The powder was mixed in a Henschel FML type mixer according to Table 1. The mass of the powder is referred to as m below. Stage 1 involves the heating stage, which is the stage up to when the mixture (powder) in the mixer reaches the maximum temperature Tmax. Tmax corresponds to the processing temperature T. B The speed of the mixer in stage 1 is called D1. The duration of stage 1 is called t1. Stage 2 is the holding stage, which maintains the reached temperature. The speed of the mixer in stage 2 is called D2. The duration of stage 2 is called t2.

[0198] The names m, Tmax, D1, D2, t1, and t2 are also used in the following examples.

[0199] Table 2 shows the obtained bulk density S, BET surface area, and particle size of 10. The fraction of powder particles m (by volume percentage) ("%") 10 m") and the quantiles d10, d50 and d90 of the particle size distribution.

[0200] Table 1

[0201]

[0202] Table 2

[0203]

[0204] Example 4

[0205] The powder of Example 3 was annealed for 3 hours at different temperatures (according to Table 3a) in a fumed furnace (Nabertherm N250 / A type) under a nitrogen atmosphere. After annealing, the powder was sieved using a 160 μm sieve on a Perflux 501 vibrating screen (Siebtechnik GmbH, Muehlheim, Germany). The obtained powder values ​​are given in Table 3a.

[0206] Test specimens were produced on an EOS P800 laser sintering system (with Startup-Kit PAEK 3302 CF) using three powders (primary powders) with the process parameters given in Table 3. The layer thickness was 120 μm and applied using a double-coating process (layer thickness 60 μm). The processability (process window) of the powders and the mechanical properties of the laser-sintered parts were analyzed. The obtained values ​​are shown in Tables 3b and 3c.

[0207] Table 3a

[0208]

[0209] Table 3b

[0210]

[0211] As can be seen, the non-coiling temperature (NCT) increases at higher annealing temperatures. Therefore, the powder needs to be built at higher process chamber temperatures (PK), which increases the aging of the powder used (a significant decrease in MVR value, see Table 3a), resulting in a poorer renewal ratio as the heat treatment temperature increases.

[0212] Table 3c

[0213]

[0214] The effect of heat treatment on mechanical properties is described. The tensile strength in z increases at an annealing temperature of 275°C.

[0215] Example 5

[0216] In Example 5, three PEKK types with different melt viscosities were prepared similarly to those in Example 4. The difference was that the polymerization time was adjusted (compared to Example 1) to obtain powders with different melt viscosities (MVR). Furthermore, the mixer processing temperature Tmax in Example 5 was between 110°C and 120°C. t2 was applied for each powder, such that t1+t2 was always maintained for 25 minutes. For all three powders, the annealing temperature in Example 5 was 265°C. The powder analysis data are shown in Table 4a.

[0217] Test specimens were produced on an EOS P800 laser sintering system (with Startup-Kit PAEK 3302 CF) using three powders (primary powders) with the process parameters given in Table 4b. The layer thickness was 120 μm, and a double-coating process (layer thickness 60 μm) was used. The processability (process window) of the powders and the mechanical properties of the laser-sintered parts were analyzed. The obtained values ​​can be found in Tables 4b and 4c.

[0218] Table 4a

[0219]

[0220] Table 4b

[0221]

[0222] As shown in Tables 4a and 4b, NCT increases with increasing powder MVR value. This means that the build temperature (Tpk) is at a higher temperature, which has a negative impact on powder aging and renewal. Furthermore, with increasing powder MVR, the process window (the difference between UBT and NCT) decreases from 13°C to only 5°C.

[0223] Table 4c

[0224]

[0225] Table 4c clearly shows the effect of melt viscosity on mechanical properties. Tensile strength and elongation at break in the xy direction increase significantly from 73 MPa to 96 MPa and from 2.1% to 3.8%, respectively, while MVR remains low. In contrast, elongation at break in the z direction decreases only slightly from 1.3% to 1.2%.

[0226] Example 6

[0227] In Example 6, two PEKK types with different particle size distributions were prepared similarly to those in Example 4. The difference was that the polymerization time was adjusted (compared to Example 1) to obtain a particle size distribution of 24 cm⁻¹ after heat treatment. 3 / 10min MVR powder. Furthermore, the processing temperature Tmax of the mixer in Example 6 was between 110°C and 120°C. t2 was applied for each powder, such that t1+t2 was always maintained for 25 minutes. For all two powders, the annealing temperature in Example 6 was 265°C. Analytical data for the primary powders are shown in Table 5a.

[0228] Table 5a

[0229]

[0230] The effect of particle size distribution on powder flowability is clearly visible. Unprocessed powder exhibits better flowability (pouring time reduced from 15 seconds to 8 seconds).

[0231] Test specimens were produced on an EOS P800 laser sintering system (with Startup-Kit PAEK 3302 CF) using powder (50% updated) with the process parameters given in Table 5b. The layer thickness was 120 μm and applied using a double-coating process (layer thickness 60 μm). The processability of the powder (process window) and the mechanical properties of the laser-sintered parts were analyzed. The obtained values ​​can be found in Table 6.

[0232] Table 5b

[0233]

[0234] Table 6

[0235]

[0236] As can be seen from Table 6, the powder with improved pourability of 8 seconds exhibits improved tensile strength and elongation at break in the xy direction.

[0237] Example 7

[0238] In Example 7, PEKK was prepared similarly to that in Example 5. The difference was that the polymerization time was adjusted (compared to Example 1) to obtain a product with a viscosity of 22 cm⁻¹ after heat treatment. 3 / 10min MVR powder. Furthermore, the mixer processing temperature Tmax of Example 7 is 116°C. t2 applies to each powder, such that t1+t2 is always maintained for 25 minutes. The annealing temperature of Example 5 is 265°C.

[0239] Table 7a

[0240]

[0241] Test specimens were produced on a P800 laser sintering system (EOS P800 with Startup-Kit PAEK 3302 CF) using powder (primary powder) with process parameters given in Table 7b. These specimens had three different layer thicknesses: 120 μm, 110 μm, and 60 μm, applied via a double-coating process (layer thicknesses of 60 μm, 50 μm, and 30 μm, respectively). The mechanical properties of the laser-sintered parts were analyzed for the different layer thicknesses. The obtained values ​​are described in Table 7c.

[0242] Table 7b

[0243]

[0244] Table 7c

[0245]

[0246] The effects on the mechanical properties and density of the component in the z-direction are clearly visible. When a reduced layer thickness of 100 μm and 60 μm is applied, the tensile strength and elongation at break in the z-direction increase.

[0247] Example 8

[0248] In Example 8, PEKK was prepared similarly to that in Example 4. The difference was that the polymerization time was adjusted (compared to Example 1) to obtain a product with a viscosity of 23 cm⁻¹ after heat treatment. 3 / 10min MVR powder. Furthermore, the processing temperature Tmax of the mixer in Example 8 was between 110°C and 120°C. t2 was applied for each powder, such that t1+t2 was always maintained at 25 minutes. Therefore, the annealing temperature was adjusted. The powder was annealed for 3 hours at different temperatures (according to Table 8a) in a fumed furnace (Nabertherm N250 / A type) under a nitrogen atmosphere. After annealing, the powder was sieved using a 160μm sieve on a Perflux 501 type vibrating screen (Siebtechnik GmbH, Muehlheim, Germany). The obtained powder values ​​are given in Table 8a.

[0249] Test specimens were produced on a P810 laser sintering system using three types of powders (primary powders) with the process parameters given in Table 8b. The layer thickness was 120 μm and applied using a double-coating process (layer thickness 60 μm). The processability (process window) of the powders and the mechanical properties of the laser-sintered parts were analyzed. The obtained values ​​are shown in Tables 3b and 3c.

[0250] Table 8a

[0251]

[0252] Table 8b

[0253]

[0254] As can be seen, the non-coiling temperature (NCT) increases at higher annealing temperatures. Therefore, the powder needs to be built at higher process chamber temperatures (PK), which increases the aging of the powder used (a significant decrease in MVR value, see Table 8a), resulting in a poorer renewal ratio as the heat treatment temperature increases. At the lowest annealing temperature, the bulk density of the powder used decreases more sharply, and therefore the powder flowability is the worst.

[0255] Table 8c

[0256]

[0257] The effect of heat treatment on mechanical properties is described. The highest value is reached at an annealing temperature of 265℃.

[0258] Example 9

[0259] In Example 9, PEKK was prepared similarly to that in Example 2 (sample number 1), but the polymerization time was adjusted to obtain a viscosity similar to that of Example 6. It was then mixed as described in Example 3, except that the mixer processing temperature Tmax was between 110°C and 120°C. t2 was adjusted so that t1+t2 was maintained for 25 minutes (sample number 2). It was then annealed similarly to that in Example 4 (sample number 3). The annealing temperature for sample 3 was 265°C. Different PEKK samples were also produced according to Example 9, sample number 3 (sample number 4). The annealing temperature for sample 4 was also 265°C. The powder data are shown in Table 9 below. The Hausner ratio of these powders was analyzed.

[0260] Table 9

[0261]

[0262] The obtained values ​​are described in Table 9. The effect of heat treatment on the Hausner ratio is visible. Heat treatment shows a particularly favorable effect on flowability, as measured by the Hausner ratio. As can be seen, sphericity is affected by both mixing and heat treatment.

[0263] Example 10

[0264] In Example 10, PEKK was prepared similarly to that in Example 2, but the polymerization time was adjusted to obtain a 29 cm⁻¹ precipitate before heat treatment. 3 The MVR powder (sample number 1) was prepared for 10 minutes. It was then mixed as described in Example 3, except that the mixer processing temperature Tmax was between 110°C and 120°C. t2 was adjusted so that t1 + t2 was maintained for 25 minutes (sample number 2). Sample number 2 was then annealed similarly to Example 4, but the annealing time was adjusted (sample number 3). The annealing temperature for sample 3 was 265°C. Data obtained from BET analysis of these samples are shown in Table 10 below.

[0265] Table 10

[0266]

[0267] The obtained values ​​are described in Table 10. The effects of mixing and heat treatment on the BET surface of the particles are visible.

[0268] Methodology section:

[0269] Rounding by thermomechanical treatment

[0270] The thermomechanical treatment of the polymer particles can preferably be carried out in a mixer at a temperature of at least 30°C and below the polymer's melting point Tm. The mixer can be, for example, a Henschel mixer of the FML type, with a machine size of 40 (Zeppelin Systems GmbH, Germany).

[0271] Hausner proportions

[0272] Hausner Ratio H provides information on the compressibility of loose materials. It is used to determine the bulk density of uncompressed loose materials (according to EN ISO-60). and tap density .

[0273]

[0274] Tap density

[0275] Determine the tap density according to DIN EN ISO 787-11.

[0276] Mechanical properties were determined by tensile testing.

[0277]

[0278] Table 11

[0279] The mechanical properties of the three-dimensional object according to the present invention can be determined based on the test samples described below.

[0280] The test methods and component dimensions of the test specimens conformed to the tensile testing standard DIN EN ISO 527-1: 2012-06. For this purpose, a Zwick TC-FR005TN.A50 material testing machine (file number: 605922) and TestExpert II V3.6 software were used.

[0281] In standardized tensile testing, the elastic modulus [GPa], tensile strength [MPa], and elongation at break are determined using tensile specimens with the dimensions listed in Table 11. The testing speed for PEKK components is 5 mm / min. The elastic modulus is determined at a testing speed of 1 mm / min.

[0282] Determine the extrapolated onset temperature of the melting peak

[0283] Materials require certain properties, which can be obtained by dynamic differential calorimetry (often called DSC, differential scanning calorimetry) based on an extrapolated initial temperature T. eim Determined. Used to determine T. eimThe corresponding DSC measurements are preferably performed according to standard ISO 11357. The apparatus is, for example, the Mettler Toledo DSC 823. Melting temperature Tm and crystallization temperature T... c T is also determined using this method. eim Tm is determined by the first heating curve.

[0284] If the thermoplastic material contains PEKK-type polymers or is a PEKK-type polymer, the deviation from the standard is 0℃-360℃-0℃-360℃. The initial temperature (0℃), maximum temperature (360℃), and minimum temperature (0℃) are held for three minutes, but not at the final temperature (360℃). Furthermore, the heating or cooling rate is 20 K / min and the measured weight is 4.5 mg to 5.5 mg.

[0285] Optical methods for determining particle size and shape

[0286] Measurements were performed using CamsizerXT64 software (version 6.6.11.1069) on a Camsizer XT device and an X-Jet model (Retsch Technology GmbH). The optical method used to determine particle size and shape conformed to standard ISO 13322-2. After determining the speed adjustment, approximately 2g of sample was dispersed with 80kPa compressed air and passed through a 4mm wide channel on a calibrated optical unit equipped with two different magnification cameras (“Basic” and “Zoom”). For evaluation, at least 10,000 individual images were recorded. To ensure good optical separation of the particles under consideration, images were only used when the areal density of the imaged particles was less than 3% (“Basic” camera) or less than 5% (“Zoom” camera). Particle size and shape were determined by defined measurement parameters. The determined size is the equivalent diameter x_area= of the conjoint circle projected by the particle. (4A / The meridional or mean values ​​of this evaluation method are comparable to those of laser diffraction (recorded as d10, d50, and d90, i.e., the 10th, 50th, and 90th quantiles of the volumetric particle size distribution). Measurements were repeated several times to form statistical measurements.

[0287] for 2g / cm 3 High-density powders or powders that are difficult to disperse may require adjustments to the method, such as adjusting the sample volume, dispersion pressure, or adding 1% of the flow aid Alu C. Adjustments should be made in such a way that variations in sample volume (up to 8 g) and dispersion pressure (up to 150 kPa) are used to achieve the smallest possible d90.

[0288] Camera parameter calibration and settings should be performed according to the device and adjusted and maintained according to the manufacturer's instructions. The following configurations are used with Camsizer XT software (also available in...). Figure 5 , Figure 6 and Figure 7 (See the original configuration printout of the software)

[0289] The following configurations for CAMSIZER XT software

[0290] CAMSIZER XT: 0301

[0291] Overlapping area:

[0292] x area: 0.080mm to 0.160mm

[0293] xc min: 0.080mm to 0.160mm

[0294] xFe min: 0.080mm to 0.160mm

[0295] xFe max: 0.080mm to 0.160mm

[0296] x area: 0.100mm to 0.160mm

[0297] xc min: 0.100mm to 0.160mm

[0298] xFE min: 0.100mm to 0.160mm

[0299] xFE max: 0.100mm to 0.160mm

[0300] x area: 0.100mm to 0.160mm

[0301] xc min: 0.100mm to 0.160mm

[0302] xFe min: 0.100mm to 0.160mm

[0303] xFe_max: 0.100mm to 0.160mm

[0304] Fixed ratio between cameras used for calculation: No

[0305] Turn off the light source: Yes

[0306]

[0307]

[0308]

[0309]

[0310]

[0311]

[0312]

[0313] Camera (measurement parameters)

[0314] CCD - Basics: Yes

[0315] Threshold for particle size

[0316] [mm] indicates less than: 0.0023

[0317] [mm] indicates above: 20

[0318] For model parameters

[0319] [mm] indicates less than: 0.0023

[0320] [mm] indicates above: 20

[0321] CCD zoom: Yes

[0322] Threshold for particle size

[0323] [mm] indicates less than: 0.0023

[0324] [mm] indicates a value higher than: 2

[0325] For model parameters

[0326] [mm] indicates less than: 0.0023

[0327] [mm] indicates a value higher than: 2

[0328] Image coverage: 100% (1:1)

[0329] If the image rate 0.95 alerts: Yes

[0330] Display interval: 80

[0331] Filled with transparent particles: Yes

[0332] Determination of lower construction temperatures (NCT)

[0333] The lower build temperature (not the curling temperature = NCT) is determined through cross-testing, for example, determining a cross-shaped test component matrix. Figure 1 4 on the smaller build platform of P800 2). For this purpose, the laser sintering machine is heated to a temperature approximately 10°C (estimated) lower than the usual build temperature, or alternatively approximately 5°C lower than the expected non-curling temperature. After automatic powder application, a cross section is exposed from a height of z=3mm. These strong process-critical curls are observed, for example, when the edges of the exposed test cross section are significantly upward, the cross section is removed from the mounting space, and the temperature increases by 2°C. The test is repeated after applying a 1.2mm powder layer (P800, 10 layers with a thickness of 0.12mm, 12 layers with a thickness of 0.10mm, or 20 layers with a thickness of 0.06mm). If only a few curls are observed, the temperature is further increased in 1°C increments until no process-critical curls are observed in the cross section test. That is, the cross section can be built up across the entire height (1.2mm high) without being torn from the powder bed by the coater during the coating process. The temperature at which no process-critical curls are observed is called the non-curling temperature and defines the lowest possible build temperature. Figure 1 The image shows the location (left) of the cross-shaped test assembly and the pyrometer measurement spot (“P”, top right corner) on the EOS P800, which is affected by the reduced installation space.

[0334] The term "non-process-critical curl" refers to curl that is not observable or only minimally observed, but occurs to such a low degree that the coating machine can no longer peel the exposed cross-section from the powder bed during powder application.

[0335] Determination of superstructure construction temperature (UBT)

[0336] The maximum build temperature is the build temperature of the powdered material at which it just barely prevents it from sticking together, thus avoiding the formation of aggregates of powder particles, and the powder material used in the coating process still has sufficient fluidity and no coating defects (e.g., banding due to clumping). The maximum process temperature depends particularly on the type of powder material used.

[0337] However, the maximum build temperature can also be reached if the (local) melt film formation of the powder is not achieved. This can be seen in glossy films (e.g., polyamide 12, PA2200) or locally dark powders (e.g., EOS PEEK-HP3 as described in the application manual).

[0338] To determine this, the process chamber temperature is gradually increased (1°C-2°C) after a lower build temperature is established, and the powder bed is precisely observed when one of the aforementioned effects occurs. Additionally or alternatively, the upper build temperature can be determined by measuring the powder bed hardness using a Shore hardness tester. This may be helpful if one of the aforementioned effects has not yet occurred. If the unsintered powder bed is too hard after the build process, it will no longer be possible to separate the exposed components from the unsintered powder. This limits the accuracy of the components. For this purpose, when the observed or assumed upper build temperature is reached, the process chamber temperature is reduced by 1°C and another 3mm layer of powder is applied as a top layer during the automated build operation. After the build process, the powder cake is cooled to room temperature. The surface of the cooled powder cake is tested in the machine's interchangeable frame using a suitable Shore hardness tester (here: Bareiss HPII) on a smaller P800 build platform (5 on xy). 2, Figure 2 The Shore hardness value is determined at the center of each sector on the matrix. It is 50% of the average of the highest measured values ​​on the matrix. If cracks appear in the powder bed in the area to be tested (due to powder loss during cooling to room temperature), the measurement in the corresponding sector must be taken at a sufficient distance of approximately 15 mm from the crack. The Shore hardness for upper building temperatures is particularly dependent on the type of powder material used. How high it is depends on the individual materials, component quality, and waste powder recycling requirements. Appropriately, the same Shore hardness is used for upper building temperatures for comparison. This is always substantially the same for all equal-proportioned refreshments. Furthermore, it should be preferred that the heating distribution of the laser sintering machine does not change between the powders being compared, as this will affect the determined Shore hardness value.

[0339] It can be determined which Shore hardness measurement is suitable for which powder. The Shore 00, Shore 000, and Shore 000S Shore hardness (also specified in ASTM D 2240) have been proven to be preferred.

[0340] These and other Shore hardness tests are described in the Bareiss HPII Operating Instructions (HPE II Shore [D], Version 26.05.2017) and the corresponding standards are listed. For example, for certain polymer powders, the Shore hardness at the top construction temperature has been determined using the Bareiss HPII Shore Hardness Tester:

[0341] 1) Polyaryletherketone

[0342] Shore-00=85

[0343] Operating temperature (TPK)

[0344] The temperature T in the process chamberPK The processing temperature is preferably selected such that it is at least 1°C higher than the lowest build temperature of the powder, more preferably at least 2°C, even more preferably at least 4°C, and / or at most at the highest build temperature, and more preferably at most 1°C, even more preferably at most 2°C, and even more preferably at most 4°C lower than the highest build temperature. Preferably, the processing temperature is higher than the lowest build temperature of the powder and lower than the highest build temperature of the powder. Sufficient process safety must be ensured (no curling, as far away from the NCT as possible). In addition, the temperature must be as high as possible without causing adhesion of the powder material.

[0345] Alternatively or additionally, the processing temperature for each powder can be determined by measuring the Shore hardness of the cooled powder cake, according to the method described in the Superstructure Temperature Measurement (UBT). The Shore hardness value should preferably be 5% lower than the Shore hardness value in the UBT, and at most 50% lower. Preferably, it should be at most 15% lower, and more preferably at most 10% lower.

[0346] Component production on a laser sintering machine

[0347] If the thermoplastic material contains polyaryletherketone (PAEK) polymers, especially PEKK, the experiment is conducted on a modified P800 with PSW 3.8 (EOSP800 with starter kit PAEK 3302 CF). After the preheating phase, during which the process chamber of the laser sintering machine is heated from room temperature to the specified building temperature or the start temperature of the temperature search within 120 minutes, 50 (layer thickness 120 μm), 60 (layer thickness 100 μm), or 120 (layer thickness 60 μm) layers are laid without exposure as the underlayer (=6 mm). After laying the underlayer, six tensile specimens (dimensions shown in Table 1) are placed side by side in the center of the construction site, with the parallel lengths aligned parallel to the x-direction, and four cuboid test assemblies (dimensions: 20 mm). 4mm A 13.56 mm layer of powder was placed on either side of the tensile specimen. An unexposed layer was laid between the components in the z-direction. At z = 9.960 mm, 25 tensile specimens were constructed (centered in the construction area, adjacent to each other, aligned with parallel lengths parallel to the z-direction). After the last layer was exposed, another 3 mm layer of powder was automatically applied, and the machine was cooled to 180°C over approximately 8 hours via a controlled cooling phase defined in the default operation before the heater was fully shut off. Once room temperature was reached, the components were manually removed, the glass beads were sandblasted, and measurements / tests were performed. Figure 3 and Figure 4 The positions of the tensile specimens in the x-direction, z-direction, and density cubes in the powder box and EOS P800 are shown.

[0348] The building area is approximately 350 mm. 120mm (approximately 1 / 8 of the total platform size, according to the EOSPEEK-HP3 application manual for the improved building space reduction variant of the P800 in the xy direction).

[0349] The working height is 72.96mm.

[0350] Select the following settings:

[0351] - The process chamber temperature during component construction is described in detail in the Examples section;

[0352] - Temperature of removable frame / construction platform: 255℃ (for PEKK);

[0353] - Default job settings: PAEK3302CF;

[0354] - Exposure parameters: Volumetric energy input as described in the Examples section;

[0355] The laser sintering machine's process chamber is heated from room temperature to a specified building temperature or the start temperature of a temperature search within 120 minutes, and 50 (120 μm thick), 60 (100 μm thick), or 120 (60 μm thick) layers are laid as the underlayer (=6 mm) without exposure. After laying the underlayer, six tensile specimens (dimensions shown in Table 1) are placed side-by-side in the center of the build site, with parallel lengths aligned parallel to the x-direction. After the final layer is exposed, another 3 mm of powder is automatically applied, and the machine is cooled to 180°C over approximately 8 hours through a controlled cooling phase defined in the default operation before the heater is completely shut off. Once room temperature is reached, the components are manually removed, glass beads are sandblasted, and measurements / tests are performed. Figure 3 The position of the tensile specimen in the x-direction is shown on the EOS P810.

[0356] The building area is approximately 350 mm. 120mm (approximately 1 / 8 of the total platform size, according to the EOS PEEK-HP3 application manual for the improved building space reduction variant of the P800 in the xy direction).

[0357] The working height is 35.16mm.

[0358] Select the following settings:

[0359] - The process chamber temperature during component construction is described in detail in the Examples section;

[0360] - Temperature of the removable frame: 265℃ and temperature of the building platform: 255℃;

[0361] - Default job settings: EOS_PAEK3304_120_000;

[0362] - Exposure parameters: Volumetric energy input as described in the Examples section.

Claims

1. A composition comprising: At least one polymer, The polymer is in powder form, and The polymer includes at least one thermoplastic polymer. The thermoplastic polymer is selected from at least one polyarylether ketone and its copolymers and / or its block copolymers and / or its polymer blends. The composition has a depth of at least 5 cm. 3 / 10min, and / or no more than 55cm 3 Melt volumetric rate (MVR) per 10 min. The composition is obtained by a method including the step of sphericalizing polymer particles, wherein spherical particles are obtained by thermomechanical treatment at a temperature of at least 30°C and below the melting point Tm of the polymer, wherein the method optionally includes the step of grinding the polymer, and The composition is obtained by a method comprising the step of annealing the polymer particles at a temperature of at least 250°C and not exceeding 285°C. Wherein, the at least one polyaryletherketone is selected from the group consisting of polyetherketoneketone (PEKK). The polyether ketone comprises the following repeating units: Repeating unit A Repeating unit B ， The ratio of repeating unit A to repeating unit B is between 70:30 and 40:

60.

2. The composition according to claim 1, in, The polymer includes at least one semi-crystalline polymer. and / or At least one amorphous polymer.

3. The composition according to claim 1 or 2, in, The polyaryletherketone has a melting temperature Tm of at least 250°C and / or at most 320°C, and / or the polyaryletherketone has a glass transition temperature Tg of at least 120°C and / or not exceeding 200°C.

4. The composition according to claim 1, in, The polyether ketone ketone (PEKK) has an extrapolated onset melt temperature T of at least 250°C and / or at most 285°C. eim .

5. The composition according to claim 1, The polymer has a process window of at least 1°C and / or no more than 200°C.

6. The composition according to claim 1, in, The polymer blend includes polyaryletherketone-polyetherimide.

7. The composition according to claim 1, in, The polymer particles of the composition have the following particle size distribution: -d10 = at least 10 μm and / or no more than 50 μm -d50 = at least 25 μm and / or no more than 100 μm -d90 = at least 50 μm and / or no more than 150 μm.

8. The composition according to claim 1, in, The polymer particles of the composition have the following particle size distribution: -d10 = at least 15 μm and / or no more than 50 μm -d50 = at least 40 μm and / or no more than 100 μm -d90 = at least 70 μm and / or no more than 150 μm; The polymer particles are obtained by grinding polymer sheets.

9. The composition according to claim 1, in, The composition has a distribution width of no more than 3 (d90-d10) / d50.

10. The composition according to claim 1 or 2, in, The polymer particles have a sphericity of at least 0.

8.

11. The composition according to claim 1, The composition comprises a main composition and the content of the main composition is above 10% by weight and / or below 60% by weight of the total composition.

12. The composition according to claim 1 or 2, The composition has a pourability of at least 1 second and / or no more than 12 seconds.

13. The composition according to claim 1, in, The composition has a Hausner factor of at least 1.01 and / or no more than 1.

7.

14. The composition according to claim 1, in, The composition includes at least one flow agent.

15. The composition according to claim 14, The content of at least one flow agent in the combination does not exceed 1% by weight.

16. The composition according to claim 1, in, The composition has at least 0.1m 2 / g and / or not exceeding 10m 2 / g BET-specific surface area.

17. A method for preparing the composition according to claim 1, wherein the method comprises the following steps: (i) Providing at least one thermoplastic polymer, wherein the thermoplastic polymer is selected from at least one polyarylether ketone and / or its copolymers and / or its block copolymers and / or its polymer blends, (ii) Optionally, the polymer may be ground. (iii) Spherical polymer particles are prepared in a mixer by thermomechanical treatment at a temperature of at least 30°C and below the polymer's melting point Tm. (iv) Anneal the polymer particles at a temperature of at least 250°C and not exceeding 285°C.

18. A method for manufacturing a building element, the method comprising the steps of: (i) Applying a layer of the composition according to claim 1 and / or a layer of the composition prepared according to claim 17 to a production panel, (ii) Selectively curing the applied layer of said composition at a location representing a cross-section of the object to be manufactured, and (iii) Lower the carrier and repeat the application and curing steps until the building element is complete.

19. The method for manufacturing a building element according to claim 18, in, Step i) of applying the layer is done by applying at least two coatings. The application of the layer is divided into the steps of applying a first layer with a first height H1 and applying a second layer with a second height H2. The second layer with height H2 is applied on the first layer with height H1.

20. The composition according to claim 1, The composition is obtained by the method according to claim 17.

21. A building element comprising the composition according to claim 1.

22. Use of the composition according to claim 1 in additive manufacturing.

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